Michael J. Welsh, MD - US grants

The main focus of this proposal is on the cell membrane ion channels in airway smooth muscle. A knowledge of the mechanism of conductive ion movement and its regulation is essential to understand the normal function of airway smooth muscle and abnormalities in disease. To directly study the ion channels, both single-channel and whole-cell electrophysiologic measurements will be made using the patch clamp technique in single isolated smooth muscle cells. The work will focus on potassium and calcium channels. In both cases, the kinetic and conductive properties of the channels will be studied. A major effort will be to understand how the channels are regulated, both by hormones and neurotransmitters and by intracellular mediators. The majority of the work will be performed with canine tracheal smooth muscle, but human tracheal smooth muscle will also be used. The findings will increase our knowledge of how the airway smooth muscle cell membrane transports ions, thereby regulating, in part, contractility. Thus, they may have direct applicability to asthma.

It is believed that, in mature animals, Sertoli cells and jgerm cells of the testis interact to coordinate germ cell differentiation with the biochemical activities and morphological changes, occuring in Sertoli cells, which are necessary for the success of the process of spermatogenesis. Although several models have been proposed for the mechanism of Sertoli-germ cell interaction, as yet no mechanism has been demonstrated to exist. Other workers have suggested that Sertoli cell response to FSH may be modulated by germ cells in vivo. Preliminary evidence from my laboratory shows that germ cells or germ cell membranes can directly stimulate Sertoli membrane adenylate cyclase to an extent comparable with FSH. Taken together, the results suggest the possibilities that Sertoligerm interaction may involve germ cell-dependent modulation of Sertoli response to FSH or may occur by a mechanism identical to the mechanism of peptide hormone action. Therefore, the goal of this proposal is to investigate the hypotheses that germ cells interact with mature Sertoli cells to modify FSH response or that germ cells may directly stimulate Sertoli cell adenylate cyclase to initiate a series of events identical to that initiated by FSH. The specific aims of the proposal are to determine if germ cells directly or, by modulation of FSH response, indirectly affect Sertoli cell FSH receptor numbers, adenylate cyclase activity, phosphorylation of proteins, cell morphology and distribution of cytoskeletal proteins. These aims will be approached by using, in a complementary manner, biochemical and morphological techniques applied primarily to an in vitro cell culture experimental model system. It is expected that the proposed research will contribute to our understanding of spermatogenesis and to cell-cell interaction in the testis and may ultimately lead to new avenues of approach to development of male contraceptives. Moreover, this research may reveal a previously unsuspected significance to our appreciation of the mechanism of peptide hormone action, namely that, in order to elicit responses in neighboring cells, cell-cell interaction may involve the same biochemical pathways as those affected by peptide hormones.

Mitosis is one of the most fundamental processes of eukaryotic cells. In mitosis duplicate copies of the genetic material are separated into the new daughter cells. Obviously, mitosis is of central importance for the development, even the basic existence of eukaryotic organisms. Abnormal mitosis can be lethal or can result in abnormal development or malignancy. We do not know how mitosis is regulated. Microtubules (MTs) are the major structural component of the mitotic apparatus (MA). Controlled disassembly of MTs in the MA is important for the normal process of mitosis. Calcium ion (Ca++) causes disassembly of MTs and evidence suggests that calmodulin (CaM) may mediate the effect of Ca++ on MTs. CaM is found in the MA and Ca++ is concentrated in membrane-bound vesicles in the MA. Therefore, it has been hypothesized that CaM and Ca++ may regulate MT structure and function during mitosis. Preliminary experiments indicate, however, that CaM may not be associated with MTs of the MA, thus suggesting that CaM may not be acting directly on MTs as is generally believed. In an effort to learn about the role played by CaM in the MA, it is proposed that studies be conducted to examine the location and proximity within the MA of CaM, Ca++ and MTs and to study the effects on mitosis of CaM inhibitors and of alteration of Ca++ in the MA. To accomplish these aims, CaM and MTs will be observed in live cells by microinjection of fluorescently labeled CaM and tubulin. The distribution of the proteins will be observed and studied using low light video recording and image analysis methods. CaM will also be localized at the EM level by a new method. Ca++ will be detected and quantitated using the calcium-specific fluorescent probe quin2. Proximity of CaM and MTs will be detected by fluorescence energy transfer between pairs of appropriately labeled fluorescent protein derivatives. To examine the effects of CaM inhibitors and competitors, cells will be microinjected with CaM inhibitors such as R24571 or trifluoperazine or with CaM-binding proteins such as CaM antibody, Fab antibody fragments, troponin I or melittin to block CaM action in the MA. Effects on mitosis will be detected by time-lapse video recording of injected cells, with rates of chromosome separation in anaphase being quantitated and used as a measure of MA function. It is expected that the results of these studies will contribute to knowledge of the role played by CaM and Ca++ in the control of mitosis and regulation of the MA. Such knowledge may open new avenues of approach to the development of rational therapies for control of malignancies.

The overall objective of this proposal is to understand the cellular mechanisms of airway epithelia ion transport. Airway epithelia secrete chloride to regulate the quantity and composition of the respiratory tract fluid, an important component of pulmonary mucociliary clearance. The main emphasis of this work is on the regulation of the ion channels in tracheal epithelia and in understanding the mechanism of ion permeation through the membrane channels. The specific aims of the proposal are; first, to understand the regulation of the apical membrane chloride channel. Specific emphasis will be on the role of cyclic AMP-dependent protein kinase, calcium, protein kinase C, and pH in regulation of the channel. The second main goal is focused on the basolateral membrane potassium channel. Preliminary studies indicate that the channel is regulated by calcium, however, an understanding of its regulation requires quantitation of the effect and examination of the possibility that other agents may interact with calcium to regulate overall channel activity. Because calcium regulates the channel, it will also be important to directly measure intracellular-free calcium concentrations in airway epithelial cells. To address these specific aims, cellular electrophysiologic techniques, including the patch-clamp technique, and optical techniques designed to measure intracelllar calcium will be used. The knowledge obtained in these studies may be of particular importance of our understanding the mechanism and regulation of chloride secretion under normal conditions and in diseases, such as cystic fibrosis. Cystic fibrosis is a disease characterized by a chloride impermeability in multiple epithelia.

Cystic fibrosis is a common lethal genetic disease characterized by abnormal electrolyte transport in several epithelia. Defective electrolyte transport provides our current best insights into the cell biologic defect. In airway epithelia, defective regulation of apical membrane ion channels produces abnormally dehydrated respiratory tract fluid and impairs mucociliary clearance. As a result infection, inflammation, and injury destroy the airways producing bronchiectasis, the major cause of morbidity and mortality in the deceased. This application contains four projects which use basic and clinical research techniques to address the major abnormalities in CF. The main goal is to investigate the normal biology of airway epithelial cells and then to use that knowledge to understand the abnormal function and pathophysiology in CF. Previous work indicates that CF airway epithelia are chloride impermeable and have an increased rat of sodium absorption because of defective regulation of apical membrane ion channels. A major focus will be to understand the normal and abnormal regulation of such channels. Our second major focus is to understand the mechanisms of inflammation and injury in airway epithelia because the airway destruction. The collaborations and interactions of the four projects and the cell culture core provide interactive and novel approaches to understanding the disease.

Both FSH and germ cells interact with Sertoli cells by different pathways to cause a rapid activation of protein kinases and/or phosphatases. Because the mechanism of germ cell activation of Sertoli cell protein phosphorylation appears to involve increased levels of intracellular calcium, the effect of hormone or germ cell treatment on calcium levels in cultured Sertoli cells will be studied using the fluorescent calcium indicators, Fura2 and Indo1. Patterns of protein phosphorylation also suggest that the mechanism by which germ cells affect Sertoli cells involves the phosphatidylinositol (PI) pathway. Therefore, studies of Sertoli cell PI metabolism will be conducted. The factor from germ cells which stimulates Sertoli cell protein phosphorylation will be isolated, characterized and used to produce antibodies in order to learn by which germ cell stage it is produced. Two proteins whose phosphorylation is specifically affected by germ cells will be purified by conventional liquid chromatography, metal chelate chromatography, affinity, chromatography and HPLC. These phosphoproteins will be isolated in order to develop antibodies to the phosphoproteins. The antibodies will then be used to localize the phosphoproteins at the light and electron microscope levels with Sertoli cells and the testis and to study the correlation of each phosphoprotein with the cycle of the seminiferous epithelium. Antibodies will also be used to screen a Sertoli cell cDNA lambda gtll expression library in order to determine the sequences of the phosphoproteins. It is expected that localization of the phosphoproteins and determination of their amino acid sequences will lead to identification of the proteins and their functions. The studies should contribute to understanding Sertoli-germ cell interaction and hormone-mediated response mechanisms of Sertoli cells during spermatogenesis.

The identification and cloning of the gene that encodes the cystic fibrosis transmembrane conductance regulator (CFTR) was a landmark in cystic fibrosis (CF) research. But as soon as the amino acid sequence was deduced several questions were obvious. What is the function of CFTR and how do its different domains control its function? How do CF- associated mutations cause dysfunction in CFTR? How do mutations in CFTR produce the pathogenesis and pathophysiology of the lung disease? These three questions re the focus of this SCOR. The application contains four projects that use basic and clinical research techniques to address the questions. The collaborations and interactions between the investigators on the four projects and the Cell Culture Core provide the best possible environment to increase our understanding of this disease.

The purpose of the Laboratory Animal Core facility is to provide selected services and animals (rats and mice) of high quality to eligible projects of the P30 Center at a reasonable price. The facility breeds and maintains a colony of Sprague-Dawley rats as required by investigators. The Core provides Center investigators with rats and mice of specific ages and sexes, and pregnant females of known gestational age. In addition, the facility provides various technical services and routine surgical procedures as needed by the investigators. The Laboratory Animal Core is a specific pathogen-free facility and strives to provide the healthiest animals possible. The personnel of the Laboratory Animal Core are available as well to teach members of the P30 Center animal handling and surgical procedures according to procedures approved by the University's Committee on Animal Use.

Mechanisms by which abnormal fetal development, or teratogenesis occurs are not understood. We hypothesize that abnormal induction of the low molecular weight stress protein, hsp27 during embryogenesis is a significant cause of teratogenesis. Because birth defects affect significant numbers of infants and result in considerable costs to the individual, the family and society over a long period of time understanding what may be a significant mechanism for teratogenesis would be extremely beneficial. Toxic agents that cause abnormal embryonic development are called teratogens and a number of teratogens specifically induce the synthesis of a low molecular weight heat-shock or stress protein in Drosophila cells. A similar stress protein, hsp27, is expressed in mammalian cells in mammalian cells also hsp27 synthesis is greatly induced by a variety of teratogens including heat oxidants anoxia heavy metals, estrogens, retinoids, ethanol and other teratogens. Hsp27 is believed to function to affect microfilaments. Altering microfilament function during critical stages of development may disrupt development and result in teratogenesis. Thus, altered microfilament function resulting from abnormal induction of hsp27 synthesis as a result of the toxic action of a teratogen may cause teratogenesis. The hypothesis to be tested is that abnormal induction of hsp27 during embryonic development result in abnormal development or teratogenesis. To test this hypothesis, we will develop transgenic mice in which synthesis of hsp27 can be specifically controlled without induciton of other stress proteins and in the absence of possible side effects resulting from treatment of animals with teratogens or toxicants. First, murine embryonic stem (ES) cells will be stably transfected with an inducible hsp27 expression system. ES cell lines will be developed in which the synthesis of sense or antisense hsp27 mRNA can be induced, thus permitting the amount of hsp27 in the cells to be controlled. The ES cells will then be used to produce transgenic mice in which embryogenesis can be studied in vivo and in vitro. Studies of embryonic development will consist of inducing the synthesis of sense or antisense hsp27 mRNA in the transgenic animal embryos (using a non-toxic inducer) at critical times during fetal development and then observing whether development is altered. It os expected that in animals induced to express sense hsp27 mRNA expression of hsp27 protein will increase above normal and lead to abnormal development in animals induced to express antisense hsp27 mRNA hsp27 protein synthesis will be inhibited and to effect on development is expected. Results of these studies are anticipated to show that abnormally increased expression of hsp27 during embryogenesis results in abnormal development. These studies should provide valuable new information concerning the mechanism of teratogenesis and the role of hsp 27 in embryonic development and organogenesis.

Cystic fibrosis (CF) is a common autosomal-recessive disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR), a regulated Cl- channel. Mutations in the CFTR gene cause a loss of function of CFTR Cl- channels, thereby causing defective fluid and electrolyte transport by affected epithelia. In the airways, these abnormalities contribute to the pathogenesis and pathophysiology of the disease. Despite therapy directed at the symptoms of lung disease, CF is a lethal disease. No available therapy treats the basic CF defect. The feasibility of correcting the molecular defect by gene transfer was demonstrated when expression of CFTR in airway epithelia in vitro restored normal Cl- transport. To develop a method of in vivo gene transfer for humans, we have developed adenoviral vectors that encode CFTR. Our preliminary studies suggest that the adenoviral vector directs expression of CFTR in airway epithelium modeled in vitro and in vivo in cotton rats and monkeys. The goal of this project is to investigate adenovirus as a vector system, to address basic issues about the requirements for gene transfer to complement the Cl- transport defect in CF airway epithelia, and to evaluate safety of the adenoviral vector system. The aims are: 1. Evaluate the efficacy of adenovirus as a vector for CF gene therapy. To address this issue, we will use adenoviral vectors encoding both beta- galactosidase, as a reporter, and CFTR. We will express these genes from several different promoters to address several questions. a) In what percent of cells does adenovirus direct recombinant protein expression? b) What percent of cells must express CFTR to complement the CF Cl- transport defect? c) Is correction of the CF fluid and electrolyte transport abnormalities dependent upon the amount of CFTR expressed per cell? d) What is the duration of adenovirus-directed protein expression? e) How can the adenoviral delivery system be optimized? 2. Safety of adenovirus as a vector for CF gene therapy. We will focus on two questions. a) What is the effect of overexpressing CFTR on fluid and electrolyte transport? b) What is the effect of repeated administration of adenovirus to the lung?

transfection /expression vector; genetic techniques; technology /technique development; cystic fibrosis; gene therapy; biomedical facility; adeno associated virus group; Adenoviridae; plasmids;

histology; biomedical facility; confocal scanning microscopy; electron microscopy;

ABSTRACT NOT PROVIDED

The goals of this study are to evaluate the safety of the cationic lipid:DNA complex, GL-67/DOPE:pCF1-CFTR administered to the nasal epithelia of cystic fibrosis (CF) patients, the ability of the cationic to enhance gene transfer to airway epithelia in vivo, and to correct the biochemical defect seen in people with CF.

The purpose of our studies is to understand the role of hsp27 in toxicant-induced disruption of spermatogenesis. We hypothesize that hsp27 regulates microfilaments (MFs) in SC and that toxicants damage spermatogenesis by altering SC MFs as a consequence of affecting the normal pattern of hsp27 expression and phosphorylation occurring during the stages of the cycle of the seminiferous epithelium. Specifically we hypothesize: 1) that variations in transcription factors HSF1 and HSF2 control expression of hsp27 during spermatogenesis and that toxicants alter HSF1 and HSF2 activation and/or expression, 2) that phosphorylation isoforms of hsp27 exhibit differential effects on MFs and that the isoforms of hsp27 will localize differently in SC, 3) that a novel protein expressed only by differentiated SC mediates hsp27 regulation of SC MFs, and 4) that selective alteration of hsp27 expression in SC of transgenic animals will result in changes in SC MF- dependent events like those caused by toxicants.

The goal of this study is to evaluate the significance of the transepithelial voltage across the nasal epithelium in normal subjects, patients with cystic fibrosis (CF), and non-CF patients with bronchiectasis.

(Adapted from the applicant's abstract) Activity of CFTR CL channels determines the composition of fluid that lines the airway surface. In cystic fibrosis (CF), the loss of this regulated channel disrupts normal electrolyte transport and may contribute directly to disease pathogenesis. Earlier work showed that the activity of CFTR CL channels in airway epithelia is regulated by changes in cellular levels of cAMP. An increase in cAMP leads to phosphorylation of CFTR's regulatory (R) domain which allows the channel to open and mediate transepithelial CL movement. This project focuses on the mechanisms by which the cytosolic R domain controls the CFTR channel. Preliminary data showed that addition of an R domain peptide (R1, containing 190 residues) to a CFTR variant in which much of the R domain had been deleted (CFTR-R/S660A) stimulated activity. However, un-phosphorylated R1 had not effect. These results show a novel mechanism of channel upregulation by a phosphorylated peptide. They also provide us with a unique system for studying the structure and function of the R domain and CFTR. The project will answer three question. 1) What parts of the R domain control the activity of CFTR? The investigators will test the hypothesis that smaller peptides from the R domain stimulate activity of CFTR-R/S660A. Conversely, they will delete smaller portions of the R domain from CFTR to learn how channel gating is altered. These two complimentary approaches will allow them to identify key functional and structural features of the domain to discover their effect on activity. 2) What is the structure of the R domain? We currently lack molecular level data about the three-dimensional structure of CFTR or any of its domains. Their preliminary data show that R domain peptide is soluble and functionally active. Thus, now is the time to solve the R domain structure. Guided by their functional studies, they will determine the high-resolution structure of functionally active R domain peptides using NMR spectroscopy. They will also test the exciting hypothesis that phosphorylation changes the structure. 3) How do alterations in R domain structure affect function? The information obtained in the first two specific aims will provide valuable framework of understanding and a model of the R domain. They will test that model using site-directed mutagenesis to address very specific questions about how structure determines function. The prospects for success in this project are enhanced by the combined electrophysiologic, biochemical, and structural skills of this unique team of investigators.

The goal of this SCOR is to understand the normal biology of airway epithelia and the pathogenesis of disease in cystic fibrosis (CF). The molecular defect in CF is the loss of CFTR Cl channel function, which results in defective transepithelial Cl transport. Recent studies that both normal and CF airway secrete substances with antibacterial activity in the airway surface fluid. Reports that CF surface fluid has a high NaCl concentration would explain the lack of bacterial killing in CF and tie the clinic defect to the molecular effect in the Cl channel. In Project 1, Drs. Welsh and Ostedgaard will focus on regulation of CFTR Cl channels by phosphorylation of the R domain. Phosphorylation is the physiologic mechanism that controls channel activity. Their studies should provide detailed functional and three-dimensional structural information about the R domain and new insights into the regulation of CFTR. In Project 4, Drs. Zabner and Smith will focus on regulation of airway surface fluid salt concentration by CFTR Cl channels. Complementary approaches will be used to measure human airway surface fluid salt concentration both in vitro and in vivo. Novel approaches to correct the abnormal composition of airway surface fluid will also be investigated. In Project 2, Drs. McCray and Tack will investigate the biology of human beta-defensins 1 and 2 (hBD-1 and -2). These salt-inhibited defensins are anti-microbial peptides expressed in airway epithelial. Their studies will determine the cell- specific localization, this diverse beta-defensin gene family. In Project 3, Dr. Engelhardt focuses on the integrated physiology of the airways. He will specifically examine the contribution of the sub-mucosal glands to airway defense mechanisms. This project uses a novel approach to the study of mouse and tracheal xenografts in the presence and absence of sub- mucosal glands. All of the projects depend on the Cell Culture Core for tissue acquisition and development of models relevant to CF airways. Insights gained from the comprehensive approach in this SCOR will improve our understanding of the pathogenesis of CF airway disease and may lead to novel therapies.

Gene transfer to airway epithelia could provide an important new treatment for cystic fibrosis (CF) lung disease. A common problem with current vector systems is that the efficiency of gene transfer to differentiated human airway epithelia is limited. In work supported by this Program, we have investigated the advantages and limitations of adenoviral and non-viral vectors. By combining the two systems, we have utilized their unique advantages and avoided many of the limitations. In so doing, we have developed novel vector systems, including Ad:CaPi co- precipitates. This vector shows markedly enhanced gene transfer to differentiated airway epithelia. Moreover, preliminary data suggest that the Ad:CaPi co-precipitates do not produce additional toxicity. In this Project we focus on six questions. 1) How do Ad:CaP co-precipitates infect cells? 2) What properties of Ad:CaPi co-precipitates are important for gene transfer? 3) What cells are targeted by Ad:CaPi co- precipitates and other complexes? 4) Can complexes shield adenovirus from neutralizing antibodies? 5) Can other vectors, including AAV, be incorporated into CaPi co-precipitates? The results of these studies will improve our understanding of the mechanisms and barriers and gene transfer, will have application of several different vector systems, and should ultimately lead to improved gene transfer for CF airway disease.

Cystic fibrosis (CF) is a common lethal genetic disease caused by mutations in the CFTR gene. Gene transfer to airway epithelial could represent an important advance in the treatment of CF lung disease, the main cause of morbidity and mortality. The three Projects in this Program interact closely to focus on issues critical to developing gene transfer for CF. Project 1 has made significant progress on a common problem with gene transfer vectors: limited efficiency for differentiated airway epithelial. The investigators have combined the advantages of viral and non-viral vectors to markedly enhance efficiency. The investigators how investigate the underlying mechanisms, adapt the system to other vectors, and proceed to study the interaction with the epithelial and the host. Project 2 also focuses on the limited efficiency of gene transfer vectors. The investigators have made important progress in understanding the biology of adenovirus vectors and their receptors on airway epithelia and have developed novel vectors with greatly improved efficiency. Building on preliminary data, they also adapt a powerful combinatorial approach to identify novel ligands that will be of value for gene transfer with many different vectors. Project 3 has very encouraging data on use of integrating vectors for gene transfer. The investigators have discovered novel ways to allow these vectors to transfer gene to differentiated airway epithelial. They now focus on issues central to the use of any integrating vector, including identification of cells that can be targeted to generate persistent transgene correction of the CF defect. The Projects are supported by a Cell Culture Core, a Gene Transfer Vector Core, and an Administration Core. Importantly, results from all three from all three projects will have implications for many different approaches to gene transfer. The combined effort of the enthusiastic group of investigators will yield new knowledge. The combined effort of the enthusiastic group of investigators will yield new knowledge to further the long-term goal of developing gene transfer to CF.

Human populations in many areas of the world are exposed to several toxic metals because they occur naturally, are in food sources, or result from industrial activities. Knowledge is scare concerning mechanisms by which low exposures may cause subtle but nonetheless harmful effects on human physiology. Even less is known about the interactive effects of toxic metals. It is well known that cells mount the stress of heat-shock response when exposed to many toxicants including to toxic metals arsenic, cadmium and mercury. It is also well known that the stress response can protect cells from the effects of toxicants. Including in the events comprising cellular stress response are increased expression, phosphorylation of HSP27 , and other sHSPs, they protect themselves as individual cells and become more likely to survive the toxic insult. We hypothesize that tissue function, which depends on functional coordination of many individual cells, is altered because sHSPs tissue function, which depends on functional coordination of many individual cells, is altered because sHSPs- dependent cell functions required for tissue integrity and function have been altered as a result of increases in amounts and phosphorylation of sHSPs. Within the context of this overall hypothesis, the four individual projects of this Program Project will investigate how the toxic metals cadmium, mercury and/or arsenic affect tissue-specific functions of kidney and muscle that involve participation of hsp27, and other sHSPs and hsp27-binding proteins. Project 1 will investigate toxic metal effects on sHSPs and differentiation, structure and function of axial and cardiac muscle in embryonic development. Project 2 will study toxic metal effects on regulation of the cell cytoskeleton and morphology of kidney podocytes to learn about toxicant-induced nephrotic syndrome. Project 2 will investigate toxic metal effects on HSP27 function in kidney tubular epithelium, and Project 4 will focus on a newly discovered sHSP, HSP22, and the association of HSP22 with other sHSPs in muscle and how metal affects sHSPs and their molecular interactions in muscle. In addition to research projects, an administrative core, and two research cores, the Molecular Reagents Core and the Molecular Imaging Core will provide important resources to all the projects. It is expected that these studies will contribute significantly to our understanding of sublethal effects of toxic metals (either singly or in combinations) and the function of sHSPs in muscle and kidney.

In cystic fibrosis (CF), loss of the CFTR CI- channel disrupts airway epithelial electrolyte transport, thereby contributing directly to the disease pathogenesis. Two processes control the activity of the CFTR CI-channel: phosphorylation of its R domain and ATP interactions with its nucleotide-binding domains (NBDs). This project focuses on these two regulatory mechanisms. 1. Regulation of CFTR CI- channel activity by phosphorylation motifs in the R domain. Our recent structural and functional studies suggest that R domain phosphorylation motifs and their flanking residues are central to regulation. We will probe CFTR function with phosphorylated and unphosphorylated R domain peptides comprising these motifs. This novel strategy will reveal mechanisms by which the R domain regulates CFTR. 2. Control of CFTR CI- channels by adenylate kinase activity. For a long time we have known that the CFTR can hydrolyze ATP (ATP++ADP+Pi). Our preliminary data suggest that in addition to its ATPase activity, CFTR has adenylate kinase activity (ATP+AMP'2ADP). We will test how this novel enzymatic activity controls channel activity and identify responsible mechanisms. By using powerful new approaches and by testing novel hypotheses, the results of this work will give us an unprecedented look at how CFTR works. As we focus on very specific structural elements and enzymatic mechanisms, our data will help explain earlier results and will yield exciting new insight into the relationship between CFTR structure and function. The results will have substantial implications for the function of other medically important ABC transporters and for the development of new treatments for CF.

DESCRIPTION (provided by applicant): The overall goal of our SCOR is to increase our understanding of normal airway biology and the pathogenesis of cystic fibrosis (CF) airway disease, and to use that knowledge to develop new therapies. The strength of our SCOR is demonstrated by the impact of our past contributions, the interactions between our project leaders, their commitment to CF research, and the quality of our current proposal. The SCOR consists of four interrelated research projects focused on CFTR and airway defenses against bacterial infection. Loss of the CFTR C1- channel disrupts airway epithelial electrolyte transport, contributing directly to disease pathogenesis. In Project 1, Drs. Welsh and Ostedgaard use powerful new approaches to learn how the cytoplasmic domains of CFTR stimulate channel activity and to test the novel hypothesis that CFTR has adenylate kinase activity that controls channel gating. The chronic airway infections that are a hallmark of CF indicate that loss of CFTR causes a local host defense defect. In Project 2, Drs. McCray, Schutte and Singh investigate the role that airway surface liquid (ASL) peptides and proteins play in airway defense. They pursue their discovery of many new antibacterial and potentially anti-inflammatory ASL factors to elucidate how these contribute to the innate immune system. The discovery that lowering ionic strength augments the in vitro activity of nearly all ASL antimicrobial factors has led Drs. Zabner, Singh and Brogden in Project 4 to test the compelling hypothesis that reducing ASL salt concentrations in vivo, by administering the non-ionic osmolyte xylitol will prevent or slow the progression of CF airway disease. They begin testing this hypothesis in mice, sheep and humans. Our ability to evaluate such therapeutic strategies and to test hypotheses about the pathogenesis of CF lung disease has been hampered by the lack of an animal model that reproduces the airway and submucosal gland phenotype of people with CF. Based on substantial preliminary data, Dr. Engelhardt in Project 3, tackles this problem with an ambitious plan to clone a CF ferret. The SCOR benefits from outstanding support by the In Vitro Models and Cell Culture Core, as well as the Administrative Core. As a whole, this SCOR will give us unprecedented insight into CF airway dysfunction and hasten the development of new treatments for this devastating disease.

DESCRIPTION (provided by applicant): This proposal requests funds for a JEOL 1230 Transmission Electron Microscope (TEM) and a BOC Edwards Auto306 Vacuum Evaporator. These instruments will be located in the University of Iowa Central Microscopy Research Facility. The JEOL 1230 is being requested because the facility currently has just one TEM, a Hitachi H-7000 purchased with university funds in 1987. During the past 12 months, 78 faculty labs have used this instrument to support their research. 60 of these investigators have NIH funded research grants. 8 students each semester are enrolled in an Electron Microscopy Techniques course and use this instrument. Investigators have to sign up for the Hitachi TEM 2 to 3 weeks in advance. A number of operators are using the TEM during evenings and weekends. There is no guarantee that the instrument will be functional at a scheduled period because of unexpected downtime for maintenance. This results from a combination of very heavy use, the age of the Hitachi, which is a design introduced in 1981, and the low level of expertise of service personnel. Investigators also need low dose imaging, automated stage controls, tomography, digital imaging and Cryo-TEM to study their samples. The Hitachi TEM lacks all of these modern capabilities. The BOC Edwards Vacuum Evaporator will replace a 30 year old Varian unit in the facility. Repair parts have been unavailable for over 15 years; it suffers from poor vacuum and inconsistent evaporation of carbon and metals. It is critical that carbon coated grids for thin-sections and carbon thin films for negative staining, metal coating and Cryo-TEM be very-thin and low contrast. The JEOL TEM and the BOC Edwards evaporator will be conveniently located in room 84 and 92 respectively in the Eckstein Medical research Building as part of the University of Iowa Central Microscopy Research Facility. Administration and maintenance, as well as high-level technical assistance and training, will be provided by experienced personnel within the facility. Institutional support is strong with $61,234.00 being provided towards purchase of the instruments, $55,133.00 in full salary support for a research assistant and $10,000.00 to partially fund the annual service contract for the JEOL TEM on a continuing basis. Welsh will study airway epithelial cell biology, airway infections and gene transfer. Apicella plans to investigate the pathogenesis of bacteria. Dailey will examine synapse development and injury in brain. McCray will be involved with gene transfer using lentiviral vectors. Tobacman will study the structure of short actin filaments. Zabner will examine the morphology of Adeno-associated virus.

DESCRIPTION (provided by applicant): Gene transfer to the airways of patients with cystic fibrosis (CF) could represent a major therapeutic advance for this lethal disease. Although previous work in vitro, in animals and in people with CF has established the feasibility of gene transfer, it has also revealed the limitations of current approaches. The two greatest barriers are limited efficiency of gene transfer from the apical surface of differentiated airway epithelia and limited persistence of expression. The projects in this program utilize novel approaches and models to overcome these barriers. Recent work showed that adeno-associated viruses-5 (AAV5) vectors target the apical surface of differentiated airway epithelia, which makes them an attractive vector. Project by Welsh (subproject 0001) focuses on overcoming the limited packaging capacity of AAV vectors and will test the long-term potential of AAV5 vectors to correct the CF C1- transport defect. In Project by Zabner (subproject 0004), the investigators will study how AAV5 interacts with its apical membrane receptors, sialic acid and PDGF-receptor. They combine this with a structural analysis of the virus and its receptor. Project by McCray (subproject 0005) takes a related approach to achieving apical targeting and long-lasting expression by developing LCMV-pseudotyped lentivirus vectors. They investigate the virus:receptor interactions and will test the ability to achieve persistent expression in airway epithelia. Our ability to answer several crucial questions about gene transfer has been hampered by the lack of an animal model that faithfully reproduces the lung disease found in humans with CF. Project by Welsh (subproject 0006) addresses this problem by developing a porcine model of CF. The PPG benefits from outstanding support by the In Vitro Models and Cell Culture Core, the Gene Transfer Vector Core, and the Administrative Core. These studies will take us closer to our long-term goal of developing new therapies for people who suffer from CF.

DESCRIPTION (provided by applicant): The overall goal of our SCOR is to increase our understanding of normal airway biology and the pathogenesis of cystic fibrosis (CF) airway disease, and to use that knowledge to develop new therapies. The strength of our SCOR is demonstrated by the impact of our past contributions, the interactions between our project leaders, their commitment to CF research, and the quality of our current proposal. The SCOR consists of four interrelated research projects focused on CFTR and airway defenses against bacterial infection. Loss of the CFTR C1- channel disrupts airway epithelial electrolyte transport, contributing directly to disease pathogenesis. In Project 1, Drs. Welsh and Ostedgaard use powerful new approaches to learn how the cytoplasmic domains of CFTR stimulate channel activity and to test the novel hypothesis that CFTR has adenylate kinase activity that controls channel gating. The chronic airway infections that are a hallmark of CF indicate that loss of CFTR causes a local host defense defect. In Project 2, Drs. McCray, Schutte and Singh investigate the role that airway surface liquid (ASL) peptides and proteins play in airway defense. They pursue their discovery of many new antibacterial and potentially anti-inflammatory ASL factors to elucidate how these contribute to the innate immune system. The discovery that lowering ionic strength augments the in vitro activity of nearly all ASL antimicrobial factors has led Drs. Zabner, Singh and Brogden in Project 4 to test the compelling hypothesis that reducing ASL salt concentrations in vivo, by administering the non-ionic osmolyte xylitol will prevent or slow the progression of CF airway disease. They begin testing this hypothesis in mice, sheep and humans. Our ability to evaluate such therapeutic strategies and to test hypotheses about the pathogenesis of CF lung disease has been hampered by the lack of an animal model that reproduces the airway and submucosal gland phenotype of people with CF. Based on substantial preliminary data, Dr. Engelhardt in Project 3, tackles this problem with an ambitious plan to clone a CF ferret. The SCOR benefits from outstanding support by the In Vitro Models and Cell Culture Core, as well as the Administrative Core. As a whole, this SCOR will give us unprecedented insight into CF airway dysfunction and hasten the development of new treatments for this devastating disease.

Gene transfer offers the potential of a new therapy to slow or prevent CF lung disease. Yet, despite outstanding progress in several areas of gene transfer, we still do not have answers to many crucial questions that will guide development of gene transfer. The major impediment to answering these and other critical questions is the lack of an animal model that faithfully replicates the lung disease in humans with CF. Therefore, the goal of this project is to develop a porcine model of CF. We chose the pig because their lungs share many anatomical, histological, biochemical and physiologic features with human lungs. In addition, our preliminary data reveal similarities to humans in gene transfer to airway epithelia. Their reproductive characteristics also make them a good model. Tile success of this endeavor is enhanced by collaboration between two laboratories; Dr. Welsh's lab has a long history of CF investigation and Dr. Prather's lab has been at the forefront in developing technology for creating gene-targeted pigs by nuclear transfer. Aim 1. Target the porcine CFTR gene in fetal fibroblasts. Because deltaF508 is the most common CF mutation, we will generate a targeting vector that encodes this mutation. We will introduce the vector into fetal fibroblasts by nuclear microinjection and identify targeted cells using strategies that maximize the frequency of homologous recombination and obviate the need to include a selectable gene. Aim 2. Nuclear transfer and generation of a pig with a targeted CFTR gene. We will transfer targeted fetal fibroblasts to enucleated oocytes, fuse and activate them. Nuclear transfer embryos will be implanted into surrogate sows to generate offspring heterozygous for the deltaF508 mutation. Importantly, the targeted pig will be identical to a wild-type pig with the exception of a 3-bp deletion that generates deltaF508. In a second line, we will delete most of CFTR exon 10 to generate a "knockout" allele. Aim 3. Do the gene-targeted pigs manifest CF defects and disease? To answer this question, we will use molecular analyses to verify targeting, and will test the hypothesis that the deltaF508 protein is expressed but misprocessed in pigs. Because defective ion transport is a hallmark of CF, we will ask whether CF pig airway epithelia show defective ion transport in vitro and in vivo. A CF pig will provide the opportunity to better understand the disease and its pathogenesis, to develop gene transfer, and to test pharmaceuticals. Thus, it will accelerate the discovery of novel therapies for this lethal disease.

Gene transfer to the airways of patients with cystic fibrosis (CF) could represent a major therapeutic advance for this lethal disease. Recombinant adeno-associated viruses (AAV) vectors offer several advantages for achieving this goal, and the recent discovery that the AAV5 serotype targets the apical surface of differentiated airway epithelia makes this a particularly attractive vector. Thus, the overall goal of this project is to test the hypothesis that an AAV5 vector can transfer the CFTR cDNA to airway epithelia and complement the CF defect. Aim 1. Will a short expression cassette placed in an AAV5 vector drive expression in differentiated airway epithelia? A major challenge in developing an AAV vector for CF gene transfer is its limited packaging capacity, which places severe constraints on the size of the expression cassette. We will construct regulatory sequences for AAV5 vectors, with a goal of obtaining a promoter that is short, that drives transgene expression in airway epithelia, that generates persistent expression, and that resists attenuation by inflammatory mediators. We will test vectors in the context of AAV5 and in differentiated human airway epithelia. Aim 2. Will an AAV5 vector expressing CFTR complement the CF defect? Using an additional approach to meet packaging size constraints, we developed a CFTR containing a partial deletion of the R domain (CFTR-deltaR). We are excited by our preliminary work showing that an AAV5 containing a short promoter and a CFTR-deltaR transgene partially corrected the CF Cl- transport defect in CF airway epithelia. This validates our general strategy. However, our current AAV5 vectors have limitations, and many questions remain. Therefore, we will test the hypothesis that a CFTR-deltaR expression cassette in AAV5 will correct the CF Cl- transport defect in vitro in differentiated CF airway epithelia. We will also test the hypothesis that CFTR-deltaR can correct clinical intestinal disease in CF mice. Aim 3. Will an AAV5 vector generate long-lasting correction in airway epithelia in vivo and in vitro? An important reason to develop an AAV5 vector is the possibility of generating prolonged transgene expression. We will test persistence in differentiated airway epithelia and in mice using reporters, and we will test the hypothesis that an AAV5 vector will yield long-lasting complementation of the CF Cl- transport defect in vivo in nasal epithelia of CF mice. These studies will take us closer to our long-term goal of developing new therapies for people who suffer from CF.

neoplasm /cancer

DESCRIPTION (provided by applicant): The overall goal of our SCOR is to increase our understanding of normal airway biology and the pathogenesis of cystic fibrosis (CF) airway disease, and to use that knowledge to develop new therapies. The strength of our SCOR is demonstrated by the impact of our past contributions, the interactions between our project leaders, their commitment to CF research, and the quality of our current proposal. The SCOR consists of four interrelated research projects focused on CFTR and airway defenses against bacterial infection. Loss of the CFTR C1- channel disrupts airway epithelial electrolyte transport, contributing directly to disease pathogenesis. In Project 1, Drs. Welsh and Ostedgaard use powerful new approaches to learn how the cytoplasmic domains of CFTR stimulate channel activity and to test the novel hypothesis that CFTR has adenylate kinase activity that controls channel gating. The chronic airway infections that are a hallmark of CF indicate that loss of CFTR causes a local host defense defect. In Project 2, Drs. McCray, Schutte and Singh investigate the role that airway surface liquid (ASL) peptides and proteins play in airway defense. They pursue their discovery of many new antibacterial and potentially anti-inflammatory ASL factors to elucidate how these contribute to the innate immune system. The discovery that lowering ionic strength augments the in vitro activity of nearly all ASL antimicrobial factors has led Drs. Zabner, Singh and Brogden in Project 4 to test the compelling hypothesis that reducing ASL salt concentrations in vivo, by administering the non-ionic osmolyte xylitol will prevent or slow the progression of CF airway disease. They begin testing this hypothesis in mice, sheep and humans. Our ability to evaluate such therapeutic strategies and to test hypotheses about the pathogenesis of CF lung disease has been hampered by the lack of an animal model that reproduces the airway and submucosal gland phenotype of people with CF. Based on substantial preliminary data, Dr. Engelhardt in Project 3, tackles this problem with an ambitious plan to clone a CF ferret. The SCOR benefits from outstanding support by the In Vitro Models and Cell Culture Core, as well as the Administrative Core. As a whole, this SCOR will give us unprecedented insight into CF airway dysfunction and hasten the development of new treatments for this devastating disease.

DESCRIPTION (provided by applicant): Eighteen years after identification of the CFTR gene we still lack answers to many crucial questions. Controversies surround the pathogenesis of airway disease, current treatments are inadequate, and cystic fibrosis (CF) remains a lethal disease. A major impediment to progress has been lack of a CF animal model other than the mouse. CF mice fail to develop lung disease, the cause of most CF morbidity and mortality. Therefore, we disrupted the CFTR gene in the pig, whose lungs resemble those of humans. In this Program four senior and highly accomplished investigators will seize the unique opportunity to use CFTR -I- pigs to answer key questions about CF lung disease. Together, the four projects will discover how loss of CFTR causes airway epithelial and submucosal gland dysfunction and how that contributes to airway inflammation and infection. The Project Leaders have an outstanding track record of collaboration in CF, and here they sharpen their focus to a common goal. Their research is highly creative and is supported by five cores that provide innovative services and infrastructure. Discoveries from this PPG will accelerate development of novel therapies for patients who suffer from this devastating disease.

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Affect; Animal Model; Animal Models and Related Studies; Animals; Apical; Area; Biochemical; CF airway; CF mice; CFTR; CFTR Protein; Clinical; Collaborations; Cystic Fibrosis; Cystic Fibrosis Transmembrane Conductance Regulator; Data; Defect; Disease; Disorder; Disruption; Distal; Dysfunction; Educational process of instructing; Electrolytes; Epithelial; Family suidae; Foundations; Functional disorder; Genes; Gland; Human; Human, General; INFLM; In Vitro; Infection; Inflammation; Ion Transport; Ions; Learning; Length of Life; Liquid substance; Longevity; Lung; Lung diseases; Mammals, Mice; Mammals, Pigs; Man (Taxonomy); Man, Modern; Measurement; Methods; Mice; Modeling; Morbidity; Morbidity - disease rate; Mortality; Mortality Vital Statistics; Mucociliary Clearance; Mucociliary Transport; Mucoviscidosis; Murine; Mus; Pathogenesis; Phenotype; Physiologic; Physiological; Physiology; Physiopathology; Pig; Pigs; Porcine Species; Process; Programs (PT); Programs [Publication Type]; Pulmonary Diseases; Pulmonary Disorder; Research; Respiratory Disease; Respiratory Disorder; Respiratory System Disease; Respiratory System Disorder; Respiratory System, Lung; Solid; Source; Suidae; Sus scrofa; Swine; System; System, LOINC Axis 4; Teaching; Testing; Time; V (voltage); Wild Boar; airway epithelium; airway surface liquid; clinical phenotype; cystic fibrosis airway; cystic fibrosis mouse; cystic fibrosis transmembrane regulator; disease/disorder; fluid; in vivo; insight; life span; lifespan; liquid; lung disorder; model organism; mouse model of CF; mouse model of cystic fibrosis; novel; pathophysiology; porcine; postnatal; programs; pulmonary; suid; voltage

Cystic fibrosis (CF) is a genetic disease caused by loss of cystic fibrosis transmembrane conductance regulator (CFTR). The disease involves many organs, and lung disease is the current major cause of morbidity and mortality. Gene transfer offers the potential to express CFTR in the lungs of patients and thereby slow or prevent disease progression. Yet despite outstanding research progress, we still lack answers to many crucial questions. A major impediment to progress has been the lack of an animal model that replicates disease typically found in humans. To circumvent limitations of current animal models, we have produced CFTR-/- and CFTRAF/- pigs. Newborn animals exhibit defective CI'transport and replicate abnormalities in newborn humans. Our preliminary data suggest that CFTR-/- pigs may also develop respiratory disease like humans. We will use this novel model to address questions key to CF. Aim 1. Will intestinal expression of CFTR prevent meconium ileus in CFTRAF508/- pigs? To answer this question, we will generate CFTRAF508/- pigs carrying a transgene expressing CFTR in the intestine. The resulting animals may be of value to other projects in the program, and the results may shed light on the underlying pathogenesis of meconium ileus and distal intestinal obstruction syndrome. Aim 2. Do genetic modifiers influence the clinical phenotype of CFTRAF508/AF508 pigs? We will cross our pigs to genetically diverse strains of pigs and ask how the CF phenotypes are altered. Discovering phenotypic changes could help identify pathways that modify the AF508 mutant protein or affect manifestations of the disease, thereby revealing novel therapeutic targets. Aim 3. When is CFTR expression required to alter the CF phenotype? We will generate CFTRAF508 pigs that express CFTR under control of an inducible promoter to answer key questions. Will CFTR expression in utero prevent disease in newborns? Will epithelial CFTR expression that begins after birth prevent lung disease? Will CFTR expression treat or slow the progression of established ainway disease? The answers will serve as a benchmark to guide therapeutic strategies including gene transfer.

? DESCRIPTION (provided by applicant): The University of Iowa's Multidisciplinary Lung Research Career Development Program (MLRCDP) trains highly motivated pre- (3 slots) and post-doctoral (12 slots) trainees for innovative and leadership careers in lung disease research. The cohesive and highly interactive program offers trainees a curriculum that provides basic, clinical, and translational research training under the close supervision and guidance of a multidisciplinary group of mentors. This program encourages trainees, including those from traditionally underrepresented populations, to pursue a career in lung disease research. The program provides the opportunity to train in a variety of research disciplines, including epidemiology, biostatistics, cell and molecular biology, neonatology, genetics, physiology, radiology, pharmacology, engineering, and pediatrics. The MLRCDP also includes training for in computational biology, genomics, and imaging. Program trainees have access to the breadth of resources and facilities that make the University of Iowa a top-ranked institution in lung health science research; these include a number of well-funded multidisciplinary research programs and graduate programs, including the Institute for Clinical and Translational Science Graduate Program in Translational Biomedicine. This program's prior trainees, have been highly successful in lung-related research. Many have become leaders of pulmonary research in academia and industry. The leadership and faculty of this training program have worked together for several years. They are an example of team science. They have developed a collegiality, stability and shared intellectual vigor that has produced an outstanding environment for lung-related research and training. The faculty is highly accomplished, both individually and collectively. Their efforts have generated many important scientific discoveries, established several multidisciplinary centers and programs, and created a training environment that continues to produce outstanding scientists in pulmonary biology. The MLRCDP leadership and faculty have developed innovative mentoring and evaluation programs that reflect the strong desire to train the next generation of outstanding lung scientists.

Cystic fibrosis (CF) is a common autosomal recessive disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) (1). CF affects multiple organs, including lungs, pancreas, intestine, liver, sweat glands, gall bladder and male genital tract. Airway infection and inflammation cun'ently cause most of the morbidity and mortality. Although several therapies have improved the lives of patients, current treatments are inadequate and CF remains a lethal disease. Our knowledge about the pathogenesis of the disease, its progression, and the state of the neonatal lung is inadequate. Moreover, despite the potential of gene transfer to be an effective treatment, some of the most fundamental questions remain unanswered. These gaps in our knowledge have hindered attempts to develop better treatments and preventions for CF lung disease. A major impediment to addressing these issues has been limitations of current animal models. Although mouse strains carrying null and missense CFTR mutations have made enormous contributions, CF mice do not develop the airway or pancreatic disease typically found in humans.

DESCRIPTION (provided by applicant): Cystic Fibrosis (CF) is the most common lethal autosomal recessive disease in Caucasians and is caused by defects in the cystic fibrosis conductance regulator (CFTR) chloride channel. Clinically relevant tissues affected in CF include the lung, pancreas, liver, intestine, and gallbladder. The progression of life-threatening lung disease can be significantly impacted by disease in other organs, through metabolic and endocrine abnormalities that are only poorly understood. For example, pancreatic disease in CF patients leads to diabetes mellitus in 10-15% of patients and these patients die earlier than other CF patients. Cystic fibrosis- related diabetes (CFRD) is clinically distinct from type 1 and type 2 diabetes, and can significantly impact the nutritional and pulmonary health of CF patients. CFRD is largely due to insulin deficiency, but insulin sensitivity and hepatic glucose production can also be altered. Metabolic disease in CFRD can be compounded by defects in intestinal absorption and by chronic inflammation, leading to a failure to thrive and a rapid decline in lung function. A lack of animal models for CFRD has hampered basic research on the pathophysiology of this disease. At the University of Iowa, we have generated two new models of CF in the ferret and pig. Unique to the CFTR-knockout ferret model is a predisposition to developing CFRD. Both the pig and ferret CF models retain the pancreatic, liver, intestinal, and lung abnormalities seen in human CF patients, and differ from CFTR-deficient mice, in which the primary affected organ is the intestine. The purpose of the proposed R24 seeding grant is to build a team of investigators and interdisciplinary relationships that will enable us to characterize the metabolic and endocrine defects observed in CF ferrets and define its relationship to CFRD. Dissection of disease processes in the CF ferret model requires expertise in a wide range of areas including: 1) comparative pathology, 2) species-specific clinical assay development, 3) bile-acid and cholesterol/lipid homeostasis, 4) lipid absorption by the intestine, 5) glucose and lipid homeostasis, 6) comparative bacteriology, and 7) comparative biology of CFTR functions and CF- related organ disease. This grant would provide the funds necessary for developing collaborative interactions between five team members at the University of Iowa and four at other institutions. Funds are requested for distribution through four principal investigators at the University of Iowa, via associated subcontracts, and would be used to establish working relationships, preliminary data, and a well-defined R24 research plan.

Twenty-three years after identification of the CFTR gene, controversies still surround the pathogenesis of airways disease, we lack answers to many crucial questions, current treatments are inadequate, and cystic fibrosis (CF) remains a life shortening and too often lethal disease. A major impediment to progress has been lack of a CF animal model other than the mouse. CF mice fail to develop lung disease, the cause of most CF morbidity and mortality. We have now developed pigs with targeted alterations of the CFTR gene. CF pigs spontaneously develop the hallmark features of CF lung disease, including airway infection, inflammation, airway wall remodeling, mucus accumulation, and airway obstruction. Within hours of birth, CF pigs fail to eradicate bacteria as effectively as wild-type pigs. In this Program three senior and highly accomplished investigators will seize the unique opportunity to use CF pigs to answer key questions about CF lung disease. Together, the three projects will discover how loss of CFTR function affects: a) mucociliary transport; b) the response of airways to viral infection; c) HCO3- secretion and control of airway surface liquid pH; and d) bacterial killing on the airway surface. The Project Leaders have an outstanding track record of collaboration in CF, and here they sharpen their focus to a common goal. Their research is highly creative and is supported by five cores that provide innovative services and infrastructure. Discoveries from this PPG will accelerate development of novel therapies for patients who suffer from this devastating disease.

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PROJECT SUMMARY (See instructions): Cystic fibrosis (CF) airway disease begins during infancy. With the advent of universal newborn CF screening, there is an opportunity to intervene early to prevent the airway disease that ultimately destroys the lungs. However, to forestall CF airway disease, we must understand its initiation and progression. It is known that CF patients manifest a defect in airway host defense. One important component of host defense is mucociliary transport (MCT), the removal of particulates and pathogens from airways. It is widely assumed that impaired MCT causes CF lung disease. That assumption derives primarily from the fact that MCT is defective when disease is advanced. However by that time, bronchiectasis could be responsible. Unfortunately, current tests of MCT have limited sensitivity and often fail to detect defects, even in CF adults. Lack of a model has prevented elucidation of pathogenic mechanisms. Our long-term goal is to understand the causes of CF airway disease and use that knowledge to prevent and treat disease. The objective of this proposal is to learn how CF alters MCT and discover the responsible mechanisms. To achieve that objective, we will study a novel porcine model of CF that closely parallels the human disease, and we will answer three general questions. Aim 1. Does loss of CFTR alter MCT in newborn pigs? We will focus on MCT in vivo at the genesis of disease. We have exciting preliminary data using a new in vivo MCT assay and interrogation of discrete particles. We predict that stimulating mucus secretion will reveal striking MCT heterogeneity in CF pigs, with some particles moving fast, some slow and some not moving at all. Aim 2. Does the development of CF airway disease impair MCT in vivo? CF is not a static disease. Once it begins in neonates, inflammation, viral and bacterial infections, and airway wall remodeling accelerate disease. We will be able to learn for the first time how MCT changes with time and how those factors alter MCT in vivo. Aim 3. What factors alter MCT in CF? To identify factors that disrupt MCT, we developed a novel ex vivo approach using freshly excised airways. Our intriguing preliminary data reveal that CF disrupts release of mucus from the airway surface. Our working hypothesis is that a reduced pH and/or HCO3 concentration in airway surface liquid impair the normal behavior of airway mucus.

Lung disease continues to be the major cause of morbidity and mortality in cystic fibrosis (CF). Gene transfer offers the potential to express the cystic fibrosis transmembrane conductance regulator (CFTR) in the lungs of people with cystic fibrosis (CF) and thereby prevent or treat lung disease. But, we lack answers to many questions that are crucial for developing gene transfer. A major impediment to progress has been lack of animal models with disease that mimics human CF. To overcome this roadblock, we developed a porcine model of CF that spontaneously develops lung disease. We discovered that loss of CFTR impairs the activity of antimicrobials in airway surface liquid (ASL) and hinders mucociliary transport (MCT). In both cases, loss of CFTR-mediated bicarbonate secretion and an abnormally acidic pH are key factors. We also developed novel assays of these host defense mechanisms for both in vitro and in vivo experiments. We will use this novel model and assays to answer questions that are key for advancing CF treatments. First, How does CFTR expression level and the fraction of cells expressing CFTR affect airway epithelial ion transport and host defense processes? Answering this question will for the first time provide key data about relationships between specific CFTR functions and host defense. Second, will CFTR expression correct host defense defects and prevent and/or treat CF lung disease in vivo? We will develop CF pigs with inducible expression of CFTR in epithelia and test the hypotheses a) that expressing CFTR in airways rescues host defense processes, b) that CFTR expression beginning shortly after birth prevents airway infection, inflammation and remodeling, c) that expressing less than wild-type levels of CFTR in airway epithelia is sufficient to prevent lung disease, and d) that CFTR expression after disease onset treats or reverses airway disease. Third, will expressing CFTR in ciliated cells rescue host defense defects and prevent clinical CF lung disease? If ciliated cell expression prevents lung disease, it will mark ciliated cells as a key target for gene transfer. If not, the data will guide studies that identify key therapeutic targets. Results from this work and synergism with Projects 1 & 3 will inform strategies for gene transfer and other therapies.

PROJECT 2 PROJECT SUMMARY/ABSTRACT Loss of the CFTR anion channel causes cystic fibrosis (CF), which is characterized by bacterial infection and inflammation. To understand how CF disrupts airway defenses, we generated CF pigs and found that on the day they are born, they have impaired respiratory host defenses. Within weeks, they spontaneously develop hallmarks of CF airways: infection, inflammation, remodeling, mucus accumulation, and obstruction. Studies of CF pigs revealed at least two respiratory host defense defects: reduced activity of antimicrobials in airway surface liquid and impaired mucociliary transport. Both defects are caused, at least in part, by an abnormally acidic airway liquid. Loss of CFTR-mediated bicarbonate secretion leaves unchecked acid secretion that reduces pH. We found that a proton pump (ATP12A) is responsible for secreting acid into the airways. The overarching goal of this project is to understand how ATP12A acid secretion impairs host defense and whether the acidic pH causes CF lung disease. The project addresses three main questions. First, how is ATP12A acid secretion regulated in CF airways? Understanding the control of ATP12A is important because varying the rate of H+ secretion will change pH, which could exacerbate or attenuate disease severity. Second what is the pH in the lumen of submucosal glands? Submucosal glands produce most of the airway mucus. Earlier work showed that mucus emerging from CF submucosal glands ducts sometimes failed to break free from the duct, which impaired mucociliary transport. Those discoveries and knowledge that an acidic pH increases mucus elasticity make it imperative to know the pH in the submucosal gland lumen. This proposal develops novel means to obtain that information. Third, does disrupting the ATP12A gene rescue CF defects? CF pigs that have a disrupted ATP12A gene will allow a test of the hypotheses that preventing acid secretion will increase pH in the submucosal gland lumen, improve mucociliary transport, and prevent CF lung disease. This research will allow us to better understand how CF alters pH in the submucosal gland lumen and at the airway surface, thereby disrupting respiratory host defenses. The knowledge of CF pathogenesis will accelerate discovery of novel therapies and cures for this lethal disease.

PROJECT 2 PROJECT SUMMARY Cystic fibrosis (CF) is caused by loss-of-function mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR) apical membrane anion channel. Loss of CFTR- mediated HCO3- and Cl- secretion by airway epithelia impairs respiratory host defenses, causing bacterial infection, inflammation, mucus accumulation, and respiratory failure. One strategy for restoring anion channel function to the apical membrane is to increase the function of mutant CFTR channels. That has proven successful for people with specific CFTR mutations. However, ~10% of people with CF have mutations that do not respond to CFTR modulators or they are not able to take modulators. Another strategy is to provide an alternative channel. Toward this end, we studied amphotericin B (AmB); earlier work showed that AmB forms anion channels. We discovered that apical AmB increased HCO3- and Cl- secretion in cultured CF airway epithelia, including those with CFTR-null mutations. AmB increased ASL pH, height, and antibacterial activity. AmB is clinically approved to treat fungal infections, and off-label lung aerosolization has an impressive safety record. Thus, AmB could potentially provide a new mutation-agnostic therapy for CF lung disease. However, many questions remain unanswered and we lack important in vivo data. Therefore, our overarching goal is to understand the mechanisms of AmB-induced anion secretion in airway epithelia and to test the hypothesis that AmB can restore CF host defenses in vivo. To achieve this goal, we will answer questions in three aims. Aim 1. What molecular and cellular mechanisms elicit AmB-mediated anion secretion? Without cAMP-dependent regulation and with half the anion selectivity of CFTR, AmB is an imperfect substitute for CFTR. We will test key hypotheses about how AmB functions in airway epithelia. Aim 2. Which epithelial cells does AmB target and how does AmB alter them? These studies will reveal AmB function in large and small airway epithelia and diverse cell-types, test AmB in airway epithelia remodeled by inflammation, and test for compensatory changes. Aim 3. Does AmB reverse CF host defense defects in vivo? Using CF pigs, we will test if nebulized AmB increases ASL pH, increases ASL antimicrobial activity and height, increases mucociliary transport, and enhances S. aureus eradication from the lungs. The results of these studies will have direct implications for developing a new genotype agnostic approach to treating CF, and will inform development of other therapies in Projects 1 and 3. Our proposal?s success is enhanced by an ongoing collaboration between the labs of Welsh (Iowa) and Burke (Illinois), by utilization of outstanding cores, and by an environment of cooperation between the Program?s projects and investigators. With this background, our track record, and our commitment, we believe this research can change the lives of people with CF.