2002 — 2003 |
Gumienny, Tina L |
F32Activity Code Description: To provide postdoctoral research training to individuals to broaden their scientific background and extend their potential for research in specified health-related areas. |
Characterizing C.Elegans Tgf-Beta Pathway Gene Lon-2 @ Rutgers the St Univ of Nj New Brunswick
DESCRIPTION (provided by applicant): The transforming growth factor-beta (TGF-beta) signaling pathway is involved in many cellular processes ranging from proliferation, differentiation, development, and programmed cell death. Disruption of this pathway can result in a variety of diseases and is often an early step in the progression of cancers. The TGF-beta signaling pathway is highly conserved and is required in worms, flies, frogs, mice, and men. Since these growth factors work similarly in all of these organisms, what we learn about their function in simpler organisms should be relevant in other species, including humans. In this research project, I propose to explore the role of lon-2, a gene in C. elegans (a nematode worm), in the TGF-beta signaling pathway and its mechanism of action. My studies in this model organism should contribute to a better understanding of the signaling pathway in general and may provide for human therapies for TGF-beta-related diseases.
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0.904 |
2011 — 2015 |
Gumienny, Tina L |
R01Activity Code Description: To support a discrete, specified, circumscribed project to be performed by the named investigator(s) in an area representing his or her specific interest and competencies. |
Molecular Mechanisms Regulating Intercellular Transit of Tgf-Beta @ Texas a&M University Health Science Ctr
DESCRIPTION (provided by applicant): A major challenge in developmental biology is to understand how quantitative information is properly relayed between cells or tissues. Transforming growth factor- beta superfamily members (TGF-betas) are critical, evolutionarily conserved messengers for cellular communication. We are using the genetic tools available in Caenorhabditis elegans to investigate several outstanding questions in intercellular TGF-beta gradient formation. The long-term objective of this study is to understand the molecular and cellular basis for the trafficking of TGF-2 molecules between cells using C. elegans. Our central hypothesis is that transport of TGF- beta between cells is mediated by a network of interactions among TGF-betas, specific extracellular proteins including proteoglycans, endocytosis machinery in the receiving cells, and other signaling pathways. To test this hypothesis, we will answer the following questions: 1) How does glypican protein sequester TGF-beta ligand? Glypicans are proteoglycans that are conserved extracellular TGF-beta regulators. Alteration of the glypican protein core is associated with developmental defects and cancers, and we have shown that glypican core protein restricts TGF-beta activity. We hypothesize that a specific region within the glypican core protein sequesters TGF-2 at a specific site to prevent TGF-2 from activating cell surface receptors. We will first identify the site(s) within the glypican protein that affect TGF-beta activity by mutating regions of the glypican and asking if the altered glypican retains function in our in vivo bioassays. We will then determine if an altered site that is required for glypican activity is sufficient by itself to inhibit TGF-beta activity. In addition, we will confirm that glypican mutant function is correlated with its ability to bind TGF-beta. Last, we will identify the region of TGF-beta that interacts with the glypican core protein. 2) How is TGF-beta signaling affected by other extracellular TGF-beta regulators? We hypothesize that other proteoglycans, proteoglycan-modifying enzymes, proteases, extracellular matrix constituents, directed endocytosis, and other signaling pathways define TGF-2 longevity and signaling range. We will characterize the roles of novel regulators we have identified in a sensitized screen, including extracellular proteins, endocytosis machinery, and another cell signaling pathway receptor. We will also 3) Identify new regulators of TGF-2 localization using a sensitized RNAi screen. Our studies to answer these questions employ a combination of transgenic and biochemical methods. The approach is innovative because we can directly observe effects of regulators on the localization of a fluorescently tagged TGF-beta we generated, and we have used this tool to screen a genomic RNAi library and identify candidates. The proposed research is significant because it is expected to produce a deeper and substantially expanded understanding of how TGF-beta ligands are regulated as they travel between cells. This contribution will have a positive impact on the cell signaling field because it provides a broad foundation from which to understand how graded growth factor distribution is achieved during development and is altered in disease states including cancers. PUBLIC HEALTH RELEVANCE: Misregulated cell-to-cell communication underlies a number of human developmental disorders and cancers. This work will characterize the functions of known and novel molecules and fundamental mechanisms that regulate the transport of messenger proteins between cells, which will clarify not only normal developmental processes, but also related pathological states including birth defects, developmental disorders, and cancers. Furthermore, this work will identify potential therapeutic targets to combat these diseases.
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0.948 |
2018 — 2019 |
Bergel, Michael (co-PI) [⬀] Gumienny, Tina L |
R03Activity Code Description: To provide research support specifically limited in time and amount for studies in categorical program areas. Small grants provide flexibility for initiating studies which are generally for preliminary short-term projects and are non-renewable. |
Chromatin Condensation as a Dna Protective Response to Uv Radiation in Human Melanocytes and Aging C. Elegans @ Texas Woman's University
UV-induced DNA damage is a major cause of age-related skin diseases and photoaging. Although the body can develop defenses over time to UV stress (i.e., melanin concentration and thickening of the stratum corneum), there is a fundamental gap in understanding whether cells can mount an effective immediate protective response to UV. We recently discovered an immediate and robust UV-induced DNA protection mechanism that involves a global chromatin compaction triggered by calcium influx. The chromatin compaction and DNA protection responses were demonstrated in human HeLa cells, and the compaction was also demonstrated in NIH2/4 mouse embryonic fibroblasts and in the roundworm C. elegans. Our long-term goal is to understand the molecular basis of this mechanism, and to investigate if it can be manipulated to increase our natural protection from UV damage. We will explore whether this mechanism declines with age like other stress resistance mechanisms. The objectives of this application are to develop the C. elegans as a model system to probe the age-dependence of this stress resistance mechanism and to use human epidermal melanocytes in combination with C. elegans to gain the first glimpse into the molecular pathway of this UV- induced DNA protective chromatin compaction. The central hypothesis is that chromatin compaction is triggered by a conserved molecular machinery of a photoreceptor acting through the G?q/11-coupled phototransduction pathway to activate a calcium influx. We hypothesize that this is an evolutionarily conserved response that is less efficient in aged organisms. The rationale for choosing C. elegans is that it is a well- established model system for studying aging with superb genetic and developmental tools. Human primary epidermal melanocytes were chosen because they are human skin cells in which a specific pathway involving photoreceptors and G?q/11 was shown to control a UV-induced calcium influx. The specific aims for this research are: 1) Test whether UV-induced chromatin compaction protects DNA from further damage in human epidermal melanocytes (HEMs) and in young and old C. elegans. We will UV irradiate HEMs and C. elegans and detect the rate of removal of photoproducts by Southwestern blotting (for HEMs and C. elegans) and in vivo (for C. elegans). 2) Determine whether UVR-induced chromatin compaction involves the G?q/11-coupled phototransduction pathway and calcium influx in human epidermal melanocytes and C. elegans. This aim will be achieved by RNAi/siRNA knock downs in C. elegans and human primary epidermal melanocytes. The proposed research is innovative because it explores a previously undescribed DNA defense mechanism from UV radiation and it sets as a goal establishing C. elegans as a model system for relating this phenomenon to aging. Adding to our innovative capacity is the ongoing cross-pollination between a C. elegans lab and a mammalian chromatin lab. The results will be significant because new potential targets that control the DNA- protective pathway will be discovered which can lead to better pharmaceutical strategies to protect from UV.
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0.948 |