Anatomy Commons^™

Cellular Bioenergetics Regulates Cell Proliferation During Mammalian Regeneration, Sandeep Saxena

Theses and Dissertations--Biology

Mammalian system consists of stress-sensing molecules that regulates their cellular response against damage, injury and oncogenic stress. During vertebrate regeneration, cells responding to injury re-enter the cell cycle and proliferate to form new tissue. Cell cycle re-entry or arrest is at least partly regulated by cellular senescence which negatively impacts the proliferative pool of cells during regeneration. What remains unclear is whether cells in regenerating systems possess an increased propensity to proliferate and are refractory to signals that induce senescence. My thesis work has focused on how fibroblasts from the ear pinna differentially regulate healing in highly regenerative mammals (e.g., …

Hdac Regulates Transcription At The Outset Of Axolotl Tail Regeneration, S. Randal Voss, Larissa V. Ponomareva, Varun B. Dwaraka, Kaitlin E. Pardue, Nour W. Al Haj Baddar, A. Katherine Rodgers, M. Ryan Woodcock, Qingchao Qiu, Anne Crowner, Dana Blichmann, Shivam Khatri, Jon S. Thorson

Neuroscience Faculty Publications

Tissue regeneration is associated with complex changes in gene expression and post-translational modifications of proteins, including transcription factors and histones that comprise chromatin. We tested 172 compounds designed to target epigenetic mechanisms in an axolotl (Ambystoma mexicanum) embryo tail regeneration assay. A relatively large number of compounds (N = 55) inhibited tail regeneration, including 18 histone deacetylase inhibitors (HDACi). In particular, romidepsin, an FDA-approved anticancer drug, potently inhibited tail regeneration when embryos were treated continuously for 7 days. Additional experiments revealed that romidepsin acted within a very narrow, post-injury window. Romidepsin treatment for only 1-minute post amputation inhibited …

Transcriptional Correlates Of Proximal-Distal Identify And Regeneration Timing In Axolotl Limbs, S. Randal Voss, David Murrugarra, Tyler B. Jensen, James R Monaghan

Neuroscience Faculty Publications

Cells within salamander limbs retain memories that inform the correct replacement of amputated tissues at different positions along the length of the arm, with proximal and distal amputations completing regeneration at similar times. We investigated the possibility that positional memory is associated with variation in transcript abundances along the proximal-distal limb axis. Transcripts were deeply sampled from Ambystoma mexicanum limbs at the time they were administered fore arm vs upper arm amputations, and at 19 post-amputation time points. After amputation and prior to regenerative outgrowth, genes typically expressed by differentiated muscle cells declined more rapidly in upper arms while cell …

Differential Requirement For Satellite Cells During Overload-Induced Muscle Hypertrophy In Growing Versus Mature Mice, Kevin A. Murach, Sarah H. White, Yuan Wen, Angel Ho, Esther E. Dupont-Versteegden, John J. Mccarthy, Charlotte A. Peterson

Physical Therapy Faculty Publications

Background: Pax7+ satellite cells are required for skeletal muscle fiber growth during post-natal development in mice. Satellite cell-mediated myonuclear accretion also appears to persist into early adulthood. Given the important role of satellite cells during muscle development, we hypothesized that the necessity of satellite cells for adaptation to an imposed hypertrophic stimulus depends on maturational age.

Methods: Pax7^CreER-R26R^DTA mice were treated for 5 days with vehicle (satellite cell-replete, SC+) or tamoxifen (satellite cell-depleted, SC-) at 2 months (young) and 4 months (mature) of age. Following a 2-week washout, mice were subjected to sham surgery or 10 day …