PROMOTING MUSCLE REGENERATION VIA THE COMBINATORIAL EFFECTS OF OXYTOCIN AND TGF-BETA PATHWAYS ON PRIMARY MYOCYTES
Adela Ramos-Martinez, Irina Conboy, Michael Conboy.
University of California, Berkeley, Berkeley, CA.
Aging, while inevitable, is a concern worth addressing due to the growing population of elderly individuals. Understanding how to manipulate aging at a molecular level via the treatment of various hormones and factors can lead to novel medical therapies such as promoting muscle regeneration in elderly individuals and patients with various muscle atrophy conditions. The aim of this study is to observe and quantify the combinatorial effects of 2 factors that work via 2 distinct pathways which promote muscle regeneration. Oxytocin (OT) is a water-soluble hormone that binds to membrane-bound receptors which turns on the mitogen activated protein kinase (MAPK) pathway. This is responsible for inducing stem cell proliferation for muscle regeneration. The transforming growth factor beta (TGF-beta) pathway is responsible for inflammation and fibrosis in muscle tissue when over stimulated. In this study, cells are subjected to different concentrations of OT and a small molecule TGF-beta pathway inhibitor (Alk5i), and cell proliferation is measured through BrdU labeling which is incorporated in the S-phase of the cell cycle to newly synthesized DNA, thus identifying proliferating cells. Cells were immunostained against BrdU, imaged, and quantified in order to determine percent proliferation. The assays reveal a comparatively high percentage of cell proliferation with relatively high concentrations of OT and Alk-5i. The assays performed demonstrate positive combinatorial effects of both factors, but we will continue to fine tune the assay of myogenic cell proliferation in response to these factors. In whole, increasing myogenic stem cell proliferation is key to improving muscle regeneration in the aged.