Abstract 15574: Adipose Tissue-Derived Mesenchymal Stem Cells with Myocardin-A and Telomerase Co-Expression Possess Augmented Capacity of Proliferation and Promyogenic Activities
Background and Objective: Myocardin-A (McA) acts as a nuclear transcription cofactor for myogenic gene expression while telomerase reverse transcriptase (TERT) maintains the telomere length and prevents cellular senescence. This study aims at testing the growth and myogenic regenerative properties of mesenchymal stem cells (MSCs), and the outcome of McA and TERT overexpression or interruption. Furthermore, a cluster of nuclear transcription or transcription-related factors involved in the development of pluripotency (Oct-4) and myogenesis (Nkx2.5, MEF2c and MLC2v) were examined in the cells.
Methods and Results: TERT and/or McA cDNA were efficiently transduced in MSCs derived from murine adipose tissue (Figure 1A) and co-immunoprecipitated. MSCs with TERT or TERT plus McA overexpressed were highly proliferative. McA transduction alone only modestly increased the cell proliferation (Figure 1B). Treatment with siRNA for TERT and/or McA significantly reduced expression of Oct-4, Nkx2.5, MLC2v and MEF2c (n=3 independent experiments by qRT-PCR, p<0.001 by ANOVA vs mock-siRNA scrambled transfected). MSCs with co-expression of TERT and McA showed active serum response factor binding to the consensus sequence for the serum response element (SRE), key for expression of many myogenic genes (Figure 1C) suggesting that augmented promyogenic activities occurred in the MSCs with McA and TERT overexpression.
Conclusions: Transduction of TERT and McA enhances the potency of growth and myogenic development of MSCs from adult adipose tissue. The two nuclear factors may interplay in promoting expression of promyogenic nuclear factors and activating the SRE-containing promoters, but exerting proliferative impacts on MSCs. The interaction between TERT and McA in promyogenic MSCs may be important in the key stage of early myogenesis and in the proliferation of MSCs. MSCs transduced with TERT and McA may have therapeutic applications for vascular and heart regeneration.
- © 2011 by American Heart Association, Inc.