Researchers at the University of Texas Southwestern Medical Center, Dallas used microarray analysis to compare miRNA expression patterns of primary rat cardiomyocytes with different levels of myocardin-related transcription factors (MRTFs). MRTFs associate with serum response factor (SRF) to drive the expression of actin and other cytoskeletal protein genes. miR-145 and miR-143 were among the most strongly upregulated miRNAs in response to MRTFs, as revealed by microarray and confirmed by real-time PCR. Further study revealed that (SRF) controls the expression of miR-143 and miR-145 in smooth muscle cells, and these miRNAs, in turn, feed back to control the expression and function of multiple components of the cytoskeleton and the SRF regulatory network. This study adds to a growing body of work demonstrating the roles of miRNAs in regulating changes in gene expression and cell functions in response to injury and stress and further underscores their potential as therapeutic targets.
Xin M, Small EM, Sutherland LB, Qi X, McAnally J, Plato CF, Richardson JA, Bassel-Duby R, Olson EN. (2009) MicroRNAs miR-143 and miR-145 modulate cytoskeletal dynamics and responsiveness of smooth muscle cells to injury. Genes Dev 23(18),2166-178. [abstract]