Role of microRNA-23b in flow-regulation of Rb phosphorylation and endothelial cell growth.
MicroRNAs (miRs) can regulate many cellular functions, but their roles in regulating responses of vascular endothelial cells (ECs) to mechanical stimuli remain unexplored. We hypothesize that the physiological responses of ECs are regulated by not only mRNA and protein signaling networks, but also expression of the corresponding miRs. EC growth arrest induced by pulsatile shear (PS) flow is an important feature for flow regulation of ECs. miR profiling showed that 21 miRs are differentially expressed (8 up- and 13 downregulated) in response to 24-h PS as compared to static condition (ST). The mRNA expression profile indicates EC growth arrest under 24-h PS. Analysis of differentially expressed miRs yielded 68 predicted mRNA targets that overlapped with results of microarray mRNA profiling. Functional analysis of miR profile indicates that the cell cycle network is highly regulated. The upregulation of miR-23b and miR-27b was found to correlate with the PS-induced EC growth arrest. Inhibition of miR-23b using antagomir-23b oligonucleotide (AM23b) reversed the PS-induced E2F1 reduction and retinoblastoma (Rb) hypophosphorylation and attenuated the PS-induced G1/G0 arrest. Antagomir AM27b regulated E2F1 expression, but did not affect Rb and growth arrest. Our findings indicate that PS suppresses EC proliferation through the regulation of miR-23b and provide insights into the role of miRs in mechanotransduction.
Department of Bioengineering and Institute of Engineering in Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
Kuei-Chun
KC
Wang
Lana Xia
LX
Garmire
Angela
A
Young
Phu
P
Nguyen
Andrew
A
Trinh
Shankar
S
Subramaniam
Nanping
N
Wang
John Y J
JY
Shyy
Yi-Shuan
YS
Li
Shu
S
Chien
D000704:Analysis of Variance; D001973:Bromodeoxyuridine; D049109:Cell Proliferation; D042783:Endothelial Cells / Q000502:physiology*; D005434:Flow Cytometry; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D035683:MicroRNAs / Q000378:metabolism / Q000502:physiology*; D020411:Oligonucleotide Array Sequence Analysis; D009841:Oligonucleotides / Q000235:genetics; D010766:Phosphorylation; D011673:Pulsatile Flow / Q000502:physiology*; D016160:Retinoblastoma Protein / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology
D035683:MicroRNAs; D009841:Oligonucleotides; D016160:Retinoblastoma Protein; D001973:Bromodeoxyuridine