Rationale:
Extracellular matrix (ECM) remodeling is a key function of vascular smooth muscle cells (SMCs). MicroRNAs (miRNAs), in particular the miR-29 family and miR-195, have been implicated in the control of ECM secretion.
Objective:
To perform a proteomics comparison of miRNA effects on ECM production by vascular SMCs.
Methods and Results:
Murine SMCs were transfected with miRNA mimics and antimiRs of miR-29b and miR-195, and their conditioned medium was analyzed by mass spectrometry. Both miRNAs targeted a cadre of ECM proteins, including proteoglycans, collagens, proteases, elastin and proteins associated with elastic microfibrils, albeit miR-29 showed a stronger effect. The proteomics findings were subsequently validated at the transcription level using quantitative polymerase chain reaction. Similar to miR-29, in vivo inhibition of miR-195 by intraperitoneal injection of cholesterol bound antagomiRs led to significant alterations of elastin expression in murine aortas. Since elastin degradation is a key event in aortic aneurysm formation, we investigated miR-195 expression in patients. In human aortic aneurysmal tissue, miR-195 expression was reduced compared to non-aneurysmal tissue. In plasma, a comparison between male patients with abdominal aortic aneurysms and controls matched for diabetes and hypertension returned a panel of five highly correlated miRNAs: miR-195, miR-125b, miR-148a, miR-20a and miR-340 showed significant inverse associations with the presence of abdominal aortic aneurysms and aortic diameter, with miR-195 dominating in terms of association strength.
Conclusions:
Using proteomic analysis, we compared the effect of miR-29 and miR-195 on ECM secretion by vascular SMCs and identified novel miRNA targets. Findings in patients support an important role for miR-195 in vascular remodeling as evidenced by reduced miR-195 expression in human aneurysmal tissue and an inverse correlation between plasma miR-195 levels and aortic diameter.
Effects of magnesium on the production of extracellular matrix metalloproteinases in cultured rat vascular smooth muscle cells
