MicroRNA-638 is highly expressed in human vascular smooth muscle cells and inhibits PDGF-BB-induced cell proliferation and migration through targeting orphan nuclear receptor NOR1

miRNA-221 and miRNA-222 synergistically function to promote vascular calcification

Vascular calcification shares many similarities with skeletal mineralisation and involves the phenotypic trans-differentiation of vascular smooth muscle cells (VSMCs) to osteoblastic cells within a calcified environment. Various microRNAs (miRs) are known to regulate cell differentiation; however, their role in mediating VSMC calcification is not fully understood. miR-microarray analysis revealed the significant down-regulation of a range of miRs following nine days in culture, including miR-199b, miR-29a, miR-221, miR-222 and miR-31 (p < 0.05). Subsequent studies investigated the specific role of the miR-221/222 family in VSMC calcification. Real-time quantitative polymerase chain reaction data confirmed the down-regulation of miR-221 (32.4%; p < 0.01) and miR-222 (15.7%; p < 0.05). VSMCs were transfected with mimics of miR-221 and miR-222, individually and in combination. Increased calcium deposition was observed in the combined treatment (two-fold; p < 0.05) but not in individual treatments. Runx2 and Msx2 expression was increased during calcification, but no difference in expression was observed following transfection with miR mimics. Interestingly, miR-221 and miR-222 mimics induced significant changes in ectonucleotide phosphodiesterase 1 (Enpp1) and Pit-1 expression, suggesting that these miRs may modulate VSMC calcification through cellular inorganic phosphate and pyrophosphate levels. © 2013 The Authors. Cell Biochemistry and Function published by John Wiley & Sons, Ltd.

Rosuvastatin suppresses platelet-derived growth factor-BB-induced vascular smooth muscle cell proliferation and migration via the MAPK signaling pathway

An imbalance in the proliferation and migration of vascular smooth muscle cells (VSMCs) is significant in the onset and progression of vascular diseases, including arteriosclerosis and restenosis subsequent to vein grafting or coronary intervention. Rosuvastatin, a selective inhibitor of hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase, has pharmacological properties including the ability to reduce low-density lipoprotein-cholesterol (LDL-C) and very low-density lipoprotein-cholesterol (VLDL-C) levels, slow atherosclerosis progression and improve coronary heart disease outcomes. However, little is known concerning the molecular mechanism by which rosuvastatin affects vascular cell dynamics. In this study, we studied the inhibitory role of rosuvastatin on platelet-derived growth factor-BB (PDGF-BB)-induced VSMC proliferation and migration, as well as the molecular mechanisms involved. MTT data showed that rosuvastatin markedly inhibited the proliferation of PDGF-BB-induced VSMCs in a time-dependent manner. VSMCs are able to dedifferentiate into a proliferative phenotype in response to PDGF-BB stimulation; however, rosuvastatin effectively attenuated this phenotype switching. Moreover, we also showed that rosuvastatin significantly suppressed PDGF-BB-induced VSMC migration, which may be a result of its inhibitory effect on the protein expression of matrix metalloproteinase-2 (MMP2) and MMP9. Investigation into the molecular mechanisms involved revealed that rosuvastatin inhibited the mitogen-activated protein kinase (MAPK) signaling pathway by downregulating extracellular signal-regulated kinase (ERK) and p38 MAPK, although the phosphorylation level of c-Jun N-terminal kinase (c-JNK) was not altered following rosuvastatin treatment. In conclusion, the present study showed that rosuvastatin suppressed PDGF-BB-induced VSMC proliferation and migration, indicating that rosuvastatin has the potential to become a promising therapeutic agent for the treatment of atherosclerosis and restenosis.