circDiaph3 regulates rat vascular smooth muscle cell differentiation, proliferation, and migration.

Intimal hyperplasia is a reaction to vascular injury, which is the primary reason for vascular restenosis caused by the diagnostic or therapeutic procedure for cardiovascular diseases. Circular RNAs (circRNAs) are known to be associated with several cardiovascular conditions, but the expression of circRNAs in the neointima has not been reported in detail. In this study, we established the balloon-injured rat carotid artery model and detected the expression of circRNAs in the carotid arteries with a microarray. We found that the circRNA expression profile of the healthy carotid arteries and the injured arteries were significantly different. We investigated the role of rno-circ_005717 ( circDiaph3) in the differentiation of rat vascular smooth muscle cells (VSMCs). We found that knockdown of circDiaph3 up-regulated the level of diaphanous-related formin-3 and promoted the differentiation of VSMCs to contractile type. In addition, circDiaph3 up-regulated the transcription of Igf1r and supported the proliferation and migration of VSMCs. circDiaph3 could be a molecular target to combat intimal hyperplasia.-Xu, J.-Y., Chang, N.-B., Rong, Z.-H., Li, T., Xiao, L., Yao, Q.-P., Jiang, R., Jiang, J. circDiaph3 regulates rat vascular smooth muscle cell differentiation, proliferation, and migration.

Expression profile of circular RNA in rat intimal hyperplasia and target gene prediction.

Intimal hyperplasia is an important cause of stenosis or occlusion after vascular injury. Circular RNAs (circRNAs) are known to be related to various cardiovascular diseases. However, the expression profile of circRNAs in the neointima has not been reported in detail. In this study, we established a rat common carotid artery (CCA) injury model. A microarray detection showed significant differences in circRNA expression between the normal and injured CCA. Real-time quantitative polymerase chain reaction verified the differences. We used bioinformatics to predict the microRNAs that possibly interact with the differentially expressed (DE) circRNAs and linked the potential functions of circRNAs to the target genes of the microRNAs. We believe that the DE circRNA in neointima may affect the differentiation, proliferation, and migration of vascular cells through a variety of target genes. The intervention or utilization of certain circRNAs should be a new method for preventing and treating intimal hyperplasia.

Endothelial Cells Inhibit the Angiotensin II Induced Phenotypic Modulation of Rat Vascular Adventitial Fibroblasts.

The phenotypic modulation of vascular adventitial fibroblasts plays an important role in vascular remodeling. Evidence have shown that endothelial cells and adventitial fibroblasts interact under certain conditions. In this study, we investigated the influence of endothelial cells on the phenotypic modulation of adventitial fibroblasts. Endothelial cells and adventitial fibroblasts from rat thoracic aorta were cultivated in a co-culture system and adventitial fibroblasts were induced with angiotensin II (Ang II). Collagen I and alpha smooth muscle actin (α-SMA) expression and migration of adventitial fibroblasts were analyzed. Ang II upregulated the expression of collagen I and α-SMA and the migration of adventitial fibroblasts. Adventitial fibroblasts-endothelial cells co-culturing attenuated the effects of Ang II. Homocysteine-treated endothelial cells, which are functionally impaired, were less inhibitory of the phenotypic modulation of adventitial fibroblasts. Supplementation of endothelial cells with L-arginine (L-Arg) or 8-bromoguanosine 3',5'-cyclic monophosphate (8-BrcGMP) enhanced the trends, while with L-NG-nitroarginine methyl ester (L-NAME) or 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) the opposite effect was observed. Under the influence of Ang II, adventitial fibroblasts were prone to undergo phenotypic modulation, which was closely related to vascular remodeling. Our study showed that endothelial cells influenced fibroblast phenotypic transformation and such effect would be mediated through the nitric oxide (NO)/cGMP signaling pathway. J. Cell. Biochem. 118: 1921-1927, 2017. © 2017 Wiley Periodicals, Inc.

Suppression of circDcbld1 Alleviates Intimal Hyperplasia in Rat Carotid Artery by Targeting miR-145-3p/Neuropilin-1.

We replicated the rat common carotid artery (CCA) intima hyperplasia model and found the expression of a circular RNA, circRNA_009723 (circDcbld1), was markedly increased in the CCA with intimal hyperplasia. In vitro, the suppression of circDcbld1 in rat vascular smooth muscle cells (VSMCs) led the increase of contractile smooth muscle cell markers and the decrease of cell migration. In vivo, the injection of chemically modified circDcbld1 small interfering RNA (siRNA) lessened the formation of neointima in rat CCA after balloon injury. Further experiments proved that circDcbld1, as a competing endogenous RNA, interacted with miR-145-3p and upregulated the level of neuropilin-1 (Nrp1), thereby regulating the migration of VSMCs. In this study, we demonstrated a new mechanism by which circular RNA promotes intimal hyperplasia. We deem that intervention in the circDcbld1-miR-145-3p/Nrp1 pathway might be a feasible approach to alleviate the post-injury intimal hyperplasia.

Cell apoptosis and proliferation in rat brains after intracerebral hemorrhage: role of Wnt/ß-catenin signaling pathway.

BACKGROUND/AIM: To investigate the role of Wnt/ß-catenin signaling pathway in cell apoptosis and proliferation in intracerebral hemorrhage (ICH) in rats. MATERIALS AND METHODS: The ICH rats were established by stereotaxic infusion of 50 µL autologous arterial blood into the right striatum. Pathological characteristics of brain tissue was assessed by hematoxylin and eosin and TUNEL staining, and the expressions of proliferating cell nuclear antigen (PCNA) and Wnt3a/ß-catenin/cyclin D1 were investigated by immunohistochemistry or reverse-transcription polymerase chain reaction. RESULTS: The number of apoptotic cells and PCNA-positive cells kept increasing from the day following the ICH induction and reached a peak on the 3rd and 14th days, respectively. Some of the PCNA-positive cells could coexpress neurofilament protein-200 or glial fibrillary acidic protein. Wnt3a, ß-catenin, cyclin D1, and PCNA mRNAs reached maximal expression levels on the 3rd, 7th, 7th, and 14th days, respectively. Moreover, the number of apoptotic cells was significantly positively correlated with the expressions of Wnt3a and ß-catenin mRNAs, and negatively correlated with the number of PCNA-positive cells. CONCLUSION: Our results suggest that the Wnt/ß-catenin signaling pathway is associated with cell apoptosis and expression of PCNA in the ICH rat brain and regulates the balance between cell apoptosis and proliferation.