microRNA-331-3p maintains the contractile type of vascular smooth muscle cells by regulating TNF-α and CD14 in intracranial aneurysm.

Dysfunction of vascular smooth muscle cells (VSMCs) may be linked to intracranial aneurysm (IA) formation. VSMCs possess a phenotypic plasticity, capable of changing from a mature, contractile to a less differentiated, synthetic phenotype. In this study, we identify a microRNA candidate miR-331-3p that participates in regulating differentiation properties of VSMCs. The expression of TNF-α and CD14 was quantified in IA wall tissues obtained from 96 IA patients and their associations with clinicopathological features of IA were assessed. Then the interactions between miR-331-3p, TNF-α and CD14 were evaluated by determination of luciferase activity. Differentiated properties of VSMCs were assessed from phenotypic markers of contractile VSMCs, a-SMA and E-cadherin, and of synthetic VSMCs, ICAM-1, MCP-1, IL-6, MMP-2 and MMP-9. Rat IA models by ligation of left carotid artery and left renal artery and histological analysis of induced IAs were performed. The TNF-α and CD14 was highly expressed in IA wall tissues and associated with the type and diameter of aneurysm. Depletion of TNF-α or CD14 retarded VSMC apoptosis and transformation to the synthetic type but facilitated cell proliferation. Elevations in miR-331-3p, a direct negative regulator of both TNF-α and CD14, also reduced VSMC apoptosis and prevented VSMCs from synthetic type and increase their proliferation. Furthermore, miR-331-3p was demonstrated to inhibit the formation of IA by down-regulating TNF-α and CD14 in vivo. In conclusion, miR-331-3p maintains the contractile type of VSMCs, thus possibly inhibiting the progression of IA. These findings provide potential new strategies for the clinical treatment of IA.

Fan W ，Liu Y ，Li C ，Qu X ，Zheng G ，Zhang Q ，Pan Z ，Wang Y ，Rong J ... -  《-》

The SNHG12/microRNA-15b-5p/MYLK axis regulates vascular smooth muscle cell phenotype to affect intracranial aneurysm formation.

Feng W ，Liang H ，Liu D ，Ruan S ... -  《-》

Phoenixin-14 maintains the contractile type of vascular smooth muscle cells in cerebral aneurysms rats.

The rupture of intracranial aneurysm (IA) is the primary reason contributing to the occurrence of life-threatening subarachnoid hemorrhages. The oxidative stress-induced phenotypic transformation from the contractile phenotype to the synthetic phenotype of vascular smooth muscle cells (VSMCs) plays a pivotal role in IA formation and rupture. Our study aimed to figure out the role of phoenixin-14 in VSMC phenotypic switching during the pathogenesis of IA by using both cellular and animal models. Primary rat VSMCs were isolated from the Willis circle of male Sprague-Dawley rats. VSMCs were stimulated by hydrogen peroxide (H2O2) to establish a cell oxidative damage model. After pretreatment with phoenixin-14 and exposure to H2O2, VSMC viability, migration, and invasion were examined through cell counting kit-8 (CCK-8), wound healing, and Transwell assays. Intracellular reactive oxygen species (ROS) production in VSMCs was evaluated by using 2',7'-Dichlorofluorescin diacetate (DCFH-DA) fluorescence probes and flow cytometry. Rat IA models were established by ligation of the left common carotid arteries and posterior branches of both renal arteries. The histopathological changes of rat intracranial blood vessels were observed through hematoxylin and eosin staining. The levels of contractile phenotype markers (alpha-smooth muscle actin [α-SMA] and smooth muscle 22 alpha [SM22α]) in VSMCs and rat arterial rings were determined through real-time quantitative polymerase chain reaction (RT-qPCR) and western blot analysis. Our results showed that H2O2 stimulated the production of intracellular ROS and induced oxidative stress in VSMCs, while phoenixin-14 pretreatment attenuated intracellular ROS levels in H2O2-exposed VSMCs. H2O2 exposure promoted VSMC migration and invasion, which, however, was reversed by phoenixin-14 pretreatment. Besides, phoenixin-14 administration inhibited IA formation and rupture in rat models. The decrease in α-SMA and SM22α levels in H2O2-exposed VSMCs and IA rat models was antagonized by phoenixin-14. Collectively, phoenixin-14 ameliorates the progression of IA through preventing the loss of the contractile phenotype of VSMCs.

Ling C ，Yang Y ，Zhang B ，Wang H ，Chen C ... -  《-》

MicroRNA-513b-5p targets COL1A1 and COL1A2 associated with the formation and rupture of intracranial aneurysm.

Collagen-type I alpha 1 chain (COL1A1) and COL1A2 are abnormally expressed in intracranial aneurysm (IA), but their mechanism of action remains unclear. This study was performed to investigate the mechanism of COL1A1 and COL1A2 affecting the occurrence and rupture of IA. Quantitative real-time polymerase chain reaction was used to measure the expression of hsa-miR-513b-5p, COL1A1, COL1A2, TNF-α, IL-6, MMP2, MMP3, MMP9 and TIMP4 in patients with ruptured IA (RA) (n = 100), patients with un-ruptured IA (UA) (n = 100), and controls (n = 100). Then, human vascular smooth muscle cells (HASMCs) were cultured, and dual luciferase reporter assay was performed to analyse the targeting relationship between miR-513b-5p and COL1A1 or COL1A2. The effects of the miR-513b-5p mimic and inhibitor on the proliferation, apoptosis, and death of HASMC and the RIP1-RIP3-MLKL and matrix metalloproteinase pathways were also explored. The effect of silencing and over-expression of COL1A1 and COL1A2 on the role of miR-513b-5p were also evaluated. Finally, the effects of TNF-α on miR-513b-5p targeting COL1A1 and COL1A2 were tested. Compared with those in the control group, the serum mRNA levels of miR-513b-5p, IL-6 and TIMP4 were significantly decreased in the RA and UA groups, but COL1A1, COL1A2, TNF-α, IL-1β, MMP2, MMP3 and MMP9 were significantly increased (p < 0.05). Compared with those in the UA group, the expression of COL1A1, COL1A2, TNF-α, IL-1β and MMP9 was significantly up-regulated in the RA group (p < 0.05). Results from the luciferase reporter assay showed that COL1A1 and COL1A were the direct targets of miR-513b-5p. Further studies demonstrated that miR-513b-5p targeted COL1A1/2 to regulate the RIP1-RIP3-MLKL and MMP pathways, thereby enhancing cell death and apoptosis. Over-expression of COL1A1 or COL1A2, rather than silencing COL1A1/2, could improve the inhibitory effect of miR-513b-5p on cell activity by regulating the RIP1-RIP3-MLKL and MMP pathways. Furthermore, over-expression of miR-513b-5p and/or silencing COL1A1/2 inhibited the TNF-α-induced cell proliferation and enhanced the TNF-α-induced cell death and apoptosis. The mechanism may be related to the inhibition of collagen I and TIMP4 expression and promotion of the expression of RIP1, p-RIP1, p-RIP3, p-MLKL, MMP2 and MMP9. MiR-513b-5p targeted the inhibition of COL1A1/2 expression and affected HASMC viability and extracellular mechanism remodelling by regulating the RIP1-RIP3-MLKL and MMP pathways. This process might be involved in the formation and rupture of IA.

Zheng Z ，Chen Y ，Wang Y ，Li Y ，Cheng Q ... -  《-》

WNTA5-mediated miR-374a-5p regulates vascular smooth muscle cell phenotype transformation and M1 macrophage polarization impacting intracranial aneurysm progression.

Li Z ，Huang J ，Yang L ，Li X ，Li W ... -  《Scientific Reports》