Omentin-1 enhances the inhibitory effect of endothelial progenitor cells on neointimal hyperplasia by inhibiting the p38 MAPK/CREB pathway.

AIMS: Endothelial progenitor cells (EPCs) play an important role in vascular repair. However, they are dysfunctional in the inflammatory microenvironment during restenosis. In this study, we investigated whether omentin-1, an anti-inflammatory factor, could reduce neointima formation after carotid artery injury (CAI) in rats by improving EPC functions that were damaged by inflammation and the underlying mechanisms. MAIN METHODS: EPCs were transfected with adenoviral vectors expressing human omentin-1 or green fluorescent protein (GFP). Then, the rats received 2 × 106 EPCs expressing omentin-1 or GFP by tail vein injection directly after CAI and again 24 h later. Hematoxylin-eosin staining and immunohistochemistry were used for analyzing neointimal hyperplasia. Besides, EPCs were treated with omentin-1 and TNF-α to examine the underlying mechanism. KEY FINDINGS: Our results showed that omentin-1 could significantly improve EPC functions, including proliferation, apoptosis and tube formation. Meanwhile, EPCs overexpressed with omentin-1 could significantly reduce neointimal hyperplasia and tumor necrosis factor-α (TNF-α) expression after CAI in rats. TNF-α could notably induce EPC dysfunction, which could be markedly reversed by omentin-1 through the inhibition of the p38 MAPK/CREB pathway. Furthermore, a p38 MAPK agonist (anisomycin) significantly abrogated the protective effects of omentin-1 on EPCs damaged by TNF-α. SIGNIFICANCE: Our results indicated that genetically modifying EPC with omentin-1 could be an alternative strategy for the treatment of restenosis.

Prophylactic exercise-derived circulating exosomal miR-125a-5p promotes endogenous revascularization after hindlimb ischemia by targeting endothelin converting enzyme 1.

Background: Prophylactic exercise improves clinical outcomes in patients experiencing severe ischemic diseases. Previous studies have shown that exercise could alter the amount or content of circulating exosomes. However, little is known about the role of precursory exercise-derived circulating exosomes (Exe-Exo) in ischemic diseases. We therefore aimed to explore the function and mechanism of Exe-Exo in endogenous revascularization and perfusion recovery in peripheral arterial disease. Methods and Results: We first determined that 4 weeks of precursory treadmill exercise improved perfusion recovery on days 7, 14 and 21 after unilateral femoral artery ligation (FAL) but had no effect immediately after ligation. Then, local muscle delivery of Exe-Exo promotes arteriogenesis, angiogenesis and perfusion recovery, which could be abolished by GW4869, a well-recognized pharmacological agent inhibiting exosome release. This suggests that Exe-Exo mediated exercise-induced revascularization. In vitro, Exe-Exo enhanced endothelial cell proliferation, migration and tube formation. In addition, we identified miR-125a-5p as a novel exerkine through exosomal miRNA sequencing and RT-qPCR validation. Inhibition of miR-125a-5p abrogated the beneficial effects of Exe-Exo both in vivo and in vitro. Mechanistically, these exercise-afforded benefits were attributed to the exosomal miR-125a-5p downregulation of ECE1 expression and the subsequent activation of the AKT/eNOS downstream signaling pathway. Specifically, skeletal muscle may be a major tissue source of exercise-induced exosomal miR-125a-5p via fluorescence in situ hybridization. Conclusions: Endogenous circulating exosomal miR-125a-5p promotes exercise-induced revascularization via targeting ECE1 and activating AKT/eNOS downstream signaling pathway. Identify exosomal miR-125a-5p as a novel exerkine, and highlight its potential therapeutic role in the prevention and treatment of peripheral arterial disease.

NFAT5 promotes arteriogenesis via MCP-1-dependent monocyte recruitment.

Studies have demonstrated that nuclear factor of activated T cells 5 (NFAT5) is not only a tonicity-responsive transcription factor but also activated by other stimuli, so we aim to investigate whether NFAT5 participates in collateral arteries formation in rats. We performed femoral artery ligature (FAL) in rats for hindlimb ischaemia model and found that NFAT5 was up-regulated in rat adductors with FAL compared with sham group. Knockdown of NFAT5 with locally injection of adenovirus-mediated NFAT5-shRNA in rats significantly inhibited hindlimb blood perfusion recovery and arteriogenesis. Moreover, NFAT5 knockdown decreased macrophages infiltration and monocyte chemotactic protein-1 (MCP-1) expression in rats adductors. In vitro, with interleukin-1ß (IL-1ß) stimulation and loss-of-function studies, we demonstrated that NFAT5 knockdown inhibits MCP-1 expression in endothelial cells and chemotaxis of THP-1 cells regulated by ERK1/2 pathway. More importantly, exogenous MCP-1 delivery could recover hindlimb blood perfusion, promote arteriogenesis and macrophages infiltration in rats after FAL, which were depressed by NFAT5 knockdown. Besides, NFAT5 knockdown also inhibited angiogenesis in gastrocnemius muscles in rats. Our results indicate that NFAT5 is a critical regulator of arteriogenesis and angiogenesis via MCP-1-dependent monocyte recruitment, suggesting that NFAT5 may represent an alternative therapeutic target for ischaemic diseases.

[General reproductive toxicity assessment in mice exposed to low-level ozone].

OBJECTIVE: To explore the general reproductive toxicity in mice exposed to low-level ozone. METHODS: Low-level (0.09 approximately 0.18 mg/m3) ozone was created by 15 W ultraviolet light. The mice in 3 experimental groups and a control group were fed in low-level ozone environment or normal environment, respectively, and then the mating experiment was conducted. The pregnancy rate and the weight variations of the female mice were observed. The weight of the live fetuses was observed, and the appearance, bone and internal organs were checked for malformation. RESULTS: There were no significant differences in any indexes between the experimental groups and the control group. CONCLUSION: Low-level ozone created by 15 W ultraviolet light may not have reproductive toxicity in mice.