Treatment of vascular tissue with low levels of lipopolysaccharide (LPS) induces nitric oxide synthase (NOS) activity and diminishes vascular contractility. However, in cultured vascular smooth muscle cells (VSMC), very high doses of LPS or the combination of LPS with cytokines are required for the induction of nitric oxide (NO) formation. The aims of this study were to establish a cell model to investigate LPS-induced hypocontractility and NO production and to test the hypothesis that responses of VSMC to LPS are differentiation regulated. We used Matrigel basement membrane matrix to maintain VSMC differentiation and found that VSMC cultured on Matrigel retained significant contractility in response to KCl stimulation. Incubation of VSMC with low levels of LPS(1-100 ng/ml) induced NOS mRNA and protein, induced NO production, and decreased cell contractility in a time- and dose-dependent fashion. The NOS inhibitor NG-nitro-L-arginine methyl ester (L-NAME) partially restored LPS-treated VSMC contractility, whereas L-arginine reversed the contractility-restoring effect of L-NAME. These results suggest that VSMC grown on Matrigel are a useful experimental model for investigations into signal transduction mechanisms responsible for LPS-induced vascular hypocontractility.

Nonalcoholic fatty liver disease (NAFLD) is prevalent clinically and can lead to more serious chronic liver disease. However, the pathological mechanism is still unclear, and thus, there are no approved drugs on the market. Transcriptional coactivator WW domain-binding protein 2 (WBP2) is a newly discovered oncogene that has an important relationship with the occurrence and development of breast cancer and mediates the interaction between Wnt and various other signaling pathways. The expression level of WBP2 was decreased in NAFLD. Overexpression of WBP2 with AAV in vivo alleviated liver fat deposition and insulin resistance induced by a high-fat diet (HFD). Knockdown of WBP2 with AAV aggravated HFD-induced fatty liver and insulin resistance. In vitro experiments showed that in the human normal hepatocyte cell line LO2 and primary hepatocytes isolated from mice, overexpression of WBP2 reduced fat deposition, and knocking out or knocking down WBP2 aggravated PA-induced fat deposition. Through mass spectrometry, we found that WBP2 can bind to AMPKβ1, and by mutating AMPKβ1, we found that WBP2 can induce phosphorylation of AMPKβ1 at S108 and then activate the AMPK pathway to affect lipid metabolism. The effect of WBP2 on NAFLD provides a possible new direction for future research on NAFLD.

The abnormal proliferation and migration of Vascular smooth muscle cells (VSMCs) are related to many cardiovascular diseases, including atherosclerosis, restenosis after balloon angioplasty, hypertension, etc. Myricanol is a diarylheptanoid that can be separated from the bark of Myrica rubra. It has been reported that myricanol can anti-inflammatory, anti-cancer, anti-neurodegenerative, promote autophagic clearance of tau and prevent muscle atrophy. But its potential role in the cardiovascular field remains unknown. In this study, we investigated the effect of myricanol on the proliferation and migration of VSMCs in vitro and on the intimal hyperplasia in vivo. In vitro experiments, we found myricanol can inhibit the proliferation and migration of VSMCs induced by PDGF-BB. In terms of mechanism, the preincubation of myricanol can suppress the PDGF-BB induced phosphorylation of PDGFRβ and its downstream such as PLCγ1, Src, and MAPKs. In addition, NF-kB p65 translocation was also suppressed by myricanol. In vivo experiments, we found myricanol can suppress the intimal hyperplasia after wire ligation of the carotid artery in mice. These results may provide a new strategy for the prevention and treatment of coronary atherosclerosis and post-stent stenosis in the future.