Non-alcoholic fatty liver disease is associated with hepatic microangiopathy and liver inflammation caused by type 2 diabetes mellitus. Oxidised LDL (oxLDL) is involved in proinflammatory and cytotoxic events in various microcirculatory systems. The lectin-like oxLDL receptor 1 (LOX1) plays a crucial role in oxLDL-induced pathological transformation. However, the underlying mechanism of oxLDL's effects on liver microcirculation disturbances remains unclear. In this study, we investigated the effects of oxLDL on LOX1 (OLR1) expression and function, as well as on the fenestration features of human liver sinusoidal endothelial cells (HLSECs) in vitro. Primary HLSECs were obtained and cultured. The cells were treated with various concentrations of oxLDL (25, 50, 100 and 200 μg/ml), and the cytotoxicity and expression of LOX1 were examined. Furthermore, LOX1 knockdown was performed using siRNA technology, and the changes in intracellular reactive oxygen species (ROS), NFκB, p65, (p65), endothelin 1 (ET1 (EDN1)), eNOS (NOS3) and caveolin 1 (CAV1) levels were measured. Cells were treated with 100 μg/ml oxLDL, and the fenestra morphology was visualised using scanning electron microscopy. oxLDL significantly increased LOX1 expression at both the mRNA and protein levels in HLSECs in a dose- and time-dependent manner. oxLDL stimulation increased ROS generation and NFκB activation, upregulated ET1 and caveolin 1 expression, downregulated eNOS expression and reduced the fenestra diameter and porosity. All of these oxLDL-mediated effects were inhibited after LOX1 knockdown. These results reveal a mechanism by which oxLDL stimulates the production of LOX1 through the ROS/NFκB signalling pathway and by which LOX1 mediates oxLDL-induced endothelial injury and the defenestration of HLSECs.
Qi Zhang, Jing Liu, Jia Liu, Wenhui Huang, Limin Tian, Jinxing Quan, Yunfang Wang and Ruilan Niu
Juan Liu, Xiaocen Kong, Long Wang, Hanmei Qi, Wenjuan Di, Xiao Zhang, Lin Wu, Xia Chen, Jing Yu, Juanmin Zha, Shan Lv, Aisen Zhang, Peng Cheng, Miao Hu, Yujie Li, Jianhua Bi, Yan Li, Fang Hu, Yi Zhong, Yong Xu and Guoxian Ding
Brown adipose tissue (BAT) increases energy expenditure and is an attractive therapeutic target for obesity. 11β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1), an amplifier of local glucocorticoid activity, has been shown to modulate white adipose tissue (WAT) metabolism and function. In this study, we investigated the roles of 11β-HSD1 in regulating BAT function. We observed a significant increase in the expression of BAT-specific genes, including UCP1, Cidea, Cox7a1, and Cox8b, in BVT.2733 (a selective inhibitor of 11β-HSD1)-treated and 11β-HSD1-deficient primary brown adipocytes of mice. By contrast, a remarkable decrease in BAT-specific gene expression was detected in brown adipocytes when 11β-HSD1 was overexpressed, which effect was reversed by BVT.2733 treatment. Consistent with the in vitro results, expression of a range of genes related to brown fat function in high-fat diet-fed mice treated with BVT.2733. Our results indicate that 11β-HSD1 acts as a vital regulator that controls the expression of genes related to brown fat function and as such may become a potential target in preventing obesity.
Rubab Akbar, Kamran Ullah, Tanzil Ur Rahman, Yi Cheng, Hai-Yan Pang, Lu-Yang Jin, Qi-Jing Wang, He-Feng Huang and Jian-Zhong Sheng
Receptive endometrium is a prerequisite for successful embryo implantation, and it follows that poor endometrial receptivity is a leading cause of implantation failure. miRNAs play important roles as epigenetic regulators of endometrial receptivity and embryo implantation through post-transcriptional modifications. However, the mechanisms of action of many miRNAs are poorly understood. In this study, we investigated the role of the miR-183 family, comprising three miRNAs (miR-183-5p, miR-182-5p, and miR-96-5p) in endometrial receptivity and embryo implantation. The miR-183 family shows estrogen-dependent upregulation in endometrial Ishikawa (IK) cells. The miR-183 family also has a positive role in migration and proliferation of IK cells. Furthermore, JAr spheroid attachment experiments show that attachment rates were significantly decreased after treatment of IK cells with inhibitors for miR-183-5p and miR-182-5p and increased after treatment with miR-183-5p-mimic and miR-96-5p-mimic, respectively. The downstream analysis shows that catenin alpha 2 (CTNNA2) is a potential target gene for miR-183-5p, and this was confirmed in luciferase reporter assays. An in vivo mouse pregnancy model shows that inhibition of miR-183-5p significantly decreases embryo implantation rates and increases CTNNA2 expression. Downregulation of CTNNA2 in endometrial cells by miR-183-5p may be significant in mediating estrogenic effects on endometrial receptivity. In conclusion, miR-183-5p and the CTNNA2 gene may be potential biomarkers for endometrial receptivity and may be useful diagnostic and therapeutic targets for successful embryo implantation.