作者机构：
[Li, Lifang] Univ South China, Dept Microbiol & Immunol, Hengyang 421001, Peoples R China.;[Xie, Feng; Guo, Yu; Li, Lanfang; Lv, Deguan; Lu, Qixuan; Tang, Guotao; Chen, Linxi] Univ South China, Inst Pharm & Pharmacol, Learning Key Lab Pharmacoprote, Hengyang 421001, Peoples R China.;[Zhang, Zidong] Univ Mississippi, Med Ctr, Dept Microbiol, Jackson, MS 39216 USA.;[Li, Jian] Beijing Hosp, Key Lab Geriatr, Beijing 100730, Peoples R China.;[Li, Jian] Minist Hlth, Beijing Inst Geriatr, Beijing 100730, Peoples R China.
通讯机构：
[Chen, Linxi] U;Univ South China, Inst Pharm & Pharmacol, Learning Key Lab Pharmacoprote, Hengyang 421001, Peoples R China.
关键词：
G protein-coupled receptor;cell proliferation;vascular smooth muscle cell;Jagged-1/Notch3
摘要：
The apelin/apelin receptor (APJ, apelin–angiotensin receptor-like 1) system is a newly deorphanized G protein-coupled receptor system. Both apelin and APJ that are important regulatory factors are expressed in the cardiovascular system. Our previous studies demonstrated that apelin-13 significantly stimulated vascular smooth muscle cell (VSMC) proliferation. In this paper, our data suggested that the Jagged-1/Notch3 signaling transduction pathway is involved in apelin-13-induced VSMC proliferation by promoting the expression of Cyclin D1. Results indicated that apelin-13 stimulates the proliferation of VSMC and the expression of Jagged-1 and Notch3 in concentration- and time-dependent manners. The increased expression of Jagged-1 and Notch3 induced by apelin-13 could be abolished by extracellular signal-regulated protein kinase (ERK) blockade. PD98059 (ERK inhibitor) can inhibit the activation of Jagged-1/Notch3 induced by apelin-13. Down-regulation of Notch3 using small interfering RNA inhibits the expression of Cyclin D1 and prevents apelin-13-induced VSMC proliferation. In conclusion, Jagged-1/Notch3 signaling transduction pathway is involved in VSMC proliferation induced by apelin-13.
作者机构：
[Garvey, W. Timothy; Fu, Yuchang; Chung, B. Hong; Luo, Nanlan] Univ Alabama Birmingham, Dept Nutr Sci, Birmingham, AL 35294 USA.;[Wang, Xiangdong] Shandong Univ, Inst Cell Biol, Jinan 250012, Peoples R China.;[Klein, Richard L.] Med Univ S Carolina, Dept Med, Charleston, SC 29425 USA.;[Tang, Chao-Ke] Univ S China, Inst Cardiovasc Res, Hengyang 421001, Peoples R China.;[Garvey, W. Timothy] Birmingham VA Med Ctr, Birmingham, AL 35233 USA.
通讯机构：
[Fu, Yuchang] U;Univ Alabama Birmingham, Dept Nutr Sci, Shelby Bldg 1213,1825 Univ Blvd, Birmingham, AL 35294 USA.
摘要：
Objective: Adiponectin is one of several important, metabolically active cytokines secreted from adipose tissue. Epidemiologic studies have associated low circulating levels of this adipokine with multiple metabolic disorders including obesity, insulin resistance, type II diabetes, and cardiovascular disease. To investigate how enhanced adiponectin-mediated changes in metabolism in vivo, we generated transgenic mice which specifically overexpress the gene coding for adiponectin receptor 1 (AdipoR1) in mouse macrophages using the human scavenger receptor A-I gene (SR-AI) enhancer/promoter. We found that macrophage-specific AdipoR1 transgenic mice (AdR1-TG) presented reduced whole body weight, fat accumulation and liver steatosis when these transgenic mice were fed with a high fat diet. Moreover, these macrophage AdR1-TG mice exhibited enhanced whole-body glucose tolerance and insulin sensitivity with reduced proinflammatory cytokines, MCP-1 and TNF-alpha, both in the serum and in the insulin target metabolic tissues. Additional studies demonstrated that these macrophage AdR1-TG animals exhibited reduced macrophage foam cell formation in the arterial wall when these transgenic mice were crossed with a low-density lipoprotein receptor (Ldlr) deficient mouse model. Conclusions: These results suggest that AdipoR1 overexpressed in macrophages can physiologically modulate metabolic activities in vivo by enhancing adiponectin actions in distal metabolically active tissues. The AdipoR1 modified macrophages provide unique interactions with the residented tissues/cells, suggesting a novel role of macrophage adiponectin receptor in improving metabolic disorders in vivo. (C) 2013 Elsevier Ireland Ltd. All rights reserved.
作者机构：
[Xiao Zhefeng; Li Guoqing; Zhan Xianquan; Li Maoyu; Chen Xiaojuan; Peng Fang; Hu Rong; Shao Meiying; Huang Ying; Chen Zhuchu] State Local Joint Engineering Laboratory for Anticancer Drugs,Hunan Engineering Laboratory for Structural Biology & Drug Design,Key Laboratory of Cancer Proteomics of Chinese Ministry of Health,Xiangya Hospital,Central South University,Changsha,P.R.China,410008;[Li Guoqing] Department of Biology,School of Pharmacy and Life Science,University of South China,Hengyang,Hunan,P.R.China,410008
摘要：
Apelin has an antiatherogenic function through activating protein kinase C (PKC) to initiate a series of cellular signaling pathways. PKC phosphorylates and stabilizes ATP-binding cassette transporter A1 (ABCA1) through inhibiting its degradation mediated by calpain. Thus, in the present study, we investigated whether apelin-13 affects expression of ABCA1 through PKC signaling. The results showed that apelin-13 dramatically increased cholesterol efflux from THP-1 macrophage-derived foam cells and reduced cellular cholesterol levels. ABCA1 protein but not mRNA levels were dramatically increased by apelin-13, and calpain-induced degradation of ABCA1 and calpain activity were suppressed with treatment of apelin-13. However, the effects of apelin-13 on ABCA1 protein expression, cellular cholesterol efflux and calpain activity were abolished by depletion of PKCα, suggesting the potential important role of PKCα. In addition, apelin-13 was shown to phosphorylate serine residues in ABCA1 through the PKCα pathway. Thus, apelin-13 appears to activate PKCα, phosphorylate ABCA1 and inhibit calpain-mediated proteolysis, thereby promoting cholesterol efflux and reducing foam cell formation. Our study herein described a possible mechanism for understanding the antiatherogenic effects of apelin on attenuating the progression of atherosclerosis.
摘要：
Tert-butylhydroquinone (tBHQ), a synthetic phenolic antioxidant, is commonly used as a food preservative because of its potent antilipid peroxidation activity. Several lines of evidence have demonstrated that dietary supplementation with antioxidants has an antiatherogenic function through reducing cholesterol uptake or promoting reverse cholesterol transport. In this study, we investigated whether tBHQ affects expression of ATP-binding cassette transporter A1 (ABCA1) and the potential subsequent effect on cellular cholesterol homeostasis. Methods and Results: tBHQ increased ABCA1 protein levels and markedly enhanced cholesterol efflux from THP-1 macrophage-derived foam cells. Furthermore, tBHQ reduced calpain-mediated ABCA1 proteolysis via activation of nuclear factor E2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1). Inhibition of HO-1 with a pharmacological inhibitor or siRNA and knockdown of Nrf2 suppressed the stimulatory effects of tBHQ on ABCA1 expression and calpain activity. Conclusions: Nrf2/HO-1 signaling is required for the regulation by tBHQ of ABCA1 expression and cholesterol efflux in macrophage-derived foam cells and an antiatherogenic role of tBHQ is suggested.
关键词：
copper;alkynes;trifluoromethylation;S-(trifluoromethyl)diarylsulfonium salt
摘要：
The copper-mediated trifluoromethylation of terminal alkynes with S-(trifluoromethyl)diarylsulfonium salt has been carefully investigated. The reactions proceeded smoothly to afford trifluoromethylated acetylenes in moderate to good yields. This approach is a convenient method to synthesize a variety of functional trifluoromethylated acetylenes.
