title: High density lipoprotein downregulates angiotensin II type 1 receptor and inhibits angiotensin II-induced cardiac hypertrophy.
abstract: Angiotensin II (AngII) and its type receptor (AT1-R) play important roles in the development of cardiac hypertrophy. Low level of high density lipoprotein (HDL) is also an independent risk factor for cardiac hypertrophy. We therefore investigated in the present study whether HDL inhibits cardiac hypertrophy relatively to inhibition of AngII and AT1-R in both in vitro and in vivo experiments. Stimulation of cultured cardiomyocytes of neonatal rats with AngII for 24 h and infusion of AngII in mice for 2 weeks resulted in marked cardiac hypertrophic responses including increased protein synthesis, enlarged sizes of cardiomyocytes and hearts, upregulated phosphorylation levels of protein kinases and reprogrammed expression of specific genes, all of which were significantly attenuated by the treatment with HDL. Furthermore, AngII-treatment induced upregulation of AT-R expression either in cultured cardiomyocytes or in hearts of mice and HDL significantly suppressed the upregulation of AT1-R. Our results suggest that HDL may abrogate AngII-induced cardiac hypertrophy through downregulation of AT1-R expression.
authors.affiliation: Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, 180 Feng Lin Road, Shanghai 200032, China.
authors.forename: Li
authors.initials: L
authors.lastname: Lin
authors.forename: Hui
authors.initials: H
authors.lastname: Gong
authors.forename: Jingyi
authors.initials: J
authors.lastname: Ge
authors.forename: Guoliang
authors.initials: G
authors.lastname: Jiang
authors.forename: Ning
authors.initials: N
authors.lastname: Zhou
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Ye
authors.forename: Guoping
authors.initials: G
authors.lastname: Zhang
authors.forename: Junbo
authors.initials: J
authors.lastname: Ge
authors.forename: Yunzeng
authors.initials: Y
authors.lastname: Zou
mesh_terms: D000804:Angiotensin II / Q000378:metabolism* / Q000494:pharmacology; D000818:Animals; D006332:Cardiomegaly / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D004195:Disease Models, Animal; D015536:Down-Regulation; D008075:Lipoproteins, HDL / Q000378:metabolism* / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D044140:Receptor, Angiotensin, Type 1 / Q000378:metabolism*
chemical_list: D008075:Lipoproteins, HDL; D044140:Receptor, Angiotensin, Type 1; D000804:Angiotensin II