title: [Effects of liraglutide on the expression of local renin-angiotensin system, transforming growth factor-β1 and collagen type III in pulmonary tissue of diabetic rats].
abstract: OBJECTIVE
  To explore the effects of GLP-1 receptor analog liraglutide on the expression of local renin-angiotensin system (RAS), TGF-β1 and collagen type III in pulmonary tissue of diabetic rats.
  
  
  METHODS
  Thirty male Wistar rats were divided into normal (N), diabetic (DM) and liraglutide treatment (LR) groups according to the table of random number. Diabetes mellitus was induced by feeding with a high-sugar and high-fat diet and a low-dose injection of streptozotocin into caudal vein for 8 weeks. After successful modeling, liraglutide (400 µg×kg(-1)×d(-1)) was administered by a subcutaneous injection for 12 weeks in LR group. At Week 12, the mRNA expression levels of AT1R and TGF-β1 were detected by real-time quantitative polymerase chain reaction (RT-qPCR), the protein expression of AngII was detected by enzyme-linked immunosorbent assay (ELISA) and the protein expression levels of AT1R and transforming growth factor-beta 1 (TGF-β1) were detected by Western blotting (WB). Collagen type III was detected by immunohistochemistry.
  
  
  RESULTS
  The expressions of AT1R,AngII, TGF-β1 and collagen type III increased in DM group than those of N group (P < 0.05). The expressions of AT1R, AngII, TGF-β1 and collagen type III were lower in LR group than those of DM group (RT-qPCR of AT1R: 0.08 ± 0.04 vs 0.32 ± 0.16, WB of AT1R: 1.20 ± 0.11 vs 1.32 ± 0.05; ELISA of AngII: (2.78 ± 0.56) vs (4.04 ± 0.13) ng/L; RT-qPCR of TGF-β1: 0.21 ± 0.11 vs 0.64 ± 0.16, WB of TGF-β1:1.01 ± 0.15 vs 1.19 ± 0.13; mean optical density of Col III:0.11 ± 0.04 vs 0.27 ± 0.04, positive area ratio of Col III:0.056 ± 0.023 vs 0.090 ± 0.026, all P < 0.05).
  
  
  CONCLUSIONS
  Liraglutide plays a role of organ protection by inhibiting the expression of TGF-β1 of pulmonary tissue of diabetic rats. And it may be related with a down-regulation of local RAS.
authors.affiliation: Department of Obesity and Metabolism, the Key Laboratory of Hormones & Development (Ministry of Health), Hospital of Metabolic Diseases & Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin 300070, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Guangmin
authors.initials: G
authors.lastname: Chen
authors.forename: Bei
authors.initials: B
authors.lastname: Sun
authors.forename: Xiao
authors.initials: X
authors.lastname: Zheng
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
authors.affiliation: Email: zh80008@163.com.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhang
mesh_terms: D000818:Animals; D024061:Collagen Type III / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D052216:Glucagon-Like Peptide 1 / Q000031:analogs & derivatives* / Q000494:pharmacology; D000069450:Liraglutide; D008168:Lung / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D012084:Renin-Angiotensin System / Q000187:drug effects*; D053773:Transforming Growth Factor beta1 / Q000378:metabolism*
chemical_list: D024061:Collagen Type III; C508962:Tgfb1 protein, rat; D053773:Transforming Growth Factor beta1; D000069450:Liraglutide; D052216:Glucagon-Like Peptide 1