title: Activation of transient receptor potential vanilloid type-1 channel prevents adipogenesis and obesity.
abstract: We tested the hypothesis that activation of transient receptor potential vanilloid type-1 (TRPV1) by capsaicin prevents adipogenesis. TRPV1 channels in 3T3-L1-preadipocytes and visceral adipose tissue from mice and humans were detected by immunoblotting and quantitative real-time RT-PCR. The effect of TRPV1 on cytosolic calcium was determined fluorometrically in 3T3-L1-preadipocytes and in human visceral fat tissue. Adipogenesis in stimulated 3T3-L1-preadipocytes was determined by oil red O-staining of intracellular lipid droplets, triglyceride levels, expression of peroxisome proliferator-activated receptor-gamma, and expression of fatty acid synthase. Long-term feeding experiments were undertaken in wild-type mice and TRPV1 knockout mice. We detected TRPV1 channels in 3T3-L1-preadipocytes and visceral adipose tissue from mice and humans. In vitro, the TRPV1 agonist capsaicin dose-dependently induced calcium influx and prevented the adipogenesis in stimulated 3T3-L1-preadipocytes. RNA interference knockdown of TRPV1 in 3T3-L1-preadipocytes attenuated capsaicin-induced calcium influx, and adipogenesis in stimulated 3T3-L1-preadipocytes was no longer prevented. During regular adipogenesis TRPV1 channels were downregulated which was accompanied by a significant and time-dependent reduction of calcium influx. Compared with lean counterparts in visceral adipose tissue from obese db/db and ob/ob mice, and from obese human male subjects we observed a reduced TRVP1 expression. The reduced TRPV1 expression in visceral adipose tissue from obese humans was accompanied by reduced capsaicin-induced calcium influx. The oral administration of capsaicin for 120 days prevented obesity in male wild type mice but not in TRPV1 knockout mice assigned to high fat diet. We conclude that the activation of TRPV1 channels by capsaicin prevented adipogenesis and obesity.
authors.affiliation: Center for Hypertension and Metabolic Diseases, Department of Hypertension and Endocrinology, Daping Hospital, Third Military Medical University, Chongqing 400042, PR China.
authors.forename: Li Li
authors.initials: LL
authors.lastname: Zhang
authors.forename: Dao
authors.initials: D
authors.lastname: Yan Liu
authors.forename: Li Qun
authors.initials: LQ
authors.lastname: Ma
authors.forename: Zhi Dan
authors.initials: ZD
authors.lastname: Luo
authors.forename: Ting Bing
authors.initials: TB
authors.lastname: Cao
authors.forename: Jian
authors.initials: J
authors.lastname: Zhong
authors.forename: Zhen Cheng
authors.initials: ZC
authors.lastname: Yan
authors.forename: Li Juan
authors.initials: LJ
authors.lastname: Wang
authors.forename: Zhi Gang
authors.initials: ZG
authors.lastname: Zhao
authors.forename: Shan Jun
authors.initials: SJ
authors.lastname: Zhu
authors.forename: Mark
authors.initials: M
authors.lastname: Schrader
authors.forename: Florian
authors.initials: F
authors.lastname: Thilo
authors.forename: Zhi Ming
authors.initials: ZM
authors.lastname: Zhu
authors.forename: Martin
authors.initials: M
authors.lastname: Tepel
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000378:metabolism; D050156:Adipogenesis; D000273:Adipose Tissue / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D018345:Mice, Knockout; D008820:Mice, Obese; D009765:Obesity / Q000517:prevention & control*; D034741:RNA, Small Interfering / Q000494:pharmacology; D013234:Stem Cells / Q000378:metabolism; D050916:TRPV Cation Channels / Q000819:agonists / Q000172:deficiency / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D014781:Viscera
chemical_list: D034741:RNA, Small Interfering; D050916:TRPV Cation Channels; C494482:TRPV1 protein, human; C493921:TRPV1 protein, mouse; D002211:Capsaicin; D002118:Calcium