title: Direct action of capsaicin in brown adipogenesis and activation of brown adipocytes.
abstract: The ingestion of capsaicin, the principle pungent component of red and chili peppers, induces thermogenesis, in part, through the activation of brown adipocytes expressing genes related to mitochondrial biogenesis and uncoupling such as peroxisome proliferator-activated receptor (Ppar) γ coactivator-1α (Pgc-1α) and uncoupling protein 1 (Ucp1). Capsaicin has been suggested to induce the activation of brown adipocytes, which is mediated by the stimulation of sympathetic nerves. However, capsaicin may directly affect the differentiation of brown preadipocytes, brown adipocyte function, or both, through its significant absorption. We herein demonstrated that Trpv1, a capsaicin receptor, is expressed in brown adipose tissue, and that its expression level is increased during the differentiation of HB2 brown preadipocytes. Furthermore, capsaicin induced calcium influx in brown preadipocytes. A treatment with capsaicin in the early stage of brown adipogenesis did not affect lipid accumulation or the expression levels of Fabp4 (a gene expressed in mature adipocytes), Pparγ2 (a master regulator of adipogenesis) or brown adipocyte-selective genes. In contrast, a treatment with capsaicin in the late stage of brown adipogenesis slightly increased the expression levels of Fabp4, Pparγ2 and Pgc-1α. Although capsaicin did not affect the basal expression level of Ucp1, Ucp1 induction by forskolin was partially inhibited by capsaicin, irrespective of the dose of capsaicin. The results of the present study suggest the direct effects of capsaicin on brown adipocytes or in the late stage of brown adipogenesis.
authors.affiliation: Division of Applied Biosciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan.
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Kida
authors.affiliation: Division of Applied Biosciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan.
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yoshida
authors.affiliation: Laboratory of Molecular Biology, Azabu University School of Veterinary Medicine, Sagamihara, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Murakami
authors.affiliation: Laboratory of Veterinary Pharmacology, Azabu University School of Veterinary Medicine, Sagamihara, Japan.
authors.forename: Mitsuyuki
authors.initials: M
authors.lastname: Shirai
authors.affiliation: Laboratory of Experimental Animal Science, Kitasato University School of Veterinary Medicine, Towada, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Hashimoto
authors.affiliation: Division of Food Science and Biotechnology, Kyoto University Graduate School of Agriculture, Kyoto, Japan.
authors.forename: Teruo
authors.initials: T
authors.lastname: Kawada
authors.affiliation: Division of Applied Biosciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan.
authors.forename: Tohru
authors.initials: T
authors.lastname: Matsui
authors.affiliation: Division of Applied Biosciences, Kyoto University Graduate School of Agriculture, Kyoto, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Funaba
mesh_terms: D052437:Adipocytes, Brown / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D050156:Adipogenesis / Q000187:drug effects*; D002001:Adipose Tissue, Brown / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002211:Capsaicin / Q000494:pharmacology*; D002478:Cells, Cultured; D050556:Fatty Acid-Binding Proteins / Q000235:genetics / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D050916:TRPV Cation Channels / Q000235:genetics / Q000378:metabolism
chemical_list: C493411:Fabp4 protein, mouse; D050556:Fatty Acid-Binding Proteins; D050916:TRPV Cation Channels; C493921:TRPV1 protein, mouse; D002211:Capsaicin
keywords: Trpv1; Ucp1; brown adipocytes; brown adipogenesis; capsaicin