title: Glucose and Insulin Stimulate Lipogenesis in Porcine Adipocytes: Dissimilar and Identical Regulation Pathway for Key Transcription Factors.
abstract: Lipogenesis is under the concerted action of ChREBP, SREBP-1c and other transcription factors in response to glucose and insulin. The isolated porcine preadipocytes were differentiated into mature adipocytes to investigate the roles and interrelation of these transcription factors in the context of glucose- and insulin-induced lipogenesis in pigs. In ChREBP-silenced adipocytes, glucose-induced lipogenesis decreased by ~70%, however insulin-induced lipogenesis was unaffected. Moreover, insulin had no effect on ChREBP expression of unperturbed adipocytes irrespective of glucose concentration, suggesting ChREBP mediate glucose-induced lipogenesis. Insulin stimulated SREBP-1c expression and when SREBP-1c activation was blocked, and the insulin-induced lipogenesis decreased by ~55%, suggesting SREBP-1c is a key transcription factor mediating insulin-induced lipogenesis. LXRα activation promoted lipogenesis and lipogenic genes expression. In ChREBP-silenced or SREBP-1c activation blocked adipocytes, LXRα activation facilitated lipogenesis and SREBP-1c expression, but had no effect on ChREBP expression. Therefore, LXRα might mediate lipogenesis via SREBP-1c rather than ChREBP. When ChREBP expression was silenced and SREBP-1c activation blocked simultaneously, glucose and insulin were still able to stimulated lipogenesis and lipogenic genes expression, and LXRα activation enhanced these effects, suggesting LXRα mediated directly glucose- and insulin-induced lipogenesis. In summary, glucose and insulin stimulated lipogenesis through both dissimilar and identical regulation pathway in porcine adipocytes.
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Zhang Guo
authors.initials: ZG
authors.lastname: Hua
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Lu Jian
authors.initials: LJ
authors.lastname: Xiong
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Chen
authors.initials: C
authors.lastname: Yan
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Dai Hong
authors.initials: DH
authors.lastname: Wei
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: ZhaXi
authors.initials: Z
authors.lastname: YingPai
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Zhao Yong
authors.initials: ZY
authors.lastname: Qing
authors.affiliation: Gansu Engineering Research Center for Animal Cell, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Qiao Zi
authors.initials: QZ
authors.lastname: Lin
authors.affiliation: Gansu Engineering Research Center for Animal Cell, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Feng Ruo
authors.initials: FR
authors.lastname: Fei
authors.affiliation: College of Life Science and Engineering, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Wang Ya
authors.initials: WY
authors.lastname: Ling
authors.affiliation: Gansu Engineering Research Center for Animal Cell, Northwest University for Nationalities, Lanzhou, Gansu 730030, China.
authors.forename: Ma Zhong
authors.initials: MZ
authors.lastname: Ren
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D000818:Animals; D005947:Glucose / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D050155:Lipogenesis / Q000187:drug effects*; D000071518:Liver X Receptors / Q000378:metabolism; D008297:Male; D051780:Sterol Regulatory Element Binding Protein 1 / Q000378:metabolism; D013552:Swine; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D007328:Insulin; D000071518:Liver X Receptors; D051780:Sterol Regulatory Element Binding Protein 1; D014157:Transcription Factors; D005947:Glucose
keywords: ChREBP; LXRα; SREBP-1c; lipogenesis; porcine adipocytes