Bouloumié A, Planat V, Devedjian J C, Valet P, Saulnier-Blache J S, Record M, Lafontan M
INSERM Unité 317, Centre Hospitalier Universitaire Rangueil, Institut L. Bugnard, Université Paul Sabatier, Toulouse, France.
J Biol Chem. 1994 Dec 2;269(48):30254-9.
Primary cultures of rat preadipocytes were shown to express alpha 2- and beta-adrenoreceptors when maintained in serum-deprived medium. alpha 2-Adrenoreceptor stimulation led to an increase in cell number, whereas beta-adrenoreceptor stimulation was without effect. On 3T3-F442A clones stably transfected with the human alpha 2-C10 gene and expressing a physiologically related number of alpha 2-adrenoreceptors to overexpression, the proliferative effect of alpha 2-adrenoreceptor agonist UK14304 was proportional to the level of alpha 2-adrenoreceptor expressed in individual clones and required alpha-2 adrenoreceptor stimulation. Analysis of the signaling pathway linked to alpha 2-adrenoreceptor activation showed that the mitogenic effect was adenylyl cyclase- and protein kinase C-independent. It was pertussis toxin-sensitive, implying the involvement of pertussis toxin-sensitive G proteins. The activation of the mitogen-activated protein kinase pathway was increased after alpha 2-adrenoreceptor stimulation in both 3T3-F442 clones and rat preadipocytes and inhibited by pertussis toxin treatment. So, catecholamines are involved in the control of white preadipocyte proliferation through the alpha 2-adrenoreceptor activation, linked to the mitogen-activated protein kinase pathway.
大鼠前脂肪细胞的原代培养物在无血清培养基中培养时，显示出表达α2 - 和β - 肾上腺素能受体。α2 - 肾上腺素能受体刺激导致细胞数量增加，而β - 肾上腺素能受体刺激则无作用。在稳定转染人α2 - C10基因并表达与过表达生理相关数量α2 - 肾上腺素能受体的3T3 - F442A克隆中，α2 - 肾上腺素能受体激动剂UK14304的增殖作用与各个克隆中表达的α2 - 肾上腺素能受体水平成正比，且需要α2 - 肾上腺素能受体刺激。对与α2 - 肾上腺素能受体激活相关的信号通路分析表明，促有丝分裂作用不依赖于腺苷酸环化酶和蛋白激酶C。它对百日咳毒素敏感，这意味着涉及百日咳毒素敏感的G蛋白。在3T3 - F442克隆和大鼠前脂肪细胞中，α2 - 肾上腺素能受体刺激后丝裂原活化蛋白激酶途径的激活增加，并被百日咳毒素处理所抑制。因此，儿茶酚胺通过与丝裂原活化蛋白激酶途径相关的α2 - 肾上腺素能受体激活参与白色前脂肪细胞增殖的控制。
