PDF(Pubmed)
Abstract：
Vitamin D-regulating action of PPARγ on obesity has been confirmed on adipocyte differentiation. However, it is not clear whether vitamin D affects the morphological size of mature adipocytes by influencing the expression of PPARγ in vivo. Our hypothesis was that Vitamin D3 (VitD3) inhibits the growth of adipocyte size by suppressing PPARγ expression in white adipocytes of obese mice. Five-week-old male C57BL/6J mice were randomly divided into normal diet and high-fat diet groups. After 10 weeks, the body weight between the two groups differed by 26.91%. The obese mice were randomly divided into a high-fat diet, solvent control, low-dose VitD3 (5000 IU/kg·food), medium-dose VitD3 (7500 IU/kg·food), high-dose VitD3 (10,000 IU/kg·food), and PPAR γ antagonist group, and the intervention lasted for 8 weeks. Diet-induced obesity (DIO) mice fed high-dose VitD3 exacerbated markers of adiposity (body weight, fat mass, fat mass rate, size of white and brown adipocytes, mRNA, and protein levels of ATGL and Fsp27), and the protein level of ATGL and Fsp27 decreased in the low-dose group. In conclusion, high-dose VitD3 possibly via inhibiting the ATGL expression, thereby inhibiting lipolysis, increasing the volume of adipocytes, and decreasing their fat-storing ability resulted in decreased Fsp27 expression. Therefore, long-term high-dose oral VitD3 may not necessarily improve obesity, and we need more clinical trials to explore the intervention dose and duration of VitD3 in the treatment of VitD3 deficiency in obese patients.
摘要：
PPARγ对肥胖的维生素D调节作用已在脂肪细胞分化中得到证实。然而,目前尚不清楚维生素D是否通过影响体内PPARγ的表达来影响成熟脂肪细胞的形态大小。我们的假设是维生素D3（VitD3）通过抑制肥胖小鼠白色脂肪细胞中PPARγ的表达来抑制脂肪细胞大小的生长。将5周龄雄性C57BL/6J小鼠随机分为正常饮食组和高脂饮食组。10周后,两组之间的体重差异为26.91％。将肥胖小鼠随机分为高脂肪饮食，溶剂控制,低剂量VitD3（5000IU/kg·食物），中等剂量VitD3（7500IU/kg·食物），高剂量VitD3（10,000IU/kg·食物），和PPARγ拮抗剂组，干预持续了8周。饲喂高剂量VitD3的饮食诱导的肥胖（DIO）小鼠加剧了肥胖的标志物（体重，脂肪量,脂肪质量率，白色和棕色脂肪细胞的大小，mRNA以及ATGL和Fsp27的蛋白质水平），低剂量组ATGL和Fsp27蛋白水平下降。总之,高剂量VitD3可能通过抑制ATGL表达，从而抑制脂解，增加脂肪细胞的体积，降低其脂肪储存能力导致Fsp27表达降低。因此,长期高剂量口服VitD3不一定能改善肥胖，我们需要更多的临床试验来探讨VitD3治疗肥胖患者VitD3缺乏的干预剂量和持续时间。
