title: Effects of 1,25-dihydroxyvitamin D3 on proliferation and differentiation of porcine preadipocyte in vitro.
abstract: 1,25-Dihydroxyvitamin D3, the physiologically active form of vitamin D3, exerts its functions through a receptor-mediated mechanism and plays an important role in the cell differentiation. This study investigated the effects of 1,25-dihydroxyvitamin D3 on the proliferation and differentiation of porcine preadipocyte. Stromal-vascular cells containing preadipocytes were prepared from dorsal subcutaneous adipose tissue of approximately 3-day-old Chinese male crossbred pigs. After confluence, the differentiation was induced by transferrin, dexamethasone and insulin for 2 days, and then subsequently cultured for 6 days. The cells were treated with 1,25-dihydroxyvitamin D3 during the induction of differentiation (the early phase of differentiation) or throughout the differentiation period. The terminal differentiation markers, such as glycerol-3-phosphate dehydrogenase activity and lipid accumulation were measured during the process of cultures. The treatment with 1,25-dihydroxyvitamin D3 severely affected the induction of all differentiation markers throughout the differentiation period. 1,25-Dihydroxyvitamin D3 suppressed the expression of peroxisome proliferator-activated receptor gamma mRNA and interfered with the induction of retinoid X receptor alpha mRNA. The mRNAs of the adipogenesis-related genes, lipoprotein lipase, stearoyl-CoA desaturase, phosphoenolpyruvate carboxykinase, glycerol-3-phosphate dehydrogenase and glucose transporter 4 were reduced when 1,25-dihydroxyvitamin D3 was added into differentiation medium. Also, 1,25-dihydroxyvitamin D3 inhibited preadipocyte differentiation in dose-dependent manner. These results suggested that 1,25-dihydroxyvitamin D3 inhibited porcine preadipocyte differentiation through suppressing PPAR gamma and RXR alpha mRNA expressions and then down regulating the expression of adipogenesis-related genes.
authors.affiliation: Laboratory of Animal Fat Deposition and Muscle Development, Northwest A & F University, Yangling, Shaanxi 712100, PR China.
authors.forename: Helin
authors.initials: H
authors.lastname: Zhuang
authors.forename: Yaqiu
authors.initials: Y
authors.lastname: Lin
authors.forename: Gongshe
authors.initials: G
authors.lastname: Yang
mesh_terms: D017667:Adipocytes / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D002117:Calcitriol / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D017931:DNA Primers; D066298:In Vitro Techniques; D008297:Male; D012333:RNA, Messenger / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction