title: Calcitriol enhances fat synthesis factors and calpain activity in co-cultured cells.
abstract: We have conducted an in vitro experiment to determine whether calcitriol can act as a fat synthesizer and/or meat tenderizer when skeletal muscle cells, adipose tissue, and macrophages are co-cultured. When co-cultured, pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) expression increased, whereas decreased anti-inflammatory cytokine (IL-10 and IL-15) expression decreased in both C2C12 and 3T3-L1 cells. Calcitriol increased reactive oxygen species (ROS) production in the media. While adiponectin gene expression decreased, leptin, resistin, CCAAT-enhancer-binding protein-beta (C/EBP-β), and peroxisome proliferator-activated receptor gamma (PPAR-γ) gene expression was significantly (P < 0.047) increased with calcitriol in 3T3-L1 cells co-cultured with two different cell types. Inducible nitric oxide synthase (iNOS) protein levels were also stimulated in the C2C12 and 3T3-L1 cells, but arginase l was attenuated by calcitriol. Cacitriol highly amplified (P = 0.008) µ-calpain gene expression in co-cultured C2C12 cells. The results showed an overall increase in pro-inflammatory cytokines and a decrease in anti-inflammatory cytokines of C2C12 and 3T3-L1 cells with calcitriol in co-culture systems. µ-Calpain protein was also augmented in differentiated C2C12 cells with calcitriol. These findings suggest that calcitriol can be used as not only fat synthesizer, but meat tenderizer, in meat-producing animals.
authors.affiliation: Department of Animal Science, Chonnam National University, Gwangju, 500-757, Korea.
authors.forename: Hyuck
authors.initials: H
authors.lastname: Choi
authors.forename: Kyuho
authors.initials: K
authors.lastname: Myung
mesh_terms: D041721:3T3-L1 Cells; D017667:Adipocytes / Q000187:drug effects / Q000378:metabolism; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002154:Calpain / Q000378:metabolism*; D018920:Coculture Techniques; D015850:Interleukin-6 / Q000378:metabolism; D050356:Lipid Metabolism / Q000187:drug effects*; D057847:Lipid Regulating Agents / Q000494:pharmacology*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism; D051379:Mice; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D015850:Interleukin-6; D057847:Lipid Regulating Agents; D014409:Tumor Necrosis Factor-alpha; D002154:Calpain; D002117:Calcitriol
keywords: adipocyte; calcitriol; calpain; cytokine; macrophage; muscle cell