title: Human resistin inhibits myogenic differentiation and induces insulin resistance in myocytes.
abstract: This study is aimed to investigate the effect of human resistin on myocyte differentiation and insulin resistance. The human resistin eukaryotic expression vector was stable transfected into C2C12 myocyte cells and was transiently transfected into COS7 cells. The effects of human resistin on cell proliferation, cell cycle, and myogenic differentiation of C2C12 cells were examined. Glucose uptake assays was performed on C2C12 myotubes by using [(3)H] 2-deoxy-D-glucose. The mRNA levels of insulin receptor (IR) and glucose transporter 4 (GLUT4) were evaluated by semiquantitative RT-PCR. Results showed by the C2C12 cells transfected with human resistin gene compared with that without transfecting gene are as follows: (1) cell proliferation was significantly promoted, (2) after inducing differentiation, the myotube's diameters and expression of desmin and myoglobin decreased, and (3) glucose uptake ratio was lowered and expression of IR and GLUT4 decreased. However, there was no significant difference in the glucose uptake ratio between C2C12 myotubes treated with a human resistin conditioned medium of COS7 cells and treated with control medium. These results suggest that maybe human resistin has not a direct role on insulin sensitivity of myocytes. However, maybe it impaired the insulin sensitivity of myocytes through suppressing myogenesis and stimulating proliferation of myoblasts.
authors.affiliation: Department of Central Research, The Third Clinical College, Jilin University, Changchun, Jilin 130033, China.
authors.forename: Chun Hua
authors.initials: CH
authors.lastname: Sheng
authors.forename: Zhen Wu
authors.initials: ZW
authors.lastname: Du
authors.forename: Yang
authors.initials: Y
authors.lastname: Song
authors.forename: Xiao Dong
authors.initials: XD
authors.lastname: Wu
authors.forename: Yu Cheng
authors.initials: YC
authors.lastname: Zhang
authors.forename: Mei
authors.initials: M
authors.lastname: Wu
authors.forename: Qian
authors.initials: Q
authors.lastname: Wang
authors.forename: Gui Zhen
authors.initials: GZ
authors.lastname: Zhang
mesh_terms: D000818:Animals; D001692:Biological Transport; D019556:COS Cells; D002453:Cell Cycle; D002454:Cell Differentiation; D002460:Cell Line; D049109:Cell Proliferation; D002522:Chlorocebus aethiops; D005947:Glucose / Q000378:metabolism; D051275:Glucose Transporter Type 4 / Q000378:metabolism; D006801:Humans; D007333:Insulin Resistance; D051379:Mice; D032342:Muscle Cells / Q000166:cytology / Q000378:metabolism*; D011972:Receptor, Insulin / Q000378:metabolism; D052243:Resistin / Q000502:physiology*
chemical_list: D051275:Glucose Transporter Type 4; C499624:RETN protein, human; D052243:Resistin; C495693:Slc2a4 protein, mouse; D011972:Receptor, Insulin; D005947:Glucose