[Induction of insulin resistance induced by PI-3K inhibitor in porcine granulosa cells].
OBJECTIVE
To investigate the biological effects of insulin resistance (IR) on the porcine granulosa cells which is induced by wortmannin, the PI-3K inhibitor and mediated by key molecules including GLUT4 and MAPK during insulin signaling.


METHODS
The model of IR porcine granulosa cell was established in in vitro culture by treatment of wortmannin, and was assessed the amount of 3H glucose uptake as well as medium glucose levels by glucose oxidase method. The protein and mRNA expression of GLUT4 and MAPK were evaluated by immunofluorescence and RT-PCR respectively.


RESULTS
The glucose intake was decreased by 40% with treatment of wortmannin at 1.5 micromol/L (P<0.05). GLUT4 and MAPK were localized mainly to cytoplasm of granulose cells. When granulosa cells were insulin resistant, the expression of GLUT4 was down-regulated whereas MAPK was up-regulated as compared with the controls.


CONCLUSIONS
Wortmannin treatment can lead to decreased expression of GLUT4 and increase of IR granulose cells. This metabolic phenotype could induce increased expression of MAPK and mitogenic potential, indicating the cross-talk between two pathways of insulin signaling within ovarian cells.
Yan
Miao-e
ME
Department of Gynaecology and Obstetrics, First Affiliated Hospital, Heilongjiang University of Chinese Medicine, Harbin 150040, China.
Wu
Xiao-ke
XK
Song
Juan-juan
JJ
Hou
Li-hui
LH
D000730:Androstadienes / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D002478:Cells, Cultured; D004195:Disease Models, Animal; D005260:Female; D005455:Fluorescent Antibody Technique; D005947:Glucose / Q000378:metabolism / Q000493:pharmacokinetics; D051275:Glucose Transporter Type 4 / Q000235:genetics / Q000378:metabolism; D006107:Granulosa Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D007333:Insulin Resistance; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D010053:Ovary / Q000166:cytology; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D013552:Swine; D000077191:Wortmannin
D000730:Androstadienes; D051275:Glucose Transporter Type 4; D000081082:Phosphoinositide-3 Kinase Inhibitors; D047428:Protein Kinase Inhibitors; D020928:Mitogen-Activated Protein Kinases; D005947:Glucose; D000077191:Wortmannin