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Increased Insulin Action in SKIP Heterozygous Knockout Mice
- Source :
- Molecular and Cellular Biology. 28:5184-5195
- Publication Year :
- 2008
- Publisher :
- Informa UK Limited, 2008.
-
Abstract
- Insulin controls glucose homeostasis and lipid metabolism, and insulin impairment plays a critical role in the pathogenesis of diabetes mellitus. Human skeletal muscle and kidney enriched inositol polyphosphate phosphatase (SKIP) is a member of the phosphatidylinositol 3,4,5-trisphosphate phosphatase family (T. Ijuin et al. J. Biol. Chem. 275:10870-10875, 2000; T. Ijuin and T. Takenawa, Mol. Cell. Biol. 23:1209-1220, 2003). Previous studies showed that SKIP negatively regulates insulin-induced phosphatidylinositol 3-kinase signaling (Ijuin and Takenawa, Mol. Cell. Biol. 23:1209-1220, 2003). We now have generated mice with a targeted mutation of the mouse ortholog of the human SKIP gene, Pps. Adult heterozygous Pps mutant mice show increased insulin sensitivity and reduced diet-induced obesity with increased Akt/protein kinase B (PKB) phosphorylation in skeletal muscle but not in adipose tissue. The insulin-induced uptake of 2-deoxyglucose into the isolated soleus muscle was significantly enhanced in Pps mutant mice. A hyperinsulinemic-euglycemic clamp study also revealed a significant increase in the rate of systemic glucose disposal in Pps mutant mice without any abnormalities in hepatic glucose production. Furthermore, in vitro knockdown studies in L6 myoblast cells revealed that reduction of SKIP expression level increased insulin-stimulated Akt/PKB phosphorylation and 2-deoxyglucose uptake. These results imply that SKIP regulates insulin signaling in skeletal muscle. Thus, SKIP may be a promising pharmacologic target for the treatment of insulin resistance and diabetes.
- Subjects :
- Male
Heterozygote
medicine.medical_specialty
medicine.medical_treatment
Cell Line
Mice
chemistry.chemical_compound
Insulin resistance
Internal medicine
medicine
Animals
Homeostasis
Humans
Insulin
Glucose homeostasis
Myocyte
Phosphatidylinositol
Muscle, Skeletal
Molecular Biology
Protein kinase B
Alleles
Adiposity
Mice, Knockout
Sequence Homology, Amino Acid
biology
Body Weight
Skeletal muscle
Feeding Behavior
Articles
Cell Biology
medicine.disease
Phosphoric Monoester Hydrolases
Diet
Rats
Insulin receptor
Germ Cells
Glucose
Phenotype
Endocrinology
medicine.anatomical_structure
chemistry
Gene Targeting
biology.protein
Insulin Resistance
Signal Transduction
Subjects
Details
- ISSN :
- 10985549
- Volume :
- 28
- Database :
- OpenAIRE
- Journal :
- Molecular and Cellular Biology
- Accession number :
- edsair.doi.dedup.....496d222d2256bbea3ba8c6afecc49eeb