Production of inhibitor of insulin-receptor tyrosine kinase in fibroblasts from patient with insulin resistance and NIDDM.
Although non-insulin-dependent diabetes mellitus (NIDDM) is associated with defects in insulin action, the molecular basis of this resistance is unknown. We studied fibroblasts from a markedly insulin-resistant patient with NIDDM but without acanthosis nigricans. Her fibroblasts were resistant to insulin when alpha-aminoisobutyric acid uptake was measured. Fibroblasts from this patient demonstrated normal insulin-receptor content as measured by both insulin-receptor radioimmunoassay and by Scatchard analysis. However, when compared with nondiabetic control subjects, insulin-receptor kinase assays of wheat-germ-purified receptors prepared from her fibroblasts showed very low basal and no insulin-stimulated tyrosine kinase activity. The insulin receptor was then removed from the wheat-germ fraction by monoclonal antibody affinity chromatography. This insulin-receptor-deficient fraction inhibited both basal and insulin-stimulated tyrosine kinase activity of highly purified insulin receptors. When the specificity of this inhibition was tested, less inhibition was seen with insulinlike growth factor I-receptor tyrosine kinase, and even less inhibition was seen with the proto-oncogene p60c-src tyrosine kinase. Thus, these studies indicate that fibroblasts from an insulin-resistant patient with NIDDM produce a relatively specific glycoprotein inhibitor of insulin-receptor tyrosine kinase. Therefore, these studies raise the possibility that this inhibitor may play an important role in the insulin resistance seen in this patient.
Sbraccia
P
P
Division of Diabetes and Endocrine Research, Mount Zion Medical Center, University of California, San Francisco 94120.
Goodman
P A
PA
Maddux
B A
BA
Wong
K Y
KY
Chen
Y D
YD
Reaven
G M
GM
Goldfine
I D
ID
D000328:Adult; D002846:Chromatography, Affinity; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D005347:Fibroblasts / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D006023:Glycoproteins / Q000032:analysis / Q000378:metabolism* / Q000494:pharmacology; D006801:Humans; D007328:Insulin / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors*; D000090063:Proto-Oncogene Mas; D011863:Radioimmunoassay; D011972:Receptor, Insulin / Q000378:metabolism
D006023:Glycoproteins; D007328:Insulin; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011505:Protein-Tyrosine Kinases; D011972:Receptor, Insulin