04-300 Sigma-AldrichAnti-phospho-Insulin Receptor (Tyr 1322) Antibody, clone 21G12

Drugs that improve chronic hyperglycemia independently of insulin signaling or reduction of adiposity or dietary fat intake may be highly desirable. Ad36, a human adenovirus, promotes glucose uptake in vitro independently of adiposity or proximal insulin signaling. We tested the ability of Ad36 to improve glycemic control in vivo and determined if the natural Ad36 infection in humans is associated with better glycemic control. C57BL/6J mice fed a chow diet or made diabetic with a high-fat (HF) diet were mock infected or infected with Ad36 or adenovirus Ad2 as a control for infection. Postinfection (pi), systemic glycemic control, hepatic lipid content, and cell signaling in tissues pertinent to glucose metabolism were determined. Next, sera of 1,507 adults and children were screened for Ad36 antibodies as an indicator of past natural infection. In chow-fed mice, Ad36 significantly improved glycemic control for 12 wk pi. In HF-fed mice, Ad36 improved glycemic control and hepatic steatosis up to 20 wk pi. In adipose tissue (AT), skeletal muscle (SM), and liver, Ad36 upregulated distal insulin signaling without recruiting the proximal insulin signaling. Cell signaling suggested that Ad36 increases AT and SM glucose uptake and reduces hepatic glucose release. In humans, Ad36 infection predicted better glycemic control and lower hepatic lipid content independently of age, sex, or adiposity. We conclude that Ad36 offers a novel tool to understand the pathways to improve hyperglycemia and hepatic steatosis independently of proximal insulin signaling, and despite a HF diet. This metabolic engineering by Ad36 appears relevant to humans for developing more practical and effective antidiabetic approaches.

We have cloned and identified a DNA sequence complementary to the mRNA of creatine kinase (CK) isozyme M, although the mRNA is a minor species of the total mRNA in developing myoblasts. Poly(A)+RNA from breast and thigh muscle of 5-week-old chicks was enriched for CK mRNA by a novel procedure of sucrose gradient centrifugation in the presence of methylmercuric hydroxide. DNA complementary to this mRNA was inserted into pBR322, and colonies containing the recombinant plasmids were screened for the ability of the plasmid DNA to hybridize with and rescue CK mRNA from total muscle mRNA. Three plasmids, pCS195, pCS192, and pM35-4, could specifically rescue CK-M mRNA. CK-M mRNA was detected by in vitro translation and specific immunoprecipitation. The identity of the in vitro translation product was further confirmed by its migration in two-dimensional gels at the isoelectric point and molecular weight of CK-M. The heterogeneity of CK-M observed in vivo also was found upon translation of the CK-M mRNA which hybridizes to the plasmid.