The serine/threonine kinase Akt/PKB plays key roles in the regulation of cell growth, survival, and metabolism. It remains unclear, however, whether the functions of individual Akt/PKB isoforms are distinct. To investigate the function of Akt2/PKBβ, mice lacking this isoform were generated. Both male and female Akt2/PKBβ-null mice exhibit mild growth deficiency and an age-dependent loss of adipose tissue or lipoatrophy, with all observed adipose depots dramatically reduced by 22 weeks of age. Akt2/PKBβ-deficient mice are insulin resistant with elevated plasma triglycerides. In addition, Akt2/PKBβ-deficient mice exhibit fed and fasting hyperglycemia, hyperinsulinemia, glucose intolerance, and impaired muscle glucose uptake. In males, insulin resistance progresses to a severe form of diabetes accompanied by pancreatic β cell failure. In contrast, female Akt2/PKBβ-deficient mice remain mildly hyperglycemic and hyperinsulinemic until at least one year of age. Thus, Akt2/PKBβ-deficient mice exhibit growth deficiency similar to that reported previously for mice lacking Akt1/PKBα, indicating that both Akt2/PKBβ and Akt1/PKBα participate in the regulation of growth. The marked hyperglycemia and loss of pancreatic β cells and adipose tissue in Akt2/PKBβ-deficient mice suggest that Akt2/PKBβ plays critical roles in glucose metabolism and the development or maintenance of proper adipose tissue and islet mass for which other Akt/PKB isoforms are unable to fully compensate.This article was published online in advance of the print edition. The date of publication is available from the JCI website, http://www.jci.org.
AimsCanagliflozin is a sodium glucose co-transporter 2 inhibitor developed for the treatment of type 2 diabetes mellitus (T2DM). This randomised, double-blind, placebo-controlled, Phase 3 study evaluated the efficacy and safety of canagliflozin as an add-on to metformin plus sulphonylurea in patients with T2DM.MethodsPatients (N = 469) received canagliflozin 100 or 300 mg or placebo once daily during a 26-week core period and a 26-week extension. Prespecified primary end-point was change in HbA1c at 26 weeks. Secondary end-points included change in HbA1c at week 52 as well as proportion of patients achieving HbA1c < 7.0%, change in fasting plasma glucose (FPG) and systolic blood pressure, and per cent change in body weight, high-density lipoprotein cholesterol, and triglycerides (weeks 26 and 52).ResultsHbA1c was significantly reduced with canagliflozin 100 and 300 mg vs. placebo at week 26 (–0.85%, –1.06%, and –0.13%; p < 0.001); these reductions were maintained at week 52 (–0.74%, –0.96%, and 0.01%). Both canagliflozin doses reduced FPG and body weight vs. placebo at week 26 (p < 0.001) and week 52. Overall adverse event (AE) rates were similar across groups over 52 weeks, with higher rates of genital mycotic infections and osmotic diuresis-related AEs seen with canagliflozin vs. placebo; these led to few discontinuations. Increased incidence of documented, but not severe, hypoglycaemia episodes was seen with canagliflozin vs. placebo.ConclusionsCanagliflozin improved glycaemic control, reduced body weight, and was generally well tolerated in T2DM patients on metformin plus sulphonylurea over 52 weeks.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.