leptin and Glycosuria

Alström syndrome is a rare recessive genetic disease caused by mutations in ALMS1, which encodes a protein that is related to cilia function and intracellular endosome trafficking. The syndrome has been linked to impaired glucose metabolism and CKD. Polymorphisms in Alms1 have likewise been linked to CKD, but little is known about the modification of the phenotype by environmental factors.. To gain further insights, the fat aussie (foz) mouse strain, a genetic murine model of Alström syndrome, was exposed to a normal chow (NC) or to a Western diet (WD, 20% fat, 34% sucrose by weight, and 0.2% cholesterol) and renal outcomes were measured.. Body weight and albuminuria were higher in foz than in wild-type (WT) mice on both diets but WD significantly increased the difference. Measurement of plasma creatinine and cystatin C indicated that glomerular filtration rate was preserved in foz versus WT independent of diet. Renal markers of injury, inflammation, and fibrosis were similar in both genotypes on NC but significantly greater in foz than in WT mice on WD. A glucose tolerance test performed in foz and WT mice on WD revealed similar basal blood glucose levels and subsequent blood glucose profiles.. WD sensitizes a murine model of Alström syndrome to kidney injury, inflammation, and fibrosis, an effect that may not be solely due to effects on glucose metabolism. Polymorphisms in Alms1 may induce CKD in part by modulating the deleterious effects of high dietary fat and sucrose on kidney outcome.

Topics: Alstrom Syndrome; Animals; Blood Glucose; Cell Cycle Proteins; Cilia; Diet, Western; Disease Models, Animal; Fibrosis; Glomerular Filtration Rate; Glycosuria; Kidney; Kidney Tubules; Leptin; Male; Mice; Nephritis; Obesity; Organ Size; Renin

Sodium-glucose cotransporter 2 (SGLT2) inhibitors are used in the treatment of human diabetics. They increase glucose excretion and correct hyperglycemia. We examined the investigational SGLT2 inhibitor velagliflozin in two groups of six neutered adult obese cats (equal gender distribution). Placebo (Pl) or drug (D; 1 mg/kg) was administered for 35 days. Routine blood examinations, fructosamine, beta-hydroxybutyrate (BHB), nonesterified fatty acids (NEFA), glucagon, adiponectin, and leptin were measured before and after treatment, also water intake, and urinary electrolytes, glucose, and volume. Indirect calorimetry, an intravenous glucose tolerance test (IVGTT; 0.8 g/kg) and insulin tolerance test (IVITT) were conducted. All cats tolerated treatment well. Significant changes with D included a decrease in the respiratory exchange ratio, an increase in cholesterol, a small increase in albumin, and a rise in BHB and NEFA. Glucose clearance was unaltered, although less insulin was secreted during the IVGTT (p = .056) suggesting improved insulin sensitivity. IVITT was unchanged. Treatment did not affect glucagon, leptin, or adiponectin. Water intake, urine output, urinary glucose excretion, and the glucose/creatinine ratio but not urinary electrolytes were significantly higher post-D. We conclude that velagliflozin is a promising drug, which increases urinary glucose excretion in cats and could thereby be beneficial for the treatment of hyperglycemia.

Topics: 3-Hydroxybutyric Acid; Adiponectin; Animals; Cat Diseases; Cats; Diabetes Mellitus; Drinking; Electrolytes; Fatty Acids, Nonesterified; Female; Fructosamine; Glucagon; Glucose Tolerance Test; Glycosuria; Hypoglycemic Agents; Leptin; Male; Nitriles; Obesity; Sodium-Glucose Transporter 2 Inhibitors

In order to examine the influence of obesity on metabolic disorder and liver pathogenesis of the Fatty Liver Shionogi (FLS) mouse, which develops hereditary fatty liver and spontaneous liver tumors, we established a new congenic strain named FLS-Lep(ob). The Lep(ob) gene of the C57BL/6JWakShi (B6)-Lep(ob)/Lep(ob) mouse was transferred into the genome of the FLS mouse, by backcross mating. FLS-Lep(ob)/Lep(ob) mice were maintained by intercrossing between Lep(ob)-heterozygous littermates. The FLS-Lep(ob)/Lep(ob) mice of both sexes developed remarkable hyperphagia, obesity and type 2 diabetes mellitus. At 12 weeks of age, glucosuria was detected in all male and female FLS-Lep(ob)/Lep(ob) mice. Biochemical examination demonstrated that the FLS-Lep(ob)/Lep(ob) mice have severe hyperlipidemia and hyperinsulinemia. The livers of FLS-Lep(ob)/Lep(ob) mice showed microvesicular steatosis and deposition of large lipid droplets in hepatocytes throughout the lobules. The steatohepatitis-like lesions including the multifocal mononuclear cell infiltration and clusters of foamy cells were observed earlier in FLS-Lep(ob)/ Lep(ob) mice than in FLS mice. B6-Lep(ob)/Lep(ob) mice did not show hepatic inflammatory change. Furthermore, FLS-Lep(ob)/Lep(ob) mice developed multiple hepatic tumors including hepatocellular adenomas and carcinomas following steatohepatitis. In conclusion, the FLS-Lep(ob)/Lep(ob) mice developed steatohepatitis and hepatic tumors following hepatic steatosis. The FLS-Lep(ob)/Lep(ob) mouse with obesity and type 2 diabetes mellitus might be a useful animal model for human non-alcoholic steatohepatitis (NASH).

Topics: Adenoma, Liver Cell; Animals; Carcinoma, Hepatocellular; Diabetes Mellitus, Type 2; Fatty Liver; Female; Gene Expression; Glucose Tolerance Test; Glycosuria; Hepatocytes; Hyperlipidemias; Insulin Resistance; Leptin; Lipids; Liver; Liver Neoplasms; Male; Mice; Mice, Congenic; Mice, Inbred C57BL; Obesity; RNA, Messenger

For experimental research on type 2 diabetes mellitus, a diet-induced obesity-dependent diabetes model developed using genetically normal animals is essential. However, attempts at feeding a high-fat diet (HFD) to major inbred strains of mice have not resulted in the establishment of an ideal model. Here, we show that BDF1 mice, the F(1) hybrids of C57BL/6 and DBA/2 normal strains, develop HFD-induced obesity-dependent diabetes. BDF1 mice fed a HFD gained weight rapidly and developed severe diabetes characterized by hyperglycemia, glucosuria, and elevation of hemoglobin A(1C) levels in 3 to 4 months. The glucose tolerance of the diabetic mice was significantly impaired, and the elevation of plasma insulin after a glucose load was significantly reduced. Isolated pancreatic islets of HFD-fed BDF1 mice showed decreased insulin content and a reduced insulin secretory response to higher concentrations of glucose. Immunohistochemical analysis of the pancreas showed reduced staining intensity to insulin and aberrant distribution of glucagon-positive cells in diabetic BDF1 mice. These observations suggest the cause of the diabetes in HFD-fed BDF1 mice to be dysfunction of the pancreatic beta-cells, which do not produce or secrete enough insulin to compensate for insulin resistance. BDF1 mice fed a HFD showing obesity-dependent diabetes are suggested to be an appropriate animal model of type 2 diabetes mellitus. This model would be useful for exploring the mechanism of obesity-dependent type 2 diabetes mellitus and evaluating antiobesity and antidiabetic drugs.

Topics: Animals; Blood Glucose; Cholesterol; Diabetes Mellitus, Type 2; Dietary Fats; Fatty Acids, Nonesterified; Glucose Tolerance Test; Glycosuria; Insulin; Insulin Secretion; Islets of Langerhans; Leptin; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Inbred Strains; Models, Biological; Obesity; Triglycerides; Weight Gain

Genetic mutations resulting in obesity and type 2 diabetes mellitus (T2D) are described for both inbred and outbred mice. However, no known mouse model completely recapitulates human T2D and its comorbidities. We identified a cohort of obese, male, outbred Swiss-Webster (SW) mice as polyuric, polydipsic, glucosuric, and hyperglycemic. Prevalence of glucosuria in the SW colony reached 60% (n=70) in males 8 weeks to 6 months of age. Despite severe obesity in some females, no females were diabetic. Pathologic findings in affected males included cachexia, dilated gastrointestinal tracts with poor muscular tone, pancreatic islet degeneration and atrophy with compensatory metaplasia and/or neogenesis, bacterial pyelonephritis, membranous glomerulopathy, and late-onset hepatic tumors with macrosteatosis, microsteatosis, and hydropic change in aged males. Serum insulin correlated with blood glucose in a nonlinear pattern, suggestive of islet exhaustion. Circulating leptin levels showed a weak inverse correlation with glucose. Diabetic males were bred with obese colony females to produce 20 male and 20 female offspring. Prevalence of diabetes in male offspring was 80% (16/20) with a median age of onset of 18 weeks. By contrast, no diabetic females were identified, despite being significantly more obese than males. Male predominance is likewise a feature of T2D in humans. To our knowledge, this is the first documentation of hepatocellular carcinoma and islet metaplasia and/or neogenesis in a spontaneous outbred mouse model of T2D. The SW availability and histopathologic features represent a promising new model for the study of T2D.

Topics: Animals; Blood Glucose; Body Weight; Carcinoma, Hepatocellular; Diabetes Mellitus, Type 2; Enzyme-Linked Immunosorbent Assay; Female; Glucose Tolerance Test; Glycosuria; Immunohistochemistry; Insulin; Kaplan-Meier Estimate; Leptin; Male; Mice; Obesity