Indapamide Increases IRS1 Expression and Modifies Adiponectin/NLRP3/PPARγ Crosstalk in Type 2 Diabetic Rats

The current study aimed to evaluate the anti-diabetic effects of canagliflozin (CANA) and indapamide (INDA) and their impacts as adiponectin modulators in experimentally induced type 2 diabetes mellitus (T2DM). T2DM was associated with a significant rise in blood glucose level and HbA1C%, andreduced adiponectin and insulin secretions. Moreover, the malondialdehyde (MDA) contents in both the epididymal adipocytes and soleus muscle significantly escalated, while the total antioxidant capacity (TAC) and epididymal adipocyte Nrf2 expression significantly declined. Moreover, serum TNF-α, epididymal adipocyte’s NOD-like receptor protein 3, NLRP3, NF-κB and CD68 expressions markedly escalated, and serum IL-10 significantly declined. Furthermore, there was a significant escalation in PPARγ expression in epididymal adipocytes, with a significant reduction in soleus muscle’s expression of IRS1. CANA and INDA treatments markedly reduced blood glucose levels, increased adiponectin and insulin secretion, enhanced anti-oxidant defenses, and reduced oxidative burden, with marked anti-inflammatory impact. Interestingly, the impact of indapamide on DM indices and oxidative and inflammatory changes was comparable to that of canagliflozin. Nevertheless, indapamide had a superior effect compared to canagliflozin on HbA1c%, expression of IRS1 and reduction of NF-κB and CD68 expressions. INDA could be effective in regulating T2DM, with underlined anti-diabetic, antioxidant, and anti-inflammatory properties. INDA increased IRS1 expression and modified adiponectin/NLRP3/PPARγ crosstalk. The impacts of INDA are comparable to those of the standard anti-diabetic drug CANA.

Deficiency of angiotensinogen in hepatocytes markedly decreases blood pressure in lean and obese male mice

We recently demonstrated that adipocyte deficiency of angiotensinogen (AGT) ablated high-fat diet-induced elevations in plasma angiotensin II (Ang II) concentrations and obesity-hypertension in male mice. Hepatocytes are the predominant source of systemic AGT. Therefore, in this study, we defined the contribution of hepatocyte-derived AGT to obesity-induced elevations in plasma AGT concentrations and hypertension. Male Agt(fl/fl) mice expressing albumin-driven Cre recombinase were bred to female Agt(fl/fl) mice to generate Agt(fl/fl) or hepatocyte AGT-deficient male mice (Agt(Alb)). Mice were fed a low-fat or high-fat diet for 16 weeks. Hepatocyte AGT deficiency had no significant effect on body weight. Plasma AGT concentrations were increased in obese Agt(fl/fl) mice. Hepatocyte AGT deficiency markedly reduced plasma AGT and Ang II concentrations in lean and obese mice. Moreover, hepatocyte AGT deficiency reduced the content and release of AGT from adipose explants. Systolic blood pressure was markedly decreased in lean (by 18 mm Hg) and obese Agt(Alb) mice (by 54 mm Hg) compared with Agt(fl/fl) controls. To define mechanisms, we quantified effects of Ang II on mRNA abundance of megalin, an AGT uptake transporter, in 3T3-L1 adipocytes. Ang II stimulated adipocyte megalin mRNA abundance and decreased media AGT concentrations. These results demonstrate that hepatocytes are the predominant source of systemic AGT in both lean and obese mice. Moreover, reductions in plasma angiotensin concentrations in obese hepatocyte AGT-deficient mice may have limited megalin-dependent uptake of AGT into adipocytes for the production of Ang II in the development of obesity-hypertension.

Serum high-molecular-weight adiponectin as a marker for the evaluation and care of subjects with metabolic syndrome and related disorders

In 1996, adiponectin was reported to be the most abundant transcript in adipose tissue. Animal studies revealed that administering adiponectin improves insulin resistance and blood glucose levels and inhibits atherosclerosis. In the present article, we review the significance of measuring serum high-molecular-weight (HMW) adiponectin levels in human subjects. Our cross-sectional studies revealed that the serum HMW adiponectin concentration was 1.9 times higher in healthy Japanese females than males and had a strong positive correlation with HDL-cholesterol but a negative correlation with BMI and the homeostasis model assessment insulin resistance index (HOMA-IR). They also indicated that the serum HMW adiponectin concentration had a stronger association with HOMA-IR and metabolic syndrome than the total adiponectin concentration. Our longitudinal study, a 6-year follow-up of Japanese men, suggested that a decreased level of HMW adiponectin is a predictor of progression to metabolic syndrome. In another intervention study, lifestyle modification for 3 months induced a decrease in BMI and waist circumference and an increase in serum HMW adiponectin but not the total adiponectin level in 16 Japanese males with metabolic syndrome. Administering thiazolidinediones to diabetic patients increased the serum HMW adiponectin concentration 3 fold and improved glucose and lipid profiles and blood pressure. Some people may inherit a lower serum concentration of adiponectin, and have a higher risk of developing cardiovascular diseases.It is suggested that HMW adiponectin is a useful marker for the evaluation and care of subjects with metabolic syndrome and related disorders.