Overexpressing IRS1 in Endothelial Cells Enhances Angioblast Differentiation and Wound Healing in Diabetes and Insulin Resistance

The effect of enhancing insulin’s actions in endothelial cells (ECs) to improve angiogenesis and wound healing was studied in obesity and diabetes. Insulin receptor substrate 1 (IRS1) was overexpressed in ECs using the VE-cadherin promoter to create ECIRS1 TG mice, which elevated pAkt activation and expressions of vascular endothelial growth factor (VEGF), Flk1, and VE-cadherin in ECs and granulation tissues (GTs) of full-thickness wounds. Open wound and epithelialization rates and angiogenesis significantly improved in normal mice and high fat (HF) diet–induced diabetic mice with hyperinsulinemia in ECIRS1 TG versus wild type (WT), but not in insulin-deficient diabetic mice. Increased angioblasts and EC numbers in GT of ECIRS1 mice were due to proliferation in situ rather than uptake. GT in HF-fed diabetic mice exhibited parallel decreases in insulin and VEGF-induced pAkt and EC numbers by >50% without changes in angioblasts versus WT mice, which were improved in ECIRS1 TG mice on normal chow or HF diet. Thus, HF-induced diabetes impaired angiogenesis by inhibiting insulin signaling in GT to decrease the differentiation of angioblasts to EC, which was normalized by enhancing insulin’s action targeted to EC, a potential target to improve wound healing in diabetes and obesity

Influence of the combination of SGLT2 inhibitors and GLP-1 receptor agonists on eGFR decline in type 2 diabetes: post-hoc analysis of RECAP study

Accumulating evidence has demonstrated that both SGLT2 inhibitors (SGLT2i) and GLP-1 receptor agonists (GLP1Ra) have protective effects in patients with diabetic kidney disease. Combination therapy with SGLT2i and GLP1Ra is commonly used in patients with type 2 diabetes (T2D). We previously reported that in combination therapy of SGLT2i and GLP1Ra, the effect on the renal composite outcome did not differ according to the preceding drug. However, it remains unclear how the initiation of combination therapy is associated with the renal function depending on the preceding drug. In this post hoc analysis, we analyzed a total of 643 T2D patients (GLP1Ra-preceding group, n = 331; SGLT2i-preceding group, n = 312) and investigated the differences in annual eGFR decline. Multiple imputation and propensity score matching were performed to compare the annual eGFR decline. The reduction in annual eGFR decline in the SGLT2i-preceding group (pre: −3.5 ± 9.4 mL/min/1.73 m2/year, post: −0.4 ± 6.3 mL/min/1.73 m2/year, p < 0.001), was significantly smaller after the initiation of GLP1Ra, whereas the GLP1Ra-preceding group tended to slow the eGFR decline but not to a statistically significant extent (pre: −2.0 ± 10.9 mL/min/1.73 m2/year, post: −1.8 ± 5.4 mL/min/1.73 m2/year, p = 0.83) after the initiation of SGLT2i. After the addition of GLP1Ra to SGLT2i-treated patients, slower annual eGFR decline was observed. Our data raise the possibility that the renal benefits—especially annual eGFR decline—of combination therapy with SGLT2i and GLP1Ra may be affected by the preceding drug

ブルーベリー ノ グルタミン ゴウセイ コウソ カッセイ ト カヨウセイ タンパク ノ SDS-ポリアクリルアミドゲル デンキ エイドウ

Glutamine synthetase activities in leaves and roots of blueberry were determined in relation to ammonium assimilation. SBS-PAGE analysis of soluble protein was also carried out. There was a little difference between in vitro and in vivo GS activities in blueberry leaves, while apple leaf GS activity was higher in in vitro than in in vivo. In vivo GS activities in leaves of blueberry and satsuma mandarin were higher in tris-HC 1 buffer than in phosphate buffer. In vivo GS activity was higher at near pH7. In vivo and in vitro GS activities in leaves and roots of blueberry were lower than those of apple. In vivo and in vitro GS activities in leaves and roots of apple were increased by addition of ATP, while those of blueberry tended to be decreased. In vivo GS activity in blueberry leaves was decreased by addition of glutamic acid from 0 to 25 mM. Leaf and root proteins analyzed by SDS-PAGE were less in blueberry than in apple. These trees had more bands in leaves than in roots. Protein bands of blueberry and apple leaves were influenced by N forms supplied

Improved endurance capacity of diabetic mice during SGLT2 inhibition: Role of AICARP, an AMPK activator in the soleus

Abstract Background Diabetes is associated with an increased risk of deleterious changes in muscle mass and function or sarcopenia, leading to physical inactivity and worsening glycaemic control. Given the negative energy balance during sodium–glucose cotransporter‐2 (SGLT2) inhibition, whether SGLT2 inhibitors affect skeletal muscle mass and function is a matter of concern. However, how SGLT2 inhibition affects the skeletal muscle function in patients with diabetes remains insufficiently explored. We aimed to explore the effects of canagliflozin (CANA), an SGLT2 inhibitor, on skeletal muscles in genetically diabetic db/db mice focusing on the differential responses of oxidative and glycolytic muscles. Methods Db/db mice were treated with CANA for 4 weeks. We measured running distance and handgrip strength to assess skeletal muscle function during CANA treatment. At the end of the experiment, we performed a targeted metabolome analysis of the skeletal muscles. Results CANA treatment improved the reduced endurance capacity, as revealed by running distance in db/db mice (414.9 ± 52.8 vs. 88.7 ± 22.7 m, P < 0.05). Targeted metabolome analysis revealed that 5‐aminoimidazole‐4‐carboxamide‐1‐β‐D‐ribofuranosyl 5′‐monophosphate (AICARP), a naturally occurring AMP‐activated protein kinase (AMPK) activator, increased in the oxidative soleus muscle (P < 0.05), but not in the glycolytic extensor digitorum longus muscle (P = 0.4376), with increased levels of AMPK phosphorylation (P < 0.01). Conclusions This study highlights the potential role of the AICARP/AMPK pathway in oxidative rather than glycolytic skeletal muscles during SGLT2 inhibition, providing novel insights into the mechanism by which SGLT2 inhibitors improve endurance capacity in patients with type 2 diabetes

Exogenous Insulin Infusion Can Decrease Atherosclerosis in Diabetic Rodents by Improving Lipids, Inflammation, and Endothelial Function

OBJECTIVE: The objective of this study is to evaluate whether exogenously induced hyperinsulinemia may increase the development of atherosclerosis. APPROACH AND RESULTS: Hyperinsulinemia, induced by exogenous insulin implantation in high-fat fed (60% fat HFD) apolipoprotein E-deficient mice (ApoE-/-) mice, exhibited insulin resistance, hyperglycemia, and hyperinsulinemia. Atherosclerosis was measured by the accumulation of fat, macrophage, and extracellular matrix in the aorta. After 8 weeks on HFD, ApoE-/- mice were subcutaneously implanted with control (sham) or insulin pellet, and phlorizin, a sodium glucose cotransporters inhibitor (1/2)inhibitor, for additional 8 weeks. Intraperitoneal glucose tolerance test showed that plasma glucose levels were lower and insulin and IGF-1 (insulin-like growth factor-1) levels were 5.3- and 3.3-fold higher, respectively, in insulin-implanted compared with sham-treated ApoE-/- mice. Plasma triglyceride, cholesterol, and lipoprotein levels were decreased in mice with insulin implant, in parallel with increased lipoprotein lipase activities. Atherosclerotic plaque by en face and complexity staining showed significant reductions of fat deposits and expressions of vascular adhesion molecule-1, tumor necrosis factor-α, interleukin 6, and macrophages in arterial wall while exhibiting increased activation of pAKT and endothelial nitric oxide synthase (P<0.05) comparing insulin-implanted versus sham HFD ApoE-/- mice. No differences were observed in atherosclerotic plaques between phlorizin-treated and sham HFD ApoE-/- mice, except phlorizin significantly lowered plasma glucose and glycated hemoglobin levels while increased glucosuria. Endothelial function was improved only by insulin treatment through endothelial nitric oxide synthase/nitric oxide activations and reduced proinflammatory (M1) and increased anti-inflammatory (M2) macrophages, which were inhibited by endothelial nitric oxide synthase inhibitor. CONCLUSIONS: Exogenous insulin decreased atherosclerosis by lowering inflammatory cytokines, macrophages, and plasma lipids in HFD-induced hyperlipidemia, insulin resistant and mildly diabetic ApoE-/- mic