Sodium–Glucose Cotransporter-2 Inhibitors and the Risk of Amputation: What Is Currently Known?

Liraglutide Promotes Diabetic Wound Healing via Myo1c/Dock5

Non-healing diabetic wounds and ulcer complications, with persistent cell dysfunction and obstructed cellular processes, are leading causes of disability and death in patients with diabetes. Currently, there is a lack of guideline-recommended hypoglycemic drugs in clinical practice, likely due to limited research and unclear mechanisms. In this study, it is demonstrated that liraglutide significantly accelerates wound closure in diabetic mouse models (db/db mice and streptozotocin-induced mice) by improving re-epithelialization, collagen deposition, and extracellular matrix remodeling, and enhancing the proliferation, migration, and adhesion functions of keratinocytes. However, these effects of improved healing by liraglutide are abrogated in dedicator of cytokinesis 5 (Dock5) keratinocyte-specific knockout mice. Mechanistically, liraglutide induces cellular function through stabilization of unconventional myosin 1c (Myo1c). Liraglutide directly binds to Myo1c at arginine 93, enhancing the Myo1c/Dock5 interaction by targeting Dock5 promoter and thus promoting the proliferation, migration, and adhesion of keratinocytes. Therefore, this study provides insights into liraglutide biology and suggests it may be an effective treatment for diabetic patients with wound-healing pathologies.

Real-world risk of lower-limb amputation associated with sodium-glucose cotransporter 2 inhibitors versus metformin: A propensity score-matched model analysis in Japan

AIMS/INTRODUCTION

We aimed to clarify the real-world risk of lower-limb amputation and identify factors related to increased risk in Japanese patients with type 2 diabetes using sodium-glucose cotransporter 2 inhibitors (SGLT2is).

MATERIALS AND METHODS

We carried out a retrospective observational cohort study utilizing the Japanese Medical Data Vision, a diagnosis procedure combination database. We identified 107,296 patients with type 2 diabetes who were initiated on SGLT2is or metformin (control; n = 53,648 per group) using 1:1 propensity score matching from April 2014 to October 2019. The hazard ratio (HR) for the risk of lower-limb amputation was analyzed using a Cox proportional hazards model adjusted for patients' baseline characteristics and use of concomitant medical agents.

RESULTS

Of the 107,296 patients, 66 (0.06%); that is, 41 (0.08%) in the SGLT2is group and 25 (0.05%) in the metformin group, underwent amputation, with no significant difference in the proportions between the groups. There was no significant difference in the risk of amputation between the SGLT2is and metformin groups (HR 1.34, 95% confidence interval [CI] 0.80-2.24). However, female sex (HR 2.78, 95% CI 1.12-6.94) and use of strong statins (HR 2.68; 95% CI 1.18-8.20) were significantly associated with a higher risk of amputation in the SGLT2is group than in the metformin group.

CONCLUSIONS

SGLT2is might not be related to an increased risk of lower-limb amputation in patients with type 2 diabetes in real-world clinical practice. The possible increased risk of SGLT2is-associated amputation in female patients with type 2 diabetes and patients with type 2 diabetes requiring strong statins is notable.

Discovery of polypodiside as a Keap1-dependent Nrf2 activator attenuating oxidative stress and accumulation of extracellular matrix in glomerular mesangial cells under high glucose

Diabetic nephropathy (DN) is a severe microvascular complication of diabetes mellitus. High glucose has resulted in oxidative stress and following renal fibrosis as the crucial nodes of this disease. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor regulating transcription of many antioxidant genes and suppressing synthesis of extracellular matrix. To discover Nrf2 activators targeting DN, we have evaluated polypodiside using cell-based assays. The results showed polypodiside inhibited the high glucose-induced self-limited proliferation of glomerular meangial cells. Activation of Nrf2 and enhanced transcription to antioxidant response elements were observed in the presence of polypodiside. Oxidative stress and accumulation of extracellular matrix induced by high glucose in glomerular meangial cells have been ameliorated by polypodiside. Further investigations revealed the effects of polypodiside on glomerular meangial cells were associated with activation of Nrf2. Co-immunoprecipitation of Nrf2 disclosed polypodiside disrupted the Kelch-like ECH-associated protein-1 (Keap1)-Nrf2 interaction. Molecular docking elucidated polypodiside could enter the Nrf2 binding cavity of Keap1 via interacting with the residues encompassing that cavity. These findings indicate polypodiside is a Keap1-dependent Nrf2 activator affording the catabatic effects against oxidative stress and accumulation of extracellular matrix in glomerular meangial cells under high glucose.