Plasma angiotensin-converting enzyme 2 (ACE2) is a marker for renal outcome of diabetic kidney disease (DKD) (U-CARE study 3).

INTRODUCTION: ACE cleaves angiotensin I (Ang I) to angiotensin II (Ang II) inducing vasoconstriction via Ang II type 1 (AT1) receptor, while ACE2 cleaves Ang II to Ang (1-7) causing vasodilatation by acting on the Mas receptor. In diabetic kidney disease (DKD), it is still unclear whether plasma or urine ACE2 levels predict renal outcomes or not. RESEARCH DESIGN AND METHODS: Among 777 participants with diabetes enrolled in the Urinary biomarker for Continuous And Rapid progression of diabetic nEphropathy study, the 296 patients followed up for 9 years were investigated. Plasma and urinary ACE2 levels were measured by the ELISA. The primary end point was a composite of a decrease of estimated glomerular filtration rate (eGFR) by at least 30% from baseline or initiation of hemodialysis or peritoneal dialysis. The secondary end points were a 30% increase or a 30% decrease in albumin-to-creatinine ratio from baseline to 1 year. RESULTS: The cumulative incidence of the renal composite outcome was significantly higher in group 1 with lowest tertile of plasma ACE2 (p=0.040). Group 2 with middle and highest tertile was associated with better renal outcomes in the crude Cox regression model adjusted by age and sex (HR 0.56, 95% CI 0.31 to 0.99, p=0.047). Plasma ACE2 levels demonstrated a significant association with 30% decrease in ACR (OR 1.46, 95% CI 1.044 to 2.035, p=0.027) after adjusting for age, sex, systolic blood pressure, hemoglobin A1c, and eGFR. CONCLUSIONS: Higher baseline plasma ACE2 levels in DKD were protective for development and progression of albuminuria and associated with fewer renal end points, suggesting plasma ACE2 may be used as a prognosis marker of DKD. TRIAL REGISTRATION NUMBER: UMIN000011525.

Metformin and Its Immune-Mediated Effects in Various Diseases.

Metformin has been a long-standing prescribed drug for treatment of type 2 diabetes (T2D) and its beneficial effects on virus infection, autoimmune diseases, aging and cancers are also recognized. Metformin modulates the differentiation and activation of various immune-mediated cells such as CD4+ and CD+8 T cells. The activation of adenosine 5'-monophosphate-activated protein kinase (AMPK) and mammalian target of rapamycin complex 1 (mTORC1) pathway may be involved in this process. Recent studies using Extracellular Flux Analyzer demonstrated that metformin alters the activities of glycolysis, oxidative phosphorylation (OXPHOS), lipid oxidation, and glutaminolysis, which tightly link to the modulation of cytokine production in CD4+ and CD+8 T cells in various disease states, such as virus infection, autoimmune diseases, aging and cancers.

Circulating GPIHBP1 levels and microvascular complications in patients with type 2 diabetes: A cross-sectional study.

BACKGROUND: Glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 (GPIHBP1) plays a crucial role in lipolytic processing. Previous studies have shown that GPIHBP1 mutations cause severe hypertriglyceridemia and that serum GPIHBP1 levels are marginally higher in patients with coronary heart disease; however, the role of GPIHBP1 in type 2 diabetes mellitus (T2DM) remains unknown. OBJECTIVE: We investigated the association between circulating GPIHBP1 levels and the prevalence of microvascular complications in T2DM. METHODS: A total of 237 subjects with T2DM and 235 non-diabetic control subjects were enrolled in this study. Their serum GPIHBP1 levels were evaluated using ELISA assays. RESULTS: Circulating GPIHBP1 levels were higher in patients with T2DM (952.7 pg/mL [761.3-1234.6], p < 0.0001) than in non-diabetic subjects (700.6 [570.8-829.6]), but did not differ in T2DM patients with or without hypertriglyceridemia. Serum GPIHBP1 levels were significantly higher in patients with T2DM with diabetic retinopathy (DR), diabetic nephropathy (DN), and microvascular complications than in those without these complications. Multivariable logistic regression and receiver operating characteristic (ROC) curve analyses revealed that the presence of microvascular complications, but not macrovascular complications, was independently associated with serum GPIHBP1 levels, which could predict the presence of diabetic microvascular complications. CONCLUSIONS: Elevated GPIHBP1 levels are associated with microvascular complications in T2DM and may help to predict their progression.

Dysfunction of CD8 + PD-1 + T cells in type 2 diabetes caused by the impairment of metabolism-immune axis.

The metabolic changes and dysfunction in CD8 + T cells may be involved in tumor progression and susceptibility to virus infection in type 2 diabetes (T2D). In C57BL/6JJcl mice fed with high fat-high sucrose chow (HFS), multifunctionality of CD8 + splenic and tumor-infiltrating lymphocytes (TILs) was impaired and associated with enhanced tumor growth, which were inhibited by metformin. In CD8 + splenic T cells from the HFS mice, glycolysis/basal respiration ratio was significantly reduced and reversed by metformin. In the patients with T2D (DM), multifunctionality of circulating CD8 + PD-1 + T cells stimulated with PMA/ionomycin as well as with HLA-A*24:02 CMV peptide was dampened, while metformin recovered multifunctionality. Both glycolysis and basal respiration were reduced in DM, and glycolysis was increased by metformin. The disturbance of the link between metabolism and immune function in CD8 + PD-1 + T cells in T2D was proved by recovery of antigen-specific and non-specific cytokine production via metformin-mediated increase in glycolytic activity.