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.

Reduced Immunogenicity of COVID-19 Vaccine in Obese Patients with Type 2 Diabetes: A Cross-Sectional Study.

The global pandemic of coronavirus infection 2019 (COVID-19) was an unprecedented public health emergency. Several clinical studies reported that heart disease, lung disease, diabetes, hypertension, dyslipidemia, and obesity are critical risk factors for increased severity of and hospitalization for COVID-19. This is largely because patients with these underlying medical conditions can show poor immune responses to the COVID-19 vaccinations. Diabetes is one of the underlying conditions most highly associated with COVID-19 susceptibility and is considered a predictor of poor prognosis of COVID-19. We therefore investigated factors that influence the anti-SARS-CoV-2 spike IgG antibody titer after three doses of vaccination in patients with type 2 diabetes. We found that obesity was associated with low anti-SARS-CoV-2 spike IgG antibody titers following three-dose vaccination in type 2 diabetics. Obese patients with type 2 diabetes may have attenuated vaccine efficacy and require additional vaccination; continuous infection control should be considered in such patients.

Role of glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 in hypertriglyceridemia and diabetes.

In diabetes, the impairment of insulin secretion and insulin resistance contribute to hypertriglyceridemia, as the enzymatic activity of lipoprotein lipase (LPL) depends on insulin action. The transport of LPL to endothelial cells and its enzymatic activity are maintained by the formation of lipolytic complex depending on the multiple positive (glycosylphosphatidylinositol-anchored high-density lipoprotein binding protein 1 [GPIHBP1], apolipoprotein C-II [APOC2], APOA5, heparan sulfate proteoglycan [HSPG], lipase maturation factor 1 [LFM1] and sel-1 suppressor of lin-12-like [SEL1L]) and negative regulators (APOC1, APOC3, angiopoietin-like proteins [ANGPTL]3, ANGPTL4 and ANGPTL8). Among the regulators, GPIHBP1 is a crucial molecule for the translocation of LPL from parenchymal cells to the luminal surface of capillary endothelial cells, and maintenance of lipolytic activity; that is, hydrolyzation of triglyceride into free fatty acids and monoglyceride, and conversion from chylomicron to chylomicron remnant in the exogenous pathway and from very low-density lipoprotein to low-density lipoprotein in the endogenous pathway. The null mutation of GPIHBP1 causes severe hypertriglyceridemia and pancreatitis, and GPIGBP1 autoantibody syndrome also causes severe hypertriglyceridemia and recurrent episodes of acute pancreatitis. In patients with type 2 diabetes, the elevated serum triglyceride levels negatively correlate with circulating LPL levels, and positively with circulating APOC1, APOC3, ANGPTL3, ANGPTL4 and ANGPTL8 levels. In contrast, circulating GPIHBP1 levels are not altered in type 2 diabetes patients with higher serum triglyceride levels, whereas they are elevated in type 2 diabetes patients with diabetic retinopathy and nephropathy. The circulating regulators of lipolytic complex might be new biomarkers for lipid and glucose metabolism, and diabetic vascular complications.

Brown Adipose Tissue PPARγ Is Required for the Insulin-Sensitizing Action of Thiazolidinediones.

Brown adipose tissue (BAT) plays a critical role in metabolic homeostasis. BAT dysfunction is associated with the development of obesity through an imbalance between energy expenditure and energy intake. The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARγ) is the master regulator of adipogenesis. However, the roles of PPARγ and thiazolidinediones (TZDs) in the regulation of BAT metabolism remain unclear. TZDs, which are selective PPARγ activators, improve systemic insulin resistance in animals and humans. In the present study, we generated brown adipocyte-specific PPARγ-deficient mice (BATγKO) to examine the in vivo roles of PPARγ and TZDs in BAT metabolism. In electron microscopic examinations, brown adipocyte-specific PPARγ deletion promoted severe whitening of brown fat and morphological alteration of mitochondria. Brown adipocyte-specific PPARγ deletion also reduced mRNA expression of BATselective genes. Although there was no difference in energy expenditure between control and BATγKO mice in calorimetry, norepinephrine-induced thermogenesis was impaired in BATγKO mice. Moreover, pioglitazone treatment improved diet-induced insulin resistance in the control mice but not in the BATγKO mice. These findings suggest that BAT PPARγ is necessary for the maintenance of brown adipocyte function and for the insulin-sensitizing action of TZDs.

Roles of Transmembrane Protein 97 (TMEM97) in Adipose Tissue and Skeletal Muscle.

The combination of sarcopenia and obesity (sarcopenic obesity) is associated with the development of metabolic syndrome and cardiovascular events. The molecular pathways that develop sarcopenic obesity have studied intensively. Transmembrane protein 97 (TMEM97) is 176 amino acids conserved integral membrane protein with four transmembrane domains that is expressed in several types of cancer. Its physiological significance in adipose tissue and skeletal muscle has been unclear. We studied TMEM97-transgenic mice and mice lacking TMEM97, and our findings indicate that TMEM97 expression is regulated in adipose tissue and skeletal muscle from obesity. TMEM97 represses adipogenesis and promotes myogenesis in vitro. Fat-specific TMEM97 transgenic mice showed systemic insulin resistance. Mice overexpressing TMEM97 in skeletal muscle exhibited systemic insulin resistance. Mice lacking TMEM97 were protected against diet-induced obesity and insulin resistance. These phenotypes are associated with the effects of TMEM97 on inflammation genes in adipose tissue and skeletal muscle. Our findings indicates that there is a link between TMEM97 and chronic inflammation in obesity.

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.

The Association of Postprandial Triglyceride Variability with Renal Dysfunction and Microalbuminuria in Patients with Type 2 Diabetic Mellitus: A Retrospective and Observational Study.

OBJECTIVE: We examined whether or not day-to-day variations in lipid profiles, especially triglyceride (TG) variability, were associated with the exacerbation of diabetic kidney disease. METHODS: We conducted a retrospective and observational study. First, 527 patients with type 2 diabetes mellitus (DM) who had had their estimated glomerular filtration rate (eGFR) checked every 6 months since 2012 for over 5 years were registered. Variability in postprandial TG was determined using the standard deviation (SD), SD adjusted (Adj-SD) for the number of measurements, and maximum minus minimum difference (MMD) during the first three years of follow-up. The endpoint was a ≥40% decline from baseline in the eGFR, initiation of dialysis or death. Next, 181 patients who had no micro- or macroalbuminuria in February 2013 were selected from among the 527 patients for an analysis. The endpoint was the incidence of microalbuminuria, initiation of dialysis, or death. RESULTS: Among the 527 participants, 110 reached a ≥40% decline from baseline in the eGFR or death. The renal survival was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p = 0.0073, 0.0059, and 0.0195, respectively). A lower SD, lower Adj-SD, and lower MMD were significantly associated with the renal survival in the adjusted model (hazard ratio, 1.62, 1.66, 1.59; 95% confidence intervals, 1.05-2.53, 1.08-2.58, 1.04-2.47, respectively). Next, among 181 participants, 108 developed microalbuminuria or death. The nonincidence of microalbuminuria was lower in the higher-SD, higher-Adj-SD, and higher-MMD groups than in the lower-SD, lower-Adj-SD, and lower-MMD groups, respectively (log-rank test p = 0.0241, 0.0352, and 0.0474, respectively). CONCLUSIONS: Postprandial TG variability is a novel risk factor for eGFR decline and the incidence of microalbuminuria in patients with type 2 DM.

Corrigendum: Upregulation of Mir342 in Diet-Induced Obesity Mouse and the Hypothalamic Appetite Control.

[This corrects the article DOI: 10.3389/fendo.2021.727915.].

Corrigendum: Upregulation of Mir342 in Diet-Induced Obesity Mouse and the Hypothalamic Appetite Control.

[This corrects the article DOI: 10.3389/fendo.2021.727915.].

Upregulation of Mir342 in Diet-Induced Obesity Mouse and the Hypothalamic Appetite Control.

In obesity and type 2 diabetes, numerous genes are differentially expressed, and microRNAs are involved in transcriptional regulation of target mRNAs, but miRNAs critically involved in the appetite control are not known. Here, we identified upregulation of miR-342-3p and its host gene Evl in brain and adipose tissues in C57BL/6 mice fed with high fat-high sucrose (HFHS) chow by RNA sequencing. Mir342 (-/-) mice fed with HFHS chow were protected from obesity and diabetes. The hypothalamic arcuate nucleus neurons co-express Mir342 and EVL. The percentage of activated NPY+pSTAT3+ neurons were reduced, while POMC+pSTAT3+ neurons increased in Mir342 (-/-) mice, and they demonstrated the reduction of food intake and amelioration of metabolic phenotypes. Snap25 was identified as a major target gene of miR-342-3p and the reduced expression of Snap25 may link to functional impairment hypothalamic neurons and excess of food intake. The inhibition of miR-342-3p may be a potential candidate for miRNA-based therapy.

Longitudinal observation of insulin secretory ability before and after the onset of immune checkpoint inhibitor-induced diabetes mellitus: A report of two cases.

Immune checkpoint inhibitor-induced diabetes mellitus is a rare immune-related adverse event. This report illustrates clinical data and insulin secretory ability before and after the onset of immune checkpoint inhibitor-induced diabetes.

Novel Urinary Glycan Biomarkers Predict Cardiovascular Events in Patients With Type 2 Diabetes: A Multicenter Prospective Study With 5-Year Follow Up (U-CARE Study 2).

Background: Although various biomarkers predict cardiovascular event (CVE) in patients with diabetes, the relationship of urinary glycan profile with CVE in patients with diabetes remains unclear. Methods: Among 680 patients with type 2 diabetes, we examined the baseline urinary glycan signals binding to 45 lectins with different specificities. Primary outcome was defined as CVE including cardiovascular disease, stroke, and peripheral arterial disease. Results: During approximately a 5-year follow-up period, 62 patients reached the endpoint. Cox proportional hazards analysis revealed that urinary glycan signals binding to two lectins were significantly associated with the outcome after adjustment for known indicators of CVE and for false discovery rate, as well as increased model fitness. Hazard ratios for these lectins (+1 SD for the glycan index) were UDA (recognizing glycan: mixture of Man5 to Man9): 1.78 (95% CI: 1.24-2.55, P = 0.002) and Calsepa [High-Man (Man2-6)]: 1.56 (1.19-2.04, P = 0.001). Common glycan binding to these lectins was high-mannose type of N-glycans. Moreover, adding glycan index for UDA to a model including known confounders improved the outcome prediction [Difference of Harrel's C-index: 0.028 (95% CI: 0.001-0.055, P = 0.044), net reclassification improvement at 5-year risk increased by 0.368 (0.045-0.692, P = 0.026), and the Akaike information criterion and Bayesian information criterion decreased from 725.7 to 716.5, and 761.8 to 757.2, respectively]. Conclusion: The urinary excretion of high-mannose glycan may be a valuable biomarker for improving prediction of CVE in patients with type 2 diabetes, and provides the rationale to explore the mechanism underlying abnormal N-glycosylation occurring in patients with diabetes at higher risk of CVE. Trial Registration: This study was registered with the University Hospital Medical Information Network on June 26, 2012 (Clinical trial number: UMIN000011525, URL: https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000013482).

Lgals9 deficiency ameliorates obesity by modulating redox state of PRDX2.

The adipose tissue is regarded as an endocrine organ and secretes bioactive adipokines modulating chronic inflammation and oxidative stress in obesity. Gal-9 is secreted out upon cell injuries, interacts with T-cell immunoglobulin-3 (Tim-3) and induces apoptosis in activated Th1 cells. Gal-9 also binds to protein disulfide isomerase (PDI), maintains PDI on surface of T cells, and increases free thiols in the disulfide/thiol cycles. To explore the molecular mechanism of obesity, we investigated Gal-9-/- and Gal-9wt/wt C57BL/6J mice fed with high fat-high sucrose (HFHS) chow. Gal-9-/- mice were resistant to diet-induced obesity associated with reduction of epididymal and mesenteric fat tissues and improved glucose tolerance compared with Gal-9wt/wt mice. However, the number of M1, M2 macrophages, and M1/M2 ratio in epididymal fat were unaltered. Under HFHS chow, Gal-9-/- mice receiving Gal-9-/- or Gal-9wt/wt bone marrow-derived cells (BMCs) demonstrated significantly lower body weight compared with Gal-9wt/wt mice receiving Gal-9-/- BMCs. We identified the binding between Gal-9 and peroxiredoxin-2 (PRDX2) in sugar chain-independent manner by nanoLC-MS/MS, immunoprecipitation, and pull-down assay. In 3T3L1 adipocytes, Gal-9 knockdown shifts PRDX2 monomer (reduced form) dominant from PRDX2 dimer (oxidized form) under oxidative stress with H2O2. The inhibition of Gal-9 in adipocytes may be a new therapeutic approach targeting the oxidative stress and subsequent glucose intolerance in obesity.

A Vaspin-HSPA1L complex protects proximal tubular cells from organelle stress in diabetic kidney disease.

Proximal tubular cells (PTCs) are crucial for maintaining renal homeostasis, and tubular injuries contribute to progression of diabetic kidney disease (DKD). However, the roles of visceral adipose tissue-derived serine protease inhibitor (vaspin) in the development of DKD is not known. We found vaspin maintains PTCs through ameliorating ER stress, autophagy impairment, and lysosome dysfunction in DKD. Vaspin-/- obese mice showed enlarged and leaky lysosomes in PTCs associated with increased apoptosis, and these abnormalities were also observed in the patients with DKD. During internalization into PTCs, vaspin formed a complex with heat shock protein family A (Hsp70) member 1 like (HSPA1L) as well as 78 kDa glucose-regulated protein (GRP78). Both vaspin-partners bind to clathrin heavy chain and involve in the endocytosis. Notably, albumin-overload enhanced extracellular release of HSPA1L and overexpression of HSPA1L dissolved organelle stresses, especially autophagy impairment. Thus, vapsin/HSPA1L-mediated pathways play critical roles in maintaining organellar function of PTCs in DKD.

Adipocyte-Specific Inhibition of Mir221/222 Ameliorates Diet-Induced Obesity Through Targeting Ddit4.

MicroRNAs expressed in adipocytes are involved in transcriptional regulation of target mRNAs in obesity, but miRNAs critically involved in this process is not well characterized. Here, we identified upregulation of miR-221-3p and miR-222-3p in the white adipose tissues in C57BL/6 mice fed with high fat-high sucrose (HFHS) chow by RNA sequencing. Mir221 and Mir222 are paralogous genes and share the common seed sequence and Mir221/222AdipoKO mice fed with HFHS chow demonstrated resistance to the development of obesity compared with Mir221/222flox/y . Ddit4 is a direct target of Mir221 and Mir222, and the upregulation of Ddit4 in Mir221/222AdipoKO was associated with the suppression of TSC2 (tuberous sclerosis complex 2)/mammalian target of rapamycin complex 1 (mTORC1)/S6K (ribosomal protein S6 kinase) pathway. The overexpression of miR-222-3p linked to enhanced adipogenesis, and it may be a potential candidate for miRNA-based therapy.

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.

The hypoglycemia-prevention effect of sensor-augmented pump therapy with predictive low glucose management in Japanese patients with type 1 diabetes mellitus: a short-term study.

AIMS/INTRODUCTION: The predictive low glucose management (PLGM) system was introduced in March 2018 in Japan. Although there are some reports demonstrating the benefit of PLGM in preventing hypoglycemia, no data are currently available in Japanese patients with type 1 diabetes mellitus (T1DM). The aim of the present study is to evaluate the effect of PLGM with sensor-augmented pump therapy in the prevention of hypoglycemia in Japanese patients. MATERIALS AND METHODS: We included 16 patients with T1DM who used the MiniMed®640G system after switching from the MiniMed®620G system. We retrospectively analysed the data of the continuous glucose monitoring system in 1 month after switching to MiniMed®640G. RESULTS: The area under the curve (AUC) of hypoglycemia of < 70 mg/dL was lowered from 0.42 ± 0.43 mg/dL day to 0.18 ± 0.18 mg/dL day (P = 0.012). Correspondingly, the duration of severe hypoglycemia (< 54 mg/dL) was reduced significantly from 15.3 ± 21.7 min/day to 4.8 ± 6.9 min/day (P = 0.019). The duration of hypoglycemia was reduced, but the reduction was not significant. Regarding the AUC for hyperglycemia > 180 mg/dL and the duration of hyperglycemia did not change. With the PLGM function, 79.3% of the predicted hypoglycemic events were avoided. CONCLUSIONS: The hypoglycemia avoidance rate was comparable to those in previous reports. In addition, we demonstrated that PLGM can markedly suppress severe hypoglycemia without deteriorating glycemic control in Japanese T1DM patients. It is necessary to further investigate the effective use of the PLGM feature such as establishing a lower limit and the timing of resumption.

A Patient with Type 3 Autoimmune Polyglandular Syndrome who Developed Systemic Lupus Erythematosus 8 years after the Diagnosis of Autoimmune Hepatitis.

Eight years prior to her present admission, a 61-year-old Japanese woman was diagnosed with autoimmune hepatitis, slowly progressive insulin-dependent diabetes mellitus, and chronic thyroiditis; she had been treated with oral prednisolone (PSL). After she suddenly discontinued PSL, she newly developed systemic lupus erythematosus. A combination therapy of oral PSL and intravenous cyclophosphamide resulted in remission. She was finally diagnosed with autoimmune polyglandular syndrome (APS) type 3 (3A ,3B, 3D), complicated with four different autoimmune diseases. Since patients with type 3 APS may present many manifestations over a long period of time, they should be carefully monitored.