Sinensetin ameliorates high glucose-induced diabetic nephropathy via enhancing autophagy in vitro and in vivo.

Diabetic nephropathy (DN) affects around 40% of people with diabetes, the final outcome of which is end-stage renal disease. The deficiency of autophagy and excessive oxidative stress have been found to participate in the pathogenesis of DN. Sinensetin (SIN) has been proven to have strong antioxidant capability. However, the effect of SIN on DN has not been studied. We examined the effect of SIN on cell viability and autophagy in the podocyte cell line, MPC5 cells, treated with high glucose (HG). For in vivo studies, DN mice models were established by intraperitoneal injected with streptozotocin (40 mg/kg) for 5 consecutive days and fed with a 60% high-fat diet, and SIN was given (10, 20, and 40 mg/kg) for 8 weeks via intraperitoneal injection. The results showed that SIN could protect MPC5 cells against HG-induced damage and significantly improve the renal function of DN mice. Moreover, SIN remarkably restored the autophagy activity of MPC5 cells which was inhibited under HG conditions. Consistent with this, SIN efficiently improved autophagy in the kidney tissue of DN mice. In brief, our findings demonstrated the protective effect of SIN on DN via restoring the autophagic function, which might provide a basis for drug development.

Renoprotective Effect of Isoorientin in Diabetic Nephropathy via Activating Autophagy and Inhibiting the PI3K-AKT-TSC2-mTOR Pathway.

Diabetic nephropathy (DN) is one of the most serious complications of diabetes and the most common cause of death. The autophagy of podocytes plays an important role in the pathogenesis of DN. Here, through screening the constituent compounds of practical and useful Chinese herbal formulas, we identified that isoorientin (ISO) strongly promoted the autophagy of podocytes and could effectively protect podocytes from high glucose (HG)-induced injury. ISO significantly improved autophagic clearance of damaged mitochondria under HG conditions. Through a proteomics-based approach, we identified that ISO could reverse the excessive phosphorylation of TSC2 S939 under HG conditions and stimulate autophagy through inhibition of the PI3K-AKT-TSC2-mTOR pathway. Furthermore, ISO was predicted to bind to the SH2 domain of PI3Kp85[Formula: see text], which is crucial for the recruitment and activation of PI3K. The protective effect of ISO and its effects on autophagy and particularly on mitophagy were further proved using a DN mice model. To summarize, our study identified the protective effects of ISO against DN and demonstrated that ISO was a strong activator of autophagy, which could provide a basis for drug development.

Establishment and validation of a clinical model for predicting diabetic ketosis in patients with type 2 diabetes mellitus.

Background: Diabetic ketosis (DK) is one of the leading causes of hospitalization among patients with diabetes. Failure to recognize DK symptoms may lead to complications, such as diabetic ketoacidosis, severe neurological morbidity, and death. Purpose: This study aimed to develop and validate a model to predict DK in patients with type 2 diabetes mellitus (T2DM) based on both clinical and biochemical characteristics. Methods: A cross-sectional study was conducted by evaluating the records of 3,126 patients with T2DM, with or without DK, at The Affiliated Hospital of Qingdao University from January 2015 to May 2022. The patients were divided randomly into the model development (70%) or validation (30%) cohorts. A risk prediction model was constructed using a stepwise logistic regression analysis to assess the risk of DK in the model development cohort. This model was then validated using a second cohort of patients. Results: The stepwise logistic regression analysis showed that the independent risk factors for DK in patients with T2DM were the 2-h postprandial C-peptide (2hCP) level, age, free fatty acids (FFA), and HbA1c. Based on these factors, we constructed a risk prediction model. The final risk prediction model was L= (0.472a - 0.202b - 0.078c + 0.005d - 4.299), where a = HbA1c level, b = 2hCP, c = age, and d = FFA. The area under the curve (AUC) was 0.917 (95% confidence interval [CI], 0.899-0.934; p<0.001). The discriminatory ability of the model was equivalent in the validation cohort (AUC, 0.922; 95% CI, 0.898-0.946; p<0.001). Conclusion: This study identified independent risk factors for DK in patients with T2DM and constructed a prediction model based on these factors. The present findings provide an easy-to-use, easily interpretable, and accessible clinical tool for predicting DK in patients with T2DM.

The role of mitochondrial fission factor in podocyte injury in diabetic nephropathy.

Diabetic nephropathy (DN) is one of the most important complications of diabetes mellitus (DM) and has become the second cause of end-stage renal disease (ESRD). This study intends to investigate the molecular mechanism of increased mitochondrial fission in podocytes under the effect of high glucose (HG), and to preliminarily study the role of mitochondrial fission factor (MFF)-mediated mitochondrial fission in podocyte injury of DN. In vitro studies, we found that HG induced increased mitochondrial fission and podocyte damage. At the same time MFF mRNA and protein levels was increased, suggesting that MFF was transcriptional upregulated under HG conditions. Consistent with this, in vivo studies found that mitochondrial fission was also significantly increased in podocytes of diabetic nephropathy mice, and MFF expression was up-regulated. Therefore, our study proves that mitochondrial fission increases in podocytes under DM both in vitro and in vivo, and the up-regulation of MFF expression may be one of the reasons for the increase of mitochondrial fission. After inhibiting the expression of MFF, the survival rate of podocytes was significantly decreased under HG conditions, suggesting that MFF may play a protective role in podocyte injury in DN.

Impaired glucose tolerance is associated with enhanced postprandial pancreatic polypeptide secretion.

BACKGROUND: The purpose of this study is to compare serum pancreatic polypeptide (PP), insulin, C-peptide, and glucagon in different glucose tolerance stages; analyze the influencing factors of PP secretion; and further explore the role of PP in the pathogenesis of diabetes mellitus. METHODS: Data were collected from 100 subjects from hospital. According to the results of oral glucose tolerance test (OGTT), the subjects were divided into a normal glucose tolerance (NGT) group, an impaired glucose regulation (IGR) group, and a newly diagnosed type 2 diabetes mellitus (T2DM) group. PP and the related parameters were measured, and the area under the curve (AUC) 120 min after OGTT was calculated. AUCpp (AUC of PP) was used as the dependent variable and the potentially influencing factors were used as the independent variable for multiple linear regression analysis. RESULTS: Postprandial 60 min PP in the IGR group was higher than those in the NGT group (2973.80 [±547.49] pg·h/mL vs 2663.55 [±594.89] pg·h/mL, p < 0.05). AUCpp was significantly higher in the IGR group (428.76 pg·h/mL, 95% confidence interval [CI] [41.06 -816.46], p = 0.031) and newly diagnosed T2DM group (404.35 pg·h/mL, 95% CI [5.37-803.33], p = 0.047) than in the NGT group. AUCpp was negatively correlated with body mass index (BMI) (r = -0.235, p = 0.038) and positively correlated with postprandial 60 min blood glucose (r = 0.370, p = 0.001) and AUCbg (AUC of blood glucose) (r = 0.323, p = 0.007). Multiple linear regression analysis indicated that there was a linear correlation between BMI, AUCbg , and AUCpp (p = 0.004, p = 0.001), and the regression equation was calculated as: AUCpp  = 6592.272 + 86.275 × AUCbg -95.291 × BMI (R2  = 12.7%, p < 0.05). CONCLUSIONS: Compared with NGT subjects, IGR and T2DM patients have an enhanced postprandial PP secretion. In T2DMs, the secretion of PP is mainly affected by BMI and blood glucose.

Orientin Protects Podocytes from High Glucose Induced Apoptosis through Mitophagy.

Diabetic nephropathy (DN) is one of the serious complications of diabetes mellitus. Orientin, a major bioactive constituent of Fenugreek, has been reported to possess antihyperglycemic properties. However, its effects on DN remain unclear. Therefore, we explored the protective effect of orientin on podocytes. Here, we assessed cell viability and toxicity, level of autophagy, mitochondrial morphological changes, and podocyte apoptosis. The results indicated that high glucose (HG) induced podocyte apoptosis as well as mitochondrial injury can be partially blocked by orientin. The results showed that orientin could repair autophagy disorder induced by HG, while 3-methyladenine (3-MA) reversed the protection of orientin. Our study demonstrated the possibility of treating DN with orientin.

The renoprotective effects of sodium-glucose cotransporter 2 inhibitors versus placebo in patients with type 2 diabetes with or without prevalent kidney disease: A systematic review and meta-analysis.

AIMS: We undertook a systematic review and meta-analysis to assess the efficacy and safety of sodium-glucose cotransporter 2 inhibitors (SGLT2is) concerning kidney outcomes in patients with type 2 diabetes mellitus (T2DM), with or without prevalent kidney disease. MATERIALS AND METHODS: PubMed, Web of science, Embase and the Cochrane Library were systematically searched for randomized controlled trials (RCTs) to assess the efficacy and safety of treatment with SGLT2is versus placebo in patients with T2DM. The weighted mean difference (WMD) and its 95% confidence interval (CI) were applied for continuous variables, and the risk ratio (RR) and corresponding 95% CI were used for dichotomous outcomes. Patients were categorized according to whether the baseline mean estimated glomerular filtration rate (eGFR) was less or was more than 60 mL/min/1.73 m2 . RESULTS: A total of 25 eligible studies with 43 721 participants were included. There was an initial and small decrease in eGFR during the early treatment period (WMD, -4.63; 95% CI, -6.08 to -3.19 mL/min/1.73 m2 ), which was noted at 1-6 weeks and gradually narrowed over time, with a decline in protection from eGFR in the long term (WMD, 3.82; 95% CI, 2.80-4.85 mL/min/1.73 m2 ). SGLT2is significantly delayed albuminuria progression (RR, 0.71; 95% CI, 0.66-0.76), promoted albuminuria regression (RR,1.71; 95% CI, 1.54-1.90), improved the composite of ≥40% decrease in eGFR, in the need for renal-replacement and in death from renal causes (RR, 0.57; 95% CI, 0.49-0.66), and reduced all-cause mortality (RR, 0.84; 95% CI, 0.75-0.94). At the same time, they significantly increased the risk of genital infection (RR, 3.43; 95% CI, 2.87-4.10) vs placebo in patients with T2DM. Meta-regression analyses showed that eGFR-preservation effects were not significantly associated with basic patient characteristics (age, BMI, HbA1c, eGFR level), but were influenced by drug administration (treatment duration, type, dosage of SGLT2is). Subgroup analyses showed that the relative effects on renal outcomes of SGLT2is vs placebo were similar across eGFR subgroups (P heterogeneity >0.05). CONCLUSIONS: SGLT2is slowed eGFR decline, lowered albuminuria progression, improved adverse renal endpoints and reduced all-cause mortality, but increased risk of genital infections vs placebo in patients with T2DM. The indication of consistent renal benefits across categories of baseline eGFR levels may allow additional individuals to benefit from SGLT2is therapy.