Liraglutide, a glucagon-like peptide-1 receptor agonist (GLP-1RA), has renoprotective effect in diabetic kidney disease (DKD). In DKD, TLR4/MYD88/NF-κB signaling is involved in the regulation of inflammatory responses and extracellular matrix (ECM) protein proliferation. Liraglutide attenuates renal inflammation and overexpression of ECM proteins by inhibiting TLR4/MYD88/NF-κB signaling pathway. Therefore, we have identified a new mechanism that contributes to the renal protection of GLP-1RA, thus helping to design innovative treatment strategies for diabetic patients with various complications.

Recent studies have demonstrated the benefits of osteocalcin (OCN) on glucose homeostasis and metabolic dysregulation. However, its role in body composition and vascular function remains unknown. This study was designed to examine changes in metabolic parameters and body composition as well as arterial stiffness after OCN treatment in type 2 diabetic rats. Adult male Sprague Dawley (SD) rats were fed chow or high fat diet (HFD) for 8 weeks, and then diabetes was induced with an injection of low-dose streptozotocin (STZ) and treated daily with intraperitoneal injections of OCN for 12 weeks. Our data showed that OCN treatment improved glucose homeostasis and lipid metabolism. Further analysis revealed that OCN treatment resulted in increased insulin sensitivity. In addition, untreated diabetic rats experienced significant weight loss, whereas OCN-treated rats better maintained body weight (300.75±38.14 g vs. 335.50±23.70, p=0.005). OCN also changed body composition, as evidenced by reduced body fat mass, specifically abdominal fat mass. OCN-treated diabetic rats also demonstrated decreased pulse-wave velocity, indicating of improved arterial stiffness. Taken together, our findings in the current study revealed that OCN therapy prevents arteriosclerosis in an induced diabetic rat model by exerting beneficial effects on glucose levels, insulin sensitivity, lipid metabolites, and body composition changes.

Glomerular mesangial cell is the major source of mesangial matrix. Our previous study demonstrated that store-operated Ca²⁺channel signaling suppressed extracellular matrix protein production by mesangial cells. Recent studies demonstrated that glucagon-like peptide-1 receptor (GLP-1R) pathway had renoprotective effects. However, the underlying mechanism(s) remains unclear. The present study was aimed to determine if activation of GLP-1R decreased extracellular matrix protein production by mesangial cells through upregulation of store-operated Ca²⁺function. Experiments were conducted in cultured human mesangial cells. Liraglutide and exendin 9–39 were used to activate and inhibit GLP-1R, respectively. Store-operated Ca²⁺function was estimated by evaluating the SOC-mediated Ca²⁺entry (SOCE). We found that liraglutide treatment reduced high glucose-stimulated production of fibronectin and collagen IV. The inhibitory effects of liraglutide were not observed in the presence of exendin 9–39. Exendin-4, another GLP-1R agonist also blunted high glucose-stimulated fibronectin and collagen IV production. Treatment of human mesangial cells with liraglutide for 24 h significantly attenuated the high glucose-induced reduction of Orai1 protein. Consistently, Ca²⁺imaging experiments showed that the inhibition of high glucose on SOCE was significantly attenuated by liraglutide. However, in the presence of exendin 9–39, liraglutide failed to reverse the high glucose effect. Furthermore, liraglutide effects on fibronectin and collagen IV protein abundance were significantly attenuated by GSK-7975A, a selective blocker of store-operated Ca²⁺. Taken together, our findings suggest that GLP-1R signaling inhibited high glucose-induced extracellular matrix protein production in mesangial cells by restoring store-operated Ca²⁺function.Impact statement: Diabetic kidney disease continues to be a major challenge to health care system in the world. There are no known therapies currently available that can cure the disease. The present study provided compelling evidence that activation of GLP-1R inhibited extracellular matrix protein production by glomerular mesangial cells. We further showed that the beneficial effect of GLP-1R was attributed to upregulation of store-operated Ca²⁺channel function. Therefore, we identified a novel mechanism contributing to the renal protective effects of GLP-1R pathway. Activation of GLP-1R pathway and/or store-operated Ca²⁺channel signaling in MCs could be an option for patients with diabetic kidney disease.

BACKGROUND The NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome may play an important role in diabetic kidney disease (DKD). However, the exact link remains unclear. AIM To investigate the role of the NLRP3 inflammasome in DKD. METHODS Using datasets from the Gene Expression Omnibus database, 30 NLRP3 inflammasome-related genes were identified. Differentially expressed genes were selected using differential expression analysis, whereas intersecting genes were selected based on overlapping differentially expressed genes and NLRP3 inflammasome-related genes. Subsequently, three machine learning algorithms were used to screen genes, and biomarkers were identified by overlapping the genes from the three algorithms. Potential biomarkers were validated by western blotting in a db/db mouse model of diabetes. RESULTS Two biomarkers, sirtuin 2 (SIRT2) and caspase 1 (CASP1), involved in the Leishmania infection pathway were identified. Both biomarkers were expressed in endothelial cells. Pseudo-temporal analysis based on endothelial cells showed that DKD mostly occurs during the mid-differentiation stage. Western blotting results showed that CASP1 expression was higher in the DKD group than in the control group (P < 0.05), and SIRT2 content decreased (P < 0.05). CONCLUSION SIRT2 and CASP1 provide a potential theoretical basis for DKD treatment.

This study explores the role of combining the controlling nutritional status (CONUT) score and the carcinoembryonic antigen (CEA) level on predicting tumor stage and prognosis in gastric cancer (GC) patients. A total of 682 GC patients were included in this retrospective study. CONUT scores and CEA levels were combined to establish a new scoring system: CONUT-CEA score. cutoff values for distinguishing patients between stage IV and non-stage IV were established by receiver operating characteristic curves. cutoff values for predicting prognosis were determined by maximum χ² method. The CONUT and CEA cutoff values for discriminating stage IV patients from non-stage IV patients were 2.0 and 5.58 ng/mL, respectively. Logistic regression model demonstrated that high CONUT-CEA score was related to advanced tumor stage. Among non-stage IV patients, CONUT and CEA cutoff values of 2.0 and 9.50 ng/mL predicted overall survival (OS), respectively. The Cox proportional risk model revealed that high CONUT-CEA score was notable related to decreased OS (2 vs 0: hazard ratios (HR) = 2.358, 95% confidence intervals (CI) = 1.412–3.940, P = .001) and decreased disease-free survival (2 vs 0: HR = 1.980, 95% CI = 1.072–3.656, P = .003). The CONUT-CEA score may be a good biomarker for predicting tumor stage and prognosis in GC patients.