Tubulointerstitial inflammation plays a key role in the pathogenesis of diabetic nephropathy (DN). Interleukin-1β (IL-1β) is the key proinflammatory cytokine associated with tubulointerstitial inflammation. The NLRP3 inflammasome regulates IL-1β activation and secretion. Reactive oxygen species (ROS) represents the main mediator of NLRP3 inflammasome activation. We previously reported that CD36, a class B scavenger receptor, mediates ROS production in DN. Here, we determined whether CD36 is involved in NLRP3 inflammasome activation and explored the underlying mechanisms. We observed that high glucose induced-NLRP3 inflammasome activation mediate IL-1β secretion, caspase-1 activation, and apoptosis in HK-2 cells. In addition, the levels of CD36, NLRP3, and IL-1β expression (protein and mRNA) were all significantly increased under high glucose conditions. CD36 knockdown resulted in decreased NLRP3 activation and IL-1β secretion. CD36 knockdown or the addition of MitoTempo significantly inhibited ROS production in HK-2 cells. CD36 overexpression enhanced NLRP3 activation, which was reduced by MitoTempo. High glucose levels induced a change in the metabolism of HK-2 cells from fatty acid oxidation (FAO) to glycolysis, which promoted mitochondrial ROS (mtROS) production after 72 h. CD36 knockdown increased the level of AMP-activated protein kinase (AMPK) activity and mitochondrial FAO, which was accompanied by the inhibition of NLRP3 and IL-1β. The in vivo experimental results indicate that an inhibition of CD36 could protect diabetic db/db mice from tubulointerstitial inflammation and tubular epithelial cell apoptosis. CD36 mediates mtROS production and NLRP3 inflammasome activation in db/db mice. CD36 inhibition upregulated the level of FAO-related enzymes and AMPK activity in db/db mice. These results suggest that NLRP3 inflammasome activation is mediated by CD36 in renal tubular epithelial cells in DN, which suppresses mitochondrial FAO and stimulates mtROS production.

Dietary protein restriction has long been thought to play an important role in the progression of chronic kidney disease (CKD); however, the effect of dietary protein on the rate of decline in kidney function remains controversial. We undertook a systematic review and meta-analysis of randomized controlled trials (RCTs) to assess the influence of protein restriction on chronic kidney disease. Ovid MEDLINE (from 1946 to March 5, 2016), EMBASE (from 1966 to March 5, 2016), and the Cochrane Library (Inception to March 5, 2016) were searched to identify RCTs comparing different levels of protein intake for at least 24 weeks in adult patients with CKD. The outcomes included kidney failure events, the rate of change in estimated glomerular filtration rate (eGFR) per year, all cause death events, and changes in proteinuria, serum phosphorus concentration, serum albumin, and body mass index (BMI). Nineteen trials with 2492 subjects were analyzed. A low protein diet reduced the risk of kidney failure (odds ratio (OR) = 0.59, 95% CI: 0.41 to 0.85) and end-stage renal disease (ESRD) (OR = 0.64, 95% CI: 0.43 to 0.96), but did not produce a clear beneficial effect for all cause death events (OR = 1.17, 95% CI: 0.67 to 2.06). The change in the mean difference (MD) for the rate of decline in the eGFR was significant (MD: −1.85, P = 0.001), and for proteinuria (MD: −0.44, P = 0.02). A low protein diet also reduced the serum phosphorus concentration (MD: −0.37, 95% CI: −0.5 to −0.24) and BMI (MD: −0.61, 95% CI: −1.05 to −0.17). However the change in albumin presented no significant difference between two groups (MD: 0.23, 95% CI: −0.51 to 0.97). Based on the findings of our meta-analysis, protein-restricted diet may reduce the rate of decline in renal function and the risk of kidney failure for CKD populations, but did not produce a clear beneficial effect for all cause death events. Besides However, the optimal level of protein intake in different participants is left unanswered, and the nutritional status should be regarded with caution.

The effects of uric acid-lowering therapy in patients with chronic kidney disease (CKD) remain uncertain. Therefore, we undertook a systematic review and meta-analysis to investigate the effects of uric acid-lowering agents on major clinical outcomes of CKD. According to the pre-specified protocol that was registered with PROSPERO (No. CRD42016038030), we searched systematically in MEDLINE, EMBASE, and the Cochrane Library for trials up to February 2016. Prospective, randomized, controlled trials assessing the effects of uric acid-lowering agents on cardiovascular and kidney outcomes in patients with CKD were included. Random-effects analytical methods were used. Sixteen eligible trials were identified, providing data for 1,211 patients with CKD, including 146 kidney failure events and 69 cardiovascular events. Uric acid-lowering therapy produced a 55% relative risk (RR) reduction (95% confidence interval [95% CI], 31–64) for kidney failure events (P < 0.001), and a 60% RR reduction (95% CI, 17–62) for cardiovascular events (P < 0.001), but had no significant effect on the risk of all-cause death (RR, 0.86; 95% CI, 0.50–1.46). The mean differences in rate of decline in the estimated glomerular filtration rate (4.10 mL/min/1.73 m² per year slower in uric acid-lowering therapy recipients, 95% CI, 1.86–6.35) and the standardized mean differences in the change in proteinuria or albuminuria (−0.23 units of standard deviation greater in uric acid-lowering therapy recipients; 95% CI, −0.43 to −0.04) were also statistically significant. Uric acid-lowering therapy seemed to improve kidney outcomes and reduce the risk of cardiovascular events in adults with CKD.

Background: Endothelial-mesenchymal transition (EndoMT) is a major source of myofibroblast formation in kidney fibrosis. Our previous study showed a profibrotic role for matrix metalloproteinase 9 (MMP-9) in kidney fibrosis via induction of epithelial-mesenchymal transition (EMT). Inhibition of MMP-9 activity reduced kidney fibrosis in murine unilateral ureteral obstruction. This study investigated whether MMP-9 also plays a role in EndoMT in human glomerular endothelial cells. Results: TGF-β1 (10 or 20 ng/ml) induced EndoMT in HKGECs as shown by morphological changes. In addition, VE-cadherin and CD31 were significantly downregulated, whereas α-SMA, vimentin, and N-cadherin were upregulated. RT-PCR revealed that Snail, a known inducer of EMT, was upregulated. The MMP inhibitor GM6001 abrogated TGF-β1-induced EndoMT. Zymography indicated that MMP-9 was also upregulated in TGF-β1-treated HKGECs. Recombinant MMP-9 (2 μg/ml) induced EndoMT in HKGECs via Notch signaling, as evidenced by increased formation of the Notch intracellular domain (NICD) and decreased Notch 1. Inhibition of MMP-9 activity by its inhibitor showed a dose-dependent response in preventing TGF-β1-induced α-SMA and NICD in HKGECs, whereas inhibition of Notch signaling by γ-secretase inhibitor (GSI) blocked rMMP-9-induced EndoMT. Conclusions: Taken together, our results demonstrate that MMP-9 plays an important role in TGF-β1-induced EndoMT via upregulation of Notch signaling in HKGECs.

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is life-saving for severe hematological conditions. However, its outcomes need further improvement, and co-infusion of mesenchymal stem cells (MSCs) may show promise. A growing body of research on this subject exists, while the results of different trials are conflicting. A systematic review and meta-analysis is needed to appraise the real efficacy and safety of MSC co-transplantation in allo-HSCT. Methods: Studies comparing MSC co-transplantation in allo-HSCT with allo-HSCT alone were searched in six medical databases from inception to June 10, 2020. The primary outcomes were engraftment and graft-versus-host disease (aGVHD and cGVHD, respectively). Other outcomes included overall survival (OS), relapse rate (RR), non-relapse mortality (NRM), and immune reconstitution. Information was independently extracted by two investigators. Methodological quality was assessed using the Cochrane Collaboration tool. Meta-analysis was performed using RevMan 5.4. Results: Six randomized controlled trials (RCTs) and 13 non-randomized controlled trials (nRCTs) were included. MSC co-infusion resulted in shorter times to neutrophil engraftment (RCTs: standardized mean difference (SMD) − 1.20, p = 0.04; nRCTs: SMD − 0.54, p = 0.04) and platelet engraftment (RCTs: SMD − 0.60, p = 0.04; nRCTs: SMD − 0.70, p = 0.01), a lower risk of cGVHD (RCTs: risk ratio (RR) 0.53, p = 0.01; nRCTs: RR 0.50, p < 0.01), and a slightly positive trend towards reducing the risk of aGVHD and NRM, without affecting RR and OS. Subgroup analyses revealed that when MSCs were co-transplanted, children and adolescents, and patients receiving human leukocyte antigen (HLA)-nonidentical HSCT showed improvements in engraftment and incidence of GVHD and NRM; adults and patients who received HLA-identical HSCT had lower cGVHD; patients with malignancies exhibited improvements in GVHD and NRM incidence; and patients with non-malignancies experienced accelerated engraftment. Notably, a reduced OS was observed in patients with hematological malignancies undergoing HLA-identical HSCT. Conclusion: MSC co-infusion generally improved engraftment and reduced cGVHD, without increasing mortality or relapse. Regarding aGVHD and NRM, the effects of MSCs were not quite significant. Specifically, our data support the utilization of MSC co-transplantation in children and young individuals with HLA-nonidentical HSCT, but not in adult patients with hematological malignancies undergoing HLA-identical HSCT.

B-cell lymphocytes have been demonstrated to play a key role in the pathogenesis underlying membranous nephropathy (MN). The aim of this study was to evaluate the therapeutic efficacy and safety of Obinutuzumab, a glycoengineered type II anti-CD20 monoclonal antibody in individuals with MN. We retrospectively analyzed data from 59 consecutive patients with primary MN who provided consent to receive Obinutuzumab and were followed for at least 6 months. The primary outcomes were complete (proteinuria <0.3 g/d) or partial (proteinuria <3.5 g/d with ≥ 50% reduction) remission of proteinuria. Twenty patients received Obinutuzumab as initial therapy, and 39 patients were previously treated with at least 1 immunosuppressant (second-line therapy). Fifty patients (84.7%) achieved complete remission (CR) or partial remission (PR) of proteinuria during the median follow-up of 9.4 months. The likelihood of remission was significantly higher when Obinutuzumab was used as initial therapy than as second-line therapy after adjusting for the baseline estimated glomerular filtration rate (eGFR), 24-hour urinary protein levels, and anti-phospholipase A₂ receptor (PLA₂R) status (adjusted hazard ratio [HR], 4.5; 95% confidence interval [CI]: 2.1–9.5, P < 0.001). Circulating CD19⁺ B-cell count decreased to <5 cells/μl in all patients within 2 weeks after infusion. Serum anti-PLA₂R concentrations decreased to <14 relative units (RU)/ml in 43 of 48 patients with PLA₂R-related MN. After Obinutuzumab administration, a significant reduction in 24-hour urine protein and increase in serum albumin were observed. No serious adverse events were observed. Obinutuzumab may represent a promising and well-tolerated therapeutic option for individuals with primary MN. The potential of Obinutuzumab was highlighted as an initial therapy for primary MN.