Inhibition of EZH2 suppresses peritoneal angiogenesis by targeting a VEGFR2/ERK1/2/HIF-1α-dependent signaling pathway.

The catalytic subunit of polycomb repressive complex 2 (PRC2), enhancer of zeste homolog 2 (EZH2), has been reported to be involved in angiogenesis in some tumors and autoimmune diseases. However, the mechanisms by which EZH2 regulates peritoneal angiogenesis remain unclear. We detected the expression of EZH2 in clinical samples and the peritoneal tissue of a mouse peritoneal fibrosis model induced by chlorhexidine gluconate (CG). In addition, we further investigated the mechanisms by which inhibition of EZH2 by 3-deazaneplanocin A (3-DZNeP) alleviated the CG-induced peritoneal fibrosis mouse model in vivo and 3-DZNeP or EZH2 siRNA treatment in cultured human peritoneal mesothelial cells (HPMCs) and human umbilical vein endothelial cells (HUVECs). The expression of EZH2 in the peritoneum of long-term peritoneal dialysis (PD) patients and the CG-induced peritoneal fibrosis mouse model was remarkably increased and this was positively associated with higher expression of vascular markers (CD31, CD34, VEGF, p-VEGFR2). Peritoneal injection of 3-DZNeP attenuated angiogenesis in the peritoneum of CG-injured mice; improved peritoneal membrane function; and decreased phosphorylation of STAT3, ERK1/2, and activation of Wnt1/ß-catenin. In in vitro experiments, we demonstrated that inhibition of EZH2 by 3-DZNeP or EZH2 siRNA decreased tube formation and the migratory ability of HUVECs via two pathways: the Wnt1/ß-catenin pathway and the IL-6/STAT3 pathway. Suppression of the Wnt1/ß-catenin pathway and the IL-6/STAT3 pathway subsequently reduced VEGF production in HPMCs. Using specific inhibitors of VEGFR2, ERK1/2, and HIF-1α, we found that a VEGFR2/ERK1/2/HIF-1α axis existed and contributed to angiogenesis in vitro. Moreover, phosphorylation of VEGFR2 and activation of the ERK1/2 pathway and HIF-1α in HUVECs could be suppressed by inhibition of EZH2. Taken together, the results of this study suggest that EZH2 may be a novel target for preventing peritoneal angiogenesis in PD patients. © 2022 The Pathological Society of Great Britain and Ireland.

Hybrid metal/Ga2O3/GaN ultraviolet detector for obtaining low dark current and high responsivity.

In this work, we have proposed and fabricated a metal/Ga2O3/GaN hybrid structure metal-semiconductor-metal ultraviolet photodetector with low dark current and high responsivity. The Schottky contact of Ni/Ga2O3 makes the Ga2O3 layer fully depleted. The strong electric field in the Ga2O3 depletion region can push the photo-induced electrons from the Ga2O3 layer into the GaN layer for more efficient carrier transport. Therefore, the hybrid structure simultaneously utilizes the advantage of the absorption to solar-blind ultraviolet light by the Ga2O3 layer and the high electron mobility of the GaN layer. Thus, the dark current and the photocurrent for the proposed device can be greatly improved. As a result, an extremely high photo-to-dark-current ratio of 1.46 × 106 can be achieved. Furthermore, quick rise and fall times of 0.213 s and 0.027 s at the applied bias of 6 V are also obtained, respectively.

A retrospective study of baseline peritoneal transport character and left ventricular hypertrophy in incident peritoneal dialysis patients: interrelationship and prognostic impacts.

BACKGROUND: Left ventricular hypertrophy is associated with adverse outcomes among peritoneal dialysis patients. The aim of this study was to evaluate the prognostic impact of baseline left ventricular hypertrophy and its relationship with baseline peritoneal transfer characteristics in peritoneal dialysis patients. METHODS: We enrolled 151 incident peritoneal dialysis patients to perform a multicentric retrospective cohort study since January 1, 2017 to January 31, 2021. Patients were grouped based on baseline dialysate-to-plasma creatinine ratio at 4 h as follows: low (<0.50), low average (0.5-0.64), high average (0.65-0.80) and high (≥0.81). Echocardiography and clinic data were recorded yearly. The Cox proportional hazards models and competing risk model were used to evaluate patients' survival. Generalized linear mixed models were performed to explore risk factors associated with left ventricular hypertrophy. RESULTS: During a median follow-up period of 33 months (range, 16-48 months), 21 (13.9%) patients died, including 16 (10.60%) cardiovascular deaths. Controlling the competing risks of switching to hemodialysis, kidney transplantation and loss to follow-up, baseline left ventricular hypertrophy was an independent risk factor for all-cause mortality (subdistribution hazard ratio, 2.645; 95% confidence interval, 1.156-6.056; p = 0.021). Baseline high and high average transport status were positively related to left ventricular mass index and left atrium diameter 2 years after PD initiation. CONCLUSION: Baseline fast peritoneal solute transport rate may be an effect factor for aggravating left ventricular hypertrophy which predicted poor outcomes for peritoneal dialysis patients. The findings offered important ideas for further prospective intervention study.

The prognosis and risk factors of baseline high peritoneal transporters on patients with peritoneal dialysis.

The relationship between baseline high peritoneal solute transport rate (PSTR) and the prognosis of peritoneal dialysis (PD) patients remains unclear. The present study combined clinical data and basic experiments to investigate the impact of baseline PSTR and the underlying molecular mechanisms. A total of 204 incident CAPD patients from four PD centres in Shanghai between 1 January 2014 and 30 September 2020 were grouped based on a peritoneal equilibration test after the first month of dialysis. Analysed with multivariate Cox and logistic regression models, baseline high PSTR was a significant risk factor for technique failure (AHR 5.70; 95% CI 1.581 to 20.548 p = 0.008). Baseline hyperuricemia was an independent predictor of mortality (AHR 1.006 95%CI 1.003 to 1.008, p < 0.001) and baseline high PSTR (AOR 1.007; 95%CI 1.003 to 1.012; p = 0.020). Since uric acid was closely related to high PSTR and adverse prognosis, the in vitro experiments were performed to explore the underlying mechanisms of which uric acid affected peritoneum. We found hyperuricemia induced epithelial-to-mesenchymal transition (EMT) of cultured human peritoneal mesothelial cells by activating TGF-ß1/Smad3 signalling pathway and nuclear transcription factors. Conclusively, high baseline PSTR induced by hyperuricaemia through EMT was an important reason of poor outcomes in CAPD patients.

Clinical outcomes, quality of life, and costs evaluation of peritoneal dialysis management models in Shanghai Songjiang District: a multi-center and prospective cohort study.

Background: The new Family-Community-Hospital (FCH) three-level comprehensive management aimed to improve the efficiency and scale of peritoneal dialysis (PD) to meet the increased population of end-stage renal disease (ESRD). Our study focused on the clinical outcomes, quality of life, and costs evaluation of this model in a multi-center and prospective cohort study.Methods: A total of 190 ESRD patients who commenced PD at Shanghai Songjiang District were enrolled. According to different PD management models, patients were divided into the Family-Community-Hospital three-level management model (n = 90) and the conventional all-course central hospital management model (n = 100). The primary outcome was clinical outcomes of PD. The secondary outcomes were health-related quality of life (HRQOL) and medical costs evaluation.Results: Compared to conventional management, community-based FCH management achieved a similar dialysis therapeutic effect, including dropout rate (p = 0.366), peritonitis rate (p = 0.965), patient survival (p = 0.441), and technique survival (p = 0.589). Follow-up data showed that similar levels of the renal and peritoneal functions, serum albumin, cholesterol and triglyceride, PTH, serum calcium, and phosphorus between the two groups (all p > 0.05). HRQOL survey showed that the FCH management model helped to improve the psychological status of PD patients, including social functioning (p = 0.006), role-emotional (p = 0.032), and mental health (p = 0.036). FCH management also reduced the hospitalization (p = 0.009) and outpatient visits (p = 0.001) and saved annual hospitalization costs (p = 0.005), outpatient costs (p = 0.026), and transport costs (p = 0.006).Conclusions: Compared with conventional management, community-based FCH management achieved similar outcomes, improved psychological health, reduced medical budgets, and thus had a good social prospect.

Delayed treatment with an autophagy inhibitor 3-MA alleviates the progression of hyperuricemic nephropathy.

Autophagy is a cell self-renewal process that relies on the degradation of the cytoplasmic proteins or organelles of lysosomes and is associated with development of numerous diseases. However, the therapeutic effect of autophagy inhibition on hyperuricemic nephropathy (HN) and the underlying mechanisms are still unknown. Here, we investigated the effect of delayed treatment with 3-methyladenine (3-MA), a specific autophagy inhibitor, on the development of HN in a rat model. Administration of 3-MA at 21 days following after uric acid injury protected kidney from hyperuricemic-related injuries, as demonstrated by improving renal dysfunction and architecture damage, blocking Beclin-1 and LC3II/I and decreasing the number of autophagic vacuoles. Late treatment with 3-MA was also effective in attenuating renal fibrosis as evidenced by reducing ECM protein deposition, blocking epithelial-to-mesenchymal transition (EMT) and decreasing the number of renal epithelial cells arrested at the G2/M phase of cell cycle. Injury to the kidney resulted in increased expression of TGFß receptor I, and phosphorylation of Smad3, 3-MA significantly abrogated all these responses. Moreover, inhibition of autophagy suppressed mitochondrial fission, downregulated the expression of Dynamin-related protein 1 (Drp-1), Cofilin and F-actin, and alleviated cell apoptosis. Finally, 3-MA effectively blocked STAT3 and NF-κB phosphorylation and suppressed infiltration of macrophages and lymphocytes as well as release of multiple profibrogenic cytokines/chemokines in the injured kidney. Taken together, these findings indicate that hyperuricemia-induced autophagy is critically involved in the activation of renal fibroblasts, EMT, mitochondrial fission and apoptosis of tubular epithelial cells and development of renal fibrosis. Thus, this study provides evidence for autophagy inhibitors as the treatment of HN patients.