Different expression levels of exosomal miR-503 in peritoneal dialysis effluent from patients of different peritoneal transport characteristics and bioinformatics analysis

Objective To compare the expression level of exosomal miR-503 in peritoneal dialysis effluent (PDE) from patients of different peritoneal transport characteristics, predict the target genes of miR-503 and provide bioinformatic data for researches of peritoneal transport characteristics. Methods Twenty-four stable peritoneal dialysis (PD) patients were selected and divided into high transport group (H group, n=12) and low transport group (L group, n=12) according to the results of peritoneal equilibration tests (PET). The 500 ml PDE that was left on the patient's abdomen overnight was collected and concentrated using ultrafiltration cell. Exosomes in PDE were resuspended in phosphate buffered saline (PBS) after ultracentrifugation and the characteristics of PDE exosomes were identified by transmission electron microscope (TEM), nanoparticle tracking analysis (NTA), Western blotting and fluorescent staining. MicroRNAs were extracted from PDE exosomes. The expression levels of PDE exosomal miR-503 in the two groups were detected by quantitative real-time PCR. Then the relations between the relative quantity of PDE exosomal miR-503 and PET values or 24 h ultrafiltration volume (UF) were analyzed. Targetscan and miRDB databases were used to predict the target genes of miR-503. Gene ontology (GO) functional enrichment and Kyoto encyclopedia of genes and genomes (KEGG) signaling pathway analysis were relied on DAVID (https://david.ncifcrf.gov/). Results The exosomes in PDE showed a round and cup-shaped morphology under TEM, and the diameters were approximately 100 nm measured by NTA. The specific biomarkers of exosomes, CD63, CD81 and heat shock protein -70 (HSP-70) were all detected by Western blotting. The internalization and uptake of the exosomes was observed after fluorescent staining. The relative expression level of PDE exosomal miR-503 in H group was found to be significantly higher than that in L group (P=0.002), and the relative quantity of PDE exosomal miR-503 was significantly positively correlated with PET values (r=0.547, P=0.006), but not 24 h UF (r=-0.297, P=0.159). There were 156 target genes of miR-503 in total that could be predicted by two different databases at the same time. GO analysis of these 156 target genes was mainly focused on kinase binding, regulation of protein modification and catabolic process as well as regulation of epithelial cell proliferation. KEGG enriched many tumor associated or classical signaling pathways, including transforming growth factor-β (TGF-β) signaling pathway and vascular endothelial growth factor (VEGF) signaling pathway. The prediction showed that vascular endothelial growth factor A (VEGFA) was a direct target gene of miR-503 and it was also related to many proteins involved in fibrosis mechanism. Conclusions The expression level of PDE exosomal miR-503 is significantly higher in H group, and positively correlates with PET values, which may regulate the angiogenesis of peritoneal vessels by targeting VEGFA.     

Clinical analysis of peritoneal dialysis in the treatment of rapidly progressive glomerulonephritis

Objective To observe the clinical characteristics and prognosis of patients with rapidly progressive glomerulonephritis (RPGN) caused by lupus nephritis, antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis, or primary glomerulonephritis who were treated with peritoneal dialysis (PD) and then withdrew PD because of renal recovery. Methods Data of the above patients were retrospectively analyzed. The patients were diagnosed as RPGN and received PD therapy in Kidney Disease Center, the First Affiliated Hospital, College of Medicine, Zhejiang University from February 2009 to August 2018. The patients were divided into early withdrawal group (PD time≤183 days, n=24) and late withdrawal group (PD time＞183 day, n=24). The differences of clinical characteristics between the two groups were compared. The cumulative incidence of adverse events in both groups was analyzed using Kaplan-Meier curves. Cox proportional hazards model was used to analyze the risk factors influencing the prognosis of patients. Results Forty-eight RPGN patients were included. The median time of maintaining PD was 178(76, 378) days. Compared with the late withdrawal group, the patients in early withdrawal group had lower levels of urine volume, serum albumin and parathyroid hormone, and lower rates of gross hematuria and hypertension at the beginning of PD, and received higher rates of methylprednisolone impulse, combined immunosuppressive agents, and hemodialysis or continuous renal replacement therapy (all P＜0.05). At the time of PD withdrawal, the levels of serum creatinine, serum calcium, serum albumin and parathyroid hormone in the early withdrawal group were significantly lower than those in the late withdrawal group (all P＜0.05). The Kaplan-Meier curves showed that there was no significant difference in the cumulative survival of patients in both groups (log-rank test χ2=3.485, P=0.062). Cox regression analysis revealed serum creatinine≥209 μmol/L at the time of PD withdrawal was an independent risk factor for poor prognosis (HR=5.253，95%CI 1.757-15.702, P=0.003). Conclusions PD can be used for RPGN patients caused by lupus nephritis, ANCA-associated vasculitis and primary nephritis. Serum creatinine≥209 μmol/L at the time of PD withdrawal is an independent risk factor for poor prognosis.     

COVID-19 Among US Dialysis Patients: Risk Factors and Outcomes From a National Dialysis Provider

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二肽基肽酶4抑制剂在控制2型糖尿病透析患者代谢指标中的作用

目的：研究3种不同二肽基肽酶4（DPP-4）抑制剂对终末期肾病合并2型糖尿病患者代谢参数的影响。方法：对200例应用DPP-4抑制剂（西格列汀、维格列汀或利格列汀）治疗2型糖尿病的终末期肾病患者进行前瞻性队列研究。DPP-4抑制剂治疗12周前后评估糖化血红蛋白（HbA1c）、空腹血糖和代谢指标的变化。结果：西格列汀、维格列汀、利格列汀治疗组HbA1c水平下降无显著性差异（分别为-0.74±1.57、-0.39±1.45和-0.08±1.40，P=0.076），空腹血糖及血脂变化亦无显著差异。在血液透析患者（n=115）中，3组间HbA1c水平变化无差异。相比之下，腹膜透析患者（n=85）用西格列汀治疗12周后，HbA1c比用维格列汀和利格列汀治疗12周降低得更多（分别为-1.58±0.95，-0.46±0.98，-0.04±1.22，P=0.001）。结论：在终末期肾病患者中使用不同DPP-4抑制剂的降糖作用差异无显著性。在腹膜透析患者中，西格列汀比其他DPP-4抑制剂可使HbA1c水平降低更多。     

Comment prendre en charge une hernie abdominale en dialyse péritonéale ?

Abdominal hernias are a frequent complication in peritoneal dialysis, representing up to 60.4% of anatomical complications. Their prevalence varies between 7 and 27.5%. Established risk factors are male gender, an older age, multiparity, a low body mass index and a paramedian approach for the catheter insertion. Polykystic renal disease and the intra-peritoneal volume are controversial risk factors. The diagnosis is mainly clinical, though peritoneography imaging can be useful in difficult cases. Hernia's complications, of strangulation, incarceration, bowel occlusion and peritonitis; can be very serious, leading to technique failure and may result in death. The complication risk varies from 4 to 20% in the literature review. There are no guidelines regarding hernia's prevention or treatment. A surgical repair is recommended, by implementing a synthetic prothesis with an inguinal approach for inguinal and femoral hernias, with a simple stitch or a bioprothesis for ombilical hernias. The management of peritoneal dialysis after hernia repair is not codified. After an initial 48 h interruption, an intermittent peritoneal dialysis program using low volume seems efficient at low risk, preventing a temporary transfer to haemodialysis.     

Peritoneal dialysis improves lung function in rats with lung injury induced by shock wave

Objective To prove the efficacy of peritoneal dialysis on shock wave-induced acute lung injury of rats, and analyze its mechanisms. Methods Forty-five adult Sprague-Dawley rats were randomly divided into three groups: control group, sham operation (Sham) group and peritoneal dialysis (PD) group. Sham group and PD group did abdominal catheterization before blast injury. The 55 kg shock wave (bst-I) was used to induce lung blast injury. After one hour of blast injury, PD group was given 2.5% peritoneal dialysate 20 ml to stay abdomen, which was released 30 min posted, repeated 12 cycles. After 6 hours of peritoneal dialysis, all of the rats were sacrificed. Partial damaged tissues in lung were used to evaluate the pathomorphologic changes by HE staining, and the remnants were used to measure the lung water content. Lung function was detected by blood gas analyzer and small animal detector from the arterial blood gas. The levels of serum inflammatory factors, such as tumor necrosis factor-α (TNF-α), interleukin (IL)-1β, IL-6 and monocyte chemoattractant protein-1 (MCP-1) were tested by ELISA. Results The relative integrity of alveolar structure, interstitial edema and inflammatory cell infiltration in PD group were significantly improved than those in control group. The lung water content of PD group was significantly lower than that of control group (P＜0.05). The levels of TNF-α, IL-1β, IL-6 and MCP-1 in serum of PD group were significantly lower than those in control group (all P＜0.05). The blood oxygen saturation, oxygen partial pressure, oxygenation index, vital capacity, functional residual volume and maximum mid-expiratory flow rate in PD group were significantly higher than those in control group (all P＜0.05). Conclusions Through reducing pulmonary edema and inflammatory factors, peritoneal dialysis can improve lung function in shock wave -induced acute lung injury of rats.