Cardiorenal Effects of Peritoneal Dialysis in the 5/6Nx Uremic Rat Model
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ABSTRACT: In this study we compare transcriptomic changes in the kidney and left ventricle in response to peritoneal dialyisis exchanges performed 3x per day for 8 days beginning 6 weeks after 5/6 nephrectomy or sham surgery in 10 week old male Sprague Dawley rats. .
Project description:Rats (Sprague-Dawley) were allotted to subtotal nephrectomy (SNX) or sham (sham) operation. After 2 and 12 weeks the experiment was terminated. RNA was isolated from small pieces of the hearts.
Project description:Peritoneal dialysis (PD) is associated with increased cardiovascular (CV) risk. Studies of PD-related CV pathology in animal models are lacking despite the clinical importance. Here we introduce the phenotypic evaluation of a rat model of cardiorenal syndrome in response to chronic PD, complemented by a rich transcriptomic dataset detailing chronic PD-induced changes in left ventricle (LV) and kidney tissues. This study aims to determine how PD alters CV parameters and risk factors while identifying pathways for potential therapeutic targets. Sprague Dawley rats underwent Sham or 5/6 nephrectomy (5/6Nx) at 10 weeks of age. Six weeks later an abdominal dialysis catheter was placed in all rats before random assignment to Control or PD (3 daily 1-h exchanges) groups for 8 days. Renal and LV pathology and transcriptomic analysis was performed. The PD regimen reduced circulating levels of BUN in 5/6Nx, indicating dialysis efficacy. PD did not alter blood pressure or cardiovascular function in Sham or 5/6Nx rats, though it attenuated cardiac hypertrophy. Importantly PD increased serum triglycerides in 5/6Nx rats. Furthermore, transcriptomic analysis revealed that PD induced numerous changed transcripts involved with inflammatory pathways, including neutrophil activation and atherosclerosis signaling. We have adapted a uremic rat model of chronic PD. Chronic PD induced transcriptomic changes related to inflammatory signaling that occur independent of 5/6Nx and augmented circulating triglycerides and predicted atherosclerosis signaling in 5/6Nx LV tissues. The changes are indicative of increased CV risk due to PD and highlight several pathways for potential therapeutic targets.
Project description:BackgroundPeritoneal dialysis (PD) is increasingly used for long-term management of Cardiorenal Syndrome (CRS). We compared outcomes in incident PD patients according to their baseline heart failure status.MethodsThis retrospective cohort study evaluated all-cause and cardiovascular mortality in incident PD patients with different heart failure status (non-CRS, acute heart failure [AHF], type II CRS, type IV CRS) who started PD between 2006 and 2016 in the Peking University Third Hospital.ResultsOf 748 patients included in the study, there were 466 (62.3%), 214 (28.6%), 27 (3.6%), and 41 (5.5%) patients in the non-CRS, AHF, type II CRS and type IV CRS groups, respectively. Patients with CRS were older (p<0.001), with more diabetes mellitus (p<0.001), coronary heart history (p<0.001), higher estimated glomerular filtration rate (eGFR) (p<0.001), lower serum creatinine (p<0.001) and phosphorus levels (p = 0.003) compared to non-CRS patients. Respective all-cause survival rates for patients with non-CRS, AHF, type II CRS and type IV CRS were 90.6%, 87.1%, 85.2% and 84.8% at 1 year, and 63.1%, 47.7%, 27.3% and 35.1% at 5 years (p<0.001). The corresponding figures for cardiovascular survival were 93%, 92%, 84% and 81% at 1 year, and 67%, 59%, 55% and 54% at 5 years (p<0.001). However, after adjusting for confounding factors, the presence of CRS was not independently associated with all-cause mortality whereas type IV CRS (HR 2.10, 95% CI 1.03-4.28, p = 0.04) was associated with higher cardiovascular mortality as compared to without CRS.ConclusionIncident PD patients with different types of CRS had higher rates of both all-cause and cardiovascular mortality compared with patients without CRS. However, these observed adverse outcomes may be related to associated older age and higher prevalence of comorbidities, rather than CRS per se, except for type IV CRS, treatment strategies to reduce high cardiovascular CVD mortality may needed.
Project description:A system for sorbent-assisted peritoneal dialysis (SAPD) has been developed that continuously recirculates dialysate via a tidal mode using a single-lumen peritoneal catheter with the regeneration of spent dialysate by means of sorbents. SAPD treatment may improve plasma clearance by the maintenance of a high plasma-to-dialysate concentration gradient and by increasing the mass transfer area coefficient (MTAC) of solutes. The system is designed for daily 8-hr treatment (12 kg, nighttime system). A wearable system (2.3 kg, daytime system) may further enhance the clearance of phosphate and organic waste solutes during the day. Uremic pigs (n = 3) were treated with the day- (n = 3) and nighttime system (n = 15) for 4-8 hr per treatment. Plasma clearance (Cl), MTAC, and total mass transport (MT) of urea, creatinine, phosphate, and potassium were compared with a static dwell (n = 28). Cl, MTAC, and MT of urea, creatinine, phosphate, and potassium were low in the pig as compared to humans due to the pig's low peritoneal transport status and could be enhanced only to a limited extent by SAPD treatment compared with a static dwell (nighttime system: Cl urea: ×1.5 (p = .029), Cl creatinine: ×1.7 (p = .054), Cl phosphate: ×1.5 (p = .158), Cl potassium: ×1.6 (p = .011); daytime system: Cl creatinine: ×2.7 (p = .040), Cl phosphate: ×2.2 (p = .039)). Sorbent-assisted peritoneal dialysis treatment in a uremic pig model is safe and enhances small solute clearance as compared to a static dwell. Future studies in humans or animal species with higher peritoneal transport should elucidate whether our SAPD system enhances clearance to a clinically relevant extent as compared to conventional PD.
Project description:BackgroundA long-term of peritoneal dialysis (PD) using a hypertonic PD solution (PDS) leads to patient's peritoneal membrane (PM) injury, resulting in ultrafiltration failure (UFF) and PD drop-out. Our previous study shows that PD effluent-derived mesenchymal stromal cells (pMSCs) prevent the PM injury in normal rats after repeated exposure of the peritoneal cavity to a PDS. This study was designed to compare the cytoprotection between pMSCs and umbilical cord-derived MSCs (UC-MSCs) in the treatment of both PM and kidney injury in uremic rats with chronic PD.Methods5/6 nephrectomized (5/6Nx) Sprague Dawley rats were intraperitoneally (IP) injected Dianeal (4.25% dextrose, 10 mL/rat/day) and were treated with pMSCs or umbilical cord (UC)-MSCs (approximately 2 × 106/rat/week, IP). Ultrafiltration was determined by IP injection of 30 mL of Dianeal (4.25% dextrose) with 1.5-h dewell time, and kidney failure by serum creatinine (SCr) and blood urea nitrogen (BUN). The structure of the PM and kidneys was assessed using histology. Gene expression was examined using quantitative reverse transcription PCR, and protein levels using flow cytometric and Western blot analyses.ResultsWe showed a slight difference in the morphology between pMSCs and UC-MSCs in plastic dishes, and significantly higher expression levels of stemness-related genes (NANOG, OCT4, SOX2, CCNA2, RAD21, and EXO1) and MSCs surface markers (CD29, CD44, CD90 and CD105) in UC-MSCs than those in pMSCs, but no difference in the differentiation to chondrocytes, osteocytes or adipocytes. pMSC treatment was more effective than UC-MSCs in the protection of the MP and remnant kidneys in 5/6Nx rats from PDS-induced injury, which was associated with higher resistance of pMSCs than UC-MSCs to uremic toxins in culture, and more reduction of peritoneal mesothelial cell death by the secretome from pMSCs than from UC-MSCs in response to PDS exposure. The secretome from both pMSCs and UC-MSCs similarly inactivated NOS2 in activated THP1 cells.ConclusionsAs compared to UC-MSCs, pMSCs may more potently prevent PDS-induced PM and remnant kidney injury in this uremic rat model of chronic PD, suggesting that autotransplantation of ex vivo-expanded pMSCs may become a promising therapy for UFF and deterioration of remnant kidney function in PD patients.
Project description:Adenine and nephrectomy can be used to establish models of uremic cardiomyopathy in rodents. Although these two approaches cause similar phenotypes of heart, adenine may directly act on cardiomyocytes and lead to different molecular changes from nephrectomy-induced uremic cardiomyopathy. Transcriptome analysis on left ventricles showed 789 upregulated and 345 downregulated genes in mice with nephrectomy-induced uremic cardiomyopathy compared to control mice, while 432 upregulated and 155 downregulated genes in mice with adenine diet-induced uremic cardiomyopathy compared to control mice. Functional analysis revealed that these DEGs were involved in pathways related to immune inflammation, metabolic responses, and synaptic transmission. Further analysis demonstrated that nephrectomy-induced uremic cardiomyopathy has enhanced cell cycle process/extracellular matrix remodeling and suppressed fatty acid metabolism, whereas adenine diet-induced uremic cardiomyopathy only exhibits increased inflammatory response/extracellular matrix remodeling. Compared with nephrectomy-induced uremic cardiomyopathy, adenine diet-induced uremic cardiomyopathy showed improved oxidative phosphorylation, aerobic electron transport chain, and tricarboxylic acid cycle, and suppressed cell cycle-related process, indicating that adenine and its derivates may affect the process of chronic kidney induced cardiac changes.
Project description:We report the changes in left ventricle mRNA and miRNA abundance in response to 5/6 nephrectomy surgery This SuperSeries is composed of the SubSeries listed below.