ABSTRACT
Objective To explore the potential mechanisms of low density lipoprotein receptor (LDLr) in high glucose peritoneal dialysis solution (PDS)-induced peritoneal fibrosis.Methods Human peritoneal mesothelial cells (PMCs) were applied.In pre-experiment,human PMCs were cultured with 1.5％ PDS,2.5％ PDS and 4.25％ PDS for 6 h,12 h and 24 h.4.25％ mannitol was used as high osmotic pressure control.In formal experiment,PMCs were divided into the control group (treated with phosphate buffer saline) and the high glucose PDS group (treated with 4.25％ PDS for 24 h).Morphological change of PMCs was observed by inverted microscope.The mRNA and protein expressions of extracellular matrix proteins such as α-smooth muscle actin (α-SMA),fibroblast specific protein-1 (FSP-1) and collagen Ⅰ in PMCs were respectively measured by real-time PCR and Western blotting.The lipid accumulation was observed by oil red O staining and filipin staining,and the content of intracellular cholesterol ester was detected by high-performance liquid chromatography.The co-expression of the sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP) with golgin was observed with immunofluorescent staining.The mRNA and protein expressions of LDLr,SREBP-2 and SCAP were respectively detected by real-time PCR and Western blotting.The mRNA and protein expressions of mammalian target of rapamycin (mTOR),eukaryotic initiation factor 4E-binding protein 1 (4EBP1),and p70 S6 kinase (S6K1) were respectively detected by real-time PCR and Western blotting.Results (1) Compared with the 1.50％ PDS stimulation,4.25％ PDS for 24 h intervention significantly increased the expression of LDLr in PMCs (P ＜ 0.05),and high osmotic pressure control at 6 h,12 h and 24 h had no statistical difference (P ＞ 0.05).(2) Compared with those in the control group,in high glucose PDS group PMCs showed notable elongation consistent with the morphology of myofibroblasts,the expressions of α-SMA,FSP-1 and collagen Ⅰ were increased (all P ＜ 0.05),and the intracellular cholesterol were enhanced (P ＜ 0.05).Meanwhile,the co-expression of SCAP with golgin was enhanced,and the mRNA and protein expressions of LDLr,SREBP-2 and SCAP were up-regulated in high glucose PDS group (all P ＜ 0.05).Further,the mRNA and protein phosphorylation of mTOR,4EBP1 and S6K1 were increased (all P ＜ 0.05).Conclusions The disruption of LDLr feedback regulation is involved in high glucose PDS-mediated cholesterol accumulation in PMCs by mammalian target of rapamycin complex 1 (mTORC1) pathway,which promotes the accumulation of extracellular matrix and peritoneal fibrosis.
ABSTRACT
Objective To investigate clinical feature,therapy and prognosis of 63 (rhabdomyolysis,RM) patients.Methods Retrospective analysis was used for the 63 patients who were from Nanjing from Janurary 2010 to August of 2016.Results Clinical history:the pathogenic factors mainly contained eating lobster,excessive exercise,lipid-lowering drugs,and minority patients were induced by infection,cardiac defibrillation,alcohol,and unexplained factors.Clinical features:most patients presented different degree of muscle soreness and weakness,and urine color of soy sauce;and few patients manifested a fever,respiratory distress and sound hoarse.Of which 11 RM patients concurrent acute kidney injury (AKI),there was no obvious bias of pathogenic factors among 11 patients.Clinical examination:the data was described by median,including creatine kinase 6 400 U/L,aspartate aminotransferase 399 U/L,lactate dehydrogenase 816 U/L,α-hydroxybutyric acid 445 U/L,and myoglobin 1 200 ng/ml.Creatine kinase and myoglobin were selected to measure muscle injure,there was no significant difference among the groups (P ＞ 0.05).Renal tubular injury index such as urincosmotic pressure,urine retinol-binding protein and N-acetyl-beta-D-glucosaminidase (NAG) enzyme,the abnormal percentage were 62.5％,50％,and 47.6％.Treatment:patients without complications through resting,water infusion,urine alkalization,were cured;and 11 cases of patients with AKI,1 case gave up,5 cases underwent hemodialysis,and 5 cases underwent conservative treatment,creatinine decreased to the basic level.Conclusions Among different pathogenic factors of RM,there were no obvious differences in clinlcal symptom,muscle damage degree,and whether the coexistence of AKI and prognosis.The understanding of RM,early diagnosis and treatment would prevent AKI and improve the prognosis.