Analysis of risk factors of severe hypocalcemia after total parathyroidectomy / 中华肾脏病杂志

Objective To analyze the incidence and risk factors of hypocalcemia after total parathyroidectomy without autotransplantation. Methods A total of 783 maintenance hemodialysis patients who underwent TPTX in the Second Affiliated Hospital of Nanjing Medical University from September 2008 to September 2017 were included in the study. The preoperative blood biochemical examination, preoperative iPTH, total mass of parathyroid gland (M) and postoperative iPTH and electrolyte results were collected. The incidence of severe hypocalcemia after TPTX were analyzed retrospectively. Binary logistic regression model was used to analyze the risk factors of severe hypocalcemia after TPTX. Results The age of 783 patients with TPTX was (46.90±10.78) years old, and the average dialysis age was (91.36±41.75) months. Postoperative severe hypocalcemia occurred in 235 cases (30.01％). Binary logistic regression analysis showed that higher preoperative blood iPTH (OR=7.56, 95％CI: 1.55-36.79, P=0.01), higher blood alkaline phosphatase (OR=36.71, 95％CI:14.75-91.36, P<0.01), blood phosphorus (OR=1.74, 95％CI: 1.11-2.71, P=0.02) and greater mass of resected glands (OR=1.18, 95％ CI: 1.06-1.31, P<0.01) were the risk factors for post-hypocalcemia. The higher preoperative serum calcium can reduce the risk of postoperative hypocalcemia (OR=0.02,95％CI: 0.01-0.07, P<0.01). Conclusions The incidence of hypocalcemia after TPTX treatment for SHPT is very high. Blood iPTH, alkaline phosphatase, phosphorus, and total mass of intraoperative parathyroid gland excision are the independent risk factors for severe hypocalcemia after surgery.

Uric acid increases fibronectin synthesis through upregulation of lysyl oxidase expression in rat renal tubular epithelial cells.

Urate is produced as the major end product of purine metabolism. In the last decade, the incidence of hyperuricemia increased markedly, and similar trends in the epidemiology of metabolic syndrome have been observed. Hyperuricemia is associated with renal disease, and recent studies have reported that mild hyperuricemia results in hypertension, intrarenal vascular disease, and renal injury. This has led to the hypothesis that uric acid may contribute to renal fibrosis and progressive renal disease. Our purpose was to investigate the relationship between uric acid and renal tubular injury. We applied the method of intraperitoneal injection of uric acid to generate the hyperuricemic mouse model. Compared with the saline injection group, the expression of lysyl oxidase (LOX) and fibronectin in kidneys was increased significantly in hyperuricemic groups. In vitro, uric acid significantly induced NRK-52E cells to express the ECM marker fibronectin, as well as LOX, which plays a pivotal role in ECM maturation, in a time- and dose-dependent manner. Upregulation of the urate transporter URAT1, which is located in the apical membrane of proximal tubules, sensitized the uric acid-induced fibronectin and LOX induction, while both knocking down URAT1 expression in tubular epithelial cells by RNA interference and inhibiting URAT1 function pharmacologically attenuated LOX and fibronectin expression. Furthermore, knockdown of LOX expression by a small interfering RNA strategy led to a decrease in fibronectin abundance induced by uric acid treatment. In addition, evidence of a uric acid-induced activation of the NF-kappaB signaling cascade was observed. Our findings highlight a need for carefully reevaluating our previous view on the pathological roles of hyperuricemia in the kidney and nephropathy induced by uric acid in clinical practice.

Vascular smooth muscle cells transformation induced by high phosphate enviroment in vitro / 中华肾脏病杂志

Objective To observe the steps of vascular smooth muscle cells (VSMCs) calcification induced by high phosphate enviroment in vitro. Methods VSMCs were incubated with high phosphate (2.5 mmol/L or 3.5 mmool/L) medium for different times. Expression of core binding factor α1(Cbfα1), osteopontin(OP), collagen type Ⅰ(Col Ⅰ), osteocalcin(OC) and α-smooth muscle actin (α-SMA) was investigated by Western blot, immunofluorcscencc staining and real time PCR. Mineral deposition was assessed by von Kossa aad Alizarin red staining. Ultrastructure of VSMCs calcification was observed by electron microscopy (EM). Results Up-regulated expression of osteoblast-specific transcription factor Cbfα1 in the nuclei oceured at as early as 12 hours. The protein of Col Ⅰ and OP was up-regalated when VSMCs were incubated in high phosphate medium for 3 days, and content of OC increased at the time of 6 days. When cultured in 2.5 mmol/L phosphate medium for 15 days, VSMCs lost their lineage marker α-SMA, developed granular calcium deposits. Moreover, the results of real time PCR indicated mRNA level of OP and Col Ⅰ increased at day 1, OC increased at day 5 and α-SMA level decreased at day 10, respectively. Ultrastructural analysis also confirmed the presence of collagen and matrix vesicles in the cells. Conclusion VSMCs phenotype transformation induced by high phosphate enviroment is an orchestrated, highly regulated process.

High glucose induces renal epithelial-mesenchymal transition through transforming growth factor β1-Smad signaling pathway / 中华肾脏病杂志

Objective To investigate the effect of high glucose on renal tubular epithelial-mesenchymal transition,and to analyze the relationship between high glucose and transforming growth factor β1(TGF-β1)and the mechanism of renal interstitial fibrosis. Methods HKC and Smad7-overexpression HKC cells were grown in DMEM/F12 medium containing 5%～10%newborn calf serum.They were cultured for 16 h in free serum medium after 80%cells were adhered onto the surface of the flask.Afterwards,they were stimulated by high glucose(glucose concentration:25 mmol/L and 50 mmol/L).The expression of α-SMA,E-cadherin and fibronectin was detected by Western blot while the supernatant level of TGF-β1 was detected by ELISA.Cell motility and migration was evaluated using Boyden chamber motogenicity assay. Results In HKC induced by high glucose,the expression of α-SMA and fibronectin protein was highly upregulated while the expression of E-cadhefin protein was down-regulated.The expression of TGF-β1was up-regulated in a dose-dependent manner.These above-mentioned effects could be obviously inhibited by anti-TGF-β1 antibody.The protein expression of α-SMA,fibronectin and E-cadherin had no obvious change in Smad7-overexpression HKC induced by high glucose.HKC exhibited enhanced motility and invasive capacity in high glucose groups,compared to that in control group.Migrated cell counting was(12.4±3.7)and(18.6±4.4)cell/HP in 25 and 50 mmol/L glucose groups respectively. Conclusion High glucose may induce renal tubular epithelialmesenchymal transition through TGF-β1 pathway,which can be inhibited by blocking the Smad signal pathway.

High-glucose up-regulates the expression of fibronectin mediated by integrin-linked kinase in renal tubular epithelial cells / 中华肾脏病杂志

Objective To investigate the relationship between high-glucose-induced fibronectin(FN) expression and up-regulation of integrin-linked kinase(ILK) in human kidney tubular epithelial cells (HKC) and kidney of CD-1 mice. Methods Cultured human kidney tubular epithelial cells and streptozotocin (STZ)-indueed diabetic model of CD-1 mice were enrolled in this study.Western blot was used to detect the expression of FN and ILK.The kinase dead ILK plasmid (pCMV-kdlLK) were transferred to HKC. Results Four weeks after injection of STZ,CD-1 mice had higher blood glucose level as compared to the control [(20.3±2.7) mmol/L vs (6.1±1.4) mmol/L,P＜0.01].Meanwhile,expression of FN and ILK was significantly increased in diabetic mice as compared to the control (P＜0.01).There was positive correlation between the expression of FN and ILK (r=0.899,P＜0.01).High-glucose could up-regulate FN and ILK expression in cultured HKC in a time- and dose-dependent manner.Blockage of ILK activation by pCMV-kdILK abrogated high-glucose-incuced FN expression in HKC. Conclusions Highglucose can induce FN expression through up-regulating ILK expression.Blockage of ILK activation abrogates this effect.