KLF2 enhancer variant rs4808485 increases lupus risk by modulating inflammasome machinery and cellular homoeostasis.

OBJECTIVE: A recent genome-wide association study linked KLF2 as a novel Asian-specific locus for systemic lupus erythematosus (SLE) susceptibility. However, the underlying causal functional variant(s), cognate target gene(s) and genetic mechanisms associated with SLE risk are unknown. METHODS: We used bioinformatics to prioritise likely functional variants and validated the best candidate with diverse experimental techniques, including genome editing. Gene expression was compared between healthy controls (HCs) and patients with SLE with or without lupus nephritis (LN+, LN-). RESULTS: Through bioinformatics and expression quantitative trait locus analyses, we prioritised rs4808485 in active chromatin, predicted to modulate KLF2 expression. Luciferase reporter assays and chromatin immunoprecipitation-qPCR demonstrated differential allele-specific enhancer activity and binding of active histone marks (H3K27ac, H3K4me3 and H3K4me1), Pol II, CTCF, P300 and the transcription factor PARP1. Chromosome conformation capture-qPCR revealed long-range chromatin interactions between rs4808485 and the KLF2 promoter. These were directly validated by CRISPR-based genetic and epigenetic editing in Jurkat and lymphoblastoid cells. Deleting the rs4808485 enhancer in Jurkat (KO) cells disrupted NLRP3 inflammasome machinery by reducing KLF2 and increasing CASPASE1, IL-1ß and GSDMD levels. Knockout cells also exhibited higher proliferation and cell-cycle progression than wild type. RNA-seq validated interplay between KLF2 and inflammasome machinery in HC, LN+ and LN-. CONCLUSIONS: We demonstrate how rs4808485 modulates the inflammasome and cellular homoeostasis through regulating KLF2 expression. This establishes mechanistic connections between rs4808485 and SLE susceptibility.

Plasma soluble tumor necrosis factor receptor I as a biomarker of lupus nephritis and disease activity in systemic lupus erythematosus patients.

OBJECTIVES: The goal of our study was to evaluate the potential role of sTNF-RI as a biomarker of renal involvement in SLE patients and active SLE. METHODS: The study sample consisted of two cohorts. The discovery cohort included 16 SLE patients without renal involvement (non-LN), 60 lupus nephritis (LN) patients and 21 healthy controls (HCs) and the replication cohort included 18 SLE non-LN patients, 116 LN patients and 36 HCs. RESULTS: The sTNF-RI levels differed significantly in the discovery cohort. The plasma sTNF-RI levels were higher in LN patients than in non-LN patients (p = .009) and HCs (p = 4 × 10-6). Plasma sTNF-RI levels were significantly higher in non-LN patients than in HCs (p = .03). The finding was confirmed in independent replication cohort (LNs vs. non-LN, p = 4.053 × 10-7; LNs vs. HCs, p = 2.395 × 10-18; non-LN vs. HCs, p = 2.51 × 10-4). The plasma sTNF-RI levels were associated with disease activity, renal function in SLE patients and urine protein in LN patients. The multivariate analysis revealed that high sTNF-RI was an independent risk factor for renal involvement. The multivariate logistic regression results suggested that high TNF-RI, high systolic blood pressure, high serum creatinine, low C4 and positive anti-dsDNA were independent risks of active SLE patients. A nomogram was constructed based on the results of multivariate logistic regression analysis and it was practical in predicting the risk of the active SLE patients. Immunohistochemistry suggested that the expression of TNF-RI in the kidney was increased. CONCLUSIONS: Plasma sTNF-RI might be a good biomarker of renal involvement and disease activity in SLE patients.

PRDX6 AS1 gene polymorphisms and SLE susceptibility in Chinese populations.

Background: Systemic lupus erythematosus (SLE) is a complex, multisystem autoimmune disease that is characterized by the production of autoantibodies. Although accumulated evidence suggests that the dysregulation of long non-coding RNAs (lncRNAs) is involved in the pathogenesis of SLE, the genetic contributions of lncRNA coding genes to SLE susceptibility remain largely unknown. Here, we aimed to provide more evidence for the role of lncRNA coding genes to SLE susceptibility. Methods: The genetic association analysis was first adopted from the previous genome-wide association studies (GWAS) and was then validated in an independent cohort. PRDX6-AS1 is located at chr1:173204199-173446294. It spans a region of approximately 240 kb, and 297 single nucleotide polymorphisms (SNPs) were covered by the previous GWAS. Differential expression at the mRNA level was analyzed based on the ArrayExpress Archive database. Results: A total of 33 SNPs were associated with SLE susceptibility, with a P<1.68×10-4. The strongest association signal was detected at rs844649 (P=2.12×10-6), according to the previous GWAS. Combining the results from the GWAS Chinese cohort and our replication cohort, we pursued a meta-analysis approach and found a pronounced genetic association between PRDX6-AS1 rs844649 and SLE susceptibility (pmeta=1.24×10-13, OR 1.50, 95% CI: 1.34-1.67). The mRNA expression of PRDX6 was elevated in peripheral blood cells, peripheral blood mononuclear cells (PBMCs), and multiple cell subpopulations, such as B cells, CD4+ T cells, CD3+ cells, and monocytes in patients with SLE. The PRDX6 protein expression level was also increased in patients with SLE compared with healthy donors. Conclusion: Our study provides new evidence that variants located in lncRNA coding genes are associated with SLE susceptibility.

The comprehensive analysis of clinical trials registration for IgA nephropathy therapy on ClinicalTrials.gov.

OBJECTIVES: IgA Nephropathy (IgAN) is common chronic kidney disease with a high incidence. This study aims to analyze comprehensively therapeutic clinical trials for IgAN registered on ClinicalTrials.gov. METHODS: Therapeutic trials for IgAN registered on ClinicalTrials.gov. up to 15 August 2021 were obtained. The general characteristics, features of experimental design, treatment strategies, and some main inclusion criteria and outcome measures were accessed. RESULTS: A total of 104 therapeutic clinical trials for IgAN were extracted on ClinicalTrials.gov up to 15 August 2021. Most of these trials explored the treatment for primary IgAN confirmed by renal biopsy in adults. Only 9% of all selected trials had results. Forty-five percent of trials recruited 50 or fewer participants, and 73% were adults or older adults. 99% of trials were interventional studies, and of all the interventional trials, 70% of trials were randomized, and 68% exercised a parallel assignment of intervention model. Immunosuppression was the most studied for the treatment of IgAN. Moreover, many novel agents had been increasingly studied in recent years. Furthermore, the inclusion criteria and primary outcome measures in these trials were diverse, and the level of proteinuria and change of proteinuria levels were the most used as inclusion criteria and primary outcome, respectively. CONCLUSIONS: The majority of therapeutic trials for IgAN were randomized, none masking and parallel-assignment interventional studies, primarily recruiting adult patients as research subjects. These trials had relatively small sample sizes and short observation. Thus, more large-scale, multicenter, and randomized controlled trials are still needed to improve the management for IgAN.

Association of the PINX1 Variant rs6984094, Which Lengthens Telomeres, with Systemic Lupus Erythematosus Susceptibility in Chinese Populations.

A recent genome-wide association study (GWAS) of Asian ancestry reported that single nucleotide polymorphism (SNP) in TERT (telomerase reverse transcriptase) was associated with systemic lupus erythematosus (SLE). TERT has a critical role in maintaining the chromosomal stability and the length of telomere. Given that only a small portion of the genetic heritability of SLE has been explained so far, we aimed to identify novel loci in telomere-related genes responsible for SLE susceptibility in Chinese populations. We performed a comprehensive genetic association analysis of SLE with telomere-related genes. To identify functional significance, we analyzed the publicly available HaploReg v4.1 and RegulomeDB databases. Differential gene expression analysis was also performed using ArrayExpress. A novel signal of PINX1 rs6984094 was identified (P discovery = 4.13 × 10-2, OR = 0.58, 95% CI 0.35-0.98) and successfully replicated (P replication = 5.73 × 10-3, OR = 0.45, 95% CI 0.26-0.81). Multiple layers of functional analysis suggested that the PINX1 rs6984094 risk T allele exhibited increased nuclear protein binding. We also observed an increased expression of PINX1 mRNA in peripheral blood mononuclear cells from SLE patients compared with healthy controls. Overall, we observed a novel genetic association between PINX1 (encodes the PinX1 protein, an inhibitory telomerase enzyme that lengthens telomeres) and SLE susceptibility in Chinese populations.

The ZNF76 rs10947540 polymorphism associated with systemic lupus erythematosus risk in Chinese populations.

Systemic lupus erythematosus (SLE) is a typical autoimmune disease with a strong genetic disposition. Genetic studies have revealed that single-nucleotide polymorphisms (SNPs) in zinc finger protein (ZNF)-coding genes are associated with susceptibility to autoimmune diseases, including SLE. The objective of the current study was to evaluate the correlation between ZNF76 gene polymorphisms and SLE risk in Chinese populations. A total of 2801 individuals (1493 cases and 1308 controls) of Chinese Han origin were included in this two-stage genetic association study. The expression of ZNF76 was evaluated, and integrated bioinformatic analysis was also conducted. The results showed that 28 SNPs were associated with SLE susceptibility in the GWAS cohort, and the association of rs10947540 was successfully replicated in the independent replication cohort (Preplication = 1.60 × 10-2, OR 1.19, 95% CI 1.03-1.37). After meta-analysis, the association between rs10947540 and SLE was pronounced (Pmeta = 9.62 × 10-6, OR 1.29, 95% CI 1.15-1.44). Stratified analysis suggested that ZNF76 rs10947540 C carriers were more likely to develop relatively high levels of serum creatinine (Scr) than noncarriers (CC + CT vs. TT, p = 9.94 × 10-4). The bioinformatic analysis revealed that ZNF76 rs10947540 was annotated as an eQTL and that rs10947540 was correlated with decreased expression of ZNF76. Remarkably, significantly reduced expression of ZNF76 was confirmed by expression data from both our laboratory and an array-based expression database. Taken together, these results suggest that ZNF76 rs10947540 is a possible susceptibility factor associated with SLE susceptibility. The mechanism underlying the relationship between ZNF76 and SLE pathogenesis still requires further investigation.

Albumin-to-globulin ratio (AGR) as a potential marker of predicting lupus nephritis in Chinese patients with systemic lupus erythematosus.

OBJECTIVES: To evaluate a potential role of albumin-to-globulin ratio (AGR) in the development of lupus nephritis (LN) and determine the potential to use AGR as a marker for future LN in systemic lupus erythematosus (SLE) patients. METHODS: 194 newly diagnosed SLE patients without renal impairment were followed. The clinical data were collected and analyzed at the time of initial diagnosis of SLE and the end of follow-up. We compared baseline characteristics between those who did or did not develop LN on follow-up. Univariate and multivariate Cox hazard analysis were used to identify predictors of lupus nephritis. RESULTS: Among the 194 newly diagnosed SLE patients without renal impairment, 26 (13.40%) patients were diagnosed with LN during a median follow-up of 53.87 months. On univariate Cox analysis, patients with the history of alopecia, higher SBP, lower AGR, lower CRP, lower C3, lower C4, higher anti-dsDNA Ab, presence of ANA homogeneous patterns or higher SLEDAI had an increased probability of developing LN. In a multivariate model, the history of alopecia (adjust hazard ratio, aHR = 3.614, 95%CI 1.365-9.571 P = 0.010), lower AGR (aHR = 6.968, 95%CI 1.873-25.919, P = 0.004), lower CRP (aHR = 4.230, 95%CI 1.591-11.247, P = 0.004) and higher level of anti-dsDNA (aHR = 2.675, 95%CI 1.008-7.093, P = 0.048) were independently associated with an increased risk of developing LN after adjusting for covariates. CONCLUSION: Our findings indicated that SLE patients with low AGR, low CRP, high anti-dsDNA and the history of alopecia were more likely to develop LN in the course of SLE. AGR shown the greatest hazard for developing LN among them, it may be a strong predictor.

SCUBE3 Is Likely a Susceptibility Gene for Systemic Lupus Erythematosus for Chinese Populations.

BACKGROUND: Systemic lupus erythematosus (SLE) is a complex autoimmune disease with strong genetic disposition with more than 100 susceptibility genes identified until now. However, our knowledge on SLE genetic background is still limited. The present study was aimed at evaluating the role of single nucleotide polymorphisms (SNPs) in SCUBE3, a TGF-ß signaling activator, with SLE susceptibility in Chinese populations. METHODS: A total of 2801 individuals (490 cases and 493 controls from GWAS cohort and 1003 cases and 815 controls from our cohort) were enrolled, and SNPs located 10 kb up- and downstream of SCUBE3 (chr6:35182190-35218609) were included in the genetic association study. Multiple layers of bioinformatics were conducted, and the levels of SCUBE3 expression were confirmed. RESULTS: Of the 31 SNPs in SCUBE3 tested, 24 SNPs were significantly associated with SLE at p ≤ 0.05. The top locus was rs1888822 with p = 8.74∗10-6 in the discovery cohort and was confirmed by the replication cohort with p = 0.012. Additionally, the levels of SCUBE3 mRNA expression were significantly lower in patients with SLE comparing with healthy controls (p = 4.28∗10-4). Further expression data from ArrayExpress showed that the expression of SCUBE3 was also lower in CD3+ T cells and B cells from patients with SLE. CONCLUSIONS: Our research revealed that variants in SCUBE3, which encode SCUBE3 as a TGF-ß signaling activator, can be considered as a new genetic susceptibility factor for systemic lupus erythematosus. And the reduced mRNA expression of SCUBE3 was first reported in patients with SLE.

Single Nucleotide Polymorphisms in PPARD Associated with Systemic Lupus Erythematosus in Chinese Populations.

BACKGROUND: Systemic lupus erythematosus (SLE) is a multifactorial autoimmune disease characterized by apoptotic clearance deficiency provoking autoimmune responses and leading to multiple organ damage. PPAR-δ, encoded by the PPARD gene, was induced in macrophages promoting the timely disposal of apoptotic cells. Biological studies had provided solid foundation of PPARD involvement in SLE; it is worthwhile to further explore the genetic contribution of PPARD to SLE. METHODS: We performed a discovery-replication genetic association study. The discovery study was based on previous reported GWAS data. And the replication study was conducted in 1003 SLE patients and 815 healthy controls from Henan, Middle East of China. Further, we analyzed the eQTL effect to identify possible functional significance. RESULTS: In the genetic association analysis, we observed significant association between the risk C allele of rs4713853 (p = 0.03, OR 1.167, 95% CI 1.015-1.341) and increased SLE susceptibility. Moreover, individuals with the risk C allele were associated with lower expression of PPARD and DEF6. Our clinical analysis showed that SLE patients with the risk C allele of rs4713853 were more likely to present a higher proportion of anti-Sm antibody presence (CC+CT vs. TT, 20.0% vs. 14.2%, p = 0.039) and higher level of Scr (median inter quarter range CC+CT vs. TT, 56 48-71 vs. 54 46-64 µmol/L, p = 0.002). CONCLUSIONS: In conclusion, our study identified a novel association between PPARD rs4713853 and SLE susceptibility in Chinese populations. By integrating multiple layers of analysis, we suggested that PPARD might be a main candidate in the pathogenesis of SLE.

Impact of antimalarial (AM) on serum lipids in systemic lupus erythematosus (SLE) patients: A systematic review and meta-analysis.

BACKGROUND: Dyslipidemia is a common disorder in systemic lupus erythematosus (SLE) patients. It is still inconclusive whether antimalarial drugs could affect the serum lipids in SLE patients, therefore we conducted a systematic review and meta-analysis of available data to address this issue. METHODS: We comprehensively searched the databases of PubMed, EMBASE and Cochrane Library from date of inception to Sep 2018 for both randomized controlled trials (RCTs) and observational studies. Review Manager 5.3 software was used for analysis. We performed meta-analysis using random-effects model and weighted the mean difference (WMD) and its 95% confidence interval (CI). The Q test was used to assess the presence of heterogeneity and the I index was used to quantify the extent of heterogeneity. RESULTS: In total, 8 studies met our selection criteria including 2 RCTs, 2 cohort studies, and 4 case-control studies. There were 717 patients (336 patients in CQ (chloroquine) or HCQ (hydroxychloroquine) group, and 381 patients in control group (SLE patients without the therapy of AM)). Compared with the control group, TC, TG, LDL-C, VLDL-C were associated with a significant decrease, respectively (WMD = -21.40 mg/dL, 95% CI -27.62 to -15.18, P < .00001), (WMD = -29.07 mg/dL, 95% CI -45.28 to -12.86, P = .0004), (WMD = -16.25 mg/dL, 95% CI -28.82 to -3.68, P = .01), (WMD = -6.41 mg/dL, 95% CI -12.39 to 0.44, P = .04), however the change of HDL-C did not reach statistically significance (WMD = 4.42 mg/dL, 95% CI -1.21 to 10.06, P = .12). CONCLUSIONS: CQ or HCQ can infect the serum lipids in SLE patients. However, these results should be interpreted with cautions since lacking sufficient RCTs.

Roles of miR-497 and its potential signaling pathway in diseases and with vascular endothelial growth factor.

MicroRNA (miRNA) is a class of small endogenous non-coding RNAs that are ∼ 22 nucleotides in length and can have structural, enzymatic and post-transcriptional regulators of gene expression targeting mRNA for translational repression and/or degradation. miR-497 is high on the list of noncoding, small, regulatory RNAs that plays important roles in the pathogenesis of some diseases and takes part in some signaling pathways in some diseases, but many questions await answers. Vascular endothelial growth factor (VEGF) is a notable chemokine that plays critical roles in angiogenesis and vasculogenesis. There might be an association between miRNA-497 and VEGF. This review was performed to sum up the roles of miR-497 and its potential signaling pathway in diseases and with VEGF.

Soluble Tie2 fusion protein decreases peritoneal angiogenesis in uremic rats.

Angiogenesis is considered to be one of the most common mechanisms leading to ultrafiltration failure (UFF) in long-term peritoneal dialysis (PD) patients. The angiopoietin (Ang)/Tie system was found to play a role in the initiation of pathological neoangiogenesis and is also involved in peritoneal angiogenesis caused by peritoneal fluid. This aim of this study was to investigate the effects of the soluble Tie2 fusion protein (sTie2/Fc) on peritoneal angiogenesis in PD-treated uremic rats. The rats were divided into 6 groups: normal, sham surgery, uremic rats without PD, uremic PD-treated rats, uremic rats treated with PD and sTie2/Fc (0.25 µg/100 g) and uremic rats treated with PD and sTie2/Fc (0.5 µg/100 g). PD rats were treated once a day for 28 days prior to testing. Real-time polymerase chain reaction (RT-PCR) or tissue immunohistochemical staining was used to detect Ang-2 mRNA or protein expression in the peritoneal tissues of each group. The microvessel density (MVD) of the peritoneum was detected and quantified by immunohistochemical staining using the anti-CD34 antibody. Compared with the control group, Ang-2 mRNA and protein expression was significantly upregulated in the uremic and PD groups (P<0.05). MVD in the experimental group increased compared with the control group. sTie2/Fc treatment decreased the levels of Ang-2 mRNA and protein expression (P<0.05) in a dose-dependent manner and decreased PD-induced MVD in the peritoneum. In conclusion, angiogenesis of the peritoneum induced by PD was inhibited using sTie2/Fc in a uremic rat model.

Clinical and prognostic implications of serum uric acid levels on IgA nephropathy: a cohort study of 348 cases with a mean 5-year follow-up.

AIM: To assess the prognostic implications of serum uric acid levels on patients with IgA nephropathy in a longitudinal 8-year follow-up study and to identify an association between serum uric acid levels and the clinical and pathological phenotypes of IgA nephropathy. SUBJECTS AND METHODS: We reviewed the files of all consecutive patients with IgA nephropathy treated at our hospital between 2001 and 2009. Analyses were performed to investigate the association between the level of serum uric acid and both clinical and pathological phenotypes of IgA nephropathy. Prognosis was assessed based on follow-up data. RESULTS: At the same glomerular filtration rate (GFR), there was no significant difference in the levels of 24 hours proteinuria, blood urea nitrogen (BUN), and serum creatinine between the two groups with different levels of serum uric acid (p > 0.05). The prevalence of glomerular sclerosis as well as the scores of tubulointerstitial and vascular injury was greater in patients with high serum uric acid levels compared to patients with normal levels of serum uric acid (p < 0.05). At the end of the follow-up period, patients with high serum uric acid levels had a higher prevalence of reduced GFR and end stage renal disease (ESRD) than those with normal serum uric acid levels (40.82 vs. 15.70% and 64.71 vs. 35.00%, respectively; p < 0.05). CONCLUSIONS: The serum uric acid level in patients with IgA nephropathy affects the pathophysiology and prognosis of the disease. We also identified a correlation between hyperuricemia and a higher risk of renal end points.

[The effects of cyclooxygenase-2 inhibitors on peritoneal lymphangiogenesis and peritoneal function in uremic rats].

OBJECTIVE: To investigate the effects of cyclooxygenase-2 (COX-2) inhibitor on peritoneal lymphangiogenesis and peritoneum function in uremic rat. METHODS: Uremic rats treated by peritoneal dialysis were intragastric administration celecoxib.Structures of peritoneum, peritoneal function, peritoneal lymphatic vessel density (LVD) were detected in every group. The mRNA of vascular endothelial growth factor-C (VEGF-C), lymphatic vessel endothelial hyaluronan receptor-1(LYVE-1) and COX-2 were tested by RT-PCR. The protein expressions of LYVE-1,VEGF-C, COX-2 were tested by western blot. RESULTS: With the extension of the duration of dialysis, the peritoneum thickness was increasing, inflammatory cell infiltrated obviously, ultrafiltration volume decreased significantly. But the celecoxib could increase ultrafiltration volume and reduce the glucose transport rate (P < 0.05) . Compared with the normal group, the levels of LVD, COX-2,VEGF-C, and LYVE-1 mRNA and protein were significantly up-regulated in uremic and dialysis groups (P < 0.05). Compared with the uremic dialysis group, the levels of LVD, COX-2,VEGF-C and LYVE-1 mRNA and protein were significantly down-regulated in the celecoxib group. There was a positive correlation between COX-2 and VEGF-C, LVD in protein levels, as well as VEGF-C and LVD(all P values<0.05). CONCLUSIONS: Hyper glucose dialysis solution and uremic condition could up-regulate the expression of COX-2,VEGF-C, LYVE-1 in gene and protein level and stimulate lymphangiogenesis. COX-2 inhibitor could delay the change of peritoneal structures and function. COX-2 inhibitor could prevent the lymphangiogenesis in uremic rat treated by peritoneal dialysis, which might down-regulate the expression of VEGF-C by COX-2 depended manner.

Decrease of renal aquaporins 1-4 is associated with renal function impairment in pediatric congenital hydronephrosis.

BACKGROUND: Renal aquaporins (AQP1-4) concentration is downregulated and is in proportion to the degree of hydronephrosis graded by ultrasound in pediatric congenital hydronephrosis (CH). However, the relationship between the expression of AQP1-4 with the changes of renal function impairment (RFI) evaluated by (99m)Tc-DTPA renal dynamic imaging is still unclear. This study aimed to investigate the relationship between AQP1-4 expression and degree of RFI in children with CH. METHODS: The expression of AQP1-4 was evaluated in 45 children with unilateral ureteropelvic junction obstruction (28 boys and 17 girls, average age: 28±10 months) and 15 children undergoing nephrectomy for nephroblastoma (8 boys and 7 girls, average age: 26±8 months) by immunoblotting and immunohistochemistry. Renal function was graded into mild and severe RFI by (99m)Tc-DTPA renal dynamic imaging. RESULTS: One-way analysis of variance with Bonferonni's correction showed a significantly reduced protein expression of AQP1-4 in the severe RFI group compared with those in both mild RFI group and controls (AQP1: 0.52±0.09 vs. 0.91±0.06 vs. 1.23±0.033; AQP2: 0.68±0.12 vs. 1.09±0.06 vs. 1.52±0.08; AQP3: 0.59±0.16 vs. 0.94±0.08 vs. 1.31±0.07; AQP4: 0.64±0.06 vs. 1.14±0.07 vs. 1.61±0.07; P<0.001, respectively). In kidneys with severe RFI, there was a reduction in the protein concentration of all four AQP isoforms which was more pronounced compared with those seen in kidneys with mild RFI and in the controls. CONCLUSION: AQP1-4 expression is reduced in proportion with the impairment degree of renal function graded by (99m)Tc-DTPA renal dynamic imaging in human CH.

Early alteration of urinary exosomal aquaporin 1 and transforming growth factor ß1 after release of unilateral pelviureteral junction obstruction.

BACKGROUND/PURPOSE: Down-regulation of aquaporin 1 (AQP1) and up-regulation of transforming growth factor ß(1) (TGF-ß(1)) in the renal parenchyma have been demonstrated in children who underwent pyeloplasty for pelviureteral junction obstruction. However, no information about urinary exosomal AQP1 and TGF-ß(1) during postobstructive polyuria in children with congenital unilateral hydronephrosis is available. The aim of the present study is to evaluate the urine concentration of exosomal AQP1 and TGF-ß(1) on the first and the second day after surgery in children who underwent pyeloplasty. METHODS: Twenty-two patients (age, 36.2 ± 17.1 months) with unilateral pelviureteral junction obstruction were examined in the study. For the first 2 days after the operation, the urine was collected separately from pyelostomy draining only from the postobstructed kidney and from the bladder catheter draining mostly from the contralateral kidney, which was used as an internal control. Urinary output, urinary osmolality, sodium, ß(2)-microglobulin (ß(2)-MG), and creatinine, as well as urinary exosomal AQP1 and TGF-ß(1) excretion, were tested in each sample. RESULTS: After pyeloplasty, a significantly decreased urinary excretion of exosomal AQP1 (≈ 64%) was found in the postobstructed kidney. The patients developed polyuria (807 ± 216 mL/24 h vs 484 ± 144 mL/24 h at day 1, 1021 ± 348 mL/24 h vs 603 ± 228 mL/24 h at day 2; P < .01) and reduced urine osmolality (115 ± 44 mOsm/kg vs 282 ± 61 mOsm/kg at day 1, 139 ± 39 vs 303 ± 46 mOsm/kg at day 2; P < .01) that persisted for 48 hours. In parallel, urinary TGF-ß(1) and ß(2)-MG (normalized for creatinine) from the postobstructed kidney were significantly higher compared with the contralateral kidney. The urine output and urinary sodium concentration from the postobstructed kidney elevated significantly on the second day after the release of obstruction compared with those on the first day. The contralateral kidney also showed same trends. CONCLUSIONS: The down-regulation of urinary exosomal AQP1 in the postobstructed kidney may account for the polyuria, hypotonic urine, and elevated urinary ß(2)-MG. The urinary TGF-ß(1) level locally increased in the postobstructed kidney may be involved in renal AQP1 down-regulation.

Effect of peritoneal dialysis on expression of vascular endothelial growth factor, basic fibroblast growth factor and endostatin of the peritoneum in peritoneal dialysis patients.

AIM: The aim of this study is to investigate the expression of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and endostatin (ES) in human peritoneum and investigate the relationship between them and peritoneum neoangiogensis in the patients with uraemia and peritoneal dialysis (PD). METHODS: Peritoneal biopsies were obtained from normal subjects (n = 8), uraemic predialysis patients (n = 12) and PD patients (n = 10). The mRNA expression of VEGF, bFGF and ES in peritoneal tissues were measured through real-time polymerase chain reaction. The protein expression of VEGF, bFGF and ES in peritoneal tissues were determined through western blot. Microvessel density (MVD) of peritoneal tissue was assessed using immunohistochemistry with CD34 monoclonal antibody. RESULTS: The mRNA and protein of VEGF, bFGF and ES were expressed in all peritoneal samples. Compared with the normal control group, the mRNA and protein expression of VEGF and bFGF in peritoneal tissues were all significantly upregulated in the uraemic predialysis and PD group (all P < 0.05). Compared with the normal control group, the protein expression of ES were significantly upregulated in the uraemic predialysis and PD group (all (P < 0.05), but the mRNA expression of ES did not have obvious differences in the uraemic predialysis and PD group as compared to the normal control group (P > 0.05). MVD of peritoneal tissue were increased in the uraemic predialysis and PD group compared with the normal group (all P < 0.05). A significant positive correlation was found between VEGF mRNA expression and MVD, bFGF mRNA expression and MVD. CONCLUSION: The mRNA expression of VEGF and bFGF, the protein expression of VEGF, bFGF, and ES and microvessel density (MVD) are increased both in the uraemic predialysis and PD patients. These results show that uraemia circumstances and non-physiological compatibility of peritoneal dialysis solution might increase VEGF, bFGF and ES expression and MVD, which might participate in the increment of the peritoneum neoangiogensis and ultrafiltration failure in PD patients.

Effects of recombinant human endostatin on peritoneal angiogenesis in peritoneal dialysis rats.

AIM: To investigate the effects of recombinant human endostatin (Endostar) on peritoneum angiogenesis in a model of dialysate exposure in rats. METHODS: Forty male Sprague-Dawley rats were randomized to five groups: normal (group 1); uraemia (group 2); 4.25% peritoneal dialysate (PD) uraemic (group 3); uraemia + PD + recombinant human endostatin 10 mg/kg PD (group 4); and uraemia + PD + recombinant human endostatin 40 mg/kg PD (group 5). The uraemic rats model was established by 5/6 nephrectomy. Endostatin was administrated by s.c. injection every other day, over 28 days. After 28 days of PD fluid exposure, immunohistochemistry and reverse transcript polymerase chain reaction were used to detect protein and mRNA expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in each group. Microvessel density (MVD) was measured by immunohistochemistry. RESULTS: Compared with group 1, the mRNA and protein expressions of VEGF and bFGF were significantly upregulated in groups 2 and 3 (P < 0.05). Compared with group 3, the mRNA and protein expressions of VEGF and bFGF were significantly downregulated in groups 4 and 5 (P < 0.05). Compared with group 4, the mRNA and protein expressions of VEGF and bFGF were significantly downregulated in group 5 (P < 0.05). Compared with group 1, MVD was significantly upregulated in groups 2 and 3 (P < 0.05). Compared with group 3, MVD was significantly downregulated in groups 4 and 5 (P < 0.05). CONCLUSION: Endostar can effectively inhibit rat peritoneum neoangiogenesis and the effect was dose-dependent.