nephrin and Sepsis

Management of children with congenital nephrotic syndrome (CNS) is challenging. Bilateral nephrectomies followed by dialysis and transplantation are practiced in most centres, but conservative treatment may also be effective.. We conducted a 6-year review across members of the European Society for Paediatric Nephrology Dialysis Working Group to compare management strategies and their outcomes in children with CNS.. Eighty children (50% male) across 17 tertiary nephrology units in Europe were included (mutations in NPHS1, n = 55; NPHS2, n = 1; WT1, n = 9; others, n = 15). Excluding patients with mutations in WT1, antiproteinuric treatment was given in 42 (59%) with an increase in S-albumin in 70% by median 6 (interquartile range: 3-8) g/L (P < 0.001). Following unilateral nephrectomy, S-albumin increased by 4 (1-8) g/L (P = 0.03) with a reduction in albumin infusion dose by 5 (2-9) g/kg/week (P = 0.02). Median age at bilateral nephrectomies (n = 29) was 9 (7-16) months. Outcomes were compared between two groups of NPHS1 patients: those who underwent bilateral nephrectomies (n = 25) versus those on conservative management (n = 17). The number of septic or thrombotic episodes and growth were comparable between the groups. The response to antiproteinuric treatment, as well as renal and patient survival, was independent of NPHS1 mutation type. At final follow-up (median age 34 months) 20 (80%) children in the nephrectomy group were transplanted and 1 died. In the conservative group, 9 (53%) remained without dialysis, 4 (24%; P < 0.001) were transplanted and 2 died.. An individualized, stepwise approach with prolonged conservative management may be a reasonable alternative to early bilateral nephrectomies and dialysis in children with CNS and NPHS1 mutations. Further prospective studies are needed to define indications for unilateral nephrectomy.

Topics: Albumins; Child; Child, Preschool; Europe; Female; Humans; Infant; Male; Membrane Proteins; Mutation; Nephrectomy; Nephrology; Nephrotic Syndrome; Pediatrics; Prospective Studies; Proteinuria; Retrospective Studies; Sepsis; Thrombosis

To investigate the potential role of long noncoding RNA (lncRNA) growth arrest specific transcript 5 (GAS5) in sepsis-induced podocyte injury and its underlying mechanism.. The sepsis model was established by lipopolysaccharide (LPS) induction in podocytes. The expression levels of Nephrin and GAS5 were detected by quantitative Real-time polymerase chain reaction (qRT-PCR) after LPS induction in podocytes for 12 h, 24 h and 36 h, respectively. Western blot was used to detect the expression level of Nephrin in sepsis-induced podocytes. The mRNA expressions of GAS5 and Nephrin in podocytes were detected after transfection of GAS5 siRNA. Albumin influx in podocytes after GAS5 knockdown was detected by Transwell assay. Western blot was used to detect the protein expression of Snail in sepsis after GAS5 knockdown. The target gene of GAS5 was predicted by bioinformatics analysis. QRT-PCR and Western blot were used to detect the protein and mRNA levels of PTEN (phosphatase and tensin homolog deleted on chromosome ten). Nephrin expression and the albumin inflow after PTEN knockdown were then measured. The expression of PI3K/AKT/GSK3β was also detected after GAS5 was downregulated while PTEN was upregulated.. LPS stimulation downregulated the mRNA expression of Nephrin in podocytes and achieved the lowest level at 24 h. The protein expression change of Nephrin was consistent with its mRNA expression. In the septic state, the albumin influx of podocytes remarkably increased, but the function of podocyte barrier was weakened. Besides, GAS5 expression decreased in a time-dependent manner in LPS-induced podocytes. After GAS5 knockdown by siRNA, Nephrin expression and the function of podocyte barrier were significantly reduced. Snail expression was also upregulated in septic state, and GAS5 knockdown increased the expressions of phosphorylated Snail and PI3K/AKT/GSK3β. After knockdown of GAS5, the mRNA and protein levels of PTEN significantly decreased, which was contract to the expression of Snail. However, overexpression of PTEN could reverse the promotive effect of GAS5 on PI3K/AKT activation.. GAS5 expression decreased in sepsis-induced podocyte injury, and GAS5 was involved in regulating sepsis-induced podocyte injury by reducing PTEN expression.

Topics: Animals; Down-Regulation; Glycogen Synthase Kinase 3 beta; Humans; Lipopolysaccharides; Membrane Proteins; Phosphatidylinositol 3-Kinases; Phosphorylation; Podocytes; PTEN Phosphohydrolase; RNA, Long Noncoding; RNA, Messenger; RNA, Small Interfering; Sepsis; Transfection; Up-Regulation

Glomerular podocytes are injured in sepsis. We studied, in a sepsis patient, whether microRNAs (miRNAs) play a role in the podocyte injury.. Podocytes were cultured and treated with lipopolysaccharide (LPS). Filtration barrier function of podocyte was analyzed with albumin influx assay. Nephrin level was analyzed with reverse transcription polymerase chain reaction (RT-PCR) and western blot. MiRNAs were detected using miRNAs PCR Array and in situ hybridization. MiRNA target sites were evaluated with luciferase reporter assays.. LPS impaired the filtration barrier function of podocytes. MiR-128 level was decreased and miR-21 level was increased in podocytes in vitro and in the sepsis patient. The decrease in miR-128 was sufficient to induce the loss of nephrin and the impairment of filtration barrier function, while the increase of miR-21 exacerbated the process. Snail and phosphatase and tensin homolog (PTEN) were identified as the targets of miR-128 and miR-21. Decreased miR-128 induced Snail expression, and the increased miR-21 stabilized Snail by regulating the PTEN/Akt/GSK3β pathway. Supplementation of miR-128 and inhibition of miR-21 suppressed Snail expression and prevented the podocyte injury induced by LPS.. Our study suggests that decreased miR-128 and increased miR-21 synergistically cause podocyte injury and are the potential therapeutic targets in sepsis.

Topics: Cells, Cultured; Down-Regulation; Glycogen Synthase Kinase 3 beta; Humans; Membrane Proteins; MicroRNAs; Permeability; Podocytes; Proto-Oncogene Proteins c-akt; PTEN Phosphohydrolase; Sepsis; Signal Transduction; Snail Family Transcription Factors; Transfection; Up-Regulation

Sepsis is induced by infectious challenges, and septic organ failure often occurs under local and systemic inflammation. Albuminuria is also evident during sepsis, but little is known about the molecular basis of septic albuminuria. Using lipopolysaccharide (LPS)-treated mice as a sepsis model, we found that the loss of nephrin, a key component for maintaining podocyte slit diaphragm, became evident in accordance with the onset of albuminuria, especially 36 h post-LPS challenge (i.e., albumiuric stage). Likewise, nephrin mRNA levels were decreased to 13% of saline-treated mice. Such a transcriptional suppression of nephrin was associated with the loss of nucleus-localized Wilms tumor-1 (WT1), a transcriptional factor for up-regulating nephrin gene. Thereafter, urinary albumin levels were decreased in mice between 72 and 96 h post-LPS challenge (i.e., recovery-stage). Notably, nuclear localization of WT1 seemed to be normalized, and nephrin mRNA and protein levels returned near the basal level 72 h post-LPS challenge. During LPS-mediated sepsis, there was a transient increase in blood interleukin-1β, a suppressor of nephrin production in podocytes. Therefore, down-regulation of nephrin by the loss in nuclear WT1, along with hyper-cytokinemia, may underlie the mechanisms by which albuminuria is induced by infectious stresses.

Topics: Albuminuria; Animals; Disease Models, Animal; Down-Regulation; Female; Interleukin-1beta; Lipopolysaccharides; Membrane Proteins; Mice; Mice, Inbred C57BL; Podocytes; RNA, Messenger; Sepsis; Transcription Factors; WT1 Proteins