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This paper describes the analysis of a flat annular-shaped diaphragm as a key part of a special pressure transducer. Such a transducer is aimed at applications down-hole of oil wells, where it occupies the annulus space between a tubing string and the casing of the well. As a key element of the transducer, the flat and annular-shaped diaphragm is used to convert pressure into a displacement of sufficient amplitude. This displacement can be further converted into an electrical signal by an appropriate displacement transducer. A mathematical model has been developed to predict the displacement of the diaphragm in response to an applied pressure, given the geometry and the material properties of the diaphragm. The model has been validated by experimental results.

The present study was conducted to determine whether two important signalling molecules of store-operated channel (SOC), stromal interaction molecule 1 (STIM1) and Orai1, were involved in glomerular podocyte injury. We explored the effects of STIM1/Orai1 overexpression on podocyte associated proteins and cell permeability.The expression of STIM1 and Orai1 were examined in the renal cortex of adriamycin-induced nephropathy mice by real-time RT-PCR. The recombinant plasmid of STIM1/Orai1, identified by restriction enzyme digestion and PCR, was transfected into MPC5 cells via lipofectamine 2000. The transfecting efficiency was observed by a fluorescence microscope. RT-PCR and Western blotting were used to evaluate the expression levels of STIM1, Orai 1 and some podocyte-associated molecules in the transfected MPC5 cells. In addition, we examined the diffusion of FITC-dextran across the podocyte monolayer to investigate whether STIM1/Orai1 overexpression could affect cell permeability.We found that the mRNA levels of STIM1 and Orai1 were increased in adriamycin-induced nephropathy mice. STIM1/Orai1 overexpression significantly decreased the expression of podocin and CD2-associated protein (CD2AP), whereas it increased the expression of α-actinin-4. The permeability was significantly increased in the STIM1/Orai1 overexpression group.Our findings suggested that STIM1/Orai1 overexpression could affect the cell permeability and the expression of partial podocyte-associated proteins, which may ultimately result in podocyte injury.

Ureteral obstruction with subsequent hydronephrosis is a common clinical complication. Downregulation of renal sodium transporters in obstructed kidneys could contribute to impaired urinary concentrating capability and salt waste following the release of a ureteral obstruction. The current study was undertaken to investigate the role of mitochondrial complex-1 inhibition in modulating sodium transporters in obstructive kidney disease. Following unilateral ureteral obstruction (UUO) for 7 days, a global reduction of sodium transporters, including NHE3, α-Na-K-ATPase, NCC, NKCC2, p-NKCC2, ENaCα and ENaCγ, was observed, as determined via qRT-PCR and/or Western blotting. Interestingly, inhibition of mitochondrial complex-1 by rotenone markedly reversed the downregulation of NKCC2, p-NKCC2 and ENaCα. In contrast, other sodium transporters were not affected by rotenone. To study the potential mechanisms involved in mediating the effects of rotenone on sodium transporters, we examined a number of known sodium modulators, including PGE2, ET1, Ang II, natriuretic peptides (ANP, BNP and CNP) and nitric oxide synthases (iNOS, nNOS and eNOS). Importantly, among these modulators, only BNP and iNOS were significantly reduced by rotenone treatment. Collectively, these findings demonstrated a substantial role of mitochondrial dysfunction in mediating the downregulation of NKCC2 and ENaCα in obstructive kidney disease, possibly via iNOS-derived nitric oxide and BNP.

Obstructive kidney disease is a common complication in the clinic. Downregulation of aquaporins (AQPs) in obstructed kidneys has been thought as a key factor leading to the polyuria and impairment of urine-concentrating capability after the release of kidney obstruction. The present study was to investigate the role of mitochondrial complex-1 in modulating AQPs in obstructive nephropathy. Following 7-day unilateral ureteral obstruction (UUO), AQP1, AQP2, AQP3, and vasopressin 2 (V2) receptor were remarkably reduced as determined by qRT-PCR and/or Western blotting. Notably, inhibition of mitochondrial complex-1 by rotenone markedly reversed the downregulation of AQP1, AQP2, AQP3, and V2. In contrast, AQP4 was not affected by kidney obstruction or rotenone treatment. In a separate study, rotenone also attenuated AQPs' downregulation after 48-h UUO. To study the potential mechanisms in mediating the rotenone effects on AQPs, we examined the regulation of the COX-2/microsomal prostaglandin E synthase (mPGES)-1/PGE2/EP pathway and found that COX-2, mPGES-1, and renal PGE2content were all significantly elevated in obstructive kidneys, which was not affected by rotenone treatment. For EP receptors, EP2and EP4but not EP1and EP3were upregulated in obstructive kidneys. Importantly, rotenone strikingly suppressed EP1and EP4but not EP2and EP3receptors. However, treatment of EP1antagonist SC-51322 could not affect AQPs' reduction in obstructed kidneys. Collectively, these findings suggested an important role of mitochondrial dysfunction in modulating AQPs and V2receptor in obstructive nephropathy possibly via prostaglandin-independent mechanisms.

Angiotensin II (ANG II) has been shown to activate c-Jun NH2-terminal kinase (JNK) in cultured mesangial cells, but the functional implication of this phenomenon remains to be determined, largely due to the lack of an effective approach to block JNK. Therefore, the present study was carried out to examine whether JNK is involved in ANG II-induced cell proliferation in cultured human mesangial cells (HMCs) with the use of a newly developed JNK-selective blocker, SP-600125. Within minutes, treatment with 100 nM ANG II activated all three members of MAP kinase family, including extracellular signal-regulated protein kinase (Erk) 1/2, JNK, and p38 in cultured HMCs, as assessed by immunoblotting detection of phosphorylation of MAP kinases. ANG II-dependent activation of JNK was further confirmed by detection of increased phosphorylation and transcription activity of c-Jun after the ANG II treatment. SP-600125 ranging from 5 to 10 μM almost completely abolished the activation of JNK by ANG II without affecting the activities of Erk1/2 and p38. After treatment with 100 ng ANG II, there was a steady increase in [3H]thymidine incorporation that was blocked by SP-60025 in a dose- and time-dependent manner. Similarly, SP-600125 dose dependently reduced the ANG II-induced increase in cell number. The antiproliferative effect of SP-60025 was further determined by cell-cycle analysis with flow cytometry. Twenty-four hours after ANG II treatment, 50% of the quiescent HMCs (G0/G1) progressed into the S phase, and the cell cycle progression was almost completely prevented in the presence of SP-60025. Our data suggest that JNK mediates the proliferative effect of ANG II in cultured HMCs and thus represents a novel therapeutic target for treatment of chronic renal diseases.

The information about the use of off-label drugs in pediatric nephrology is still lacking, which leads to increased adverse reactions and medical disputes. We retrospectively analyzed the use of off-label drugs in the in-patient ward of the nephrology department of Nanjing Children’s Hospital, China in order to provide more complete information about the use of drugs for children. Proportional stratified random sampling was applied to select patients with renal diseases aged 1 month to 18 years, who were admitted to the hospital from October 1, 2012 to September 30, 2013. All nephrology-related drugs prescribed in the hospitalization period and take-home drugs prescribed on discharge were recorded and evaluated as off-label drugs or not from three different perspectives: person-time, prescription, and drug category. From 385 person-times of patients with 1424 prescriptions, according to the ratio between off-label drugs and person-times, drug prescriptions, and drug products, the rates of off-label drugs were 40.78%, 16.64%, and 31.43%, respectively. Low-molecular-weight heparin, alfacalcidol and diltiazem were the most commonly used off-label drugs. Infants and younger children were the high-risk population of off-label drug use. The high rate off-label nephrology-related drug use in children was mainly related to lacking clinical research into drugs in children and the pace of drug label’s revision, which cannot follow the development of medical science. Approximaely half of pediatric patients with renal diseases are usually prescribed with off-label nephrology-related drugs. Analyzing the off-label conditions from different perspectives may lead to various results. More clinical research into drugs for infants and younger children is needed so as to update drug descriptions.

An eight-year-old girl, presenting with palpebral edema, gross hematuria, and foam in urine, was admitted to our hospital. Investigations indicated increased serum antistreptolysin O (ASO) and anti-mycoplasma antibody titers. Renal biopsy showed crescentic poststreptococcal acute glomerulonephritis (CPAGN) with isolated C3 deposition in the glomeruli. Electro-microscope examination showed subepithelial deposition of electron dense material. She received the double pulse therapies of methylprednisolone and cyclophosphamide as well as the treatment of oral prednisolone, angiotensin converting enzyme-II (ACE-II) inhibitor, dipyridamole and traditional Chinese medicine. The complete clinical remission was achieved after 9 months. No serious adverse effects were observed during the follow-up. Our findings indicated that CPAGN with isolated C3 deposition might have a favorable prognosis after aggressive immunosuppressive treatment. However, the influence of isolated C3 deposition on CPAGN prognosis remains to be clarified.

Proteinuria is, not only a hallmark of glomerular disease, but also a contributor to kidney injury. However, its pathogenic mechanism is still elusive. In the present study, the effects of albumin on renal tubular tight junctions and the potential molecular mechanisms of those effects were investigated. In mouse proximal tubular cells (mPTCs), albumin treatment resulted in a significant loss of the cellular tight junction proteins zonula occludens-1 (ZO-1) and claudin-1 in a time- and dose-dependent manner, indicating a severe impairment of the tight junctions. On the basis of our previous study showing that albumin stimulated NLRP3 [neuronal apoptosis inhibitor protein, major histocompatibility complex class 2 transcription activator, incompatibility locus protein from Podospora anserina, and telomerase-associated protein (NACHT); leucine-rich repeat (LRR); and pyrin domain (PYD) domains-containing protein 3] inflammasome activation in mPTCs, we pretreated mPTCs with NLRP3 siRNA (siNLRP3) and found that NLRP3 knockdown significantly blocked the downregulation of ZO-1 and claudin-1 induced by albumin. Similarly, in albumin-overloaded wild-type mice, both ZO-1 and claudin-1 were downregulated at the protein and mRNA levels in parallel with the impaired formation of the tight junctions on transmission electron microscopy and the abnormal renal tubular morphology on periodic acid-Schiff staining, which contrasted with the stimulation of NLRP3 in the renal tubules. In contrast, NLRP3 knockout (NLRP3−/−) mice preserved normal ZO-1 and claudin-1 expression as well as largely normal tight junctions and tubular morphology. More importantly, deletion of the NLRP3 pathway downstream component caspase-1 similarly blocked the albumin overload-induced downregulation of ZO-1 and claudin-1. Taken together, these findings demonstrated an important role of the albumin-NLRP3 inflammasome axis in mediating the impairment of renal tubular tight junctions and integrity.

It is well documented that oxidative stress is involved in the pathogenesis of idiopathic nephrotic syndrome (INS). Malondialdehyde (MDA) is a measurement of lipid oxidation; vitamin C and E are important components of antioxidants. However, the association between MDA, vitamin C or E levels and INS remains elusive. A meta-analysis was performed to investigate the alteration of serum levels of MDA, vitamin C and E in INS compared with controls. Eight studies were included in our meta-analysis according to predefined criteria. Active INS patients demonstrated significantly higher level of serum MDA (SMD: 2.13, 95% CI: 1.511 to 2.749, p < 10(-4)), markedly lower levels of serum vitamin C (SMD: -1.449, 95% CI: -2.616 to -0.281, p = 0.015) and E (SMD: -1.45, 95% CI: -2.544 to -0.356, p = 0.009) compared with those in controls. Active steroid-sensitive nephrotic syndrome (SSNS) patients showed comparable levels of serum vitamin C and E to those in controls. INS subjects in the remission stage demonstrated significantly higher level of serum MDA (SMD: 1.028, 95% CI: 0.438 to 1.617, p < 10(-4)), markedly lower level of serum vitamin C (SMD: -2.235, 95% CI: -3.048 to -1.421, p < 10(4)) and similar level of serum vitamin E compared with those in controls. No significant publication bias was observed. In conclusion, the disorder of MDA and vitamin C persists in the remission stage of INS. It seems that the serum levels of vitamin C and E is associated with the responsiveness of INS to steroids. However, more studies should be performed in the future.

Hyperuricemia is associated with kidney complications including glomerulosclerosis and mesangial cell (MC) proliferation by poorly understood mechanisms. The present study investigated the underlying mechanisms that mediate uric acid (UA)-induced MC proliferation. A rat MC line, HBZY-1, was treated with various concentrations of UA in the presence or absence of a specific extracellular-regulated protein kinase 1/2 (ERK1/2) inhibitor (U0126), apocynin. UA dose dependently stimulated MC proliferation as shown by increased DNA synthesis and number of cells in the S and G2 phases in parallel with the upregulation of cyclin A2 and cyclin D1. In addition, UA time dependently promoted MC proliferation and significantly increased phosphorylation of ERK1/2 but not c-Jun NH2-terminal kinase and p38 MAPK in MCs as assessed by immunoblotting. Inhibition of ERK1/2 signaling via U0126 markedly blocked UA-induced MC proliferation. More importantly, UA induced intracellular reactive oxygen species (ROS) production of MCs dose dependently, which was completely blocked by apocynin, a specific NADPH oxidase inhibitor. Toll-like receptor (TLR)2 and TLR4 signaling had no effect on NADPH-derived ROS and UA-induced MC proliferation. Interestingly, pretreatment with apocynin inhibited ERK1/2 activation, the upregulation of cyclin A2 and cyclin D1, and MC proliferation. In conclusion, UA-induced MC proliferation was mediated by NADPH/ROS/ERK1/2 signaling pathway. This novel finding not only reveals the mechanism of UA-induced MC cell proliferation but also provides some potential targets for future treatment of UA-related glomerular injury.

Mitochondria are cellular organelles that produce the energy required for cellular processes through synthesis of adenosine triphosphate (ATP). They also contribute to a wide range of cellular functions, including reactive oxygen species (ROS) generation, calcium homeostasis, and induction of apoptosis. Mitochondria also contain their own DNA, known as mitochondrial DNA (mtDNA). Through these varied roles, mitochondria are important in heredity, growth, metabolism, and the occurrence and progression of diseases. Podocytes are highly specialized epithelial cells of the kidney. Podocyte injury is considered a key factor in the development of many forms of glomerular disease. A description of the structure and functions of mitochondria is provided, before focusing on mitochondrial dysfunction in podocyte injury. Changes in mtDNA are discussed, using focal segmental glomerulosclerosis as an example of a nuclear-encoded mitochondrial disease. ATP synthesis in podocytes is then examined; as the kidney consumes a large amount of energy, any disruption in supply is likely to cause renal dysfunction. Mitochondrial ROS production and calcium disorders, and mitophagy and mitochondrial dynamics are also discussed. Finally, an outline of the numerous challenges in understanding the biological processes involved with mitochondrial dysfunction and podocyte injury required to develop strategies for improving human health is provided.

Aims To evaluate the association between vitamin D receptor (VDR) gene polymorphisms and the risk of rickets among Asians. Methods Eligible studies were included in our meta-analysis by searching PubMed, Embase, Cochrane and China National Knowledge Infrastructure databases according to a predefined criteria. A random effects model was used to calculate the combined ORs and its corresponding 95% CI. Results 16 studies were recruited for the analysis of the association between VDR BsmI (rs1544410), TaqI (rs731236), FokI (rs2228570) and ApaI (rs7975232) gene polymorphisms and the risk of rickets among Asians, most of whom were from China. B allele/BB genotype was associated with the susceptibility of rickets (p=0.017 and 0.044, respectively), and bb genotype was associated with lower risk of rickets (p=0.033). F allele/FF genotype was associated with the susceptibility of rickets (p −4 ), and ff genotype was associated with lower risk of rickets (p −4 ). AA genotype was associated with the onset of rickets (p=0.044). No significant association was observed between TaqI polymorphism the risk of rickets. A allele/aa genotype was not associated with the risk of rickets. No evidence of publication bias was observed. Conclusions B allele/BB genotype at the BsmI site, F allele/FF genotype at the FokI site and AA genotype at the ApaI site may be risk factors for the onset of rickets among Asians; bb genotype at the BsmI site and ff genotype at the FokI site may be protective factors against the risk of rickets among Asians.

Mitochondrial dysfunction has gained recognition as a contributing factor in many diseases. The kidney is a kind of organ with high energy demand, rich in mitochondria. As such, mitochondrial dysfunction in the kidney plays a critical role in the pathogenesis of kidney diseases. Despite the recognized importance mitochondria play in the pathogenesis of the diseases, there is limited understanding of various aspects of mitochondrial biology. This review examines the physiology and pathophysiology of mitochondria. It begins by discussing mitochondrial structure, mitochondrial DNA, mitochondrial reactive oxygen species production, mitochondrial dynamics, and mitophagy, before turning to inherited mitochondrial cytopathies in kidneys (inherited or sporadic mitochondrial DNA or nuclear DNA mutations in genes that affect mitochondrial function). Glomerular diseases, tubular defects, and other renal diseases are then discussed. Next, acquired mitochondrial dysfunction in kidney diseases is discussed, emphasizing the role of mitochondrial dysfunction in the pathogenesis of chronic kidney disease and acute kidney injury, as their prevalence is increasing. Finally, it summarizes the possible beneficial effects of mitochondrial-targeted therapeutic agents for treatment of mitochondrial dysfunction-mediated kidney injury-genetic therapies, antioxidants, thiazolidinediones, sirtuins, and resveratrol-as mitochondrial-based drugs may offer potential treatments for renal diseases.

It is well documented that hyperhomocysteinemia induces renal injury. However, the association between homocysteine level and type 2 diabetic nephropathy (T2DN) remains elusive.We evaluated the alteration of plasma level of homocysteine in T2DN patients with macroalbuminuria or microalbuminuria compared with type 2 diabetes mellitus (T2DM) controls without albuminuria by performing a meta-analysis. We searched the PubMed, Embase and Cochrane databases from January 1990 to October 2013 to identify studies that met predefined criteria.Seven studies were included in this investigation. T2DN patients with macroalbuminuria demonstrated a significantly higher level of plasma homocysteine than T2DM without albuminuria (4 studies, random effects SMD: 1.66, 95% CI: 0.46 to 2.87, P=0.007) and T2DN with microalbuminuria (3 studies, random effects SMD: 0.99, 95% CI: 0.62 to 1.36, P0.001). T2DN patients with microalbuminuria demonstrated significantly higher level of plasma homocysteine than T2DM without albuminuria (6 studies, random effects SMD: 1.29, 95%. CI: 0.59 to 2, P0.001). Exclusion of any single study had little impact on the pooled SMDs. No evidence of publication bias was observed.Our findings indicate that the status of plasma homocysteine is associated with both the risk and severity of nephropathy in T2DM. Frequent monitoring and early intervention should be recommended.

OBJECTIVE To evaluate the association between vitamin D receptor (VDR) BsmI gene polymorphism and the risk of end-stage renal disease (ESRD). METHODS All eligible studies were included in our meta-analysis of a search of the PubMed, Embase, Cochrane and China National Knowledge Infrastructure (CNKI) databases according to predefined criteria. The fixed-effects or, in the presence of heterogeneity, random-effects models were used to calculate the pooled odds ratio (OR) and corresponding 95% confidence interval (CI). MATERIALS Six studies including 863 patients and 1,063 controls were recruited for the analysis of the association between the VDR BsmI gene polymorphism and the risk of ESRD. RESULTS The B allele/BB genotype was not associated with the ESRD risk in the overall population, Caucasians or Asians (overall population: p=0.492 and 0.382, Caucasians: p=0.765 and 0.522, Asians: p=0.607 and 0.481). The Bb/bb genotype was also not associated with the risk of ESRD in the overall population, Caucasians or Asians (overall population: p=0.556 and 0.166, Caucasians: p=0.770 and 0.965, Asians: p=0.411 and 0.098). The exclusion of any single study had little impact on the p value in the overall population. No evidence of publication bias was observed. CONCLUSION VDR BsmI gene polymorphism appears to not be associated with the risk of ESRD in the overall population, Caucasians or Asians. However, more studies should be performed in the future.

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (Nox), a major source of reactive oxygen species, is a critical mediator of redox signaling. It is well-documented that oxidative stress is associated with the development of glomerular diseases (GN). Hence, the Nox was also thought to be involved in the pathogenesis of GN. However, the expression of Nox in various GN was not consistent, the mechanisms by which the activity of the Nox enzymes in regulating renal cells remains unclear. Signaling pathways might be very important in the pathogenesis of GN. We performed this review to provide a relatively complete signaling pathways flowchart for Nox to the investigators who were interested in the role of Nox in the pathogenesis of GN. Here, we reviewed the signal transduction pathway of Nox and its role in the pathogenesis of GN.

Pediatric primary nephrotic syndrome (PNS) is a chronic disease promoted by metabolic and immune dysfunctions. Peroxisome proliferator-activated receptor (PPAR) polymorphisms have been associated with a variety of metabolic and kidney disorders. We therefore hypothesized that PPAR polymorphisms might be involved in the pathophysiology of PNS. We compared the distributions of the PPAR-γPro12Ala and Val290Met, PPAR-γcoactivator-α(PGC-1α) Gly482Ser, and PPAR-αLeu162Val single nucleotide polymorphisms (SNPs) between children with PNS and normal controls and analyzed their correlations with clinical and metabolic indicators and steroid responsiveness. There were no significant differences in distributions of any of the polymorphisms between PNS cases and controls. However, PNS patients with the PPAR-γ(Pro12Ala) PP genotype had significantly higher fasting serum insulin, IgA, and HOMA-IR levels and lower insulin sensitivity than did patients with PA and AA genotypes. Additionally, the PGC-1α(Gly482Ser) A allele was associated with lower CD8+ T-cell counts and higher triglyceride and complement C3 levels compared with the G allele. No polymorphisms were related to hormone sensitivity. These results suggest that the PPAR-γ(Pro12Ala) and PGC-1α(Gly482Ser) SNPs may influence insulin and triglyceride metabolism in children with PNS and may thus be relevant to the prognosis of this chronic condition.

The association between angiotensin II type 1 receptor (AT1R) A 1166C (rs5186) gene polymorphism and end-stage renal disease (ESRD) risk remains controversial. We aimed to assess the association between AT1R A1166C gene polymorphism and ESRD susceptibility by performing a meta-analysis. Eligible studies were searched according to a predefined criterion using electronic databases. Eight articles were identified for the analysis of the association between AT1R A1166C gene polymorphism and ESRD risk. A allele and AA genotype were not associated with ESRD risk in overall populations, Caucasians and Asians (overall populations: p = 0.834 and 0.832, Caucasians: p = 0.853 and 0.884, Asians: p = 0.243 and 0.982). CC and AC genotype were not associated with ESRD risk in overall populations, Caucasians and Asians (overall populations: p = 0.304 and 0.712, Caucasians: p = 0.510 and 0.987, Asians: p = 0.319 and 0.225). In conclusion, AT1R A1166C gene polymorphism may not be correlated with ESRD risk in overall populations, Caucasians and Asians. However, more studies should be performed in the future.

It is well documented that oxidative stress is involved in the pathogenesis of bladder cancer. Zinc (Zn) and copper (Cu) are important components of antioxidants. However, the association between Zn or Cu levels and bladder cancer remains elusive. The present study was designed to investigate the alteration of serum and urinary levels of Zn or Cu in bladder cancer patients compared with controls by performing a systematic review. We searched the PubMed, Embase, and Cochrane databases from January 1990 to March 2013 to identify studies that met our predefined criteria. Six studies were included. Bladder cancer patients demonstrated significantly lower levels of serum Zn (three studies, random effects standard mean deviation (SMD): -1.072, 95 % CI: -1.489 to -0.656, P

Multiphase flowmeters (MPFMs) available today are mostly based on a combination of differential pressure measurement, provided by at least one flow constriction, such as a Venturi device, with phase holdup measurement based on nuclear techniques, electromagnetic techniques, or both. This paper investigates the issues of combining the ultrasonic Doppler velocity measurement with the differential pressure measurement for multiphase flow metering. The intention is to measure at least one "useful" velocity of the flow, such as the bulk liquid velocity or the homogeneous mixture velocity, which can then be combined with a measured differential pressure across a "constriction" device, such as a Venturi, to derive parameters needed to calculate liquid and gas flow rates. An ultrasonic Doppler velocity sensor has been tested in combination with a Venturi under multiphase flow conditions. The results show that, due to the effect of gas bubbles in the liquid phase, the interrogation depth of the ultrasonic wave is often limited to a shallow liquid region near the pipe wall. As a result, the ultrasonic Doppler sensor can measure neither the bulk liquid velocity nor the homogeneous velocity reliably. It is generally difficult to interpret the measured Doppler velocity and to derive the flow rates of a multiphase flow without employing an elaborate flow model. This work was part of a project co-funded by the UK Technology Strategy Board1, with industry partners The University of Manchester, Schlumberger Gould Research, and TUV-NEL.

Denys–Drash syndrome (DDS) is a rare disorder characterized by nephropathy, male pseudohermaphroditism, and wilms tumor. Cases are thought to arise sporadically through a de novo mutation in the wilms tumor suppressor gene (WT1), which encodes a zinc finger protein that not only acts as a tumor suppressor but is essential for normal gonadogenesis, nephrogenesis, and development of the urogenital tract. In this report, we describe a family with the well-known missense mutation in exon 9 of the WT1 gene, 1180C>T (R394W), causing incomplete DDS and no symptoms in their father. The proband, a boy with 46, XY karyotype, was born with ambiguous genitalia, penoscrotal hypospadias, and bilateral inguinal hernias. At 2 years of age, he has proteinuria and diffuse mesangial sclerosis, but no wilms tumor has been detected. The elder sister of the proband, at 3 years of age, has normal genitalia, proteinuria, focal mesangial sclerosis but no wilms tumor. The WT1 mutation was detected in both patients, who have suspected DDS, and their father, who is phenotypically normal. Conclusion: This case is unusual in that the 1180C>T mutation, which has been found in approximately 50 % of patients with complete DDS, has been inherited and is causing mild or no symptoms of DDS.

Epithelial–mesenchymal transition (EMT) plays a pivotal role in the pathogenesis of renal tubulointerstitial fibrosis. We previously demonstrated that aldosterone (Aldo)-induced EMT is dependent on mitochondrial-derived oxidative stress. This study investigated whether mitochondrial dysfunction (MtD) is involved in the pathogenesis of EMT and whether peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), a major regulator of oxidative metabolism and mitochondrial function, prevents EMT by improving MtD. Aldo decreased PGC-1α expression while increasing its acetylation and induced MtD, as evidenced by oxidative stress, mitochondrial membrane potential collapse, mitochondrial DNA damage, and mitochondrial complex activity reduction. Aldo time-dependently induced p66Shc phosphorylation and expression. Mineralocorticoid receptor antagonist eplerenone and p66Shc short interfering RNA prevented Aldo-induced MtD and EMT, as evidenced by downregulation of α-smooth muscle actin and upregulation of E-cadherin. Mitochondrial DNA depletion by ethidium bromide or mitochondrial transcription factor A inhibitory RNA (RNAi) induced MtD, further promoting EMT. RNAi-mediated suppression of PGC-1α induced MtD and EMT, whereas overexpression of PGC-1α prevented Aldo-induced MtD and inhibited EMT. Similarly, overexpression of silent mating type information regulation 2 homolog 1 (SIRT1), a gene upstream of PGC-1α, or the SIRT1 activator resveratrol restored Aldo-induced MtD and EMT by upregulating PGC-1α. These findings, which implicate a role for MtD in EMT and suggest that SIRT1 and PGC-1α coordinate to improve mitochondrial function and EMT, may guide us in therapeutic strategies for renal tubulointerstitial fibrosis.

Insulin resistance (IR) is an independent risk factor for atherosclerosis or cardiovascular events and renal function impairment. The aim of this study was to investigate IR in children with primary nephrotic syndrome (NS). One-hundred and nineteen primary NS patients with normal renal function and 125 normal controls were studied. Fasting blood glucose, fasting serum insulin, and fasting serum C-peptide were measured. The Homa index of insulin resistance (HOMA-IR), Islet B cell function, and insulin sensitivity index were calculated. Correlations were assessed between HOMA-IR, fasting serum C-peptide, blood pressure, blood lipids, renal function, coagulation, clinical disease type, pathology and the early therapeutic effectiveness of high-dose glucocorticoids. There was no evidence of IR in the primary NS group. Although levels of fasting blood glucose, fasting serum insulin and fasting serum C-peptide were all within the normal ranges, fasting serum C-peptide was significantly higher compared to the controls. There was no disorder of carbohydrate metabolism in different hormone therapy efficacy and pathological diagnosis. Although IR was not detected, a significant increase in blood pressure, uric acid, blood lipids and coagulability was observed in the primary NS group. A correlation observed between HOMA-IR, age, blood pressure, serum creatinine (Cr) and triglyceride may suggest that insulin sensitivity will emerge as renal disease progresses. Fasting serum C-peptide levels were increased in the primary NS group, suggesting that fasting serum C-peptide may be a protective factor.

Currently, almost all gas-oil-water multiphase flow meters used in the oil industry, for production monitoring and/or well testing, rely on radioactive source emitting gamma rays. These meters are, however, expensive and sometimes have logistic issues in deployment. A team of researchers from The University of Manchester and Schlumberger Cambridge Research have developed a research prototype flow meter based on non-radioactive, multi-modality measurements, including electrical capacitance tomography (ECT) sensors for sensing oil-continuous flow conditions. The prototype has been tested at NEL Multiphase Flow Facility. In this paper the principle of the ECT part of the research prototype and initial test results are presented.

Aldosterone (Aldo) causes podocyte damage by an unknown mechanism. We examined the role of mitochondrial dysfunction (MtD) in Aldo-treated podocytes in vitro and in vivo. Exposure of podocytes to Aldo reduced nephrin expression dose dependently, accompanied by increased production of reactive oxygen species (ROS). The ROS generation and podocyte damage were abolished by the mitochondrial (mt) respiratory chain complex I inhibitor rotenone. Pronounced MtD, including reduced mt membrane potential, ATP levels, and mtDNA copy number were seen in Aldo-treated podocytes and in the glomeruli of Aldo-infused mice. The mineralocorticoid receptor antagonist eplerenone significantly inhibited Aldo-induced MtD. The MtD was associated with higher levels of ROS, reduction in the activity of complexes I, III, and IV, and expression of the peroxisome proliferator-activated receptor-γ (PPARγ) coactivator-1α and mt transcription factor A. Both the PPARγ agonist rosiglitazone and PPARγ overexpression protected against podocyte injury by preventing MtD and oxidative stress, as evidenced by reduced ROS production, by maintenance of mt morphology, by restoration of mtDNA copy number, by decrease in mt membrane potential loss, and by recovery of mt electron transport function. The protective effect of rosiglitazone was abrogated by the specific PPARγ small interference RNA, but not a control small interference RNA. We conclude that MtD is involved in Aldo-induced podocyte injury, and that the PPARγ agonist rosiglitazone may protect podocytes from this injury by improving mitochondrial function.

Huang Qi Huai (HQH) granules, a mixture of Chinese herbs, contains trametes robiniophila murr, wolfberry fruit, and Polygonatum. We investigated the mechanism of the protective effects of HQH on adriamycin nephrosis (ADR) in rats. Adriamycin nephrotic rats were induced by a single dose of 5 mg/kg adriamycin. For the HQH-treated adriamycin nephrosis group, 1 day after treatment with 5 mg/kg adriamycin, the rats were administered once-daily oral gavage of 2 mg/kg HQH for 15 days. All the rats were killed at day 15. Histological changes were observed by light microscopy and transmission electron microscope. Nephrin and podocin expression levels were measured by real-time RT-PCR and Western blot. Proteinuria was measured by the Bradford protein assay. Serum TNF-α and IL-1β levels were evaluated by ELISA. Macrophage infiltration was detected by immunohistochemistry and immunoblotting, respectively. ADR rats showed heavy proteinuria, podocyte and tubulointerstitial injury, macrophage infiltration, and increased levels of serum cytokines TNF-α and IL-1β. HQH significantly ameliorated the adriamycin-induced renal injury. These data were validated in the cultured podocytes. The podocytes were treated by adriamycin in the presence or absence of HQH and nephrin and podocin expression and TNF-α and IL-1β synthesis and secretion were determined by real-time RT-PCR, immunoblotting, and ELISA, respectively. Adriamycin significantly reduced nephrin and podocin expression, which was significantly restored by the treatment of HQH. HQH treatment inhibited adriamycin-induced TNF-α and IL-1β expression. Our findings suggest that HQH significantly reduces proteinuria, prevents podocyte injury, and ameliorates tubulointerstitial damage. Inhibition of inflammatory cytokine expression and macrophage infiltration may be the protective mechanism of HQH.

Polyomavirus enhancer activator 3 (Pea3), belonging to the PEA3 subfamily of Ets transcription factors, is essential for certain organogenesis in mammals. Previously, we found that pea3 correlated with wt1 expression and may contribute to nephrogenesis in rats. Here, we observed that pea3 was mainly expressed in the zebrafish pronephric glomerulus. We further performed functional analyses by in situ hybridization of pea3 in zebrafish embryos after pea3 messenger RNA (mRNA) overexpression and inhibition of double-target genes (pea3 and erm, another member of the PEA3 subfamily) by antisense morpholino-oligonucleotides (MO). Overexpression of pea3 induced abnormal pronephrogenesis. However, MO-pea3 coinjected with MO-erm, but not alone, inhibited zebrafish pronephros development, and these defects were rescued by overexpression of the zebrafish wt1a gene. Thus, pea3 and erm are required for zebrafish pronephrogenesis and can functionally complement each other, and the wt1a gene may be one of their downstream targets.

Objective Monocytes/macrophages, proinflammatory cytokines and chemokines are important in the pathogenesis of glomerulonephritis. Interleukin (IL) -13 has been shown to exert potent anti-inflammatory properties. This study was designed to investigate the effect of IL-13 on the expression of proinflammatory cytokines, chemokines and profibrogenic cytokines and the involved molecular mechanism in cultured human mesangial cells (HMCs). Methods The expressions of proinflammatory cytokines, chemokines and profibrogenic cytokines were determined by ribonuclease protection assay (RPA). Activity of nuclear factor-kappa B (NF-κB) and activator protein-1 (AP-1) was examined by electrophoretic mobility shift assay (EMSA). NF-κB subunit p65 nuclear transportation and c-Jun N-terminal kinase (JNK) activity were assayed by immunoblot. Results Recombinant IL-13 inhibited tumor necrosis factor-α (TNF-α), IL-1α, IL-1β, monocyte chemoattractant protein-1 (MCP-1), IL-8, and transforming growth factor-β1 (TGF-β1) mRNA expressions in a dose-dependent manner. Lipopolysacchorides (LPS) dramatically increased NF-κB DNA binding activity of HMCs, which was inhibited by IL-13 in a dose-dependent manner. LPS-activated NF-κB contained p50 and p65 dimers, but not c-Rel subunit. IL-13 blocked LPS-induced NF-κB subunit p65. LPS stimulated JNK/AP-1 activation, which was inhibited by IL-13 in a dose-dependent manner. Conclusion IL-13 inhibits proinflammatory cytokines, chemokines, and profibrogenic cytokines synthesis by blocking NF-κB and JNK/AP-1 activation. These observations point to the importance of IL-13 in the modulation of inflammatory processes in the renal glomerulus.

We investigated the role of c-Jun NH2-terminal kinase (JNK), a member of the mitogen-activated protein kinase family, in the expression of angiotensin II (Ang II)-induced monocyte chemoattractant protein-1 (MCP-1) and transforming growth factor-1 (TGF-1), and in the production of fibronectin (FN), by human mesangial cells (HMCs).JNK activation in cultured human mesangial cells was determined by Western blotting with an antibody against the phosphorylated Ser63 residue of c-Jun. Binding of the activator protein (AP-1) to the MCP-1 AP-1 motif was detected via the electrophoretic mobility shift assay (EMSA). The transient luciferase reporter was used to examine MCP-1 promoter activity; an RNase protection assay and ELISA were used respectively to detect the expression of MCP-1 mRNA and production of MCP-1, TGF-beta and FN.Anthra (1,9-cd) pyrazol-6(2H)-one (SP600125), a pharmacological inhibitor of JNK, almost completely abolished Ang II-induced Ser63 phosphorylation of c-Jun at concentrations of 5-20 micromol/L: JNK activity was reduced by 75% with 10 micromol/L SP600125, and by 90% with 20 micromol/L. Ang II increased AP-1 binding to the MCP-1 AP-1 motif in a time-dependent manner, as detected by EMSA, while SP600125 effectively blocked this increased AP-1 binding in a concentration-dependent manner. Treatment with 100 nmol/L Ang II led to a steady increase in MCP-1 mRNA expression, and to an enhanced production of MCP-1, TGF-beta and FN. These effects were blocked by SP60025 in a dose-dependent manner. SP600125 also reduced MCP-1 mRNA stability: the halflife of MCP-1 mRNA was approximately 5 hours in cells treated with Ang II only, but was reduced to 2 hours when treated with a combination of Ang II and SP600125.These results show that the JNK/AP-1 pathway is involved in the expression of MCP-1 and TGF-beta, and in extracellular matrix production. JNK is an important therapeutic target for glomerulonephritis and glomerulosclerosis.

Aldosterone (Aldo) stimulates glomerular mesangial cell (MC) proliferation, in part, through an ERK1/2-dependent pathway. In this study, we examined whether Aldo activation of ERK1/2 in MC is mediated through redox-dependent EGF receptor (EGFR) transactivation, as well as the involvement of other signaling mechanisms in Aldo-induced MC proliferation. Aldo increased human MC proliferation, as determined by [3H]thymidine incorporation and cell counts. This increase in proliferation was blocked by inhibition of the mineralocorticoid receptor (MR). Continuing our observations downstream in the signaling pathway, we examined the ability of Aldo to activate both the Ras/MAPK and the PI3K signaling pathways. Aldo increased Ki-RasA and Ki-RasA:GTP levels, and sequentially phosphorylated c-Raf, MAPK kinase (MEK1/2), and ERK1/2. Ki-RasA small interfering RNA (siRNA), the c-Raf inhibitor GW5074, and the MEK1/2 inhibitor PD98059 reduced Aldo-induced cell proliferation by ∼65%. Aldo also increased phosphorylation of PI3K, Akt, the mammalian target of rapamycin (mTOR), and the 70-kDa ribosomal S6 kinase (p70S6K1). Inhibition of the PI3K pathways by the selective PI3K inhibitor LY 294002, an Akt inhibitor, or the mTOR inhibitor rapamycin reduced cell proliferation by 51%. Combining LY 294002 and PD98059 completely blocked Aldo-induced MC proliferation. Next, we confirmed that Aldo exerts its effect on MAPK and PI3K activation, as well as on cell proliferation, by activating the EGFR. Pretreatment with the EGFR antagonist AG1478 inhibited MC proliferation, as well as the activation of Ras/MAPK and PI3K/Akt, suggesting that Ras/MAPK and PI3K/Akt activation occur downstream of EGFR activation. Finally, we examined the role of reactive oxygen species (ROS) in Aldo-induced transactivation of the EGFR. Aldo-induced ROS were predominantly generated by mitochondria. Pretreatment with the antioxidant N-acetyl-l-cysteine, catalase, SOD, mitochondrial respiratory chain complex I inhibitor rotenone (Rot), NADPH oxidase inhibitor apocynin, and DPI significantly inhibited Aldo-stimulated MC proliferation as well as EGFR transactivation. However, Rot reduced MC proliferation more potently than apocynin and DPI. In conclusion, Aldo stimulated cell proliferation through MR-mediated, redox-sensitive EGFR transactivation, which was dependent on the Ki-RasA/c-Raf/MEK/ERK and PI3K/Akt/mTOR/p70S6K1 signaling pathways in human MCs.

Background: While early kidney development has been studied exhaustively, the later stages of nephrogenesis that occur after birth in the rodent are relatively poorly understood. To gain insight into this process, we detected the alterations in gene expression in rat kidney at two postnatal stages, P0 (0 day after birth), the time at which nephrogensis is still active, and P21 (21 days after birth), when nephrogenesis is complete. Methods: Sprague-Dawley rats were mated, and appearance of a vaginal plug was designated as E0. Kidneys were dissected from embryos at E13, E15, E17 and E19, and from postnatal days P0, P7, P14, P21 and adult rats. Suppression subtractive hybridization (SSH) analysis was performed and highly expressed genes were evaluated as molecular markers by real-time reverse transcription-polymerase chain reaction (RT-PCR), in situ hybridization, immunofluorescence, and Western blot. Results: Several differentially expressed genes were identified, including rPEA3, a member of the PEA3 subfamily of Ets domain transcription factors. Real time RT-PCR analysis revealed that rPEA3 exhibited dynamic developmental regulation, with high levels of expression from embryonic day E15 until birth, and declining levels thereafter. By in situ hybridization, rPEA3 mRNA was detected in the ureteric bud (UB) and surrounding metanephric mesenchyme of the kidneys from E15 until birth, but was undetectable in mature kidneys. Double-immunofluorescence staining showed that both rPEA3 and WT1 expressed in the condensed mesenchymal cells at E15 and E17; and later from E19 to P7, both expressed in the epithelial cells of ureteric bud and their branches. Conclusions: These studies provide compelling evidence that SSH is an effective method for identifying genes that are regulated during renal development, and suggest that the newly identified gene rPEA3 may play an important role in kidney development and differentiation.