scholarly journals Novel Mutations of the Chloride Channel Kb Gene in Two Japanese Patients Clinically Diagnosed as Bartter Syndrome with Hypocalciuria

2004 ◽  
Vol 89 (11) ◽  
pp. 5847-5850 ◽  
Author(s):  
Shigeru Fukuyama ◽  
Misako Hiramatsu ◽  
Motohiro Akagi ◽  
Mutumi Higa ◽  
Takao Ohta
Keyword(s):  
Direct Sequencing ◽  
Japanese Patients ◽  
Bartter Syndrome ◽  
Calcium Handling ◽  
K Channel ◽  
Renal Tubular Cells ◽  
Sequencing Method ◽  
Renal Tubular ◽  
Intron 2 ◽  
Genotype Correlation

Abstract Hypokalemic metabolic tubulopathy, such as in Bartter syndrome and Gitelman syndrome, is caused by the dysfunction of renal electrolyte transporters. Despite advances in molecular genetics with regard to hypokalemic metabolic tubulopathy, recent reports have suggested that the phenotype-genotype correlation is still confusing, especially in classic Bartter and Gitelman syndromes. We report here two Japanese patients who suffered from clinically diagnosed classic Bartter syndrome but who presented hypocalciuria. Hypocalciuria is generally believed to be a pathognomonic finding of NCCT malfunction. To better understand the genotype-phenotype correlation in these two cases, we screened four renal electrolyte transporter genes [Na-K-2Cl cotransporter (NKCC2), renal outer medullary K channel (ROMK), Cl channel Kb (ClC-Kb), and Na-Cl cotransporter (NCCT)] by the PCR direct sequencing method. We identified three ClC-Kb allelic variants, including two new mutations (L27R and W610X in patient 1 and a G to C substitution of a 3′ splice site of intron 2 and W610X in patient 2). We did not find any mutations in the other three genes. Our present data suggest that some ClC-Kb mutations may affect calcium handling in renal tubular cells.

scholarly journals Novel Mutations in Thiazide-Sensitive Na-Cl Cotransporter Gene of Patients with Gitelman's Syndrome

2000 ◽  
Vol 11 (1) ◽  
pp. 65-70
Author(s):  
TOSHIAKI MONKAWA ◽  
ISAO KURIHARA ◽  
KAZUO KOBAYASHI ◽  
MATSUHIKO HAYASHI ◽  
TAKAO SARUTA
Keyword(s):  
Missense Mutation ◽  
Direct Sequencing ◽  
Gene Mutations ◽  
Autosomal Recessive Disorder ◽  
Japanese Patients ◽  
Paternal Allele ◽  
Homozygous Mutation ◽  
Gitelman's Syndrome ◽  
Sequencing Method

Abstract. Gitelman's syndrome (GS) is an autosomal recessive disorder characterized by metabolic alkalosis, hypokalemia, hypomagnesemia, and hypocalciuria that has recently been reported to be linked to thiazide-sensitive Na-Cl cotransporter (TSC) gene mutations. In this study, possible mutations in the TSC gene of six Japanese patients clinically diagnosed with GS were investigated. Twenty-six exons encoding TSC were amplified by PCR and then completely sequenced by the direct sequencing method. Patient A showed a missense mutation of Arg 642 to Cys on the paternal allele and a missense mutation of Val 578 to Met and a 2-bp deletion (nucleotide 2543-2544) on the maternal allele. This deletion results in a frameshift that alters codon 837 to encode a stop signal rather than phenylalanine, and it is predicted to lead to loss of the latter half of the intracellular carboxy terminus. In the second family, two affected sisters, patients B and C, had a homozygous missense mutation of Thr 180 to Lys. Both of their parents, who are consanguineously married, have a heterozygous Thr180Lys mutation. Patient D has a homozygous mutation Thr180Lys, which is the same as the second family. Haplotype analysis indicates that patients B and C are not related to patient D. In patients E and F, we could identify only one mutant allele; Ala569Glu and Leu849His, respectively. All of the mutations identified are novel except for the Arg642Cys mutation, which has been found in a Japanese GS patient. Although further in vitro study is required to prove that the mutations are responsible for GS, it is possible that Thr180Lys and Arg642Cys mutations might be common mutations in Japanese GS.

scholarly journals Gitelman syndrome and ectopic calcification in the retina and joints

2021 ◽  
Author(s):  
Yeji Ham ◽  
Heather Mack ◽  
Deb Colville ◽  
Philip Harraka ◽  
B Biomed ◽  
...  
Keyword(s):  
Calcium Pyrophosphate ◽  
Bartter Syndrome ◽  
Gitelman Syndrome ◽  
Ectopic Calcification ◽  
Aggressive Management ◽  
Renal Tubular Disorder ◽  
Rate Of Progression ◽  
Renal Tubular ◽  
Retinal Photography

ABSTRACT Gitelman syndrome is a rare inherited renal tubular disorder with features that resemble thiazide use, including a hypokalemic metabolic alkalosis, hypomagnesemia, hypocalciuria, a low or normal blood pressure, and hyperreninemia and hyperaldosteronism. Treatment is primarily correction of the K and Mg levels. The diagnosis is confirmed with genetic testing but Gitelman syndrome is often not suspected. However the association with ectopic calcification in the retina, blood vessels and chondrocalcinosis in the joints is a useful pointer to this diagnosis. Bilateral symmetrical whitish deposits of calcium pyrophosphate are visible superotemporally on ophthalmoscopy and retinal photography but are actually located beneath the retina in the sclerochoroid. Optical coherence tomography is even more sensitive for their detection. These deposits increase in size with time, but the rate of progression slows with long-term correction of the hypomagnesemia. Calcification may be complicated by atrophy of the overlying retina and visual loss. The deposits often correlate with ectopic calcification in the aorta, coronary and cerebral vessels. Chondrocalcinosis occurs in the large joints such as the knees. Ectopic calcification in Gitelman syndrome indicates the need for more aggressive management of Ca and Mg levels. Calcification is much less common in Bartter syndrome which itself is rarer and associated less often with hypomagnesemia.

scholarly journals Permissive effect of GSK3β on profibrogenic plasticity of renal tubular cells in progressive chronic kidney disease

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Bohan Chen ◽  
Pei Wang ◽  
Xianhui Liang ◽  
Chunming Jiang ◽  
Yan Ge ◽  
...  
Keyword(s):  
Chronic Kidney Disease ◽  
Kidney Disease ◽  
Renal Fibrosis ◽  
Binding Protein ◽  
Renal Tubules ◽  
Genetic Ablation ◽  
Renal Tubular Cells ◽  
Renal Tubular ◽  
Renal Fibrogenesis ◽  
Tgf Β1

AbstractRenal tubular epithelial cells (TECs) play a key role in renal fibrogenesis. After persistent injuries that are beyond self-healing capacity, TECs will dedifferentiate, undergo growth arrest, convert to profibrogenic phenotypes, and resort to maladaptive plasticity that ultimately results in renal fibrosis. Evidence suggests that glycogen synthase kinase (GSK) 3β is centrally implicated in kidney injury. However, its role in renal fibrogenesis is obscure. Analysis of publicly available kidney transcriptome database demonstrated that patients with progressive chronic kidney disease (CKD) exhibited GSK3β overexpression in renal tubulointerstitium, in which the predefined hallmark gene sets implicated in fibrogenesis were remarkably enriched. In vitro, TGF-β1 treatment augmented GSK3β expression in TECs, concomitant with dedifferentiation, cell cycle arrest at G2/M phase, excessive accumulation of extracellular matrix, and overproduction of profibrotic cytokines like PAI-1 and CTGF. All these profibrogenic phenotypes were largely abrogated by GSK3β inhibitors or by ectopic expression of a dominant-negative mutant of GSK3β but reinforced in cells expressing the constitutively active mutant of GSK3β. Mechanistically, GSK3β suppressed, whereas inhibiting GSK3β facilitated, the activity of cAMP response element-binding protein (CREB), which competes for CREB-binding protein, a transcriptional coactivator essential for TGF-β1/Smad signaling pathway to drive TECs profibrogenic plasticity. In vivo, in mice with folic acid-induced progressive CKD, targeting of GSK3β in renal tubules via genetic ablation or by microdose lithium mitigated the profibrogenic plasticity of TEC, concomitant with attenuated interstitial fibrosis and tubular atrophy. Collectively, GSK3β is likely a pragmatic therapeutic target for averting profibrogenic plasticity of TECs and improving renal fibrosis.

scholarly journals Hypoxic mesenchymal stem cells ameliorate acute kidney ischemia-reperfusion injury via enhancing renal tubular autophagy

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Wei-Cheng Tseng ◽  
Pei-Ying Lee ◽  
Ming-Tsun Tsai ◽  
Fu-Pang Chang ◽  
Nien-Jung Chen ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Renal Recovery ◽  
Trophic Factors ◽  
Left Renal Artery ◽  
Renal Tubular Cells ◽  
Cell Based Therapy ◽  
Renal Tubular

Abstract Background Acute kidney injury (AKI) is an emerging global healthcare issue without effective therapy yet. Autophagy recycles damaged organelles and helps maintain tissue homeostasis in acute renal ischemia-reperfusion (I/R) injury. Hypoxic mesenchymal stem cells (HMSCs) represent an innovative cell-based therapy in AKI. Moreover, the conditioned medium of HMSCs (HMSC-CM) rich in beneficial trophic factors may serve as a cell-free alternative therapy. Nonetheless, whether HMSCs or HMSC-CM mitigate renal I/R injury via modulating tubular autophagy remains unclear. Methods Renal I/R injury was induced by clamping of the left renal artery with right nephrectomy in male Sprague-Dawley rats. The rats were injected with either PBS, HMSCs, or HMSC-CM immediately after the surgery and sacrificed 48 h later. Renal tubular NRK-52E cells subjected to hypoxia-reoxygenation (H/R) injury were co-cultured with HMSCs or treated with HMSC-CM to assess the regulatory effects of HSMCs on tubular autophagy and apoptosis. The association of tubular autophagy gene expression and renal recovery was also investigated in patients with ischemic AKI. Result HMSCs had a superior anti-oxidative effect in I/R-injured rat kidneys as compared to normoxia-cultured mesenchymal stem cells. HMSCs further attenuated renal macrophage infiltration and inflammation, reduced tubular apoptosis, enhanced tubular proliferation, and improved kidney function decline in rats with renal I/R injury. Moreover, HMSCs suppressed superoxide formation, reduced DNA damage and lipid peroxidation, and increased anti-oxidants expression in renal tubular epithelial cells during I/R injury. Co-culture of HMSCs with H/R-injured NRK-52E cells also lessened tubular cell death. Mechanistically, HMSCs downregulated the expression of pro-inflammatory interleukin-1β, proapoptotic Bax, and caspase 3. Notably, HMSCs also upregulated the expression of autophagy-related LC3B, Atg5 and Beclin 1 in renal tubular cells both in vivo and in vitro. Addition of 3-methyladenine suppressed the activity of autophagy and abrogated the renoprotective effects of HMSCs. The renoprotective effect of tubular autophagy was further validated in patients with ischemic AKI. AKI patients with higher renal LC3B expression were associated with better renal recovery. Conclusion The present study describes that the enhancing effect of MSCs, and especially of HMCSs, on tissue autophagy can be applied to suppress renal tubular apoptosis and attenuate renal impairment during renal I/R injury in the rat. Our findings provide further mechanistic support to HMSCs therapy and its investigation in clinical trials of ischemic AKI.

scholarly journals Human antigen R regulates hypoxia‐induced mitophagy in renal tubular cells through PARKIN/BNIP3L expressions

2021 ◽  
Author(s):  
Shao‐Hua Yu ◽  
Kalaiselvi Palanisamy ◽  
Kuo‐Ting Sun ◽  
Xin Li ◽  
Yao‐Ming Wang ◽  
...  
Keyword(s):  
Tubular Cells ◽  
Human Antigen R ◽  
Renal Tubular Cells ◽  
Renal Tubular

scholarly journals Interleukin-22 attenuates renal tubular cells inflammation and fibrosis induced by TGF-β1 through Notch1 signaling pathway

Renal Failure ◽  
2020 ◽  
Vol 42 (1) ◽  
pp. 381-390 ◽  
Author(s):  
Rong Tang ◽  
Xiangcheng Xiao ◽  
Yang Lu ◽  
Huihui Li ◽  
Qiaoling Zhou ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Tubular Cells ◽  
Interleukin 22 ◽  
Renal Tubular Cells ◽  
Notch1 Signaling ◽  
Renal Tubular ◽  
Notch1 Signaling Pathway ◽  
Tgf Β1

Redistribution and dysfunction of integrins in cultured renal epithelial cells exposed to oxidative stress

1993 ◽  
Vol 264 (1) ◽  
pp. F149-F157 ◽  
Author(s):  
J. Gailit ◽  
D. Colflesh ◽  
I. Rabiner ◽  
J. Simone ◽  
M. S. Goligorsky
Keyword(s):  
Oxidative Stress ◽  
Cell Adhesion ◽  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Surface ◽  
Apical Cell ◽  
Flow Cytometric Analysis ◽  
Adhesion Properties ◽  
Renal Tubular Cells ◽  
Renal Tubular

Tubular obstruction by detached renal tubular epithelial cells is a major cause of oliguria in acute renal failure. Viable renal tubular cells can be recovered from urine of patients with acute tubular necrosis, suggesting a possible defect in cell adhesion to the basement membrane. To study this process of epithelial cell desquamation in vitro, we investigated the effect of nonlethal oxidative stress on the integrin adhesion receptors of the primate kidney epithelial cell line BS-C-1. Morphological and functional studies of cell adhesion properties included the following: interference reflection microscopy, intravital confocal microscopy and immunocytochemistry, flow cytometric analysis of integrin receptor abundance, and cell-matrix attachment assay. High levels of the integrin subunits alpha 3, alpha v, and beta 1 were detected on the cell surface by fluorescence-activated cell sorting (FACS) analysis, as well as lower levels of alpha 1, alpha 2, alpha 4, alpha 5, alpha 6, and beta 3. Exposure of BS-C-1 cells to nonlethal oxidative stress resulted in the disruption of focal contacts, disappearance of talin from the basal cell surface, and in the redistribution of integrin alpha 3-subunits from predominantly basal location to the apical cell surface. As measured in a quantitative cell attachment assay, oxidative stress decreased BS-C-1 cell adhesion to type IV collagen, laminin, fibronectin, and vitronectin. Defective adhesion was not associated with a loss of alpha 3-, alpha 4-, or alpha v-integrin subunits from the cell surface.(ABSTRACT TRUNCATED AT 250 WORDS)

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