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Objective To investigate the effects of rotavirus ( RV) on the expression and bioactiv-ity of Na+-H+ exchanger 3 ( NHE3 ) in Caco-2 cells and the possible regulatory mechanism. Methods Caco-2 cells expressing NHE3 were constructed and divided into four groups as follows: control ( CTL ) group, RV group, BAPTA-AM ( a Ca2+ chelator) group and BAPTA-AM+RV group. Na+-H+ exchanger ac-tivity and NHE3 expression on cell surface were determined using BCECF-AM and biotinylation assay, re-spectively. Expression of Cdc42 at protein level was measured by Western blot. Results Compared with the control group, RV infection significantly decreased the activity of NHE3 and its expression on cell surface. BATPA-AM antagonized the inhibitory effects on NHE3. Moreover, the expression of Cdc42 at protein level was increased following RV infection, which was also antagonized by BATPA-AM. Conclusions Intracellu-lar Ca2+-mediated Cdc42-dependent endocytosis pathway might be involved in regulating the expression and bioactivity of NHE3 during RV infection.
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Objective To study the detection of Na+/H+exchanger regulatory factor 3(NHERF3) protein expression in renal carcinoma and its correlation with malignant biological behavior. Methods Renal clear cell carcinoma and their adjacent tissues of forty- eight patients were collected. Immunohistochemical method was used to detect the positive expression of NHERF3 protein,and specific expression was detected by Western-blot.Patients were further divided into high NHERF3 group and low NHERF3 group according to median expression of NHERF3 protein,and each group had 24 cases.The expressions of proliferation,invasion and autophagy genes in tumor tissues were detected by fluorescent quantitative PCR.Results The positive rate of NHERF3 protein and the expression of NHERF3 protein in renal carcinoma tissue was significantly lower than that in paracancerous tissue(P<0.05).Expressions of proliferation genes such as k-Ras,c-Myc,TRPC1 mRNA in low NHERF3 group were higher than those in high NHERF3 group:141.74 ± 18.95 vs. 100.00 ± 0.00, 135.88 ± 16.32 vs. 100.00 ± 0.00, 137.21 ± 16.98 vs.100.00 ± 0.00;MIIP,FOXO1 mRNA levels were lower than those in high NHERF3 group: 43.19 ± 5.88 vs. 100.00 ± 0.00, 38.76 ± 4.51 vs. 100.00 ± 0.00; expressions of invasion genes such as CD74, Fascin, MACC1, TRPM8 mRNA were significantly higher than those in high NHERF3 group:152.18 ± 17.64 vs. 100.00 ± 0.00, 146.29 ± 17.63 vs. 100.00 ± 0.00, 139.76 ± 15.82 vs. 100.00 ± 0.00,150.47 ± 17.95 vs.100.00 ± 0.00;expressions of autophagy genes such as Beclin-1,LC3 mRNA were significantly lower than those in high NHERF3 group: 63.21 ± 7.09 vs. 100.00 ± 0.00, 56.28 ± 7.15 vs. 100.00 ± 0.00; EZH2 mRNA level was higher than that in high NHERF3 group:159.47 ± 17.82 vs.100.00 ± 0.00,and there were significant differences(P<0.05).Conclusions The positive rate of NHERF3 protein expression and the amount of protein expression in renal carcinoma tissue is increased, and the specific expression is closely related to tumor proliferation, invasion and activity of autophagy.
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Objective To observe the effect of rotavirus (RV) infection on expression level and bioactivity of Na+-H+ exchanger 3 (NHE3) in Caco-2 cells. Methods Model of NHE3-expressing Caco-2 cells was constructed and studied in terms of intervention: control, RV, clathrin antagonist chlorpromazine (CPZ), and CPZ + RV. NHE3 activity and NHE3 protein amount on cell surface were determined by BCECF-AM and biotinylation, respectively. Expression level of clathrin was assayed by Western blot. Results Compared with control group, NHE3 activity and NHE3 surface protein level significantly decreased when the cells were treated with RV. These effects could not be completely cancelled by clathrin antagonist CPZ. Moreover, RV treatment could increase cellular protein level of clathrin, which was cancelled by CPZ. Conclusions The effect of RV infection on NHE3 expression level and biological activity may be related to clathrin-dependent endocytosis pathway, and may be also affected by other endocytosis pathways.
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Objective To observe the effects and regulatory mechanism of rotavirus infection on the expression and bioactivity of Na+/H+exchanger 3 (NHE3) on Caco-2 cells. Methods A cell model of Caco-2 cells expressing NHE3 was constructed. Four groups were set up,which were control(CTL) group, rotavirus(RV) infection group, Cdc42 inhibitor (Pirl-1) group and Pirl-1+RV group. Bioactivity and ex-pression of NHE3 on the surface of Caco-2 cells were determined by BCECF-AM and biotinylation method, respectively. Expression of Cdc42 protein was measured by Western blot. Co-immunoprecipitation was per-formed to detect the interaction between NHE3 and Cdc42. Results Compared with the CTL group,RV in-fection significantly inhibited the bioactivity and expression of NHE3 on Caco-2 cells. These inhibitory effects were antagonized by Pirl-1. Moreover,RV infection enhanced the expression of Cdc42 protein and promoted the interaction between NHE3 and Cdc42, which were also antagonized by Pirl-1. Conclusion RV infec-tion might regulate the expression and bioactivity of NHE3 through Cdc42-dependent endocytosis pathway.
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Objective To explore the effects of Na+ H-exchanger 1(NHE1) knockdown on ATP binding cassette transporter A1 (ABCA1) protein expression levels and cholesterol efflux in the hypoxic RAW264.7 cells.Methods The RAW264.7 cells were infected with lentiviral vectors expressing shRNA specific for NHE1(siNHE1) or scramble RNA (siNC).The expression of NHE1 at mRNA or protein level was detected by qRT-PCR and Western blotting respectively in the infected cells after 24 h in a hypoxia condition.In the meantime,the methods of SNARF-1,Fluo-4 NW andSuc-LLVY-aminoluciferin were employed to determine NHE1 activity,intracellular Ca2+ ([Ca2+]i) and calpain activity,respectively.Furthermore,ABCA1 protein levels were detected by Western blotting in the 24 h hypoxic cells.In parallel,the intracellular cholesterol content and cholesterol efflux were analyzed by the methods of combined enzymatic HLPC and 3 H-cholesterol.Results The hypoxia condition versus the normoxia condition up-regulated NHE1 mRNA and protein expression level and activity by 2.48 folds,1.28 folds and 61.96％ (all P＜0.05),and increased[Ca2+]i and calpain activity by 4.51 folds and 2.41 folds(all P＜0.05).Whereas the NHE1 mRNA and protein expression and activity at the presence of hypoxia were inhibited by siNHE1 with the inhibition ratio of 84.95％,60.75％ and 66.44％,respectively (all P＜0.05)and[Ca2+]i and calpain activity were reduced by 59.23％ and 54.66％ (P＜0.05).Furthermore,the ABCA1 protein level was 61.67％ lower in the hypoxic cells than in the normoxic cells (P＜0.05),and siNHE1 was increased by 56.52％ after treatment of Hypoxia.Hypoxia elevated intracellular total cholesterol and cholesterol ester by 74.57 ％ and 101.81％ (all P＜0.05).Treatment with siNHE1 in the hypoxia condition can reduce total cholesterol and cholesterol ester by 34.24 ％ 及 49.66 ％ (all P＜0.05).Hypoxia reduced the cholesterol efflux by 34.79％(P＜0.05),which were partially reversed by siNHE1.Conclusions NHE1 might play an important role in hypoxia-induced ABCA1 protein attenuation and reverse cholesterol transport dysfunction through[Ca2+]i/calpain pathway.
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Objective@#To observe the effects of Na+ /H+ exchanger 1 (NHE1) inhibitor on intestinal injury of rats with burn sepsis, and to explore the possible mechanism preliminarily.@*Methods@#Ninety SD rats were divided into control group, pure sepsis group, and NHE1 inhibitor group according to the random number table, with 30 rats in each group. Full-thickness scald (hereinafter referred to as burn) model with 20% total body surface area were reproduced on the back of rats in pure sepsis and NHE1 inhibitor groups, and then 50 μL liquid of Pseudomonas aeruginosa ATCC 27853 (2×105 colony forming unit/mL) were injected into the center of wounds on the back. Rats in NHE1 inhibitor group were intraperitoneally injected with 0.1 mmol/L NHE1 inhibitor cariporide (0.4 mg/kg) rapidly after the successful establishment of burn sepsis model, while rats in pure sepsis group were injected with the same volume of normal saline. Except for not being made burn wounds nor receiving bacterination, rats in control group were treated the same as those in pure sepsis group. Rats with burn sepsis in each group were laparotomized and injected with 200 mL fluorescein isothiocyanate (FITC)-dextran in the concentration of 0.1 mol/L in terminal ileum at 12 hours post injury, and their left ventricular blood and terminal ileum were collected 30 minutes later. The serum content of FITC-dextran was detected with fluorescence spectrophotometer (n=10); the morphology of intestinal tissue was observed with HE staining (n=10); the content of interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) in serum and intestinal tissue was determined with enzyme-linked immunosorbent assay (n=20); the activity of myeloperoxidase (MPO) in serum and intestinal tissue was detected with colorimetric method (n=20); the protein expression of nuclear factor-kappa B-p65 (NF-κB-p65) and phosphorylation levels of mitogen-activated protein kinase (MAPK) signal pathway related proteins p38MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2), and c-Jun N-terminal kinase 1/2 (JNK1/2) were determined by Western blotting (n=4). The same samples of rats in control group were collected for related detection at the same time point as above. Data were processed with one-way analysis of variance and SNK test.@*Results@#(1) The serum content of FITC-dextran of rats in pure sepsis group was significantly higher than that in control group (P<0.01), while the serum content of FITC-dextran of rats in NHE1 inhibitor group was significantly lower than that in pure sepsis group (P<0.01). Compared with that in control group, infiltration of a large number of inflammatory cells, ulcer and necrosis of intestinal mucosa of rats in pure sepsis group were observed. The injury condition of intestine of rats in NHE1 inhibitor group was better than that in pure sepsis group. (2) The serum content of IL-6, TNF-α, and MPO of rats in pure sepsis group was (387±42) and (164.7±10.1) ng/mL, and (7.5±1.5) U/mL, respectively, significantly higher than that in control group [(75±17) and (13.1±6.5) ng/mL, and (2.3±0.7) U/mL, respectively, with P values below 0.01]. The serum content of IL-6, TNF-α, and MPO of rats in NHE1 inhibitor group was (176±37) and (64.9±9.3) ng/mL, and (5.9±0.8) U/mL, respectively, which was significantly lower than that in pure sepsis group (with P values below 0.01). (3) The content of IL-6, TNF-α, and MPO in intestinal tissue of rats in pure sepsis group was (190±13) and (172.8±29.7) ng/mL, and (8.7±1.5) U/mL, respectively, significantly higher than that in control group [respectively (20±3) and (11.9±2.3) ng/mL, and (2.9±0.3) U/mL, with P values below 0.01]. The content of IL-6, TNF-α, and MPO of intestinal tissue of rats in NHE1 inhibitor group was (35±6) and (45.2±6.1) ng/mL, and (5.3±0.6) U/mL, respectively, significantly lower than that in pure sepsis group (with P values below 0.01). (4) The protein expression of NF-κB-p65 and phosphorylation levels of p38MAPK and ERK1/2 in intestinal tissue of rats in pure sepsis group were significantly higher than those in control group (with P values below 0.01); the protein expression of NF-κB-p65 and the phosphorylation level of p38MAPK in intestinal tissue of rats in NHE1 inhibitor group were significantly lower than those in pure sepsis group (with P values below 0.01); phosphorylation levels of JNK1/2 in intestinal tissue of rats in the three groups were similar (with P values above 0.05).@*Conclusions@#The inhibition of NHE1 can significantly alleviate the intestinal injury, and the mechanisms may be attributed to the regulation of NF-κB and p38MAPK signal pathway, resulting in inhibition of the inflammatory response of intestinal tract.
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The Na⁺/H⁺ exchanger-1 (NHE-1) is a ubiquitously expressed pH-regulatory membrane protein that functions in the brain, heart, and other organs. It is increased by intracellular acidosis through the interaction of intracellular H⁺ with an allosteric modifier site in the transport domain. In the previous study, we reported that glutamate-induced NHE-1 phosphorylation mediated by activation of protein kinase C-β (PKC-β) in cultured neuron cells via extracellular signal-regulated kinases (ERK)/p90 ribosomal s6 kinases (p90RSK) pathway results in NHE-1 activation. However, whether glutamate stimulates NHE-1 activity solely by the allosteric mechanism remains elusive. Cultured primary cortical neuronal cells were subjected to intracellular acidosis by exposure to 100 μM glutamate or 20 mM NH₄Cl. After the desired duration of intracellular acidosis, the phosphorylation and activation of PKC-β, ERK1/2 and p90RSK were determined by Western blotting. We investigated whether the duration of intracellular acidosis is controlled by glutamate exposure time. The NHE-1 activation increased while intracellular acidosis sustained for >3 min. To determine if sustained intracellular acidosis induced NHE-1 phosphorylation, we examined phosphorylation of NHE-1 induced by intracellular acidosis by transient exposure to NH₄Cl. Sustained intracellular acidosis led to activation and phosphorylation of NHE-1. In addition, sustained intracellular acidosis also activated the PKC-β, ERK1/2, and p90RSK in neuronal cells. We conclude that glutamate stimulates NHE-1 activity through sustained intracellular acidosis, which mediates NHE-1 phosphorylation regulated by PKC-β/ERK1/2/p90RSK pathway in neuronal cells.
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Acidose , Technique de Western , Encéphale , Extracellular Signal-Regulated MAP Kinases , Acide glutamique , Coeur , Protéines membranaires , Neurones , Phosphorylation , Phosphotransferases , Protein kinasesRésumé
AIM:To explore the mechanisms underlying contraction induced by extracelluar acidosis (pHex6.8) in rat isolated coronary artery (RCA).METHODS:Using the microvessel tension recorder system, the effects of acid-base transporters on RCA contraction induced by pHex6.8 were explored by applying the selective pharmacological inhibitors of Na+-H+ exchanger 1 (NHE-1) and Na+-HCO-3 cotransporter (NBC), HOE-642 and S0859, respectively.The effects of chloride channel on RCA contraction induced by pHex6.8 were explored by applying the inhibitors of chloride channel (NPPB and NFA), and by replacing the extracellular NaCl with equimolar NaBr.RESULTS:pHex6.8 augmented the resting tension of RCA, and the maximum contraction was (3.90±0.95) mN.HOE-642 at 30 μmol/L and S0859 at 100 μmol/L both inhibited the contraction of RCA induced by pHex6.8 (P<0.01).NPPB and NFA both inhibited the contraction of RCA induced by pHex6.8 or KCl (60 mmol/L) in a concentration-dependent manner.NPPB and NFA (100 μmol/L) both inhibited the contraction of RCA induced by U46619 (1 μmol/L).Replacing the extracellular NaCl with equimolar NaBr almost completely inhibited RCA contraction induced by pHex6.8 (P<0.01), but had no obvious effect on the contraction induced by KCl (60 mmol/L) or U46619 (1 μmol/L).CONCLUSION:Extracellular acidosis-induced contraction in RCA may be related to the activated NHE-1 and NBC, and it may be also related to the enhanced chloride transport across the membrane.
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Objective: To observe the effects of NHE -1 (Na+/H+ exchanger 1) gene on the proliferative and invasive abilities of esophageal cancer cell line KYSE-70. Methods: The expressions of NHE-1 mRNA and protein in esophageal cancer EC-9706, KYSE-450, EC-1 and KYSE-70 cells were detected by realtime fluorescence quantitative-PCR and Western blotting, respectively. Chemically synthesized siRNA (small interference RNA) targeting NHE -1 was transfected into KYSE-70 cells. The expression levels of NHE-1 mRNA and protein in esophageal cancer KYSE-70 cells 24, 48 and 72 h after transfection with NHE-1 siRNA were detected by real-time fluorescence quantitative-PCR and Western blotting, respectively. The proliferative and invasive abilities of KYSE-70 cells were detected by MTT method and Boyden chamber assay, respectively. Results: NHE-1 mRNA and protein were highly expressed in KYSE-70 cells. As compared with the negative control (transfected with nonsense siRNA) and blank control (KYSE-70 cells without transfection), the expression levels of NHE-1 mRNA and protein in KYSE-70 were significantly decreased after transfection with siRNA targeting NHE -1 (all P < 0.05). As compared with the negative control, blank control and the KYSE-70 cells transfected with NHE-1 siRNA for 24 h, the proliferative and invasive abilities of KYSE-70 were inhibited after transfection with NHE-1 siRNA for 48 and 72 h (all P < 0.05). Conclusion: Silencing the expression of NHE -1 gene can inhibit the proliferative and invasive abilities of esophageal cancer KYSE-70 cells in vitro . NHE -1 gene is expected to become an important target for gene therapy of esophageal cancer. Copyright © 2013 by TUMOR.
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The objectives of the present study were to identify the cis-elements of the promoter absolutely required for the efficient rat NHE3 gene transcription and to locate positive and negative regulatory elements in the 5’-flanking sequence (5’FS), which might modulate the gene expression in proximal tubules, and to compare this result to those reported for intestinal cell lines. We analyzed the promoter activity of different 5’FS segments of the rat NHE3 gene, in the OKP renal proximal tubule cell line by measuring the activity of the reporter gene luciferase. Because the segment spanning the first 157 bp of 5’FS was the most active it was studied in more detail by sequential deletions, point mutations, and gel shift assays. The essential elements for gene transcription are in the region -85 to -33, where we can identify consensual binding sites for Sp1 and EGR-1, which are relevant to NHE3 gene basal transcription. Although a low level of transcription is still possible when the first 25 bp of the 5’FS are used as promoter, efficient transcription only occurs with 44 bp of 5’FS. There are negative regulatory elements in the segments spanning -1196 to -889 and -467 to -152, and positive enhancers between -889 and -479 bp of 5’FS. Transcription factors in the OKP cell nuclear extract efficiently bound to DNA elements of rat NHE3 promoter as demonstrated by gel shift assays, suggesting a high level of similarity between transcription factors of both species, including Sp1 and EGR-1.
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Animaux , Régulation de l'expression des gènes/génétique , Tubules contournés proximaux/métabolisme , Régions promotrices (génétique)/génétique , Antiport des ions sodium-hydrogène/génétique , Régions terminatrices (génétique)/génétique , Transcription génétique/génétique , /génétique , Didelphis , Intestins/cytologie , Intestins/métabolisme , Tubules contournés proximaux/cytologie , Mutation ponctuelle/génétique , Antiport des ions sodium-hydrogène/métabolismeRésumé
Objective To explore the mechanism of protecting cells from ischemic reperfusion injury by constructing specific small interference RNA (siRNA) to inhibit Na+-H+exchanger-1 (NHE-1) expression in human renal tubular epithelial cell (HKC). Methods The siRNA was designed and synthesized based on human NHE-1 complete sequence,and was transfected into HKC.The irrespective siRNA transfected group was used as control.The cells were treated with 10 μmol/L antimyein A to induce ischemia and anoxyaemia environment.NHE-1expression was examined by RT-PCR and Western blot.The intraeellular pH (pHi),Ca2+ or Na+ concentrations were detected by BCECF/AM,Fluo-3/AM and SBFI-AM,respectively,combining with laser eonfocal assay system.Nucleic morphology was determined by Hoechst 33342.Cellular apoptosis was examined by Annexin V/PI staining and flow eytometry.Fluorescent probe JC-1 was used to detect the change of mitechondrial transmembrane potential. Results The specific siRNA could efficiently inhibit NHE-1 expression in HKC.Compared with the irrespective siRNA transfected group,the mRNA and protein expression of NHE-1 was significantly down-regulated in NHE-1 siRNA transfeeted group (all P＜0.05).After treatment with antimyein A,the mRNA and protein expression of NHE-1 was significantly up-regulated in both groups,however,it was less than that in irrespective siBNA transfected group.At the same time,the ratio of apoptosis decreased (8.9% +2.9% vs 18.8%±3.2% , 17.4%±3.6% ,P＜0.05) and mitochondrial transmembrane potential rose significantly in NHE-1 siRNA transfected group as compared to irrespective siRNA transfected group and antimycin A group.The intracellular Na+,H+ and Ca2+concentrations increased in NHE-1 siRNA transfected group treated with antimyein A,but their levels were lower than those in irrespective siRNA transfected group with the same treatment(P＜0.05). Conclusions The synthesized siBNA can inhibit the expression of NHE-1 and can protect HKC from isehemia reperfasion injury induced by antimyein A.The mechanism might be via suppressing the expression of NHE-1 to delay intracelluar Na+ accumulation,attenuate intracellular Ca2+ overloading,and inhibit the decrease of mitechondrion transmembrane potential and reduce cellular apoptosis.
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Metabolic acidosis was shown to correlate with deterioration of renal function in patients with rhabdomyolysis. The present study was aimed to investigate whether the changes of type 3 Na+/H+ exchanger (NHE3), type 1 Na+/HCO3- cotransporter (NBC1), and Na+,K+-ATPase alpha1 subunit may play a role in the pathogenesis of metabolic acidosis in glycerol-induced experimental rhabdomyolysis. Male Sprague-Dawley rats were deprived of fluid intake for 24 hours, and then were injected with 50% glycerol in normal saline (10 mL/kg, intramuscularly). At 24 hours after the glycerol injection, rats were sacrificed by decapitation. Control rats were injected with normal saline. The protein expression of NHE3, NBC1 and Na+,K+-ATPase alpha1 subunit was determined in the cortex of the kidney by immunoblotting and immunohistochemistry. Following the treatment of glycerol, creatinine clearance was significantly decreased, and high anion gap metabolic acidosis developed. In the experimental group, the expression of Na+,K+-ATPase alpha1 subunit was significantly decreased in the cortex of the kidney. On the contrary, the expression of NHE3 and NBC1 was significantly increased. Immunohistochemical analyses confirmed the immunoblotting data. In conclusion, the coordinate up-regulation of NHE3 and NBC1 may play an adaptive role against the metabolic acidosis in glycerol-induced rhabdomyolysis.
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Animaux , Humains , Mâle , Rats , Équilibre acido-basique , Acidose , Créatinine , Décollation , Glycérol , Immunotransfert , Immunohistochimie , Rein , Rat Sprague-Dawley , Rhabdomyolyse , Régulation positiveRésumé
BACKGROUND:Cytoprotective effect of Na+/H+ exchanger type 1 (NHE1) inhibitors has been studied in ischemic/reperfusion (IR) injury. The aim of this study was to evaluate the renoprotective effect and the mechanism of NHE1 inhibitor (Cariporide(R)) on IR injury of rat kidney. METHODS:IR injury was produced by clamping both renal arteries and then rats were treated with intravenous (IV) Cariporide(R) (0.5 or 1.0 mg/kg) in Sprague-Dawley rats. The effects of Cariporide(R) treatment on subsequent IR injury were evaluated in terms of renal function, tubular injury, inflammatory cytokines (IL-1beta, TNF-alpha), apoptosis, and the expression of MAPKs. RESULTS:BUN and serum creatinine increased after IR injury compared with sham-operated controls. However, treatment with Cariporide(R) significantly reduced BUN and serum creatinine. IR injury caused severe destruction of renal tubular cells in the outer medulla, but treatment with Cariporide(R) decreased the tubular damage. Treatment with Cariporide(R) also significantly decreased the expression of IL-1beta and TNF-alpha mRNA compared with IR injury. Apoptotic cell death was increased with I/R injury, but was significantly decreased in kidneys treated with Cariporide(R). At molecular basis, caspase 3 protein decreased more in Cariporide(R)-treated group than in IR injury group. The expression of MAPKs significantly increased with IR injury compared with sham- operated controls. However, kidneys treated with Cariporide(R) showed further increase of ERK expression compared with IR injury, but showed a significant decrease of JNK expression. CONCLUSIONS:NHE1 inhibitors, Cariporide(R), partially prevented IR injury-induced acute renal failure by the mechanism involving apoptosis, inflammation and MAPKs.
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Animaux , Rats , Atteinte rénale aigüe , Apoptose , Caspase-3 , Mort cellulaire , Constriction , Créatinine , Cytokines , Inflammation , Rein , Rat Sprague-Dawley , Artère rénale , ARN messager , Facteur de nécrose tumorale alphaRésumé
The marked hemodynamic and hormonal changes of normal pregnancy are associated with striking alterations in renal physiology involving structure, dynamics, tubular function, and volume homeostasis. A number of acid-base or electrolyte disorders are associated with decreased or increased HCO3-reabsorption in the renal tubules. The present study was to examine the alterations of expression and distribution of Na+/HCO3-cotransporter (NBC), Na+/H+ exchanger-3 (NHE-3), and carbonic anhydrase I and II (CA I, II) proteins in the kidneys of non-pregnant (NP) and pregnant rats using Western blot analysis and immunohistochemistry. Sprague-Dawley female rats were studied on days 10 (P 10), 12 (P 12), 14 (P 14), 17 (P 17), and 19 (P 19) of pregnancy. Western blot analysis demonstrated that the expression of NBC, ~110 kDa at molecular mass, was increased in pregnant rats, particularly P 12, compared with NP rat. The expression of NHE-3, ~83 kDa at molecular mass, was increased in pregnant rats, particularly P 12 and P 14. The expression of CA I, ~30 kDa at molecular mass, was decreased in pregnant rats, particularly P 14, but, CA II protein, ~30 kDa at molecular mass, was similar NP rat. In immunohistochemistry, strong immunoreactivity of NBC of NP rat was exclusively detected in the basolateral membranes of S1 and S2 segment of proximal tubules whereas not in S3 segment. In pregnant rats, the pattern of cellular labeling of NBC was identical to that of NP rat, but signal intensity was increased, particularly P 12. In NHE-3, strong immunoreactivity was detected in apical membranes and brush borders of S3 segments and moderate in S1 and S2 segments. In pregnant rats, the pattern of cellular labeling was identical to that of NP rat, but the signal intensity was increased, particularly P 12 and P 14. Expression of CA I and II proteins was detected in entire collecting duct. Signal intensity was prominent in type A intercalated cells and moderate in type B intercalated cells. In pregnant rats, the pattern of cellular labeling of CA I and II proteins was identical to that of non-pregnant rat, but the signal intensity of CA I was decreased in cortical collecting duct, particularly P 14 and CA II was identical to that of NP rat. These results suggest that the regulation of NBC and NHE-3 expressions in the proximal tubules and CA I expression in cortical collecting duct may maintain HCO3-concentration during the pregnancy.
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Animaux , Femelle , Humains , Grossesse , Rats , Hydrogénocarbonates , Technique de Western , Carbonic anhydrase I , Hémodynamique , Homéostasie , Immunohistochimie , Rein , Membranes , Microvillosités , Physiologie , Rat Sprague-Dawley , Contrôle social formel , GrèvesRésumé
Objective To explore the role of Na~+/H~+ exchanger 1(NHE1) in injury of human renal tubular cells(HK-2) induced by postasphyxial-serum of neonates.Methods HK-2 was used as the target cell.The attacking concentration of postasphyxial-serum of neonates was 200 mL/L.First,the experiment was designed as control group and asphyxia group,the expression of NHE1 in the HK-2 was detected by immunohisto chemical method in the cells.Second,the experiment group was designed as control group,asphyxia group,and pretreatment with 5-N-Ethyl-N-isopropylamiloride(EIPA) group,then the change of morphology was observed under inverted microscope,and the cell viability was measured by methyl thiazolyl tetrazolium(MTT) method,and the leakage rate of lactate dehydrogenase(LDH) was determined by biochemical methods.Results Compared with blank control group,the expression of NHE1 in the HK-2 was increased signi-ficantly in asphyxia group,the changes of morphology of HK-2 was most serious and obvious,the cell viability decreased,and the leakage rate of LDH increased significantly in asphyxia group.But compared with asphyxia group,the change of morphology of HK-2 was greatly improved,the cell injury was decreased obviously,the leakage rate of LDH was increased and viability was decreased in pretreatment group in a dose 2 ?mol/L.Conclusions The postasphyxial-serum may induce the expression of NHE1,which plays an important role in injury of renal tubular cell induced by postasphyxial-serum in neonates,and inhibiting activity of NHE1 may relieve the injury of renal tubular cells induced by postasphyxial-serum in neonates.
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A number of acid-base or electrolyte disorders are associated with decreased or increased HCO3- reabsorption in the renal tubules. There has been a general agreement that potassium depletion induces and maintains metabolic alkalosis in rats. However, many researchers have approached such issue only from functional studies to investigate Na+/H+ exchanger (NHE-3) and Na+/HCO(3-) cotransporter (NBC) activity which closely relates to potassium depletion. In addition the results obtained vary according to their researchers. Thus the present study was employed Western blot analysis and immunohistochemistry together, to examine the alterations of expression and distribution of NHE-3 and NBC-1 with reference to HCO3- reabsorption in the kidneys of rats fed potassium free diets according to the periods. Western blot analysis demonstrated that NHE-3 protein, ~83 kDa at molecular mass, was abundantly expressed in normal group. All potassium-depleted groups showed significantly increased NHE-3 protein compared to normal group. NBC-1 protein, ~110 kDa at molecular mass, was moderately expressed in normal group. All potassium-depleted groups had much higher amounts of the protein than normal group. There was a highly increased amount of NBC-1 protein especially in K-depleted 1 week group. Immunohistochemistry showed positive immunoreactivity of NHE-3 in the apical membranes and brush borders of proximal renal tubule cells. Its reactivity was most prominent in the S3.S1 and S2 had moderate immunoreactivity. Potassium-depleted groups had an identical pattern of cellular labeling of NHE-3 protein compared with that of normal group. However the signal intensity of NHE-3 protein in potassium-depleted groups was much higher than that of normal group. Immunoreactivity of NBC-1 was observed exclusively in the basolateral plasma membranes of proximal tubule cells. There was a strong reactivity in the S1 and S2, whereas S3 did not show any reactivity. Potassium-deprived rats exhibited an identical pattern of cellular labeling of NBC-1 protein compared with that of normal rats. However, the signal intensity of NBC-1 protein was markedly increased in potassium-deprived rats. These results suggest that increased NHE-3 and NBC-1 expression resulted from potassium depletion in the renal proximal tubules, enhances HCO3-reabsorption and consequently maintains metabolic alkalosis.
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Animaux , Rats , Alcalose , Hydrogénocarbonates , Technique de Western , Membrane cellulaire , Régime alimentaire , Hypokaliémie , Immunohistochimie , Tubules contournés proximaux , Rein , Membranes , Microvillosités , Potassium , Contrôle social formelRésumé
Aim To investigate the effects of Cariporide on expression of intercellular adhesion molecule-1(ICAM-1) and P-selectin and adhesion of monocytes and endothelial cells induced by lysophophatidylcholine(LPC).Methods The ratio of adhesion of monocytes and endothelial cells was assessed by measuring protein content.The expression of ICAM-1 and P-selectin in endothelial cells was examined by enzyme-linked immunosorbent assay(ELISA).Intracellular pH of endothelial cells was measured with 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein(BCECF).Results The results showed that LPC enhanced the adhesion of monocytes and endothelial cells in a concentration-dependant and time-related manner.The dosage of 5,10 and 20 ?mol?L-1 Cariporide reduced the adhesive ratio of endothelial cells induced by LPC(5 mg?L-1)from 36% to 23%,18% and 16%(P
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No abstract available.
Sujets)
Souris , Xanthine(isobutyl-3 methyl-1)/pharmacologie , Composés d'ammonium/pharmacologie , Animaux , Transport biologique/physiologie , Transport biologique/effets des médicaments et des substances chimiques , Membrane cellulaire/métabolisme , AMP cyclique/métabolisme , Colforsine/pharmacologie , Guanidines/pharmacologie , Souris knockout , Conduits pancréatiques/métabolisme , Inhibiteurs de la phosphodiestérase/pharmacologie , Protons , Antiport des ions sodium-hydrogène/métabolisme , Antiport des ions sodium-hydrogène/génétique , Sulfones/pharmacologieRésumé
No abstract available.
Sujets)
Animaux , Isomérie , Salive/métabolisme , Antiport des ions sodium-hydrogène/métabolisme , Antiport des ions sodium-hydrogène/physiologie , Antiport des ions sodium-hydrogène/composition chimiqueRésumé
No abstract available.