Clearance effect of regulation of serine/threonine protein kinase-1 signaling pathway by insulin on pulmonary edema in mice with acute lung injury / 中国生物制品学杂志

@#Objective To investigate the mechanism of insulin alleviating pulmonary edema in mice with acute lung injury(ALI) by serine/threonine protein kinase-1(SGK1).Methods 32 male adult C3H/HeN mice were randomly divided into control group(only pumped with the same amount of normal saline as the treatment group),ALI group(continuously pumped with the same amount of normal saline as the treatment group after modeling),treatment group [continuously pumped with 0.1 U/(kg·h) of insulin through jugular vein after establishing ALI model] and SGK1 siRNA group[continuously pumped with 0.1 U/(kg·h) of insulin and given SGK1 siRNA(75 μg SGK1 siRNA diluted in 100 μL saline) simultaneously after establishing ALI model] with 8 mice in each group.After 8 h,the mice were killed for arterial blood gas analysis(1 h after establishment of the model) and the changes of plasma glucose levels were detected(0,1,4and 8 h);The bronchoalveolar lavage fluid(BALF) was collected to detect the content of total protein,and the alveolar epithelial permeability and lung water content were measured;The pathological changes of lung tissue and apoptosis of lung epithelial cells were observed;The protein expressions of alveolar epithelial sodium channel(ENaC) and α_1-Na~+,K~+-ATPase and the phosphorylation level of SGK1 were determined by Western blot.Results There was no significant difference in plasma glucose level of ALI and treatment group at 0,1,4 and 8 h after insulin infusion(t=1.330 0,0.986 0,0.565 7 and 0.724 3,P=0.204 7,0.340 7,0.580 6 and 0.480 8,respectively).Compared with ALI group,the partial pressure of oxygen in arterial blood in treatment group increased significantly(t=6.026,P <0.000 1),while the BALF protein content,alveolar epithelial permeability,lung water content and lung epithelial cells apoptosis decreased significantly(t=7.39,5.286,5.651 and 3.312,P <0.000 1,=0.000 4,=0.000 2 and=0.007 8,respectively),and the expression of α-ENaC and α_1-Na~+,K~+-ATPase and the phosphorylation level of SGK1 in lung tissue significantly increased(t=26,18.67 and 8.547,P <0.000 1,<0.000 1 and=0.000 1,respectively);Compared with the treatment group,the BALF protein content,alveolar epithelial permeability,lung water content and lung epithelial cells apoptosis increased significantly in SGK1 siRNA group(t=5.964,3.449,3.148 and 3.520,P=0.000 2,0.006 2,0.010 4 and0.016 9,respectively),while α-ENaC and α_1-Na~+,K~+-ATPase protein expression and SGK1 phosphorylation level decreased significantly(t=13,9.874 and 7.741,P <0.000 1,<0.000 1 and=0.001 5,respectively).Conclusion Exogenous insulin can alleviate the pulmonary edema in ALI mice,which might be mediated via up-regulation of the expressions of α-ENaC and α_1-Na~+,K~+-ATPase by SGK1.

Mechanism of Xiao Qinglongtang Regulating Lung Water Transport-related Proteins Based on Theory of Lung Controlling Water Movement / 中国实验方剂学杂志

ObjectiveTo observe the regulatory effect of Xiao Qinglongtang and its ingredients on lung water transport-related proteins， and to explain the biological connotation of lung governing water movement， based on which the regulatory mechanism of Xiao Qinglongtang will be explored. MethodAccording to the composition rules of classical formula， Xiao Qinglongtang （11.22 g·kg-1）， Guizhi Gancao （2.70 g·kg-1）， Shaoyao Gancao （2.70 g·kg-1）， Jiangxinwei （3.90 g·kg-1）and Banxia Muahuang （0.032 7 g·kg-1） were prepared. The pathological model of syndrome of cold fluid accumulated in lung of rats was established by the "coldness of body + drinking cold + cold bath" method， and Xiao Qinglongtang and its ingredients were administrated to intervene with the model rats. Lung function parameters of forced vital capacity （FVC）， functional residual capacity （FRC）， mean mid-expiratory flow （MMEF）， inspiratory time （tI）， and inspiratory time （tE） were determined by lung function analyzer. Hematoxylin and eosin （HE） staining was used to observe the changes in pathological morphology. The expression of aquaporin （AQP）1， AQP5， epithelial sodium channel α subunit（α-ENaC） and Na+-K+-ATPase in lung tissues of rats， the content of tumor necrosis factor -α（TNF-α）， the mRNA expression of cyclic adenosine monophosphate （cAMP）， protein kinase A （PKA） and cAMP-response element binding protein （CREB）， and the protein expression of cAMP， PKA， CREB， and phosphorylated-CREB （p-CREB） were detected by immunohistochemistry （IHC）， enzyme-linked immunosorbent assay （ELISA）， Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR）， and Western blot， respectively. ResultCompared with normal group， functions of FVC， FRC and MMEF in model group were significantly decreased (P<0.01)， and the time of tI and tE was significantly prolonged （P<0.05，P<0.01）. The content of TNF-α in lung tissue was significantly increased （P<0.01）. The mRNA and protein expressions of cAMP， PKA and CREB in lung tissue were significantly decreased （P<0.01）. The expression of AQP5 and α-ENAC in lung tissue decreased significantly. The alveolar cavity of rats was filled with edema fluid， surrounding tissue hyperemia， inflammatory cell infiltration, bronchial mucosa epithelial adhesion. Compared with model group， Xiao Qinglongtang and its fangyuan group could significantly enhance the FVC, FRC and MMEF functions of model rats （P<0.05，P<0.01）， and tI and tE time were shortened （P<0.05，P<0.01）. The content of TNF-α in lung tissues of Xiao Qinglongtang group， Guizhi Gancao group and Banxia Mahuang group was significantly decreased （P<0.01）. The mRNA expressions of cAMP， PKA and CREB in Xiao Qinglongtang group were significantly up-regulated （P<0.01）， and the mRNA expressions of cAMP and PKA in Guizhi Gancao， Jiangxinwei and Banxia Mahuang groups were significantly up-regulated （P<0.01）. The protein expressions of cAMP， PKA and CREB in Xiao Qinglongtang group， Guizhi Gancao group， Jiangxinwei group and Banxia Mahuang group were significantly up-regulated （P<0.01）， and the protein expression of CREB in Shaoyao Gancao group was significantly up-regulated（P<0.05）. Xiao Qinglongtang could up-regulate the positive expression of AQP5 and α-ENAC， and Guizhi Gancao group could up-regulate the positive expression of α-ENAC. Xiao Qinglongtang and its fangyuan can reduce the lung edema， inflammatory cell infiltration and bronchial mucosal adhesion of model rats. ConclusionXiao Qinglongtang and its ingredients can reduce lung edema and inhibit inflammation by improving the expression of lung water transport-related proteins AQP1， AQP5， and α-ENaC through cAMP/PKA pathway， thereby restoring the lung functions in rats with syndrome of cold fluid accumulated in lung. Na+-K+-ATPase may play an auxiliary role in the regulation of lung water transport. This provides a certain objective basis for preliminarily elucidating the connotation of lung governing water movement from the perspective of lung water transport-related proteins.

Cystic fibrosis lung disease: Current perspectives

Cystic fibrosis (CF) is an autosomal recessive disease caused by mutations in the gene encoding the cystic fibrosis transmembrane conductance regulator (CFTR). These mutations alter the synthesis, processing, function, or half-life of CFTR, the main chloride channel expressed in the apical membrane of epithelial cells in the airway, intestine, pancreas, and reproductive tract. Lung disease is the most critical manifestation of CF. It is characterized by airway obstruction, infection, and inflammation that lead to fatal tissue destruction, which causes most CF morbidity and mortality. This article reviews the pathophysiology of CF, recent animal models, and current treatment of CF.

A study to assess the prevalence of hypertension in children with nephrotic syndrome

Background: Hypertension is been one of the most common co morbidity of this disease. It was mostly attributed to sodium retention, which is a major clinical feature of nephrotic syndrome. These mechanisms likely have a role in the development of hypertension in nephrotic syndrome, where hypertension may be difficult to control, and provide new therapeutic options for the management of blood pressure in the setting of nephrotic syndrome. Objective of study the prevalence of hypertension in children with NS and also the number of antihypertensive required to control it.Method: A Retrospective study of the hospital records of 100 children diagnosed with nephrotic syndrome admitted to Pediatric and Nephrology Ward at YMCH was accessed.Results: In our study 35 (35%) of them were Infrequent relapse nephrotic syndrome (IFNS) and 35(35%) were' Frequent relapse nephrotic syndrome (FRNS) ,while 30 cases (30%) were First episode nephrotic syndrome (FENS). 65 cases were steroid sensitive, while 28 and 7 of them were steroid dependent and resistant respectively. Of the 100 study population 54 of them had hypertension while 46 of them did not develop it .Of the 54 hypertensive nephrotic syndrome children, 15 of them (28.%) required three anti hypertensives to control the pressure, while 19 (35%) and 20 (37%) required single and dual anti hypertensives respectively.Conclusion: Prevalence of hypertension is increasing among the children with nephrotic syndrome. Its more prevalent among the male then female FRNS, SRNS and SDNS are more prone to develop hypertension and also they needed two or more antihypertensives to control the hypertension, whereas hypertension in SSNS could be managed with single drug.

The expression and function of acid-sensing ion channels in auditory system and vestibular system / 中华耳鼻咽喉头颈外科杂志

Acid-sensing ion channels are a class of extracellular H+ activated cation channels, belonging to the amiloride-sensitive epithelial Na+ channel/degenerin (ENaC/DEG) superfamily. During extracellular acidification, the channels are activated and produce corresponding action potential. Acid-sensing ion channels are extensively expressed in the peripheral and central nervous system. It plays an important in synaptic plasticity, mechanical sensation, injury sensation related to acidosis of local tissues, acid reception and retinal regulation. This article reviews the expression, biological characteristics and functions of acid-sensing ion channels in cochlea, vestibular tissue and auditory center, so as to improve the understanding of physiology and pathophysiology of auditory system.

Effect of Topically Epithelial Sodium Channel Inhibitors Eyedrops on Tear Production in Rabbit with Scopolamine Induced Dry Eye / 中山大学学报(医学科学版)

@#【Objective】To test the hypothesis that inhibiting sodium absorption via the epithelial sodium channel（ENaC） will increase ocular hydration and cure the rabbit′ s dry eye induced by scopolamine. 【Methods】In the experiment，24 New Zealand rabbits weighing about 2.0- 2.5 kg were divided into 3 groups：tested group（8 rabbits）， control group （8 rabbits），and treatment group （8 rabbits）. For the rabbits in the tested group，they were given subcutaneous injection of scopolamine 4 times a day for 12 consecutive days to induce the dry eye. For the rabbits in the control group，they accepted subcutaneous injection of saline solution. For the rabbits in the treatment group ，they were firstly given the same treatment as the rabbits in the tested group. Then，the local regions in their right eyes received the application of 100 mmol/L amiloride （a sodium channel inhibitor）. Meanwhile，the local regions in their left eyes received the application of equivalent saline solution. We detected ENAC α and ENAC γ subunits of epithelial sodium channel in conjunctival epithelium by fluorescence quantitative PCR and detected the opening of epithelial sodium channel by short- circuit current technology. Finally，we compared the ENaC α and ENaC γ gene expression，corneal fluorescein sodium staining and tear secretion among the 3 groups. Fluorescence quantitative PCR was used to detect ENaC α and ENaC γ subunits of epithelial sodium channel in conjunctival epithelium and short-circuit current was used to detect the opening of epithelial sodium channel. The ENaC α and ENaC γ gene expression，corneal fluorescein sodium staining and tear secretion （immerged length） were compared among 3 groups.【Results】 The results showed that the quantity of tear secretion was（17.00 ± 0.37）mm for the control group，（4.42 ± 1.34）mm for the tested group（P<0.001 vs Control，n=8） and（14.25 ± 0.54）mm for the treatment group（P>0.05 vs Control，n=8）. The results of short-circuit current detection showed that the sodium current was（5.72 ± 0.35）μA /cm2 in normal model and（12.24 ± 0.54）μA /cm2 in dry eye model（P<0.001）. After Amiloride treatment，the sodium current decreased to（4.00 ± 0.61）μA/cm2 （P>0.05） and there was no statistical difference compared with the normal group. According to the results of fluorescence quantitative PCR，the expression of ENaC α and ENaC γ subunits and IL- β in in dry eye model were up-regulated（P<0.01） compared with that in normal group. After topical amiloride application，there were no statistical differences in inflammatory cytokines IL- 1 β，ENaC α，and ENaC γ between the normal group and treatment group（P>0.05，n=8）. After treatment，tear secretion increased （P<0.001），and ocular surface staining improved significantly.【Conclusion】 Topical application of amiloride increase the quantity of preocular tears owing to inhibition of conjunctival sodium channels and could provide an effective new therapy for chronic dry eye.

Advances in Study on Relationship Between Epithelial Sodium Channel and Inflammatory Bowel Disease / 胃肠病学

Inflammatory bowel disease (IBD)is an autoimmune disease leading to diarrhea,abdominal pain,and weight loss. The pathogenesis of diarrhea remains unclear,however,increasing evidence has shown that the epithelial sodium channel (ENaC)is associated with diarrhea. ENaC is crucial in the control of sodium homeostasis,extracellular fluid volume,blood pressure. This article reviewed advances in study on relationship between ENaC and IBD.

Lipoxin A4 Ameliorates Lipopolysaccharide-Induced A549 Cell Injury through Upregulation of N-myc Downstream-Regulated Gene-1 / 中华医学杂志(英文版)

<p><b>Background</b>Lipoxin A4 (LXA4) can alleviate lipopolysaccharide (LPS)-induced acute lung injury (ALI) and acute respiratory distress syndrome through promoting epithelial sodium channel (ENaC) expression in lung epithelial cells. However, how LXA4 promote ENaC expression is still largely elusive. The present study aimed to explore genes and signaling pathway involved in regulating ENaC expression induced by LXA4.</p><p><b>Methods</b>A549 cells were incubated with LPS and LXA4, or in combination, and analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) of ENaC-α/γ. Candidate genes affected by LXA4 were explored by transcriptome sequencing of A549 cells. The critical candidate gene was validated by qRT-PCR and Western blot analysis of A549 cells treated with LPS and LXA4 at different concentrations and time intervals. LXA4 receptor (ALX) inhibitor BOC-2 was used to test induction of candidate gene by LXA4. Candidate gene siRNA was adopted to analyze its influence on A549 viability and ENaC-α expression. Phosphoinositide 3-kinase (PI3K) inhibitor LY294002 was utilized to probe whether the PI3K signaling pathway was involved in LXA4 induction of candidate gene expression.</p><p><b>Results</b>The A549 cell models of ALI were constructed and subjected to transcriptome sequencing. Among candidate genes, N-myc downstream-regulated gene-1 (NDRG1) was validated by real-time-PCR and Western blot. NDRG1 mRNA was elevated in a dose-dependent manner of LXA4, whereas BOC-2 antagonized NDRG1 expression induced by LXA4. NDRG1 siRNA suppressed viability of LPS-treated A549 cells (treatment vs. control, 0.605 ± 0.063 vs. 0.878 ± 0.083, P = 0.040) and ENaC-α expression (treatment vs. control, 0.458 ± 0.038 vs. 0.711 ± 0.035, P = 0.008). LY294002 inhibited NDRG1 (treatment vs. control, 0.459 ± 0.023 vs. 0.726 ± 0.020, P = 0.001) and ENaC-α (treatment vs. control, 0.236 ± 0.021 vs. 0.814 ± 0.025, P < 0.001) expressions and serum- and glucocorticoid-inducible kinase 1 phosphorylation (treatment vs. control, 0.442 ± 0.024 vs. 1.046 ± 0.082, P = 0.002), indicating the PI3K signaling pathway was involved in regulating NDRG1 expression induced by LXA4.</p><p><b>Conclusion</b>Our research uncovered a critical role of NDRG1 in LXA4 alleviation of LPS-induced A549 cell injury through mediating PI3K signaling to restore ENaC expression.</p>

Resveratrol up-regulates the expression of alveolar epithelialsodium channel in acute lung injury mice via activation of SGK1 / 基础医学与临床

Objective To investigate the effect of resveratrol on alveolar epithelial sodium channel in acute lung injury mice and the potential mechanism.Methods Twenty-four C57BL/6 mice were randomly divided into control group, LPS group, RES group and PP242(mTORC inhibitor) group with 6 mice in each group.The pathological changes in lung tissue were evaluated by HE staining;the concentrations of total protein in bronchoalveolar lavage fluid (BALF) were assessed by BCA (bicinchoninic acid).The levels of inflammatory cytokines in BALF were determined by ELISA.The proportions of polymorphonuclear neutrophil (PMN) in BALF were detected by Flow Cytometry.The transcription levels of α-ENaC mRNA were assessed by qPCR while the protein levels of α-ENaC and p-GSK1 were measured by Western blot.Results 1)Compared with mice in control group, severe pathological lung injury changes were observed in mice of LPS group, with increased total protein levels, PMN proportions,levels of inflammatory cytokines in BALF (P<0.05), accompanied by down-regulated level of α-ENaC and p-SGK1 in lung tissues (P<0.05).2)Compared with mice in LPS group, resveratrol significantly reversed lung injury triggered by LPS, decreased total protein levels, PMN proportions, levels of inflammatory cytokines in BALF (P<0.05), with down-regulated levels of α-ENaC and p-SGK1 in lung tissues (P<0.05).3)However, PP242 prevented beneficial effects of RES on ALI.Conclusions Up-regulation of α-ENaC expression via activation of SGK1 takes part in the protective effects of RES on LPS-induced ALI in mice.

Adipolin/CTRP12 protects against LPS-induced ARDS by up-regulating alveolar epithelial sodium channel in mice / 中国病理生理杂志

[ ABSTRACT] AIM:To investigate the effect of adipolin/CTRP12 in LPS-induced acute respiratory distress syn-drome (ARDS) and its potential regulation on alveolar epithelial sodium channel (ENaC) in mice.METHODS:C57BL/6J mice (n=40) were randomly divided into control group, LPS group, adipolin group and wortmannin (PI3K inhibitor) group with 10 mice in each group using random number table.The pathological changes of the lung tissues were evaluated by HE staining.The alveolar fluid clearance ( AFC) was measured by Evans blue-marked albumin, and the concentrations of total protein in bronchoalveolar lavage fluid ( BALF) were assessed by bicinchoninic acid ( BCA) method.In BALF, the levels of IL-1βand TNF-αwere determined by ELISA, and the activity of myeloperoxidase ( MPO) was detected by an MPO assay kit.The total cell counts and polymorphonuclear neutrophil ( PMN) counts in the BALF were analyzed by Gi-emsa staining.The mRNA levels of α-ENaC were assessed by qPCR, while the protein levels of α-ENaC and p-Akt were determined by Western blot.RESULTS: Compared with control group, the classic ARDS pathological changes were ob-served in the mice in LPS group, manifesting by severe pathological lung injury (P 0.05), accompanied by down-regulated levels of α-ENaC and p-Akt in the lung tissues (P<0.05).The deteriorating effects triggered by LPS were significantly reversed by administration of adipolin.However, PI3K inhibitor wortmannin can-celed the beneficial effects of adipolin on LPS-induced ARDS, as evidenced by aggravated lung injury, increased levels of W/D weight ratio, protein levels, cell counts, MPO activity, and IL-1βand TNF-αlevels in the BALF (P<0.05), and decreased levels of AFC,α-ENaC and p-Akt in the lung tissues.CONCLUSION:Adipolin protects against LPS-induced ARDS in the mice by up-regulatingα-ENaC and enhancing AFC via PI3K/Akt signal pathway.

Antioxidants effects of Platinum Nanoparticles: A Potential Alternative Treatment to Lung Diseases.

Imbalance oxidative status occurs when oxidative stress is higher in the body due to the production of reactive oxygen species. Thus, antioxidants are needed to counteract the production of free radicals. Reoccurrence of oxidative stress in the lung cells will eventually lead to inflammation and edema. This will result to a severe prognosis of lung diseases. Our interest is to populate certain mechanisms that can be activated during this process by reversing the oxidative stress status. Platinum nanoparticles (PtNPs) have been suggested as one of the powerful antioxidants that can quench free radicals. The mechanistic pathway may involve Protein Kinase C, which correlates well with the expression of the Epithelial Sodium Channel (ENaC). ENaC plays an important role in sodium uptake thus stimulate lung liquid clearance. The failure of lung clearance will interrupt gaseous exchange thus eventually lead to death. This review will discuss on the antioxidant properties of PtNPs as well as the underlying mechanism of PKC and ENaC in maintaining the oxidative status in the lung cells.

Effects of 1,25-Dihydroxyvitamin D3 on Alveolar Fluid Clearance in Mice / 中国医科大学学报

Objective To explore the relationship between 1,25-dihydroxyvitamin D3(1,25-VD3)and alveolar fluid clearance(AFC)in mice in vivo,and investigate its effects in the process of lung fluid clearance. Methods KM male mice were treated with active vitamin D analogue parical-citol(daily i.p. injection)for 2 weeks,and then the in vivo AFC of these mice was measured by bovine serum albumin protein assays. western blot was applied to determine epithelial sodium channel protein levels in lungs of these mice. Results In vivo total AFC was 31.9%±3.8%in vitamin D-treated mice,and significantly lower in the vehicle-treated controls(19.7%±1.9%,P<0.05). Amiloride-sensitive AFC was increased approximate-ly 50%by vitamin D. western blot showed that the expression ofα-epithelial sodium channel was significantly elevated in paricalcitol-treated mouse lungs. Conclusion These observations suggest that vitamin D augments AFC in mice,which may be related to the augment of epithelial sodium channel protein expression. The clinical application of vitamin D therapy may ameliorate pulmonary edema of patients.

The Influence of Epithelial Sodium Channels in Isolated Goat Ileum Segment; Interaction with Steroids.

The contractile effect of Acetylcholine (Ach) in the isolated longitudinal ileal muscle of adult goats was studied over a varying concentration range. Ach produced a concentration dependent-response curve indicative of an interaction with muscarinic receptors in the ileum, with a maximum contraction seen at 12 μM. On the other hand, pretreatment with the ENaC blocker, Amiloride (100 μM) substantially reduced the Ach induced contractions by 67.11 %. However, pretreatment with Prednisolone (2mM) restored this effect and the relaxation induced was only 14.26 %. This change was found to be statistically significant. This study emphasizes the importance of ENaC channels in the goat intestinal smooth muscle.

The effect of hyperoxia on fluid transport by fetal distal lung epithelia / 国际儿科学杂志

Objective To investigate the effect of hyperoxia on fluid transport by fetal distal lung epithelia(FDLE) and the expression of epithelial sodium channel(ENaC) in these cells.Methods FDLE were isolated and randomized into hyperoxia group and normoxia group,which were primarily cultured under hyperoxic or normoxic conditions,respectively.Fluid transport was measured using monolayers of FDLE cultured on Transwell permeable inserts.Western blot was applied to examine the α-ENaC expression.Results Fluid transport across monolayer of FDLE was increased in cells exposed to hyperoxia compaired with cells cultured in normoxic conditions (1.78 ± 0.19 vs 1.06 ± 0.11,P ＜ 0.001).Amiloride significantly decreased the fluid transport in both of the hyperoxia and normoxia groups,but in the presence of amiloride there were no difference between the two groups.The expression of α-ENaC was inhibited by hyperoxia to some extent(24h:0.44 ±0.04 vs 0.40 ±0.04,P=0.22; 48h:0.35 ±0.03 vs 0.47 ±0.06,P =0.03).Conclusion Hyperoxia enhanced total and amiloride-sensitive fluid transport by FDLE.However,the expression of α-ENaC decreased in these cells.

The roles of cytokines and water sodium channel proteins in acute kidney injury-induced acute lung injury rats / 中华急诊医学杂志

Objective To observe the physiopathologic changes of lung in rats with acute ischemic kidney injury,and to study the roles of cytokine,epithelial sodium channel protein (ENaC) and aquaporin 1 (AQP1) in acute lung injury brought on by acute ischemic kidney injury in rats.Methods A total of 60 healthy male Wistar rats (300-320 g) were randomly (random number) divided into control groups (group A,n =30) and acute kidney injury group (group B,n =30).The model of acute ischemic kidney injury in rats was made by bilateral renal arteiovenous blockage with clamps.Six rats of each group were sacrificed at 0,2,4,6 and 8 hours after modeling.Lung tissue of rats was harvested and stained with hematoxylin-eosin (HE) staining method,and the pathological changes of lung were observed under microscope.The ratio of wet and dry weight (W/D) of lung was calculated.The levels of protein in bronchoalveolar lavage fluid (BALF) were measured.The levels of IL-6 and TNF-α both in serum and BALF were tested.The concentrations of AQP1 and α-ENaC in lung were measured.Results At six hours after modeling,the pH value of arterial blood of rats in group B began to get lowered compared to group A.There was no difference in partial pressure of oxygen in arterial blood between two groups during entire period of experiment (P ＞0.05).Protein level in BALF and W/D of lung increased significantly two hours after modeling in rats of group B (P ＜ 0.05).The histopathological changes of acute lung injury including swollen aleolar epithelium,widened interalveolar septum,edema of alveoli and alveolar interstitium,alveolar neurophil sequestration,erythrocytes and protein in exudates were observed.The levels of TNF-α and IL-6 in serum and in BALF began to increase at two hours after modeling.The levels of AQP1 and α-ENaC of lung in rats with acute kidney injury decreased gradually and were lower than those in rats of group A (P ＜0.05).Conclusions Aleolar epithelial-endothelial barrier function was already compromised at the beginning of AKI,suggesting the acute lung injury was already brought on.The levels of TNF-α,IL-6 in serum and in BALF increased after the occurrence of acute kidney injury.The decreases in lung AQP1 and α-ENaC might contribute to the lung injury caused by early acute kidney injury.

The role of epithelial sodium channel in the neonatal rat bronchopulmonary dysplasia early pulmonary edema induced by hyperoxia / 中国综合临床

Objective To investigate the changes of epithelial sodium channel(ENaC) expression and sodium and water transport function in the neonatal rat pulmonary edema induced by hyperoxia.Methods The neonatal rats were randomly divided into the hyperoxia group and the control group.After 1,3,5 and 7 d hyperoxia exposure,the lung tissues were collected to measure the wet-to-dry weight ratio and the expression of α-,β-and γ-ENaC subunits were detected by western blot analysis.Alveolar fluid clearance (AFC) and amiloride-sensitive AFC were measured after 5 d to reveal the effect of hyperoxia on the activity of ENaC.Results The lung water contents significantly increased in the hyperoxia group indicating that pulmonary edemahappened(3 d:(6.37 ±0.64) vs (5.56±0.15),t=3.46,P＜0.01;5 d:(5.86 +0.52) vs (5.11±0.21),t=-3.82,P ＜0.01;7 d:(5.56±0.45) vs (4.80±0.09),t =-4.72,P ＜0.01).AFC increased significantly,but no significant difference was found in amiloride-insensitive AFC between the two groups which indicate that amiloride-sensitive AFC increased significantly (AFC:(20.32 ± 3.33) ％ vs (12.97 ± 2.46) ％,t =-6.16,P ＜ 0.01 ; amiloride-insensitive AFC:(10.42 ± 3.44) ％ vs (8.67 ± 3.13) ％,t =-1.30 P =0.21).The expression of α-,β-and γ-ENaC did not reduced after hyperoxia exposure compared with the control group.Conclusion Although bronchopulmonary dysplasia of early pulmonary edema induced by hyperoxia,dysfunctional transport of Na + may not be a key factor involved in pulmonary edema at the early stage of bronchopulmonary dysplasia.

Pseudohypoaldosteronism Type 1

Pseudohypoaldosteronism (PHA), a rare syndrome of systemic or renal mineralocorticoid resistance, is clinically characterized by hyperkalemia, metabolic acidosis, and elevated plasma aldosterone levels with either renal salt wasting or hypertension. PHA is a heterogeneous disorder both clinically and genetically and can be divided into three subgroups; PHA type 1 (PHA1), type 2 (PHA2) and type 3 (PHA3). PHA1 and PHA2 are genetic disorders, and PHA3 is a secondary disease of transient mineralocorticoid resistance mostly associated with urinary tract infections and obstructive uropathies. PHA1 includes two different forms with different severity of the disease and phenotype: a systemic type of disease with autosomal recessive inheritance (caused by mutations of the amiloride-sensitive epithelial sodium channel, ENaC) and a renal form with autosomal dominant inheritance (caused by mutations of the mineralocorticoid receptor, MR). In the kidneys, the distal nephron takes charge of the fine regulation of water absorption and ion handling under the control of aldosterone. Two major intracellular actors necessary for the action of aldosterone are the MR and the ENaC. Impairment of the intracellular aldosterone signal transduction pathway results in resistance to the action of mineralocorticoids, which leads to PHA. Herein, ion handling the distal nephron and the clinico-genetic findings of PHA are reviewed with special emphasis on PHA type 1.

El litio y su relación con la acuaporina-2 y el canal de sodio ENaC / Lithium and its relation with the epithelial sodium channel and aquaporin-2

Desde hace más de cuarenta años que el litio es usado para el tratamiento de la enfermedad bipolar; recientes estudios sugieren también su utilidad en el trastorno cognitivo mínimo tipo amnésico. El litio es filtrado en el glomérulo y un 65-75% del mismo es reabsorbido en el túbulo contorneado proximal y en el asa ascendente de Henle por el transportador Na+, K+, 2Cl- y vía paracelular. Una pequeña fracción del litio entra en las células principales del túbulo colector por medio del canal epitelial de sodio sensible al amiloride (ENaC) localizado en la membrana apical de la célula. Luego de 10- 20 años de tratamiento con litio los enfermos pueden desarrollar poliuria, acidosis tubular e insuficiencia renal crónica que puede terminar en una forma de diabetes que no responde a la arginina vasopresina llamada diabetes insípida nefrogénica. Se cree que estas fallas renales son consecuencias de una reducción en el número de moléculas de acuaporina 2 en la membrana apical. Las causas para esto son complejas. El litio es un poderoso inhibidor de la isoforma beta de la enzima glicógeno sintetasa quinasa y esto está asociado a una menor actividad de la adenilato ciclasa que lleva a una disminución en la concentración intracelular de cAMP. Esto finalmente interferiría con la síntesis de nuevas moléculas de acuaporina 2 y con el tráfico de ellas desde la zona subapical de la célula hacia la membrana celular, causando la disminución en la reabsorción de agua en la parte distal del nefrón.

For more than 40 years lithium has been used to treat bipolar disorder and recent trials suggest a potential efficacy also in the treatment of the amnestic mild cognitive impairment. Lithium is filtered by the glomerulus and 65% - 75% of the filtered amount is reabsorbed along the proximal tubule and in the thick ascending limb of Henle's loop by the Na+, K+, 2Cl- transporter and via paracellular. A small fraction of lithium is reabsorbed in the collecting duct's principal cells through the epithelial Na channel (ENaC) located on the apical side of the cells. Polyuria, renal tubular acidosis and chronic renal failure are the most frequent adverse effects of lithium after 10-20 years of treatment and these alterations can reach to a vasopressin nonresponding form of diabetes insipidus entity called nephrogenic diabetes insipidus. It is believed that the molecular mechanisms of these renal changes are related to a reduction in the number of aquaporin-2 inserted in the apical membrane of the cells. The causes of this are complex. Lithium is a powerful inhibitor of the enzyme glycogen synthase kinase 3β and this is associated with a lower activity of adenylate cyclase with a reduction in the cAMP levels inside of the cells. The latter may interfere with the synthesis of aquaporin-2 and also with the traffic of these molecules from the subapical site to membrane promoting the impairment of water reabsorption in the distal part of the kidney.

Expression and transport function of epithelial sodium channel in alveolar epithelial type Ⅱ cells of hyperoxia-exposed neonatal rat / 中国小儿急救医学

Objective To investigate the effect of hyperoxia on the expression and transport function of epithelial sodium channel (ENaC) in neonatal rat alveolar epithelial type Ⅱ(AT Ⅱ) cells.Methods AT Ⅱ cells were isolated from neonatal rats,and primarily cultured under hyperoxic or normoxic conditions.Western blot was applied to examine the ENaC expression,and the amiloride-sensitive Na + currents were recorded using the whole-cell patch clamp technique.Results Hyperoxia upregulate the expression of β-ENaC and γ-ENaC subunits in the neonatal rat ATⅡ cells(β-ENaC:1 d:0.43 ±0.06 vs0.32 ±0.04,P =0.047;2 d:0.73±0.06 vs 0.50±0.08,P =0.019;3 d:0.72 ±0.08 vs 0.52 ±0.06,P =0.027;γ-ENaC:1 d:0.64±0.05 vs0.53 ±0.05,P =0.044;2 d:0.76 ±0.03 vs 0.52 ±0.04,P =0.001 ;3 d:0.77 ±0.06 vs 0.61 ±0.05,P =0.025).In addition,the amiloride-sensitive Na+ currents in hyperoxia-exposed AT Ⅱ cells were also increased (1d:13.71 ±2.77 vs8.92±1.38,P＜0.001;2d:29.12±11.03 vs 10.41 ±1.80,P＜0.001),which was consistent with the upregulated expression of β-ENaC and γ-ENaC.However,the expression of α-ENaC was inhibited by hyperoxia to some extent (1 d:0.31 ± 0.05 vs 0.46 ± 0.05,P =0.025 ; 2 d:0.30 ±0.01 vs0.38±0.02,P=0.002;3d:0.37±0.06 vs 0.37 ± 0.08,P =0.983).Conclusion Hyperoxia enhanced the transport function of ENaC in neonatal rat AT Ⅱ cells.Dysfunctional transport of Na + may not be a key factor involving in pulmonary edema at the early stage of bronchopulmonary dysplasia.

Influence of nebulized Pulmicort respules inhalation after endoscopic sinus surgery on expression of ENaC protein / 上海交通大学学报（医学版）

Objective To investigate the influence of nebulized Pulmieort respules inhalation after endoscopic sinus surgery (ESS)on the expression of epithelial Na~+ channel(ENaC)protein in nasal mucosa. Methods Forty-four patients with nasal polyps undergoing ESS were randomly divided into Pulmieort respules treatment group(n=21,nebulized Pulmieort respules inhalation for 10 d after ESS)and Rhinocort control group(n=23,Rhinoeort aqueous nasal spray for 10 d after ESS).All the patients were performed biopsy of membrane on the residual middle turbinate 14 d after ESS,eosinophils (Eos)and neutrophils(Neu)per hundred inflammation cells were counted under microscope during ESS and after ESS,and the expression of ENaC protein was detected by immunofluorescence assay. Results The percentages of Eos and Neu decreased in two groups after treatment,and the percentage of Neu in Pulmieort respules treatment group was significantly lower than that in Rhinoeort control group(P<0.05).The expression of ENaC protein after treatment in Pulmieort respules treatment group was significantly lower than that in Rhinoeort control group(P<0.01). Conclusion Application of pulmieort respules after ESS can decrease Neu infiltration and inhibit expression of ENaC protein,which can relieve acute inflammation and edema of nasal mucosa.