Mechanism of Retinoic Acid and Mitogen-activated Protein Kinases Regulating Hyperoxia Lung Injury

Acute and chroniclunginjury are major causesresponsible for the mortality and morbidityin bothpretermand termneonates .Prolonged exposure tohyperoxia inthe developinglungis believedto playcritical roles in the development of acute and chro-nic lung injury[1]. Recent studies demonstratedthat mitogen-activated protein kinases ( MAPKs)play an i mportant role in hyperoxia-induced lunginjury[2]. The processes of lung growth,develop-ment ,injury and repair are extremely complex,in-volving a multit…     

高氧、维甲酸对胎鼠肺成纤维细胞c-Jun、c-Fos表达的影响

目的 探讨维甲酸对高氧暴露下胎鼠肺成纤维细胞c—Jun、c—Fos表达的影响。方法 取第2代胎鼠肺成纤维细胞作体外培养，待生长至接近融合状态时，随机分为：空气组，空气 维甲酸组，高氧组，高氧 维甲酸组。于培养30min和1、2、6、12、24、48、72h时，行细胞固定后，应用免疫组化方法捡测c—Jun、c—Fos表达强度并结合计算机图像处理系统进行分析。结果 与空气组相比，高氧1h时c—Jun表达明显增强(P＜0．01)，6—12h时达高峰，以后开始下降，但仍高于正常水平(P＜0．01)；c—Fos的表达在高氧30min即增强(P＜0．01)，2—6h达高峰，以后开始下降，24h后恢复到正常水平。维甲酸能明显下调高氧所诱导的c—Jun、c—Fos高表达，但并不能完全阻止c—Jun、c—Fos的过度表达。结论 c—Jun、c—Fos可能参与了高氧暴露下胎鼠肺成纤维细胞的信号转导过程；维甲酸可部分抑制由高氧所诱导的c—Jun、c—Fos的过度表达。     

不同剂量乌司他丁对脂多糖致急性肺损伤新生大鼠MMP-2表达的影响

目的:探讨乌司他丁(ulinastatin,UTI)对脂多糖(LPS)诱导的急性肺损伤新生大鼠MMP-2表达的影响。方法:选择40只新生7日龄SD大鼠,随机分为生理盐水对照组、急性肺损伤模型组、乌司他丁小剂量组(2.5万U.kg-1)、乌司他丁中剂量组(5.0万U.kg-1)、乌司他丁大剂量组(10.0万U.kg-1),每组8只。以5 mg.kg-1 LPS腹腔注射制作急性肺损伤模型,同时予以乌司他丁腹腔注射进行干预,4 h后观察新生大鼠肺组织的病理改变,用免疫组化和逆转录-聚合酶链反应(RT-PCR)方法检测肺组织中MMP-2的蛋白和mRNA的表达。结果:乌司他丁中、大剂量组的MMP-2水平明显低于急性肺损伤模型组(分别P<0.05,P<0.01),乌司他丁小剂量组虽低于急性肺损伤模型组,但差异无统计学意义(P>0.05)。结论:乌司他丁对LPS致新生大鼠急性肺损有保护作用,可能是通过抑制肺组织MMP-2的表达水平实现的,且其抑制作用呈剂量依赖性。     

Effects of U0126 on growth and activation of mitogen-activated protein kinases in Aspergillus fumigatus

Background Invasive aspergillosis (IA),which is mainly caused by Aspergillus fumigatus (A.fumigatus),is a major cause of morbidity and mortality in immunocompromised patients.Despite considerable progr...     

Effect of Retinoic Acid on Lung Injury in Hyperoxia-Exposed Newborn Rats

Bronchopulmonary dysplasia(BPD) is a chroniclung condition which has been associated withpreterm delivery,infection and continuous exposureto hyperoxia.Impaired septal formation and de-creased alveolarization are characteristic features ofBPD[1] .Attempts to limit the incidence and severityof BPD by lowering oxygen concentration and by re-ducing barotrauma through early weaning from me-chanical ventilation have been helped by the use ofglucocorticoids in the postnatal period.Several stud-i…     

MMP-9和TIMP-1在新生大鼠持续高氧暴露后肺组织中的动态表达

目的:探讨基质金属蛋白酶9(MMP-9)和金属蛋白酶组织抑制剂1(TIMP-1)在高氧致慢性肺疾病(CLD)新生大鼠肺组织中的动态变化和意义。方法:足月新生大鼠生后12h分别持续吸入0.90～0.95的高氧和空气,于1,3,7,14,21d应用免疫组化和RT-PCR方法分别检测肺组织MMP-9和TIMP-1蛋白及mRNA表达。结果:MMP-9在高氧3d时蛋白和mRNA表达均较空气组增强(P<0.05,P<0.01);TIMP-1蛋白在高氧组表达高于空气组,3d和7d比较P<0.05,14d和21d比较P<0.01;TIMP-1 mRNA水平高氧组高于空气组,3d和7d比较P<0.05,和14d比较P<0.01,和21d比较无差异。结论:高氧暴露后MMP-9和TIMP-1的表达在不同阶段的变化不一致,MMP-9/TIMP-1平衡状态遭到破坏,可能是高氧后胶原异常沉积以及正常肺泡化过程受阻的重要因素。     

E2F1蛋白在高氧致慢性肺疾病早产鼠肺组织的动态表达及意义

目的:通过检测E2F1 蛋白在高氧致慢性肺疾病早产鼠肺组织中的动态表达, 初步探讨E2F1 蛋白与慢性肺疾病肺间质纤维化发生发展的关系。方法:剖宫术取出孕21 d Wistar 大鼠作为早产鼠, 生后12 h 随机分为高氧组和对照组, 高氧组持续暴露于90% 氧气中, 空气组置于同一室内常压空气中。分别于暴露3, 7, 14 d 时, 每组取动物10 只, 留取其肺组织标本。应用HE 染色观察不同时间点其肺组织病理改变, 在光镜下进行肺组织纤维化评分, 并采用免疫组织化学法及Western 印迹检测不同时间点肺组织E2F1 蛋白的表达。结果:早产鼠高氧暴露3 d 后未出现纤维化改变, 7 d 后出现少许纤维化改变, 14 d 后纤维化改变明显;E2F1 在高氧暴露3 d 在肺组织中E1F1 蛋白表达虽较同时间点空气组有所升高, 但差异无统计学意义(P>0.05), 高氧暴露7 d 及14 d E2F1 蛋白表达明显高于同时间点空气组(P<0.05, P<0.01)。结论:高氧导致早产鼠肺组织E2F1 表达持续性增高, 其异常表达可能是导致肺成纤维细胞过度增殖, 最终发生肺间质纤维化的重要原因。     

丝裂原活化蛋白激酶在力达霉素抑制鼠骨髓瘤细胞增殖和诱导凋亡中的作用

目的: 研究力达霉素(LDM)对鼠骨髓瘤细胞丝裂原活化蛋白激酶(MAPKs) 信号传导通路的影响及MAPKs在LDM抑制鼠骨髓瘤细胞增殖和诱导凋亡中的作用,为LDM治疗人多发性骨髓瘤的研究提供依据。方法: 选取处于对数生长期鼠骨髓瘤细胞株SP2/0,随机分为空白对照组、4种不同浓度LDM组,采用Western blotting 方法检测各组细胞48 h后MAPK家族的三个主要成员c-Jun氨基末端激酶(JNK)、细胞外信号调节激酶(ERK)和p38 MAPK的表达水平。选取处于对数生长期SP2/0,随机分为对照组、LDM组、SP600125组(JNK抑制剂)、SB203580组(p38抑制剂)、U0126组(ERK抑制剂)、LDM+SP600125组、LDM+SB203580组和LDM+U0126组,采用MTS法和流式细胞术分别检测各组细胞增殖和凋亡情况。结果: 细胞培养48 h后,不同浓度LDM组JNK、ERK和p38 MAPK的表达水平高于空白对照组（P<0.05）;各抑制剂组细胞增殖率和细胞凋亡率与空白对照组比较差异无统计学意义(P>0.05),即对细胞的增殖抑制和凋亡诱导作用均不明显;但LDM+SP600125组、LDM +SB203580组LDM对细胞的增殖抑制和凋亡诱导作用均降低（P<0.05）,而LDM+U0126组LDM对细胞的增殖抑制和凋亡诱导作用则增强（P<0.05）。结论: LDM能够通过激活JNK、p38 MAPK抑制鼠骨髓瘤细胞SP2/0细胞增殖,诱导其凋亡。     

外源性视黄酸对小鸡后极部巩膜MMP-2及TIMP-2转录的影响

目的 探讨外源性视黄酸(retinoic Acid,RA)对小鸡后极部巩膜基质金属蛋白酶2(matrix metalloproteinase-2,MMP-2)及其特异性组织抑制剂(tissue inhibitor of matrix metalloproteinase-2,TIMP-2)mRNA转录水平的影响.方法 取1d龄来亨雏鸡,实验组右眼球后注射RA 1次,对侧眼为自身对照组,阴性对照组右眼球后注射生理盐水;正常对照组不做任何处理.分别于注射后12h,24h,48h,72h摘取眼球,采用逆转录-多聚酶链反应(RT-PCR法)检测每组小鸡后极部巩膜MMP-2与TIMP-2 mRNA转录水平.结果 与正常组、阴性对照组相比,实验组后极部巩膜MMP-2 mRNA转录显著增高,TIMP-2 mRNA转录降低,组间差异有显著性(P＜0.01).注射后随时间延长MMP-2 mRNA转录逐渐上调,48h达最高峰,至72h有降低.不同时间组内差异显著(P＜0.01),而TIMP-2 mRNA转录与之相反.自身对照组MMP-2 mRNA转录较同龄正常对照组有轻度上调,TIMP-2有下调,组间差异有显著性(P＜0.01).结论 外源性RA可以调节小鸡巩膜MMP-2/TIMP-2转录的平衡,并可能由此启动巩膜细胞外基质的主动重塑.     

Role of mitogen-activated protein kinases in the regulation of paraventricular nucleus to gastric ischemia-reperfusion injuries

Background We investigated the role in electrical stimulations of paraventricular nucleus （PVN） on gastric mucosal cells and the activity of mitogen-activated protein kinases （MAPKs） family members induced by gastric ischemia-reperfusion （GI-R）. And we elucidated the molecular mechanisms of the protection of PVN from GI-R injuries. Methods Sprague-Dawley rats were divided randomly into 4 groups： Group I, the sham-operated GI-R control group; Group II, the sham-operated electrical stimulations to PVN ＋ sham-operated GI-R control group; Group III, the GI-R group; and Group IV, the electrical stimulations to PVN ＋ GI-R group. In all of the experiments, the PVN was stimulated prior to the induction of GI-R. The GI-R model was established by clamping the celiac artery for 30 minutes to induce ischemia and then was released to allow reperfusion for 30 minutes, 1 hour, 3 hours and 6 hours, respectively. The gastric mucosal cellular apoptosis, proliferation, and the expression and activity of MAPKs protein were observed by immunohistochemistry and Western blotting, respectively. Results Compared with the GI-R group, the application of electrical stimulations in the PVN significantly depressed gastric mucosal cellular apoptosis and enhanced gastric mucosal cellular proliferation following the 30-minute, 1-hour and 3-hour intervals of reperfusion; it also promoted the activation of p-ERK during the early phase of reperfusion but inhibited the activation of p-JNK1/2 and p-p38 following the 30-minute, 1-hour and 3-hour intervals of reperfusion. Conclusions The protection of PVN against GI-R injuries may attribute to the inhibition of apoptosis and the promotion of the proliferation of gastric mucosal cells during GI-R. This protective effect is mediated by activating the ERK pathway and depressing the JNK, the JNK. p38 MAPK oathwavs of the oastric mucosal cells.     

高氧致CLD早产鼠肺上皮细胞凋亡及相关基因表达的动态研究

目的:探讨高氧致早产鼠慢性肺疾病(CLD)发生中肺泡上皮细胞(AEC)凋亡的动态变化规律及Bax和Bcl-2基因的调控作用.方法:将60例早产鼠随机分为实验组和对照组,制备高氧致早产鼠CLD模型,应用TUNEL及免疫组织化学技术,观察生后1,3,7,14,21 d AEC的凋亡指数(AI)和肺组织Bax及Bcl-2基因蛋白的表达强度.结果:实验组3 d AEC的AI明显升高(P＜0.01),7～21 d持续于高水平(P＜0.001);Bax基因蛋白表达3 d开始增加(P＜0.05),7～21 d明显增加(P＜0.01),Bcl-2基因表达7 d开始降低(P＜0.05),14～21 d明显降低(P＜0.01);实验组AI与Bax表达呈正相关(r=0.571,P＜0.05)、与Bcl-2表达呈负相关(r=-0.543,P＜0.05).结论:暴露高氧环境中早产鼠,由肺组织Bax及Bcl-2基因表达异常而介导的AEC程序性死亡机制参与了CLD的发生过程.     

全反式维甲酸可增强大鼠系膜细胞uPA和MMP—2表达

目的 研究全反式维甲酸对体外培养大鼠系膜细胞uPA和MMP－2表达的影响,探讨全反式维甲酸抗肾小球硬化的机制。方法 分别应用Northern blot、Western blot和酶谱法检测全反式维甲酸对培养大鼠系膜细胞uPA和MMP－2表达的影响。结果 ATRA可促进系膜细胞uPA和MMP-2蛋白表达,提高其酶活性,并增强MMP－2mRNA表达。结论 ATRA可增强大鼠系膜细胞的uPA和MMP－2表达,为进一步阐明ATRA拮抗肾小球硬化机制提供了直接的实验依据。     

MMP-2/TIMP-2在妊娠滋养细胞疾病组织中的表达及意义

目的 探讨金属基质蛋白酶-明胶酶A(MMP-2)及其抑制剂(TIMP-2)在妊娠滋养细胞疾病发生、发展及预后中的作用.方法 采用原位杂交、免疫组化法分别从mRNA、蛋白质水平检测MMP-2/TIMP-2在正常早孕绒毛及妊娠滋养细胞疾病中的表达.结果 未恶性转化葡萄胎MMP-2低表达,TIMP-2高表达,恶性转化葡萄胎、侵蚀性葡萄胎、绒癌中MMP-2表达逐渐增强,TIMP-2表达相反.妊娠滋养细胞肿瘤组与正常绒毛、葡萄胎组相比,MMP-2、TIMP-2的表达均有显著性差异(P＜0.01,P＜0.001).结论 金属基质蛋白酶的激活与抑制比例失衡在妊娠滋养细胞疾病发展、浸润和转移中起重要作用.     

WAVE1、MMP-2及MMP-9在卵巢癌组织中的表达及意义

目的 探讨WASP家族富含脯氨酸同源蛋白1(WASP-family verprolin-homologous protein 1,WAVE1)及基质金属蛋白酶-2(matrix metalloproteinases-2,MMP-2)和基质金属蛋白酶-9(MMP-9)在卵巢癌的表达及临床意义.方法 采用免疫组化SABC三步法检测47例卵巢癌、30例卵巢良性肿瘤和21例正常卵巢组织中WAVE1、MMP-2、MMP-9的表达,并对卵巢癌组织WAVE1与MMP-2、MMP-9的表达进行相关性分析.结果 ①WAVE1、MMP-2及MMP-9在卵巢癌中的表达均高于在正常卵巢组织及卵巢良性组织中的表达,差异有统计学意义(P＜0.05);Spearman相关分析显示,WAVE1和MMP-2、MMP-9两两表达成正相关(r=0.773,r=0.664,P＜0.05).②WAVE1的表达与卵巢癌的临床分期、组织分化及Ca-125水平有关(P＜0.05),与年龄、肿瘤的直径无关(P＞0.05).MMP-2、MMP-9表达与卵巢癌的临床分期有关(P＜0.05),与年龄、组织分化、Ca-125水平及肿瘤直径无关(P＞0.05).结论WAVE1和MMP-2、MMP-9在卵巢癌中呈现高表达,早期联合筛查WAVE1和MMP-2、MMP-9指标对卵巢癌病情演变和预后评估有着重要的临床意义.     

生存素反义寡核苷酸对乳腺癌MCF-7细胞株MMP-2及MMP-9表达的影响

目的:研究生存素(survivin)反义寡核苷酸(antisense oligodeoxynucleotide,ASODN)对人乳腺癌MCF-7细胞株基质金属蛋白酶(matrix metalloproteinase,MMP)-2及MMP-9表达的影响,以进一步阐明生存素介导乳腺癌浸润及转移的机制.方法:经脂质体介导将生...     

乌索酸通过抑制A549细胞中ERK的激活而抑制COX-2的表达

研究乌索酸对A59细胞的抗肿瘤作用及其机制.首先,通过MTT方法检测乌索酸对A549细胞增殖的影响;然后,用Westrn blot方法检测乌索酸对COX-2表达水平及MAPKs的作用.结果表明,乌索酸能够抑制A549细胞的增殖,并能抑制COX-2的表达及ERK的激活,ERK特异性抑制剂PD98059能够与乌索酸协调抑制...     

Ammonia induces upregulation of aquaporin-4 in neocortical astrocytes of rats through the p38 mitogen-activated protein kinase pathway

Background Astrocyte swelling is an important consequence of hepatic encephalopathy, and aquaporin-4 has been reported to play a vital role in this swelling. Ammonia causes astrocyte swelling and is also known to modulate aquaporin-4 expression in the astrocyte foot processes. The purpose of this study was to explore the mechanism of ammonia-induced aquaporin-4 expression, which has been suggested to involve the p38 mitogen-activated protein kinase pathway. Methods We exposed cultured astrocytes to ammonium chloride, an in vitro model of hepatic encephalopathy. The purity of cultured astrocytes was evaluated by fluorescent glial fibrillary acidic protein labeling; cell morphology was assessed by light microscopy; the expression of aquaporin-4, phospho-p38, and p38 were detected by Western blotting analysis. Statistical analysis was performed by one-way factorial analysis of variance, and the relationship between variables was calculated by linear regression using SPSS version 13.0 program for Windows （SPSS, Chicago, IL, USA）. Results The purity of cultured astrocytes was （96.6±1.4）%. Astrocytes swelled significantly when exposed to 5 mmol/L ammonium chloride for 24 hours as compared to non-exposed astrocytes. Co-treatment with 10 μmol/L SB203580 （an inhibitor of p38） attenuated the degree of ammonium chloride induced astrocyte swelling. Western blotting analysis revealed that the expression levels of phospho-p38 and aquaporin-4 in ammonium chloride treated cells were significantly increased relative to the control group （P 〈0.001）; SB203580 co-treatment inhibited the increased expression of phospho-p38 and aquaporin-4 relative to the ammonium chloride treated group （P=0.002 and P=0.015 respectively）. The phosphorylation of p38 and upregulation of aquaporin-4 were highly correlated （r=0.909）. There were no significant differences in total p38 expression among the groups （P=0.341）. Conclusions Ammonium chloride induced upregulation of aquaporin-4 in astrocytes is regulated by the p38 mitogen-activated protein kinase pathway. Inhibiting p38 activation prevented ammonium chloride induced aquaporin-4 protein upregulation.