水杨酸钠对体外培养的人晶状体上皮细胞中HSP27表达的影响

本实验观察水杨酸钠对H：O：诱导体外培养的人晶状体上皮细胞（lens epithelial cell．LECs）中热休克蛋白27（heat shock protein 27，HSP27）表达的影响．探讨水杨酸钠在延缓白内障发病中的作用机制．     

地塞米松对人晶状体上皮细胞核转录因子κB及其抑制蛋白α的表达和细胞凋亡的影响

背景长期全身或眼局部应用糖皮质激素可诱导皮质类固醇性白内障,但其作用机制尚不明确。目的研究地塞米松作用于人晶状体上皮细胞（LECs）后对LECs中核转录因子κB（NF—κB）／NF—κB抑制蛋白κ（IκBκ）表达的影响及LECs凋亡的发生情况,了解皮质类固醇性白内障的发病机制。方法取人LECs系（HLE283）在含质量分数20％胎牛血清的DMEM中进行培养和传代。将不同浓度的地塞米松（0．01、0．1、1、10、100μmol／L）分别加入DMSO无血清DMEM培养液中作为不同浓度地塞米松组,不含地塞米松的DMSO无血清DMEM培养液培养的LECs作为空白对照组。采用逆转录聚合酶链反应（RT—PCR）、Western blot、流式细胞术等方法,分别在基因水平、蛋白水平检测LECs中NF—κB／IκB α浓度的改变及LECs凋亡率的变化。结果扩增的基因片段与所设计片段大小一致。地塞米松作用后NF—α核蛋白在LECs中的表达量随着地塞米松浓度的增加而下降,差异有统计学意义（F=36．077,P=0．004）;IκBα蛋白的表达随着地塞米松浓度的增加而上升,差异有统计学意义（F=35．741,P=0．002）。在同浓度地塞米松组,NF—κB核蛋白在LECs中的表达量随作用时间的不同差异有统计学意义（F=16．606,P=0．01）,与地塞米松作用24h时的表达量比较,36h和48h时的NF—κB核蛋白表达量明显下降,差异有统计学意义（P=0．002;P=0．01）。与地塞米松作用24h时的表达量比较,36h和48hIκBα蛋白在LECs中的表达量明显增加,差异均有统计学意义（P=0．014;P=0．002）。流式细胞仪检测显示LECs的凋亡率随着地塞米松浓度的增加明显上升,与空白对照组相比差异有统计学意义（P〈0．05）。结论地塞米松通过上调IκBα的表达而过度抑制了NF—κB的活性,并导致LECs凋亡,其作用呈浓度依赖性,这可能是皮质类固醇性白内障发生发展的细胞学和分子生物学机制之一。     

TGF-β2作用于人晶状体上皮细胞后Smad 4与p-Smad2／3的动态表达

目的观察转化生长因子β2（TGF-β2）作用于人晶状体上皮细胞（LECs）后2类通路转导蛋白Smad4和p-Smad2／3的动态表达变化。方法体外培养的人LECs中添加10ng／mL人TGF—β2,RT-PCR方法测定不同时间点Smadg mRNA的表达,Western blot观察p-Smad2／3的表达,免疫组织化学法观察p-Smad2／3在LECs表达的特点。结果人LECs添加了外源性人TGF-β2,后1h,可出现Smad 4 mRNA表达增高,16h时达峰值（0．72±0．07）,并持续至24h。与对照组比较差异无统计学意义（P〈0．05）。p-Smad2／3在2h后逐渐增强,与对照组比较差异明显,16h达到峰值（2．53g／L）。16h有p-Smad2／3颗粒胞浆表达,24b向核内聚集。结论TGF-β2刺激LECs后,可激活膜受体激活型Smad和通用型Smad,TGF-β2对Smad通路蛋白的激活存在时效关系。TGF—β2可通过特异性激活Smad通路,将信号转导至细胞核内。     

EGF诱导人RPE细胞表达整合素α5过程中丝裂原激活的蛋白激酶的作用

目的探讨表皮生长因子（EGF）诱导人视网膜色素上皮（RPE）细胞表达整合素α5过程中丝裂原激活的蛋白激酶（MAPK）的作用。方法将人RPE细胞分为对照组、EGF组和PD98059组,RT—PCR及流式细胞术观察各组整合素α5mRNA和蛋白的表达;Westernblot法检测各组人RPE细胞中MAPK的磷酸化水平。结果对照组的整合素α5mRNA／β-actinmRNA像素值的比值为0．93±0．06,PD98059组为1．06±0．07,EGF组为1．97±0．09,EGF组与其他2组相比,差异有统计学意义（P〈0．01）;流式细胞术检测显示,24h后整合素α5的荧光强度分别为1．94±0．22、4．56±0．25、2．39±0．104,差异有统计学意义（P〈0．05）。Westernblot检测显示,30min后EGF组细胞外信号调节激酶（ERK）1／2的磷酸化激活水平最高,PD98059组抑制ERK1／2的磷酸化激活,对照组ERK1／2的磷酸化激活作用很弱。结论ERK1／2的磷酸化激活参与EGF诱导人RPE表达整合素α5的过程。EGF激活ERK1／2通路刺激人RPE细胞整合素α5mRNA的表达。     

多西他赛对人晶状体上皮细胞的抑制作用

背景一些已知的抑制人晶状体上皮细胞（LECs）增生的药物由于严重的不良反应限制了其临床应用，寻找高效、安全的抑制LECs增生的药物是防治晶状体后囊膜混浊（PCO）的研究热点。目的探讨多西他赛对LECs增生的影响，并与盐酸表柔比星、盐酸吡柔比星和雷替曲塞的作用进行比较。方法对永生系人LECs细胞株SRAOI／04进行培养及传代，将不同浓度的多西他赛、盐酸表柔比星、盐酸吡柔比星和雷替曲塞加入LECs中分别作用24、48、72h，以MTT法评价不同浓度的多两他赛对人LECs增牛的抑制作用并与其他药物进行比较。用流式细胞术分析不同浓度的多西他赛作用48h后对LECs细胞周期的影响，采片jAnnexinV-FITC／PI标记法和蛋白印迹分析法评估不同浓度的多西他赛作用48h后LECs细胞bcl-2蛋白的表达和凋亡情况。结果8～519pmol／L多西他赛组LECs的增生率为100％，LECs形态正常，而66nmol／L多西他赛组干预48h和72h后LECs的增生率分别为34．7％和27．4％，LECs形态出现异常。23．22～523．56μmol／L雷替曲塞对人LECs的增生无明显抑制作用。多西他赛作用48h和72h时，半数抑制量（IC50）明显低于盐酸吡柔比星和盐酸表柔比星。多西他赛作用LECs48h后，随着多西他赛浓度的增高，处于G2／M期的LECs百分数明显增加，各组的总体差异有统计学意义（F=2633．05，P〈0．01）；8．3nmol／L和266nmol／L多西他赛浓度组干预48h后，LECs的凋亡率分别为22．4％和27．9％，较细胞对照组升高，差异均有统计学意义（χ2=20．00，P〈0．01；χ2=42．68，P〈0．01）。Westernblot检测表明不同浓度多西他赛干预后bcl-2蛋白在LECs中的表达条带均较对照组淡，8．3nmol／L多西他赛组bcl-2蛋白表达降低更为明显。结论多西他赛、盐酸表柔比星和盐酸吡柔比星均可抑制人LECs的增生，而雷替曲塞对人LECs的增生无明显的抑制作用。多西他赛对LECs增生的抑制作用强于其他药物，其作用强度呈浓度和时间依赖性。     

TGF-β1对Tenon囊成纤维细胞增生和HSP47表达的影响

目的探讨转化生长因子B1（TGF-β1）对人Tenon囊成纤维细胞（HTF）增生和热休克蛋白47（HSP47）表达的影响。方法青光眼患者Tenon囊组织体外培养，用不同质量浓度0．01、0．1、1、5、10ng／mLTGF-β1处理细胞，继续培养24h，用MTT比色法检测吸光度值（A），用免疫细胞化学检测HSP47和Ⅰ型胶原纤维蛋白含量，用实时荧光定量PCR检测HSP47和Ⅰ型胶原mRNA表达。结果TGF-β1能促进HTF的增生（P〈0．05），诱导HTF表达HSP47和Ⅰ型胶原纤维蛋白（P〈0．05），促进HTF表达HSP47和Ⅰ型胶原纤维mRNA（P〈0．05），其作用随TGF-β1质量浓度的增加而增强。结论TGF-β1通过促进HTF纤维增生，诱导下游介质HSP47和Ⅰ型胶原蛋白表达而促进HTF纤维化，可能是青光眼滤过手术后瘢痕形成的重要机制。     

LY294002对bFGF诱导的兔晶状体上皮细胞增生的影响

目的探讨LY294002对碱性成纤维细胞生长因子（bFGF）诱导的兔晶状体上皮细胞（LECs）增生的影响。方法兔眼LECs经培养后,将10^-8、10^-7、10^-6、10^-5、10^-4mol／LLY294002分别加入LECs培养基中培养48h为LY294002组。另将10^-8、10^-7、10^-6、10^-5、10^-4mol／LLY294002＋bFGF（10mg／L）加入培养基中培养LECs48h。bFGF（10mg／L）诱导LECs增生48h为阳性对照组,空白对照组仅用无血清DMEM。MTT比色法测定吸光度（A）值,分析各组药物对LECs增生的抑制率,流式细胞仪检测各细胞周期的LECs百分率。结果bFGF组与空白对照组相比A值升高,LY294002组随着药物浓度的增加,4值明显降低,差异有统计学意义（P〈0．01）。bFGF＋LY294002组与LY294002组相比,A值下降更明显,差异有统计学意义（P〈0．01）。流式细胞仪分析LY294002对LECs的抑制作用与MTT呈现相同趋势,随着LY294002浓度的增加,处于G0／G1期的LECs逐渐增加（P〈0．01）,而S期和G2／M期逐渐减少。结论LY294002可明显抑制体外培养的bFGF诱导的兔LECs的增生,并呈剂量依赖关系,为临床筛选防治后发性白内障的药物提供依据。     

ILK siRNA对高浓度葡萄糖诱导的人LECs增生和上皮向间质转化的抑制作用

目的探讨整合素连接激酶（ILK）对高浓度葡萄糖诱导的人晶状体上皮细胞（LECs）增生和转化的作用。方法将体外培养的人LECs系SRA01/04细胞分别培养在含葡萄糖5.5mmol/L（正常对照组）和30.5mmol/L（高糖组）的培养液中,用RT-PCR检测培养0、6、24h后ILK mRNA的表达;用ILK siRNA脂质体转染细胞,转染6h后,加入2组培养液处理24h,检测ILK、细胞增生核抗原（PCNA）、LECs转化指标α-SMA和FN在mRNA水平的表达。结果高糖组培养6h和24h,SRA01/04细胞ILK mRNA是正常对照组的2.48倍和2.32倍（P〈0.01）,刺激后24h,SRA01/04细胞PCNA、α-SMA、FN的mRNA表达分别是正常对照组的1.75、1.96和1.75倍（P〈0.01）。ILK siRNA干扰后,正常对照组ILK的表达是非转染细胞的30%,高糖组转染细胞ILK mRNA水平（P〈0.01）是非转染细胞的21%（P〈0.01）,转染细胞PCNA、α-SMA和FN的表达分别是非转染细胞的29%、33%和39%（P〈0.01）。结论高浓度葡萄糖可诱导LECs增生、上皮向间质转化及ILK表达上调,抑制ILK的高表达能阻止这些过程。     

P38有丝分裂素激活蛋白激酶信号转导通路介导过氧化氢诱导的人晶状体上皮细胞中热休克蛋白27表达的研究

目的研究P38有丝分裂素激活蛋白激酶(MAPK)在H2O2诱导的人晶状体上皮细胞热休克蛋白质27(HSP27)表达中的作用。方法使用100和200μmol/LH2O2分别以不同时间刺激培养的人晶状体上皮细胞系B3,在阻断实验中加入特异性P38MAPK阻断剂SB203580阻断P38MAPK信号转导通路。采用逆转录聚合酶链反应检测刺激不同时间的人晶状体上皮细胞HSP27mRNA的表达情况,采用免疫印迹法(Westernblotting)检测细胞中HSP27和磷酸化P38MAPK的表达情况。结果(1)H2O2刺激后的人晶状体上皮细胞中HSP27mRNA及其蛋白的表达显著增加;(2)100和200μmol/LH2O2刺激30min,人晶状体上皮细胞应激活化蛋白激酶的活性(平均灰度值)分别增强至800±081和825±050,6h后恢复至基线水平(P<001);磷酸化P38MAPK的表达随H2O2浓度的增高而增加,且在H2O2刺激后15min达到峰值,随后逐渐下降;(3)加用特异性P38MAPK阻断剂SB203580预处理后,200μmol/LH2O2刺激6h的人晶状体上皮细胞HSP27表达(平均灰度值)从3600±082降至875±126,受到显著抑制(P<001)。结论P38MAPK信号转导途径参与H2O2诱导的人晶状体上皮细胞HSP27的表达。(中华眼科杂志,2005,414751)     

RGDRGD肽对人晶状体上皮细胞黏附与增生作用的影响

背景RGD肽是一类含有精氨酸-甘氨酸-天冬氨酸的小分子多肽,其在抑制肿瘤细胞黏附、转移和肿瘤新生血管的生成中起重要作用。研究证实RGD肽能够抑制晶状体上皮细胞（LECs）的黏附和增生,RGDRGD肽串联起来作用增强。目的研究RGDRGD肽对体外培养的人LECs黏附与增生的影响,并与RGD肽的作用进行比较。方法将在体外分离培养的LECs中分别加入250、500、1000mg／L的RGDRGD肽和RGD肽作为实验组,仅加入细胞培养液作为对照组。将LECs以2×10。／ml密度接种到含有纤维连接蛋白（FN）和I型胶原蛋白预孵化的96孔培养板中,培养1h后用MTT比色法检测RGDRGD肽与RGD肽对细胞黏附率的影响。将LECs接种于培养板,分别加入250、500、1000、2000mg／L的RGDRGD肽和RGD肽培养24、48、72h,检测RGDRGD肽和RGD肽对LECs增生的影响。结果RGDRGD肽对人LECs黏附率的抑制呈明显的剂量依赖性,随着其质量浓度的增加,对细胞黏附的抑制作用越强,500mg／L的RGDRGD肽比RGD肽抑制人LECs黏附的作用更强（P〈0．01）。RGDRGD肽对人LECs增生的抑制呈明显的时间剂量依赖性,1000mg／L的RGDRGD肽作用48h比RGD肽对人LECs增生的抑制作用更强（P〈0．01）。结论RGDRGD肽抑制LECs黏附与增生的作用强于RGD肽,为进一步临床应用提供了理论依据。     

Hepatocyte growth factor induces proliferation of lens epithelial cells through activation of ERK1/2 and JNK/SAPK

PURPOSE: Posterior capsule opacification (PCO) is caused by proliferation and migration of lens epithelial cells (LECs) remaining after cataract surgery. In this study, the effect of HGF in LECs and the signaling pathways that contribute to HGF-induced proliferation were investigated. METHODS: Capsular bags prepared from porcine eyes were maintained in serum-free DMEM. The human lens epithelial B3 cells (HLE B3) and rat lens epithelial explants were cultured in MEM supplemented with 20% FCS and medium 199 with 0.1% BSA, respectively. Cell proliferation was determined by MTT assay, proliferating cell nuclear antigen (PCNA) expression, or flow cytometry. An antisense oligonucleotide was used to inhibit cyclin D1 expression. Activation of the mitogen activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways was detected by immunoblot analysis. RESULTS: The proliferation of LECs in a capsular bag culture was significantly inhibited by treatment with the neutralizing antibody for HGF receptor. Stimulation of HLE B3 with hepatocyte growth factor (HGF) activated the MAPKs, ERK, and JNK/SAPK, but not p38. Activation of both ERK and JNK/SAPK was necessary for the HGF-stimulated induction of cyclin D1, which in turn was necessary for the HGF-induced proliferation of LECs. PI3K also participated in the regulation of cyclin D1 expression upstream of ERK and JNK/SAPK. CONCLUSIONS: The data indicate that HGF is a potent growth factor for LECs and may contribute to the development of PCO and suggest that the signaling pathways involved in HGF-stimulated proliferation may constitute potential therapeutic targets in the treatment of PCO.     

Differential dependence of regulatory volume decrease behavior in rabbit corneal epithelial cells on MAPK superfamily activation

We characterized the dependence of hypotonicity-induced regulatory volume decrease (RVD) responses on mitogen-activated protein kinase (MAPK) pathway signaling in SV40-immortalized rabbit corneal epithelial cells (RCEC). Following calcein-AM loading, RVD was monitored using a microplate fluorescence reader. Western blot analysis determined MAPK activation. After 30 min, the RVD response restored the relative cell volume to nearly isotonic values, whereas it was inhibited when cells were bathed either in a Cl- -free solution or with the Cl- -channel inhibitors: 5-nitro-2-(3-phenylpropylamino)benzoic acid or niflumic acid. Similar declines occurred with either a high-K+ (20 mM) supplemented solution or the K+ channel inhibitor 4-aminopyridine. Activation of extracellular signal-regulated kinase (ERK), p38, and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) was time and tonicity-dependent. Stimulation of ERK and SAPK/JNK was maximized earlier than that of p38. Activation of ERK and SAPK/JNK was insensitive to Cl- and K+ channel inhibitors, whereas inhibition with either PD98059 or SP600125, respectively, blocked RVD. However, inhibition of p38 with SB203580had no effect on RVD. Suppression of RVD instead blocked p38 activation. Differences in the dependence of RVD activation on Erk1/2 and p38 signaling were validated in dominant negative (d/n)-Erk1 and d/n-p38 cells. Volume-sensitive Cl- and K+ channel activation contributes, in concert, to RVD in RCEC. Therefore, swelling-induced ERK and SAPK/JNK stimulation precedes Cl- and K+ channel activation, whereas p38 activation occurs as a consequence of RVD.     

Quercetin对晶状体上皮细胞HSP70、HSP27表达的调节作用

目的研究大鼠眼钝挫伤后晶状体上皮细胞(LECs)热休克蛋白(HSP)70、HSP27的表达,并给予喂饲Quercetin(HSP阻滞剂),观察Quercetin对LECsHSP70及HSP27表达的调节。方法SD大鼠48只,随机分成拍打组和Quercetin组,每组各24只24眼,右眼为实验眼。拍打组:20g铁球20cm高度拍打眼球100次。Quercetin组:给大鼠喂饲Quercetin(100mg/kg),2-3h后再拍打眼球。RT-PCR检测LECsHSP70、HSP27基因表达。结果钝挫性眼外伤可造成LECsHSP70基因表达的增强,拍打眼球后1hHSP70表达开始升高,3h后达到高峰,24h后降至正常。Quercetin组HSP70基因表达随时间亦出现相应的提高,但与拍打组相比其峰值下降,差异有非常显著性意义。两组HSP27基因表达均无明显改变。结论钝挫性眼外伤中LECsHSP70表达的增强提示HSP70可能在钝挫性外伤性白内障形成过程中对晶状体变性蛋白起保护作用,预先喂饲Quercetin可抑制LECsHSP70基因的表达,其作用机制可能发生于HSP转录水平。     

H2O2对小窝蛋白在人晶状体上皮细胞中分布与表达的影响

目的 观察以H2O2刺激晶状体上皮细胞（LECs）后对细胞活性的影响及小窝蛋白（caveolin）在LECs膜及胞浆内的分布和表达量的改变。方法 用lmmol／LH2O2刺激LECs不同时间，MTT法观察细胞活性；激光共聚焦显微镜观察caveolin在细胞膜和胞浆内的分布；Western—blot法检测caveolin表达量的变化。结果 H2O2作用时间越长，细胞活性越低；对照组与试验组的差异有显著统计学意义。激光共聚焦显微镜观察到人LECs有丰富的caveolin；无刺激时主要分布在膜上；刺激后在膜及胞浆内的分布增多。Western-blot法发现H2O2作用后，caveolin的表达量减少。结论 H2O2对人LECs的活性产生影响，并导致细胞caveolin重新分布、表达量减少。     

杞精明目汤颗粒剂对肿瘤坏死因子-α刺激下结膜松弛症成纤维细胞MAPK信号通路的影响

目的　观察肿瘤坏死因子α（tumor necrosis factor-α,TNF-α）刺激下,杞精明目汤颗粒剂对结膜松弛症（conjunctivochalasis,CCH）结膜成纤维细胞表达丝裂原活化蛋白激酶（mitogen-activated protein kinase,MAPK）的影响,探讨CCH的发病机制及有效治疗策略。方法　体外培养CCH结膜成纤维细胞,分为CCH组、CCH+TNF-α组及CCH+TNF-α+杞精明目汤组。CCK-8确定杞精明目汤颗粒剂有效浓度,用含10^-2 mg·L^-1的TNF-α刺激培养的成纤维细胞,加入杞精明目汤颗粒剂干预48 h,分别采用ELISA、Western Blot和RT-PCR检测MAPK信号通路相关蛋白及mRNA的表达,并行统计学分析。结果　CCK-8确定杞精明目汤颗粒剂有效浓度为1.61 g·L^-1。三组MAPK信号通路相关分子细胞外调节蛋白激酶（extracellular regulated protein kinase,ERK）、c-jun氨基末端激酶（c-jun N-terminal kinase,JNK）、p38 MAPK及其磷酸化水平的吸光度（A₄₅₀）值总体差异均有统计学意义（均为P<0.05）,且TNF-α可明显上调CCH表达ERK1/2、JNK1/2、p-JNK1/2、p38 MAPK、p-p38 MAPK（均为P<0.05）,而杞精明目汤可显著下调TNF-α刺激后的CCH成纤维细胞表达ERK1/2、p-ERK1/2、JNK1/2、p38 MAPK、p-p38 MAPK（均为P<0.05）。三组p-ERK1/2、p38 MAPK、p-p38 MAPK蛋白总体差异均有统计学意义（均为P<0.05）,且TNF-α可明显上调CCH成纤维细胞p-ERK1/2、p-JNK1/2、p38 MAPK、p-p38 MAPK蛋白的表达（均为P<0.05）,杞精明目汤可显著下调TNF-α刺激后的CCH成纤维细胞表达p-ERK1/2、p38 MAPK（均为P<0.05）。三组ERK1/2、p38 MAPK mRNA表达总体差异均有统计学意义（均为P<0.05）,且TNF-α可明显上调CCH成纤维细胞ERK1/2、p38 MAPK mRNA的表达（均为P<0.05）,杞精明目汤可显著下调TNF-α刺激后的CCH成纤维细胞p38 MAPK mRNA表达（P<0.05）。结论　TNF-α可上调CCH成纤维细胞MAPK信号通路的表达,导致CCH的发生发展,而杞精明目汤颗粒剂在一定程度上可下调MAPK信号通路的表达从而发挥治疗作用。     

Fate of hypertonicity-stressed corneal epithelial cells depends on differential MAPK activation and p38MAPK/Na-K-2Cl cotransporter1 interaction

The capacity of the corneal epithelium to adapt to hypertonic challenge is dependent on the ability of the cells to upregulate the expression and activity of cell membrane-associated Na-K-2Cl cotransporter1 (NKCC1). Yet, the signaling pathways that control this response during hypertonic stress are still unclear. We studied stress-induced changes in proliferation and survival capacity of SV40-immortalized human (HCEC) and rabbit (RCEC) corneal epithelial cells as a function of (i) the magnitude of the hypertonic challenge, (ii) differential changes in activation of mitogen-activated protein kinase (MAPK), and (iii) the extent of p38MAPK interaction with NKCC1. Cells were incubated in hypertonic (up to 600 mOsm) media for varying time periods up to 24 h. Phosphorylated forms of p44/42, p38, and stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK) MAPK were immunoprecipitated from cell lysates, and the amount of each activated NKCC1-associated MAPK was evaluated by Western blot/ECL assay. DNA integrity was assessed by electrophoresis in a 2% agarose gel. Cell survival and proliferation were evaluated based on three criteria: protein content, cell count, and the MTT assay. Exposure to media of 325-350 mOsm increased proliferation of HCEC up to 75%, whereas this response was limited to <16% in RCEC. At higher osmolarities, cell proliferation decreased in both species. SAPK/JNK activity increased 150-fold in HCEC and <10-fold in RCEC, while DNA fragmentation occurred only in HCEC. Compared to HCEC, the better RCEC survival rate was associated with higher p38MAPK activity and near complete restoration of p44/42MAPK activity after the first 30 min. In both cell lines, the amount of phospho-NKCC1 that coimmunoprecipitated with phospho-p38MAPK was proportional to the magnitudes of their respective activation levels. However, no such associations occurred between amounts of phosphorylated p44/42MAPK or SAPK/JNK and phospho-NKCC1. Under isotonic conditions, with bumetanide-induced inhibition of RCEC and HCEC NKCC1 activities, p44/42MAPK activity declined by 40 and 60%, respectively. Such declines led to proportional decreases in cell proliferation. Survival of hypertonicity-stressed corneal epithelial cells depends both on p38MAPK activation capacity and the ability of p38MAPK to stimulate NKCC1 activity through protein-protein interaction. The level of NKCC1 activation affects the extent of cell volume recovery and, in turn, epithelial survival capacity.     

硫酸镍与芪归解毒汤对人晶状体上皮细胞中HSP27表达的影响

目的:探讨硫酸镍损伤后人晶状体上皮细胞(lens epithelial cell,LECs)中热休克蛋白27(heat shock protein27,HSP27)表达情况,并给予芪归解毒汤干预,观察晶状体上皮细胞HSP27表达的变化。方法:体外培养正常人晶状体上皮细胞分为正常组,硫酸镍组和中药组,分别作用24h后,逆转录聚合酶链反应(RT-PCR)检测晶状体上皮细胞HSP27 mRNA的表达水平。结果:硫酸镍损伤可造成晶状体上皮细胞HSP27 mRNA表达水平上调(P<0.05),预先的中药干预能使HSP27 mRNA表达水平上调(P<0.05)。结论:硫酸镍损伤后晶状体上皮细胞HSP27mRNA表达水平上调,给予预先的中药干预可能通过提高HSP27的表达水平从而保护晶状体上皮细胞。     

Phosphorylation of MAP kinase in corneal epithelial cells during wound healing

PURPOSE: To investigate the role of mitogen-activated protein kinase (MAPK), such as p44/42 MAPK, p38 MAPK and stress-activated protein kinase (SAPK), in corneal epithelial cells during the wound healing process. METHODS: A single non-penetrating incision was produced on rat cornea. Then the corneal wound healing process was observed with an immunocytochemical technique using specific antibodies reacting only with phosphorylated p44/42 MAPK, p38 MAPK or SAPK. Cell lysates of corneal epithelial cells in rabbits stimulated with keratinocyte growth factor (KGF) and hepatocyte growth factor (HGF) were processed for Western blot using antibodies to phosphorylated p44/42 MAPK. RESULTS: Maximum activation of p44/42 MAPK was observed in wing and basal cells at wounded regions in rat cornea at 1 hour after the incision. Activation of p44/42 MAPK was still detected in all basal and wing cells at wounded regions at up to 24 hours when the incisions were completely closed, and then receded to normal intensity after 7 days. Neither p38 MAPK nor SAPK were activated during the wound healing process. Western blot analysis of cultured corneal epithelial cells in rabbits showed phosphorylation of p44/42 MAPK after 30 minutes in response to KGF and HGF, whereas non-activated p44/42 MAPK was ordinarily detected even at the absence of KGF or HGF. CONCLUSIONS: These results demonstrate that p44/42 MAPK is activated during the corneal wound healing process and suggest that KGF and HGF play an important role in initiation of cell migration and proliferation in the initial wound healing process by activating p44/42 MAPK.