目的 研究缺氧对肠上皮细胞丝切蛋白活化的影响及丝切蛋白活化与紧密连接蛋白带状闭合蛋白1(ZO-1)分布变化的关系. 方法 建立人肠上皮细胞株Caco-2单层细胞培养模型,取部分细胞按照随机数字表法分为对照组(不处理)、缺氧组(置于缺氧环境下)和常氧组(置于常氧环境下),取对照组细胞(样本数为9)及其他2组培养1、2、6、12、24 h的细胞(各时相点样本数均为9)采用蛋白质印迹法检测丝切蛋白及磷酸化丝切蛋白的表达.另取细胞,按照随机数字表法分为缺氧组和对照组(处理同前),取对照组细胞和缺氧组缺氧1、2、6、12、24 h的细胞采用激光扫描共聚焦显微镜观察纤维状肌动蛋白的形态与分布,荧光法检测纤维状肌动蛋白与球状肌动蛋白含量的比值,激光扫描共聚焦显微镜观察细胞形态及ZO-1的分布;该3个实验中对照组样本数依次为3、6、3,缺氧组各时相点样本数依次为3、6、3.对数据行重复测量方差分析、配对t检验、LSD-t检验. 结果 与对照组比较,常氧组细胞培养1 ~24 h丝切蛋白及磷酸化丝切蛋白表达量均无明显变化(t值分别为-0.385 ~1.701、0.040 ~1.538,P值均大于0.05).与对照组比较,缺氧组细胞培养1~24 h丝切蛋白表达量也无明显变化(t值为1.032 ~2.390,P值均大于0.05);但磷酸化丝切蛋白表达量均明显降低(t值为4.563 ~ 22.678,P值均小于0.01),其中培养24 h降至最低值.常氧组、缺氧组细胞各时相点丝切蛋白表达量相近(t值为-0.904 ~1.433,P值均大于0.05);缺氧组细胞培养1、2、6、12、24 h时磷酸化丝切蛋白表达量分别为0.87±0.08、0.78±0.05、0.89±0.07、0.68±0.07、0.57±0.06,均低于常氧组(0.90±0.07、0.97±0.06、1.00±0.06、1.00±0.05、0.99±0.05,t值为3.193 ~16.434,P值均小于0.01).对照组细胞胞质内纤维状肌动蛋白丰富,大多呈束状;缺氧组细胞从缺氧1h起纤维状肌动蛋白走向混乱、长度变短甚至消散.缺氧组细胞缺氧12、24 h时纤维状肌动蛋白与球状肌动蛋白含量比值分别为0.89±0.12、0.84±0.19,均明显低于对照组(1.00,t值分别为3.622、3.577,P值均小于0.01);其余时相点两者的比值与对照组接近(t值为0.447~ 1.526,P值均大于0.05).对照组细胞排列紧密,ZO-1沿细胞膜连续分布;缺氧组从缺氧2h起细胞形态不规则,其中缺氧24 h时ZO-1沿细胞膜分布不再连续,出现断裂. 结论 缺氧可能通过诱导肠上皮细胞丝切蛋白活化,引起纤维状肌动蛋白与球状肌动蛋白动态平衡失调,从而导致紧密连接蛋白ZO-1分布发生改变.
目的 研究缺氧對腸上皮細胞絲切蛋白活化的影響及絲切蛋白活化與緊密連接蛋白帶狀閉閤蛋白1(ZO-1)分佈變化的關繫. 方法 建立人腸上皮細胞株Caco-2單層細胞培養模型,取部分細胞按照隨機數字錶法分為對照組(不處理)、缺氧組(置于缺氧環境下)和常氧組(置于常氧環境下),取對照組細胞(樣本數為9)及其他2組培養1、2、6、12、24 h的細胞(各時相點樣本數均為9)採用蛋白質印跡法檢測絲切蛋白及燐痠化絲切蛋白的錶達.另取細胞,按照隨機數字錶法分為缺氧組和對照組(處理同前),取對照組細胞和缺氧組缺氧1、2、6、12、24 h的細胞採用激光掃描共聚焦顯微鏡觀察纖維狀肌動蛋白的形態與分佈,熒光法檢測纖維狀肌動蛋白與毬狀肌動蛋白含量的比值,激光掃描共聚焦顯微鏡觀察細胞形態及ZO-1的分佈;該3箇實驗中對照組樣本數依次為3、6、3,缺氧組各時相點樣本數依次為3、6、3.對數據行重複測量方差分析、配對t檢驗、LSD-t檢驗. 結果 與對照組比較,常氧組細胞培養1 ~24 h絲切蛋白及燐痠化絲切蛋白錶達量均無明顯變化(t值分彆為-0.385 ~1.701、0.040 ~1.538,P值均大于0.05).與對照組比較,缺氧組細胞培養1~24 h絲切蛋白錶達量也無明顯變化(t值為1.032 ~2.390,P值均大于0.05);但燐痠化絲切蛋白錶達量均明顯降低(t值為4.563 ~ 22.678,P值均小于0.01),其中培養24 h降至最低值.常氧組、缺氧組細胞各時相點絲切蛋白錶達量相近(t值為-0.904 ~1.433,P值均大于0.05);缺氧組細胞培養1、2、6、12、24 h時燐痠化絲切蛋白錶達量分彆為0.87±0.08、0.78±0.05、0.89±0.07、0.68±0.07、0.57±0.06,均低于常氧組(0.90±0.07、0.97±0.06、1.00±0.06、1.00±0.05、0.99±0.05,t值為3.193 ~16.434,P值均小于0.01).對照組細胞胞質內纖維狀肌動蛋白豐富,大多呈束狀;缺氧組細胞從缺氧1h起纖維狀肌動蛋白走嚮混亂、長度變短甚至消散.缺氧組細胞缺氧12、24 h時纖維狀肌動蛋白與毬狀肌動蛋白含量比值分彆為0.89±0.12、0.84±0.19,均明顯低于對照組(1.00,t值分彆為3.622、3.577,P值均小于0.01);其餘時相點兩者的比值與對照組接近(t值為0.447~ 1.526,P值均大于0.05).對照組細胞排列緊密,ZO-1沿細胞膜連續分佈;缺氧組從缺氧2h起細胞形態不規則,其中缺氧24 h時ZO-1沿細胞膜分佈不再連續,齣現斷裂. 結論 缺氧可能通過誘導腸上皮細胞絲切蛋白活化,引起纖維狀肌動蛋白與毬狀肌動蛋白動態平衡失調,從而導緻緊密連接蛋白ZO-1分佈髮生改變.
목적 연구결양대장상피세포사절단백활화적영향급사절단백활화여긴밀련접단백대상폐합단백1(ZO-1)분포변화적관계. 방법 건립인장상피세포주Caco-2단층세포배양모형,취부분세포안조수궤수자표법분위대조조(불처리)、결양조(치우결양배경하)화상양조(치우상양배경하),취대조조세포(양본수위9)급기타2조배양1、2、6、12、24 h적세포(각시상점양본수균위9)채용단백질인적법검측사절단백급린산화사절단백적표체.령취세포,안조수궤수자표법분위결양조화대조조(처리동전),취대조조세포화결양조결양1、2、6、12、24 h적세포채용격광소묘공취초현미경관찰섬유상기동단백적형태여분포,형광법검측섬유상기동단백여구상기동단백함량적비치,격광소묘공취초현미경관찰세포형태급ZO-1적분포;해3개실험중대조조양본수의차위3、6、3,결양조각시상점양본수의차위3、6、3.대수거행중복측량방차분석、배대t검험、LSD-t검험. 결과 여대조조비교,상양조세포배양1 ~24 h사절단백급린산화사절단백표체량균무명현변화(t치분별위-0.385 ~1.701、0.040 ~1.538,P치균대우0.05).여대조조비교,결양조세포배양1~24 h사절단백표체량야무명현변화(t치위1.032 ~2.390,P치균대우0.05);단린산화사절단백표체량균명현강저(t치위4.563 ~ 22.678,P치균소우0.01),기중배양24 h강지최저치.상양조、결양조세포각시상점사절단백표체량상근(t치위-0.904 ~1.433,P치균대우0.05);결양조세포배양1、2、6、12、24 h시린산화사절단백표체량분별위0.87±0.08、0.78±0.05、0.89±0.07、0.68±0.07、0.57±0.06,균저우상양조(0.90±0.07、0.97±0.06、1.00±0.06、1.00±0.05、0.99±0.05,t치위3.193 ~16.434,P치균소우0.01).대조조세포포질내섬유상기동단백봉부,대다정속상;결양조세포종결양1h기섬유상기동단백주향혼란、장도변단심지소산.결양조세포결양12、24 h시섬유상기동단백여구상기동단백함량비치분별위0.89±0.12、0.84±0.19,균명현저우대조조(1.00,t치분별위3.622、3.577,P치균소우0.01);기여시상점량자적비치여대조조접근(t치위0.447~ 1.526,P치균대우0.05).대조조세포배렬긴밀,ZO-1연세포막련속분포;결양조종결양2h기세포형태불규칙,기중결양24 h시ZO-1연세포막분포불재련속,출현단렬. 결론 결양가능통과유도장상피세포사절단백활화,인기섬유상기동단백여구상기동단백동태평형실조,종이도치긴밀련접단백ZO-1분포발생개변.
Objective To study the effect of hypoxia on cofilin activation in intestinal epithelial cells and its relation with distribution of tight junction protein zonula occludens 1 (ZO-1).Methods The human intestinal epithelial cell line Caco-2 was used to reproduce monolayer cells.The monolayer-cell specimens were divided into control group (no treatment),hypoxic group (exposed to hypoxia),and normoxic group (exposed to normoxia) according to the random number table.Western blotting was used to detect the protein expressions of cofilin and phosphorylated cofilin (p-cofilin) of cells in normoxic group and hypoxic group exposed to normoxia or hypoxia for 1,2,6,12,and 24 h and control group,with 9 samples in control group and 9 samples at each time point in the other two groups.The other monolayer-cell specimens were divided into hypoxic group (exposed to hypoxia) and control group (no treatment) according to the random number table.Cells in hypoxic group exposed to hypoxia for 1,2,6,12,and 24 h and control group were obtained.Morphology and distribution of F-actin was observd with laser scanning confocal microscopy,the ratio of F-actin to G-actin was determined by fluorescence method,and distribution of ZO-1 and cellular morphology were observed with laser scanning confocal microscopy.The sample number of last 3 experiments was respectively 3,6,and 3 in both hypoxic group (at each time point) and control group.Data were processed with paired t test,analysis of variance of repeated measurement,and LSD-t test.Results The protein expressions of cofilin and p-cofilin of cells between normoxic group exposed to normoxia for 1 to 24 h and control group showed no significant changes (with t cofilin values from-0.385 to 1.701,t p-cofilin values from 0.040 to 1.538,P values above 0.05).There were no obvious differences in protein expressions of cofilin of cells between hypoxic group exposed to hypoxia for 1 to 24 h and control group (with t values from 1.032 to 2.390,P values above 0.05).Compared with that in control group,the protein expressions of p-cofilin of cells were greatly reduced in hypoxic group exposed to hypoxia for 1 to 24 h (with t values from 4.563 to 22.678,P values below 0.01),especially exposed to hypoxia for 24 h.The protein expressions of cofilin of cells between normoxic group and hypoxic group at each time point were close (with t values from -0.904 to 1.433,P values above 0.05).In hypoxic group,the protein expressions of p-cofilin of cells exposed to hypoxia for 1,2,6,12,and 24 h were 0.87 ±0.08,0.78 ±0.05,0.89 ±0.07,0.68 ±0.07,and 0.57 ± 0.06,respectively,significantly lower than those in normoxic group (0.90 ± 0.07,0.97 ± 0.06,1.00 ±0.06,1.00 ±0.05,and 0.99 ±0.05,with t values from 3.193 to 16.434,P values below 0.01).In control group,F-actin in the cytoplasm was abundant,most of it was in bunches.The trend of F-actin was disorderly in hypoxic group from being exposed to hypoxia for 1 h,shortened in length or even dissipated.The ratios of F-actin to G-actin of cells in hypoxic group exposed to hypoxia for 12 and 24 h (0.89± 0.12 and 0.84 ± 0.19) were obviously decreased as compared with that in control group (1.00,with t values respectively 3.622 and 3.577,P values below 0.01).There were no obvious differences in the ratios of F-actin to G-actin of cells between hypoxic group exposed to hypoxia for 1,2,and 6 h and control group (with t values from 0.447 to 1.526,P values above 0.05).In control group,cells were compact in arrangement,and ZO-1 was distributed continuously along the cytomembrane.From being exposed to hypoxia for 2 h,cells became irregular in shape in hypoxic group.ZO-1 was distributed in discontinuous fashion along the cytomembrane with breakage in hypoxic group exposed to hypoxia for 24 h.Conclusions Hypoxia may cause the disorder of dynamic balance between F-actin and G-actin by inducing cofilin activation,which in turn leads to the changes in distribution of tight junction protein ZO-1 in intestinal epithelial cells.