In vitro and in vivo evaluation of effects of Mg-6Zn alloy on tight junction of intestinal epithelial cell

The effects of biodegradable Mg?6Zn alloy on tight junction of intestinal epithelial cells (IEC-6) were investigated. In the in vitro experiments, the cells were exposed to Mg?6Zn alloy extracts with different concentrations (0, 20% and 40%) for 1, 3 and 5 d. The real-time polymerase chain reaction (PCR) results show that when the cells are treated with 40% and 20% extracts, the expression of Zona Occludens 1 (ZO-1) and Occludin increase as compared with those in the control group. In the in vivo experiments, Mg?6Zn alloy and titanium staples were implanted into rabbits’ intestinal tract for 1, 2 and 3 weeks. By immunohistochemical staining of peri-implant intestinal tissue, increased expression of Occludin and ZO-1 are observed in the Mg?6Zn alloy groups as compared with those in the titanium and control groups. The results show that Mg?6Zn alloy in intestine may promote the regeneration of tight junction, and the extract with a certain concentration can induce the expression of tight junction related genes in IEC-6 cells.

In Vitro Evaluation of Effects of Mg-6Zn Alloy Extracts on Apoptosis of Intestinal Epithelial Cells

We assessed the in vitro cytotoxicity of Mg-6Zn alloy and analyzed the cell apoptosis rate and the expression of caspase-3 to evaluate the effects of Mg-6Zn alloy extracts on apoptosis of intestinal epithelial cells（IEC）-6. IEC-6 cells were cultured in different concentrations of Mg-6Zn alloy extracts（40%, 20%） and in the control group. The indirect effects of Mg-6Zn alloy on IEC-6 cells were studied by calculating the cell relative growth rate（RGR）, measuring the apoptosis of IEC-6 cells through flow cytometry, and investigating the expression of caspase-3 using real-time polymerase chain reaction. The experimental results show that the cytotoxicity of these extracts is Grade 0-1. The level of apoptosis in IEC-6 cells cultured in 40% Mg-6Zn alloy extracts is significantly higher than that in cells treated with 20% extract and the control group. The expression of caspase-3 is found to be up-regulated in the 40% extract as compared to 20% extract and the control group. Taken together, the data show that the Mg-6Zn alloy in 40% and 20% concentration extracts proves noncytotoxicity. But the 40% concentration of Mg-6Zn alloy extract can induce the apoptosis and the related caspase-3 expression in vitro.

Differential activation of mitogen-activated protein kinases by γ-irradi-ation in IEC-6 cells: Role of intracellular Ca^(2+)

Objective: To explore the effects of γ-irradiation on mitogen-activated protein kinases (MAPKs) and role of intracellular calcium in this event in intestinal epithelial cell line 6 (IEC-6 cells). Methods: After cultured rat IIEC-6 cells with or without the pretreatment of intracellular Ca2+ chelator were exposed to Y-ir-radiation of 6 Gy, the total and phosphorylated MAPKs in the cells were determined with Western blotting and apoptosis was examined with flow cytometry. Activities of Extracellular signal-regulated protein kinase (ERK) and p38 MAPK were determined by using immuoprecipitation followed by Western blotting. Results: In response to γ-irradiation, phosphorylation of ERK was not significantly observed, while the levels of phosphorylated c-Jun NH2-terminal kinase (JNK) and p38 MAPK were increased in 30 min and reached the peak 2 h after exposure to 6 Gy γ-irradiation, though the cell viability was significantly lowered 12 h. On the other hand, no obvious changes were seen in the total protein levels of ERK, JNK and p38 MAPK. Chelation of intracellular Ca2+ almost completely suppressed the JNK and p38 MAPK phosphorylation induced by γ-irradia-tion, but removal of external Ca2+ had no such effect. Activation of p38 MAPK, but not of ERK, was seen to have a correlation with γ-irradiation induced apoptosis. Conclusion: The results suggest that γ-irradiation is a potent activator for JNK and p38 MAPK, and Ca2+ mobilized from intracellular stores plays an important role in the activation of MAPKs and the induction of apoptosis in IEC-6 cells.

黑灵芝多糖对脂多糖诱导的IEC-6肠上皮细胞损伤的保护作用

目的:探究黑灵芝多糖(PSG-1)对脂多糖(LPS)诱导的IEC-6肠上皮细胞损伤的保护作用及其机制。方法:采用LPS构建肠上皮细胞IEC-6损伤模型,研究PSG-1对IEC-6细胞的干预效果。采用细胞计数盒(cck-8)法测定PSG-1干预对细胞活力的影响。运用western-blot技术探究细胞中肠道紧密连接蛋白和环氧化酶cox-2表达的变化,基于转录组测序技术分析PSG-1潜在的保护机制并对其进行验证。结果:PSG-1干预可以显著提升LPS造成的细胞活力降低和肠道紧密连接蛋白ZO-1、Claudin-1和Occludin的表达,而且PSG-1对LPS引起的cox-2异常高表达具有抑制效果。转录组测序及划痕试验和蛋白免疫印迹试验结果表明:PSG-1能显著增强细胞的迁移能力并抑制促凋亡蛋白Bax、Caspase-3和Caspase-9的表达。结论:PSG-1对LPS诱导的肠上皮细胞IEC-6具有显著的保护作用,细胞迁移和凋亡可能是PSG-1发挥其保护效应的关键途径。

骆驼刺提取物对脂多糖诱导的IEC-6细胞损伤模型NLRP3炎症小体及相关细胞因子的影响

目的研究骆驼刺提取物(Alhagi pseudalhagi(M.B.)Desv.Extract,APE)对脂多糖诱导的大鼠小肠隐窝上皮细胞(Intestinal epithelial cell,IEC-6)损伤模型NLRP3炎症小体及相关细胞因子的影响。方法培养IEC-6细胞,将其分为空白组、模型组、APE低、中、高浓度组,用1.0μg/mL的脂多糖(Lipopolysaccharide,LPS)诱导建立细胞炎症损伤模型,APE(低、中、高浓度:15、25、35μg/mL)干预后采用CCK-8法检测细胞的存活率,通过ELISA试剂盒检测炎症因子IL-1β、IL-18、TNF-α的分泌水平。蛋白质印迹法(WB)检测核苷酸结合寡聚化结构域样受体蛋白3(Nucleotide-binding oligomerization domain-like receptor protein 3,NLRP3)炎症小体信号通路5个关键蛋白:NLRP3、半胱氨酸天冬氨酸蛋白酶1(Cystein-asparate protease-1,Caspase-l)、凋亡相关斑点样蛋白(Apoptosis-associated speck-like protein containing a CARD,ASC)及抗凋亡蛋白Bcl-2(Anti-apoptosis Protein Bcl-2)和Bcl-xl(Anti-apoptosis Protein Bcl-xl)表达。结果与空白组比较,模型组IEC-6细胞的存活率降低,NLRP3、Caspase-1、ASC蛋白表达水平升高,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平降低,促炎因子IL-1β、IL-18和TNF-α的分泌水平升高,差异有统计学意义(P<0.05)。与模型组比较,APE低、中、高浓度组细胞存活率升高,35μg/mL APE组IEC-6细胞的NLRP3、Caspase-1、ASC蛋白相对表达水平降低,抗凋亡蛋白Bcl-2、Bcl-xl的表达水平升高,差异有统计学意义(P<0.05)。中、高浓度的APE能够抑制炎症因子分泌,25μg/mL APE对IL-1β、IL-18、TNF-α炎症因子分泌水平抑制率分别为31.60%、31.19%和31.09%(P<0.05)。结论骆驼刺提取物通过提高抗凋亡蛋白Bcl-2、Bcl-xl的表达水平,下调NLRP3炎症小体组成成分以及促炎因子IL-1β、IL-18和TNF-α分泌,从而抑制NLRP3炎症小体组装和激活,实现缓解LPS对IEC-6细胞的损伤。

Ubiquitin-specific protease 47 regulates intestinal inflammation through deubiquitination of TRAF6 in epithelial cells

Deubiquitinates(DUBs) alter the stabilities, localizations or activities of substrates by removing their ubiquitin conjugates,which are closely related to the development of inflammatory response. Here, we show that ubiquitin-specific protease 47(USP47) prevents inflammation development in inflammatory bowel disease(IBD). Compared with wild-type mice, Usp47 knockout mice are more susceptible to dextran sodium sulfate(DSS)-induced acute and chronic colitis with higher inflammatory cytokines expression and severe intestinal tissue damage. Chimeric mouse experiments suggest that non-hematopoietic cells mainly contribute to the phenotype. And, DSS-induced colitis of the Usp47 knockout mice depends on commensal bacteria.Mechanistically, down-regulation of USP47 aggravates the activation of NF-κB signaling pathway by increasing the K63-linked poly-ubiquitination of tumor necrosis factor receptor-associated factor 6(TRAF6) in intestinal epithelial cells. Furthermore, the expression of USP47, negatively correlated with the degree of inflammation, is lower at colonic inflammatory lesions than that non-inflammatory sites from the intestine from ulcerative colitis(UC) and Crohn's disease(CD) patients. These data, taken together, indicate that USP47 regulates intestinal inflammation through de-ubiquitination of K63-linked poly-ubiquitination TRAF6 in intestinal epithelial cells.

四君子汤多糖对IEC-6细胞迁移、钾通道蛋白及膜电位的影响

目的:观察四君子汤多糖对小肠上皮IEC-6细胞迁移及多胺调控信号通路钾通道蛋白和膜电位的影响,探讨四君子汤修复胃肠黏膜损伤的作用机制。方法:划痕法建立IEC-6细胞迁移模型,观察正常培养及α-二氧甲基乌氨酸(DFMO,多胺合成抑制剂)或4-氨基吡啶(4-AP,钾通道抑制剂)负荷下四君子汤多糖对IEC-6细胞迁移的影响;分别以荧光定量PCR法和Western blot法检测四君子汤多糖对IEC-6细胞钾通道蛋白kv1.1 mRNA和蛋白表达的影响;流式细胞仪检测四君子汤多糖对IEC-6细胞膜电位的影响。结果:与空白对照组比较,四君子汤多糖(40、80、160 mg/L)可促进IEC-6细胞迁移,提高IEC-6细胞kv1.1 mRNA和蛋白表达水平及细胞膜电位超极化水平(P<0.05或P<0.01);与DFMO模型组比较,四君子汤多糖(40、80、160 mg/L)可逆转DFMO所致细胞迁移数减少、kv1.1 mRNA和蛋白表达的降低以及细胞膜电位去极化(P<0.05或P<0.01);与4-AP模型组比较,四君子汤多糖(20、40、80 mg/L)可逆转4-AP所致细胞迁移的抑制、kv1.1 mRNA和蛋白表达的降低(P<0.05或P<0.01)。结论:四君子汤多糖可促进IEC-6细胞迁移,作用机制与影响多胺调控信号通路钾通道蛋白表达和细胞膜电位有关。

白术提取物对IEC-6细胞迁移过程Rho GTPaes及肌球蛋白II表达的影响

目的观察白术提取物对小肠上皮细胞(IEC-6)迁移多胺介导钾通道激活信号通路指标Rho GTPaes(Rho A、Rac1和Cdc42)表达的影响,对肌球蛋白II(myosinⅡ)分布和表达的影响,以探讨益气健脾中药白术对胃肠黏膜损伤修复的作用机制。方法荧光定量PCR法检测Rho A、Rac1和Cdc42 mRNA表达;Western blot法检测Rho A、Rac1和Cdc42蛋白表达;免疫荧光法检测myosinⅡ蛋白分布和表达。结果白术提取物能提高细胞迁移过程Rho A、Rac1、Cdc42 mRNA和蛋白表达,逆转多胺合成抑制剂二氟甲基鸟氨酸(DFMO)所致的Rho A、Rac1、Cdc42 mRNA和蛋白表达抑制;提高细胞迁移过程myosinⅡ表达,从而增加细胞骨架应力纤维形成,改善DFMO所致的myosinⅡ蛋白表达和分布的抑制。结论白术提取物促进IEC-6细胞迁移的作用机制,与其影响多胺介导钾通道激活信号通路有关。

正交设计优化低温应激诱导IEC-6细胞损伤条件的实验研究

目的采用正交实验设计法,优化低温应激诱导大鼠小肠隐窝上皮细胞(intestinal epithelial crypt,IEC-6)损伤的条件。方法以温度、处理时间和接种密度为正交优化的3个因素,每个因素设定3个水平,分别为处理温度(4℃,10℃,22℃),低温处理时间(2 h,4 h,6 h),接种密度(1×105/m L,2. 5×105/m L,5×105/m L),根据三因素三水平设计正交实验表,得到9个实验组,按相应条件处理,细胞增殖/毒性检测试剂法分析细胞毒性,在50%<细胞存活率<90%范围内获得最优组合条件。应用最优组合条件处理实验组IEC-6细胞,同时设置正常对照,镜下观察细胞形态,流式细胞术检测细胞凋亡和线粒体膜电位。结果 (1)在50%<细胞存活率<90%范围内,低温应激诱导IEC-6细胞损伤的最优组合条件为:处理温度4℃,接种密度5×105/m L,低温处理时间4 h。(2)与对照组相比,最优组合条件下实验组细胞失去正常形态,同时线粒体膜电位去极化增强,细胞凋亡显著加重(P<0. 01)。表现为前者以早期凋亡为主,细胞凋亡率为(4. 41±1. 36)%,低强度红色荧光细胞(R2)占比(5. 24±0. 57)%,后者则以晚期凋亡和坏死为主,细胞凋亡率为(23. 70±2. 94)%,低强度红色荧光细胞(R2)占比(31. 12±3. 66)%。结论在50%<细胞存活率<90%范围内,低温应激诱导IEC-6细胞损伤的最优组合条件为处理温度4℃、接种密度5×105/m L、低温处理时间4 h,在该条件下,IEC-6细胞出现明显凋亡。

紫云英苷对LPS诱发的大鼠小肠上皮细胞(IEC-6)的抗炎作用

本研究探究了紫云英苷对脂多糖(LPS)诱发的大鼠小肠上皮隐窝细胞(Rat intestinal epithelial cells,IEC-6)炎症模型抗炎作用。构建LPS诱发IEC-6细胞炎症模型,采用MTT法、酶联免疫吸附试验(ELISA)、实时荧光定量PCR和Western Blot法检测紫云英苷对IEC-6炎症细胞的存活率、相关炎症因子、基因及蛋白表达水平;结果显示,随着紫云英苷浓度的增加,IEC-6细胞的存活率逐渐增加,紫云英苷剂量(50μg/m L、100μg/m L)组存活率为90.68%和95.76%(p<0.05或p<0.01);酶联免疫吸附试验表明,与LPS组相比,紫云英苷50μg/m L,100μg/m L剂量显著抑制炎症因子,对IL-6炎症因子分泌水平抑制率分别为21.98%(p<0.05)和29.05%(p<0.01),m RNA表达水平分别降低了34.90%(p<0.05)和41.60%(p<0.01)。TNF-α炎症因子分泌水平抑制率分别为16.25%(p<0.05)和23.37%(p<0.01),m RNA表达水平分别降低了34.11%(p<0.05)和43.84%(p<0.01);蛋白通路方面,100μg/m L的紫云英苷可显著抑制LPS诱导的IEC-6细胞NF-κB通路中P-IKKα/β降低了27.46%(p<0.05)、P-IκBα降低了41.52%(p<0.05)、P-p65降低了37.78%(p<0.01)。本探究为紫云英苷作为一种潜在缓解炎症性肠病药物的开发提供了可靠的依据。

Synthesis of quaternary 8-(1-acylethene-1-yl)-13-methylcoptisine chlorides and their selective growth inhibitory activity between human cancer cell lines and normal intestinal epithelial cell-6

In this paper, quaternary 8-（1-acylethene-l-yl）-13-methylcoptisine chlorides targeting thioredoxin reductases （TrxRs） were designed to test the growth inhibitory activity against human cancer cell lines and the effect on viability of the normal intestinal epithelial cell-6 （IEC-6） in vitro and to evaluate structure-activity relationship （SAR）. The introduced α, β-unsaturated ketone groups at C-8 consisting of n-alkanoyls possessing five to ten carbons or aroyls or cyclohexylcarbonyl increased the tested activity against the target cancer cell lines. By and large, this type of improvement was increasingly graced by the elongation of the aliphatic chain of the n-alkanoyls in the range of less than ten carbon atoms. The relatively more polar l-acylethene-l-yls displayed no effect on improving the activity. All the explored aroyls showed significant effect on improving the activity of the target compounds against the tested cancer cell lines with no SAR being observed, The findings of this study suggested that oil]water partition coefficient of the test compounds was one of the key factors impacting the target activity against the tested cancer cell lines. At the concentration of 10 μmol/L, except for the compounds with n-all（anoyls possessing seven or more carbons or with α-naphthoyl, none of the other compounds displayed obvious cytotoxicity on normal IEC-6 cell when co-incubated. The survival rate of IEC-6 cell ranged from 75% to 100% for the noncytotoxic compounds.

Polysaccharide extracts of Astragalus membranaceus and Atractylodes macrocephala promote intestinal epithelial cell migration by activating the polyamine-mediated K^+ channel

Astragalus membranaceus(Radix Astragali, RA) and Atractylodes macrocephala(Rhizoma Atractylodis Macrocephalae, RAM) are often used to treat gastrointestinal diseases. In the present study, we determined the effects of polysaccharides extracts from these two herbs on IEC-6 cell migration and explored the potential underlying mechanisms. A migration model with IEC-6 cells was induced using a single-edged razor blade along the diameter of cell layers in six-well polystyrene plates. The cells were grown in control--media or media containing spermidine(5 μmol·L^(-1), SPD), alpha-difluoromethylornithine(2.5 mmol·L^(-1), DFMO), 4-Aminopyridine-(40 μ-mol·L^(-1), 4-AP), the polysaccharide extracts of RA or RAM(50, 100, or 200 mg·L^(-1)), DFMO plus SPD, or DFMO plus polysaccharide extracts of RA or RAM for 12 or 24 h. Next, cytosolic free Ca^(2+)([Ca^(2+)]cyt) was measured using laser confocal microscopy, and cellular polyamine content was quantified with HPLC. Kv1.1 mRNA expression was assessed using RT-qPCR and Kv1.1 and RhoA protein expressions were measured with Western blotting analysis. A cell migration assay was carried out using Image-Pro Plus software. In addition, GC-MS was introduced to analyze the monosaccharide composition of both polysaccharide extracts. The resutls showed that treatment with polysaccharide extracts of RA or RAM significantly increased cellular polyamine content, elevated [Ca^(2+)]cyt and accelerated migration of IEC-6 cells, compared with the controls(P < 0.01). Polysaccharide extracts not only reversed the inhibitory effects of DFMO on cellular polyamine content and [Ca^(2+)]cyt, but also restored IEC-6 cell migration to control level(P < 0.01 or < 0.05). Kv1.1 mRNA and protein expressions were increased(P < 0.05) after polysaccharide extract treatment in polyamine-deficient IEC-6 cells and RhoA protein expression was increased. Molar ratios of D-ribose, D-arabinose, L-rhamnose, D-mannose, D-glucose, and D-galactose was 1.0:14.1:0.3:19.9:181.3:6.3 in RA and 1.0:4.3:0.1:5.7:2.8:2.2 in RAM. In conclusion, treatment with RA and RAM polysaccharide extracts stimulated migration of intestinal epithelial cells via a polyamine-Kv1.1 channel activated signaling pathway, which facilitated intestinal injury healing.

肠致病性大肠杆菌毒力因子EspF对肿瘤坏死因子-α、白细胞介素-6和白细胞介素-8的影响

目的研究肠致病性大肠杆菌(EPEC)毒力因子EspF转染人肠上皮细胞(HIC)株时,血清肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)和IL-8水平的动态变化及与HIC凋亡的关系。方法以Annexin V FITC/PI双染流式细胞仪检测HIC的凋亡率,并用酶联免疫吸附测定法检测转染0、6、12、24、48 h细胞培养上清液中TNF-α、IL-6和IL-8浓度的变化。结果 EspF转染HIC后TNF-α、IL-6和IL-8活性均显著增加,HIC凋亡率在转染后逐渐增高,HIC凋亡率与TNF-α、IL-6和IL-8的水平呈正相关。结论 EspF可激活多种炎症介质和诱导HIC凋亡,EspF转染HIC后TNF-α、IL-6和IL-8水平的升高在EPEC致病过程中起重要作用。

甘草黄酮提取物对小肠上皮细胞IEC-6迁移及多胺的影响

目的观察甘草黄酮提取物对小肠隐窝上皮细胞IEC-6迁移及迁移过程细胞内多胺量的影响。方法划痕法制备细胞迁移模型,观察在多胺合成抑制剂二氟甲基鸟氨酸(DFMO)及钾通道抑制剂4-氨基吡啶(4-AP)存在情况下,甘草黄酮提取物对细胞迁移的影响;柱前衍生-高效液相色谱法检测IEC-6细胞在正常及DFMO存在条件下,给予甘草黄酮提取物12、24 h后细胞内多胺(精脒)的量。结果甘草黄酮提取物可逆转DFMO或4-AP所致IEC-6细胞迁移抑制;其给药12、24 h后可提高细胞内精脒的量,并逆转DFMO对多胺合成的抑制。结论甘草黄酮提取物促进细胞迁移的作用与影响细胞内多胺调控信号通路有关。

白术多糖调控钙离子以促进细胞迁移及E-钙黏蛋白表达的研究

目的观察白术多糖对大鼠小肠上皮细胞(IEC-6)钙离子水平、细胞迁移和E-钙黏蛋白表达的影响,探讨益气健脾中药白术促进胃肠黏膜损伤修复的作用机制。方法:流式细胞仪检测白术多糖对细胞游离钙离子水平([Ca^(2+)]cyt)的影响;划痕法复制细胞迁移模型,观察白术多糖对细胞迁移的影响;Western blot法和免疫荧光法检测白术多糖对细胞E-钙黏蛋白表达的影响。结果白术多糖(25,50,100 mg·L^(-1))可增加细胞[Ca^(2+)]cyt、促进细胞迁移、提高E-钙黏蛋白表达,与正常对照组比较,差异有统计学意义(P<0.05,P<0.01);可逆转多胺合成抑制剂α-二氟甲基鸟氨酸(DFMO)所致的[Ca^(2+)]cyt降低、细胞迁移抑制和E-钙黏蛋白表达减少,与DFMO组比较,差异有统计学意义(P<0.05,P<0.01)。结论白术多糖可通过提高细胞钙离子水平以促进细胞迁移和E-钙黏蛋白表达,为探讨益气健脾中药白术修复胃肠黏膜损伤的作用机制提供参考。

角质细胞生长因子对肠上皮细胞辐射损伤的防护作用

目的 探讨角质细胞生长因子 (KGF)的辐射防护作用与机制 ,为应用KGF防护肠道辐射损伤提供实验依据。方法 应用正常及不同剂量γ射线损伤的肠上皮细胞 (IEC 6) ,通过在培养体系中加入不同剂量的KGF后检测细胞增殖活性的变化以及凋亡细胞百分率 ,作为KGF辐射防护效应和细胞辐射敏感性变化的指标。结果 正常培养的IEC 6细胞 ,KGF呈剂量依赖型促细胞增殖作用 ;10Gy照射后KGF促细胞增殖作用显著减弱。KGF预处理能显著降低IEC 6细胞辐射敏感性 ,其IP50 ( 50 %增殖抑制照射量 )从对照( 15.3± 0 .6)Gy降至 ( 12 .2± 0 .4 )Gy。结论 KGF具有促肠上皮细胞增殖作用 ,其辐射防护作用表现为降低细胞辐射敏感性 ,抑制辐射诱导的细胞凋亡可能是其作用机制之一。

肿瘤坏死因子-α对肠黏膜上皮细胞谷氨酰胺载体功能及其表达的影响

目的肿瘤坏死因子-α(TNF-α)是感染中最重要的调节因子,谷氨酰胺需经过其载体转运至细胞内才能被利用。文中研究TNF-α对肠黏膜上皮细胞株(intestinal epithelial cell line,IEC)-6细胞膜谷氨酰胺载体功能、ASCT2mRNA及蛋白表达的可能影响,揭示TNF-α对细胞膜谷氨酰胺载体功能的影响机制。方法体外培养IEC-6,分为对照组(不与TNF-α共孵育)和实验组(与TNF-α共孵育):实验组与不同剂量的TNF-α(2、5、8、10ng/ml)共孵育2h后,测定细胞[3H]-L-谷氨酰胺摄取率;实验组与5ng/mlTNF-α共孵育不同时段(2、5、8、10h)后,测定ASCT2载体mRNA水平;实验组与5ng/mlTNF-α共孵育不同时段(2、6h)后,检测载体ASCT2蛋白表达水平。结果不同TNF-α剂量孵育的实验组[3H]-L-谷氨酰胺摄取率显著低于对照组(P<0.01),实验组之间差异无显著性意义(P>0.05);孵育2h的实验组ASCT2载体mRNA水平显著高于对照组(P<0.01),时间延长后逐渐下降,10h则与对照组差异无显著性意义(P>0.05);不同时段实验组载体ASCT2蛋白表达水平均显著低于对照组(P<0.01),实验组间差异无显著性意义(P>0.05)。结论TNF-α抑制IEC-6细胞膜谷氨酰胺载体的摄取功能,抑制ASCT2蛋白表达,但不抑制IEC-6细胞ASCT2载体mRNA的表达。TNF-α对细胞膜谷氨酰胺载体功能的抑制可能发生在载体蛋白的翻译或以后水平。

亮菌多糖对LPS诱导的肠上皮细胞炎性损伤的保护作用及机制探讨

目的观察在脂多糖(LPS)诱导的IEC-6肠上皮细胞损伤的情况下,亮菌多糖(ATPS)对细胞活性、闭合素(Occludin)、细胞紧密连接蛋白1(ZO-1)的影响,并探讨ATPS对肠黏膜屏障损伤的保护机制。方法利用LPS构建的IEC-6肠上皮细胞体外损伤模型,将细胞随机分为对照组、LPS组、LPS+ATPS组、LPS+Matrine组(阳性对照),使用普通显微镜和MTT法观察细胞的活性;免疫荧光和流式细胞术检测细胞的凋亡情况;Western blot检测膜蛋白ZO-1和跨膜蛋白Occludin的表达水平。同时Western blot检测与介导细胞凋亡密切相关的内质网应激(ERS)通路上磷酸化蛋白激酶R样内质网调节激酶(p-PERK)、磷酸化真核细胞翻译起始因子(p-eIF2α)、葡萄糖调节蛋白78(GRP78)、内质网应激相关蛋白(CHOP)以及调节肠黏膜损伤重要分子β-抑制蛋白1(Arrb1)的表达水平。结果与对照组、LPS组比较,随着ATPS的浓度增加,LPS+ATPS组中细胞的活性越多且免疫荧光和流式检测也表明细胞的凋亡率减少;Occludin、ZO-1的表达水平增多,明显高于LPS组;与LPS组相比,LPS+ATPS组中p-PERK、p-eIF2α、GRP78、CHOP及Arrb1蛋白的水平降低。结论ATPS可通过抑制Occludin、ZO-1的破坏来保护LPS介导的肠上皮细胞炎性损伤,其机制可能与介导细胞凋亡的内质网应激蛋白以及调节肠黏膜损伤的重要分子Arrb1有关。

4种中药提取物对大鼠小肠上皮细胞IEC-6增殖及其葡萄糖吸收的影响

目的利用大鼠小肠上皮细胞系(IEC-6),研究单味中药提取物对小肠上皮细胞增殖和葡萄糖吸收转运功能的调控作用。方法藿香、苍术、黄柏和石膏等4种中药被定向提取,MTT细胞增殖试验筛选提取物的适宜作用质量浓度,测定各处理组细胞的葡萄糖吸收率和Na+,K+-SATP酶活性,同时采用荧光定量PCR技术分析细胞中钠-葡萄糖共转运载体(SGLT1)、葡萄糖转运载体2(GLUT2)和Na+,K+-ATP酶的mRNA表达量。结果各中药提取物对大鼠小肠上皮细胞增殖的影响与其作用质量浓度有关。50μg/mL苍术挥发油和10μg/mL黄柏生物碱可提高IEC-6细胞葡萄糖的吸收功能,并显著上调了SGLT1和Na+,K+-ATP酶mRNA表达量;50μg/mL藿香挥发油促进了细胞的葡萄糖吸收,但仅对GLUT2的基因表达有上调效应(P<0.05);而50μg/mL石膏水提物对细胞葡萄糖的吸收无促进作用(P>0.05)。结论苍术挥发油、藿香挥发油和黄柏生物碱对细胞增殖和葡萄糖吸收均有促进作用,但其影响机制并不完全一样。

白术多糖对小肠上皮细胞细胞屏障及黏附连接蛋白表达的影响

目的观察白术多糖对小肠上皮细胞(IEC-6)渗透性的影响,并从其对黏附连接蛋白表达影响的角度,探讨白术多糖对肠黏膜上皮屏障的作用及机制。方法在3种实验条件下[正常含钙、含钙+多胺合成抑制剂(DFMO)、无钙培养],以检测Transwell小室酚红透过率的方法观察细胞间渗透性;以Western Blot法检测细胞黏附连接蛋白(E-cadherin、α-catenin和β-catenin)的表达。结果(1)正常含钙培养时,白术多糖(25、50、100 mg·L-1)能降低细胞间渗透性并提高黏附连接蛋白表达(P<0.05或P<0.01);(2)含钙+DFMO负荷时,细胞间渗透性增加且黏附连接蛋白表达下降(P<0.01);各剂量的白术多糖能逆转DFMO所致的细胞间渗透性增加,且对黏附连接蛋白表达下降有拮抗作用(P<0.05或P<0.01);(3)无钙培养时,细胞间渗透性增加且黏附连接蛋白表达下降(P<0.01),各剂量的白术多糖可逆转无钙培养所致的细胞间渗透性增加及E-cadherin表达降低(P<0.05或P<0.01),但对α-catenin和β-catenin表达无明显影响。结论白术多糖有增强小肠上皮屏障的作用,其机制与影响黏附连接蛋白表达有关,研究结果为探讨益气健脾中药白术对胃肠黏膜保护作用提供了参考。