四君子汤对脾虚大鼠肠黏膜 TFF3蛋白表达及 TFF3mRNA 表达的影响

目的：探讨四君子汤对脾虚大鼠肠道黏膜 TFF3蛋白表达及 TFF3mRNA 表达的影响。方法大鼠随机分为正常对照组、脾虚模型组、自然复健组和四君子汤组,蛋白印迹（Western-Blot）法测定回肠黏膜 TFF3蛋白表达的变化,采用逆转录-聚合酶链式反应（RT-PCR）法检测 TFF3mRNA。结果与正常对照组相比,脾虚各组大鼠肠黏膜 TFF3蛋白表达,TFF3mRNA 降低。经四君子汤治疗后,大鼠肠黏膜 TFF3蛋白表达,TFF3mRNA 明显上调,优于自然复健组（P ＜0．01）。结论研究表明,四君子汤可增强 TFF3mRNA 与蛋白的表达,促进受损肠黏膜的重建与修复,增强肠黏膜防御能力。     

脓毒症大鼠肠黏膜免疫屏障功能的变化

目的 研究脓毒症对大鼠肠黏膜免疫屏障功能的影响.方法 60只SD大鼠随机(随机数字法)分为对照组(n=15)和脓毒症组(n=45),采用盲肠结扎穿孔术(CLP)建立脓毒症模型.模型建立后3 h、6 h和12 h留取回肠黏膜和全血标本.分别进行肠黏膜形态学观察、肠防御素5(RD-5)及肠三叶因子3(TFF_3)Mrna表达水平检测、肠黏膜淋巴细胞凋亡分析,以及外周血中肠源性细菌DNA定性检测.结果 CLP所致脓毒症导致大鼠回肠黏膜明显损害,主要表现为上皮脱落、固有层分离、毛细血管出血和溃疡形成;脓毒症组模型建立后3 h即出现RD-5和TFF_3 Mrna表达显著性减少(与正常组比较,P<0.05),且6 h和12 h组进行下降(与3 h组比较,P<0.05),肠黏膜淋巴细胞凋亡数亦显著增加(P<0.05);同时,脓毒症组全血肠源性细菌DNA扩增全部阳性.结论 脓毒症时大鼠肠黏膜免疫屏障功能显著减退,且随脓毒症的发展而进行性恶化.     

乌司他丁对脓毒症大鼠肠道防御素5 mRNA表达的影响

目的 探讨乌司他丁(ulinastatin,LTI)对脓毒症大鼠肠道潘氏细胞防御素5(rat defemin-5,RD-5)mRNA表达的影响.方法 实验在中山大学医学院药理实验室完成.60只SD大鼠随机分为对照组、脓毒症组、预处理组及治疗组(n=15).后三组采用盲肠结扎穿孔术(cecal ligation andpuncture,CLP)制作大鼠脓毒症模型.预处理组在CLP前2h经尾静脉注射UTI 25 000 U/kg,治疗组在CLP后2 h经尾静脉注射UTI 50 000 U/kg.于模犁建立后12 h取回肠黏膜,观察其病理改变并以RT-PCR法检测RD-5 mRNA的表达.数据以SPSS 13.0统计软件处理,采用方差分析及LSD-t检验进行数据分析.结果 RD-5 mRNA在脓毒症组显著下降(P<0.05),预处理组及治疗组较脓毒症组有明显升高(P<0.05),预处理组较治疗组明显升高(P<0.05).结论 脓毒症大鼠RD-5mRNA表达明显下降,乌司他丁可显著上调其表达,保护肠黏膜,预防用药较治疗给药可能更有意义.     

阻滞交感神经改善脓毒症大鼠肠道微循环

因胃肠道局部缺血、缺氧、黏膜屏障作用受损导致的肠道内细菌／毒素移位与脓毒症发生发展密切相关，在生理条件下阻滞交感神经可提高肠道灌注压。瑞士学者研究了硬膜外麻醉阻滞交感神经对脓毒症大鼠肠黏膜微循环障碍的影响。研究者采用大鼠盲肠结扎穿孔术制备脓毒症模型，然后经胸椎硬膜外导管连续24h给予质量分数为0.125％的布比卡因（n=10）和生理盐水（n=9），     

乌司他丁对脓毒症大鼠肠黏膜上皮防御屏障的影响

目的 探讨乌司他丁(UTI)对脓毒症大鼠肠黏膜上皮防御屏障的影响.方法 50只SD大鼠被随机分为对照组、模型组、UTI预处理组及UTI治疗组,后3组再按盲肠结扎穿孔术(CLP)后3、6和12 h分为3个亚组,每个亚组5只.采用改良的CLP制备大鼠脓毒症模型,预处理组在CLP前2 h经尾静脉注射UTI 25 kU/kg,治疗组在CLP后2 h经尾静脉注射UTI 50 kU/kg.分别于CLP后3、6和12 h活杀大鼠,取回肠黏膜光镜下观察组织病理学变化,用逆转录-聚合酶链反应(RT-PCR)检测肠黏膜防御素-5(RD-5)和肠三叶因子家族3(TFF3)的mRNA表达水平.结果 模型组小肠绒毛顶端上皮脱落,固有层崩解,毛细血管出血和溃疡形成,UTI治疗组和预处理组能显著减轻上述改变.模型组RD-5和TFF3的mRNA表达水平较对照组显著降低,UTI治疗组和预处理组能显著升高其表达水平(P<0.05或P<0.01);预处理组CLP后12 h较治疗组升高最为显著,差异有统计学意义(P均<0.05).结论 脓毒症时肠黏膜上皮屏障功能受损,UTI对其有保护作用,从而遏制脓毒症的发生发展.     

血必净对脓毒症大鼠肠黏膜屏障及巨噬细胞抗体表达的作用

目的 观察血必净对脓毒症大鼠肠黏膜屏障和巨噬细胞抗体表达的变化的影响作用,探讨其在脓毒症发病中的作用机制及意义.方法 Wistar大鼠150只,分成脓毒症组、血必净干预组和假手术组.采用肓肠结扎穿孔术建立脓毒症大鼠模型,模型标准是发热、呼吸频率增加、心率加快和白细胞总数改变.血必净组大鼠术前12 h、术后腹腔内注射4 mL/kg血必净,1次/12 h,共3 d;其余两组大鼠同时注射相同体积的生理盐水.利用图像分析系统检测三组大鼠肠黏膜病理变化和巨噬细胞的表达水平,并运用等级资料秩和检验和方差分析进行统计学分析.结果 假手术组大鼠小肠黏膜多为基本正常黏膜,12 h,24 h,48 h,72 h脓毒症组、血必净组大鼠肠道黏膜出现病变;脓毒症组病变较血必净组更为严重,差异具有统计学意义(H=19.732,P<0.01).在0 h三组小肠黏膜巨噬细胞抗体的表达数基本一致,12 h,24 h,48 h,72 h脓毒症组和血必净组间差异具有统计学意义,且均较C组变化差异具有统计学意义(F=560.13,P<0.05).结论 脓毒症大鼠肠道黏膜机械屏障和免疫屏障均有不同程度的损害,血必净注射液可部分保护肠道黏膜机械屏障和免疫屏障.     

乌司他丁对肠源性脓毒症大鼠D-二聚体和蛋白C系统的影响

目的：观察乌司他丁（ulinastatin，UTI）对肠源性脓毒症大鼠D-二聚体（DD）、蛋白C（PS）系统的影响。方法：将Wistar大鼠随机分为4组，假手术组（SH组，n=36）、脓毒症组（SEP组，n=30）、UTI3h给药组（UTI3h组。n=30）和12h给药组（UTI12h组，n=18）。利用经典盲肠结扎穿孔法建立肠源性脓毒症大鼠模型，分别于正常对照组及制模后6、12、24、48及72h组心脏取血测定DD、PC和蛋白S（PS）。结果：与SH组相比，SEP组大鼠DD在造模后逐渐升高，PC、PS含量降低，差异有显著性（P〈0．05）。与SEP组相比，UTI3h,UTI12h组大鼠的DD降低，PC含量下降趋势减弱，差异有显著性（P〈0．05）。结论：UTI能有效改善脓毒症期间的抗凝抑制和继发性纤溶亢进。     

脓毒症对大鼠海马区caspase-3表达的影响

目的 探讨脓毒症对大鼠海马区神经元的凋亡蛋白酶caspase-3表达的影响。 方法 80只30日龄健康雄性Wistar大鼠,随机分为盲肠结扎穿孔术（CLP） 组（n=50）和对照组（n=30）。CLP组采用CLP建立脓毒症模型,对照组行假手术不造成脓毒症模型。于手术后6、12、24 h,CLP组和对照组分别取10只大鼠,5只做神经行为学评分,另外5只处死取脑,采用蛋白免疫印迹法观察caspase-3的表达,术后24 h,两组各取3只大鼠,采用免疫荧光检测caspase-3的表达。 结果 对照组大鼠大脑海马区仅微量表达caspase-3,神经行为学评分较高。CLP组大鼠caspase-3的表达量于CLP后6 h就开始升高,24 h达高峰,均明显高于对照组（P＜0.05）,大鼠的神经行为学评分在CLP后6 h开始降低,并随着时间逐渐下降,均明显低于对照组（P＜0.05）。 结论 脓毒症脑损伤时大鼠的神经行为学评分降低,海马区神经元caspase-3表达上调,并随时间变化而波动。     

紧密连接蛋白occludin在三硝基苯磺酸诱导大鼠结肠炎肠黏膜屏障中的作用研究

目的探讨紧密连接蛋白occludin在三硝基苯磺酸（trinitro-benzen-sulfonic acid,TNBS）诱导大鼠结肠炎肠黏膜屏障中的作用。方法建立大鼠结肠炎模型。SD大鼠18只,按随机数字表法分为TNBS诱导大鼠结肠炎模型组（n=10）和正常对照组（n=8）,进行疾病活动指数（DAI）和组织学损伤评分,用ELISA法测定结肠组织肿瘤坏死因子-α（TNF-α）、白介素-10（IL-10）和血清内毒素,采用免疫组织学染色检测紧密连接（tight junction,TJ）相关蛋白occludin的分布。结果TNBS诱导大鼠结肠炎后,和正常组比较,TJ结构遭到破坏,TJ相关蛋白的表达亦减少,结肠组织TNF-α水平升高、IL-10水平降低和血清内毒素水平升高（P〈0.05）。结论TNBS诱导大鼠结肠炎肠黏膜上皮细胞TJ相关蛋白occludin表达下降,肠黏膜上皮屏障的完整性被破坏,导致肠黏膜屏障功能低下,促发炎症反应。     

影响脓毒症受损肠黏膜修复的机制

目的 探讨影响脓毒症肠黏膜损害后修复的因素。方法 采用肓肠结扎穿孔(CLP)所致脓毒症模型,分别以CLP后6,24,48 h不同时间段观测肠黏膜损伤程度和修复过程,前者包括形态学观察及细胞凋亡的测定,后者包括肠黏膜修复的杯状细胞变化、黏膜肠三叶因子3(TFF3)、转化生长因子β1(TGF-β1)以及TNF-α、IL-1含量。结果 形态学观察显示肠黏膜呈持续损害状态,6h的损害积分明显小于24h,48 h组(P＜0.05),后两组之间差异无统计学意义(P＞0.05);磷酸化caspase-3蛋白在3组均高于sham组4倍以上;黏膜IL-1,TNF-α含量明显高于sham组3～4倍,其中24h及48 h组明显高于6h组。肠黏膜的修复过程不明显,损伤黏膜未见到明显的杯状细胞积聚;TFF3在6h组轻度增高,24h及48 h组表达下降;杯状细胞数量在CLP的3个组明显减少;TGF-β1在6h组增高,其他两组均接近于sham组。结论 严重脓毒症肠黏膜持续的高炎症状态、杯状细胞功能以及黏膜重建能力下降,影响了受损肠屏障的修复。     

JAK/STAT通路介导脓毒症大鼠肝组织高迁移率族蛋白B1 mRNA表达的研究

目的：探讨Janusk激酶／信号转导和转录激活子（JAK／STAT）通路对盲肠结扎穿孔术（CLP）所致脓毒症大鼠肝组织高迁移率族蛋白B1（HMGB1）mRNA表达和急性肝损害的影响。方法：采用CLP模型，大鼠随机分为正常对照组、CLP脓毒症组、JAK2激酶抑制剂AG490和STAT抑制剂雷帕霉素（RPM）处理组。采用逆转录多聚酶链式反应测定肝HMGB1 mRNA，全自动生化分析仪测定肝功能指标。结果：与正常对照组相比，CLP后6－48h HMGB1 mRNA表达显著升高（P＜0．01）；血清天冬氨酸转氨酶（AST）在6－48h增高明显（P＜0．05），丙氨酸转氨酶（ALT）、AST在24h升高非常显著（P＜0．01）。与CLP组相比，AG490预处理组24h HMGB1 mRNA和ALT水平显著下降（P均＜0．01），24h和48h AST亦明显降低（P均＜0．01）；同样，RPM干预后HMGB1 mRNA表达在6h 和24h显著抑制（P＜0．05和P＜0．01），ALT、AST在24h和48h均不同程度下降（P＜0．01和P＜0．05）。结论：抑制JAK／STAT通路活化可明显下调肝组织HMGB1 mRNA表达，并有助于减轻CLP所致急性肝损伤。     

血必净调节脓毒症脾组织Fas Bax蛋白表达改善免疫麻痹的实验研究

目的观察血必净对脓毒症大鼠脾组织促调亡相关蛋白表达及细胞免疫功能的影响。方法96只Wistar大鼠随机分为正常对照组(8只)、假手术组(8只)、模型组(40只)和血必净组(40只),以盲肠结扎穿孔法(CLP)制备脓毒症模型。ELISA法检测血清IL-2、IL-10水平,免疫组化法检测脾组织Fas、Bax蛋白表达水平。结果模型组大鼠脾组织Fas、Bax表达明显增多,同时于造模后36、48h,血清IL-2水平明显下降,IL-10水平显著升高。血必净干预后可明显降低脾组织Fas、Bax表达,提高IL-2水平,同时可降低IL-10水平,减轻重要脏器的病理损伤。结论血必净干预可通过降低促凋亡相关蛋白表达缓解脓毒症时的免疫麻痹状态。     

Changes of the immunological barrier of intestinal mucosa in rats with sepsis

BACKGROUND:

Sepsis has become the greatest threat to in-patients, with a mortality of over 25%. The dysfunction of gut barrier, especially the immunological barrier, plays an important role in the development of sepsis. This dysfunction occurs after surgery, but the magnitude of change does not differentiate patients with sepsis from those without sepsis. Increased intestinal permeability before surgery is of no value in predicating sepsis. The present study aimed to observe the changes of intestinal mucosal immunologic barrier in rat models of sepsis induced by cecal ligation and puncture.

METHODS:

Sixty Sprague-Dawley rats were randomly divided into a sepsis group (n=45) and a control group (n=15). The rats in the sepsis group were subjected to cecal ligation and puncture (CLP), whereas the rats in the control group underwent a sham operation. The ileac mucosa and segments were harvested 3, 6 and 12 hours after CLP, and blood samples were collected. Pathological changes, protein levels of defensin-5 (RD-5) and trefoil factor-3 (TFF₃) mRNA, and lymphocytes apoptosis in the intestinal mucosa were determined. In an additional experiment, the gut-origin bacterial DNA in blood was detected.

RESULTS:

The intestinal mucosa showed marked injury with loss of ileal villi, desquamation of epithelium, detachment of lamina propria, hemorrhage and ulceration in the sepsis group. The expression of TFF₃ mRNA and level of RD-5 protein were decreased and the apoptosis of mucosal lymphocyte increased (P<0.05) in the sepsis group compared with the control group. Significant differences were observed in RD-5 and TFF₃ mRNA 3 hours after CLP and they were progressively increased 6 and 12 hours after CLP in the sepsis group compared with the control group (P<0.05, RD-5 F=11.76, TFF₃ F=16.86 and apoptosis F=122.52). In addition, the gut-origin bacterial DNA detected in plasma was positive in the sepsis group.

CONCLUSION:

The immunological function of the intestinal mucosa was impaired in septic rats and further deteriorated in the course of sepsis.KEY WORDS: Sepsis, Mucosal immunology, Defensin-5, Trefoil factor family 3, Cecal ligation and puncture     

血必净对脓毒症大鼠回肠黏膜形态学的影响

目的 观察不同给药途径及不同给药时间情况下,血必净注射液对脓毒症大鼠回肠黏膜形态学的影响.方法 91只健康Sprague-Dawley大鼠由中山大学实验动物中心提供,随机分为正常对照组(n=7)、脓毒症组(n=21)、灌胃给药+脓毒症组(预处理组)(n=21)、静脉给药+脓毒症组(预处理组)(n=21)和脓毒症+静脉给药组(治疗组)(n=21).除正常对照组外,其余各组按手术后3 h,6 h,12 h再分3组,每组7只.采用盲肠结扎穿孔法制作脓毒症模型.正常对照组不予任何处理,灌胃给药+脓毒症组于术前2 h灌胃给药(5 mL/kg血必净);静脉给药+脓毒症组于术前2 h尾静脉给药(5 mL/kg血必净);脓毒症+静脉给药组于术后2 h尾静脉给药(5 mL/kg血必净).正常对照组不作任何处理,直接留取组织标本;其余各组于术后3 h,6 h,12 h分别活杀大鼠留取回肠标本,用以进行形态学观察及回肠上皮损伤指数测定.用SPSS 13.0统计软件进行统计学分析;组间比较用方差分析,P<0.05为差异具有统计学意义.结果 预处理组及治疗组大鼠回肠上皮损伤程度均较脓毒症组减轻(P<0.01);预处理组中,静脉给药较灌胃给药的保护效果更好(P<0.05).结论 血必净注射液能减轻脓毒症大鼠回肠黏膜的损伤程度,预先静脉给药效果更佳.     

Repair of damaged intestinal mucosa in a mouse model of sepsis

BACKGROUND:

The intestine is not only the main target attacked by sepsis but also the vital organ which mediated sepsis. The recovery of the damaged intestinal barrier structure and function is related to the occurrence and outcome of multiple organ dysfunction syndrome (MODS). How to protect and reduce the damage of the intestinal mucosa and how to promote the reconstruction of the intestinal mucosa have been the important topics in sepsis for many years. This study aimed to investigate the influential factors of intestinal mucosal reconstruction after intestinal epithelial injury in vivo in a mouse model of sepsis.

METHODS:

Mice were subjected to cecal ligation and puncture (CLP) for induction of sepsis to assess intestinal mucosal damage, epithelial cell apoptosis, and transformed number of goblet cells, and to detect the concentration of TNF-α, IL-1 and TGF-β1 and TFF3 (trefoil factor 3) expression in the small intestinal mucosa. All above were performed by HE staining, western blot, ELISA and immunohistochemistry respectively. The experimental animals were divided into a sepsis group and a sham-operation group. The animals with sepsis were separately killed at 6 (7 animals), 24 (7 animals) and 48 hours (7 animals) after CLP.

RESULTS:

Injured intestinal mucosa was observed in the 3 groups under a light microscope, in which damage scores in the 24-hour and 48-hour groups were higher than in the 6-hour group and no difference was found between the two groups. Moreover, less of goblet cells or other epithelial cells adjacent to the injured surface migrated into the wound to cover the denuded area. The number of goblet cells was substantially decreased in the three CLP groups compared with the sham-operation group. Protein levels of IL-1 and TNF-α were significantly increased by 3–4 fold at all time points when compared with the sham-operation group, and cleaved caspase-3 by 4 fold. Although TFF3 expression was modestly increased for 6 hours after the onset of CLP, it appeared to decline at 24 hours and 48 hours as shown by Western blot. A similar tendency was observed upon TGF-β1, i.e. the protein level was not elevated at 24 hours and 48 hours, but increased modestly at 6 hours.

CONCLUSIONS:

Sepsis from CLP shows less restitution on the surface of injured intestinal mucosa. There is evidence that both constant inflammatory reaction and epithelial cell apoptosis may affect mucosal reestablishment of the intestine at the onset of sepsis. Mucosa after severe sepsis showed the state of high inflammation, and declined goblet cell function and mucosal reconstruction, which affected the repair of damaged intestinal barrier. Constant inflammatory reaction, and declined goblet cell function and mucosal reconstruction ability may affect the reestablishment of intestinal mucosa at the onset of sepsis.KEY WORDS: Sepsis, Cecal ligation and puncture, Intestinal mucosa, Restitution, Goblet cells, Intestinal trefoil factor 3, Transforming growth factor β1, Cysteine-containing aspartate-specific proteases