肠三叶因子对新生鼠NEC模型PI3K和caspase-3/9的影响

目的 利用PI3K的特异性抑制剂Wortmannin阻断PI3K/Akt细胞信号转导通路,观察ITF对新生鼠NEC模型caspase-3及caspase-9水平的影响,探讨ITF对NEC的保护作用机制.方法 建立NEC模型,对新生一日龄Wistar大鼠予100%氮气,1 min后放4℃冷环境中持续10min,每日2次,随后放回自制的保温箱内人工喂养,第四天处死,取肠组织待检.新生鼠50只随机分为5组,每组10只,A组为NEC模型后予以腹腔注射生理盐水0.2 ml;B组NEC模型后予以腹腔注射ITF0.2 mg;C组为NEC模型后腹腔内注射wortmannin(0.1 mg/kg);D组为NEC模型后腹腔内注射ITF+wortmannin;E组为正常对照组.取近回盲部1～2 cm肠道组织固定包埋、切片、HE染色做病理学检查,其他肠道组织制备组织匀浆取上清液应用ELISA试剂盒检测PI3K的含量及用分光光度法检测caspase-3/9的活性.结果 病理切片显示A组HE染色见肠壁损伤轻重不一,可见全肠黏膜绒毛坏死,病理评分中位积分3分;B组病变明显减轻,肠上皮细胞少量脱落,顶端绒毛坏死,病理评分中位积分1分;C、D组病理评分中位积分3分.A组组织匀浆中PI3K的含量(pg/ml)较E组略升高(P<0.05),与D组差异无统计学意义(P>0.05);B组PI3K表达水平较其他组显著升高(P<0.01);C组与E组比较显著降低,差异有统计学意义(P<0.01).Caspase-3及caspase-9活性在A组较B、E组明显升高,差异有统计学意义(P<0.01),C组更加明显升高(P<0.01),A、D组及B、E组之间,差异无统计学意义(P>0.05).结论 通过腹腔注射ITF可以减轻NEC后的肠道炎症反应,ITF有可能为治疗NEC提供新的方法 ;PI3K/Akt细胞信号转导通路参与了NEC发病过程,并起着信号转导作用.而ITF可能是通过激活PI3K/Akt信号转导途径来下调caspase-3/9的水平,从而保护新生Wistar大鼠NEC模型肠道损伤.     

肠三叶因子对新生鼠NEC模型PI3K和caspase-3/9的影响

Objective To study the effects of ITF on PI3K (phosphatidylinositol 3-kinase) and caspases-3/9 (cysteinyl aspartate-specific protea-ses) in neonatal rat NEC model. Methods NEC model of neonatal rats was established. Asphyxia stress was accomplished by exposure to l00% nitrogen for 60s, followed by exposure to coldness (4 ℃ ) for 10 min twice daily. Neonatal rats were fed formula (200 kcal/kg/day) every 3 h via an gavage tube. The feeding volume began at 0. 1 cc every 3 h and was increased incrementally. This procedure is done once everyday and continued for 3 days. On the 4th day,all the subjects were sacrificed. Fifty neonatal rats were randomized into five groups: A) NEC + NS0. 2mi, (B) NEC + ITF 0. 2 mg, (C) NEC(Wortmannin (0. 1 mg/kg) (D) NEC + ITF 0. 2 mg + Wortmannin (0. 1 mg/kg), (E) control. The intestinal tissue located at the boundary of ileum and cecum was sampled for histology. The remaining intestinal tissue was homogenized. After the homogenate was centrifuged,supernatants were used to assay PI3K and Caspase-3 and caspase-9. Results The pathological lesions showed that intestinal necrosis was severe in group A、C and D, which was graded as 3points. They were significantly decreased in group B,which was graded 1 point. The level of PI3K(pg/ml)in Group A was higher than those in group E (P<0. 05), the latter had difference with those in group D(P>0. 05). The level of PI3K(pg/ml) were the strongest in group B and were lowest in group C. The activity of Caspase-3 and Caspase-9 were significantly increased in group A compared to those in group B and E (P<0. 01 ),and was significantly increased in Group C(P<0. 01 ). Caspase-3 and Caspase-9 levels of group A and D,group B and E showed no significant difference(P>0. 05). Conclusions Intestinal inflammation was ameliorated by intraperitoneal ITF. ITF may provide a new therapy for NEC; PI3K/Akt signal pathways might play important roles in signal transduction during NEC;ITF may protect the intestinal injury of neonatal Wistar rat by activation of PI3K/Akt signal transduction pathway, and down regulation of caspase-9.     

肠三叶因子对新生鼠NEC模型PI3K和caspase-3/9的影响

Objective To study the effects of ITF on PI3K (phosphatidylinositol 3-kinase) and caspases-3/9 (cysteinyl aspartate-specific protea-ses) in neonatal rat NEC model. Methods NEC model of neonatal rats was established. Asphyxia stress was accomplished by exposure to l00% nitrogen for 60s, followed by exposure to coldness (4 ℃ ) for 10 min twice daily. Neonatal rats were fed formula (200 kcal/kg/day) every 3 h via an gavage tube. The feeding volume began at 0. 1 cc every 3 h and was increased incrementally. This procedure is done once everyday and continued for 3 days. On the 4th day,all the subjects were sacrificed. Fifty neonatal rats were randomized into five groups: A) NEC + NS0. 2mi, (B) NEC + ITF 0. 2 mg, (C) NEC(Wortmannin (0. 1 mg/kg) (D) NEC + ITF 0. 2 mg + Wortmannin (0. 1 mg/kg), (E) control. The intestinal tissue located at the boundary of ileum and cecum was sampled for histology. The remaining intestinal tissue was homogenized. After the homogenate was centrifuged,supernatants were used to assay PI3K and Caspase-3 and caspase-9. Results The pathological lesions showed that intestinal necrosis was severe in group A、C and D, which was graded as 3points. They were significantly decreased in group B,which was graded 1 point. The level of PI3K(pg/ml)in Group A was higher than those in group E (P<0. 05), the latter had difference with those in group D(P>0. 05). The level of PI3K(pg/ml) were the strongest in group B and were lowest in group C. The activity of Caspase-3 and Caspase-9 were significantly increased in group A compared to those in group B and E (P<0. 01 ),and was significantly increased in Group C(P<0. 01 ). Caspase-3 and Caspase-9 levels of group A and D,group B and E showed no significant difference(P>0. 05). Conclusions Intestinal inflammation was ameliorated by intraperitoneal ITF. ITF may provide a new therapy for NEC; PI3K/Akt signal pathways might play important roles in signal transduction during NEC;ITF may protect the intestinal injury of neonatal Wistar rat by activation of PI3K/Akt signal transduction pathway, and down regulation of caspase-9.     

双歧杆菌对坏死性小肠结肠炎新生大鼠肠道β-防御素-2表达的影响

目的 探讨双歧杆菌对坏死性小肠结肠炎（NEC）新生大鼠肠道β-防御素-2（BD-2）表达的影响。方法 将40只大鼠分为正常对照组、双歧杆菌对照组、NEC模型组和双歧杆菌干预组（n=10）。采用缺氧+冷刺激+人工喂养的方法建立NEC模型。双歧杆菌对照组和双歧杆菌干预组在每日冷刺激后经胃管注入双歧杆菌,每天1次,连续3 d。收集各组大鼠末段回肠组织于光镜下观察形态学改变并对肠道损伤进行评分,采用免疫组织化学法、qRT-PCR法分别检测各组大鼠回肠黏膜组织中BD-2蛋白及mRNA的表达水平。结果 NEC模型组肠道损伤评分分别高于正常对照组、双歧杆菌对照组、双歧杆菌干预组（P < 0.05）;双歧杆菌干预组的肠道损伤评分高于正常对照组和双歧杆菌对照组（P < 0.05）。正常对照组BD-2 mRNA及蛋白的表达低于双歧杆菌对照组、NEC模型组和双歧杆菌干预组（P < 0.05）;双歧杆菌对照组BD-2 mRNA及蛋白的表达高于NEC模型组和双歧杆菌干预组（P < 0.05）;双歧杆菌干预组BD-2 mRNA及蛋白的表达高于NEC模型组（P < 0.05）。结论 双歧杆菌可诱导大鼠肠道表达BD-2,其可能通过增加BD-2的表达而减轻肠道炎症反应,发挥对新生大鼠NEC模型的保护作用。     

坏死性小肠结肠炎动物模型建立方法的改进与评价

目的目前新生儿坏死性小肠结肠炎(necrotizing enterocolitis, NEC)动物模型的构建方式仍不统一, 本研究旨在明确更贴切临床NEC患儿实际情况的动物建模方式。方法随机将54只C57BL/6新生小鼠分为五组, 依次为:对照组(Ctrl组, 10只)、缺氧+人工喂养组(HF组, 10只)、缺氧+人工喂养+冷刺激组(Cold组, 12只)、缺氧+人工喂养+脂多糖(lipopdysaccharide, LPS)组(LPS组, 11只)、缺氧+人工喂养+NEC肠内细菌组(Bac组, 11只);分别建立NEC动物模型后, 评估肠道组织病理、NEC相关肠上皮屏障蛋白(β-catenin、Occludin)和肠上皮细胞死亡标记性分子(CC3、RIPK1、PARP1)以及促炎细胞因子(IL-6、TNF-α、MCP1)的表达变化。结果按照肠道组织学Nadler评分≥2分视为NEC样肠道损伤。本研究除Ctrl组和HF组外, 其余三组NEC造模的肠道组织病理均满足NEC样肠道损伤标准。与HF组(30%)、Cold组(83.3%)和LPS组(81.8%)相比, Bac组的建模成功率最高(...     

人β-防御素-3通过调控肠上皮细胞自噬对新生大鼠坏死性小肠结肠炎发挥保护作用的实验研究

目的:研究人β-防御素-3(human beta-defensin-3,hBD3)对肠上皮细胞自噬的调节作用及其介导的自噬调控对肠上皮细胞迁移的影响。方法:应用雷帕霉素(Rapamycin)诱导肠上皮细胞IEC-6构建细胞自噬模型。根据实验设计分为对照(Control)组、雷帕霉素(Rapamycin)组和人β-防御素...     

早产极低出生体重儿肠道菌群变化与坏死性小肠结肠炎的相关性

目的:探讨早产极低出生体重儿（VLBWI）坏死性小肠结肠炎（NEC）发生前肠道菌群结构特征变化。方法:采用前瞻性巢式病例对照研究。将2018年4月20日至11月20日生后24 h内收住苏州大学附属儿童医院或苏州市立医院新生儿重症监护病房（NICU）且出生体重<1 500 g、出生胎龄<35周的46例早产VLBWI作为研...     

坏死性小肠结肠炎体内外模型的研究进展

坏死性小肠结肠炎(necrotizing enterocolitis, NEC)是早产儿胃肠外科最常见急症之一。在过去50年里,为了研究该病的病理生理学特点以及明确新治疗策略的有效性,多种多样的实验模型应运而生。目前对于NEC的病因研究主要采用肠上皮细胞和NEC动物模型,然而细胞模型无法还原患儿肠组织体内生物学特性,动物模型无法反映人体疾病的相关特性。近年来肠道干细胞标记物Lgr5+的发现,使新型肠道体外模型——肠道类器官模型得以逐渐兴起。本文将就上述NEC体内外实验模型的研究进展进行综述,分析每种模型的特点与优劣势,进而帮助研究人员理解和选择与研究目的相关的NEC实验模型。     

β-胡萝卜素对坏死性小肠结肠炎新生小鼠肠道氧化应激的保护作用

目的运用坏死性小肠结肠炎(necrotizing enterocolitis, NEC)新生小鼠模型,探讨β-胡萝卜素对NEC新生小鼠肠道损伤的作用。方法选用5日龄C57BL/6新生小鼠15只,按随机数字法分为三组,每组5只。对照组:母鼠哺乳喂养,无其他任何干预;NEC组:通过对新生小鼠缺氧刺激,人工喂养及脂多糖干预诱导产生NEC;β-胡萝卜素干预组:在诱导产生NEC的同时,给予新生小鼠胃管灌注β-胡萝卜素(1 mg/kg)。于生后第9日收集各组新生小鼠末端回肠组织,分析比较NEC病理评分,肠道炎症反应,肠上皮细胞增殖、凋亡及氧化应激水平。结果与对照组相比,NEC组肠道出现明显损伤(0/5比5/5,P<0.05),炎症反应(1.0122±0.03比9.5367±3.025,P<0.01)及氧化应激水平(TBARS 6.9292±0.129比11.4420±0.074,P<0.01; GPx 25.21±7.113比17.5674±5.769,P<0.01)明显升高,肠上皮细胞增殖能力下降(5.36±0.308比1.48±0.212,P<0.01),且凋亡增...     

肠三叶因子在新生鼠坏死性小肠结肠炎模型中对Bax和Bcl-2及Caspase-3表达的影响及意义

目的 通过研究肠三叶因子(ITF)对新生大鼠坏死性小肠结肠炎(NEC)模型肠组织病理学改变及肠道组织中蛋白酶Caspase-3、蛋白Bax和Bcl-2的含量变化,探讨ITF对NEC保护作用的可能机制.方法 30只新生1日龄Wistar大鼠随机分为3组,正常对照组、实验组、干预组,每组10只.实验组为NEC模型后加生理盐水0.2 ml腹腔注射;干预组为NEC模型后予以腹腔注射TTF 0.2 mg(0.2 ml);正常对照组未予处理.第4天处死所有大鼠,取肠组织待检,取近回盲部1～2 cm肠道组织,采用分光光度法检查Caspase-3的表达、采用免疫组化法检测肠道组织中Bax及Bcl-2的含量变化并做病理学检查.结果 实验组Caspase-3表达高于正常对照组和干预组(P均＜0.05),干预组与正常对照组比较差异无统计学意义(P＞0.05);实验组Bax表达高于正常对照组和干预组(P均＜0.05),干预组与正常对照组相近(P＞0.05);干预组Bcl-2表达高于正常对照组和干预组(P均＜0.05),实验组高于正常对照组(P＜0.05).正常对照组的肠组织病理学未见异常,病理评分为0分;实验组HE染色切片见肠壁损伤轻重不一,可见全肠黏膜绒毛坏死,病理评分的中位积分为3分;干预组肠上皮细胞少量脱落,顶端绒毛坏死,病理评分的中位积分为1分.与实验组比较,ITF治疗后NEC导致的组织病理学改变明显减轻.结论 注射ITF可通过减少Caspase-3、Bax表达和增加Bcl-2表达减轻NEC肠道损伤.     

肠三叶因子在新生鼠坏死性小肠结肠炎模型中对Bax和Bcl-2及Caspase-3表达的影响及意义

目的通过研究肠三叶因子(ITF)对新生大鼠坏死性小肠结肠炎(NEC)模型肠组织病理学改变及肠道组织中蛋白酶Caspase-3、蛋白Bax和Bcl-2的含量变化,探讨ITF对NEC保护作用的可能机制。方法30只新生1日龄Wistar大鼠随机分为3组,正常对照组、实验组、干预组,每组10只。实验组为NEC模型后加生理盐水0.2ml腹腔注射;干预组为NEC模型后予以腹腔注射ITF 0.2 mg(0.2 ml);正常对照组未予处理。第4天处死所有大鼠,取肠组织待检,取近回盲部1～2 cm肠道组织,采用分光光度法检查Caspase-3的表达、采用免疫组化法检测肠道组织中Bax及Bcl-2的含量变化并做病理学检查。结果实验组Caspase-3表达高于正常对照组和干预组(P均<0.05),干预组与正常对照组比较差异无统计学意义(P>0.05);实验组Bax表达高于正常对照组和干预组(P均<0.05),干预组与正常对照组相近(P>0.05);干预组Bcl-2表达高于正常对照组和干预组(P均<0.05),实验组高于正常对照组(P<0.05)。正常对照组的肠组织病理学未见异常,病理评分为0分;实验组HE染色切片见肠壁损伤轻重不一...     

反复热性惊厥大鼠海马IL-1β和IL-1ra表达的变化

目的 探讨大鼠反复热性惊厥(FS)后海马白细胞介素-1β(IL-1β)和白细胞介素-1受体拈抗剂(IL-1ra)表达的变化.方法 清洁级21日龄雄性SD大鼠随机分为正常对照组(NC组)、高热对照组(HC组)和热性惊厥组(FS组).末次热水浴后12 h处死动物,用ELISA法检测海马IL-1β和IL-1ra的含量;RT-PCR法测海马IL-1β和IL-1ra mRNA的表达水平.结果 Fs组大鼠海马IL-1β蛋白和IL-1β mRNA水平均明显高于NC组和HC组,差异均具有显著性(P＜0.01和P＜0.05);FS组大鼠海马IL-1ra蛋白及IL-1ra mRNA水平亦明显高于HC组和NC组,差异均具有显著性(P＜0.01和P＜0.05).各组大鼠海马IL-1ra/IL-1β蛋白比值差异无显著性(P＞0.05).结论 短期内反复FS可导致海马IL-1β和IL-1ra表达增加,提示IL-1β和IL-1ra可能参与FS脑损伤发病的病理过程.     

肾积水大鼠模型肾脏CD40、血管内皮生长因子和转化生长因子-β表达的意义

目的探讨肾小管间质CD3 T淋巴细胞浸润,及肾小管上皮细胞CD40、血管内皮生长因子(VEGF)和转化生长因子-β(TGF-β)在梗阻性肾积水大鼠肾小管损伤和肾间质纤维化发病机制中的作用及其关系。方法22只健康雄性Wistar-Imamichi(WI)大鼠和5只纯合子WI种群先天性肾积水(CHN)大鼠饲养于塑料笼中,至4周龄通过手术完全或部分阻断其输尿管制备单侧输尿管梗阻(UUO)模型。6周龄时处死全部大鼠,取其肾组织进行常规病理和免疫组织化学分析,观察肾组织基本病理变化、肾间质纤维化、小管间质CD3 T淋巴细胞浸润及肾小管上皮细胞CD40、VEGF和TGF-β表达,并与正常对照组大鼠进行比较。结果与正常对照组比较:CHN、完全单侧输尿管梗阻(CUUO)和部分单侧输尿管梗阻(PUUO)组多数积水肾肾盂肾盏明显扩张,扩张的肾盂肾盏上方的肾实质变薄,肾小管上皮细胞萎缩,肾小球数量减少。肾间质增宽,伴细胞浸润和纤维化。各实验组积水肾间质区CD3 T淋巴细胞均较对照组显著增多(Pa<0.05),其中CUUO组和PUUO组肾间质CD3 T淋巴细胞较CHN组显著增多(Pa<0.05),而CUUO组与PUUO组间比较无显著性差异(P>0.05)。与正常对照组比较,CUUO组、PUUO组和CHN组积水肾肾小管CD40、TGF-β表达均显著增强(Pa<0.05);PUUO组积水肾肾小管CD40表达与CHN组比较显著增强(P<0.05);CUUO组肾小管CD40阳性表达率介于PUUO组和CHN组之间,与两组比较均无显著性差异(Pa>0.05)。肾小管TGF-β表达在3组间均无显著性差异(P>0.05)。3组VEGF肾小管阳性表达率均低于对照组,其中PUUO组和CHN组肾小管表达率显著降低(Pa<0.05),CUUO组肾小管表达率与对照组比较无显著性差异。相关性分析发现,各组大鼠小管间质CD3 T淋巴细胞数与肾小管CD40表达率呈正相关(P<0.05),与肾小管VEGF表达呈负相关(P<0.05)。肾小管上皮细胞TGF-β表达与其他3个细胞因子间均无相关性(P>0.05)。结论肾间质CD3 T淋巴细胞浸润、肾小管CD40和TGF-β表达显著增加,VEGF表达显著减弱,可能是肾脏慢性炎性反应和肾间质纤维化发生、发展的重要影响因素。