党参总皂苷对TNBS诱导的大鼠溃疡性结肠炎的保护作用及其机制

目的: 探讨党参总皂苷(TSC)对大鼠实验性溃疡性结肠炎(UC)的治疗作用及其作用机制。方法: 50只雄性Wistar大鼠随机分为5组:对照组、模型组、柳氮磺胺嘧啶(SASP)阳性对照组(0.3 g/kg)、TSC高剂量组(1.2 g/kg)、TSC低剂量组(0.4 g/kg),用三硝基苯磺酸(TNBS)/乙醇联合灌肠制作大鼠UC模型,给药21 d后,通过观察大鼠症状和体征、疾病活动指数(DAI)、结肠粘膜损伤指数(CMDI)、结肠组织形态;测定结肠组织中超氧化物歧化酶(SOD)、丙二醛(MDA)、炎症因子白介素-6(IL-6)、白介素-10(IL-10)、肿瘤坏死因子α(TNF-α)的含量;检测结肠组织中细胞核内核转录因子-κB(NF-κB)蛋白表达;最终评价TSC的治疗效果。结果: 与对照组比较,模型组大鼠DAI、CMDI评分显著升高,结肠粘膜损伤严重,说明造模成功。与模型组比较,TSC高低剂量组均能显著降低UC大鼠DAI评分、CMDI评分(P＜0.05);改善结肠黏膜形态;升高结肠组织中SOD活力,降低MDA含量(P＜0.05),抑制结肠组织中IL-6、TNF-α mRNA水平,促进IL-10 mRNA表达(P＜0.01);同时降低结肠中NF-κB蛋白表达(P＜ 0.01),且TSC高剂量组优于低剂量组(P＜0.05)。结论: TSC对UC大鼠结肠黏膜损伤具有显著保护作用,以高剂量组为佳;其机制可能与抗脂质过氧化,抑制NF-κB信号通路从而调控炎性因子的释放有关。     

马齿苋水提物对溃疡性结肠炎保护作用的实验研究

目的:探讨马齿苋水提物对溃疡性结肠炎(Ulcerative colitis,UC)的保护作用。方法:利用葡聚糖硫酸钠(Dextran sulfate sodium,DSS)诱导C57BL/6复制UC模型,将小鼠随机分为6组,分别为正常组,DSS模型组,SASP对照组,马齿苋低、中、高剂量组(100,200 mg/kg和400 mg/kg),每天ig给药1次,记录小鼠体重并统计疾病活动指数(Disease activity index,DAI)评分,连续7天。于第8天,测定结肠长度,测定MDA、SOD以及NO含量,观察结肠病理学形态变化,并测定IL-6,IL-1β与TNF-αm RNA的表达。结果:模型组与正常组比较,小鼠体重,结肠长度及SOD有显著降低(P0.05),而DAI评分,MDA、NO含量以及TNF-α,IL-6与IL-1βm RNA的表达有明显升高(P0.05)。而马齿苋水提物中、高组与模型组比较,小鼠的体重,结肠长度以及SOD含量均有显著性提高(P0.05),结肠组织病理损伤有所改善,DAI评分MDA、NO含量以及TNF-α,IL-6与IL-1βm RNA的表达均有明显降低(P0.05)。结论:马齿苋水提物对UC具有保护作用,可能与改变SOD、NO与MDA而抑制氧化应激反应及下调TNF-α,IL-6与IL-1β等细胞因子m RNA的表达而降低炎症反应有关。     

携带IL-10基因的双歧杆菌对 溃疡性结肠炎小鼠肠道屏障功能的影响

目的观察表达IL-10基因的双歧杆菌对溃疡性结肠炎(UC)小鼠肠道屏障功能的影响,进一步探讨转基因双歧杆菌治疗UC的相关机制。方法 25只小鼠分为空白对照组、结肠炎组(UC-blank组)、双歧杆菌治疗组(UC-bacteria组)、空质粒双歧杆菌治疗组(UC-pBBAD/X-bacteria组)和表达IL-10基因双歧杆菌治疗组(UC-BL-hIL-10-bacteria组),每组5只。采用5%DSS诱导建立UC小鼠模型,利用前期研究已成功筛选出的可稳定表达hIL-10蛋白的BL-hIL-10菌株对小鼠进行治疗。采用HE染色评估小鼠结肠炎症情况;采用荧光定量PCR检测小鼠结肠组织Claudin1、2、4、5、7和8的表达水平;计算小鼠DAI。结果 (1)BL-hIL-10菌株可以降低UC小鼠DAI,减轻UC小鼠结肠组织炎症程度。(2)BL-hIL-10菌株能下调UC小鼠结肠组织Claudin2表达水平,同时能够上调Claudin1、4、5、7和8的表达水平。(3)UC-BL-hIL-10-bacteria组UC小鼠的治疗效果明显优于UC-bacteria组和UC-pBBAD/Xbacteria组。结论 BL-hIL-10菌株能改善UC小鼠结肠黏膜的通透性,其机制可能与其能上调Claudin1、4、5、7和8的表达水平,同时降低Claudin-2的表达水平有关。     

携带IL-10基因的双歧杆菌对溃疡性结肠炎模型小鼠血浆及结肠组织NO和VEGF-A表达影响

目的观察携带IL-10基因的双歧杆菌对溃疡性结肠炎(UC)小鼠血浆及结肠组织一氧化氮(NO)与血管内皮生长因子A(VEGF-A)表达的影响,进一步探讨携带IL-10基因的双歧杆菌治疗UC的相关机制。方法筛选出能稳定表达具有生物活性hIL-10蛋白的BL-hIL-10菌株。用5%DSS诱导UC小鼠模型,50只小鼠分为正常对照组、UC模型组、BL治疗组、BL0治疗组和BL-hIL-10治疗组,每组10只。计算小鼠DAI、HE染色评估结肠组织病理学变化;ELISA法测小鼠血浆及结肠组织IL-13、VEGF-A和NO的含量。结果 (1)BL-hIL-10可以降低UC小鼠DAI,减轻UC小鼠结肠组织炎症程度。(2)BL-hIL-10能降低UC小鼠血浆和结肠组织NO、VEGF-A和IL-13水平。结论口服BL-hIL-10对UC小鼠的治疗作用可能与抑制NO产生及下调VEGF-A表达有关。     

双歧杆菌调节VIP/cAMP/PKA和mTOR通路改善溃疡性结肠炎小鼠的实验研究

摘要 目的：探讨双歧杆菌MIMBb75通过调节血管活性肠肽（VIP）/环磷酸腺苷（cAMP）/蛋白激酶A（PKA）和哺乳动物雷帕霉素靶蛋白（mTOR）通路对溃疡性结肠炎（UC）小鼠的影响。方法：BALB/c小鼠随机分为正常对照（NC）组、结肠炎模型（UC）组、Mesalazine组和MIMBb75低、高剂量组、MIMBb75高剂量+VIP antagonist组、MIMBb75高剂量+MHY1485组（每组10只）,除NC组外均采用5%葡聚糖硫酸钠（DSS）诱导UC模型。治疗结束后,观察小鼠的一般情况及UC疾病活动指数（DAI）,检测小鼠肠道组织病理损伤、结肠组织中髓过氧化物酶（MPO）活性、肠道菌群多样性（Chao指数、Shannon指数和Simpson指数）及结肠组织VIP、cAMP、PKA、水通道蛋白3（AQP3）、mTOR、核糖体蛋白S6激酶（S6K1）的mRNA和蛋白水平。结果：与UC组相比,MIMBb75低、高剂量组和Mesalazine组小鼠的体重升高、DAI评分降低,组织病理损伤得到改善,结肠长度增加,MPO活性降低,Chao指数、Shannon指数和Simpson指数升高;VIP、cAMP、PKA、AQP3的mRNA水平和VIP、cAMP、AQP3蛋白的表达及PKA的磷酸化水平升高,mTOR和S6K1 mRNA及其蛋白的磷酸化水平降低（P<0.05）。与MIMBb75高剂量组相比,MIMBb75高剂量+VIP antagonist组VIP、cAMP、PKA、AQP3的mRNA水平和VIP、cAMP、AQP3蛋白的表达及PKA的磷酸化水平降低（P<0.05）;MIMBb75高剂量+MHY1485组mTOR和S6K1 mRNA及其蛋白的磷酸化水平升高（P<0.05）。VIP antagonist和MHY1485均能逆转MIMBb75对UC小鼠的保护作用,使其结肠损伤加重,MPO活性增高（P<0.05）。结论：双歧杆菌可改善UC小鼠的结肠损伤,增加肠道菌群的多样性,这可能与激活VIP/cAMP/PKA通路、抑制mTOR通路有关。     

温补脾肾法对脾肾阳虚型UC大鼠结肠组织趋化因子信号通路的影响

目的寻找脾肾阳虚型UC的特异性靶点。方法 96只Wistar大鼠随机分为模型组、高剂量组、中剂量组、低剂量组、SASP组,治疗组给予相应药物灌胃治疗。分别选取空白组大鼠结肠组织与模型组大鼠病变部位结肠组织进行高通量测序。RT-qPCR法检测筛选的趋化因子的基因表达。结果与模型组大鼠相比较,根据q-value≦0.05,fold-change≧1.5筛选出空白组大鼠差异表达的基因。通过GO功能分类分析显示,差异基因功能主要富集在生物过程(biological process,BP)、细胞成分(cellular component,CC)、分子功能(molecular function,MF)三个层面。通过差异基因KEGG富集分析发现趋化因子信号通路中CXCL1、CXCL2、CXCR2、CXCL6、CCL7、CCL12基因表达显著上调;并通过RT-qPCR法验证,以上因子的基因表达变化与测序结果一致,经温补脾肾方药治疗后,以上因子表达明显下调。结论脾肾阳虚型溃疡性结肠炎趋化因子信号通路中CXCL1、CXCL2、CXCR2、CXCL6、CCL7、CCL12基因表达显著上调,可作为UC黏膜炎症活动的客观指标。具有温补脾肾作用的理中汤合四神丸复方中药颗粒可以有效下调以上因子的表达,减缓炎症反应,促进受损伤的结肠黏膜的修复。     

桂皮醛对DSS诱导的溃疡性结肠炎小鼠的保护作用研究

为探讨桂皮醛(CA)对实验性溃疡性结肠炎(UC)小鼠的保护作用及其初步机制,用柳氮磺胺吡啶(300 mg/kg)做为阳性对照,CA分别以150、250、500 mg/kg的剂量对3%葡聚硫酸钠(DSS)诱导的UC小鼠进行灌胃治疗。观察小鼠给药前后状态的变化并进行DAI评分,HE染色法观察小鼠结肠组织形态的变化并进行病理评估;ELISA试剂盒、Western blot技术分别检测小鼠血清中炎症因子及小鼠结肠上皮炎症相关蛋白表达水平的变化。结果显示,与模型组比较,CA在实验剂量范围内可保护UC小鼠结肠组织形态完整,改善结肠黏膜损伤;升高血清中IL-4、IL-10含量(P<0.01),降低IL-6、IL-8及TNF-α含量(P<0.01);上调结肠组织NF-κB在胞质内表达量,并抑制STAT3磷酸化水平。综上所述,CA对UC小鼠具有保护作用,可减轻结肠组织损伤程度,抑制炎症反应,更深入的作用机制还有待进一步研究。     

理中丸对脾虚型腹泻大鼠结肠黏膜屏障IL-22-MUC2/claudin-2信号通路的影响

目的 探讨理中丸对脾虚型腹泻大鼠结肠黏膜IL-22-MUC2/claudin-2信号通路的调控作用。方法 采用番泻叶水煎液1.2 g/mL联合疲劳游泳建立脾虚型腹泻大鼠模型。模型大鼠随机分为模型组、蒙脱石散组(0.9 g/kg)和理中丸低、高剂量组(0.81和3.24 g/kg),每组8只;另选8只正常大鼠作为空白组。连续给药14 d,造模结束后可见大鼠体重减轻,精神倦怠、眯眼聚堆、少动,大便质地偏软或者便溏,肛周污秽,提示模型复制成功。采用比色法检测血清淀粉酶和D-木糖水平,阿利新蓝和过碘酸雪夫(AB-PAS)染色检测结肠黏膜形态结构,蛋白免疫印迹法(Western Blot)检测黏蛋白2(MUC2)和水通道蛋白3/4(AQP3、AQP4)的表达,免疫荧光法检测结肠组织claudin-2蛋白表达,实时荧光定量-PCR(RT-PCR)法检测白介素-22(IL-22)和肠黏膜上皮跨膜蛋白2(claudin-2)基因相对表达量(2^-ΔΔCt值)。结果 与空白组比较,模型组大鼠稀便率、稀便级和腹泻指数显著增加,结肠组织黏膜层上皮细胞出现不同程度的萎缩,黏膜表面结构疏松水...     

柠檬苦素对葡聚糖硫酸钠诱导的小鼠结肠炎的治疗作用及机制

探讨柠檬苦素(limonin)对葡聚糖硫酸钠(dextran sulfate sodium salt,DSS)致实验性小鼠溃疡性结肠炎(ulcerative colitis,UC)模型的治疗作用及其机制。将20只8周龄雌性C57BL/6J小鼠,随机分为正常对照组、模型组、柠檬苦素组和5-氨基水杨酸组,每组5只。正常的小鼠每日给予蒸馏水饮用,其余各组小鼠给予30 g/L DSS连续饮用7 d后,继续饮用正常水3 d,诱导小鼠急性UC模型。药物治疗组小鼠分别灌胃给予柠檬苦素和5-氨基水杨酸的剂量为50和50 mg/(kg·d),每日1次,连续灌胃治疗10 d。实验终点时,分析实验动物的体质量变化、结肠长度、结肠组织病理学变化及细胞核转录因子kappa B (NF-κB)的蛋白表达。结果发现:与模型组比较,柠檬苦素可显著改善DSS诱导的小鼠急性结肠炎症状,包括体质量降低、结肠长度缩短、稀便和血便等,减轻小鼠急性结肠炎结肠组织的病理损伤,抑制炎症细胞的浸润和肠黏膜坏死。此外,柠檬苦素亦可以降低结肠炎小鼠结肠组织细胞核内NF-κB p65蛋白表达,抑制NF-κB p65的激活。柠檬苦素通过抑制NF-κB p65的激活,缓解DSS诱导的小鼠结肠炎症,发挥治疗作用。     

葛花解酲汤对脾虚湿热型溃疡性结肠炎“炎-癌转化”中相关原抑癌基因表达的影响CSCD

探讨葛花解酲汤对脾虚湿热型溃疡性结肠炎(ulcerative colitis, UC)-溃疡性结肠炎相关癌变(ulcerative colitis associated carcinogenesis, UCAC)的“炎-癌转化”小鼠结肠组织中相关原抑癌基因表达的影响。80只SPF级C57BL/6雄性小鼠随机选出10只为空白组(K组),其余70只建立脾虚湿热模型。脾虚湿热模型建立后,将其随机分为模型1、2、3周期组(M1、M2、M3组)、葛花解酲汤高、中、低剂量组(G、Z、D组)和阳性对照美沙拉嗪组(Y组),10只/组,以氧化偶氮甲烷(azoxymethane, AOM)/葡聚糖硫酸钠(dextran sodium sulfate, DSS)继续建立UC-UCAC的“炎-癌转化”模型。各组给予对应药物治疗4周。观察小鼠一般状态;统计小鼠体重变化;电镜下观察小鼠结肠黏膜超微结构;WB和RT-qPCR分别检测小鼠结肠组织中c-jun、c-fos、c-myc、p53、RB1蛋白及基因的表达。与K组比,M3组小鼠一般状态差,体重增长量显著下降(P<0.01),结肠黏膜上皮细胞核染色不均匀,细胞内线粒体等见大量增生肿胀,c-jun、c-fos、c-myc蛋白及基因表达显著升高(P<0.01),p53、RB1蛋白及基因表达显著降低(P<0.01);与M3组比,各治疗组小鼠一般状态改善,体重增长量升高,结肠黏膜上皮细胞核染色较均匀,细胞内线粒体等增生肿胀情况改善,c-jun、c-fos、c-myc蛋白及基因表达降低,p53、RB1蛋白及基因表达升高,以G、Z和Y组最为显著(P<0.01,P<0.05)。葛花解酲汤可能通过抑制原癌基因c-jun、c-fos、c-myc的激活,促进抑癌基因p53、RB1的表达,调控细胞增殖与凋亡,延缓炎-癌转化进程,修复受损的结肠黏膜组织,预防UCAC的发生。     

Effects of oral <Emphasis Type="Italic">Lactobacillus plantarum</Emphasis> on hepatocyte tight junction structure and function in rats with obstructive jaundice

Surgery and infection are prominent risk factors for the development of obstructive cholestasis which in turn is associated with failure of the liver barrier. We studied the effects of oral Lactobacillus plantarum (LP) supplementation on endotoxemia, oxidative stress, apoptosis, and tight junctions of hepatocytes in an experimental model of obstructive jaundice. Fifty male Wistar rats were randomly divided into five groups of 10 each: group I, sham-operated; group II, ligation and division of the common bile duct (BDL); group III, BLD followed by oral LP treatment; group IV, BDL followed by internal biliary drainage (IBD); group V, BDL followed by IBD and oral LP treatment. Hepatocyte apoptosis, plasma reduced glutathione (GSH) and oxidized glutathione (GSSG) levels, and portal blood endotoxin levels were measured and changes in tight junction-associated proteins occludin, claudin-1, claudin-4, and ZO-1 were observed. Compared to the sham-operated group I, significant increases in endotoxemia, apoptosis, and GSSG were observed in group II and significant decreases were observed in group V. Tight junctions were destroyed in group II animals but were not in animals treated with oral LP (groups III and V). An increase in occludin, claudin-1, claudin-4, and ZO-1 mRNA and protein levels were detected in livers in LP-treated animals (group V) compared with group II levels. Oral LP treatment of rats with obstructive jaundice assisted in the return of active hepatic barrier function. These results may lead to treatments to prevent the deleterious effects of obstructive jaundice.     

Picroside III,an Active Ingredient of Picrorhiza scrophulariiflora,Ameliorates Experimental Colitis by Protecting Intestinal Barrier Integrity

This study aims to explore the protective effects of Picroside III, an active ingredient of Picrorhiza scrophulariiflora, on the intestinal epithelial barrier in tumor necrosis factor-α (TNF-α) induced Caco-2 cells and dextran sulfate sodium (DSS) induced colitis in mice. Results show that Picroside III significantly alleviated clinical signs of colitis including body weight loss, disease activity index increase, colon shortening, and colon tissue damage. It also increased claudin-3, ZO-1 and occludin expressions and decreased claudin-2 expression in the colon tissues of mice with colitis. In vitro, Picroside III also significantly promoted wound healing, decreased the permeability of cell monolayer, upregulated the expressions of claudin-3, ZO-1 and occludin and downregulated the expression of claudin-2 in TNF-α treated Caco-2 cells. Mechanism studies show that Picroside III significantly promoted AMP-activated protein kinase (AMPK) phosphorylation in vitro and in vivo, and blockade with AMPK could significantly attenuate the upregulation of Picroside III in ZO-1 and occludin expressions and the downregulation of claudin-2 expression in TNF-α treated Caco-2 cells. In conclusion, this study demonstrates that Picroside III attenuated DSS-induced colitis by promoting colonic mucosal wound healing and epithelial barrier function recovery via the activation of AMPK.     

红景天苷调节AMPK/mTOR/ULK1信号通路对结肠癌SW480细胞裸鼠的肝脏损伤的影响

摘要 目的：探讨红景天苷（Sal）调节单磷酸腺苷活化蛋白激酶（AMPK）/哺乳动物雷帕霉素靶蛋白（mTOR）/Unc51样激酶1（ULK1）信号通路对结肠癌SW480细胞裸鼠肝脏损伤的影响。方法：通过皮下注射SW480细胞悬浮液建立肝转移裸鼠模型,将造模后的裸鼠随机分为模型组、Sal低剂量（Sal-L,50 mg/kg Sal）组、Sal中剂量（Sal-M,100 mg/kg Sal）组、Sal高剂量（Sal-H,200 mg/kg Sal）组,Sal-H+AMPK抑制剂（Compound C,200 mg/kg Sal+10 mg/kg Compound C）组,以未接种SW480细胞悬液的裸鼠作为对照组。腹部主动脉取血,检测裸鼠血清中丙氨酸氨基转移酶（AST）、天冬氨酸氨基转移酶（ALT）水平;处死裸鼠,检测肝转移瘤数目及肝脏重量;HE染色观察肝脏组织病理变化;qRT-PCR检测肝脏组织中AMPK、mTOR、ULK1 mRNA表达水平;Western blot检测肝脏组织中自噬（Beclin1、p62）蛋白及通路相关蛋白表达。结果：与对照组相比,模型组裸鼠组织中出现肝转移瘤,肝脏重量、AST、ALT水平、mTORmRNA、ULK1 mRNA、p62表达显著增加（P<0.05）;Beclin1、AMPK mRNA及蛋白表达显著降低（P<0.05）;与模型组相比,Sal-L、Sal-M、Sal-H组肝转移瘤数目、肝脏重量、AST、ALT水平、mTORmRNA、ULK1 mRNA、p62表达显著降低（P<0.05）;Beclin1、AMPK mRNA及蛋白表达显著增加（P<0.05）;与Sal-H组相比,Sal-H+Compound C组肝转移瘤数目、肝脏重量、AST、ALT水平、mTORmRNA、ULK1 mRNA、p62表达显著增加（P<0.05）;Beclin1、AMPK mRNA及蛋白表达显著降低（P<0.05）。结论：Sal可通过减少裸鼠肝转移瘤形成,保护裸鼠肝脏,其机制可能与激活AMPK/mTOR/ULK1信号通路,促进肝脏自噬有关。     

PRDX2在乙醇致雄性小鼠生殖损害中的机制研究

目的:探讨过氧化氧化还原蛋白2(PRDX2)在乙醇所致的雄性小鼠生殖损害中的作用机制。方法:以雄性昆明小鼠为研究对象,分为对照组及模型组,分别以蒸馏水和乙醇灌胃处理12周,采集血清用于激素水平测定;收集精子,一部分用于精液分析,另一部分用于Q-PCR检测PRDX2、BCL-2、BAX、Caspase3的m RNA表达,Western blot检测PRDX2、BCL-2、BAX、Caspase3和Cleaved-Caspase3的蛋白表达,免疫荧光法鉴定PRDX2的表达;统计分析研究结果。结果:与对照组比较,模型组小鼠的精子活率降低,雌激素水平升高而雄激素水平降低(P0.05);模型组小鼠的PRDX2、BCL-2蛋白及m RNA水平较对照组均降低(P0.05),免疫荧光显示PRDX2可在精子中表达,且模型组小鼠精子的荧光强度明显减低;在BAX及Caspase3 m RNA的表达上,模型组高于对照组(P0.05),模型组小鼠的BAX及Cleaved-Caspase3的蛋白表达亦高于对照组(P0.05);Pearson相关系数分析显示PRDX2与BCl-2呈正相关、与BAX、Caspase3呈负相关,差异均有统计学意义(P0.05)。结论:乙醇造成精子PRDX2表达降低,间接诱导精子发生凋亡,影响精子的生成和发育,损害雄性小鼠的生殖功能。     

Claudin-2 knockdown decreases matrix metalloproteinase-9 activity and cell migration via suppression of nuclear Sp1 in A549 cells

AimsClaudin expression is altered in lung cancer, but the pathophysiological role of claudin is not well understood. We examined the effect of claudin-2 expression on cell migration using human adenocarcinoma A549 cells.Main methodsThe mRNA level was measured by real time polymerase chain reaction. To knockdown claudin-2 expression, we made the cells expressing doxycycline-inducible claudin-2 shRNA vector. The protein level was examined by Western blotting. Cell migration was measured by wound-healing assay. The enzymatic activity of MMP-9 was assessed by gelatin zymography.Key findingsIn A549 cells, claudin-2 expression was higher than in normal lung tissue. Claudin-2 knockdown did not affect the expression of other junctional proteins including claudin-1, occludin and E-cadherin. Claudin-2 knockdown decreased cell migration concomitant with a decrease in the mRNA level and enzymatic activity of MMP-9. The expression level of Sp1 in the nuclei was decreased by claudin-2 knockdown. In contrast, the expression levels of c-Fos, c-Jun and NF-kB p65 in the nuclei were not changed by claudin-2 knockdown. The knockdown of Sp1 expression by siRNA decreased cell migration, and the mRNA expression, enzymatic activity, and promoter activity of MMP-9.SignificanceClaudin-2 may increase the mRNA level and enzymatic activity of MMP-9 mediated by the elevation of nuclear distribution of Sp1, resulting in the up-regulation of A549 cell migration.     

Gegen Qinlian decoction maintains colonic mucosal homeostasis in acute/chronic ulcerative colitis via bidirectionally modulating dysregulated Notch signaling

BackgroundGegen Qinlian decoction (GQ) is a well-known traditional Chinese medicine that has been clinically proven to be effective in treating ulcerative colitis (UC). However, its therapeutic mechanism has not been fully elucidated. Notch signaling plays an essential role in the regeneration of the intestinal epithelium.PurposeThis study was designed to ascertain the mechanism by which GQ participates in the recovery of the colonic mucosa by regulating Notch signaling in acute and chronic UC models.MethodsAcute and chronic UC mice (C57BL/6) were established with 3 and 2% dextran sulfate sodium (DSS), respectively, and treated with oral administration of GQ. The expression of the Notch target gene Hes1 and the Notch-related proteins RBP-J, MAML and Math1 was analyzed by western blotting. PTEN mRNA levels were detected by qRT-PCR. Mucin production that is characteristic of goblet cells was determined by Alcian blue/periodic acid-Schiff staining and verified by examining MUC2 mRNA levels by qRT-PCR. Cell proliferation was assayed by immunohistochemistry analysis of Ki67. HT-29 and FHC cells and Toll-like receptor 4 knockout (TLR4^−/−) acute UC mice were also used in this study.ResultsGQ restored the injured colonic mucosa in both acute and chronic UC models. We found that Notch signaling was hyperactive in acute UC mice and hypoactive in chronic UC mice. GQ downregulated Hes1, RBP-J and MAML proteins and augmented goblet cells in the acute UC models, whereas GQ upregulated Hes1, RBP-J and MAML proteins in chronic UC mice, reducing goblet cell differentiation and promoting crypt base columnar (CBC) stem cell proliferation. Hes1 mRNA was suppressed in TLR4^−/− UC mice, and GQ treatment reversed this effect. In vitro, GQ reduced Hes1 protein in Notch-activated HT29 and FHC cells but increased Hes1 protein in Notch-inhibited cells.ConclusionsGQ restored the colonic epithelium by maintaining mucosal homeostasis via bidirectional regulation of Notch signaling in acute/chronic UC models.     

Enhanced therapeutic efficacy of a novel colon-specific nanosystem loading emodin on DSS-induced experimental colitis

BackgroundUlcerative colitis (UC) is an intricate enteric disease with a rising incidence that is closely related to mucosa-barrier destruction, gut dysbacteriosis, and immune disorders. Emodin (1,3,8-trihydroxy-6-methyl-9,10-anthraquinone, EMO) is a natural anthraquinone derivative that occurs in many Polygonaceae plants. Its multiple pharmacological effects, including antioxidant, immune-suppressive, and anti-bacteria activities, make it a promising treatment option for UC. However, its poor solubility, extensive absorption, and metabolism in the upper gastrointestinal tract may compromise its anti-colitis effects.PurposeEMO was loaded in a colon-targeted delivery system using multifunctional biomedical materials and the enhanced anti-colitis effect involving mucosa reconstruction was investigated in this study.MethodsEMO-loaded Poly (DL-lactide-co-glycolide)/Eudragit^Ⓡ S100/montmorillonite nanoparticles (EMO/PSM NPs) were prepared by a versatile single-step assembly approach. The colon-specific release behavior was characterized in vitro and in vivo, and the anti-colitis effect was evaluated in dextran sulfate sodium (DSS)-induced acute colitis in mice by weight loss, disease activity index (DAI) score, colon length, histological changes, and colitis biomarkers. The integrity of the intestinal mucosal barrier was evaluated through transwell co-culture model in vitro and serum zonulin-related tight junctions and mucin2 (MUC2) in vivo.ResultsEMO/PSM NPs with a desirable hydrodynamic diameter (~ 235 nm) and negative zeta potential (~ -31 mV) could prevent the premature drug release (< 4% in the first 6 h in vitro) in the upper gastrointestinal tract (GIT) and boost retention in the lower GIT and inflamed colon mucosa in vivo. Compared to free EMO-treatment of different doses in UC mice, the NPs could enhance the remedial efficacy of EMO in DAI decline, histological remission, and regulation of colitis indicators, such as myeloperoxidase (MPO), nitric oxide (NO), and glutathione (GSH). The inflammatory factors including induced nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-1β were suppressed by EMO/PSM NPs at both mRNA and protein levels. The obtained NPs could also promote the regeneration of the mucosal barrier via reduced fluorescein isothiocyanate (FITC)-dextran leakage in the transwell co-culture model and decreased serum zonulin levels, which was demonstrated to be associated with the upregulated tight junctions (TJs)-related proteins (claudin-2, occludin, and zo-1) and MUC2 at mRNA level. Moreover, the NPs could contribute to attenuating the liver injury caused by free EMO under excessive immune inflammation.ConclusionOur results demonstrated that EMO/PSM NPs could specifically release EMO in the diseased colon, and effectively enhance the anti-colitis effects of EMO related to intestinal barrier improvement. It can be considered as a novel potential alternative for oral colon-targeted UC therapy by increasing therapeutic efficacy and reducing side-effects.