氧化苦参碱介导细胞自噬减轻溃疡性结肠炎小鼠结肠黏膜氧化性损伤的作用机制研究

目的 探讨氧化苦参碱介导细胞自噬减轻溃疡性结肠炎（ulcerative colitis,UC）小鼠结肠黏膜氧化性损伤的作用机制。方法 采用2,4,6-三硝基苯磺酸灌肠复制小鼠UC模型,将造模成功小鼠按体质量随机分为模型组、氧化苦参碱组（50 mg·kg^-1·d^-1,ig）、羟基氯喹组（50 mg·kg^-1·d^-1,ig）、氧化苦参碱+羟基氯喹组,另设正常组,每组10只。治疗1周后测定各组小鼠疾病活动度（disease activity,DAI）、结肠质量系数及病理形态;MitoSOX Red法测定结肠ROS含量,ELISA法测定结肠组织SOD、MDA、MPO、GSH-PX含量;透射电镜结合免疫荧光观测结肠细胞自噬程度,Western blot测定Atg5和Beclin-1蛋白表达。结果 与模型组和羟基氯喹组比较,氧化苦参碱组小鼠DAI和结肠质量系数均有显著减小（P<0.01）,结肠病理损伤明显减轻;ROS、MDA和MPO含量极显著降低（P<0.01）,SOD和GSH-PX含量极显著增加（P<0.01）;结肠黏膜细胞自噬,程度显著增强,Atg5和Beclin-1蛋白表达极显著上调（P<0.01）。结论 氧化苦参碱可促进UC小鼠细胞自噬,减轻小鼠结肠黏膜氧化性损伤。     

疾病以及配伍对人参皂苷在大鼠体内的药动学影响

目的 建立SD大鼠血浆中人参皂苷Rb1、Rb2和Rg1的HPLC分析方法,对比分析配伍白术挥发油前后,人参皂苷在慢性萎缩性胃炎模型大鼠体内药动学特征。方法 SD大鼠分为4组,其中单用正常组和单用模型组均给药人参总皂苷292 mg·kg^-1,配伍正常组和配伍模型组均给药人参总皂苷292 mg·kg^-1和白术挥发油0.1 mL·kg^-1。于给药前和给药后不同时间点进行眼眶取血,采用HPLC测定各成分的血药浓度,并采用Winnolin 6.3软件计算其药动学参数。结果 与单用正常大鼠比较,单用模型组大鼠体内人参皂苷Rb1的C_max和AUC值降低,T_max、T_1/2以及MRT增加,人参皂苷Rb2和Rg1则呈现出AUC增加的变化;而配伍正常组大鼠体内人参皂苷Rb1、Rb2和Rg1的C_max和AUC值均增加,T_max、T_1/2以及MRT值均缩短。与单用模型组大鼠比较,配伍模型组大鼠体内人参皂苷Rb1和Rg1的C_max和AUC值均增加,T_max、T_1/2以及MRT值均降低。结论 在相同给药剂量下,疾病状态机体对人参皂苷的吸收和代谢呈现缓慢趋势,而配伍后能促进皂苷成分在体内的吸收,同时加快代谢消除,为人参的临床用药提供参考依据。     

盐酸小檗碱对溃疡性结肠炎小鼠结肠组织TNF-α、IL-1β和IL-10表达的影响

目的 观察盐酸小檗碱（berberine hydrochloride,BBR）对溃疡性结肠炎模型小鼠结肠组织TNF-α、IL-1β和IL-10表达的影响,探讨其治疗UC的可能作用机制。方法 BALB/c小鼠随机分为模型对照组、BBR低、高剂量组、柳氮磺吡啶阳性对照组和空白对照组。采用右旋葡聚糖硫酸钠法复制UC小鼠模型后,每日灌胃给药1次,连续7 d。实验期间每天观察小鼠一般情况并评估疾病活动指数（DAI）;末次给药后解剖观察并评估结肠大体形态损伤指数（CMDI）;组织切片染色,光镜下观察结肠组织的病理学变化并评估组织损伤指数（TDI）;ELISA酶联法检测结肠组织中细胞因子TNF-α、IL-1β和IL-10的含量。结果 与模型对照组比较,BBR治疗组小鼠的结肠炎临床表现明显改善,其DAI、CMDI和TDI评分显著下降,小鼠结肠组织中TNF-α、IL-1β水平均明显降低,IL-10水平升高（P<0.05）。结论 BBR能有效治疗UC小鼠的结肠炎症,其机制可能与其抑制结肠组织中TNF-α和IL-1β、提高IL-10的表达有关。     

rasH2转基因小鼠与C57BL/6小鼠单次灌胃F3SM动力学参数比较

目的 比较C57BL/6小鼠(简称C57小鼠)和rasH2转基因小鼠(Tg rasH2小鼠)单次给予相同剂量受试药物F3SM后, 代谢动力学参数的差异, 观察两种动物对于F3SM的代谢动力学的一致性。方法 选用相同周龄的C57小鼠和Tg rasH2小鼠各4只, ig给予相同剂量(60 mg/kg)的F3SM羧甲基纤维素钠溶液。在给药后5、15、30 min及1、3、10、24 h各时间点进行采血, 采血量≥40 μL, 从血样中分离出10 μL血浆, 采用LC-MS/MS方法对样品的药物浓度进行检测, 用软件计算得出AUC_(0-t)、MRT_(0-t)、t_1/2、T_max和C_max, 用配对t检验进行差异性分析。结果 对C57小鼠和rasH2转基因小鼠的AUC_(0-t)、MRT_(0-t)、t_1/2、T_max和C_max进行配对t检验, 显示差异无显著性;二者药时曲线也大致相近。结论 单次给药后, C57小鼠和Tg rasH2小鼠对药物F3SM的代谢特征无显著差异, 提示C57小鼠与Tg rasH2小鼠对本药物的代谢特征相似, 提示在开展Tg rasH2小鼠研究中, 可首先采用C57小鼠进行毒性预探研究.     

高渗氯化钠溶液在高血压脑出血术后颅内压增高患者中的应用效果

目的 探讨高渗氯化钠溶液（HSS）降颅压的效果及特点，为临床HSS的应用提供一定参考。方法 收集2013年7月至2015年7月芜湖市第二人民医院高血压脑出血术后颅内压增高患者33例临床资料，按治疗方法不同分为HSS组及MAN组。快速降颅压，HSS组采用3.0% HSS 250 mL，MAN组采用20%甘露醇250 mL，监测并记录首次降颅压治疗时不同时间段各组被试颅内压（ICP）值；长期降颅压，HSS组采用20%甘露醇125 mL联合3.0% HSS 125 mL，MAN组采用20%甘露醇250 mL，连续监测2周ICP值。结果 快速降颅压比较显示，HSS组各时间点的ICP值差异有统计学意义（P<0.05）；两两比较，T₂与T₀比较差异有统计学意义（P<0.05）；T₇与T₂比较，差异无统计学意义（P>0.05）；与T₀比较，T₄ ICP下降幅度最大，为7.65 mmHg。MAN组各时间点的ICP值差异有统计学意义（P<0.05）；两两比较，T₁与T₀比较差异有统计学意义（P<0.05）；T₆与T₁比较差异无统计学意义（P>0.05）；与T₀比较，T₃ ICP下降幅度最大，为12.31 mmHg。结论 HSS具有降颅压作用但幅度及速度不及甘露醇，对于急性颅内压增高患者仍建议用甘露醇；HSS长期应用降颅压平稳、无反跳现象且并发症少，推荐HSS与甘露醇配伍长期使用。     

青藤碱对TNBS诱导的慢性小鼠结肠炎的治疗作用

摘 要 目的：评价青藤碱对2,4,6 三硝基苯磺酸（TNBS）灌肠引起的Th1细胞介导的小鼠实验性结肠炎的治疗作用,并探讨其作用机制。方法: 为评价青藤碱对结肠炎的治疗作用,将Balb/c 小鼠随机分为乙醇对照组,TNBS模型组,青藤碱低（50 mg·kg^-1）、中（100 mg·kg^-1）、高（200 mg·kg^-1）剂量组,每组10只。为观察青藤碱对TNBS结肠炎的治疗作用,第1剂TNBS给药后7 d开始灌胃给予青藤碱,持续给药21 d。第28天处死动物,观察结肠黏膜的损伤程度, 测定结肠髓过氧化物酶（MPO）活性,ELISA法分别测定结肠炎症细胞因子 （TNF-α、IL-17和IL-23）蛋白水平。结果: 与TNBS模型组比较,青藤碱中、高剂量组的体质量、大体损伤评分及组织学表现均显著改善（P<0.05）,MPO酶活性显著降低（P<0.05）,结肠黏膜中TNF-α 、IL-17和IL-23的蛋白水平均较TNBS组下降（P<0.05）。结论:青藤碱对TNBS诱导的慢性小鼠结肠炎具有治疗作用,作用机制与青藤碱对Th1炎症细胞因子的抑制有关。     

高脂饮食对双嘧达莫在中国健康人体内药动学的影响

目的 观察中国健康受试者空腹和高脂高热量饮食情况下口服双嘧达莫片的药动学特征。方法 75名健康受试者分别在空腹或高脂饮食条件下单剂量口服双嘧达莫片25 mg,分别在不同时间点采集静脉血样。采用LC-MS/MS测定人血浆中双嘧达莫的浓度,用PhoenixWinNonlin 8.0软件按非房室模型计算药动学参数。结果 空腹和高脂饮食后双嘧达莫片的主要药动学参数如下：C_max分别为(594.69±172.14),(333.64±167.18) ng·mL^-1,餐后较空腹C_max降低了43.9%(P<0.01);t_1/2分别为(9.87±4.21),(10.57±3.75) h;AUC_0-t分别为(1 733.22±715.49),(1 268.61±571.07) ng·mL^-1·h,AUC_0-∞分别为(1 801.69±707.61),(1 353.64±602.29) ng·mL^-1·h,餐后较空腹AUC_0-t及AUC_0-∞分别降低26.8%,24.9%(P<0.01);T_max中位数(范围)分别为0.75[0.50,5.00] h和1.50[0.49,4.52] h,餐后服药的T_max明显延迟(P<0.01)。结论 高脂饮食后服药较空腹条件下服药,C_max、AUC_0-t及AUC_0-∞均明显降低,T_max明显延迟,说明食物对双嘧达莫片的吸收速度、吸收程度均有显著影响。     

排脓散对葡聚糖硫酸钠诱导结肠炎小鼠的治疗作用

目的 考察排脓散对结肠炎小鼠的治疗作用，为其临床使用提供依据。方法 采用♂BALB/c小鼠，设置正常组、模型组、柳氮磺吡啶组和排脓散高、中、低剂量组，在日常饮水中给予3%葡聚糖硫酸钠（dextran sodium sulfate，DSS）构建结肠炎模型，通过测定小鼠体质量、疾病活动指数（disease activity index，DAI）评分情况、结肠长度和结肠炎性因子表达水平，研究排脓散对小鼠结肠炎的治疗作用。结果 与模型组相比，排脓散各剂量组和柳氮磺吡啶组的小鼠体质量下降均有不同程度的缓解，DAI评分均显著降低（P<0.05），并部分恢复结肠长度。排脓散可以减少结肠部位IL-1β、TNF-α和IL-6表达，提高IL-10表达。结论 排脓散可以减轻DSS诱导的结肠炎症状，改善炎症相关因子表达。     

依托考昔片在中国健康受试者的药动学及安全性研究

目的 研究中国健康受试者空腹、餐后单次口服依托考昔片的药动学及安全性。方法 将68例健康受试者随机分为空腹组和餐后组，采用双周期交叉试验设计进行给药，LC-MS/MS测定人血浆中依托考昔浓度，用WinNonLin软件计算药动学参数，比较国产依托考昔片和原研参比制剂药动学差异以及不同性别和进食对托考昔片药动学的影响。以受试者生命体征及体格检查、实验室检查值以及心电图变化为指标进行依托考昔片安全性评价。结果 空腹组受试制剂和参比制剂的药动学参数T_max为1.25，1.25 h，C_max为（2 767.50±421.89），（2 707.81±674.90） ng·mL^-1，AUC_0-∞为（52 967.87±13 843.25），（53 479.56±16 066.32） h·ng·mL^-1；餐后组受试制剂和参比制剂的药动学参数T_max为2.50，1.75 h，C_max为（2 000.61±314.89），（2 209.06±429.05） ng·mL^-1，AUC_0-∞为（51 450.80±17 241.02），（49 287.23±16 192.87） h·ng·mL^-1；餐后组受试制剂和参比制剂T_max差异具有统计学意义（P<0.05），但不具有临床意义。受试者空腹、餐后口服依托考昔片后，T_max、C_max差异具有统计学意义（P<0.01），但AUC_0-∞差异无统计学意义；不同性别受试者空腹口服依托考昔片后，主要药动学参数T_max、C_max、AUC_0-∞均无统计学意义，但女性受试者餐后口服依托考昔片后t_1/2、AUC_0-∞较男性受试者高（P<0.05）。空腹和餐后给药后不良事件涉及多系统，均为轻度，无严重不良反应。结论 国产依托考昔片和原研参比制剂具有生物等效性；进食影响依托考昔片的吸收速度，但不影响其吸收程度；空腹给药后依托考昔片的药动学参数无性别差异，但餐后给药后t_1/2、AUC_0-∞存在性别差异。依托考昔片在中国健康受试者中具有良好的安全性和耐受性。     

肠上皮Metrnl基因敲除对肠道菌群以及溃疡性结肠炎的影响

目的 探讨肠上皮Metrnl对葡聚糖硫酸钠盐（DSS）诱导的溃疡性结肠炎小鼠模型的作用及其对肠道菌群调节机制的影响。方法 应用不同浓度的DSS（3%和1%）对C57 小鼠进行造模,确定实验条件。给予肠上皮Metrnl特异性敲除小鼠（Metrnl^(-/-)）及其对照小鼠（Metrnl^(+/+)）3%DSS造模5 d,观察模型小鼠的生存时间、体重、疾病评分（DAI）、结肠长度以及结肠组织切片病理学变化等指标。使用16S核糖体RNA基因测序技术检测肠道菌群组成。结果 与1%DSS相比,3% DSS可显著缩短C57小鼠的生存时间（P<0.05）,降低体重（P<0.05）,增加DAI评分（P<0.05）,缩短结肠长度（P<0.05）,增加病理学评分（P<0.05）。给予3%DSS造模5 d后,与对照组Metrnl^(+/+)小鼠相比,Metrnl^(-/-)小鼠体重下降更多（P<0.05）,DAI评分更高（P<0.05）,结肠长度更短（P<0.05）以及病理学评分更高（P<0.05）。检测16S核糖体RNA结果显示,Metrnl^(-/-)小鼠的肠道菌群多样性下降,拟杆菌（Bacteroidetes）和变形杆菌（Proteobacteria）显著降低,而厚壁菌（Firmicutes）显著升高。结论 Metrnl对3%DSS诱导的溃疡性结肠炎小鼠有保护作用,该作用可能与Metrnl对肠道菌群的调节作用相关。     

具备高同型半胱氨酸血症的实验性结肠炎模型的建立

目的建立具备高同型半胱氨酸血症(HHcy)的实验性结肠炎模型,初步探讨Hcy对结肠炎症损伤的影响。方法将SD大鼠分为4组:正常对照组(NS灌肠+皮下注射NS)、正常对照+Hcy注射组(NS灌肠+皮下注射Hcy)、TN-BS模型对照组(TNBS/乙醇灌肠+皮下注射NS)、TNBS模型+Hcy注射组(TNBS/乙醇灌肠+皮下注射Hcy)。以TN-BS/乙醇混合溶液(100 mg·kg-1TNBS加入等体积NS)灌肠1次制备结肠炎模型后,采用皮下注射同型半胱氨酸(0.03μmol·kg-1,每天2次,间隔8 h,连续30 d)造成HHcy模型。实验结束后通过高效液相荧光法(HPLC-FD)检测血浆和结肠粘膜Hcy水平,进行DAI评分并取结肠组织进行HE染色评分,结肠组织匀浆检测MPO活性。结果与正常对照组比较,TNBS模型对照组大鼠DAI和HI评分增高(P<0.01),结肠组织MPO活性增高(P<0.01)。与TNBS模型对照组比较,TNBS模型+Hcy注射组大鼠血浆和结肠粘膜Hcy水平明显增高(P<0.01),DAI和HI评分明显增高(P<0.01),结肠组织MPO活性明显增高(P<0.01)。结论皮下注射同型半胱氨酸可以建立具备高同型半胱氨酸血症的实验性结肠炎模型,可用于探讨Hcy在结肠炎中的作用机制。     

布地奈德脂质体温敏凝胶对溃疡性结肠炎模型小鼠的药效研究

目的:研究布地奈德脂质体温敏凝胶剂(Bud-Lip-TSG)对葡聚糖硫酸钠(dextran sulfate sodium salt,DSS)致急性溃疡性结肠炎(ulcerative colitis,UC)昆明小鼠的药效作用。方法:建立DSS诱导的小鼠UC模型。实验动物分为正常对照组、模型组、阳性对照组及Bud-Lip-TSG低、中、高剂量组。测定小鼠给药前后疾病活动指数(DAI)、肠黏膜损伤评分(CMDI)、脏器指数、结肠组织病理评分,血清中IL-6、IL-10水平,结肠组织中的TNF-α、IL-10、髓过氧化酶(MPO)水平变化。结果:Bud-Lip-TSG各剂量组小鼠的DAI评分、CMDI、结肠组织病理评分、脾脏指数降低;结肠长度、结肠湿质量、结肠指数增加;各给药组结肠组织中IL-10显著升高,TNF-α水平、MPO活力显著降低,;Bud-Lip-TSG高剂量组血液中IL-6显著降低、IL-10显著升高,Bud-Lip-TSG中、高剂量组胸腺指数显著增加。结论:Bud-Lip-TSG可改善模型小鼠UC症状,对结肠黏膜有修复作用,可改善炎症因子的表达失衡状态。     

Protective effect of simvastatin and rosuvastatin on trinitrobenzene sulfonic acid-induced colitis in rats

Objective:Statins have anti-inflammatory effects that are not directly related to their cholesterol lowering activity. This study was carried out to evaluate the effect of simvastatin or rosuvastatin on the extent of colonic mucosal damage and on the inflammatory response in trinitrobenzene sulfonic acid (TNBS)-induced ulcerative colitis.Result:Disease activity index score in TNBS-treated rats, as determined by weight loss, stool consistency, fecal occult blood, were significantly lowers in simvastatin or rosuvastatin-treated rats than TNBS-treated animals. Simvastatin or rosuvastatin counteracted the reduction in colon length, decreased colon weight, neutrophil accumulation, and tumor necrosis factor-alpha level in TNBS-induced colitis. Simvastatin and rosuvastatin also inhibited the increase in oxidative stress levels after TNBS administration.Conclusions:These results suggest that simvastatin and rosuvastatin significantly ameliorate experimental colitis in rats, and these effects could be explained by their anti-inflammatory and antioxidant activity.KEY WORDS: Rosuvastatin, simvastatin, trinitrobenzene sulfonic acid, tumor necrosis factor-α, ulcerative colitis     

PARP inhibition reduces acute colonic inflammation in rats

Poly(ADP-ribose) polymerases (PARP) comprise a family of enzymes which catalyse poly(ADP-ribosyl)ation of DNA-binding proteins. Multiple researches indicate the importance of PARP in promoting cell recruitment and thereby inducing organ injury in various forms of inflammation, such as colitis. We have evaluated the effects of two PARP inhibitors, nicotinamide and 1,5-dihydroxyisoquinoline, in acute colitis induced by trinitrobenzensulfonic acid (TNBS) in rats. Nicotinamide (20-40 mg/kg) and 1,5-dihydroxyisoquinoline (4-8 mg/kg) were administered 48, 24 and 1 h prior to the induction of colitis as well as 24 h later. 48 h after colitis induction the lesions were blindly scored and quantified as ulcer index. Histological study and colonic inflammation were assessed by gross appearance and myeloperoxidase (MPO) activity. Prostaglandin E2 (PGE2) synthesis and, cyclooxygenase-1 and cyclooxygenase-2 expressions by Western blotting and immunohistochemistry were also performed. Inflammation following TNBS induction was characterized by increased colonic wall thickness, oedema, diffuse inflammatory cells infiltration in the mucosa and necrosis. Furthermore, increased MPO activity, cyclooxygenase-2 expression and PGE2 synthesis were significantly augmented after TNBS instillation. On the contrary, treatment with 1,5-dihydroxyisoquinoline significantly reduced the degree of colon injury and also caused a substantial reduction in the rise in MPO activity, in the increase of staining for cyclooxygenase-2, as well as in the up-regulation of PGE2 caused by TNBS in the colon. Although nicotinamide significantly did not reduce macroscopic damage, it decreased both MPO activity and PGE2 colonic levels. In conclusion, we demonstrated that PARP inhibition can exert beneficial effects in experimental colitis and may, therefore, be useful in the treatment of ulcerative colitis.     

Evaluation of protein arginine deiminase-4 inhibitor in TNBS- induced colitis in mice

Background and aimMany evidences indicated that neutrophil extracellular traps (NETs) are involved in the pathogenesis of inflammatory bowel disease (IBD). Citrullination of histones by Protein Arginine Deiminase-4 (PAD4) is central for NETs formation. This paper aimed to explore the definite role of NETs in mouse model of Crohn's disease (CD) with 2,4,6-trinitrobenzene sulfonic acid (TNBS).MethodsThe expression of NETs-associated proteins and mRNAs in colon tissue were detected by immunohistochemistry and Real-time Quantitative PCR (QPCR) respectively. Neutrophils were isolated and stimulated in vitro to form NETs. In addition, we also administered Cl-amidine, PAD4 inhibitor, resulting in less NETs formation to investigate protective effect by measuring weight loss, gross bleeding, colon length, myeloperoxidase (MPO) activity, and cytokine expression in mice.ResultsThe results showed enhanced expression of Ly6G, citrullinated histone H3 (CitH3), and PAD4 in TNBS-induced colitis mice and higher ability of neutrophil to produce NETs in vitro. Blocking NETs formation through Cl-amidine effectively alleviated the clinical colitis index and tissue inflammation in TNBS mice, regulated the expression of pro- or anti-inflammatory cytokines. In addition, Cl-amidine reduced the gene expression of PAD4 and the expression of NETs-associated proteins in the colon of TNBS mice and inhibited the formation of NETs in vitro.ConclusionsOur data showed that Cl-amidine could alleviate the clinical colitis index in TNBS mice to some extend and suggested blocking NETs formation through inhibition of PAD4 as therapeutic targets for the treatment of CD.     

Effect of intracolonic benzalkonium chloride on trinitrobenzene sulphonic acid-induced colitis in the rat

Background:

We investigated the effects of benzalkonium chloride (BAC) on trinitrobenzene sulphonic acid (TNBS)-induced colitis in rats.

Methods:

TNBS was administered intrarectally before and/or after BAC treatment. In the first study, the effects of treatment with BAC 6, 12 or 24 h after TNBS were examined. In the second study, animals were treated with BAC before, after or before and after TNBS, and were examined 7 days later. The severity of colitis was assessed by macroscopic and histological scoring of the colonic damage and by determination of colonic myeloperoxidase (MPO) activity. Macrophages and CD4⁺ and CD8⁺ T cells were examined by immuno-histochemistry.

Results:

When BAC was instilled into the colon 6, 12 or 24 h after TNBS, weight loss and macroscopic and histological features of the colon were similar to that of controls (TNBS alone). In contrast, MPO activity was significantly reduced in all three groups post-treated with BAC. In the groups examined 7 days after TNBS treatment, rats post-treated with BAC exhibited increased weight gain and significantly reduced macroscopic damage and MPO activity compared to the TNBS control group. Rats pre-treated with BAC exhibited less macroscopic damage of the colon than rats receiving only TNBS, but histological damage, MPO and weight gain were unchanged from TNBS controls. Immunohistochemistry revealed that BAC pre-treatment increased the numbers of macrophages and T cells in the colon. After TNBS treatment, macrophage accumulation was evident in the colon, but T cells were scarce. However, these cells were preserved or enhanced in the colonic mucosa in TNBS-treated rats that had been pre-treated with BAC.

Conclusions:

Treatment with BAC, particularly after induction of colitis, produces a significant reduction in the severity of tissue injury and inflammation through mechanisms that are not fully understood.

     

Maresin 1 alleviates dextran sulfate sodium-induced ulcerative colitis by regulating NRF2 and TLR4/NF-kB signaling pathway

ObjectiveUlcerative colitis (UC) is one of the most common gastrointestinal diseases, characterized as a chronic, relapsing inflammation that causes damage to the colonic mucosa. Maresin 1 (MaR1), a specialized proresolving mediator, has powerful anti-inflammatory activity that prevents the occurrence of various inflammatory diseases. The aim of this study was to explore the role and potential mechanism of MaR1 in DSS-induced ulcerative colitis.MethodsIn the present study, we established dextran sulfate sodium (DSS)-induced ulcerative colitis rat model in vivo. Rats with colitis received tail vein injection of MaR1, with or without intraperitoneal injection of ML385. The changes of body weight, colon length, disease activity index (DAI), colonic histopathology, inflammatory cytokines, the activity of myeloperoxidase (MPO) and reactive oxygen species (ROS), and infiltration of macrophages expressing F4/80 were analyzed for the evaluation of colitis severity. In addition, protein expressions were detected using western blot.ResultsMaR1 significantly reduced inflammatory cytokines production, and restored body weight, DAI and colonic histopathology. Besides, MaR1 improved the expression of tight junction (TJ) proteins and reduced the infiltration of neutrophil and macrophages, as well as a decreased activity of MPO and ROS. Meanwhile, MaR1 activated Nrf2 signaling and decreased toll-like receptor 4(TLR4)/nuclear factor-κB(NF-κB) activation. Furthermore, ML385, an inhibitor of Nrf2, significantly reversed the protective effect of MaR1.ConclusionMaR1 play a protective role in DSS-induced colitis by activating Nrf2 signaling and inactivating Nrf2-mediated TLR4/NF-κB signaling pathway, which mediate proinflammatory mediators and intestinal TJ proteins in rats, providing novel insights into the therapeutic strategy of colitis.     

核受体与溃疡性结肠炎大鼠疾病转归的相关性研究

目的 研究大鼠结肠组织中相关核受体的表达与溃疡性结肠炎（ulcerative colitis，UC）大鼠疾病转归的相关性。方法 SD大鼠一次性结肠灌注2，4，6-三硝基苯磺酸（2，4，6-trinitrobenzene sulfonic acid，TNBS）造模，诱导UC急性期和UC炎症消退后恢复期，收集大鼠血浆和结肠组织。计算疾病活动指数、粪便含水率，考察结肠病理变化，评估大鼠UC模型是否成功；ELISA测定血浆肿瘤坏死因子-α（tumor necrosis factor，TNF-α），γ干扰素（interferon-γ，IFN-γ），白细胞介素4（interleukin 4，IL-4）和IL-13的含量；比色法检测结肠髓过氧化物酶（myeloperoxidase，MPO）活性；Real-time PCR测定法尼醇X受体（farnesoid X receptor，FXR）、孕烷X受体（pregnane X receptor，PXR）、组成型雄甾烷受体（constitutive androstane receptor，CAR）、过氧化物酶体增殖物激活受体γ（peroxisome proliferators activate receptor g，PPAR γ）mRNA的表达；R软件评估核受体与炎症因子之间的相关性。结果 模型组大鼠疾病活动指数和粪便含水率均明显下降，提示UC大鼠模型建立成功。与正常对照组相比，急性炎症期组大鼠结肠FXR、CAR、PPARγ mRNA表达水平明显下降，血浆TNF-α和IFN-γ含量呈显著负相关升高（P<0.05），FXR与IL-4显著正相关（P<0.05）；结肠PXR表达水平降低，与炎症因子无相关性；此外，大鼠血浆MPO含量升高，与PPARg呈显著负相关（P<0.05）。与急性炎症期组相比，炎症消退后恢复期组大鼠血浆促炎因子TNF-α、IFN-γ含量及血浆MPO活性显著降低（P<0.05），而血浆抑炎因子IL-4与IL-13含量显著升高（P<0.05），结肠FXR、PXR、CAR、PPARγ mRNA表达水平则明显升高（P<0.05）。结论 UC大鼠结肠组织核受体FXR、CAR、PPARγ水平与UC大鼠的发病及转归具有相关性。