沉默信息调节因子1(SIRT1)作为一种去乙酰化酶,可以脱去多种靶蛋白赖氨酸残基的乙酰基.近年来,越来越多的研究证实SIRT1在肠道疾病的发病机制中占有重要的地位.因此,SIRT1可能成为治疗肠道疾病的潜在靶点.本文综述了SIRT1对氧化应激,炎症与细胞凋亡等生物效应的调控作用;归纳总结了SIRT1在脓毒症肠损伤,肠缺血再灌注损伤,放射性肠损伤,肠道炎症性疾病等疾病中的变化和作用,以及靶向SIRT1治疗肠道疾病的药物研究进展,旨在探讨肠道疾病新的防治策略.

Objective To explore the effect of overwork (OW) on extracellular matrix of arterial vessel wall in rats. Methods Random number grouping method was employed to assign 18 Sprague-Dawley rats into three groups(n=6):the control group(no special treatment),group OW(forced swimming twice a day for 15 days),and sleep deficiency(SD)+OW group(in addition to forced swimming twice a day,the rats were put on the platforms in water to limit sleep for 15 days).On the 16th day,the abdominal aorta and common carotid artery were collected after blood sampling from heart under deep anesthesia.A part of the abdominal aorta sample was taken for Masson staining of collagen fiber,and Verhoeff-Van Gieson staining was carried out for the elastic fiber of common carotid artery.Image J was employed for the quantitative analysis of collagen fiber and elastic fiber content.The expression of collagen 1(Col-1) protein was quantified by immunohistochemistry and the ultrastructure of vascular matrix was examined by transmission electron microscopy.The other part of the abdominal aorta sample was used to determine the mRNA levels of matrix metalloproteinase(MMP)-1,MMP-2,MMP-9,tissue inhibitor of metalloproteinases-1(TIMP-1),and Col-1 by quantitative real-time polymerase chain reaction. Results Compared with that in control group,the content of collagen fiber in groups OW and SD+OW had no significant change(all P>0.05);the content of elastic fiber in groups OW and SD+OW decreased(all P<0.001) and had no significant difference between each other(P>0.05).The vascular vessel wall of group OW showed slight fiber breakage,while that of group SD+OW presented wormhole-like or spongy fiber fragmentation.The mRNA levels of MMP-1 and MMP-2 in groups OW and SD+OW had no significant difference between each other(P>0.05) but were higher than that in control group(all P<0.001).The mRNA levels of MMP-9 and TIMP-1 had no significant difference among the three groups(all P>0.05).Groups OW and SD+OW had lower mRNA level(all P<0.001) and protein level(all P<0.001) of Col-1 than control group,while the mRNA and protein levels of Col-1 had no significant difference between groups OW and SD+OW(P>0.05). Conclusion OW can reduce the content of Col-1 and elastic fibers in the extracellular matrix of arterial vessels,destroy the elastic lamina of vascular wall,up-regulate the expression of MMP-1 and MMP-2,thereby injuring arterial vessels.

目的 探讨富氢水(hydrogen-rich water)对高氧环境下小鼠肠道屏障和菌群的影响.方法 选取SPF级C57BL/6雄性小鼠24只,随机分为4组(n=6):对照组(C组)、对照+富氢水组(CH组)、高氧组(H组)和高氧+富氢水组(HH组).C组、CH组小鼠饲养于常氧环境,H组、HH组小鼠饲养于85％高氧环境.CH组和HH组小鼠每天给予富氢水0.1mL/10g灌胃2次,持续7d;C组和H组小鼠给予等体积生理盐水.第7天采集小鼠粪便,心脏采血,处死动物并切取末端回肠组织5 cm.HE染色观察肠组织病理学变化,行肠黏膜损伤评分;透射电镜观察肠上皮细胞超微结构;测定肠组织丙二醛(MDA)水平,超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活力,肠分泌型免疫球蛋白A(sIgA)水平;测定血清二胺氧化酶(DAO)水平;提取粪便DNA行肠道菌群检测和分类.结果 与C组、CH组小鼠相比,H组肠黏膜损伤评分升高,肠道SOD、CAT活力下降,sIgA、MDA水平升高,血清DAO水平升高(均P＜0.05);与H组小鼠相比,HH组肠黏膜损伤评分下降,MDA水平下降,肠道SOD、CAT活力升高,血清DAO水平下降(均P＜0.05).基因测序分析发现4组小鼠间肠道菌群多样性差异无统计学意义(P＞0.05),但菌群的组成有明显差异:H组小鼠肠道菌群F16科、梭状芽胞杆菌属、葡萄球菌属和理研菌属富集;HH组小鼠肠道菌群蓝细菌门、双歧杆菌属和阿克曼菌属富集.结论 高氧7d后小鼠肠屏障功能受到氧化应激损伤,并影响了肠道菌群组成.富氢水可减轻高氧肠损伤,其机制与上调抗氧化酶SOD、CAT活力,降低氧化应激产物MDA水平,保持肠道机械屏障完整和肠道有益菌富集有关.

Objective To determine the effect of overworking on vascular smooth muscle cells (VSMC) in rats. Methods Clean SD rats were randomly divided into control group (CON), overworking group (OW) and overworking and sleep deficiency group (OW+SD). The rat model of overworking was established by exhaustive swimming in the latter 2 groups, and the rats of the last group was subjected to sleep deprivation with an underwater platform. In 15 d later, the abdominal aorta of rats was collected for pathological observation by HE staining, and the thickness of media was measured with aid of Image J software. The intracellular ultrastructure was observed by transmission electron microscopy. The apoptotic rate of VSMC was detected by TUNEL, the mRNA expression of Caspsae-3, Bax, Bcl-2 and Ki67 in the VSMC were detected by RT-qPCR, and the content of apoptotic protein Caspase-3 was measured by immunohistochemical assay. Results ① The results of HE staining showed that VSMC were in disordered arrangment and formed vacuole-like cells in the OW and OW+SD groups, and the vascular intima-media thickness was significantly thicker in the OW and OW+SD groups than the CON group (P < 0.05). ② Electron microscopy displayed the apoptotic bodies in the VSMC of the OW and OW+SD groups. ③TUNEL results showed that the apoptotic rate of VSMC was significantly higher in the OW and OW+SD groups than the CON group (P < 0.05). ④RT-qPCR showed that the expression levels of Bax and Ki67 were significantly increased (P < 0.05), while those of Caspase-3 and Bcl-2 were not obviously changed in OW and OW+SD groups (P>0.05) when compared with the CON group. ⑤ Immunohistochemical results showed that the protein content of Caspase-3 in vascular middle membrane of the OW and OW+SD groups was increased significantly than that in the CON group (P < 0.05). Conclusion Overworking aggravates the apoptosis of VSMC and induces the proliferation and repair of VSMC, which form the pathological basis of early arterial lesions. During the experimental time, sleep could not alleviate the injury of VSMC caused by overworking.

目的 研究富氢水(HRW)通过调节沉默信息调节因子1/核因子E2相关因子2/血红素加氧酶-1(SIRT1/Nrf2/HO-1)通路对小鼠高氧肠损伤发挥保护作用的机制.方法 C57BL/6小鼠24只,随机分为常氧组(N组)、高氧组(O组)和富氢水组(H组)和富氢水联合SIRT1抑制剂组(HE组),每组6只.N组小鼠置于室内环境(FiO2=21％)中,O组、H组和HE组小鼠置于高氧环境(FiO2=85％)中,持续7 d.H组给予0.1 mL/10 g富氢水灌胃,2次/d,连续7 d;HE组在H组基础上每天腹腔注射SIRT1抑制剂EX52710 mg/kg 1次,连续7 d;N组和O组给予等体积生理盐水.每天称质量并记录小鼠体质量,7 d后安乐死小鼠并留取标本.取回肠组织制备切片并行Chiu病理评分,透射电镜观察回肠组织超微结构,检测回肠组织超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量,Western blot检测回肠组织SIRT1、Nrf2、HO-1表达水平.结果 与N组比较,O组、H组、HE组实验后小鼠体质量减轻,Chiu病理评分、MDA含量升高,SOD活性降低;与O组比较,H组实验后小鼠体质量增加,H组、HE组Chiu病理评分、MDA含量降低SOD活性升高;与H组比较,HE组实验后小鼠体质量减轻,Chiu病理评分、MDA含量升高,SOD活性降低[体质量(g):N组23.17±1.70,O组17.60±1.58,H组20.87±1.24,HE组17.20±1.27;Chiu病理评分(分):N组0.33±0.27,O组3.44±0.37,H组2.11±0.25,HE组3.06±0.23;MDA含量(nmol/mg):N组59.15±3.77,O组86.18±3.88,H组68.12±2.27,HE组76.94±5.26;SOD活性(U/mg):N组105.51±7.67,O组64.58±4.62,H组86.45±5.51,HE组72.43±4.27;均P<0.05].与N组比较,O组SIRT1表达下调,Nrf2、HO-1表达上调,H组、HE组SIRT1、Nrf2、HO-1表达上调;与O组比较,H组SIRT1、Nrf2、HO-1表达上调,HE组SIRT1、Nrf2表达上调;与H组比较,HE组SIRT1、Nrf2、HO-1表达下调(SIRT1:N组0.17±0.01,O组0.13±0.01,H组0.66±0.04,HE组0.36±0.01;Nrf2:N组0.07±0.01,O组0.23±0.02,H组0.54±0.02,HE组0.38±0.02;HO-1:N组0.37±0.01,O组0.42±0.02,H组0.56±0.02,HE组0.44±0.02;均P<0.05).结论 富氢水预处理可通过激活SIRT1/Nrf2/HO-1信息通路,对小鼠高氧肠损伤发挥保护作用.