肝星状细胞的激活与肝纤维化的研究进展

肝纤维化是肝脏对慢性损伤的一种修复反应,其特征表现为细胞外基质的过度沉积.肝星状细胞的激活是肝纤维化的关键环节.此文概述了细胞因子、细胞外基质、氧化应激和核转录因子对肝星状细胞激活的作用.     

丙泊酚与肝脏缺血/再灌注损伤

缺血/再灌注对肝脏造成损伤.众多资料显示丙泊酚对肝脏缺血/再灌注损伤有保护作用,这一保护作用与其抗氧化,阻断钙超载,减轻炎性细胞导致的损伤有关.肝脏缺血/再灌注也影响了丙泊酚的代谢.     

Picroside II decreases the development of fibrosis induced by ischemia/reperfusion injury in rats

In kidney transplantation, renal ischemia and reperfusion injury was one of the leading factors to the development of renal fibrosis, which was the main cause of graft loss. The fibrogenic changes were associated with the long term inflammation elicited by ischemia and reperfusion injury. In the present study, we investigated the role of the Picroside II, the main active constituents of the extract of picrorrhiza scrophulariiflora roots, in attenuating renal fibrosis in a renal ischemia and reperfusion injury model. We induced ischemia and reperfusion injury in kidneys treated with or without Picroside II. We observed that inflammation and tissue fibrosis were increased in ischemia and reperfusion injury group compared to Picroside II group, however, these changes were significantly decreased by the treatment with Picroside II. We concluded that Picroside II can protect the ischemic kidney against renal fibrosis and its mechanism may be through the inhibition of the long term inflammation.     

Earlier renal fibrosis aggravates acute kidney injury induced by ischemia reperfusion in mice

Objective To investigate the influence of earlier renal fibrosis on ischemia and reperfusion induced acute kidney injury. Methods Male C57BL/6 mice at eight to twelve weeks old age were divided into 4 groups randomly: (1)Sham (n=3); (2)Unilateral ureter obstruction (UUO, n=6): UUO for 3 days (UUO3d, n=3) and UUO for 5 days (UUO5d, n=3);(3)Ischemia and reperfusion (IR, n=7): bilateral kidney ischemia for 40 minutes followed by 24 hours of reperfusion; (4)UUO for 3 days plus IR (UUO3d+IR, n=6): bilateral kidney ischemia after UUO 2 days for 40 minutes followed by 24 hours of reperfusion, and the real time for UUO was 3 days. Pathologic analysis for acute or chronic injury was performed on paraffin embedded kidney sections with hematoxylin and eosin (HE) or Masson staining. Apoptosis was detected by immunohistochemistry(IHC) and Western blotting with anti-caspase-3 antibody, and proliferation was observed by IHC with anti-ki67 antibody. Results On kidney sections with HE or Masson staining, it showed that the chronic kidney lesions and fibrosis got more severe as time of UUO prolonged from 3 days to 5 days; the area of matrix deposition increased in UUO5d and UUO3d mice significantly compared to Sham mice (P＜0.05) and was smaller in UUO3d mice compared with UUO5d mice obviously (P＜0.05). Acute kidney injury could be observed in UUO3d+IR mice, such as massive inflammatory cells infiltration, tubules dilation, brush border disappearance, tubular epithelial cells vacuolar degeneration, necrosis, casting formation, coexisting with chronic lesions: thinner cortex, broadened interstitial space, and increased blue stained matrix. Acute kidney injury score in UUO3d+IR mice was higher than that in IR mice significantly (P＜0.05), and serum creatinine level increased significantly in UUO3d+IR mice compared to Sham mice (P＜0.05). Caspase-3 expression increased and ki67 positive tubular cells decreased in UUO3d+IR mice than those in IR mice obviously (P＜0.05). Conclusion Earlier renal fibrosis aggravates acute kidney injury induced by ischemia reperfusion in mice through increasing apoptosis and decreasing proliferation of tubular epithelial cells.     

内毒素血症加重实验大鼠肝缺血再灌注损伤

目的探讨内毒素血症对肝缺血再灌注(I／R)损伤的影响。方法对24只大白鼠于术前1h静脉注射0．8mg／kg的LPS，检测肝门血流阻断30min的情况下复流后2h、6h、12h和24h4个时间点血清ALT与AST值，用ELISA法检测了复流后2h和6h2个时间点的循环TNF-α水平和肝组织中TNF-α含量，于复流后24h取缺血部分肝组织行组织病理学检查。24只未注射LPS的I／R肝损伤模型大鼠作为对照组。结果实验组大鼠术后各时刻ALT和AST升高幅度均明显大于对照组，并且下降缓慢；循环和肝组织中的TNF-α也明显高于对照组，复流后24h的肝组织存在片状坏死，伴大量多形核细胞浸润。结论内毒素通过升高循环和肝组织局部的TNF-α加重了缺血后再灌注肝损伤。     

星状神经节阻滞对心肌缺血再灌注损伤的影响

目的：探讨左侧星状神经节阻滞对心肌缺血再灌注损伤的预防作用及其机制，以建立一种新的围术期心肌保护方法。方法：选用健康新西兰白兔32只，随机分为4组，A组为对照组，其他3组为缺血再灌注组，其中B组采用左侧星状神经节阻滞。常规建立在体心肌缺血再灌注损伤模型。分别于开胸后10min，阻断左前降支（LAD）前，再灌注5、30、90min测心率（HR）、左室峰压（LVP）、左室内压最大上升速率（ dp/dtmax），并经冠状静脉窦口抽血测神经肽Y(NPY）和去甲肾上腺素（NE）。结果：左侧星状神经节阻滞组，在心肌缺血再灌注5、30、90min时间点，冠状静脉血血浆NPY和NE水平均明显降低；在再灌注90min时，血流动力学指标LVP、 dp/dtmax值明显上升。结论：左侧星状神经节阻滞对心肌缺血再灌注损伤有一定预防作用。     

牛磺酸对大鼠肝缺血再灌注后小肠损伤的保护作用

目的探讨牛磺酸对大鼠肝缺血再灌注(I/R)后小肠损伤的保护作用。方法将大鼠随机分成假手术组,肝I/R组,牛磺酸预处理+肝I/R组;采用阻断肝动脉、门静脉30min后再灌注的方法,制作肝I/R模型。各组于再灌注3,6,24h分别采血,测定二胺氧化酶(DAO)数值,检测小肠功能;同步切取小肠,测定肠道组织中的SOD及MDA含量,评价肠道自由基损伤程度;切片后行苏木素-伊红(HE)染色,观察病理形态学改变;原位末端标记法(TUNEL)测定细胞凋亡;免疫组化法测定caspase-3表达。结果与假手术组比较,肝I/R组SOD水平明显降低(P<0.05),MDA和DAO水平明显升高(P<0.05),小肠病理损伤严重,凋亡指数明显升高(P<0.05),caspase-3阳性率明显增加(P<0.05)。与I/R组同时间点比较,牛磺酸预处理+I/R组各项指标均明显改善(均P<0.05)。结论牛磺酸对肝I/R后小肠损伤具有保护作用。     

谷氨酰胺对肝缺血再灌注损伤的影响

研究显示,门静脉淤血所致的再灌注损伤在肝缺血再灌注损伤中具有重要作用~([1]),因而维护肠道屏障以减轻肝缺血再灌注损伤,具有重要意义.为此,笔者采用肝缺血再灌注动物模型,探讨谷氨酰胺(Gln)对肝脏高迁移率族蛋白B1(HMGB1)基因表达、内毒素血症和炎性介质的影响及其与肝损伤的关系.     

肝硬变大鼠肝脏缺血再灌注损伤

为比较硬化肝与正常肝在缺血再灌注损伤时的差异和意义。作者采用四氯化碳复制大鼠肝硬变模型,通过大鼠肝脏缺血再灌注损伤模型,检查不同时限大鼠门静脉血内毒素、肝静脉血一氧化氮。结果显示：肝硬变大鼠再灌注时门静脉内毒素水平更高;肝脏ＮＯ合成释放显著增加。作者认为肝硬变时对缺血再灌注损伤反应与正常大鼠不同,可能是肝硬变时对缺血再灌注损伤更敏感,更易发生肝功能衰竭的重要原因。     

瘦素在肝缺血/再灌注致肾损伤中作用的研究

目的：研究瘦素（Leptin）在肝缺血/再灌注（I/R）后肾组织中的表达变化,探讨其与肝I/R介导的肾损伤的关系。方法：建立大鼠70%肝I/R模型,设立假手术和缺血60min后再灌注60、150、240、360min组,观察肾脏的病理学变化,检测各组血清尿酸、总抗氧化能力,肾Leptin蛋白及其mRNA表达的变化。结果：与假手术组比较,缺血60min/再灌注150min及再灌注240min组血清尿酸显著升高,以再灌注240min升高最为显著;再灌注240min和360min组血清总抗氧化能力显著升高,以再灌注240min升高最为显著;再灌注150、240和360min组肾Leptin蛋白表达显著升高,再灌注60、240、360min组肾LeptinmRNA表达显著升高,而再灌注150min组LeptinmRNA显著降低。病理学观察提示肝I/R早期的肾损伤较重而后期显著减轻。结论：Leptin在肝I/R后肾组织内的表达变化与肾损伤密切相关,提示它可能作为一种保护因子对抗肝I/R介导的肾损伤。     

AMPK attenuates inflammation to reduce fibrosis induced by acute ischemia reperfusion injury in mice

Objective To observe the effect of adenosine monophosphate activated protein kinase (AMPK) on attenuating inflammation in fibrosis induced by acute ischemia reperfusion injury (IRI) in mice. Methods Forty eight male C57BL/6 mice were randomly divided into four groups: sham operation group (sham group), IRI group, AMPK inhibitor+IRI group (AMPK/IRI group) and normal saline+IRI group (NS/IRI group), 12 mice each group. The mice with renal IRI were occluded for 30 min through clipping bilateral renal pedicle, then released renal perfusion. Mice in sham group were performed the separation of renal pedicle without clipping. Mice in AMPK/IRI group and NS/IRI group were respectively intraperitoneal injected AMPK inhibitor and normal saline before IRI. At the 2 d after operation, 6 randomly-selected mice from each group were blooded by extraction eyeball to detect BUN and Scr. The renal histopathological changes were observed through HE staining. The mRNA expression of IL-1β, IL-6 and TNF-α was detected by real time PCR, and the level of AMPK phosphorylation was detected by Western blotting. At the 14 d after operation, Collagen 1 (COL1), α-SMA and fibronectin (FN) were detected by immunofluorescence and Western blotting in 6 remained mice from each group. The degree of kidney fibrosis was observed through sirus red staining. Results Compared with those in sham group, tubular interstitial damage was aggravated (P＜0.05), BUN and Scr were increased (P＜0.05), the mRNA expression of IL-1β, IL-6 and TNF-α was increased at the 2 d after operation (all P＜0.05), and the level of AMPK phosphorylation was activated in IRI group and NS/IRI group (all P＜0.05); the degree of kidney fibrosis and the expression of COL1, α-SMA and FN were increased obviously at the 14 d (all P＜0.05). Compared with those in IRI group, in AMPK/IRI group tubular interstitial damage was aggravated (P＜0.05), BUN and Scr were increased (all P＜0.05), the mRNA expression of IL-1β, IL-6 and TNF-α was increased at the 2 d (all P＜0.05), and the level of AMPK phosphorylation was decreased (P＜0.05). Moreover, the degree of kidney fibrosis and the expression of COL1, α-SMA and FN were increased obviously at the 14 d in AMPK/IRI group (all P＜0.05). Conclusions AMPK can ameliorate the acute renal ischemia reperfusion injury induce fibrosis in mice, and the mechanism may be related to the decrease of inflammatory reaction.     

肝脏Toll样受体4的激活与小鼠肝脏部分缺血再灌注损伤的关系

目的探讨TOLL样受体4(toll-like receptor 4,TLR4)的激活与肝缺血再灌注损伤的关系.方法以BALB/c小鼠复制肝脏部分缺血再灌注损伤模型,采用免疫组织化学法观察TLR4在肝脏的分布和表达量,同时监测血浆丙氨酸氨基转移酶(alanine aminotransferase,ALT)及门静脉血清内毒素(endotoxin,EN)和肿瘤坏死因子-α(tumor necrosis factor-alpha,TNF-α)的变化;再以TLR4先天性缺损小鼠C3H/Hej和野生型鼠C3H/Heouj为模型,观察ALT和门静脉血清TNF-α的变化.结果 1. BALB/c小鼠肝脏左中叶缺血1 h后,再灌注1、3 h,缺血肝叶内TLR4表达增加,且再灌注1 h最强,阳性细胞主要是枯否细胞及血管内中性粒细胞;2.门静脉血清EN在各时间点与假手术组相比无显著差异(P>0.05);3.再灌注3 h,TNF-α较假手术组升高[Hej(152±43)pg/ml vs. (18±10)pg/ml,n=6,t=5.26,P<0.01;Heouj(249±52)pg/ml vs. (25±13)pg/ml,n=6,t=7.24,P<0.01];4. Hej组小鼠肝功能损伤轻于Heouj组小鼠[再灌注1 h(662±106)pg/ml vs. (1 216±174)pg/ml,n=6,t=4.21,P<0.01;再灌注3 h(1 145±132)pg/ml vs. (2 958±187)pg/ml,n=6,t=13.72, P<0.01],且再灌注3 h其血清TNF-α水平明显低于Heouj组小鼠[(152±43)pg/ml vs. (249±52)pg/ml,n=6,t=3.94,P<0.01].结论 TLR4受体在肝脏缺血再灌注损伤过程中被激活,通过TNF-α等细胞因子介导参与了肝脏缺血再灌注损伤的过程.     

大鼠肝缺血及再灌注所致小肠过氧化损伤及丹参的保护作用

目的 观察大鼠肝缺血再灌注小肠过氧化损伤及丹参预处理的保护作用.方法 首先将SD大鼠随机分为正常对照组(CO组)、假手术组(SO组)、缺血再灌注组(IR组)、丹参预处理组(SM组),分别在肝缺血30、45、60 min时取上段空肠进行大体病理学检测;然后在肝缺血45 min条件下,动物亦随机分为4组(CO组、SO组、IR组、SM组),按再灌注后不同时间(0、3、12、24、72 h)分为5个亚组,每组5只.SM组在阻断第一肝门30 min前经尾静脉推注丹参注射液6 g/kg加生理盐水40 ml/kg,其余各组按40 ml/kg给予生理盐水尾静脉注入,SO组开腹后仅解剖肝门,不钳夹肝蒂.分别在再灌注0、3、12、24、72 h取上段空肠行病理学检查、丙二醛(MDA)含量测定、髓过氧化物酶(MPO)活性测定.结果 空肠黏膜损伤评分随肝缺血时限延长而加重;在肝缺血45 min再灌注不同时限点SM组空肠黏膜损伤较IR组明显减轻,且肠组织MDA含量、MPO活性均低于IR组(P<0.05).结论 肝缺血再灌注所致小肠明显淤血性损伤,MDA含量、MPO活性升高,丹参预处理对肝缺血再灌注所致小肠损伤具有保护作用.     

肝脏缺血再灌注后急性肺损伤的机制及丙泊酚对其的保护作用

目的 观察肝脏缺血再灌注后急性肺损伤的发病机制及丙泊酚的保护作用.方法 成年封闭群SD雄性大鼠48只,采用随机数字表法随机分为:假手术组(Sham):假手术2 h(Sham2)组;假手术6 h(Sham6)组;缺血再灌注组(IR):缺血再灌注2 h(IR2)组;缺血再灌注6 h(IR6)组及丙泊酚组(P):丙泊酚2 h...