Tamoxifen Prevents D-galactosamine/Lipopolysaccharide-Induced Murine Acute Hepatic Failure through Inhibition of Oxidative Stress and Mmd-2 Upregulation

Oxidative stress is considered one of the major mechanisms underlying lipopolysaccharide (LPS)-induced acute liver failure (ALF). Tamoxifen has been reported to ameliorate LPS-induced ALF via the induction of monocyte to macrophage differentiation-associated 2 (Mmd-2). Whether antioxidant effects are involved remains unknown. Mice were given tamoxifen (TAM) once a day for 3 days. Twelve hours later, d-galactosamine (GaIN) and LPS were injected intraperitoneally to induce ALF. N-Acetylcysteine (NAC) was administered immediately after ALF induction as a positive control. The results showed that serum transaminases increased and hepatic antioxidants decreased significantly in the model group. ALF was alleviated markedly by TAM or NAC treatment. This demonstrated that ALF may be associated with excessive oxidative stress caused by decreased expression of antioxidant enzymes. Both TAM and NAC increased the levels and activity of these antioxidant enzymes significantly (p < 0.05). Hepatic Mmd-2 expression was downregulated in the control group while remaining stable or exhibiting elevated levels in the TAM or NAC groups. The results indicate that TAM may protect mice from GaIN/LPS-induced ALF through increased activity of antioxidant enzymes and upregulation of Mmd-2 expression.     

IL-18在实验性暴发型肝衰竭发病机制中的作用

为探讨IL 18在暴发型肝衰竭发生中的表达变化及对其他细胞因子的调控作用。采用D 氨基半乳糖 (D Gal) 90 0mg/kg与脂多糖 (LPS ) 10 μg/kg诱导BALB/c小鼠暴发型肝衰竭 ,检测不同时间点血清转氨酶 (ALT、AST )和肝组织病理、DNA梯形条带 ,评估肝损伤情况 ;用半定量RT PCR和相应的分析软件分析不同时间点肝组织中IL 18mRNA、TNF αmRNA和IFN γmRNA表达及ELISA方法检测血浆IL 18、TNF α和IFN γ的蛋白表达。结果 :D Gal/LPS给予后 4h血清转氨酶明显升高 ,7h小鼠开始死亡 ,10h死亡率达 80 %。肝组织病理学检查发现 ,5h肝窦扩张、炎性细胞浸润、枯否细胞增生 ;7h肝细胞大量凋亡、坏死或肝组织出现大量出血性坏死 ;5h电镜示肝细胞核仁碎裂、线粒体肿胀或空泡变性 ;7h核仁边聚 ,呈半月型 ,表现为典型的凋亡形态学变化 ,线粒体大部分空泡变性。DNA电泳显示 5h始出现梯形条带。正常小鼠肝组织IL 18mRNA有少量表达 ,TNF αmRNA、IFN γmRNA微量表达。给药后 ,三者的mRNA分别在 1h、 2h、 3h达高峰 ,血浆中TNF α、IFN γ水平与其mRNA变化显著正相关 (rTNF α=0 4 3,P =0 0 1;rIFN γ=0 6 9,P <0 0 0 1) ,而血浆IL 18与其mRNA表达无明显相关 (r= 0 12 ,P =0 2 5 )。本实验诱导的暴发型肝衰竭模型中 ,肝细?     

The antagonistic effect of tamoxifen against d-galactosamine/lipopolysaccharide-induced acute liver failure is associated with reactivation of hepatic nuclear factor-κB

Context: Tamoxifen (TAM) ameliorates D-galactosamine/lipopolysaccharide (Gal/LPS)-induced acute liver failure (ALF) through its antioxidative effect; thus, this study was designed to determine whether the effectiveness of TAM is related to nuclear factor-κB (NF-κB) reactivation.

Materials and methods: Experimental mice were injected with TAM once daily for 3 consecutive days intraperitoneally (i.p). Twelve hours after pretreatment, Gal/LPS was given to mice (i.p) for ALF induction. In the positive control group, N-acetylcysteine (NAC) was administered immediately after ALF establishment. Except for survival observation, other animals were sacrificed 7?h after Gal/LPS treatment. Survival and hepatic failure were evaluated. For the oxidation assessment, the reduced/oxidized glutathione (GSH/GSSG) ratio and hepatic superoxide dismutase (SOD) activity were analyzed using both colorimetry and Western blotting. Lastly, hepatic NF-κB activation was measured through Western blot analysis of p65 and IκBα.

Results: The results indicated that pretreatment with TAM dramatically attenuated Gal/LPS-induced ALF, as demonstrated by improved survival (70%), decreased transaminase levels, and reversed histopathological manifestation. In addition, the hepatic GSH/GSSG ratio and SOD activity were decreased in the ALF model. However, to some degree, TAM and NAC effectively prevented this undesirable phenomenon in contrast to the ALF model. Western blotting revealed that compared with mice in the ALF model group, mice treated with TAM or NAC showed reactivation of hepatic NF-κB.

Conclusions: Taking the results together with those of other studies, we conclude that TAM may attenuate Gal/LPS-induced ALF by antagonizing oxidative stress through NF-κB reactivation.     

The regulatory role of microRNA-1187 in TNF-α-mediated hepatocyte apoptosis in acute liver failure

In the current study, we aimed at elucidating the regulatory mechanisms through which microR-1187 (miR-1187) participates in hepatocyte apoptosis in acute liver failure (ALF). An ALF model was induced with D-galactosamine (D-GalN) plus lipopolysaccharide (LPS) in BALB/c mice. The hepatic miRNA expression profile was detected by microarray analysis and verified by quantitative real-time PCR (qRT-PCR). The possible underlying mechanism was investigated in vitro using an embryonic murine hepatocyte cell line (BNLCL2) and miR-1187 mimic. Caspase-8 protein was detected by Western blotting and cell apoptosis was assayed by flow cytometry. Hepatic miR-1187 was down-regulated in ALF mice based on microarray data (P<0.001) and verified by qRT-PCR (P<0.01). Target scan revealed that caspase-8 was the putative target of miR-1187. In an in vitro study, miR-1187 showed the highest up-regulation in BNLCL2 cells transfected with the miR-1187 mimic at a 50 nM concentration for 12 h compared with cells transfected with the non-specific mimic (P<0.001). miR-1187 was down-regulated (P<0.01) but caspase-8 mRNA (P<0.01) as well as protein (P<0.05) were up-regulated in the BNLCL2 cells treated with D-GalN/TNF. Furthermore, overexpressed miR-1187 reduced caspase-8 expression at both the mRNA and protein levels significantly (P<0.01 and P<0.05 respectively), and significantly attenuated the apoptotic rate of BNLCL2 cells (P<0.05). We show that miR-1187 regulates hepatocyte apoptosis by targeting caspase-8. miR-1187 may serve as a potential therapeutic target for the treatment of ALF.     

Oxidative stress promotes d-GalN/LPS-induced acute hepatotoxicity by increasing glycogen synthase kinase 3β activity

Objective

Our previous studies have demonstrated that glycogen synthase kinase 3β (GSK3β) activity is increased in the progression of acute liver failure (ALF), which aggravates liver injury, while its regulatory mechanism remains elusive. This study is designated to address whether oxidative stress activates GSK3β to promote ALF.

Methods

In a murine model induced by d-galactosamine (d-GalN) (700 mg/kg) and LPS (10 μg/kg), N-acetylcysteine (300 mg/kg) or SB216763 (25 mg/kg) was used to inhibit oxidative stress or GSK3β activity, respectively. Serum alanine aminotransferase and aspartate aminotransferase levels were assessed. The parameters of oxidative stress were evaluated in liver tissue. Whether GSK3β inhibition protects hepatocytes from oxidative stress-induced cell apoptosis was investigated in vitro. Moreover, the activity of GSK3β was measured in the liver of chronic hepatitis B (CHB) patients and ALF patients.

Results

In vivo, N-acetylcysteine ameliorated the d-GalN/LPS-induced hepatotoxicity and reduced GSK3β activity; GSK3β inhibition increased hepatic superoxide dismutase activity and the glutathione content, decreased malondialdehyde production in the liver tissues; while GSK3β inhibition suppressed the JNK activation in the liver and decreased cytochrome c release from mitochondria. In vitro, GSK3β inhibition lessened hepatocytes apoptosis induced by H₂O₂ or Antimycin A, as demonstrated by decreased LDH activity, and reduced cleavage of caspase-3 expression. Furthermore, GSK3β activity in the CHB patients was increased in the phase of ALF.

Conclusions

Results indicate that GSK3β activation contributes to liver injury by participating in oxidative stress response in ALF and is, therefore, a potential therapeutic target for ALF.     

Dysregulated production of interleukin-1β upon activation of the NLRP3 inflammasome in patients with familial Mediterranean fever

Familial Mediterranean fever (FMF) is caused by mutations in pyrin, a protein expressed in innate immune cells that interacts with caspase-1 and other inflammasome components to regulate interleukin (IL)-1β maturation. Since NLRP3 inflammasome represents major source of IL-1β, we studied its protein expression and function in FMF. We isolated peripheral white blood cells (WBCs) from 20 symptoms-free FMF patients and 21 healthy individuals. Intracellular protein expression of NLRP3, caspase-1, IL-1β at baseline and after LPS/ATP sequential treatment for NLRP3 activation was assessed by immunoblotting. Secreted IL-1β was quantified by ELISA. THP-1 cells were transfected with wild-type or mutant pyrin and IL-1β secretion was measured. FMF WBCs exhibited lower NLRP3 and active caspase-1 protein expression compared to healthy individuals, and LPS/ATP treatment resulted in significantly lower intracellular IL-1β levels in FMF patients. Likewise, LPS/ATP induced caspase-1-dependent IL-1β release at significantly lower amounts in the FMF group (1182 ± 192 versus 2134 ± 245 pg/mL in controls, p = 0.004). Consistently, THP-1 cells transfected with FMF-associated M694V mutant pyrin displayed lower LPS/ATP-induced IL-1β compared with wild-type pyrin-transfected cells. FMF WBCs demonstrate reduced NLRP3-mediated IL-1β production. Additional studies are needed to define whether this finding represents a compensatory mechanism to control inflammation or is directly linked to disease pathogenesis.     

D-半乳糖胺和脂多糖介导大鼠急性肝衰竭的机理研究

目的研究D-半乳糖胺和脂多糖导致大鼠急性肝衰竭的发病机理。方法8周龄雄性SD大鼠,使用D-半乳糖胺（D-GalN,1250mg／kg）和脂多糖（LPS,200μg／kg）腹腔注射建立急性肝衰竭模型,并研究肝衰竭大鼠血清和肝匀浆的各种生化指标及肝组织的病理学改变。结果使用1250mg／kg的D-GalN和200μg／kg的LPS腹腔注射能够导致大鼠出现急性致死性的肝损伤,大鼠血清中TNF-α、IL-1β显著升高;大鼠肝组织中GSH、GR和SOD降低,MDA、NO、T—NOS和iNOS升高;与正常大鼠的肝匀浆蛋白分离图相比,肝衰竭大鼠肝匀浆蛋白的1峰升高较明显。5峰、6峰降低较明显。结论使用1250mg／kg的D—GalN和200μg／kg的LPS腹腔注射能够制备急性肝衰竭大鼠模型,其发病机理可能与D—GalN和LPS能够促进炎症细胞因子TNF—α、IL-1等大量的产生。促进机体过度的氧化反应及氧化产物的产生,导致肝组织中某些分子量范围内蛋白的增加及另外一些分子量范围内蛋白的减少有关。     

丙酮酸乙酯对LPS致急性肺损伤大鼠肺组织NF-κB p65及TNF-α和IL-lβ的影响

目的:观察丙酮酸乙酯(EP)对内毒素性急性肺损伤(ALI)大鼠肺组织核转录因子-κB(NF-κB)p65表达及肿瘤坏死因子-α(TNF-α)、白介素-1β(IL-1β)含量的影响,探讨EP可能的肺保护机制。方法:雄性SD大鼠30只随机分为三组(n均=10):正常对照组,静脉注射与其它二组等量生理盐水;LPS组,静脉注射脂多糖(LPS)5mg/kg复制大鼠ALI模型;EP+LPS组,于静脉注射LPS前1h腹腔内注射EP(40mg/kg)。所有动物于注射LPS或生理盐水后4h颈动脉放血处死,取肺组织用Westernblot测定其NF-κBp65的表达,用ELISA测定其TNF-α和IL-1β的含量。结果:与对照组相比,LPS组、EP+LPS组肺组织NF-κBp65表达增加,肺组织TNF-α和IL-lβ含量升高(P0.05);与LPS组相比,EP+LPS组肺组织NF-κBp65表达降低,肺组织TNF-α和IL-lβ含量降低(P0.05)。结论:EP通过下调大鼠LPS诱导的肺组织NF-κBp65表达,降低了TNF-α和IL-lβ的释放。EP可减轻ALI大鼠肺的炎症反应。     

MiR-24 inhibits inflammatory responses in LPS-induced acute lung injury of neonatal rats through targeting NLRP3

Inflammation plays an important role in the development of acute lung injury (ALI) in preterm infants. Despite the critical role of microRNA in inflammatory response, little is known about its function in ALI. In this study, we investigate the role of MicroRNA-24 (miR-24) in lipopolysaccharide (LPS) induced neonatal rats ALI and its potential mechanism. LPS was used to induce ALI neonatal animal model. miR-24 expression in the lung tissues of LPS-challenged neonatal rats was detected by qPCR. Proinflammatory factors, including tumor necrosis factor-alpha (TNF-α), IL-1β, IL-18 in the bronchoalveolar lavage fluid and lung tissues of LPS-challenged neonatal rats were measured by qRT-PCR and western blot, respectively. The mRNA levels of surfactant protein A (SP-A) and D (SP-D) was measured by qRT-PCR. Direct binding of miR-24 and pyrin domain-containing 3(NLRP3) were determined by dual luciferase assay. The levels of NLRP3, apoptosis-associated speck-like protein containing a C?terminal caspase recruitment domain (ASC) and caspase-1 protein expression were detected by immunohistochemistry (IHC) staining and western blot, respectively. Our data indicated that LPS-induced lung injury in neonatal rats and resulted in significant downregulated of miR-24 expression. Overexpression of miR-24 significantly reduced LPS-induced lung damage and decreased the release of proinflammatory cytokine TNF-α, IL-6, IL-1β and SP-A, SP-D expression induced by LPS. In addition, miR-24 inhibited the expression of NLRP3 by directly targeting to the CDS region of NLRP3 mRNA. Furthermore, miR-24 overexpression attenuated lung inflammation and deactivated the NLRP3/caspase-1/IL-1β pathway in LPS-challenged neonatal rats. These data show that miR-24 alleviated inflammatory responses in LPS-induced ALI via targeting NLRP3.     

Ellagic acid protects against LPS-induced acute lung injury through inhibition of nuclear factor kappa B,proinflammatory cytokines and enhancement of interleukin-10

Ellagic acid is a naturally occurring polyphenolic compound which is found in many fruits, nut galls and plant extracts. In the present study, we explored the ability of ellagic acid to modulate lipopolysaccharides (LPS) response using macrophage-mediated inflammatory conditions and acute lung injury (ALI). The data showed that ellagic acid reduced TNF-α, IL-6 and IL-1β secretions, enhance IL-10 production by LPS-stimulated RAW 264.7 macrophages in vitro. In murine ALI model, mice were treated with ellagic acid prior to LPS challenge. The data showed that ellagic acid possess a protective effect on LPS-induced ALI in mice. The underlying mechanism may be through shocking the NF-κB pathway to attenuate the nonspecific pulmonary inflammation induced by LPS administration.     

Inhibition of pro-inflammatory cytokines and inducible nitric oxide by extract of Emilia sonchifolia L. aerial parts

Emilia sonchifolia L. (Asteraceae) is used in ethnomedicine for the treatment of a wide array of inflammatory disorders. This practice has also been supported by scientific reports which showed that extracts of E. sonchifolia possess anti-inflammatory effects in rodents. However, the mechanism(s) through which the extracts produce these effects is not known. In this study, the effect of a methanol/methylene chloride extract of E. sonchifolia (ES) on the levels of IL-1β and TNF-α after an intraperitoneal lipopolysaccharide (LPS; 1?mg/kg) challenge was investigated in mice. The effect of ES on TNF-α and inducible nitric oxide (iNO) production by LPS-stimulated bone marrow-derived macrophages (BMMDM) was also investigated in vitro. BMMDM were pre-incubated for 2?h with ES (20, and 100 μg/mL) or with Pyrrolidine dithiocarbamate, PDTC (100 µM) and then activated with LPS, and then the IL-1β, TNF-α and NO production measured in the cell-free conditioned culture supernatant after 24?h of incubation. In groups of mice pre-treated with ES, the systemic levels of IL-1β and TNF-α induced by LPS were found to be significantly (p < 0.05) lower. In vitro, ES treatment caused a concentration-dependent decrease in LPS-inducible IL-1β, TNF-α, and NO production by BMDM compared to the effects of treatment of the cells with LPS alone without affecting the viability of the cells. The results of these studies suggest that treatment with ES alleviated inflammatory responses possibly through a suppression of pro-inflammatory mediators and cytokines such as IL-1β, TNF-α, and iNO.     

虫草素联合谷氨酰胺对LPS诱导的脓毒症大鼠炎症失衡及肝肺病理变化的影响

目的　研究虫草素（cordycepin,Cop）联合谷氨酰胺（glutamine,Gln）对脂多糖（lipopolysaccharides,LPS）诱导的脓毒症大鼠炎症失衡和肝肺病理变化的影响及其可能机制。 方法　将大鼠按体重随机分为5组：对照组、模型组（LPS组）、LPS+Cop组、LPS+Gln组和LPS+Cop+Gln组,腹腔注射LPS（5 mg/kg）诱导建立脓毒症大鼠模型。ELISA检测外周血中炎症因子IL-6、TNF-α、IL-1β和IL-10的含量;HE染色观察肝肺组织的病理损伤情况;TUNEL染色观察肝肺组织的细胞凋亡情况;Western blot检测肝肺组织中Caspase-3表达水平及NF-κB p65的磷酸化情况 。 结果　LPS+Cop组、LPS+Gln组和LPS+Cop+Gln组均能逆转LPS诱导的促炎因子（IL-6、TNF-α、IL-1β）的高表达和抗炎因子（IL-10）的低表达（P<0.05）,减轻病理损伤,抑制细胞凋亡（P<0.05）,降低凋亡蛋白Caspase-3高表达（P<0.05）,下调NF-κB p65的磷酸化水平（P<0.05）。 结论　在LPS诱导的脓毒症大鼠模型中,虫草素联合谷氨酰胺能有效改善其炎症失衡和肝肺病理变化。     

虫草素联合谷氨酰胺对LPS诱导的脓毒症大鼠炎症失衡及肝肺病理变化的影响

目的　研究虫草素（cordycepin,Cop）联合谷氨酰胺（glutamine,Gln）对脂多糖（lipopolysaccharides,LPS）诱导的脓毒症大鼠炎症失衡和肝肺病理变化的影响及其可能机制。 方法　将大鼠按体重随机分为5组：对照组、模型组（LPS组）、LPS+Cop组、LPS+Gln组和LPS+Cop+Gln组,腹腔注射LPS（5 mg/kg）诱导建立脓毒症大鼠模型。ELISA检测外周血中炎症因子IL-6、TNF-α、IL-1β和IL-10的含量;HE染色观察肝肺组织的病理损伤情况;TUNEL染色观察肝肺组织的细胞凋亡情况;Western blot检测肝肺组织中Caspase-3表达水平及NF-κB p65的磷酸化情况 。 结果　LPS+Cop组、LPS+Gln组和LPS+Cop+Gln组均能逆转LPS诱导的促炎因子（IL-6、TNF-α、IL-1β）的高表达和抗炎因子（IL-10）的低表达（P<0.05）,减轻病理损伤,抑制细胞凋亡（P<0.05）,降低凋亡蛋白Caspase-3高表达（P<0.05）,下调NF-κB p65的磷酸化水平（P<0.05）。 结论　在LPS诱导的脓毒症大鼠模型中,虫草素联合谷氨酰胺能有效改善其炎症失衡和肝肺病理变化。     

对脂多糖攻击小鼠血及肝IL-6和TNF-α含量的影响

目的：研究重组人白细胞介素-10（rhIL-10）对脂多糖（LPS）诱导的血、肝IL-6和TNF-α炎症介质含量变化的影响。 方法： 小鼠腹腔注射LPS建立炎症模型，并同时静脉注射不同剂量的rhIL-10，ELISA法测定12 h、24 h、48 h和72 h肝组织和血清IL-6和TNF-α的含量。 结果： 注射rhIL-10后12 h，肝组织和血清IL-6、TNF-α水平开始下调，24-48 h抑制作用最明显（P＜0.05），72 h后抑制作用减弱，且呈剂量效应关系。 结论： 利用基因工程技术制备的重组人白细胞介素10（rhIL-10）显著下调肝组织和血清IL-6和TNF-α的水平。     

Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines

Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis.     

地塞米松对大鼠内毒素急性肺损伤肺泡灌洗液中白细胞介素-1β和肿瘤坏死因子-α含量的影响

目的 探讨地塞米松对大鼠内毒素（LPS）急性肺损伤（ALI）肺泡灌洗液中白细胞介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）含量的影响.方法 将48只雄性SD大鼠随机分为正常对照组、急性肺损伤组（内毒素ALI模型组）、地塞米松干预组,每组16只.每组大鼠依据不同的观察时间点（以大鼠气管内滴注LPS的时刻为起始时刻后的1、2、4、8 h 4个时间点）分为4个亚组（n=4）.给予正常对照组气管内滴注0.9%氯化钠溶液 0.3 mL,10 min后股静脉注射0.9%氯化钠溶液 1 mL;急性肺损伤组气管内滴注LPS 0.2 mg/kg（溶于0.3 mL 0.9%氯化钠溶液）,10 min后股静脉注射0.9%氯化钠溶液 1 mL;地塞米松干预组气管内滴注LPS 0.2 mg/kg,10 min后股静脉注射地塞米松注射液3 mg/kg（溶于1 mL 0.9%氯化钠溶液）.各组于1、2、 4、8 h 4个时间点于心脏抽血检测动脉血氧分压（PaO2）;取肺组织进行肺湿/干质量比值（W/D）测定,并采用苏木精-伊红（HE）染色观察肺组织形态学变化;用酶联免疫吸附测定（ELISA）法检测肺泡灌洗液（BALF）中IL-1β和TNF-α的含量.结果 给予气管内滴注LPS后于1、2、4、8 h观察大鼠动脉血PaO2,急性肺损伤组、地塞米松干预组较正常对照组显著降低,两组PaO2均在4 h时达最低点,各时间点动脉血PaO2对比,地塞米松干预组均显著高于急性肺损伤组,差异均有统计学意义（P〈0.05）.在LPS致炎后1、2、4、8 h 4个时间点急性肺损伤组、地塞米松干预组各时间点W/D比值均较正常对照组显著增加,两组间比较地塞米松干预组较急性肺损伤组降低,差异具有统计学意义（P〈0.05）.病理形态学观察可见急性肺损伤组与地塞米松干预组均出现肺水肿、出血、炎性细胞浸润,而地塞米松干预组肺损伤程度较急性肺损伤组减轻.ELISA试验结果显示急性肺损伤组在气管内滴入LPS 1 h后BALF中IL-1β、TNF-α含量迅速升高,4 h时达峰值,地塞米松干预后IL-1β、TNF-α表达在相同时间点均较模型组显著降低,差异具有统计学意义（P〈0.05）;而正常对照组BALF中IL-1β、TNF-α在不同时间点无明显变化.结论 地塞米松可通过抑制内毒素性大鼠ALI肺组织中IL-1β、TNF-α的表达,改善呼吸氧合功能,减轻肺损伤.     

miR-133靶向NLRP3对小鼠Kupffer细胞炎性活化的影响

目的:探究微小RNA-133(miR-133)靶向核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)对小鼠库普弗(Kupffer)细胞(KCs)炎症活化的影响。方法:从小鼠肝脏中分离KCs并鉴定。鉴定成功后用1 mg/L脂多糖(LPS)诱导KCs,并分别转染miR-133 inhibitor和miR-133 mimic。采用RT-qPCR检测细胞中miR-133和NLRP3的mRNA水平;ELISA法检测细胞培养液中白细胞介素1β(IL-1β)和肿瘤坏死因子α(TNF-α)水平;Western blot实验检测细胞中NLRP3、含胱天蛋白酶募集结构域的凋亡相关斑点样蛋白(ASC)和胱天蛋白酶1(caspase-1)蛋白水平;TargetScan查找NLRP3 mRNA的3’UTR与miR-133的结合位点,并经双萤光素酶报告基因检测试剂盒鉴定。结果:72 h时KCs体积较24 h时大,边界清晰,形态基本稳定;碳素墨水实验观察到细胞中有大量黑色颗粒,证明该细胞有较强的吞噬能力,为KCs。1 mg/L LPS诱导后KCs中miR-133水平降低,NLRP3 mRNA和蛋白、caspase-1蛋白及细胞培养液中IL-1β和TNF-α水平升高(P<0.05)。转染miR-133 inhibitor后细胞中miR-133水平降低,细胞中NLRP3mRNA和蛋白、caspase-1蛋白及细胞培养液中IL-1β和TNF-α水平升高(P<0.05);转染miR-133 mimic后细胞中miR-133水平升高,细胞中NLRP3 mRNA和蛋白、caspase-1蛋白及细胞培养液中IL-1β和TNF-α水平降低(P<0.05)。TargetScan分析显示,NLRP3 mRNA的3’UTR含有miR-133序列保守碱基。转染miR-133 mimic的细胞萤光素酶相对活性下降(P<0.05)。结论:miR-133可通过靶向NLRP3减轻小鼠KCs炎症,实现对KCs的保护。     

Cepharanthine, an Alkaloid from Stephania cepharantha Hayata, Inhibits the Inflammatory Response in the RAW264.7 Cell and Mouse Models

The aim of this study was to investigate the protective effects of cepharanthine (CEP) on inflammation in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in vitro and a LPS-induced lung injury model in vivo. RAW264.7 cells were treated with various concentrations of CEP for 1 h followed by incubation with or without 1 μg/ml LPS for 18 h. TNF-α, IL-6, and IL-1β in the supernatants were measured by ELISA. Nuclear factor-κB (NF-κB) and mitogen-activated protein kinase pathways were analyzed by Western blot. Mice were randomly divided into control group, LPS group, CEP?+?LPS group, and dexamethasone?+?LPS group. A male BALB/c mouse model of acute lung injury was induced by LPS. Bronchoalveolar lavage fluid was collected for inflammatory cell count and cytokine assays. Histopathologic examination was performed on mice that were not subjected to bronchoalveolar lavage fluid collection. CEP dose-dependently inhibited the release of TNF-α, IL-6, and IL-1β in LPS-stimulated RAW264.7 cells. Significantly, CEP dose-dependently suppressed NF-κB activation, IκBα degradation, and phosphorylation of ERK, JNK, and p38 induced by LPS. In vivo, it was also observed that CEP attenuated lung histopathologic changes and down-regulated the level of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, in the mouse acute lung injury model. These results suggest that CEP potentially decreases inflammation in vitro and in vivo and might be a therapeutic agent against inflammatory diseases.     

不同原因致大鼠急性肺损伤炎性因子水平及地塞米松干预效果的差异

目的： 探讨经静脉注射脂多糖（LPS）、向气管内滴入盐酸（HCl）致两种急性肺损伤大鼠炎症反应及其对激素反应的差异。 方法： SD大鼠96只，随机分为6组（每组16只）： NS组、 LPS组、 HCl组、NS+Dex组、LPS+Dex组、HCl+Dex组，每个组又分为两个亚组：灌洗组和非灌洗组。检测各组BALF中细胞总数、中性粒细胞百分比、巨噬细胞百分比、淋巴细胞百分比、蛋白含量和肺湿/干重比（W/D），比较各组血清和BALF中致炎因子TNF-α、IL-1β和抗炎因子IL-4、IL-10的水平。 结果： （1） LPS组、HCl组BALF中细胞总数、中性粒细胞百分比、蛋白含量和肺W/D均高于NS组(P<0.05)。LPS+Dex组巨噬细胞百分比高于LPS组(P<0.05)。（2）LPS组和HCl组血清和BALF中TNF-α、IL-4、IL-10水平均高于NS组的相应水平(P<0.01)。各组血清中IL-1β的含量均未测出。LPS+Dex组BALF中TNF-α、IL-1β含量低于LPS组的相应水平(P<0.05)，而IL-10高于LPS组的相应水平(P<0.01)。 结论： 两个模型组在炎症因子水平、蛋白渗漏存在一定的差异，糖皮质激素对LPS所致的ALI有拮抗作用，但对HCl所致ALI无作用。