TGF-β与转录因子在肝纤维化中的相互作用

肝纤维化的形成是由于肝脏持续性损伤以及细胞外基质合成和降解失衡所引起的。转化生长因子-β(Transforming growth factor-β,TGF-β)是肝纤维化形成中的关键细胞因子,在肝纤维化发生、发展过程中起着至关重要的作用。一些与TGF-β相关的转录因子如AP1、STAT3及Foxo3a等也参与肝纤维化的调控过程。现就在肝纤维化中TGF-β与转录因子AP1、STAT3和Foxo3a的相互作用作一综述。     

细胞因子在银屑病中的作用及中医药干预

银屑病是一种由T淋巴细胞(T lymphocyte,T)介导的免疫性皮肤疾病，以角质形成细胞异常增殖和炎症细胞浸润为特征。银屑病的发病机制十分复杂，各型细胞因子均参与银屑病的发病过程。细胞因子中以白介素(interleukin)、肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、γ-干扰素(interferon-γ,IFN-γ)作用较为重要。各因子相互影响，形成网络状细胞因子通路。其中，肿瘤坏死因子、IFN-γ具有起始炎性反应的作用，通过炎性反应，增加作为银屑病发生发展的核心因子白介素17(interleukin-17,IL-17)的表达，同时上调促炎因子[TNF-α、IFN-γ、白介素-23(interleukin-23,IL-23)]、生长因子[(血管内皮生长因子(vascular endothelial growth factor,VEGF)、转化生长因子-β(transforming growth factor-β,TGF-β)]表达，引起细胞增殖及分化异常、炎症因子水平升高等病理性改变，共同构成银屑病患者体内炎性微环境。70%以上的患者会在此通路...     

内毒素和细胞因子在酒精性肝病中的作用

酒精性肝病发病机制比较复杂,其中内毒素、细胞因子导致的肝细胞凋亡发挥了关键作用.酒精致肠道粘膜通透性增加,引起高内毒素血症,内毒素作用于kupffer细胞产生过量细胞因子如肿瘤坏死因子a(TNF-a)等,TNF-a与肝细胞表面的相应受体结合,诱导肝细胞凋亡,引起肝细胞损害.     

TGF-β/Smads信号通路与胃癌关系研究进展

转化生长因子-β(transforming growth factor-β,TGF-β)是一种具有多种生物学活性的细胞因子,参与调节细胞的增殖、分化、凋亡和胚胎发育等多种生命活动。TGF-β在肿瘤发生、发展中具有双重作用:在肿瘤发生的起始阶段TGF-β抑制肿瘤生长,而在进展期TGF-β起着促进肿瘤浸润转移的作用。研究表明TGF-β/Smads信号通路中任何一个环节出现异常都可导致信号转导的紊乱,从而导致胃癌的发生与发展。     

白细胞介素-6在酒精性肝病中的作用

酒精性肝病（alcoholic liver disease,ALD）是由于长期过量饮酒导致肝的内部组织发生炎症损伤的慢性肝病。乙醇及其衍生物在代谢过程中直接或间接诱导引起的肝炎症反应可能是ALD发病的重要机制。然而,该过程内在的细胞分子机制尚不明确。最新研究发现,白细胞介素-6（interleukin-6,IL-6）对乙醇介导的肝细胞炎症反应具有双重作用,既参与了酒精损伤的炎症驱动过程,激活细胞凋亡的信号通路来刺激巨噬细胞和淋巴细胞合成急性反应蛋白加剧炎症反应,又能引起肝细胞再生,上调抗炎性细胞因子水平,发挥抗炎症功能来改善肝损伤程度。而运动应激可造成肌源性IL-6暂时性显著增加,改变肝的氧化-炎症状态,将机体保持在长期抗炎症的适应性状态中,并防治肝细胞炎症损伤。本文在加深对酒精性肝病炎症病理机制理解的同时,综述有关酒精性肝细胞炎症相关因子变化及IL-6调控途径。考虑临床利用IL-6联合炎性因子途径的靶向治疗,将有望成为一种可行性新颖的疗法,有利于实验室筛选炎症相关酒精性肝病干预药物,为酒精性肝疾病的预防与治疗提供新的靶点与思路。     

抵抗素对NAFLD肝纤维化的影响及可能的体内外机制

应用高脂饮食饲养Wistar大鼠建立非酒精性脂肪肝病(non-alcoholic fatty liver disease,NAFLD)肝纤维化体内模型,选用重组抵抗素作用于肝星状细胞(hepatic stellate cell-t6,HSC-T6)建立体外模型。观察肝组织纤维化的情况;检测体内体外Ⅲ型前胶原(PCⅢ)、透明质酸(HA)、Ⅳ型胶原(CIV)、层黏蛋白(LN)水平;检测肝组织抵抗素mRNA和蛋白的表达水平;检测HSC-T6中转化生长因子β-1(TGF-β1)mRNA及肿瘤坏死因子α(TNF-α)mRNA表达水平。结果显示,随着高脂喂养时间的延长,大鼠肝组织抵抗表达逐渐增加且纤维化程度逐渐加重;随着抵抗素浓度的增加,HSC-T6上清中纤维化指标升高,细胞中TGF-β1mRNA及TNF-αmRNA表达增加。与对照组比较,各指标差异均有显著性(P<0.05或0.01)。上述结果显示抵抗素通过TNF-α、TGF-β1诱导NAFLD肝纤维的发生和发展。     

细胞因子和脂肪细胞因子在非酒精性脂肪肝中研究新进展

非酒精性脂肪性肝病(Non-alcoholic fatty liver disease,NAFLD)是遗传-环境-代谢应激相关因素所致的以肝细胞脂肪变性为主的临床病理综合征,其发生、发展均与细胞因子及脂肪细胞因子密切相关.本文回顾了肿瘤坏死因子-α(Tumor necrosis factor-α,INF-α)、白介素-6(interleukin-6,IL-6)、脂联素等经典因子与NAFLD的关系研究新进展,并介绍了视黄醇结合蛋白4(retinol binding protein4,RBP4)、apelin、visfatin等新脂肪细胞因子在NAFLD中的作用.     

儿童过敏性紫癜血清IL-21、TGF-β1、TNF-α、IgA1的变化与紫癜性肾炎发生的相关性研究

探讨儿童过敏性紫癜(henoch-schonlein purpura,HSP)患儿血清中白细胞介素-21(Interleukin-21,IL-21)、肿瘤坏死因子-α(Tumor necrosis factor-α,TNF-α)、免疫球蛋白A1(Immunoglobulin A1,Ig A1)和转化生长因子-β1(Transforming growth factor-β1,TGF-β1)的含量变化,并研究这些因子与HSP发展为紫癜性肾炎(Henoch-SchOnlein purpura nephritis,HSPN)的相关性。选取我院2015年1月~2016年1月确诊的急性期过敏性紫癜患儿共72例作为本研究的实验对象。根据HSP患儿病症是否累积到肾脏,再分为普通HSP组(39例)和HSPN组(33例),另对照组为30例同期健康体检儿童。通过酶联免疫吸附(ELISA法)对检测血清中白细胞介素-21、转化生长因子-β1以及肿瘤坏死因子-α含量,采用全自动化生化分析仪检测血清免疫球蛋白A1的含量,同时研究此类因子与紫癜性肾炎是否存在一定的相关性。3组结果对照,HSPN组和HSP组转化生长因子-β1、肿瘤坏死因子-α和免疫球蛋白A1水平均高于对照组,差异具有显著意义(p0.05);HSPN组IL-21、TGF-β1、TNF-α和Ig A1水平均高于HSP组,差异具有显著意义p0.05)。HSP患儿血浆TGF-β1水平与TNF-α呈正相关(r=0.478,p0.05)。IL-21、TGF-β1、TNF-α和Ig A1可能参与HSP和HSPN的发病过程,HSP患儿TNF-α水平的升高可能和TGF-β1水平改变有关,了解这些因子在HSP发病和发展过程的作用可以更好地指导临床对过敏性紫癜肾脏合并症的发生率和预后判断。     

Apelin 通过调节ROS 水平抑制TNF-α 诱导的HepG2 细胞凋亡

目的:探讨apelin在肿瘤坏死因子(tumor necrosis factor-α,TNF-α)诱导的肝细胞凋亡中的作用及可能机制。方法:PCR检测HepG2细胞和原代小鼠肝细胞中APJ受体的表达;采用Hoechst 33342染色检测TNF-α诱导的HepG2细胞凋亡;用活性氧(ROS)检测试剂盒结合流式细胞术测定细胞内ROS水平;通过Western blot检测信号分子JNK的磷酸化水平;比较给予apelin处理对上述指标的影响。结果:HepG2细胞和原代小鼠肝细胞均表达APJ受体;apelin可抑制TNF-α导致的细胞内ROS生成增多和JNK磷酸化水平升高并减少TNF-α诱导的HepG2细胞凋亡。结论:Apelin可能通过拮抗TNF-α诱导的细胞内ROS水平升高,使JNK信号失活,从而抑制HepG2细胞凋亡。     

胰高血糖素样肽-1及其类似物抗胰岛β细胞凋亡作用及机制的研究进展

胰高血糖素样肽-1(glucagon-like peptide-1,GLP-1)及其类似物通过提高增殖、减少凋亡,从而有效地保护β细胞数量及功能。该文综述了GLP-1及其类似物能够对抗引起β细胞凋亡的多种有害因素——如细胞因子(IL-1β、TNF-α和IFN-γ等)、高游离脂肪酸血症、高血糖或低血糖等——进而降低胰岛β细胞的凋亡率,并探讨了相关的作用机制。     

Lipidic last breath of life in patients with alcoholic liver disease

Alcoholic liver disease (ALD) begins with the accumulation of lipid droplets in the liver. Lipids which accumulate in the liver can stimulate inflammation, and the fatty acid derivatives, hydroxyeicosatetraenoic acids (HETEs) and hydroxyoctadecadienoic acids (HODEs), may play an important role in this process. We evaluated the concentrations of linoleic and arachidonic acid derivatives in the plasma of patients with ALD, non-alcoholic fatty liver disease (NAFLD) and healthy individuals. The groups consisted of 173 subjects: 63 patients with ALD, 90 with NAFLD and 20 healthy volunteers. Plasma 12-, 15-, and 5-HETE as well as 9- and 13-HODE were assessed using HPLC and isoprostane 8-epi-PGF 2α III was evaluated with an ELISA. In addition the mRNA expression of lipoxygenases (5-LOX, 15-LOX-1, 15-LOX-2) in the liver samples of patients with ALD cirrhosis was measured. A significant difference between the plasma concentrations of the analyzed derivatives was found when divided according to gender. The most significant differences were found between healthy individuals and ALD patients, as well as ALD and NAFLD individuals regardless of gender. The increased plasma HODEs and HETEs concentrations were in line with the increase in 5- and 15-LOX-1 and 15-LOX-2 mRNA in liver samples from ALD cirrhosis patients. LOXs expression and peroxidation of polyunsaturated fatty acids by free radical-propagated chemical oxidation may be contributing factors in liver necroinflammatory injury in ALD.     

Noncoding RNAs in alcoholic liver disease

Alcoholic liver disease (ALD) is a complex process with high morbitity and can cause liver dysfunction, which contains a wide spectrum of hepatic lesions, including steatohepatitis, fibrosis, cirrhosis, and eventually hepatocellular carcinoma. To date, the molecular mechanisms for ALD have not been fully explored and an effective therapy is still missing. Overwhelming evidence shows dysregulation of noncoding RNAs (ncRNAs), particularly microRNAs (miRNAs), is correlated with etiopathogenesis and progress of ALD including hepatocyte damage, disrupted lipid metabolism, aggressive inflammatory responses, oxidative stress, programmed cell death, fibrosis, and epigenetic changes induced by alcohol. For example, circulating miRNA-122 is a marker of hepatocyte damage, and miRNA-155 is a potential marker of inflammation, indicating their diagnosis therapeutic potential in ALD. In addition, roles for long noncoding RNAs (lncRNAs) and circular RNAs in ALD are being uncovered. Further, circulating ncRNAs and exosome-derived ncRNAs have attracted more attention lately, suggesting a role in the prevention and treatment of ALD. This review covers the roles of ncRNAs in ALD, and the potential uses as markers for diagnosis and therapeutic options.     

Free radical mechanisms in immune reactions associated with alcoholic liver disease.

Immune reactions toward the liver have been implicated in the pathogenesis of alcoholic liver disease (ALD), however the antigens involved are still poorly characterized. The contribution of free radical mechanisms to the immune reactions associated with ALD first emerged from the observation that the binding of hydroxyethyl free radicals (HER) to hepatic proteins, including cytochrome P4502E1 (CYP2E1), stimulates the production of specific antibodies in both alcohol-fed rats and alcoholic patients. We have subsequently observed that ALD patients have increased titers of antibodies directed against protein adducts with different lipid peroxidation products and antigens derived from the combination of malonildialdehyde and acetaldehyde. Free radical mechanisms can also contribute in promoting the autoimmune reactions often associated with ALD. Indeed, we have observed that antiphospholipid antibodies present in more than 50% of ALD patients recognize oxidized cardiolipin complexed with beta2-glycoprotein 1. Furthermore, a strict association between anti-HER IgG and the development of autoantibodies against CYP2E1 indicates that CYP2E1 modification by HER might promote anti-CYP2E1 autoreactivity in subjects with alcoholic cirrhosis. Altogether, these observations suggest the importance of ethanol-induced oxidative stress in stimulating immune reactions towards both liver allo-and self-antigens.     

The functional role of microRNAs in alcoholic liver injury

The function of microRNAs (miRNAs) during alcoholic liver disease (ALD) has recently become of great interest in biological research. Studies have shown that ALD associated miRNAs play a crucial role in the regulation of liver‐inflammatory agents such as tumour necrosis factor‐alpha (TNF‐α), one of the key inflammatory agents responsible for liver fibrosis (liver scarring) and the critical contributor of alcoholic liver disease. Lipopolysaccharide (LPS), a component of the cell wall of gram‐negative bacteria, is responsible for TNF‐α release by Kupffer cells. miRNAs are the critical mediators of LPS signalling in Kupffer cells, hepatocytes and hepatic stellate cells. Certain miRNAs, in particular miR‐155 and miR‐21, show a positive correlation in up‐regulation of LPS signalling when they are exposed to ethanol. ALD is related to enhanced gut permeability that allows the levels of LPS to increase, leads to increased secretion of TNF‐α by the Kupffer cells and subsequently promotes alcoholic liver injury through specific miRNAs. Meanwhile, two of the most frequently dysregulated miRNAs in steatohepatitis, miR‐122 and miR‐34a are the critical mediators in ethanol/LPS activated survival signalling during ALD. In this review, we summarize recent findings regarding the experimental and clinical aspects of functions of specific microRNAs, focusing mainly on inflammation and cell survival after ethanol/LPS treatment, and advances on the role of circulating miRNAs in human alcoholic disorders.     

Genetic variants of TNFα, IL10, IL1β, CTLA4 and TGFβ1 modulate the indices of alcohol-induced liver injury in East Indian population

Alcohol induced liver disease or alcoholic liver disease (ALD), a complex trait, encompasses a gamut of pathophysiological alterations in the liver due to continuous exposure to a toxic amount of alcohol (more than 80g per day). Of all chronic heavy drinkers, only 15-20% develops hepatitis or cirrhosis concomitantly or in succession. Several studies revealed that inter-individual as well as inter-ethnic genetic variation is one of the major factors that predispose to ALD. The role of genetic factors in ALD has long been sought for in ethnically distinct population groups. ALD is fast emerging as an important cause of chronic liver disease in India; even in populations such as "Bengalis" who were "culturally immune" earlier. While the genetic involvement in the pathogenesis of ALD is being sought for in different races, the complex pathophysiology of ALD as well as the knowledge of population level diversity of the relevant alcohol metabolizing and inflammatory pathways mandates the need for well designed studies of genetic factors in ethnically distinct population groups. An array of cytokines plays a critical role as mediators of injury, inflammation, fibrosis and cirrhosis in ALD. We, therefore, studied the association of polymorphisms in five relevant cytokine genes with "clinically significant" ALD in an ethnic "Bengali" population in Eastern India. Compared with "alcoholic" controls without liver disease (n=110), TNFα -238AA genotype, IL1β -511CC genotype, TGFβ1 -509CC genotype and IL10 -592AA genotype were significantly overrepresented in ALD patients (n=181; OR=2.4 and 95% CI 1.2-5.5, P(genotype)=0.042, P(allelic)=0.008; OR=2.7 and 95% CI 1.2-5.9, P(genotype)=0.018, P(allelic)=0.023; OR=4.7 and 95% CI 1.7-13.1, P(genotype)=0.003, P(allelic)=0.014; and OR=2.2 and 95% CI 1.1-4.8, P(genotype)=0.04, P(allelic)=0.039 respectively). Moreover a cumulative genetic risk analysis revealed a significant trend for developing ALD with an increase in the number of risk alleles on IL10 and TGFβ1 loci among alcoholics. The risk genotype of IL1β and TGFβ1 also influences the total bilirubin, albumin and alanine aminotransferase levels among alcoholic "Bengalis". The present study is the first case-control study from Eastern India that comprehensively identified polymorphic markers in TNFα, IL10, IL1β and TGFβ1 genes to be associated with ALD in the Bengali population, accentuating the significance of genetic factors in clinical expressions of ALD.     

樟芝发酵滤液干膏对酒精性肝病小鼠的保护作用

研究樟芝发酵滤液干膏（剂量为350,700和1 050mg/kg）对慢性酒精喂养加急性酒精灌胃的酒精性肝病小鼠模型的保肝作用。结果表明,樟芝发酵滤液干膏能显著降低小鼠血清谷丙转氨酶（ALT）和谷草转氨酶（AST）活力;降低小鼠血清游离脂肪酸（NEFA）、总胆固醇（TC）和甘油三酯（TG）的水平;H&E染色和油红O染色显示樟芝发酵滤液干膏可以改善肝组织脂质堆积。研究结果表明樟芝发酵滤液干膏对酒精性肝病有改善作用,可能是通过保护肝细胞、肝组织及整体肝脏降低了肝功酶的释放,减少肝脏脂质堆积来对酒精性肝病起到保护作用,可用于相关功能性食品及药品的开发。     

Plasma levels of soluble ST2, but not IL‐33, correlate with the severity of alcoholic liver disease

Alcoholic liver disease (ALD) is a complication that is a burden on global health and economy. Interleukin‐33 (IL‐33) is a newly identified member of the IL‐1 cytokine family and is released as an “alarmin” during inflammation. Soluble suppression of tumourigenicity 2 (sST2), an IL‐33 decoy receptor, has been reported as a new biomarker for the severity of systemic and highly inflammatory diseases. Here, we found the levels of plasma sST2, increased with the disease severity from mild to severe ALD. Importantly, the plasma sST2 levels in ALD patients not only correlated with scores for prognostic models (Maddrey's discriminant function, model for end‐stage liver disease and Child‐Pugh scores) and indexes for liver function (total bilirubin, international normalized ratio, albumin, and cholinesterase) but also correlated with neutrophil‐associated factors as well as some proinflammatory cytokines. In vitro, lipopolysaccharide‐activated monocytes down‐regulated transmembrane ST2 receptor but up‐regulated sST2 mRNA and protein expression and produced higher levels of tumour necrosis factor‐α (TNF‐α). By contrast, monocytes pretreated with recombinant sST2 showed decreased TNF‐α production. In addition, although plasma IL‐33 levels were comparable between healthy controls and ALD patients, we found the IL‐33 expression in liver tissues from ALD patients was down‐regulated at both RNA and protein levels. Immunohistochemical staining further showed that the decreased of IL‐33‐positive cells were mainly located in liver lobule area. These results suggested that sST2, but not IL‐33, is closely related to the severity of ALD. Consequently, sST2 could be used as a potential biomarker for predicting the prognosis of ALD.     

Depdc5 deficiency exacerbates alcohol-induced hepatic steatosis via suppression of PPARα pathway

Alcohol-related liver disease (ALD), a condition caused by alcohol overconsumption, occurs in three stages of liver injury including steatosis, hepatitis, and cirrhosis. DEP domain-containing protein 5 (DEPDC5), a component of GAP activities towards Rags 1 (GATOR1) complex, is a repressor of amino acid-sensing branch of the mammalian target of rapamycin complex 1 (mTORC1) pathway. In the current study, we found that aberrant activation of mTORC1 was likely attributed to the reduction of DEPDC5 in the livers of ethanol-fed mice or ALD patients. To further define the in vivo role of DEPDC5 in ALD development, we generated Depdc5 hepatocyte-specific knockout mouse model (Depdc5-LKO) in which mTORC1 pathway was constitutively activated through loss of the inhibitory effect of GATOR1. Hepatic Depdc5 ablation leads to mild hepatomegaly and liver injury and protects against diet-induced liver steatosis. In contrast, ethanol-fed Depdc5-LKO mice developed severe hepatic steatosis and inflammation. Pharmacological intervention with Torin 1 suppressed mTORC1 activity and remarkably ameliorated ethanol-induced hepatic steatosis and inflammation in both control and Depdc5-LKO mice. The pathological effect of sustained mTORC1 activity in ALD may be attributed to the suppression of peroxisome proliferator activated receptor α (PPARα), the master regulator of fatty acid oxidation in hepatocytes, because fenofibrate (PPARα agonist) treatment reverses ethanol-induced liver steatosis and inflammation in Depdc5-LKO mice. These findings provide novel insights into the in vivo role of hepatic DEPDC5 in the development of ALD.Subject terms: Alcoholic liver disease, Experimental models of disease