Histone deacetylase inhibitor suberoylanilide hydroxamic acid alleviates liver fibrosis by suppressing the transforming growth factor-β1 signal pathway

Background: Histone deacetylases(HDACs) inhibitors are new anti-fibrotic drugs that inhibit the activity of hepatic stellate cells. The present study focused on the anti-fibrotic function of HDAC inhibitor suberoylanilide hydroxamic acid(SAHA) by suppressing transforming growth factor-β1(TGF-β1) signaling. Methods: Male Sprague-Dawley rats were used to induce liver fibrosis with carbon tetrachloride(CCl 4) and LX2 cell(human hepatic stellate cell line) was stimulated by TGF-β1. Both animals and cells were treated with SAHA. The Smad7 and connective tissue growth factor(CTGF) mRNA levels were detected by real-time polymerase chain reaction(PCR). Western blotting was used to examine the protein levels of CTGF, Histone H3(H3), Smad7, Smad2/3, Acetyl-Histone H3(AH3), HDAC2, α-smooth muscle actin( α-SMA), HDAC6, p-Smad2/3 and HDAC8. In addition, the TGF-β1 and liver enzyme levels from rat serum were detected. Histopathological changes were examined by hematoxylin and eosin(HE), Sirius red and Masson trichrome staining. The α-SMA expression was detected by immumohistochemical staining. Results: Compared with control group, the TGF-β1 and liver enzyme levels from rat serum, together with the mRNA levels of CTGF and protein levels of CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were elevated in fibrotic rats( P 0.01). But the Smad7 mRNA and AH3 protein levels were notably suppressed in the fibrotic rats( P 0.01). Pathological examination showed the typical changes of liver fibrosis in the fibrotic rats. After the treatment with SAHA, the levels of liver enzymes, TGF-β1, CTGF, HDAC2, α-SMA, HDAC6, p-Smad2/3 and HDAC8 were reduced( P 0.01) and Smad7 and AH3 protein contents were elevated in liver fibrotic rats( P 0.01). Moreover, immumohistochemistry showed that SAHA significantly suppressed the α-SMA protein content in fibrotic liver( P 0.01). Conclusion: The HDAC inhibitor SAHA alleviated liver fibrosis by suppressing the TGF-β1 signaling.     

Testicular orphan receptor 4 induced hepatic stellate cells activation via the regulation of TGF-β receptor Ⅰ/Smad2/3 signaling pathway

Introduction and ObjectivesLiver fibrosis is a common pathological change in many chronic liver diseases. Activation of hepatic stellate cells (HSCs) is the core event in liver fibrosis. This study aimed to investigate the role of testicular orphan receptor 4 (TR4) in the activation of HSCs.Materials and MethodsIn vivo, bile duct ligation (BDL)-induced rat liver fibrosis model was established, and the expressions of TR4 and α-smooth muscle actin (α-SMA) in liver tissues were detected. In vitro, TR4 knockdown and overexpression in JS-1 cells using lentiviral vectors were constructed, and the expressions of TR4, α-SMA, Col-I, and TGF-β1/smads and retinoid X receptor (RXR) pathway-related genes were detected.ResultsTR4 was highly expressed in BDL-induced fibrotic liver, accompanied by increased expression of α-SMA. Knockdown of TR4 significantly inhibited the expressions of α-SMA, Col-I, p-TβRI, and p-Smad2/3, and up-regulated the expression of RXRα in HSCs in vitro. In contrast, TR4 overexpression significantly increased the expressions of α-SMA, Col-I, p-TβRI, and p-Smad2/3, and inhibited the expression of RXRα.ConclusionsTR4 may promote the activation of HSCs by up-regulating TβR I/Smad2/3 signaling pathway and down-regulating RXRα signaling, thereby promoting the progression of liver fibrosis. Our findings may provide a new therapeutic target against hepatic fibrosis.     

Curcumin prevents human aortic smooth muscle cells migration by inhibiting of MMP-9 expression

Background and aimThe migration of vascular smooth muscle cells from the tunica media to the subendothelial region is a key event in the development of atherosclerosis. Curcumin, which is consumed daily by millions of people, is a polyphenol derived from the plant Curcuma longa. In this study, we investigated the effects of curcumin on tumor necrosis factor-α (TNF-α)-induced cell migration, the formation of intracellular reactive oxygen species (ROS), the translocation of nuclear factor-κB (NFκB) and the activation and expression of MMP-9 in human aortic smooth muscle cells (HASMCs).Methods and resultsThe Matrigel migration assay showed that curcumin (10 and 20 μmol/l) effectively inhibited TNF-α-induced migration of HASMCs as compared with the control group. To explain this inhibitory effect, MMP-9 was assayed by gelatin zymography and Western blot. The results indicated that curcumin inhibited MMP-9 activity and expression. Furthermore, the production of ROS and the nuclear translocation of NF-κB p50 and p65 induced by TNF-α were dose-dependently suppressed by curcumin pretreatment.ConclusionThese results indicate that curcumin has anti-inflammatory properties and may prevent the migration of HASMCs by suppressing MMP-9 expression through down-regulation of NF-κB.     

Butein inhibits ethanol-induced activation of liver stellate cells through TGF-β, NFκB, p38, and JNK signaling pathways and inhibition of oxidative stress

Background

Butein has been reported to prevent and partly reverse liver fibrosis in vivo; however, the mechanisms of its action are poorly understood. We, therefore, aimed to determine the antifibrotic potential of butein.

Methods

We assessed the influence of the incubation of hepatic stellate cells (HSCs) and hepatoma cells (HepG2) with butein on sensitivity to ethanol- or acetaldehyde-induced toxicity; the production of reactive oxygen species (ROS); the expression of markers of HSC activation, including smooth muscle α-actin (α-SMA) and procollagen I; and the production of transforming growth factor-β1 (TGF-β1), metalloproteinases-2 and -13 (MMP-2and MMP-13), and tissue inhibitors of metalloproteinases (TIMPs). The influence of butein on intracellular signals in HSCs; i.e., nuclear factor-κB (NFκB), c-Jun N-terminal kinase (JNK), and p38 mitogen-activated protein kinase (p38 MAPK) induced by ethanol was estimated.

Results

Butein protected HSCs and HepG2 cells against ethanol toxicity by the inhibition of ethanol- or acetaldehyde-induced production of ROS when cells were incubated separately or in co-cultures; butein also inhibited HSC activation measured as the production of α-SMA and procollagen I. As well, butein downregulated ethanol- or acetaldehyde-induced HSC migration and the production of TGF-β, TIMP-1, and TIMP-2; decreased the activity of MMP-2; and increased the activity of MMP-13. In ethanol-induced HSCs, butein inhibited the activation of the p38 MAPK and JNK transduction pathways as well as significantly inhibiting the phosphorylation of NF κB inhibitor (IκB) and Smad3.

Conclusions

The results indicated that butein inhibited ethanol- and acetaldehyde-induced activation of HSCs at different levels, acting as an antioxidant and inhibitor of ethanol-induced MAPK, TGF-β, and NFκB/IκB transduction signaling; this result makes butein a promising agent for antifibrotic therapies.     

Rosiglitazone prevents nutritional fibrosis and steatohepatitis in mice

Objective. Currently, no agent has been confirmed as preventing the fibrosing progression of non-alcoholic steatohepatitis (NASH). In this study, rosiglitazone was used in the clinical treatment of insulin resistance in patients with type 2 diabetes mellitus. However, its protective effect on non-alchoholic fibrosing steatohepatitis is not clear. The study aimed to elucidate the effect and the mechanism of rosiglitazone in inhibiting nutrition-related fibrosis in mice. Methods. C57BL6/J mice were fed a high fat, methionine-choline deficient (MCD) diet for 8 weeks to induce hepatic fibrosis, and rosiglitazone was given in the treated group. The effect of rosiglitazone was assessed by comparing the severity of hepatic fibrosis in liver sections, the activation of hepatic stellate cells (HSCs) and the expression of TGF-β1 and connective tissue growth factor (CTGF). Results. At week 8, MCD-diet-induced fibrosing NASH models showed increased serum ALT and AST levels, severe hepatic steatosis, and infiltration of inflammation and fibrosis which, associated with down-regulated PPARγ mRNA and protein expression, up-regulated α-SMA protein expression and enhanced TGF-β1, CTGF mRNA and protein expression. Rosiglitazone significantly lowered serum ALT and AST and it reduced MCD-induced fibrosis by repressing levels of α-SMA protein expression and pro-fibrosis factors TGF-β1 and CTGF. It also restored expression of PPARγ. Conclusions. The present study provides clear morphological and molecular biological evidence of the protective role of rosiglitazone in ameliorating nutritional fibrosing steatohepatitis. Rosiglitazone may ameliorate hepatic fibrosis by activating PPARγ, which can inhibit HSC activation and suppress TGF-β1 and CTGF expression.     

Long noncoding RNA GAS5 inhibits LX-2 cells activation by suppressing NF-κB signalling through regulation of the miR-433–3p/TLR10 axis

BackgroundLiver fibrosis is a common disease that can lead to hepatic failure.AimsOur aims were to reveal the role of GAS5 in the regulation of liver fibrosis.MethodsLX-2 human hepatic satellite cells (HSCs) were cultured and activated using TGF-β1 treatment. A CCK-8 assay was performed to assess cell viability. A luciferase assay was employed to monitor the interactions between miR-433–3p and GAS5 or toll-like receptor 10 (TLR10). Western blotting and real-time quantitative PCR (RT-qPCR) were applied to detect the expression levels of α-SMA, Col. I, PCNA-, MMP2-, MMP9-, TLR10-, and NF-κB-related molecules at the protein and RNA levels.ResultsGAS5 and TLR10 were decreased while miR-433–3p was upregulated in TGF-β1-activated LX-2 cells. Upregulation of GAS5 or downregulation of miR-433–3p suppressed HSC activation, and luciferase assays indicated that miR-433–3p binds with GAS5 and the 3′-UTR of TLR10. MiR-433–3p upregulation and TLR10 downregulation rescued the impacts of GAS5 overexpression or miR-433–3p knockdown on LX-2 cells. Upregulation of GAS5 also suppressed the phosphorylation of NF-κB through the miR-433–3p/TLR10 axis.ConclusionLncRNA GAS5 exerts an inhibitory effect on HSC activation by suppressing NF-κB signalling through regulation of the miR-433–3p/TLR10 axis.     

Antifibrotic Mechanism of Pinocembrin: Impact on Oxidative Stress,Inflammation and TGF-β /Smad Inhibition in Rats

Introduction. The present study aimed to elucidate the potential antifibrotic effects of pinocembrin (PIN), a flavanone found abundantly in honey and propolis, by studying its effect on different oxidative stress, inflammatory and fibrosis markers in an experimental model of CCl₄-induced liver fibrosis.Material and methods. PIN (20 mg/kg) was given orally 3 times/week for 6 consecutive weeks alternating with CCl₄ (0.5 mL/kg, 1:1 mixture with corn oil, i. p.) twice weekly. Different hepatotoxicity indices, oxidative stress, inflammatory and liver fibrosis markers were assessed.Results. PIN significantly restored liver transaminases and total cholesterol to normal levels. Also, PIN ameliorated oxidative stress injury evoked by CCl₄ as evidenced by inhibition of reduced glutathione depletion and lipid peroxidation as well as elevation of antioxidant enzyme superoxide dismutase (SOD). Further, PIN up-regulated the nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), thereby inducing the expression and activity of the cytoprotective enzyme hemeoxygenase-1 (HO-1). Moreover, PIN alleviated pro-inflammatory cytokines such as TNF-α via inhibiting nuclear factor-KB (nF-kB) activation. As markers of fibrosis, collagen and α-SMA expression increased markedly in the CCl₄ group and PIN prevented these alterations. In addition, PIN down-regulated TGFβ1 and p-Smad2/3, thereby inhibiting TGFβ1/Smad signaling pathway.Conclusion. These results suggest that PIN possess potent antifibrotic effects that can be explained on its antioxidant properties. It ameliorates oxidative stress and inflammation during induction of fibrogenesis via its ability to augment cellular antioxidant defenses, activating Nrf2-mediated HO-1 expression and modulating NF-KB and TGF-β1/Smad signaling pathway.     

NO-releasing xanthine KMUP-1 bonded by simvastatin attenuates bleomycin-induced lung inflammation and delayed fibrosis

Background and purposePulmonary fibrosis (PF) is a progressing lung injury initiated by pulmonary inflammation (PI). Bleomycin (BLM) is the most common pathogenesis of PF through early PI and extensive extracellular matrix deposition. This study is aimed to determine whether NO-releasing KMUP-1 inhibits PI and PF, and if so, the benefits of KMUP-1S resulted from simvastatin (SIM)-bonding to KMUP-1.Experiment approachC57BL/6 male mice were intra-tracheally administered BLM (4 U/kg) at day 0. KMUP-1 (1–5 mg/kg), KMUP-1S (2.5 mg/kg), SIM (5 mg/kg), Plus (KMUP-1 2.5 mg/kg + SIM 2.5 mg/kg), and clarithromycin (CAM, 10 mg/kg) were orally and daily administered for 7 and 28 days, respectively, to mice, sacrificed at day-7 and day-28 to isolate the lung tissues, for examining the inflammatory and fibrotic signaling and measuring the cell population and MMP-2/MMP-9 activity in broncholaveolar lavage fluid (BAL).Key resultsKMUP-1 and KUP-1S significantly decreased neutrophil counts in BAL fluid. Fibroblastic foci were histologically assessed by H&E and Masson's trichrome stain and treated with KMUP-1 and references. Lung tissues were determined the contents of collagen and the expressions of TGF-β, α-SMA, HMGB1, CTGF, eNOS, p-eNOS, RhoA, Smad3, p-Smad3, MMP-2 and MMP-9 by Western blotting analyses, respectively. These changes areregulated by NO/cGMP and inhibited by various treatments. KMUP-1 and KMUP-1S predominantly prevented HMGB1/MMP-2 expression at day-7 and reduced TGF-β/phosphorylated Smad3 and CTGF at day-28.Conclusions and implicationsKMUP-1 and KMUP-S restore eNOS, inhibit iNOS/ROCKII/MMP-2/MMP-9, attenuate histologic collagen disposition and reduce BALF inflammatory cells, potentially useful for the treatment of BLM-lung PF.     

Protective effects of edaravone on experimental chronic pancreatitis induced by dibutyltin dichloride in rats

Background/aimsTo investigate the effects of edaravone, a potent free radical scavenger, on dibutyltin dichloride (DBTC)-induced chronic pancreatitis (CP) and pancreatic fibrosis.MethodsMale Sprague–Dawley rats were randomly divided into four groups (n = 16 each): control, DBTC, DBTC + edaravone, and control + edaravone. Edaravone or normal saline at a daily dose of 6 mg/kg body weight was given intraperitoneally from day 5 to day 28 after DBTC administration. On days 14 and 28, the rats were evaluated morphologically and biochemically. The expression of cytokines in pancreas TGF-β, IL-6 and TNF<alpha> was detected using RT-PCR. The activation of nuclear factor (NF)-κB in pancreatic tissue was evaluated by immunostaining and western-blot for NF-κB p65. α-smooth muscle actin (α-SMA) expression was also evaluated by immunostaining and western-blot to investigate the activation of pancreatic stellate cells (PSCs).ResultEdaravone treatment improved the rats' body weight (p < 0.01) and feed intake levels (p < 0.05), improved the histological scores and alleviated the fibrosis of pancreas samples (p < 0.05), as well as markedly increased superoxide dismutase (SOD) activity and decreased malondialdehyde (MDA) concentrations in pancreatic tissue (p < 0.01 for both). The expression of cytokines TGF-β, IL-6 and TNF<alpha> in pancreas of DBTC group was also down-regulated by edaravone after treatment. Edaravone inhibited the activation of NF-κB and PSCs and exhibited protective effects on pancreatic tissue damage in CP.ConclusionsThis antioxidant may be a promising therapeutic intervention for human CP.     

Glycyrrhizic acid inhibits apoptosis and fibrosis in carbontetrachloride-induced rat liver injury

AIM:To investigate anti-apoptotic effects of glycyrrhizic acid(GA) against fibrosis in carbon tetrachloride(CCl4)-induced liver injury and its contributing factors.METHODS:Liver fibrosis was induced by administration of CCl4 for 8 wk.Pathological changes in the liver of rats were examined by hematoxylin-eosin staining.Collagen fibers were detected by Sirius red staining.Hepatocyte apoptosis was determined by TUNEL assay and the expression levels of cleaved caspase-3,Bax,α-SMA,connective tissue growth factor(CTGF),matrix metalloproteinase(MMP) 2 and MMP9 proteins were evaluated by western blot analysis,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were estimated by real-time PCR.RESULTS:Treatment with GA significantly improved the pathological changes in the liver and markedly decreased the positive area of Sirius red compared with rats in the CCl4-treated group.TUNEL assay showed that GA significantly reduced the number of TUNEL-positive cells compared with the CCl4-treated group.The expression levels of cleaved caspase-3,Bax,α-SMA,CTGF,MMP2 and MMP9 proteins,and α-SMA m RNA,collagen type Ⅰ and Ⅲ m RNA were also significantly reduced by GA compared with the CCl4-treated group(P 0.05).CONCLUSION:GA treatment can ameliorate CCl4-induced liver fibrosis by inhibiting hepatocyte apoptosis and hepatic stellate cell activation.     

ACEI attenuates the progression of CCl4-induced rat hepatic fibrogenesis by inhibiting TGF-β1, PDGF-BB, NF-κB and MMP-2,9

AIM: Angiotensin Ⅱ has pro-fibrotic function in the liver.Blockade of the renin-angiotensin-aldosterone-system (RAAS) attenuates hepatic fibrosis. The aim of the present study was to determine the mechanism of angiotensinconverting enzyme inhibitor (ACEI) on the progression of rat hepatic fibrosis.METHODS: Forty male Wistar rats were divided into three groups. Model group (Mo): The rats were injected subcutaneously with 40% of CCl4 0.25 mL/100 g. Perindopril group (Pe): The rats were injected subcutaneously with administrated. Control group (Nc): the rats were treated with olive oil only. After 4 and 6 wk, the rats were killed.The liver sections were stained with Masson. The protein expressions of AT1R, TGF-β1 and PDGF-BB were examined by Western blot. Nuclear factor κB (NF-κB) DNA binding activity was examined by EMSA (Electrophoretic gel mobility shift assay). Matrix metalloproteinase-2,9(MMP-2,9) activity was assessed by zymography. Serum laminin (LN) and hyaluronic acid (HA) were measured using radioimmunoassays.RESULTS: Using Western blot, we clearly provided direct evidence for the expression of AT1R in liver. The expression was up-regulated when fibrogenesis occurred. Perindopril treatment significantly reduced mean fibrosis score,protein levels of AT1R, TGF-β1 and PDGF-BB, serum levels of HA and LN, and the activity of MMP-2,9. NF-κB DNA binding activity markedly increased in model group, perindopril treatment considerably reduced NF-κB DNA binding activity.CONCLUSION: Perindopril attenuates CCl4-induced hepatic fibrogenesis of rat by inhibiting TGF-β1, PDGF-BB,NF-κB and MMP-2,9.     

雷公藤甲素对雨蛙素诱导的慢性胰腺炎小鼠模型胰腺纤维化的影响

目的基于NF-κB/IL-6信号通路研究雷公藤甲素对雨蛙素诱导的慢性胰腺炎(CP)小鼠模型胰腺纤维化的影响。方法随机将15只C57BL/6雄性小鼠分为对照组(生理盐水处理,n=5)、雨蛙素组(雨蛙素诱导CP模型,n=5)和雷公藤甲素组(雨蛙素诱导+雷公藤甲素治疗,n=5)。6周后采集样本进行检测。对小鼠胰腺称重;苏木素-伊红染色、天狼猩红及马松染色观察胰腺组织形态及胶原沉积;ELISA检测血清中IL-6的表达;免疫组化检测α平滑肌肌动蛋白(α-SMA)、NF-κB/p65的表达情况;蛋白质免疫印迹检测NF-κB/p65、IL-6及α-SMA的表达。计量资料多组间比较采用单因素方差分析,进一步两两比较采用LSD-t检验。结果3组间胰腺组织重量,IL-6水平,病理评分,天狼猩红染色、马松染色、α-SMA阳性信号、NF-κB/p65阳性信号的平均光密度值比较差异均有统计学意义(F值分别为64.87、15.85、145.33、141.80、121.77、250.22、69.22,P值均<0.001)。与雨蛙素组相比,雷公藤甲素组胰腺重量明显增加,IL-6的表达明显降低,胰腺组织纤维化及胶原沉积明显减弱,α-SMA与NF-κB/p65表达量降低(P值均<0.05)。蛋白质免疫印迹检测结果显示,3组间NF-κB/p65、IL-6、α-SMA表达水平比较差异均有统计学意义(F值分别为8.86、6.74、16.23,P值均<0.05),雷公藤甲素组胰腺组织NF-κB/p65、IL-6及α-SMA表达量明显低于雨蛙素组(P值均<0.05)。结论雷公藤甲素可抑制NF-κB/p65及IL-6蛋白的表达,缓解雨蛙素诱导的CP小鼠模型的胰腺纤维化。     

姜黄素对肺炎支原体感染肺炎幼鼠抗炎作用及机制初步探讨

目的基于NF-κB途径探讨姜黄素对肺炎支原体感染肺炎幼鼠抗炎作用及机制初步探讨。方法选取50只SPF级BALB/c小鼠随机分为五组,分别为空白对照组(A组)、模型组(B组)、姜黄素高剂量组(C组),姜黄素中剂量组(D组)和姜黄素低剂量组(E组),模型组及姜黄素治疗组采用肺炎支原体标准株滴鼻法进行建模,HE染色观察肺脏病理组织学变化;免疫组化染色测定肺组织中NF-κB p65阳性细胞的积分光密度;采用Western blot实验检测肺组织中NF-κB p65蛋白表达变化;使用ELISA法检测IL-6、IL-8和TNF-α水平。结果模型组小鼠肺组织病理改变明显,姜黄素高剂量组小鼠肺组织与模型组相比,小鼠肺泡结构比较完整,肺泡与气管结构清晰,炎细胞明显减少,姜黄素中剂量组对小鼠有一定的治疗效果,姜黄素低剂量组小鼠和模型组小鼠比较并无明显差异;与空白对照组相比,模型组小鼠肺组织中NF-κB p65的IOD值、NF-κB p65蛋白表达和支气管灌洗液中IL-6、IL-8和TNF-α表达明显升高(P<0.01),与模型组小鼠相比,姜黄素高剂量组和姜黄素中剂量组小鼠肺组织中NF-κB p65的IOD值、NF-κB p65蛋白表达和支气管灌洗液中IL-6、IL-8和TNF-α表达明显降低(P<0.01)。与模型组小鼠相比,姜黄素低剂量组与模型组小鼠肺组织中NF-κB p65的IOD值、NF-κB p65蛋白表达和支气管灌洗液中IL-6、IL-8和TNF-α表达相比差异无统计学意义(P>0.05)。结论姜黄素可改善肺炎支原体感染幼鼠症状且能够抑制炎症因子,其机制可能是通过抑制NF-κB通路的激活,表明姜黄素可作为治疗肺炎支原体感染的潜在药物。     

Proinflammatory cytokines induce crosstalk between colonic epithelial cells and subepithelial myofibroblasts: Implication in intestinal fibrosis

Background and aimsColonic epithelial cells and adjacent subepithelial myofibroblasts are important counterparts in the pathogenesis of intestinal inflammation and fibrosis. We investigated the possible crosstalk between them, whilst focusing on the mucosal inflammation pathways that potentially trigger intestinal fibrosis.MethodsWe studied the effects of proinflammatory cytokines (IL-1α, TNF-α, IFN-γ) on human colonic epithelial cell lines and the effects of epithelial cell-conditioned media on primary human colonic subepithelial myofibroblasts isolated from normal controls or patients with inflammatory Crohn's disease along with the corresponding 18CO cell line. Readouts included production of TGF-β and TIMP-1, total collagen synthesis, matrix metalloproteinases MMP-2 and MMP-9 and myofibroblast migration/mobility.ResultsProinflammatory cytokines upregulated TGF-β and TIMP-1 in colonic epithelial cells. Conditioned medium from these epithelial cell cultures induced production of MMP-9 and collagen and inhibited the migration/mobility of subepithelial myofibroblasts. MMP-9 production depended on endothelin receptor A signalling on responding myofibroblasts. Collagen up-regulation was independent of TGF-β, CTGF, TF and endothelin. Subepithelial myofibroblasts isolated from Crohn's disease patients had similar responses to those isolated from normal controls, with the exception of higher basal collagen production.ConclusionsOur study indicates that colonic epithelial cells may respond to an inflammatory milieu by inducing myofibroblast functions similar to those observed during intestinal fibrosis.     

Effects of curcumin on proinflammatory cytokines and tissue injury in the early and late phases of experimental acute pancreatitis

Background & aimsAcute pancreatitis (AP) varies from mild to severe necrotizing changes with high mortality. The objective of the current study was to investigate the effects of curcumin on tissue injury and proinflammatory cytokines in the early and late phases of AP.MethodsAP was induced by sodium taurocholate in rats (n = 140). First group was left untreated. Group II received 100 mg/kg curcumin daily starting 20 days before AP induction. The rats were allocated into 7 sub-groups (n:5) and were sacrificed at 2, 6, 12, 24, 72, 144 and 288 h following the induction of AP. Blood and pancreatic tissue samples were collected for biochemical and histopathologic evaluations and the assessment of protein and mRNA levels, as well.ResultsCurcumin decreased total histopathologic scores in comparison with those of the taurocholate group (P < 0.05). Curcumin increased Caspase-3 activity and decreased trypsin activity, while inhibited nuclear factor-κ (NF-κB) at all time points (P < 0.05) and moreover reduced activator protein-1 (AP-1). Curcumin decreased chemokine (except for 288 h), TNF-α (except for 2 and 24 h), IL-6 (except for 2, 6 and 288 h) and iNOS (except for 144 and 288 h) mRNA levels (P < 0.05). Curcumin serum nitric oxide (NO) (except for 144 and 288 h) levels were reduced, as well.ConclusionsIn conclusion, curcumin reduced tissue injury, trypsin activation and inhibited NF-κB and AP-1. However TNF-α, IL-6 and iNOS and NO were not inhibited at all time points. Therefore no direct correlation was detected in the subgroups between tissue injury, proinflammatory cytokines and oxidative enzymes.     

Caffeine mitigates experimental nonalcoholic steatohepatitis and the progression of thioacetamide-induced liver fibrosis by blocking the MAPK and TGF-β/Smad3 signaling pathways

Introduction and objectivesCaffeine consumption is associated with beneficial effects on hepatic disorders. The objectives of this study were to evaluate the antifibrotic effects of caffeine on experimental nonalcoholic steatohepatitis (NASH) induced with a high-fat, high-sucrose, high-cholesterol diet (HFSCD), as well as to evaluate the ability of caffeine to prevent the progression of experimental liver fibrosis induced by the administration of thioacetamide (TAA) in rats and explore the mechanisms of action.MethodsNASH and fibrosis were induced in rats by the administration of an HFSCD for 15 weeks, and liver fibrosis was induced by intraperitoneal administration of 200 mg/kg TAA 3 times per week, for 6 weeks. Caffeine was administered at a dose of 50 mg/kg body weight. The effects of diet, TAA, and caffeine on fibrosis were evaluated by biochemical and histological examinations. The profibrotic pathways were analyzed by western blotting and immunohistochemistry.ResultsRats exhibited liver fibrosis after HFSCD feeding and the administration of TAA. Caffeine could reduce the hepatic level of collagen and the fibrotic area in the liver. Caffeine prevented the progression of liver fibrosis by decreasing transforming growth factor-beta (TGF-β), connective tissue growth factor (CTGF), and alpha-smooth muscle actin (α-SMA) expression and by inhibiting the activation of mitogen-activated protein kinases (MAPKs) and Smad3 phosphorylation.ConclusionsCaffeine attenuates NASH and the progression of liver fibrosis due to its antifibrotic effects and modulating the MAPK and TGF-β pathways. Therefore, caffeine could be a suitable candidate for treating liver diseases associated with fibrosis.     

An aqueous extract of Stevia rebaudiana variety Morita II prevents liver damage in a rat model of cirrhosis that mimics the human disease

Introduction and aimStevia has exhibited antioxidant, antihyperglycemic, antihypertensive and anti-inflammatory properties in several in vivo and in vitro models. The objective of this study was to investigate the ability of an aqueous extract of stevia (AES) to prevent experimental cirrhosis in rats and to explore its mechanism of action.Materials and methodsLiver cirrhosis was induced by administering carbon tetrachloride (CCl₄) (400 mg/kg by i.p. injection 3 times a week for 12 weeks); AES was administered (100 mg/kg by gavage daily) during the CCl₄ treatment. Fibrosis was evaluated with histological, biochemical and molecular approaches, and liver damage was assessed with standardized procedures. The profibrotic pathways were analyzed by western blotting, qRT-PCR and immunohistochemistry.Results and conclusionsChronic CCl₄ administration increased nuclear factor kappa B (NF-κB) and proinflammatory cytokine production as well as oxidative parameters such as lipid peroxidation and 4-hydroxynonenal levels, whereas GSH and nuclear factor-E2-related factor 2 (Nrf2) levels were decreased. CCl₄ induced profibrogenic mediator expression, hepatic stellate cell (HSC) activation and, consequently, extracellular matrix production. AES exhibited antioxidant, anti-inflammatory and antifibrotic properties, probably because of its capacity to induce Nrf2 expression, reduce NF-κB expression and block several profibrogenic signaling pathways, subsequently inhibiting HSC activation and preventing fibrosis induced by chronic CCl₄ administration.     

风湿性心脏病患者致心力衰竭心肌组织中IL-1β TGF-β1和NF-κB/p65的表达及意义

目的:研究风湿性心脏病(风心病)致心力衰竭(心衰)患者心肌组织中白细胞介素-1β(IL-1β)、转化生长因子β1(TGF-β1)和核转录因子κB/p65(NF-κB/p65)的表达及其临床病理意义。方法:18例风心病(实验组)和10例正常人(对照组)左心室心肌组织,经4%甲醛固定后常规制作石蜡包埋切片,应用EnvisionTM免疫组化法检测IL-1β、TGF-β1和NF-κB/p65的表达。结果:风心病NYHA分级Ⅲ级或Ⅳ级心衰患者的IL-1β、TGF-β1和NF-κB/p65的表达阳性率及其评分明显高于NYHAⅠ级(P<0.05);实验组(包括pAF组和cAF组)的IL-1β、TGF-β1和NF-κB/p65的表达阳性率及其评分明显高于对照组(RSR组)(P<0.05);IL-1β、TGF-β1和NF-κB/p65的表达评分互相均存在密切正相关(P<0.05),且与左心室射血分数呈负相关,与左心室舒张末期直径呈正相关。结论:IL-1β、TGF-β1和NF-κB/p65在风心病心衰、心室重构的发生、发展中起着重要的促进作用。