S-腺苷蛋氨酸治疗胆汁淤积性肝病伴抑郁/焦虑的临床效果研究

目的:研究S-腺苷蛋氨酸治疗胆汁淤积性肝病伴抑郁/焦虑患者的临床效果。方法:选择2011年3月~2013年3月我院收治的51例不同病因的胆汁淤积性肝病(药物性肝损害13例、慢性乙型肝硬化14例、酒精性肝硬化11例、自身免疫性肝病6例、肝癌5例、胆管癌2例)并抑郁/焦虑的患者,予S-腺苷蛋氨酸1.0 g治疗2周,应用SDS/SAS量表分别评估和比较治疗前后各组患者抑郁/焦虑程度的评分情况。结果:S-腺苷蛋氨酸治疗后,所有组别胆汁淤积性肝病肝病改善的临床总有效率94.12%,其中药物性肝损害、慢性乙型肝硬化、酒精性肝硬化、自身免疫性肝硬化总有效率均为100.00%,肝癌的有效率为60.00%,胆管癌的有效率为50.00%,药物性肝损害患者临床疗效与其他各组有差异(P0.05);药物性肝病患者SDS和SAS评分均较治疗前显著降低(P0.05)。而慢性乙型肝硬化、酒精性肝硬化、自身免疫性肝病、肝癌、胆管癌患者SDS和SAS评分与治疗前相比均无统计学差异(P0.05)。结论:S-腺苷蛋氨酸可改善药物性胆汁淤积性肝病并轻、中度抑郁/焦虑患者的肝功能,并有效减轻其抑郁/焦虑情绪。     

甲硫氨酸腺苷转移酶1A/2A平衡与肝细胞癌

肝细胞癌是一种死亡率极高的癌症,大多数病人发现时已属晚期.甲硫氨酸腺苷转移酶(MAT)是细胞生命活动的关键酶,可以通过催化甲酼氨酸和三磷酸腺苷(ATP)结合,促进生物甲基供体S-腺苷甲酼氨酸(SAMe)的生物合成.正常肝细胞中MAT1A与MAT2A存在动态平衡,共同维持细胞内SAMe稳态;肝细胞癌中MAT1A转变成MAT2A,会使SAMe生物合成减少,为癌细胞生长提供有利条件,故MAT1A表达降低而MAT2A增高.因此,促进MAT2A向MAT1A转化,进而提高MAT1A/MAT2A的比值可能成为治疗肝细胞癌的关键靶点之一.本文就MAT1A/MAT2A平衡在肝细胞癌中的重要作用作一综述,旨在为寻找肝细胞癌防治靶点提供新的思路.     

S-腺苷蛋氨酸治疗胆汁淤积性肝病伴抑郁／焦虑的临床效果研究

目的：研究s-腺苷蛋氨酸治疗胆汁淤积性肝病伴抑郁／焦虑患者的临床效果。方法：选择2011年3月-2013年3月我院收治的51例不同病因的胆汁淤积性肝病（药物性肝损害13例、慢性乙型肝硬化14例、酒精性肝硬化11例、自身免疫性肝病6例、肝癌5例、胆管癌2例）并抑郁／焦虑的患者,予s-腺苷蛋氨酸1．0g治疗2周,应用SDS／SAS量表分别评估和比较治疗前后各组患者抑郁／焦虑程度的评分情况。结果：S-腺苷蛋氨酸治疗后,所有组别胆汁淤积性肝病肝病改善的临床总有效率94．12％,其中药物性肝损害、慢性乙型肝硬化、酒精性肝硬化、自身免疫性肝硬化总有效率均为100．00％,肝癌的有效率为60．00％,胆管癌的有效率为50．00％,药物性肝损害患者临床疗效与其他各组有差异（P〈0．05）;药物性肝病患者SDS和SAS评分均较治疗前显著降低（P〈0．05）。而慢性乙型肝硬化、酒精性肝硬化、自身免疫性肝病、肝癌、胆管癌患者SDS和SAS评分与治疗前相比均无统计学差异（P〉0．05）。结论：S-腺苷蛋氨酸可改善药物性胆汁淤积性肝病并轻、中度抑郁／焦虑患者的肝功能,并有效减轻其抑郁／焦虑情绪。     

S- 腺苷蛋氨酸对梗阻性黄疸患者术后肝功能及营养状况影响的临床研究

目的：探讨S-腺苷蛋氨酸对梗阻性黄疸患者术后肝功能及营养状况的影响。方法：选择2010 年8 月至2012年7 月我院肝 胆病区收治的90 例梗阻性黄疸患者为研究对象,随机分为S- 腺苷蛋氨酸治疗组（48 例）和对照组（42 例）,比较和分析静脉滴注 S-腺苷蛋氨酸对梗阻性黄疸患者术后第5 d、10 d肝功能及营养指标的影响。结果：术后5 d、10 d,两组患者血总胆红素、直接胆 红素、谷丙转氨酶、酌-谷氨酰转肽酶、碱性磷酸酶水平较术前1d 显著降低,且组内比较差异有统计学意义（P<0.05）,治疗组以上指 标的下降程度较对照组更明显,差异有统计学意义（P<0.05）。术后第10d,两组患者的血白蛋白、前白蛋白、转铁蛋白水平较术后 第5 d显著改善（P<0.05）;术后第5、10 d,两组组间血白蛋白、前白蛋白、转铁蛋白水平比较差异有统计学意义（P<0.05）。结论：梗 阻性黄疸患者术后应用腺苷蛋氨酸能促进黄疸消退,加快胆红素的排泄和肝功能的恢复,有利于患者营养状况的改善。     

三七总皂苷抗肝纤维化作用机制的研究进展

肝纤维化是各种慢性肝病共同的病理基础,是慢性肝病发展到肝硬化、肝癌的必经途径。寻找有效的抗肝纤维化药物是近年研究的热点,其中对三七的研究也取得了很大进展。现综述近几年三七皂苷在保护肝细胞、抑制肝星形细胞活化、促进肝星形细胞凋亡、抑制细胞外基质的合成及促使其降解等方面的作用及可能机制,同时也阐述了三七总皂苷在抗肝纤维化中的重要意义及应用前景。     

S-腺苷蛋氨酸对梗阻性黄疸患者术后肝功能及营养状况影响的临床研究

目的：探讨S-腺苷蛋氨酸对梗阻性黄疸患者术后肝功能及营养状况的影响。方法：选择2010年8月至2012年7月我院肝胆病区收治的90例梗阻性黄疸患者为研究对象,随机分为S-腺苷蛋氨酸治疗组（48例）和对照组（42例）,比较和分析静脉滴注S-腺苷蛋氨酸对梗阻性黄疸患者术后第5d、10d肝功能及营养指标的影响。结果：术后5d、10d,两组患者血总胆红素、直接胆红素、谷丙转氨酶、1．谷氨酰转肽酶、碱性磷酸酶水平较术前1d显著降低,且组内比较差异有统计学意义（P〈0．05）,治疗组以上指标的下降程度较对照组更明显,差异有统计学意义（P〈0．05）。术后第10d,两组患者的血白蛋白、前白蛋白、转铁蛋白水平较术后第5d显著改善（P〈0．05）;术后第5、10d,两组组间血白蛋白、前白蛋白、转铁蛋白水平比较差异有统计学意义（P〈0．05）。结论：梗阻性黄疸患者术后应用腺苷蛋氨酸能促进黄疸消退,加快胆红素的排泄和肝功能的恢复,有利于患者营养状况的改善。     

S-腺苷蛋氨酸研究进展

S-腺苷蛋氨酸(SAM)是生物体内重要的中间代谢物质,参与多种生化反应．重点介绍了 S-腺苷蛋氨酸的制备和稳定性研究,同时综述了其生理功能、提取纯化和分析检测及临床应用．     

PPARs在非酒精性脂肪性肝病发病机制中的作用

非酒精性脂肪性肝病(non-alcoholic fatty liver disease,NAFLD)是西方国家最常见的慢性肝脏疾病,其疾病谱包括肝脂肪变性,脂肪性肝炎,进一步的肝纤维化、肝硬化,甚至肝细胞性肝癌。其发病机制尚未明确,通常解释为"二次打击"学说。然而新的研究发现非甘油三酯在肝脏的沉积,而是脂肪酸(fatty acids,FAs)及其代谢产物等可能对肝脏有毒性作用。过氧化物酶体增殖物激活受体(PPARs)是配体激活的转录因子,是核受体超家族成员之一,具有调节脂质及糖代谢、抗炎和抗纤维化作用,尤其在FAs储存及分解代谢中起到核心作用,与NAFLD的发生发展密切相关,可能作为治疗NAFLD有效靶点。本文将对PPARs在NAFLD发病机制中的作用做一综述。     

穿心莲内酯联合S-腺苷甲硫氨酸抑制乙醇诱导肝细胞氧化应激损伤

氧化应激是酒精性肝病(ALD)发生的主要机制,因此具有抗氧化作用的活性物质对ALD具有潜在的治疗意义。在本研究当中,我们探讨了S-腺苷甲硫氨酸(SAM)和(或)穿心莲内酯(AD)对乙醇诱导肝细胞氧化应激损伤的保护作用。首先我们体外培养肝细胞L-02,用100 mmol/L乙醇作用24 h后发现,细胞的活性明显降低,胞内活性氧(ROS)含量显著增多以及脂质蓄积,同时细胞释放多种与肝病相关酶类如甘油三脂、胆固醇、转氨酶以及同型半胱氨酸等物质。而乙醇刺激前采用100μmol/L SAM或(和)30μmol/L AD处理细胞后,可明显降低细胞的氧化应激水平,同时能减少上述肝病相关标志物的的释放。此外,乙醇处理也可降低细胞内去乙酰化酶SIRT1的表达并抑制其核转位,而采用SAM或(和)AD处理后可进一步改善SIRT1的表达及活性。以上结果表明SAM或(和)AD能降低乙醇所致的氧化应激水平,两者联合应用可能对ALD具有潜在的治疗效果。     

补加前体L-蛋氨酸对高密度发酵生产S-腺苷-L-蛋氨酸的影响

将高密度发酵技术成功应用于S-腺苷-L-蛋氨酸的生产。考察了补加前体L-蛋氨酸的量以及补加策略对酿酒酵母G14发酵生产S-腺苷-L-蛋氨酸的影响。实验发现补加前体L-蛋氨酸能明显促进S-腺苷-L-蛋氨酸的积累。同时还发现不同的补加策略对菌体浓度以及S-腺苷-L-蛋氨酸的产量和浓度有不同的影响。确定了补加L-蛋氨酸不应低于0.7g/10g菌体干重。比较了五种不同的补加前体L-蛋氨酸的方式。结果表明在菌体干重达到高密度的情况下(120g/L)补加前体L-蛋氨酸进行转化生产S-腺苷-L-蛋氨酸能达到比较好的效果一次性补加9g L-蛋氨酸,SAM的积累量在补加后的18h达到最高,为4.31g/L;采取流加方式补加L-蛋氨酸,流加速率为2g/h,共流加5h,流加结束28h后SAM达到最高积累量后者达到4.98g/L。两者最终的生物量均可达到130g/L以上。     

Modulation of endotoxin stimulated interleukin-6 production in monocytes and Kupffer cells by S-adenosylmethionine (SAMe)

Interleukin-6 (IL-6) is a multifunctional cytokine having primarily anti-apoptotic and anti-inflammatory effects. Recent reports have documented that IL-6 plays a key role in liver regeneration. Intracellular deficiency of S-adenosylmethionine (SAMe) is a hallmark of toxin-induced liver injury. Although the administration of exogenous SAMe attenuates liver injury, its mechanisms of action are not fully understood. Here we investigated the effects of exogenous SAMe on IL-6 production in monocytes and Kupffer cells. RAW 264.7 cells, a murine monocyte cell line, and isolated rat Kupffer cells were stimulated with lipopolysaccharide (LPS) in the absence or presence of exogenous SAMe. IL-6 production was assayed by ELISA and intracellular SAMe concentrations were measured by HPLC. We have found that exogenous SAMe administration enhanced both IL-6 protein production and gene expression in LPS-stimulated monocytes and Kupffer cells. Cycloleucine (CL), an inhibitor for extrahepatic methionine adenosyltransferases (MAT), inhibited LPS-stimulated IL-6 production. The enhancement of LPS-stimulated IL-6 production by SAMe was inhibited by ZM241385, a specific antagonist of adenosine (A2) receptor. Our results demonstrate that SAMe administration may exert its anti-inflammatory and hepatoprotective effects, at least in part, by enhancing LPS-stimulated IL-6 production.     

S-adenosylmethionine exerts a protective effect against thioacetamide-induced injury in primary cultures of rat hepatocytes

S-adenosylmethionine (SAMe) has been shown to protect hepatocytes from toxic injury, both experimentally-induced in animals and in isolated hepatocytes. The mechanisms by which SAMe protects hepatocytes from injury can result from the pathways of SAMe metabolism. Unfortunately, data documenting the protective effect of SAMe against mitochondrial damage from toxic injury are not widely available. Thioacetamide is frequently used as a model hepatotoxin, which causes in vivo centrilobular necrosis. Even though thioacetamide-induced liver necrosis in rats was alleviated by SAMe, the mechanisms of this protective effect remain to be verified. The aim of our study was to determine the protective mechanisms of SAMe on thioacetamide-induced hepatocyte injury by using primary hepatocyte cultures. The release of lactate dehydrogenase (LDH) from cells incubated with thioacetamide for 24 hours, was lowered by simultaneous treatment with SAMe, in a dose-dependent manner. The inhibitory effect of SAMe on thioacetamide-induced lipid peroxidation paralleled the effect on cytotoxicity. A decrease in the mitochondrial membrane potential, as determined by Rhodamine 123 accumulation, was also prevented. The attenuation by SAMe of thioacetamide-induced glutathione depletion was determined after subsequent incubation periods of 48 and 72 hours. SAMe protects both cytoplasmic and mitochondrial membranes. This effect was more pronounced during the development of thioacetamide-induced hepatocyte injury that was mediated by lipid peroxidation. Continuation of the SAMe treatment then led to a reduction in glutathione depletion, as a potential consequence of an increase in glutathione production, for which SAMe is a precursor.     

S-adenosylmethionine (SAMe) modulates interleukin-10 and interleukin-6, but not TNF, production via the adenosine (A2) receptor

S-adenosylmethionine (SAMe) is the first product in methionine metabolism and serves as a precursor for glutathione (GSH) as well as a methyl donor in most transmethylation reactions. The administration of exogenous SAMe has beneficial effects in many types of liver diseases. One mechanism for the hepatoprotective action is its ability to regulate the immune system by modulating cytokine production from LPS stimulated monocytes. In the present study, we investigated possible mechanism(s) by which exogenous SAMe supplementation modulated production of TNF, IL-10 and IL-6 in LPS stimulated RAW 264.7 cells, a murine monocyte cell line. Our results demonstrated that exogenous SAMe supplementation inhibited TNF production but enhanced both IL-10 and IL-6 production. SAMe increased intracellular GSH level, however, N-acetylcysteine (NAC), the GSH pro-drug, decreased the production of all three cytokines. Importantly, SAMe increased intracellular adenosine levels, and exogenous adenosine supplementation had effects similar to SAMe on TNF, IL-10 and IL-6 production. 3-Deaza-adenosine (DZA), a specific inhibitor of S-adenosylhomocysteine (SAH) hydrolase, blocked the elevation of IL-10 and IL-6 production induced by SAMe, which was rescued by the addition of exogenous adenosine. Furthermore, the enhancement of LPS-stimulated IL-10 and IL-6 production by both SAMe and adenosine was inhibited by ZM241385, a specific antagonist of the adenosine (A(2)) receptor. Our results suggest that increased adenosine levels with subsequent binding to the A(2) receptor account, at least in part, for SAMe modulation of IL-10 and IL-6, but not TNF production, from LPS stimulated monocytes.     

S-adenosyl-L-methionine (SAMe) halts the autoimmune response in patients with primary biliary cholangitis (PBC) via antioxidant and S-glutathionylation processes in cholangiocytes

S-adenosyl-L-methionine is an endogenous molecule with hepato-protective properties linked to redox regulation and methylation. Here, the potential therapeutic value of SAMe was tested in 17 patients with PBC, a cholestatic disease with autoimmune phenomena targeting small bile ducts. Nine patients responded to SAMe (SAMe responders) with increased serum protein S-glutathionylation. That posttranslational protein modification was associated with reduction of serum anti-mitochondrial autoantibodies (AMA-M2) titers and improvement of liver biochemistry. Clinically, SAMe responders were younger at diagnosis, had longer duration of the disease and lower level of serum S-glutathionylated proteins at entry. SAMe treatment was associated with negative correlation between protein S-glutathionylation and TNFα. Furthermore, AMA-M2 titers correlated positively with INFγ and FGF-19 while negatively with TGFβ. Additionally, cirrhotic PBC livers showed reduced levels of glutathionylated proteins, glutaredoxine-1 (Grx-1) and GSH synthase (GS). The effect of SAMe was also analyzed in vitro. In human cholangiocytes overexpressing miR-506, which induces PBC-like features, SAMe increased total protein S-glutathionylation and the level of γ-glutamylcysteine ligase (GCLC), whereas reduced Grx-1 level. Moreover, SAMe protected primary human cholangiocytes against mitochondrial oxidative stress induced by tBHQ (tert-Butylhydroquinone) via raising the level of Nrf2 and HO-1. Finally, SAMe reduced apoptosis (cleaved-caspase3) and PDC-E2 (antigen responsible of the AMA-M2) induced experimentally by glycochenodeoxycholic acid (GCDC). These data suggest that SAMe may inhibit autoimmune events in patients with PBC via its antioxidant and S-glutathionylation properties. These findings provide new insights into the molecular events promoting progression of PBC and suggest potential therapeutic application of SAMe in PBC.     

S-Adenosyl-L-Methionine for the Treatment of Chronic Liver Disease: A Systematic Review and Meta-Analysis

It has been well established that S-adenosyl-L-methionine (SAMe) is the principal methyl donor in methyltransferase reactions and that SAMe supplementation restores hepatic glutathione (GSH) deposits and attenuates liver injury. However, the effectiveness of SAMe therapy in chronic liver disease has not been adequately addressed. We searched globally recognized electronic databases, including PubMed, the Cochrane Database and EMBASE, to retrieve relevant randomized controlled trials (RCTs) of chronic liver disease published in the past 20 years. We then performed a systematic review and meta-analysis of the enrolled trials that met the inclusion criteria.The results showed that twelve RCTs from 11 studies, which examined 705 patients, were included in this research. For liver function, certain results obtained from data synthesis and independent comparisons demonstrated significant differences between the levels of total bilirubin (TBIL) and aspartate transaminase (AST). However, no studies identified significant differences regarding alanine transaminase (ALT) levels. An analysis of the adverse events and long-term prognosis also indicated no significant differences between the SAMe and the placebo groups. In a subgroup analysis of gravidas and children, several of the included data indicated that there was a significant difference in the pruritus score. Furthermore, the results regarding ursodeoxycholic acid (UDCA) and stronger neo-minophagen C (SNMC) indicated that both treatments were more effective than SAMe was in certain chronic liver diseases. These findings suggest that SAMe could be used as the basis of a medication regimen for liver function improvement because of its safety. However, SAMe also demonstrated limited clinical value in the treatment of certain chronic liver diseases.     

Protective effect of S-adenosylmethionine against galactosamine-induced injury of rat hepatocytes in primary culture

The protective effect of S-adenosylmethionine (SAMe) on D-galactosamine (GalN)-induced damage to rat hepatocytes was tested in primary cultures. SAMe at concentrations of 50 and 1000 mg/l significantly reduced lactate dehydrogenase release from cells injured by 40 mM GalN after 24 h of incubation. There were no significant changes in urea production after 24 h among tested groups, including control hepatocytes. Exposure of hepatocytes to GalN leads to 3.5-fold decrease in urea synthesis after 48 h in comparison with control cell cultures. Addition of the highest dose of SAMe (1000 mg/l) into the culture media attenuated this decrease by 180 %. None of the tested doses of SAMe (5, 25, 50 and 1000 mg/l) affected considerably the reduced activity of mitochondrial dehydrogenases. The content of reduced and oxidized glutathione in GalN-exposed cells was diminished to 1.5 % and 16 %, respectively, of the control values after 24 h. Using only the highest concentration SAMe increased significantly these contents. SAMe had no effect on dramatically decreased albumin synthesis. These findings indicate beneficial effect of SAMe, especially of the highest concentration, on GalN-induced toxicity to rat hepatocytes in primary culture. This action of SAMe seems to be associated with reduction of plasma membrane damage and increased synthesis of glutathione.     

Nonalcoholic fatty liver disease: Update on pathogenesis,diagnosis, treatment and the role of S-adenosylmethionine

Nonalcoholic fatty liver disease (NAFLD) is currently the most common liver disease worldwide affecting over one-third of the population in the U.S. It has been associated with obesity, type 2 diabetes, hyperlipidemia, and insulin resistance and is initiated by the accumulation of triglycerides in hepatocytes. Isolated hepatic steatosis (IHS) remains a benign process, while a subset develops superimposed inflammatory activity and progression to nonalcoholic steatohepatitis (NASH) with or without fibrosis. However, the molecular mechanisms underlying NAFLD progression are not completely understood. Liver biopsy is still required to differentiate IHS from NASH as easily accessible noninvasive biomarkers are lacking. In terms of treatments for NASH, pioglitazone, vitamin E, and obeticholic acid have shown some benefit. All of these agents have potential complications associated with long-term use. Nowadays, a complex hypothesis suggests that multiple parallel hits are involved in NASH development. However, the ‘key switch’ between IHS and NASH remains to be discovered. We have recently shown that knocking out enzymes involved in S-adenosylmethionine (SAMe) metabolism, the main biological methyl donor in humans that is abundant in the liver, will lead to NASH development in mice. This could be due to the fact that a normal SAMe level is required to establish the proper ratio of phosphatidylethanolamine to phosphatidylcholine that has been found to be important in NAFLD progression. New data from humans have also suggested that these enzymes play a role in the pathogenesis of NAFLD and that some of SAMe cycle metabolites may serve as noninvasive biomarkers of NASH. In this review, we discuss the evidence of the role of SAMe in animal models and humans with NAFLD and how studying this area may lead to the discovery of new noninvasive biomarkers and possibly personalized treatment for NASH.