体外功能性肺组织模型构建、调控及在肺纤维化和COVID-19中的应用

肺纤维化是很多肺部疾病发生发展过程中出现的病理现象。近年出现的2019冠状病毒病(coronavirus disease 2019, COVID-19)引发的呼吸系统综合征也会出现弥漫性肺泡损伤,并诱发肺纤维化。因此,开展肺纤维化和COVID-19体外模型构建与调控研究在肺部疾病治疗和药物筛选方面意义重大。目前,现有研究已建立了多种体外肺组织二维、三维细胞培养模型,本文将全面概述这些模型的构建方法,并结合这些模型在肺纤维化及COVID-19中的应用研究,对体外肺组织模型在药物传递、高通量药物筛选及发病机制研究等生物医学领域中的应用前景进行综述,为其进一步研究提供参考。     

诱导性多能干细胞与神经系统疾病模型的构建(英文)

利用外源性转录因子将已分化成熟的细胞诱导为多能干细胞(induced pluripotent stem cells,iPS细胞)对构建神经发育性和神经退行性疾病的体外模型具有重要意义。从患有特定疾病或具有明确遗传基因异常的患者身上获取体细胞进行诱导建立的iPS细胞具有潜在的疾病原特质,这种疾病特异性iPS细胞可以用来研究疾病的发病机制和病理过程,也为药物筛选、药物毒性检测以及个体化治疗方案的制定提供了可能。本文概述了目前用于建立神经系统疾病模型的干细胞类型,重点讨论了利用iPS细胞技术建立脊髓性肌萎缩症、肌萎缩性脊髓侧索硬化症和帕金森病等常见中枢神经系统疾病模型和药物干预的最新进展,并对该研究领域所面临的问题进行了详尽的分析。     

三维肝细胞模型及其在化学性肝损伤评价中的应用

肝脏是机体代谢外源性化学物的主要场所,也是化学物及其代谢产物毒作用的重要靶器官。为了更加快速、准确地对化学物引起的肝损伤进行评估,选择贴近人体的细胞模型和培养方法至关重要。近年来研究发展了多种人源体外肝细胞模型,其中新兴的三维(3D)肝细胞体外模型具有类似体内肝脏表型、代谢能力,并适于长期体外培养,为药物等化学物的肝毒性测试提供了有力的体外评价工具。本文主要介绍目前常用的肝细胞模型的特点,以及球体模型、生物反应器、3D打印和肝脏芯片等3D培养系统,概述了这些模型在化学性肝损伤评估中的应用进展。     

不同类型急性药物性肝损伤的临床特点分析

目的:分析不同类型急性药物性肝损伤的药物种类、生化学特点及病理学特征.方法:采用回顾性研究方法,总结分析急性药物性肝损伤的临床分型、药物种类、临床表现、生化学指标及病理学特征.结果:209例急性药物性肝损伤患者最常见的致肝损伤药物为中药(45.93％),其次为解热镇痛药(NSAIDs) (15.31％)、抗生素(11.96％).最常见的临床症状包括乏力(72.25％)、纳差(62.68％)、尿黄(61.72％);三种临床类型间的临床症状比较,差异无统计学意义0＞0.05).三种临床类型间生化学指标(ALT、AST、ALP、GGT、TBIL、DBIL)比较,差异有统计学意义(P＜0.05).病理学特征主要为肝细胞点灶状坏死(94.26％)、混合性炎细胞浸润(83.73％)、凋亡小体(82.30％)、纤维组织增生(68.90％)、肝细胞水样变性(60.29％).三种临床类型间肝细胞或Kuffer细胞内色素颗粒沉着、融合性坏死及肝细胞和(或)毛细胆管淤胆比较,差异均有统计学意义(P＜0.05),其他病理特征比较,差异均无统计学意义(P＞0.05).结论:中药已成为目前药物性肝损伤的主要病因;现用临床分型标准尚需要进一步研究完善.     

综述与专论: 内脏痛实验动物模型的研究进展

内脏痛是内脏器官受到机械性牵拉、炎症、痉挛、应激和缺血等刺激所致的疼痛，是一种临床上常见病症。与躯体痛相比，内脏痛的产生、维持和调控机制更为复杂，因此是目前疼痛基础研究领域中的重点和难点之一。建立符合临床内脏疾病病理生理学特征的实验动物模型对研究内脏痛的产生、维持、调控机制及筛选相关内脏疾病的治疗药物具有重要意义。目前内脏痛动物模型主要按照造模刺激方式进行分类，分为炎性内脏痛模型、电刺激性内脏痛模型、机械扩张性内脏痛模型及缺血性内脏痛模型等，且每种动物模型具有不同特点。本文就近年来内脏痛基础研究中常用的实验动物模型的制备及特点做一简要综述，以期为研究者选择合适的内脏痛动物模型提供参考，为更深入研究内脏痛的复杂机制及筛选相关治疗药物奠定基础。     

工程化骨软骨生理微环境构建方法及研究进展

骨组织工程是通过在体外构建有正常组织功能或疾病生理特点的临床模型,用以药物筛选,或研究疾病发生发展过程。骨骼肌肉系统是载重系统,其功能与组织结构、细胞外基质等密切相关。在构建骨组织体外模型时,需要结合骨、软骨及其他构成成分的生理微环境,表现关节骨软骨接合处的生理特点及作用机制,进而模拟正常及病理状态下骨组织系统对刺激的反应。本综述从骨软骨组织的生理构造入手,阐述了骨软骨连接处在退行性关节病变发生发展过程中的作用,并系统的论述了体外构建三维骨软骨组织的方法及这些方法的优势和局限性,为体外构建骨软骨组织工程在临床上应用提供支持。     

中暑致肝损伤机制的研究进展

中暑是常发生在夏季高温环境或大量运动时的急危重症,可导致包括肝脏在内的多器官功能损害。中暑的发生及发展过程经历了代偿期、急性反应期和失代偿期。近年来国内外关于中暑致肝损伤机制方面的研究表明,中暑致肝脏功能损伤可能与热的直接作用、肝细胞内线粒体功能障碍和级联放大的炎症反应有关,各环节相互促进,最终导致肝脏的损伤。而且,在肝窦内的级联放大炎症反应在中暑致肝损伤中可能起主要作用。因此,本文对近年来中暑的病理生理和中暑致肝损伤机制方面的研究及进展作一综述,为中暑致肝损伤的临床防治提供思路。     

干细胞疾病模型在肝脏代谢疾病研究和药物研发中的应用

新药研发的失败率之高众所周知,其中一个原因是依靠动物实验获得的临床前数据无法真实反映人类生理情况,不可避免地在药物进入临床试验后产生偏差,最终可能导致研发失利。基于人诱导性多能干细胞(induced pluripotent stem cells,iPSCs)或成体干细胞建立的疾病模型一方面提供了大量的细胞原材料;另一方面,由于iPSCs或成体干细胞可来源于患者,因而可准确模拟疾病的遗传背景。因此,干细胞疾病模型为药物临床前试验提供了更贴近人体生理和病理情况的体外细胞模型。更进一步地,通过建立群体iPSCs细胞库,可在体外细胞培养皿内进行人类遗传学研究,采用全基因组关联研究(genome-wide association study, GWAS)及定量性状基因座(quantitative trait locus, QTL)等方法筛选人群中与疾病、药物敏感性差异、细胞毒性差异相关的易感位点,为特定药物的毒性、易感性人群间差异等提供遗传学基础,进而为后续临床试验中合适的试验人群的招募提供理论依据。因而,干细胞疾病模型可潜在辅助新药研发,提高新药临床前试验的准确率,降低新药研发的周期和成本。本文以肝脏代谢疾病为对象,对干细胞来源的肝脏细胞疾病模型在代谢功能方面的生理机制研究、药物筛选和评估等领域进行综述。     

具有保肝作用的天然药物开发进展

肝脏是机体代谢的最主要场所,也是机体最容易遭受到损伤的脏器之一,各种因素引起的肝损伤已成为威胁人类健康的重要疾病之一。肝损伤机制主要与线粒体损伤、自由基脂质过氧化、炎症细胞因子分泌和细胞膜损伤有关。目前已报道很多天然药物具有显著保肝作用,且具有疗效稳定、副作用低、多途径作用、作用温和持久等优势,已广泛用于肝脏疾病的防治。本文对肝损伤的生理机制以及具有保肝作用的天然药物开发进展进行了综述,提出了目前存在的一些问题并进行了展望。     

急性药物性肝损伤65例临床分析

目的:探讨急性药物性肝损伤的致病药物、临床特点及预后.方法:回顾性分析近年来本院确诊的急性药物性肝损伤患者的临床情况.结果:本组引起急性药物性肝损伤的最常见药物为抗结核药,占47.69％,其次为中草药、抗肿瘤药、滋补药、抗真菌药,分别占16.92％、9.23％、7.69％、3.61％.引起肝损伤发生时间因所用药物不同而差异较大,用药后出现药物性肝损伤的时间分别为用药2周内(36.92％)、2-4周内(32.31％)、4周-12周内(23.08％)、大于12周(7.69％),大多数病例出现于服药后12周内(92.31％.本组急性药物性肝损伤的临床表现主要为消化道症状明显,乏力、食欲下降,占89.23％;巩膜黄染、尿黄,占43.08％;皮肤瘙痒38.46％;恶心、呕吐,占35.38％;药物性肝损伤临床分型以肝细胞损伤型多见,占61.54％,其次为胆汁淤积型(29.23％),混合型较少(9.23％).结论:引起急性药物性肝损伤的药物种类繁多,很多临床常见的药物可引起肝损伤,早期诊断并停止用药、积极治疗是阻止疾病进展和改善预后的关键.     

In vitro hepatic steatosis model based on gut–liver-on-a-chip

Hepatic steatosis, also known as fatty liver disease, occurs due to abnormal lipid accumulation in the liver. It has been known that gut absorption also plays an important role in the mechanism underlying hepatic steatosis. Conventional in vitro cell culture models have limitations in recapitulating the mechanisms of hepatic steatosis because it does not include the gut absorption process. Previously, we reported development of a microfluidic gut–liver chip that can recapitulate the gut absorption of fatty acids and subsequent lipid accumulation in liver cells. In this study, we performed a series of experiments to verify that our gut–liver chip reproduces various aspects of hepatic steatosis. The absorption of fatty acids was evaluated under various culture conditions. The anti-steatotic effect of turofexorate isopropyl (XL-335) and metformin was tested, and both drugs showed different action mechanisms. In addition, the oxidative stress induced by lipid absorption was evaluated. Our results demonstrate the potential of the gut–liver chip for use as a novel, physiologically realistic in vitro model to study fatty liver disease.     

Asiatic acid inhibits liver fibrosis by blocking TGF-beta/Smad signaling in vivo and in vitro

Liver fibrosis is a major cause of liver failure, but treatment remains ineffective. In the present study, we investigated the mechanisms and anti-hepatofibrotic activities of asiatic acid (AA) in a rat model of liver fibrosis induced by carbon tetrachloride (CCl(4)) and in vitro in TGF-beta1-stimulated rat hepatic stellate cell line (HSC-T6). Treatment with AA significantly attenuated CCl(4)-induced liver fibrosis and functional impairment in a dosage-dependent manner, including blockade of the activation of HSC as determined by inhibiting de novo alpha smooth muscle actin (a-SMA) and collagen matrix expression, and an increase in ALT and AST (all p<0.01). The hepatoprotective effects of AA on fibrosis were associated with upregulation of hepatic Smad7, an inhibitor of TGF-beta signaling, thereby blocking upregulation of TGF-beta1 and CTGF and the activation of TGF-beta/Smad signaling. The anti-fibrosis activity and mechanisms of AA were further detected in vitro in HSC-T6. Addition of AA significantly induced Smad7 expression by HSC-T6 cells, thereby inhibiting TGF-beta1-induced Smad2/3 activation, myofibroblast transformation, and collagen matrix expression in a dosage-dependent manner. In contrast, knockdown of Smad7 in HSC-T6 cells prevented AA-induced inhibition of HSC-T6 cell activation and fibrosis in response to TGF-beta1, revealing an essential role for Smad7 in AA-induced anti-fibrotic activities during liver fibrosis in vivo and in vitro. In conclusion, AA may be a novel therapeutic agent for liver fibrosis. Induction of Smad7-dependent inhibition of TGF-beta/Smad-mediated fibrogenesis may be a central mechanism by which AA protects liver from injury.     

The HepaRG cell line,a superior in vitro model to L-02, HepG2 and hiHeps cell lines for assessing drug-induced liver injury

Drug-induced liver injury (DILI) is a leading cause of discontinuation of new drug approval or withdrawal of marketed medicine based on safety due to organ vulnerability. The aim of this research is to investigate the potential abilities of four different in vitro cell models (L-02, HepG2, HepaRG, and hiHeps cell lines) in assessing marketed drugs labeled with apparently different types of liver injury. A total of 17 drugs with versatile pharmacological profiles were chosen, of which, 14 drugs are recognized as DILI agents and 3 drugs are DILI irrelevant. Preliminary cellular screening assays indicated that the HepaRG cell line had an advantage over other cell lines in predicting drugs associated with DILI in vitro as it had the highest Youden’s index (71.4 %). A multi-parametric screening assay showed that oxidative stress, mitochondrial damage, and disorders of neutral lipid metabolism were changed notably in the HepaRG cell line after DILI-related drugs exposure, accounting for its high sensitivity in comparison with other three cell lines. In addition, aspartate aminotransferase (AST), lactate dehydrogenase (LDH), and malate dehydrogenase (MDH) all correlated with the cytotoxic effects of diclofenac sodium (p?<?0.05), buspirone hydrochloride (p?<?0.01), and danazol (p?<?0.01) in the HepaRG cell line. We conclude that the HepaRG cell line is a superior in vitro cell model to other three cell lines for evaluating drugs with DILI potential.     

Effects of endothelins on hepatic stellate cell synthesis of endothelin-1 during hepatic wound healing

Endothelin-1 production is increased after liver injury and the subsequent wounding response. Further, endothelin-1 has prominent effects on hepatic stellate cells (key effectors of the hepatic wounding response), including on collagen synthesis, proliferation, and expression of smooth muscle proteins. We tested the hypothesis that endothelins (ETs) may regulate endothelin-1 production during hepatic wounding, and have investigated potential mechanisms underlying this process. Studies were performed on isolated stellate cells from normal and injured livers; in addition, potential autocrine effects of ET were assessed in vivo using an ET receptor antagonist in a model of liver injury. In stellate cells isolated from either normal or injured rat livers, ET receptor stimulation with endothelin-3 or sarafotoxin S6C (preferential ET(B) agonists) caused a dose-dependent increase in endothelin-1 production. Additionally, administration of a mixed ET antagonist in vivo during injury led to reduced stellate cell production of endothelin-1. The mechanism by which ETs stimulated endothelin-1 in this system appeared to be through upregulation of ET converting enzyme-1 (which converts precursor ET to mature peptide), rather than by modulation of precursor endothelin-1. We conclude that during liver injury and wound healing, stellate cell endothelin-1 production is, at least partially, stimulated by ETs via autocrine mechanisms that occur at the level of ET converting enzyme-1.     

Hepatic progenitor cell resistance to TGF-beta1's proliferative and apoptotic effects

The success of hepatocellular therapies using stem or progenitor cell populations is dependent upon multiple factors including the donor cell, microenvironment, and etiology of the liver injury. The following experiments investigated the impact of TGF-beta1 on a previously described population of hepatic progenitor cells (HPC). The majority of the hepatic progenitor cells were resistant to endogenously produced TGF-beta1's proapoptotic and anti-proliferative effects unlike more well-differentiated cellular populations (e.g., mature hepatocytes). Surprisingly, in vitro TGF-beta1 supplementation significantly inhibited de novo hepatic progenitor cell colony formation possibly via an indirect mechanism(s). Therefore despite the HPC's direct resistance to supplemental TGF-beta1, this cytokine's inhibitory effect on colony formation could have a potential negative impact on the use of these cells as a therapy for patients with liver disease.     

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...     

蟛蜞菊内酯对四氯化碳致小鼠肝损伤的保护作用

目的:研究中药活性物质蟛蜞菊内酯的保肝作用及其机制。方法:采用小鼠腹腔注射CCl4制作肝损伤模型,测定小鼠血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)、丙二醛(MDA),谷胱甘肽(GSH)和超氧化物歧化酶(SOD)指标,进行肝脏的组织病理学检查,观察蟛蜞菊内酯对CCl4所致肝损伤的保护作用。结果:蟛蜞菊内酯能明显降低肝损伤小鼠的血清ALT、AST和肝组织匀浆中MDA含量,SOD活力增强,明显减轻肝组织变性。结论蟛蜞菊内酯对CCl4引起的肝损伤有明显的保护作用,其机制可能与其抗氧化作用有关。     

Innate immunity of the liver microcirculation

The liver is a complex organ with a unique microcirculation and both synthetic and immune functions. Innate immune responses have been studied in response to single inflammatory mediators and several clinically relevant models of infection and injury. While standard histological techniques have been used in many models, the liver microcirculation is also amenable to in vivo examination using epifluorescent, confocal and transillumination intravital microscopy. These techniques have begun to clarify not only the molecular mechanisms but also the specific cell populations involved in the liver inflammation. In this review, we discuss the cells and mediators involved in hepatic innate immunity in simple and complex models of injury and infection, and present the view that the liver microcirculation utilizes non-classical pathways for leukocyte recruitment.     

Molecular mechanisms of hepatic apoptosis

Apoptosis is a prominent feature of liver diseases. Causative factors such as alcohol, viruses, toxic bile acids, fatty acids, drugs, and immune response, can induce apoptotic cell death via membrane receptors and intracellular stress. Apoptotic signaling network, including membrane death receptor-mediated cascade, reactive oxygen species (ROS) generation, endoplasmic reticulum (ER) stress, lysosomal permeabilization, and mitochondrial dysfunction, is intermixed each other, but one mechanism may dominate at a particular stage. Mechanisms of hepatic apoptosis are complicated by multiple signaling pathways. The progression of liver disease is affected by the balance between apoptotic and antiapoptotic capabilities. Therapeutic options of liver injury are impacted by the clear understanding toward mechanisms of hepatic apoptosis.     

p53 involvement in the pathogenesis of fatty liver disease

Obesity is a major health problem in industrialized societies, and fatty liver disease (hepatic steatosis) is common in obese individuals. Oxidative stress originating from increased intracellular levels of fatty acids has been implicated as a cause of hepatocellular injury in steatosis, although the precise mechanisms remain to be elucidated. p53, widely known as a tumor suppressor, has been shown often to be activated in stressed cells, inducing cell cycle arrest or death. Here we demonstrate that p53 is involved in the molecular mechanisms of hepatocellular injury associated with steatosis. We found that p53 in the nucleus is induced in the liver from two mouse models of fatty liver disease, ob/ob and a transgenic mouse model that overexpresses an active form of sterol regulatory element-binding protein-1 in the liver (TgSREBP-1), the one with obesity and the other without obesity. This activation of the p53 pathway leads to the elevation of p21 mRNA expression, which can be considered an indicator of p53 activity, because ob/ob mice lacking p53 generated by targeting gene disruption exhibited the complete restoration of the p21 elevation to wild type levels. Consistent with these results, the amelioration of hepatic steatosis caused by Srebp-1 gene disruption in ob/ob mice lowered the p21 expression in a triglyceride content-dependent manner. Moreover, p53 deficiency in ob/ob mice resulted in a marked improvement of plasma alanine aminotransferase levels, demonstrating that p53 is involved in the mechanisms of hepatocellular injury. In conclusion, we revealed that p53 plays an important role in the pathogenesis of fatty liver disease.