中国人肝细胞系作为生物人工肝细胞材料的可行性探讨

目的探讨国内人肝细胞系作为生物人工肝细胞材料的可行性. 方法收集国内 9株人肝细胞系,体外培养,光镜、电镜下观察细胞生长分化特性;以流式细胞仪测定其 DNA指数值;测定培养上清中人白蛋白、尿素含量及安定转化量;将 CL-1细胞接种到裸鼠皮下,观察其致瘤性. 结果 9株人肝细胞系中, CL-1细胞分化最好, DI值与正常人淋巴细胞的 DI值最接近,生物合成及代谢功能最好,但有一定的致瘤性. 结论 9株人肝细胞系中, CL-1人肝细胞系最可能用作 BAL细胞材料,有进一步研究的价值.     

中国人肝细胞系作为生物人工肝细胞材料的可行性探讨

目的：探讨国内人肝细胞系作为生物人工肝细胞材料的可行性。方法：收集国内9株人肝细胞系，体外培养，光镜、电镜下观察细胞生长分化特性；以流式细胞仪测定其DNA指数值；测定培养上清中人白蛋白、尿素含量及安定转化量；将CL-1细胞接种到裸鼠皮下，观察其致瘤性。结果：9株人肝细胞系中，CL-1细胞分化最好，DI值与正常人淋巴细胞的DI值最接近，生物合成及代谢功能最好，但有一定的致瘤性。结论：9株人肝细胞系中，CL-1人肝细胞系最可能用作BAL细胞材料，有进一步研究的价值。     

C3A细胞与L-02永生化肝细胞低温保存条件下的生物学特性比较

背景:获得大量功能良好的肝细胞是生物人工肝的核心。探索出一种可靠的肝细胞低温保存方法进而构建一个肝细胞库是目前生物人工肝研究的热点。目的:比较用UW液在4℃条件下保存已经进入Ⅲ期临床试验的C3A细胞与国内构建的永生化肝细胞株L-02细胞的生物学特性。方法:贴壁培养C3A与L-02细胞,胰酶消化,制备成细胞悬液,UW液保存。4℃低温保存0,24,48及72h后,采用流式细胞术分别测定细胞存活率与凋亡率,测定谷草转氨酶与乳酸脱氢酶释放、尿素合成功能及白蛋白分泌功能。结果与结论:随低温保存时间延长,C3A与L-02细胞存活率呈下降的趋势,但C3A细胞的存活率明显高于L-02细胞(P<0.01);细胞凋亡率呈上升趋势,但48h后C3A细胞同L-02细胞无差异(P>0.05)。谷草转氨酶及乳酸脱氢酶释放呈现上升的趋势,但C3A细胞明显低于L-02细胞(P<0.01)。白蛋白分泌功能呈下降的趋势,但C3A细胞明显优于L-02细胞(P<0.01)。尿素合成功能呈下降的趋势,但是L-02细胞明显优于C3A细胞(P<0.01)。结果提示,UW液4℃保存C3A细胞与L-02细胞时间不易超过48h。以C3A细胞为材料的人工肝可能更适用于肝功能衰竭合并低白蛋白血症,以L-02细胞为材料的人工肝更适用于肝功能衰竭合并肝性脑病。     

C3A细胞与L-02永生化肝细胞低温保存条件下的生物学特性比较

背景：获得大量功能良好的肝细胞是生物人工肝的核心。探索出一种可靠的肝细胞低温保存方法进而构建一个肝细胞库是目前生物人工肝研究的热点。目的：比较用UW液在4℃条件下保存已经进入Ⅲ期临床试验的C3A细胞与国内构建的永生化肝细胞株L-02细胞的生物学特性。方法：贴壁培养C3A与L-02细胞,胰酶消化,制备成细胞悬液,UW液保存。4℃低温保存0,24,48及72h后,采用流式细胞术分别测定细胞存活率与凋亡率,测定谷草转氨酶与乳酸脱氢酶释放、尿素合成功能及白蛋白分泌功能。结果与结论：随低温保存时间延长,C3A与L-02细胞存活率呈下降的趋势,但C3A细胞的存活率明显高于L-02细胞（P〈0.01）;细胞凋亡率呈上升趋势,但48h后C3A细胞同L-02细胞无差异（P〉0.05）。谷草转氨酶及乳酸脱氢酶释放呈现上升的趋势,但C3A细胞明显低于L-02细胞（P〈0.01）。白蛋白分泌功能呈下降的趋势,但C3A细胞明显优于L-02细胞（P〈0.01）。尿素合成功能呈下降的趋势,但是L-02细胞明显优于C3A细胞（P〈0.01）。结果提示,UW液4℃保存C3A细胞与L-02细胞时间不易超过48h。以C3A细胞为材料的人工肝可能更适用于肝功能衰竭合并低白蛋白血症,以L-02细胞为材料的人工肝更适用于肝功能衰竭合并肝性脑病。     

中国人肝细胞系1运用于生物人工肝的生物代谢功能

背景：前期研究发现,中国人肝细胞系1细胞分化程度高且生物代谢功能良好,并且中国人肝细胞系1细胞组织学上来源于正常肝组织,较其他来源于肿瘤源性的肝细胞系更为安全。目的：探讨中国人肝细胞系中国人肝细胞系1细胞在混合型生物人工肝中的生物代谢功能。方法：15只食蟹猴随机分成对照组（n=5）和治疗组（n=10）,均建立急性肝功能衰竭模型,治疗组接受以全接触灌流型生物反应器接种微载体微重力中国人肝细胞系1细胞建立的人源细胞混合型生物人工肝进行治疗。结果与结论：急性肝功能衰竭食蟹猴血清谷氨酸转氨酶、总胆红素、总胆汁酸、尿素氮、肌酐、血氨均明显上升,而白蛋白、Fischer指数则显著下降;人源细胞混合型生物人工肝治疗后,急性肝功能衰竭食蟹猴血清谷氨酸转氨酶、总胆红素、总胆汁酸、尿素氮、肌酐、血氨和白蛋白均恢复。提示中国人肝细胞系1细胞在混合型生物人工肝中生物代谢功能良好,表现出良好的肝特异性生物合成及生物代谢功能。     

人骨髓干细胞在中空纤维滤器中诱导分化构建生物人工肝反应器的可行性研究

目的 探讨以人骨髓干细胞在中空纤维滤器中直接扩增并诱导分化为类肝细胞,从而直接构建成生物人工肝反应器的可行性. 方法 取志愿者骨髓血,人骨髓间充质干细胞分离、扩增至107数量级后种植入中空纤维滤器,继续培养扩增10 d后,以含重组人肝细胞生长因子(rhHGF)、重组人碱性成纤维细胞生长因子4(rhFGF-4)、重组人制瘤素M(rhOSM)等细胞因子的培养液诱导分化,检测培养上清液中白蛋白、甲胎蛋白(AFP)水平;诱导18 d后检测氨代谢、安定代谢及尿素合成等功能.培养结束后以流式细胞仪检测消化滤器内细胞白蛋白表达率.培养全过程监测滤器内培养液葡萄糖浓度变化. 结果 ①扩增培养期人骨髓间充质干细胞在中空纤维滤器内种植后的葡萄糖摄取量呈进行性升高,在诱导分化期保持相对平稳,诱导培养结束时细胞总数达109数量级.②进行诱导培养后6 d,培养上清液中出现AFP,12 d达到峰值;9 d出现白蛋白并持续进行性升高;诱导培养18 d时,滤器内细胞总体氨清除速率为2.0～2.7 mmol/24 h,尿素产生速率为1.8～2.2 mmol/24 h,安定清除速率为3.2～3.8 mg/24 h.③21 d滤器内细胞白蛋白表达率为66.18%～76.91%. 结论 人骨髓干细胞可在中空纤维滤器内扩增,并分化为肝细胞样细胞,成为具有一定功能的生物人工肝反应器.     

生物人工肝肝细胞培养研究进展

近年来,体外人工肝支持系统得到了极大的发展,先后出现了多种模式,Uchino等将人工肝分为生物型、非生物型、中间型及杂合生物型等四种类型。目前公认以杂合性生物人工肝效果最好,是人工肝支持系统(BALSS)的主流模式。杂合性生物人工肝一般由三部分组成:①生物成份;②生物反应器;③血液灌流系统。在这三部分中,生物成份是BALSS的核心,主要为动物或人的肝细胞培养物,发挥肝细胞的合成、代谢、解毒、排泄以及免疫等功能。可以说,获得大量具有良好肝特异功能的细胞是关     

壳聚糖球形多孔微载体支持下培养的肝细胞功能及其代谢活性检测

背景:在肝细胞移植及生物型人工肝研究中,肝细胞培养仍然是其关键,如何方便地获取足够数量、活性较好、功能良好的肝细胞已经成为其首要问题。微载体培养技术作为一项体外高密度细胞培养技术,近年来已在肝细胞的体外培养中得到应用。目的:对壳聚糖球形多孔微载体培养的人肝细胞L-02进行定时的细胞功能和代谢活性检测。方法:对以自制的壳聚糖球形多孔微载体样本为支架培养的人肝细胞L-02进行定时的细胞功能检测(包括测定谷草转氨酶,谷丙转氨酶和乳酸脱氢酶质量浓度)和代谢活性检测(包括检测培养基中白蛋白、尿素、葡萄糖含量),其中实验组为壳聚糖球形多孔微载体支持下培养人肝细胞L-02,对照组为无壳聚糖球形多孔微载体支持下培养人肝细胞L-02,检测时间点为人肝细胞L-02培养的第1,2,3,4,5天。结果与结论:实验组和对照组测定的谷草转氨酶、谷丙转氨酶和乳酸脱氢酶活性在前3d持续下降,第3天降到最低,而从第4天开始重新反弹上升;但白蛋白、尿素和葡萄糖水平在前3d持续上升,第3天升到最高值,而从第4天开始逐渐下降,实验组每天测定上述各项水平始终明显高于对照组(P<0.05),提示实验组中的人肝细胞L-02代谢活性较对照组增强。     

生物人工肝的研究与进展

目的:分析近些年来生物人工肝相关的研究,对生物人工肝的发展作一总结.资料来源:以bioartificial liver, liver cell, hepatocyte culture, bioreactor为检索词,检索Ovid、SpringerLink数据库(1990-09/2008-09);以生物人工肝、肝细胞、细胞培养、生物反应器为检索词,检索维普数据库、中国期刊网及万方数据库(1990-09/2008-09).文献检索语种限制为英文和中文.资料选择:纳入有关生物人工肝肝细胞、反应器及辅助装置的研究,排除生物人工肝免疫和动物传染的研究.结局评价指标:①生物人工肝肝细胞的来源、数量及培养方式.②生物反应器的类型及主要结构膜的性质及类别.③生物人工肝供氧及温控装置的构成.结果:计算机初检得到3 898篇文献,根据纳入排除标准,对29篇进行分析.生物人工肝是在体外生物反应器中培养肝细胞,当患者的血液流经生物反应器时,通过半透膜或直接接触的方式与培养的肝细胞进行物质交换,使其中的肝细胞发挥解毒、合成、生物转化等功能,以达到支持和治疗目的.它不但具有解毒功能,而且还能参与3大营养物质代谢,分泌促进肝细胞生长的物质等,可有效替代肝脏的解毒功能和合成功能,并可较好地预防肝性脑病、肝昏迷和脑水肿,临床上可作为肝衰竭患者肝移植前的过渡辅助措施.结论:生物人工肝研究虽然取得了重大进展,但仍然面临寻找理想肝细胞来源,长期维持肝细胞的活性和功能,进一步优化反应器设计等问题.     

模拟构建人肝衰竭血清对体外培养肝细胞功能的影响

背景:生物人工肝核心材料为肝细胞,其功能好坏直接影响临床效果.目的:模拟构建一种能够和肝衰竭血清对体外培养肝细胞具有相同生物学效应的组合物.方法:观察和对比模拟肝衰竭血清、人肝衰竭血清和体积分数10%胎牛血清对培养的 CL-1 细胞形态学和细胞活力的变化,检测 CL-1 细胞酶包括乳酸脱氢酶、谷丙转氨酶、谷草转氨酶及谷胱甘肽的分泌量.结果与结论:模拟肝衰竭血清和人肝衰竭血清对培养的 CL-1 细胞活力,乳酸脱氢酶、谷丙转氨酶、谷草转氨酶和谷胱甘肽的分泌量的影响差异无显著性意义(P>0.05),CL-1细胞的生长均受到抑制,体积分数10%胎牛血清细胞功能良好.结果提示,模拟肝衰竭血清组合物与人肝衰竭血清对CL-1细胞的生物学效应基本相同.     

人骨髓干细胞异体内诱导分化为肝细胞的实验

背景:如何获取来源丰富的高质量人源性肝细胞是生物人工肝和肝细胞移植共同面临的问题。骨髓干细胞在适当条件下可分化为肝细胞,为获取肝细胞提供了新的思路。目的:探讨人骨髓干细胞在大鼠体内诱导分化为肝细胞的方法,为解决临床肝脏移植和生物人工肝来源提供新的思路。设计:随机对照实验。单位:南方医科大学珠江医院普通外科。材料:实验于2004-05/2005-02在南方医科大学珠江医院中心实验室完成。选取雄性清洁级SD大鼠40只,随机分为5组:单纯模型组、造模 人骨髓干细胞移植14d组、造模 人骨髓干细胞移植28d组、造模 CL-1细胞(人肝细胞系)移植14d组、造模 CL-1细胞(人肝细胞系)移植28d组,8只/组。方法:①5组均建立2-乙酰氨基芴 四氯化碳 环磷酰胺肝损伤模型。②利用治疗性肝再生策略,将人骨髓干细胞移植到大鼠肝脏内诱导分化为肝细胞。造模 人骨髓干细胞移植14d组移植人骨髓干细胞后观察14d,造模 人骨髓干细胞移植28d组移植人骨髓干细胞后观察28d,造模 CL-1细胞移植14d组移植CL-1细胞后观察14d,造模 CL-1细胞移植28d组移植CL-1细胞后观察28d,单纯模型组未进行细胞移植。③各组在正常状态下以及移植前后进行血清标本的采集与肝功能检测。应用免疫组化、聚合酶链反应法、实时荧光定量反转录聚合酶链反应技术检测各组大鼠肝脏内人白蛋白的mRNA的表达。主要观察指标:①人骨髓干细胞移植对大鼠肝功能转氨酶及总胆红素含量的影响。②各组大鼠病理切片肝细胞形态检查结果。③各组大鼠肝脏中人主要组织相容性抗原-Ⅰ类阳性率。④各组大鼠肝脏中大鼠Sox11序列、人Alu-sx序列、人白蛋白mRNA基因的表达。结果:实验选用40只大鼠,全部进入结果分析。①人骨髓干细胞移植对大鼠肝功能转氨酶及总胆红素含量的影响:各细胞移植组在正常状态以及细胞移植前与单纯模型组基本相似(P>0.05);与正常状态比较,细胞移植前各组均显著增高(P<0.01);与细胞移植前比较,各细胞移植组在细胞移植后均显著降低(P<0.01),但仍高于正常状态下的转氨酶、总胆红素含量(P<0.01)。②各组大鼠病理切片肝细胞形态检查结果:正常情况下肝脏病理切片显示肝细胞排列成条索状,围绕中央静脉成放射状排列,汇管区无炎性细胞浸润;单纯模型组呈大片状坏死表现;人骨髓干细胞移植组可见一些坏死后增生性改变;CL-1细胞移植组可见卵圆细胞以及小胆管增生。③各组大鼠肝脏中人主要组织相容性抗原-Ⅰ类阳性率:单纯模型组为0,造模 人骨髓干细胞移植14d组为(13.03±0.18)%,造模 人骨髓干细胞移植28d组为(9.47±0.46)%,造模 CL-1细胞移植14d组为(10.27±0.50)%,造模 CL-1细胞移植28d组为(9.84±0.23)%。④各组大鼠肝脏中基因序列聚合酶链反应检测结果:单纯模型组大鼠肝脏中只检测到大鼠Sox11序列;而人骨髓干细胞移植、CL-1细胞移植各时间组均可检测到人Alu-sx序列和大鼠Sox11序列。⑤各组大鼠肝脏组织实时荧光定量反转录聚合酶链反应检测结果:单纯模型组大鼠肝脏组织中未检测到人白蛋白mRNA基因表达,人骨髓干细胞移植、CL-1细胞移植各时间组以及阳性对照均可检测到人白蛋白mRNA基因表达。结论:人骨髓干细胞移植能促进肝损伤大鼠的肝功能恢复,人源性细胞在肝损伤大鼠肝脏中的替代率约10%,提示人骨髓干细胞在异体内均可转化为肝细胞并可实现部分替代。     

Biotransformation of diazepam in a clinically relevant flat membrane bioreactor model using primary porcine hepatocytes

In vitro biotransformation of drug using commercial culture medium with serum may not be the ideal culture medium for clinical application in extracorporeal bioartificial liver support (BAL) systems. In these systems, patient’s blood or plasma is plumbed to primary hepatocytes within a seeded bioreactor, creating interaction between plasma and seeded hepatocytes. To address this situation, we investigated the biotransformation potential of diazepam in primary porcine hepatocytes with a flat membrane bioreactor (FMB); we used human plasma exposure and serum‐free media in organotypical double gel culture model for long‐term culture. We investigated diazepam clearance and all major metabolites of diazepam, such as oxazepam, temazepam, and desmethyldiazepam, in conventional single gel and organotypical sandwich models and compared them to the FMB model. Diazepam elimination was higher in double gel cultures with exposure to both SF 3 medium conditions and plasma, when compared to the single gel model in a Petri dish. It was observed that in the FMB, diazepam elimination was stable at about 3 pg/h/cell in plasma and SF 3 exposure. Oxazepam synthesis in the bioreactor was approximately one quarter less than in the Petri dish, but there were no differences between N‐desmethyldiazepam and temazepam synthesis in double gel culture. In the flat membrane bioreactor, there was no decrease in the biotransformation of diazepam in plasma exposure compared with the control group. Our results suggest that this plasma exposure bioreactor may offer a useful approach in clinical use of extracorporeal BAL, as well as for drug metabolite investigation into toxicological research.     

Differentiation of human‐induced pluripotent stem cell under flow conditions to mature hepatocytes for liver tissue engineering

Hepatic differentiation of human‐induced pluripotent stem cells (hiPSCs) under flow conditions in a 3D scaffold is expected to be a major step forward for construction of bioartificial livers. The aims of this study were to induce hepatic differentiation of hiPSCs under perfusion conditions and to perform functional comparisons with fresh human precision‐cut liver slices (hPCLS), an excellent benchmark for the human liver in vivo. The majority of the mRNA expression of CYP isoenzymes and transporters and the tested CYP activities, Phase II metabolism, and albumin, urea, and bile acid synthesis in the hiPSC‐derived cells reached values that overlap those of hPCLS, which indicates a higher degree of hepatic differentiation than observed until now. Differentiation under flow compared with static conditions had a strong inducing effect on Phase II metabolism and suppressed AFP expression but resulted in slightly lower activity of some of the Phase I metabolism enzymes. Gene expression data indicate that hiPSCs differentiated into both hepatic and biliary directions. In conclusion, the hiPSC differentiated under flow conditions towards hepatocytes express a wide spectrum of liver functions at levels comparable with hPCLS indicating excellent future perspectives for the development of a bioartificial liver system for toxicity testing or as liver support device for patients.     

Ammonia and glutamine metabolism in human liver slices: new aspects on the pathogenesis of hyperammonaemia in chronic liver disease

Ammonia and glutamine metabolism was studied in slices from normal, fatty and cirrhotic human livers. The liver disease was evaluated by histological examination. With respect to ammonia removal, urea and glutamine synthesis in human liver represent low and high affinity systems with k0.5(NH4+) values of 3.6 and 0.11 mM, respectively. Compared with normal control livers, cirrhotic livers showed a decreased glutamine synthesis from NH4Cl by about 80%. The same was true for urea synthesis. Conversely, flux through hepatic glutaminase was increased in cirrhosis 4-6-fold. These changes in hepatic glutamine and ammonia metabolism were observed regardless of whether reference was made to liver wet weight, DNA or protein content. Acetazolamide inhibited urea synthesis in cirrhotic liver slices by about 50%, indicating that mitochondrial carbonic anhydrase is required for urea synthesis also in cirrhosis. There was a significant correlation between the in-vitro determined capacity for urea synthesis from NH4Cl and the in-vivo determined plasma bicarbonate concentration.(ABSTRACT TRUNCATED AT 250 WORDS)     

体外生物人工肝支持系统治疗肝功能衰竭的系统评价

背景：生物人工肝支持系统由生物反应器和细胞材料组成,治疗过程中可部分替代肝脏的主要功能如解毒、合成、分泌和生物转化等功能。目的：回顾和评价体外生物人工肝支持系统近15年来治疗肝功能衰竭的疗效。方法：检索1995至2009年PubMed和Cochrane数据库有关生物人工肝支持系统的临床研究。被纳入的研究类型包括随机对照试验、临床对照试验和病例报告。结果与结论：共纳入31项研究,在生物人工肝支持系统治疗之后,患者生化指标呈现好转趋势,且大部分患者神经系统症状均得到改善,但多数患者生存率未见明显改善。说明尽管生物人工肝支持系统被证明具有一定治疗效果,但今后仍然有许多方面需要改进。     

Serum protein binding of phenytoin, diazepam and propranolol in age-related decrease in renal function

The serum protein binding of phenytoin, diazepam and propranolol was investigated in vitro in 32 elderly people with an age-related decrease in renal function by a pressure ultrafiltration method at 37 degrees C. The mean age of the patients was 88 +/- 1 years (mean +/- SE), and their mean 51Cr-EDTA clearance 46 +/- 4 ml/min. The main reason for hospitalization of these patients was their age. The free fraction of phenytoin correlated negatively with the serum albumin concentration, and that of propranolol with the alpha 1-acid glycoprotein (alpha 1-AGP) concentration. The free fraction of diazepam did not correlate with either of these binding proteins. In stepwise multiple regression analysis, the most significant variable for phenytoin free fraction was serum albumin concentration, with the serum urea concentration coming in second place. For the diazepam free fraction, the only significant variable was the serum urea level, although in the correlation matrix the correlation with creatinine was also significant. When the effect of serum albumin level was corrected mathematically, the urea level was the best determinant in regression analysis for both the phenytoin and diazepam free fractions. It can be concluded that an age-dependent decrease in renal function increases the free fraction of phenytoin and diazepam and is, together with hypoalbuminaemia, responsible for the increased free fraction of these drugs in the elderly. For propranolol the only important factor is the serum alpha 1-acid glycoprotein concentration.     

Multipotent adult progenitor cells from bone marrow differentiate into functional hepatocyte-like cells

We have derived from normal human, mouse, and rat postnatal bone marrow primitive, multipotent adult progenitor cells (MAPCs) that can differentiate into most mesodermal cells and neuroectodermal cells in vitro and into all embryonic lineages in vivo. Here, we show that MAPCs can also differentiate into hepatocyte-like cells in vitro. Human, mouse, and rat MAPCs, cultured on Matrigel with FGF-4 and HGF, differentiated into epithelioid cells that expressed hepatocyte nuclear factor-3beta (HNF-3beta), GATA4, cytokeratin 19 (CK19), transthyretin, and alpha-fetoprotein by day 7, and expressed CK18, HNF-4, and HNF-1alpha on days 14-28. Virtually all human, as well as a majority of rodent cells stained positive for albumin and CK18 on day 21; 5% (rodent) to 25% (human) cells were binucleated by day 21. These cells also acquired functional characteristics of hepatocytes: they secreted urea and albumin, had phenobarbital-inducible cytochrome p450, could take up LDL, and stored glycogen. MAPCs, which can be expanded in vitro and maintained in an undifferentiated state for more than 100 population doublings, can thus differentiate into cells with morphological, phenotypic, and functional characteristics of hepatocytes. MAPCs may therefore be an ideal cell for in vivo therapies for liver disorders or for use in bioartificial liver devices.