Investigating Nonalcoholic Fatty Liver Disease in a Liver-on-a-Chip Microfluidic Device.
Investigating Nonalcoholic Fatty Liver Disease in a Liver-on-a-Chip Microfluidic Device.
复制标题
DOI：
10.1371/journal.pone.0159729
复制
发表时间：
2016
期刊：
影响因子：
3.7
通讯作者：
Rainer A
中科院分区：
文献类型：
--
作者：
Gori M;Simonelli MC;Giannitelli SM;Businaro L;Trombetta M;Rainer A
非酒精性脂肪性肝病（NAFLD）是一种世界范围内的慢性肝病，从单纯性脂肪变性到非酒精性脂肪性肝炎，其可能进展为肝硬化，最终导致肝细胞癌（HCC）。HCC是全球癌症相关死亡的第三大原因，需要早期诊断NAFLD作为潜在的风险因素。然而，NAFLD的分子机制仍在研究中。到目前为止，许多关于NAFLD的体外研究都受到2D培养系统的限制，其中细胞迅速失去组织特异性功能。目前的肝芯片方法旨在填补常规体外模型（通常几乎不能预测体内条件）与动物模型（可能因其异种性质而产生偏差）之间的差距。将HepG 2细胞在游离脂肪酸（FFA）补充下（即棕榈酸和油酸）培养到微流体灌注装置中24小时和48小时。该装置模拟了肝窦的内皮-实质界面，允许类似于肝微血管的营养物质扩散和废物清除。通过使用基于荧光的功能探针的高含量分析方法，对细胞内脂质蓄积、细胞活力/细胞毒性和FFA过载引起的氧化应激进行评估。该芯片能够在微流体动态与2D静态培养物中实现逐渐和较低的细胞内脂质积累、较高的肝细胞活力和最小的氧化应激，从而更接近地模拟体内观察到的脂肪变性的慢性病症。总的来说，肝芯片系统提供了一个合适的培养微环境，代表了一个更可靠的模型相比，2D文化研究NAFLD发病机制。因此，我们的系统是在微流体装置内以窦状隙方式开发的人类NAFLD的第一个体外模型之一，为肝细胞的长期培养提供了比传统的2D静态培养更宽松的组织样微环境。
Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease worldwide, ranging from simple steatosis to nonalcoholic steatohepatitis, which may progress to cirrhosis, eventually leading to hepatocellular carcinoma (HCC). HCC ranks as the third highest cause of cancer-related death globally, requiring an early diagnosis of NAFLD as a potential risk factor. However, the molecular mechanisms underlying NAFLD are still under investigation. So far, many in vitro studies on NAFLD have been hampered by the limitations of 2D culture systems, in which cells rapidly lose tissue-specific functions. The present liver-on-a-chip approach aims at filling the gap between conventional in vitro models, often scarcely predictive of in vivo conditions, and animal models, potentially biased by their xenogeneic nature. HepG2 cells were cultured into a microfluidically perfused device under free fatty acid (FFA) supplementation, namely palmitic and oleic acid, for 24h and 48h. The device mimicked the endothelial-parenchymal interface of a liver sinusoid, allowing the diffusion of nutrients and removal of waste products similar to the hepatic microvasculature. Assessment of intracellular lipid accumulation, cell viability/cytotoxicity and oxidative stress due to the FFA overload, was performed by high-content analysis methodologies using fluorescence-based functional probes. The chip enables gradual and lower intracellular lipid accumulation, higher hepatic cell viability and minimal oxidative stress in microfluidic dynamic vs. 2D static cultures, thus mimicking the chronic condition of steatosis observed in vivo more closely. Overall, the liver-on-a-chip system provides a suitable culture microenvironment, representing a more reliable model compared to 2D cultures for investigating NAFLD pathogenesis. Hence, our system is amongst the first in vitro models of human NAFLD developed within a microfluidic device in a sinusoid-like fashion, endowing a more permissive tissue-like microenvironment for long-term culture of hepatic cells than conventional 2D static cultures.