METHODS: RNAseq was performed to identify molecular signaling pathways affected by all-trans retinoid acid (atRA) treatment in HepaRG LPCs. Functional assays were performed in HepaRG cells treated with atRA or cocultured with LX-2 cells and in the liver tissue of patients suffering from ALF.
RESULTS: Under ALF conditions, activated HSCs secreted RA, inducing RARα nuclear translocation in LPCs. RNAseq data and investigations in HepaRG cells revealed that atRA treatment activated the WNT-β-Catenin pathway, enhanced stemness genes (SOX9, AFP, and others), increased energy storage, and elevated the expression of ATP-binding cassette transporters in a RARα nuclear translocation-dependent manner. Further, atRA treatment-induced pathways were confirmed in a coculture system of HepaRG with LX-2 cells. Patients suffering from ALF who displayed RARα nuclear translocation in the LPCs had significantly better MELD scores than those without.
CONCLUSIONS: During ALF, RA secreted by activated HSCs promotes LPC activation, a prerequisite for subsequent LPC-mediated liver regeneration.
方法:进行RNAseq以鉴定HepaRGLPCs中全反式维甲酸(atRA)处理影响的分子信号通路。在用atRA处理或与LX-2细胞共培养的HepaRG细胞中以及患有ALF的患者的肝组织中进行功能测定。
结果:在ALF条件下,激活的HSC分泌RA,在LPCs中诱导RARα核易位。在HepaRG细胞中的RNAseq数据和研究表明,atRA治疗激活了WNT-β-Catenin通路,增强的干性基因(SOX9,AFP,和其他),增加能量储存,并以RARα核易位依赖性方式提高了ATP结合盒转运蛋白的表达。Further,在HepaRG与LX-2细胞的共培养系统中证实了atRA治疗诱导的途径。在LPC中显示RARα核易位的患有ALF的患者的MELD评分明显优于没有的患者。
结论:在ALF期间,激活的HSC分泌的RA促进LPC激活,随后LPC介导的肝脏再生的先决条件。