Transcriptional profile of LPCs and HSCs following co-culture or conditioned-medium experiments

The aim of this project was to co-culture HSCs (LX-2 cells) with wildtype or c-MET deleted LPCs (BMOL-TAT cells). Additionally, BMOL-TAT cells were indirectly co-cultured by the addition of LX-2-conditioned medium. Bulk RNA-sequencing was then performed to assess transcriptional changes during cellular crosstalk. The results identified that LX-2 cells were not greatly affected at the transcriptional level following 48-hour co-culture with BMOL-TAT cells. However, wildtype and c-MET deleted BMOL-TAT cells were greatly affected at the transcriptomic level by signalling molecules present in LX-2-conditioned medium. This further reinforces the communicative relationship of LPCs and HSCs in diseased liver states. Upon addition of LX-2 conditioned medium on wildtype BMOL-TAT cells, BMOL-TAT cells upregulated expression of ECM remodelling genes, while downregulating expression of ECM deposition genes and cell adhesion genes. This was contrary to c-MET deleted BMOL-TAT cells in LX-2-conditioned medium experiments, as BMOL-TAT cells without the presence of the c-MET receptor decreased expression of ECM remodelling genes, while increasing expression of ECM deposition genes and cell adhesion genes. The data suggests that upon HSC stimulus, LPCs degrade ECM, to migrate to sites of injury and potentially aid in regeneration of the liver. However, without c-MET regulation, this process is hindered.

本研究旨在以LX-2细胞系作为肝星状细胞（Hepatic Stellate Cells，HSCs）的模型，与野生型或c-MET基因缺失的BMOL-TAT细胞系（肝祖细胞，Liver Progenitor Cells，LPCs）开展共培养实验。此外，本研究还通过添加LX-2细胞条件培养基的方式，对BMOL-TAT细胞进行间接共培养。随后采用批量RNA测序（bulk RNA-sequencing）技术，评估细胞互作过程中的转录组变化。
研究结果显示，与BMOL-TAT细胞共培养48小时后，LX-2细胞在转录水平未出现显著改变。然而，经LX-2细胞条件培养基处理后，野生型与c-MET基因缺失的BMOL-TAT细胞的转录组均受到显著调控。这进一步证实了病变肝脏状态下LPCs与HSCs之间的信号交流关系。
当向野生型BMOL-TAT细胞中添加LX-2细胞条件培养基时，BMOL-TAT细胞会上调细胞外基质（Extracellular Matrix，ECM）重塑相关基因的表达，同时下调ECM沉积相关基因与细胞黏附相关基因的表达。这一现象与经LX-2细胞条件培养基处理的c-MET基因缺失BMOL-TAT细胞的变化截然相反：缺失c-MET受体的BMOL-TAT细胞会下调ECM重塑相关基因的表达，同时上调ECM沉积相关基因与细胞黏附相关基因的表达。
上述数据表明，在受到HSCs刺激时，LPCs可通过降解细胞外基质迁移至损伤部位，进而助力肝脏再生；但在缺乏c-MET调控的情况下，这一过程会受到阻滞。