Investigation of hepatic stellate cell proteomics during activa-tion with fetal bovine serum

Hepatic stellate cells (HSCs) are the major driving factor in liver fibrosis. Upon liver inflammation caused by alcohol abuse and/or a fatty liver, HSCs transform from a quiescent- into a proliferating, fibrotic phenotype. We study this transformation termed “activation”, using state of the art TIMS-TOF mass spectrometry proteomics, as well as phenotype analysis of the immortalized LX-2 HSC cell line. In our work we employ a simple, yet reliable model of HSC activation via an in-crease in growth media serum concentration (serum activation). Protein network analysis of ac-tivated LX 2 cells reveals an increase in the production of ribosomal proteins and proteins related to migration. Interestingly, we could also observe a decrease in the expression of lipogenic pro-teins and a loss of cytosolic lipid droplets during activation. Especially the downregulation of proteins associated with cholesterol biosynthesis might be a promising target for further study. This work provides an update on HSC activation characteristics using contemporary proteomic and bioinformatic analysis and presents an accessible model for HSC activation.