LC-MS/MS of mouse hepatocytes sorted by lobule layers

Hepatocytes of the mammalian liver are organized in liver lobules and operate in a spatially-dependent manner. Cells in different positions along the lobule’s porto-cenrtal axis, defined by the directionality of blood flow, express different genes and perform different liver tasks. Gradients of the transcriptome along liver lobule axis has been recently established, yet not for the hepatocyte proteome. We used two surface markers whose levels are inversely zonated – CD73 with a decreasing gradient from pericentral to periportal hepatocytes and E-cadherin with increasing gradient from portal to central hepatocytes. By staining for both surface markers, we efficiently isolated bulk populations of hepatocytes from distinct lobule layers by Fluorescence Activated Cell Sorting (FACS). Over all, we sorted 100,000 hepatocytes from each of eight spatially distinct populations, from five different mice. Cells were washed, digested by trypsin and subjected to LC-MS/MS. More cells from same populations from the same mice were also collected for mRNA sequencing and microRNA microarray profiling, to achieve a multi-omic view on spatially sorted hepatocytes, for better understanding of the transcriptomic and post-transcriptomic levels of regulation of liver zonation.