Project description:Age-related decline in brain endothelial cell (BEC) function critically contributes to cerebrovascular and neurodegenerative disease. Comprehensive atlases of the BEC transcriptome have become available but results from proteomic profiling are lacking. To gain insights into endothelial pathways affected by aging, we developed a magnetic-activated cell sorting (MACS)-based mouse BEC enrichment protocol compatible with high-resolution mass-spectrometry and analysed the profiles of protein abundance changes across multiple time points between 3 and 18 months of age and identified Arf6 as one of the most prominently downregulated vesicle-mediated transport protein during BEC aging. To understand the role of ARF6 in human ECs, first we compared GFP-AAV treated human iECs differentiated from ARF6-KO vs WT iPSCs, next we compared ARF6-GFP-AAV vs GFP-AAV treated iECs differentiated from WT iPSCs. During the ARF6-KO vs WT iEC comparison we found 983 vs 741 proteins significantly down- and upregulated, respectively. Enrichment analyses of significantly downregulated proteins revealed mRNA processing among the most significantly affected biological processes. During the ARF6-GFP-AAV vs GFP-AAV treated WT iEC comparison we found 1106 vs 1218 proteins significantly down- and upregulated, respectively. Enrichment analyses of significantly upregulated proteins revealed endocytic recycling, retrograde transport (endosome to Golgi), and ER-Golgi vesicle-mediated transport among the most significantly affected biological processes. Specifically, ARF6 and its binding-protein GGA2, DNM1L and several subunits of the Conserved oligomeric Golgi complex (COG) were upregulated. Our approach uncovered changes not picked up by transcriptomic studies such as accumulation of vesicle cargo and receptor ligands including Apoe, a major regulator of brain lipid metabolism. Proteomic analysis of BECs from Apoe deficient mice revealed a signature of accelerated aging. To explore the role of APOE in human endothelial cells, in this experiment we compared human iECs differentiated from APOE-KO and WT iPSCs and found 326 significantly altered proteins. Enrichment analyses of significantly downregulated proteins revealed vesicle-mediated transport and vesicle fusion to be among the most significantly affected biological processes. Specifically, among the 34 significantly altered vesicle-mediated transport proteins 26 were downregulated. Accordingly, we found reduced levels of endocytosis of FM1-43FX in newly formed vesicles in APOE-KO iECs.
Project description:M. tuberculosis strain 1254 wild type (WT) and its isogenic delta Rv3662c-Rv3665c KO (opp KO) and complemented opp::opp were cultured in vitro, in liquid 7H9 media supplemented with OADC and 0.05% Tween 80, 0.5% glycerol, in a 150 mL volume, contained in roller bottles, incubated at 37oC. Growth was monitored as OD600 nm and recorded on a daily basis. In all experiments, the starting OD600 nm was 0.04-0.05. Aliquots were removed at each OD600 nm to make serial dilutions, plate onto 7H10 OADC agar plates for CFU counts. When cells reached OD600 nm of 0.3, 1.0, and 1.5, a 10-30 mL aliquot was taken, centrifuged 3 min at 3000 g, at room temperature, and the supernatant was discarded, with cell pellets being immediately frozen by inclusion into dry ice. Frozen cell pellets were stored at -80oC for later RNA isolation. In all experiments, RNA from WT was labeled with Cy5, and RNA from the opp KO was labeled with Cy3. In all experiments, the microarray comparsion used RNA from cells of the same growth stage, i.e., WT OD 0.3 vs opp KO OD 0.3, WT OD 1.0 vs opp KO OD 1.0, and WT OD 1.5 vs opp KO OD 1.5. When comparing the Complemented opp::opp vs the mutant opp KO, RNA from the later strain was Cy3-labeled. A cell type comparison design experiment design type compares cells of different type for example different cell lines.