Project description:The cells and mechanisms involved in blood clot resorption are only partially known. Regulatory T cells (Treg) accumulate in venous blood clots and regulate thrombolysis by controlling the recruitment, differentiation and matrix metalloproteinase (MMP) activity of monocytes. The clot Treg population is heterogeneous and contains a population of Treg that forms the matricellular acid- and cysteine-rich protein (SPARC). SPARC induces MMP activity in monocytes and SPARC+ Treg are required for clot resorption.
Project description:Transcriptional profiling shows that Treg in venous thrombi take on a repair Treg profile and produce the matricellular protein SPARC
Project description:The aim of this study was evaluate the transcriptome changes in the comparison between triple negative tumors with increased SPARC expression and triple negative tumors with decreased SPARC expression according to Nagai et al., 2011 (Breast Cancer Res Treat (2011) 126:1–14) The results generated could be of particular interest to better define the prognostic impact of SPARC expression in triple negative breast tumors
Project description:Two matched groups of Heart Failure with reduced ejection fraction patients with no peripheral venous congestion were studied: with recent prior heart failure hospitalization vs. without recent heart failure hospitalization. Peripheral venous congestion was modeled by inflating a cuff around the dominant arm, targeting an ~30mmHg increase in venous pressure (venous stress test). Blood and endothelial cells were sampled before and after 90 minutes of venous stress test.
Project description:SPARC is a matricellular glycoprotein involved in regulation of the extracellular matrix, growth factors, adhesion, and migration. SPARC-null mice have altered basement membranes and develop posterior sub-capsular cataracts with cell swelling and equatorial vacuoles. Exchange of fluid, nutrients, and waste products in the avascular lens is driven by a unique circulating ion current. Here we demonstrate that SPARC-null mouse lenses exhibit abnormal circulation of fluid, ion, and small molecules which leads to altered fluorescein distribution in vivo, loss of resting membrane polarization, and altered distribution of small molecules. Microarray analysis of SPARC-null lenses showed changes in gene expression of ion channels and receptors, matrix and adhesion genes, cytoskeleton, immune response genes, and cell signaling molecules. Our results demonstrate that the regulation of SPARC on cell-capsular matrix interactions can influence the circulation of fluid and ions in the lens, and the phenotype in the SPARC-null mouse lens is the result of multiple intersecting pathways.
Project description:SPARC is a matricellular glycoprotein involved in regulation of the extracellular matrix, growth factors, adhesion, and migration. SPARC-null mice have altered basement membranes and develop posterior sub-capsular cataracts with cell swelling and equatorial vacuoles. Exchange of fluid, nutrients, and waste products in the avascular lens is driven by a unique circulating ion current. Here we demonstrate that SPARC-null mouse lenses exhibit abnormal circulation of fluid, ion, and small molecules which leads to altered fluorescein distribution in vivo, loss of resting membrane polarization, and altered distribution of small molecules. Microarray analysis of SPARC-null lenses showed changes in gene expression of ion channels and receptors, matrix and adhesion genes, cytoskeleton, immune response genes, and cell signaling molecules. Our results demonstrate that the regulation of SPARC on cell-capsular matrix interactions can influence the circulation of fluid and ions in the lens, and the phenotype in the SPARC-null mouse lens is the result of multiple intersecting pathways. Experiment Overall Design: Lens epithelial cells from 7 lenses of littermate mice were isolated by laser capture microdissection. 3 wild-type lenses from 3 different mice and 4 knock-out lenses from 3 different mice were used as biological replicates.
Project description:The vasculature of the liver is highly specialized and critical to organ function as well as future efforts to engineer new liver tissue. One key vascular sub type, the liver sinusoidal endothelial cell (LSEC) lines the hepatic sinusoid mediating functions such as passing nutrients to hepatocytes, scavenging blood components, secreting FVIII, and mediating regeneration. To better understand human LSECs and to generate them from human pluripotent stem cells, we differentiated hPSCs to venous endothelial progenitors known as angioblasts, transplanted them intrahepatically in NSG newborn mice, waited 77-days, and isolated the hPSC-derived cells (DAPI-, tdRFP+) for scRNA-seq. This scRNA-seq sample represents a large number of hPSC-derived, matured hepatic- origin fibroblast and endothelial cell types. Providing a high resolution, large sample population of cells that correlate closely to MacParland et al. (2018, Nat. Commun.) hepatic endothelial clusters providing increased cell population resolution sufficient for human LSEC zonation assessment in a tractable transplantation system.
Project description:Repair of the pulmonary vascular bed and the origin of new vasculature remains underexplored despite the critical necessity to meet oxygen demands after injury. Given their critical role in angiogenesis in other settings, we investigated the role of venous endothelial cells in endothelial regeneration after adult lung injury. Using single cell transcriptomics, we identified the norepinephrine transporter Slc6a2 as a marker of pulmonary venous endothelial cells and targeted that locus to generate a venous-specific, inducible Cre mouse line. Contributions of the venous endothelial cells to angiogenesis were examined during postnatal development, adult viral injury, and adult hyperoxia injury. Remarkably, we observed that venous endothelial cells proliferate into the adjacent capillary bed upon influenza injury and hyperoxia injury, but not during normal postnatal development. Imaging analysis demonstrated that venous endothelial cells exhibit the ability to proliferate and differentiate into general capillary and CAR4 expressing aerocyte capillary endothelial cells after infection, thus contributing to repair of the capillary plexus vital for gas exchange. Single cell transcriptomic analysis of Slc6a2 lineage traced cells confirmed these observations, with progeny exhibiting significant loss of venous identity and gain of capillary marker expression upon injury resolution. Our studies thus establish that venous endothelial cells exhibit demonstrable progenitor capacity upon respiratory viral injury and sterile injury, contributing to repair of the alveolar capillary bed responsible for pulmonary function.