Project description:Purpose:Single cell RNA sequencing to identify PDGFR-beta expressing cells in the normal adult lung Methods: Adult Pdgfrb-CreERT2, ROSA26R(Zs/+) mice were induced with tamoxifen (1mg/day for 5 days) and rested for 5 days. Lungs were then harvested and prepared to obtain single cell suspension. Live Zs+ and Zs- cells were isolated by FACS and hash-tagged. Cells were then pooled together in PBS with 0.04% bovine serum albumin and subjected to library preparation and DropSeq. scRNA-seq data was processed with Cell Ranger v 3.1.0. Reads were aligned to a modified version of the mouse transcriptome mm10, including the sequence for the gene ZsGreen1. The top cell barcodes selected by Cell Ranger were utilized for downstream analysis. Results: In lung mesenchymal cells, populations of fibroblasts and pericytes express Pdgfr-beta.
Project description:Kidney fibrosis is characterized by expansion and activation of platelet-derived growth factor receptor-β (PDGFR-β) positive mesenchymal cells. To study the consequences of PDGFR-ß activation, we developed a model of primary renal fibrosis using transgenic mice with PDGFR-β activation specifically in renal mesenchymal cells, driving their pathological proliferation and phenotypic switch towards myofibroblasts. This resulted in progressive mesangioproliferative glomerulonephritis, mesangial sclerosis and interstitial fibrosis with progressive anemia due to loss of erythropoietin production by fibroblasts. We used microarrays to compare wildtype animals (Foxd1_wt Pdgfrb_wt) to animals with constitutive mesenchymal PDGFR-β activation (Foxd1_mt Pdgfrb V536A) in the kidney to identify target genes of PDGFR-β signaling.
Project description:Purpose: The goal of this study was to determine biological consequences during liver regeneration following partial hepatectomy in mice by next-generation sequencing. A particular interest was to compare mice with either a floxed b-PDGFR allele to mice that harbored a deletion of b-PDGFR in hepatic stellate cells (HSCs), by crossing b-PDGFR fl/fl mice with transgenic GFAP-Cre mice. Methods: b-PDGFR fl/fl mice or mice with a HSC-specific deletion of b-PDGFR underwent either sham operation or 70% partial hepatectomy. Following 72 hours, livers were collected and total RNA was extracted using tizol, followed by a purification using Quiagen spin columns including an on-column DNAse digestion step. Conclusion: Our study represents a detailed analysis of hepatic transcriptome, with biologic replicates, generated by RNA-seq technology of livers following sham operation or partial hepatectomy in b-PDGFR fl/fl mice or b-PDGFRfl/fl/GRAP-Cre mice. Whole liver mRNA profiles of sham operated livers or livers collected 72hours after partial hepatectomy of beta-PDGFR fl/fl and beta-PDGFR fl/fl/GFAP-Cre (creating a hepatic stellate cell-specific deletion of b-PDGFR) mice were generated by deep sequencing, in duplicate, using Illumina HiSeq2000.
Project description:The scaffold protein synectin plays a critical role in the trafficking and regulation of membrane receptor pathways. As the platelet derived growth factor receptor (PDGFR) pathway is essential for hepatic stellate cell (HSC) activation and liver fibrosis, we sought to determine the role of synectin on the PDGFR pathway in HSC. To study the role of synectin in the development of liver fibrosis, mice with selective deletion of synectin from HSC were generated and found to be protected from fibrosis. RNAseq revealed that knockdown of synectin in HSC demonstrated reductions in the fibrosis pathway of genes including PDGFR-β, but not PDGFR-α. Chromatin Immunoprecipitation assay of the PDGFR-β promoter upon synectin knockdown revealed a pattern of histone marks associated with decreased transcription, dependent on p300. In contradistinction, synectin was found to regulate PDGFR-α through an alternative mechanism: protection from autophagic degradation. Site directed mutagenesis revealed that ubiquitination of specific PDGFR-α lysine residues is responsible for its autophagic degradation. Furthermore, functional studies showed decreased PDGF dependent proliferation and migration after synectin knockdown. Finally, human cirrhotic livers demonstrated increased synectin expression. This work provides insight into differential transcriptional and post-translational mechanisms of synectin regulation of PDGFRs, which are critical to fibrogenesis.
Project description:Purpose: The goal of this study was to determine biological consequences during liver regeneration following partial hepatectomy in mice by next-generation sequencing. A particular interest was to compare mice with either a floxed b-PDGFR allele to mice that harbored a deletion of b-PDGFR in hepatic stellate cells (HSCs), by crossing b-PDGFR fl/fl mice with transgenic GFAP-Cre mice. Methods: b-PDGFR fl/fl mice or mice with a HSC-specific deletion of b-PDGFR underwent either sham operation or 70% partial hepatectomy. Following 72 hours, livers were collected and total RNA was extracted using tizol, followed by a purification using Quiagen spin columns including an on-column DNAse digestion step. Conclusion: Our study represents a detailed analysis of hepatic transcriptome, with biologic replicates, generated by RNA-seq technology of livers following sham operation or partial hepatectomy in b-PDGFR fl/fl mice or b-PDGFRfl/fl/GRAP-Cre mice.
Project description:Anti-PDGF agents are routinely used as a key component in front-line therapy for the treatment of various cancers. However, molecular mechanisms underlying their impact on vascular remodeling in relation to the dose issue remain poorly understood. Here we show that in high PDGF-BB-producing tumors, anti-PDGF drugs significantly inhibited tumor growth and metastasis by preventing pericyte (PC) loss and vascular permeability. Surprisingly, the same anti-PDGF-BB drugs promoted tumor cell dissemination and metastasis in PDGF-BB-low-producing or negative tumors by ablating PCs from tumor vessels. At the molecular level, we show that the PDGFR-β signaling pathway in PCs mediated the opposing effects and persistent exposure of PCs to PDGF-BB led to marked downregulation of PDGFR-β. Inactivation of the PDGFR-β signaling system led to decreased levels of integrin α1β1, resulted in impaired adhesion of PCs to collagen I, IV and laminin, two principal extracellular matrix components in blood vessels for interaction with these integrins. Our data suggest that tumor PDGF-BB levels may serve as an important biomarker for selection of tumor-bearing hosts for beneficial therapy and unsupervised practice of this group of drugs could potentially promote tumor invasion and metastasis.
Project description:Cutaneous melanoma is the most aggressive skin cancer showing high mortality at advanced clinical stages. Platelet-Derived Growth Factor Receptor alpha (PDGFR-alpha) is known to strongly inhibit melanoma and endothelial cell proliferation, in vitro as well in vivo. PDGFR-alpha expression has been found to be reduced in metastatic human melanoma-biopsies, as compared to benign nevi-biopsies, thus implying a negative selection of PDGFR-alpha expressing cells, in melanoma. In the present study PDGFR-alpha was transiently overexpressed in endothelial (HUVEC) and melanoma (SK-Mel-28) human cells; a strong anti-proliferation effect was observed, along with profound effects on mRNA and miR- expression. More in detail, gene-expression profiling showed that PDGFR-alpha over-expression affects the expression of 82 genes in HUVEC (41 up-, 41 down-regulated), and 52 genes in SK-Mel-28 (43 up-, 9 down-regulated). miRNA profiling showed that 14 miRs are up-regulated and 40 are down-regulated in PDGFR-alpha overexpressing cells. Accurate validation with alternative techniques demonstrated that CXCL10 gene expression is one of the most significantly up-regulated at both gene- and protein level, in combination with a strong down-regulation of miR-503 in both HUVEC and SK-Mel-28 overexpressing PDGFR-alpha. We then demonstrate that CXCL10 is a validated miR-503 target, and that the anti-proliferation effect of PDGFR-alpha is reverted by specific CXCL-10 neutralization. Several molecular pathways were identified in cells overexpressing PDGFR-alpha, according to KEGG and Gene Ontology analysis (p < 0.01). In conclusion, PDGFR-alpha overexpression strongly inhibits endothelial- and melanoma- proliferation in a CXCL-10 dependent way, by significantly down-regulating miR-503 expression. This dataset contains the results of the microRNA analysis.
Project description:Cutaneous melanoma is the most aggressive skin cancer showing high mortality at advanced clinical stages. Platelet-Derived Growth Factor Receptor alpha (PDGFR-alpha) is known to strongly inhibit melanoma and endothelial cells proliferation, in vitro as well in vivo. PDGFR-alpha expression has been found to be reduced in metastatic human melanoma-biopsies, as compared to benign nevi-biopsies, thus implying a negative selection of PDGFR-alpha expressing cells, in melanoma. In the present study PDGFR-alpha was transiently overexpressed in endothelial (HUVEC) and melanoma (SK-Mel-28) human cells; a strong anti-proliferation effect was observed, along with profound effects on mRNA and miRNA expression. In detail, gene-expression profiling showed that PDGFR-alpha over-expression affects the expression of 82 transcripts in HUVEC (41 up-, 41 down-regulated), and 52 Transcripts in SK-Mel-28 (43 up-, 9 down-regulated). Finally, a miRNA profiling showed that 14 miRs are up-regulated and 39 are down-regulated in PDGFR-alpha overexpressing cells. Accurate validation with alternative techniques demonstrated that CXCL10 is one of the most significantly up-regulated at both gene- and protein level, in combination with a strong down-regulation of miR-503 in both HUVEC and SK-Mel-28 overexpressing PDGFR-alpha. We then demonstrate that CXCL10 is a validated miR-503 target, and that the anti-proliferation effect of PDGFR-alpha is reverted by specific CXCL-10 neutralization. In conclusion, PDGFR-alpha overexpression strongly inhibits endothelial- and melanoma- proliferation in a CXCL-10 dependent way, by significantly down-regulating miR-503 expression. This data set contains the results of the mRNA analysis.