Project description:We applied the transcriptome profiling (RNA-seq) for high-throughput profiling of genes changes in VSMC dedifferentiation. Rat primary VSMCs were divided into 3 groups, control, PDGF-BB, PDGF-BB+PJ34,and mRNA sequence were performed. We found that PDGF-BB could upregualted the genes involved in cell proliferation and migration, and downregulated the VSMC contractile genes, all of which could be reversed by PARP inhibitor PJ34. Then we knockdowned the co-factor Myocardin in VSMCs, and found the above effects of PJ34 were nearly abolished.Our study first provided the transcription changes by RNA-seq in VSMC dedifferentiation, and demonstrated the key roles of PARP1 and the PARylation process in VSMC phenotypic switch.
Project description:Hutchinson Gilford Progeria Syndrome is a premature aging disease caused by LMNA gene mutation and the production of a truncated lamin A protein “progerin” that elicits cellular and organismal toxicity. Progerin accumulates in the vasculature, being especially toxic for vascular smooth muscle cells (VSMC). Patients' autopsies show that vessel stiffening, and aortic atherosclerosis is accompanied by VSMC depletion in the medial layer, altered extracellular matrix (ECM), and thickening of the adventitial layer. Mechanisms whereby progerin causes massive VSMC loss and vessel alterations remain poorly understood. Mature VSMC retain phenotypic plasticity and can switch to a synthetic/proliferative phenotype. Here we show that progerin expression in human and mouse VSMC causes a switch towards the synthetic/proliferative phenotype. This switch elicits some level of replication stress in normal cells, which is exacerbated in the presence of progerin, leading to telomere fragility, genomic instability, and ultimately VSMC death. Importantly, calcitriol prevents replication stress, telomere fragility, and genomic instability, reducing VSMC death. In addition, RNAseq analysis shows induction of a profibrotic and proinflammatory aging-associated secretory phenotype upon progerin expression in human primary VSMC. Our data suggest that phenotypic switch-induced replication stress might be an underlying cause of VSMC loss in progeria, which together with loss of contractile features and gain of profibrotic and proinflammatory signatures contribute to vascular stiffness in HGPS. Preventing the phenotypic switch-induced replication stress with compounds such as calcitriol might ameliorate CVD in HGPS patients
Project description:Trabectedin is a DNA-damaging agent with a peculiar mechanism of action; it traps the DNA repair machinery leading to DNA single- and double-strand breaks, particularly in BRCA1/2-deficient tumors. We hypothesized that trabectedin-induced DNA damage might activate PARP1 (a DNA-repair machinery key player), and consequently, PARP1 inhibition would perpetuate trabectedin-induced DNA damage. In several tumor histotypes, we demonstrated a different degree of synergism between trabectedin and PARP1 inhibitors (PARP1-Is). Independent of BRCA1/2 status, PARP1 expression dictated the degree of synergism. Namely, silenced PARP1 reduced trabectedin-PARP1-Is synergism, whereas overexpressed PARP1 increased combination efficacy. High-PARP1 expression and specific gene signatures associated with DNA damage response and repair (DDR-R) were predictive of trabectedin+PARP1-I synergy. These findings pave the way for the clinical development of this novel combination therapy, as well as evaluation of PARP1 expression and DDR-R signatures in tumor samples as predictive biomarkers of response
Project description:NIH3T3 cell transiently transfected with myocardin-EGFP or EGFP. Transfection: Lipofectamine 2000 according to the manufacturers instructions (Invitrogen).
Project description:BACKGROUND & AIMS: The immune system comprises an innate and an adaptive immune response to combat pathogenic agents. The human enteropathogen Salmonella enterica serovar Typhimurium invades the intestinal mucosa and triggers an early innate pro-inflammatory host gene response, which results in diarrheal disease. Several host factors are involved in the acute early response to Salmonella infection. Transcription factors and transcription co-regulators have an especially important function, because they are required for the expression and synthesis of pro-inflammatory cytokines, chemokines and adhesion molecules. A central transcription factor involved in inflammation is NF-κB, which requires the nuclear protein PARP1 as co-factor for the expression of some of its target genes. Here, we investigated the role of PARP1 during Salmonella infection using a mouse model for Salmonella-induced colitis. METHODS: To study enterocolitis by Salmonella Typhimurium, an established mouse model system, which relies on streptomycin-pretreatment prior to Salmonella infection, was employed. Histopathologic signs of inflammation and cecum colonization at various time-points after infection of wild type and PARP1 knockout mice were analyzed. PARP1 expression in the gut mucosa was studied by quantitative RT-PCR, Western blot and immunofluorescence. Gene expression profiles of infected and control infected mice in the wild type or PARP1 knockout background were obtained by whole mouse genome arrays and confirmed by quantitative RT-PCR. 2 genotypes (wildtype, PARP1 knockout), 2 treatments (Salmonella SB300 infection, Salmonella SB161 control infection), 2 time-points (6h, 10h). 2-3 replicates/condition.
Project description:Trabectedin is a DNA-damaging agent with a peculiar mechanism of action; it traps the DNA repair machinery leading to DNA single- and double-strand breaks, particularly in BRCA1/2-deficient tumors. We hypothesized that trabectedin-induced DNA damage might activate PARP1 (a DNA-repair machinery key player), and consequently, PARP1 inhibition would perpetuate trabectedin-induced DNA damage. In several tumor histotypes, we demonstrated a different degree of synergism between trabectedin and PARP1 inhibitors (PARP1-Is). Independent of BRCA1/2 status, PARP1 expression dictated the degree of synergism. Namely, silenced PARP1 reduced trabectedin-PARP1-Is synergism, whereas overexpressed PARP1 increased combination efficacy. High-PARP1 expression and specific gene signatures associated with DNA damage response and repair (DDR-R) were predictive of trabectedin+PARP1-I synergy. These findings pave the way for the clinical development of this novel combination therapy, as well as evaluation of PARP1 expression and DDR-R signatures in tumor samples as predictive biomarkers of response.
Project description:transcriptional effects of mis-expression of full length (935) myocardin in growing human skeletal myoblasts Experiment Overall Design: Compare transcriptional profiles of Ad-myocardin infected SKM5 cells with that of Ad-B-gal infected cells