Project description:Analysis of p53-deficient (E6-expressing) human vascular smooth muscle cells (VSMCs) that express progerin, a mutated form of lamin A resposible for Hutchinson- Gilford progeria syndrome (HGPS). p53 pathway is associated with HGPS. Results provide insight into molecular mechanisms underlying vascular dysfunction of HGPS caused by other than p53 pathway. The gene expression of VSMCs induced to express E6 and either lamin A or progerin by retroviral vectors.
Project description:Analysis of p53-deficient (E6-expressing) human vascular smooth muscle cells (VSMCs) that express progerin, a mutated form of lamin A resposible for Hutchinson- Gilford progeria syndrome (HGPS). p53 pathway is associated with HGPS. Results provide insight into molecular mechanisms underlying vascular dysfunction of HGPS caused by other than p53 pathway.
Project description:Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal human premature aging disease1-5, characterized by premature atherosclerosis and degeneration of vascular smooth muscle cells (SMCs)6-8. HGPS is caused by a single-point mutation in the LMNA gene, resulting in the generation of progerin, a truncated mutant of lamin A. Accumulation of progerin leads to various aging-associated nuclear defects including disorganization of nuclear lamina and loss of heterochromatin9-12. Here, we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts obtained from patients with HGPS. HGPS-iPSCs show absence of progerin, and more importantly, lack the nuclear envelope and epigenetic alterations normally associated with premature aging. Upon differentiation of HGPS-iPSCs, progerin and its associated aging consequences are restored. In particular, directed differentiation of HGPS-iPSCs to SMCs leads to the appearance of premature senescent SMC phenotypes associated with vascular aging. Additionally, our studies identify DNA-dependent protein kinase catalytic subunit (DNAPKcs) as a component of the progerin-containing protein complex. The absence of nuclear DNAPKcs correlates with premature as well as physiological aging. Since progerin also accumulates during physiological aging6,12,13, our results provide an in vitro iPSC-based model with an acceleration progerin accumulation to study the pathogenesis of human premature and physiological vascular aging. Microarray gene expression profiling was done to: (1) Compare differences between WT fibroblasts and fibroblasts from patients suffering of the Hutchinson-Gilford progeria syndrome (2) Check that iPSC originating from WT and patients are in fact similar to ESC
Project description:Hutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal human premature aging disease1-5, characterized by premature atherosclerosis and degeneration of vascular smooth muscle cells (SMCs)6-8. HGPS is caused by a single-point mutation in the LMNA gene, resulting in the generation of progerin, a truncated mutant of lamin A. Accumulation of progerin leads to various aging-associated nuclear defects including disorganization of nuclear lamina and loss of heterochromatin9-12. Here, we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts obtained from patients with HGPS. HGPS-iPSCs show absence of progerin, and more importantly, lack the nuclear envelope and epigenetic alterations normally associated with premature aging. Upon differentiation of HGPS-iPSCs, progerin and its associated aging consequences are restored. In particular, directed differentiation of HGPS-iPSCs to SMCs leads to the appearance of premature senescent SMC phenotypes associated with vascular aging. Additionally, our studies identify DNA-dependent protein kinase catalytic subunit (DNAPKcs) as a component of the progerin-containing protein complex. The absence of nuclear DNAPKcs correlates with premature as well as physiological aging. Since progerin also accumulates during physiological aging6,12,13, our results provide an in vitro iPSC-based model with an acceleration progerin accumulation to study the pathogenesis of human premature and physiological vascular aging.
Project description:Platelet-derived growth factor (PDGF) signalling and the subsequent activation of the calcium ion channel, ORAI1 are critical drivers of pathological remodelling of native vascular smooth muscle cells to proliferative state, which is a process associated with various vascular diseases. This study aims to reveal transcriptional networks altered following ORAI1 inhibition in vascular smooth muscle cells. To study the effect of ORAI1 inhibition on VSMC biology, we performed RNA-Seq analysis of PDGF-stimulated primary human aortic smooth muscle cells treated with either ORAI1 inhibitor, (n=4) or with vehicle (n=4), and investigated the effect of ORAI1 inhibition on the transcriptional response of cells.