Cardiovascular research, 2015-06, Vol.106 (3), p.488-497
2015
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Details
- Autor(en) / Beteiligte
- Titel
- DNA-dependent protein kinase (DNA-PK) permits vascular smooth muscle cell proliferation through phosphorylation of the orphan nuclear receptor NOR1
- Ist Teil von
- Cardiovascular research, 2015-06, Vol.106 (3), p.488-497
- Ort / Verlag
- England
- Erscheinungsjahr
- 2015
- Quelle
- Oxford Journals 2020 Medicine
- Beschreibungen/Notizen
- Being central part of the DNA repair machinery, DNA-dependent protein kinase (DNA-PK) seems to be involved in other signalling processes, as well. NOR1 is a member of the NR4A subfamily of nuclear receptors, which plays a central role in vascular smooth muscle cell (SMC) proliferation and in vascular proliferative processes. We determined putative phosphorylation sites of NDA-PK in NOR1 and hypothesized that the enzyme is able to modulate NOR1 signalling and, this way, proliferation of SMC. Cultured human aortic SMC were treated with the specific DNA-PK inhibitor NU7026 (or siRNA), which resulted in a 70% inhibition of FCS-induced proliferation as measured by BrdU incorporation. Furthermore, FCS-stimulated up-regulation of NOR1 protein as well as the cell-cycle promoting proteins proliferating cell nuclear antigen (PCNA), cyclin D1, and hyperphosphorylation of the retinoblastoma protein were prevented by DNA-PK inhibition. Co-immunoprecipitation studies from VSM cell lysates demonstrated that DNA-PK forms a complex with NOR1. Mutational analysis and kinase assays demonstrated that NOR1 is a substrate of DNA-PK and is phosphorylated in the N-terminal domain. Phosphorylation resulted in post-transcriptional stabilization of the protein through prevention of its ubiquitination. Active DNA-PK and NOR1 were found predominantly expressed within the neointima of human atherosclerotic tissue specimens. In mice, inhibition of DNA-PK significantly attenuated neointimal lesion size 3 weeks after wire-injury. DNA-PK directly phosphorylates NOR-1 and, this way, modulates SMC proliferation. These data add to our understanding of vascular remodelling processes and opens new avenues for treatment of vascular proliferative diseases.
- Sprache
- Englisch
- Identifikatoren
- ISSN: 0008-6363eISSN: 1755-3245DOI: 10.1093/cvr/cvv126Titel-ID: cdi_proquest_miscellaneous_1681263679
- Format
- –
- Schlagworte
- Animals, Atherosclerosis - enzymology, Atherosclerosis - genetics, Atherosclerosis - pathology, Cell Proliferation - drug effects, Cells, Cultured, Cyclin D1 - metabolism, Disease Models, Animal, DNA-Activated Protein Kinase - antagonists & inhibitors, DNA-Activated Protein Kinase - genetics, DNA-Activated Protein Kinase - metabolism, DNA-Binding Proteins - antagonists & inhibitors, DNA-Binding Proteins - metabolism, Enzyme Inhibitors - pharmacology, Femoral Artery - drug effects, Femoral Artery - enzymology, Femoral Artery - injuries, Femoral Artery - pathology, Humans, Male, Membrane Transport Proteins - genetics, Membrane Transport Proteins - metabolism, Mice, Inbred C57BL, Muscle, Smooth, Vascular - drug effects, Muscle, Smooth, Vascular - enzymology, Muscle, Smooth, Vascular - pathology, Myocytes, Smooth Muscle - drug effects, Myocytes, Smooth Muscle - enzymology, Myocytes, Smooth Muscle - pathology, Neointima, Nuclear Proteins - antagonists & inhibitors, Nuclear Proteins - genetics, Nuclear Proteins - metabolism, Phosphorylation, Proliferating Cell Nuclear Antigen - metabolism, Protein Stability, Proteolysis, Retinoblastoma Protein - metabolism, RNA Interference, Signal Transduction, Time Factors, Transfection, Ubiquitination, Vascular Remodeling - drug effects, Vascular System Injuries - drug therapy, Vascular System Injuries - enzymology, Vascular System Injuries - pathology