DNA-PKcs participated in hypoxic pulmonary hypertension

Abstract

Background: Hypoxic pulmonary hypertension (HPH) is a common complication of chronic lung disease, which severely affects the survival and prognosis of patients. Several recent reports have shown that DNA damage and repair plays a crucial role in pathogenesis of pulmonary arterial hypertension. DNA-dependent protein kinase catalytic subunit (DNA-PKcs) as a part of DNA-PK is a molecular sensor for DNA damage that enhances DSB repair. This study aimed to demonstrate the expression and potential mechanism of DNA-PKcs on the pathogenesis of HPH.Methods: Levels of DNA-PKcs and other proteins in explants of human and rats pulmonary artery from lung tissues and pulmonary artery smooth muscle cells (PASMC) were measured by immunohistochemistry and western blot analysis. The mRNA expression levels of DNA-PKcs and NOR1 in PASMCs were quantified with qRT-PCR. Meanwhile, the interaction among proteins were detected by Co-immunoprecipitation (Co-IP) assays. Cell proliferation and apoptosis was assessed by cell counting kit-8 assay(CCK-8), EdU incorporation and flow cytometry. Rat models of HPH were constructed to verify the role of DNA-PKcs in pulmonary vascular remodeling in vivo.Results: DNA-PKcs protein levels were both significantly up-regulated in explants of pulmonary artery from HPH models and lung tissues of patients with hypoxemia. In human PASMCs, hypoxia up-regulated DNA-PKcs in a timedependent manner. Downregulation of DNA-PKcs by targeted siRNA or small-molecule inhibitor NU7026 both induced cell proliferation inhibition and cell cycle arrest. DNA-PKcs affected proliferation by regulating NOR1 protein synthesis followed by the expression of cyclin D1. Co-immunoprecipitation of NOR1 with DNA-PKcs was severely increased in hypoxia. Meanwhile, hypoxia promoted G 2 + S phase, whereas the down-regulation of DNA-PKcs and NOR1 attenuated the effects of hypoxia. In vivo, inhibition of DNA-PKcs reverses hypoxic pulmonary vascular remodeling and prevented HPH. Conclusions:Our study indicated the potential mechanism of DNA-PKcs in the development of HPH. It might provide insights into new therapeutic targets for pulmonary vascular remodeling and pulmonary hypertension.

DNA-dependent protein kinase catalytic subunit (DNA-PKcs) drives angiotensin II-induced vascular remodeling through regulating mitochondrial fragmentation

“…Emerging evidence has suggested an involvement of DNA-PKcs in the pathogenesis of cardiovascular diseases including cardiac ischemia perfusion injury [ 14 ] and hypoxic pulmonary hypertension [ 39 ]. However, little is known with regards to the role of DNA-PKcs in Ang II-induced vascular remodeling.…”

“…As expected, our results showed that NU7441 markedly attenuated progression of vascular remodeling, and VSMC proliferative and migratory phenotypes. Of note, pharmacological inhibition of DNA-PKcs using NU7026 significantly attenuated PAH and neointima formation after wire-injury through suppressing neuron-derived orphan receptor (NOR1)-mediated VSMC proliferation [ 39 , 44 ]. These data indicated that targeting DNA-PKcs might be a new avenue for the treatment of vascular proliferative diseases, although DNA-PKcs played an important role in DNA quality control.…”

The DNA-dependent protein kinase catalytic subunit promotes sepsis-induced cardiac dysfunction through disrupting INF-2-dependent mitochondrial dynamics

“…In vascular diseases, DNA-PKcs contributes to endothelial dysfunction and atherosclerosis [16]. It influences the balance between endothelial repair and injury, and modulates inflammatory responses in atherosclerotic plaques [17]. This dual role of DNA-PKcs in both myocardial and vascular pathology marks it as a critical factor in the broader spectrum of cardiovascular diseases, offering a novel avenue for targeted therapies.…”