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Pulmonary arterial hypertension (PAH)-pulmonary artery smooth muscle cells (PASMCs) display elevated levels of DNA damage/replication stress and exhibit constitutive activation of the ATR (ataxia telangiectasia and Rad3-related)/CHK1 (checkpoint kinase 1) pathway.
Source publication
Objective:
Pulmonary arterial hypertension (PAH) is a debilitating disease associated with progressive vascular remodeling of distal pulmonary arteries leading to elevation of pulmonary artery pressure, right ventricular hypertrophy, and death. Although presenting high levels of DNA damage that normally jeopardize their viability, pulmonary artery...
Contexts in source publication
Context 1
... first compared levels of CHK1 expression and activity in isolated PASMCs from control and patients with PAH. We found that hyperproliferating PAH-PASMCs, but not PAH-PAECs, exhibit significantly increased CHK1 protein expression compared with their normal counterparts ( Figure 1A and Figure I in the online-only Data Supplement). In addition, CHK1 auto-phosphorylation (S296), a marker of CHK1 kinase activity, was increased in isolated PAH-PASMCs ( Figure 1A). ...
Context 2
... found that hyperproliferating PAH-PASMCs, but not PAH-PAECs, exhibit significantly increased CHK1 protein expression compared with their normal counterparts ( Figure 1A and Figure I in the online-only Data Supplement). In addition, CHK1 auto-phosphorylation (S296), a marker of CHK1 kinase activity, was increased in isolated PAH-PASMCs ( Figure 1A). To further demonstrate that PAH-PASMCs experience endogenous DNA damage/RS, phosphorylation levels of H2AX and RPA32, 2 markers of DNA damage and RS, 24 were measured. ...
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... further demonstrate that PAH-PASMCs experience endogenous DNA damage/RS, phosphorylation levels of H2AX and RPA32, 2 markers of DNA damage and RS, 24 were measured. Consistent with above findings showing elevated CHK1 expression and activity in PAH-PASMCs compared with control cells, phospho-RPA32 (S4/S8) and H2AX (S139) were increased in PAH-PASMCs ( Figure 1A). Since numerous studies implicate ATR as a major kinase mediating DNA damage/RS and a direct upstream activator of CHK1, 13,25 we next measured expression of total ATR, ATR autophosphorylation at Thr 1989 (a marker for ATR activation 26 ), CHK1 phosphorylation at S345 (an ATR phosphorylation site 25 ), as well as CLSPN (known to mediate ATR-CHK1 physical interaction 27 ) and BLM (Bloom's syndrome protein helicase; a responder to RS regulated by CHK1 28 ). ...
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... numerous studies implicate ATR as a major kinase mediating DNA damage/RS and a direct upstream activator of CHK1, 13,25 we next measured expression of total ATR, ATR autophosphorylation at Thr 1989 (a marker for ATR activation 26 ), CHK1 phosphorylation at S345 (an ATR phosphorylation site 25 ), as well as CLSPN (known to mediate ATR-CHK1 physical interaction 27 ) and BLM (Bloom's syndrome protein helicase; a responder to RS regulated by CHK1 28 ). Whereas no significant difference was observed for ATR, PAH-PASMCs exhibited increased expression of phospho-ATR, phospho-CHK1, CLSPN, and BLM compared with control cells ( Figure 1B and Figure IIA in the online-only Data Supplement). Additionally, along with CHK2, activity of DNA-PK (DNA-dependent protein kinase), required to maintain CHK1-CLSPN complex stability for optimal RS response, 29 was increased ( Figure IIB (Figure 2A and Figure III in the online-only Data Supplement); a feature recapitulated in rats (monocrotaline and FHR), as well as simian immunodeficiency virus-infected macaques exhibiting hemodynamic and structural manifestations of PAH ( Figure 2B and 2C and Figure III in the online-only Data Supplement). ...
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... first compared levels of CHK1 expression and activity in isolated PASMCs from control and patients with PAH. We found that hyperproliferating PAH-PASMCs, but not PAH-PAECs, exhibit significantly increased CHK1 protein expression compared with their normal counterparts ( Figure 1A and Figure I in the online-only Data Supplement). In addition, CHK1 auto-phosphorylation (S296), a marker of CHK1 kinase activity, was increased in isolated PAH-PASMCs ( Figure 1A). ...
Context 6
... found that hyperproliferating PAH-PASMCs, but not PAH-PAECs, exhibit significantly increased CHK1 protein expression compared with their normal counterparts ( Figure 1A and Figure I in the online-only Data Supplement). In addition, CHK1 auto-phosphorylation (S296), a marker of CHK1 kinase activity, was increased in isolated PAH-PASMCs ( Figure 1A). To further demonstrate that PAH-PASMCs experience endogenous DNA damage/RS, phosphorylation levels of H2AX and RPA32, 2 markers of DNA damage and RS, 24 were measured. ...
Context 7
... further demonstrate that PAH-PASMCs experience endogenous DNA damage/RS, phosphorylation levels of H2AX and RPA32, 2 markers of DNA damage and RS, 24 were measured. Consistent with above findings showing elevated CHK1 expression and activity in PAH-PASMCs compared with control cells, phospho-RPA32 (S4/S8) and H2AX (S139) were increased in PAH-PASMCs ( Figure 1A). Since numerous studies implicate ATR as a major kinase mediating DNA damage/RS and a direct upstream activator of CHK1, 13,25 we next measured expression of total ATR, ATR autophosphorylation at Thr 1989 (a marker for ATR activation 26 ), CHK1 phosphorylation at S345 (an ATR phosphorylation site 25 ), as well as CLSPN (known to mediate ATR-CHK1 physical interaction 27 ) and BLM (Bloom's syndrome protein helicase; a responder to RS regulated by CHK1 28 ). ...
Context 8
... numerous studies implicate ATR as a major kinase mediating DNA damage/RS and a direct upstream activator of CHK1, 13,25 we next measured expression of total ATR, ATR autophosphorylation at Thr 1989 (a marker for ATR activation 26 ), CHK1 phosphorylation at S345 (an ATR phosphorylation site 25 ), as well as CLSPN (known to mediate ATR-CHK1 physical interaction 27 ) and BLM (Bloom's syndrome protein helicase; a responder to RS regulated by CHK1 28 ). Whereas no significant difference was observed for ATR, PAH-PASMCs exhibited increased expression of phospho-ATR, phospho-CHK1, CLSPN, and BLM compared with control cells ( Figure 1B and Figure IIA in the online-only Data Supplement). Additionally, along with CHK2, activity of DNA-PK (DNA-dependent protein kinase), required to maintain CHK1-CLSPN complex stability for optimal RS response, 29 was increased ( Figure IIB (Figure 2A and Figure III in the online-only Data Supplement); a feature recapitulated in rats (monocrotaline and FHR), as well as simian immunodeficiency virus-infected macaques exhibiting hemodynamic and structural manifestations of PAH ( Figure 2B and 2C and Figure III in the online-only Data Supplement). ...
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Background
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Citations
... Unrepaired DNA damage is a striking feature of both EC and SMC in PAH [9][10][11][12] . In SMC, PARP1 10 , EYA3 11 and checkpoint kinase-1 (CHK-1) 12 are upregulated to stimulate DNA repair, but this results in proliferation and resistance to apoptosis of SMC with damaged DNA. ...
... Unrepaired DNA damage is a striking feature of both EC and SMC in PAH [9][10][11][12] . In SMC, PARP1 10 , EYA3 11 and checkpoint kinase-1 (CHK-1) 12 are upregulated to stimulate DNA repair, but this results in proliferation and resistance to apoptosis of SMC with damaged DNA. Moreover, cultured PAEC from PAH patients carry somatic chromosomal deletions that were not found in blood and other lung cell types of the same patient 13 . ...
Pulmonary arterial hypertension (PAH) is a progressive disease in which pulmonary arterial (PA) endothelial cell (EC) dysfunction is associated with unrepaired DNA damage. BMPR2 is the most common genetic cause of PAH. We report that human PAEC with reduced BMPR2 have persistent DNA damage in room air after hypoxia (reoxygenation), as do mice with EC-specific deletion of Bmpr2 (EC-Bmpr2-/-) and persistent pulmonary hypertension. Similar findings are observed in PAEC with loss of the DNA damage sensor ATM, and in mice with Atm deleted in EC (EC-Atm-/-). Gene expression analysis of EC-Atm-/- and EC-Bmpr2-/- lung EC reveals reduced Foxf1, a transcription factor with selectivity for lung EC. Reducing FOXF1 in control PAEC induces DNA damage and impaired angiogenesis whereas transfection of FOXF1 in PAH PAEC repairs DNA damage and restores angiogenesis. Lung EC targeted delivery of Foxf1 to reoxygenated EC-Bmpr2-/- mice repairs DNA damage, induces angiogenesis and reverses pulmonary hypertension.
... In PASM cells obtained from individuals with pulmonary hypertension, expression of Checkpoint kinase 1 (CHK1) is elevated, and in addition, in pulmonary hypertension animal model hemodynamic changes and pulmonary vessel remodeling may be decreased in vivo by suppressing CHK1 pharmacologically. P53 protein genetic deletion and suppression of its function in animal model led to deterioration of pulmonary hypertension and vessel remodeling related to it [47]. On the contrary, Jones and colleagues showed that proliferation and migration of cells may be suppressed by inducing the A2B adenosine receptor (A2BAR) in pulmonary artery smooth muscle cells [48]. ...
PurposeAt first, p53 was believed to be present primarily in malignant cells. In fact, p53 turned out to play a major role in vascular remodeling associated with transplantation surgery or intraluminal intervention. The purpose of this review was to describe the multiple processes which include p53 activation and to analyze its impact on cellular proliferation and migration, as well as its involvement in such conditions as pulmonary arterial hypertension, subarachnoid hemorrhage, ischemia and others.Methods
To select the initial sources for our review, we searched the PubMed database with the keywords “p53 mechanisms”, “p53 atherosclerosis”, “p53 cardiovascular”, etc. To maintain the relevance, we selected only papers published in 2018 and later.ResultsOverall, p53 is proved to have a strong relationship with the whole cardiovascular system. Available data also indicate a connection of p53 to the atherosclerosis initiation and progression. P53 might become a promising therapeutic target for treatment of acute and chronic cardiovascular diseases due to its ability to influence various vascular mechanisms.Conclusion
Modifying the synthesis of this protein and the expression of the corresponding genes to create models, cellular and animal, that allow us to better understand about complex nature of the pathogenesis of atherosclerosis seems to be promising. Also, p53 can be considered as a possible target for the development of therapeutic strategies. The same is true both for the protein itself and for all participants in the pathway of its metabolism.
... 273 Here, AZD6738 (a highly selective ATR inhibitor) was able to decrease cardiac remodeling and p53 depletion in cardiomyocytes imitated the cardioprotective function of AZD6738. 7.2.4 | DNA-PK inhibition DNA-PKs are aberrantly activated in various CVDs such as myocardial IRI, 274 cardiac hypertrophy, 266 atherosclerosis, 93,156,275 and diabetic cardiomyopathy. 276 Genetic and pharmacological inhibition of DNA-PKs showed favorable effects in atherosclerosis. ...
... DNA-PK was excessively activated in response to IRI-induced stress, and DNA-PK inhibition was reported to have protective effects. 274 Interestingly, cardiomyocyte-specific DNA-PK depletion prevented inflammation and apoptosis and preserved cardiac function during IRI injury. ...
... Several investigations have recently reported a role for CHK1/2 kinases in pulmonary artery hypertension 274 and heart failure. 275 Cardiomyocyte apoptosis is associated with CHK2 activation and telomere shortening. ...
DNA damage response (DDR) signaling ensures genomic and proteomic homeostasis to maintain a healthy genome. Dysregulation either in the form of down‐ or upregulation in the DDR pathways correlates with various pathophysiological states, including cancer and cardiovascular diseases (CVDs). Impaired DDR is studied as a signature mechanism for cancer; however, it also plays a role in ischemia‐reperfusion injury (IRI), inflammation, cardiovascular function, and aging, demonstrating a complex and intriguing relationship between cancer and pathophysiology of CVDs. Accordingly, there are increasing number of reports indicating higher incidences of CVDs in cancer patients. In the present review, we thoroughly discuss (1) different DDR pathways, (2) the functional cross talk among different DDR mechanisms, (3) the role of DDR in cancer, (4) the commonalities and differences of DDR between cancer and CVDs, (5) the role of DDR in pathophysiology of CVDs, (6) interventional strategies for targeting genomic instability in CVDs, and (7) future perspective.
... There are many genes involved in DDR, including checkpoint kinase 1 (CHK1), poly(ADP-ribose) polymerase 1 (PARP1), Pim-1, mitochondrial heat shock protein 90 (HSP90) etc. Several studies have shown specific pharmacological inhibitors like MK-8776 (CHK1 inhibitor), ABT-888 (PARP1 inhibitor), SGI-1776 (PIM1 inhibitor) and gamitrinib (mitochondrial HSP90 inhibitor) downregulated their target genes, leading to reduced proliferation and increased apoptosis, suggesting their therapeutic potential in PAH [14][15][16][17][18]. ...
... To this date, there are few studies about the role of DNA repair on hypoxic pulmonary hypertension [16,[22][23][24]. Previous reports have identified the elevation of DNA damage markers and the role of DNA repair molecules in pulmonary hypertension, such as poly (ADP-ribose) polymerase-1 (PARP-1) and X-box-binding protein 1 [13][14][15][16][17][18][19][20][21][22]. In this research, we first explored the function of another DNA repair molecules, DNA-PKcs, in hypoxia induced pulmonary vascular remodeling. ...
... As a principal cellular internal mechanism, DNA repair plays an indispensable role in decreasing the risk of cancer and some other critical human diseases [11][12][13][14][15][16][17][18][19]. Being central part of the DNA repair machinery, DNA-dependent protein kinase (DNA-PK) seems to be involved in other signalling processes [20,21]. ...
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 time-dependent 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 G2 + 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.
... Endothelial mitochondrial dysfunction [1] and DNA damage [21][22][23][24][25] have been separately linked to pulmonary hypertension (PH), but any shared mechanistic regulation of these dynamic endothelial phenotypes in PH was previously undefined. Building upon data that links FXN reduction to Fe-S-specific nuclear damage [17], FXN deficiency disrupted mitochondrial function by preventing Fe-S-dependent glucose oxidation which led to upregulated glycolytic activity and reactive oxygen species. ...
Deficiency of iron-sulfur (Fe-S) clusters promotes metabolic rewiring of the endothelium and the development of pulmonary hypertension (PH) in vivo . Joining a growing number of Fe-S biogenesis proteins critical to pulmonary endothelial function, recent data highlighted that frataxin (FXN) reduction drives Fe-S-dependent genotoxic stress and senescence across multiple types of pulmonary vascular disease. Trinucleotide repeat mutations in the FXN gene cause Friedreich’s ataxia, a disease characterized by cardiomyopathy and neurodegeneration. These tissue-specific phenotypes have historically been attributed to mitochondrial reprogramming and oxidative stress. Whether FXN coordinates both nuclear and mitochondrial processes in the endothelium is unknown. Here, we aim to identify the mitochondria-specific effects of FXN deficiency in the endothelium that predispose to pulmonary hypertension. Our data highlight an Fe-S-driven metabolic shift separate from previously described replication stress whereby FXN knockdown diminished mitochondrial respiration and increased glycolysis and oxidative species production. In turn, FXN-deficient endothelial cells exhibited a vasoconstrictive phenotype consistent with PH. These data were observed in both primary pulmonary endothelial cells after pharmacologic inhibition of FXN and inducible pluripotent stem cell-derived endothelial cells from patients with FXN mutations. Altogether, this study defines FXN as a shared upstream driver of pathologic aberrations in both metabolism and genomic stability. Moreover, our study highlights FXN-specific vasoconstriction, suggesting available and future therapies may be beneficial and targeted for PH subtypes with FXN deficiency.
Graphical Abstract
... [62][63][64] In a recent publication, the author's group implicated CHK1 in PAH PASMC upregulation of proliferation and apoptosis resistance via downregulation of DNA repair protein RAD 51 and showed selective CHK1 pharmacological inhibition using MK-8776 improved vascular remodeling and hemodynamics in PAH animal models. 65 In the current work presented at the ATS 2020 Conference, Wu et al. also showed an increase in DNA damage assessed by increased phosphorylation of replication protein A 32 (RPA32) and expression of H2A histone family member X and gamma (cH2AX), correlating with increased PA remodeling and fibrosis in IPF patient tissues. Using pharmacological CHK inhibitors (MK-8776 and Prexasertib) in vitro decreased both IPF-fibroblast and PASMC proliferation and increased apoptosis by blocking DNA repair. ...
Each year the American Thoracic Society (ATS) Conference brings together scientists who conduct basic, translational and clinical research to present on the recent advances in the field of respirology. Due to the Coronavirus Disease of 2019 (COVID-19) pandemic, the ATS2020 Conference was held online in a series of virtual meetings. In this review, we focus on the breakthroughs in pulmonary hypertension (PH) research. We have selected ten of the best basic science abstracts which were presented at the ATS2020 Assembly on Pulmonary Circulation mini-symposium âWhatâs new in Pulmonary Arterial Hypertension (PAH) and Right Ventricular (RV) Signaling: Lessons from the Best Abstractsâ, reflecting the current state-of-the-art and associated challenges in PH. Particular emphasis is placed on understanding the mechanisms underlying RV failure, the regulation of inflammation, and the novel therapeutic targets that emerged from preclinical research. The pathologic interactions between PH, RV function and COVID-19 are also discussed.
... reverse the lung parenchymal and vascular remodelling process is a pressing need. Although the precise molecular mechanisms that drive the development of fibrosis and PA remodelling in the setting of IPF is incompletely understood, accumulating evidence indicates that interstitial LFs and PASMCs have similarly developed an intensified DNA damage response (DDR) ensuring efficient sensing, signalling and repair of DNA damages, [7][8][9][10][11] accounting for their enhanced capacity to survive and proliferate under stressful conditions. Considering this unique and shared property, targeting therapies aimed at compromising this over-efficient DDR offers the potential to induce DNA damage overload and selective cell death and thus to impede pathological lung remodelling. ...
... [12][13][14] In line with this, we recently demonstrated that CHK1 is overexpressed in PASMCs from PAH patients and that its pharmacological inhibition significantly improves PA remodelling and haemodynamic parameters in preclinical PAH models. 9 Surprisingly, despite the fact that CHK1/2 appears closely involved in pathological lung remodelling, its implication in IPF with or without PH remains unexplored. ...
... 8 46 As such, the inhibition of CHK1/2 has been largely documented to increase cells' sensitivity to accumulating DNA damage, providing therapeutic benefit in numerous hyperproliferating diseases, including cancer 13 14 and PAH. 9 Besides their role in the DDR, persistent activation of CHK1/2 in response to DNA damage is also known to promote survival and inflammation through NF-κB signalling and induction of NF-κB-regulated genes, including interleukin (IL)-6, IL-1β, CXCL1 and CXCL10. 47 48 Many of them have been documented to participate in the adverse parenchymal Effects of LY2606368 on lung hydroxyproline content (n=6-15/group). ...
Background
Idiopathic pulmonary fibrosis (IPF) is a chronic lung disease characterised by exuberant tissue remodelling and associated with high unmet medical needs. Outcomes are even worse when IPF results in secondary pulmonary hypertension (PH). Importantly, exaggerated resistance to cell death, excessive proliferation and enhanced synthetic capacity are key endophenotypes of both fibroblasts and pulmonary artery smooth muscle cells, suggesting shared molecular pathways. Under persistent injury, sustained activation of the DNA damage response (DDR) is integral to the preservation of cells survival and their capacity to proliferate. Checkpoint kinases 1 and 2 (CHK1/2) are key components of the DDR. The objective of this study was to assess the role of CHK1/2 in the development and progression of IPF and IPF+PH.
Methods and results
Increased expression of DNA damage markers and CHK1/2 were observed in lungs, remodelled pulmonary arteries and isolated fibroblasts from IPF patients and animal models. Blockade of CHK1/2 expression or activity-induced DNA damage overload and reverted the apoptosis-resistant and fibroproliferative phenotype of disease cells. Moreover, inhibition of CHK1/2 was sufficient to interfere with transforming growth factor beta 1-mediated fibroblast activation. Importantly, pharmacological inhibition of CHK1/2 using LY2606368 attenuated fibrosis and pulmonary vascular remodelling leading to improvement in respiratory mechanics and haemodynamic parameters in two animal models mimicking IPF and IPF+PH.
Conclusion
This study identifies CHK1/2 as key regulators of lung fibrosis and provides a proof of principle for CHK1/2 inhibition as a potential novel therapeutic option for IPF and IPF+PH.
... Our laboratory and others have described the hyperplastic phenotype of PASMC from subjects with PAH as continuing to proliferate under normally non-proliferative conditions [2][3][4][5][6][7]. Studies have pointed out vast differences in proliferative phenotype between PAH and normal control HPASMC [2,6,8,9], 2 of 16 their migration [10][11][12], DNA repair/cell survival [13][14][15][16], ion channel signaling [17][18][19], and PDGF signaling [20,21]. Recently, the PAH HPASMC were found to have increased expression of the transcription factor FOXM1 and the proto-oncogene polo-like kinase 1 (PLK1) [5,13,22]. ...
A key feature of pulmonary arterial hypertension (PAH) is the hyperplastic proliferation exhibited by the vascular smooth muscle cells from patients (HPASMC). The growth inducers FOXM1 and PLK1 are highly upregulated in these cells. The mechanism by which these two proteins direct aberrant growth in these cells is not clear. Herein, we identify cyclin-dependent kinase 1 (CDK1), also termed cell division cycle protein 2 (CDC2), as having a primary role in promoting progress of the cell cycle leading to proliferation in HPASMC. HPASMC obtained from PAH patients and pulmonary arteries from Sugen/hypoxia rats were investigated for their expression of CDC2. Protein levels of CDC2 were much higher in PAH than in cells from normal donors. Knocking down FOXM1 or PLK1 protein expression with siRNA or pharmacological inhibitors lowered the cellular expression of CDC2 considerably. However, knockdown of CDC2 with siRNA or inhibiting its activity with RO-3306 did not reduce the protein expression of FOXM1 or PLK1. Expression of CDC2 and FOXM1 reached its maximum at G1/S, while PLK1 reached its maximum at G2/M phase of the cell cycle. The expression of other CDKs such as CDK2, CDK4, CDK6, CDK7, and CDK9 did not change in PAH HPASMC. Moreover, inhibition via Wee1 inhibitor adavosertib or siRNAs targeting Wee1, Myt1, CDC25A, CDC25B, or CDC25C led to dramatic decreases in CDC2 protein expression. Lastly, we found CDC2 expression at the RNA and protein level to be upregulated in pulmonary arteries during disease progression Sugen/hypoxia rats. In sum, our present results illustrate that the increased expression of FOXM1 and PLK1 in PAH leads directly to increased expression of CDC2 resulting in potentiated growth hyperactivity of PASMC from patients with pulmonary hypertension. Our results further suggest that the regulation of CDC2, or associated regulatory proteins, will prove beneficial in the treatment of this disease.
... PIM1 inhibition resulted in decreased non-homologous end-joining DNA repair and decreased PAH-PASMCs proliferation [181]. Moreover, PAH-PASMCs overexpress NUDT1, preventing the incorporation of oxidized nucleotides into DNA [182], and Check Point Kinase 1 (CHK1), which mitigates the anti-proliferative and pro-apoptotic effects of DNA damage [183]. Pharmacological inhibition of NUDT1 or CHK1, using (S)-crizotinib and MK-8776, respectively, decreased pulmonary vascular remodeling and improved hemodynamics and cardiac function in rodent models of PH [182,183]. ...
... Moreover, PAH-PASMCs overexpress NUDT1, preventing the incorporation of oxidized nucleotides into DNA [182], and Check Point Kinase 1 (CHK1), which mitigates the anti-proliferative and pro-apoptotic effects of DNA damage [183]. Pharmacological inhibition of NUDT1 or CHK1, using (S)-crizotinib and MK-8776, respectively, decreased pulmonary vascular remodeling and improved hemodynamics and cardiac function in rodent models of PH [182,183]. ...
Pulmonary hypertension is a rare disease with high morbidity and mortality which mainly affects women of reproductive age. Despite recent advances in understanding the pathogenesis of pulmonary hypertension, the high heterogeneity in the presentation of the disease among different patients makes it difficult to make an accurate diagnosis and to apply this knowledge to effective treatments. Therefore, new studies are required to focus on translational and personalized medicine to overcome the lack of specificity and efficacy of current management. Here, we review the majority of public databases storing ‘omics‘ data of pulmonary hypertension studies, from animal models to human patients. Moreover, we review some of the new molecular mechanisms involved in the pathogenesis of pulmonary hypertension, including non-coding RNAs and the application of ‘omics’ data to understand this pathology, hoping that these new approaches will provide insights to guide the way to personalized diagnosis and treatment.
... Our laboratory and others have described the hyperplastic phenotype of PASMC from subjects with PAH as continuing to proliferate under normally non-proliferative conditions [2][3][4][5][6][7]. Studies have pointed out vast differences in proliferative phenotype between PAH and normal control HPASMC [2,6,8,9], their migration [10][11][12], DNA repair/cell survival [13][14][15][16], ion channel signaling [17][18][19] and PDGF signaling [20,21]. Recently the PAH HPASMC were found to have increased expression of the transcription factor FOXM1 and the proto-oncogene polo-like kinase 1 (PLK1) [5,13,22]. ...
A key feature of pulmonary arterial hypertension (PAH) is the hyperplastic proliferation exhibited by the vascular smooth muscle cells from patients (HPASMC). The growth inducers FOXM1 and PLK1 are highly upregulated in these cells. The mechanism by which these two proteins direct aberrant growth in these cells is not clear. Herein we identify cyclin dependent kinase 1 (CDK1) also termed cell division cycle protein 2 (CDC2), as having a primary role in promoting progress of the cell cycle leading to proliferation in HPASMC. HPASMC obtained from PAH patients and pulmonary arteries from Sugen/hypoxia rats were investigated for their expression of CDC2. Protein levels of CDC2 were much higher in PAH than in cells from normal donors. Knocking down FOXM1 or PLK1 protein expression with siRNA or pharmacological inhibitors lowered the cellular expression of CDC2 considerably. However, knockdown of CDC2 with siRNA or inhibiting its activity with RO-3306 did not reduce the protein expression of FOXM1 or PLK1. Expression of CDC2 and FOXM1 reached its maximum at G1/S, while PLK1 reached its maximum at G2/M phase of the cell cycle. The expression of other CDKs such as CDK2, CDK4, CDK6, CDK7 and CDK9 did not change in PAH HPASMC. Moreover, inhibition via Wee1 inhibitor adavosertib or siRNAs targeting Wee1, Myt1, CDC25A, CDC25B, or CDC25C led to dramatic decreases in CDC2 protein expression. Lastly, we found CDC2 expression at the RNA and protein level to be upregulated in pulmonary arteries during disease progression Sugen/hypoxia rats. In sum, our present results illustrate that the increased expression of FOXM1 and PLK1 in PAH leads directly to increased expression of CDC2 resulting in a potentiated growth hyperactivity of PASMC from patients with pulmonary hypertension. Our results further suggest that the regulation of CDC2, or associated regulatory proteins, will prove beneficial in the treatment of this disease.
