scholarly journals Overexpression of Msx1 in Mouse Lung Leads to Loss of Pulmonary Vessels Following Vascular Hypoxic Injury

Cells ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 2306
Author(s):  
James West ◽  
Anandharajan Rathinasabapathy ◽  
Xinping Chen ◽  
Sheila Shay ◽  
Shanti Gladson ◽  
...  

Pulmonary arterial hypertension (PAH) is a progressive lung disease caused by thickening of the pulmonary arterial wall and luminal obliteration of the small peripheral arteries leading to increase in vascular resistance which elevates pulmonary artery pressure that eventually causes right heart failure and death. We have previously shown that transcription factor Msx1 (mainly expressed during embryogenesis) is strongly upregulated in transformed lymphocytes obtained from PAH patients, especially IPAH. Under pathological conditions, Msx1 overexpression can cause cell dedifferentiation or cell apoptosis. We hypothesized that Msx1 overexpression contributes to loss of small pulmonary vessels in PAH. In IPAH lung, MSX1 protein localization was strikingly increased in muscularized remodeled pulmonary vessels, whereas it was undetectable in control pulmonary arteries. We developed a transgenic mouse model overexpressing MSX1 (MSX1OE) by about 4-fold and exposed these mice to normoxic, sugen hypoxic (3 weeks) or hyperoxic (100% 02 for 3 weeks) conditions. Under normoxic conditions, compared to controls, MSX1OE mice demonstrated a 30-fold and 2-fold increase in lung Msx1 mRNA and protein expression, respectively. There was a significant retinal capillary dropout (p < 0.01) in MSX1OE mice, which was increased further (p < 0.03) with sugen hypoxia. At baseline, the number of pulmonary vessels in MSX1OE mice was similar to controls. In sugen-hypoxia-treated MSX1OE mice, the number of small (0–25 uM) and medium (25–50 uM) size muscularized vessels increased approximately 2-fold (p < 0.01) compared to baseline controls; however, they were strikingly lower (p < 0.001) in number than in sugen-hypoxia-treated control mice. In MSX1OE mouse lung, 104 genes were upregulated and 67 genes were downregulated compared to controls. Similarly, in PVECs, 156 genes were upregulated and 320 genes were downregulated from siRNA to MSX1OE, and in PVSMCs, 65 genes were upregulated and 321 genes were downregulated from siRNA to MSX1OE (with control in the middle). Many of the statistically significant GO groups associated with MSX1 expression in lung, PVECs, and PVSMCs were similar, and were involved in cell cycle, cytoskeletal and macromolecule organization, and programmed cell death. Overexpression of MSX1 suppresses many cell-cycle-related genes in PVSMCs but induces them in PVECs. In conclusion, overexpression of Msx1 leads to loss of pulmonary vessels, which is exacerbated by sugen hypoxia, and functional consequences of Msx1 overexpression are cell-dependent.

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Paul A Corris

[No abstract. Showing first paragraph of article]Pulmonary arterial hypertension (PAH) is a chronic disease of the pulmonary vasculature characterized by progressive narrowing of the pulmonary arteries leading to increased pulmonary vascular resistance, right heart failure, and ultimately premature death.There has been a significant improvement in the available medical therapeutic options in this field that have impacted the short-term survival and morbidity in these patients. However, the median survival post-diagnosis remains unacceptable at 7 years.Physicians’ ability to predict PAH disease progression and risk allows them to determine the patient’s prognosis, make informed adjustments to therapy, and monitor his or her response to therapy . If widely adopted, risk prediction can enhance the consistency of treatment approaches and improve the timeliness of referral for lung transplantation. This approach should lead optimal, directed care that ultimately reduces morbidity and improves mortality in patients with PAH.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
France Dierick

AIM: PW1+ progenitors were identified in various adult tissues and can differentiate in smooth muscle cells (SMC) in vitro. Our hypothesis is that PW1+ progenitors are recruited to participate in the vascular remodeling during pulmonary arterial hypertension (PAH). METHODS: PW1IRESnLacZ+/- mice express the β-galactosidase as a reporter gene for PW1 expression allowing to follow the lineage of PW1+ cells during a few days. These mice were exposed to chronic hypoxia (CH) to induce PAH, lung vessels neomuscularisation and SMC proliferation. PW1+ and β-Gal+ cells were studied by FACS and by immunofluorescence. RESULTS: PW1+ cells are localized in the lung parenchyma and in the perivascular zone in rodent and human lung. Two PW1+ populations were identified by flow cytometry in the mouse lung 1/ a Sca-1high/CD34high/PDGFR-α+ population which differentiates into calponin+ or α-SMA+ SMC and into vWF+ endothelial cell and 2/ a CD34-/CD146+ population expressing pericyte markers. After 2-4 days of CH, the number of lung PW1+ cells is increased (x3.5, p<0.01) and, in small pulmonary vessels media, the proportion of β-Gal+ SMC derived from PW1+ cells is increased (64±6% vs 35±3%, p<0.05) suggesting a recruitment and differentiation of PW1+ cells into lung vascular SMC. Moreover WT mice irradiated and engrafted with GFP+/β-Gal+ bone marrow cells do not show any increase in GFP+ SMC in lung vessels and do not show any β-Gal+ cells in the lung indicating that the lung PW1+ progenitors are not derived from bone marrow . Moreover, in the human PAH lung, PW1+ cells were observed in remodeled vascular structures: in the media of remodeled vessel and in plexiform lesions. CONCLUSION: These results suggest that lung resident PW1+ progenitors are recruited to participate in the vascular remodeling of small pulmonary vessels in experimental and human PAH. These progenitors show characteristics of pericytes and of vascular progenitors.


2012 ◽  
Vol 108 (12) ◽  
pp. 1049-1060 ◽  
Author(s):  
Mardi Gomberg-Maitland ◽  
Adaani Frost ◽  
Robert Frantz ◽  
Marc Humbert ◽  
Michael McGoon ◽  
...  

SummaryPulmonary arterial hypertension (PAH) is characterised by increased pressure in the pulmonary arteries leading to right-sided ventricular failure, and death. Identification of factors that affect patient survival is important to improve patient management and outcomes. The first registry to evaluate survival and develop a prognostic model was the National Institutes of Health (NIH) registry in 1981. Importantly this prognostic model is based on data collected prior to availability of PAH-targeted therapies and does not reflect survival rates for treated patients. Since the 1980s, however, four modern registries of PAH now exist which compensate for the NIH equations shortcomings and include the French National registry, Pulmonary Hypertension Connection registry, the Mayo registry, and the Registry to Evaluate Early and Long-Term PAH Disease Management (REVEAL). The similarities and difference in these registries are highlighted in this review and although similar in many respects, the four registries vary in patient population, including the numbers of newly and previously diagnosed patients, as well as the era of observation, period of survival, and timing of assessment of potential predictive factors. Despite this, the predictive factors identified in each registry and described in detail within the body of this manuscript share surprising homology in that disease aetiology, patient gender and factors reflective of right heart failure are integral in depicting survival. Future modifications of modern prognostic equations should be an ongoing goal of the PAH community in order to provide increased accuracy with identification of novel risk factors and prediction of disease course.


2015 ◽  
Vol 35 (4) ◽  
pp. 1467-1481 ◽  
Author(s):  
Rui-Xing Wang ◽  
Rui-Lan He ◽  
Hai-Xia Jiao ◽  
Mao Dai ◽  
Yun-Ping Mu ◽  
...  

Background: Pulmonary hypertension (PH) is characterized by sustained vasoconstriction, enhanced vasoreactivity and vascular remodeling, which leads to right heart failure and death. Despite several treatments are available, many forms of PH are still incurable. Ginsenoside Rb1, a principle active ingredient of Panax ginseng, exhibits multiple pharmacological effects on cardiovascular system, and suppresses monocrotaline (MCT)-induced right heart hypertrophy. However, its effect on the pulmonary vascular functions related to PH is unknown. Methods: We examined the vasorelaxing effects of ginsenoside Rb1 on endothelin-1 (ET-1) induced contraction of pulmonary arteries (PAs) and store-operated Ca2+ entry (SOCE) in pulmonary arterial smooth muscle cells (PASMCs) from chronic hypoxia (CH) and MCT-induced PH. Results: Ginsenoside Rb1 elicited concentration-dependent relaxation of ET-1-induced PA contraction. The vasorelaxing effect was unaffected by nifedipine, but abolished by the SOCE blocker Gd3+. Ginsenoside Rb1 suppressed cyclopiazonic acid (CPA)-induced PA contraction, and CPA-activated cation entry and Ca2+ transient in PASMCs. ET-1 and CPA-induced contraction, and CPA-activated cation entry and Ca2+ transients were enhanced in PA and PASMCs of CH and MCT-treated rats; the enhanced responses were abolished by ginsenoside Rb1. Conclusion: Ginsenoside Rb1 attenuates ET-1-induced contractile response via inhibition of SOCE, and it can effectively antagonize the enhanced pulmonary vasoreactivity in PH.


Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 477
Author(s):  
Marceau Quatredeniers ◽  
Pedro Mendes-Ferreira ◽  
Diana Santos-Ribeiro ◽  
Morad K. Nakhleh ◽  
Maria-Rosa Ghigna ◽  
...  

Pulmonary arterial hypertension (PAH) is a severe cardiovascular disease that is caused by the progressive occlusion of the distal pulmonary arteries, eventually leading to right heart failure and death. Almost 40% of patients with PAH are iron deficient. Although widely studied, the mechanisms linking between PAH and iron deficiency remain unclear. Here we review the mechanisms regulating iron homeostasis and the preclinical and clinical data available on iron deficiency in PAH. Then we discuss the potential implications of iron deficiency on the development and management of PAH.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Yann Grobs ◽  
Marie-Claude Lampron ◽  
Geraldine Vitry ◽  
Mark Orcholski ◽  
Steeve Provencher ◽  
...  

Background: Pulmonary arterial hypertension (PAH) is a rapidly progressing disease of the lung vasculature, characterized by the remodeling of small pulmonary arteries in which pulmonary arterial smooth muscle cells (PASMCs) exhibit a cancer-like phenotype, with uncontrolled replication, self-sustaining growth signals, evasion of growth suppressors and resistance to apoptosis. In healthy cells, cell division is controlled by the circadian clock resulting in timed mitosis and rhythmic DNA replication. This suggests that impaired circadian clock might be involved in the cell cycle disorders seen in PAH. Especially, impaired function of the nuclear receptor Rev-Erbα (a core clock protein) has been associated with circadian clock impairment and cell cycle disorders in cancer. Hypothesis: Rev-Erbα impairment is involved in PAH pathogenesis. Methods & Results: We synchronized (Zeitgeber method using 50% horse serum for 2 hours) human PASMCs isolated from 4 PAH patients and 4 controls, and demonstrated a reduced (p=0.0192) (immunoblot) expression of Rev-Erbα 12 hours post synchronization in PAH-PASMCs compared to controls, associated with increased proliferation (Ki67 assay) and resistance to apoptosis (annexin V assay) (p<0.05), which were reversed by the Rev-Erbα agonist SR9011 (10μM for 24h). RNAseq (n=4/group) demonstrated that most of the downregulated (2-fold cut-off) genes following SR9011 treatments were involved in cytokinesis, meiosis, mitotic processes, cell cycle progression, chromosome segregation and recombination (p<0.05). In vivo , Rev-Erbα was also significantly decreased in male and female monocrotaline rats. SR9011 treatments (n=15/group) for 2 weeks (50mg/kg, i.p.) improved PA hemodynamics ( RVSP:47.80mmHg vs 75.29mmHg \mPAP:26.69mmHg vs 44.36mmHg, p<0.0001); vascular remodeling, decreased proliferation(p=0.0001), increased apoptosis(p=0.0002)) and decreased RV hypertrophy (Fulton Index:0.3869 vs 0.5093 p=0.0006) compare to vehicle treated rats. These results were also repeated in the Fawn Hooded rats model. Conclusion: Our results suggest the involvement of Clock pathways in PAH etiology and thus open new avenue of investigation in PAH and new therapeutic options using clock-modulating small molecules.


2013 ◽  
Vol 305 (4) ◽  
pp. L312-L321 ◽  
Author(s):  
Jun Yang ◽  
Xiaohui Li ◽  
Ying Li ◽  
Mark Southwood ◽  
Lingying Ye ◽  
...  

Bone morphogenetic protein type II receptor (BMPR-II) mutations are responsible for over 70% of cases of heritable pulmonary arterial hypertension (PAH). Loss of BMP signaling promotes pulmonary vascular remodeling via modulation of pulmonary artery smooth muscle cell (PASMC) proliferation. Id proteins (Id1–4) are major downstream transcriptional targets of BMP signaling. However, the impact of BMPR-II mutation on the expression of the range of Id proteins and the contribution of individual Id proteins to abnormal PASMC function remain unclear. Human PASMCs were used to determine the expression of Id proteins (Id1–4) by real-time PCR and immunoblotting. The BMP responses in control cells were compared with PASMCs harboring BMPR-II mutations and cells in which BMPR-II was knocked down by siRNA transfection. Id3 expression in pulmonary vessels was also investigated in BMPR-II mutant mice and in patients with heritable PAH. BMP4 and BMP6, but not BMP9, induced mRNA expression of Id1, Id2, and Id3. The BMP-stimulated induction of Id1 and Id3 was markedly reduced in BMPR-II mutant PASMCs and in control PASMCs following siRNA silencing of BMPR-II. Pulmonary arteries in BMPR-II mutant mice and patients with heritable PAH demonstrated reduced levels of Id3 compared with control subjects. Lentiviral overexpression of Id3 reduced cell cycle progression and inhibited proliferation of PASMCs. Lipopolysaccharide further reduced Id3 expression in mutant PASMCs. In conclusion, Id proteins, and particularly Id1 and Id3, are critical downstream effectors of BMP signaling in PASMCs. Loss of BMPR-II function reduces the induction of Id genes in PASMCs, Id1, and Id3 regulate the proliferation of PASMCs via cell cycle inhibition, an effect that may be exacerbated by inflammatory stimuli.


2019 ◽  
Vol 316 (5) ◽  
pp. H1091-H1104 ◽  
Author(s):  
Michal Schäfer ◽  
D. Dunbar Ivy ◽  
Steven H. Abman ◽  
Kurt Stenmark ◽  
Lorna P. Browne ◽  
...  

Despite different developmental and pathological processes affecting lung vascular remodeling in both patient populations, differences in 4D MRI findings between children and adults with PAH have not been studied. The purpose of this study was to compare flow hemodynamic state, including flow-mediated shear forces, between pediatric and adult patients with PAH matched by severity of pulmonary vascular resistance index (PVRi). Adults ( n = 10) and children ( n = 10) with PAH matched by pulmonary vascular resistance index (PVRi) and healthy adult ( n = 10) and pediatric ( n = 10) subjects underwent comprehensive 4D-flow MRI to assess peak systolic wall shear stress (WSSmax) measured in the main (MPA), right (RPA), and left pulmonary arteries (LPA), viscous energy loss (EL) along the MPA-RPA and MPA-LPA tract, and qualitative analysis of secondary flow hemodynamics. WSSmax was decreased in all pulmonary vessels in children with PAH when compared with the same age group (all P < 0.05). Similarly, WSSmax was decreased in all pulmonary vessels in adult PAH patients when compared with healthy adult subjects (all P < 0.01). Average EL was increased in adult patients with PAH when compared with the same age group along both MPA-RPA ( P = 0.020) and MPA-LPA ( P = 0.025) tracts. There were no differences in EL indices between adults and pediatric patients. Children and adult patients with PAH have decreased shear hemodynamic forces. However, pathological flow hemodynamic formations appear to be more consistent in adult patients, whereas flow hemodynamic abnormalities appear to be more variable in children with PAH for comparable severity of PVRi. NEW & NOTEWORTHY Both children and adult patients with PAH have decreased shear hemodynamic forces inside the pulmonary arteries associated with the degree of vessel dilation and stiffness. These differences also exist between healthy normotensive children and adults. However, pathological flow hemodynamic formations appear to more uniform in adult patients, whereas in children with PAH flow, hemodynamic abnormalities appear to be more variable. Pathological flow formations appear not to have a major effect on viscous energy loss associated with the flow conduction through proximal pulmonary arteries.


2017 ◽  
Vol 8 (2-3) ◽  
pp. 47-64 ◽  
Author(s):  
Jessica B. Badlam ◽  
Todd M. Bull

Pulmonary arterial hypertension (PAH) is a chronic disease that results in narrowing of the small pre-capillary pulmonary arteries leading to elevation of pulmonary artery pressure and pulmonary vascular resistance, subsequent right ventricular failure, and if unchecked, death. Advances in the treatment of PAH over the last two decades have markedly improved survival. These improvements reflect a combination of changes in treatments, improved patient care strategies, and varying disease phenotypes in the PAH population. Currently approved therapies for PAH are directed at the recognized abnormalities within the pulmonary vasculature and include endothelin receptor antagonists, phosphodiesterase-5 inhibitors, soluble guanylate cyclase stimulators, and prostacyclin pathway agents. Most of these drugs have been approved on the basis of short-term trials that mainly demonstrated improvements in exercise capacity. More recently, long-term, event-driven trials of novel drugs have been performed, demonstrating new efficacy parameters. There have also been exciting advances in the understanding of right heart failure pathophysiology in PAH that have the potential to inspire the development of right ventricular targeted therapy and continued discoveries in the heterogeneity of disease and response to treatment has great potential for developing more ‘personalized’ therapeutic options. In this article, we review the current available data regarding the management of PAH, with an emphasis on the pharmacologic therapies and discussion of novel therapeutic directions for the treatment of this fatal disease.


2009 ◽  
pp. S79-S86 ◽  
Author(s):  
M Chovanec ◽  
J Novotná ◽  
J Wilhelm ◽  
V Hampl ◽  
M Vízek ◽  
...  

Chronic lung hypoxia results in hypoxic pulmonary hypertension. Concomitant chronic hypercapnia partly inhibits the effect of hypoxia on pulmonary vasculature. Adult male rats exposed to 3 weeks hypoxia (Fi02=0.1) combined with hypercapnia (FiC02=0.04-0.05) had lower pulmonary arterial blood pressure, increased weight of the right heart ventricle, and less pronounced structural remodeling of the peripheral pulmonary arteries compared with rats exposed only to chronic hypoxia (Fi02=0.1). According to our hypothesis, hypoxic pulmonary hypertension is triggered by hypoxic injury to the walls of the peripheral pulmonary arteries. Hypercapnia inhibits release of both oxygen radicals and nitric oxide at the beginning of exposure to the hypoxic environment. The plasma concentration of nitrotyrosine, the marker of peroxynitrite activity, is lower in hypoxic rats exposed to hypercapnia than in those exposed to hypoxia alone. Hypercapnia blunts hypoxia-induced collagenolysis in the walls of prealveolar pulmonary arteries. We conclude that hypercapnia inhibits the development of hypoxic pulmonary hypertension by the inhibition of radical injury to the walls of peripheral pulmonary arteries.


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