scholarly journals CTGF disrupts alveolarization and induces pulmonary hypertension in neonatal mice: implication in the pathogenesis of severe bronchopulmonary dysplasia

2011 ◽  
Vol 300 (3) ◽  
pp. L330-L340 ◽  
Author(s):  
Shaoyi Chen ◽  
Min Rong ◽  
Astrid Platteau ◽  
Dorothy Hehre ◽  
Heather Smith ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Bronchopulmonary Dysplasia ◽  
Vascular Remodeling ◽  
Tissue Growth ◽  
Clara Cell ◽  
Alveolar Type ◽  
Lung Pathology ◽  
Pulmonary Vascular Remodeling ◽  
Neonatal Mice ◽  
Gsk 3Β

The pathological hallmarks of bronchopulmonary dysplasia (BPD), one of the most common long-term pulmonary complications associated with preterm birth, include arrested alveolarization, abnormal vascular growth, and variable interstitial fibrosis. Severe BPD is often complicated by pulmonary hypertension characterized by excessive pulmonary vascular remodeling and right ventricular hypertrophy that significantly contributes to the mortality and morbidity of these infants. Connective tissue growth factor (CTGF) is a multifunctional protein that coordinates complex biological processes during tissue development and remodeling. We have previously shown that conditional overexpression of CTGF in airway epithelium under the control of the Clara cell secretory protein promoter results in BPD-like architecture in neonatal mice. In this study, we have generated a doxycycline-inducible double transgenic mouse model with overexpression of CTGF in alveolar type II epithelial (AT II) cells under the control of the surfactant protein C promoter. Overexpression of CTGF in neonatal mice caused dramatic macrophage and neutrophil infiltration in alveolar air spaces and perivascular regions. Overexpression of CTGF also significantly decreased alveolarization and vascular development. Furthermore, overexpression of CTGF induced pulmonary vascular remodeling and pulmonary hypertension. Most importantly, we have also demonstrated that these pathological changes are associated with activation of integrin-linked kinase (ILK)/glucose synthesis kinase-3β (GSK-3β)/β-catenin signaling. These data indicate that overexpression of CTGF in AT II cells results in lung pathology similar to those observed in infants with severe BPD and that ILK/GSK-3β/β-catenin signaling may play an important role in the pathogenesis of severe BPD.

scholarly journals Serotonin 2A receptor inhibition protects against the development of pulmonary hypertension and pulmonary vascular remodeling in neonatal mice

2018 ◽  
Vol 314 (5) ◽  
pp. L871-L881 ◽  
Author(s):  
Cassidy Delaney ◽  
Laurie Sherlock ◽  
Susan Fisher ◽  
Joanne Maltzahn ◽  
Clyde Wright ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Injury ◽  
Vascular Remodeling ◽  
Tryptophan Hydroxylase ◽  
Mapk Signaling ◽  
Akt Signaling ◽  
Pulmonary Vascular Remodeling ◽  
Neonatal Mice ◽  
Neonatal Lung ◽  
Neonatal Lung Injury

Pulmonary hypertension (PH) complicating bronchopulmonary dysplasia (BPD) worsens clinical outcomes in former preterm infants. Increased serotonin (5-hydroxytryptamine, 5-HT) signaling plays a prominent role in PH pathogenesis and progression in adults. We hypothesized that increased 5-HT signaling contributes to the pathogenesis of neonatal PH, complicating BPD and neonatal lung injury. Thus, we investigated 5-HT signaling in neonatal mice exposed to bleomycin, previously demonstrated to induce PH and alveolar simplification. Newborn wild-type mice received intraperitoneal PBS, ketanserin (1 mg/kg), bleomycin (3 U/kg) or bleomycin (3 U/kg) plus ketanserin (1 mg/kg) three times weekly for 3 wk. Following treatment with bleomycin, pulmonary expression of the rate-limiting enzyme of 5-HT synthesis, tryptophan hydroxylase-1 (Tph1), was significantly increased. Bleomycin did not affect pulmonary 5-HT 2A receptor (R) expression, but did increase pulmonary gene expression of the 5-HT 2BR and serotonin transporter. Treatment with ketanserin attenuated bleomycin-induced PH (increased RVSP and RVH) and pulmonary vascular remodeling (decreased vessel density and increased muscularization of small vessels). In addition, we found that treatment with ketanserin activated pulmonary MAPK and Akt signaling in mice exposed to bleomycin. We conclude that 5-HT signaling is increased in a murine model of neonatal PH and pharmacological inhibition of the 5-HT 2AR protects against the development of PH in neonatal lung injury. We speculate this occurs through restoration of MAPK signaling and increased Akt signaling.

Metalloproteinase inhibition by Batimastat attenuates pulmonary hypertension in chronically hypoxic rats

2003 ◽  
Vol 285 (1) ◽  
pp. L199-L208 ◽  
Author(s):  
Jan Herget ◽  
Jana Novotná ◽  
Jana Bíbová ◽  
Viera Povýšilová ◽  
Marie Vaňková ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Chronic Hypoxia ◽  
Causative Factor ◽  
Systemic Arterial Pressure ◽  
Collagenolytic Activity ◽  
Pulmonary Vascular Remodeling ◽  
Arterial Blood ◽  
Fraction Of Inspired Oxygen ◽  
Lung Vessels

Chronic hypoxia induces lung vascular remodeling, which results in pulmonary hypertension. We hypothesized that a previously found increase in collagenolytic activity of matrix metalloproteinases during hypoxia promotes pulmonary vascular remodeling and hypertension. To test this hypothesis, we exposed rats to hypoxia (fraction of inspired oxygen = 0.1, 3 wk) and treated them with a metalloproteinase inhibitor, Batimastat (30 mg/kg body wt, daily ip injection). Hypoxia-induced increases in concentration of collagen breakdown products and in collagenolytic activity in pulmonary vessels were inhibited by Batimastat, attesting to the effectiveness of Batimastat administration. Batimastat markedly reduced hypoxic pulmonary hypertension: pulmonary arterial blood pressure was 32 ± 3 mmHg in hypoxic controls, 24 ± 1 mmHg in Batimastat-treated hypoxic rats, and 16 ± 1 mmHg in normoxic controls. Right ventricular hypertrophy and muscularization of peripheral lung vessels were also diminished. Batimastat had no influence on systemic arterial pressure or cardiac output and was without any effect in rats kept in normoxia. We conclude that stimulation of collagenolytic activity in chronic hypoxia is a substantial causative factor in the pathogenesis of pulmonary vascular remodeling and hypertension.

scholarly journals The role of inflammation in hypoxic pulmonary hypertension: from cellular mechanisms to clinical phenotypes

2015 ◽  
Vol 308 (3) ◽  
pp. L229-L252 ◽  
Author(s):  
Steven C. Pugliese ◽  
Jens M. Poth ◽  
Mehdi A. Fini ◽  
Andrea Olschewski ◽  
Karim C. El Kasmi ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Signaling Pathways ◽  
Vascular Remodeling ◽  
Mesenchymal Cells ◽  
World Health ◽  
Small Subset ◽  
Cellular Interactions ◽  
Pulmonary Vascular Remodeling ◽  
Hypoxic Pulmonary Hypertension ◽  
Group I

Hypoxic pulmonary hypertension (PH) comprises a heterogeneous group of diseases sharing the common feature of chronic hypoxia-induced pulmonary vascular remodeling. The disease is usually characterized by mild to moderate pulmonary vascular remodeling that is largely thought to be reversible compared with the progressive irreversible disease seen in World Health Organization (WHO) group I disease. However, in these patients, the presence of PH significantly worsens morbidity and mortality. In addition, a small subset of patients with hypoxic PH develop “out-of-proportion” severe pulmonary hypertension characterized by pulmonary vascular remodeling that is irreversible and similar to that in WHO group I disease. In all cases of hypoxia-related vascular remodeling and PH, inflammation, particularly persistent inflammation, is thought to play a role. This review focuses on the effects of hypoxia on pulmonary vascular cells and the signaling pathways involved in the initiation and perpetuation of vascular inflammation, especially as they relate to vascular remodeling and transition to chronic irreversible PH. We hypothesize that the combination of hypoxia and local tissue factors/cytokines (“second hit”) antagonizes tissue homeostatic cellular interactions between mesenchymal cells (fibroblasts and/or smooth muscle cells) and macrophages and arrests these cells in an epigenetically locked and permanently activated proremodeling and proinflammatory phenotype. This aberrant cellular cross-talk between mesenchymal cells and macrophages promotes transition to chronic nonresolving inflammation and vascular remodeling, perpetuating PH. A better understanding of these signaling pathways may lead to the development of specific therapeutic targets, as none are currently available for WHO group III disease.

scholarly journals HIF2α–arginase axis is essential for the development of pulmonary hypertension

2016 ◽  
Vol 113 (31) ◽  
pp. 8801-8806 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Alexi Crosby ◽  
David Macias ◽  
Cristina Branco ◽  
Renato D. D. R. Colaço ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Systolic Pressure ◽  
Hypoxic Exposure ◽  
Pulmonary Vascular Remodeling ◽  
Ventricular Systolic Pressure ◽  
Pulmonary Endothelium ◽  
Arginase 1

Hypoxic pulmonary vasoconstriction is correlated with pulmonary vascular remodeling. The hypoxia-inducible transcription factors (HIFs) HIF-1α and HIF-2α are known to contribute to the process of hypoxic pulmonary vascular remodeling; however, the specific role of pulmonary endothelial HIF expression in this process, and in the physiological process of vasoconstriction in response to hypoxia, remains unclear. Here we show that pulmonary endothelial HIF-2α is a critical regulator of hypoxia-induced pulmonary arterial hypertension. The rise in right ventricular systolic pressure (RVSP) normally observed following chronic hypoxic exposure was absent in mice with pulmonary endothelial HIF-2α deletion. The RVSP of mice lacking HIF-2α in pulmonary endothelium after exposure to hypoxia was not significantly different from normoxic WT mice and much lower than the RVSP values seen in WT littermate controls and mice with pulmonary endothelial deletion of HIF-1α exposed to hypoxia. Endothelial HIF-2α deletion also protected mice from hypoxia remodeling. Pulmonary endothelial deletion of arginase-1, a downstream target of HIF-2α, likewise attenuated many of the pathophysiological symptoms associated with hypoxic pulmonary hypertension. We propose a mechanism whereby chronic hypoxia enhances HIF-2α stability, which causes increased arginase expression and dysregulates normal vascular NO homeostasis. These data offer new insight into the role of pulmonary endothelial HIF-2α in regulating the pulmonary vascular response to hypoxia.

Hypoxia-Induced Changes in the Mechanical Properties of the Mouse Pulmonary Artery

2003 ◽  
Author(s):  
Ryan W. Kobs ◽  
Nidal E. Muvarak ◽  
Naomi C. Chesler
Keyword(s):  
Mechanical Properties ◽  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Vascular Remodeling ◽  
Hypobaric Hypoxia ◽  
Vessel Wall ◽  
Main Pulmonary Artery ◽  
Collagen Content ◽  
Pulmonary Vascular Remodeling ◽  
Induced Changes

Hypobaric hypoxia produces pulmonary hypertension in mice which causes pulmonary vascular remodeling. To study the biomechanics of this process, mice were exposed to hypoxia for 0-(control), 10-, and 15-days. Using a pressurized arteriograph system, mechanical properties of the main pulmonary artery were measured and compared to the biological changes in the vessel wall measured histologically. 10- and 15-day hypoxic vessels were significantly stiffer when compared to 0-day vessels. This stiffness correlated with greater elastin and collagen content in the vessel wall.

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