Global gene annotation analysis and transcriptional profiling identify key biological modules in hypoxic pulmonary hypertension

2005 ◽  
Vol 22 (1) ◽  
pp. 14-23 ◽  
Author(s):  
Sina A. Gharib ◽  
Daniel L. Luchtel ◽  
David K. Madtes ◽  
Robb W. Glenny
Keyword(s):  
Cluster Analysis ◽  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Molecular Mechanisms ◽  
Gene Annotation ◽  
Expression Profiles ◽  
Transcriptional Profiling ◽  
Hypoxic Pulmonary Hypertension ◽  
Iq Motif ◽  
Biological Modules

Chronic hypoxic pulmonary hypertension is an important clinical disorder causing significant morbidity. Despite recent discoveries, many molecular mechanisms involved in its pathogenesis remain unexplored. We have undertaken a systematic and unbiased approach to gain global insights into this complex process. By combining transcriptional profiling with rigorous statistical methods and cluster analysis, we identified the dominant temporal patterns of gene expression during progression and regression of hypoxic pulmonary hypertension. We next integrated these results with global gene annotation analysis to identify key biological themes involved in the development and resolution of hypoxic pulmonary hypertension and vascular remodeling. This novel approach assigned biological roles to thousands of candidate genes based on their temporal expression profiles and membership in specific biological modules. Our procedure confirmed several molecular pathways and gene products known to be important in hypoxic pulmonary hypertension. Furthermore, we discovered several novel candidates and molecular mechanisms, including IQ motif containing GTPase-activating protein-1 (IQGAP1), decorin, insulin-like growth factor binding protein-3 (IGFBP3), and lactotransferrin, that may play crucial roles in hypoxic pulmonary hypertension and vascular remodeling. Our methodology of integrating transcriptional profiling, cluster analysis, and global gene annotation provides new insights into the pathophysiology of pulmonary hypertension and is applicable to other models of human disease.

KLF5 mediates vascular remodeling via HIF-1α in hypoxic pulmonary hypertension

2016 ◽  
Vol 310 (4) ◽  
pp. L299-L310 ◽  
Author(s):  
Xiaochen Li ◽  
Yuanzhou He ◽  
Yongjian Xu ◽  
Xiaomin Huang ◽  
Jin Liu ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Smooth Muscle ◽  
Right Ventricular ◽  
Vascular Remodeling ◽  
Molecular Mechanisms ◽  
Systolic Pressure ◽  
Cyclin B1 ◽  
Dependent Manner ◽  
Hypoxic Pulmonary Hypertension ◽  
Pulmonary Arterial

Hypoxic pulmonary hypertension (HPH) is characterized by active vasoconstriction and profound vascular remodeling. KLF5, a zinc-finger transcription factor, is involved in the excessive proliferation and apoptotic resistance phenotype associated with monocrotaline-induced pulmonary hypertension. However, the molecular mechanisms of KLF5-mediated pathogenesis of HPH are largely undefined. Adult male Sprague-Dawley rats were exposed to normoxia or hypoxia (10% O2) for 4 wk. Hypoxic rats developed pulmonary arterial remodeling and right ventricular hypertrophy with significantly increased right ventricular systolic pressure. The levels of KLF5 and hypoxia-inducible factor-1α (HIF-1α) were upregulated in distal pulmonary arterial smooth muscle from hypoxic rats. The knockdown of KLF5 via short-hairpin RNA attenuated chronic hypoxia-induced hemodynamic and histological changes in rats. The silencing of either KLF5 or HIF-1α prevented hypoxia-induced (5%) proliferation and migration and promoted apoptosis in human pulmonary artery smooth muscle cells. KLF5 was immunoprecipitated with HIF-1α under hypoxia and acted as an upstream regulator of HIF-1α. The cell cycle regulators cyclin B1 and cyclin D1 and apoptosis-related proteins including bax, bcl-2, survivin, caspase-3, and caspase-9, were involved in the regulation of KLF5/HIF-1α-mediated cell survival. This study demonstrated that KLF5 plays a crucial role in hypoxia-induced vascular remodeling in an HIF-1α-dependent manner and provided a better understanding of the pathogenesis of HPH.

scholarly journals Pirfenidone Inhibits Hypoxic Pulmonary Hypertension through the NADPH/ROS/p38 Pathway in Adventitial Fibroblasts in the Pulmonary Artery

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Song Zhang ◽  
ZongXiu Yin ◽  
WeiDong Qin ◽  
XiaoLi Ma ◽  
Yao Zhang ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Vascular Remodeling ◽  
Molecular Mechanisms ◽  
Control Group ◽  
Hypoxic Pulmonary Hypertension ◽  
Hypoxic Conditions ◽  
Cell Counts ◽  
Adventitial Fibroblasts ◽  
And Migration

Hypoxic pulmonary hypertension (HPH) is a devastating disease characterized by progressive vasoconstriction and vascular remodeling. Pirfenidone (PFD) inhibits the progression of HPH, though the molecular mechanisms remain unknown. This study is aimed at determining the role and mechanism of PFD in HPH in human pulmonary artery adventitial fibroblasts (HPAAFs), which were cultured under normal or hypoxic conditions. NOX4 and Rac1 were inhibited or overexpressed by shRNA or pcDNA3.1, respectively. Proliferation of HPAAFs was quantified by colorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assays to assess cellular metabolic activity, cell counts, and ethynyldeoxyuridine (EdU) assays to detect DNA synthesis. Migration of HPAAFs was assessed by a wound healing assay. The expression levels of smooth muscle alpha-actin (a-SMA) and procollagen I (COL1A1) were assessed by RT-PCR and western blot analysis. PFD suppressed hypoxia-induced proliferation and migration of HPAAFs. Compared with the hypoxic control group, PFD reduced the expression of a-SMA and procollagen I (COL1A1). PFD reduced hypoxia-induced phosphorylation of p38 through the NOX4/reactive oxygen species (ROS) signaling pathway. Moreover, Rac1 also decreased hypoxia-induced phosphorylation of p38, without any cross-interaction with NOX4. These findings demonstrate that PFD is a novel therapeutic agent to prevent cell proliferation, migration, and fibrosis, which might be useful in inhibiting vascular remodeling in patients with HPH.

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.

Contribution of xanthine oxidase-derived superoxide to chronic hypoxic pulmonary hypertension in neonatal rats

2008 ◽  
Vol 294 (2) ◽  
pp. L233-L245 ◽  
Author(s):  
Robert P. Jankov ◽  
Crystal Kantores ◽  
Jingyi Pan ◽  
Jaques Belik
Keyword(s):  
Pulmonary Hypertension ◽  
Xanthine Oxidase ◽  
Vascular Remodeling ◽  
Cellular Proliferation ◽  
Critical Role ◽  
Normal Growth ◽  
Neonatal Rats ◽  
Hypoxic Pulmonary Hypertension ◽  
Arterial Relaxation ◽  
Ros Scavengers

Xanthine oxidase (XO)-derived reactive oxygen species (ROS) formation contributes to experimental chronic hypoxic pulmonary hypertension in adults, but its role in neonatal pulmonary hypertension has received little attention. In rats chronically exposed to hypoxia (13% O2) for 14 days from birth, we examined the effects of ROS scavengers (U74389G 10 mg·kg−1·day−1 or Tempol 100 mg·kg−1·day−1 ip) or a XO inhibitor, Allopurinol (50 mg·kg−1·day−1 ip). Both ROS scavengers limited oxidative stress in the lung and attenuated hypoxia-induced vascular remodeling, confirming a critical role for ROS in this model. However, both interventions also significantly inhibited somatic growth and normal cellular proliferation in distal air spaces. Hypoxia-exposed pups had evidence of increased serum and lung XO activity, increased vascular XO-derived superoxide production, and vascular nitrotyrosine formation. These changes were all prevented by treatment with Allopurinol, which also attenuated hypoxia-induced vascular remodeling and partially reversed inhibited endothelium-dependent arterial relaxation, without affecting normal growth and proliferation. Collectively, our findings suggest that XO-derived superoxide induces endothelial dysfunction, thus impairing pulmonary arterial relaxation, and contributes to vascular remodeling in hypoxia-exposed neonatal rats. Due to the potential for adverse effects on normal growth, targeting XO may represent a superior “antioxidant” strategy to ROS scavengers for neonates with pulmonary hypertension.

scholarly journals TRB3 mediates vascular remodeling by activating the MAPK signaling pathway in hypoxic pulmonary hypertension

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Xiaopei Cao ◽  
Xiaoyu Fang ◽  
Mingzhou Guo ◽  
Xiaochen Li ◽  
Yuanzhou He ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Protein Expression ◽  
Signaling Pathway ◽  
P38 Mapk ◽  
Vascular Remodeling ◽  
Mapk Signaling ◽  
Mapk Signaling Pathway ◽  
Clinical Samples ◽  
Hypoxic Pulmonary Hypertension

Abstract Background Hypoxic pulmonary hypertension (PH) is a refractory pulmonary vascular remodeling disease, and the efficiency of current PH treatment strategies is unsatisfactory. Tribbles homolog 3 (TRB3), a member of the pseudokinase family, is upregulated in diverse types of cellular stresses and functions as either a pro-proliferative or pro-apoptotic factor depending on the specific microenvironment. The regulatory mechanisms of TRB3 in hypoxic PH are poorly understood. Methods We performed studies using TRB3-specific silencing and overexpressing lentiviral vectors to investigate the potential roles of TRB3 on hypoxic pulmonary artery smooth muscle cells (PASMCs). Adeno-associated virus type 1(AVV1) vectors encoding short-hairpin RNAs against rat TRB3 were used to assess the role of TRB3 on hypoxic PH. TRB3 protein expression in PH patients was explored in clinical samples by western blot analysis. Results The results of whole-rat genome oligo microarrays showed that the expression of TRB3 and endoplasmic reticulum stress (ERS)-related genes was upregulated in hypoxic PASMCs. TRB3 protein expression was significantly upregulated by hypoxia and thapsigargin. In addition, 4-PBA and 4μ8C, both inhibitors of ERS, decreased the expression of TRB3. TRB3 knockdown promoted apoptosis and damaged the proliferative and migratory abilities of hypoxic PASMCs as well as inhibited activation of the MAPK signaling pathway. TRB3 overexpression stimulated the proliferation and migration of PASMCs but decreased the apoptosis of PASMCs, which was partly reversed by specific inhibitors of ERK, JNK and p38 MAPK. The Co-IP results revealed that TRB3 directly interacts with ERK, JNK, and p38 MAPK. Knockdown of TRB3 in rat lung tissue reduced the right ventricular systolic pressure and decreased pulmonary medial wall thickness in hypoxic PH model rats. Further, the expression of TRB3 in lung tissues was higher in patients with PH compared with those who have normal pulmonary artery pressure. Conclusions TRB3 was upregulated in hypoxic PASMCs and was affected by ERS. TRB3 plays a key role in the pathogenesis of hypoxia-induced PH by binding and activating the ERK, JNK, and p38 MAPK pathways. Thus, TRB3 might be a promising target for the treatment of hypoxic PH.

scholarly journals Niacin Attenuates Pulmonary Hypertension Through H-PGDS in Macrophages

2020 ◽  
Vol 127 (10) ◽  
pp. 1323-1336
Author(s):  
Daile Jia ◽  
Peiyuan Bai ◽  
Naifu Wan ◽  
Jiao Liu ◽  
Qian Zhu ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Vascular Remodeling ◽  
Molecular Mechanisms ◽  
Growth Factor Receptor ◽  
Lipid Lowering ◽  
Hypoxic Exposure ◽  
Protective Effects ◽  
Perivascular Inflammation ◽  
Lowering Drug ◽  
Endothelial Growth Factor

Rationale: Pulmonary arterial hypertension (PAH) is characterized by progressive pulmonary vascular remodeling, accompanied by varying degrees of perivascular inflammation. Niacin, a commonly used lipid-lowering drug, possesses vasodilating and proresolution effects by promoting the release of prostaglandin D 2 (PGD 2 ). However, whether or not niacin confers protection against PAH pathogenesis is still unknown. Objective: This study aimed to determine whether or not niacin attenuates the development of PAH and, if so, to elucidate the molecular mechanisms underlying its effects. Methods and Results: Vascular endothelial growth factor receptor inhibitor SU5416 and hypoxic exposure were used to induce pulmonary hypertension (PH) in rodents. We found that niacin attenuated the development of this hypoxia/SU5416–induced PH in mice and suppressed progression of monocrotaline-induced and hypoxia/SU5416–induced PH in rats through the reduction of pulmonary artery remodeling. Niacin boosted PGD 2 generation in lung tissue, mainly through H-PGDS (hematopoietic PGD 2 synthases). Deletion of H-PGDS, but not lipocalin-type PGDS, exacerbated the hypoxia/SU5416–induced PH in mice and abolished the protective effects of niacin against PAH. Moreover, H-PGDS was expressed dominantly in infiltrated macrophages in lungs of PH mice and patients with idiopathic PAH. Macrophage-specific deletion of H-PGDS markedly decreased PGD 2 generation in lungs, aggravated hypoxia/SU5416–induced PH in mice, and attenuated the therapeutic effect of niacin on PAH. Conclusions: Niacin treatment ameliorates the progression of PAH through the suppression of vascular remodeling by stimulating H-PGDS–derived PGD 2 release from macrophages.

Role of angiotensin-converting enzyme and angiotensin II in development of hypoxic pulmonary hypertension

1995 ◽  
Vol 269 (4) ◽  
pp. H1186-H1194 ◽  
Author(s):  
N. W. Morrell ◽  
K. G. Morris ◽  
K. R. Stenmark
Keyword(s):  
Pulmonary Hypertension ◽  
Angiotensin Ii ◽  
Receptor Antagonist ◽  
Vascular Remodeling ◽  
Ace Inhibition ◽  
Protective Effects ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Hypoxic Pulmonary Hypertension

Although angiotensin converting enzyme (ACE) inhibitors are known to attenuate the development of hypoxic pulmonary hypertension in rats, the precise mechanism of this protective effect remains unknown. Thus we utilized specific angiotensin II (ANG II)-receptor antagonists to investigate whether ANG II is involved directly in the hemodynamic and structural changes of pulmonary hypertension, and we tested whether the protective effects of ACE inhibition can be attributed partly to potentiation of bradykinin. During 14 days of hypobaric hypoxia, rats received, via intraperitoneal osmotic minipumps, either 1) the ACE inhibitor captopril, 2) captopril plus the bradykinin B2-receptor antagonist CP-0597, 3) the ANG II type 1 receptor antagonist losartan, 4) the ANG II type 2 receptor antagonist PD-123319, or 5) saline. At 14 days, mean pulmonary arterial pressure (MPAP) was reduced (P < 0.05) in hypoxic rats treated with captopril (26.6 +/- 0.8 mmHg) or losartan (24.4 +/- 1.0 mmHg) compared with saline (32.0 +/- 1.4 mmHg) but was unaffected by PD-123319 (29.5 +/- 1.7 mmHg). Right ventricular hypertrophy was reduced in hypoxic rats treated with captopril or losartan compared with saline-treated rats. Morphometry showed less medial thickening and peripheral muscularization of small pulmonary arteries in hypoxic animals treated with captopril or losartan. Coadministration of CP-0597 did not reverse the protective effects of captopril on pulmonary vascular remodeling. These results suggest a novel role for endogenous ANG II, acting through the type 1 receptor, in the vascular remodeling associated with hypoxic pulmonary hypertension. The beneficial effects of ACE inhibition in this model can be attributed to reduced ANG II production rather than potentiation of bradykinin.

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