scholarly journals Extracellular retention of PDGF-B directs vascular remodeling in mouse hypoxia-induced pulmonary hypertension

2018 ◽  
Vol 314 (4) ◽  
pp. L593-L605 ◽  
Author(s):  
Philip Tannenberg ◽  
Ya-Ting Chang ◽  
Lars Muhl ◽  
Bàrbara Laviña ◽  
Hanna Gladh ◽  
...  

Pulmonary hypertension (PH) is a lethal condition, and current vasodilator therapy has limited effect. Antiproliferative strategies targeting platelet-derived growth factor (PDGF) receptors, such as imatinib, have generated promising results in animal studies. Imatinib is, however, a nonspecific tyrosine kinase inhibitor and has in clinical studies caused unacceptable adverse events. Further studies are needed on the role of PDGF signaling in PH. Here, mice expressing a variant of PDGF-B with no retention motif ( Pdgfbret/ret), resulting in defective binding to extracellular matrix, were studied. Following 4 wk of hypoxia, right ventricular systolic pressure, right ventricular hypertrophy, and vascular remodeling were examined. Pdgfbret/ret mice did not develop PH, as assessed by hemodynamic parameters. Hypoxia did, however, induce vascular remodeling in Pdgfbret/ret mice; but unlike the situation in controls where the remodeling led to an increased concentric muscularization of arteries, the vascular remodeling in Pdgfbret/ret mice was characterized by a diffuse muscularization, in which cells expressing smooth muscle cell markers were found in the interalveolar septa detached from the normally muscularized intra-acinar vessels. Additionally, fewer NG2-positive perivascular cells were found in Pdgfbret/ret lungs, and mRNA analyses showed significantly increased levels of Il6 following hypoxia, a known promigratory factor for pericytes. No differences in proliferation were detected at 4 wk. This study emphasizes the importance of extracellular matrix-growth factor interactions and adds to previous knowledge of PDGF-B in PH pathobiology. In summary, Pdgfbret/ret mice have unaltered hemodynamic parameters following chronic hypoxia, possibly secondary to a disorganized vascular muscularization.

2011 ◽  
Vol 301 (6) ◽  
pp. L872-L880 ◽  
Author(s):  
R. Bierer ◽  
C. H. Nitta ◽  
J. Friedman ◽  
S. Codianni ◽  
S. de Frutos ◽  
...  

Pulmonary hypertension occurs with prolonged exposure to chronic hypoxia in both adults and neonates. The Ca2+-dependent transcription factor, nuclear factor of activated T cells isoform c3 (NFATc3), has been implicated in chronic hypoxia-induced pulmonary arterial remodeling in adult mice. Therefore, we hypothesized that NFATc3 is required for chronic hypoxia-induced pulmonary hypertension in adult and neonatal mice. The aim of this study was to determine whether 1) NFATc3 mediates chronic hypoxia-induced increases in right ventricular systolic pressure in adult mice; 2) NFATc3 is activated in neonatal mice exposed to chronic hypoxia; and 3) NFATc3 is involved in chronic hypoxia-induced right ventricular hypertrophy and pulmonary vascular remodeling in neonatal mice. Adult mice were exposed to hypobaric hypoxia for 2, 7, and 21 days. Neonatal mouse pups were exposed for 7 days to hypobaric chronic hypoxia within 2 days after delivery. Hypoxia-induced increases in right ventricular systolic pressure were absent in NFATc3 knockout adult mice. In neonatal mice, chronic hypoxia caused NFAT activation in whole lung and nuclear accumulation of NFATc3 in both pulmonary vascular smooth muscle and endothelial cells. In addition, heterozygous NFATc3 neonates showed less right ventricular hypertrophy and pulmonary artery wall thickness in response to chronic hypoxia than did wild-type neonates. Our results suggest that NFATc3 mediates pulmonary hypertension and vascular remodeling in both adult and neonatal mice.


2020 ◽  
Author(s):  
Heshen Tian ◽  
Lei Liu ◽  
Ying Wu ◽  
Ruiwen Wang ◽  
Yongliang Jiang ◽  
...  

Abstract BACKGROUND: Pulmonary arterial smooth muscle cell (PASMC) proliferation plays a crucial role in hypoxia-induced pulmonary hypertension (HPH). Previous studies have found that resistin-like molecule β (RELM-β) is upregulated de novo in response to hypoxia in cultured human PASMCs (hPASMCs). RELM-β has been reported to promote hPASMC proliferation and is involved in pulmonary vascular remodeling in patients with PAH. However, the expression pattern, effects, and mechanisms of action of RELM-β in HPH remain unclear.METHODS: We assessed the expression pattern, mitogenetic effect, and mechanism of action of RELM-β in a rat HPH model and in hPASMCs.RESULTS: Overexpression of RELM-β caused hemodynamic changes in a rat model of HPH similar to those induced by chronic hypoxia, including increased mean right ventricular systolic pressure (mRVSP), right ventricular hypertrophy index (RVHI) and thickening of small pulmonary arterioles. Knockdown of RELM-β partially blocked the increases in mRVSP, RVHI, and vascular remodeling induced by hypoxia. The phosphorylation levels of the PI3K, Akt, mTOR, PKC, and MAPK proteins were significantly up- or downregulated by RELM-β gene overexpression or silencing, respectively. Recombinant RELM-β protein increased the intracellular Ca2+ concentration in primary cultured hPASMCs and promoted hPASMC proliferation. The mitogenic effects of RELM-β on hPASMCs and the phosphorylation of PI3K, Akt, mTOR, PKC, and MAPK were suppressed by a Ca2+ inhibitor.CONCLUSIONS: Our findings suggest that RELM-β acts as a cytokine-like growth factor in the development of HPH and that the effects of RELM-β are likely to be mediated by the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK pathways.


2021 ◽  
Vol 22 (18) ◽  
pp. 9916
Author(s):  
Vijaya Karoor ◽  
Derek Strassheim ◽  
Timothy Sullivan ◽  
Alexander Verin ◽  
Nagavedi S. Umapathy ◽  
...  

Pulmonary hypertension (PH) is a progressive cardiovascular disorder in which local vascular inflammation leads to increased pulmonary vascular remodeling and ultimately to right heart failure. The HDAC inhibitor butyrate, a product of microbial fermentation, is protective in inflammatory intestinal diseases, but little is known regarding its effect on extraintestinal diseases, such as PH. In this study, we tested the hypothesis that butyrate is protective in a Sprague–Dawley (SD) rat model of hypoxic PH. Treatment with butyrate (220 mg/kg intake) prevented hypoxia-induced right ventricular hypertrophy (RVH), hypoxia-induced increases in right ventricular systolic pressure (RVSP), pulmonary vascular remodeling, and permeability. A reversal effect of butyrate (2200 mg/kg intake) was observed on elevated RVH. Butyrate treatment also increased the acetylation of histone H3, 25–34 kDa, and 34–50 kDa proteins in the total lung lysates of butyrate-treated animals. In addition, butyrate decreased hypoxia-induced accumulation of alveolar (mostly CD68+) and interstitial (CD68+ and CD163+) lung macrophages. Analysis of cytokine profiles in lung tissue lysates showed a hypoxia-induced upregulation of TIMP-1, CINC-1, and Fractalkine and downregulation of soluble ICAM (sICAM). The expression of Fractalkine and VEGFα, but not CINC-1, TIMP-1, and sICAM was downregulated by butyrate. In rat microvascular endothelial cells (RMVEC), butyrate (1 mM, 2 and 24 h) exhibited a protective effect against TNFα- and LPS-induced barrier disruption. Butyrate (1 mM, 24 h) also upregulated tight junctional proteins (occludin, cingulin, claudin-1) and increased the acetylation of histone H3 but not α-tubulin. These findings provide evidence of the protective effect of butyrate on hypoxic PH and suggest its potential use as a complementary treatment for PH and other cardiovascular diseases.


2020 ◽  
Author(s):  
Heshen Tian ◽  
Lei Liu ◽  
Ying Wu ◽  
Ruiwen Wang ◽  
Yongliang Jiang ◽  
...  

Abstract BACKGROUND: Pulmonary arterial smooth muscle cell (PASMC) proliferation plays a crucial role in hypoxia-induced pulmonary hypertension (HPH). Previous studies have found that resistin-like molecule β (RELM-β) is upregulated de novo in response to hypoxia in cultured human PASMCs (hPASMCs). RELM-β has been reported to promote hPASMC proliferation and is involved in pulmonary vascular remodeling in patients with PAH. However, the expression pattern, effects, and mechanisms of action of RELM-β in HPH remain unclear.METHODS: We assessed the expression pattern, mitogenetic effect, and mechanism of action of RELM-β in a rat HPH model and in hPASMCs.RESULTS: Overexpression of RELM-β caused hemodynamic changes in a rat model of HPH similar to those induced by chronic hypoxia, including increased mean right ventricular systolic pressure (mRVSP), right ventricular hypertrophy index (RVHI) and thickening of small pulmonary arterioles. Knockdown of RELM-β partially blocked the increases in mRVSP, RVHI, and vascular remodeling induced by hypoxia. The phosphorylation levels of the PI3K, Akt, mTOR, PKC, and MAPK proteins were significantly up- or downregulated by RELM-β gene overexpression or silencing, respectively. Recombinant RELM-β protein increased the intracellular Ca2+ concentration in primary cultured hPASMCs and promoted hPASMC proliferation. The mitogenic effects of RELM-β on hPASMCs and the phosphorylation of PI3K, Akt, mTOR, PKC, and MAPK were suppressed by a Ca2+ inhibitor.CONCLUSIONS: Our findings suggest that RELM-β acts as a cytokine-like growth factor in the development of HPH and that the effects of RELM-β are likely to be mediated by the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK pathways.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Heshen Tian ◽  
Lei Liu ◽  
Ying Wu ◽  
Ruiwen Wang ◽  
Yongliang Jiang ◽  
...  

Abstract Background Pulmonary arterial smooth muscle cell (PASMC) proliferation plays a crucial role in hypoxia-induced pulmonary hypertension (HPH). Previous studies have found that resistin-like molecule β (RELM-β) is upregulated de novo in response to hypoxia in cultured human PASMCs (hPASMCs). RELM-β has been reported to promote hPASMC proliferation and is involved in pulmonary vascular remodeling in patients with PAH. However, the expression pattern, effects, and mechanisms of action of RELM-β in HPH remain unclear. Methods We assessed the expression pattern, mitogenetic effect, and mechanism of action of RELM-β in a rat HPH model and in hPASMCs. Results Overexpression of RELM-β caused hemodynamic changes in a rat model of HPH similar to those induced by chronic hypoxia, including increased mean right ventricular systolic pressure (mRVSP), right ventricular hypertrophy index (RVHI) and thickening of small pulmonary arterioles. Knockdown of RELM-β partially blocked the increases in mRVSP, RVHI, and vascular remodeling induced by hypoxia. The phosphorylation levels of the PI3K, Akt, mTOR, PKC, and MAPK proteins were significantly up- or downregulated by RELM-β gene overexpression or silencing, respectively. Recombinant RELM-β protein increased the intracellular Ca2+ concentration in primary cultured hPASMCs and promoted hPASMC proliferation. The mitogenic effects of RELM-β on hPASMCs and the phosphorylation of PI3K, Akt, mTOR, PKC, and MAPK were suppressed by a Ca2+ inhibitor. Conclusions Our findings suggest that RELM-β acts as a cytokine-like growth factor in the development of HPH and that the effects of RELM-β are likely to be mediated by the Ca2+-dependent PI3K/Akt/mTOR and PKC/MAPK pathways.


2017 ◽  
Vol 41 (6) ◽  
pp. 2333-2349 ◽  
Author(s):  
Songhe Liang ◽  
Hao Yu ◽  
Xinxin Chen ◽  
Tingting Shen ◽  
Zhongqi Cui ◽  
...  

Background: Accumulating evidence suggests that platelet-derived growth factor-BB (PDGF-BB) and vascular endothelial growth factor(VEGF) play a role in the progression of pulmonary arterial hypertension (PAH).Since chronic hypoxia is responsible for intimal hyperplasia and disordered angiogenesis of pulmonary arteries, which are histological hallmarks of PAH, we explored the role of the PDGF-BB/KLF4/VEGF signaling axis in the angiogenesis of pulmonary artery endothelial cells (PAECs). Methods: Adult male Wistar rats were used to study hypoxia-induced or monocrotaline (MCT)-induced right ventricular (RV) remodeling as well as systolic function and hemodynamics using echocardiography and a pressure-volume admittance catheter. Morphometric analyses of lung vasculature and RV vessels were performed. Results: The results revealed that both the PDGF receptor-tyrosine kinase inhibitor imatinib and the multi-targeted VEGF and PDGF receptor inhibit or sunitinib malate reversed hypoxia-induced increases in right ventricular systolic pressure (RVSP), right ventricular function and thickening of the medial walls. Mechanistically VEGF/VEGFR and PDGF/PDGFR formed a biological complex. We also showed that PDGF-BBincreasedKLF4 promoter activity transcriptionally activating VEGF expression, which regulates PAEC proliferation; migration; and the cell-cycle transition from G0/G1phase to S phase and G2/M-phase and eventually leads to PAEC angiogenesis Conclusion: Our study indicates that hypoxia-induced angiogenesis of PAECs is associated with increased levels of PDGF-BB/KLF4/VEGF, which contribute to pulmonary vascular remodeling. Overall, our study contributes to a better understanding of PAH pathogenesis.


2021 ◽  
Author(s):  
Hongxia Jiang ◽  
Dandan Ding ◽  
Yuanzhou He ◽  
Xiaochen Li ◽  
Yongjian Xu ◽  
...  

Pulmonary hypertension (PH) is a life-threatening disease characterized by vascular remodeling. Exploring new therapy target is urgent. The purpose of this study is to investigate whether and how spliced x-box binding protein 1 (xbp1s), a key component of endoplasmic reticulum stress (ERS), contributes to the pathogenesis of PH. Forty male SD rats were randomly assigned to four groups: Control, Monocrotalin (MCT), MCT+AAV-CTL (control), and MCT+AAV-xbp1s. The xbp1s protein levels were found to be elevated in lung tissues of the MCT group. Intratracheal injection of adeno-associated virus serotype 1 carrying xbp1s shRNA (AAV-xbp1s) to knock down the expression of xbp1s effectively ameliorated the MCT-induced elevation of right ventricular systolic pressure (RVSP), total pulmonary resistance (TPR), right ventricular hypertrophy and medial wall thickness of muscularized distal pulmonary arterioles. The abnormally increased positive staining rates of PCNA and Ki67 and decreased positive staining rates of TUNEL in pulmonary arterioles were also reversed in the MCT+AAV-xbp1s group. For mechanistic exploration, bioinformatic prediction of the protein network was performed on the STRING database, and further verification was performed by qRT-PCR, western blots and coimmunoprecipitation. Ddit3 (DNA damage-inducible transcript 3) was identified as a downstream protein that interacted with xbp1s. Overexpression of Ddit3 restored the decreased proliferation, migration, and cell viability caused by silencing of xbp1s. The protein level of Ddit3 was also highly consistent with xbp1s in the animal model. Taken together, our study demonstrated that xbp1s-Ddit3 may be a potential target to interfere with vascular remodeling in PH.


1993 ◽  
Vol 264 (2) ◽  
pp. L100-L106 ◽  
Author(s):  
D. Katayose ◽  
M. Ohe ◽  
K. Yamauchi ◽  
M. Ogata ◽  
K. Shirato ◽  
...  

To study the molecular basis of vascular remodeling in pulmonary hypertension, we developed an experimental system in which male Sprague-Dawley rats were exposed to hypoxia for up to 3 wk. Both the right ventricular systolic pressure and gravimetric index for right ventricular hypertrophy were higher in rats exposed to hypoxia for 3 wk than those of age-matched control rats (P < 0.01), indicating that pulmonary hypertension was established under conditions used. To examine the possible involvement of platelet-derived growth factor (PDGF) in the pulmonary vascular remodeling caused by hypoxia, we cloned rat PDGF A- and B-chain cDNA and prepared specific cRNA probes. Northern blot analysis revealed that PDGF B-chain mRNA levels in the lungs were increased, reached a maximum of day 1, and were sustained at day 3, whereas PDGF A-chain mRNA levels reached a maximum on day 3. Thus the increase in the PDGF B-chain mRNA level precedes that in the PDGF A-chain mRNA level. These results suggest that the PDGF A- and B-chain products may be coordinately and sequentially involved in hypoxic pulmonary vascular remodeling.


2015 ◽  
Vol 309 (10) ◽  
pp. L1164-L1173 ◽  
Author(s):  
Michiel Alexander de Raaf ◽  
Yvet Kroeze ◽  
Anthonieke Middelman ◽  
Frances S. de Man ◽  
Helma de Jong ◽  
...  

Increased serotonin serum levels have been proposed to play a key role in pulmonary arterial hypertension (PAH) by regulating vessel tone and vascular smooth muscle cell proliferation. An intact serotonin system, which critically depends on a normal function of the serotonin transporter (SERT), is required for the development of experimental pulmonary hypertension in rodents exposed to hypoxia or monocrotaline. While these animal models resemble human PAH only with respect to vascular media remodeling, we hypothesized that SERT is likewise required for the presence of lumen-obliterating intima remodeling, a hallmark of human PAH reproduced in the Sugen hypoxia (SuHx) rat model of severe angioproliferative pulmonary hypertension. Therefore, SERT wild-type (WT) and knockout (KO) rats were exposed to the SuHx protocol. SERT KO rats, while completely lacking SERT, were hemodynamically indistinguishable from WT rats. After exposure to SuHx, similar degrees of severe angioproliferative pulmonary hypertension and right ventricular hypertrophy developed in WT and KO rats (right ventricular systolic pressure 60 vs. 55 mmHg, intima thickness 38 vs. 30%, respectively). In conclusion, despite its implicated importance in PAH, SERT does not play an essential role in the pathogenesis of severe angioobliterative pulmonary hypertension in rats exposed to SuHx.


2002 ◽  
Vol 283 (5) ◽  
pp. H2021-H2028 ◽  
Author(s):  
Yasuhiro Ikeda ◽  
Yoshikazu Yonemitsu ◽  
Chu Kataoka ◽  
Shiro Kitamoto ◽  
Terutoshi Yamaoka ◽  
...  

Monocyte/macrophage chemoattractant protein-1 (MCP-1), a potent chemoattractant chemokine and an activator for mononuclear cells, may play a role in the initiation and/or progression of pulmonary hypertension (PH). To determine whether blockade of a systemic MCP-1 signal pathway in vivo may prevent PH, we intramuscularly transduced a naked plasmid encoding a 7-NH2terminus-deleted dominant negative inhibitor of the MCP-1 (7ND MCP-1) gene in monocrotaline-induced PH. We also simultaneously gave a duplicate transfection at 2-wk intervals or skeletal muscle-directed in vivo electroporation (EP) to evaluate whether a longer or higher expression might be more effective. The intramuscular reporter gene expression was enhanced 10 times over that by EP than by simple injection, and a significant 7ND MCP-1 protein in plasma was detected only in the EP group. 7ND MCP-1 gene transfer significantly inhibited the progression of MCT-induced PH as evaluated by right ventricular systolic pressure, right ventricular hypertrophy, medial hypertrophy of pulumonary arterioles, and mononuclear cell infiltration into the lung. Differential effects of longer or higher transgene expression were not apparent. Although the in vivo kinetics of 7ND MCP-1 gene therapy should be studied further, these encouraging results suggest that an anti-inflammatory strategy via blockade of the MCP-1 signal pathway may be an alternative approach to treat subjects with PH.


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