scholarly journals Brief Report: Case Comparison of Therapy With the Histone Deacetylase Inhibitor Vorinostat in a Neonatal Calf Model of Pulmonary Hypertension

2021 ◽  
Vol 12 ◽  
Author(s):  
Tanya J. Applegate ◽  
Greta M. Krafsur ◽  
June A. Boon ◽  
Hui Zhang ◽  
Min Li ◽  
...  

Pulmonary hypertension (PH) is an incurable condition in humans; driven by pulmonary vascular remodeling partially mediated by epigenetic mechanisms; and leading to right ventricular hypertrophy, failure, and death. We hypothesized that targeting chromatin-modifying histone deacetylases may provide benefit. In this Brief Report we describe case comparison studies using the histone deacetylase inhibitor vorinostat (suberanilohydroxamic acid, 5 mg/kg/day for the first 5 study days) in an established model of severe neonatal bovine PH induced by 14 days of environmental hypoxia. Echocardiographic, hemodynamic, and pharmacokinetic data were obtained in hypoxia-exposed (one each, vorinostat-treated vs. untreated) and normoxic vorinostat-treated control animals (n = 2). Echocardiography detected PH changes by day 4 and severe PH over 14 days of continued hypoxic exposure. RV dysfunction at day 4 was less severe in vorinostat-treated compared to untreated hypoxic calves. Cardioprotective effects were partially maintained following cessation of treatment through the duration of hypoxic exposure, accompanied by hemodynamic evidence suggestive of reduced pulmonary vascular stiffening, and modulated expression of HDAC1 protein and genes involved in RV and pulmonary vascular remodeling and pathological RV hypertrophy. Control calves did not develop PH, nor show adverse cardiac or clinical effects. These results provide novel translation of epigenetic-directed therapy to a large animal severe PH model that recapitulates important features of human disease.

2016 ◽  
Vol 113 (31) ◽  
pp. 8801-8806 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Alexi Crosby ◽  
David Macias ◽  
Cristina Branco ◽  
Renato D. D. R. Colaço ◽  
...  

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.


1992 ◽  
Vol 73 (3) ◽  
pp. 1084-1092 ◽  
Author(s):  
S. Ono ◽  
J. Y. Westcott ◽  
N. F. Voelkel

Chronic hypoxia causes pulmonary hypertension and pulmonary vascular remodeling in rats. Because platelet-activating factor (PAF) levels increase in lung lavage fluid and in plasma from chronically hypoxic rats, we examined the effect of two specific, structurally unrelated PAF antagonists, WEB 2170 and BN 50739, on hypoxia-induced pulmonary vascular remodeling. Treatment with either agent reduced hypoxia-induced pulmonary hypertension and right ventricular hypertrophy at 3 wk of hypoxic exposure (simulated altitude 5,100 m) but did not affect cobalt (CoCl2)-induced pulmonary hypertension. The PAF antagonists had no effect on the hematocrit of normoxic or chronically hypoxic rats or CoCl2-treated rats. Hypoxia-induced pulmonary hypertension was associated with an increase in the vessel wall thickness of the muscular arteries and reduction in the number of peripheral arterioles. In WEB 2170-treated rats, these changes were significantly less severe than those observed in untreated chronically hypoxic rats. PAF receptor blockade had no acute hemodynamic effects; i.e., it did not affect pulmonary arterial pressure or cardiac output nor did it affect the magnitude of acute hypoxic pulmonary vasoconstriction in awake normoxic or chronically hypoxic rats. Isolated lungs from chronically hypoxic rats showed a pressor response to the chemotactic tripeptide N-formyl-Met-Leu-Phe (fMLP) and an increase in the number of leukocytes lavaged from the pulmonary circulation. In vivo treatment with WEB 2170 significantly reduced the fMLP-induced pressor response compared with that observed in isolated lungs from untreated chronically hypoxic rats. These results suggest that PAF contributes to the development of chronic pulmonary hypertension induced by chronic hypoxia.(ABSTRACT TRUNCATED AT 250 WORDS)


1995 ◽  
Vol 79 (6) ◽  
pp. 2122-2131 ◽  
Author(s):  
S. J. Chen ◽  
Y. F. Chen ◽  
Q. C. Meng ◽  
J. Durand ◽  
V. S. Dicarlo ◽  
...  

The current study examined the effects of bosentan, an orally active antagonist of endothelin-A and -B receptors, on the development and maintenance of hypoxia (10% O2)-induced pulmonary hypertension and vascular remodeling in the rat. Pretreatment with bosentan (100 mg.kg-1.day-1, 1 gavage/day for 2 days) completely blocked the pulmonary vasoconstrictor response to acute hypoxia. Chronic bosentan treatment (100 mg.kg-1.day-1 po in the food) instituted 48 h before hypoxic exposure prevented the subsequent development of pulmonary hypertension, attenuated the associated right heart hypertrophy, and prevented the remodeling of small (50–100 microns) pulmonary arteries without altering systemic arterial pressure. Institution of bosentan treatment (for 4 wk) after 2 wk of hypoxia produced a significant reversal of established hypoxia-induced pulmonary hypertension (from 36 +/- 1 to 25 +/- 1 mmHg), right heart hypertrophy, and pulmonary vascular remodeling despite continuing hypoxic exposure. These findings support the hypothesis that endogenous endothelin-1 plays a major role in hypoxic pulmonary vasoconstriction and/or hypertension, right heart hypertrophy, and pulmonary vascular remodeling and suggest that endothelin-receptor blockade may be useful in the treatment of hypoxic pulmonary hypertension humans.


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