Enhanced inflammatory cell profiles in schistosomiasis-induced pulmonary vascular remodeling

Background: Vitamin D (vitD) deficiency is highly prevalent in patients with pulmonary arterial hypertension (PAH). Moreover, PAH-patients with lower levels of vitD have worse prognosis. We hypothesize that recovering optimal levels of vitD in an animal model of PAH previously depleted of vitD improves the hemodynamics, the endothelial dysfunction and the ionic remodeling. Methods: Male Wistar rats were fed a vitD-free diet for five weeks and then received a single dose of Su5416 (20 mg/Kg) and were exposed to vitD-free diet and chronic hypoxia (10% O2) for three weeks to induce PAH. Following this, vitD deficient rats with PAH were housed in room air and randomly divided into two groups: (a) continued on vitD-free diet or (b) received an oral dose of 100,000 IU/Kg of vitD plus standard diet for three weeks. Hemodynamics, pulmonary vascular remodeling, pulmonary arterial contractility, and K+ currents were analyzed. Results: Recovering optimal levels of vitD improved endothelial function, measured by an increase in the endothelium-dependent vasodilator response to acetylcholine. It also increased the activity of TASK-1 potassium channels. However, vitD supplementation did not reduce pulmonary pressure and did not ameliorate pulmonary vascular remodeling and right ventricle hypertrophy. Conclusions: Altogether, these data suggest that in animals with PAH and severe deficit of vitD, restoring vitD levels to an optimal range partially improves some pathophysiological features of PAH.

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Endothelial cell-related autophagic pathways in Sugen/hypoxia-exposed pulmonary arterial hypertensive rats

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00527.2016 ◽

2017 ◽

Vol 313 (5) ◽

pp. L899-L915 ◽

Cited By ~ 8

Author(s):

Fumiaki Kato ◽

Seiichiro Sakao ◽

Takao Takeuchi ◽

Toshio Suzuki ◽

Rintaro Nishimura ◽

...

Keyword(s):

Flow Cytometry ◽

Endothelial Cell ◽

Vascular Remodeling ◽

Time Dependent ◽

Causative Role ◽

Dependent Manner ◽

Vascular Endothelial ◽

Pulmonary Vascular Remodeling ◽

Pulmonary Arterial

Pulmonary arterial hypertension (PAH) is characterized by progressive obstructive remodeling of pulmonary arteries. However, no reports have described the causative role of the autophagic pathway in pulmonary vascular endothelial cell (EC) alterations associated with PAH. This study investigated the time-dependent role of the autophagic pathway in pulmonary vascular ECs and pulmonary vascular EC kinesis in a severe PAH rat model (Sugen/hypoxia rat) and evaluated whether timely induction of the autophagic pathway by rapamycin improves PAH. Hemodynamic and histological examinations as well as flow cytometry of pulmonary vascular EC-related autophagic pathways and pulmonary vascular EC kinetics in lung cell suspensions were performed. The time-dependent and therapeutic effects of rapamycin on the autophagic pathway were also assessed. Sugen/hypoxia rats treated with the vascular endothelial growth factor receptor blocker SU5416 showed increased right ventricular systolic pressure (RVSP) and numbers of obstructive vessels due to increased pulmonary vascular remodeling. The expression of the autophagic marker LC3 in ECs also changed in a time-dependent manner, in parallel with proliferation and apoptotic markers as assessed by flow cytometry. These results suggest the presence of cross talk between pulmonary vascular remodeling and the autophagic pathway, especially in small vascular lesions. Moreover, treatment of Sugen/hypoxia rats with rapamycin after SU5416 injection activated the autophagic pathway and improved the balance between cell proliferation and apoptosis in pulmonary vascular ECs to reduce RVSP and pulmonary vascular remodeling. These results suggested that the autophagic pathway can suppress PAH progression and that rapamycin-dependent activation of the autophagic pathway could ameliorate PAH.

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Metalloproteinase inhibition by Batimastat attenuates pulmonary hypertension in chronically hypoxic rats

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00167.2002 ◽

2003 ◽

Vol 285 (1) ◽

pp. L199-L208 ◽

Cited By ~ 28

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.

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