Dataset Information

The ALK-1/SMAD/ATOH8 axis attenuates hypoxic responses and protects against the development of pulmonary arterial hypertension.

ABSTRACT: Dysregulated bone morphogenetic protein (BMP) signaling in endothelial cells (ECs) is implicated in vascular diseases such as pulmonary arterial hypertension (PAH). Here, we showed that the transcription factor ATOH8 was a direct target of SMAD1/5 and was induced in a manner dependent on BMP but independent of Notch, another critical signaling pathway in ECs. In zebrafish and mice, inactivation of Atoh8 did not cause an arteriovenous malformation-like phenotype, which may arise because of dysregulated Notch signaling. In contrast, Atoh8-deficient mice exhibited a phenotype mimicking PAH, which included increased pulmonary arterial pressure and right ventricular hypertrophy. Moreover, ATOH8 expression was decreased in PAH patient lungs. We showed that in cells, ATOH8 interacted with hypoxia-inducible factor 2α (HIF-2α) and decreased its abundance, leading to reduced induction of HIF-2α target genes in response to hypoxia. Together, these findings suggest that the BMP receptor type II/ALK-1/SMAD/ATOH8 axis may attenuate hypoxic responses in ECs in the pulmonary circulation and may help prevent the development of PAH.

SUBMITTER: Morikawa M

PROVIDER: S-EPMC6908447 | biostudies-literature | 2019 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

The ALK-1/SMAD/ATOH8 axis attenuates hypoxic responses and protects against the development of pulmonary arterial hypertension.

Morikawa Masato M Mitani Yoshihide Y Holmborn Katarina K Kato Taichi T Koinuma Daizo D Maruyama Junko J Vasilaki Eleftheria E Sawada Hirofumi H Kobayashi Mai M Ozawa Takayuki T Morishita Yasuyuki Y Bessho Yasumasa Y Maeda Shingo S Ledin Johan J Aburatani Hiroyuki H Kageyama Ryoichiro R Maruyama Kazuo K Heldin Carl-Henrik CH Miyazono Kohei K

Science signaling 20191112 607

Dysregulated bone morphogenetic protein (BMP) signaling in endothelial cells (ECs) is implicated in vascular diseases such as pulmonary arterial hypertension (PAH). Here, we showed that the transcription factor ATOH8 was a direct target of SMAD1/5 and was induced in a manner dependent on BMP but independent of Notch, another critical signaling pathway in ECs. In zebrafish and mice, inactivation of <i>Atoh8</i> did not cause an arteriovenous malformation-like phenotype, which may arise because of ...[more]

PMID: 31719172

Similar Datasets

Project description:MicroRNAs (miRs) are reported to serve key roles in pulmonary arterial hypertension (PAH). miR‑1 has been found in cardiovascular diseases. The present study aimed to determine whether the knockdown of miR‑1 could inhibit right ventricle (RV) remodeling and thereby control PAH in model rats. PAH model rats were established by exposing rats to hypoxia, while cardiac fibroblasts (CFs) obtained from PAH model rats were treated with hypoxia to establish an in vitro model, and RV remodeling was evaluated by Masson staining and the levels of collagen I, collagen III, α‑smooth muscle actin (α‑SMA) and connective tissue growth factor (CTGF) evaluated by western blotting or reverse transcription‑quantitative PCR. The results revealed that the expression levels of miR‑1 were upregulated in the RV of PAH model rats induced with hypoxia and in the CFs treated with hypoxia. The mean pulmonary arterial pressure, RV systolic pressure, RV/(left ventricle + interventricular septum) and RV/tibia length were increased in PAH rats; however, the increases in all parameters were subsequently reversed by transfection with a miR‑1 antagomiR in PAH model rats. The transfection with the miR‑1 antagomiR inhibited the development of RV fibrosis and downregulated the mRNA expression levels of collagen I, collagen III, α‑SMA and CTGF in the RV tissue of PAH model rats. The upregulation of collagen I, collagen III, α‑SMA and CTGF expression levels in hypoxia‑treated CFs was also subsequently reversed by miR‑1 antagomiR transfection. The expression levels of collagen I, collagen III, α‑SMA and CTGF were also upregulated in the CFs obtained from PAH model rats, and these increases were attenuated by miR‑1 antagomiR transfection. The expression levels of phosphorylated (p)‑PI3K and p‑AKT were also upregulated in hypoxia‑treated CFs, and these increases were also inhibited by transfection with miR‑1 antagomiR. In conclusion, these results indicated that inhibiting miR‑1 may attenuate RV hypertrophy and fibrosis in PAH model rats, a mechanism that may involve the PI3K/AKT signaling pathway.

Project description:Rationale17β-Estradiol (E2) attenuates hypoxic pulmonary vasoconstriction and hypoxic pulmonary hypertension (HPH) through an unknown mechanism that may involve estrogen receptors (ER) or E2 conversion to catecholestradiols and methoxyestradiols with previously unrecognized effects on cardiopulmonary vascular remodeling.ObjectivesTo determine the mechanism by which E2 exerts protective effects in HPH.MethodsMale rats were exposed to hypobaric hypoxia while treated with E2 (75 μg/kg/d) or vehicle. Subgroups were cotreated with pharmacologic ER-antagonist or with inhibitors of E2-metabolite conversion. Complementary studies were performed in rats cotreated with selective ERα- or ERβ-antagonist. Hemodynamic and pulmonary artery (PA) and right ventricular (RV) remodeling parameters, including cell proliferation, cell cycle, and autophagy, were measured in vivo and in cultured primary rat PA endothelial cells.Measurements and main resultsE2 significantly attenuated HPH endpoints. Hypoxia increased ERβ but not ERα lung vascular expression. Co-treatment with nonselective ER inhibitor or ERα-specific antagonist rendered hypoxic animals resistant to the beneficial effects of E2 on cardiopulmonary hemodynamics, whereas ERα- and ERβ-specific antagonists opposed the remodeling effects of E2. In contrast, inhibition of E2-metabolite conversion did not abolish E2 protection. E2-treated hypoxic animals exhibited reduced ERK1/2 activation and increased expression of cell-cycle inhibitor p27(Kip1) in lungs and RV, with up-regulation of lung autophagy. E2-induced signaling was recapitulated in hypoxic but not normoxic endothelial cells, and was associated with decreased vascular endothelial growth factor secretion and cell proliferation.ConclusionsE2 attenuates hemodynamic and remodeling parameters in HPH in an ER-dependent manner, through direct antiproliferative mechanisms on vascular cells, which may provide novel nonhormonal therapeutic targets for HPH.

Dataset Information

The ALK-1/SMAD/ATOH8 axis attenuates hypoxic responses and protects against the development of pulmonary arterial hypertension.

Publications

The ALK-1/SMAD/ATOH8 axis attenuates hypoxic responses and protects against the development of pulmonary arterial hypertension.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets