Inhibition of expression of hypoxia-inducible factor-1α mRNA by nitric oxide in hypoxic pulmonary hypertension rats

2004 ◽  
Vol 24 (1) ◽  
pp. 5-8 ◽  
Author(s):  
AO Qilin ◽  
Huang Lei ◽  
Zhu Pengcheng ◽  
Xiong Mi ◽  
Wang Dixun
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Hypertension ◽  
Hypoxia Inducible Factor ◽  
Hypoxic Pulmonary Hypertension ◽  
Hypoxia Inducible Factor 1Α

Transgelin as a therapeutic target to prevent hypoxic pulmonary hypertension

2014 ◽  
Vol 306 (6) ◽  
pp. L574-L583 ◽  
Author(s):  
Ruifeng Zhang ◽  
Liuhong Shi ◽  
Lin Zhou ◽  
Gensheng Zhang ◽  
Xiaohong Wu ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Lentiviral Vector ◽  
Hypoxia Inducible Factor ◽  
Systolic Pressure ◽  
Cellular Migration ◽  
Regulation Mechanism ◽  
Migration Ability ◽  
Pulmonary Vessel ◽  
Hypoxic Pulmonary Hypertension

We previously observed that transgelin was preferentially expressed in human pulmonary arterial smooth muscle cells (PAMSCs) under hypoxia and that the upregulation of transgelin was independent of hypoxia-inducible factor 1α (HIF-1α). Reduced transgelin expression was accompanied by significantly impaired migration ability in vitro. However, the regulation mechanism of transgelin and its function in preventing hypoxic pulmonary hypertension (HPH) was unclear. In the present study, RNA interference with hypoxia-inducible factor 2α (HIF-2α) was employed in human PASMCs. Transgelin expression was diminished in HIF-2α-siRNA-treated cells at both the mRNA and protein levels under hypoxia. However, HIF-2α did not transactivate the transgelin promoter directly. TGF-β1 concentration in human PASMCs culture medium was higher under hypoxia, and the accumulated TGF-β1 under hypoxia was regulated by HIF-2α. Furthermore, luciferase and chromatin immunoprecipitation assays indicated that TGF-β1/Smad3 could bind to the transgelin promoter, resulting in increased transgelin expression. In addition to nonintact cellular migration, inhibition of transgelin expression resulted in impaired proliferation in vitro under hypoxia. A lentiviral vector used to inhibit transgelin expression was constructed and intratracheally instilled in rats 3 wk prior to hypoxia treatment. Our final results indicated that inhibition of transgelin expression locally could attenuate increased right ventricular systolic pressure and its associated cardiac and pulmonary vessel remodeling under hypoxia. Our findings indicate that HIF-2α upregulates transgelin indirectly and that accumulated TGF-β1 is a mediator in the upregulation of transgelin by HIF-2α under hypoxia. Inhibition of transgelin expression locally could prevent HPH and pulmonary vascular remodeling in vivo.

scholarly journals MiRNA let-7b promotes the development of hypoxic pulmonary hypertension by targeting ACE2

2019 ◽  
Vol 316 (3) ◽  
pp. L547-L557 ◽  
Author(s):  
Ruifeng Zhang ◽  
Hua Su ◽  
Xiuqing Ma ◽  
Xiaoling Xu ◽  
Li Liang ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Hypoxia Inducible Factor ◽  
Underlying Mechanism ◽  
Pulmonary Vessel ◽  
Hypoxic Pulmonary Hypertension ◽  
And Migration ◽  
Ventricle Hypertrophy ◽  
Proliferation And Migration

Angiotensin-converting enzyme 2 (ACE2) protects against hypoxic pulmonary hypertension (HPH) by inhibiting the proliferation and migration of pulmonary artery smooth muscle cells (PASMCs). Under hypoxia, the hypoxia-inducible factor 1α (HIF-1α) inhibits ACE2 indirectly; however, the underlying mechanism is unclear. In the present study, we found that exposure to chronic hypoxia stimulated microRNA (miRNA) let-7b expression in rat lung via a HIF-1α-dependent pathway. Let-7b downregulated ACE2 expression by directly targeting the coding sequence of ACE2. Our in vitro and in vivo results revealed that let-7b contributed to the pathogenesis of HPH by inducing PASMCs proliferation and migration. Let-7b knockout mitigated right ventricle hypertrophy and pulmonary vessel remodeling in HPH by restoring ACE2 expression. Overall, we demonstrated that HIF-1α inhibited ACE2 expression via the HIF-1α-let-7b-ACE2 axis, which contributed to the pathogenesis of HPH by stimulating PASMCs proliferation and migration. Since let-7b knockout alleviated the development of HPH, let-7b may serve as a potential clinical target for the treatment of HPH.

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