scholarly journals Enhancement of Angiogenesis Through Stabilization of Hypoxia-inducible Factor-1 by Silencing Prolyl Hydroxylase Domain-2 Gene

2008 ◽  
Vol 16 (7) ◽  
pp. 1227-1234 ◽  
Author(s):  
Shourong Wu ◽  
Nobuhiro Nishiyama ◽  
Mitsunobu R Kano ◽  
Yasuyuki Morishita ◽  
Kohei Miyazono ◽  
...  
Keyword(s):  
Hypoxia Inducible Factor ◽  
Prolyl Hydroxylase ◽  
Hypoxia Inducible Factor 1 ◽  
Prolyl Hydroxylase Domain

scholarly journals Isolated Erythrocytosis Associated With 3 Novel Missense Mutations in the EGLN1 Gene

2020 ◽  
Vol 8 ◽  
pp. 232470962094725
Author(s):  
Joseph A. Moore ◽  
Maimon E. Hubbi ◽  
Chenliang Wang ◽  
Yingfei Wang ◽  
Weibo Luo ◽  
...  
Keyword(s):  
Protein Stability ◽  
Cultured Cells ◽  
Hypoxia Inducible Factor ◽  
Prolyl Hydroxylase ◽  
Missense Mutations ◽  
Novel Mutations ◽  
Gene Encoding ◽  
Protein Levels ◽  
Hypoxia Inducible Factor 1 ◽  
Prolyl Hydroxylase Domain

Hypoxia-inducible factor-1 (HIF-1) is a key regulator of erythropoiesis. In this article, we report 3 novel mutations, P378S, A385T, and G206C, on the EGLN1 gene encoding the negative HIF-1α regulator prolyl hydroxylase domain-2 (PHD2) in 3 patients with isolated erythrocytosis. These mutations impair PHD2 protein stability and partially reduce PHD2 activity, leading to increased HIF-1α protein levels in cultured cells.

Abstract 396: Inhibition of Prolyl Hydroxylase Domain-containing Protein Downregulates Vascular Angiotensin II Type 1 Receptor

Hypertension ◽  
2012 ◽  
Vol 60 (suppl_1) ◽  
Author(s):  
Toshihiro Ichiki
Keyword(s):  
Cellular Response ◽  
Target Genes ◽  
Interstitial Fibrosis ◽  
Critical Role ◽  
Hypoxia Inducible Factor ◽  
Renin Angiotensin System ◽  
Prolyl Hydroxylase ◽  
Ang Ii ◽  
Prolyl Hydroxylase Domain

Background: Prolyl hydroxylase domain-containing protein (PHD) mediates hydroxylation of hypoxia-inducible factor (HIF)-1α and thereby induces proteasomal degradation of HIF-1α. Inhibition of PHD by hypoxia or hypoxia mimetics such as cobalt chloride (CoCl2) stabilizes HIF-1 and increases the expression of target genes such as vascular endothelial growth factor (VEGF). Although hypoxia activates the systemic renin angiotensin system (RAS), the role of PHD in regulating RAS remains unknown. We examined the effect of PHD inhibition on the expression of angiotensin (Ang) II type 1 receptor (AT1R) and its signaling. Methods and Results: Hypoxia (1% O2), CoCl2 (100-300 μmol/L), and dimethyloxalylglycine (0.25-1.0 mmol/L), all known to inhibit PHD, reduced AT1R expression by 37.7±7.6, 39.6±8.4-69.7±9.9, and 13.4±6.1-25.2±7.0%, respectively (p<0.01) in cultured vascular smooth muscle cell. The same stimuli increased the expression of nuclear HIF-1α and VEGF (p<0.05), suggesting that PHD activity is inhibited. Knockdown of PHD2, a major isoform of PHDs, by RNA interference also reduced AT1R expression by 55.3±6.0% (p<0.01). CoCl2 decreased AT1R mRNA through transcriptional and posttranscriptional mechanisms (p<0.01 and <0.05, respectively). CoCl2 and PHD2 knockdown diminished Ang II-induced ERK phosphorylation (P<0.01). Over-expression of the constitutively active HIF-1α did not impact the AT1R gene promoter activity. Oral administration of CoCl2 (14 mg/kg/day) to C57BL/6J mice receiving Ang II infusion (490 ng/kg/min) for 4 weeks significantly reduced the expression of AT1R in the aorta by 60.9±11.3% (p<0.05) and attenuated coronary perivascular fibrosis by 85% (p<0.01) without affecting blood pressure. However, CoCl2 did not affect Ang II-induced renal interstitial fibrosis. Conclusion: PHD inhibition downregulates AT1R expression independently of HIF-1α, reduces the cellular response to Ang II, and attenuates profibrotic effect of Ang II on the coronary arteries. PHD inhibition may be beneficial for the treatment of cardiovascular diseases, in which activation of RAS plays a critical role.

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