Endothelial Cell PHD2-HIF1α-PFKFB3 Contributes to Right Ventricle Vascular Adaptation in Pulmonary Hypertension

Author(s):  
Biruk Kassa ◽  
Rahul Kumar ◽  
Claudia Mickael ◽  
Linda Sanders ◽  
Christine U Vohwinkel ◽  
...  

Background: Humans and animals with pulmonary hypertension (PH) show right ventricular (RV) capillary growth, which positively correlates with overall RV hypertrophy. However, molecular drivers of RV vascular augmentation in PH are unknown. Prolyl hydroxylase (PHD2) is a regulator of hypoxia-inducible factors (HIFs), which transcriptionally activates several proangiogenic genes, including the glycolytic enzyme PFKFB3. We hypothesized that a signaling axis of PHD2-HIF1α-PFKFB3 contributes to adaptive coupling between the RV vasculature and tissue volume to maintain appropriate vascular density in PH. Methods and Results: We used design-based stereology to analyze endothelial cell (EC) proliferation and the absolute length of the vascular network in the RV free wall, relative to the tissue volume in mice challenged with hypoxic PH. We observed increased RV EC proliferation starting after 6 hours of hypoxia challenge. Using parabiotic mice, we found no evidence for a contribution of circulating EC precursors to the RV vascular network. Mice with transgenic deletion or pharmacologic inhibition of PHD2, HIF1α, or PFKFB3 all had evidence of impaired RV vascular adaptation following hypoxia PH challenge. Conclusions: PHD2-HIF1α-PFKFB3 contributes to structural coupling between the RV vascular length and tissue volume in hypoxic mice, consistent with homeostatic mechanisms which maintain appropriate vascular density. Activating this pathway could help augment the RV vasculature and preserve RV substrate delivery in PH, as an approach to promote RV function.

2017 ◽  
Vol 232 (1) ◽  
pp. R27-R44 ◽  
Author(s):  
D S Boeldt ◽  
I M Bird

Maternal vascular adaptation to pregnancy is critically important to expand the capacity for blood flow through the uteroplacental unit to meet the needs of the developing fetus. Failure of the maternal vasculature to properly adapt can result in hypertensive disorders of pregnancy such as preeclampsia (PE). Herein, we review the endocrinology of maternal adaptation to pregnancy and contrast this with that of PE. Our focus is specifically on those hormones that directly influence endothelial cell function and dysfunction, as endothelial cell dysfunction is a hallmark of PE. A variety of growth factors and cytokines are present in normal vascular adaptation to pregnancy. However, they have also been shown to be circulating at abnormal levels in PE pregnancies. Many of these factors promote endothelial dysfunction when present at abnormal levels by acutely inhibiting key Ca2+ signaling events and chronically promoting the breakdown of endothelial cell–cell contacts. Increasingly, our understanding of how the contributions of the placenta, immune cells, and the endothelium itself promote the endocrine milieu of PE is becoming clearer. We then describe in detail how the complex endocrine environment of PE affects endothelial cell function, why this has contributed to the difficulty in fully understanding and treating this disorder, and how a focus on signaling convergence points of many hormones may be a more successful treatment strategy.


2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Ha-Rim Seo ◽  
Hyo Eun Jeong ◽  
Hyung Joon Joo ◽  
Seung-Cheol Choi ◽  
Jong-Ho Kim ◽  
...  

Background: Human body contains many kinds of different type of endothelial cells (EC). However, cellular difference of their angiogenic potential has been hardly understood. We compared in vitro angiogenic potential between arterial EC and venous EC and investigated its underlying molecular mechanisms. Method: Used human aortic endothelial cells (HAEC) which was indicated from arterial EC and human umbilical vein endothelial cells (HUVEC) indicated from venous EC. To explore angiogenic potential in detail, we adopted a novel 3D microfluidic angiogenesis assay system, which closely mimic in vivo angiogenesis. Results: In 3D microfluidic angiogenesis assay system, HAEC demonstrated stronger angiogenic potential compared to HUVEC. HAEC maintained its profound angiogenic property under different biophysical conditions. In mRNA microarray sorted on up- regulated or down-regulated genes, HAEC demonstrated significantly higher expression of gastrulation brain homeobox 2 (GBX2), fibroblast grow factor 2 (FGF2), FGF5 and collagen 8a1. Angiogenesis-related protein assay revealed that HAEC has higher secretion of endogenous FGF2 than HUVEC. HAEC has only up-regulated FGF2 and FGF5 in this part of FGF family. Furthermore, FGF5 expression under vascular endothelial growth factor-A (VEGF-A) stimulation was higher in HAEC compared to HUVEC although VEGF-A augmented FGF5 expression in both HAEC and HUVEC. Those data suggested that FGF5 expression in both HAEC and HUVEC is partially dependent to VEGF-A stimulate. HUVEC and HAEC reduced vascular density after FGF2 and FGF5 siRNA treat. Conclusion: HAEC has stronger angiogenic potential than HUVEC through up-regulation of endogenous FGF2 and FGF5 expression


2021 ◽  
Vol 118 (17) ◽  
pp. e2023130118
Author(s):  
Zdravka Daneva ◽  
Corina Marziano ◽  
Matteo Ottolini ◽  
Yen-Lin Chen ◽  
Thomas M. Baker ◽  
...  

Recent studies have focused on the contribution of capillary endothelial TRPV4 channels to pulmonary pathologies, including lung edema and lung injury. However, in pulmonary hypertension (PH), small pulmonary arteries are the focus of the pathology, and endothelial TRPV4 channels in this crucial anatomy remain unexplored in PH. Here, we provide evidence that TRPV4 channels in endothelial cell caveolae maintain a low pulmonary arterial pressure under normal conditions. Moreover, the activity of caveolar TRPV4 channels is impaired in pulmonary arteries from mouse models of PH and PH patients. In PH, up-regulation of iNOS and NOX1 enzymes at endothelial cell caveolae results in the formation of the oxidant molecule peroxynitrite. Peroxynitrite, in turn, targets the structural protein caveolin-1 to reduce the activity of TRPV4 channels. These results suggest that endothelial caveolin-1–TRPV4 channel signaling lowers pulmonary arterial pressure, and impairment of endothelial caveolin-1–TRPV4 channel signaling contributes to elevated pulmonary arterial pressure in PH. Thus, inhibiting NOX1 or iNOS activity, or lowering endothelial peroxynitrite levels, may represent strategies for restoring vasodilation and pulmonary arterial pressure in PH.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
S Sakai ◽  
H Maruyama ◽  
M Ieda

Abstract Background Endothelial dysfunction is thought to be a major contributor to overall pathogenesis of vasculopathy seen in pulmonary hypertension (PH), which is manifested by the impaired release of nitric oxide (NO) generated through endothelial nitric oxide synthase (eNOS) in endothelial cells. Activation of human eNOS is regulated by phosphorylation at multiple sites including Thr33 and Ser114, which residues are followed by Pro. The peptidyl isomerase Pin1 specifically isomerizes the phospho-protein having Ser/Thr-Pro bond and regulates their activity. Pin1 is involved in proliferation, cell cycle, and apoptosis in cancer, by isomerizing some functional molecules such as JNK, JUN, cyclin D, BAX, etc. However, it is controversial whether direct interaction of Pin1 with eNOS and how eNOS activity is altered by Pin1, especially in PH. Purpose We aimed to clarify whether Pin1 contributes to the PH development using Pin1 knockout mice and Pin1 affects the expression of phosphorylated eNOS (p-eNOS) molecule and pulmonary arterial endothelial cell (PAEC) apoptosis. Methods and results Wild (WT) and Pin1-deficient mice (KO) were exposed to hypoxia (10% O2) or normoxia for 3 weeks to generate hypoxia-induced PH. Hypoxia-inducible factor (HIF1α) expression in lungs was significantly enhanced in WT-hypoxia (WH, n=6) and KO-hypoxia (KH, n=6), suggesting that hypoxic response was certainly occurred in these mice. Pulmonary arterial pressure did not elevate in KH compared with KO-normoxia (KN, n=6) and WT-normoxia (WN, n=6), it was significantly increased only in WH (P<0.01), indicating that KO did not develop PH by hypoxia. The gain of RV weight was parallel to the increase of pulmonary arterial pressure. Western blot showed that p-eNOS expression in lungs was significantly decreased in WH compared to WN, however, the expression was not different between KH and KN. It suggests that Pin1 plays a regulatory role in p-eNOS expression in hypoxic response. In cultured PAECs, the expression of p-eNOS and eNOS was markedly increased by siRNA-mediated Pin1 knockdown. Immunoprecipitation study showed the possibility of Pin1 binding to p-eNOS molecule. Apoptosis evaluated by caspase-3/7 activity by fluorescent assay and cleaved caspase-3 expression by Western blot was significantly increased by Pin1 overexpression in PAECs; however, it was significantly decreased by Pin1 knockdown. Moreover, the exaggeration of apoptosis induced by doxorubicin was markedly increased by Pin1 overexpression compared with control in PAECs; however, it was clearly suppressed by Pin1 knockdown. Conclusion This study suggests that endogenous Pin1 contributes to the development of PH partly via the dysfunction of PAECs, that is, by the interference with p-eNOS expression and by the increase of apoptosis inducibility to external stimuli. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): JSPS KAKENHI


2003 ◽  
Vol 284 (6) ◽  
pp. L926-L937 ◽  
Author(s):  
Vanessa Louzier ◽  
Bernadette Raffestin ◽  
Aude Leroux ◽  
Didier Branellec ◽  
Jean Michel Caillaud ◽  
...  

Angiogenic factors exert protective effects on the lung. To investigate the effect of VEGF-B, a factor coexpressed in the lung with VEGF-A, we assessed chronic hypoxic pulmonary hypertension in VEGF-B knockout mice (VEGF-B−/−) and in rats with lung overexpression of VEGF-B induced by adenovirus transfer. No significant difference in pulmonary hemodynamics, right ventricular hypertrophy, distal vessel muscularization, or vascular density was found between VEGF-B−/− and control mice after 3 wk of hypoxia. When overexpressed, VEGF-B167 or VEGF-B186 had protective effects similar to those of human VEGF-A165. Lung endothelial nitric oxide synthase (eNOS) expression was increased by 5 days of hypoxia or VEGF-A adenovirus vector (Ad.VEGF-A) overexpression, whereas VEGF-B167 or VEGF-B186had no effect. With hypoxia or normoxia, the wet-to-dry lung weight ratio was increased 5 days after Ad.VEGF-A administration compared with control (Ad.nul), Ad.VEGF-B167, or Ad.VEGF-B186. Endogenous VEGF-B does not counteract the development of hypoxic pulmonary hypertension. However, when overexpressed in the lung, VEGF-B can be as potent as VEGF-A in attenuating pulmonary hypertension, although it has no effect on eNOS expression or vascular permeability.


2004 ◽  
Vol 183 (1) ◽  
pp. 1-17 ◽  
Author(s):  
P D Taylor ◽  
S G Hillier ◽  
H M Fraser

Angiogenesis is required for normal follicular development but the role of gonadotrophins in the control of follicular angiogenesis remains to be elucidated. This study investigated the effects of treatment with GnRH antagonist in vivo on follicular development and angiogenesis in the marmoset. GnRH antagonist was administered on either follicular day 0 or day 5 of the 10-day follicular phase with ovaries collected on day 10. Ovaries from control marmosets were studied at day 5 (mid follicular phase) and day 10 (periovulatory period). Ovaries were fixed, serial sectioned and subjected to morphological analysis and immunocytochemistry to determine cell proliferation and follicular endothelial cell area and in situ hybridization to assess changes in expression of vascular endothelial growth factor (VEGF). Treatment with GnRH antagonist from day 0–10 resulted in an absence of dominant preovulatory follicles seen in controls. In the remaining tertiary follicles granulosa, theca and endothelial cell proliferation was reduced, resulting in a minor reduction in vascular density. However, VEGF mRNA expression was unaffected by treatment. Treatment from day 5–10 did not prevent development of ovulatory size follicles, but they were atretic and lacked VEGF mRNA. These results suggest that while VEGF expression in the preovulatory follicle is under gonadotrophic control it is not dependent on normal gonadotrophin secretion in tertiary follicles, indicating that there are other paracrine factors regulating VEGF expression in the developing ovarian follicle.


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