scholarly journals HIF-1α stabilization modified by glutaredoxin-1 is critical for intestinal angiogenesis in NEC pathogenesis

Author(s):  
Yunfei Zhang ◽  
Xiao Zhang ◽  
Bing Tian ◽  
Qin Deng ◽  
Chunbao Guo

Abstract Background: Hypoxia inducible factor (HIF-1α) are essential in the pathogenesis of necrotizing enterocolitis (NEC), which is stabilized by Grx1 deletion. Until now, the mechanism of HIF-1α in the intestinal microcirculation in NEC is not well defined. We intend to investigate the role of HIF-1α in the development of NEC in regulating the microcirculation and the following vasodilatory signal, VEGF. Materials and methods: Experimental NEC was induced in full-term C57BL/6 mouse and Grx1-/-pups through the formula gavage and hypoxia technique. The HIF-1α signal was blocked utilizing the HIF-1α inhibitor, YC-1. Intestinal tissues were collected at predetermined time points for the assessment of intestinal microcirculation and the HIF-1α activity involved signal. Results: We found that NEC inducement impaired the intestinal microcirculation, but intestinal blood flow and capillary density were ameliorated in Grx1-/-mice, which was associated with the GSH-protein adducts of HIF-1α in the intestinal tissue. Grx1 ablation could also promote vascular endothelial growth factor (VEGFA) production in the intestinal tissue. This intestinal microvascular improvement was not found in the HIF-1α inhibited mice, suggesting the HIF-1α dependent manner for intestinal microcirculatory perfusion. Conclusion: The current data demonstrated that HIF-1α signaling is involved in the intestinal microvascular modification during the pathogenesis of NEC, suggesting that targeting with HIF-1α might be a promising strategy for NEC treatment.

2021 ◽  
Author(s):  
Yunfei Zhang ◽  
Xiao Zhang ◽  
Bing Tian ◽  
Xionghui Ding ◽  
Cuilian Ye ◽  
...  

AbstractBackgroundHypoxia inducible factor (HIF-1α) are essential in the pathogenesis of necrotizing enterocolitis (NEC), which is stabilized by Grx1 deletion. Until now, the mechanism of HIF-1α in the intestinal microcirculation in NEC is not well defined. We intend to investigate the role of HIF-1α in the development of NEC in regulating the microcirculation and the following vasodilatory signal, VEGF.Materials and methodsExperimental NEC was induced in full-term C57BL/6 mouse and Grx1-/- pups through the formula gavage and hypoxia technique. The HIF-1α signal was blocked utilizing the HIF-1α inhibitor, YC-1. Intestinal tissues were collected at predetermined time points for the assessment of intestinal microcirculation and the HIF-1α activity involved signal.ResultsWe found that NEC inducement impaired the intestinal microcirculation, but intestinal blood flow and capillary density were ameliorated in Grx1-/- mice, which was associated with the GSH-protein adducts of HIF-1α in the intestinal tissue. Grx1 ablation could also promote vascular endothelial growth factor (VEGFA) production in the intestinal tissue. This intestinal microvascular improvement was not found in the HIF-1α inhibited mice, suggesting the HIF-1α dependent manner for intestinal microcirculatory perfusion.ConclusionThe current data demonstrated that HIF-1α signaling is involved in the intestinal microvascular modification during the pathogenesis of NEC, suggesting that targeting with HIF-1α might be a promising strategy for NEC treatment.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Takeshi Ninchoji ◽  
Dominic T Love ◽  
Ross O Smith ◽  
Marie Hedlund ◽  
Dietmar Vestweber ◽  
...  

Background:Hypoxia and consequent production of vascular endothelial growth factor A (VEGFA) promote blood vessel leakiness and edema in ocular diseases. Anti-VEGFA therapeutics may aggravate hypoxia; therefore, therapy development is needed.Methods:Oxygen-induced retinopathy was used as a model to test the role of nitric oxide (NO) in pathological neovascularization and vessel permeability. Suppression of NO formation was achieved chemically using L-NMMA, or genetically, in endothelial NO synthase serine to alanine (S1176A) mutant mice.Results:Suppression of NO formation resulted in reduced retinal neoangiogenesis. Remaining vascular tufts exhibited reduced vascular leakage through stabilized endothelial adherens junctions, manifested as reduced phosphorylation of vascular endothelial (VE)-cadherin Y685 in a c-Src-dependent manner. Treatment with a single dose of L-NMMA in established retinopathy restored the vascular barrier and prevented leakage.Conclusions:We conclude that NO destabilizes adheren junctions, resulting in vascular hyperpermeability, by converging with the VEGFA/VEGFR2/c-Src/VE-cadherin pathway.Funding:This study was supported by the Swedish Cancer foundation (19 0119 Pj ), the Swedish Research Council (2020-01349), the Knut and Alice Wallenberg foundation (KAW 2020.0057) and a Fondation Leducq Transatlantic Network of Excellence Grant in Neurovascular Disease (17 CVD 03). KAW also supported LCW with a Wallenberg Scholar grant (2015.0275). WCS was supported by Grants R35 HL139945, P01 HL1070205, AHA MERIT Award. DV was supported by grants from the Deutsche Forschungsgemeinschaft, SFB1450, B03, and CRU342, P2.


2001 ◽  
Vol 21 (12) ◽  
pp. 3995-4004 ◽  
Author(s):  
Erik Laughner ◽  
Panthea Taghavi ◽  
Kelly Chiles ◽  
Patrick C. Mahon ◽  
Gregg L. Semenza

ABSTRACT Hypoxia-inducible factor 1 (HIF-1) is a transcriptional activator composed of HIF-1α and HIF-1β subunits. Several dozen HIF-1 targets are known, including the gene encoding vascular endothelial growth factor (VEGF). Under hypoxic conditions, HIF-1α expression increases as a result of decreased ubiquitination and degradation. The tumor suppressors VHL (von Hippel-Lindau protein) and p53 target HIF-1α for ubiquitination such that their inactivation in tumor cells increases the half-life of HIF-1α. Increased phosphatidylinositol 3-kinase (PI3K) and AKT or decreased PTEN activity in prostate cancer cells also increases HIF-1α expression by an undefined mechanism. In breast cancer, increased activity of the HER2 (also known as neu) receptor tyrosine kinase is associated with increased tumor grade, chemotherapy resistance, and decreased patient survival. HER2 has also been implicated as an inducer of VEGF expression. Here we demonstrate that HER2 signaling induced by overexpression in mouse 3T3 cells or heregulin stimulation of human MCF-7 breast cancer cells results in increased HIF-1α protein and VEGF mRNA expression that is dependent upon activity of PI3K, AKT (also known as protein kinase B), and the downstream kinase FRAP (FKBP-rapamycin-associated protein). In contrast to other inducers of HIF-1 expression, heregulin stimulation does not affect the half-life of HIF-1α but instead stimulates HIF-1α synthesis in a rapamycin-dependent manner. The 5′-untranslated region of HIF-1α mRNA directs heregulin-inducible expression of a heterologous protein. These data provide a molecular basis for VEGF induction and tumor angiogenesis by heregulin-HER2 signaling and establish a novel mechanism for the regulation of HIF-1α expression.


2017 ◽  
Vol 29 (8) ◽  
pp. 1530 ◽  
Author(s):  
Jinhai Gou ◽  
Jia Jia ◽  
Juntao Feng ◽  
Xia Zhao ◽  
Tao Yi ◽  
...  

The aim of the present study was to explore the potential mechanism underlying stathmin 1 (Stmn1) regulation of embryo implantation, as a continuation of previous proteomic research. Adult healthy female mice were mated naturally with fertile males. Murine uterine tissue was collected during the peri-implantation period. Local expression of Stmn1 during embryo implantation was detected by immunohistochemistry (IHC), which showed that Stmn1 was extensively expressed in endometrial glandular epithelium, vascular endothelium, luminal epithelium and the underlying stromal cells at the implantation site on Day 5. The role of Stmn1 during embryo implantation was evaluated by transient knockdown of Stmn1 in vivo using short interference (si) RNA, and some associated factors including Akt, phosphorylated (p-) Akt, hypoxia-inducible factor (HIF)-1α, prolactin (PRL), insulin-like growth factor binding protein (IGFBP) 1 and vascular endothelial growth factor (VEGF) were examined by western blotting analysis and ELISA. The number of embryos implanted after Stmn1-siRNA infusion into the lumen of one uterine horn was lower than that with normal pregnancies (2.2 ± 1.5 vs 8.6 ± 0.5 respectively; P < 0.05). The expression of VEGF, HIF-1α, p-Akt and the decidualisation biomarkers PRL and IGFBP 1 was upregulated at the implantation site on Day 5, but downregulated after Stmn1-siRNA infusion. These findings suggest that during embryo implantation, knockdown of Stmn1 suppresses decidualisation by inhibiting the expression of p-Akt, HIF-1α and VEGF, thus leading to impaired embryo implantation. These findings provide clues for understanding the complicated process of embryo implantation and the potential role of Stmn1 during embryo implantation.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
G. Wetzel ◽  
B. Relja ◽  
A. Klarner ◽  
D. Henrich ◽  
N. Dehne ◽  
...  

Background. Hypoxia-inducible factor-1α(HIF-1α) and NF-κB play important roles in the inflammatory response after hemorrhagic shock and resuscitation (H/R). Here, the role of myeloid HIF-1αin liver hypoxia, injury, and inflammation after H/R with special regard to NF-κB activation was studied.Methods. Mice with a conditional HIF-1αknockout (KO) in myeloid cell-line and wild-type (WT) controls were hemorrhaged for 90 min (30±2 mm Hg) and resuscitated. Controls underwent only surgical procedures.Results. After six hours, H/R enhanced the expression of HIF-1α-induced genes vascular endothelial growth factor (VEGF) and adrenomedullin (ADM). In KO mice, this was not observed. H/R-induced liver injury in HIF-1αKO was comparable to WT. Elevated plasma interleukin-6 (IL-6) levels after H/R were not reduced by HIF-1αKO. Local hepatic hypoxia was not significantly reduced in HIF-1αKO compared to controls after H/R. H/R-induced NF-κB phosphorylation in liver did not significantly differ between WT and KO.Conclusions. Here, deleting HIF-1αin myeloid cells and thereby in Kupffer cells was not protective after H/R. This data indicates that other factors, such as NF-κB, due to its upregulated phosphorylation in WT and KO mice, contrary to HIF-1α, are rather key modulators of inflammation after H/R in our model.


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