scholarly journals C-Abl Is Required for the Development of Hyperoxia-Induced Retinopathy

2001 ◽  
Vol 193 (12) ◽  
pp. 1383-1392 ◽  
Author(s):  
Irene Nunes ◽  
Rosemary D. Higgins ◽  
Lucia Zanetta ◽  
Peter Shamamian ◽  
Stephen P. Goff

The requirement for the nonreceptor tyrosine kinase c-abl in the pathogenesis of retinopathy of prematurity (ROP) was examined using the mouse model for ROP and c-abl–deficient mice. Hyperoxia-induced retinal neovascularization was observed in wild-type and heterozygous mice but animals that were homozygous null for c-abl did not develop a vasoproliferative retinopathy in response to hyperoxia. Two gene products, endothelin-1 (ET-1) and vascular endothelial growth factor (VEGF), have been implicated in the pathogenesis of ROP. The mRNA expression of ET-1 and VEGF was assessed in mice maintained in normoxia and in hyperoxia-exposed mice. ET-1 mRNA levels were unchanged in wild-type mice throughout the hyperoxia treatment, suggesting that ET-1 mRNA expression is not regulated by the increase in inspired oxygen. In wild-type mice maintained in room air, VEGF mRNA levels rose threefold from postnatal day 6 (P6) to P17. When wild-type mice were treated with the hyperoxia regimen, a fivefold decrease in VEGF mRNA expression was observed from P7 to P16. However, retinal VEGF expression in hyperoxia-treated homozygous null mice did not decrease and remained at control levels. These data suggest that c-abl is required for the hyperoxia-induced retinal neovascularization and hyperoxia-induced decrease in VEGF mRNA levels.

Biomolecules ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1405
Author(s):  
Deokho Lee ◽  
Yukihiro Miwa ◽  
Jing Wu ◽  
Chiho Shoda ◽  
Heonuk Jeong ◽  
...  

Neovascular retinal degeneration is a leading cause of blindness in advanced countries. Anti-vascular endothelial growth factor (VEGF) drugs have been used for neovascular retinal diseases; however, anti-VEGF drugs may cause the development of chorioretinal atrophy in chronic therapy as they affect the physiological amount of VEGF needed for retinal homeostasis. Hypoxia-inducible factor (HIF) is a transcription factor inducing VEGF expression under hypoxic and other stress conditions. Previously, we demonstrated that HIF was involved with pathological retinal angiogenesis in murine models of oxygen-induced retinopathy (OIR), and pharmacological HIF inhibition prevented retinal neovascularization by reducing an ectopic amount of VEGF. Along with this, we attempted to find novel effective HIF inhibitors. Compounds originally isolated from mushroom-forming fungi were screened for prospective HIF inhibitors utilizing cell lines of 3T3, ARPE-19 and 661W. A murine OIR model was used to examine the anti-angiogenic effects of the compounds. As a result, 2-azahypoxanthine (AHX) showed an inhibitory effect on HIF activation and suppressed Vegf mRNA upregulation under CoCl2-induced pseudo-hypoxic conditions. Oral administration of AHX significantly suppressed retinal neovascular tufts in the OIR model. These data suggest that AHX could be a promising anti-angiogenic agent in retinal neovascularization by inhibiting HIF activation.


2004 ◽  
Vol 183 (3) ◽  
pp. 527-533 ◽  
Author(s):  
T Sakurai ◽  
K Tamura ◽  
H Kogo

Vascular endothelial growth factor (VEGF) is known to be necessary for the vascularization of the developing corpus luteum. Our recent data suggested that cyclooxygenase-II (COX-II) may play a role in the formation of vascular plexuses in developing corpora lutea of the rat. Here we examined the relationship between VEGF and the expression of prostaglandin (PG)- metabolizing enzymes in rat ovarian luteal cells. VEGF treatment caused a dose-dependent increase in the expression of COX-II and membrane-associated PGE synthase (mPGES) mRNA in cultured rat luteal cells. However, pretreatment of the luteal cells with a selective COX-II inhibitor, NS-398, abolished the VEGF-enhanced mPGES mRNA expression. VEGF also increased PGE2 secretion. Conversely, PGE2 dose-dependently stimulated VEGF mRNA expression. Furthermore, VEGF induced VEGF mRNA expression, but this effect was abolished by NS-398 pretreatment. These findings suggest that VEGF enhances PGE2 production by stimulating COX-II and mPGES expression in rat corpus luteum and that the effect of VEGF on luteal cells may be partially mediated by this stimulation of PGE2 production.


2009 ◽  
Vol 21 (1) ◽  
pp. 111 ◽  
Author(s):  
P. P. Borowicz ◽  
M. L. Johnson ◽  
R. Beraldi ◽  
A. Edwards ◽  
A. T. Grazul-Bilska ◽  
...  

Pregnancies obtained via somatic cell nuclear transfer (SCNT) show an increased incidence of pregnancy complications, including poor placental vascularization, hydrops placenta, and abnormal placental morphology. In a preliminary study of hydrops placentas from SCNT clones v. control cow placentas close to term, we observed a thickening of the endometrial epithelium, which appeared pseudostratified; in addition, the subepithelial endometrial vascular bed consisted of large, rare arterioles with thick basement membranes compared with the normal capillary bed observed in control animals. The fetal membranes of hydrops placenta from bovine SCNT clones also exhibited macroscopic morphological differences, which included edema, increased membrane thickness, and a gelatinous appearance. All of these morphological differences were similar to those we have reported for sheep SCNT clones (Palmieri et al. 2007 Placenta 28, 577–584). In the search for biomarkers that may indicate abnormal placental development early in pregnancy, placental tissues were collected on day 40 from pregnancies established after transfer of embryos created through SCNT (n = 17) or IVF (n = 6). Nuclear donor cells used to obtain SCNT embryos were those we have previously found to be highly susceptible to hydrops (from 5 to 19%), whereas the incidence of hydrops in IVF and controls in our laboratories did not exceed 0.5%. A sample of fetal membranes was fixed in 10% buffered formalin for histological analysis; another sample was snap-frozen in liquid nitrogen for analysis of mRNA levels for vascular endothelial growth factor (VEGF) and its receptors (KDR and FLT) by quantitative, real-time RT-PCR. Histological analysis of cell proliferation rate was performed using immunohistochemical localization of proliferating cell nuclear antigen and image analysis software (Image-Pro Plus). There were no differences (P = 0.39) in the rate of cell proliferation of the trophoblast in SCNT v. IVF (29.4 ± 4.9% v. 22.1 ± 3%). However, VEGF mRNA expression was less (P < 0.04) in the fetal membranes of SCNT than IVF on day 40 of pregnancy (0.30 ± 0.04 v. 0.53 ± 0.12, normalized to α-actin mRNA levels). The mRNA expression for KDR and FLT were similar in SCNT and IVF. These data suggest that the lower expression of VEGF, a major placental angiogenic factor, in fetal membranes of early pregnant SCNT fetuses may be an early biomarker for the development of hydrops placenta later in pregnancy. NDAES Proj. ND01727.


2006 ◽  
Vol 20 (4) ◽  
pp. 916-930 ◽  
Author(s):  
Nadia Cherradi ◽  
Cyrille Lejczak ◽  
Agnes Desroches-Castan ◽  
Jean-Jacques Feige

Abstract Expression of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen and a potent angiogenic factor, is up-regulated by a variety of factors including hypoxia, growth factors, and hormones. In the adrenal cortex, regulation of VEGF expression by the pituitary hormone ACTH ensures the maintenance of the organ vasculature. We have previously shown that ACTH evokes a rapid and transient increase in VEGF mRNA levels in primary adrenocortical cells through transcription-independent mechanisms. We further demonstrated that the zinc finger RNA-binding protein Tis11b (tetradecanoyl phorbol acetate-inducible-sequence 11b) destabilizes VEGF mRNA through its 3′-untranslated region (3′-UTR) and that Tis11b is involved in the decay phase of ACTH-induced VEGF mRNA expression. In the present study, we attempted to determine the mechanisms underlying ACTH-elicited increase in VEGF mRNA levels in adrenocortical cells. We show that ACTH triggers an increase in the levels of the mRNA-stabilizing protein HuR in the cytoplasm and a concomitant decrease in the levels of HuR in the nucleus. This process is accompanied by an increased association of HuR with the nucleocytoplasmic shuttling protein pp32, indicating that ACTH induces HuR translocation from the nuclear to the cytoplasmic compartment. Leptomycin B, a specific inhibitor of CRM1-dependent nuclear export of pp32, significantly reduced ACTH-induced VEGF mRNA levels. Furthermore, RNA interference-mediated depletion of HuR in adrenocortical cells abrogated ACTH-induced VEGF mRNA expression. Finally, we show that Tis11b and HuR exert antagonistic effects on VEGF 3′-UTR in vitro. Although both proteins could bind simultaneously on VEGF 3′-UTR, Tis11b markedly decreases HuR-binding to this RNA sequence. Altogether, these results suggest that the RNA-stabilizing protein HuR is instrumental to ACTH-induced expression of VEGF mRNA and that the nuclear export of HuR is a rate-limiting step in this process. HuR appears to transiently stabilize VEGF transcripts after ACTH stimulation of adrenocortical cells, and Tis11b appears to subsequently trigger their degradation.


Endocrinology ◽  
2005 ◽  
Vol 146 (9) ◽  
pp. 3950-3958 ◽  
Author(s):  
Tatiana Kisliouk ◽  
Helena Podlovni ◽  
Katharina Spanel-Borowski ◽  
Oded Ovadia ◽  
Qun-Yong Zhou ◽  
...  

Abstract A highly vascular endocrine gland, the corpus luteum (CL) is an excellent model for the study of angiogenic factors. Prokineticins (PK-1 and -2), also termed endocrine-gland-derived vascular endothelial growth factor (VEGF) and BV8 are newly identified proteins described as selective angiogenic mitogens. We previously identified PK binding sites, two closely homologous G protein-coupled receptors (PK-R1 and PK-R2) in human and bovine ovarian cells, but their function remained unknown. In this study we examined the presence and effects of PK in CL-derived endothelial and steroidogenic cell types (LEC and LSC, respectively). PK-1 mRNA was identified in CL and follicles by real-time PCR, using primers specific for the bovine PK-1 sequence (retrieved from Bos taurus whole genome shotgun database). PK were potent angiogenic mitogens for LEC; they enhanced cell proliferation, elevated [3H]thymidine incorporation, MAPK activation, and c-jun/fos mRNA expression. The effects of PK proteins on cell survival were examined by nuclear morphology (4′,6-diamidino-2-phenylindole dihydrochloride staining), measurement of DNA fragmentation (terminal dUTP nucleotide end labeling assay), and caspase-3 cleavage. Results obtained by these techniques demonstrated that PK protected LEC from serum starvation-induced apoptosis. Stress conditions such as serum withdrawal, TNF-α, and hypoxia markedly increased PK-R2 expression, whereas mRNA levels of PK-R1 remained unchanged. These suggest that the antiapoptotic effect of PK-1 on LEC may be mediated via PK-R2. PK-1 increased VEGF mRNA expression by LSC, implying that it could also indirectly, via VEGF, affect luteal angiogenesis. Together, these findings suggest an important role for PK-1 in luteal function by acting as a mitogen and survival factor in LEC.


1999 ◽  
Vol 67 (4) ◽  
pp. 1633-1639 ◽  
Author(s):  
K. Matsushita ◽  
R. Motani ◽  
T. Sakuta ◽  
S. Nagaoka ◽  
T. Matsuyama ◽  
...  

ABSTRACT We investigated whether vascular endothelial growth factor (VEGF) production by human pulp cells (HPC) is regulated by lipopolysaccharide (LPS) in relation to the pathogenesis of pulpitis. Although HPC incubated with medium alone only marginally expressed VEGF mRNA and produced a low level of VEGF as detected by enzyme-linked immunosorbent assay, the VEGF mRNA expression and VEGF production were markedly enhanced upon stimulation with LPS from Escherichia coli. Prevotella intermedia LPS, phorbol 12-myristate 13-acetate, and interleukin-6 also induced VEGF mRNA expression in HPC. A simian virus 40-infected HPC line also exhibited increased VEGF mRNA expression in response to E. coli LPS, but lung and skin fibroblasts did not. Fetal bovine serum (FBS) increased the sensitivity of HPC to LPS in a dose-dependent manner. HPC did not express membrane CD14 on their surfaces. However, the anti-CD14 monoclonal antibody MY4 inhibited VEGF induction upon stimulation with LPS in HPC cultures in the presence of 10% FBS but not in the absence of FBS. LPS augmented the VEGF production in HPC cultures in the presence of recombinant human soluble CD14 (sCD14). To clarify the mechanisms of VEGF induction by LPS, we examined the possible activation of the transcription factor AP-1 in HPC stimulated with LPS, by a gel mobility shift assay. AP-1 activation in HPC was clearly observed, whereas that in skin fibroblasts was not. The AP-1 inhibitor curcumin strongly inhibited LPS-induced VEGF production in HPC cultures. In addition, a protein synthesis inhibitor, cycloheximide, inhibited VEGF mRNA accumulation in response to LPS. These results suggest that the enhanced production of VEGF in HPC induced by LPS takes place via an sCD14-dependent pathway which requires new protein synthesis and is mediated in part through AP-1 activation.


1997 ◽  
Vol 273 (2) ◽  
pp. H938-H944 ◽  
Author(s):  
Y. Ni ◽  
V. May ◽  
K. Braas ◽  
G. Osol

This study examined a potential role for vascular endothelial growth factor (VEGF) in uterine artery remodeling and vasodilation during pregnancy. Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect VEGF mRNA in uterine tissues from nonpregnant (NP), midpregnant (MP, 15-16 days), and late-pregnant (LP, 19-21 days) rats and in placentas from MP and LP rats. VEGF mRNA levels in uteri and placentas were determined by Northern blotting, and the vasorelaxant activity of recombinant human VEGF (rh-VEGF) was tested and compared in isolated uterine arteries from LP and NP animals. VEGF120 and VEGF164 were the major isoforms detected in uterine tissues; all members of the VEGF family (VEGF120, VEGF164, VEGF188, and VEGF205) were expressed in LP placentas. VEGF mRNA levels increased 60% in MP and 80% in LP above those in NP (P < 0.05) in uterine tissues; VEGF mRNA levels were also detectable in placentas and elevated approximately fivefold in LP vs. MP tissues (P < 0.01). Phenylephrine-preconstricted uterine arcuate arteries (NP and LP) dilated in response to rhVEGF, an effect that was completely abolished by endothelial denudation or pretreatment with genistein, a tyrosine kinase inhibitor. The magnitude of dilation to an intermediate concentration of rhVEGF (1 nM) was greater in LP than in NP vessels (55 +/- 8 vs. 24 +/- 11%; P < 0.05), and this effect was diminished comparably in both groups (approximately 60% by N omega-nitro-L-arginine, an inhibitor of nitric oxide synthesis. These results suggest that VEGF may play a role in the vascular remodeling and vasodilation that lead to decreased uterine vascular resistance and increased uterine blood flow during pregnancy.


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