[The effect of epidermal growth factor on corneal endothelial wound healing in rabbits].
2
Citation
0
Reference
10
Related Paper
Citation Trend
Abstract:
We investigated the effect of epidermal growth factor (EGF) on rabbit corneal endothelial wound healing in vivo. After a 6 mm-diameter metallic cryoprobe was applied to rabbit corneas, 0.1 ml of recombinant human EGF (100 micrograms/ml) or saline was injected into the anterior chamber. Corneas were excised on 1, 2, and 7 days postoperatively, labeled with 3H-thymidine and subjected to autoradiography. Some corneas were examined by scanning electron microscopy. Autoradiography showed that the number of endothelial cells incorporating 3H-thymidine in corneas treated with EGF was significantly greater than that in the control. Scanning electron microscopy demonstrated the effect of EGF on accelerating endothelial healing. These findings indicate that EGF has a stimulatory effect on the proliferation of wounded rabbit corneal endothelial cells in vivo. Under the conditions tested in the present study, there were no side effects of EGF such as neovascularization or cellular proliferation in the angle. The results suggest that EGF might be clinically applicable for corneal endothelial disorders.Keywords:
Thymidine
Lagomorpha
Corneal Neovascularization
Cite
The object of this study was to test vascular endothelial growth factor (VEGF) for angiogenic activity in the rabbit corneal assay. VEGF doses ranging from 20 ng to 1000 ng were incorporated into a slow release polymer and implanted into the avascular rabbit cornea. Capillary formation in the cornea was visually analyzed on a daily basis and examined with histology, transmission electron microscopy and scanning electron microscopy of vascular corrosion casts on days 2 and 7 post-implantation. VEGF implants (200ng to 1000ng) consistently stimulated angiogenesis. This neovascularization occurred in the absence of inflammation. We conclude that VEGF acts directly on endothelial cells, initiating and mediating the formation of capillaries.
Corneal Neovascularization
Lagomorpha
Cite
Citations (134)
To investigate the expression of vascular endothelial growth factor (VEGF) in rat cornea after cautery with alkali.In Sprague-Dawley rats, inflammatory corneal neovascularization was induced by cautery with alkali. VEGF was detected in corneal samples at different times by Western-blot, and immunohistochemistry method was used to investigate the distribution of VEGF at rat cornea after cautery with alkali.The normal rat corneas did not express VEGF. The expression of VEGF increased with time after corneal cautery. The rat corneas were infiltrated by massive inflammatory cells that, especially adjacent to the cautery lesion, showed staining for VEGF.VEGF production by inflammatory cells participates in inflammatory angiogenesis in rat corneas. VEGF has the effects on the induction and supporting of cautery-induced angiogenesis in rat cornea.
Corneal Neovascularization
Cite
Citations (1)
The objective of this study was to determine the angiogenic potential of transforming growth factor-alpha (TGF-a). Recombinant human TGF-a (0.25 to 5.0 ug) was implanted in the rabbit cornea. The eyes were monitored daily for corneal opacification, dilation of limbal blood vessels, and the growth of new capillaries toward the implanted TGF-a. Two, 3 and 7 days post-implantation, the eyes were harvested for histology, transmission electron microscopy, or examination of vascular corrosion casts with scanning electron microscopy. TGF-a (2.5-5.0 ug) consistently elicited an influx of inflammatory cells followed by capillary formation. To determine if these inflammatory cells were the initiators and mediators of the angiogenic response, they were depleted by local administration of methylprednisolone acetate (MPA). The angiogenesis was reduced, but not completely blocked. These results suggest that TGF-a is capable of directly stimulating neovascularization. However, the direct angiogenesis appears to be augmented by the products of the recruited inflammatory cells.
Chorioallantoic membrane
Corneal Neovascularization
Cite
Citations (2)
To evaluate whether the vascular endothelial growth factor A (VEGF-A) in the recipient cornea measured at the time of penetrating keratoplasty (PK) can act as a prognostic factor for corneal graft reaction development.The study included 25 eyes (of 25 patients) scheduled for PK. According to preoperative clinical finding, patients were divided into three groups: inflammatory with neovascularization (n = 11); inflammatory without neovascularization (n = 7); and non-inflammatory (n = 7). One half of the recipient cornea was analyzed for the levels of VEGF-A protein using a commercial enzyme-linked immunosorbent assay; the other half was analyzed to determine the loci of VEGF-A production by immunohistochemistry. The frequencies of corneal graft reaction and rejection were recorded, together with the improvement of visual acuity. Twenty-five donor corneas obtained from cadaver eyes represented the control group (n = 25).There was a statistically significant difference in the levels of VEGF-A protein between the recipient corneal buttons obtained from eyes with inflammatory changes and neovascularization, and those from the non-inflammatory group and controls (p < 0.01). The level of VEGF-A was 287.74 pg/ml (standard deviation [SD] = 129.181) in the inflammatory with corneal neovascularization group, 227.64 pg/ml (SD = 85.590) in the inflammatory without neovascularization group, 115.37 pg/ml (SD = 105.93) in the non-inflammatory group, and 142.28 pg/ml (SD = 93.081) in the control group. Graft reaction/rejection rate was 54.5%/45.5% in the inflammatory with neovascularization group, 14.3%/0% in the inflammatory without neovascularization group, and 14.3%/14.3% in non-inflammatory group. Patients who developed clinical signs of graft reaction during the postoperative follow-up had a significantly higher level of VEGF-A (307.4 pg/ml, SD = 100.058) compared with those without any signs of graft reaction (182.8 pg/ml, SD = 124.987).Our results suggest that both graft reaction and final graft rejection occur more often in patients with increased levels of VEGF-A in a recipient cornea at the time of PK.
Corneal Neovascularization
Corneal Transplant
Cite
Citations (3)
<b><i>Purpose:</i></b> This study was undertaken to investigate the effects of recombinant human epidermal growth factor (rhEGF) and basic fibroblast growth factor (bFGF) on corneal wound healing and neovascularization (CNV). <b><i>Methods:</i></b> The positive effects of 10 ng/ml rhEGF and bFGF on the proliferation of corneal epithelial cells (SD-HCEC1s), rabbit keratocyte cells (RKCs) and human umbilical vein endothelial cells (HUVECs) as well as the effects on the migration capacity on HUVECs were observed. An animal central corneal wound and CNV model was established in rabbits. One eye of each group was chosen randomly for topical administration of rhEGF, bFGF or normal saline, and variability in the area of corneal epithelial wound healing and CNV was observed. <b><i>Results:</i></b> The optimal concentration of rhEGF and bFGF for the proliferation of corneal epithelial cells was 10 ng/ml. The promotive effect of 10 ng/ml rhEGF on the proliferation of RKCs and HUVECs was less than that of 10 ng/ml bFGF. In the animal experiment, the healing rate of the corneal epithelium in the rhEGF group was better than in the other groups on day 1. On day 3, the healing rates of the 3 groups were nearly equal. The CNV area in the rhEGF group was less than that of the bFGF group. <b><i>Conclusions:</i></b> rhEGF and bFGF both had promotive effects on corneal epithelial wound healing, but rhEGF had a weaker promotive effect on CNV than bFGF. With long-term application of growth factor drugs, rhEGF is suggested for lessening the growth of CNV.
Corneal Neovascularization
Eye drop
Cite
Citations (51)
We investigated the effect of epidermal growth factor (EGF) on rabbit corneal endothelial wound healing in vivo. After a 6 mm-diameter metallic cryoprobe was applied to rabbit corneas, 0.1 ml of recombinant human EGF (100 micrograms/ml) or saline was injected into the anterior chamber. Corneas were excised on 1, 2, and 7 days postoperatively, labeled with 3H-thymidine and subjected to autoradiography. Some corneas were examined by scanning electron microscopy. Autoradiography showed that the number of endothelial cells incorporating 3H-thymidine in corneas treated with EGF was significantly greater than that in the control. Scanning electron microscopy demonstrated the effect of EGF on accelerating endothelial healing. These findings indicate that EGF has a stimulatory effect on the proliferation of wounded rabbit corneal endothelial cells in vivo. Under the conditions tested in the present study, there were no side effects of EGF such as neovascularization or cellular proliferation in the angle. The results suggest that EGF might be clinically applicable for corneal endothelial disorders.
Thymidine
Lagomorpha
Corneal Neovascularization
Cite
Citations (2)
To determine the efficacy of the angiogenic inhibitor TNP-470 on inflammatory corneal neovascularization. Topical and systemic delivery of the drug were investigated in a murine model as well as inhibition of endothelial cell proliferation in vitro and in vivo.The effect of TNP-470 on VEGF- and bFGF-stimulated bovine capillary endothelial (BCE) cell proliferation was evaluated in vitro. Corneal neovascularization was induced in vivo by mechanical debridement of the corneal and limbal epithelium with 0.15 M NaOH on C57BL6 mice. TNP-470 was administered systemically at 30 mg/kg body weight (BW) every other day or topically three times daily in a concentration of 5 ng/ml dissolved in methylcellulose. Vessel length was investigated on day 7. VEGF protein content in murine corneas was analyzed by ELISA on days 2, 4, and 7 of treatment. A modified bromouridine (BrdU) ELISA was used to quantify endothelial cell proliferation.TNP-470 exerted a dose-dependent inhibition of bFGF- and VEGF-induced endothelial cell proliferation in vitro. Both systemic and topical application of TNP-470 led to a significant reduction of inflammatory corneal neovascularization (P < 1 x 10(-5)). BrdU labeling showed that TNP-470 inhibited endothelial cell proliferation. VEGF protein levels were reduced by systemic TNP-470 treatment.These results suggest that TNP-470 reduces inflammatory corneal angiogenesis by directly inhibiting endothelial cell proliferation. Topical and systemic treatment with TNP-470 reduces VEGF levels that are responsible for vessel growth during the neovascularization process.
Corneal Neovascularization
Cite
Citations (42)
Abstract: Vascular endothelial cell growth factor (VEGF) has strong stimulating effects on vascularization. Though very potent, VEGF is rapidly degraded due to its short half‐life and when administrated by uncontrolled and nonspecific methods; however, its systemic administration in large doses can cause harmful side effects. Controlled release technology would allow delivering desired levels of bioactive VEGF within extended periods and permit examination of the in vivo effects of the compound in a broader way. The objective of this study was to determine the in vitro release behavior of VEGF from calcium alginate microspheres and the potency of this controlled release system in promoting localized neovascularization at the subcutaneous site of the rat model. In vitro release of human VEGF 165 (2 and 4 μg/cm 3 microsphere) was studied for 3 weeks under static conditions at 25°C, and daily hormone release was measured using a competitive enzyme immunoassay. Following an uncontrolled release within the first 4 days, a quite constant zero‐order VEGF release of 50 to 90 and 70 to 120 ng/day was achieved from 2 and 4 μg/cm 3 polymer loaded microspheres respectively. In vivo angiogenesis was studied for a period of 8 weeks and evaluated using immunoperoidase staining and histopathological measurements. In vivo studies with rats (n = 24) showed a considerable level of capillary network formation at the epigastric groin fascia of VEGF microsphere‐implanted rats starting from the first week. The most extensive neovascularization was observed in the group with 3 week postimplanted 4 μg VEGF containing microspheres; this level of vascularization was quite similar after 8 weeks. While the control group showed no evidence of angiogenesis, the difference in VEGF‐induced neovascularization is statistically significant (p < 0.03). Immunostaining of the specimens showed a strong relationship between the release of human VEGF and neovascularization. The controlled VEGF release system described here promotes vigorous angiogenesis and has applicability for tissue engineering and wound healing studies.
Therapeutic angiogenesis
Cite
Citations (218)
The influence on human epidermal growth factor (hEGF) on the healing of a standardized corneal alkali wound was studied in the rabbit. The epithelial, stromal, and endothelial healing processes were followed separately for three weeks using quantitative methods. Epithelial and stromal healing was statistically significantly better with h-EGF (0.05 mg/ml) applied topically three times per day. However, hEGF induced considerable neovascularization, and some of the positive influence could be a result of the new vessel formation.
Corneal Neovascularization
Rabbit (cipher)
Cite
Citations (20)
Chronic wounds are associated with a number of deficiencies in critical wound healing processes, including growth factor signaling and neovascularization. Human-derived placental tissues are rich in regenerative cytokines and have been shown in randomized clinical trials to be effective for healing chronic wounds. In this study, PURION® Processed (MiMedx Group, Marietta, GA) dehydrated human amnion/chorion membrane tissue allografts (dHACM, EpiFix®, MiMedx) were evaluated for properties to support wound angiogenesis.Angiogenic growth factors were identified in dHACM tissues using enzyme-linked immunosorbent assays (ELISAs), and the effects of dHACM extract on human microvascular endothelial cell (HMVEC) proliferation and production of angiogenic growth factors was determined in vitro. Chemotactic migration of human umbilical vein endothelial cells (HUVECs) toward pieces of dHACM tissue was determined using a standard in vitro transwell assay. Neovascularization of dHACM in vivo was determined utilizing a murine subcutaneous implant model.Quantifiable levels of the angiogenic cytokines angiogenin, angiopoietin-2 (ANG-2), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), heparin binding epidermal growth factor (HB-EGF), hepatocyte growth factor (HGF), platelet derived growth factor BB (PDGF-BB), placental growth factor (PlGF), and vascular endothelial growth factor (VEGF) were measured in dHACM. Soluble cues promoted HMVEC proliferation in vitro and increased endogenous production of over 30 angiogenic factors by HMVECs, including granulocyte macrophage colony-stimulating factor (GM-CSF), angiogenin, transforming growth factor β3 (TGF-β3), and HB-EGF. 6.0 mm disks of dHACM tissue were also found to recruit migration of HUVECs in vitro. Moreover, subcutaneous dHACM implants displayed a steady increase in microvessels over a period of 4 weeks, indicative of a dynamic intra-implant neovascular process.TAKEN TOGETHER, THESE RESULTS DEMONSTRATE THAT DHACM GRAFTS: 1) contain angiogenic growth factors retaining biological activity; 2) promote amplification of angiogenic cues by inducing endothelial cell proliferation and migration and by upregulating production of endogenous angiogenic growth factors by endothelial cells; and 3) support the formation of blood vessels in vivo. dHACM grafts are a promising wound care therapy with the potential to promote revascularization and tissue healing within poorly vascularized, non-healing wounds.
Angiogenin
Chorioallantoic membrane
Cite
Citations (166)