ABSTRACT
PURPOSE: To investigate the potential role of endothelin-1 (ET-1), a potent vasoconstrictor with mitogenic properties, in the pathogenesis of proliferative diabetic retinopathy (PDR). METHODS: Plasma and vitreous samples were collected from normal patients (controls; n = 25), diabetic patients with PDR (n = 25), and diabetic patients with non-PDR (n = 25). The patients had to have epiretinal membranes (ERMs) or other ocular conditions that made them candidates for vitrectomy. Immunoreactive ET-1 (IR-ET-1) was assayed in plasma and vitreous samples by radioimmunoassay. IR-ET-1 was immunohistochemically localized in ERMs. Expression of endothelin receptors A (ETA) and B (ETB) was confirmed by reverse transcription-polymerase chain reaction analysis. RESULTS: IR-ET-1 levels in plasma and vitreous samples from diabetic patients were higher (P < 0.0001) than those in samples from the control group. The levels for patients with PDR were even higher (P < 0.0001) than those for patients with non-PDR. Eyes with ERMs in the PDR group had the highest vitreous IR-ET-1 levels (14.67 +/- 0.67 pg/mL). IR-ET-1 was localized in the cellular and stromal components of ERMs in diabetic and nondiabetic patients. Furthermore, the ETA and ETB receptors were expressed in both diabetic and nondiabetic ERMs. CONCLUSIONS: Diabetic patients with PDR and ERMs had the highest plasma and vitreous IR-ET-1 levels. ET-1 and its ETA and ETB receptors were present in ERMs. These data suggest that ET-1 is involved in diabetic vitreoretinal disease.
Subject(s)
Diabetic Retinopathy/metabolism , Endothelin-1/metabolism , Epiretinal Membrane/metabolism , Vitreous Body/metabolism , Aged , Aged, 80 and over , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 2/metabolism , Endothelin-1/genetics , Female , Humans , Immunoenzyme Techniques , Male , Middle Aged , RNA, Messenger/metabolism , Radioimmunoassay , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
PURPOSE: Endothelin one (ET-1) is a vasomodulator peptide that plays a role on ocular blood flow, glial proliferation, and collagen matrix contraction by retinal pigmented epithelial (RPE) cells. Both glial and RPE cells have been involved in the formation of epiretinal membranes (ERMs). This investigation was conducted to determine whether ET-1 may be associated with ERMs, either idiopathic (IERMs) or from proliferative vitreoretinopathy (PVR). METHODS: Plasma and vitreous samples were collected from patients classified by the presence of PVR membranes, retinal detachment (RD), and other ocular conditions, such as IERMs, that made the patients candidates for vitrectomy. Immunoreactive endothelin one (IR-ET-1) was tested in plasma and vitreous by radioimmunoassay. Immunoreactive-ET-1 was localized in IERMs and PVR membranes immunohistochemically. Expression of endothelin receptors A (ETA) and B (ETB) was confirmed by reverse transcription-polymerase chain reaction. RESULTS: IR-ET-1 levels in plasma and vitreous were higher in patients with PVR and in patients with RD than in those of the control group. Eyes with IERMs also showed higher IR-ET-1 levels than the control group cases. IR-ET-1 levels in eyes with PVR were higher than those in eyes with IERMs. IR-ET-1 levels in eyes with RD were also higher than those of eyes with IERMs. Immunoreactive ET-1 was localized in the cellular and stromal components of both IERMs and PVR membranes. Furthermore, ETA and ETB receptors were expressed in both IERMs and PVR membranes. CONCLUSIONS: IR-ET-1 in human vitreous is elevated in PVR, RD, and IERMs. ET-1 and its receptors ETA and ETB are present in epiretinal tissue of both idiopathic and PVR membranes. These data suggest an involvement of ET-1 in retinal disease.
Subject(s)
Endothelin-1/metabolism , Epiretinal Membrane/metabolism , Vitreoretinopathy, Proliferative/metabolism , Vitreous Body/metabolism , Adult , Aged , Aged, 80 and over , Female , Glial Fibrillary Acidic Protein/metabolism , Humans , Keratins/metabolism , Male , Middle Aged , RNA, Messenger/metabolism , Radioimmunoassay , Receptor, Endothelin A/genetics , Receptor, Endothelin A/metabolism , Receptor, Endothelin B/genetics , Receptor, Endothelin B/metabolism , Retinal Detachment/metabolism , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
PURPOSE: Atrial natriuretic peptide (ANP) has been recently described as an endogenous inhibitor of the synthesis and angiogenic action of vascular endothelial growth factor (VEGF). Given VEGF's key role in promoting neovascularization in proliferative diabetic retinopathy (PDR), this study was designed to evaluate the possibility that ANP could be involved in the neovascular and fibrotic complications of PDR. METHODS: We determined ANP by radioimmunoassay in plasma and vitreous humor samples collected from diabetic patients with and without PDR and from non-diabetic subjects. ANP was also immunohistochemically localized in the epiretinal membranes of patients with PDR. RESULTS: Vitreous ANP concentrations were significantly higher in patients with active PDR compared to patients with quiescent PDR, diabetes without PDR or controls <0.05. Significant differences were also observed between vitreous ANP levels in diabetic patients without PDR and control subjects. There was no significant correlation between serum and vitreous ANP levels in any of the patient groups. ANP was detected in the fibrovascular epiretinal tissue of patients with PDR. CONCLUSIONS: Diabetic patients with active neovascularization have significantly higher levels of ANP in the vitreous humor than those without active PDR. Diabetic patients without PDR were also found to have significantly higher vitreous ANP levels than non-diabetic patients. Since plasma and vitreous ANP concentrations were found to be unrelated, we suggest intraocular ANP synthesis and/or an increase in the release of ANP into the vitreous, as opposed to diffusion from the blood, as the main factors contributing to the high vitreous ANP levels observed in diabetic patients. In the fibrovascular epiretinal tissue of these patients, ANP was found to be localized in vascular, glial, fibroblast-like and retinal pigment epithelium cells. Our findings suggest a role for ANP in PDR.
Subject(s)
Atrial Natriuretic Factor/metabolism , Diabetic Retinopathy/metabolism , Epiretinal Membrane/metabolism , Vitreous Body/metabolism , Adult , Aged , Diabetes Mellitus, Type 1/metabolism , Diabetes Mellitus, Type 2/metabolism , Diabetic Retinopathy/surgery , Epiretinal Membrane/surgery , Female , Glial Fibrillary Acidic Protein/metabolism , Humans , Immunoenzyme Techniques , Keratins/metabolism , Male , Middle Aged , Radioimmunoassay , Retinal Neovascularization/metabolism , VitrectomyABSTRACT
We evaluated the association of nasopharyngeal carcinoma (NPC) and Epstein-Barr virus (EBV) in Spanish patients, and studied the expression of EBV products (latent membrane protein-1 [LMP-1] and ZEBRA proteins) by NPC cells and its possible prognostic value. In situ hybridization (ISH) for EBV-encoded nonpolyadenylated RNAs (EBERs) and immunohistochemical expression of LMP-1 and ZEBRA proteins by immunohistochemistry were examined in formalin-fixed, paraffin-embedded NPC specimens from 30 patients, and a survival analysis was done by the Kaplan-Meier method. We detected EBERs by ISH in 96.67% of the NPC cases, and detected expression of LMP-I in 43.33% of the NPC cases and expression of ZEBRA protein in 6.67% of the NPC cases. We conclude that ISH for expression of EBERs is an adequate method for detection of EBV in NPC. LMP-1 is not frequently expressed in NPC cells (43.33%). Most NPC cells carry a latent EBV infection. LMP-1 expression might have worsened the prognosis of NPC in our series.
