Expression of Angiogenic MicroRNAs in Endothelial Progenitor Cells From Type 1 Diabetic Patients With and Without Diabetic Retinopathy.

Purpose: MicroRNA (miR) expression in endothelial progenitor cells (EPCs) in type 1 diabetes (DM1) and its relation with different stages of diabetic retinopathy (DR) have not been reported to date. Our aim was to analyze miR-222, miR-221, and miR-126 expression in EPCs from DM1 patients with and without DR.

Methods: We included 41 patients with DR, 35 without DR, and 38 controls.

Retinal detachment and proliferative vitreoretinopathy: central retinal artery blood velocities, intraocular pressure, and endothelin 1.

Purpose: To analyze if endothelin 1 may have an effect on central retinal artery (CRA) blood flow velocities and intraocular pressure (IOP) in retinal detachment.

Methods: Using radioimmunoassay, immunoreactive endothelin 1 levels were tested in both plasma and subretinal fluid specimens from patients with retinal detachment, while only plasma specimens from healthy subjects were tested. Central retinal artery Doppler sonography parameters and IOP were measured in eyes with retinal detachment, with and without proliferative vitreoretinopathy, their respective healthy fellow eyes, and normal eyes.

Circulating endothelial progenitor cells are reduced in rat oxygen-induced retinopathy despite a retinal SDF-1/CXCR4 and VEGF proangiogenic response.

Aims: The purpose of this study is to investigate circulating endothelial progenitor cells (EPCs) and the signaling pathways involved in their recruitment in the ischemic retina of the 50/10 rat model of oxygen-induced retinopathy (OIR).

Main Methods: Within 12h after birth, litters of Sprague-Dawley rats and their mothers were exposed to alternating oxygen concentrations, followed by a room air exposition, to induce OIR. Retinopathy was quantified by ADPase stain in flat-mounted retinas and pre-ILM nuclei count in retinal sections.

Modelling postoperative visual acuity with and without proliferative vitreoretinopathy associated with primary rhegmatogenous retinal detachment.

Purpose: To find models that will explain the variability in postoperative visual acuity (VA) (logarithmic: logMAR) associated with unilateral primary rhegmatogenous retinal detachment (RD).

Methods: This was a prospective clinical cohort study of 33 patients with proliferative vitreoretinopathy (PVR: PVR View Article and Find Full Text PDF

Preoperative duration of retinal detachment and subretinal immunoreactive endothelin-1: repercussion on logarithmic visual acuity.

Purpose: To analyze whether preoperative duration of primary rhegmatogenous retinal detachment (RD) influences endothelin-1 (ET-1)--a vasoactive, mitogenic, and pro-apoptotic peptide- levels with repercussions on logarithmic (LogMAR) visual acuity (VA).

Methods: Prospective clinical cohort study on 66 healthy patients [33 with proliferative vitreoretinopathy (PVR) and 33 with no PVR] with unilateral RD candidates for scleral buckling (SB) surgery. Using radioimmunoassay, immunoreactive ET-1 (IR-ET-1) was tested in both plasma and subretinal fluid (SRF) of these RD patients.

Apoptosis in the trabecular meshwork of glaucomatous patients.

We established and validated an in toto method to perform TdT-mediated dUTP nick end labeling to study apoptosis in human trabecular meshwork tissue obtained during trabeculectomy in glaucoma patients. In specimens from patients with primary open-angle glaucoma and primary angle-closure glaucoma, we detected a tendency for more apoptotic cells to accumulate in patients with primary open-angle glaucoma. The utility of this method to study apoptosis in the trabecular meshwork is discussed, as well as its application as a tool in biologic samples.

Retinal detachment: visual acuity and subretinal immunoreactive endothelin-1.

Purpose: To analyze whether subretinal (SRF) endothelin-1 (ET-1) - a vasoactive, mitogenic, and pro-apoptotic peptide - levels are related to visual acuity (VA) in rhegmatogenous retinal detachment (RD).

Patients And Methods: Sixty-six healthy patients between 42 and 70 years of age with unilateral RD, all candidates for scleral buckling surgery (PVR View Article and Find Full Text PDF

Expression of nitrotyrosine and oxidative consequences in the trabecular meshwork of patients with primary open-angle glaucoma.

Purpose: To evaluate the possible correlation between the visual field defects in patients with primary open-angle glaucoma (POAG) and the expression and enzymatic activity of nitric oxide synthase (NOS) isoenzymes and nitrotyrosine in trabecular meshwork (TM) samples.

Methods: TM specimens were collected from 146 patients with POAG by using standard filtration surgery. Visual field defects were evaluated by perimetry.

Retinal detachment and proliferative vitreoretinopathy: ophthalmic artery blood velocities, intraocular pressure, and endothelin-1.

Purpose: To analyze if endothelin-1 (ET-1) may have an effect on ophthalmic artery (OA) blood flow velocities and intraocular pressure (IOP) in retinal detachment (RD).

Methods: Using radioimmunoassay, immunoreactive (IR) ET-1 levels were tested in both plasma and subretinal fluid (SRF) specimens from patients with RD, while only plasma specimens from normal (healthy) subjects were tested. OA Doppler sonography parameters and IOP were measured in eyes with RD, with and without proliferative vitreoretinopathy (PVR), their respective healthy fellow eyes, and normal eyes.

Immunoreactive endothelin-1 in the vitreous humor and epiretinal membranes of patients with proliferative diabetic retinopathy.

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 in the vitreous humor and epiretinal membranes of patients with proliferative vitreoretinopathy.

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).

Downregulation of the atrial natriuretic peptide/natriuretic peptide receptor-C system in the early stages of diabetic retinopathy in the rat.

Purpose: Atrial natriuretic peptide (ANP) is a known vascular antipermeability and antiangiogenic factor, but its possible alteration during the early stages of diabetic retinopathy has not yet been explored. The present study sought to investigate the expression of ANP and its receptors using a model of streptozotocin (STZ) induced diabetes in the rat.

Methods: Diabetes was induced in male Wistar rats by an intraperitoneal injection of STZ.

Atrial natriuretic peptide in the vitreous humor and epiretinal membranes of patients with proliferative diabetic retinopathy.

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.

Natriuretic peptide system in the human retina.

Purpose: The natriuretic peptide (NP) family includes atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). Natriuretic peptides are known to inhibit vascular cell growth and regulate vessel tone. There is also much evidence to suggest they modulate vascular permeability and angiogenesis, as well as regulating aqueous humor production in the eye.

Effects of bosentan on neointimal response following coronary angioplasty.

Background: Endothelins are important vasoconstrictors and cellular-growth promoters. ETA-specific antagonists have been shown to reduce neointimal response to injury in some experimental angioplasty models. However, there is little information on the effects of dual ETA/ETB receptor blockers, such as bosentan, on neointimal proliferation following experimental coronary angioplasty.

Localization of endothelin-1 mRNA expression and immunoreactivity in the anterior segment of human eye: expression of ETA and ETB receptors.

Purpose: Endothelin-1 (ET-1), a potent vasoactive peptide, is an important regulator of intraocular pressure. Actually, there is evidence of a role for ET-1 in the pathogenesis of glaucoma. However, the expression pattern of ET-1 and its receptors, ETA and ETB, in the anterior segment of human eye are not known.

Localisation of endothelin-1 mRNA expression and immunoreactivity in the retina and optic nerve from human and porcine eye. Evidence for endothelin-1 expression in astrocytes.

We have investigated the localisation of endothelin-1 (ET-1) mRNA and ET-1-like immunoreactivity in retina and anterior portion of optic nerve from human and porcine eyes. In situ hybridisation method revealed expression of ET-1 mRNA mainly in the innermost layers of the retinas, in the retinal pigment epithelium cells as well as in the astrocytes of the optic nerve. Immunohistochemical studies showed that ET-1-like immunoreactivity appeared in the same regions where ET-1 mRNA was expressed as well as in the inner nuclear layer and in the inner segments of photoreceptors.

Changes in the density and localisation of endothelin receptors in the early stages of rat diabetic retinopathy and the effect of insulin treatment.

Aims/hypothesis: The endothelin system (ET system) has been implicated in the retinal blood flow abnormalities that precede the onset of diabetic retinopathy. This study was undertaken to assess whether the density and localisation of both the immunoreactive endothelin-1 and endothelin receptors in rat retina change in the early stages of diabetes and the insulin treatment would affect those changes.

Methods: Untreated streptozotocin-diabetic, insulin-treated streptozotocin-diabetic and age-matched control rats were killed 15, 45 and 90 days after the induction of diabetes.

Higher proportions of type C than of types A and B natriuretic peptide receptors exist in the rat ciliary body.

We investigate the interaction of atrial natriuretic peptide (ANP) brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) with their receptors (NPRA, NPRB and NPRC), as well as the proportion and localization of those receptors in the rat ciliary body. Binding assays and affinity cross-linking experiments demonstrated the presence of the NPRC receptor type. However, the three natriuretic peptides stimulate the guanylate cyclase activity in the ciliary body membranes suggesting the presence of the NPRA and NPRB receptor type.

Type B and type C natriuretic peptide receptors modulate intraocular pressure in the rabbit eye.

We investigated (1) the in vivo functional significance of the type B (ANP(B)) and type C (ANP(C)) natriuretic peptide receptors in the rabbit eye by evaluating the effect of intracameral administration of C-type natriuretic peptide (CNP) and C-ANP-(4-23) on intraocular pressure, and (2) the action of CNP on guanylate cyclase activity in the rabbit ciliary process membranes. Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were also studied for comparison. We demonstrated that the natriuretic peptides decrease intraocular pressure and stimulate guanylate cyclase activity, CNP being the most potent.

Identification of endothelin receptor subtypes in rat ciliary body using subtype-selective ligands.

The endothelins are important vasoactive ocular peptides and there is some evidence that they may modulate intraocular pressure. We investigated the existence and localization of endothelin receptor subtypes using subtype selective ligands in rat ciliary body. Scatchard transformation of saturation binding experiments revealed that the KD and Bmax for [125I]ET-1 and [125I]ET-3 to membranes from ciliary body were 41.

Messenger RNAs encoding the natriuretic peptides and their receptors are expressed in the eye.

The rates of secretion and removal of aqueous humour are major determinants of intraocular pressure (IOP). The natriuretic peptides, atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP) and C-type natriuretic peptide (CNP) are vasodilators with variable effects on electrolyte and water transport at sites such as the nephron. There is some evidence that they may also affect fluid balance in the eye.

Identification of endothelin receptor subtypes in rat retina using subtype-selective ligands.

We investigate the existence of endothelin receptor subtypes using subtype selective ligands and the presence of immunoreactive (IR) endothelin (ET)-3 (IR-ET-3) by radioimmunoassay (RIA) in rat retina. Scatchard transformation of saturation binding experiments with [125I]ET-3 revealed specific binding sites with a Kd and Bmax values of 42 +/- 12 pM and 111 +/- 24 fmol/mg of protein, respectively. The Kd was similar to that obtain in previous studies using [125I]ET-1.