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ABSTRACT: Many viruses can evolve different strategies to exploit the ubiquitin-proteasome pathway (UPP) for their own benefit. Some data have recently established connections between UPP and osteoarthritis (OA). The aim of this study was to determine the possible involvement of viral infections linked with the UPP in the physiopathology of OA. Samples of human cartilage were obtained from 12 patients with clinical and radiological features of OA and from 12 normal controls. DNA was extracted from cultured chondrocytes from these patients, and quantitative real-time PCR was performed to analyse the DNA/RNA prevalence and viral loads of HSV, EBV, HCMV, enterovirus, and HTLV-1. The prevalence of total viral DNA/RNA among patients with OA was 16.7% (mean viral load of 7.86 copies/mug DNA), EBV being responsible for the two positive samples, while the prevalence in controls was 0%. We did not detect any positive samples for HSV, CMV, enterovirus, and HTLV-1 among patients with OA and controls. This first approach to the study of the prevalence of viruses linked to the UPP in articular cartilage of end-stage OA patients provides evidences supporting the risk of EBV transmission or reactivation in a subset of patients with disorders requiring tissue regeneration.
Rheumatology International 04/2009; 29(8):969-72. · 1.88 Impact Factor
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ABSTRACT: To determine the expression of the genes that code for the isoforms of transforming growth factor-beta (TGF-beta) and TGF-beta receptors (TBR) in mesenchymal stem cells (MSC) from patients with osteoarthritis (OA).
Total RNA was extracted from primary cultures of MSC and quantitative real-time reverse transcription-polymerase chain reaction was performed to analyze gene expression.
MSC from patients with OA showed significantly increased total TGF-beta, TGF-beta1 isoform, TBR-II, and TBR-III mRNA expression compared to controls.
Our study is the first reporting the gene expression levels of TGF-beta and its isoforms and receptors in patients with OA. These findings might have pathological significance for OA disease.
The Journal of Rheumatology 06/2008; 35(5):904-6. · 3.69 Impact Factor
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ABSTRACT: To investigate the potential role of endothelin-1 (ET-1), a potent vasoconstrictor with mitogenic properties, in the pathogenesis of proliferative diabetic retinopathy (PDR).
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.
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.
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.
Retina 03/2007; 27(2):222-35. · 2.81 Impact Factor
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ABSTRACT: 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).
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.
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.
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.
Molecular vision 02/2005; 11:461-71. · 2.20 Impact Factor
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ABSTRACT: 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.
Diabetes was induced in male Wistar rats by an intraperitoneal injection of STZ. Age matched animals served as control. One and 3 months after the onset of diabetes, the expression of ANP mRNA and that of its receptors (NPRA, NPRB, NPRC) and the immunoreactive ANP was quantified in retinal tissue by quantitative real time reverse transcription-polymerase chain reaction (RT-PCR) and radioimmunoassay, respectively. The locations of ANP and glial fibrillary acidic protein (GFAP) in normal and diabetic retinas were also established by immunohistochemistry.
No alteration in the gene expression of the retinal natriuretic peptide system was noted after 1 month of diabetes. However, 3 months after the onset of diabetes, significantly diminished ANP and NPRC mRNA levels were detected in the retina of diabetic rats compared to controls, while NPRA, NPRB mRNA levels remained unchanged. At this time point, retinal ANP concentrations were significantly diminished in the diabetic rats compared to control rats. However, at 1 month retinal ANP concentrations in diabetic retina were similar to control rats. Diabetes caused the downregulation of ANP protein expression in the layers of the retina at 3 months after the induction of diabetes. ANP immunoreactivity was detected in the cell bodies of the astrocytes and in their processes enveloping vessels.
The downregulation of ANP and NPRC in retinas of diabetic rats suggests a role for this peptide in experimental diabetic retinopathy. Further studies should address the possible involvement of the ANP/NPRC system in the pathophysiology of diabetic retinopathy.
Molecular vision 02/2005; 11:216-24. · 2.20 Impact Factor
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ABSTRACT: 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. All these data indicate that the natriuretic peptide system might be involved in the development of diabetic retinopathy and glaucoma. Given the expression pattern of natriuretic peptides (NPs) and their receptors, natriuretic peptide receptor A (NPRA), natriuretic peptide receptor B (NPRB) and natriuretic peptide receptor C (NPRC) in the human retina has not yet been established, the present study was designed to determine ANP, BNP and CNP gene expression and localize the mature peptides in this tissue. The expression pattern of the genes encoding the different NP receptor subtypes was also examined.
Eyes (n=10) from human donors with no history of eye disease were fixed and processed for routine paraffin embedding. The cellular location of the NPs was established by immunohistochemistry. Real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR) was used to evaluate the expression of NP and NP receptor genes in neural retinas obtained from the contralateral eyes.
Immunohistochemistry revealed the presence of NPs in the neural retina and retinal pigment epithelium. Positive NP immunostaining was observed within the astrocytes and in their processes enveloping vessels. In the anterior portion of the optic nerve, NPs were intensely labeled in neural bundles. We were able to detect NP gene expression in the human retina. The levels of NP receptor-encoding transcripts detected indicated no significant differential expression of genes coding for the different receptor subtypes.
Our finding that NP receptor transcripts are expressed along with ANP, BNP, and CNP mRNA in the human retina provides evidence for a local system in this tissue. The expression of NPs in neural retinal, glial, and vascular elements of the normal adult retina suggests a role for these peptides in maintaining both the neural and vascular integrity of the mature retina.
Molecular vision 02/2004; 10:15-22. · 2.20 Impact Factor
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ABSTRACT: 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. In the current study, we have examined the expression and distribution of ET-1 as well as the expression profile of ETA and ETB genes in the iris, ciliary muscle, and ciliary processes of human eyes.
Six normal human eyes with no history of eye diseases were fixed, embedded in paraffin and sectioned. Cellular localization of ET-1 was identified by in situ hybridization and immunohistochemistry. Iris, ciliary processes, and ciliary muscles were dissected from six normal human eyes and quantitative real time RT-PCR was used to quantify the expression of ETA and ETB.
In situ hybridization revealed the presence of ET-1 transcripts in the iris, nonpigmented epithelial ciliary cells, and ciliary muscle. Immunohistochemical studies showed that ET-1-like immunoreactivity appeared in the same regions where ET-1 mRNA was expressed as well as in trabecular cells, inner and outer endothelial cells lining Schlemm's canal, corneal epithelial, and limbus cells. Quantitative real time RT-PCR demonstrated that the expression of ETA and ETB receptors is greatest in the iris, followed by ciliary muscle and ciliary processes.
ET-1 and its receptors ETA and ETB are constitutively expressed in the anterior segment of human eye. These results indicate that ET-1 may play a physiological role in the regulation of intraocular pressure through its ETA and ETB receptors in human eye. In addition, ET-1 present in corneal epithelium and limbus may function in regulating cell proliferation and/or differentiation.
Molecular vision 05/2003; 9:103-9. · 2.20 Impact Factor
