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Tadros D, Abdelhalim TI, Sarhan N, El-Anwar N, Elkholy RA, Tahoon D, Sorour OA. Histopathology and electron microscopy evaluation of the sildenafil effect on diabetic rats' retinae. Indian J Ophthalmol 2024; 72:S111-S118. [PMID: 38131552 PMCID: PMC10833156 DOI: 10.4103/ijo.ijo_976_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 09/25/2023] [Accepted: 10/01/2023] [Indexed: 12/23/2023] Open
Abstract
PURPOSE Although there is increasing evidence that phosphodiesterase-5 (PDE-5) inhibitors modify the effect of diabetes on different tissues, its effect on diabetic retinopathy is not well studied. METHODS Forty male Sprague-Dawley (SD) rats were divided into four groups: group I = control group that received no treatment; group II (diabetic group), in which diabetes was induced by a single streptozotocin injection; group III (sildenafil small dose, SSD), in which diabetes was similarly introduced (however, rats received daily oral 1 mg/kg sildenafil citrate (SC) for 3 months); and group IV (sildenafil large dose, SLD), which was as in group 3, but SC was 2.5 mg/kg. After 3 months, globes were removed and retinae were dissected; one globe from each rat was examined by light microscopy (LM), and the other by electron microscopy (EM). RESULTS In contrast to the control group, diabetic rats in group II demonstrated well-established diabetic changes in the form of capillary congestion, decreased cell population, hyaline changes of capillary walls, and degenerated nerve fiber layer by LM. Similarly, EM demonstrated photoreceptor degeneration, mitochondrial cristolysis, and vacuolated depleted cells among other features in group II. These diabetic features were less prominent in group III and nearly absent in group IV. CONCLUSION SC use in the early stages of DR may prevent/delay diabetic retinopathy development or progression in diabetic rat models, an effect that seems to be dose-related.
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Affiliation(s)
- Dina Tadros
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Egypt
| | - Tamer I Abdelhalim
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Egypt
| | - Naglaa Sarhan
- Department of Histology, Faculty of Medicine, Tanta University, Egypt
| | - Noha El-Anwar
- Department of Pathology, Faculty of Medicine, Tanta University, Egypt
- Department of Pathology, Armed Forces, College of Medicine, Egypt
| | - Reem A. Elkholy
- Department of Pharmacology, Faculty of Medicine, Tanta University, Egypt
- Department of Pharmacology, School of Medicine, Badr University In Cairo, Egypt
| | - Dina Tahoon
- Department of Pharmacology, Faculty of Medicine, Tanta University, Egypt
| | - Osama A Sorour
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Egypt
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Sorour OA, Nassar E, Sarhan N, El-Anwar N, ElKholy RA, Tahoon DM, Sweilam A, Tadros D. Chronic sildenafil citrate use decreases retinal vascular endothelial growth factor expression in diabetic rats: a pilot study. Int J Retina Vitreous 2023; 9:42. [PMID: 37460929 PMCID: PMC10351124 DOI: 10.1186/s40942-023-00480-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 07/01/2023] [Indexed: 07/20/2023] Open
Abstract
BACKGROUND Sildenafil citrate (SC) attenuates endothelial dysfunction. However, its effects on diabetic retinopathy (DR), which is mainly a microvascular disease, remain unclear. Vascular endothelial growth factor (VEGF) is known to be a critical mediator of DR. Therefore, we investigated the effects of SC on diabetic retina by measuring VEGF levels. METHODS In this study, twenty-eight rats were divided into the following groups: group I, the control group; group II, rats with streptozotocin-induced diabetes; group III, rats with streptozotocin-induced diabetes receiving daily oral sildenafil at 1 mg/kg; and group IV, rats with streptozotocin-induced diabetes receiving high-dose daily sildenafil at 2.5 mg/kg. After 3 months, VEGF was measured in the retina specimen in one eye and the vitreous body in the other eye by immunohistochemistry and enzyme-linked immunosorbent assay, respectively. RESULTS We found that VEGF expression in the retina was low in all rats from groups I and IV and in 30% of rats from group III; 80% of rats in group II demonstrated high VEGF expression in the retinae (P < 0.001). VEGF concentrations in the vitreous body samples were 32 ± 2, 61 ± 4, 44 ± 5, and 36 ± 3 pg/l in groups I-IV, respectively (P < 0.001). CONCLUSION VEGF decreased significantly in the eyes of diabetic rats after chronic oral sildenafil citrate treatment. SC may have a modifying/attenuating effect on DR. However, further studies are needed to evaluate its use as an adjunctive treatment.
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Affiliation(s)
- Osama A Sorour
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt.
| | - Elsayed Nassar
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Naglaa Sarhan
- Department of Histology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Noha El-Anwar
- Department of Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt
- Department of Pathology, Armed Forces College of Medicine, Heliopolis, Egypt
| | - Reem A ElKholy
- Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt
- Department of Pharmacology, School of medicine, Badr University, Badr, Egypt
| | - Dina M Tahoon
- Department of Pharmacology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Aalaa Sweilam
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt
- Department of Clinical Pathology, Faculty of Medicine, Tanta University, Tanta, Egypt
| | - Dina Tadros
- Department of Ophthalmology, Faculty of Medicine, Tanta University, Tanta, Egypt
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Sela TC, Zahavi A, Friedman-Gohas M, Weiss S, Sternfeld A, Ilguisonis A, Badash D, Geffen N, Ofri R, BarKana Y, Goldenberg-Cohen N. Azithromycin and Sildenafil May Have Protective Effects on Retinal Ganglion Cells via Different Pathways: Study in a Rodent Microbead Model. Pharmaceuticals (Basel) 2023; 16:ph16040486. [PMID: 37111243 PMCID: PMC10142588 DOI: 10.3390/ph16040486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 03/12/2023] [Accepted: 03/22/2023] [Indexed: 03/29/2023] Open
Abstract
Decreased blood flow to the optic nerve (ON) and neuroinflammation are suggested to play an important role in the pathophysiology of glaucoma. This study investigated the potential neuroprotective effect of azithromycin, an anti-inflammatory macrolide, and sildenafil, a selective phosphodiesterase-5 inhibitor, on retinal ganglion cell survival in a glaucoma model, which was induced by microbead injection into the right anterior chamber of 50 wild-type (WT) and 30 transgenic toll-like receptor 4 knockout (TLR4KO) mice. Treatment groups included intraperitoneal azithromycin 0.1 mL (1 mg/0.1 mL), intravitreal sildenafil 3 µL, or intraperitoneal sildenafil 0.1 mL (0.24 μg/3 µL). Left eyes served as controls. Microbead injection increased intraocular pressure (IOP), which peaked on day 7 in all groups and on day 14 in azithromycin-treated mice. Furthermore, the retinas and ON of microbead-injected eyes showed a trend of increased expression of inflammatory- and apoptosis-related genes, mainly in WT and to a lesser extent in TLR4KO mice. Azithromycin reduced the BAX/BCL2 ratio, TGFβ, and TNFα levels in the ON and CD45 expression in WT retina. Sildenafil activated TNFα-mediated pathways. Both azithromycin and sildenafil exerted a neuroprotective effect in WT and TLR4KO mice with microbead-induced glaucoma, albeit via different pathways, without affecting IOP. The relatively low apoptotic effect observed in microbead-injected TLR4KO mice suggests a role of inflammation in glaucomatous damage.
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Affiliation(s)
- Tal Corina Sela
- Clalit Health Services, Tel Aviv 6209804, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Alon Zahavi
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Ophthalmology, Rabin Medical Center-Beilinson Hospital, Petach Tikva 4941492, Israel
- Laboratory of Eye Research, Felsenstein Medical Research Center, Petach Tikva 4941492, Israel
| | - Moran Friedman-Gohas
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Shirel Weiss
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Amir Sternfeld
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Ophthalmology, Rabin Medical Center-Beilinson Hospital, Petach Tikva 4941492, Israel
- Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Astrid Ilguisonis
- Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Danielle Badash
- Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel
| | - Noa Geffen
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Ophthalmology, Rabin Medical Center-Beilinson Hospital, Petach Tikva 4941492, Israel
| | - Ron Ofri
- Koret School of Veterinary Medicine, Hebrew University of Jerusalem, Rehovot 7610001, Israel
| | - Yaniv BarKana
- The Glaucoma Innovations and Research Laboratory, The Sam Rothberg Glaucoma Center, Sheba Medical Center, Tel Hashomer 5262000, Israel
| | - Nitza Goldenberg-Cohen
- Krieger Eye Research Laboratory, Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 3200003, Israel
- Department of Ophthalmology, Bnai Zion Medical Center, Haifa 3339419, Israel
- Bruce and Ruth Faculty of Medicine, Technion, Technion-Israel Institute of Technology, Haifa 3200003, Israel
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Rodrigues BD, Montiani-Ferreira F, Bortolini M, Somma AT, Komáromy AM, Dornbusch PT. Intraocular pressure measurements using the TONOVET ® rebound tonometer: Influence of the probe-cornea distance. Vet Ophthalmol 2020; 24 Suppl 1:175-185. [PMID: 33070466 DOI: 10.1111/vop.12832] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Revised: 09/09/2020] [Accepted: 09/17/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To demonstrate the effect of different probe-cornea distances during intraocular pressure (IOP) data acquisition in dogs and rats. ANIMALS STUDIED Twenty-four conscious dogs and 15 anesthetized Wistar rats. METHODS Three interchangeable three-dimensional printed polylactide plastic spacer collars were used in place of the original Icare TonoVet® collar piece, which provided different distances (4, 6, and 8 mm) between the instrument's probe and the corneal surface. IOP values were obtained in sequence by a single observer, with the tonometer probe at a 4-, 6-, and 8-mm distance from the corneal surface. The dogs were gently restrained, and the rats were anesthetized with isoflurane. RESULTS Intraocular pressure values obtained at 4, 6, and 8 mm from the TonoVet® probe to corneal surface distance in both dogs and rats were significantly different (P < .01). There was a small positive correlation between IOP (mm Hg) and probe-cornea distance (mm) (rs = 0.39 for dogs and rs = 0.51 for rats). In dogs, the mean IOP (± SD mm Hg) obtained at different distances were 16.2 ± 3.0 at 4 mm; 17.6 ± 3.4 at 6 mm; and 19.8 ± 3.8 at 8 mm. In rats, IOP values were 8.2 ± 1.5 at 4-mm; 9.4 ± 1.8 at 6-mm; and 10.5 ± 1.5 mm Hg at 8-mm distance. CONCLUSIONS Probe-cornea distance of the Icare TonoVet® significantly affects IOP readings, even within the 4- to 8-mm range recommended by the manufacturer.
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Affiliation(s)
- Blanche D Rodrigues
- Graduate School of Veterinary Sciences, Department of Veterinary Medicine, Federal University of Paraná, Curitiba, Brazil.,Integrated Center of Veterinary Specialties (CIEV), Curitiba, Brazil
| | - Fabiano Montiani-Ferreira
- Graduate School of Veterinary Sciences, Department of Veterinary Medicine, Federal University of Paraná, Curitiba, Brazil
| | - Mariza Bortolini
- Graduate School of Veterinary Sciences, Department of Veterinary Medicine, Federal University of Paraná, Curitiba, Brazil
| | - André T Somma
- Graduate School of Veterinary Sciences, Department of Veterinary Medicine, Federal University of Paraná, Curitiba, Brazil.,Integrated Center of Veterinary Specialties (CIEV), Curitiba, Brazil
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Peterson Triches Dornbusch
- Graduate School of Veterinary Sciences, Department of Veterinary Medicine, Federal University of Paraná, Curitiba, Brazil
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Resveratrol protects retinal ganglion cell axons through regulation of the SIRT1-JNK pathway. Exp Eye Res 2020; 200:108249. [PMID: 32956685 DOI: 10.1016/j.exer.2020.108249] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 08/12/2020] [Accepted: 09/14/2020] [Indexed: 01/21/2023]
Abstract
It is reported that Ischemia and reperfusion damage (I/R damage) can lead to retinal ganglion cell (RGC) death and neurodegeneration, which in turn can lead to irreversible vision loss. In this study, we sought to understand the neuroprotective effect of resveratrol, the important activator of sirtuin1 (SIRT1), on RGC survival in I/R damage model and the molecular mechanism that mediate this effect. Our results show that resveratrol could reverse axonal swelling, holes, and the chaos of the nucleus in axons of RGCs caused by I/R. At the same time, resveratrol could also reverse the activation of retinal astrocytes and the loss of RGCs caused by I/R. Resveratrol increased the expression of SIRT1 while decreasing the phosphorylation of N-terminal kinase (JNK). SP600125(JNK inhibitor) decreased the phosphorylation of JNK while increasing the expression of SIRT1, indicating that SIRT1 and JNK can interact with each other. Simultaneous administration of resveratrol and sirtinol (SIRT1 inhibitor) neither increased the expression of SIRT1 nor decreased the phosphorylation of JNK, indicating that resveratrol affects the phosphorylation of JNK by SIRT1. In total, our research shows that resveratrol treatment significantly reduces apoptosis and axonal degeneration of RGCs, and this protection is partly mediated through the SIRT1-JNK pathway.
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Rodríguez Villanueva J, Martín Esteban J, Rodríguez Villanueva LJ. Retinal Cell Protection in Ocular Excitotoxicity Diseases. Possible Alternatives Offered by Microparticulate Drug Delivery Systems and Future Prospects. Pharmaceutics 2020; 12:pharmaceutics12020094. [PMID: 31991667 PMCID: PMC7076407 DOI: 10.3390/pharmaceutics12020094] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Revised: 01/17/2020] [Accepted: 01/22/2020] [Indexed: 12/11/2022] Open
Abstract
Excitotoxicity seems to play a critical role in ocular neurodegeneration. Excess-glutamate-mediated retinal ganglion cells death is the principal cause of cell loss. Uncontrolled glutamate in the synapsis has significant implications in the pathogenesis of neurodegenerative disorders. The exploitation of various approaches of controlled release systems enhances the pharmacokinetic and pharmacodynamic activity of drugs. In particular, microparticles are secure, can maintain therapeutic drug concentrations in the eye for prolonged periods, and make intimate contact by improving drug bioavailability. According to the promising results reported, possible new investigations will focus intense attention on microparticulate formulations and can be expected to open the field to new alternatives for doctors, as currently required by patients.
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Affiliation(s)
- Javier Rodríguez Villanueva
- Human resources for I+D+i Department, National Institute for Agricultural and Food Research and Technology, Ctra. de la Coruña (Autovía A6) Km. 7.5, 28040 Madrid, Spain
- Correspondence: ; Tel.: +34-91-347-4158
| | - Jorge Martín Esteban
- University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600, 28805 Alcalá de Henares, Madrid, Spain; (J.M.E.); (L.J.R.V.)
| | - Laura J. Rodríguez Villanueva
- University of Alcalá, Ctra. de Madrid-Barcelona (Autovía A2) Km. 33,600, 28805 Alcalá de Henares, Madrid, Spain; (J.M.E.); (L.J.R.V.)
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Inafuku S, Klokman G, Connor KM. The Alternative Complement System Mediates Cell Death in Retinal Ischemia Reperfusion Injury. Front Mol Neurosci 2018; 11:278. [PMID: 30174588 PMCID: PMC6107794 DOI: 10.3389/fnmol.2018.00278] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/23/2018] [Indexed: 11/13/2022] Open
Abstract
Ischemia reperfusion (IR) injury induces retinal cell death and contributes to visual impairment. Previous studies suggest that the complement cascade plays a key role in IR injury in several systemic diseases. However, the role of the complement pathway in the ischemic retina has not been investigated. The aim of this study is to determine if the alternative complement cascade plays a role in retinal IR injury, and identify which components of the pathway mediate retinal degeneration in response to IR injury. To accomplish this, we utilized the mouse model of retinal IR injury, wherein the intraocular pressure (IOP) is elevated for 45 min, collapsing the retinal blood vessels and inducing retinal ischemia, followed by IOP normalization and subsequent reperfusion. We found that mRNA expression of complement inhibitors complement receptor 1-related gene/protein-y (Crry), Cd55 and Cd59a was down-regulated after IR. Moreover, genetic deletion of complement component 3 (C3−/−) and complement factor b (Fb−/−) decreased IR-induced retinal apoptosis. Because vascular dysfunction is central to IR injury, we also assessed the role of complement in a model of shear stress. In human retinal endothelial cells (HRECs), shear stress up-regulated complement inhibitors Cd46, Cd55, and Cd59, and suppressed complement-mediated cell death, indicating that a lack of vascular flow, commonly observed in IR injury, allows for complement mediated attack of the retinal vasculature. These results suggested that in retinal IR injury, the alternative complement system is activated by suppression of complement inhibitors, leading to vascular dysfunction and neuronal cell death.
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Affiliation(s)
- Saori Inafuku
- Angiogenesis Laboratory, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Harvard University, Boston, MA, United States.,Department of Ophthalmology, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Garrett Klokman
- Angiogenesis Laboratory, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Harvard University, Boston, MA, United States.,Department of Ophthalmology, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Kip M Connor
- Angiogenesis Laboratory, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Harvard University, Boston, MA, United States.,Department of Ophthalmology, Harvard Medical School, Harvard University, Boston, MA, United States
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