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Retinal Toxicity Induced by Chemical Agents. Int J Mol Sci 2022; 23:ijms23158182. [PMID: 35897758 PMCID: PMC9331776 DOI: 10.3390/ijms23158182] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/21/2022] [Accepted: 07/22/2022] [Indexed: 11/16/2022] Open
Abstract
Vision is an important sense for humans, and visual impairment/blindness has a huge impact in daily life. The retina is a nervous tissue that is essential for visual processing since it possesses light sensors (photoreceptors) and performs a pre-processing of visual information. Thus, retinal cell dysfunction or degeneration affects visual ability and several general aspects of the day-to-day of a person's lives. The retina has a blood-retinal barrier, which protects the tissue from a wide range of molecules or microorganisms. However, several agents, coming from systemic pathways, reach the retina and influence its function and survival. Pesticides are still used worldwide for agriculture, contaminating food with substances that could reach the retina. Natural products have also been used for therapeutic purposes and are another group of substances that can get to the retina. Finally, a wide number of medicines administered for different diseases can also affect the retina. The present review aimed to gather recent information about the hazard of these products to the retina, which could be used to encourage the search for more healthy, suitable, or less risky agents.
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OUP accepted manuscript. Hum Mol Genet 2022; 31:2194-2206. [DOI: 10.1093/hmg/ddac020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 11/13/2022] Open
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Nourinia R, Borna F, Rahimi A, Jabbarpoor Bonyadi MH, Amizadeh Y, Daneshtalab A, Kheiri B, Ahmadieh H. Repeated Injection of Methotrexate into Silicone Oil-Filled Eyes for Grade C Proliferative Vitreoretinopathy: A Pilot Study. Ophthalmologica 2019; 242:113-117. [PMID: 31163427 DOI: 10.1159/000500271] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/10/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE To evaluate the effects of repeated intra-silicone oil (SO) injections of methotrexate (MTX) on the outcomes of surgery for rhegmatogenous retinal detachment (RRD) with grade C proliferative vitreoretinopathy (PVR-C). METHODS In this prospective pilot case series, eyes with RRD and PVR-C underwent pars plana vitrectomy and intraocular injection of SO. At the conclusion of the procedure, 250 µg of MTX was injected into the SO-filled vitreous cavity. Intra-SO injection was repeated at weeks 3 and 6; the minimum follow-up period was 6 months. The main outcome measure was retinal reattachment rate. RESULTS Eleven eyes of 11 patients (mean age, 52.73 ± 18.01 years) were included. The mean follow-up period was 9 ± 3 months (range, 6-15 months). Total retinal detachment with anterior and/or posterior PVR-C was present in all eyes before surgery. Mean preoperative best-corrected visual acuity (BCVA) was 2.62 ± 0.04 logMAR. All operated eyes exhibited retinal reattachment posterior to the equator during the follow-up period. Mean postoperative BCVA was significantly improved to 1.02 ± 0.51 logMAR (p = 0.003). No ocular or systemic side effects were observed. CONCLUSION Repeated intra-SO injection of MTX as an adjunctive therapy for RRD complicated by PVR showed promising results and was not associated with adverse effects. Further studies are needed to confirm its possible beneficial effects on the final anatomic and functional outcomes in these cases.
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Affiliation(s)
- Ramin Nourinia
- Ocular Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farinaz Borna
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | | | - Yashar Amizadeh
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Arash Daneshtalab
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Bahareh Kheiri
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hamid Ahmadieh
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran,
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Sobaci G, Bayraktar M, Karslioğlu Y, Durukan A, Hurmeriç V, Aykaş S. Hypericin-Enhanced Argon Laser Photocoagulation for Subfoveal Choroidal Neovascular Membrane in Age-Related Macular Degeneration: A Pilot Study. Eur J Ophthalmol 2018. [DOI: 10.1177/112067210601600119] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Purpose To evaluate the efficacy and safety of hypericin-enhanced argon laser photocoagulation (H-ALP) in the treatment of subfoveal choroidal neovascular membrane (CNM) secondary to age-related macular degeneration (ARMD). Methods After preliminary studies for definition of parameters, argon-green laser was administered 4 hours after single dose of oral 1800 mg hypericin (Saint-John's wort tablets, 0.3%, 300 mg) with a subthreshold light fluence, 24 J/cm2 in 34 eyes (20 with subfoveal classical and 14 with subfoveal occult CNM). Additionally, histopathologic examination was done in two eyes destined for enucleation and exenteration. Maintenance therapy (one tablet, twice a day) was performed for the following 6 months. Anatomic (complete closure of CNM) and functional success (improvement of final visual acuity in three or more Snellen lines) were analyzed with minimum 6-month follow-ups. Results Histopathologic examinations revealed photothrombosed choriocapillaries together with minimal retinal pigment epithelial disruption in H-ALP exposed areas. One to four (mean 1.88±0.91) treatment sessions were applied in 6 to 29 months (mean 12.2±5.1 months) follow-up period. Twenty-three (67.6%) eyes had 12 months follow-up. Two eyes in each group had functional success (20% in subfoveal classical and 14.3% in subfoveal occult CNM), which had a minimum 12-month follow-up. Anatomic success was achieved in 16 of 20 (80%) eyes with subfoveal classical and 10 of 14 (71.4%) eyes with subfoveal occult CNM. Severe gastric irritation was noted in 1 (2.9%) and pigment epithelial rupture in 2 (5.9%) patients. Conclusions H-ALP is a novel and low-cost treatment for subfoveal CNM secondary to ARMD. It seems its efficacy depends on the photodynamic and antiproliferative properties of hypericin. Comparative studies are required to apply this new technique in ophthalmic practice.
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Affiliation(s)
- G. Sobaci
- Department of Ophthalmology, Gülhane Military Medical Academy and Medical School (GMMA-MS), Ankara -Turkey
| | - M.Z. Bayraktar
- Department of Ophthalmology, Gülhane Military Medical Academy and Medical School (GMMA-MS), Ankara -Turkey
| | - Y. Karslioğlu
- Department of Pathology, Gülhane Military Medical Academy and Medical School (GMMA-MS), Ankara -Turkey
| | - A.H. Durukan
- Department of Ophthalmology, Gülhane Military Medical Academy and Medical School (GMMA-MS), Ankara -Turkey
| | - V. Hurmeriç
- Department of Ophthalmology, Gülhane Military Medical Academy and Medical School (GMMA-MS), Ankara -Turkey
| | - S. Aykaş
- Department of Ophthalmology, Gülhane Military Medical Academy and Medical School (GMMA-MS), Ankara -Turkey
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He H, Kuriyan AE, Su CW, Mahabole M, Zhang Y, Zhu YT, Flynn HW, Parel JM, Tseng SCG. Inhibition of Proliferation and Epithelial Mesenchymal Transition in Retinal Pigment Epithelial Cells by Heavy Chain-Hyaluronan/Pentraxin 3. Sci Rep 2017; 7:43736. [PMID: 28252047 PMCID: PMC5333089 DOI: 10.1038/srep43736] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Accepted: 01/30/2017] [Indexed: 01/15/2023] Open
Abstract
Proliferative vitreoretinopathy (PVR) is mediated by proliferation and epithelial mesenchymal transition (EMT) of retinal pigment epithelium (RPE). Because heavy chain-hyaluronic acid/pentraxin 3 (HC-HA/PTX3) purified from human amniotic membrane exerts anti-inflammatory and anti-scarring actions, we hypothesized that HC-HA/PTX3 could inhibit these PVR-related processes in vitro. In this study, we first optimized an ARPE-19 cell culture model to mimic PVR by defining cell density, growth factors, and cultivation time. Using this low cell density culture model and HA as a control, we tested effects of HC-HA/PTX3 on the cell viability (cytotoxicity), proliferation (EGF + FGF-2) and EMT (TGF-β1). Furthermore, we determined effects of HC-HA/PTX3 on cell migration (EGF + FGF-2 + TGF-β1) and collagen gel contraction (TGF-β1). We found both HA and HC-HA/PTX3 were not toxic to unstimulated RPE cells. Only HC-HA/PTX3 dose-dependently inhibited proliferation and EMT of stimulated RPE cells by down-regulating Wnt (β-catenin, LEF1) and TGF-β (Smad2/3, collagen type I, α-SMA) signaling, respectively. Additionally, HA and HC-HA/PTX3 inhibited migration but only HC-HA/PTX3 inhibited collagen gel contraction. These results suggest HC-HA/PTX3 is a non-toxic, potent inhibitor of proliferation and EMT of RPE in vitro, and HC-HA/PTX3’s ability to inhibit PVR formation warrants evaluation in an animal model.
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Affiliation(s)
- Hua He
- TissueTech, Inc., Miami, FL, 33173, USA
| | - Ajay E Kuriyan
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, 33136, USA.,Flaum Eye Institute, University of Rochester Medical Center, Rochester, NY, 14642, USA
| | | | | | - Yuan Zhang
- Ocular Surface Center and Ocular Surface Research &Education Foundation, Miami, FL, 33173, USA
| | | | - Harry W Flynn
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Jean-Marie Parel
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, 33136, USA
| | - Scheffer C G Tseng
- TissueTech, Inc., Miami, FL, 33173, USA.,Ocular Surface Center and Ocular Surface Research &Education Foundation, Miami, FL, 33173, USA
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Juel HB, Faber C, Svendsen SG, Vallejo AN, Nissen MH. Inflammatory cytokines protect retinal pigment epithelial cells from oxidative stress-induced death. PLoS One 2013; 8:e64619. [PMID: 23705001 PMCID: PMC3660526 DOI: 10.1371/journal.pone.0064619] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 04/15/2013] [Indexed: 11/29/2022] Open
Abstract
Purpose To investigate the effects of inflammatory factors and oxidative stress on cell survival of the human retinal pigment epithelial (RPE) cell line, ARPE-19. Methods Confluent RPE cells were treated with peripheral blood mononuclear cells-conditioned medium (PCM), H2O2, NaIO3, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, or combinations of these. Cell viability was determined by viability assays and by light microscopy. Effector molecules of cell death were investigated by immunofluorescence microscopy and flow cytometry. Microarrays were performed to screen for differential expression of anti-oxidative enzymes, and protein expression was validated by immunoblotting. Results Viability of RPE cells was reduced by exposure to inflammatory agents (PCM, IFNγ+/-TNFα) or to oxidative agents (H2O2 or NaIO3). Unexpectedly, cells treated with either H2O2 or NaIO3 were partially protected from cell death by the addition of PCM. This protection was conferred, at least in part, by IFNγ and TNFα. Cell death induced by H2O2 or NaIO3 was preceded by mitochondrial dysfunction and by p62 upregulation, both of which were attenuated by PCM and/or by IFNγ+TNFα. RPE cells co-cultured with activated T cells, or treated with cytokines showed increased expression of anti-oxidative genes, with upregulation of superoxide dismutase 2 protein following PCM treatment. Conclusion Oxidative stress-induced cell death was reduced by concomitant inflammatory stress. This is likely due to the cytokine-mediated induction of the anti-oxidative stress response, upregulating protective anti-oxidant pathway(s). These findings suggest caution for the clinical use of anti-inflammatory agents in the management of immune-associated eye diseases such as age-related macular degeneration.
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Affiliation(s)
- Helene B Juel
- Eye Research Unit, Department of International Health, Immunology and Microbiology, University of Copenhagen, Copenhagen, Denmark.
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Gao Q, Wang W, Lan Y, Chen X, Yang W, Yuan Y, Tan J, Zong Y, Jiang Z. The inhibitory effect of small interference RNA protein kinase C-alpha on the experimental proliferative vitreoretinopathy induced by dispase in mice. Int J Nanomedicine 2013; 8:1563-72. [PMID: 23626468 PMCID: PMC3632628 DOI: 10.2147/ijn.s37635] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Aim To evaluate the effects of small interference RNA protein kinase C-alpha (siRNA-PKCα) on experimental proliferative vitreoretinopathy (PVR) induced by dispase in mice. Methods C57BL/6 mice PVR models (4–6 weeks old) were induced by intravitreal injection of dispase and then equally divided into six groups. After 1 week, the five treatment groups received 2 μL, intravitreal injections of siRNA-PKCα at a concentration of 250 nM, 500 nM, 750 nM, 1000 nM, and 1500 nM, respectively, while the negative control group received 2 μL of 500 nM no-silencing siRNA. SiRNA-PKCα was transfected by a square wave electroporator. Postoperative ophthalmic observations of lens clarity and the fundus of the eyes were performed periodically. The eyeballs of the mice were enucleated and imbedded in optimal cutting temperature to perform histological and immunofluorescence analysis at the end of a 4-week observation period. Results Four weeks after the siRNA-PKCα injections, there are 100% lens dissolution and 100% PVR in the 250 nM group and 70%, 70%, 70%, and 50% PVR in the 500 nM, 750 nM, 1000 nM, and 1500 nM groups, respectively, which is significantly different from the negative group. Abnormalities in fundus appearance were related to the concentrations of siRNA-PKCα; a higher concentration of siRNA-PKCα resulted in a more normal fundus. Histological sections by hematoxylin-eosin staining of the eyes support the clinical observation. Immunofluorescence analysis showed that RPE65, glutamine synthase, glial acidic fibrillary protein, and α-smooth muscle actin were increasing in the retina with the decreasing concentration of siRNA-PKCα, indicating that intraocular siRNA-PKCα can partly inhibit changes of markers for glia cells, fibroblast cells, retinal pigment epithelium cells, and Müller cells in the process of PVR. Conclusion Gene therapy with siRNA-PKCα could effectively inhibit PVR in mice and provide us with a novel therapeutic target on PVR.
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Affiliation(s)
- Qianying Gao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, People's Republic of China.
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Lee SY, Ryan SJ. Pathophysiology of Ocular Trauma. Retina 2013. [DOI: 10.1016/b978-1-4557-0737-9.00098-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Fu PP, Xia Q, Zhao Y, Wang S, Yu H, Chiang HM. Phototoxicity of herbal plants and herbal products. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART C, ENVIRONMENTAL CARCINOGENESIS & ECOTOXICOLOGY REVIEWS 2013; 31:213-255. [PMID: 24024520 DOI: 10.1080/10590501.2013.824206] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Plants are used by humans in daily life in many different ways, including as food, herbal medicines, and cosmetics. Unfortunately, many natural plants and their chemical constituents are photocytotoxic and photogenotoxic, and these phototoxic phytochemicals are widely present in many different plant families. To date, information concerning the phototoxicity and photogenotoxicity of many plants and their chemical constituents is limited. In this review, we discuss phototoxic plants and their major phototoxic constituents; routes of human exposure; phototoxicity of these plants and their constituents; general mechanisms of phototoxicity of plants and phototoxic components; and several representative phototoxic plants and their photoactive chemical constituents.
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Affiliation(s)
- Peter P Fu
- a National Center for Toxicological Research , Jefferson , Arkansas , USA
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Abstract
The human eye is constantly exposed to sunlight and artificial lighting. Light transmission through the eye is fundamental to its unique biological functions of directing vision and circadian rhythm and therefore light absorbed by the eye must be benign. However, exposure to the very intense ambient radiation can pose a hazard particularly if the recipient is over 40 years of age. There are age-related changes in the endogenous (natural) chromophores (lipofuscin, A2E and all-trans-retinal derivatives) in the human retina that makes it more susceptible to visible light damage. Intense visible light sources that do not filter short blue visible light (400-440 nm) used for phototherapy of circadian imbalance (i.e. seasonal affective disorder) increase the risk for age-related light damage to the retina. Moreover, many drugs, dietary supplements, nanoparticles and diagnostic dyes (xenobiotics) absorb ocular light and have the potential to induce photodamage to the retina, leading to transient or permanent blinding disorders. This article will review the underlying reasons why visible light in general and short blue visible light in particular dramatically raises the risk of photodamage to the human retina.
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Affiliation(s)
- Albert R Wielgus
- Department of Ophthalmology, Duke University Medical Center, Durham, NC, USA
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Chen X, Liu Y, Jiang Z, Zhou L, Ge J, Gao Q. Protein kinase Cα downregulation via siRNA-PKCα released from foldable capsular vitreous body in cultured human retinal pigment epithelium cells. Int J Nanomedicine 2011; 6:1303-11. [PMID: 21753881 PMCID: PMC3131196 DOI: 10.2147/ijn.s19405] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2011] [Indexed: 11/23/2022] Open
Abstract
We previously found that downregulation of protein kinase Cα (PKCα) can inhibit retinal pigment epithelium (RPE) cell proliferation involved in the development of proliferative vitreoretinopathy (PVR). In this study, we tested whether PKCα could be downregulated via small interfering RNA (siRNA)-PKCα released from foldable capsular vitreous body (FCVB) in cultured human RPE cells. SiRNA-PKCα content, determined by ultraviolet (UV) spectrophotometer, was released from FCVB containing 200, 300, 400, 500, and 600 nm siRNA-PKCα in a time-dependent manner from 1 to 96 hours and a dose-dependent manner at five concentrations. The content (y) had a good linear relationship with time (x), especially in the 600 nm siRNA-PKCα group (y = 16.214x, R2 = 0.9809). After treatment with siRNA-PKCα released from FCVBs, the PKCα was significantly decreased by RT-PCR, Western blot, and immunofluorescence analysis in RPE cells. These results indicate that PKCα was significantly downregulated by siRNA-PKCα released from FCVB in human RPE cells and provide us with a new avenue to prevent PVR.
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Affiliation(s)
- Xiaoqing Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, People's Republic of China
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Booth JN, McGwin G. The association between self-reported cataracts and St. John's Wort. Curr Eye Res 2010; 34:863-6. [PMID: 19895314 DOI: 10.3109/02713680903144692] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND/AIMS Recent interest in Hypericum perforatum, or St. John's Wort (SJW), is related to its observed utility in treating depression. However, mounting evidence suggests one component, hypericin, may be associated with cataractogenesis. To date, this association has not been evaluated in humans. Therefore, the current study assesses the relationship between self-reported SJW use and cataracts utilizing data from a large, population-based sample. METHODS Self-reported data on SJW use in the past 12 months and cataract were obtained from the 2002 National Health Interview Survey, a nationally representative population-based sample. Crude and adjusted odds ratios (OR) and 95% confidence intervals (CI) between SJW use and cataracts were estimated using logistic regression. RESULTS After adjusting for potential confounding characteristics, participants that reported having cataracts were 59% more likely to report SJW use (OR 1.59; 95% CI 1.02-2.46). CONCLUSIONS The results of the current study provide support for an association between SJW use and cataracts. Based on the methodological limitations of this study, further investigation is required.
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Affiliation(s)
- John N Booth
- Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Alabama35294-0009, USA
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Involvement of protein kinase C in phagocytosis of human retinal pigment epithelial cells and induction of matrix metalloproteinase secretion. Int Ophthalmol 2008; 29:333-41. [PMID: 18641922 DOI: 10.1007/s10792-008-9241-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 05/20/2008] [Indexed: 10/21/2022]
Abstract
Protein kinase C (PKC) is involved in cell activation. We investigated PKC-mediated pathways and secretion of matrix metalloproteinases (MMPs) in phagocytosis by human retinal pigment epithelial cells (RPE). We used time-resolved fluorometry for europium-labeled microsphere uptake and gel zymography to assay the influence of PKC modulators. PKC inhibitors blocked phagocytosis by RPE. ARPE-19, a human RPE-cell line, showed reduced secretion of MMP-2, although MMP-9 secretion by PKC activation was conserved in both cell types, namely in the primary RPEs and in the RPE-cell line. Particle uptake by RPE cells requires activation of PKC; the use of PKC inhibitors as new anticancer drugs may possibly cause ocular side-effects.
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Bernd A, Simon S, Bosca AR, Kippenberger S, Alperi JD, Miquel J, Garcia JFV, Mira DP, Kaufmann R. Phototoxic Effects ofHypericumExtract in Cultures of Human Keratinocytes Compared with Those of Psoralen. Photochem Photobiol 2008. [DOI: 10.1111/j.1751-1097.1999.tb03276.x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Wielgus AR, Chignell CF, Miller DS, Van Houten B, Meyer J, Hu DN, Roberts JE. Phototoxicity in human retinal pigment epithelial cells promoted by hypericin, a component of St. John's wort. Photochem Photobiol 2007; 83:706-13. [PMID: 17576381 PMCID: PMC2092452 DOI: 10.1562/2006-08-09-ra-1001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
St. John's wort (SJW), an over-the-counter antidepressant, contains hypericin, which absorbs light in the UV and visible ranges. In vivo studies have determined that hypericin is phototoxic to skin and our previous in vitro studies with lens tissues have determined that it is potentially phototoxic to the human lens. To determine if hypericin might also be phototoxic to the human retina, we exposed human retinal pigment epithelial (hRPE) cells to 10(-7) to 10(-5) M hypericin. Fluorescence emission detected from the cells (lambda(ex) = 488 nm; lambda(em) = 505 nm) confirmed hypericin uptake by human RPE. Neither hypericin exposure alone nor visible light exposure alone reduced cell viability. However when irradiated with 0.7 J cm(-2) of visible light (lambda > 400 nm) there was loss of cell viability as measured by MTS and lactate dehydrogenase assays. The presence of hypericin in irradiated hRPE cells significantly changed the redox equilibrium of glutathione and a decrease in the activity of glutathione reductase. Increased lipid peroxidation as measured by the thiobarbituric acid reactive substances assay correlated to hypericin concentration in hRPE cells and visible light radiation. Thus, ingested SJW is potentially phototoxic to the retina and could contribute to retinal or early macular degeneration.
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Affiliation(s)
- Albert R. Wielgus
- Laboratory of Chemistry and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC
| | - Colin F. Chignell
- Laboratory of Chemistry and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC
| | - David S. Miller
- Laboratory of Chemistry and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC
| | - Ben Van Houten
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NC
| | - Joel Meyer
- Laboratory of Molecular Genetics, National Institute of Environmental Health Sciences, Research Triangle Park, NC
| | | | - Joan E. Roberts
- Fordham University, Department of Natural Sciences, New York, NY
- *Corresponding author’s name and e-mail: Fordham University, Department of Natural Sciences, 113 West 60th Street, Room 813, New York, NY 10023, USA. Fax: 212-636-6754; e-mail:
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Schey KL, Patat S, Chignell CF, Datillo M, Wang RH, Roberts JE. Photooxidation of Lens α-Crystallin by Hypericin (Active Ingredient in St. John's Wort)¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2000)0720200polcbh2.0.co2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Sgarbossa A, Lenci F. Spectroscopic Study of Visible-light Effects on Hypericin-lens Proteins Systems†¶. Photochem Photobiol 2007. [DOI: 10.1562/0031-8655(2001)0740196ssovle2.0.co2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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He YY, Chignell CF, Miller DS, Andley UP, Roberts JE. Phototoxicity in Human Lens Epithelial Cells Promoted by St. John's Wort¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2004.tb00133.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Taroni P, Valentini G, Comelli D, D'Andrea C, Cubeddu R, Hu DN, Roberts JE. Time-resolved Microspectrofluorimetry and Fluorescence Lifetime Imaging of Hypericin in Human Retinal Pigment Epithelial Cells¶. Photochem Photobiol 2007. [DOI: 10.1111/j.1751-1097.2005.tb00220.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Kocanova S, Hornakova T, Hritz J, Jancura D, Chorvat D, Mateasik A, Ulicny J, Refregiers M, Maurizot JC, Miskovsky P. Characterization of the interaction of hypericin with protein kinase C in U-87 MG human glioma cells. Photochem Photobiol 2006; 82:720-8. [PMID: 16396605 DOI: 10.1562/2005-09-26-ra-696] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A fluorescence imaging technique was used to monitor intracellular localization of protein kinase C (PKC) in U-87 MG human glioma cells in the presence of hypericin (Hyp) and phorbol 12-myristate-13-acetate (PMA). It is shown that PKC localization, which reflects its activity, is influenced by Hyp and this influence is different from that observed for PMA which acts as PKC activator. Fluorescence binding experiments were used to determine the binding constants of Hyp to several isoforms of PKC. The obtained values of K(d)s (approximately 100 nM) suggest that Hyp binds with high affinity to PKC. Finally, molecular modeling was used to compare structural models of the interaction of C1B domain of PKC (PKC isoforms alpha, delta, gamma) with Hyp and our previously published model of the (C1B domain PKCgamma)/PMA complex. The influence of Hyp on PKC translocation in U-87 MG cells in comparison with PMA, colocalization fluorescence pattern of Hyp and PKC, the higher binding affinity of Hyp to PKC in comparison with known binding constants of phorbol esters, as well as the binding mode of Hyp and PMA to the C1B domain of PKC suggested by molecular modeling, support the idea that Hyp and PMA might competitively bind to the regulatory domain of PKC.
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Affiliation(s)
- Silvia Kocanova
- Department of Biophysics, University of PJ Safarik, Kosice, Slovak Republic
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Ryan SJ, Yoon YH. Posterior Segment Trauma: Open Globe. Retina 2006. [DOI: 10.1016/b978-0-323-02598-0.50144-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Holstege CP, Mitchell K, Barlotta K, Furbee RB. Toxicity and drug interactions associated with herbal products: ephedra and St. John's Wort. Med Clin North Am 2005; 89:1225-57. [PMID: 16227061 DOI: 10.1016/j.mcna.2005.08.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Health care providers are being increasingly confronted with the use of herbal medications by their patients. It is imperative that patients be questioned regarding herbal preparation use and that health care providers become familiar with these agents. Research into the active components and mechanisms of action of various herbals is ongoing [350]. Long-range studies need to be performed to follow patients for efficacy or toxicity in chronic use [351,352]. Adverse reactions to herbal remedies should be reported to the FDA MedWatch at http://www.fda.gov/medwatch. As withany therapeutic agent, risk of use must always be weighed against potential benefits.
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Affiliation(s)
- Christopher P Holstege
- Division of Medical Toxicology, University of Virginia, Charlottesville, VA 22908-0774, USA.
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Hoffmann S, Balthasar S, Friedrichs U, Ehren M, Ryan SJ, Wiedemann P. Inhibitory effects of verapamil isomers on the proliferation of choroidal endothelial cells. Graefes Arch Clin Exp Ophthalmol 2005; 244:376-81. [PMID: 16088412 DOI: 10.1007/s00417-004-1104-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2004] [Revised: 10/20/2004] [Accepted: 12/08/2004] [Indexed: 12/01/2022] Open
Abstract
PURPOSE To evaluate the effects of verapamil isomers on in vitro proliferation of bovine choroidal endothelial cells (CECs). MATERIALS AND METHODS CECs were isolated from bovine eyes and cultured in endothelial growth medium (EGM). For the proliferation assays, CECs were exposed to verapamil isomers (0.1-100 microM) in EGM with 2% fetal bovine serum or basic fibroblast growth factor (bFGF) (10 ng/ml). After 72 h of incubation with the desired drug, the cellular proliferation was determined by an MTT assay and a BrdU assay. In addition, the drug toxicity on CECs stimulated with EGM was evaluated by cell counting with trypan blue. RESULTS All verapamil isomers inhibited the bFGF- or medium-stimulated growth significantly in a concentration range of 10-40 microM without toxicity. No significant differences were seen between the inhibitory effects of the various isomers. Cell toxicity was detected at a concentration of 100 microM verapamil isomers on EGM-stimulated CECs. CONCLUSION The results demonstrate the efficacy of all verapamil isomers in inhibiting CEC proliferation involved in the process of choroidal neovascularization. D: -(+)-Verapamil may be recommended for further in vivo evaluation in an animal model of exudative AMD; it has fewer systemic and local side effects because calcium channels are not blocked.
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Affiliation(s)
- Stephan Hoffmann
- Department of Ophthalmology, University of Leipzig, Liebigstrasse 10-14, 04103, Leipzig, Germany.
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Gao Q, Ge J. The Inhibition of Ca 2+ Influx Induced by Hypericin in Cultured Human Retinal Pigment Epithelial Cells Analyzed by Confocal Imaging. Ophthalmic Res 2005; 37:128-35. [PMID: 15821349 DOI: 10.1159/000084999] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2004] [Accepted: 08/11/2004] [Indexed: 12/23/2022]
Abstract
PURPOSE Hypericin, a specific inhibitor of protein kinase C, has been reported to have potential as a therapeutic drug for proliferative vitreoretinopathy (PVR) in vitro and in vivo. In the present studies, we analyzed the dynamic changes in Ca2+ influx and free intracellular Ca2+ concentration ([Ca2+]i) of cultured human retinal pigment epithelial (RPE) cells after stimulation with hypericin in an attempt to elucidate its mechanism as a therapeutic drug for PVR. METHODS RPE cells were plated in a special plastic dish and then stimulated with 100 nM phorbol-12-myristate-13-acetate (PMA) and/or 6 hypericin concentrations (0.5, 1, 2, 3, 4 and 5 microM), after which Ca2+ influx and [Ca2+]i were determined using the fluorescence Ca2+ dye fluo-3 AM and laser scanning confocal microscopy. RESULTS The fluorescence in resting RPE cells was strong and distributed throughout the cells. The nucleus appeared more fluorescent than the cytoplasm. After stimulation with 0.5 microM hypericin, no obvious change of Ca2+ influx and [Ca2+]i was observed. In contrast, stimulation with higher concentrations of hypericin (1-5 microM) led to a rapid decrease in Ca2+ influx and [Ca2+]i, which was significantly different from those detected without hypericin (control experiments). In addition, no significant differences in [Ca2+]i were found between 1 and 5 microM hypericin used. Stimulation with hypericin, which was applied immediately after preincubation with PMA for 24 h did not further change Ca2+ influx and [Ca2+]i. CONCLUSION In RPE cells, high concentrations of hypericin (1-5 microM) significantly inhibit Ca2+ influx and induce a decrease in [Ca2+]i. Therefore, hypericin has potential as a therapeutic drug for PVR maybe through its inhibition of the Ca2+ influx pathway.
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Affiliation(s)
- QianYing Gao
- Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Taroni P, Valentini G, Comelli D, D'Andrea C, Cubeddu R, Hu DN, Roberts JE. Time-resolved Microspectrofluorimetry and Fluorescence Lifetime Imaging of Hypericin in Human Retinal Pigment Epithelial Cells¶. Photochem Photobiol 2005. [DOI: 10.1562/2004-11-30-ir-385.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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He YY, Chignell CF, Miller DS, Andley UP, Roberts JE. Phototoxicity in Human Lens Epithelial Cells Promoted by St. John's Wort¶. Photochem Photobiol 2004; 80:583-6. [PMID: 15623347 DOI: 10.1562/0031-8655(2004)080<0583:pihlec>2.0.co;2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
St. John's Wort (SJW), an over-the-counter antidepressant, contains hypericin, which absorbs light in the UV and visible ranges and is phototoxic to skin. To determine if it also could be phototoxic to the eye, we exposed human lens epithelial cells to 0.1-10 microM hypericin and irradiated them with 4 J/cm2 UV-A or 0.9 J/cm2 visible light. Neither hypericin exposure alone nor light exposure alone reduced cell viability. In contrast, cells exposed to hypericin in combination with UV-A or visible light underwent necrosis and apoptosis. The ocular antioxidants lutein and N-acetyl cysteine did not prevent damage. Thus, ingested SJW is potentially phototoxic to the eye and could contribute to early cataractogenesis. Precautions should be taken to protect the eye from intense sunlight while taking SJW.
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Affiliation(s)
- Yu-Ying He
- Laboratory of Chemistry and Pharmacology, National Institute of Environmental Health Sciences, Research Triangle Park, NC 10023, USA
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28
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Troger J, Sellemond S, Kieselbach G, Kralinger M, Schmid E, Teuchner B, Nguyen QA, Schretter-Irschick E, Göttinger W. Inhibitory effect of certain neuropeptides on the proliferation of human retinal pigment epithelial cells. Br J Ophthalmol 2003; 87:1403-8. [PMID: 14609844 PMCID: PMC1771909 DOI: 10.1136/bjo.87.11.1403] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/23/2003] [Indexed: 12/30/2022]
Abstract
AIMS To define the effect of the neuropeptides substance P, calcitonin gene related peptide, vasoactive intestinal polypeptide, neuropeptide Y, and secretoneurin on the proliferation of human retinal pigment epithelial (RPE) cells. METHODS ARPE-19 cells were used. The cells were cultured in Dulbecco's modified Eagle's medium. 1000 and 2000 cells were incubated with the peptides for 3 and 5 days, and the effect of the peptides was evaluated by an ATP lite assay dose dependently. Furthermore, specific antagonists at 10(-6) M were used to find out whether the effect would be reversed. RESULTS In brief, each of the peptides tested had an inhibiting effect. This inhibiting effect was weak but highly significant, averaging 10% to 15%, and was most pronouncedly seen at concentrations between 10(-10) M and 10(-14) M. Each antagonist reversed the inhibiting effect fully. CONCLUSIONS These results clearly indicate that RPE cells are under neural control and the low effective concentration of the peptides may be the one physiologically acting on these cells. The results are of important relevance both physiologically and pathophysiologically: physiologically, the inhibitory effect may mean that these peptides cause the cells to remain in a differentiated condition. Pathophysiologically, the findings are relevant in proliferative vitreoretinopathy where RPE cells proliferate in excess. The authors hypothesise that the inhibiting effect diminishes when these cells are swept out and actively migrate from their physiological location and thus, dedifferentiate and begin to proliferate. This hypothesis improves the knowledge of the initial processes in the pathogenesis of the disease as there seems to be a discrepancy between facilitatory and inhibitory influences favouring the former in proliferative vitreoretinopathy. Furthermore, these neuropeptides constitute the first endogenous inhibitors of RPE cell proliferation.
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Affiliation(s)
- J Troger
- Department of Ophthalmology and Optometry, University Clinic, Anichstrasse 35, 6020 Innsbruck, Austria.
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Yoshida A, Elner SG, Bian ZM, Kindezelskii AL, Petty HR, Elner VM. Activated monocytes induce human retinal pigment epithelial cell apoptosis through caspase-3 activation. J Transl Med 2003; 83:1117-29. [PMID: 12920241 DOI: 10.1097/01.lab.0000082393.02727.b5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Dysfunction and loss of human retinal pigment epithelial (HRPE) cells is a significant component of many ocular diseases, in which mononuclear phagocyte infiltration at the HRPE-related interface is also observed. In this study, we investigated whether HRPE cell apoptosis may be induced by overlay of IFN-gamma-activated monocytes. Human monocytes primed with IFN-gamma overlaid directly onto HRPE cells elicited significant increases in terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL)-positive HRPE cells (p < 0.0001) and decreases of proliferating cell nuclear antigen-positive (p < 0.0001) HRPE cells. The activated monocytes also induced HRPE cell caspase-3 activation, which was inhibited by the caspase-3 inhibitor, Z-DEVD-fmk. However, co-incubations in which activated monocytes were prevented from direct contact with HRPE cells or in which the monocytes were separated from the HRPE cells after 30 minutes of direct contact, did not induce significant HRPE cell apoptosis. Function-blocking anti-CD18 and anti-intercellular adhesion molecule-1 (ICAM-1) antibodies significantly reduced activated monocyte-induced TUNEL-positive HRPE cells by 48% (p = 0.0051) and 38% (p = 0.046), respectively. Anti-CD18 and anti-ICAM-1 antibodies significantly inhibited caspase-3 activity by 56% (p < 0.0001) and 45% (p < 0.0001), respectively. However, antibodies to vascular cell adhesion molecule-1, TNF-alpha, IL-1beta, or TNF-related apoptosis-inducing ligand did not inhibit apoptosis or caspase-3 activation. Direct overlay of monocytes also induced reactive oxygen metabolites (ROM) within HRPE cells. The intracellular HRPE cell ROM production was inhibited by the anti-CD18 and anti-ICAM-1 antibodies, but not by superoxide dismutase, presumably due to its failure to penetrate into HRPE cells. Accordingly, neither superoxide dismutase nor N(G)-monomethyl-L-arginine had significant effects on HRPE cell apoptosis or caspase-3 activation. Our results suggest that activated monocytes may induce ROM in HRPE cells through cell-to-cell contact, in part via CD18 and ICAM-1, and promote HRPE cell apoptosis. These mechanisms may compromise HRPE cell function and survival in a variety of retinal diseases.
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Affiliation(s)
- Ayako Yoshida
- Department of Ophthalmology, University of Michigan, Ann Arbor, Michigan 48105, USA
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Agostinis P, Vantieghem A, Merlevede W, de Witte PAM. Hypericin in cancer treatment: more light on the way. Int J Biochem Cell Biol 2002; 34:221-41. [PMID: 11849990 DOI: 10.1016/s1357-2725(01)00126-1] [Citation(s) in RCA: 278] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Photodynamic therapy (PDT) has been described as a promising new modality for the treatment of cancer. PDT involves the combination of a photosensitizing agent (photosensitizer), which is preferentially taken up and retained by tumor cells, and visible light of a wavelength matching the absorption spectrum of the drug. Each of these factors is harmless by itself, but when combined they ultimately produce, in the presence of oxygen, cytotoxic products that cause irreversible cellular damage and tumor destruction. Hypericin, a powerful naturally occurring photosensitizer, is found in Hypericum perforatum plants, commonly known as St. John's wort. In recent years increased interest in hypericin as a potential clinical anticancer agent has arisen since several studies established its powerful in vivo and in vitro antineoplastic activity upon irradiation. Investigations of the molecular mechanisms underlying hypericin photocytotoxicity in cancer cells have revealed that this photosensitizer can induce both apoptosis and necrosis in a concentration and light dose-dependent fashion. Moreover, PDT with hypericin results in the activation of multiple pathways that can either promote or counteract the cell death program. This review focuses on the more recent advances in the use of hypericin as a photodynamic agent and discusses the current knowledge on the signaling pathways underlying its photocytotoxic action.
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Affiliation(s)
- Patrizia Agostinis
- Division of Biochemistry, Faculty of Medicine, KULeuven, Leuven, Belgium
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Enzmann V, Hollborn M, Wiedemann P, Kohen L. Minor influence of the immunosuppressive cytokines IL-10 and TGF-beta on the proliferation and apoptosis of human retinal pigment epithelial (RPE) cells in vitro. Ocul Immunol Inflamm 2001; 9:259-66. [PMID: 11935436 DOI: 10.1076/ocii.9.4.259.3950] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Undesirable immune reactions such as uveitis or graft rejection after corneal and subretinal transplantations are serious inflammations in the eye. Minimizing this process by means of physiological suppressors, either through systemic or intraocular administration with or without gene therapy, is a future therapeutic possibility. In our study, we used different concentrations of transforming growth factor-beta (TGF-beta; 5, 10, and 50 ng/ml) and interleukin-10 (IL-10; 100, 200, and 500 U/ml), both known as modulators of the suppression process, to treat human retinal pigment epithelium (RPE) cells in vitro. The influence of both cytokines on the viability and proliferation of the RPE cells was measured. Furthermore, the secretion of typical markers of the apoptosis process, such as Fas, soluble Fas ligand, and bcl-2, was investigated. Our results show that the concentrations of TGF-beta and IL-10 used have only a slight influence on RPE cells. Cell proliferation under the influence of TGF-beta was significantly reduced, whereas more Fas protein could be found in the cell lysate of the IL-10 samples. In general, IL-10 seemed to have less effect on the physiology of RPE cells. The discussion of the therapeutic use of an immunosuppressive factor in the eye should therefore be focused more on this cytokine.
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Affiliation(s)
- V Enzmann
- Department of Ophthalmology, Faculty of Medicine, University of Leipzig, Liebigstrasse 10-14, 04103 Leipzig, Germany
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Abstract
Molecular interactions between hypericin and alpha-, beta- and gamma-crystallin proteins have been studied by means of absorption and steady-state fluorescence spectroscopy, aiming to clarify if and how the pigment binds to the proteins and to investigate the effects of visible-light irradiation on these molecular systems. Such a study is a prerequisite for assessing the possibility of using hypericin as a mild antidepressant and/or as a photodynamic agent for the treatment of eye tumors and eye viral and bacterial diseases without side injuries to the lens. We have shown that in dark-kept samples, with increasing alpha-crystallin concentration, both the fluorescence emission intensity and the ratio of the absorption maxima around 590 and 550 nm of hypericin increase. These effects have been attributed to the monomerization of nonfluorescent hypericin aggregates caused by the binding of the pigment to alpha-crystallin. The binding constant of hypericin has been evaluated to be of the order of 3.0 (mg/mL)-1, corresponding to a dissociation constant of the order of 0.3 mg/mL. Following irradiation with light of wavelengths over 400 nm, at an irradiance of 20 mW/cm2, both tryptophan and hypericin fluorescence emission intensities decrease. These effects are suggested to be the consequence of a spatial rearrangement of the protein framework which takes place following the alpha-crystallin photopolymerization sensitized by hypericin itself described in the literature. For the sake of comparison hypericin has been studied also in the presence of beta H-, beta L- and gamma-crystallins at the same concentration.
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Affiliation(s)
- A Sgarbossa
- CNR Area Ricerca San Cataldo, Istituto Biofisica, Pisa, Italy
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Agostinis P, Assefa Z, Vantieghem A, Vandenheede JR, Merlevede W, De Witte P. Apoptotic and anti-apoptotic signaling pathways induced by photodynamic therapy with hypericin. ADVANCES IN ENZYME REGULATION 2000; 40:157-82. [PMID: 10828351 DOI: 10.1016/s0065-2571(99)00021-7] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- P Agostinis
- Division of Biochemistry, Faculty of Medicine, KU Leuven, Leuven, Belgium
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Schey KL, Patat S, Chignell CF, Datillo M, Wang RH, Roberts JE. Photooxidation of lens alpha-crystallin by hypericin (active ingredient in St. John's Wort). Photochem Photobiol 2000; 72:200-3. [PMID: 10946573 DOI: 10.1562/0031-8655(2000)072<0200:polcbh>2.0.co;2] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Hypericin is the active ingredient in the over the counter antidepressant medication St. John's Wort. Hypericin produces singlet oxygen and other excited state intermediates that indicate it should be a very efficient phototoxic agent in the eye. Furthermore it absorbs in the UV and visible range, which means it can potentially damage both the lens and the retina. Lens alpha-crystallin, isolated from calf lenses, was irradiated in the presence of hypericin (5 x 10(-5) M, 10 mM ammonium bicarbonate, pH 7.0) and in the presence and absence of light (> 300 nm, 24 mW/cm2). Hypericin-induced photosensitized photopolymerization as assessed by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Further analysis of the oxidative changes occurring in alpha-crystallin using mass spectrometry showed specific oxidation of methionine, tryptophan and histidine residues, which increased with irradiation time. Hypericin did not damage the lens protein in the dark. Damage to alpha-crystallin could undermine the integrity of the lens directly by protein denaturation and indirectly by disturbing chaperone function. Therefore, in the presence of light, hypericin can induce changes in lens protein that could lead to the formation of cataracts. Appropriate precautions should be taken to protect the eye from intense sunlight while on this antidepressant medication.
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Affiliation(s)
- K L Schey
- Department of Cell and Molecular Pharmacology and Experimental Therapeutics, Medical University of South Carolina, Charleston, USA
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Hypericum Perforatum - St. John's Wort Chemical, Pharmacological and Clinical Aspects. ACTA ACUST UNITED AC 2000. [DOI: 10.1016/s1572-5995(00)80037-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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36
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Assefa Z, Vantieghem A, Declercq W, Vandenabeele P, Vandenheede JR, Merlevede W, de Witte P, Agostinis P. The activation of the c-Jun N-terminal kinase and p38 mitogen-activated protein kinase signaling pathways protects HeLa cells from apoptosis following photodynamic therapy with hypericin. J Biol Chem 1999; 274:8788-96. [PMID: 10085120 DOI: 10.1074/jbc.274.13.8788] [Citation(s) in RCA: 183] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
In this study, we elucidate signaling pathways induced by photodynamic therapy (PDT) with hypericin. We show that PDT rapidly activates JNK1 while irreversibly inhibiting ERK2 in several cancer cell lines. In HeLa cells, sustained PDT-induced JNK1 and p38 mitogen-activated protein kinase (MAPK) activations overlap the activation of a DEVD-directed caspase activity, poly(ADP-ribose) polymerase (PARP) cleavage, and the onset of apoptosis. The caspase inhibitors benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (zVAD-fmk) and benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone (zDEVD-fmk) protect cells against apoptosis and inhibit DEVD-specific caspase activity and PARP cleavage without affecting JNK1 and p38 MAPK activations. Conversely, stable overexpression of CrmA, the serpin-like inhibitor of caspase-1 and caspase-8, has no effect on PDT-induced PARP cleavage, apoptosis, or JNK1/p38 activations. Cell transfection with the dominant negative inhibitors of the c-Jun N-terminal kinase (JNK) pathway, SEK-AL and TAM-67, or pretreatment with the p38 MAPK inhibitor PD169316 enhances PDT-induced apoptosis. A similar increase in PDT-induced apoptosis was observed by expression of the dual specificity phosphatase MKP-1. The simultaneous inhibition of both stress kinases by pretreating cells with PD169316 after transfection with either TAM-67 or SEK-AL produces a more pronounced sensitizing effect. Cell pretreatment with the p38 inhibitor PD169316 causes faster kinetics of DEVD-caspase activation and PARP cleavage and strongly oversensitizes the cells to apoptosis following PDT. These observations indicate that the JNK1 and p38 MAPK pathways play an important role in cellular resistance against PDT-induced apoptosis with hypericin.
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Affiliation(s)
- Z Assefa
- Division of Biochemistry, Faculty of Medicine, KULeuven, Herestraat 49, B-3000 Leuven, Belgium
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Vantieghem A, Assefa Z, Vandenabeele P, Declercq W, Courtois S, Vandenheede JR, Merlevede W, de Witte P, Agostinis P. Hypericin-induced photosensitization of HeLa cells leads to apoptosis or necrosis. Involvement of cytochrome c and procaspase-3 activation in the mechanism of apoptosis. FEBS Lett 1998; 440:19-24. [PMID: 9862416 DOI: 10.1016/s0014-5793(98)01416-1] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Here we report that photoactivated hypericin can induce either apoptosis or necrosis in HeLa cells. Under apoptotic conditions the cleavage of poly(ADP-ribose) polymerase (PARP) into the 85-kDa product is blocked by the caspase inhibitors benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk) and benzyloxycarbonyl-Asp-Glu-Val-Asp-fluoromethylketone (z-DEVD-fmk). Both inhibitors protect cells from apoptosis but cannot prevent hypericin-induced necrosis. Conversely, HeLa cells overexpressing the viral cytokine response modifier A (CrmA), which inhibits caspase-1 and -8, still undergo hypericin-induced apoptosis and necrosis. Evidence is provided for the release of mitochondrial cytochrome c in the cytosol and for procaspase-3 activation in the hypericin-induced cell killing.
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Affiliation(s)
- A Vantieghem
- Division of Biochemistry, Faculty of Medicine, KU Leuven, Belgium
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Vandenbogaerde AL, Kamuhabwa A, Delaey E, Himpens BE, Merlevede WJ, de Witte PA. Photocytotoxic effect of pseudohypericin versus hypericin. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1998; 45:87-94. [PMID: 9868799 DOI: 10.1016/s1011-1344(98)00163-8] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Pseudohypericin and hypericin, the major photosensitizing constituents of Hypericum perforatum, are believed to cause hypericism. Since hypericin has been proposed as a photosensitizer for photodynamic cancer therapy, the photocytotoxicity of its congener pseudohypericin has been investigated. The presence of foetal calf serum (FCS) or albumin extensively inhibits the photocytotoxic effect of pseudohypericin against A431 tumour cells, and is associated with a large decrease in cellular uptake of the compound. These results suggest that pseudohypericin, in contrast to hypericin, interacts strongly with constituents of FCS, lowering its interaction with cells. Since pseudohypericin is two to three times more abundant in Hypericum than hypericin and the bioavailabilities of pseudohypericin and hypericin after oral administration are similar, these results suggest that hypericin, and not pseudohypericin, is likely to be the constituent responsible for hypericism. Moreover, the dramatic decrease of photosensitizing activity of pseudohypericin in the presence of serum may restrict its applicability in clinical situations.
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Affiliation(s)
- A L Vandenbogaerde
- Laboratorium voor Farmaceutische Biologie en Fytofarmacologie, Faculteit Farmacie, Leuven, Belgium
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Hoffman S, Gopalakrishna R, Gundimeda U, Murata T, Spee C, Ryan SJ, Hinton DR. Verapamil inhibits proliferation, migration and protein kinase C activity in human retinal pigment epithelial cells. Exp Eye Res 1998; 67:45-52. [PMID: 9702177 DOI: 10.1006/exer.1998.0491] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effects of three calcium channel blockers, verapamil, diltiazem and nifedipine, were examined on in vitro proliferation and migration of human retinal pigment epithelial cells. Human retinal pigment epithelial cells were seeded in Dulbecco's modified essential medium with 10% fetal bovine serum and different concentrations of the three calcium channel blockers. After 3 days of treatment, cell proliferation was determined by cell counting and by [3H]-thymidine uptake. Cell viability was determined with trypan blue exclusion. For determination of cell migration, retinal pigment epithelial cells were grown to confluence and then growth-inhibited with mitomycin C. After a 3 mm zone was denuded, the cells were treated with different concentrations of the calcium channel antagonists. After 24 hr, the cells that had migrated over the wound edge were counted. To determine the involvement of protein kinase C in the verapamil effect, its activity was measured in both verapamil-treated and untreated cells. Verapamil dose dependently inhibited serum-induced proliferation of retinal pigment epithelial cells, when measured by cell number (IC50 14.6 microM) or [3H]-thymidine incorporation (IC50 11.3 microM). At concentrations of 15 microM and below, there was no effect on cell viability, as determined by morphology and trypan blue exclusion. Diltiazem inhibited cell proliferation at a concentration of 100 microM; however, 100 microM nifedipine had no effect. Verapamil showed a significant inhibition of serum-induced migration in the range of 10 microM to 0.1 microM. The IC50 of the inhibition of retinal pigment epithelial cell proliferation and migration by verapamil is significantly higher than that seen for effects on calcium channel blockage. Eight micromolar verapamil reversibly inhibited total protein kinase-C activity in retinal pigment epithelial cells suggesting the possibility that the drug may act by inhibiting the protein kinase-C pathway. These data suggest the potential of the calcium channel blocker verapamil as a pharmacological modulator of disorders such as proliferative vitreoretinopathy in which there is increased retinal pigment epithelial cell proliferation and migration.
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Affiliation(s)
- S Hoffman
- Doheny Eye Institute, Los Angeles, CA, USA
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Oshima Y, Sakamoto T, Kawano Y, Hata Y, Yoshikawa H, Sonoda KH, Ishibashi T, Inomata H. Synergistic effect of electric pulses and bleomycin on cultured rabbit subconjunctival fibroblasts. Graefes Arch Clin Exp Ophthalmol 1998; 236:52-60. [PMID: 9457517 DOI: 10.1007/s004170050042] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND The combined effect of electric pulses (EP) and antiproliferative agents on the proliferation of rabbit Tenon's capsule fibroblasts was investigated. METHODS Rabbit Tenon's capsule fibroblasts were cultured. Some of these cells were exposed to various intensities of EP alone (500-2500 V/cm). Other cells were then exposed for 30 min to an antiproliferative agent: bleomycin (BLM; 0.0005-50 mumol/l), mitomycin C (MMC; 0.0005-50 mumol/l), 5-fluorouracil (5-FU; 0.05-5000 mumol/l), or streptomycin (SM; 0.0005-50 mumol/l) with or without EP (2000 V/cm, 99 mus, eight pulses). Cell proliferation was assessed by cell counting on day 3 and by a 3H-thymidine uptake assay. DNA fragmentation was assessed by flow-cytometric analysis and agarose gel electrophoresis. RESULTS A significant reduction in the cell number was observed only at 2500 V/cm (P < 0.05). BLM, MMC and 5-FU treatment inhibited cell proliferation in a dose-dependent manner either with or without EP (ID50: BLM alone, 0.029 mumol/l; BLM and EP, 0.00022 mumol/l; MMC alone, 41.6 mumol/l; MMC and EP, 27.5 mumol/l; 5-FU alone, 1045 mumol/l; 5-FU and EP, 690.2 mumol/l; P < 0.05). EP treatment induced an inhibitory effect of BLM on cell proliferation which was 100 times more prominent than BLM alone (0.0005 mumol/l of BLM alone 103.4 +/- 4.4%, 0.0005 mumol/l of BLM and EP 26.0 +/- 4.4%; P = 0.021). BLM treatment with EP also augmented the apoptotic-like DNA fragmentation in both a flow-cytometric DNA histogram and agarose gel-electrophoresis. CONCLUSION EP treatment enhanced the inhibitory effect of BLM on the cell proliferation of Tenon's capsule fibroblasts of rabbits. The combination of electric pulses and antiproliferative drug treatments may therefore reduce the necessary dose of antiproliferative agents in filtering surgery.
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Affiliation(s)
- Y Oshima
- Department of Ophthalmology, Faculty of Medicine, Kyushu University, Fukuoka, Japan
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