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Dörschmann P, Seeba C, Thalenhorst T, Roider J, Klettner A. Anti-inflammatory properties of antiangiogenic fucoidan in retinal pigment epithelium cells. Heliyon 2023; 9:e15202. [PMID: 37123974 PMCID: PMC10130777 DOI: 10.1016/j.heliyon.2023.e15202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 03/27/2023] [Accepted: 03/29/2023] [Indexed: 05/02/2023] Open
Abstract
Age-related macular degeneration (AMD) is a multifactorial disease in which angiogenesis, oxidative stress and inflammation are important contributing factors. In this study, we investigated the anti-inflammatory effects of a fucoidan from the brown algae Fucus vesiculosus (FV) in primary porcine RPE cells. Inflammation was induced by lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (Poly I:C), Pam2CSK4 (Pam), or tumor necrosis factor alpha (TNF-α). Cell viability was tested with thiazolyl blue tetrazolium bromide (MTT) test, barrier function by measuring transepithelial electric resistance (TEER), interleukin 6 (IL-6) and interleukin 8 (IL-8) secretion in ELISA, retinal pigment epithelium-specific 65 kDa protein (RPE65) and protectin (CD59) expression in Western blot, gene expression with quantitative polymerase chain reaction (qPCR) (IL6, IL8, MERTK, PIK3CA), and phagocytotic activity in a microscopic assay. FV fucoidan did not influence RPE cell viability. FV fucoidan reduced the Poly I:C proinflammatory cytokine secretion of IL-6 and IL-8. In addition, it decreased the expression of IL-6 and IL-8 in RT-PCR. LPS and TNF-α reduced the expression of CD59 in Western blot, this reduction was lost under FV fucoidan treatment. Also, LPS and TNF-α reduced the expression of visual cycle protein RPE65, this reduction was again lost under FV fucoidan treatment. Furthermore, the significant reduction of barrier function after Poly I:C stimulation is ameliorated by FV fucoidan. Concerning phagocytosis, however, the inflammation-induced reduction was not improved by FV fucoidan. FV and proinflammatory milieu did not relevantly influence phagocytosis relevant gene expression either. In conclusion, we show that fucoidan from FV can reduce proinflammatory stimulation in RPE induced by toll-like receptor 3 (TLR-3) activation and is of high interest as a potential compound for early AMD treatment.
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Sharif NA. Therapeutic Drugs and Devices for Tackling Ocular Hypertension and Glaucoma, and Need for Neuroprotection and Cytoprotective Therapies. Front Pharmacol 2021; 12:729249. [PMID: 34603044 PMCID: PMC8484316 DOI: 10.3389/fphar.2021.729249] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 08/18/2021] [Indexed: 12/11/2022] Open
Abstract
Damage to the optic nerve and the death of associated retinal ganglion cells (RGCs) by elevated intraocular pressure (IOP), also known as glaucoma, is responsible for visual impairment and blindness in millions of people worldwide. The ocular hypertension (OHT) and the deleterious mechanical forces it exerts at the back of the eye, at the level of the optic nerve head/optic disc and lamina cribosa, is the only modifiable risk factor associated with glaucoma that can be treated. The elevated IOP occurs due to the inability of accumulated aqueous humor (AQH) to egress from the anterior chamber of the eye due to occlusion of the major outflow pathway, the trabecular meshwork (TM) and Schlemm’s canal (SC). Several different classes of pharmaceutical agents, surgical techniques and implantable devices have been developed to lower and control IOP. First-line drugs to promote AQH outflow via the uveoscleral outflow pathway include FP-receptor prostaglandin (PG) agonists (e.g., latanoprost, travoprost and tafluprost) and a novel non-PG EP2-receptor agonist (omidenepag isopropyl, Eybelis®). TM/SC outflow enhancing drugs are also effective ocular hypotensive agents (e.g., rho kinase inhibitors like ripasudil and netarsudil; and latanoprostene bunod, a conjugate of a nitric oxide donor and latanoprost). One of the most effective anterior chamber AQH microshunt devices is the Preserflo® microshunt which can lower IOP down to 10–13 mmHg. Other IOP-lowering drugs and devices on the horizon will be also discussed. Additionally, since elevated IOP is only one of many risk factors for development of glaucomatous optic neuropathy, a treatise of the role of inflammatory neurodegeneration of the optic nerve and retinal ganglion cells and appropriate neuroprotective strategies to mitigate this disease will also be reviewed and discussed.
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Affiliation(s)
- Najam A Sharif
- Global Alliances and External Research, Ophthalmology Innovation Center, Santen Inc., Emeryville, CA, United States
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3
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Retinal Pigment Epithelium Expressed Toll-like Receptors and Their Potential Role in Age-Related Macular Degeneration. Int J Mol Sci 2021; 22:ijms22168387. [PMID: 34445096 PMCID: PMC8395065 DOI: 10.3390/ijms22168387] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/03/2021] [Accepted: 08/03/2021] [Indexed: 01/17/2023] Open
Abstract
(1) Background: Inflammation is a major pathomechanism in the development and progression of age-related macular degeneration (AMD). The retinal pigment epithelium (RPE) may contribute to retinal inflammation via activation of its Toll-like receptors (TLR). TLR are pattern recognition receptors that detect the pathogen- or danger-associated molecular pattern. The involvement of TLR activation in AMD is so far not understood. (2) Methods: We performed a systematic literature research, consulting the National Library of Medicine (PubMed). (3) Results: We identified 106 studies, of which 54 were included in this review. Based on these studies, the current status of TLR in AMD, the effects of TLR in RPE activation and of the interaction of TLR activated RPE with monocytic cells are given, and the potential of TLR activation in RPE as part of the AMD development is discussed. (4) Conclusion: The activation of TLR2, -3, and -4 induces a profound pro-inflammatory response in the RPE that may contribute to (long-term) inflammation by induction of pro-inflammatory cytokines, reducing RPE function and causing RPE cell degeneration, thereby potentially constantly providing new TLR ligands, which could perpetuate and, in the long run, exacerbate the inflammatory response, which may contribute to AMD development. Furthermore, the combined activation of RPE and microglia may exacerbate neurotoxic effects.
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Musi CA, Agrò G, Santarella F, Iervasi E, Borsello T. JNK3 as Therapeutic Target and Biomarker in Neurodegenerative and Neurodevelopmental Brain Diseases. Cells 2020; 9:cells9102190. [PMID: 32998477 PMCID: PMC7600688 DOI: 10.3390/cells9102190] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/21/2020] [Accepted: 09/24/2020] [Indexed: 01/01/2023] Open
Abstract
The c-Jun N-terminal kinase 3 (JNK3) is the JNK isoform mainly expressed in the brain. It is the most responsive to many stress stimuli in the central nervous system from ischemia to Aβ oligomers toxicity. JNK3 activity is spatial and temporal organized by its scaffold protein, in particular JIP-1 and β-arrestin-2, which play a crucial role in regulating different cellular functions in different cellular districts. Extensive evidence has highlighted the possibility of exploiting these adaptors to interfere with JNK3 signaling in order to block its action. JNK plays a key role in the first neurodegenerative event, the perturbation of physiological synapse structure and function, known as synaptic dysfunction. Importantly, this is a common mechanism in many different brain pathologies. Synaptic dysfunction and spine loss have been reported to be pharmacologically reversible, opening new therapeutic directions in brain diseases. Being JNK3-detectable at the peripheral level, it could be used as a disease biomarker with the ultimate aim of allowing an early diagnosis of neurodegenerative and neurodevelopment diseases in a still prodromal phase.
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Affiliation(s)
- Clara Alice Musi
- Department of Pharmacological and Biomolecular Sciences, Milan University, 20133 Milan, Italy;
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, 20156 Milan, Italy; (G.A.); (F.S.); (E.I.)
| | - Graziella Agrò
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, 20156 Milan, Italy; (G.A.); (F.S.); (E.I.)
| | - Francesco Santarella
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, 20156 Milan, Italy; (G.A.); (F.S.); (E.I.)
| | - Erika Iervasi
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, 20156 Milan, Italy; (G.A.); (F.S.); (E.I.)
- Department of Experimental Medicine, University of Genoa, Via De Toni 14, 16132 Genoa, Italy
| | - Tiziana Borsello
- Department of Pharmacological and Biomolecular Sciences, Milan University, 20133 Milan, Italy;
- Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri-IRCCS, 20156 Milan, Italy; (G.A.); (F.S.); (E.I.)
- Correspondence: or ; Tel.: +39-023-901-4469; Fax: +39-023-900-1916
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5
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Wu X, Pang Y, Zhang Z, Li X, Wang C, Lei Y, Li A, Yu L, Ye J. Mitochondria-targeted antioxidant peptide SS-31 mediates neuroprotection in a rat experimental glaucoma model. Acta Biochim Biophys Sin (Shanghai) 2019; 51:411-421. [PMID: 30811524 DOI: 10.1093/abbs/gmz020] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/28/2019] [Accepted: 02/01/2019] [Indexed: 01/08/2023] Open
Abstract
To investigate the neuroprotective effects of the mitochondria-targeted antioxidant Szeto-Schiller peptide 31 (SS-31) in a rat experimental glaucoma model, SS-31 was intraperitoneally (IP) injected into Sprague-Dawley rats, followed by intracameral injection of polystyrene microspheres to induce elevated intraocular pressure (IOP). After 6 weeks, electroretinography (ERG) and flash visual-evoked potentials (F-VEPs) were recorded to assess retinal function. Hematoxylin-eosin staining was performed on retinal cross-sections to measure ganglion cell complex (GCC) thickness. Apoptotic retinal cells were assessed by TUNEL staining. Brn3a-positive retinal ganglion cells (RGCs) were counted in retinal flat mounts via immunofluorescence. The retinal total SOD, SOD2, and MDA expression levels were assessed in retinal tissue homogenates. The cyt c, Bax, and Bcl-2 protein levels in rat retinas were detected by western blot analysis. Bax and Bcl-2 expressions were also evaluated using immunohistochemistry in paraffinized sections. Our results showed that the rats that received microsphere injection developed elevated IOP. SS-31 ameliorated the reductions in the a- and b-wave amplitudes on ERG and the F-VEP amplitude in glaucomatous eyes. GCC thickness was preserved, TUNEL-positive cells were decreased in the retina, and Brn3a-positive RGCs were increased in the SS-31-treated glaucoma group compared with those in the non-treated glaucoma group. SS-31 significantly reduced MDA levels and increased SOD2 levels after glaucoma induction. Significant suppression of cyt c release, upregulation of Bcl-2, and downregulation of Bax were observed following SS-31 administration. In summary, SS-31 exerts neuroprotective effects in this experimental glaucoma model by inhibiting mitochondrial dysfunction and therefore represents a promising therapeutic agent for glaucoma.
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Affiliation(s)
- Xiaoqiong Wu
- Department of Ophthalmology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yu Pang
- Department of Ophthalmology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Zhilin Zhang
- Department of Ophthalmology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Xiabin Li
- Department of Pathology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Chao Wang
- Department of Ophthalmology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Yingqing Lei
- Department of Ophthalmology, Affiliated Hospital of Southwest Medical University, Luzhou, China
| | - Ailing Li
- Center of Evidence-Based Medicine at Southwest Medical University; School of Public Health of Southwest Medical University, Luzhou, China
| | - Ling Yu
- Department of Ophthalmology, Affiliated Hospital of Southwest Medical University, Luzhou, China
- Department of Ophthalmology, Institute of Surgery Research, Daping Hospital, Army Medical Center of PLA, Army Medical University, Chongqing, China
| | - Jian Ye
- Department of Ophthalmology, Institute of Surgery Research, Daping Hospital, Army Medical Center of PLA, Army Medical University, Chongqing, China
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6
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Protective Effects of Lycium barbarum Extracts on UVB-Induced Damage in Human Retinal Pigment Epithelial Cells Accompanied by Attenuating ROS and DNA Damage. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:4814928. [PMID: 30524656 PMCID: PMC6247443 DOI: 10.1155/2018/4814928] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 08/21/2018] [Accepted: 09/03/2018] [Indexed: 01/15/2023]
Abstract
The medicinal herb Lycium barbarum fruit has been widely used for improving and maintaining the health of the eyes in the Far East for many centuries. This study is aimed at investigating whether protective effects generated from the aqueous (LBA) and ethanol (LBE) extracts of the L. barbarum fruit existed against oxidative stress-induced apoptosis in human retinal pigment epithelial cells. L. barbarum extracts LBA and LBE exerted the activity of ROS scavenging and rescued UVB irradiation-induced growth inhibition in retinal pigment epithelial ARPE-19 cells. Compared to LBA, the ethanol extract LBE exerted a superior protective activity on UVB-induced growth arrest in ARPE-19 cells. Both L. barbarum extracts significantly reduced cell cycle G2-arrest population in ARPE-19 cells. Furthermore, the cytometer-based Annexin V/propidium iodide staining assay further showed that both L. barbarum extracts protected ARPE-19 cells from UVB-induced apoptosis. L. barbarum extracts also reduced the activation of γH2AX, a sensor of DNA damage in ARPE-19 cells in a dose-responsive manner. By using Ingenuity Pathway Analysis (IPA), the bioinformatics revealed that the protective effects of both LBA and LBE extracts might be involved in three signaling pathways, especially the Toll-like receptor (TLR) pathway associated with cellular proliferation. Our study suggests that both ethanol and aqueous extracts of L. barbarum exhibit antioxidant activity and rescue UVB-induced apoptosis of ARPE-19 cells. Collectively, the ethanol extract exerts a superior effect on rescuing UVB-induced growth arrest of ARPE-19 compared to the aqueous extract, which might be associated with the activation of TLR signaling. Our present work will benefit the preventive strategy of herbal medicine-based vision protection for treating eye diseases such as age-related macular degeneration in the future.
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7
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Liu C, Zhang CW, Zhou Y, Wong WQ, Lee LC, Ong WY, Yoon SO, Hong W, Fu XY, Soong TW, Koo EH, Stanton LW, Lim KL, Xiao ZC, Dawe GS. APP upregulation contributes to retinal ganglion cell degeneration via JNK3. Cell Death Differ 2017; 25:663-678. [PMID: 29238071 PMCID: PMC5864187 DOI: 10.1038/s41418-017-0005-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Revised: 09/29/2017] [Accepted: 10/06/2017] [Indexed: 11/20/2022] Open
Abstract
Axonal injury is a common feature of central nervous system insults. Upregulation of amyloid precursor protein (APP) is observed following central nervous system neurotrauma and is regarded as a marker of central nervous system axonal injury. However, the underlying mechanism by which APP mediates neuronal death remains to be elucidated. Here, we used mouse optic nerve axotomy (ONA) to model central nervous system axonal injury replicating aspects of retinal ganglion cell (RGC) death in optic neuropathies. APP and APP intracellular domain (AICD) were upregulated in retina after ONA and APP knockout reduced Tuj1+ RGC loss. Pathway analysis of microarray data combined with chromatin immunoprecipitation and a luciferase reporter assay demonstrated that AICD interacts with the JNK3 gene locus and regulates JNK3 expression. Moreover, JNK3 was found to be upregulated after ONA and to contribute to Tuj1+ RGC death. APP knockout reduced the ONA-induced enhanced expression of JNK3 and phosphorylated JNK (pJNK). Gamma-secretase inhibitors prevented production of AICD, reduced JNK3 and pJNK expression similarly, and protected Tuj1+ RGCs from ONA-induced cell death. Together these data indicate that ONA induces APP expression and that gamma-secretase cleavage of APP releases AICD, which upregulates JNK3 leading to RGC death. This pathway may be a novel target for neuronal protection in optic neuropathies and other forms of neurotrauma.
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Affiliation(s)
- Chao Liu
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 16 Medical Drive, Singapore, 117600, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore
| | - Cheng-Wu Zhang
- Key Laboratory of Flexible Electronics (KLOFE) and Institute of Advanced Materials (IAM), Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Technical University (Nanjing Tech), 30 South Puzhu Road, Nanjing, 211816, P. R. China.,Neurodegeneration Research Laboratory, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Yi Zhou
- Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 8 Medical Drive, Singapore, 117596, Singapore
| | - Wan Qing Wong
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 16 Medical Drive, Singapore, 117600, Singapore.,Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Singapore Institute for Neurotechnology (SINAPSE), Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Stem Cell and Regenerative Biology Group, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672, Singapore
| | - Liying Corinne Lee
- Department of Physiology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore
| | - Wei Yi Ong
- Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Department of Anatomy, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 4 Medical Drive, Singapore, 117594, Singapore
| | - Sung Ok Yoon
- Department of Biological Chemistry and Pharmacology, Wexner Medical Center, The Ohio State University, Columbus, OH, 43210, USA
| | - Wanjin Hong
- Institute of Molecular and Cell Biology, Agency for Science, Technology and Research (A*STAR), Proteos, 61 Biopolis Drive, Singapore, 138673, Singapore
| | - Xin-Yuan Fu
- Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 8 Medical Drive, Singapore, 117596, Singapore
| | - Tuck Wah Soong
- Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore
| | - Edward H Koo
- Department of Physiology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore.,Department of Medicine, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 12 Science Drive 2, Singapore, 117549, Singapore
| | - Lawrence W Stanton
- Stem Cell and Regenerative Biology Group, Genome Institute of Singapore, 60 Biopolis Street, Singapore, 138672, Singapore
| | - Kah-Leong Lim
- Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.,Department of Physiology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 2 Medical Drive, Singapore, 117597, Singapore.,Neurodegeneration Research Laboratory, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore
| | - Zhi-Cheng Xiao
- Department of Anatomy and Developmental Biology, Monash University, Clayton, Melbourne, 3800, Australia. .,The Key Laboratory of Stem Cell and Regenerative Medicine, Institute of Molecular and Clinical Medicine, Kunming Medical College, Kunming, 650031, China.
| | - Gavin S Dawe
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University Health System, National University of Singapore, 16 Medical Drive, Singapore, 117600, Singapore. .,Neurobiology and Ageing Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore. .,Singapore Institute for Neurotechnology (SINAPSE), Centre for Life Sciences, National University of Singapore, 28 Medical Drive, Singapore, 117456, Singapore.
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8
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A Ser75-to-Asp phospho-mimicking mutation in Src accelerates ageing-related loss of retinal ganglion cells in mice. Sci Rep 2017; 7:16779. [PMID: 29196663 PMCID: PMC5711949 DOI: 10.1038/s41598-017-16872-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 11/18/2017] [Indexed: 11/08/2022] Open
Abstract
Src knockout mice show no detectable abnormalities in central nervous system (CNS) post-mitotic neurons, likely reflecting functional compensation by other Src family kinases. Cdk1- or Cdk5-dependent Ser75 phosphorylation in the amino-terminal Unique domain of Src, which shares no homology with other Src family kinases, regulates the stability of active Src. To clarify the roles of Src Ser75 phosphorylation in CNS neurons, we established two types of mutant mice with mutations in Src: phospho-mimicking Ser75Asp (SD) and non-phosphorylatable Ser75Ala (SA). In ageing SD/SD mice, retinal ganglion cell (RGC) number in whole retinas was significantly lower than that in young SD/SD mice in the absence of inflammation and elevated intraocular pressure, resembling the pathogenesis of progressive optic neuropathy. By contrast, SA/SA mice and wild-type (WT) mice exhibited no age-related RGC loss. The age-related retinal RGC number reduction was greater in the peripheral rather than the mid-peripheral region of the retina in SD/SD mice. Furthermore, Rho-associated kinase activity in whole retinas of ageing SD/SD mice was significantly higher than that in young SD/SD mice. These results suggest that Src regulates RGC survival during ageing in a manner that depends on Ser75 phosphorylation.
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9
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Yao B, Wang S, Xiao P, Wang Q, Hea Y, Zhang Y. MAPK signaling pathways in eye wounds: Multifunction and cooperation. Exp Cell Res 2017; 359:10-16. [DOI: 10.1016/j.yexcr.2017.06.024] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/29/2017] [Indexed: 12/12/2022]
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10
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Zhang L, Li G, Shi M, Liu HH, Ge S, Ou Y, Flanagan JG, Chen L. Establishment and Characterization of an Acute Model of Ocular Hypertension by Laser-Induced Occlusion of Episcleral Veins. Invest Ophthalmol Vis Sci 2017; 58:3879-3886. [PMID: 28763561 PMCID: PMC6108309 DOI: 10.1167/iovs.16-20807] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Purpose This study was designed to develop and characterize a laser-induced model of acute intraocular hypertension that permits the study of the anterior segment of the eye. Methods CD1 mice aged 5 and 8 weeks were examined for elevation of IOP induced by laser photocoagulation. We compared between occlusion of episcleral veins alone and when combined with 270° limbal vessel occlusion. Anterior chamber angle, corneal thickness, and retinal nerve fiber layer (RNFL) thickness were evaluated by anterior- and posterior-segment optical coherence tomography (OCT). Additionally, at day 7 post-procedure, the anterior segment was evaluated for inflammatory cellular presentation by histologic analysis and OCT, and limbal vessels and whole-mount retina were immunostained for CD31 and Brn3a, respectively. Brn3a-positive retinal ganglion cells (RGCs) were quantified with ImageJ software. Results After single or combined laser treatment in mice aged 5 or 8 weeks, IOP was significantly elevated for 5 to 6 days before returning to the baseline by day 7 post-procedure. Anterior segment assessment indicated less synechiae in the anterior chamber angle and better preserved limbal vessels with single versus combined laser treatment. Corneal thickness was significantly increased after single or combined treatment. No inflammatory cells were detected in the anterior chamber. The thickness of the RNFL and the density of RGCs were both significantly reduced after single or combined treatment. Conclusions Laser photocoagulation of episcleral veins alone in CD1 mice aged 5 to 8 weeks may be used to induce ocular hypertension resulting in RNFL thinning and ganglion cell loss. This model permits the study of the anterior as well as the posterior segment of the eye.
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Affiliation(s)
- Liwei Zhang
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States 2School of Optometry and Vision Science, University of California, Berkeley, California, United States 3Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Guangyu Li
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States 2School of Optometry and Vision Science, University of California, Berkeley, California, United States
| | - Meng Shi
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States 2School of Optometry and Vision Science, University of California, Berkeley, California, United States 3Department of Ophthalmology, Second Xiangya Hospital, Central South University, Changsha, China
| | - Hsin-Hua Liu
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States 2School of Optometry and Vision Science, University of California, Berkeley, California, United States
| | - Shaokui Ge
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States 2School of Optometry and Vision Science, University of California, Berkeley, California, United States
| | - Yvonne Ou
- Department of Ophthalmology, University of California, San Francisco, California, United States
| | - John G Flanagan
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States 2School of Optometry and Vision Science, University of California, Berkeley, California, United States
| | - Lu Chen
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States 2School of Optometry and Vision Science, University of California, Berkeley, California, United States
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11
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Chang B, Quan Q, Lu S, Wang Y, Peng J. Molecular mechanisms in the initiation phase of Wallerian degeneration. Eur J Neurosci 2016; 44:2040-8. [PMID: 27062141 DOI: 10.1111/ejn.13250] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Revised: 04/06/2016] [Accepted: 04/06/2016] [Indexed: 12/20/2022]
Abstract
Axonal degeneration is an early hallmark of nerve injury and many neurodegenerative diseases. The discovery of the Wallerian degeneration slow mutant mouse, in which axonal degeneration is delayed, revealed that Wallerian degeneration is an active progress and thereby illuminated the mechanisms underlying axonal degeneration. Nicotinamide mononucleotide adenylyltransferase 2 and sterile alpha and armadillo motif-containing protein 1 play essential roles in the maintenance of axon integrity by regulating the level of nicotinamide adenine dinucleotide, which seems to be the key molecule involved in the maintenance of axonal health. However, the function of nicotinamide mononucleotide remains debatable, and we discuss two apparently conflicting roles of nicotinamide mononucleotide in Wallerian degeneration. In this article, we focus on the roles of these molecules in the initiation phase of Wallerian degeneration to improve our understanding of the mechanisms underpinning this phenomenon.
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Affiliation(s)
- Biao Chang
- Institute of Orthopedics, General Hospital of People's Liberation Army, 28th Fuxing Road, Beijing, China.,Beijing Key Laboratory of Regenerative Medicine in Orthopedics, Beijing, China.,Key Laboratory of Musculoskeletal Trauma & War Injuries, People's Liberation Army, Beijing, China
| | - Qi Quan
- Institute of Orthopedics, General Hospital of People's Liberation Army, 28th Fuxing Road, Beijing, China.,Beijing Key Laboratory of Regenerative Medicine in Orthopedics, Beijing, China.,Key Laboratory of Musculoskeletal Trauma & War Injuries, People's Liberation Army, Beijing, China
| | - Shibi Lu
- Institute of Orthopedics, General Hospital of People's Liberation Army, 28th Fuxing Road, Beijing, China.,Beijing Key Laboratory of Regenerative Medicine in Orthopedics, Beijing, China.,Key Laboratory of Musculoskeletal Trauma & War Injuries, People's Liberation Army, Beijing, China
| | - Yu Wang
- Institute of Orthopedics, General Hospital of People's Liberation Army, 28th Fuxing Road, Beijing, China.,Beijing Key Laboratory of Regenerative Medicine in Orthopedics, Beijing, China.,Key Laboratory of Musculoskeletal Trauma & War Injuries, People's Liberation Army, Beijing, China.,The Neural Regeneration Co-innovation Center of Jiangsu Province, Nantong, China
| | - Jiang Peng
- Institute of Orthopedics, General Hospital of People's Liberation Army, 28th Fuxing Road, Beijing, China.,Beijing Key Laboratory of Regenerative Medicine in Orthopedics, Beijing, China.,Key Laboratory of Musculoskeletal Trauma & War Injuries, People's Liberation Army, Beijing, China.,The Neural Regeneration Co-innovation Center of Jiangsu Province, Nantong, China
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Chintala SK. Tissue and urokinase plasminogen activators instigate the degeneration of retinal ganglion cells in a mouse model of glaucoma. Exp Eye Res 2015; 143:17-27. [PMID: 26474495 DOI: 10.1016/j.exer.2015.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2015] [Revised: 08/25/2015] [Accepted: 10/05/2015] [Indexed: 01/16/2023]
Abstract
Elevated intraocular pressure (IOP) promotes the degeneration of retinal ganglion cells (RGCs) during the progression of Primary Open-Angle Glaucoma (POAG). However, the molecular mechanisms underpinning IOP-mediated degeneration of RGCs remain unclear. Therefore, by employing a mouse model of POAG, this study examined whether elevated IOP promotes the degeneration of RGCs by up-regulating tissue plasminogen activator (tPA) and urokinase plasminogen activator (uPA) in the retina. IOP was elevated in mouse eyes by injecting fluorescent-microbeads into the anterior chamber. Once a week, for eight weeks, IOP in mouse eyes was measured by using Tono-Pen XL. At various time periods after injecting microbeads, proteolytic activity of tPA and uPA in retinal protein extracts was determined by fibrinogen/plasminogen zymography assays. Localization of tPA and uPA, and their receptor LRP-1 (low-density receptor-related protein-1) in the retina was determined by immunohistochemistry. RGCs' degeneration was assessed by immunostaining with antibodies against Brn3a. Injection of microbeads into the anterior chamber led to a progressive elevation in IOP, increased the proteolytic activity of tPA and uPA in the retina, activated plasminogen into plasmin, and promoted a significant degeneration of RGCs. Elevated IOP up-regulated tPA and LRP-1 in RGCs, and uPA in astrocytes. At four weeks after injecting microbeads, RAP (receptor associated protein; 0.5 and 1.0 μM) or tPA-Stop (1.0 and 4.0 μM) was injected into the vitreous humor. Treatment of IOP-elevated eyes with RAP led to a significant decrease in proteolytic activity of both tPA and uPA, and a significant decrease in IOP-mediated degeneration of RGCs. Also, treatment of IOP-elevated eyes with tPA-Stop decreased the proteolytic activity of both tPA and uPA, and, in turn, significantly attenuated IOP-mediated degeneration of RGCs. Results presented in this study provide evidence that elevated IOP promotes the degeneration of RGCs by up-regulating the levels of proteolytically active tPA and uPA.
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Affiliation(s)
- Shravan K Chintala
- Laboratory of Ophthalmic Neurobiology, Eye Research Institute of Oakland University, 2200 N. Squirrel Road, 409 DHE, Rochester MI 48309, USA.
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Chintala S, Cheng M, Zhang X. Decreased Expression of DREAM Promotes the Degeneration of Retinal Neurons. PLoS One 2015; 10:e0127776. [PMID: 26020793 PMCID: PMC4447264 DOI: 10.1371/journal.pone.0127776] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Accepted: 04/18/2015] [Indexed: 12/27/2022] Open
Abstract
The intrinsic mechanisms that promote the degeneration of retinal ganglion cells (RGCs) following the activation of N-Methyl-D-aspartic acid-type glutamate receptors (NMDARs) are unclear. In this study, we have investigated the role of downstream regulatory element antagonist modulator (DREAM) in NMDA-mediated degeneration of the retina. NMDA, phosphate-buffered saline (PBS), and MK801 were injected into the vitreous humor of C57BL/6 mice. At 12, 24, and 48 hours after injection, expression of DREAM in the retina was determined by immunohistochemistry, western blot analysis, and electrophoretic mobility-shift assay (EMSA). Apoptotic death of cells in the retina was determined by terminal deoxynucleotidyl transferace dUTP nick end labeling (TUNEL) assays. Degeneration of RGCs in cross sections and in whole mount retinas was determined by using antibodies against Tuj1 and Brn3a respectively. Degeneration of amacrine cells and bipolar cells was determined by using antibodies against calretinin and protein kinase C (PKC)-alpha respectively. DREAM was expressed constitutively in RGCs, amacrine cells, bipolar cells, as well as in the inner plexiform layer (IPL). NMDA promoted a progressive decrease in DREAM levels in all three cell types over time, and at 48 h after NMDA-treatment very low DREAM levels were evident in the IPL only. DREAM expression in retinal nuclear proteins was decreased progressively after NMDA-treatment, and correlated with its decreased binding to the c-fos-DRE oligonucleotides. A decrease in DREAM expression correlated significantly with apoptotic death of RGCs, amacrine cells and bipolar cells. Treatment of eyes with NMDA antagonist MK801, restored DREAM expression to almost normal levels in the retina, and significantly decreased NMDA-mediated apoptotic death of RGCs, amacrine cells, and bipolar cells. Results presented in this study show for the first time that down-regulation of DREAM promotes the degeneration of RGCs, amacrine cells, and bipolar cells.
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Affiliation(s)
- Shravan Chintala
- Laboratory of Ophthalmic Neurobiology, and Eye Research Institute of Oakland University, Rochester, Michigan, United States of America
- * E-mail:
| | - Mei Cheng
- Laboratory of Ophthalmic Neurobiology, and Eye Research Institute of Oakland University, Rochester, Michigan, United States of America
| | - Xiao Zhang
- Laboratory of Ophthalmic Neurobiology, and Eye Research Institute of Oakland University, Rochester, Michigan, United States of America
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