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Jiang J, Zhang L, Zou J, Liu J, Yang J, Jiang Q, Duan P, Jiang B. Phosphorylated S6K1 and 4E-BP1 play different roles in constitutively active Rheb-mediated retinal ganglion cell survival and axon regeneration after optic nerve injury. Neural Regen Res 2023; 18:2526-2534. [PMID: 37282486 PMCID: PMC10360084 DOI: 10.4103/1673-5374.371372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023] Open
Abstract
Ras homolog enriched in brain (Rheb) is a small GTPase that activates mammalian target of rapamycin complex 1 (mTORC1). Previous studies have shown that constitutively active Rheb can enhance the regeneration of sensory axons after spinal cord injury by activating downstream effectors of mTOR. S6K1 and 4E-BP1 are important downstream effectors of mTORC1. In this study, we investigated the role of Rheb/mTOR and its downstream effectors S6K1 and 4E-BP1 in the protection of retinal ganglion cells. We transfected an optic nerve crush mouse model with adeno-associated viral 2-mediated constitutively active Rheb and observed the effects on retinal ganglion cell survival and axon regeneration. We found that overexpression of constitutively active Rheb promoted survival of retinal ganglion cells in the acute (14 days) and chronic (21 and 42 days) stages of injury. We also found that either co-expression of the dominant-negative S6K1 mutant or the constitutively active 4E-BP1 mutant together with constitutively active Rheb markedly inhibited axon regeneration of retinal ganglion cells. This suggests that mTORC1-mediated S6K1 activation and 4E-BP1 inhibition were necessary components for constitutively active Rheb-induced axon regeneration. However, only S6K1 activation, but not 4E-BP1 knockdown, induced axon regeneration when applied alone. Furthermore, S6K1 activation promoted the survival of retinal ganglion cells at 14 days post-injury, whereas 4E-BP1 knockdown unexpectedly slightly decreased the survival of retinal ganglion cells at 14 days post-injury. Overexpression of constitutively active 4E-BP1 increased the survival of retinal ganglion cells at 14 days post-injury. Likewise, co-expressing constitutively active Rheb and constitutively active 4E-BP1 markedly increased the survival of retinal ganglion cells compared with overexpression of constitutively active Rheb alone at 14 days post-injury. These findings indicate that functional 4E-BP1 and S6K1 are neuroprotective and that 4E-BP1 may exert protective effects through a pathway at least partially independent of Rheb/mTOR. Together, our results show that constitutively active Rheb promotes the survival of retinal ganglion cells and axon regeneration through modulating S6K1 and 4E-BP1 activity. Phosphorylated S6K1 and 4E-BP1 promote axon regeneration but play an antagonistic role in the survival of retinal ganglion cells.
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Affiliation(s)
- Jikuan Jiang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Lusi Zhang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Jingling Zou
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Jingyuan Liu
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Jia Yang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Qian Jiang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Peiyun Duan
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
| | - Bing Jiang
- Department of Ophthalmology, Second Xiangya Hospital, Central South University; Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan Province, China
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2
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Siyanaki MRH, Azab MA, Lucke-Wold B. Traumatic Optic Neuropathy: Update on Management. ENCYCLOPEDIA 2023; 3:88-101. [PMID: 36718432 PMCID: PMC9884099 DOI: 10.3390/encyclopedia3010007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Traumatic optic neuropathy is one of the causes of visual loss caused by blunt or penetrating head trauma and is classified as both direct and indirect. Clinical history and examination findings usually allow for the diagnosis of traumatic optic neuropathy. There is still controversy surrounding the management of traumatic optic neuropathy; some physicians advocate observation alone, while others recommend steroid therapy, surgery, or both. In this entry, we tried to highlight traumatic optic neuropathy's main pathophysiologic mechanisms with the most available updated treatment. Recent research suggests future therapies that may be helpful in traumatic optic neuropathy cases.
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Affiliation(s)
| | - Mohammed A. Azab
- Department of Neurosurgery, University of Cairo University, Cairo 12613, Egypt
| | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32608, USA
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3
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Wang R, Liu Y, Xiao W, Yi Q, Jiang M, Guo R, Song L, Li M, Li F, Shi D, Zhao L, Huang W, Zuo X, Mao X. Framework Nucleic Acids as Blood-Retinal-Barrier-Penetrable Nanocarrier for Periocular Administration. ACS APPLIED MATERIALS & INTERFACES 2023; 15:541-551. [PMID: 36534594 DOI: 10.1021/acsami.2c18042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Designing an ocular drugs delivery system that can permeate the outer blood-retinal barrier (oBRB) is crucial for the microinvasive or noninvasive treatment of ocular fundus diseases. However, due to the lack of a nanocarrier that can maintain structure and composition at the oBRB, only intravitreal injection at the eyeball can deliver therapeutics directly to the ocular fundus via paracellular and intercellular routes, despite the intraocular operations risks. Here, we demonstrated tetrahedral framework nucleic acids (tFNAs) can penetrate the oBRB and deliver therapeutic nucleic acids to the retina of the rat eye in vivo following subconjunctival injection. We also discovered that tFNAs were transported via a paracellular route across the intercellular tight junctions at the oBRB. The histology analysis for ocular layers indicated that individual and aptamer/doxorubicin-loaded tFNAs penetrated all layers of the posterior segment of the eyeball to reach the innermost retina and persisted for over 3 days with minimal systemic biodistribution. We expect that the programmability and penetrability of tFNAs will provide a promising method for drug delivery across oBRB and long-term sustenance at the target site via periocular administration to various tissues.
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Affiliation(s)
- Ruobing Wang
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Yanhan Liu
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Wenjuan Xiao
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Qiuxue Yi
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Mengmeng Jiang
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Ruiyan Guo
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
- Key Laboratory of Bioanalysis and Metrology for State Market Regulation, Shanghai Institute of Measurement and Testing Technology, Shanghai 201203, China
| | - Lu Song
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Min Li
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Fan Li
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Danli Shi
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Lingyi Zhao
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Weiyi Huang
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Xiaolei Zuo
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
| | - Xiuhai Mao
- Institute of Molecular Medicine, Shanghai Key Laboratory for Nucleic Acid Chemistry and Nanomedicine and Department of Ophthalmology, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, China
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4
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Guo M, Zhu Y, Shi Y, Meng X, Dong X, Zhang H, Wang X, Du M, Yan H. Inhibition of ferroptosis promotes retina ganglion cell survival in experimental optic neuropathies. Redox Biol 2022; 58:102541. [PMID: 36413918 PMCID: PMC9679710 DOI: 10.1016/j.redox.2022.102541] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 10/04/2022] [Accepted: 11/12/2022] [Indexed: 11/16/2022] Open
Abstract
Retinal ganglion cell (RGC) death is a hallmark of traumatic optic neuropathy, glaucoma, and other optic neuropathies that result in irreversible vision loss. However, therapeutic strategies for rescuing RGC loss still remain challenging, and the molecular mechanism underlying RGC loss has not been fully elucidated. Here, we highlight the role of ferroptosis, a non-apoptotic form of programmed cell death characterized by iron-dependent lethal lipid peroxides accumulation, in RGC death using an experimental model of glaucoma and optic nerve crush (ONC). ONC treatment resulted in significant downregulation of glutathione peroxidase 4 (GPx4) and system xc(-) cystine/glutamate antiporter (xCT) in the rat retina, accompanied by increased lipid peroxide and iron levels. The reduction of GPx4 expression in RGCs after ONC was confirmed by laser-capture microdissection and PCR. Transmission electron microscopy (TEM) revealed alterations in mitochondrial morphology, including increased membrane density and reduced mitochondrial cristae in RGCs after ONC. Notably, the ferroptosis inhibitor ferrostatin-1 (Fer-1) significantly promoted RGC survival and preserved retinal function in ONC and microbead-induced glaucoma mouse models. In addition, compared to the apoptosis inhibitor Z-VAD-FMK, Fer-1 showed better effect in rescuing RGCs death in ONC retinas. Mechanistically, we found the downregulation of GPx4 mainly occurred in the mitochondrial compartment, accompanied by increased mitochondrial reactive oxygen species (ROS) and lipid peroxides. The mitochondria-selective antioxidant MitoTEMPO attenuated RGC loss after ONC, implicating mitochondrial ROS and lipid peroxides as major mechanisms in ferroptosis-induced RGC death in ONC retinas. Notably, administering Fer-1 effectively prevented the production of mitochondrial lipid peroxides, the impairment of mitochondrial adenosine 5'-triphosphate (ATP) production, and the downregulation of mitochondrial genes, such as mt-Cytb and MT-ATP6, in ONC retinas. Our findings suggest that ferroptosis is a major form of regulated cell death for RGCs in experimental glaucoma and ONC models and suggesting targeting mitochondria-dependent ferroptosis as a protective strategy for RGC injuries in optic neuropathies.
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Affiliation(s)
- Miao Guo
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China
| | - Yanfang Zhu
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China
| | - Ying Shi
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China,Department of Pharmacology and Tianjin Key Laboratory of Inflammation Biology, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of Basic Medical Sciences, Tianjin Medical University, 300070, Tianjin, China
| | - Xiangda Meng
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China
| | - Xue Dong
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China
| | - Haokun Zhang
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China
| | - Xiaohong Wang
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China,Department of Pharmacology and Tianjin Key Laboratory of Inflammation Biology, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of Basic Medical Sciences, Tianjin Medical University, 300070, Tianjin, China,Corresponding author. Tianjin Medical University, No. 22, Qixiangtai Road, Tianjin, 300070, China.
| | - Mei Du
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China,Department of Pharmacology and Tianjin Key Laboratory of Inflammation Biology, The Province and Ministry Co-sponsored Collaborative Innovation Center for Medical Epigenetics, School of Basic Medical Sciences, Tianjin Medical University, 300070, Tianjin, China,Corresponding author. Tianjin Medical University, No. 22, Qixiangtai Road, Tianjin, 300070, China.
| | - Hua Yan
- Department of Ophthalmology, Tianjin Medical University General Hospital, 300052, Tianjin, China,Laboratory of Molecular Ophthalmology and Tianjin Key Laboratory of Ocular Trauma, Tianjin Medical University, 300070, Tianjin, China,School of Medicine, Nankai University, 300071, Tianjin, China,Corresponding author. Tianjin Medical University General Hospital, No. 154, Anshan Road, Tianjin, 300052, China.
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5
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Traumatic optic neuropathy: a review of current studies. Neurosurg Rev 2022; 45:1895-1913. [PMID: 35034261 DOI: 10.1007/s10143-021-01717-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 10/26/2021] [Accepted: 12/09/2021] [Indexed: 10/24/2022]
Abstract
Traumatic optic neuropathy (TON) is a serious complication of craniofacial trauma that directly or indirectly damages the optic nerve and can cause severe vision loss. The incidence of TON has been gradually increasing in recent years. Research on the protection and regeneration of the optic nerve after the onset of TON is still at the level of laboratory studies and which is insufficient to support clinical treatment of TON. And, due to without clear guidelines, there is much ambiguity regarding its diagnosis and management. Clinical interventions for TON include observation only, treatment with corticosteroids alone, or optic canal (OC) decompression (with or without steroids). There is controversy in clinical practice concerning which treatment is the best. A review of available studies shows that the visual acuity of patients with TON can be significantly improved after OC decompression surgery (especially endoscopic transnasal/transseptal optic canal decompression (ETOCD)) with or without the use of corticosteroids. And new findings of laboratory studies such as mitochondrial therapy, lipid change studies, and other studies in favor of TON therapy have also been identified. In this review, we discuss the evolving perspective of surgical treatment and experimental study.
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6
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Jász DK, Szilágyi ÁL, Tuboly E, Baráth B, Márton AR, Varga P, Varga G, Érces D, Mohácsi Á, Szabó A, Bozó R, Gömöri K, Görbe A, Boros M, Hartmann P. Reduction in hypoxia-reoxygenation-induced myocardial mitochondrial damage with exogenous methane. J Cell Mol Med 2021; 25:5113-5123. [PMID: 33942485 PMCID: PMC8178286 DOI: 10.1111/jcmm.16498] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/23/2021] [Accepted: 03/05/2021] [Indexed: 12/15/2022] Open
Abstract
Albeit previous experiments suggest potential anti‐inflammatory effect of exogenous methane (CH4) in various organs, the mechanism of its bioactivity is not entirely understood. We aimed to investigate the potential mitochondrial effects and the underlying mechanisms of CH4 in rat cardiomyocytes and mitochondria under simulated ischaemia/reperfusion (sI/R) conditions. Three‐day‐old cultured cardiomyocytes were treated with 2.2% CH4‐artificial air mixture during 2‐hour‐long reoxygenation following 4‐hour‐long anoxia (sI/R and sI/R + CH4, n = 6‐6), with normoxic groups serving as controls (SH and SH + CH4; n = 6‐6). Mitochondrial functions were investigated with high‐resolution respirometry, and mitochondrial membrane injury was detected by cytochrome c release and apoptotic characteristics by using TUNEL staining. CH4 admixture had no effect on complex II (CII)‐linked respiration under normoxia but significantly decreased the complex I (CI)‐linked oxygen consumption. Nevertheless, addition of CH4 in the sI/R + CH4 group significantly reduced the respiratory activity of CII in contrast to CI and the CH4 treatment diminished mitochondrial H2O2 production. Substrate‐induced changes to membrane potential were partially preserved by CH4, and additionally, cytochrome c release and apoptosis of cardiomyocytes were reduced in the CH4‐treated group. In conclusion, the addition of CH4 decreases mitochondrial ROS generation via blockade of electron transport at CI and reduces anoxia‐reoxygenation‐induced mitochondrial dysfunction and cardiomyocyte injury in vitro.
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Affiliation(s)
| | | | - Eszter Tuboly
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Bálint Baráth
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | | | - Petra Varga
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Gabriella Varga
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Dániel Érces
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Árpád Mohácsi
- MTA-SZTE Research Group on Photoacoustic Spectroscopy, University of Szeged, Szeged, Hungary
| | - Anna Szabó
- MTA-SZTE Research Group on Photoacoustic Spectroscopy, University of Szeged, Szeged, Hungary
| | - Renáta Bozó
- Department of Dermatology and Allergology, University of Szeged, Szeged, Hungary
| | - Kamilla Gömöri
- Department of Biochemistry, University of Szeged, Szeged, Hungary
| | - Anikó Görbe
- Department of Biochemistry, University of Szeged, Szeged, Hungary
| | - Mihály Boros
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Petra Hartmann
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
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7
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Niu J, Zhao W, Lu DQ, Xie JJ, He XS, Fang HH, Liao SY. Dual-Function Analysis of Astaxanthin on Golden Pompano ( Trachinotus ovatus) and Its Role in the Regulation of Gastrointestinal Immunity and Retinal Mitochondrial Dysfunction Under Hypoxia Conditions. Front Physiol 2020; 11:568462. [PMID: 33335485 PMCID: PMC7736049 DOI: 10.3389/fphys.2020.568462] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Accepted: 10/22/2020] [Indexed: 11/17/2022] Open
Abstract
The present study investigated the potential mechanisms of astaxanthin in the regulation of gastrointestinal immunity and retinal mitochondrial function of golden pompano (Trachinotus ovatus). Triplicate groups of juvenile T. ovatus (mean initial weight: 6.03 ± 0.01 g) were fed one of six diets (D1, D2, D3, D4, D5, and D6) for 8 weeks, with each diet containing various concentrations of astaxanthin (0, 0.0005, 0.001, 0.005, 0.01, or 0.1%, respectively). Growth performance of fish fed the D2–D5 diets was higher than that of fish fed the D1 diet; however, growth performance and survival of fish deteriorated sharply in fish fed the D6 diet. Gut villus in fish fed the D2–D5 diets were significantly longer and wider than that of fish fed the D6 diet. Feeding with D2–D5 diets led to increased abundance of Bacillus, Pseudomonas, Oceanobacillus, Lactococcus, Halomonas, Lactobacillus, and Psychrobacter while abundance of Vibrio and Bacterium decreased. Additionally, feeding with the D6 diet resulted in a sharp decline in Pseudomonas and Lactobacillus abundance and a sharp increase in Vibrio abundance. A low dissolved oxygen environment (DO, 1.08 mg/L) was conducted for 10 h after the rearing trial. No fish mortality was observed for any of the diet treatments. Lysozyme (LZY) activity in fish fed the D6 diet decreased sharply and was significantly lower than that in other groups. ROS production also decreased sharply in fish fed the D6 diet. Moreover, the conjunctiva and sclera in the fish fed the D6 diet were indistinguishable. Suitable dietary astaxanthin supplementation levels (0.005–0.1%) exerting a neuroprotective effect from low dissolved oxygen environments is due to up-regulated expression of anti-apoptotic factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3β (pGSK-3β), Bcl-2 extra large (Bcl-xL), and down-regulated expression of Bcl-2-associated X protein (Bax) pro-apoptotic factor in retinas. Furthermore, suitable dietary astaxanthin levels (0.0005–0.01%) suppressed up-regulation of critical mitochondrial components, such as peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), mitochondrial transcription factor A (TFAM), and mitochondrial DNA (mtDNA), while excessive astaxanthin supplementation produces the opposite effect. In brief, high-dose astaxanthin arouses and aggravates low dissolved oxygen-induced inflammation, oxidative stress, intestinal disorder, retinal apoptosis, and retinal mitochondrial dysfunction in T. ovatus. Second-degree polynomial regression of WG indicated that the optimum dietary astaxanthin for juvenile T. ovatus is 0.049%.
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Affiliation(s)
- Jin Niu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animal and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Wei Zhao
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animal and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Dan-Qi Lu
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animal and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Jia-Jun Xie
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animal and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Xuan-Shu He
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animal and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Hao-Hang Fang
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animal and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shi-Yu Liao
- State Key Laboratory of Biocontrol, Institute of Aquatic Economic Animal and Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
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8
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Huang W, Lan Q, Jiang L, Yan W, Tang F, Shen C, Huang H, Zhong H, Lv J, Zeng S, Li M, Mo Z, Hu B, Liang N, Chen Q, Zhang M, Xu F, Cui L. Fasudil attenuates glial cell-mediated neuroinflammation via ERK1/2 and AKT signaling pathways after optic nerve crush. Mol Biol Rep 2020; 47:8963-8973. [PMID: 33161529 DOI: 10.1007/s11033-020-05953-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 10/28/2020] [Indexed: 11/28/2022]
Abstract
To investigate the functional role of fasudil in optic nerve crush (ONC), and further explore its possible molecular mechanism. After ONC injury, the rats were injected intraperitoneally either with fasudil or normal saline once a day until euthanized. RGCs survival was assessed by retrograde labeling with FluoroGold. Retinal glial cells activation and population changes (GFAP, iba-1) were measured by immunofluorescence. The expressions of cleaved caspase 3 and 9, p-ERK1/2 and p-AKT were detected by western blot. The levels of the pro-inflammatory cytokines were determined using real-time polymerase chain reaction. Fasudil treatment inhibited RGCs apoptosis and reduced RGCs loss demonstrated by the decreased apoptosis-associated proteins expression and the increased fluorogold labeling of RGCs after ONC, respectively. In addition, the ONC + fasudil group compared had a significantly lower expression of GFAP and iba1 compared with the ONC group. The levels of pro-inflammatory cytokines were significantly reduced in the ONC + fasudil group than in the ONC group. Furthermore, the phosphorylation levels of ERK1/2 and AKT (p-ERK1/2 and p-AKT) were obviously elevated by the fasudil treatment. Our study demonstrated that fasudil attenuated glial cell-mediated neuroinflammation by up-regulating the ERK1/2 and AKT signaling pathways in rats ONC models. We conclude that fasudil may be a novel treatment for traumatic optic neuropathy.
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Affiliation(s)
- Wei Huang
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China.,Guangxi Medical University, Nanning, 530021, China
| | - Qianqian Lan
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Li Jiang
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Wenya Yan
- Guangzhou Medical University, Guangzhou, 511436, China
| | - Fen Tang
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Chaolan Shen
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Hui Huang
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Haibin Zhong
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Jian Lv
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Siming Zeng
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Min Li
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Zhongxiang Mo
- Laboratory Animal Center, Guangxi Medical University, Nanning, 530021, China
| | - Bing Hu
- Laboratory Animal Center, Guangxi Medical University, Nanning, 530021, China
| | - Ning Liang
- Laboratory Animal Center, Guangxi Medical University, Nanning, 530021, China
| | - Qi Chen
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China
| | - Mingyuan Zhang
- Laboratory Animal Center, Guangxi Medical University, Nanning, 530021, China
| | - Fan Xu
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China.
| | - Ling Cui
- Department of Ophthalmology, People's Hospital of Guangxi Zhuang Autonomous Region, Nanning, 530021, Guangxi, China.
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Poles MZ, Juhász L, Boros M. Methane and Inflammation - A Review (Fight Fire with Fire). Intensive Care Med Exp 2019; 7:68. [PMID: 31807906 PMCID: PMC6895343 DOI: 10.1186/s40635-019-0278-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 10/24/2019] [Indexed: 12/23/2022] Open
Abstract
Mammalian methanogenesis is regarded as an indicator of carbohydrate fermentation by anaerobic gastrointestinal flora. Once generated by microbes or released by a non-bacterial process, methane is generally considered to be biologically inactive. However, recent studies have provided evidence for methane bioactivity in various in vivo settings. The administration of methane either in gas form or solutions has been shown to have anti-inflammatory and neuroprotective effects in an array of experimental conditions, such as ischemia/reperfusion, endotoxemia and sepsis. It has also been demonstrated that exogenous methane influences the key regulatory mechanisms and cellular signalling pathways involved in oxidative and nitrosative stress responses. This review offers an insight into the latest findings on the multi-faceted organ protective activity of exogenous methane treatments with special emphasis on its versatile effects demonstrated in sepsis models.
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Affiliation(s)
- Marietta Zita Poles
- Institute of Surgical Research, University of Szeged, Pulz u. 1., Szeged, H-6724, Hungary
| | - László Juhász
- Institute of Surgical Research, University of Szeged, Pulz u. 1., Szeged, H-6724, Hungary
| | - Mihály Boros
- Institute of Surgical Research, University of Szeged, Pulz u. 1., Szeged, H-6724, Hungary.
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10
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Quan Y, Wu Y, Zhan Z, Yang Y, Chen X, Wu K, Yu M. Inhibition of the leucine-rich repeat protein lingo-1 enhances RGC survival in optic nerve injury. Exp Ther Med 2019; 19:619-629. [PMID: 31885701 PMCID: PMC6913235 DOI: 10.3892/etm.2019.8250] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Accepted: 03/26/2019] [Indexed: 01/02/2023] Open
Abstract
Leucine-rich repeat and immunoglobulin-like domain-containing nogo receptor-interacting protein 1 (lingo-1) is selectively expressed on neurons and oligodendrocytes in the central nervous system and acts as a negative regulator in neural repair, implying a potential role in optic neuropathy. The aim of the present study was to determine whether adeno-associated virus serotype 2 (AAV2) vector-mediated transfer of lingo-1 short hairpin RNA could reduce nerve crush-induced axonal degeneration and enhance axonal regeneration following optic nerve (ON) injury in vivo. The expression of lingo-1 was knocked down in vivo using a green fluorescent protein (GFP)-tagged AAV2 encoding lingo-1 shRNA via intravitreal injection in adult Sprague-Dawley rats. Silencing effects of AAV2-lingo-1-shRNA were confirmed by detecting GFP labelling of RGCs, and by quantifying lingo-1 expression levels with reverse transcription-quantitative polymerase chain reaction and western blotting. Rats received an intravitreal injection of AAV2-lingo-1-shRNA or negative control shRNA. The ON crush (ONC) injury was performed 2 weeks after the intravitreal injection. RGC density, lesion volume of the injured ON and the visual electrophysiology [flash visual evoked potential (F-VEP)] at different time points post-injury were determined. Transduction with lingo-1-shRNA decreased lingo-1 expression levels and promoted RGC survival following ONC. Lingo-1-shRNA promoted ON tissue repair and functional recovery. The mechanism underlying the effect of AAV2-lingo-1-shRNA on RGCs may be the phosphorylation of protein kinase B (Akt) at Ser473 and activation of the Akt signaling pathway acting downstream of lingo-1. The results of the current study indicate that the inhibition of lingo-1 may enhance RGC survival and facilitate functional recovery following ON injury, representing a promising potential strategy for the repair of optic neuropathy.
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Affiliation(s)
- Yadan Quan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yali Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Zongyi Zhan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Yangfan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Xiaotao Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Kaili Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong 510060, P.R. China
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11
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Boros M, Keppler F. Methane Production and Bioactivity-A Link to Oxido-Reductive Stress. Front Physiol 2019; 10:1244. [PMID: 31611816 PMCID: PMC6776796 DOI: 10.3389/fphys.2019.01244] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Accepted: 09/10/2019] [Indexed: 12/15/2022] Open
Abstract
Biological methane formation is associated with anoxic environments and the activity of anaerobic prokaryotes (Archaea). However, recent studies have confirmed methane release from eukaryotes, including plants, fungi, and animals, even in the absence of microbes and in the presence of oxygen. Furthermore, it was found that aerobic methane emission in plants is stimulated by a variety of environmental stress factors, leading to reactive oxygen species (ROS) generation. Further research presented evidence that molecules with sulfur and nitrogen bonded methyl groups such as methionine or choline are carbon precursors of aerobic methane formation. Once generated, methane is widely considered to be physiologically inert in eukaryotes, but several studies have found association between mammalian methanogenesis and gastrointestinal (GI) motility changes. In addition, a number of recent reports demonstrated anti-inflammatory potential for exogenous methane-based approaches in model anoxia-reoxygenation experiments. It has also been convincingly demonstrated that methane can influence the downstream effectors of transiently increased ROS levels, including mitochondria-related pro-apoptotic pathways during ischemia-reperfusion (IR) conditions. Besides, exogenous methane can modify the outcome of gasotransmitter-mediated events in plants, and it appears that similar mechanism might be active in mammals as well. This review summarizes the relevant literature on methane-producing processes in eukaryotes, and the available results that underscore its bioactivity. The current evidences suggest that methane liberation and biological effectiveness are both linked to cellular redox regulation. The data collectively imply that exogenous methane influences the regulatory mechanisms and signaling pathways involved in oxidative and nitrosative stress responses, which suggests a modulator role for methane in hypoxia-linked pathologies.
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Affiliation(s)
- Mihály Boros
- Institute of Surgical Research, Interdisciplinary Centre of Excellence, University of Szeged, Szeged, Hungary
| | - Frank Keppler
- Institute of Earth Sciences, Heidelberg University, Heidelberg, Germany
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12
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Ali SA, Zaitone SA, Dessouki AA, Ali AA. Pregabalin affords retinal neuroprotection in diabetic rats: Suppression of retinal glutamate, microglia cell expression and apoptotic cell death. Exp Eye Res 2019; 184:78-90. [PMID: 31002823 DOI: 10.1016/j.exer.2019.04.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 02/25/2019] [Accepted: 04/15/2019] [Indexed: 01/22/2023]
Abstract
Pregabalin is the first drug to receive FDA approval for treating diabetic neuropathic pain. This study investigated the neuroprotective effect of pregabalin in an experimental model of diabetic retinopathy and tested some possible mechanisms underlying the putative neuroprotective effect. Male Wistar rats received streptozotocin (45 mg/kg) to induce type 1 diabetes mellitus. After two weeks, a course of pregabalin (3, 10 and 30 mg/kg) has been launched for five consecutive weeks. Retinal expression of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) was estimated by real-time PCR and retinal glutamate content was also estimated. Further, retinal caspase-3 immunoblotting and DNA fragmentation assays determined the degree of apoptosis. Pregabalin improved histopathological abnormalities in diabetic retinas and suppressed the diabetes-enhanced retinal expression of IL-1β, TNF-α, CD11b (a surface marker for microglia) while attenuated expression of caspase-3 and DNA fragmentation versus the diabetic group. In addition, diabetic rats treated with pregabalin displayed reductions in retinal glutamate, nitric oxide and malondialdehyde (MDA) and enhanced reduced glutathione (GSH) content versus the diabetic controls. Furthermore, pregabalin enhanced the histopathological picture and reduced fibrosis in the optic nerve of diabetic rats in addition to suppression of the content of the glia fibrillary acidic protein. The findings provide the first evidence demonstrating that pregabalin alleviates retinal neuroinflammation, apoptosis and oxidative stress in an experimental type 1 diabetes mellitus. Therefore, pregabalin might serve as a potential therapy for retinopathy after adequate clinical research.
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Affiliation(s)
| | - Sawsan A Zaitone
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Suez Canal University, Ismailia, 41522, Egypt; Department of Pharmacology and Toxicology, Faculty of Pharmacy, University of Tabuk, Tabuk, Saudi Arabia.
| | - Amina A Dessouki
- Department of Pathology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia, Egypt
| | - Azaa A Ali
- Department of Pharmacology and Toxicology, Faculty of Pharmacy (girls), Al-Azhar University, Cairo, Egypt
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13
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Toms M, Burgoyne T, Tracey-White D, Richardson R, Dubis AM, Webster AR, Futter C, Moosajee M. Phagosomal and mitochondrial alterations in RPE may contribute to KCNJ13 retinopathy. Sci Rep 2019; 9:3793. [PMID: 30846767 PMCID: PMC6405871 DOI: 10.1038/s41598-019-40507-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 02/18/2019] [Indexed: 12/29/2022] Open
Abstract
Mutations in KCNJ13 are associated with two retinal disorders; Leber congenital amaurosis (LCA) and snowflake vitreoretinal degeneration (SVD). We examined the retina of kcnj13 mutant zebrafish (obelixtd15, c.502T > C p.[Phe168Leu]) to provide new insights into the pathophysiology underlying these conditions. Detailed phenotyping of obelixtd15 fish revealed a late onset retinal degeneration at 12 months. Electron microscopy of the obelixtd15 retinal pigment epithelium (RPE) uncovered reduced phagosome clearance and increased mitochondrial number and size prior any signs of retinal degeneration. Melanosome distribution was also affected in dark-adapted 12-month obelixtd15 fish. At 6 and 12 months, ATP levels were found to be reduced along with increased expression of glial fibrillary acidic protein and heat shock protein 60. Quantitative RT-PCR of polg2, fis1, opa1, sod1/2 and bcl2a from isolated retina showed expression changes consistent with altered mitochondrial activity and retinal stress. We propose that the retinal disease in this model is primarily a failure of phagosome physiology with a secondary mitochondrial dysfunction. Our findings suggest that alterations in the RPE and photoreceptor cellular organelles may contribute to KCNJ13-related retinal degeneration and provide a therapeutic target.
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Affiliation(s)
- Maria Toms
- UCL Institute of Ophthalmology, London, UK
| | | | | | | | - Adam M Dubis
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Andrew R Webster
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | | | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, UK. .,Moorfields Eye Hospital NHS Foundation Trust, London, UK. .,Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
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14
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Yao F, Zhang E, Gao Z, Ji H, Marmouri M, Xia X. Did you choose appropriate tracer for retrograde tracing of retinal ganglion cells? The differences between cholera toxin subunit B and Fluorogold. PLoS One 2018; 13:e0205133. [PMID: 30289890 PMCID: PMC6173421 DOI: 10.1371/journal.pone.0205133] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 09/19/2018] [Indexed: 12/31/2022] Open
Abstract
Cholera toxin subunit B (CTB) and Fluorogold(FG) are two widely utilized retrograde tracers to assess the number and function of retinal ganglion cells (RGCs). However, the relative advantages and disadvantages of these tracers remain unclear, which may lead to their inappropriate application. In this study, we compared these tracers by separately injecting the tracer into the superior Colliculi (SC) in rats, one or 2 weeks later, the rats were sacrificed, and their retinas, brains, and optic nerves were collected. From the first to second week, FG displayed a greater number of labeled RGCs and a larger diffusion area in the SC than CTB; The number of CTB labeled RGCs and the diffusion area of CTB in the SC increased significantly, but there was no distinction between FG; Furthermore, CTB exhibited more labeled RGC neurites and longer neurites than FG, but no difference was evident between the same trace; The optic nerves labeled using CTB were much clearer than those labeled using FG. In conclusion, both CTB and FG can be used for the retrograde labeling of RGCs in rats at 1 or 2 weeks. FG achieves retrograde labeling of a greater number of RGCs than CTB, whereas CTB better delineates the morphology of RGCs. Furthermore, CTB seems more suitable for retrograde labeling of some small, non-image forming nuclei in the brain to which certain RGC subtypes project their axons.
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Affiliation(s)
- Fei Yao
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Endong Zhang
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Zhaolin Gao
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hongpei Ji
- Department of Ophthalmology, The People’s Hospital of Guizhou Province, Guiyang, Guizhou, China
| | - Mahmoud Marmouri
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Xiaobo Xia
- Department of Ophthalmology, Xiangya Hospital, Central South University, Changsha, Hunan, China
- * E-mail:
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15
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Zaninello M, Scorrano L. Rapidly purified ganglion cells from neonatal mouse retinas allow studies of mitochondrial morphology and autophagy. Pharmacol Res 2018; 138:16-24. [PMID: 30077733 DOI: 10.1016/j.phrs.2018.07.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 07/27/2018] [Accepted: 07/29/2018] [Indexed: 01/09/2023]
Abstract
Retinal explants and mixed primary cultures are currently used to investigate retinal ganglion cells (RGCs) pathophysiology and pharmacology, but information on yield, quality and quantity of contaminant cells for the available RGCs enrichment techniques is lacking. Here we compare two methods of mouse primary RGCs purification and show that mitochondrial and autophagy parameters can be measured in rapidly purified RGCs. RGCs were purified from P0 mouse eyes using two methods based on the surface antigen Thy1. In a two-step immunopanning purification, a subtraction plate bound macrophage antiserum removed contaminant macrophages and endothelial cells; unbound RGCs were then affinity selected using a plate-bound antiThy1 antibody. In an immunopanning-magnetic separation, macrophage-antiserum bound cells were first subtracted and then RGCs were positively selected using an antiThy1 antibody bound to a magnetic column. The two-steps immunopanning yielded low amounts of 90% pure RGCs, whereas RGCs represented 30% of the 6-fold more cells collected by immunopanning-magnetic separation. RGCs purified with both methods could be microelectroporated to image expressed mitochondria and autophagosomes fluorescent probes and to show that expression of pathogenic Optic atrophy 1 mutants causes mitochondrial fragmentation. Thus, these two methods purify primary mouse RGCs amenable to studies of cell morphology, mitochondrial biology and autophagy.
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Affiliation(s)
- Marta Zaninello
- Venetian Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; Department of Biology, University of Padova, Via U. Bassi 58B, 35121 Padova, Italy
| | - Luca Scorrano
- Venetian Institute of Molecular Medicine, Via Orus 2, 35129 Padova, Italy; Department of Biology, University of Padova, Via U. Bassi 58B, 35121 Padova, Italy.
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16
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Inhibition of miR-21 ameliorates excessive astrocyte activation and promotes axon regeneration following optic nerve crush. Neuropharmacology 2018; 137:33-49. [PMID: 29709341 DOI: 10.1016/j.neuropharm.2018.04.028] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/18/2018] [Accepted: 04/26/2018] [Indexed: 12/15/2022]
Abstract
Optic nerve injury is a leading cause of irreversible visual impairment worldwide and can even cause blindness. Excessive activation of astrocytes has negative effects on the repair and recovery of retinal ganglion cells following optic nerve injury. However, the molecular and cellular mechanisms underlying astrocyte activation after optic nerve injury remain largely unknown. In the present study, we explored the effects of microRNA-21 (miR-21) on axon regeneration and flash visual evoked potential (F-VEP) and the underlying mechanisms of these effects based on astrocyte activation in the rat model of optic nerve crush (ONC). To the best of our knowledge, this article is the first to report that inhibition of miR-21 enhances axonal regeneration and promotes functional recovery in F-VEP in the rat model of ONC. Furthermore, inhibition of miR-21 attenuates excessive astrocyte activation and glial scar formation, thereby promoting axonal regeneration by regulating the epidermal growth factor receptor (EGFR) pathway. In addition, we observed that the expression of tissue inhibitor of metalloproteinase-3, a target gene of miR-21, was inhibited during this process. Taken together, these findings demonstrate that inhibition of miR-21 regulates the EGFR pathway, ameliorating excessive astrocyte activation and glial scar progression and promoting axonal regeneration and alleviating impairment in F-VEP function in a model of ONC. This study's results suggest that miR-21 may represent a therapeutic target for optic nerve injury.
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17
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Mészáros AT, Szilágyi ÁL, Juhász L, Tuboly E, Érces D, Varga G, Hartmann P. Mitochondria As Sources and Targets of Methane. Front Med (Lausanne) 2017; 4:195. [PMID: 29181377 PMCID: PMC5693848 DOI: 10.3389/fmed.2017.00195] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/25/2017] [Indexed: 12/14/2022] Open
Abstract
This review summarizes the current knowledge on the role of mitochondria in the context of hypoxic cell biology, while providing evidence of how these mechanisms are modulated by methane (CH4). Recent studies have unambiguously confirmed CH4 bioactivity in various in vitro and in vivo experimental models and established the possibility that CH4 can affect many aspects of mitochondrial physiology. To date, no specific binding of CH4 to any enzymes or receptors have been reported, and it is probable that many of its effects are related to physico-chemical properties of the non-polar molecule. (i) Mitochondria themselves can be sources of endogenous CH4 generation under oxido-reductive stress conditions; chemical inhibition of the mitochondrial electron transport chain with site-specific inhibitors leads to increased formation of CH4 in eukaryote cells, in plants, and in animals. (ii) Conventionally believed as physiologically inert, studies cited in this review demonstrate that exogenous CH4 modulates key events of inflammation. The anti-apoptotic effects of exogenously administered CH4 are also recognized, and these properties also suggest that CH4-mediated intracellular signaling is closely associated with mitochondria. (iii) Mitochondrial substrate oxidation is coupled with the reduction of molecular oxygen, thus providing energy for cellular metabolism. Interestingly, recent in vivo studies have shown improved basal respiration and modulated mitochondrial oxidative phosphorylation by exogenous CH4. Overall, these data suggest that CH4 liberation and effectiveness in eukaryotes are both linked to hypoxic events and redox regulation and support the notion that CH4 has therapeutic roles in mammalian pathophysiologies.
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Affiliation(s)
| | | | - László Juhász
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Eszter Tuboly
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Dániel Érces
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Gabriella Varga
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
| | - Petra Hartmann
- Institute of Surgical Research, University of Szeged, Szeged, Hungary
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