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Shakya M, Holland A, Klein AR, Rees GN, Laird J, McCallum JC, Ryan CG, Silvester E. Biomolecular modifications in the sacfry of Mogurnda adspersa in response to copper stress. AQUATIC TOXICOLOGY (AMSTERDAM, NETHERLANDS) 2022; 248:106179. [PMID: 35576718 DOI: 10.1016/j.aquatox.2022.106179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 03/29/2022] [Accepted: 04/22/2022] [Indexed: 06/15/2023]
Abstract
Copper (Cu) is one of the most harmful contaminants in fresh-water systems. Fish larvae such as sacfry are particularly vulnerable to metals such as copper (Cu) due to a less-developed excretory organ system and permeable skin that can absorb metals directly from the water. However, the sublethal effects of metals on this life stage are not well understood. This study assessed the sublethal toxicity of Cu on purple-spotted gudgeon sacfry (PSG, Mogurnda adspersa). For this purpose, 96 h Cu toxicity bioassays were performed and toxic effects of Cu on PSG were measured at different levels of biological organization, from the individual (loss of equilibrium, wet weight), to tissue (chemical changes in retinal tissue composition) and molecular responses (whole body amino acid (AA) profiles). The EC10 and EC50 (ECx: effect concentration that affected X% of test organisms) were found to be 12 (9 - 15) µg Cu L-1 and 22 (19 - 24) µg Cu L-1, respectively. Copper stress caused a decrease in total amino acid content and changed the AA profile of PSG compared to the controls. Proton-induced X-ray emission (PIXE) mapping techniques showed accumulation of Cu in the retinal tissues disturbing the distribution of other elements such as zinc, sulfur, phosphorus and potassium. Fourier-transform infrared (FTIR) microspectroscopy of control and Cu treated eye tissues revealed a change in protein secondary structure in retinal tissues in response to Cu accumulation, as well as decreased levels of the molecular retinal, consistent with the degradation of rhodopsin, a key protein in the visual sensory system. This is the first study to demonstrate the multi-level responses of PSG arising from exposure to environmentally realistic Cu concentrations and suggests that AA profiling can serve as a useful tool to assess the impacts of metals on fresh-water organisms.
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Affiliation(s)
- Manisha Shakya
- Centre for Freshwater Ecosystems, Department of Ecology, Environment and Evolution (DEEE), La Trobe University, Albury/Wodonga Campus, VIC, 3690, Australia.
| | - Aleicia Holland
- Centre for Freshwater Ecosystems, Department of Ecology, Environment and Evolution (DEEE), La Trobe University, Albury/Wodonga Campus, VIC, 3690, Australia
| | - Annaleise R Klein
- Infrared Microspectroscopy (IRM) Beamline, ANSTO - Australian Synchrotron, 800 Blackburn Road, Clayton, VIC, 3168, Australia
| | - Gavin N Rees
- CSIRO Land and Water, and Institute for Land, Water and Society, Charles Sturt University, PO Box 789, Albury, NSW, 2640, Australia
| | - Jamie Laird
- School of Chemistry, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Jeffrey C McCallum
- School of Physics, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Chris G Ryan
- Commonwealth Scientific and Industrial Research Organisation, Normanby Road, Clayton, VIC, Australia
| | - Ewen Silvester
- Centre for Freshwater Ecosystems, Department of Ecology, Environment and Evolution (DEEE), La Trobe University, Albury/Wodonga Campus, VIC, 3690, Australia
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He Z, Zhao D, van Koeverden AK, Nguyen CT, Lim JKH, Wong VHY, Vingrys AJ, Bui BV. A Model of Glaucoma Induced by Circumlimbal Suture in Rats and Mice. J Vis Exp 2018. [PMID: 30346390 DOI: 10.3791/58287] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The circumlimbal suture is a technique for inducing experimental glaucoma in rodents by chronically elevating intraocular pressure (IOP), a well-known risk factor for glaucoma. This protocol demonstrates a step-by-step guide on this technique in Long Evans rats and C57BL/6 mice. Under general anesthesia, a "purse-string" suture is applied on the conjunctiva, around the equator and behind the limbus of the eye. The fellow eye serves as an untreated control. Over the duration of our study, which was a period of 8 weeks for rats and 12 weeks for mice, IOP remained elevated, as measured regularly by rebound tonometry in conscious animals without topical anesthesia. In both species, the sutured eyes showed electroretinogram features consistent with preferential inner retinal dysfunction. Optical coherence tomography showed selective thinning of the retinal nerve fiber layer. Histology of the rat retina in cross-section found reduced cell density in the ganglion cell layer, but no change in other cellular layers. Staining of flat-mounted mouse retinae with a ganglion cell specific marker (RBPMS) confirmed ganglion cell loss. The circumlimbal suture is a simple, minimally invasive and cost-effective way to induce ocular hypertension that leads to ganglion cell injury in both rats and mice.
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Affiliation(s)
- Zheng He
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Da Zhao
- Department of Optometry and Vision Sciences, University of Melbourne
| | | | | | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Algis J Vingrys
- Department of Optometry and Vision Sciences, University of Melbourne
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne;
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Aboualizadeh E, Hirschmugl CJ. Highlighting IR Spectrochemical Imaging of the Retina. Trends Biochem Sci 2018; 43:650-653. [PMID: 29729937 DOI: 10.1016/j.tibs.2018.04.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 04/05/2018] [Accepted: 04/08/2018] [Indexed: 12/16/2022]
Abstract
An emerging application of mid-IR spectrochemical imaging of the retina is its utility in studying the highly localized biomolecular alterations in the chemistry of retinal cell layers associated with several pathological conditions. Spatially resolved IR images highlight simultaneous chemical composition of the entire span of the retina in a label-free manner.
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Affiliation(s)
| | - Carol J Hirschmugl
- Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI, USA; McPherson Eye Research Institute, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
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Liu HH, Zhang L, Shi M, Chen L, Flanagan JG. Comparison of laser and circumlimbal suture induced elevation of intraocular pressure in albino CD-1 mice. PLoS One 2017; 12:e0189094. [PMID: 29190824 PMCID: PMC5708743 DOI: 10.1371/journal.pone.0189094] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/18/2017] [Indexed: 12/23/2022] Open
Abstract
Animal models of ocular hypertension are important tools for glaucoma studies. Both acute transient models and chronic models of ocular hypertension may be useful to investigate specific aspects of neurodegeneration. In this study, we compare the intraocular pressure (IOP) and inner retinal changes induced by 1) laser photocoagulation of both episcleral veins and limbal vessels and 2) circumlimbal suture in CD-1 mice. The suture group is divided into 3 subgroups depending on the level of the immediate IOP spike (acute > 55 mmHg or chronic < 55 mmHg) and time period of monitoring (7 or 28 days). The laser group is followed for 7 days. IOP data show that it peaks at 5 hours and returns to normal level within 7 days in the laser group. In all suture groups, IOP spikes initially and decreases gradually, but it remains significantly elevated at 7 days. In 7 days, the acute suture model generates rapid loss of retinal nerve fiber layer (RNFL) and retinal ganglion cells (RGCs) when compared to the gradual loss by the chronic suture model, possibly due to retinal ischemia and reperfusion within the first few hours after treatment. The laser model falls between the acute suture and chronic suture models resulting in less RNFL and RGC loss than the acute suture model but significantly more loss than the chronic suture model. These results suggest that when using suture models of IOP elevation, it is critical to take the initial IOP spike into consideration and to choose between the acute and chronic models depending on respective research purposes.
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Affiliation(s)
- Hsin-Hua Liu
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
- * E-mail:
| | - Liwei Zhang
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - Meng Shi
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - Lu Chen
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
| | - John G. Flanagan
- School of Optometry and Vision Science, University of California, Berkeley, California, United States of America
- Center for Eye Disease and Development, Vision Science Graduate Program, University of California, Berkeley, California, United States of America
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Wang S, Hu T, Wang Z, Li N, Zhou L, Liao L, Wang M, Liao L, Wang H, Zeng L, Fan C, Zhou H, Xiong K, Huang J, Chen D. Macroglia-derived thrombospondin 2 regulates alterations of presynaptic proteins of retinal neurons following elevated hydrostatic pressure. PLoS One 2017; 12:e0185388. [PMID: 28953973 PMCID: PMC5617560 DOI: 10.1371/journal.pone.0185388] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 09/12/2017] [Indexed: 02/03/2023] Open
Abstract
Many studies on retinal injury and repair following elevated intraocular pressure suggest that the survival ratio of retinal neurons has been improved by various measures. However, the visual function recovery is far lower than expected. The homeostasis of retinal synapses in the visual signal pathway is the key structural basis for the delivery of visual signals. Our previous studies found that complicated changes in the synaptic structure between retinal neurons occurred much earlier than obvious degeneration of retinal ganglion cells in rat retinae. The lack of consideration of these earlier retinal synaptic changes in the rescue strategy may be partly responsible for the limited visual function recovery with the types of protective methods for retinal neurons used following elevated intraocular pressure. Thus, research on the modulatory mechanisms of the synaptic changes after elevated intraocular pressure injury may give new light to visual function rescue. In this study, we found that thrombospondin 2, an important regulator of synaptogenesis in central nervous system development, was distributed in retinal macroglia cells, and its receptor α2δ-1 was in retinal neurons. Cell cultures including mixed retinal macroglia cells/neuron cultures and retinal neuron cultures were exposed to elevated hydrostatic pressure for 2 h. The expression levels of glial fibrillary acidic protein (the marker of activated macroglia cells), thrombospondin 2, α2δ-1 and presynaptic proteins were increased following elevated hydrostatic pressure in mixed cultures, but the expression levels of postsynaptic proteins were not changed. SiRNA targeting thrombospondin 2 could decrease the upregulation of presynaptic proteins induced by the elevated hydrostatic pressure. However, in retinal neuron cultures, elevated hydrostatic pressure did not affect the expression of presynaptic or postsynaptic proteins. Rather, the retinal neuron cultures with added recombinant thrombospondin 2 protein upregulated the level of presynaptic proteins. Finally, gabapentin decreased the expression of presynaptic proteins in mixed cultures by blocking the interaction of thrombospondin 2 and α2δ-1. Taken together, these results indicate that activated macroglia cells may participate in alterations of presynaptic proteins of retinal neurons following elevated hydrostatic pressure, and macroglia-derived thrombospondin 2 may modulate these changes via binding to its neuronal receptor α2δ-1.
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Affiliation(s)
- Shuchao Wang
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Tu Hu
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Zhen Wang
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Na Li
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Lihong Zhou
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Lvshuang Liao
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Mi Wang
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Libin Liao
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Hui Wang
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Leping Zeng
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Chunling Fan
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Hongkang Zhou
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Kun Xiong
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
| | - Jufang Huang
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
- * E-mail: (JH); (DC)
| | - Dan Chen
- Department of Anatomy and Neurobiology, Central South University School of Basic Medical Sciences, Changsha, Hunan, China
- * E-mail: (JH); (DC)
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