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Leary P, Bellegarda C, Quainoo C, Goldblatt D, Rosti B, Schoppik D. Development of the Motor Periphery is the Rate-Limiting Step in the Ontogeny of the Vestibulo-ocular Reflex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.17.594732. [PMID: 38798369 PMCID: PMC11118585 DOI: 10.1101/2024.05.17.594732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
Sensory deprivation reshapes developing neural circuits, and sensory feedback adjusts the strength of reflexive behaviors throughout life. Sensory development might therefore limit the rate with which behaviors mature, but the complexity of most sensorimotor circuits preclude identifying this fundamental constraint. Here we compared the functional development of components of the vertebrate vestibulo-ocular reflex circuit that stabilizes gaze. We found that vestibular interneuron responses to body tilt sensation developed well before behavioral performance peaked, even without motor neuron-derived feedback. Motor neuron responses developed similarly. Instead, the ontogeny of behavior matched the rate of neuromuscular junction development. When sensation was delayed until after the neuromuscular junction developed, behavioral performance was immediately strong. The matching timecourse and ability to determine behavior establish the development of the neuromuscular junction, and not sensory-derived information, as the rate-limiting process for an ancient and evolutionarilyconserved neural circuit.
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Affiliation(s)
- Paige Leary
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
| | - Celine Bellegarda
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
| | - Cheryl Quainoo
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
| | - Dena Goldblatt
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
- Center for Neural Science, New York University
| | - Başak Rosti
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
| | - David Schoppik
- Depts. of Otolaryngology, Neuroscience & Physiology, and the Neuroscience Institute, NYU Grossman School of Medicine
- Lead Contact
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Hao J, Wang M, Liu J, Yusufu M, Cao K, Fu J. Alteration of Neurotrophic Factors and Innervation in Extraocular Muscles of Individuals With Concomitant Esotropia. Invest Ophthalmol Vis Sci 2024; 65:1. [PMID: 38441891 PMCID: PMC10916883 DOI: 10.1167/iovs.65.3.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 02/15/2024] [Indexed: 03/07/2024] Open
Abstract
Purpose To determine whether neurotrophic factors and innervation in extraocular muscles (EOMs) were altered in different types of concomitant esotropia, and to explore the possible association between neurotrophic factors and innervation of EOMs in humans. Methods Patients with concomitant esotropia who required strabismus surgery were recruited from January to December 2022. Lateral rectus EOMs were obtained from patients, and controls were obtained from deceased organ donors. Immunofluorescence (IF) was performed to detect innervation of EOMs (neurofilament and synaptophysin), and immunohistochemistry (IHC) was used to detect the neurotrophic factors insulin-like growth factor-1 (IGF-1), brain-derived neurotrophic factor (BDNF), glial cell-derived neurotrophic factor (GDNF), and neurotrophin-3 (NT-3). The positive IHC results were further verified using western blotting (WB). One-way ANOVA followed by a Dunnett's multiple comparison post hoc test was used for continuous variables and the χ2 test for categorical variables. Spearman correlation analysis was used for the correlation analysis. Results We collected lateral rectus EOM samples from acute and chronic types of concomitant esotropia and controls. Consistent with IHC, WB showed that IGF-1 was significantly increased in patients with acute acquired comitant esotropia or essential infantile esotropia compared with controls. In IF, synaptophysins were significantly increased only in acute acquired comitant esotropia compared with controls. Furthermore, Spearman correlation analysis showed that the correlation between IGF-1 and synaptophysin was borderline (P = 0.057) for patients with acute acquired comitant esotropia. Conclusions Our study highlights the role of IGF-1 and altered innervation of EOMs in acute acquired comitant esotropia, suggesting that an effect of increased IGF-1 on nerve innervation may temporarily cause a compensatory increase in the strength of lateral rectus muscles.
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Affiliation(s)
- Jie Hao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Meixu Wang
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Jiawen Liu
- Industrial Engineering and Operations Research, University of California, Berkeley, California, United States
| | - Mayinuer Yusufu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia
- Department of Surgery (Ophthalmology), The University of Melbourne, Melbourne, Australia
| | - Kai Cao
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
| | - Jing Fu
- Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China
- Beijing Key Laboratory of Ophthalmology & Visual Sciences, Beijing, China
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3
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Zehra Z, Khan N, Nadeem M, Siddiqui SN, von Bartheld CS, Azam M, Qamar R. Association of IGF1 polymorphisms with exotropia in a Pakistani cohort. Mol Vis 2022; 28:369-377. [PMID: 36338665 PMCID: PMC9603902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 10/04/2022] [Indexed: 06/16/2023] Open
Abstract
PURPOSE Strabismus (STBMS) is a multifactorial ocular disorder in children that leads to misalignment of the eyes. Insulin-like growth factor 1 (IGF1) has been shown to be involved in the development of extraocular muscles and myopia; however, data are limited on the genetic associations of IGF1 with STBMS in Pakistan. METHODS Two hundred seventy-four STBMS cases and 272 unaffected controls were recruited, and their DNA was extracted. Two IGF1 single nucleotide polymorphisms, rs6214 and rs5742632, were genotyped using PCR-restriction fragment length polymorphism. Univariate logistic regression analysis was performed to determine the association of these single nucleotide polymorphisms with STBMS, and the results were adjusted for age and sex. In addition, 26 extraocular muscle tissues were collected from patients with STBMS undergoing squint correction surgery, along with 3 deceased control samples. IGF1 mRNA expression was measured by quantitative PCR; the Mann-Whitney U test was applied, and fold change was calculated. Logistic regression analysis was applied to determine the association of RNA expression and fold change with genotype. RESULTS Multivariate logistic regression analysis revealed that rs5742632 (odds ratio [95% confidence interval] = 1.05[1.01-1.06], p = 0.03) is associated with STBM. Moreover, rs6214 (1.03[1.01-1.05], p = 0.03) and rs5742632 (1.09[1.04-1.11], p = 0.04) were associated with exotropia. Statistically, no significant difference in IGF1 mRNA expression in the extraocular muscles between the STBMS cases and the controls was observed. CONCLUSIONS IGF1 polymorphisms rs5742632 (A>G) and rs6214 (C>T) are plausible risk factors for the development of exotropia. However, the physiologic mechanism requires further evaluation.
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Affiliation(s)
- Zainab Zehra
- Translational Genomics Laboratory, Department of Biosciences, COMSATS University Islamabad, Pakistan
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, NV
| | - Netasha Khan
- Translational Genomics Laboratory, Department of Biosciences, COMSATS University Islamabad, Pakistan
| | - Minhal Nadeem
- Translational Genomics Laboratory, Department of Biosciences, COMSATS University Islamabad, Pakistan
| | | | | | - Maleeha Azam
- Translational Genomics Laboratory, Department of Biosciences, COMSATS University Islamabad, Pakistan
| | - Raheel Qamar
- Translational Genomics Laboratory, Department of Biosciences, COMSATS University Islamabad, Pakistan
- Pakistan Academy of Sciences, Islamabad, Pakistan
- Science and Technology Sector, ICESCO, Rabat, Morocco
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Rudell JC, McLoon LK. Effect of Fibroblast Growth Factor 2 on Extraocular Muscle Structure and Function. Invest Ophthalmol Vis Sci 2021; 62:34. [PMID: 34293078 PMCID: PMC8300058 DOI: 10.1167/iovs.62.9.34] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Mutations in the fibroblast growth factor (FGF) receptor can result in strabismus, but little is known about how FGFs affect extraocular muscle structure and function. These were assessed after short-term and long-term exposure to exogenously applied FGF2 to determine the effect of enhanced signaling. Methods One superior rectus muscle of adult rabbits received either a series of three injections of 500 ng, 1 µg, or 5 µg FGF2 and examined after 1 week, or received sustained treatment with FGF2 and examined after 1, 2, or 3 months. Muscles were assessed for alterations in force generation, myofiber size, and satellite cell number after each treatment. Results One week after the 5 µg FGF2 injections, treated muscles showed significantly increased force generation compared with naïve controls, which correlated with increased myofiber cross-sectional areas and Pax7-positive satellite cells. In contrast, 3 months of sustained FGF2 treatment resulted in decreased force generation, which correlated with decreased myofiber size and decreased satellite cells compared with naïve control and the untreated contralateral side. Conclusions FGF2 had distinctly different effects when short-term and long-term treatments were compared. The decreased size and ability to generate force correlated with decreased myofiber areas seen in individuals with Apert syndrome, where there is sustained activation of FGF signaling. Knowing more about signaling pathways critical for extraocular muscle function, development, and disease will pave the way for improved treatment options for strabismus patients with FGF abnormalities in craniofacial disease, which also may be applicable to other strabismus patients.
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Affiliation(s)
- Jolene C Rudell
- Department of Ophthalmology, University of California San Diego, San Diego, California, United States
| | - Linda K McLoon
- Departments of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States.,Stem Cell Institute, University of Minnesota, Minneapolis, Minnesota, United States
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Rudell JC, Fleuriet J, Mustari MJ, McLoon LK. Childhood Onset Strabismus: A Neurotrophic Factor Hypothesis. J Binocul Vis Ocul Motil 2021; 71:35-40. [PMID: 33872122 PMCID: PMC8102408 DOI: 10.1080/2576117x.2021.1893585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 02/15/2021] [Accepted: 02/17/2021] [Indexed: 10/21/2022]
Abstract
Strabismus is a genetically heterogeneous disorder with complex molecular and neurophysiological causes. Evidence in the literature suggests a strong role for motor innervation in the etiology of strabismus, which connects central neural processes to the peripheral extraocular muscles. Current treatments of strabismus through surgery show that an inherent sensorimotor plasticity in the ocular motor system decreases the effectiveness of treatment, often driving eye alignment back toward its misaligned pre-surgical state by altering extraocular muscle tonus. There is recent interest in capitalizing on existing biological processes in extraocular muscles to overcome these compensatory mechanisms. Neurotrophins are trophic factors that regulate survival and development in neurons and muscle, including extraocular muscles. Local administration of neurotrophins to extraocular muscles partially reversed strabismus in an animal model of strabismus. The hypothesis is that sustained release of neurotrophins gives more time for the ocular motor system to adapt to a slow change in alignment in the desired direction. The effect of neurotrophins on extraocular muscles is complex, as different neurotrophic factors have diverse effects on extraocular muscle contraction profiles, patterns of innervation, and density of extraocular muscle precursor cells. Neurotrophic factors show promise as a therapeutic option for strabismus, which may help to improve treatment outcomes and offset devastating amblyopia and psychosocial effects of disease in strabismus patients.
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Affiliation(s)
- Jolene C Rudell
- Department of Ophthalmology, University California San Diego, San Diego, California
| | - Jérome Fleuriet
- Assistance Publique-Hôpitaux de Paris, Intensive Care Unit, Raymond Poincaré Hospital, Garches, France
| | - Michael J Mustari
- Washington National Primate Research Center, University of Washington, Seattle, Washington
- Department of Ophthalmology, University of Washington, Seattle, Washington
| | - Linda K McLoon
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota
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Eye alignment changes caused by sustained GDNF treatment of an extraocular muscle in infant non-human primates. Sci Rep 2020; 10:11927. [PMID: 32681083 PMCID: PMC7368047 DOI: 10.1038/s41598-020-68743-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 06/04/2020] [Indexed: 12/16/2022] Open
Abstract
The ability of sustained treatment of a single extraocular muscle with glial cell line-derived neurotrophic factor (GDNF) to produce a strabismus in infant non-human primates was tested. Six infant non-human primates received a pellet containing GDNF, releasing 2 µg/day for 90 days, on one medial rectus muscle. Eye alignment was assessed up to 6 months. Five of the six animals showed a slow decrease in eye misalignment from the significant exotropia present at birth, ending with approximately 10° of exotropia. Controls became orthotropic. Misalignment averaged 8° three months after treatment ended. After sustained GDNF treatment, few changes were seen in mean myofiber cross-sectional areas compared to age-matched naïve controls. Neuromuscular junction number was unaltered in the medial rectus muscles, but were significantly reduced in the untreated lateral recti. Neuromuscular junctions on slow fibers became multiply innervated after this sustained GDNF treatment. Pitx2-positive cells significantly decreased in treated and contralateral medial rectus muscles. Our study suggests that balanced GDNF signaling plays a role in normal development and maintenance of orthotropia. Sustained GDNF treatment of one medial rectus muscle resulted in a measurable misalignment largely maintained 3 months after treatment ended. Structural changes suggest mechanisms for producing an imbalance in muscle function.
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7
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Mustari MJ. Nonhuman Primate Studies to Advance Vision Science and Prevent Blindness. ILAR J 2018; 58:216-225. [PMID: 28575309 DOI: 10.1093/ilar/ilx009] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 03/03/2017] [Indexed: 02/05/2023] Open
Abstract
Most primate behavior is dependent on high acuity vision. Optimal visual performance in primates depends heavily upon frontally placed eyes, retinal specializations, and binocular vision. To see an object clearly its image must be placed on or near the fovea of each eye. The oculomotor system is responsible for maintaining precise eye alignment during fixation and generating eye movements to track moving targets. The visual system of nonhuman primates has a similar anatomical organization and functional capability to that of humans. This allows results obtained in nonhuman primates to be applied to humans. The visual and oculomotor systems of primates are immature at birth and sensitive to the quality of binocular visual and eye movement experience during the first months of life. Disruption of postnatal experience can lead to problems in eye alignment (strabismus), amblyopia, unsteady gaze (nystagmus), and defective eye movements. Recent studies in nonhuman primates have begun to discover the neural mechanisms associated with these conditions. In addition, genetic defects that target the retina can lead to blindness. A variety of approaches including gene therapy, stem cell treatment, neuroprosthetics, and optogenetics are currently being used to restore function associated with retinal diseases. Nonhuman primates often provide the best animal model for advancing fundamental knowledge and developing new treatments and cures for blinding diseases.
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Affiliation(s)
- Michael J Mustari
- Washington National Primate Research Center, University of Washington, Seattle, WA.,Department of Ophthalmology, University of Washington, Seattle, WA
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Fleuriet J, McLoon LK. Visualizing Neuronal Adaptation Over Time After Treatment of Strabismus. Invest Ophthalmol Vis Sci 2018; 59:5022-5024. [PMID: 30326069 PMCID: PMC6188464 DOI: 10.1167/iovs.18-25651] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Affiliation(s)
- Jérome Fleuriet
- Washington National Primate Research Center, University of Washington, Seattle, Washington, United States
- Department of Ophthalmology, University of Washington, Seattle, Washington, United States
| | - Linda K. McLoon
- Department of Ophthalmology and Visual Neurosciences, Minneapolis, Minnesota, United States;
- Graduate Program in Neuroscience, University of Minnesota, Minneapolis, Minnesota, United States
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Fitzpatrick KR, Cucak A, McLoon LK. Changing muscle function with sustained glial derived neurotrophic factor treatment of rabbit extraocular muscle. PLoS One 2018; 13:e0202861. [PMID: 30142211 PMCID: PMC6108505 DOI: 10.1371/journal.pone.0202861] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Accepted: 08/10/2018] [Indexed: 01/05/2023] Open
Abstract
Recent microarray and RNAseq experiments provided evidence that glial derived neurotrophic factor (GDNF) levels were decreased in extraocular muscles from human strabismic subjects compared to age-matched controls. We assessed the effect of sustained GDNF treatment of the superior rectus muscles of rabbits on their physiological and morphological characteristics, and these were compared to naïve control muscles. Superior rectus muscles of rabbits were implanted with a sustained release pellet of GDNF to deliver 2μg/day, with the contralateral side receiving a placebo pellet. After one month, the muscles were assessed using in vitro physiological methods. The muscles were examined histologically for alteration in fiber size, myosin expression patterns, neuromuscular junction size, and stem cell numbers and compared to age-matched naïve control muscles. GDNF resulted in decreased force generation, which was also seen on the untreated contralateral superior rectus muscles. Muscle relaxation times were increased in the GDNF treated muscles. Myofiber mean cross-sectional areas were increased after the GDNF treatment, but there was a compensatory increase in expression of developmental, neonatal, and slow tonic myosin heavy chain isoforms. In addition, in the GDNF treated muscles there was a large increase in Pitx2-positive myogenic precursor cells. One month of GDNF resulted in significant extraocular muscle adaptation. These changes are interesting relative to the decreased levels of GDNF in the muscles from subjects with strabismus and preliminary data in infant non-human primates where sustained GDNF treatment produced a strabismus. These data support the view that GDNF has the potential for improving eye alignment in subjects with strabismus.
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Affiliation(s)
- Krysta R. Fitzpatrick
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Anja Cucak
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Linda K. McLoon
- Department of Ophthalmology and Visual Neurosciences, University of Minnesota, Minneapolis, Minnesota, United States of America
- Department of Ophthalmology and Visual Neurosciences and Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, United States of America
- * E-mail:
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Ma WX, Huang XG, Yang TK, Yao JY. Involvement of dysregulated coding and long non‑coding RNAs in the pathogenesis of strabismus. Mol Med Rep 2018; 17:7737-7745. [PMID: 29620205 PMCID: PMC5983965 DOI: 10.3892/mmr.2018.8832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Accepted: 03/09/2018] [Indexed: 01/05/2023] Open
Abstract
Strabismus is a common ocular disorder in children and may result in exterior abnormalities and impaired visual functions. However, the detailed pathogenesis of strabismus unclear. The present study assessed the comprehensive analyses on the roles of RNAs in the development of strabismus. The public datasets of strabismus and the corresponding control tissues were downloaded from the Gene Expression Omnibus (GEO). Reannotations of the dysregulated coding and long non-coding RNAs (lncRNAs) and functional enrichments of the differently expressed genes (DEGs) were conducted. A total of 790 DEGs were screened (648 upregulated and 142 downregulated) in the present study. Among the DEGs, a total of 32 differently expressed lncRNAs were detected (14 upregulated and 18 downregulated). When the Gene Ontology (GO) enrichment was considered, it was identified that a total of 143 GO terms (82 for biological process, 31 for cellular component and 30 for molecular function) were identified. Among all the 57 detected Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, the phagosome pathway, which was labeled as hsa004145, demonstrated the most bioinformatics importance. However, most lncRNAs, except LINC01279 and LOC643733, indicated <3 target mRNAs and were not suitable for advanced bioinformatics analyses. Bioinformatics analyses demonstrated that there was a GO term for each lncRNA (proteinaceous extracellular for LINC01279 and cell surface for LOC643733). In conclusion, a set of coding RNA as well as lncRNAs differentially expressed in strabismus EOM samples were indicated. Notably, the present findings important information for advanced pathogenesis research and biomarkers detection.
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Affiliation(s)
- Wen-Xiu Ma
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| | - Xiao-Gang Huang
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| | - Tian-Ke Yang
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
| | - Jing-Yan Yao
- Department of Ophthalmology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, P.R. China
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11
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Hopker LM, Neves JDC, Nascimento DJ, Campos ED, Mendonça TS, Zanoteli E, Allemann N. Histological changes underlying bupivacaine's effect on extra ocular muscle. Exp Eye Res 2018. [PMID: 29530812 DOI: 10.1016/j.exer.2018.03.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
To determine the changes in the cross-sectional area (CSA) of myofibers and their subtype distribution based on the myosin isoform expression after bupivacaine (BUP) injection in the EOM of rabbits and help the understanding of strabismus correction after BUP injection in the clinical practice. A total of 32 rabbits received 0.3 mL of 1.5% BUP in the superior rectus muscle (SR) of the right eye (OD) and were sacrificed at days 7, 28, 60, and 92. Additional eight untouched rabbits were included as controls. Hematoxylin and eosin staining was performed, and ImageJ software was used to measure CSA. Immunohistochemical analysis was performed to analyze the proportion of myofibers positive for myosin types 1 (slow), 2 (fast) and embryonic. Myofiber area measurement decreased 7 days after BUP injection [SR, 1271 ± 412 μm2 (control) to 909 ± 255 μm2 (day 7)] after BUP injection, followed by an increasing trend after 28 days and normalization after 92 days [SR; 1062 ± 363 μm2 (day 28), 1492 ± 404 μm2 (day 60), 1317 ± 334 μm2 (day 92)]. The proportion of slow myosin-positive fibers increased in the 60-day group (88.5% ± 16.2%). There was no statistically significant difference in fast myosin-positive fibers. The inferior rectus of both eyes showed an increase in CSA. No increase of endomysial fibrous tissue was observed after 60 and 92 days of BUP injection. Bupivacaine, when injected into the SR of rabbits, initially decreases the fiber area followed by a transient increasing trend and normalization. There is a transient increase in the proportion of slow myosin-positive fibers in the injected muscle. Muscle adaptation in untreated EOM was found with increased CSA. These findings help clarify the clinical effects of BUP in extraocular muscle.
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Affiliation(s)
- Luisa Moreira Hopker
- Federal University of Sao Paulo (UNIFESP), Sao Paulo, Brazil; Evangelical Hospital of Curitiba, Curitiba, Brazil.
| | | | | | | | | | - Edmar Zanoteli
- Faculdade de Medicina da Universidade de São Paulo, Sao Paulo, Brazil
| | - Norma Allemann
- Federal University of Sao Paulo (UNIFESP), Sao Paulo, Brazil; University of Illinois at Chicago (UIC), Chicago, IL, USA
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12
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Walton MMG, Pallus A, Fleuriet J, Mustari MJ, Tarczy-Hornoch K. Neural mechanisms of oculomotor abnormalities in the infantile strabismus syndrome. J Neurophysiol 2017; 118:280-299. [PMID: 28404829 DOI: 10.1152/jn.00934.2016] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 04/03/2017] [Accepted: 04/07/2017] [Indexed: 02/08/2023] Open
Abstract
Infantile strabismus is characterized by numerous visual and oculomotor abnormalities. Recently nonhuman primate models of infantile strabismus have been established, with characteristics that closely match those observed in human patients. This has made it possible to study the neural basis for visual and oculomotor symptoms in infantile strabismus. In this review, we consider the available evidence for neural abnormalities in structures related to oculomotor pathways ranging from visual cortex to oculomotor nuclei. These studies provide compelling evidence that a disturbance of binocular vision during a sensitive period early in life, whatever the cause, results in a cascade of abnormalities through numerous brain areas involved in visual functions and eye movements.
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Affiliation(s)
- Mark M G Walton
- Washington National Primate Research Center, University of Washington, Seattle, Washington;
| | - Adam Pallus
- Washington National Primate Research Center, University of Washington, Seattle, Washington.,Department of Ophthalmology, University of Washington, Seattle, Washington
| | - Jérome Fleuriet
- Washington National Primate Research Center, University of Washington, Seattle, Washington.,Department of Ophthalmology, University of Washington, Seattle, Washington
| | - Michael J Mustari
- Washington National Primate Research Center, University of Washington, Seattle, Washington.,Department of Ophthalmology, University of Washington, Seattle, Washington.,Department of Biological Structure, University of Washington, Seattle, Washington; and
| | - Kristina Tarczy-Hornoch
- Department of Ophthalmology, University of Washington, Seattle, Washington.,Seattle Children's Hospital, Seattle, Washington
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