1
|
Tonellato MH, Cates VC, Dickenson JA, Day TA, Strzalkowski NDJ. The effects of acute normobaric hypoxia on standing balance while dual-tasking with and without visual input. Eur J Appl Physiol 2024:10.1007/s00421-024-05469-4. [PMID: 38573534 DOI: 10.1007/s00421-024-05469-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 03/09/2024] [Indexed: 04/05/2024]
Abstract
PURPOSE To investigate the influence of acute normobaric hypoxia on standing balance under single and dual-task conditions, both with and without visual input. METHODS 20 participants (7 female, 20-31 years old) stood on a force plate for 16, 90-s trials across four balance conditions: single-task (quiet stance) or dual-task (auditory Stroop test), with eyes open or closed. Trials were divided into four oxygen conditions where the fraction of inspired oxygen (FIO2) was manipulated (normoxia: 0.21 and normobaric hypoxia: 0.16, 0.145 and 0.13 FIO2) to simulate altitudes of 1100, 3,400, 4300, and 5200 m. Participants breathed each FIO2 for ~ 3 min before testing, which lasted an additional 7-8 min per oxygen condition. Cardiorespiratory measures included heart rate, peripheral blood oxygen saturation, and pressure of end tidal (PET) CO2 and O2. Center of pressure measures included total path length, 95% ellipse area, and anteroposterior and mediolateral velocity. Auditory Stroop test performance was measured as response accuracy and latency. RESULTS Significant decreases in oxygen saturation and PETO2, and increased heart rate were observed between normoxia and normobaric hypoxia (P < 0.0001). Total path length was higher at 0.13 compared to 0.21 FIO2 for the eyes closed no Stoop test condition (P = 0.0197). No other significant differences were observed. CONCLUSION These findings suggest that acute normobaric hypoxia has a minimal impact on standing balance and does not influence auditory Stroop test or dual-task performance. Further investigation with longer exposure is required to understand the impact and time course of normobaric hypoxia on standing balance.
Collapse
Affiliation(s)
- Marshall H Tonellato
- Department of Biology, Faculty of Science and Technology, Mount Royal University, 4826Mount Royal Gate SW, Calgary, AB, T3E 6K6, Canada
| | - Valerie C Cates
- Department of Biology, Faculty of Science and Technology, Mount Royal University, 4826Mount Royal Gate SW, Calgary, AB, T3E 6K6, Canada
| | - Jessica A Dickenson
- Department of Biology, Faculty of Science and Technology, Mount Royal University, 4826Mount Royal Gate SW, Calgary, AB, T3E 6K6, Canada
| | - Trevor A Day
- Department of Biology, Faculty of Science and Technology, Mount Royal University, 4826Mount Royal Gate SW, Calgary, AB, T3E 6K6, Canada
| | - Nicholas D J Strzalkowski
- Department of Biology, Faculty of Science and Technology, Mount Royal University, 4826Mount Royal Gate SW, Calgary, AB, T3E 6K6, Canada.
| |
Collapse
|
2
|
Han C, Zheng XX, Zhang WF. High altitude retinopathy: An overview and new insights. Travel Med Infect Dis 2024; 58:102689. [PMID: 38295966 DOI: 10.1016/j.tmaid.2024.102689] [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: 09/01/2023] [Revised: 12/30/2023] [Accepted: 01/15/2024] [Indexed: 02/04/2024]
Abstract
High altitude retinopathy (HAR) is a common ocular disorder that occurs on ascent to high altitude. There are many clinical symptoms, retinal vascular dilatation, retinal edema and hemorrhage are common. These usually do not or slightly affect vision; rarely, severe cases develop serious or permanent vision loss. At present, the research progress of HAR mainly focuses on hemodynamic changes, blood-retinal barrier damage, oxidative stress and inflammatory response. Although the related studies on HAR are limited, it shows that HAR still belongs to hypoxia, and hypobaric hypoxia plays an aggravating role in promoting the development of the disease. Various studies have demonstrated the correlation of HAR with acute mountain sickness (AMS) and high-altitude cerebral edema (HACE), so a deeper understanding of HAR is important. The slow ascent rates and ascent altitude are the key to preventing any altitude sickness. Research on traditional chinese medicine (TCM) and western medicine has been gradually carried out. Further exploration of the pathogenesis and prevention strategies of HAR will provide better guidance for doctors and high-altitude travelers.
Collapse
Affiliation(s)
- Cong Han
- Department of Ophthalmology, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, 730000, Gansu, PR China.
| | - Xing-Xing Zheng
- Department of Ophthalmology, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, 730000, Gansu, PR China.
| | - Wen-Fang Zhang
- Department of Ophthalmology, The Second Hospital & Clinical Medical School, Lanzhou University, Lanzhou, 730000, Gansu, PR China.
| |
Collapse
|
3
|
Lee CY, Hsia Y, Tsui MC, Wang SW, Huang CJ, Ma IH, Hung KC, Chen MS, Ho TC. Correlation of Visual Acuity and Outer Retinal Thickness in Myopic Atrophic Maculopathy: A Retrospective Review. Ophthalmol Ther 2023; 12:1989-2003. [PMID: 37171558 PMCID: PMC10287860 DOI: 10.1007/s40123-023-00710-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2023] [Accepted: 04/05/2023] [Indexed: 05/13/2023] Open
Abstract
INTRODUCTION Myopic atrophic maculopathy is prevalent among patients with pathologic myopia and frequently leads to relentless vision loss. Several grading systems were established to facilitate the understanding of myopic atrophic maculopathy. However, the anatomical details in different stages of myopic maculopathy are so far not clearly elucidated. This study aims to investigate the visual acuity and retinal sublayer features in highly myopic eyes with varying severities of myopic atrophic maculopathy (MAM). METHODS The clinical records of 111 consecutive patients (158 eyes) with high myopia (refractive error ≤ -6.0 D and axial length ≥ 26.0 mm) were reviewed. Fundus photography, optical coherence tomography (OCT), and best-corrected visual acuity (BCVA) were measured. MAM was graded according to the META-analysis for Pathologic Myopia (META-PM) classification system. Myopic choroidal neovascularization (mCNV) and dome-shaped macula (DSM) were also investigated. RESULTS Among the 158 eyes, 18 (11%), 21(13%), 24 (15%), 25 (16%), 23 (15%), and 24 (15%) had tessellated fundus, diffuse chorioretinal atrophy, diffuse chorioretinal atrophy with DSM, patchy atrophy, patchy atrophy with DSM, and MAM with mCNV, respectively. A total of 23 (15%) eyes had macular atrophy without mCNV. Progressive thinning in the Henle's fiber and outer nuclear layers, myoid and ellipsoid zone (MEZ), outer segment (OS), and interdigitation zone and retinal pigmented epithelium based on the severity of MAM (p-value < 0.001) was found. MEZ and OS were most significantly reduced in thickness (p-value < 0.001). The presence of mCNV demonstrated significant outer retinal layer thinning compared with that of the tessellated fundus (p-value = 0.031). Patchy atrophy with DSM showed statistically poorer BCVA compared with that without (p-value = 0.008). CONCLUSION Visual acuity and outer retinal sublayer characteristics were correlated with the severity of MAM. Outer retinal sublayer analysis by spectrum-domain OCT shed some light on the mechanisms of MAM progression.
Collapse
Affiliation(s)
- Cheng-Yung Lee
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
| | - Yun Hsia
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
- Department of Ophthalmology, National Taiwan University Hospital Hsin-Chu, Hsinchu, Taiwan
| | - Mei-Chi Tsui
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
| | - Shih-Wen Wang
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
- Department of Ophthalmology, Shuang Ho Hospital, Taipei Medical University, New Taipei City, Taiwan
| | - Chien-Jung Huang
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
- Department of Ophthalmology, Fu Jen Catholic University Hospital, New Taipei City, Taiwan
| | - I-Hsin Ma
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
- Department of Ophthalmology, National Taiwan University Hospital Hsin-Chu, Hsinchu, Taiwan
| | - Kuo-Chi Hung
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
- Universal Eye Clinic, Taipei, Taiwan
| | - Muh-Shy Chen
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan
- Department of Ophthalmology, Cardinal Tien Hospital, New Taipei City, Taiwan
| | - Tzyy-Chang Ho
- Department of Ophthalmology, National Taiwan University Hospital, College of Medicine, National Taiwan University, No 7, Chung-Shan S. Rd., Taipei, 10002, Taiwan.
| |
Collapse
|
4
|
Aboouf MA, Thiersch M, Soliz J, Gassmann M, Schneider Gasser EM. The Brain at High Altitude: From Molecular Signaling to Cognitive Performance. Int J Mol Sci 2023; 24:10179. [PMID: 37373327 DOI: 10.3390/ijms241210179] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 06/13/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023] Open
Abstract
The brain requires over one-fifth of the total body oxygen demand for normal functioning. At high altitude (HA), the lower atmospheric oxygen pressure inevitably challenges the brain, affecting voluntary spatial attention, cognitive processing, and attention speed after short-term, long-term, or lifespan exposure. Molecular responses to HA are controlled mainly by hypoxia-inducible factors. This review aims to summarize the cellular, metabolic, and functional alterations in the brain at HA with a focus on the role of hypoxia-inducible factors in controlling the hypoxic ventilatory response, neuronal survival, metabolism, neurogenesis, synaptogenesis, and plasticity.
Collapse
Affiliation(s)
- Mostafa A Aboouf
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Department of Biochemistry, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Markus Thiersch
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Jorge Soliz
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
| | - Max Gassmann
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, 8057 Zurich, Switzerland
| | - Edith M Schneider Gasser
- Institute of Veterinary Physiology, Vetsuisse Faculty, University of Zürich, 8057 Zurich, Switzerland
- Institute Universitaire de Cardiologie et de Pneumologie de Québec (IUCPQ), Faculty of Medicine, Université Laval, Québec, QC G1V 4G5, Canada
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
| |
Collapse
|
5
|
Wang Y, Yu X, Liu Z, Lv Z, Xia H, Wang Y, Li J, Li X. Influence of hypobaric hypoxic conditions on ocular structure and biological function at high attitudes: a narrative review. Front Neurosci 2023; 17:1149664. [PMID: 37229428 PMCID: PMC10203194 DOI: 10.3389/fnins.2023.1149664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 04/04/2023] [Indexed: 05/27/2023] Open
Abstract
Background With the development of science and technology, high-altitude environments, involving aviation, aerospace, and mountainous regions, have become the main areas for human exploration, while such complex environments can lead to rapid decreases in air and oxygen pressure. Although modern aircrafts have pressurized cabins and support equipment that allow passengers and crew to breathe normally, flight crew still face repeated exposure to hypobaric and hypoxic conditions. The eye is a sensory organ of the visual system that responds to light and oxygen plays a key role in the maintenance of normal visual function. Acute hypoxia changes ocular structure and function, such as the blood flow rate, and can cause retinal ischemia. Methods We reviewed researches, and summarized them briefly in a review. Results The acute hypobaric hypoxia affects corneal, anterior chamber angle and depth, pupils, crystal lens, vitreous body, and retina in structure; moreover, the acute hypoxia does obvious effect on visual function; for example, vision, intraocular pressure, oculometric features and dynamic visual performance, visual field, contrast sensitivity, and color perception. Conclusion We summarized the changes in the physiological structure and function of the eye in hypoxic conditions and to provide a biological basis for the response of the human eye at high-altitude.
Collapse
Affiliation(s)
- Yuchen Wang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Xinli Yu
- School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Ziyuan Liu
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Zhongsheng Lv
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Huaqin Xia
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Yiren Wang
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Jiaxi Li
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| | - Xuemin Li
- Department of Ophthalmology, Peking University Third Hospital, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, Beijing, China
| |
Collapse
|
6
|
Todorova V, Stauffacher MF, Ravotto L, Nötzli S, Karademir D, Ebner LJA, Imsand C, Merolla L, Hauck SM, Samardzija M, Saab AS, Barros LF, Weber B, Grimm C. Deficits in mitochondrial TCA cycle and OXPHOS precede rod photoreceptor degeneration during chronic HIF activation. Mol Neurodegener 2023; 18:15. [PMID: 36882871 PMCID: PMC9990367 DOI: 10.1186/s13024-023-00602-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 02/03/2023] [Indexed: 03/09/2023] Open
Abstract
BACKGROUND Major retinal degenerative diseases, including age-related macular degeneration, diabetic retinopathy and retinal detachment, are associated with a local decrease in oxygen availability causing the formation of hypoxic areas affecting the photoreceptor (PR) cells. Here, we addressed the underlying pathological mechanisms of PR degeneration by focusing on energy metabolism during chronic activation of hypoxia-inducible factors (HIFs) in rod PR. METHODS We used two-photon laser scanning microscopy (TPLSM) of genetically encoded biosensors delivered by adeno-associated viruses (AAV) to determine lactate and glucose dynamics in PR and inner retinal cells. Retinal layer-specific proteomics, in situ enzymatic assays and immunofluorescence studies were used to analyse mitochondrial metabolism in rod PRs during chronic HIF activation. RESULTS PRs exhibited remarkably higher glycolytic flux through the hexokinases than neurons of the inner retina. Chronic HIF activation in rods did not cause overt change in glucose dynamics but an increase in lactate production nonetheless. Furthermore, dysregulation of the oxidative phosphorylation pathway (OXPHOS) and tricarboxylic acid (TCA) cycle in rods with an activated hypoxic response decelerated cellular anabolism causing shortening of rod photoreceptor outer segments (OS) before onset of cell degeneration. Interestingly, rods with deficient OXPHOS but an intact TCA cycle did not exhibit these early signs of anabolic dysregulation and showed a slower course of degeneration. CONCLUSION Together, these data indicate an exceeding high glycolytic flux in rods and highlight the importance of mitochondrial metabolism and especially of the TCA cycle for PR survival in conditions of increased HIF activity.
Collapse
Affiliation(s)
- Vyara Todorova
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Mia Fee Stauffacher
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Luca Ravotto
- Institute of Pharmacology and Toxicology and Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
| | - Sarah Nötzli
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Duygu Karademir
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Lynn J A Ebner
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Cornelia Imsand
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Luca Merolla
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Stefanie M Hauck
- Metabolomics and Proteomics Core, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Munich, Germany
| | - Marijana Samardzija
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland
| | - Aiman S Saab
- Institute of Pharmacology and Toxicology and Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
| | - L Felipe Barros
- Centro de Estudios Científicos (CECs), Valdivia, Chile.,Universidad San Sebastián, Valdivia, Chile
| | - Bruno Weber
- Institute of Pharmacology and Toxicology and Neuroscience Center Zurich, University and ETH Zurich, Winterthurerstr. 190, 8057, Zurich, Switzerland
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, Switzerland.
| |
Collapse
|
7
|
Ma J, Niu H, Han C, Qu Y. Quantify retinal structure in high-altitude residents with and without high altitude polycythemia. BMC Ophthalmol 2023; 23:6. [PMID: 36597056 PMCID: PMC9811807 DOI: 10.1186/s12886-022-02674-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 11/07/2022] [Indexed: 01/05/2023] Open
Abstract
BACKGROUND To assess retinal structural parameters in high-altitude (HA) residents with and without high altitude polycythemia (HAPC) and to elucidate the relationship between retinal structural parameters and hemoglobin (HGB). METHODS This cross-sectional study included 55 HAPC patients and 52 healthy HA residents. Retinal structural parameters included retinal nerve fiber layer (RNFL) thickness, optic nerve head (ONH) parameters and retinal vessel diameter. RNFL thickness were acquired from spectral domain optical coherence tomography (SD-OCT) built-in software. ONH parameters including neuroretina rim height, cup area, disc area and vertical cup/disc ratio were obtained by OCT built-in software and ImageJ software. Retinal vessel measurements including central retinal artery equivalent (CRAE), central retinal vein equivalent (CRVE) and AVR (artery/vein ratio) were calculated by revised formulas for summarizing retinal vessel diameters. All parameters were compared between HAPC group versus healthy HA group. The associations between retinal parameters and HGB were assessed by Pearson correlation analyses. RESULTS In comparison of HAPC group versus healthy HA group, RNFL thickness was thicker in the nasal quadrant of the optic disc in HAPC group (74.82 ± 14.4 VS. 66.06 ± 13.71 μm, P = 0.002). Bigger disc area and bigger cup area were also observed in HAPC group (all P < 0.05). Meanwhile, the value of CRVE was higher in HAPC group which suggested that retinal veins dilated significantly in HAPC patients (P < 0.001), however, CRAE and AVR were comparable between groups. Pearson analyses revealed that HGB was positive correlated with CRVE in HAPC group (r = 0.469, P = 0.003). CONCLUSIONS long-term HA exposure secondary HAPC could result in thickened RNFL, enlarged ONH and dilated retinal veins. Moreover, increased blood viscosity caused by HGB should be responsible for dilated veins, but not for thickened RNFL and enlarged ONH. This study deepens the understanding of the impact of HA environment on retina.
Collapse
Affiliation(s)
- Jinlan Ma
- Department of Ophthalmology, Affiliated Hospital of Qinghai University, Xining, China.,Department of Health Care, Qilu Hospital of Shandong University, No. 107, Wenhuaxi Road, Jinan, 250012, China
| | - Haoyu Niu
- Department of Ophthalmology, Affiliated Hospital of Qinghai University, Xining, China
| | - Changjing Han
- Department of Ophthalmology, Affiliated Hospital of Qinghai University, Xining, China
| | - Yi Qu
- Department of Health Care, Qilu Hospital of Shandong University, No. 107, Wenhuaxi Road, Jinan, 250012, China.
| |
Collapse
|
8
|
The Assessment of Acute Chorioretinal Changes Due to Intensive Physical Exercise in Senior Elite Athletes. J Aging Phys Act 2022; 31:497-505. [PMID: 36640780 DOI: 10.1123/japa.2022-0231] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 09/03/2022] [Accepted: 09/23/2022] [Indexed: 12/25/2022]
Abstract
Regular physical exercise is known to lower the incidence of age-related eye diseases. We aimed to assess the acute chorioretinal alterations in older adults following intense physical strain. Seventeen senior elite athletes were recruited who underwent an aerobic exercise on a cycle ergometer and macular scanning by optical coherence tomography. A significant thinning of the entire retina was observed 1 min after exercise, followed by a thickening at 5 min, after which the thickness returned to baseline. This trend was similar in almost every single retinal layer, although a significant change was observed only in the inner retina. Choroidal thickness changes were neither significant nor did they correlate with the thickness changes of intraretinal layers. The mechanism of how these immediate retinal changes chronically impact age-related sight-threatening pathologies that, in turn, result in a substantially reduced quality of life warrants further investigation on nontrained older adults as well.
Collapse
|
9
|
Xie D, Hu J, Wu T, Cao K, Luo X. Potential Biomarkers and Drugs for Nanoparticle-Induced Cytotoxicity in the Retina: Based on Regulation of Inflammatory and Apoptotic Genes. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095664. [PMID: 35565057 PMCID: PMC9099825 DOI: 10.3390/ijerph19095664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 05/03/2022] [Accepted: 05/05/2022] [Indexed: 02/01/2023]
Abstract
The eye is a superficial organ directly exposed to the surrounding environment. Thus, the toxicity of nanoparticle (NP) pollutants to the eye may be potentially severer relative to inner organs and needs to be monitored. However, the cytotoxic mechanisms of NPs on the eyes remain rarely reported. This study was to screen crucial genes associated with NPs-induced retinal injuries. The gene expression profiles in the retina induced by NPs [GSE49371: Au20, Au100, Si20, Si100; GSE49048: presumptive therapeutic concentration (PTC) TiO2, 10PTC TiO2] and commonly used retinal cell injury models (optic nerve injury procedure: GSE55228, GSE120257 and GSE131486; hypoxia exposure: GSE173233, GSE151610, GSE135844; H2O2 exposure: GSE122270) were obtained from the Gene Expression Omnibus database. A total of 381 differentially expressed genes (including 372 mRNAs and 9 lncRNAs) were shared between NP exposure and the optic nerve injury model when they were compared with their corresponding controls. Function enrichment analysis of these overlapped genes showed that Tlr2, Crhbp, Ccl2, Cxcl10, Fas, Irf8, Socs3, Stat3, Gbp6, Casp1 and Syk were involved in inflammatory- and apoptotic-related processes. Protein-protein interaction network analysis revealed eight of them (Tlr2, Ccl2, Cxcl10, Irf8, Socs3, Stat3, Casp1 and Syk) were hub genes. Moreover, Socs3 could interact with upstream Stat3 and downstream Fas/Casp1/Ccl2/Cxcl10; Irf8 could interact with upstream Tlr2, Syk and downstream Cxcl10. Competing endogenous RNAs network analysis identified Socs3, Irf8, Gdf6 and Crhbp could be regulated by lncRNAs and miRNAs (9330175E14Rik-mmu-miR-762-Socs3, 6430562O15Rik-mmu-miR-207-Irf8, Gm9866-mmu-miR-669b-5p-Gdf6, 4933406C10Rik-mmu-miR-9-5p-Crhbp). CMap-CTD database analyses indicated the expression levels of Tlr2, Ccl2, Cxcl10, Fas, Irf8, Socs3, Stat3, Gbp6, Casp1 and Syk could be reversed by folic acid. Crhbp and Gdf6 were also verified to be downregulated, while Tlr2, Ccl2, Irf8, Socs3 and Stat3 were upregulated in hypoxia/H2O2-induced retinal injury models. Hereby, our findings suggest that Crhbp, Irf8, Socs3 and Gdf6 as well as their upstream mRNAs, lncRNAs and miRNAs may be potential monitoring biomarkers and therapeutic targets for NP-induced retinal injuries. Folic acid supplementation may be a preventive and therapeutic approach.
Collapse
Affiliation(s)
- Dongli Xie
- College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou 215123, China; (D.X.); (J.H.)
| | - Jianchen Hu
- College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou 215123, China; (D.X.); (J.H.)
| | - Tong Wu
- Shanghai Jing Rui Yang Industrial Co., Ltd., 3188 Xiupu Road, Pudong New Area, Shanghai 200122, China;
| | - Kangli Cao
- Shanghai Institute of Spacecraft Equipment, 251 Huaning Road, Shanghai 200240, China;
| | - Xiaogang Luo
- College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou 215123, China; (D.X.); (J.H.)
- Correspondence: ; Tel.: +86-0512-67162531
| |
Collapse
|
10
|
Karademir D, Todorova V, Ebner LJA, Samardzija M, Grimm C. Single-cell RNA sequencing of the retina in a model of retinitis pigmentosa reveals early responses to degeneration in rods and cones. BMC Biol 2022; 20:86. [PMID: 35413909 PMCID: PMC9006580 DOI: 10.1186/s12915-022-01280-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Accepted: 03/12/2022] [Indexed: 11/18/2022] Open
Abstract
Background In inherited retinal disorders such as retinitis pigmentosa (RP), rod photoreceptor-specific mutations cause primary rod degeneration that is followed by secondary cone death and loss of high-acuity vision. Mechanistic studies of retinal degeneration are challenging because of retinal heterogeneity. Moreover, the detection of early cone responses to rod death is especially difficult due to the paucity of cones in the retina. To resolve heterogeneity in the degenerating retina and investigate events in both types of photoreceptors during primary rod degeneration, we utilized droplet-based single-cell RNA sequencing in an RP mouse model, rd10. Results Using trajectory analysis, we defined two consecutive phases of rod degeneration at P21, characterized by the early transient upregulation of Egr1 and the later induction of Cebpd. EGR1 was the transcription factor most significantly associated with the promoters of differentially regulated genes in Egr1-positive rods in silico. Silencing Egr1 affected the expression levels of two of these genes in vitro. Degenerating rods exhibited changes associated with metabolism, neuroprotection, and modifications to synapses and microtubules. Egr1 was also the most strongly upregulated transcript in cones. Its upregulation in cones accompanied potential early respiratory dysfunction and changes in signaling pathways. The expression pattern of EGR1 in the retina was dynamic during degeneration, with a transient increase of EGR1 immunoreactivity in both rods and cones during the early stages of their degenerative processes. Conclusion Our results identify early and late changes in degenerating rd10 rod photoreceptors and reveal early responses to rod degeneration in cones not expressing the disease-causing mutation, pointing to mechanisms relevant for secondary cone degeneration. In addition, our data implicate EGR1 as a potential key regulator of early degenerative events in rods and cones, providing a potential broad target for modulating photoreceptor degeneration. Supplementary Information The online version contains supplementary material available at 10.1186/s12915-022-01280-9.
Collapse
Affiliation(s)
- Duygu Karademir
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland. .,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.
| | - Vyara Todorova
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Lynn J A Ebner
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Marijana Samardzija
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.,Zurich Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| |
Collapse
|
11
|
Peters F, Ebner LJA, Atac D, Maggi J, Berger W, den Hollander AI, Grimm C. Regulation of ABCA1 by AMD-Associated Genetic Variants and Hypoxia in iPSC-RPE. Int J Mol Sci 2022; 23:ijms23063194. [PMID: 35328615 PMCID: PMC8953808 DOI: 10.3390/ijms23063194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 02/04/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive disease of the macula characterized by atrophy of the retinal pigment epithelium (RPE) and photoreceptor degeneration, leading to severe vision loss at advanced stages in the elderly population. Impaired reverse cholesterol transport (RCT) as well as intracellular lipid accumulation in the RPE are implicated in AMD pathogenesis. Here, we focus on ATP-binding cassette transporter A1 (ABCA1), a major cholesterol transport protein in the RPE, and analyze conditions that lead to ABCA1 dysregulation in induced pluripotent stem cell (iPSC)-derived RPE cells (iRPEs). Our results indicate that the risk-conferring alleles rs1883025 (C) and rs2740488 (A) in ABCA1 are associated with increased ABCA1 mRNA and protein levels and reduced efficiency of cholesterol efflux from the RPE. Hypoxia, an environmental risk factor for AMD, reduced expression of ABCA1 and increased intracellular lipid accumulation. Treatment with a liver X receptor (LXR) agonist led to an increase in ABCA1 expression and reduced lipid accumulation. Our data strengthen the homeostatic role of cholesterol efflux in the RPE and suggest that increasing cellular cholesterol export by stimulating ABCA1 expression might lessen lipid load, improving RPE survival and reducing the risk of developing AMD.
Collapse
Affiliation(s)
- Florian Peters
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
| | - Lynn J. A. Ebner
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
| | - David Atac
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Anneke I. den Hollander
- Department of Ophthalmology, Radboud University Medical Center, 6525 Nijmegen, The Netherlands;
- AbbVie, Genomic Research Center, 200 Sidney Street, Cambridge, MA 02139, USA
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
| |
Collapse
|