Details of a Researcher - Kurihara, Toshihide

Papers - Kurihara, Toshihide

Division display 21 - 40 of about 204 ／ All the affair displays >>

Drusen in AMD from the Perspective of Cholesterol Metabolism and Hypoxic Response

Ban N, Shinojima A, Negishi K, Kurihara T*

J Clin Med. (Journal of Clinical Medicine) 13 ( 9 ) 2608 2024.04

Last author, Corresponding author, Accepted

Drusen are one of the most characteristic pathologies of precursor lesion of age-related macular degeneration (AMD). Drusen comprise a yellowish white substance that accumulates typically under the retinal pigment epithelium (RPE), and their constituents are lipids, complement, amyloid, crystallin, and others. In the past, many researchers have focused on drusen and tried to elucidate the pathophysiology of AMD because they believed that disease progression from early AMD to advanced AMD might be based on drusen or drusen might cause AMD. In fact, it is well established that drusen are the hallmark of precursor lesion of AMD and a major risk factor for AMD progression mainly based on their size and number. However, the existence of advanced AMD without drusen has long been recognized. For example, polypoidal choroidal vasculopathy (PCV), which comprises the majority of AMD cases in Asians, often lacks drusen. Thus, there is the possibility that drusen might be no more than a biomarker of AMD and not a cause of AMD. Now is the time to reconsider the relationship between AMD and drusen. In this review, we focus on early AMD pathogenesis based on basic research from the perspective of cholesterol metabolism and hypoxic response in the retina, and we discuss the role of drusen.

Access to Document (DOI)

Halofuginone prevents outer retinal degeneration in a mouse model of light-induced retinopathy

Miwa Y*, Lee D*, Shoda C, Jeong H, Negishi K, Kurihara T†

PLOS ONE (Public Library of Science (PLoS)) 19 ( 3 ) e0300045 2024.03

Last author, Corresponding author, Accepted

Photoreceptor cell death can cause progressive and irreversible visual impairments. Still, effective therapies on retinal neuroprotection are not available. Hypoxia-inducible factors (HIFs) are transcriptional factors which strongly regulate angiogenesis, erythropoiesis, intracellular metabolism, and programed cell death under a hypoxic or an abnormal metabolic oxidative stress condition. Therefore, we aimed to unravel that inhibition of HIFs could prevent disease progression in photoreceptor cell death, as recent studies showed that HIFs might be pathologic factors in retinal diseases. Adult male balb/cAJcl (8 weeks old; BALB/c) were used to investigate preventive effects of a novel HIF inhibitor halofuginone (HF) on a murine model of light-induced retinopathy. After intraperitoneal injections of phosphate-buffered saline (PBS) or HF (0.4 mg/kg in PBS) for 5 days, male BALB/c mice were subjected to a dark-adaption to being exposed to a white LED light source at an intensity of 3,000 lux for 1 hour in order to induce light-induced retinal damage. After extensive light exposure, retinal damage was evaluated using electroretinography (ERG), optical coherence tomography (OCT), and TUNEL assay. Light-induced retinal dysfunction was suppressed by HF administration. The amplitudes of scotopic a-wave and b-wave as well as that of photopic b-wave were preserved in the HF-administered retina. Outer retinal thinning after extensive light exposure was suppressed by HF administration. Based on the TUNEL assay, cell death in the outer retina was seen after light exposure. However, its cell death was not detected in the HF-administered retina. Halofuginone was found to exert preventive effects on light-induced outer retinal cell death.

Access to Document (DOI)

Scleral remodeling during myopia development in mice eyes: a potential role of thrombospondin-1

Chen J*, Ikeda SI*, Yang Y, Zhang Y, Ma Z, Liang Y, Negishi K, Tsubota K†, Kurihara T†

Mol Med. (Molecular Medicine) 30 ( 1 ) 25 2024.02

Last author, Corresponding author, Accepted, ISSN 10761551

Background: Scleral extracellular matrix (ECM) remodeling plays a crucial role in the development of myopia, particularly in ocular axial elongation. Thrombospondin-1 (THBS1), also known as TSP-1, is a significant cellular protein involved in matrix remodeling in various tissues. However, the specific role of THBS1 in myopia development remains unclear. Method: We employed the HumanNet database to predict genes related to myopic sclera remodeling, followed by screening and visualization of the predicted genes using bioinformatics tools. To investigate the potential target gene Thbs1, we utilized lens-induced myopia models in male C57BL/6J mice and performed Western blot analysis to detect the expression level of scleral THBS1 during myopia development. Additionally, we evaluated the effects of scleral THBS1 knockdown on myopia development through AAV sub-Tenon’s injection. The refractive status and axial length were measured using a refractometer and SD-OCT system. Results: During lens-induced myopia, THBS1 protein expression in the sclera was downregulated, particularly in the early stages of myopia induction. Moreover, the mice in the THBS1 knockdown group exhibited alterations in myopia development in both refraction and axial length changed compared to the control group. Western blotting analysis confirmed the effectiveness of AAV-mediated knockdown, demonstrating a decrease in COLA1 expression and an increase in MMP9 levels in the sclera. Conclusion: Our findings indicate that sclera THBS1 levels decreased during myopia development and subsequent THBS1 knockdown showed a decrease in scleral COLA1 expression. Taken together, these results suggest that THBS1 plays a role in maintaining the homeostasis of scleral extracellular matrix, and the reduction of THBS1 may promote the remodeling process and then affect ocular axial elongation during myopia progression.

Access to Document (DOI)

Slowing of Greater Axial Length Elongation Stemming from the COVID-19 Pandemic with Increasing Time Outdoors: The Tokyo Myopia Study

Yotsukura E, Torii H†, Mori K, Ogawa M, Hanyuda A, Negishi K, Kurihara T†, Tsubota K†

Ophthalmol Sci. (Elsevier BV) 4 ( 5 ) 100491 - 100491 2024.02

Corresponding author, Accepted, ISSN 2666-9145

Purpose: To investigate the changes in axial length (AL) elongation and other ocular parameters before and during the coronavirus disease 2019 pandemic. Design: A longitudinal school-based study. Participants: Public elementary schoolchildren in Tokyo (grades 1–6; age, 6–12 years) participated in this study from 2018 to 2021. Methods: All participants underwent eye examinations and provided written consent to measurements of the noncycloplegic refraction and ocular biometry including AL, among others. The students’ parents also completed a questionnaire about the students’ lifestyles. We included the right eye in our analysis and compared the changes in the ocular parameters among the periods using a linear mixed-effects model for repeated measures and examined the univariate and step-wise multiple regression analyses to evaluate the associations between myopia and other covariates. Main Outcome Measures: Changes in AL elongation and other ocular parameters from 2018 to 2019 (prepandemic), that of 2019 to 2020 (immediately after the pandemic onset), and that of 2020 to 2021 (during the pandemic). Results: A total of 578 students before the pandemic period, 432 immediately after the pandemic onset, and 457 during the pandemic period were evaluated. The changes in the ALs and spherical equivalents (SEs) a year before, immediately after onset, and during the pandemic were 0.31 mm/−0.20 diopter, 0.38 mm/−0.27 diopter, and 0.28 mm/−0.47 diopter, respectively (ALs, P < 0.001; SEs, P = 0.014). The results of the questionnaire showed that time spent outdoors daily had changed during the 3 years to 79, 63, and 77 minutes/day, respectively (P < 0.001). Time spent using smartphones or tablets increased year by year to 41, 52, and 62 minutes/day (P < 0.001). The greatest AL elongation occurred during the period when the shortest amount of time was spent outdoors during the 3 years. Conclusions: These results suggested that the school closures and decreasing time spent outdoors might have caused greater AL elongation among schoolchildren in Tokyo; however, it is possible that, although the time spent in near work still increased, the return to the time spent outdoors to the prepandemic levels may have affected the slowing of AL elongation after lockdown. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Access to Document (DOI)

Deep Learning Segmentation of Non-perfusion Area from Color Fundus Images and AI-generated Fluorescein Angiography

Masayoshi K*, Katada Y*, Ozawa N, Ibuki M, Negishi K, Kurihara T†

Res Sq. (Research Square Platform LLC) 14 ( 1 ) https://doi.org/10.21203/rs.3.rs-3871406/v1 2024.01

Last author, Corresponding author

Abstract

The non-perfusion area (NPA) of the retina is an important indicator in the visual prognosis of patients with retinal vein occlusion (RVO). However, the current evaluation method of NPA, fluorescein angiography (FA), is invasive and burdensome. In this study, we examined the use of deep learning models for detecting NPA in color fundus images, bypassing the need for FA, and we also investigated the utility of synthetic FA generated from color fundus images. The models were evaluated using the Dice score and Monte Carlo dropout uncertainty. We retrospectively collected 403 sets of color fundus and FA images from 319 RVO patients. We trained three deep learning models on FA, color fundus images, and synthetic FA. As a result, though the FA model achieved the highest score, the other two models also performed comparably. We found no statistical significance in median Dice scores between the models. However, the color fundus model showed significantly higher uncertainty than the other models (p < 0.05). In conclusion, deep learning models can detect NPAs from color fundus images with reasonable accuracy, though with somewhat less prediction stability. Synthetic FA stabilizes the prediction and reduces misleading uncertainty estimates by enhancing image quality.

Access to Document (DOI)

Modulation of Hypoxia-Inducible Factors and Vascular Endothelial Growth Factor Expressions by Superfood Camu-Camu (Myrciaria dubia) Treatment in ARPE-19 and Fetal Human RPE Cells

Nakai A, Lee D, Shoda C, Negishi K, Nakashizuka H, Yamagami S, Kurihara T†

J Ophthalmol. (Hindawi Limited) 2023 6617981 2023.12

Last author, Corresponding author, Accepted, ISSN 2090-004X

Background. Anti-vascular endothelial growth factor (anti-VEGF) therapy via intravitreal injection is an effective treatment for patients with abnormal ocular neovascularization, such as age-related macular degeneration (AMD) and diabetic macular edema (DME). However, prolonged and frequent anti-VEGF treatment is associated with a risk of local and systemic adverse events, including geographic atrophy, cerebrovascular disease, and death. Furthermore, some patients do not adequately respond to anti-VEGF therapy. Hypoxia-inducible factor (HIF) is a transcription factor that controls the expression of hypoxia-responsive genes involved in angiogenesis, inflammation, and metabolism. The HIF/VEGF pathway plays an important role in neovascularization, and the inhibition of HIF activation could be an effective biomolecular target for neovascular diseases. The demand for disease prevention or treatment using functional foods such as superfoods has increased in recent years. Few reports to date have focused on the antineovascular effects of superfoods in the retinal pigment epithelium (RPE). In light of the growing demand for functional foods, we aimed to find novel HIF inhibitors from superfoods worked in RPE cells, which could be an adjuvant for anti-VEGF therapy. Methods. Seven superfoods were examined to identify novel HIF inhibitor candidates using luciferase assay screening. We used the human RPE cell line ARPE-19 and fetal human RPE (fhRPE) to investigate the biomolecular actions of novel HIF inhibitors using quantitative PCR and western blotting. Results. Under CoCl2-induced pseudohypoxic condition and 1% oxygen hypoxic incubation, camu-camu (Myrciaria dubia) showed HIF inhibitory effects determined by luciferase assays. Camu-camu downregulated HIF-1α and VEGFA mRNA expressions in a concentration-dependent manner. Camu-camu also inhibited HIF-1α protein expressions, and its inhibitory effect was greater than that of vitamin C, which is present at high levels in camu-camu. Conclusion. The camu-camu extract suppressed the activation of HIF and VEGF in RPE cells. This could assist anti-VEGF therapy in patients with abnormal ocular neovascularization.

Access to Document (DOI)

Inhibition of hypoxia-inducible factors suppresses subretinal fibrosis

Shoda C*, Lee D*, Miwa Y, Yamagami S, Nakashizuka H, Nimura K, Okamoto K, Kawagishi H, Negishi K, Kurihara T†

FASEB J. (Cold Spring Harbor Laboratory) 38 ( 13 ) 571193 2023.12

Last author, Corresponding author, ISSN 08926638

Age-related macular degeneration (AMD) is a common cause of vision loss. The aggressive form of AMD is associated with ocular neovascularization and subretinal fibrosis, representing a responsive outcome against neovascularization mediated by epithelial-mesenchymal transition of retinal pigment epithelium cells. A failure of the current treatment (anti-vascular endothelial growth factor therapy) has also been attributed to the progression of subretinal fibrosis. Hypoxia-inducible factors (HIFs) increase gene expressions to promote fibrosis and neovascularization. HIFs act as a central pathway in the pathogenesis of AMD. HIF inhibitors may suppress ocular neovascularization. Nonetheless, further investigation is required to unravel the aspects of subretinal fibrosis. In this study, we used RPE-specific HIFs or von Hippel-Lindau (VHL, a regulator of HIFs) conditional knockout (cKO) mice, along with pharmacological HIF inhibitors, to demonstrate the suppression of subretinal fibrosis. Fibrosis was suppressed by treatments of HIF inhibitors, and similar suppressive effects were detected in RPE-specific Hif1a/Hif2a- and Hif1a-cKO mice. Promotive effects were observed in RPE-specific Vhl-cKO mice, where fibrosis-mediated pathologic processes were evident. Marine products extracts and their component taurine suppressed fibrosis as HIF inhibitors. Our study shows critical roles of HIFs in the progression of fibrosis, linking them to the potential development of therapeutics for AMD.

Access to Document (DOI)

Tight junction component protein claudin-1 deficiency in retinal pigment epithelium leads to early and intermediate age-related macular degeneration phenotypes in mice.

Nakai A, Lee D, Zhang Y, Shoda C, Imanishi S, Jeong H, Ikeda SI, Negishi K, Nakashizuka H, Yamagami S, Kubo A, Kurihara T†

bioRxiv. (Cold Spring Harbor Laboratory) 570525 2023.12

Last author, Corresponding author

The early and intermediate age-related macular degeneration (AMD) is characterized by the presence of drusen and pigmentary abnormalities in the retinal pigment epithelial (RPE) cells which form the outer blood retinal barrier (oBRB). Fluid leakage through the disrupted oBRB from the choroid to the neural retina has been implicated in the pathogenesis of AMD, however; the molecular mechanisms still remain unclear. The family of four transmembrane proteins, claudins are known to form tight junctions (TJs) in the oBRB. Nonetheless, there are few reports showing how they function in the oBRB in vivo. We found that claudin-1 is dominantly expressed in TJs of the mouse RPE. To investigate the role of claudin-1 in the RPE, we generated RPE-specific Cldn1 conditional knockout mice (Best1-Cre+/- Cldn1flox/flox mice: Cldn1 cKO mice). Deficiency of Cldn1 led to age-related lipid deposits such as subretinal drusenoid deposits (SDD), increased lipid droplets in the RPE, basal lamellar deposits (BlamD) and membranous debris in the Bruch's membrane. In addition, pigmentary abnormalities such as RPE hypertrophy, multilayered-RPE cells, and ectopic pigment granules outside the RPE were observed in Cldn1 cKO mice. Our study provides new insights into the possible association of the TJ protein claudin-1 with lipid metabolism and cellular ageing in the RPE contributing to the early onset of AMD.

Access to Document (DOI)

Topical application of bunazosin hydrochloride suppresses myopia progression with an increase in choroidal blood perfusion

Jeong H, Lee D, Jiang X, Negishi K, Tsubota K†, Kurihara T†

Invest Ophthalmol Vis Sci. (Investigative ophthalmology & visual science) 64 ( 14 ) 15 2023.11

Last author, Corresponding author, Accepted, ISSN 01460404

Purpose: The incidence of myopia has rapidly increased in recent decades, making it a growing public health concern worldwide. Interventions to suppress the progression of myopia are needed; one suggested strategy is the prevention of choroidal thinning, which can improve choroidal blood perfusion (ChBP). Bunazosin hydrochloride (BH) is an alpha1-adrenergic blocker and commercialized glaucoma eye drop that increases in blood circulation in the eye. In this study, we evaluated the efficacy of BH in suppressing the progression of myopia in a lens-induced murine model. Methods: Lens-induced myopia was induced in 3-week-old C57BL/6 J mice with -30 diopter (D) lenses for three weeks. Refractive error, axial length, and choroidal thickness were evaluated at three and six weeks of age using an infrared photorefractor and a spectral domain optical coherence tomography (OCT) system. Moreover, ChBP and scleral thickness were evaluated using swept-source OCT and histological analysis. Results: Compared with the controls, the administration of BH eye drops suppressed the myopic shift of refractive error (mean difference ± standard error in the eye with -30 D lens, -13.65 ± 5.69 D vs. 2.55 ± 4.30 D; P < 0.001), axial elongation (0.226 ± 0.013 mm vs. 0.183 ± 0.023 mm; P < 0.05), choroidal thinning (-2.01 ± 1.80 µm vs. 1.88 ± 1.27 µm; P < 0.001), and scleral thinning (11.41 ± 3.91 µm vs. 19.72 ± 4.01 µm; P < 0.01) with myopia progression and increased ChBP (52.0% ± 4.1% vs. 59.5% ± 6.3%; P < 0.05). The suppressive effect of BH eye drops was dose-dependent and higher than that of other glaucoma eye drops and alpha1 blockers. Conclusions: These results demonstrate the potential of BH eye drops in the treatment of myopia and support further investigation of their efficacy in humans. Further studies are needed to determine the mechanism of action and long-term safety of this treatment.

Access to Document (DOI)

Establishment of a novel ER-stress induced myopia model in mice

Kang L*, Ikeda SI*, Yang Y, Jeong H, Chen J, Zhang Y, Negishi K, Tsubota K†, Kurihara T†

Eye Vis. (Eye and Vision) 10 ( 1 ) 44 2023.11

Last author, Corresponding author, Accepted

Background: Recent studies have indicated a strong correlation between endoplasmic reticulum (ER) stress and myopia and that eyedrops containing the ER stress inducer tunicamycin (Tm) can induce myopic changes in C57BL/6 J mice. Therefore, this study aimed to create a new myopia model using Tm eyedrops and to explore the mechanism of ER stress-mediated myopia development. Methods: Three-week-old C57BL/6 J mice were treated with different concentrations (0, 25, 50, and 100 μg/mL) and/or number of applications (zero, one, three, and seven) of Tm eyedrops. Refraction and axial length (AL) were measured before and one week after Tm treatment. Scleral collagen alterations were evaluated under polarised light after picrosirius red staining. ER stress-related indicators, such as the expression of collagen I and cleaved collagen were detected using Western blotting. Results: Compared with the control group, mice administered eyedrops with 50 μg/mL Tm only once showed the greatest myopic shifts in refraction and AL elongation and reduced scleral expression of collagen I. Picrosirius red staining showed a lower percentage of bundled collagen in the Tm group. Expression of ER-stress indicators increased in the Tm groups. Furthermore, optimised administration of Tm induced matrix metalloproteinase-2 (MMP2) expression in the sclera, which plays a major role in collagen degradation. Conclusions: We have demonstrated that ER stress in the sclera is involved in myopia progression. Tm eyedrops induced myopic changes, loosening of the scleral collagen and decreased expression of collagen I. This process may be associated with ER stress in the sclera, which upregulates the expression of MMP2 leading to collagen degradation.

Access to Document (DOI)

Bisphenol A exposure triggers endoplasmic reticulum stress pathway leading to ocular axial elongation in mice

Chen J*, Ikeda SI*, Kang L, Negishi K, Tsubota K†, Kurihara T†

Front Med. (Frontiers in Medicine) 10 1255121 2023.08

Last author, Corresponding author, Accepted

Background: Ocular axial elongation is one of the features of myopia progression. Endoplasmic reticulum (ER) stress-associated scleral remodeling plays an important role in ocular axial elongation. Bisphenol A (BPA) is one of the most common environmental pollutants and is known to affect various human organs through ER stress. However, whether BPA exerts an effect on scleral remodeling remains unknown. The purpose of this study was to determine the effect of BPA on the development of myopia and scleral ER stress. Methods: BPA was administered by intraperitoneal injection. 4-PBA was administered as an endoplasmic reticulum stress inhibitor by eye drops. Refraction and axial length were measured by refractometer and SD-OCT system. Western blot was performed to detect the expression level of ER stress-related proteins. Results: BPA-administered mice exhibit axial elongation and myopic refractive shift with endoplasmic reticulum stress in the sclera. BPA administration activated scleral PERK and ATF6 pathways, and 4-PBA eye drops attenuated ER stress response and suppressed myopia progression. Conclusion: BPA controlled axial elongation during myopia development in a mouse model by inducing scleral ER stress and activation of the PERK/ATF6 pathway. 4-PBA eye drops as ER stress inhibitor suppressed BPA-induced myopia development.

Access to Document (DOI)

“Fruiting Liquid” of Mushroom-Forming Fungi, A Novel Source of Bioactive Compounds – Fruiting-Body Inducer and HIF and Axl Inhibitors

Wu J, Uchida K, Yoshikawa A, Hashimoto M, Kondo M, Nihei K, Ishii M, Choi JH, Miwa Y, Shoda C, Lee D, Nakai A, Kurihara T, D’Alessandro-Gabazza CN, Toda M, Yasuma T, Gabazza EC, Hirai H, Kawagishi H†

J Agric Food Chem. (American Chemical Society (ACS)) 71 ( 36 ) 13338 - 13345 2023.08

Accepted, ISSN 0021-8561

In general, mushroom-forming fungi secrete liquid on the surface of mycelia just before fruiting-body formation. However, no researchers in mushroom science have paid attention to the liquid until now. We formulated a hypothesis that the liquid plays an important role(s) in the formation of the fruiting body and produces various bioactive compounds and named it the “fruiting liquid (FL)”. Four novel compounds (1-4) were isolated from FL of Hypholoma lateritium and Hericium erinaceus. The structures of 1-4 except for their stereochemistry were determined by interpretation of MS and NMR data. The absolute configurations of compounds 1-4 were determined by quantum chemical calculation of the ECD spectrum, by single-crystal X-ray diffraction analyses, or by chemical syntheses. Compounds 1, 3, and 4 induced fruiting body formation of Flammulina velutipes. Compound 4 inhibited the activity of hypoxia-inducible factor, and compounds 2-4 suppressed receptor tyrosine kinase (Axl) expression.

Access to Document (DOI)

Highly-sensitive visual restoration and protection via ectopic expression of chimeric rhodopsin in mice

Katada Y, Yoshida K, Serizawa N, Lee D, Kobayashi K, Negishi K, Okano H, Kandori H, Tsubota K, Kurihara T†

iScience. (Elsevier BV) 26 ( 10 ) 107716 2023.08

Last author, Corresponding author, Accepted, ISSN 2589-0042

Photoreception requires amplification by mammalian rhodopsin through G protein activation, which requires a visual cycle. To achieve this in retinal gene therapy, we incorporated human rhodopsin cytoplasmic loops into Gloeobacter rhodopsin, thereby generating Gloeobacter and human chimeric rhodopsin (GHCR). In a murine model of inherited retinal degeneration, we induced retinal GHCR expression by intravitreal injection of a recombinant adeno-associated virus vector. Retinal explant and visual thalamus electrophysiological recordings, behavioral tests, and histological analysis showed that GHCR restored dim-environment vision and prevented the progression of retinal degeneration. Thus, GHCR may be a potent clinical tool for the treatment of retinal disorders.

Access to Document (DOI)

Identification of potential therapeutic targets for myopic choroidal neovascularization via discovery-driven data mining

Chen J, Ikeda SI, Negishi K, Tsubota K†, Kurihara T†

Curr Eye Res. (Current Eye Research) 48 ( 12 ) 1160 - 1169 2023.08

Last author, Corresponding author, Accepted, ISSN 02713683

Purpose: Myopic choroidal neovascularization (mCNV) is a prevalent cause of vision loss. However, the development of effective therapeutic targets for mCNV has been hindered by the paucity of suitable animal models. Therefore, the aim of this study is to identify potential genes and pathways associated with mCNV and to unearth prospective therapeutic targets that can be utilized to devise efficacious treatments. Methods: Text data mining was used to identify genes linked to choroid, neovascularization, and myopia. g: Profiler was utilized to analyze the biological processes of gene ontology and the Reactome pathways. Protein interaction network analysis was performed using strings and visualized in Cytoscape. MCODE and cytoHubba were used for further screening. Results: Discovery-driven text data mining identified 55 potential genes related to choroid, neovascularization, and myopia. Gene enrichment analysis revealed 11 biological processes and seven Reactome pathways. A protein-protein interaction network with 47 nodes was constructed and analyzed using centrality ranking. Key clusters were identified through algorithm tools. Finally, 14 genes (IL6, FGF2, MMP9, IL10, TNF, MMP2, HGF, MMP3, IGF1, CCL2, CTNNB1, BDNF, NGF, and EDN1), in addition to VEGFA, were evaluated as targets with potential as future therapeutics. Conclusions: This study provides new potential therapeutic targets for mCNV, including IL6, FGF2, MMP9, IL10, TNF, MMP2, HGF, MMP3, IGF1, CCL2, CTNNB1, BDNF, NGF, and EDN1, which correspond to seven potential enriched pathways. These findings provide a basis for further research and offer new possibilities for developing therapeutic interventions for this condition.

Access to Document (DOI)

Long chain acyl-CoA synthetase 6 facilitates the local distribution of di-docosahexaenoic acid- and ultra-long-chain-PUFA-containing phospholipids in the retina to support normal visual function in mice

Kuroha S, Katada Y, Isobe Y, Uchino H, Shishikura K, Nirasawa T, Tsubota K, Negishi K, Kurihara T†, Arita M†

FASEB J. (FASEB Journal) 37 ( 9 ) e23151 2023.08

Corresponding author, Accepted, ISSN 08926638

Docosahexaenoic acid (DHA) and ultra-long-chain polyunsaturated fatty acids (ULC–PUFAs) are uniquely enriched in membrane phospholipids of retinal photoreceptors. Several studies have shown that di-DHA- and ULC–PUFA-containing phospholipids in photoreceptors have an important role in maintaining normal visual function; however, the molecular mechanisms underlying the synthesis and enrichment of these unique lipids in the retina, and their specific roles in retinal function remain unclear. Long-chain acyl-coenzyme A (CoA) synthetase 6 (ACSL6) preferentially converts DHA into DHA–CoA, which is a substrate during DHA-containing lipid biosynthesis. Here, we report that Acsl6 mRNA is expressed in the inner segment of photoreceptor cells and the retinal pigment epithelial cells, and genetic deletion of ACSL6 resulted in the selective depletion of di-DHA– and ULC–PUFA-containing phospholipids, but not mono-DHA-containing phospholipids in the retina. MALDI mass spectrometry imaging (MALDI–MSI) revealed the selective distribution of di-DHA– and ULC–PUFA-containing phospholipids in the photoreceptor outer segment (OS). Electroretinogram of Acsl6−/− mice exhibited photoreceptor cell-derived visual impairment, whereas the expression levels and localization of opsin proteins were unchanged. Acsl6−/− mice exhibited an age-dependent progressive decrease of the thickness of the outer nuclear layers, whereas the inner nuclear layers and OSs were normal. These results demonstrate that ACSL6 facilitates the local enrichment of di-DHA– and ULC–PUFA-containing phospholipids in the retina, which supports normal visual function and retinal homeostasis.

Access to Document (DOI)

Associations between fatty acid intake and diabetic retinopathy in a Japanese population

Sasaki M†, Yuki K, Hanyuda A, Yamagishi K†, Motomura K, Kurihara T, Tomita Y, Mori K, Ozawa N, Ozawa Y, Sawada N, Negishi K, Tsubota K, Tsugane S, Iso H

Sci Rep. (Springer Science and Business Media LLC) 13 ( 1 ) 12903 2023.08

Accepted

Abstract

Residents of Chikusei City, aged 40–74 years, underwent systemic and ophthalmological screening, and participants with diabetes were included in this analysis. Dietary intake was assessed using a food frequency questionnaire and calculated as a percentage of the total energy. The presence of diabetic retinopathy (DR) was defined as Early Treatment Diabetic Retinopathy Study levels ≥ 20 in either eye. The association between dietary fatty acid intake and DR has been examined in a cross-sectional study. Among the 647 diabetic participants, 100 had DR. The mean total fat and saturated fatty acid (SFA) intakes were 22.0% and 7.3% of the total energy intake, respectively. After adjusting for potential confounders, the highest quartiles of total fat and SFA intake were positively associated with the presence of DR compared with the lowest quartiles (odds ratios (95% confidence intervals), 2.61 (1.07–6.39), p for trend = 0.025, and 2.40 (1.12–5.17), p for trend = 0.013, respectively). No significant associations were found between DR prevalence and monounsaturated or unsaturated fatty acid intake. These results suggest that a high intake of fat and SFA may affect the development of DR, even in individuals whose total fat intake is generally much lower than that of Westerners.

Access to Document (DOI)

System for Transmitting Laser and its Safety Evaluation for Measuring Metabolites in Aqueous Humor

Toshihide Kurihara, Ari Shinojima, Taku Kinoshita, Saori Nishizaki, Yoshinori Shirakawa, Sho Kimura, Deokho Lee, Yuki Hidaka, Yasuyo Nishi, Yukari Tsuneyoshi, Hidemasa Torii, Kazuo Tsubota, Kazuno Negishi

J Jpn Ophthalmol Soc. 127 ( 7 ) 672 - 679 2023.07

Lead author, Corresponding author, Accepted

Nicotinamide mononucleotide, a potential future treatment in ocular diseases

Lee D, Tomita Y, Shinojima A, Ban N, Yamaguchi S, Nishioka K, Negishi K, Yoshino J, Kurihara T†

Graefes Arch Clin Exp Ophthalmol. (Graefe's Archive for Clinical and Experimental Ophthalmology) 262 ( 3 ) 689 - 700 2023.06

Last author, Corresponding author, Accepted, ISSN 0721832X

Purpose: The burden of ocular diseases has been gradually increasing worldwide. Various factors are suggested for the development and progression of ocular diseases, such as ocular inflammation, oxidative stress, and complex metabolic dysregulation. Thus, managing ocular diseases requires the modulation of pathologic signaling pathways through many mechanisms. Nicotinamide mononucleotide (NMN) is a bioactive molecule naturally found in life forms. NMN is a direct precursor of the important molecule nicotinamide adenine dinucleotide (NAD+), an essential co-enzyme required for enormous cellular functions in most life forms. While the recent experimental evidence of NMN treatment in various metabolic diseases has been well-reviewed, NMN treatment in ocular diseases has not been comprehensively summarized yet. In this regard, we aimed to focus on the therapeutic roles of NMN treatment in various ocular diseases with recent advances. Methods: How we came to our current opinion with a recent summary was described based on our own recent reports as well as a search of the related literature. Results: We found that NMN treatment might be available for the prevention of and protection from various experimental ocular diseases, as NMN treatment modulated ocular inflammation, oxidative stress, and complex metabolic dysregulation in murine models for eye diseases such as ischemic retinopathy, corneal defect, glaucoma, and age-related macular degeneration. Conclusion: Our current review suggests and discusses new modes of actions of NMN for the prevention of and protection from various ocular diseases and can urge future research to obtain more solid evidence on a potential future NMN treatment in ocular diseases at the preclinical stages.

Access to Document (DOI)

The orientation of choroidal macrophage polarization significantly influences the development of myopia in murine models

Hou J*, Ikeda SI*, Mori K, Jeong H, Torii H, Negishi K, Tsubota K†, Kurihara T†

bioRxiv. (Cold Spring Harbor Laboratory) 544445 2023.06

Last author, Corresponding author

Abstract

Myopia is a primary contributor to visual impairment and has emerged as a global public health concern. Evidence indicates that one of the main structural features of myopia is the corresponding decrease in choroidal thickness, and choroidal macrophages play an important role in maintaining the choroidal thickness. Nevertheless, the effect of choroidal macrophages on myopia remains unclear. Here, we discovered that the continuous intraperitoneal injection of clodronate liposomes depleted choroidal macrophages and leads to myopia, which confirmed that the presence of choroidal macrophages plays an important role in myopia development.

Subsequently, based on the phenotypic characteristics of macrophages, experiments were designed to study the effects of different polarization directions of macrophages on myopia development. We found that lipopolysaccharides (LPS) injection can induce the polarization of choroidal M1 macrophages and result in myopia. Conversely, IL-4 or IL-13 injection causes choroidal M2 macrophage polarization and suppresses the progression of myopia. Additionally, we demonstrated that the opposite effects of M1 and M2 macrophages on myopia development may be related to their impacts on inflammation and oxidative stress response. These findings establish that choroidal macrophages are critically important in the development of myopia and provide new strategies for the development of myopic therapies.

Access to Document (DOI)

Encephalopsin (OPN3) is required for normal refractive development and the GO/GROW response to induced myopia

Linne C, Mon KY, D’Souza S, Jeong H, Jiang X, Brown DM, Zhang K, Vemaraju S, Tsubota K, Kurihara T, Pardue MT, Lang RA†

Mol Vis. (Molecular vision) 29 39 - 57 2023.05

Accepted

Purpose: Myopia, or nearsightedness, is the most common form of refractive error and is increasing in prevalence. While significant efforts have been made to identify genetic variants that predispose individuals to myopia, these variants are believed to account for only a small portion of the myopia prevalence, leading to a feedback theory of emmetropization, which depends on the active perception of environmental visual cues. Consequently, there has been renewed interest in studying myopia in the context of light perception, beginning with the opsin family of G-protein coupled receptors (GPCRs). Refractive phenotypes have been characterized in every opsin signaling pathway studied, leaving only Opsin 3 (OPN3), the most widely expressed and blue-light sensing noncanonical opsin, to be investigated for function in the eye and refraction. Methods: Opn3 expression was assessed in various ocular tissues using an Opn3eGFP reporter. Weekly refractive development in Opn3 retinal and germline mutants from 3 to 9 weeks of age was measured using an infrared photorefractor and spectral domain optical coherence tomography (SD-OCT). Susceptibility to lens-induced myopia was then assessed using skull-mounted goggles with a -30 diopter experimental and a 0 diopter control lens. Mouse eye biometry was similarly tracked from 3 to 6 weeks. A myopia gene expression signature was assessed 24 h after lens induction for germline mutants to further assess myopia-induced changes. Results: Opn3 was found to be expressed in a subset of retinal ganglion cells and a limited number of choroidal cells. Based on an assessment of Opn3 mutants, the OPN3 germline, but not retina conditional Opn3 knockout, exhibits a refractive myopia phenotype, which manifests in decreased lens thickness, shallower aqueous compartment depth, and shorter axial length, atypical of traditional axial myopias. Despite the short axial length, Opn3 null eyes demonstrate normal axial elongation in response to myopia induction and mild changes in choroidal thinning and myopic shift, suggesting that susceptibility to lens-induced myopia is largely unchanged. Additionally, the Opn3 null retinal gene expression signature in response to induced myopia after 24 h is distinct, with opposing Ctgf, Cx43, and Egr1 polarity compared to controls. Conclusions: The data suggest that an OPN3 expression domain outside the retina can control lens shape and thus the refractive performance of the eye. Prior to this study, the role of Opn3 in the eye had not been investigated. This work adds OPN3 to the list of opsin family GPCRs that are implicated in emmetropization and myopia. Further, the work to exclude retinal OPN3 as the contributing domain in this refractive phenotype is unique and suggests a distinct mechanism when compared to other opsins.

　 Previous page - Next page 　