The Necroptosis Pathway Is Upregulated in the Cornea in Mice With Ocular Graft-Versus-Host Disease.

Purpose: To identify molecular signatures specific for ocular graft-versus-host disease (GVHD) by proteomic analysis of corneas from mice with GVHD. Methods: We identified differentially expressed proteins (DEPs) in corneal samples from GVHD model mice and syngeneic control mice 4 weeks after bone marrow transplantation. Data-independent acquisition analysis was performed on individual samples, and the roles of DEPs in biological pathways related to GVHD were evaluated via bioinformatics and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses. Results: Three important signaling pathways were upregulated in the cornea in mice with GVHD: (1) the necroptosis pathway, (2) the mitogen-activated protein kinase (MAPK) pathway, and (3) as previously reported, the neutrophil extracellular trap (NET) pathway. In those signaling pathways, we identified new upregulated molecules, including (1) receptor-interacting protein kinase 1 (RIPK1), RIPK3, interferon regulatory factor 9, the interferon-induced double-stranded RNA-activated protein kinase lipoxygenase, and high mobility group box1 (HMGB1) which are damage-associated molecular patterns (DAMPs) in the necroptosis pathway; (2) the sequentially upregulated interleukin 1 (IL-1) receptor-associated kinase (IRAK), an evolutionarily conserved signaling intermediate in the Toll pathway (ECSIT), and p38, which is downstream of the IL-1 receptor and increased CDC42/Rac (Rac2), a Rho family GTPase in the MAPK pathway; and (3) the integrin components CR3 and macrophage-1 antigen (MAC-1), which are DAMPs, and the pyroptosis-related protein gasdermin D (GSDMD) in the NET pathway. Conclusions: These novel molecules may help researchers elucidate the pathogenesis of GVHD and identify new therapeutic targets for corneal changes in patients with ocular GVHD.

Choroidal thinning in myopia is associated with axial elongation and severity of myopic maculopathy.

High myopia can lead to pathologic myopia and visual impairment, whereas its causes are unclear. We retrospectively researched high myopia cases from patient records to investigate the association between axial elongation and myopic maculopathy. Sixty-four eyes were examined in patients who visited the department between July 2017 and June 2018, had an axial length of 26 mm or more, underwent fundus photography, and had their axial length measured twice or more. The average axial length was 28.29 ± 1.69 mm (mean ± standard deviation). The average age was 58.3 ± 14.4 years old. Myopic maculopathy was categorized as mild (grades 0 and 1) and severe (grades 2, 3, and 4). The severe group had longer axial lengths than the mild group (P < 0.05). Moreover, the severe group exhibited thinner choroidal thickness than the mild group (P < 0.05). When subjects were grouped by axial elongation over median value within a year, the elongation group showed thinner central choroidal thickness than the non-elongation group (142.1 ± 91.9 vs. 82.9 ± 69.8, P < 0.05). In conclusion, in patients with high myopia, the severity of maculopathy correlated with choroidal thickness and axial length. Thinner choroidal thickness was associated with axial elongation based on the baseline axial length.

Establishment of an in vitro choroid complex system for vascular response screening.

The choroid, a vascularized tissue situated between the retina and the sclera, plays a crucial role in maintaining ocular homeostasis. Despite its significance, research on choroidal abnormalities and the establishment of effective in vitro models have been limited. In this study, we developed an in vitro choroid model through the co-culture of human induced pluripotent stem cells (hiPSC)-derived endothelial cells (ECs) and mouse choroidal fibroblasts (msCFs) with hiPSC-derived retinal pigment epithelial (RPE) cells via a permeable membrane. This model, inclusive of ECs, CFs, and RPE cells, exhibited similarities with in vivo choroidal vessels, as confirmed through immunohistochemistry of extracellular matrix markers and vascular-related markers, as well as choroid angiogenesis sprouting assay analysis. The effectiveness of our in vitro model was demonstrated in assessing vascular changes induced by drugs targeting vasoregulation. Our model offers a valuable tool for gaining insights into the pathological mechanisms underlying choroid development and the progression of choroidal vascular diseases.

Slowing of Greater Axial Length Elongation Stemming from the Coronavirus Disease 2019 Pandemic with Increasing Time Outdoors: The Tokyo Myopia Study.

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 Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Myopia Is an Ischemic Eye Condition: A Review from the Perspective of Choroidal Blood Flow.

Myopia is a common refractive error that affects a large proportion of the population. Recent studies have revealed that alterations in choroidal thickness (ChT) and choroidal blood flow (ChBF) play important roles in the progression of myopia. Reduced ChBF could affect scleral cellular matrix remodeling, which leads to axial elongation and further myopia progression. As ChT and ChBF could be used as potential biomarkers for the progression of myopia, several recent myopia treatments have targeted alterations in ChT and ChBF. Our review provides a comprehensive overview of the recent literature review on the relationship between ChBF and myopia. We also highlight the importance of ChT and ChBF in the progression of myopia and the potential of ChT as an important biomarker for myopia progression. This summary has significant implications for the development of novel strategies for preventing and treating myopia.

Single-cell RNA-sequencing reveals the transcriptional landscape of lacrimal gland in GVHD mouse model.

PURPOSE: To investigate the global transcriptional landscape of lacrimal gland cell populations in the GVHD mouse model. METHODS: Single-cell RNA sequencing and further bioinformatic analysis of dissociated lacrimal gland (LG) cells from the mouse model were performed. Parts of transcriptional results were confirmed by immunofluorescence staining. RESULTS: We identified 23 cell populations belonging to 11 cell types. In GVHD LG, the proportion of acinar cells, myoepithelial cells, and endothelial cells was remarkably decreased, while T cells and macrophages were significantly expanded. Gene expression analysis indicated decreased secretion function, extracellular matrix (ECM) synthesis, and increased chemokines of myoepithelial cells. A newly described epithelial population named Lrg1high epithelial cells, expressing distinct gene signatures, was exclusively identified in GVHD LG. The fibroblasts exhibited an inflammation gene pattern. The gene pattern of endothelial cells suggested an increased ability to recruit immune cells and damaged cell-cell junctions. T cells were mainly comprised of Th2 cells and effective memory CD8+ T cells. GVHD macrophages exhibited a Th2 cell-linked pattern. CONCLUSIONS: This single-cell atlas uncovered alterations of proportion and gene expression patterns of cell populations and constructed cell-cell communication networks of GVHD LG. These data may provide some new insight into understanding the development of ocular GVHD.

Cellular senescence promotes meibomian gland dysfunction in a chronic graft-versus-host disease mouse model.

PURPOSE: Aging is a well-established risk factor for meibomian gland dysfunction (MGD). We previously reported an accelerated cellular senescence phenomenon in the lacrimal glands of a murine model of chronic graft-versus-host disease (cGVHD). Herein, we aimed to elucidate the relationship between cellular senescence and MGD in cGVHD mice, utilizing the senolytic agent ABT-263. METHODS: A cGVHD mouse model was established through allogeneic bone marrow transplantation (BMT) from B10.D2 to BALB/c mice. Subsequently, cGVHD mice were treated with either ABT-263 or vehicle. The eyelids of recipients were analyzed at 4-week intervals post-BMT in both groups. RESULTS: Meibomian gland (MG) area was significantly smaller in cGVHD mice than in syngeneic control mice. ABT-263-treated mice retained a significantly larger MG area than their vehicle-treated counterparts. Pathological and immunohistochemical examinations revealed significant reductions in eyelid tissue inflammation and pathological fibrosis in the ABT-263 group compared to that in the vehicle-treated group. Additionally, expression of DNA damage markers, senescent cell markers, and senescence-associated secretory phenotype (SASP) factors was elevated in the eyelids of cGVHD mice compared with that in syngeneic mice. The expression of these cellular senescence-associated molecules was considerably suppressed in ABT-263-treated eyelids compared to that in vehicle-treated ones. CONCLUSIONS: Cellular senescence, along with expression of SASP factors, exhibited increased activity in the eyelids, particularly in the MGs of cGVHD mice. ABT-263 mitigated the severity of MGD. These findings highlight the potential of targeting cellular senescence as an effective approach for MGD treatment in cGVHD.

Electroencephalogram-detected stress levels in the frontal lobe region of patients with dry eye.

PURPOSE: To evaluate stress levels extracted from prefrontal electroencephalogram (EEG) signals and investigate their relationship with dry eye symptoms. METHODS: This prospective, cross-sectional, comparative study included 25 eyes of 25 patients with aqueous tear-deficient dry eye (low Schirmer group), 25 eyes of 25 patients with short tear breakup time dry eye (short breakup time group), and 24 eyes of 24 individuals without dry eye. An EEG test, the Japanese version of the Ocular Surface Disease Index (OSDI), and a stress questionnaire were administered. EEG-detected stress levels were assessed under three conditions: eyes closed, eyes open, and eyes open under ocular surface anesthesia. RESULTS: Stress levels were significantly lower when the eyes were closed than when they were open in all groups (all P < 0.05). Stress levels during eyes open under ocular surface anesthesia were significantly lower than those during eyes open without anesthesia only in the low Schirmer group; no differences were found between the short breakup time and control groups. OSDI scores were associated with EEG-detected stress levels (P = 0.06) and vital staining score (P < 0.05) in the low Schirmer group; they were not associated with EEG-detected stress (P > 0.05), but with subjective stress questionnaire scores and breakup time values in the short breakup time group (P < 0.05). CONCLUSIONS: In the low Schirmer group, peripheral nerve stimulation caused by ocular surface damage induced stress reactions in the frontal lobe, resulting in dry eye symptoms. Conversely, in the short breakup time group, the stress response in the frontal lobe was not related to symptom development.

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

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.

Evaluation of a new portable corneal topography system for self-measurement using smartphones: a pilot study.

PURPOSE: Herein, we propose the use of the "KeraVio Ring", which is a portable, selfie-based, smartphone-attached corneal topography system that is based on the Placido ring videokeratoscope. The goal of this study was to evaluate and compare corneal parameters between KeraVio Ring and conventional corneal tomography images. METHODS: We designed the KeraVio Ring as a device comprising 3D-printed LED rings for generating Placido rings that can be attached to a smartphone. Two LED rings are attached to a cone-shaped device, and both corneas are illuminated. Selfies were taken using the KeraVio Ring attached to the smartphone without assistance from any of the examiners. Captured Placido rings on the cornea were analysed by intelligent software to calculate corneal parameters. Patients with normal, keratoconus, or LASIK-treated eyes were included. Anterior segment optical coherence tomography (AS-OCT) was also performed for each subject. RESULTS: We found highly significant correlations between the steepest and flattest keratometry, corneal astigmatism, and vector components obtained with the KeraVio Ring and AS-OCT. In subjects with normal, keratoconus, and LASIK-treated eyes, the mean difference in corneal astigmatism between the two devices was -0.8 ± 1.4 diopters (D) (95% limits of agreement (LoA), -3.6 to 2.0), -1.8 ± 3.7 D (95% LoA, -9.1 to 5.5), and -1.5 ± 1.3 D (95% LoA, -4.0 to 1.1), respectively. CONCLUSIONS: The experimental results showed that the corneal parameters obtained by the KeraVio Ring were correlated with those obtained with AS-OCT. The KeraVio Ring has the potential to address an unmet need by providing a tool for portable selfie-based corneal topography.

Safety and efficacy of long-term nicotinamide mononucleotide supplementation on metabolism, sleep, and nicotinamide adenine dinucleotide biosynthesis in healthy, middle-aged Japanese men.

Obesity and aging are major risk factors for several life-threatening diseases. Accumulating evidence from both rodents and humans suggests that the levels of nicotinamide adenine dinucleotide (NAD+), a regulator of many biological processes, declines in multiple organs and tissues with aging and obesity. Administration of an NAD+ intermediate, nicotinamide mononucleotide (NMN), replenishes intracellular NAD+ levels and mitigates aging- and obesity-associated derangements in animal models. In this human clinical study, we aimed to investigate the safety and effects of 8-week oral administration of NMN on biochemical, metabolic, ophthalmologic, and sleep quality parameters as well as on chronological alterations in NAD+ content in peripheral tissues. An 8-week, single-center, single-arm, open-label clinical trial was conducted. Eleven healthy, middle-aged Japanese men received two 125-mg NMN capsules once daily before breakfast. The 8-week NMN supplementation regimen was well-tolerated; NAD+ levels in peripheral blood mononuclear cells increased over the course of NMN administration. In participants with insulin oversecretion after oral glucose loading, NMN modestly attenuated postprandial hyperinsulinemia, a risk factor for coronary artery disease (n = 3). In conclusion, NMN overall safely and effectively boosted NAD+ biosynthesis in healthy, middle-aged Japanese men, showing its potential for alleviating postprandial hyperinsulinemia.

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

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.

Topical Application of Bunazosin Hydrochloride Suppresses Myopia Progression With an Increase in Choroidal Blood Perfusion.

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.

Non-apoptotic regulated cell death in Fuchs endothelial corneal dystrophy.

Introduction: Fuchs endothelial corneal dystrophy (FECD) is the leading cause of corneal blindness in developed countries. Corneal endothelial cells in FECD are susceptive to oxidative stress, leading to mitochondrial dysfunction and cell death. Oxidative stress causes many forms of cell death including parthanatos, which is characterized by translocation of apoptosis-inducing factor (AIF) to the nucleus with upregulation of poly (ADP-ribose) polymerase 1 (PARP-1) and poly (ADP-ribose) (PAR). Although cell death is an important aspect of FECD, previous reports have often analyzed immortalized cell lines, making the evaluation of cell death difficult. Therefore, we established a new in vitro FECD model to evaluate the pathophysiology of FECD. Methods: Corneal endothelial cells were derived from disease-specific induced pluripotent stem cells (iPSCs). Hydrogen peroxide (H2O2) was used as a source for oxidative stress to mimic the pathophysiology of FECD. We investigated the responses to oxidative stress and the involvement of parthanatos in FECD-corneal endothelial cells. Results: Cell death ratio and oxidative stress level were upregulated in FECD with H2O2 treatment compared with non-FECD control, indicating the vulnerability of oxidative stress in FECD. We also found that intracellular PAR, as well as PARP-1 and AIF in the nucleus were upregulated in FECD. Furthermore, PARP inhibition, but not pan-caspase inhibition, rescued cell death, DNA double-strand breaks, mitochondrial membrane potential depolarization and energy depletion, suggesting that cell death was mainly due to parthanatos. Conclusions: We report that parthanatos may be involved in the pathophysiology of FECD and targeting this cell death pathway may be a potential therapeutic approach for FECD.

Opsin 5 mediates violet light-induced early growth response-1 expression in the mouse retina.

Myopia is an abnormal vision condition characterized by difficulties in seeing distant objects. Myopia has become a public health issue not only in Asian countries but also in Western countries. Previously, we found that violet light (VL, 360-400 nm wavelength) exposure effectively suppressed myopia progression in experimental chick and mice models of myopia. The inhibitory effects of VL on myopia progression are reduced in retina-specific opsin 5 (Opn5) knockout (KO) mice. Furthermore, VL exposure upregulated early growth response-1 (Egr-1) expression in the chorioretinal tissues of chicks. However, the expression of EGR-1 and role of OPN5 in mice following VL exposure remain unclear. In this study, we examined whether VL exposure-induced EGR-1 upregulation depends on Opn5 expression in the mouse retina. EGR-1 mRNA and protein expressions increased in the mouse retina and mouse retinal 661W cells following VL exposure. These increases were consistently reduced in retina specific Opn5 conditional KO mice and Opn5 KO 661W cells. Our results suggest that OPN5 mediates VL-induced EGR-1 upregulation in mice. These molecular targets could be considered for the prevention and treatment of myopia.

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

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.

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

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.

Breakfast Skipping is associated with More Deleterious Lifestyle Behaviors among Japanese Men: The TRF-Japan Study Using the Original "Taberhythm" Smartphone Application.

Background: Time-restricted eating has been increasingly recognized as a promising option to reduce food intake and combat obesity. Especially in Asian countries such as Japan, because of the wide variety of food choices available, a dietary approach that emphasizes meal timing can be more practical and easier to implement and adhere to, compared with approaches that focus on specific dietary content, such as low-fat or low-carbohydrate diets. Objectives: We aimed to identify eating patterns among Japanese men and women using a smartphone application (app) called "Taberhythm." In addition, we sought to evaluate the relationship of breakfast eating habits with lifestyle behaviors and body mass index, and determine whether sex differences were present. Methods: A total of 3369 smartphone users were eligible to participate in this observational study. Users recorded 1 mo of lifestyle logs using the app; 254 participants (178 women, 38 ± 12 y old, body mass index 23.3 ± 4.9 kg/m2) had sufficient records to calculate daily fasting duration and sleep duration, and were eligible for the analyses. Results: Fasting duration was ∼12.6 h and was longer in women than men, among participants who never skipped breakfast. Breakfast skipping was associated with longer screen time, and more frequent snacking, only in men. Men with irregular breakfast eating patterns had a longer duration of fasting after awakening that was associated with obesity. Conclusions: We investigated eating patterns among Japanese people using a smartphone app and revealed that skipping breakfast was more deleterious in men than in women.

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.

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.