Tsubota Laboratory, Inc.

While endoplasmic reticulum (ER) stress has been implicated in various aspects of graft-versus-host disease (GVHD), its effects on the eyelids and ocular surface in patients with chronic GVHD (cGVHD) remains poorly understood. We aimed to investigate the relationship between ER stress and ocular GVHD using the ER stress suppressor, 4-phenylbutyric acid (PBA).

The study used allogeneic bone marrow transplantation (BMT) and syngeneic BMT to establish a cGVHD mouse model. cGVHD mice were treated with either intraperitoneal administration of PBA or 2 % PBA eye drops following BMT.

The Intraperitoneal PBA-treated (PBAip) group retained a larger meibomian gland (MG) area and corneal epithelial damage and inflammatory and fibrotic cell infiltration in the ocular surface was attenuated compared to vehicle-treated cGVHD mice. The expression of unfolded protein response markers was significantly elevated in the vehicle group compared to the syngeneic control and the PBAip group. Electron microscopy and immunohistochemistry revealed that fibroblasts and macrophages infiltrated the eyelids and ocular surface of cGVHD mice under ER stress. The corneal fluorescein staining score was significantly lower in the PBA eye drop-treated group than in the vehicle-treated group. The numbers of leukocyte marker CD45-, T cell marker CD4-, and macrophage marker F4/80-positive cells were significantly reduced in the PBA eye drop-treated group compared to the vehicle group.

The study suggests that the ER stress response, which is triggered by cGVHD in ocular surface tissues, can be suppressed by PBA, an ER stress suppressor, potentially offering therapeutic benefits in ocular GVHD.

The prevalence of myopia has increased worldwide in recent decades, shifting the focus in research from genetic to environmental factors. The roles of diet in the development of myopia may be directly associated with gut microbiota composition. Therefore this study evaluated the effects of antibiotic-induced gut dysbiosis on the development of negative lens-induced myopia.

We administered several antibiotics (ampicillin, vancomycin, neomycin, or a mixture) to induce gut dysbiosis in male C57BL/6J mice with negative lens-induced myopia. Gut microbiome profiles were analyzed by 16 S rRNA gene sequencing.

Mice administered vancomycin, neomycin, and a mixture of three antibiotics exhibited resistance to lens-induced myopia, unlike control or ampicillin-administered mice. Further analyses revealed no specific trend in the gut microbiota composition and diversity related to myopia resistance, except for an increase in the abundance of Clostridiaceae.

These findings demonstrate the potential role of the gut microbiome, particularly Clostridiaceae family, in myopia susceptibility. This study offers new insights into the preventive strategies and therapeutic interventions to mitigate myopia development.

This study aimed to evaluate the efficacy of photoimmunotherapy (PIT) targeting VEGFR2 for the treatment of neovascular AMD and to investigate its potential as a novel therapeutic strategy.

DC101-IR700, a conjugate of the anti-mouse VEGFR2 monoclonal antibody DC101 and the photosensitizer IR700, was investigated both in vitro and in vivo. VEGFR2 expression in endothelial cells was confirmed via qPCR and immunocytochemistry. Laser-induced choroidal neovascularization (CNV) was established in C57BL/6J mice. Localization of DC101-IR700 within CNV lesions was assessed by immunofluorescence. After PIT was performed using either a 690 nm near-infrared manual laser or a slit lamp laser, CNV volumes were quantified through confocal microscopy. Cell viability post PIT was measured using MTT assay and cell death in CNV lesions was evaluated using TUNEL staining.

DC101-IR700 localized specifically to VEGFR2-positive cells in CNV lesions, and PIT induced significant VEGFR2-dependent cytotoxicity in vitro. In vivo, both PIT and directional PIT using slit lamp laser significantly reduced CNV volumes compared with controls. TUNEL staining confirmed VEGFR2-specific cell death in treated CNV lesions. Directional PIT achieved similar efficacy to PIT, demonstrating its potential as a clinically viable alternative.

PIT targeting VEGFR2 selectively induced cell death in pathological neovascular tissues, significantly reducing CNV volume in an AMD model. These findings suggest that VEGFR2-specific PIT represents a promising and targeted approach for treating neovascular AMD, offering advantages over conventional anti-VEGF therapies by potentially decreasing treatment frequency and improving efficacy.