Intravitreal Administration of Retinal Organoids-Derived Exosomes Alleviates Photoreceptor Degeneration in Royal College of Surgeons Rats by Targeting the Mitogen-Activated Protein Kinase Pathway.

Increasing evidence suggests that exosomes are involved in retinal cell degeneration, including their insufficient release; hence, they have become important indicators of retinopathies. The exosomal microRNA (miRNA), in particular, play important roles in regulating ocular and retinal cell functions, including photoreceptor maturation, maintenance, and visual function. Here, we generated retinal organoids (ROs) from human induced pluripotent stem cells that differentiated in a conditioned medium for 60 days, after which exosomes were extracted from ROs (Exo-ROs). Subsequently, we intravitreally injected the Exo-RO solution into the eyes of the Royal College of Surgeons (RCS) rats. Intravitreal Exo-RO administration reduced photoreceptor apoptosis, prevented outer nuclear layer thinning, and preserved visual function in RCS rats. RNA sequencing and miRNA profiling showed that exosomal miRNAs are mainly involved in the mitogen-activated protein kinase (MAPK) signaling pathway. In addition, the expression of MAPK-related genes and proteins was significantly decreased in the Exo-RO-treated group. These results suggest that Exo-ROs may be a potentially novel strategy for delaying retinal degeneration by targeting the MAPK signaling pathway.

Prevalence of soy protein hypersensitivity in cow's milk protein-sensitive children in Korea.

This study was aimed to evaluate the prevalence of soy protein hypersensitivity in cow's milk protein-sensitive children in Korea. A total of 1,363 patients with atopic dermatitis, urticaria, enterocolitis syndrome, bronchial asthma or allergic rhinitis were recruited. First, we estimated the prevalence of sensitization to soy in children sensitized to cow's milk. Specific IgE levels > 0.7 kU/L by CAP assay were considered positive. Next, the prevalence of soy allergy in cow's milk allergy (CMA) patients was investigated. Those children whose parents agreed to participate the open challenge test with soy had a convincing history of allergic reactions elicited by cow's milk and these symptoms were relieved by elimination. All of them had negative soy-specific IgE. Patients with positive soy-specific IgE accounted for 18.3% of 224 children sensitized to cow's milk protein. The prevalence of sensitization to soy decreased with age (36.8% in the first year of life, 16.4% in the second year, and 13.7% in the third year). Of 21 CMA patients, 42.9% (n=9) were determined to have soy allergy (mean age 10.3 months). Our results suggest that soy protein formula should be carefully used as a substitute for cow's milk in CMA patients, especially during infancy.