Development of Non-Invasive miRNA Markers for Assessing the Quality of Human Induced Pluripotent Stem Cell-Derived Retinal Organoids.

Human retinal organoids (ROs) have emerged as valuable tools for studying retinal development, modeling human retinal diseases, and screening drugs. However, their application is limited primarily due to time-intensive generation, high costs, and low reproducibility. Quality assessment of RO differentiation is crucial for their application in research. However, traditional methods such as morphological evaluation and immunohistochemical analysis have limitations due to their lack of precision and invasiveness, respectively. This study aims to identify non-invasive biomarkers for RO differentiation quality using exosomal microRNAs (miRNAs), which are known to reflect cell-specific functions and development in the retina. We differentiated ROs from human induced pluripotent stem cells (hiPSCs) and classified them into 'superior' and 'inferior' groups based on morphological and immunohistochemical criteria. Exosomes from the conditioned media were isolated and analyzed for miRNA content. Our findings revealed distinct miRNA profiles between superior and inferior ROs, with superior ROs exhibiting higher miRNA diversity and specifically up- or down-regulated miRNAs. Gene ontology and pathway enrichment analyses indicated that the target genes of these miRNAs are involved in neuron proliferation and differentiation. The study suggests the potential of exosomal hsa-miR-654-3p and hsa-miR-451a as non-invasive biomarkers for real-time monitoring of RO quality, facilitating the development of standardized, efficient, and cost-effective culture methods.

Anatomical Characteristics of the Anterior Jugular Vein and Its Clinical Relevance.

INTRODUCTION: The anterior jugular vein (AJV) is part of the superficial venous drainage system of the head and neck. Recently, interest in AJV is increasing as various surgical procedures have been developed. The authors conducted a cadaveric study to determine characteristics of AJV in Koreans. METHODS: A total of 44 cadavers were dissected. Anatomical characteristics were analyzed for 34 cadavers in which AJV was well observed. RESULTS: In this study, 21 were males and 13 were females. There were 8 cadavers with only 1 AJV from both sides. There was no significant difference in anatomical characteristics according to gender or AJV variation except for a difference in the length of the neck according to gender. However, it was possible to find a safety zone at the main landmark of the neck that could avoid AJV damage. CONCLUSIONS: By using this safety zone, it is possible to prevent damage to the AJV and reduce complications during various surgical procedures on the head and neck.