16S rRNA sequencing in chronic dacryocystitis.

CLINICAL RELEVANCE: The pathogenesis of chronic dacryocystitis (CDC) is associated with a variety of bacteria. Investigating microflora has the potential to provide a theoretical basis for preventing and treating CDC. BACKGROUND: 16S rRNA sequencing is a sequence-based bacterial analysis. The application of 16S rRNA sequencing in CDC is rarely reported. METHODS: A case-control study of infected and healthy eyes diagnosed as CDC patients was conducted. Seventy-eight patients were divided into A (conjunctival sac secretions from healthy eyes), B (conjunctival sac secretions from affected eyes), and C (lacrimal sac secretions from affected eyes) groups. The flora of samples was analysed with 16S rRNA sequencing, and the data was analysed using QIIME, R, LefSE and other software. The potential functions were analysed by PICRUSt. RESULTS: A total of 1440 operational taxonomic units (OTUs) were obtained, 139 specific to group A, 220 specific to group B, and 239 specific to group C. There was no significant difference in α index between the three groups. The beta diversity and grouping analysis data indicated that the three groups of flora were similar in species richness and diversity, but there were some differences in composition. In group A, the abundance of Pseudomonadaceae, Chlorobacteria, Moraceae, Staphylococcaceae, Bacillariophyceae, Immunobacterium spp. and Bacillus spp. was higher; in group B, the abundance of Burkholderiaceae, Sphingomonas, Rhizobia, Stalked Bacteria, Sphingomonadaceae, Enterobacteriaceae, Shortwaveomonas spp. was higher; in group C, the abundance of Streptococcus digestiveis, Propionibacterium, Enterobacteriaceae, Anaerobacteriaceae, Propionibacteriaceae, Bacillus spp. Neisseria spp. and Shortactomonas spp. was higher. Six pathways were identified to assess the potential microbial functions. CONCLUSION: Alterations in the microbiota of the conjunctiva and lacrimal sac are associated with the pathogenesis of CDC, which may provide certain guidance for antibiotic treatment of CDC.

eIF4A3-mediated circEHMT1 regulation in retinal microvascular endothelial dysfunction in diabetic retinopathy.

BACKGROUND AND OBJECTIVE: Literature has reported that circular RNAs (circRNAs) are crucially associated with diabetic retinopathy (DR). Furthermore, circEHMT1 has been identified to maintain endothelial cell barrier function. This study aimed to investigate the mechanisms that regulate aberrant circEHMT1 expression and its role in the pathogenesis of DR. METHODS: In this study, retinal microvascular endothelial cells were exposed to a high glucose (HG) environment, and subsequently, tube formation and intercellular junction proteins were evaluated. Furthermore, the biological functions of circEHMT1 and its potential regulatory factor, eIF4A3, in microvascular endothelial cells under HG conditions were also assessed. In addition, the regulatory role of eIF4A3 on circEHMT1 expression was confirmed. Moreover, to elucidate the in vivo functions of eIF4A3 and circEHMT1, streptozotocin (STZ) was used to establish a DR model in rats. RESULTS: It was revealed that HG condition decreased circEHMT1 and eIF4A3 expressions and reduced ZO-1, Claudin-5, and Occludin levels in retinal microvascular endothelial cells. Furthermore, it was observed that eIF4A3 could regulate the expression of circEHMT1. Overexpression of eIF4A3 or circEHMT1 under HG conditions improved endothelial cell injury and decreased tube-formation ability. Additionally, in the DR rat model, eIF4A3 overexpression restored circEHMT1 levels and ameliorated retinal vasculature changes. CONCLUSION: Altogether, eIF4A3 regulates circEHMT1 expression, thereby affecting microvascular endothelial cell injury and tube formation. Further understanding the regulatory effect of eIF4A3 on circEHMT1 may provide novel therapeutic targets for DR.

Applications of hydrogel materials in different types of corneal wounds.

Severe corneal injury can lead to a decrease in light transmission and even blindness. Currently, corneal transplantation has been applied as the primary treatment for corneal blindness; however, the worldwide shortage of suitable corneal donor tissue means that a large proportion of patients have no access to corneal transplants. This situation has contributed to the rapid development of various corneal substitutes. The development and optimization of novel hydrogels that aim to replace partial or full-thickness pathological corneas have advanced in the last decade. Meanwhile, with the help of 3D bioprinting technology, hydrogel materials can be molded to a refined and controllable shape, attracting many scientists to the field of corneal reconstruction research. Although hydrogels are not yet available as a substitute for traditional clinical methods of corneal diseases, their rapid development makes us confident that they will be in the near future. We summarize the application of hydrogel materials for various types of corneal injuries frequently encountered in clinical practice, especially focusing on animal experiments and preclinical studies. Finally, we discuss the development and achievements of 3D bioprinting in the treatment of corneal injury.