Background: In this study, the relationship between depression and stress-coping strategies among public enterprise workers whose workplaces were relocated to a newly-built innovation city was investigated. Methods: This study included a total of 922 public enterprise workers living in Naju Innovation City. Along with their sociodemographic data, each subject was assessed concerning depression, occupational stress, and stress-coping strategies using the Center for Epidemiologic Studies Depression Scale(CES-D), Korean Occupational Stress Scale (KOSS), and stress-coping scale (SCS), respectively. Logistic regression was performed to investigate the impact of the relevant factors on depressive symptoms. Results: The overall prevalence of depressive symptoms was 14%. Some sociodemographic variables, the total scores of the KOSS, and four subscales of the SCS revealed significant differences between the depressed and normal groups. Multivariate regression analysis revealed that the KOSS (odds ratio [OR], 1.17; p<0.001) and SCS, such as problem-solving-focused (OR, 0.75; p<0.001), emotion-focused (OR, 1.15; p<0.05), and wishful-thinking-focused (OR, 1.10; p<0.05), were significantly associated with depression. Conclusion The results indicated that depressive symptoms were highly prevalent among workers whose workplaces were relocated. In addition, these symptoms were found to be related with occupational stress and stress-coping strategies. Our findings also suggest that promoting healthy stress-coping strategies and reducing occupational stress may help in preventing the occurrence of depression and managing depressed workers.

BACKGROUND: Retinal degenerative disease (RDD), one of the most common causes of blindness, is predominantly caused by the gradual death of retinal pigment epithelial cells (RPEs) and photoreceptors due to various causes. Cell-based therapies, such as stem cell implantation, have been developed for the treatment of RDD, but potential risks, including teratogenicity and immune reactions, have hampered their clinical application. Stem cell-derived extracellular vesicles (EVs) have recently emerged as a cell-free alternative therapeutic strategy; however, additional invasiveness and low yield of the stem cell extraction process is problematic. METHODS: To overcome these limitations, we developed therapeutic EVs for the treatment of RDD which were extracted from tonsil-derived mesenchymal stem cells obtained from human tonsil tissue discarded as medical waste following tonsillectomy (T-MSC EVs). To verify the biocompatibility and cytoprotective effect of T-MSC EVs, we measured cell viability by co-culture with human RPE without or with toxic all-trans-retinal. To elucidate the cytoprotective mechanism of T-MSC EVs, we performed transcriptome sequencing using RNA extracted from RPEs. The in vivo protective effect of T-MSC EVs was evaluated using Pde6b gene knockout rats as an animal model of retinitis pigmentosa. RESULTS: T-MSC EVs showed high biocompatibility and the human pigment epithelial cells were significantly protected in the presence of T-MSC EVs from the toxic effect of all-trans-retinal. In addition, T-MSC EVs showed a dosedependent cell death-delaying effect in real-time quantification of cell death. Transcriptome sequencing analysis revealed that the efficient ability of T-MSC EVs to regulate intracellular oxidative stress may be one of the reasons explaining their excellent cytoprotective effect. Additionally, intravitreally injected T-MSC EVs had an inhibitory effect on the destruction of the outer nuclear layer in the Pde6b gene knockout rat. CONCLUSIONS Together, the results of this study indicate the preventive and therapeutic effects of T-MSC EVs during the initiation and development of retinal degeneration, which may be a beneficial alternative for the treatment of RDD.