Objectives: This study examined the association between loneliness and alcohol consumption among Korean adults and explored the differences across sociodemographic subgroups, including sex, age, income, occupation, and marital status. Methods: Data were obtained from the 2021 National Mental Health Survey of Korea, including 5491 adults aged 18 years or older. Loneliness was measured using the Loneliness and Social Isolation Measure-6 (LSIS-6). Alcohol consumption was categorized as abstinence, moderate drinking, or high-risk drinking. Depressive symptoms were classified according to the KoreanComposite International Diagnostic Interview (K-CIDI) criteria. The group differences were assessed using analysis of variance (ANOVA) and chi-square tests. Complex-sample multinomial logistic regression was performed to examine the associations between loneliness and alcohol consumption while adjusting for age, gender, income, occupation, and marital status. Results: Sociodemographic characteristics significantly differed across alcohol-use groups. After adjusting for the covariates and depressive symptoms, loneliness remained positively associated with high-risk drinking. Age-stratified analyses suggested that this association was observed only among adults aged 60 years and older. Moderate drinking was not significantly associated with loneliness in all age groups. Conclusion Loneliness was independently associated with high-risk drinking in Korean adults, particularly in older adults. These findings highlight the importance of incorporating social isolation and loneliness into alcohol-related screening and prevention strategies, especially for aging populations.

Ubiquitination of proteins plays an essential role in various cellular processes, including protein degradation, DNA repair, and cell signaling pathways. Previous studies have shown that protein ubiquitination is implicated in regulating pluripotency as well as fate determination of stem cells. To identify how protein ubiquitination affects differentiation of embryonic stem cells, we analyzed microarray data, which are available in the public domain, of E3 ligases and deubiquitinases whose levels changed during stem cell differentiation. Expression of pja2, a member of the RING-type E3 ligase family, was up-regulated during differentiation of stem cells. Wnt/β-catenin signaling is one of the most important signaling pathways for regulation of the self-renewal and differentiation of embryonic stem cells. Pja2 was shown to bind to TCF/LEF1, which are transcriptional factors for Wnt/β-catenin signaling, and regulate protein levels by ubiquitination, leading to down-regulation of Wnt signaling activity. Based on these results, we suggest that E3 ligase Pja2 regulates stem cell differentiation by controlling the level of TCF/LEF1 by ubiquitination.
DNA Repair ; Down-Regulation ; Embryonic Stem Cells ; Humans ; Ligases ; Proteolysis ; Public Sector ; Stem Cells ; Ubiquitin ; Ubiquitin-Protein Ligases ; Ubiquitin-Specific Proteases ; Ubiquitination