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Epigallocatechin gallate (EGCG) is a catechin and an abundant polyphenol in green tea. Although several papers have evaluated EGCG as a cosmetic constituent, the skin hydration effect of EGCG is poorly understood. We aimed to investigate the mechanism by which EGCG promotes skin hydration by measuring hyaluronic acid synthase (HAS) and hyaluronidase (HYAL) gene expression and antioxidant and anti-pigmentation properties using cell proliferation assay, Western blotting analysis, luciferase assay, 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and reverse transcription polymerase chain reaction (RT-PCR) analysis. RT-PCR showed that EGCG increased the expression of natural moisturizing factor-related genes filaggrin (FLG), transglutaminase-1, HAS-1, and HAS-2. Under UVB irradiation conditions, the expression level of HYAL was decreased in HaCaT cells. Furthermore, we confirmed the antioxidant activity of EGCG and also showed a preventive effect against radical-evoked apoptosis by downregulation of caspase-8 and -3 in HaCaT cells. EGCG reduced melanin secretion and production in melanoma cells. Together, these results suggest that EGCG might be used as a cosmetic ingredient with positive effects on skin hydration, moisture retention, and wrinkle formation, in addition to radical scavenging activity and reduction of melanin generation.

The emergence of drug-resistant Mycobacterium tuberculosis ( M . tb ) has led to the development of novel anti-tuberculosis (anti-TB) drugs. Common methods for testing the efficacy of new drugs, including two-dimensional cell culture models or animal models, have several limitations. Therefore, an appropriate model representative of the human organism is required. Here, we developed an M . tb infection model using human lung organoids (hLOs) and demonstrated that M . tb H37Rv can infect lung epithelial cells and human macrophages (hMφs) in hLOs. This novel M . tb infection model can be cultured long-term and split several times while maintaining a similar number of M . tb H37Rv inside the hLOs. Anti-TB drugs reduced the intracellular survival of M . tb in hLOs. Notably, M . tb growth in hLOs was effectively suppressed at each passage by rifampicin and bedaquiline. Furthermore, a reduction in inflammatory cytokine production and intracellular survival of M . tb were observed upon knockdown of MFN2 and HERPUD1 (host-directed therapeutic targets for TB) in our M . tb H37Rv-infected hLO model. Thus, the incorporation of hMφs and M . tb into hLOs provides a powerful strategy for generating an M . tb infection model. This model can effectively reflect host-pathogen interactions and be utilized to test the efficacy of anti-TB drugs and host-directed therapies.

Alternative pre-mRNA splicing is a critical mechanism that generates multiple mRNA from a single gene, thereby increasing the diversity of the proteome. Recent research has highlighted the significance of specific splicing isoforms in cellular processes, particularly in regulating cell numbers. In this review, we examine the current understanding of the role of alternative splicing in controlling cancer cell growth and discuss specific splicing factors and isoforms and their molecular mechanisms in cancer progression. These isoforms have been found to intricately control signaling pathways crucial for cell cycle progression, proliferation, and apoptosis. Furthermore, studies have elucidated the characteristics and functional importance of splicing factors that influence cell numbers. Abnormal expression of oncogenic splicing isoforms and splicing factors, as well as disruptions in splicing caused by genetic mutations, have been implicated in the development and progression of tumors. Collectively, these findings provide valuable insights into the complex interplay between alternative splicing and cell proliferation, thereby suggesting the potential of alternative splicing as a therapeutic target for cancer.

Background The Dokdo sea lion ( Zalophus japonicus ), commonly referred to as Gangchi in Korea and the Japanese sea lion internationally, was endemic to the Northwest Pacific before its extinction in the 1950s. However, its origins, speciation, and genetic diversity remain poorly understood. Results To address this, we sequenced DNA from 16 Z. japonicus bone fragments, obtained from Dokdo and Ulleungdo islands in Korea. Our genome-wide SNP analyses reveal Z. japonicus as the earliest diverged species within its genus, redefining its evolutionary relationship with the California ( Z. californianus ) and Galapagos ( Z. wollebaeki ) sea lions. Our research further elucidates the phylogeny of Z. japonicus , shedding light on the complexity of the genetic isolation process within its genus that was prompted by the geographic isolation of the three populations of Zalophus ancestral stock. Conversely, the genetic signature of the Dokdo sea lion genome can be modeled as an evolutionary pathway involving gene flow from Otariidae species with shared range. In addition, we discovered that the population decline of Z. japonicus started already over 100,000 years ago; however, Z. japonicus genome maintained a relatively high heterozygosity despite nearing extinction. Conclusions Our genome-scale analysis sheds light on the phylogeny of Z. japonicus , the evolutionary pathways underlying its speciation, and its genetic diversity before extinction. Broadly, we elucidate Zalophus gene flow complexity and genetic diversities among extant species. Furthermore, this study offers retrospective genomic insights into the extinction process of a carnivorous marine mammal, information that could aid conservation efforts for extant Otariidae species.

Background Earthquakes are global natural disasters and can cause loss of property, livelihood and affect human health. A 5.4 magnitude earthquake, the Pohang earthquake, occurred in South Korea in 2017. In this study, based on a health-related quality of life (HRQOL) conceptual model, we examined the HRQOL and its associated factors among older adults who had experienced the earthquake. Methods A cross-sectional study was conducted with a quota sample of 312 older adults living in eight villages of a district that was the most damaged area during the Pohang earthquake. Data were collected from January 15–March 19, 2019, via face-to-face interviews using structured questionnaires. Structural equation modeling was performed to explore the associations among depression, posttraumatic stress symptoms, community resilience, social support, disaster preparedness, and HRQOL. Results The mean age of the participants was 77.93 ± 6.11 years. HRQOL scores were 49.85 ± 18.07 (physical health), 50.16 ± 18.75 (psychological health), 61.93 ± 19.20 (social relations), and 49.53 ± 16.37 (environment). The structural equation modeling analysis showed a good fit. Depression had direct ( β  =  − 2.21; p  < 0.001), indirect ( β  =− 0.23; p  < 0.001), and total effects on HRQOL ( β  =  − 2.44; p  < 0.001). Community resilience ( β  = 6.05; p  = 0.001) and social support ( β  = 0.12, p  = 0.001) had direct and total effects on HRQOL. Disaster preparedness had indirect ( β  = 0.40; p  = 0.001) and total ( β  = 0.69, p  = 0.031) effects on HRQOL. In contrast, posttraumatic stress symptoms did not have significant effects on HRQOL. Conclusions Our findings indicated that lower depression, higher community resilience, social support, and disaster preparedness were associated with increased HRQOL. Thus, it is helpful to decrease depression and strengthen community resilience, social support, and disaster preparedness to promote HRQOL among older adults who have experienced earthquakes. These results can inform the development of HRQOL in socio-psychological improvement programs for older adults in community health centers and disaster-relief psychological support centers.

Reactive oxygen species (ROS) are generated from diverse cellular processes or external sources such as chemicals, pollutants, or ultraviolet (UV) irradiation. Accumulation of radicals causes cell damage that can result in degenerative diseases. Antioxidants remove radicals by eliminating unpaired electrons from other molecules. In skin health, antioxidants are essential to protect cells from the environment and prevent skin aging. (−)-Epigallocatechin-3-(3″-O-methyl) gallate (3″Me-EGCG) has been found in limited oolong teas or green teas with distinctive methylated form, but its precise activities have not been fully elucidated. In this study, we examined the antioxidant roles of 3″Me-EGCG in keratinocytes (HaCaT cells). 3″Me-EGCG showed scavenging effects in cell and cell-free systems. Under H2O2 exposure, 3″Me-EGCG recovered cell viability and increased the expression of heme oxygenase 1 (HO-1). Under ultraviolet B (UVB) and sodium nitroprusside (SNP) exposure, 3″Me-EGCG protected keratinocytes and regulated the survival protein AKT1. By regulating the AKT1/NF-κB pathway, 3″Me-EGCG augmented cell survival and proliferation in HaCaT cells. These results indicate that 3″Me-EGCG exhibits antioxidant properties, resulting in cytoprotection against various external stimuli. In conclusion, our findings suggest that 3″Me-EGCG can be used as an ingredient of cosmetic products or health supplements.

TREM2 plays a critical role in the alleviation of Alzheimer’s disease by promoting Aβ phagocytosis by microglia, but the detailed molecular mechanism underlying TREM2-induced direct phagocytic activity of Aβ remains to be revealed. We found that learning and memory functions were improved in aged TREM2 TG mice, with the opposite effects in KO mice. The amount of phagocytosed Aβ was significantly reduced in the primary microglia of KO mice. CD36 expression in primary microglia was greater in TG than in WT mice but was substantially decreased in KO mice. The expression of C/EBPα, an upstream transcriptional activator of CD36, was also elevated in primary microglia of TG mice but decreased in KO mice. The transcription of CD36 was markedly increased by TREM2 overexpression, and this effect was suppressed by a mutation of the C/EBPα binding site on the CD36 promoter. The TREM2-induced expression of CD36 and C/EBPα was inhibited by treatment with PI3K/AKT signaling blockers, and phosphorylation of AKT was elevated in TREM2-overexpressing BV2 cells. The present study provides evidence that TREM2 is required for preventing loss of memory and learning in Alzheimer’s disease by regulating C/EBPα-dependent CD36 expression and the consequent Aβ phagocytosis.

Cryptosporidium spp. are protozoan parasites that belong to subphylum apicomplexa and cause diarrhea in humans and animals worldwide. Data on the prevalence of Cryptosporidium spp. and its subtypes among calves in the Republic of Korea (KOR) are sparse. Hence, our study aimed to investigate the prevalence and association between the age of calf and the identified Cryptosporidium spp. and to determine the genotypes/subtypes of Cryptosporidium spp. in pre-weaned calves with diarrhea in the KOR. A total of 460 diarrheic fecal samples were collected from calves aged 1−60 days and screened for Cryptosporidium spp. by the 18S rRNA gene. Species identification was determined using the sequencing analysis of the 18S rRNA gene, and C . parvum -positive samples were subtyped via the sequence analysis of the 60-kDa glycoprotein ( gp60 ) gene. Sequence analysis based on the 18S rRNA gene revealed the presence of three Cryptosporidium spp., namely, C . parvum ( n = 72), C . ryanae ( n = 12), and C . bovis ( n = 2). Co-infection by these species was not observed. The infection rate was the highest in calves aged 11−20 days (26.1%, 95% CI 17.1−35.1), whereas the lowest rate was observed in calves aged 21−30 days (7.7%, 95% CI 0.0−16.1). The prevalence of C . parvum was detected exclusively in calves aged ≤20 days, and the highest infection rate of C . ryanae was seen in calves ≥31 days of age. The occurrence of C . parvum (χ 2 = 25.300, P = 0.000) and C . ryanae (χ 2 = 18.020, P = 0.001) was significantly associated with the age of the calves. Eleven different subtypes of the IIa family that belonging to C . parvum were recognized via the sequence analyses of the gp60 gene. Except for two (IIaA18G3R1 and IIaA15G2R1) subtypes, nine subtypes were first identified in calves with diarrhea in the KOR. IIaA18G3R1 was the most frequently detected subtype (72.2% of calves), followed by IIaA17G3R1 (5.6%), IIaA15G2R1 (4.2%), IIaA19G4R1 (4.2%), IIaA16G4R1 (2.8%), IIaA17G4R1 (2.8%), IIaA19G3R (2.8%), IIaA14G1R1 (1.4%), IIaA14G3R1 (1.4%), IIaA15G1R1 (1.4%), and IIaA19G1R1 (1.4%) These results suggest that the prevalence of Cryptosporidium spp. is significantly associated with calf age. Furthermore, the findings demonstrate the high genetic diversity of C . parvum and the widespread occurrence of zoonotic C . parvum in pre-weaned calves. Hence, calves are a potential source of zoonotic transmission with considerable public health implications.

Benign paroxysmal positional vertigo (BPPV) is the most common cause of peripheral vertigo, which results from dislodged vestibular otoliths. Because the otoliths are mainly composed of calcium carbonate, it has been suggested that BPPV may be associated with osteoporosis. We aimed to assess the incidence and recurrence of BPPV in osteoporosis patients using a nationwide population-based cohort study with matched control. We used the database of the National Health Insurance Service of Korea, a universal system covering all 50 million Koreans. Osteoporosis was defined as patients who underwent bone mineral density tests and visited a clinic three or more times between Jan 2004 and Dec 2006. A control cohort consisted of non-osteoporotic subjects socio-demographically matched in a ratio of 1:1. The incidence and recurrence of BPPV between Jan 2007 and Dec 2016 were evaluated. A total of 177,797 osteoporosis patients and the same number of matched controls were identified. The incidence rates (IR) of BPPV in the osteoporosis patients and controls were 31.58 and 18.09 per 1000 persons, respectively (ratio of IR, IRR = 1.75, 95% CI 1.67–1.83). The IRs of recurrent BPPV were 187.3/1000 in the osteoporosis, 163.5/1000 in the controls (IRR = 1.15, 95% CI 1.02–1.28). In multivariate analysis, osteoporosis, female gender (adjusted HR = 1.76), age <65 (adjusted HR = 0.8), living in a metropolis, earning more than the lowest income and hypertension were significantly associated with increased risk of BPPV development. For recurrence, osteoporosis was the only meaningful risk factor (adjusted HR = 1.12). In conclusion, the risks of BPPV development and recurrence are higher in osteoporosis. Physicians might consider informing osteoporosis patients of the risk of developing BPPV and related falls.

Aims This study aimed to establish a cross‐cultural adaptation of the Communities Advancing Resilience Toolkit (CART) assessment survey for Korean communities (K‐CART) and evaluated its psychometric properties of K‐CART. Design A cross‐sectional study design was used. Methods A forward and backward translation of the CART was conducted. The psychometric properties of K‐CART were evaluated with test–retest reliability, internal consistency, content validity and construct validity. A field study was conducted involving 315 older adults in Pohang city, South Korea from January to March, 2019. Two versions of K‐CART were analysed, based on the four‐factor and the expanded five‐factor K‐CART. Results The test–retest reliability and internal consistency were acceptable (intraclass consistency coefficient = .90). The consistency reliability was satisfactory (Cronbach's α = 0.91). The content validity index (CVI) was found to be acceptable; wherein the item‐CVI and scale‐CVI were both 0.95. Confirmatory factor analysis confirmed that the construct validity of the expanded K‐CART with five factors reached a more acceptable model fit (χ2/df = 2.27, CFI = 0.89, TLI = 0.86, RMESA = 0.05).