Metallo-ß-lactamase inhibitors: A continuing challenge for combating antibiotic resistance.

ß-lactam antibiotics are the most successful and commonly used antibacterial agents, but the emergence of resistance to these drugs has become a global health threat. The expression of ß-lactamase enzymes produced by pathogens, which hydrolyze the amide bond of the ß-lactam ring, is the major mechanism for bacterial resistance to ß-lactams. In particular, among class A, B, C and D ß-lactamases, metallo-ß-lactamases (MBLs, class B ß-lactamases) are considered crucial contributors to resistance in gram-negative bacteria. To combat ß-lactamase-mediated resistance, great efforts have been made to develop ß-lactamase inhibitors that restore the activity of ß-lactams. Some ß-lactamase inhibitors, such as diazabicyclooctanes (DBOs) and boronic acid derivatives, have also been approved by the FDA. Inhibitors used in the clinic can inactivate mostly serine-ß-lactamases (SBLs, class A, C, and D ß-lactamases) but have not been effective against MBLs until now. In order to develop new inhibitors particularly for MBLs, various attempts have been suggested. Based on structural and mechanical studies of MBL enzymes, several MBL inhibitor candidates, including taniborbactam in phase 3 and xeruborbactam in phase 1, have been introduced in recent years. However, designing potent inhibitors that are effective against all subclasses of MBLs is still extremely challenging. This review summarizes not only the types of ß-lactamase and mechanisms by which ß-lactam antibiotics are inactivated, but also the research finding on ß-lactamase inhibitors targeting these enzymes. These detailed information on ß-lactamases and their inhibitors could give valuable information for novel ß-lactamase inhibitors design.

YES1 as a potential target to overcome drug resistance in EGFR-deregulated non-small cell lung cancer.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (TKIs) such as gefitinib and osimertinib have primarily been used as first-line treatments for patients with EGFR-activating mutations in non-small cell lung cancer (NSCLC). Novel biomarkers are required to distinguish patients with lung cancer who are resistant to EGFR-TKIs. The aim of the study is to investigate the expression and functional role of YES1, one of the Src-family kinases, in EGFR-TKI-resistant NSCLC. YES1 expression was elevated in gefitinib-resistant HCC827 (HCC827/GR) cells, harboring EGFR mutations. Moreover, HCC827/GR cells exhibited increased reactive oxygen species (ROS) levels compared to those of the parent cells, resulting in the phosphorylation/activation of YES1 due to oxidation of the cysteine residue. HCC827/GR cells showed elevated expression levels of YES1-associated protein 1 (YAP1), NF-E2-related factor 2 (Nrf2), cancer stemness-related markers, and antioxidant proteins compared to those of the parent cells. Knockdown of YES1 in HCC827/GR cells suppressed YAP1 phosphorylation, leading to the inhibition of Bcl-2, Bcl-xL, and Cyclin D1 expression. Silencing YES1 markedly attenuated the proliferation, migration, and tumorigenicity of HCC827/GR cells. Dasatinib inhibited the proliferation of HCC827/GR cells by targeting YES1-mediated signaling pathways. Furthermore, the combination of gefitinib and dasatinib demonstrated a synergistic effect in suppressing the proliferation of HCC827/GR cells. Notably, YES1- and Nrf2-regulated genes showed a positive regulatory relationship in patients with lung cancer and in TKI-resistant NSCLC cell lines. Taken together, these findings suggest that modulation of YES1 expression and activity may be an attractive therapeutic strategy for the treatment of drug-resistant NSCLC.

Emerging Roles of YES1 in Cancer: The Putative Target in Drug Resistance.

Src family kinases (SFKs) are non-receptor tyrosine kinases that are recognized as proto-oncogenic products. Among SFKs, YES1 is frequently amplified and overexpressed in a variety of human tumors, including lung, breast, ovarian, and skin cancers. YES1 plays a pivotal role in promoting cell proliferation, survival, and invasiveness during tumor development. Recent findings indicate that YES1 expression and activation are associated with resistance to chemotherapeutic drugs and tyrosine kinase inhibitors in human malignancies. YES1 undergoes post-translational modifications, such as lipidation and nitrosylation, which can modulate its catalytic activity, subcellular localization, and binding affinity for substrate proteins. Therefore, we investigated the diverse mechanisms governing YES1 activation and its impact on critical intracellular signal transduction pathways. We emphasized the function of YES1 as a potential mechanism contributing to the anticancer drug resistance emergence.

Structural Insights into the Penicillin-Binding Protein 4 (DacB) from Mycobacterium tuberculosis.

Mycobacterium tuberculosis, a major cause of mortality from a single infectious agent, possesses a remarkable mycobacterial cell envelope. Penicillin-Binding Proteins (PBPs) are a family of bacterial enzymes involved in the biosynthesis of peptidoglycan. PBP4 (DacB) from M. tuberculosis (MtbPBP4) has been known to function as a carboxypeptidase, and the role and significance of carboxypeptidases as targets for anti-tuberculosis drugs or antibiotics have been extensively investigated over the past decade. However, their precise involvement remains incompletely understood. In this study, we employed predictive modeling and analyzed the three-dimensional structure of MtbPBP4. Interestingly, MtbPBP4 displayed a distinct domain structure compared to its homologs. Docking studies with meropenem verified the presence of active site residues conserved in PBPs. These findings establish a structural foundation for comprehending the molecular function of MtbPBP4 and offer a platform for the exploration of novel antibiotics.

Targeting dysregulated lipid metabolism in the tumor microenvironment.

The reprogramming of lipid metabolism and its association with oncogenic signaling pathways within the tumor microenvironment (TME) have emerged as significant hallmarks of cancer. Lipid metabolism is defined as a complex set of molecular processes including lipid uptake, synthesis, transport, and degradation. The dysregulation of lipid metabolism is affected by enzymes and signaling molecules directly or indirectly involved in the lipid metabolic process. Regulation of lipid metabolizing enzymes has been shown to modulate cancer development and to avoid resistance to anticancer drugs in tumors and the TME. Because of this, understanding the metabolic reprogramming associated with oncogenic progression is important to develop strategies for cancer treatment. Recent advances provide insight into fundamental mechanisms and the connections between altered lipid metabolism and tumorigenesis. In this review, we explore alterations to lipid metabolism and the pivotal factors driving lipid metabolic reprogramming, which exacerbate cancer progression. We also shed light on the latest insights and current therapeutic approaches based on small molecular inhibitors and phytochemicals targeting lipid metabolism for cancer treatment. Further investigations are worthwhile to fully understand the underlying mechanisms and the correlation between altered lipid metabolism and carcinogenesis.

Oral health of older Koreans by region and family status in 2020-2021.

OBJECTIVE: To describe the oral health of older people by region and family status using data from the National Health and Nutrition Survey. BACKGROUND: As the ageing of Korean society intensifies, health inequalities based on region and family status are also deepening. METHODS: Data from the 8th National Health and Nutrition Survey (2020-2021) conducted by the Korea Centers for Disease Control and Prevention were used, and a total of 3437 older people aged 65 or older were selected as study participants. Chewing discomfort and oral health behaviours were assessed by region and family status using multivariable logistic regression analysis with the complex sample survey design. RESULTS: We found an association between living alone and greater chewing discomfort. Residing in rural areas was also associated with a higher prevalence of this. In urban areas, chewing discomfort was 1.27 times higher among older people living alone than in those not living alone, while in rural areas, the discomfort was 1.52 times higher among the older people who lived alone. CONCLUSIONS: Region and family status were associated with greater chewing discomfort in older people. In Korean society, where the number of single-person older people households is increasing, along with the ageing population, attention to resolving the disparities in oral health in older people is needed.

Association between patient choice of provider and patient-reported experience.

Health providers are striving to create a more positive, patient-centred experience. However, existing scholarly research about the association between determinants of patient choice of provider and patient-reported experience remains insufficient to effectively promote patient-centredness in healthcare systems. This study used a sample from the nationally representative 2020 Healthcare Experience Survey. Among the respondents (n = 12 133), 6809 who used outpatient services were selected for analysis. The variable of interest was the determinant of the patient choice of provider, and the dependent variables were patient-reported experiences (e.g. general satisfaction, experience with doctors, and experience with health providers and nurses). Data were analyzed using a multivariable logistic regression model by correcting for covariates. General satisfaction was positively associated with providers' expertise factors and public image factors [providers' expertise factors: odds ratio (OR), 2.96; 95% confidence interval (CI), 2.44-3.59; public image factors: OR, 1.26; 95% CI, 1.02-1.55] satisfied more general satisfaction. Similar results were found for experience with doctors (providers' expertise factors: OR, 4.50; 95% CI, 2.77-7.32; other factors: OR, 0.37; 95% CI, 0.16-0.81) and experience with health providers and nurses (providers' expertise factors: OR, 2.66; 95% CI, 1.99-3.57; image factors: OR, 1.53; 95% CI, 1.09-2.14). Our study's findings suggest that to improve patient-reported experience, health providers must better manage providers' expertise factors and public image factors. Health providers can improve patient-reported experience by increasing communication skills and proper information about the nature is important. Moreover, health providers must manage public image factors comprehensively and continuously by maintaining good quality of care and to brand patients.

Poor sleep is associated with energy drinks consumption among Korean adolescents.

OBJECTIVE: A growing number of Korean adolescents consume energy drinks, which may increase the risk of obesity, anxiety and insomnia. We examined whether poor sleep was associated with energy drink consumption among study participants. DESIGN: We used a cross-sectional design. SETTING: The Korea Youth Risk Behavior Web-Based Survey data from 2019. PARTICIPANTS: To determine the association between sleep and energy drink consumption, we compared the independent variables for 50,455 adolescents in Korea (aged 14-19 years) using multivariate logistic regression and sensitivity analyses. RESULTS: In Korea, 69·5 % adolescents consumed energy drinks, 17·1 % slept for less than 5 h, 22·4 % slept for 5-6 h, 23·8 % slept for 6-7 h, 19·9 % slept for 7-8 h and 16·7 % slept for 8 h or more. Regarding sleep satisfaction, 21·0 % reported sufficient, 32·6 % reported just enough and 46·5 % reported insufficient. Regarding sleep duration, it was found that less than 5 h (OR, 2·36; 95 % CI (2·14, 2·60)) and lower sleep satisfaction (OR, 1·12; 95 % CI (1·03, 1·21)) were highly associated with energy drink consumption, with statistical significance at P < 0·05. Adolescents with lower sleep duration (adjusted OR (aOR), 6·37; 95 % CI (4·72, 8·61)) and a lack of sleep satisfaction (aOR, 1·44; 95 % CI (1·16, 1·78)) reported drinking a high amount of energy drinks, that is, at least once a day. CONCLUSION: In addition to efforts to decrease the amount of energy drinks consumed, sleep hygiene education needs to be strengthened.

Association of behavior pattern with overweight and obesity in South Korean adults-A multi correspondence analysis (KNHANES-2018-2020).

The objective was to determine the association between health-related behaviour with overweight and obesity in South Korean adults by using the Korean National Health and Nutritional Examination Survey (KNHANES) 2018-2020. The study participants were 16,784 aged ≥ 20years. The variables were socio-demographic, lifestyle, food habits and metabolic conditions. The logistic regression analysis performed to find the association by the odds ratio (OR, 95% CI). MCA performed to identify risk factors were computed for overweight and obesity. Overweight and obesity were significantly associated with health behaviour, high income (OR = 1.26; 95% CI: 1.15-1.39), smoking(OR = 1.29; 95% CI: 1.08-1.53), low physical activity(OR = 3.23; 95% CI: 1.79-4.69), diabetes(OR = 2.70; 95% CI: 1.62-4.50), high cholesterol and low HDL(OR = 3.98; 95%CI:2.65-5.97). The high discriminant variables of MCA were aged over 60years, lower education, high income, diabetes, lack of physical activity, and high cholesterol. The findings confirm that the OR of obesity and overweight was likely associated with health behaviour patterns. Besides, it indicates the MCA would be very effective to identify the population-based data context than individual data and it may suggest that more research on association between health behaviours and obesity prevention interventions should be developed for each age group for better health outcomes.

Factors related to the frequent use of emergency department services in Korea.

BACKGROUND: Frequent Emergency Department (ED) visitors are identified by the policymakers to reduce avoidable ED visits and lessen the financial and operational burden. This study aimed to identify the factors related to the frequent use of ED services. METHODS: This nationwide, cross-sectional observational study was conducted using information obtained from the 2019 National Emergency Department Information System (NEDIS) database. Frequent ED users were defined as patients with four or more ED visits a year. We performed multiple logistic regression analyses to verify the relationship among sociodemographic characteristics, residential characteristics, clinical characteristics, and frequency of ED visits. RESULTS: Among 4,063,640 selected patients, 137,608 patients visited the ED four or more times a year (total number of visits = 735,502 times), which accounted for 3.4% and 12.8% of the total number of ED users and ED visits, respectively. A high ED visit frequency was associated with male sex, age < 9 or ≥ 70 years, Medical Aid (based on the insurance type), lower number of medical institutions and beds compared with that of the national average, and conditions, such as cancer, diabetes, renal failure, and mental illness. A low ED-visit frequency was associated with residence in regions vulnerable to emergency medical care and regions with high income. The possibility of frequent ED visits was high for patients with level 5 severity (non-emergent) and those with an increased need for medical treatment, including older patients and patients with cancer or mental illness. The possibility of frequent ED visits was low for patients aged > 19 years with level 1 severity (resuscitation). CONCLUSIONS: Health service accessibility factors, including low income and medical resource imbalance, were associated with frequent ED visits. Future large-scale prospective cohort studies are warranted to establish an efficient emergency medical system.

Prognostic significance of albuminuria in elderly of various ages with diabetes.

It remains uncertain whether albuminuria can identify elderly patients with diabetes at a high risk of incident end-stage kidney disease (ESKD) or mortality. 3065 patients (aged ≥ 65 years) with type 2 diabetes were included. We examined the association between albuminuria stages (normoalbuminuria, A1; microalbuminuria, A2; and macroalbuminuria, A3) and the risk of incident ESKD and all-cause mortality for each age group (65-69, 70-74, and ≥ 75 years). A2 and A3 were observed in 25.5% and 9.4% of the subjects, respectively. For A1, A2, and A3, the probabilities of ESKD at 8 years were 1.0%, 6.3%, and 29.7% (P < 0.001 for all), and the all-cause mortality was 13.1%, 27.4%, and 31.7% (P < 0.001 for A1 vs A2, P < 0.001 for A1 vs A3), respectively. Albuminuria stages were independently associated with an increased risk of ESKD [fully adjusted hazard ratios (HR): 3.650 (1.987-6.702) for A2, 10.404 (5.706-18.972) for A3 vs. A1]. The HRs of all-cause mortality were 1.742 (1.411-2.153) for A2 and 1.810 (1.344-2.441) for A3. The associations between albuminuria stages and the risk of ESKD and all-cause mortality were consistent across all age groups. Even microalbuminuria is also a risk factor for incident ESKD and mortality in elderly patients with diabetes.

Stearoyl-CoA Desaturase 1 as a Therapeutic Biomarker: Focusing on Cancer Stem Cells.

The dysregulation of lipid metabolism and alterations in the ratio of monounsaturated fatty acids (MUFAs) to saturated fatty acids (SFAs) have been implicated in cancer progression and stemness. Stearoyl-CoA desaturase 1 (SCD1), an enzyme involved in lipid desaturation, is crucial in regulating this ratio and has been identified as an important regulator of cancer cell survival and progression. SCD1 converts SFAs into MUFAs and is important for maintaining membrane fluidity, cellular signaling, and gene expression. Many malignancies, including cancer stem cells, have been reported to exhibit high expression of SCD1. Therefore, targeting SCD1 may provide a novel therapeutic strategy for cancer treatment. In addition, the involvement of SCD1 in cancer stem cells has been observed in various types of cancer. Some natural products have the potential to inhibit SCD1 expression/activity, thereby suppressing cancer cell survival and self-renewal activity.

Domain swapping of the C-terminal helix promotes the dimerization of a novel ribonuclease protein from Mycobacterium tuberculosis.

Polyketide metabolism-associated proteins in Mycobacterium tuberculosis play an essential role in the survival of the bacterium, which makes them potential drug targets for the treatment of tuberculosis (TB). The novel ribonuclease protein Rv1546 is predicted to be a member of the steroidogenic acute regulatory protein-related lipid-transfer (START) domain superfamily, which comprises bacterial polyketide aromatase/cyclases (ARO/CYCs). Here, we determined the crystal structure of Rv1546 in a V-shaped dimer. The Rv1546 monomer consists of four α-helices and seven antiparallel ß-strands. Interestingly, in the dimeric state, Rv1546 forms a helix-grip fold, which is present in START domain proteins, via three-dimensional domain swapping. Structural analysis revealed that the conformational change of the C-terminal α-helix of Rv1546 might contribute to the unique dimer structure. Site-directed mutagenesis followed by in vitro ribonuclease activity assays was performed to identify catalytic sites of the protein. This experiment suggested that surface residues R63, K84, K88, and R113 are important in the ribonuclease function of Rv1546. In summary, this study presents the structural and functional characterization of Rv1546 and supplies new perspectives for exploiting Rv1546 as a novel drug target for TB treatment.

Association between Socioeconomic Status and Healthcare Utilization for Children with Allergic Diseases: Korean National Health and Nutritional Examination Survey (2015-2019).

This study aimed to investigate the association between socioeconomic status (SES) and healthcare utilization by children with allergic diseases. We determined SES based on parental occupation and household income. A cross-sectional study was conducted using the Korean National Health and Nutritional Examination Survey (KNHANES) between 2015 and 2019 with participants who were under 18 years of age. The presence of allergic conditions was determined by a self-reported survey of parental response and healthcare utilization data (such as inpatient and outpatient visits). Moreover, we categorized SES into four quantiles (Q1-Q4) based on household income per annum. Then, the data were analyzed using chi-square tests and multivariate logistic regression analysis with confidence intervals (CIs) of 95%, and p < 0.05 was considered significant. A total of 3250 participants were involved in this study. The percentage of allergic diseases was 67.9% for allergic asthma and 32.1% for atopic dermatitis. It was found that the participants who were over 13 years old had atopic dermatitis and were more likely to visit the hospital than younger children. Additionally, the highest SES group in Q4 demonstrated higher healthcare utilization (OR = 1.58; 95% CI, 1.14-1.76) than other SES groups. Our study reveals that parental socioeconomic characteristics are related to the use of healthcare services for children with allergic disorders in Korea. These results highlight the need for public health actions and research to overcome the SES gap among children with allergic diseases.

ARD1 stabilizes NRF2 through direct interaction and promotes colon cancer progression.

AIMS: Aberrant overactivation/overexpression of NRF2 is implicated as a driving event in tumor progression, which has been attributed to its mutation or inactivation of the inhibitory protein, KEAP1. However, alternative mechanisms responsible for sustained activation of NRF2 are less understood. MAIN METHODS: Human colon cancer cell lines and tissues obtained from colorectal cancer (CRC) patients were used. To examine the expression levels of ARD1 and NRF2, Western blot and immunofluorescence analyses were performed. To investigate the potential relevance of NRF2 and ARD1 to human CRC, NRF2 and ARD1 were individually silenced in human colon cancer cells (HCT-116) by transfection with their specific small interfering RNA (siRNA). To determine the functional role of ARD1 in NRF2 regulation, in situ proximate ligation, co-immunoprecipitation, nano-LC-ESI MS/MS, and in vitro acetylation assays were performed. KEY FINDINGS: ARD1 knockdown in human colon cancer cell lines significantly reduced the protein levels of NRF2 without affecting its mRNA expression; however, silencing of NRF2 did not alter ARD1 protein expression. In addition, these two proteins were co-localized and physically interacted with each other both in human colon cancer cells (HCT-116) and human colon tumor tissues. Mechanistically, ARD1 overexpression increased the acetylation levels of NRF2. Moreover, an in vitro acetylation assay and mass spectrometric analysis demonstrated that ARD1 could directly acetylate NRF2. Ectopic expression of mutant forms of ARD1 with defective acetyltransferase activity reduced the stability of NRF2. SIGNIFICANCE: In conclusion, ARD1 may potentiate the oncogenic function of NRF2 in human colon cancer by stabilizing this transcription factor.

Overactivated NRF2 induces pseudohypoxia in hepatocellular carcinoma by stabilizing HIF-1α.

Hypoxia-inducible factor-1α (HIF-1α) is highly expressed/activated in most hypoxic tumors including hepatocellular carcinoma (HCC). Another key transcription factor, nuclear factor erythroid 2-related factor 2 (NRF2), is also constitutively overactivated in HCC. In an attempt to determine whether HIF-1α and NRF2 could play complementary roles in HCC growth and progression, we investigated the crosstalk between these two transcription factors and underlying molecular mechanisms in cultured HCC cells and experimentally induced hepatocarcinogenesis as well as clinical settings. While silencing of HIF-1α in HepG2 human hepatoma cells did not alter the protein expression of NRF2, NRF2 knockdown markedly reduced the nuclear accumulation of HIF-1α without influencing its mRNA expression. In diethylnitrosamine-induced hepatocarcinogenesis in wild type mice, there was elevated NRF2 expression with concomitant upregulation of HIF-1α. However, this was abolished in Nrf2 knockout mice. NRF2 and HIF-1α co-localized and physically interacted with each other as assessed by in situ proximity ligation and immunoprecipitation assays. In addition, the interaction between NRF2 and HIF-1α as well as their overexpression was found in tumor specimens obtained from HCC patients. In normoxia, HIF-1α undergoes hydroxylation by a specific HIF-prolyl hydroxylase domain protein (PHD), which facilitates ubiquitination and proteasomal degradation of HIF-1α. NRF2 contributes to pseudohypoxia, by directly binding to the oxygen-dependent degradation (ODD) domain of HIF-1α, which hampers the PHD2-mediated hydroxylation, concomitant recruitment of von-Hippel-Lindau and ubiquitination of HIF-1α.

Tracing the geographical origin of bottled water collected in South Korea via isotopic and elemental analyses.

RATIONALE: The production of bottled water requires a forensic discriminant technique that enables the identification of the brands or accidents caused by intended contaminants. The bottled water poisoning crimes have drawn much attention, and such crimes may recur in the future. The water is colorless and odorless, and thus it is difficult to detect contaminated water through visual observation. Thus, bottled water can be easily exploited for poisoning, and a method for tracing their origin is currently required. METHODS: In this study, a total of 27 brands of bottled water samples were analyzed to determine stable oxygen isotopes, strontium isotopes, major and trace elements. The geographical origin of the water was traced based on the climatic and geographical characteristics of the location from where water was sourced, which was assumed to be reflected in the bottled water. Furthermore, we investigated whether this method can be applied to identify bottled water products. RESULTS: The results demonstrated that the characteristics of the bottled water, including the oxygen stable isotope ratios, reflect the latitude and altitude of bottled water source in South Korea, from the high-latitude region to the coastal regions. In addition, the results indicated that excellent discrimination was achieved using strontium isotopes to identify source areas with different types of bedrock, complex underlying lithologies, and ocean areas in South Korea. A statistical method based on discriminant analysis was applied to measure trace elements, and the results effectively reflected the characteristics of water-rock interactions (cross-validated classification probability: ≥92%). CONCLUSIONS: These data suggest that the geographical characteristics of the source area are well reflected in commercial bottled water in South Korea. The proposed analytical methods can be utilized to trace the geographical origin of different bottled water samples and identify bottled water products used in poisoning crimes.

Sleep and Mental Health Among Adolescents During the COVID-19 Pandemic.

OBJECTIVE: This study aimed to investigate the association of sleep with mental health among Korean adolescents during the coronavirus disease (COVID-19) pandemic. METHODS: Using data from the 16th Korea Youth Risk Behavior Web-Based Survey (2020) of 46,475 adolescents, we examined sleep duration and satisfaction and examined mental health for depressive symptoms, anxiety, and suicidal ideation. The data were analyzed using complex sample descriptive statistics and a multiple logistic regression model. RESULTS: In 2020, the average sleep duration was 6.3 hours, and the sleep satisfaction rate was 30.8%. Depressive symptom and suicidal ideation rates were 24.2 and 10.3, respectively. These values are slightly better than those previously reported, before COVID-19. However, poor sleep was still associated with mental health. The likelihood of mental health problems was higher among those who slept for six hours or less than for those who slept for eight hours or more (p<0.05). Additionally, the results showed that the lower the sleep satisfaction, the higher the likelihood of mental health problems (p<0.05). CONCLUSION: Even after the COVID-19 outbreak, poor sleep associated with mental health problems remained as high as before the outbreak of COVID-19.

Family economic hardship and adolescent mental health during the COVID-19 pandemic.

Objective: This study examined whether pandemic related family economic hardships influenced adolescents' mental health during the COVID-19 pandemic in Korea. Methods: Data were collected from 54,948 adolescents who participated in the 2020 Korea Youth Risk Behavior Web-Based Survey. We performed a multiple logistic regression analysis to examine the association between family economic hardship and mental health (anxiety, depressive symptoms, and suicidal ideation). Results: Among the adolescents, 39.7, 24.7, and 5.9% reported slight, moderate, and severe economic hardship, respectively. COVID-19 related family economic hardship was significantly associated with higher odds of adolescents reporting anxiety, depressive symptoms, and suicidal ideation. This association was stronger among adolescents with low to middle family economic status. Conclusions: This study suggests that adolescents from more economically vulnerable families are likely to be at a higher risk for long-term mental health effects due to the financial consequences of the COVID-19 pandemic.

The Haemophilus influenzae HipBA toxin-antitoxin system adopts an unusual three-com-ponent regulatory mechanism.

Type II toxin-antitoxin (TA) systems encode two proteins: a toxin that inhibits cell growth and an antitoxin that neutralizes the toxin by direct inter-molecular protein-protein inter-actions. The bacterial HipBA TA system is implicated in persister formation. The Haemophilus influenzae HipBA TA system consists of a HipB antitoxin and a HipA toxin, the latter of which is split into two fragments, and here we investigate this novel three-com-ponent regulatory HipBA system. Structural and functional analysis revealed that HipAN corresponds to the N-ter-minal part of HipA from other bacteria and toxic HipAC is inactivated by HipAN, not HipB. This study will be helpful in understanding the detailed regulatory mechanism of the HipBAN+C system, as well as why it is constructed as a three-com-ponent system.