The m6A reader IGF2BP2 regulates glycolytic metabolism and mediates histone lactylation to enhance hepatic stellate cell activation and liver fibrosis.

Evidence for the involvement of N6-Methyladenosine (m6A) modification in the etiology and progression of liver fibrosis has emerged and holds promise as a therapeutic target. Insulin-like growth factor 2 (IGF2) mRNA-binding protein 2 (IGF2BP2) is a newly identified m6A-binding protein that functions to enhance mRNA stability and translation. However, its role as an m6A-binding protein in liver fibrosis remains elusive. Here, we observed that IGF2BP2 is highly expressed in liver fibrosis and activated hepatic stellate cells (HSCs), and inhibition of IGF2BP2 protects against HSCs activation and liver fibrogenesis. Mechanistically, as an m6A-binding protein, IGF2BP2 regulates the expression of Aldolase A (ALDOA), a key target in the glycolytic metabolic pathway, which in turn regulates HSCs activation. Furthermore, we observed that active glycolytic metabolism in activated HSCs generates large amounts of lactate as a substrate for histone lactylation. Importantly, histone lactylation transforms the activation phenotype of HSCs. In conclusion, our findings reveal the essential role of IGF2BP2 in liver fibrosis by regulating glycolytic metabolism and highlight the potential of targeting IGF2BP2 as a therapeutic for liver fibrosis.

Association between social integration and loneliness among the female migrant older adults with children: the mediating effect of social support.

BACKGROUND: The number of migrant older adults with children (MOAC) in China has been increasing in recent years, and most of them are women. This study aimed to explore the mediating effect of social support between social integration and loneliness among the female MOAC in Jinan, China. METHODS: In this study, 418 female MOAC were selected using multi-stage cluster random sampling in Jinan, Shandong Province, China. Loneliness was measured by the eight-item version of the University of California Los Angeles Loneliness Scale (ULS-8), and social support was measured by The Social Support Rating Scale (SSRS). Descriptive analyses, t-tests, ANOVA, and structural equation modeling (SEM) were used to illustrate the relationship between social integration, social support, and loneliness. RESULTS: The average scores of ULS-8 and SSRS were 12.9 ± 4.0 and 39.4 ± 5.9 among female MOAC in this study. Social integration and social support were found to be negatively related to loneliness, and the standardized direct effect was -0.20 [95% CI: -0.343 to -0.068] and -0.39 [95% CI: -0.230 to -0.033], respectively. Social support mediated the relationship between social integration and loneliness, and the indirect effect was -0.16 [95% CI: -0.252 to -0.100]. CONCLUSION: The female MOAC's loneliness was at a relatively lower level in this study. It was found that social integration was negatively associated with loneliness, and social support mediated the relationship between them. Helping female MOAC integrate into the inflow city and improving their social support could be beneficial for alleviating their loneliness.

Short- and medium-chain chlorinated paraffins in sediment from the Haihe River Basin: Sources, distributions, and ecological risk assessment.

Chlorinated paraffins (CPs) can accumulate in sediment and pose risks to ecological systems and human health. The Haihe River Basin is one of the seven main river basins in China and is mainly in the Beijing-Tianjin-Hebei region, which is densely populated and very urbanized. There is therefore a high probability of CP pollution in the Haihe River Basin. However, CP pollution and the environmental risks posed by CPs in the Haihe River are not well understood. In this study, the concentrations of short-chain CPs (SCCPs) and medium-chain CPs (MCCPs) in sediment from six rivers in the Haihe River Basin system were determined using two-dimensional gas chromatography electron-capture negative ionization mass spectrometry. The total SCCP and MCCP concentrations in the sediment samples ranged from 131.83 to 1767.71 and from 89.72 to 1442.82 ng/g dry weight, respectively. The total organic carbon content did not significantly correlate with the CP concentrations. The dominant SCCP congener groups were C10Cl6-7 and the dominant MCCP congener groups were C14Cl7-8. Significant relationships (R = 0.700, p < 0.05) were found between the SCCP and MCCP concentrations, indicating that SCCPs and MCCPs may have similar sources. Hierarchical cluster analysis and principal component analysis indicated that sediment in the study area was contaminated with CPs through the use of the CP-42 and CP-52 commercial products in industrial processes and human activities. The ecological risks posed by CPs were assessed and SCCPs were found to pose high risks in the Yongding New River but moderate risks in the other rivers. MCCPs were found to pose minimal risks to the aquatic environment at most of the sampling points.

The chain mediation model of social support and life satisfaction among migrant older adults with children: The role of mental health and sleep quality.

INTRODUCTION: Few studies have examined the life satisfaction of migrant older adults with children (MOAC), who emerged due to rapid urbanization and population aging in China. This study aimed to explore the chain mediating effect of mental health and sleep quality on the association between social support and life satisfaction among MOAC in Weifang, China. METHODS: A cross-sectional study was conducted using multi-stage cluster random sampling, and 613 participants were included. The Social Support Rating Scale, Depression Anxiety Stress Scale, Pittsburgh Sleep Quality Index, and Scale with Life Satisfaction were used to measure the social support, mental health, sleep quality, and life satisfaction of MOAC, respectively. Descriptive statistics, t-tests, and ANOVA were used to explore the relationship between sociodemographic variables and life satisfaction. Pearson's correlation analysis and structural equation modeling (SEM) were conducted to investigate the association between social support, mental health, sleep quality, and life satisfaction. RESULTS: The mean total SWLS score was 27.87±5.58. SEM analysis demonstrated that social support had a positive effect on life satisfaction (ß= 0.197). Mental health and sleep quality partially mediated the association between social support and life satisfaction (95% CI: 0.083-0.193), and the mediating effect accounted for 39.198% of the total effect. CONCLUSION: Life satisfaction was relatively high, and mental health and sleep quality partially mediated the association between social support and life satisfaction. Policy suggestions were provided based on these results.

The relationships of preventive behaviors and psychological resilience with depression, anxiety, and stress among university students during the COVID-19 pandemic: A two-wave longitudinal study in Shandong Province, China.

Introduction: Studies have shown that the psychological impact of the COVID-19 pandemic may lead to long-term health problems; therefore, more attention should be paid to the mental health of university students. This study aimed to explore the longitudinal effects of preventive behaviors and psychological resilience on the mental health of Chinese college students during COVID-19. Methods: We recruited 2,948 university students from five universities in Shandong Province. We used a generalized estimating equation (GEE) model to estimate the impact of preventive behaviors and psychological resilience on mental health. Results: In the follow-up survey, the prevalence of anxiety (44.8% at T1 vs 41.2% at T2) and stress (23.0% at T1 vs 19.6% at T2) decreased over time, whereas the prevalence of depression (35.2% at T1 vs 36.9% at T2) increased significantly (P < 0.001). Senior students were more likely to report depression (OR = 1.710, P < 0.001), anxiety (OR = 0.815, P = 0.019), and stress (OR = 1.385, P = 0.011). Among all majors, medical students were most likely to report depression (OR = 1.373, P = 0.021), anxiety (OR = 1.310, P = 0.040), and stress (OR = 1.775, P < 0.001). Students who wore a mask outside were less likely to report depression (OR = 0.761, P = 0.027) and anxiety (OR = 0.686, P = 0.002) compared to those who did not wear masks. Students who complied with the standard hand-washing technique were less likely to report depression (OR = 0.628, P < 0.001), anxiety (OR = 0.701, P < 0.001), and stress (OR = 0.638, P < 0.001). Students who maintained a distance of one meter in queues were less likely to report depression (OR = 0.668, P < 0.001), anxiety (OR = 0.634, P < 0.001), and stress (OR = 0.638, P < 0.001). Psychological resilience was a protective factor against depression (OR = 0.973, P < 0.001), anxiety (OR = 0.980, P < 0.001), and stress (OR = 0.976, P < 0.001). Discussion: The prevalence of depression among university students increased at follow-up, while the prevalence of anxiety and stress decreased. Senior students and medical students are vulnerable groups. University students should continue to follow relevant preventive behaviors to protect their mental health. Improving psychological resilience may help maintain and promote university students' mental health.

Relationship between Cognition, Depression, and Oral health status in Older adults: A longitudinal cross-lagged analysis.

BACKGROUND: The world's population is aging increasingly, and older adults' physical and mental health needs to be prioritized. Although several studies have explored the relationship between cognition, depression, and oral health in older adults, the exact nature and direction of this relationship are poorly understood. Moreover, most studies to date have been cross-sectional, with fewer longitudinal studies. The current longitudinal study explored the relationship between cognition, depression, and oral health in older adults. METHODS: We used data from two waves (2018, 2020) of the Korean Longitudinal Study of Aging, which included 4543 older adults aged 60 years and older. General socio-demographic characteristics were analyzed using descriptive analysis, and study variables were described using t-tests. Generalized Estimating Equations (GEE) and cross-lagged models were used to examine the longitudinal associations between cognition, depression, and oral health. RESULTS: The GEE results suggested that better cognition and less depression over time were associated with better oral health in older adults. Cross-lagged models further validated the effect of depression on oral health over time. LIMITATIONS: The directionality of the influence of cognition on oral health could not be determined. CONCLUSIONS: Although there were several limitations, our study provided novel ideas for verifying the effects of cognition and depression on oral health in older adults.

The mediating effect of social support on the association between socioeconomic status and self-reported oral health status among the migrant elderly following children in Weifang, China: a cross-sectional study.

BACKGROUND: Driven by population aging and the rapid urbanization in China, many migrant elderly following children (MEFC) moved to big cities to care for their grandchildren. The purpose of this study is to clarify the mediating effect of social support on the relationship between socioeconomic status (SES) and self-reported oral health status among the MEFC in Weifang, China. METHODS: Multistage cluster random sampling was used to select the participants and finally 613 MEFC were included in the survey. The Social Support Rating Scale (SSRS) and the Chinese version of the Geriatric Oral Health Assessment Index (GOHAI) scale were used for data collection. Descriptive analysis, Rao-Scott test, t-test and structural equation modeling (SEM) were conducted in this study. RESULTS: Mean score of GOHAI of the MEFC was 54.95 ± 6.47. The SES of MEFC exerted positive direct effect both on social support (standardized coefficient = 0.15) and self-reported oral health status (standardized coefficient = 0.22); social support exerted positive direct effect on self-reported oral health status (standardized coefficient = 0.17). Social support partially mediated the association between SES and self-reported oral health status [95% confidence interval (CI) 0.003-0.064, P < 0.05], and the mediating effect of social support accounted for 12.0% of the total effect. CONCLUSIONS: Higher GOHAI score of MEFC indicated their better self-reported oral health status. MEFCs' SES could exert positive effect both on social support and self-reported oral health status, while the mediating effect of social support between SES and self-reported oral health status of MEFC was established.

The Effects of Living Environment, Health Status of Family Members, and Migrant Elderly following Children's Attitude about Care on Grandchildren's Health Status in Weifang, China.

As urbanization is growing quickly in China, many migrant elderly following children (MEFC) migrate to big cities to care for their grandchildren (grandchildren of MEFC=GMEFC). This study aimed to explore the effects of the living environment, health statuses of family members, and MEFC's attitude regarding the care of their children (children of MEFC=CMEFC) for their GMEFC on GMEFC's health statuses in Weifang, China. Multistage cluster random sampling was used to select the participants, and 613 MEFC were included in total. Descriptive analysis, univariate analysis and binary logistic regression were used to investigate the association between the related variables and GMEFC's health statuses. It was found that 74.9% of the GMEFC had excellent health statuses. The GMEFC who had siblings, the CMEFC with excellent health statuses, and the MEFC with excellent health statuses were more likely to have excellent health statuses. Moreover, the GMEFC who were female, elevators occasionally malfunctioned, the MEFC who were dissatisfied with the CMEFC's time spent on caring, and the MEFC who did not understand or forgive the CMEFC's limited time on caring were less likely to have GMEFC with excellent health statuses. The results indicated that a better living environment, better health statuses of family members, and a positive attitude of the MEFC regarding the care of CMEFC for GMEFC would result in a better health status of GMEFC.

The effects of oral health and social support on health-related quality of life of migrant older with children in Weifang, China.

BACKGROUND: With the accelerated urbanization and aging population in China, more and more migrant older with children (MOC) moved to new cities. Previous studies mainly explored the acculturation of MOC, yet few focused on the health conditions of this vulnerable group. This study aimed to investigate the effects of oral health and social support on health-related quality of life (HRQOL) of MOC in Weifang, China. METHOD: This study was a cross-sectional study and participants were selected by multi-stage cluster random sampling in Weifang, China. The HRQOL was assessed via the 12-item Short-Form Health Survey (SF-12) which included the mental component summary (MCS) and the physical component summary (PCS). The oral health was evaluated by the Geriatric Oral Health Assessment Index (GOHAI). The social support was administered using the Social Support Rating Scale (SSRS). Descriptive analysis was used to describe participants' sociodemographic variables, oral health and social support. Univariate analysis and binary logistic regression analysis was used to investigate the association between the social support, oral health and HRQOL. RESULTS AND DISCUSSION: It was found that 25.0% of MOC were defined as MCS poor and PCS poor, respectively. Those participants with average and low monthly household income compared to those around them, average and poor oral health, and low levels of social support were more likely to have poor PCS. Those with temporary residence permits, fair and poor oral health, and medium and low levels of social support were more likely to report poor MCS. CONCLUSION: Results indicated that better social support and oral health led to higher HRQOL of MOC. Implications for the government, communities and families of MOC were given to improve their HRQOL.

Assessing Knowledge, Preventive Practices, and Depression Among Chinese International Students and Local Korean Students in South Korea During the COVID-19 Pandemic: An Online Cross-Sectional Study.

Depression among university students and international university students is an increasing problem globally. This study aimed to clarify the differences on the conditions and determinants of the knowledge, preventive practices and depression of the Chinese international students and local Korean students in South Korea during the COVID-19 pandemic. An online cross-sectional questionnaire including general demographic characteristics, COVID-19-related knowledge, preventive practice, and the Patient Health Questionnaire (PHQ-9) was applied from March 23 to April 22, 2020. A total of 533 university students (171 Chinese international students and 362 local South Korean students) were included in the study. The majority of both Chinese international students and local South Korean students had a good comprehension of COVID-19. Chinese international students in South Korea showed better preventive practice than local Korean students, while the proportion of moderate to severe depression of Chinese international students was relatively higher (28.07%) than that of local Korean students (22.38%). Determinants of depression of Chinese international students in South Korea were information satisfaction, likelihood of survival after infection, symptoms of a cough and feelings of discrimination, while for local Korean students were gender, educational level, family, suspected symptoms, self-assessed physical health status, COVID-19 detection, population contact history and online sources of information. These results could be used as a reference for decreasing the depressive symptoms among the university students.

The relationship between oral health status, loneliness, and sleep quality among the migrant elderly following children in Weifang, Shandong Province, China: A comparative analysis on different migration types.

Background: The migrant elderly following children (MEFC) are a vulnerable group that emerged during fast urbanization in China. The MEFC faced physical and psychological discomfort upon their arrival in the inflow city, particularly those who came from rural areas. Objective: This study aimed to explore the relationship between oral health status, loneliness, and sleep quality among the MEFC in China and to clarify the disparities in the above mentioned relationship by migration type. Methods: In 2021, a cross-sectional survey was conducted in Weifang, Shandong Province, using multistage cluster random sampling to collect data from the MEFC aged 60 years and over. In total, 613 respondents [525 rural-to-urban (RTU) and 88 urban-to-urban (UTU)] were included in the final database. The chi-square test, t-test, and structural equation modeling (SEM) were used to investigate the relationship between oral health status, loneliness, and sleep quality among the RTU and UTU MEFC. Results: Total scores [mean ± standard deviation (SD)] for oral health status, loneliness, and sleep quality were 54.95 ± 6.47, 8.58 ± 3.03, and 4.47 ± 3.60, respectively. SEM revealed that, among the RTU and UTU MEFC, oral health status was positively and significantly related to sleep quality; however, the correlation was slightly stronger in the UTU MEFC. In both groups, there was a significant negative correlation between oral health status and loneliness, which was stronger in the UTU MEFC. In the RTU MEFC, a significant negative correlation between loneliness and sleep quality was observed, and in the UTU MEFC, no significant association between loneliness and sleep quality was observed. Conclusion: The sleep quality among the MEFC in this study was higher compared to previous studies. Oral health status was negatively correlated with loneliness and positively associated with sleep quality, whereas loneliness was negatively correlated with sleep quality. These three associations differed significantly between the UTU and RTU MEFC. The government, society, and families should take measures to improve oral health and reduce loneliness among the MEFC to improve their sleep quality.

Resting-State fMRI in Studies of Acupuncture.

Research exploring the mechanism of acupuncture has been a hot topic in medicine. Resting-state functional magnetic resonance imaging (rs-fMRI) research is a noninvasive and extensive method, which is aimed at the research of the mechanism of acupuncture. Researchers use fMRI technologies to inspect the acupuncture process. The authors reviewed the application of rs-fMRI in acupuncture research in recent 10 years from the aspects of studying acupoints, subjects, acupuncture methods, and intensities. The results found that the application of rs-fMRI in acupuncture research mainly includes research on the onset mechanism of acupuncture treatment; visual evidence of diagnosis and treatment of dominant diseases; efficacy assessments; physiological mechanism of acupoint stimulation; and specific visualization of acupoints.

Spatial occurrence and composition profile of organophosphate esters (OPEs) in farmland soils from different regions of China: Implications for human exposure.

The environmental load of organophosphate ester (OPE) flame retardants has caused a series of problems due to their extensive use. The soil matrix, as an ultimate sink for organic pollution, plays a vital part in the fate of OPEs in the environment. In this study, the spatial occurrence, composition profile and health risk of 13 OPE species in farmland soils from four provinces of China were characterized. Excluding tris(2,3-dibromopropyl) phosphate (TDBPP) and ethylhexyl diphenyl phosphate (EHDPP), the remaining eleven OPEs had a high detection frequency (DF) ranging from 60% to 100%. The range of total OPE (ΣOPE) concentrations were 62.3-394 ng/g dry weight (dw), with a median of 228 ng/g dw. Among these OPEs, tris(2-ethylhexyl) phosphate (TEHP) with a median of 143 ng/g dw) was the predominant species, followed by tricresyl phosphate (TCP; median of 20.1 ng/g dw) and tris(2-chloroethyl) phosphate (TCEP; median of 17.9 ng/g dw). In terms of geographical distribution, significantly lower OPEs levels were found in samples from Heilongjiang (159 ± 47.0 ng/g dw) than in those of Guangxi (264 ± 66.0 ng/g dw), Henan (252 ± 74.5 ng/g dw) and Hubei (242 ± 52.8 ng/g dw) provinces. Principal component analysis and Spearman's correlations were used to reveal potential sources of OPEs in the different provincial regions. Health risk exposure to OPEs in farmland soils was at an acceptable level (<1.20 × 10-5 for non-carcinogenic risk to children as the most sensitive age group; and <6.47 × 10-10 for carcinogenic risk to adults as the most sensitive age group) at the present detected concentrations. However, TCEP and TEHP, the predominant risk contributors, should be paid more attention.

Changes in Brain Function Networks in Patients With Amnestic Mild Cognitive Impairment: A Resting-State fMRI Study.

Patients with amnestic mild cognitive impairment (aMCI) are at high risk of developing dementia. This study used resting-state functional magnetic resonance imaging (rs-fMRI) and an independent component analysis (ICA) approach to explore changes in functional connectivity (FC) in the default mode network (DMN), executive control network (ECN), and salience network (SN). Thirty patients with aMCI and 30 healthy controls (HCs) were enrolled. All the participants underwent an rs-fMRI scan. The brain FC in DMN, ECN, and SN was calculated using the ICA approach. We found that the FC of brain regions in DMN decreased significantly and that of brain regions in ECN increased, which was in accordance with the findings of previous studies on Alzheimer's disease (AD) and aMCI. We also found that the FC of brain regions in SN increased, which was different from the findings of previous studies on AD. The increase in FC in brain regions in SN might result from different pathophysiological states in AD and aMCI, indicating that a decrease in FC in SN does not occur in a person with aMCI. These results are consistent with those of previous studies using the voxel-mirrored homotopic connectivity approach and seed-based correlation analysis. We therefore considered that the decrease in FC in DMN and the increase in FC in ECN and SN might be peculiar patterns observed on the rs-fMRI of a person with aMCI. These findings may contribute to the development of imaging biomarkers for the diagnosis of aMCI.

Comparison of serum exosome isolation methods on co-precipitated free microRNAs.

BACKGROUND: Exosomes are nano-sized extracellular vesicles containing different biomolecules such as proteins and microRNAs (miRNAs) that mediate intercellular communication. Recently, numerous studies have reported the important functions of exosomal miRNAs in disease development and the potential clinical application as diagnostic biomarkers. Up to now, the most commonly used methods to extract exosomes are ultracentrifugation (UC) and precipitation-based commercial kit (e.g., ExoQuick). Generally, both UC and ExoQuick method could co-isolate contaminating proteins along with exosomes, with the UC method yielding even purer exosomes than ExoQuick. However, the comparison of these two methods on co-precipitated free miRNAs is still unknown. METHODS: In this study, we isolated exosomes from the human serum with exogenously added cel-miR-39 by UC and ExoQuick and compared the proportion of cel-miR-39 co-precipitated with exosomes extracted by these two methods. RESULTS: Using exogenous cel-miR-39 as free miRNAs in serum, we concluded that ExoQuick co-isolates a small proportion of free miRNAs while UC hardly precipitates any free miRNAs. We also found that incubation at 37 °C for 1 h could decrease the proportion of free miRNAs, and exosomal miRNAs like miR-126 and miR-152 also decreased when RNase A was used. In conclusion, our findings provide essential information about the details of serum exosome isolation methods for further research on exosomal miRNAs.

The proton electrochemical gradient induces a kinetic asymmetry in the symport cycle of LacY.

LacY catalyzes accumulation of galactosides against a concentration gradient by coupling galactoside and H+ transport (i.e., symport). While alternating access of sugar- and H+-binding sites to either side of the membrane is driven by binding and dissociation of sugar, the electrochemical H+ gradient ([Formula: see text]) functions kinetically by decreasing the Km for influx 50- to 100-fold with no change in Kd The affinity of protonated LacY for sugar has an apparent pK (pKapp) of ∼10.5, due specifically to the pKa of Glu325, a residue that plays an irreplaceable role in coupling. In this study, rates of lactose/H+ efflux were measured from pH 5.0 to 9.0 in the absence or presence of a membrane potential (ΔΨ, interior positive), and the effect of the imposed ΔΨ on the kinetics of efflux was also studied in right-side-out membrane vesicles. The findings reveal that [Formula: see text] induces an asymmetry in the transport cycle based on the following observations: 1) the efflux rate of WT LacY exhibits a pKapp of ∼7.2 that is unaffected by the imposed ΔΨ; 2) ΔΨ increases the rate of efflux at all tested pH values, but enhancement is almost 2 orders of magnitude less than observed for influx; 3) mutant Glu325 - Ala does little or no efflux in the absence or presence of ΔΨ, and ambient pH has no effect; and 4) the effect of ΔΨ (interior positive) on the Km for efflux is almost insignificant relative to the 50- to 100-fold decrease in the Km for influx driven by ΔΨ (interior negative).

Functional analysis of a miRNA-like small RNA derived from Bombyx mori cytoplasmic polyhedrosis virus.

Bombyx mori cytoplasmic polyhedrosis virus (BmCPV) is a major pathogen of the economic insect silkworm, Bombyx mori. Virus-encoded microRNAs (miRNAs) have been proven to play important roles in host-pathogen interactions. In this study we identified a BmCPV-derived miRNA-like 21 nt small RNA, BmCPV-miR-1, from the small RNA deep sequencing of BmCPV-infected silkworm larvae by stem-loop quantitative real-time PCR (qPCR) and investigated its functions with qPCR and lentiviral expression systems. Bombyx mori inhibitor of apoptosis protein (BmIAP) gene was predicted by both target prediction software miRanda and Targetscan to be one of its target genes with a binding site for BmCPV-miR-1 at the 5' untranslated region. It was found that the expression of BmCPV-miR-1 and its target gene BmIAP were both up-regulated in BmCPV-infected larvae. At the same time, it was confirmed that BmCPV-miR-1 could up-regulate the expression of BmIAP gene in HEK293T cells with lentiviral expression systems and in BmN cells by transfecting mimics. Furthermore, BmCPV-miR-1 mimics could up-regulate the expression level of BmIAP gene in midgut and fat body in the silkworm. In the midgut of BmCPV-infected larvae, BmCPV-miR-1 mimics could be further up-regulated and inhibitors could lower the virus-mediated expression of BmIAP gene. With the viral genomic RNA segments S1 and S10 as indicators, BmCPV-miR-1 mimics could up-regulate and inhibitors down-regulate their replication in the infected silkworm. These results implied that BmCPV-miR-1 could inhibit cell apoptosis in the infected silkworm through up-regulating BmIAP expression, providing the virus with a better cell circumstance for its replication.

Polychlorinated naphthalene (PCN) emissions and characteristics during different secondary copper smelting stages.

The amounts and characteristics of polychlorinated naphthalenes (PCNs) emitted by a secondary copper smelter were investigated. Differences in the amounts and characteristics of PCNs emitted during different smelting stages were investigated, and the main stage during which PCNs were emitted was identified. PCN concentrations in stack gases emitted during secondary copper smelting were 477.0-762.5 ng/m3 (4.4-8.3 pg toxic equivalents/m3). The contributions of the different stages to total PCN emissions decreased in the order feeding-fusion stage (65% of total PCN emissions) > oxidation stage (27%) > deoxidation stage (8%). The main contributor to PCN emissions during secondary copper smelting was the feeding-fusion stage. PCN concentrations and profiles in stack gas, fly ash, and deposit ash collected during different smelting stages were determined. PCNs in stack gases were mainly less-chlorinated homologs, and fly ash and deposit ash were dominated by highly-chlorinated homologs. These results will help improve strategies for decreasing and eliminating PCN emissions during secondary copper production.

Crystal Structure of a ligand-bound LacY-Nanobody Complex.

The lactose permease of Escherichia coli (LacY), a dynamic polytopic membrane transport protein, catalyzes galactoside/H+ symport and operates by an alternating access mechanism that exhibits multiple conformations, the distribution of which is altered by sugar-binding. Camelid nanobodies were made against a double-mutant Gly46 → Trp/Gly262 → Trp (LacYWW) that produces an outward-open conformation, as opposed to the cytoplasmic open-state crystal structure of WT LacY. Nanobody 9047 (Nb9047) stabilizes WT LacY in a periplasmic-open conformation. Here, we describe the X-ray crystal structure of a complex between LacYWW, the high-affinity substrate analog 4-nitrophenyl-α-d-galactoside (NPG), and Nb9047 at 3-Å resolution. The present crystal structure demonstrates that Nb9047 binds to the periplasmic face of LacY, primarily to the C-terminal six-helical bundle, while a flexible loop of the Nb forms a bridge between the N- and C-terminal halves of LacY across the periplasmic vestibule. The bound Nb partially covers the vestibule, yet does not affect the on-rates or off-rates for the substrate binding to LacYWW, which implicates dynamic flexibility of the Nb-LacYWW complex. Nb9047-binding neither changes the overall structure of LacYWW with bound NPG, nor the positions of side chains comprising the galactoside-binding site. The current NPG-bound structure exhibits a more occluded periplasmic vestibule than seen in a previous structure of a (different Nb) apo-LacYWW/Nb9039 complex that we argue is caused by sugar-binding, with major differences located at the periplasmic ends of transmembrane helices in the N-terminal half of LacY.

AmDREB2C, from Ammopiptanthus mongolicus, enhances abiotic stress tolerance and regulates fatty acid composition in transgenic Arabidopsis.

Dehydration-responsive element-binding (DREB) transcription factors (TFs) play a vital role in plant response to abiotic stresses. However, little is known about DREB TFs in plants adapted to harsh environments and in the formation of polyunsaturated fatty acids (PUFAs), a major membrane component closely associated with plant stress tolerance. Here, we characterized AmDREB2C in Ammopiptanthus mongolicus (Maxim. ex kom.) Cheng F., a desert evergreen broadleaf shrub with a high tolerance to harsh environments. AmDREB2C encodes a canonical DREB2-type TF, and the protein was localized in the nucleus. AmDREB2C had the highest expression levels in leaves of naturally growing shrubs in the wild during the winter season of a year of sampling. The expression was also induced by cold, heat and drought stresses in laboratory-cultured seedlings. Moreover, AmDREB2C was most abundantly expressed in young leaves and immature seeds rather than other tissues of the shrubs. Constitutive expression of AmDREB2C in Arabidopsis enhanced freezing, heat and drought tolerances of the transgenic plants, likely through inducing the expression of important stress-responsive genes. The transgene also increased the level of linolenic acid (C18:3), a major PUFA in most plant species, in leaves and seeds of the transgenic plants. Correspondingly, the transcription of FAD3, FAD7 and FAD8, three genes encoding fatty acid desaturases (FADs) responsible for the production of C18:3, showed a differential up-regulation in these two organs. This study provides new insight into the underlying molecular mechanisms of A. mongolicus' ability to endure harsh environments and DREB TF regulation of fatty acid desaturation.