AL008 Enhances Myeloid Antitumor Function by Inhibiting SIRPα Signaling and Activating Fc Receptors.

Antagonizing the CD47-signal regulatory protein (SIRP)α pathway, a critical myeloid checkpoint, promotes antitumor immunity. In this study, we describe the development of AL008, a pan-allelic, SIRPα-specific Ab that triggers the degradation of SIRPα and, concurrently, stimulates FcγR activation of myeloid cells through an engineered Fc domain. AL008 showed superior enhancement of phagocytosis of tumor cells opsonized with antitumor Ag Abs compared with another SIRPα Ab tested. Unlike ligand-blocking SIRPα Abs, AL008 demonstrated single-agent activity by increasing tumor cell engulfment by human monocyte-derived macrophages even in the absence of opsonizing agents. This effect was due to enhanced Fc function, as blocking FcγR2A abrogated AL008-mediated phagocytic activity. AL008 also promoted human monocyte-derived dendritic cell-mediated T cell proliferation. In humanized mouse models, AL008 induced internalization of SIRPα and increased expression of CD86 and HLA-DR on human tumor-associated macrophages, confirming that the mechanism of action is retained in vivo. Monotherapy treatment with AL008 significantly reduced tumor growth in humanized mice implanted with human MDA-MB-231 tumor cells. AL008 also significantly potentiated the effects of T cell checkpoint blockade with anti-programmed death ligand-1 in syngeneic tumor models. This dual and specific mechanism of AL008, to our knowledge, provides a novel therapeutic strategy for targeting myeloid cells for immune activation.

LINE-1 repression in Epstein-Barr virus-associated gastric cancer through viral-host genome interaction.

Long INterspersed Element 1 (LINE-1 or L1) acts as a major remodeling force in genome regulation and evolution. Accumulating evidence shows that virus infection impacts L1 expression, potentially impacting host antiviral response and diseases. The underlying regulation mechanism is unclear. Epstein-Barr virus (EBV), a double-stranded DNA virus linked to B-cell and epithelial malignancies, is known to have viral-host genome interaction, resulting in transcriptional rewiring in EBV-associated gastric cancer (EBVaGC). By analyzing publicly available datasets from the Gene Expression Omnibus (GEO), we found that EBVaGC has L1 transcriptional repression compared with EBV-negative gastric cancer (EBVnGC). More specifically, retrotransposition-associated young and full-length L1s (FL-L1s) were among the most repressed L1s. Epigenetic alterations, especially increased H3K9me3, were observed on FL-L1s. H3K9me3 deposition was potentially attributed to increased TASOR expression, a key component of the human silencing hub (HUSH) complex for H3K9 trimethylation. The 4C- and HiC-seq data indicated that the viral DNA interacted in the proximity of the TASOR enhancer, strengthening the loop formation between the TASOR enhancer and its promoter. These results indicated that EBV infection is associated with increased H3K9me3 deposition, leading to L1 repression. This study uncovers a regulation mechanism of L1 expression by chromatin topology remodeling associated with viral-host genome interaction in EBVaGC.

Lpar1-mediated Effects in Endothelial Progenitor Cells Are Crucial for Lung Repair in Acute Respiratory Distress Syndrome/Acute Lung Injury.

Acute respiratory distress syndrome/acute lung injury (ARDS/ALI) involves acute respiratory failure characterized by vascular endothelial and lung alveolar epithelial injury. Endothelial progenitor cells (EPCs) can mediate vasculogenesis. However, the limitations of EPCs, such as low survival and differentiation, are believed to inhibit the effectiveness of autologous cell therapies. This study demonstrated that lysophosphatidic acid (LPA), a bioactive small molecule without immunogenicity, is involved in the survival and antiapoptotic effects in human umbilical cord mesenchymal stem cells. This study aimed to explore whether LPA improves the survival of EPCs, enhancing the cellular therapeutic efficacy in ARDS, and these results will expand the application of LPA in stem cells and regenerative medicine. LPA promoted the colony formation, proliferation, and migration of EPCs and upregulated the expression of vascular endothelial-derived growth factor (VEGF) in EPCs. LPA pretreatment of transplanted EPCs improved the therapeutic effect by increasing EPC numbers in the rat lungs. LPA enhanced EPC proliferation and migration through Lpar1 coupled to Gi/o and Gq/11, respectively. Activation of extracellular signal-related kinase 1/2, or ERK1/2, was related to LPA-induced EPC proliferation but not migration. LPA/Lpar1-mediated Gi/o protein was also shown to be involved in promoting VEGF expression and inhibiting IL-1α expression in EPCs. Low LPA concentrations are present after lung injury; thus, the restoration of LPA may promote endothelial cell homeostasis and lung repair in ARDS. Inhalation of LPA significantly promoted the homing of endogenous EPCs to the lung and reduced lung injury in both rats with LPS-induced ALI and Streptococcus pneumoniae-infected mice. Taken together, these data indicated that LPA/Lpar1-mediated effects in EPCs are involved in maintaining endothelial cell homeostasis and lung tissue repair under physiological conditions.

Anxiety symptoms and health-related quality of life in mainland Chinese pregnant women: a cross-sectional study.

OBJECTIVE: Health-related quality of life allows the health care professionals to envisage new axes of improvement in antenatal care and is a core aspect of contemporary maternity care provision. This study aims to estimate the prevalence of anxiety symptoms and explore the relationship between anxiety symptoms and health-related quality of life among Chinese pregnant women. METHODS: A cross-sectional study was conducted in a local teaching hospital in Guangzhou, China between April and June, 2018. Seven hundred and seventy Chinese pregnant women completed the 36-Item Short-Form Health Survey (SF-36), the Self-rating Anxiety Scale (SAS) and socio-demographic questionnaires. RESULTS: 18.2% women were classified as having elevated anxiety symptoms as evidenced by a SAS score ≥50. Compared with women without anxiety symptoms, the pregnant women with anxiety symptoms had worse physical (SF36-PCS) and mental (SF36-MCS) health-related quality of life and a lower level of seven domains of SF-36 (GH, RP, BP, VT, SF, RE and MH). Elevated anxiety symptoms predicted worse physical (SF36-PCS) and mental (SF36-MCS) health-related quality of life. The third trimester predicted a lower level of physical (SF36-PCS) health-related quality of life, while an unsatisfied relationship with mother-in-law predicted a lower level of mental (SF36-MCS) health-related quality of life. CONCLUSIONS: The pregnant women with anxiety symptoms had impaired health-related quality of life. Health care professionals should identify pregnant women with anxiety symptoms and facilitate their treatment, which could improve their health-related quality of life.

Incidence and correlates of insomnia and its impact on health-related quality of life among Chinese pregnant women: a cross-sectional study.

OBJECTIVE: The aims of this study were to examine the incidence and correlates of insomnia and its impact on health-related quality of life among Chinese pregnant women. METHOD: A cross-sectional study was performed from November 2018 to April 2019 in a university-affiliated general hospital in Guangzhou, China. Seven hundred and seventeen pregnant women completed the 36-item Short-Form Health Survey (SF-36), the Self-Rating Anxiety Scale (SAS), the Self-Rating Depression Scale (SDS), and the obstetric and sociodemographic data sheet. FINDINGS: 24.3% of the pregnant women suffered from insomnia. Compared with women without insomnia, those with insomnia had a significantly lower health-related quality of life during pregnancy. Maternal age, educational level, occupation, economic status, insurance coverage, gestational age, the woman's relationship with her mother-in-law and anxiety were significantly associated with insomnia among pregnant women. CONCLUSION: The incidence of insomnia among pregnant women is high, and insomnia is negatively correlated with health-related quality of life. Appropriate measures and practical therapeutic programmes should be provided to prevent the adverse effects of insomnia in pregnant women with advanced maternal age, lower education, lower economic status, unemployment, lack of insurance coverage, unsatisfied with their relationships with their mothers-in-law, and suffering from anxiety symptoms, especially in the third trimester.

A Longitudinal Study of Stress in New Nurses in their First Year of Employment.

Objective: This study aimed to analyze changes in occupational stress in new nurses during the first year of employment. Methods: A prospective longitudinal study was conducted from 2020 to 2021 using one questionnaire four times on 127 newly employed nurses in a tertiary general teaching hospital in the province of Fujian. Results: The results showed that new nurses had moderate to high levels of stress in all four stages, with the highest stress level at 4 and 8 months of employment and the lowest stress level at 12 months; the differences in stress scores at different time points were statistically significant (p < 0.05). The trends in each stressor dimension varied across different periods. The highest scores were for pressure caused by "time allocation and workload," which peaked in month 8. The same trend was observed for stress from "patient care" and "work environment and equipment." "Management and interpersonal relationships" scored the highest overall stress score at the start of employment before declining. The lowest stress score was from "work environment and equipment" at the start of employment, and the lowest was from "management and interpersonal relationships" from month 4 onward. Conclusion: New nurses had higher overall occupational stress during their first year of employment under different stressors. Therefore, nursing managers should actively focus on stress factors of new nurses and provide targeted interventions to help them during their training period.

Analysis of the miRNA expression profile of laboratory red crucian carp under low-dose caesium-137 irradiation.

Radiation can cause the differential expression of biological miRNA molecules. This research was based on the development of the laboratory red crucian carp (LRCC) to explore the feasibility of its application in the detection of low-dose ionizing radiation-induced biological damage in aquatic environments and the development of related molecular markers. Adult LRCC were irradiated with caesium-137 at 0.3 Gy, while RNA-seq and bioinformatics techniques were used to identify miRNAs that were differentially expressed relative to their levels in the nonirradiation group. Analysis of liver sections showed that liver cells in the radiation group showed nuclear pyknosis. In this study, 34 miRNAs differentially expressed in the liver of LRCC after irradiation were identified, among which seven were new crucian carp miRNAs; a total of 632 target genes were predicted in the prediction analysis. The results of comprehensive GO enrichment and KEGG pathway analyses showed that these target genes were mainly involved in energy transfer and material catabolism, especially malonyl-CoA biosynthesis, acetyl-CoA carboxylase activity, fatty acid biosynthesis and metabolism, and pyruvate metabolism; in addition, the AMPK signalling pathway was the most active pathway. This study shows that the LRCC is sensitive to radiation, or can be used as a candidate experimental animal to study the biological effects of radiation, and the screened miRNA can be used as a pre-selected biomarker for radiation damage detection and radiation biological environmental monitoring. CLINICAL TRIALS REGISTRATION: None.

Super-Enhancer-Associated Transcription Factors Maintain Transcriptional Regulation in Mature Podocytes.

BACKGROUND: Transcriptional programs control cell fate, and identifying their components is critical for understanding diseases caused by cell lesion, such as podocytopathy. Although many transcription factors (TFs) are necessary for cell-state maintenance in glomeruli, their roles in transcriptional regulation are not well understood. METHODS: The distribution of H3K27ac histones in human glomerulus cells was analyzed to identify superenhancer-associated TFs, and ChIP-seq and transcriptomics were performed to elucidate the regulatory roles of the TFs. Transgenic animal models of disease were further investigated to confirm the roles of specific TFs in podocyte maintenance. RESULTS: Superenhancer distribution revealed a group of potential TFs in core regulatory circuits in human glomerulus cells, including FOXC1/2, WT1, and LMX1B. Integration of transcriptome and cistrome data of FOXC1/2 in mice resolved transcriptional regulation in podocyte maintenance. FOXC1/2 regulated differentiation-associated transcription in mature podocytes. In both humans and animal models, mature podocyte injury was accompanied by deregulation of FOXC1/2 expression, and FOXC1/2 overexpression could protect podocytes in zebrafish. CONCLUSIONS: FOXC1/2 maintain podocyte differentiation through transcriptional stabilization. The genome-wide chromatin resources support further investigation of TFs' regulatory roles in glomeruli transcription programs.

Chromatin architecture reveals cell type-specific target genes for kidney disease risk variants.

BACKGROUND: Cell type-specific transcriptional programming results from the combinatorial interplay between the repertoire of active regulatory elements. Disease-associated variants disrupt such programming, leading to altered expression of downstream regulated genes and the onset of pathological states. However, due to the non-linear regulatory properties of non-coding elements such as enhancers, which can activate transcription at long distances and in a non-directional way, the identification of causal variants and their target genes remains challenging. Here, we provide a multi-omics analysis to identify regulatory elements associated with functional kidney disease variants, and downstream regulated genes. RESULTS: In order to understand the genetic risk of kidney diseases, we generated a comprehensive dataset of the chromatin landscape of human kidney tubule cells, including transcription-centered 3D chromatin organization, histone modifications distribution and transcriptome with HiChIP, ChIP-seq and RNA-seq. We identified genome-wide functional elements and thousands of interactions between the distal elements and target genes. The results revealed that risk variants for renal tumor and chronic kidney disease were enriched in kidney tubule cells. We further pinpointed the target genes for the variants and validated two target genes by CRISPR/Cas9 genome editing techniques in zebrafish, demonstrating that SLC34A1 and MTX1 were indispensable genes to maintain kidney function. CONCLUSIONS: Our results provide a valuable multi-omics resource on the chromatin landscape of human kidney tubule cells and establish a bioinformatic pipeline in dissecting functions of kidney disease-associated variants based on cell type-specific epigenome.

Health related quality of life in Chinese pregnant women at advanced maternal age: a cross-sectional study.

OBJECTIVE: This study aims to explore the relationship between advanced maternal age (AMA) and health-related quality of life in Chinese pregnant women. METHODS: A cross-sectional study was conducted in Guangzhou, China between September 2018 and June 2019. Four hundred and twenty-seven AMA women and the equal number of their younger counterparts completed the 36-Item Short-Form Health Survey (SF-36). RESULTS: Compared with younger women, the AMA women were more likely to be employed; have a higher monthly household income and insurance covered; have a satisfied relationship with their husband and mother-in-law; and had a significantly lower level of physical (SF36-PCS) health-related quality of life and a higher level of mental (SF36-MCS) health-related quality of life during the pregnancy. The association of maternal age with health-related quality of life varies according with the trimester of pregnancy. Maternal age was a significant predictor of SF36-PCS and SF36-MCS. The third trimester was the significant predictor of SF36-PCS while the relationship with the mother-in-law was the significant predictor of SF36-MCS. CONCLUSIONS: The SF36-PCS in the AMA women decreased with advancing age. However, their SF36-MCS was better over their younger counterparts. Age-related biological disadvantages may be offset by social/psychological advantages in AMA women.

Targeted resequencing showing novel common and rare genetic variants increases the risk of asthma in the Chinese Han population.

BACKGROUND: Although studies have identified hundreds of genetic variants associated with asthma risk, a large fraction of heritability remains unexplained, especially in Chinese individuals. METHODS: To identify genetic risk factors for asthma in a Han Chinese population, 211 asthma-related genes were first selected based on database searches. The genes were then sequenced for subjects in a Discovery Cohort (284 asthma patients and 205 older healthy controls) using targeted next-generation sequencing. Bioinformatics analysis and statistical association analyses were performed to reveal the associations between rare/common variants and asthma, respectively. The identified common risk variants underwent a validation analysis using a Replication Cohort (664 patients and 650 controls). RESULTS: First, we identified 18 potentially functional rare loss-of-function (LOF) variants in 21/284 (7.4%) of the asthma cases. Second, using burden tests, we found that the asthma group had nominally significant (p < 0.05) burdens of rare nonsynonymous variants in 10 genes. Third, 23 common single-nucleotide polymorphisms were associated with the risk of asthma, 7/23 (30.4%) and 9/23 (39.1%) of which were modestly significant (p < 9.1 × 10-4 ) in the Replication Cohort and Combined Cohort, respectively. According to our cumulative risk model involving the modestly associated alleles, middle- and high-risk subjects had a 2.0-fold (95% CI: 1.621-2.423, p = 2.624 × 10-11 ) and 6.0-fold (95% CI: 3.623-10.156, p = 7.086 × 10-12 ) increased risk of asthma, respectively, compared with low-risk subjects. CONCLUSION: This study revealed novel rare and common genetic risk factors for asthma, and provided a cumulative risk model for asthma risk prediction and stratification in Han Chinese individuals.

A nonsynonymous polymorphism (rs117179004, T392M) of hyaluronidase 1 (HYAL1) is associated with increased risk of idiopathic pulmonary fibrosis in Southern Han Chinese.

BACKGROUND: Idiopathic pulmonary fibrosis (IPF) is a genetic heterogeneous disease with high mortality and poor prognosis. Hyaluronidase 1 (HYAL1) was found to be upregulated in fibroblasts from IPF patients, and overexpression of HYAL1 could prevent human fetal lung fibroblast proliferation. However, the genetic correlation between the HYAL1 and IPF or connective tissue diseases related interstitial lung disease (CTD-ILD) has not been determined. METHODS: A two-stage study was conducted in Southern Han Chinese population. We sequenced the coding regions and flanking regulatory regions of HYAL1 in stage one (253 IPF cases and 125 controls). A statistically significant variant was further genotyped in stage two (162 IPF cases, 182 CTD-ILD cases, and 225 controls). RESULTS: We identified a nonsynonymous polymorphism (rs117179004, T392M) significantly associated with increased IPF risk (dominant model: OR = 2.239, 95% CI = 1.212-4.137, p = 0.010 in stage one; OR = 2.383, 95% CI = 1.376-4.128, p = 0.002 in stage two). However, we did not observe this association in CTD-ILD (OR = 1.401, 95% CI = 0.790-2.485, p = 0.248). CONCLUSION: Our findings suggest that the nonsynonymous polymorphism (rs117179004, T392M) may confer susceptibility to IPF in Southern Han Chinese, but is not associated with susceptibility to CTD-ILD.

A multicenter RCT of noninvasive ventilation in pneumonia-induced early mild acute respiratory distress syndrome.

RATIONALE: Our pilot study suggested that noninvasive ventilation (NIV) reduced the need for intubation compared with conventional administration of oxygen on patients with "early" stage of mild acute respiratory distress syndrome (ARDS, PaO2/FIO2 between 200 and 300). OBJECTIVES: To evaluate whether early NIV can reduce the need for invasive ventilation in patients with pneumonia-induced early mild ARDS. METHODS: Prospective, multicenter, randomized controlled trial (RCT) of NIV compared with conventional administration of oxygen through a Venturi mask. Primary outcome included the numbers of patients who met the intubation criteria. RESULTS: Two hundred subjects were randomized to NIV (n = 102) or control (n = 98) groups from 21 centers. Baseline characteristics were similar in the two groups. In the NIV group, PaO2/FIO2 became significantly higher than in the control group at 2 h after randomization and remained stable for the first 72 h. NIV did not decrease the proportion of patients requiring intubation than in the control group (11/102 vs. 9/98, 10.8% vs. 9.2%, p = 0.706). The ICU mortality was similar in the two groups (7/102 vs. 7/98, 4.9% vs. 3.1%, p = 0.721). Multivariate analysis showed minute ventilation greater than 11 L/min at 48 h was the independent risk factor for NIV failure (OR, 1.176 [95% CI, 1.005-1.379], p = 0.043). CONCLUSIONS: Treatment with NIV did not reduce the need for intubation among patients with pneumonia-induced early mild ARDS, despite the improved PaO2/FIO2 observed with NIV compared with standard oxygen therapy. High minute ventilation may predict NIV failure. TRIAL REGISTRATION: NCT01581229 . Registered 19 April 2012.

Targeted resequencing reveals genetic risks in patients with sporadic idiopathic pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a genetic heterogeneous disease with high mortality and poor prognosis. However, a large fraction of genetic cause remains unexplained, especially in sporadic IPF (∼80% IPF). By systemically reviewing related literature and potential pathogenic pathways, 92 potentially IPF-related genes were selected and sequenced in genomic DNAs from 253 sporadic IPF patients and 125 matched health controls using targeted massively parallel next-generation sequencing. The identified risk variants were confirmed by Sanger sequencing. We identified two pathogenic and 10 loss-of-function (LOF) candidate variants, accounting for 4.74% (12 out of 253) of all the IPF cases. In burden tests, rare missense variants in three genes (CSF3R, DSP, and LAMA3) were identified that have a statistically significant relationship with IPF. Four common SNPs (rs3737002, rs2296160, rs1800470, and rs35705950) were observed to be statistically associated with increased risk of IPF. In the cumulative risk model, high risk subjects had 3.47-fold (95%CI: 2.07-5.81, P = 2.34 × 10-6 ) risk of developing IPF compared with low risk subjects. We drafted a comprehensive map of genetic risks (including both rare and common candidate variants) in patients with IPF, which could provide insights to help in understanding mechanisms, providing genetic diagnosis, and predicting risk for IPF.

Renal tubules transcriptome reveals metabolic maladaption during the progression of ischemia-induced acute kidney injury.

Renal tubular epithelial cells (TECs) play a critical role in driving acute kidney injury (AKI) progression, but the key molecular features in TECs during this process is not clear. To better understand the molecular characteristics in renal TECs during AKI and renal fibrogenesis, an irreversible AKI mouse model induced by ischemia/reperfusion injury (IRI) was used in this study. The renal tubules were isolated and tubule specific transcriptome was detected by RNA-seq at different stages in the progression of AKI in this model. The overall transcriptome indicated injury and repair process of TEC after renal IRI. In addition, metabolism maladaption was observed during AKI progression to chronic fibrosis. Particularly, we found dysregulation of multiple steps of lipid metabolism in tubule transcriptomes. Oil red O staining revealed massive lipid droplets accumulation in TECs at day 10, thus confirming the defect of lipid metabolism. This is the first study to charaterize renal tubule specific transcriptome during AKI progression. The results shed light on the molecular features in TECs for progressive AKI.

Non-Target and Suspect Screening of Per- and Polyfluoroalkyl Substances in Airborne Particulate Matter in China.

Airborne particulate matter (APM) has an important role in inhalation exposure, especially in China. The environmental occurrence of conventional and unknown per- and polyfluoroalkyl substances (PFASs) in APM remains unclear. Therefore, in this study, a two-stage experiment was designed to identify potential PFASs and to investigate their distribution in APM. Indoor and outdoor APM samples were collected from five selected cities in China. Through PFAS homologue analysis and suspect screening, 50 peaks were identified with different confidence levels (levels 1-3). Among the identified PFASs, 34 emerging PFASs including p-perfluorous nonenoxybenzenesulfonate, 6:2 polyfluoroalkyl phosphate diester, n:2 fluorotelomer sulfonates, n:2 fluorinated telomer acids, n:2 chlorinated polyfluoroalkyl ether sulfonic acids, 1:n polyfluoroalkyl ether carboxylic acids (1:n PFECAs), perfluoroalkyl dioic acids (PFdiOAs), hydro-substituted perfluoroalkyl dioic acids (H-PFdiOAs), and unsaturated perfluorinated alcohols (UPFAs) were identified in APM. In particular, 1:n PFECAs, PFdiOAs, H-PFdiOAs, and UPFAs were first detected in APM. Although human exposure to perfluorooctanoic acid via inhaled APM was noted to not be a risk (hazard quotient <0.1) in this study, the expansion of the PFASs screened in APM implies that human exposure to PFASs might be much more serious and should be considered in future risk assessments in China.

Lysophosphatidic acid enhances human umbilical cord mesenchymal stem cell viability without differentiation via LPA receptor mediating manner.

Human umbilical cord mesenchymal stem cells (hUC-MSCs) are potential stromal cells which are regarded as the most feasible stem cell group in cell therapy. The maintenance of cell survival without differentiation is important in cell transplantation and stem cell therapy. However, negative factors exist in cell transplantation. Lysophosphatidic acid (LPA) is a non-antigenic small molecule phospholipid which induced several fundamental cellular responses, such as cell proliferation, apoptosis and migration. In this study we aimed to explore the effects of LPA on the survival and differentiation of MSCs and its availability in cell therapy. We found that LPA stimulated hUC-MSC proliferation and protected hUC-MSCs from lipopolysaccharide (LPS) induced apoptosis. We also observed that CD29, CD44, CD73, CD90 and CD105 were expressed, whereas CD34 and CD45 were not expressed in hUC-MSCs, and these makers have no change in LPA containing medium, which indicated that LPA accelerated the survival of hUC-MSCs in an undifferentiating status. We also demonstrated that higher expressed LPAR1 involved in LPA stimulated cell survival action. LPA stimulated cell proliferation was associated with LPAR1 mediated Gi/o-proteins/ERK1/2 pathway. On the other hand, LPA protected hUC-MSCs from LPS-induced apoptosis through suppressing caspase-3 activation by LPAR1 coupled with a G protein, but not Gi/o or Gq/11 in hUC-MSC. Collectively, this study demonstrated that LPA increased the proliferation and survival of hUC-MSCs without differentiation through LPAR1 mediated manner. Our findings provide that LPA as a anti-apoptotic agent having potential application prospect in cell transplantation and stem cell therapy.

Enantioselective bioreduction of benzo-fused cyclic ketones with engineered Candida glabrata ketoreductase 1 - a promising synthetic route to ladostigil (TV3326).

Biocatalysis has been recently emerging as a promising alternative to traditional chemical synthesis because of its "green" characteristics and comparable selectivities, which accord with the concept of sustainable development and demand for asymmetric synthesis. In this study, whole-cell biocatalysts containing glucose dehydrogenase (GDH) and Candida glabrata ketoreductase 1 (CgKR1) variants were constructed. These biocatalysts were applied to the reduction of benzo-fused cyclic ketones and showed good to high activities and enantioselectivities. Particularly, CgKR1 variants displayed high activities (90.6%-98.4% conversions) and enantioselectivities (>99.9% ee) towards 5a, a key intermediate of ladostigil (TV3326). Based on these results, a chemoenzymatic synthesis of (S)-5b was developed by using biocatalytic asymmetric reduction as a key step, giving the product with a total yield of 34.0% and 99.9% ee.

Molecular Mechanisms of Perfluorooctanoate-Induced Hepatocyte Apoptosis in Mice Using Proteomic Techniques.

The stability of perfluorooctanoate (PFOA) coupled with its wide use cause serious concerns regarding its potential risk to human health. The molecular mechanisms of PFOA-induced hepatotoxicity relevant to human health was investigated using both in vivo (mouse model) and in vitro (human hepatocyte cells, HL-7702) techniques. Both male and female Balb/c mice were administered PFOA at 0.05, 0.5, or 2.5 mg/kg-d for 28-d, with serum PFOA concentrations after exposure being found at environmentally relevant levels. Liver samples were examined for histology and proteomic change using iTRAQ and Western Blotting, showing dose-dependent hepatocyte apoptosis and peroxisome proliferation. At high doses, genotoxicity resulting from ROS hypergeneration was due to suppression of Complex I subunits in the electron transport chain and activation of PPARα in both genders. However, at 0.05 mg/kg-d, Complex I suppression occurred only in females, making them more sensitive to PFOA-induced apoptosis. In vitro assays using HL-7702 cells confirmed that apoptosis was also induced through a similar mechanism. The dose/gender-dependent toxicity mechanisms help to explain some epidemiological phenomena, i.e., liver cancer is not often associated with PFOA exposure in professional workers. Our results demonstrated that a proteomic approach is a robust tool to explore molecular mechanisms of toxic chemicals at environmentally relevant levels.

The BEAF-32 insulator coordinates genome organization and function during the evolution of Drosophila species.

Understanding the relationship between genome organization and expression is central to understanding genome function. Closely apposed genes in a head-to-head orientation share the same upstream region and are likely to be coregulated. Here we identify the Drosophila BEAF-32 insulator as a cis regulatory element separating close head-to-head genes with different transcription regulation modes. We then compare the binding landscapes of the BEAF-32 insulator protein in four different Drosophila genomes and highlight the evolutionarily conserved presence of this protein between close adjacent genes. We find that changes in binding of BEAF-32 to sites in the genome of different Drosophila species correlate with alterations in genome organization caused by DNA rearrangements or genome size expansion. The cross-talk between BEAF-32 genomic distribution and genome organization contributes to new gene-expression profiles, which in turn translate into specific and distinct phenotypes. The results suggest a mechanism for the establishment of differences in transcription patterns during evolution.