Network pharmacology, molecular docking and experimental study on the mechanism of Curcumin's anti-ferroptosis in melanocytes.

Ferroptosis is a form of regulated nonapoptotic cell death associated with iron-dependent lipid peroxidation, closely associated with Vitiligo. Although the impact of Curcumin (Cur), a polyphenolic compound derived from the plant Curcuma longa Linn, on vitiligo has been established, the specific role and potential mechanistic pathways through which Cur modulates ferroptosis in vitiligo remain elusive. In this study, the critical targets and potential mechanisms of Cur in treating vitiligo were predicted by network pharmacology and molecule docking. Then, the effects of Cur on Erastin-induced ferroptosis were investigated in melanocytes induced by Erastin in vitro. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of Cur acting on Vitiligo found that these intersection genes are associated with the vitiligo oxidative stress pathway, including nuclear factor erythroid 2-related factor 2(Nrf2)/Heme Oxygenase 1(HO-1) signaling pathway. Further molecular docking shows that Cur has a good binding effect with Nrf2(the binding energy of Cur and Nrf2 protein is -6 kcal/mol). Through the CCK8 assay, showed that 10 µM Cur treatment 24 h after Erastin significantly improved cell viability In vitro. Then we found that Erastin induced cell death, ROS production, the mitochondrial membrane potential(MMP) decreased, Superoxide dismutase (SOD) and Glutathione (GSH) levels reduced, Malonaldehyde (MDA) and iron ion accumulation in melanocytes. In addition, the expression of glutathione peroxidase 4(GPX4) mRNA and protein was inhibited, while the expression of acyl-CoA synthetase long-chain family member 4(ACSL4), Transferrin Receptor Protein 1(TFR1) mRNA and protein was increased. However, the damage induced by Erastin was significantly relieved by Cur and Fer-1 treatment. Mechanistically, Cur treatment significantly promoted nuclear translocation of transcriptional factor Nrf2 and HO-1 expression. Interestingly, pretreatment with ML385, a selective Nrf2 inhibitor, counteracted anti-ferroptosis effects induced by Cur treatment. Taken together, these results demonstrate that Cur inhibits ferroptosis by regulating the Nrf2/HO-1 pathway to protect melanocytes.

Chiral Supramolecular Nanofibers Regulated Tumor-Derived Exosomes Secretion for Constructing an Anti-Tumor Extracellular Microenvironment.

Tumor-derived exosomes (TDEs) induced extracellular microenvironment has recently been validated to be critical for tumor progression and metastasis, however, remodeling it for oncotherapy still remains a major challenge due to difficulty in regulation of TDEs secretion. Herein, the supramolecular chiral nanofibers, composed of L/D-phenylalanine derivates (L/D-Phe) and linear hyaluronic acid (HA), are successfully employed to construct TDEs induced anti-tumor extracellular microenvironment. The left-handed L-Phe @HA nanofibers significantly inhibit TDEs secretion into extracellular microenvironment, which results in suppression of tumor proliferation and metastasis in vitro and vivo. Biological assays and theoretical modeling reveal that these results are mainly attributed to strong adsorption of the key exosomes transporters (Ras-related protein Rab-27A and synaptosome-associated protein 23) on left-handed L-Phe @HA nanofibers via enhanced stereoselective interaction, leading to degradation and phosphorylated dropping of exosomes transporters. Subsequently, transfer function of exosomes transporters is limited, which causes remarkable inhibition of TDEs secretion. These findings provide a promising novel insight of chiral functional materials to establish an anti-tumor extracellular microenvironment via regulation of TDEs secretion.

Association Between Cost Sharing and Naloxone Prescription Dispensing.

Importance: Increasing access to naloxone (an opioid antagonist that can reverse overdose) could slow the US opioid epidemic. Prior studies suggest cost sharing may be a barrier to dispensing of naloxone prescriptions, but these studies were limited by their cross-sectional designs and use of databases that do not capture prescriptions that are not filled (abandoned). Objective: To evaluate the association between cost sharing and naloxone prescription abandonment (nondispensing of naloxone prescriptions). Design, Setting, and Participants: This cross-sectional, regression discontinuity analysis exploited the fact that deductibles typically reset at the beginning of the year in commercial and Medicare plans. The included data were derived from the 2020-2021 IQVIA Formulary Impact Analyzer (a pharmacy transactions database that represents 63% of prescriptions at US pharmacies). The analysis included claims for naloxone nasal spray among commercially insured patients and Medicare patients that occurred during the 60 days before January 1, 2021, through 59 days after January 1, 2021. Exposure: Cost sharing, which is defined as the amount patients would have to pay to fill prescriptions. Main Outcomes and Measures: Local linear regression models were used to assess for abrupt changes in cost sharing and the probability of prescription abandonment on January 1, 2021. To estimate the association between cost sharing and prescription abandonment, a fuzzy regression discontinuity analysis was conducted. Results: These analyses included naloxone claims for 71 306 commercially insured patients and 101 706 Medicare patients (40 019 [56.1%] and 61 410 [60.4%], respectively, were female). The commercially insured patients and Medicare patients accounted for 73 311 and 106 076 naloxone claims, respectively. On January 1, 2021, the mean cost sharing per claim increased by $15.0 (95% CI, $13.8-$16.2) for commercially insured patients and increased by $12.3 (95% CI, $10.9-$13.6) for Medicare patients and the probability of abandonment increased by 4.7 (95% CI, 3.2-6.2) percentage points and 2.8 (95% CI, 1.6-4.1) percentage points, respectively. The results from the fuzzy regression discontinuity analysis suggest a decision by commercial and Medicare plans to increase naloxone cost sharing by $10 would be associated with percentage-point increases of 3.1 (95% CI, 2.2-4.1) and 2.3 (95% CI, 1.4-3.2), respectively, in the probability of abandonment. Conclusions: The elimination of cost sharing might be associated with increased naloxone dispensing to commercially insured and Medicare patients.

NeuCA web server: a neural network-based cell annotation tool with web-app and GUI.

SUMMARY: Correctly annotating individual cell's type is an important initial step in single-cell RNA sequencing (scRNA-seq) data analysis. Here, we present NeuCA web server, a neural network-based scRNA-seq cell annotation tool with web-app portal and graphical user interface, for automatically assigning cell labels. NeuCA algorithm is accurate and exhaustive, maximizing the usage of measured cells for downstream analysis. NeuCA web server provides over 20 ready-to-use pre-trained classifiers for commonly used tissue types. As the first web-app tool with neural-network infrastructure implemented, NeuCA web will facilitate the research community in analyzing and annotating scRNA-seq data. AVAILABILITY AND IMPLEMENTATION: NeuCA web server is implemented with R Shiny application online at https://statbioinfo.shinyapps.io/NeuCA/. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

A comparative study on ctDNA and tumor DNA mutations in lung cancer and benign cases with a high number of CTCs and CTECs.

BACKGROUND: Liquid biopsy provides a non-invasive approach that enables detecting circulating tumor DNA (ctDNA) and circulating tumor cells (CTCs) using blood specimens and theoretically benefits early finding primary tumor or monitoring treatment response as well as tumor recurrence. Despite many studies on these novel biomarkers, their clinical relevance remains controversial. This study aims to investigate the correlation between ctDNA, CTCs, and circulating tumor-derived endothelial cells (CTECs)  while also evaluating whether mutation profiling in ctDNA is consistent with that in tumor tissue from lung cancer patients. These findings will help the evaluation and utilization of these approaches in clinical practice. METHODS: 104 participants (49 with lung cancer and 31 with benign lesions) underwent CTCs and CTECs detection using integrating subtraction enrichment and immunostaining-fluorescence in situ hybridization (SE-iFISH) strategy. The circulating cell-free DNA (cfDNA) concentration was measured and the mutational profiles of ctDNA were examined by Roche AVENIO ctDNA Expanded Kit (targeted total of 77 genes) by next generation sequencing (NGS) in 28 patients (20 with lung cancer and 8 with benign lesions) with highest numbers of CTCs and CTECs. Mutation validation in matched tumor tissue DNA was then performed in 9 patients with ctDNA mutations using a customized xGen pan-solid tumor kit (targeted total of 474 genes) by NGS. RESULTS: The sensitivity and specificity of total number of CTCs and CTECs for the diagnosis of NSCLC were 67.3% and 77.6% [AUC (95%CI): 0.815 (0.722-0.907)], 83.9% and 77.4% [AUC (95%CI): 0.739 (0.618-0.860)]. The concentration of cfDNA in plasma was statistically correlated with the size of the primary tumor (r = 0.430, P = 0.022) and CYFRA 21-1 (r = 0.411, P = 0.041), but not with the numbers of CTCs and CTECs. In this study, mutations were found to be poorly consistent between ctDNA and tumor DNA (tDNA) in patients, even when numerous CTCs and CTECs were present. CONCLUSION: Detection of CTCs and CTECs could be the potential adjunct tool for the early finding of lung cancer. The cfDNA levels are associated with the tumor burden, rather than the CTCs or CTECs counts. Moreover, the poorly consistent mutations between ctDNA and tDNA require further exploration.

Assembly of Helical Nanostructures: Solvent-Induced Morphology Transition and Its Effect on Cell Adhesion.

Being able to precisely manipulate both the morphology and chiroptical signals of supramolecular assemblies will help to better understand the natural biological self-assembly mechanism. Two simple l/d-phenylalanine-based derivatives (L/DPFM) have been designed, and their solvent-dependent morphology evolutions are illustrated. It was found that, as the content of H2 O in aqueous ethanol solutions was increased, LPFM self-assembles first into right-handed nanofibers, then flat fibrous structures, and finally inversed left-handed nanofibers. Assemblies in ethanol and H2 O exhibit opposite conformations and circular dichroism (CD) signals even though they are constructed from the same molecules. Thus, the morphology-dependent cell adhesion and proliferation behaviors are further characterized. Left-handed nanofibers are found to be more favorable for cell adhesion than right-handed nanostructures. Quantitative AFM analysis showed that the L929 cell adhesion force on left-handed LPFM fibers is much higher than that on structures with inversed handedness. Moreover, the value of cell Young's modulus is lower for left-handed nanofibrous films, which indicates better flexibility. The difference in cell-substrate interactions might lead to different effects on cell behavior.

PSGL-1 restricts HIV-1 infectivity by blocking virus particle attachment to target cells.

P-selectin glycoprotein ligand-1 (PSGL-1) is a dimeric, mucin-like, 120-kDa glycoprotein that binds to P-, E-, and L-selectins. PSGL-1 is expressed primarily on the surface of lymphoid and myeloid cells and is up-regulated during inflammation to mediate leukocyte tethering and rolling on the surface of endothelium for migration into inflamed tissues. Although it has been reported that PSGL-1 expression inhibits HIV-1 replication, the mechanism of PSGL-1-mediated anti-HIV activity remains to be elucidated. Here we report that PSGL-1 in virions blocks the infectivity of HIV-1 particles by preventing the binding of particles to target cells. This inhibitory activity is independent of the viral glycoprotein present on the virus particle; the binding of particles bearing the HIV-1 envelope glycoprotein or vesicular stomatitis virus G glycoprotein or even lacking a viral glycoprotein is impaired by PSGL-1. Mapping studies show that the extracellular N-terminal domain of PSGL-1 is necessary for its anti-HIV-1 activity, and that the PSGL-1 cytoplasmic tail contributes to inhibition. In addition, we demonstrate that the PSGL-1-related monomeric E-selectin-binding glycoprotein CD43 also effectively blocks HIV-1 infectivity. HIV-1 infection, or expression of either Vpu or Nef, down-regulates PSGL-1 from the cell surface; expression of Vpu appears to be primarily responsible for enabling the virus to partially escape PSGL-1-mediated restriction. Finally, we show that PSGL-1 inhibits the infectivity of other viruses, such as murine leukemia virus and influenza A virus. These findings demonstrate that PSGL-1 is a broad-spectrum antiviral host factor with a unique mechanism of action.

Adult-Onset CNS Sulfatide Deficiency Causes Sex-Dependent Metabolic Disruption in Aging.

The interconnection between obesity and central nervous system (CNS) neurological dysfunction has been widely appreciated. Accumulating evidence demonstrates that obesity is a risk factor for CNS neuroinflammation and cognitive impairment. However, the extent to which CNS disruption influences peripheral metabolism remains to be elucidated. We previously reported that myelin-enriched sulfatide loss leads to CNS neuroinflammation and cognitive decline. In this study, we further investigated the impact of CNS sulfatide deficiency on peripheral metabolism while considering sex- and age-specific effects. We found that female sulfatide-deficient mice gained significantly more body weight, exhibited higher basal glucose levels, and were glucose-intolerant during glucose-tolerance test (GTT) compared to age-matched controls under a normal diet, whereas male sulfatide-deficient mice only displayed glucose intolerance at a much older age compared to female sulfatide-deficient mice. Mechanistically, we found that increased body weight was associated with increased food intake and elevated neuroinflammation, especially in the hypothalamus, in a sex-specific manner. Our results suggest that CNS sulfatide deficiency leads to sex-specific alterations in energy homeostasis via dysregulated hypothalamic control of food intake.

Process Optimization, Amino Acid Composition, and Antioxidant Activities of Protein and Polypeptide Extracted from Waste Beer Yeast.

Repurposing of waste beer yeast (WBY) that a main by-product of brewing industry has attracted considerable attention in recent years. In this study, the protein and polypeptide were extracted by ultrasonic-assisted extraction and enzymatic hydrolysis with process optimization, which resulted in a maximum yield of 73.94% and 61.24%, respectively. Both protein and polypeptide of WBY were composed of 17 Amino acids (AA) that included seven essential amino acids (EAA), and typically rich in glutamic acid (Glu) (6.46% and 6.13%) and glycine (Gly) (5.26% and 6.02%). AA score (AAS) revealed that the threonine (Thr) and SAA (methionine + cysteine) were the limiting AA of WBY protein and polypeptide. Furthermore, the antioxidant activities of WBY polypeptide that lower than 10 kDa against hydroxyl radical, DPPH radical, and ABTS radical were 95.10%, 98.37%, and 69.41%, respectively, which was significantly higher than that of WBY protein (25-50 kDa). Therefore, the protein and polypeptide extracted from WBY can be a source of high-quality AA applying in food and feed industry. Due to small molecular weight, abundant AA, and great antioxidant activity, WBY polypeptide can be promisingly used as functional additives in the pharmaceutical and healthcare industry.

A systematic review and meta-analysis of children with coronavirus disease 2019 (COVID-19).

To provide a comprehensive and systematic analysis of demographic characteristics, clinical symptoms, laboratory findings, and imaging features of coronavirus disease 2019 (COVID-19) in pediatric patients. A meta-analysis was carried out to identify studies on COVID-19 from 25 December 2019 to 30 April 2020. A total of 48 studies with 5829 pediatric patients were included. Children of all ages were at risk for COVID-19. The main illness classification ranged as: 20% (95% confidence interval [CI]: 14%-26%; I2 = 91.4%) asymptomatic, 33% (95% CI: 23%-43%; I2 = 95.6%) mild and 51% (95% CI: 42%-61%; I2 = 93.4%) moderate. The typical clinical manifestations were fever 51% (95% CI: 45%-57%; I2 = 78.9%) and cough 41% (95% CI: 35%-47%, I2 = 81.0%). The common laboratory findings were normal white blood cell 69% (95% CI: 64%-75%; I2 = 58.5%), lymphopenia 16% (95% CI: 11%-21%; I2 = 76.9%) and elevated creatine-kinase MB 37% (95% CI: 25%-48%; I2 = 59.0%). The frequent imaging features were normal images 41% (95% CI: 30%-52%; I2 = 93.4%) and ground-glass opacity 36% (95% CI: 25%-47%; I2 = 92.9%). Among children under 1 year old, critical cases account for 14% (95% CI: 13%-34%; I2 = 37.3%) that should be of concern. In addition, vomiting occurred in 33% (95% CI: 18%-67%; I2 = 0.0%) cases that may also need attention. Pediatric patients with COVID-19 may experience milder illness with atypical clinical manifestations and rare lymphopenia. High incidence of critical illness and vomiting symptoms reward attention in children under 1 year old.

Validation of an 8-item Recovery Assessment Scale (RAS-8) for people with schizophrenia in China.

BACKGROUND: The 24-item Recovery Assessment Scale (RAS) is the most widely-used and well-validated tool for measuring recovery for people with mental illness. The current study aims to assess the reliability and validity of an 8-item short form of RAS (RAS-8) among a Chinese sample of people living with schizophrenia. METHODS: A sample of 400 people living with schizophrenia were recruited for scale validation. Internal consistency was tested by calculating Cronbach's α. Test-retest reliability was calculated using the intraclass correlation coefficient (ICC) for the total score and weighted kappa for each item. Factor structure was tested with confirmatory factor analysis, and concurrent validity was examined by investigating the correlation of the RAS-8 with patient symptoms, disability, depression, anxiety, patient functioning, quality of life and general health. RESULTS: The RAS-8 full scale and subscales showed good internal consistency with Cronbach's alpha ranging from 0.87 to 0.92. ICC of 0.99 and weighted kappa ranged from 0.62 to 0.88, which generally indicates good test-retest reliability. The findings supported an a priori two-factor structure, χ2/df = 2.93, CFI = 0.98, TLI = 0.98, RMSEA = 0.07, SRMR = 0.035. Concurrent validity of the RAS-8 was further supported by its significant negative correlations with patient symptoms (r = -0.24, p < 0.01), disability (r = -0.30, p < 0.01), depression (r = -0.16, p < 0.05), and anxiety (r = -0.14, p < 0.05), and its significant positive relationships with patient functioning (r = 0.26, p < 0.01), quality of life (r = 0.39, p < 0.01) and general health (r = 0.34, p < 0.01). CONCLUSIONS: This study confirmed the reliability and validity of an 8-item short-form RAS for people living with schizophrenia in Chinese communities. The validation of the RAS-8 allows for its use as an alternative for the full RAS as a rapid assessment tool in clinical and research settings. The findings are discussed for their implications for application and validation with other populations and in other countries.

Detectable SARS-CoV-2 viral RNA in feces of three children during recovery period of COVID-19 pneumonia.

Coronavirus Disease 2019 (COVID-19) is a newly emerging infectious disease caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). After its first occurrence in Wuhan of China from December 2019, COVID-19 rapidly spread around the world. According to the World Health Organization statement on 13 March 2020, there had been over 132 500 confirmed cases globally. Nevertheless, the case reports of children are rare, which results in the lack of evidence for preventing and controlling of children's infection. Here, we report three cases of SARS-CoV-2 infected children diagnosed from 3 February to 17 February 2020 in Tianjin, China. All of these three cases experienced mild illness and recovered soon after the treatment, with the nucleic acid of throat swab turning negative within 14, 11, and 7 days after diagnosis, respectively. However, after been discharged, all three cases were tested SARS-CoV-2 positive in the stool samples within 10 days, in spite of their remained negative nucleic acid in throat swab specimens. Therefore, it is necessary to be aware of the possibility of fecal-oral transmission of SARS-CoV-2 infection, especially for children cases.

Children with coronavirus disease 2019: A review of demographic, clinical, laboratory, and imaging features in pediatric patients.

There is a current outbreak of coronavirus disease 2019 (COVID-19), with a global spread. With the rapid increase in the number of infections, an increase is observed in the number of children with COVID-19. Most research findings are regarding adult cases, which are not always transferrable to children. Evidence-based studies are still expected to formulate clinical decisions for pediatric patients. In this review, we included 2597 pediatric patients that reported recently and evaluated the demographic, clinical, laboratory, and imaging features of children with COVID-19. We found that even lymphopenia was the most common lab finding in adults; it infrequently occurred in children (9.8%). Moreover, elevated creatine kinase MB isoenzyme was much more commonly observed in children (27.0%) than that in adults, suggesting that heart injury would be more likely to occur in pediatric patients. Our analysis may contribute to determine the spectrum of disease in children and to develop strategies to control the disease transmission.

DsbA-L prevents obesity-induced inflammation and insulin resistance by suppressing the mtDNA release-activated cGAS-cGAMP-STING pathway.

Chronic inflammation in adipose tissue plays a key role in obesity-induced insulin resistance. However, the mechanisms underlying obesity-induced inflammation remain elusive. Here we show that obesity promotes mtDNA release into the cytosol, where it triggers inflammatory responses by activating the DNA-sensing cGAS-cGAMP-STING pathway. Fat-specific knockout of disulfide-bond A oxidoreductase-like protein (DsbA-L), a chaperone-like protein originally identified in the mitochondrial matrix, impaired mitochondrial function and promoted mtDNA release, leading to activation of the cGAS-cGAMP-STING pathway and inflammatory responses. Conversely, fat-specific overexpression of DsbA-L protected mice against high-fat diet-induced activation of the cGAS-cGAMP-STING pathway and inflammation. Taken together, we identify DsbA-L as a key molecule that maintains mitochondrial integrity. DsbA-L deficiency promotes inflammation and insulin resistance by activating the cGAS-cGAMP-STING pathway. Our study also reveals that, in addition to its well-characterized roles in innate immune surveillance, the cGAS-cGAMP-STING pathway plays an important role in mediating obesity-induced metabolic dysfunction.

Research Advances of Purple Sweet Potato Anthocyanins: Extraction, Identification, Stability, Bioactivity, Application, and Biotransformation.

Purple sweet potato anthocyanins are kinds of natural anthocyanin red pigments extracted from the root or stem of purple sweet potato. They are stable and have the functions of anti-oxidation, anti-mutation, anti-tumor, liver protection, hypoglycemia, and anti-inflammation, which confer them a good application prospect. Nevertheless, there is not a comprehensive review of purple sweet potato anthocyanins so far. The extraction, structural characterization, stability, functional activity, application in the food, cosmetics, medicine, and other industries of anthocyanins from purple sweet potato, together with their biotransformation in vitro or by gut microorganism are reviewed in this paper, which provides a reference for further development and utilization of anthocyanins.

Discovery of Novel Small-Molecule Inhibitors of LIM Domain Kinase for Inhibiting HIV-1.

A dynamic actin cytoskeleton is necessary for viral entry, intracellular migration, and virion release. For HIV-1 infection, during entry, the virus triggers early actin activity by hijacking chemokine coreceptor signaling, which activates a host dependency factor, cofilin, and its kinase, the LIM domain kinase (LIMK). Although knockdown of human LIM domain kinase 1 (LIMK1) with short hairpin RNA (shRNA) inhibits HIV infection, no specific small-molecule inhibitor of LIMK has been available. Here, we describe the design and discovery of novel classes of small-molecule inhibitors of LIMK for inhibiting HIV infection. We identified R10015 as a lead compound that blocks LIMK activity by binding to the ATP-binding pocket. R10015 specifically blocks viral DNA synthesis, nuclear migration, and virion release. In addition, R10015 inhibits multiple viruses, including Zaire ebolavirus (EBOV), Rift Valley fever virus (RVFV), Venezuelan equine encephalitis virus (VEEV), and herpes simplex virus 1 (HSV-1), suggesting that LIMK inhibitors could be developed as a new class of broad-spectrum antiviral drugs.IMPORTANCE The actin cytoskeleton is a structure that gives the cell shape and the ability to migrate. Viruses frequently rely on actin dynamics for entry and intracellular migration. In cells, actin dynamics are regulated by kinases, such as the LIM domain kinase (LIMK), which regulates actin activity through phosphorylation of cofilin, an actin-depolymerizing factor. Recent studies have found that LIMK/cofilin are targeted by viruses such as HIV-1 for propelling viral intracellular migration. Although inhibiting LIMK1 expression blocks HIV-1 infection, no highly specific LIMK inhibitor is available. This study describes the design, medicinal synthesis, and discovery of small-molecule LIMK inhibitors for blocking HIV-1 and several other viruses and emphasizes the feasibility of developing LIMK inhibitors as broad-spectrum antiviral drugs.

[Effect of Doxorubicin on abcb4 Gene Expression in Zebrafish (Danio rerio) Embryos].

OBJECTIVE: To determine the effect of doxorubicin (DOX) on abcb4 gene expression and the role of abcb4 gene in multidrug-resistance. METHODS: Zebrafish embryos were treated with 2 mL/L DMSO, 10 µmol/L DOX and 2 mL/L DMSO+10 µmol/L DOX, respectively. The zebrafish embryos treated with Eggwater served as controls. Exposures started at 4 to 16 cell stage of the embryos and terminated 120 hours post fertilization (hpf). The expression of abcb4 gene in zebrafish embryos was examined on 48, 72, 96, and 120 hpf with whole-mount in situ hybridization (WISH) and quantitative real-time PCR (qPCR). RESULTS: Compared with the controls, DOX-exposed embryos had higher level of abcb4 gene expression (P < 0.05), but not for abcb5 gene. WISH showed that abcb4 gene was expressed in the guts of zebrafish embryos. However, those exposed to DOX also showed strong WISH signals in the brain and heart. CONCLUSION: Doxorubicin increases the expression of abcb4 gene in zebrafish embryos. abcb4 gene may play an imoortant role in multidrug-resistance.

HIV-1 triggers WAVE2 phosphorylation in primary CD4 T cells and macrophages, mediating Arp2/3-dependent nuclear migration.

The human immunodeficiency virus type 1 (HIV-1) initiates receptor signaling and early actin dynamics during viral entry. This process is required for viral infection of primary targets such as resting CD4 T cells. WAVE2 is a component of a multiprotein complex linking receptor signaling to dynamic remodeling of the actin cytoskeleton. WAVE2 directly activates Arp2/3, leading to actin nucleation and filament branching. Although several bacterial and viral pathogens target Arp2/3 for intracellular mobility, it remains unknown whether HIV-1 actively modulates the Arp2/3 complex through virus-mediated receptor signal transduction. Here we report that HIV-1 triggers WAVE2 phosphorylation at serine 351 through gp120 binding to the chemokine coreceptor CXCR4 or CCR5 during entry. This phosphorylation event involves both Gαi-dependent and -independent pathways, and is conserved both in X4 and R5 viral infection of resting CD4 T cells and primary macrophages. We further demonstrate that inhibition of WAVE2-mediated Arp2/3 activity through stable shRNA knockdown of Arp3 dramatically diminished HIV-1 infection of CD4 T cells, preventing viral nuclear migration. Inhibition of Arp2/3 through a specific inhibitor, CK548, also drastically inhibited HIV-1 nuclear migration and infection of CD4 T cells. Our results suggest that Arp2/3 and the upstream regulator, WAVE2, are essential co-factors hijacked by HIV for intracellular migration, and may serve as novel targets to prevent HIV transmission.

Foxa1 contributes to the repression of Nanog expression by recruiting Grg3 during the differentiation of pluripotent P19 embryonal carcinoma cells.

Transcription factor Foxa1 plays a critical role during neural differentiation and is induced immediately after retinoic acid (RA)-initiated differentiation of pluripotent P19 embryonal carcinoma cells, correlated with the downregulated expression of pluripotency-related genes such as Nanog. To study whether Foxa1 participates in the repression of pluripotency factors, we expressed Foxa1 ectopically in P19 cells and identified that Nanog was repressed directly by Foxa1. We confirmed that Foxa1 was able to interact with Grg3, which is a transcriptional corepressor that expresses in P19 cells as well as during RA-induced P19 cell differentiation. Knockdown of Foxa1 or Grg3 delayed the downregulation of Nanog expression during RA-induced P19 cell differentiation. Furthermore, we found that Foxa1 recruited Grg3 to the Nanog promoter -2kb upstream region and switched the promoter to an inactive chromatin status represented by typical modifications in histone H3. Together, our results suggested a critical involvement of Foxa1 in the negative regulation of Nanog expression during the differentiation of pluripotent stem cells.

Surviving the Storm: The Role of Poly- and Depolyploidization in Tissues and Tumors.

Polyploidization and depolyploidization are critical processes in the normal development and tissue homeostasis of diploid organisms. Recent investigations have revealed that polyaneuploid cancer cells (PACCs) exploit this ploidy variation as a survival strategy against anticancer treatment and for the repopulation of tumors. Unscheduled polyploidization and chromosomal instability in PACCs enhance malignancy and treatment resistance. However, their inability to undergo mitosis causes catastrophic cellular death in most PACCs. Adaptive ploid reversal mechanisms, such as multipolar mitosis, centrosome clustering, meiosis-like division, and amitosis, counteract this lethal outcome and drive cancer relapse. The purpose of this work is to focus on PACCs induced by cytotoxic therapy, highlighting the latest discoveries in ploidy dynamics in physiological and pathological contexts. Specifically, by emphasizing the role of "poly-depolyploidization" in tumor progression, the aim is to identify novel therapeutic targets or paradigms for combating diseases associated with aberrant ploidies.