Utilizing noncatalytic ACE2 protein mutant as a competitive inhibitor to treat SARS-CoV-2 infection.

Introduction: Angiotensin converting-enzyme 2 (ACE2) is an enzyme catalyzing the conversion of angiotensin 2 into angiotensin 1-7. ACE2 also serves as the receptor of several coronaviruses, including SARS-CoV-1 and SARS-CoV-2. Therefore, ACE2 could be utilized as a therapeutic target for treating these coronaviruses, ideally lacking enzymatic function. Methods: Based on structural analysis, specific mutations were introduced to generate mutants of ACE2 and ACE2-Fc (fusion protein of ACE2 and Fc region of IgG1). The enzyme activity, binding affinity, and neutralization abilities were measured. Results and discussion: As predicted, five mutants (AMI081, AMI082, AMI083, AMI084, AMI090) have completely depleted ACE2 enzymatic activities. More importantly, enzyme-linked receptor-ligand assay (ELRLA) and surface plasmon resonance (SPR) results showed that 2 mutants (AMI082, AMI090) maintained binding activity to the viral spike proteins of SARS-CoV-1 and SARS-CoV-2. In An in vitro neutralization experiment using a pseudovirus, SARS-CoV-2 S1 spike protein-packed lentivirus particles, was also performed, showing that AMI082 and AMI090 significantly reduced GFP transgene expression. Further, in vitro virulent neutralization assays using SARS-CoV-2 (strain name: USA-WA1/2020) showed that AMI082 and AMI090 had remarkable inhibitory effects, indicated by comparable IC50 to wildtype ACE2 (5.33 µg/mL). In addition to the direct administration of mutant proteins, an alternative strategy for treating COVID-19 is through AAV delivery to achieve long-lasting effects. Therefore, AAV5 encoding AMI082 and AMI090 were packaged and transgene expression was assessed. In summary, these ACE2 mutants represent a novel approach to prevent or treat COVID-19 and other viruses with the same spike protein.

Bioinformatics analysis highlights CCNB1 as a potential prognostic biomarker and an anti-kidney renal papillary cell carcinoma drug target.

Kidney renal papillary cell carcinoma (KIRP) is a common urinary tumor that causes lymph node invasion. Once metastatic, the prognosis is poor and there is a lack of effective early diagnostic markers for this tumor. The expression of CCNB1 in KIRP tumor tissues was significantly higher than that in normal tissues in The Cancer Genome Atlas database with or without the genotype-tissue expression database, and a consistent result was obtained in 32 paired tissues. In addition, CCNB1 expression increased remarkably with the progression of the T and M stages. Moreover, using the online HPA database, we verified that the immunohistochemical scores of CCNB1 in KIRP were higher than those in the normal kidney tissues. The higher expression group of CCNB1 showed a worse prognosis in KIRP. Moreover, the receiver operating characteristic curve, univariate and multivariate analyses, and construction of the column diagram further illustrated that CCNB1 was an independent prognostic factor for KIRP. Meanwhile, CCNB1 could better predict the 1- and 3-year survival rates of KIRP. Six genes were significantly and positively co-expressed with CCNB1. We also found that the CCNB1 high-expression group was enriched in the ECM_RECEPTOR_INTERACTION and FOCAL_ADHESION pathways. Finally, drug sensitivity analysis combined with molecular docking identified 5 targeting drugs with the strongest binding activity to CCNB1. CCNB1 is a potential and reliable biomarker for KIRP diagnosis and can be used to predict the survival of patients with KIRP. The 5 selected drugs targeting CCNB1 may provide new hopes for patients with KIRP metastasis.

Analysis of 14 ß-agonists in pork using an automated wooden tip-based solid-phase microextraction device and ultra-high-performance liquid chromatography-tandem mass spectrometry.

This study introduces a cost-effective, automated ultra-high-performance liquid chromatography-tandem mass spectrometry method for the detection of 14 ß-agonists in pork using a novel solid-phase microextraction probe composed of polyacrylonitrile and molecularly imprinted polymer. Integrated into an automated extraction device, the probe optimizes extraction prior to analysis while reducing expenses and time compared to traditional solid-phase extraction procedures. The method validation followed the Chinese National Standard (GB/T 27404-2008) and examined limits of detection, limits of quantification, matrix effects, linearity, intraday, and interday precision. Average recovery rates ranged from 71.6% to 82.2%, with relative standard deviations less than 15%. Limits of detection and limits of quantification ranged from 0.09 to 0.39 and 0.27 to 0.99 µg/kg, respectively. The new method identified positive samples more accurately than the current National Standard GB/T 31658.22-2022 and demonstrated its potential for routine assessment and regulatory compliance in the detection of ß-agonists in pork.

Network pharmacology to unveil the mechanism of suanzaoren decoction in the treatment of alzheimer's with diabetes.

BACKGROUND: Suanzaoren Decoction (SZRD), a well-known formula from traditional Chinese medicine, has been shown to have reasonable cognitive effects while relaxing and alleviating insomnia. Several studies have demonstrated significant therapeutic effects of SZRD on diabetes and Alzheimer's disease (AD). However, the active ingredients and probable processes of SZRD in treating Alzheimer's with diabetes are unknown. This study aims to preliminarily elucidate the potential mechanisms and potential active ingredients of SZRD in the treatment of Alzheimer's with diabetes. METHODS: The main components and corresponding protein targets of SZRD were searched on the TCMSP database. Differential gene expression analysis for diabetes and Alzheimer's disease was conducted using the Gene Expression Omnibus database, with supplementation from OMIM and genecards databases for differentially expressed genes. The drug-compound-target-disease network was constructed using Cytoscape 3.8.0. Disease and SZRD targets were imported into the STRING database to construct a protein-protein interaction network. Further, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were performed on the intersection of genes. Molecular docking and molecular dynamics simulations were conducted on the Hub gene and active compounds. Gene Set Enrichment Analysis was performed to further analyze key genes. RESULTS: Through the Gene Expression Omnibus database, we obtained 1977 diabetes related genes and 622 AD related genes. Among drugs, diabetes and AD, 97 genes were identified. The drug-compound-target-disease network revealed that quercetin, kaempferol, licochalcone a, isorhamnetin, formononetin, and naringenin may be the core components exerting effects. PPI network analysis identified hub genes such as IL6, TNF, IL1B, CXCL8, IL10, CCL2, ICAM1, STAT3, and IL4. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses showed that SZRD in the treatment of Alzheimer's with diabetes is mainly involved in biological processes such as response to drug, aging, response to xenobiotic, and enzyme binding; as well as signaling pathways such as Pathways in cancer, Chemical carcinogenesis - receptor activation, and Fluid shear stress and atherosclerosis. Molecular docking results showed that licochalcone a, isorhamnetin, kaempferol, quercetin, and formononetin have high affinity with CXCL8, IL1B, and CCL2. Molecular dynamics simulations also confirmed a strong interaction between CXCL8 and licochalcone a, isorhamnetin, and kaempferol. Gene Set Enrichment Analysis revealed that CXCL8, IL1B, and CCL2 have significant potential in diabetes. CONCLUSION: This study provides, for the first time, insights into the active ingredients and potential molecular mechanisms of SZRD in the treatment of Alzheimer's with diabetes, laying a theoretical foundation for future basic research.

Bioinformatics Analysis of the Prognostic Significance of VPS16 in Hepatocellular Carcinoma and Its Role in Drug Screening.

Background: Vacuolar protein sorting 16 (VPS16) overexpression was recently considered related to cancer growth and drug resistance; however, little is known about whether VPS16 plays a vital role in liver hepatocellular carcinoma (LIHC). Methods: The TIMER2 online database was used to analyze the expression of VPS16 in pancancer, and the Xena Browser was used to explore the correlation between VPS16 expression level and survival time. R language was used to test the survival data of 374 LIHC cases in the TCGA database. DESeq2 was used for differentially expressed gene (DEG) analysis. The HPA database was used to verify the expression level of VPS16 in LIHC. The clusterProfiler package was used to analyze functions and related signaling pathways via GO/KEGG enrichment analysis. Drug sensitivity analysis and molecular docking technology were used to screen the most sensitive drugs targeting VPS16 molecules. Results: Pancancer analysis showed that VPS16 was highly expressed in various tumors, especially in LIHC. With the increase in the T stage and grade of LIHC, the expression level of VPS16 was also increased. The expression of VPS16 was negatively correlated with the overall survival of LIHC patients. The stage can be used as an independent prognostic factor. A total of 63 sensitive drugs were found, and 19 drugs were displaying strong molecular binding energy with VPS16. Conclusion: VPS16 may be a potential biomarker for the diagnosis and prognosis of LIHC. Drugs targeting VPS16 may be used in the treatment of LIHC in the future.

Analysis of melanoma tumor antigens and immune subtypes for the development of mRNA vaccine.

Melanoma has a high degree of malignancy and mortality. While there are some hopeful clinical trials for melanoma treatment in progress, they have not yet to yield significant long-term cure rates. Cancer vaccines including mRNA are currently one of the most promising strategy for tumor immunotherapy. The aim of this study was to analyze the potential tumor antigens in melanoma that could be used to develop mRNA vaccines and identify suitable vaccine populations. The gene expression data and complete clinical information of 471 melanoma samples and 1 normal tissue were retrieved from TCGA. Then, 812 samples of normal skin and their corresponding gene expression data were obtained from GTEx. Overexpressed genes, mutated genes and IRDEGs are used to identify potential tumor antigens. The relationship between the expression level of potential antigen and prognosis was analyzed in GEPIA, and then the immune cell infiltration was estimated based on TIMER algorithm. The expression profiles of IRDEGs were used to identify consensus clusters and immune subtypes of melanoma. Finally, mutational status and immune microenvironment characterization in immune subtypes were analyzed. Five tumor antigens (PTPRC, SIGLEC10, CARD11, LILRB1, ADAMDEC1) were identified as potential tumor antigens according to overexpressed genes, mutated genes and immune-related genes. They were all associated with OS, DFS and APCs. We identified two immune subtypes of melanoma, named IS1 and IS2, which exhibit different clinical features and immune landscapes. Based on the different immune landscape, we may conclude that IS1 is immunophenotypically "cold", while IS2 is "hot". The present research implicates that PTPRC, SIGLEC10, CARD11, LILRB1 and ADAMDEC1 may be the antigenic targets for melanoma mRNA vaccines and IS2 patients may be more effective to these vaccines.

A new core-shell magnetic mesoporous surface molecularly imprinted composite and its application as an MSPE sorbent for determination of phthalate esters.

In this study, a new core-shell magnetic mesoporous surface molecularly imprinted polymer (Fe3O4@SiO2@mSiO2-MIPs) which has specific adsorption and rapid adsorption rate for phthalate esters (PAEs) was prepared by a convenient method. Based on this composite as a magnetic solid phase extraction (MSPE) material, a rapid, efficient and sensitive matrix dispersion magnetic solid-phase extraction gas chromatography-mass spectrometry method (DMSPE-GC/MS) was developed for the determination of PAEs in multiple liquid samples. It is the first time that Fe3O4@SiO2@mSiO2-MIPs have been prepared by bonding amino groups on the surface of a double layer silicon substrate with diisononyl phthalate (DINP) as virtual template and 3-(2-aminoethyl)-aminopropyl trimethoxymethylsilane (TSD) as functional monomer. FT-IR, TEM, EDS, SEM, XRD, BET and VSM were used to characterize the composite. The adsorption isotherm and kinetics of Fe3O4@SiO2@mSiO2-MIPs showed that it possessed fast adsorption rates (approximately 5 min to reach equilibrium), high adsorption capacities (523.9 mg g-1) and good recognition of PAEs. The real samples were preconcentrated by Fe3O4@SiO2@mSiO2-MIPs, under the optimum DMSPE-GC/MS conditions. Validation experiments showed that the method presented good linearity (R 2 > 0.9971), satisfactory precision (RSD < 5.7%) and high recovery (92.1-105.8%), and the limits of detection ranged from 1.17 ng L-1 to 3.03 ng L-1. The results indicated that the novel method had good sensitivity, high efficiency and wide sample application and was suitable for the determination of PAEs in liquid drink samples such as water, alcohol, beverages and so on.

Analysis of differences in the transcriptomic profiles of eutopic and ectopic endometriums in women with ovarian endometriosis.

BACKGROUND: Endometriosis is a common gynecological disease among women in their reproductive years. Although much effort has been made, the pathogenesis of this disease and the detailed differences between eutopic endometrial cells and ectopic endometrial cells are still unclear. METHODS: In this study, eutopic and ectopic endometrial cells were collected from patients with and without endometriosis and RNA sequencing was performed. The gene expression patterns and differentially expressed genes (DEGs) in eutopic and ectopic endometrial cells, as well as control endometrial cells, were analyzed using a weighted gene co-expression network analysis (WGCNA) and the DESeq2 package. The functions of significant genes were detected using Gene ontology (GO) enrichment analysis, and qRT-PCR validation was performed. RESULTS: The results indicated that eight gene modules were found among these three groups. They also indicated that the gene module, which is highly related to eutopic endometrial cells, was mainly enriched in cell adhesion, embryo implantation, etc., while the gene module related to ectopic endometrial cells was mainly enriched in cell migration, etc. The results of differential expression analysis were generally consistent with the WGCNA results through identified significant DEGs between different groups. These DEGs may play an important role in the occurrence of endometriosis, including the infertility associated gene ARNTL and PIWIL2, tissue remodeling gene MMP11, cell survival and migration gene FLT1, inflammatory response gene GNLY, the tumor suppressor genes PLCD1, etc. Further analysis suggested the function of adhesion is stronger in ectopic endometrial cells than in eutopic endometrial cells, while the ectopic endometrium may have a higher potential risk of malignant transformation than eutopic endometrium. CONCLUSIONS: Overall, these data provide a reference for understanding the pathogenesis of endometriosis and its relationship with malignant transformation.

CT features of coronavirus disease 2019 (COVID-19) in the original district of this disease (Wuhan): a pictorial review.

On December 31, 2019, the Wuhan Health Commission reported the discovery of an "unexplained" pneumonia for the first time; the pathogen was confirmed as novel coronavirus pneumonia (2019-nCoV) on January 7, 2020. As one of the important examination methods for the Corona Virus Disease 2019 (COVID-19), Computed Tomography (CT) examination plays an important role in the clinical discovery of suspected cases, diagnosis, and treatment review. This paper reviews the published papers in order to offer help in early clinical screening, disease diagnosis, disease severity determination and post-treatment review.

Preparation and characterization of lutein loaded folate conjugated polymeric nanoparticles.

AIM: To prepare and characterise lutein-loaded polylactide-co-glycolide-polyethylene glycol-folate (PLGA-PEG-FOLATE) nanoparticles and evaluate enhanced uptake in SK-N-BE(2) cells. METHODS: Nanoparticles were prepared using O/W emulsion solvent evaporation and characterised using DLS, SEM, DSC, FTIR and in-vitro release. Lutein-uptake in SK-N-BE(2) cells was determined using flow-cytometry, confocal-microscopy and HPLC. Control was lutein PLGA nanoparticles. RESULTS: The size of lutein-loaded PLGA and PLGA-PEG-FOLATE nanoparticles were 189.6 ± 18.79 nm and 188.0 ± 4.06 nm, respectively. Lutein entrapment was ∼61%(w/w) and ∼73%(w/w) for PLGA and PLGA-PEG-FOLATE nanoparticles, respectively. DSC and FTIR confirmed encapsulation of lutein into nanoparticles. Cellular uptake studies showed ∼1.6 and ∼2-fold enhanced uptake of lutein from PLGA-PEG-FOLATE nanoparticles compared to PLGA nanoparticles and lutein, respectively. Cumulative release of lutein was higher in PLGA nanoparticles (100% (w/w) within 24 h) compared to PLGA-PEG-FOLATE nanoparticles (∼80% (w/w) in 48 h). CONCLUSION: Lutein-loaded PLGA-PEG-FOLATE nanoparticles could be a potential treatment for hypoxic ischaemic encephalopathy.

CT characteristics and diagnostic value of COVID-19 in pregnancy.

OBJECTIVE: To investigate the computed tomography (CT) characteristics and diagnostic value of novel coronavirus pneumonia (NCP or COVID-19) in pregnancy. METHODS: This study included ten pregnant women infected with COVID-19, treated in the Zhongnan Hospital of Wuhan University from January 20, 2020 to February 6, 2020. Clinical and chest CT data were collected and clinical symptoms, laboratory indicators, and CT images were analyzed to explore CT characteristics and diagnostic value for COVID-19 during pregnancy. RESULTS: Laboratory examination showed that white blood cell count was normal in nine patients, and slightly higher in one patient (10.23 × 109). The lymphocyte ratio decreased in two patients by 12% and 14%, respectively. The levels of C-reactive protein was elevated in seven patients (range, 21.16-60.3 mg/L) and the levels of D-dimer was increased in eight patients (range, 507-2141 ng/mL). Six patients had low levels of total protein (range, 35.3-56.5 mg/L). Two patients showed small patchy ground glass opacity (GGO) involving single lung, while eight patients showed multilobe GGO in both the lungs, with partial consolidation. Peripheral and non-peripheral lesion distributions were seen in ten (100%) and four (40%) patients, respectively. There were four patients who had signs of intra-bronchial air-bronchogram, six patients had small bilateral pleural effusions, while none had lymphadenopathy. Dynamic observations were performed in four patients after COVID-19 treatment. Among these four patients, one patient showed normal on the initial examination, and new lesions were observed after 3 days; 1 patient showed progression after 7 days of treatment, with expansion of the lesion area; and the other 2 patients showed improvement after 14 days of treatment, with reduction in the density and area of lesions and appearance of linear opacity. CONCLUSIONS: The CT characteristics of COVID-19 in pregnancy were mainly observed in early and progressive stages, and multiple new lesions were common. And there were consolidations of varying sizes and degrees within the lesion. Moreover, the original ground glass lesions could be fused or partially absorbed. Six patients had small bilateral pleural effusion. In summary, CT scans can play an important role in early screening, dynamic observation, and efficacy evaluation of suspected or confirmed cases of pregnant women with COVID-19.

Fabrication of amine functionalized CdSe@SiO2 nanoparticles as fluorescence nanosensor for highly selective and sensitive detection of picric acid.

In this work, amino functionalized CdSe-silica core-shell nanoparticles (NH2-CdSe@SiO2 NPs) were constructed as probe to detect picric acid (PA). The CdSe QDs were embedded in SiO2 nanoparticles and modified with amino groups on the surface. The nitro explosives are electron deficient in nature, which will have stronger affinity for amines and resulted in fluorescence quenching of quantum dots. It was proved that this strategy is selective, easy and sensitive enough for sensing PA with a detection limit of 0.5 × 10-7 M.

ß-Carotene 15,15'-oxygenase inhibits cancer cell stemness and metastasis by regulating differentiation-related miRNAs in human neuroblastoma.

Neuroblastoma (NB) is the most common pediatric malignancy and is considered to possess cancer stem cells (CSCs) properties which can drive tumor initiation and metastasis. ß-carotene 15,15'-oxygenase (BCO1) is the main enzyme that catalyzes the first step in vitamin A biosynthesis from pro-vitamin A carotenoids. Retinoids (vitamin A) play a critical role in NB differentiation. However, the biological functions of BCO1 in NB remained to be elucidated. Here, we investigated the effects of BCO1 on NB CSCs with stably expressing BCO1 in NB cells. We show that BCO1 significantly suppressed self-renewal and markers of NB CSCs. Moreover, BCO1 inhibited the metastatic potential of NB cells and suppressed the enzymatic activity and expression of MMPs, as well as expression of HIF-1α and its downstream targets. In vivo, BCO1 reduced the metastatic incidence and volumes of metastatic tumors and downregulated the expression of CSCs markers, MMPs, and HIF-1α in tumor tissues of a mouse xenograft model. A possible mechanism underlying the anti-cancer activities of BCO1 is proposed based on miRNAs sequencing array data which suggests a role for BCO1 in regulating miRNAs associated with neuronal differentiation, cell-cell adhesion, and the Wnt signaling pathway. Thus, our results demonstrate new chemotherapeutic roles for BCO1 in malignant NB that mediate suppression of cancer stemness and metastasis.

Paclitaxel-Loaded Core-Shell Magnetic Nanoparticles and Cold Atmospheric Plasma Inhibit Non-Small Cell Lung Cancer Growth.

Nanoparticle-based drug delivery allows effective and sustained delivery of therapeutic agents to solid tumors and has completely changed how cancer is treated. As a new technology for medical applications, cold atmospheric plasma (CAP) shows a great potential in selective cancer treatment. The aim of this work is to develop a new dual cancer treatment approach by integrating CAP with novel paclitaxel (PTX)-loaded nanoparticles for targeting A549 cells. For this purpose, PTX-loaded core-shell magnetic nanoparticles were prepared through coaxial electrospraying, and various characteristics were investigated. Biodegradable poly(lactic- co-glycolic acid) was selected as the polymer shell to encapsulate the anticancer therapeutics. Results demonstrated a uniform size distribution and high drug encapsulation efficiency of the electrosprayed nanoparticles, which had sustained release characteristics and a variety of excellent properties. An in vitro study showed that PTX-loaded nanoparticles and CAP synergistically inhibited the growth of A549 cells more effectively than when each was used individually. We also found that CAP could induce the PTX-loaded nanoparticles in tumor cells to increase the effective drug concentration to a level that might be conducive to reduce drug resistance. Therefore, the integration of PTX-encapsulated nanoparticles and CAP provides a promising tool for the development of a new non-small cell lung cancer treatment strategy.

Carotenoid Lutein Selectively Inhibits Breast Cancer Cell Growth and Potentiates the Effect of Chemotherapeutic Agents through ROS-Mediated Mechanisms.

Increasing evidence suggests that dietary carotenoids may reduce the risk of breast cancer. However, anti-breast cancer effects of carotenoids have been controversial, albeit understudied. Here, we investigated the effects of specific carotenoids on a wide range of breast cancer cell lines, and found that among several carotenoids (including ß-carotene, lutein, and astaxanthin), lutein significantly inhibits breast cancer cell growth by inducing cell-cycle arrest and caspase-independent cell death, but it has little effect on the growth of primary mammary epithelial cells (PmECs). Moreover, lutein-mediated growth inhibition of breast cancer cells is quantitatively similar to that induced by chemotherapeutic taxanes, paclitaxel and docetaxel, and exposure to lutein plus taxanes additively inhibits breast cancer cell growth. Analysis of mechanisms showed that lutein treatment significantly increases the intracellular reactive oxygen species (ROS) production in triple-negative breast cancer (TNBC) cells, but not in normal PmECs. Lutein-induced growth inhibition is also attenuated by the radical oxygen scavenger N-acetyl cysteine, suggesting a role for ROS generation in the growth inhibitory effect of lutein on TNBC cells. Additionally, we found that the p53 signaling pathway is activated and HSP60 levels are increased by lutein treatment, which may contribute partly to the induction of growth inhibition in TNBC cells. Our findings show that lutein promotes growth inhibition of breast cancer cells through increased cell type-specific ROS generation and alternation of several signaling pathways. Dietary lutein supplementation may be a promising alternative and/or adjunct therapeutic candidate against breast cancer.

Involvement of NAC transcription factor SiNAC1 in a positive feedback loop via ABA biosynthesis and leaf senescence in foxtail millet.

MAIN CONCLUSION: The foxtail millet NAC transcription factor NAC1, an ortholog of Arabidopsis NAP, is induced by ABA and senescence and accelerates leaf senescence by promoting ABA biosynthesis. Leaf senescence, a unique developmental stage involving macromolecule degradation and nutrient remobilization, is finely tuned and tightly controlled by different gene families. NO APICAL MERISTEM, ARABIDOPSIS ATAF1, and CUP-SHAPED COTYLEDON (NAC) transcription factors have been demonstrated to be involved in the modulation of leaf senescence in many land plant species. Foxtail millet (Setaria italica L.), an important food and fodder crop, has been studied for its strong stress tolerance and potential to be a biofuel model plant. However, the functional roles of senescence-associated NACs in foxtail millet are still unknown. In this study, we characterized a nuclear localized NAC transcription factor, SiNAC1, which is induced by senescence and concentrated in senescent leaves in foxtail millet. SiNAC1 also positively responds to abscisic acid (ABA) treatment in foxtail millet. Moreover, SiNAC1 promotes the natural and dark-induced leaf senescence by an ABA-dependent manner in Arabidopsis thaliana. NCED2 and NCED3 are elevated by SiNAC1 overexpression, which subsequently promotes ABA biosynthesis in Arabidopsis. Finally, as a homolog of AtNAP, SiNAC1 can partially rescue the delayed leaf senescence phenotype in atnap mutants. Overall, our results demonstrate that SiNAC1 functions as a positive regulator of leaf senescence and is involved in a positive feedback loop via ABA biosynthesis and leaf senescence.

MEF2 transcription factors in human placenta and involvement in cytotrophoblast invasion and differentiation.

Development of the human placenta and its trophoblast cell types is critical for a successful pregnancy. Defects in trophoblast invasion and differentiation are associated with adverse pregnancy outcomes, including preeclampsia. The members of myocyte enhancer factor-2 (MEF2) family of transcription factors are key regulators of cellular proliferation, differentiation, and invasion in various cell types and tissues and might play a similarly important role in regulating trophoblast proliferation, invasion, and differentiation during human placental development. In the present study, using human cytotrophoblast cell lines (HTR8/SVneo and BeWo) and primary human cytotrophoblasts (CTBs), we show that members of the MEF2 family are differentially expressed in human placental CTBs, with MEF2B and MEF2D being highly expressed in first trimester extravillous CTBs. Overexpression of MEF2D results in cytotrophoblast proliferation and enhances the invasion and migration of extravillous-like HTR8/SVneo cells. This invasive property is blocked by overexpression of a dominant negative MEF2 (dnMEF2). In contrast, MEF2A is the principal MEF2 isoform expressed in term CTBs, MEF2C and MEF2D being expressed more weakly, and MEF2B expression being undetected. Overexpression of MEF2A induces cytotrophoblast differentiation and syncytium formation in BeWo cells. During in vitro differentiation of primary CTBs, MEF2A expression is associated with CTB differentiation into syncytiotrophoblast. Additionally, the course of p38 MAPK and ERK5 activities parallels the increase in MEF2A expression. These findings suggest individual members of MEF2 family distinctively regulate cytotrophoblast proliferation, invasion, and differentiation. Dysregulation of expression of MEF2 family or of their upstream signaling pathways may be associated with placenta-related pregnancy disorders.

Effects of the Macular Carotenoid Lutein in Human Retinal Pigment Epithelial Cells.

Retinal pigment epithelial (RPE) cells are central to retinal health and homoeostasis. Oxidative stress-induced damage to the RPE occurs as part of the pathogenesis of age-related macular degeneration and neovascular retinopathies (e.g., retinopathy of prematurity, diabetic retinopathy). The xanthophyll carotenoids, lutein and zeaxanthin, are selectively taken up by the RPE, preferentially accumulated in the human macula, and transferred to photoreceptors. These macular xanthophylls protect the macula (and the broader retina) via their antioxidant and photo-protective activities. This study was designed to investigate effects of various carotenoids (ß-carotene, lycopene, and lutein) on RPE cells subjected to either hypoxia or oxidative stress, in order to determine if there is effect specificity for macular pigment carotenoids. Using human RPE-derived ARPE-19 cells as an in vitro model, we exposed RPE cells to various concentrations of the specific carotenoids, followed by either graded hypoxia or oxidative stress using tert-butyl hydroperoxide (tBHP). The results indicate that lutein and lycopene, but not ß-carotene, inhibit cell growth in undifferentiated ARPE-19 cells. Moreover, cell viability was decreased under hypoxic conditions. Pre-incubation of ARPE-19 cells with lutein or lycopene protected against tBHP-induced cell loss and cell co-exposure of lutein or lycopene with tBHP essentially neutralized tBHP-dependent cell death at tBHP concentrations up to 500 µM. Our findings indicate that lutein and lycopene inhibit the growth of human RPE cells and protect the RPE against oxidative stress-induced cell loss. These findings contribute to the understanding of the protective mechanisms attributable to retinal xanthophylls in eye health and retinopathies.

Inhibition of pulmonary ß-carotene 15, 15'-oxygenase expression by glucocorticoid involves PPARα.

ß-carotene 15,15'-oxygenase (BCO1) catalyzes the first step in the conversion of dietary provitamin A carotenoids to vitamin A. This enzyme is expressed in a variety of developing and adult tissues, suggesting that its activity may regulate local retinoid synthesis. Vitamin A and related compounds (retinoids) are critical regulators of lung epithelial development, integrity, and injury repair. A balance between the actions of retinoids and glucocorticoids (GCs) promotes normal lung development and, in particular, alveolarization. Alterations in this balance, including vitamin A deficiency and GC excess, contribute to the development of chronic lung disorders. Consequently, we investigated if GCs counteract retinoid effects in alveolar epithelial cells by mechanisms involving BCO1-dependent local vitamin A metabolism. We demonstrate that BCO1 is expressed in human fetal lung tissue and human alveolar epithelial-like A549 cells. Our results indicate A549 cells metabolize ß-carotene to retinal and retinoic acid (RA). GCs exposure using dexamethasone (DEX) decreases BCO1 mRNA and protein levels in A549 cells and reduces BCO1 promoter activity via inhibiting peroxisome proliferator-activated receptor γ (PPARγ) DNA binding. DEX also induces expression of PPARα, which in turn most likely causes a decrease in PPARγ/RXRα heterodimer binding to the bco1 gene promoter and consequent inhibition of bco1 gene expression. PPARα knockdown with siRNA abolishes DEX-induced suppression of BCO1 expression, confirming the requirement for PPARα in this DEX-mediated BCO1 mechanism. Taken together, these findings provide the first evidence that GCs regulate vitamin A (retinoid) signaling via inhibition of bco1 gene expression in a PPARα-dependent manner. These results explicate novel aspects of local GC:retinoid interactions that may contribute to alveolar tissue remodeling in chronic lung diseases that affect children and, possibly, adults.