Honokiol:a promising small molecular weight natural agent for the growth inhibition of oral squamous cell carcinoma cells

Honokiol （HNK） is a small organic molecule purified from magnolia species and has demonstrated anticancer activities in a variety of cancer cell lines; however, its effect on oral squamous cell carcinoma （OSCC） cells is unknown. We investigated the antitumor activities of HNK on OSCC ceils in vitro for the first time. The inhibitory effects of HNK on the growth and proliferation of OSCC cells were demonstrated via in vitro 3-（4,5-dimethyl thiazol-2-yl）-2,5-diphenyltetrazolium bromide （MTT） and propidium iodide （PI） assays, and the apoptotic cells were investigated by the observation of morphological changes and detection of DNA fragmentation via PI, TdT-mediated dUTP-biotin nick end labeling （TUNEL）, and DNA ladder assays, as well as flow cytometry assay. The results showed that HNK inhibited the growth and proliferation of OSCC cells in vitro in a time and dose-dependent manner. The inhibitory effect was associated with the cell apoptosis induced by HNK, evidenced by the morphological features of apoptotic cells, TUNEL-positive cells and a degradation of chromosomal DNA into small internucleosomal fragments. The study also demonstrated here that the inhibition or apoptosis mediated by 15 μg.mL-1 or 20 μg.mL-1 of HNK were more stronger compared with those of 20 μg-mL-1 5-fluorouracil （5-Fu, the control） applied to OSCC cells, when the ratio of OSCC cell numbers were measured between the treatment of different concentrations of HNK to the 5-Fu treatment for 48 h. HNK is a promising compound that can be potentially used as a novel treatment agent for human OSCC.

The 2019 novel coronavirus disease(COVID-19) pandemic: A zoonotic prospective

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),a novel coronavirus(CoV),has recently emerged as a significant pathogen for humans and the cause for the recent outbreak of the 2019 novel coronavirus disease(COVID-19)throughout the globe.For developing any preventive measure,an understanding of the zoonotic pattern for this virus is a necessity.We should have a clear knowledge of its reservoir host,its distribution pattern and spreading routes.Information about zoonotic reservoirs and its transmission among them can help to understand the COVID-19 outbreaks.In this article,we discuss about the bats as the zoonotic reservoir of several CoV strains,co-existence of bats and CoV/viruses,the sequence similarity of SARS-CoV-2 with bat SARS-like CoV,the probable source of the origin of SARS-CoV-2 strain and COVID-19 outbreak,intermediate host of CoVs and SARS-CoV-2,human to human transmission and the possibility to maintain the zoonotic barriers.Our knowledge about the zoonotic reservoir of SARS-CoV-2 and its transmission ability may help develop the preventive measures and control for the future outbreak of CoV.

Toxicity Evaluation of Acrylamide on the Early Life Stages of the Zebrafish Embryos (<i>Danio rerio</i>)

Acrylamide is a chemical used mainly in industrial applications and the treatment of drinking and wastewater, making it easy to enter aquatic ecosystems. There are few studies known about the toxicity of acrylamide to aquatic organisms which have shown evidence of a number of histopathological effects. To assess the effects of acrylamide to freshwater fish, Zebrafish (Danio rerio) embryos were exposed to serial concentrations of acrylamide (0, 100, 300, and 500 mg/L) to investigate the acute toxicity effects on teleost embryogenesis. Embryos less than 24 hrs old were exposed under static non-renewal conditions for ten days or until hatching. The toxic endpoints evaluated include: egg/embryo viability, hatchability, and morphological/developmental anomalies during organogenesis. The acute toxicity test resulted in a 48 h-LC50 of 585 mg/L for egg viability. Exposure of embryos significantly reduced hatchability and larval survival, in a concentration dependent manner. Dimethyl sulfoxide (DMSO) was used as a solvent carrier to permeate the uptake of acrylamide through the chorion membrane. No significant damages or complications were observed in embryos exposed to DMSO. At 500 mg/L, the highest test concentration, the survival of embryos was greatly reduced within 24 hrs of exposure. The lower test, 100 mg/L, produced a significant number of developmental anomalies to the Zebrafish that included dorsal tail flexure, severe pericardial edema, facial and cranial defects and decreased heartrate (40 bpm). Premature hatching of embryos and developmental arrest was observed in all concentrations. The severity of these anomalies was concentration-dependent and resulted in low survival rate and high frequency of malformations. These results indicate that acrylamide is teratogenic and provide support for sub-lethal toxicity testing using Zebrafish embryos.

Dual activities of a silencing information regulator complex in yeast transcriptional regulation and DNA-damage response

The Saccharomyces cerevisiae silencing information regulator(SIR)complex contains up to four proteins,namely Sir1,Sir2,Sir3,and Sir4.While Sir2 encodes a NAD-dependent histone deacetylase,other SIR proteins mainly function as structural and scaffold components through physical interaction with various proteins.The SIR complex displays different conformation and composition,including Sir2 homotrimer,Sir1-4 heterotetramer,Sir2-4 heterotrimer,and their derivatives,which recycle and relocate to different chromosomal regions.Major activities of the SIR complex are transcriptional silencing through chromosomal remodeling and modulation of DNA double-strand-break repair pathways.These activities allow the SIR complex to be involved in mating-type maintenance and switching,telomere and subtelomere gene silencing,promotion of nonhomologous end joining,and inhibition of homologous recombination,as well as control of cell aging.This review explores the potential link between epigenetic regulation and DNA damage response conferred by the SIR complex under various conditions aiming at understanding its roles in balancing cell survival and genomic stability in response to internal and environmental stresses.As core activities of the SIR complex are highly conserved in eukaryotes from yeast to humans,knowledge obtained in the yeast may apply to mammalian Sirtuin homologs and related diseases.

Attenuated retinoic acid signaling is among the early responses in mouse uterus approaching embryo attachment

The uterus is transiently receptive for embryo implantation.It remains to be understood why the uterus does not reject a semi-allogeneic embryo(to the biological mother)or an allogeneic embryo(to a surrogate)for implantation.To gain insights,we examined uterine early response genes approaching embryo attachment on day 3 post coitum(D3)at 22 hours when blue dye reaction,an indication of embryo attachment,had not manifested in mice.C57BL/6 pseudo-pregnant(control)and pregnant mouse uteri were collected on D3 at 22 hours for microarray analysis.The self-assembling-manifold(SAM)algorithm identified 21,858 unique probesets.Principal component analysis indicated a clear separation between the pseudo-pregnant and pregnant groups.There were 106 upregulated and five downregulated protein-coding genes in the pregnant uterus with fold change(fc)>1.5 andq value<5%.Gene ontology(GO)analysis of the 106 upregulated genes revealed 38 significant GO biological process(GOBP)terms(P<0.05),and 32(84%)of them were associated with immune responses,with a dominant natural killer(NK)cell activation signature.Among the top eight upregulated protein-coding genes,Cyp26a1 inactivates retinoic acid(RA)whileLrat promotes vitamin A storage,both of which are expected to attenuate RA bioavailability;Atp6v0d2 andGjb2 play roles in ion transport and transmembrane transport;Gzmb,Gzmc,andIl2rb are involved in immune responses;andTdo2 is important for kynurenine pathway.Most of these genes or their related pathways have functions in immune regulations.RA signaling has been implicated in immune tolerance and immune homeostasis,and uterine NK cells have been implicated in immunotolerance at the maternal-fetal interface in the placenta.The mechanisms of immune responses approaching embryo attachment remain to be elucidated.The coordinated effects of the early response genes may hold the keys to the question of why the uterus does not reject an implanting embryo.

An association between mitochondria and microglia effector function: what do we think we know?

While resident innate immune cells of the central nervous system, the microglia, represent a cell population unique in origin, microenvironment, and longevity, they assume many properties displayed by peripheral macrophages. One prominent shared property is the ability to undergo a metabolic switch towards glycolysis and away from oxidative phosphorylation (OXPHOS) upon activation by the pro-inflammatory stimuli lipopolysaccharide. This shift serves to meet specific cellular demands and allows for cell survival, similar to the Warburg effect demonstrated in cancer cells. In contrast, normal surveillance phenotype or stimulation to a non-proinflammatory phenotype relies primarily on OXPHOS and fatty acid oxidation. Thus, mitochondria appear to function as a pivotal signaling platform linking energy metabolism and macrophage polarization upon activation. These unique shifts in cell bioenergetics in response to different stimuli are essential for proper effector responses at sites of infection, inflammation, or injury. Here, we present a summary of recent developments as to how these dynamics characterized in peripheral macrophages are displayed in microglia. The new insights provided by an increased understanding of metabolic reprogramming in macrophages may allow for translation to the central nervous system and a better understanding of microglia heterogeneity, regulation, and function.

Latent, sex-specific metabolic health effects in CD-1 mouse offspring exposed to PFOA or HFPO-DA (GenX) during gestation

Background:Perfluorooctanoic acid(PFOA)is an environmental contaminant associated with adverse metabolic outcomes in developmentally exposed human populations and mouse models.Hexafluoropropylene oxide-dimer acid(HFPO-DA,commonly called GenX)has replaced PFOA in many industrial applications in the U.S.and Europe and has been measured in global water systems from<1 to 9350 ng/L HFPO-DA.Health effects data for GenX are lacking.Objective:Determine the effects of gestational exposure to GenX on offspring weight gain trajectory,adult metabolic health,liver pathology and key adipose gene pathways in male and female CD-1 mice.Methods:Daily oral doses of GenX(0.2,1.0,2.0 mg/kg),PFOA(0.1,1.0 mg/kg),or vehicle control were administered to pregnant mice(gestation days 1.5-17.5).Offspring were fed a high-or low-fat diet(HFD or LFD)at weaning until necropsy at 6 or 18 weeks,and metabolic endpoints were measured over time.PFOA and GenX serum and urine concentrations,weight gain,serum lipid parameters,body mass composition,glucose tolerance,white adipose tissue gene expression,and liver histopathology were evaluated.Results:Prenatal exposure to GenX led to its accumulation in the serum and urine of 5-day old pups(P=0.007,P<0.001),which was undetectable by weaning.By 18 weeks of age,male mice fed LFD in the 2.0 mg/kg GenX group displayed increased weight gain(P<0.05),fat mass(P=0.016),hepatocellular microvesicular fatty change(P=0.015),and insulin sensitivity(P=0.014)in comparison to control males fed LFD.Female mice fed HFD had a significant increase in hepatocyte single cell necrosis in 1.0 mg/kg GenX group(P=0.022)and 1.0 mg/kg PFOA group(P=0.003)compared to control HFD females.Both sexes were affected by gestational GenX exposure;however,the observed phenotype varied between sex with males displaying more characteristics of metabolic disease and females exhibiting liver damage in response to the gestational exposure.Conclusions:Prenatal exposure to 1 mg/kg GenX and 1 mg/kg PFOA induces adverse metabolic outcomes in adult mice that are diet-and sex-dependent.GenX also accumulated in pup serum,suggesting that placental and potentially lactational transfer are important exposure routes for GenX.

Deletion of Mitochondrial Porin Alleviates Stress Sensitivity in the Yeast Model of Shwachman-Diamond Syndrome

Shwachman-Diamond syndrome （SDS） is a multi-system disorder characterized by bone marrow failure, pancreatic insufficiency, skeletal abnormalities, and increased risk of leukemic transformation. Most patients with SDS contain mutations in the Shwachman- Bodian-Diamond syndrome gene （SBDS）, encoding a highly conserved protein that has been implicated in ribosome biogenesis. Emerging evidence also suggests a distinct role of SBDS beyond protein translation. Using the yeast model of SDS, we examined the underlying mechanisms that cause cells lacking Sdolp, the yeast SBDS ortholog, to exhibit reduced tolerance to various stress conditions. Our analysis indicates that the environmental stress response （ESR）, heat shock response （HSR）, and endoplasmic reticulum unfolded protein response （UPR） of sdolA cells are functional and that defects in these pathways do not produce the phenotypes observed in sdolh yeast. Depletion of mitochondlial DNA （mtDNA） was observed in sdolh cells, and this is a probable cause of the mitochondrial insufficiency in SDS. Prior disruption of POR1, encoding the mitochondrial voltage dependent anion channel （VDAC）, abrogated the effects of SD01 deletion and substantially restored resistance to environmental stressors and protected against damage to mtDNA. Conversely, wild-type cells over-expressing POR1 exhibited growth impairment and increased stress sensitivity similar to that seen in sdolA cells. Overall, our results suggest that specific VDAC inhibitors may have therapeutic benefits for SDS patients.

Effects of Mycoestrogens on Female Reproduction

Zearalenone(ZEA)is produced by Fusarium species and a common contaminant in food.ZEA and its metabolites,α-andβ-zearalenol,α-andβ-zearalanol,and zearalanone,are mycoestrogens that can interfere with estrogen signaling.High levels of mycoestrogens reduced female fertility in farm animals and rodents,in which adverse effects of mycoestrogens on major events in female reproduction,including ovarian folliculogenesis,ovulation,ovarian steroidogenesis,fertilization,preimplantation embryo development and transport,embryo implantation,placentation,parturition,and lactation,have been reported in different experimental settings.Here,we review the in vivo effects of mycoestrogens on the main events in female reproduction.

Functions of Lysosomes in Mammalian Female Reproductive System

The lysosome is the most acidic membrane-bound intracellular organelle.Lysosomal acidity is primarily maintained by vacuolar H+-ATPase(V-ATPase)and counter ion channels.There are>60 hydrolytic enzymes in the lysosome for its fundamental digestive role.Lysosomes also play important roles in endocytosis,exocytosis,autophagy,and cell death.Studies that have implicated roles of lysosomes in the female reproductive system are reviewed here.In the ovary,lysosomes are implicated in the preparation of free cholesterol for steroidogenesis and degradation of regulators of steroidogenesis,regulation of follicular atresia,follicle rupture during ovulation,luteal cell survival,and luteal regression.In the oviduct,lysosomes are involved in endocytosis of both serum and oviductal luminal components.In the uterus during the menstrual/estrous cycle,lysosomes are associated with endometrial secretion,apoptosis,and menstruation.In the uterus during early pregnancy,lysosomes are involved in the temporal and directional changes of endocytosis,uterine epithelial acidification upon embryo implantation initiation,and embryo-maternal mutual communications via extracellular vesicles.In the placenta,lysosomes are implicated in nutrient transport and placental separation from the uterus for parturition.In the mammary gland,lysosomes are important for mammary gland development and involution.These findings suggest/demonstrate functions of lysosomes in multiple processes of female reproduction,from ovulation to ovarian steroidogenesis for pregnancy maintenance,and from essential in utero nurturing of developing embryos/fetuses via embryo/fetal-maternal communications,to optional postpartum nurturing of newborns via lactation.Future studies using genetically or modified animal models and pharmacological approaches will provide novel insights into the functions and mechanisms of lysosomes in the mammalian female reproductive system.

Cancer and the environment: Filling knowledge gaps together

When considering disease etiology,we need to view the role of the environment along the continuum from health to disease for individuals because we know that there are complex interactions between genes,their molecular expression,and environmental factors over a person’s lifetime.We clearly have huge gaps in our knowledge along this continuum,and these gaps are natural opportunities for research.There are many factors to consider as we assess the relationship between environmental exposures over a lifetime.One factor is persistence of chemicals that“live”beyond their initial intended use.Another factor is the fact that“inert ingredients”are not really inert.

Generalization of Reference System for Calculating the Second Dimension Retention Index in GC×GC-MS

Using C_(4)-C_(25)fatty acid methyl esters(C_(4)-C_(25)FAMEs)as a sample reference series,a method was developed to generalize the reference system for calculating the second dimension retention index(2I)of compounds analyzed by comprehensive two-dimensional gas chromatography-mass spectrometry(GC×GC-MS).The second dimension elution temperature(2Te),second dimension unadjusted retention time(2tR),and the linear retention index(IT)of C_(4)-C_(25)FAMEs were used to form a second dimension retention index surface(2IS)via a three-dimensional surface fitting model.The 2I of an analyte analyzed by GC×GC-MS was then calculated from the 2IS based on its 2tR and 2Te.The developed method was validated by calculat-ing the 2I of n-alkanes,80 compounds,and two commercially available mixtures(MegaMix A and MegaMix B).Compared to the conventional method,the developed method keeps the 2I in n-alkane retention index scale,and enables using any compounds as references to obtain a much increased separation space in the second dimension GC.