Identification of ferroptosis related genes and pathways in prostate cancer cells under erastin exposure.

BACKGROUND: Few studies are focusing on the mechanism of erastin acts on prostate cancer (PCa) cells, and essential ferroptosis-related genes (FRGs) that can be PCa therapeutic targets are rarely known. METHODS: In this study, in vitro assays were performed and RNA-sequencing was used to measure the expression of differentially expressed genes (DEGs) in erastin-induced PCa cells. A series of bioinformatic analyses were applied to analyze the pathways and DEGs. RESULTS: Erastin inhibited the expression of SLC7A11 and cell survivability in LNCaP and PC3 cells. After treatment with erastin, the concentrations of malondialdehyde (MDA) and Fe2+ significantly increased, whereas the glutathione (GSH) and the oxidized glutathione (GSSG) significantly decreased in both cells. A total of 295 overlapping DEGs were identified under erastin exposure and significantly enriched in several pathways, including DNA replication and cell cycle. The percentage of LNCaP and PC3 cells in G1 phase was markedly increased in response to erastin treatment. For four hub FRGs, TMEFF2 was higher in PCa tissue and the expression levels of NRXN3, CLU, and UNC5B were lower in PCa tissue. The expression levels of SLC7A11 and cell survivability were inhibited after the knockdown of TMEFF2 in androgen-dependent cell lines (LNCaP and VCaP) but not in androgen-independent cell lines (PC3 and C4-2). The concentration of Fe2+ only significantly increased in TMEFF2 downregulated LNCaP and VCaP cells. CONCLUSION: TMEFF2 might be likely to develop into a potential ferroptosis target in PCa and this study extends our understanding of the molecular mechanism involved in erastin-affected PCa cells.

Predictive model and risk analysis for coronary heart disease in people living with HIV using machine learning.

OBJECTIVE: This study aimed to construct a coronary heart disease (CHD) risk-prediction model in people living with human immunodeficiency virus (PLHIV) with the help of machine learning (ML) per electronic medical records (EMRs). METHODS: Sixty-one medical characteristics (including demography information, laboratory measurements, and complicating disease) readily available from EMRs were retained for clinical analysis. These characteristics further aided the development of prediction models by using seven ML algorithms [light gradient-boosting machine (LightGBM), support vector machine (SVM), eXtreme gradient boosting (XGBoost), adaptive boosting (AdaBoost), decision tree, multilayer perceptron (MLP), and logistic regression]. The performance of this model was assessed using the area under the receiver operating characteristic curve (AUC). Shapley additive explanation (SHAP) was further applied to interpret the findings of the best-performing model. RESULTS: The LightGBM model exhibited the highest AUC (0.849; 95% CI, 0.814-0.883). Additionally, the SHAP plot per the LightGBM depicted that age, heart failure, hypertension, glucose, serum creatinine, indirect bilirubin, serum uric acid, and amylase can help identify PLHIV who were at a high or low risk of developing CHD. CONCLUSION: This study developed a CHD risk prediction model for PLHIV utilizing ML techniques and EMR data. The LightGBM model exhibited improved comprehensive performance and thus had higher reliability in assessing the risk predictors of CHD. Hence, it can potentially facilitate the development of clinical management techniques for PLHIV care in the era of EMRs.

HERVK-mediated regulation of neighboring genes: implications for breast cancer prognosis.

Human endogenous retroviruses (HERVs) are the remnants of ancient retroviral infections integrated into the human genome. Although most HERVs are silenced or rendered inactive by various regulatory mechanisms, they retain the potential to influence the nearby genes. We analyzed the regulatory map of 91 HERV-Ks on neighboring genes in human breast cancer and investigated the impact of HERV-Ks on the tumor microenvironment (TME) and prognosis of breast cancer. Nine RNA-seq datasets were obtained from GEO and NCBI SRA. Differentially expressed genes and HERV-Ks were analyzed using DESeq2. Validation of high-risk prognostic candidate genes using TCGA data. These included Overall survival (multivariate Cox regression model), immune infiltration analysis (TIMER), tumor mutation burden (maftools), and drug sensitivity analysis (GSCA). A total of 88 candidate genes related to breast cancer prognosis were screened, of which CD48, SLAMF7, SLAMF1, IGLL1, IGHA1, and LRRC8A were key genes. Functionally, these six key genes were significantly enriched in some immune function-related pathways, which may be associated with poor prognosis for breast cancer (p = 0.00016), and the expression levels of these genes were significantly correlated with the sensitivity of breast cancer treatment-related drugs. Mechanistically, they may influence breast cancer development by modulating the infiltration of various immune cells into the TME. We further experimentally validated these genes to confirm the results obtained from bioinformatics analysis. This study represents the first report on the regulatory potential of HERV-K in the neighboring breast cancer genome. We identified three key HERV-Ks and five neighboring genes that hold promise as novel targets for future interventions and treatments for breast cancer.

Senolytic Drug Quercetin Rescues Survival from Blue Light Toxicity in Drosophila Model.

With the increasing frequency of human exposure to blue light, the harmfulness of blue light has received wider attention. The damaging effect of blue light is complex and long-lasting. In this study, Drosophila melanogaster was used as a model organism to investigate the protective effect of the senolytic drug quercetin on blue light toxicity. As one of the first senolytic drugs discovered, quercetin not only has antioxidant properties, but also has been used to treat various neurological disorders. Our study shows that quercetin can effectively prolong the survival of flies under blue light irradiation, and it significantly increases the egg production of female flies under blue light. In addition, after flies intaking quercetin under blue light, both the spontaneous activity and nutrient metabolism show significant sex-specificity. The experimental results provide a potentially effective intervention method for organisms to defend against blue light toxicity, and reveal a new function of the senolytic drug quercetin from another perspective.

Sex-specific effects of PET-MPs on Drosophila lifespan.

In recent years, as an emerging pollutant, microplastic (MPs) pollution is gradually becoming a research hotspot. MPs are ubiquitous in the entire ecological environment. Organisms can be exposed to MPs via inhalation or ingestion. In view of the widespread of MPs pollution, the impact of MPs on biology should be further investigated. In previous experiments, we have conducted research on the physiology of Drosophila exposed to polyethylene terephthalate microplastics (PET-MPs). However, will the lifespan of Drosophila be affected under long-term PET-MPs exposure? The analysis of variance analysis of our experimental results indicates that there are significant differences between males and females, F(1, 895) = 68.19, p < 0.001, between PET-MPs concentration, F(3, 895) = 8.11, p < 0.001. There are also significant interactions between sex and MP concentration, F(3, 895) = 4.00, p < 0.01. For Cox and log-rank test, 1 g/L of PET-MPs prolongs the lifespan of male flies. The reason for this phenomenon may be the hormesis effect.

Sex Specific Effects of Prunella vulgaris on Longevity Regulation.

The sudden outbreak of COVID-19 in over 200 countries globally, brought serious effects on our daily lives. Traditional Chinese Medicine (TCM) in combination with regional characteristics has achieved remarkable results in China. Prunella vulgaris is one of the ingredients of commercially available canned Chinese herbal tea which demonstrated lifespan extending effect on Drosophila in our previous study, whereas it is unknown which ingredients contribute to it. This study used Drosophila as the model to explore whether Prunella vulgaris is the component taking effect on Drosophila longevity. Results showed that Prunella vulgaris can extend the lifespan of female flies by 10.42%, and improve their endurance under heat stress by 18.46%.

Dietary Phytochemicals that Can Extend Longevity by Regulation of Metabolism.

Diet provides energy and nutrition for human survival, and also provides various joy of taste. Extensive studies have shown that the major components of diet, such as protein, carbohydrate and fat, play important roles in regulating aging and longevity. Whether other dietary ingredients can help prevent aging and extend longevity is a very interesting question. Here based on recent findings, we discussed dietary plant ingredients that can extend longevity by regulation of metabolism, targeting TRP channels, mitophagy, senescence pathways and circadian rhythms. Better understanding of the detailed effects and mechanisms of dietary ingredients on longevity regulation, would be helpful for developing new intervention tools for preventing aging and aging related diseases.

Introduction of COVID-19 knowledge via film teaching method.

The outbreak of the COVID-19 has provided new challenges and also opportunities for the development of online education. Based on our experience from the online education after the outbreak of the COVID-19, this article proposes to introduce COVID-19 knowledge through film teaching methods. Films can stimulate students' interest in learning and improve the teaching efficiency of online education with its rich storylines, high-quality pictures, interesting, and entertaining nature. Teachers can carry out online teaching with the aid of films through four key steps: determining the key points of the teaching content, choosing matching films, setting up topic-related questions, and communicating and discussing after watching the film.

Effects of Chinese herbal medicines on lifespan in Drosophila.

Food ingredients have shown beneficial effect in delaying aging and extend lifespan. There are Chinese herbal medicines in the category of "homology of medicine and food". In order to find out whether these herbal medicines can act as food component to slow aging, this study selected 12 Chinese herbal medicines containing strong antioxidant components, Canarium album, Amomum villosum, Elsholtzia splendens, Foeniculum vulgare, Fructus hordei germinatus, stir-baked Fructus hordei germinatus, Lilium brownie, Citrus medica, Sophora japonica, Myristica fragrans, Herba houttuyniae, Carthamus tinctoriu, and examined the effects on lifespan using Drosophila melanogaster as the model organism. Our results show that the extracts of the 12 Chinese herbal medicines have various effects on longevity. Some reduced the lifespan in both sexes. Some only shortened the lifespan in one sex. Some have no significant effect in both sexes. There are two herbal medicine extended lifespan, but only in females. The present results suggest that herbal medicines may provide potential candidates for anti-aging ingredients.

Challenges for graduate students' mentors during COVID-19 pandemic.

The outbreak of COVID-19 pandemic results in the suspension of universities' academic laboratory activities. This brought a difficult time for graduate students majored in molecular biology and their mentors, since the student's thesis progress relies on the data from wet experiments in the lab. Even facing the challenges during the pandemic, mentors could still play an active role. This COVID-19 crisis requires mentors to have more thinking, innovation, and sharing in guiding graduate students.

Effects of PET microplastics on the physiology of Drosophila.

Microplastics, as a new type of pollution, have attracted global attention and have become a research focus in recent years. Given the small size of microplastics, they can be ingested by many organisms. In addition, microplastics can enter the human body through the food chain. So, the potential dangers of microplastics can't be ignored. This study took Drosophila as a model organism to delve the physiological effects of polyethylene terephthalate microplastics (PET-MPs). Here, we reported that the higher concentration of PET-MPs was, the more obvious the effect became. The amount of oviposition decreased in female flies exposed, indicating that microplastics affected reproduction. PET-MPs caused the decrease of triglyceride and glucose content in male flies, as well as the decrease of starvation resistance, suggesting the effect of microplastics on energy metabolism. In addition, the 24-h spontaneous activity of flies exposed to PET-MPs increased significantly. The experimental results can help understand the potential impact of microplastics on physiology.

Green light extends Drosophila longevity.

The role of visible light on longevity is incompletely understood. Here we show the effect of visible light in Drosophila melanogaster is wavelength specific. Life span was significantly extended by green light, whereas blue light reduced longevity dramatically, and minor impact was observed with red light. While oxidative stress, heat stress, or caloric restriction does not contribute to the beneficial effect of green light, our study found that the life span extension effect of green light might be mediated by microbiota or photosensitive micronutrients in food medium. In conclusion, we report that green light can extend longevity and present the potential of light as a noninvasive therapy for aging-related diseases.

Sex specific effects of capsaicin on longevity regulation.

The consumption of spicy food in daily diets have been found to be inversely associated with human mortality. However, whether intake of spices is the reason for reduced mortality, and whether capsaicin, the main bioactive component of spices, plays a major role, remain elusive. Here, we report that low concentration of capsaicin can indeed extend life span. Capsaicin had no effect on food consumption, reproductive fitness, or stress tolerance. However, it did appear to decrease the daytime activity of females. We hypothesize that this decrease in activity may be a contributing factor in the life span extending property of capsaicin.

Nanodomain Formation in Planar Supported Lipid Bilayers Composed of Fluid and Polymerized Dienoyl Lipids.

Polymerization of synthetic phospholipid monomers has been widely used to enhance the stability of lipid membranes in applications such as membrane-based biosensing, where the inherent instability of fluid-phase lipid bilayers can be problematic. However, lipid polymerization typically decreases membrane fluidity, which may be required to maintain the activity of reconstituted integral proteins and peptides. Prior work has shown that a bilayer composed of binary mixtures of poly(lipid) and fluid lipid exhibits enhanced stability and supports the function of incorporated biomolecules. This work examines the structural basis of these findings using planar supported lipid bilayers (PSLBs) composed of binary mixtures of a polymerizable lipid, 1,2-bis[10-(2',4'-hexadienoloxy)decanoyl]-sn-glycero-3-phosphocholine (bis-SorbPC), and a nonpolymerizable lipid, 1,2-diphytanoyl-sn-glycero-3-phosphocholine (DPhPC). Fluorescence recovery after photobleaching (FRAP) measurements showed that long-range lateral diffusion was minimally affected when the poly(lipid) mole ratio was ≤0.7. Atomic force microscopy, used to examine phase segregation in these PSLBs, showed that DPhPC forms a continuous lipid matrix that is 0.2-0.4 nm thicker than the island-like poly(bis-SorbPC) domains, with lateral dimensions of ≤200 nm. The nanoscale phase segregation allows for long-range lateral diffusion of lipid probes in the DPhPC matrix. The combination of fluidity and stability in these materials should make them useful in membrane-based biosensing applications.

Involvement of gap junctions in astrocyte impairment induced by manganese exposure.

Glutamate excitotoxicity, characterized as excessive glutamate stress, is considered to be involved in cerebral ischaemia, brain trauma, and neurodegenerative diseases such as Parkinson's disease and Alzheimer's disease. Glutamate homeostasis disruption was highlighted in Mn neurotoxicity caused by high levels of Mn. Astrocytes, accounting for approximately 50% of the neuronal cells in the central nervous system and maintain glutamate homeostasis, are sensitive to neurotoxicity induced by Mn exposure. Astrocytes are tightly coupled with gap junctions (GJ), which are comprised of connexins, mainly connexin43 (Cx43). The gap junctional intercellular communication (GJIC) pathway allows small signal molecules, such as glutamate, ATP (adenosine triphosphate, ATP) and tropic factors, etc., to transfer between adjacent cells. Evidence has shown that astrocytes execute the bystander effect during cell death through the GJIC pathway. However, the pathogenic mechanism of the gap junction underlying glutamate neurotoxicity induced by manganese exposure has not been elucidated yet. In the present study, primary astrocytes were cultured and then exposed to different levels of Mn (ranging from 0 to 1000 µM) for 4/16 h to investigate the function of the GJIC in apoptosis induced by Mn. The cellular toxicity was confirmed by cell viability and apoptotic percentage through MTT assay and flow cytometry (FC). The levels of intracellular/extracellular glutamate were measured by high-performance liquid chromatography (HPLC). The fluorescent dye, Lucifer Yellow (LY), was used to assess the status of gap junctions among astrocytes after Mn exposure. The protein/gene expression of major gap junctional forming protein, Cx43, was also investigated. Cell viability was distinctly reduced when exposed to 500 and 1000 µM MnCl2 compared with control cells at both time points. The percentage of apoptosis was significantly increased among all detected Mn levels (125, 500 and 1000 µM MnCl2) of exposure (p < 0.05) with a concentration-dependent manner at either time point. Mn administration for 4/16 h also caused a remarkable intracellular/extracellular glutamate increase in a concentration-dependent manner for extracellular glutamate levels (p < 0.01). Gap junctions were prominently inhibited by Mn with Cx43 protein shown as shortening of the LY dye transfer distance at both time points. In-cell western blot indicated that Mn caused a decrease in Cx43 protein/gene expression in a dose-dependent manner. These results suggested that the gap junction intercellular communication and its forming protein, Cx43, are likely involved in glutamate excitotoxicity induced by Mn exposure.

Development and Validation of Quantitative Ultraperformance Liquid Chromatography-Tandem Mass Spectrometry Assay for Anticoagulant Rodenticides in Liver.

Anticoagulant rodenticides (ARs) are used to control rodent populations; however, exposure to nontarget animals occurs. A sensitive and rugged quantitative method was developed, optimized, and validated for eight ARs in liver. Target analytes comprised two chemical classes: hydroxycoumarins (warfarin, coumachlor, dicoumarol, bromadiolone, brodifacoum, and difethialone) and indanediones (diphacinone and chlorophacinone). In this method, liver extracts were cleaned using dispersive solid phase extraction (d-SPE) to remove matrix interferences and analyzed by reverse phase ultraperformance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Electrospray ionization in negative ion mode combined with multiple reaction monitoring (MRM) using a triple quadrupole mass spectrometer provided simultaneous confirmation and quantitation. Detection limits spanned 0.75-25 ng/g, and lower quantitation limits were established as 50 ng/g. Interassay method accuracy ranged from 92 to 110% across the analytical range (50-2500 ng/g) using matrix-matched calibrants with good repeatability (relative standard deviations 2-16%). Successful method transfer to another laboratory utilizing an Orbitrap mass analyzer, providing high mass accuracy, was assessed by good method reproducibility during blinded study analyses (6-29%; Horwitz ratios (HORRAT) ≤ 1.5).

Label-free detection and identification of protein ligands captured by receptors in a polymerized planar lipid bilayer using MALDI-TOF MS.

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) coupled with affinity capture is a well-established method to extract biological analytes from complex samples followed by label-free detection and identification. Many bioanalytes of interest bind to membrane-associated receptors; however, the matrices and high-vacuum conditions inherent to MALDI-TOF MS make it largely incompatible with the use of artificial lipid membranes with incorporated receptors as platforms for detection of captured proteins and peptides. Here we show that cross-linking polymerization of a planar supported lipid bilayer (PSLB) provides the stability needed for MALDI-TOF MS analysis of proteins captured by receptors embedded in the membrane. PSLBs composed of poly(bis-sorbylphosphatidylcholine) (poly(bis-SorbPC)) and doped with the ganglioside receptors GM1 and GD1a were used for affinity capture of the B subunits of cholera toxin, heat-labile enterotoxin, and pertussis toxin. The three toxins were captured simultaneously, then detected and identified by MS on the basis of differences in their molecular weights. Poly(bis-SorbPC) PSLBs are inherently resistant to nonspecific protein adsorption, which allowed selective toxin detection to be achieved in complex matrices (bovine serum and shrimp extract). Using GM1-cholera toxin subunit B as a model receptor-ligand pair, we estimated the minimal detectable concentration of toxin to be 4 nM. On-plate tryptic digestion of bound cholera toxin subunit B followed by MS/MS analysis of digested peptides was performed successfully, demonstrating the feasibility of using the PSLB-based affinity capture platform for identification of unknown, membrane-associated proteins. Overall, this work demonstrates that combining a poly(lipid) affinity capture platform with MALDI-TOF MS detection is a viable approach for capture and proteomic characterization of membrane-associated proteins in a label-free manner.