Cell Defense Research Articles

Reactive Molecular Dynamics Simulation on Interaction Mechanisms of Cold Atmospheric Plasma and Phosphatidylcholine in Cell Membrane Structure

ABSTRACTCold atmospheric plasma (CAP)‐assisted cancer therapy has garnered significant attention in the field of plasma medicine. The key mechanism involves inducing oxidative stress, which has been proven to be an effective approach for triggering apoptosis in cancer cells, and the reactive oxygen species (ROS) generated by CAP are believed to play a pivotal role in this process. In this study, our focus is on the cell membrane, which serves as the first line of defense for cancer cells, and the primary constituent of the membrane, phosphatidylcholine (POPC), is used as the reaction model. The lipid oxidative stress interaction mechanism of ROS (specifically O atoms, OH radicals, and molecules) with POPC at the molecular level is investigated by reactive molecular dynamics (MD) simulation. The simulation results show that the oxidative processes usually start with H‐abstraction reactions, then are followed by the formation of several biologically functional groups. For instance, fatty acid saturation‐altering double and conjugated dilute bonds, hydrophilic alcohol and aldehyde‐ketone groups, epoxy rings with possible genotoxic impurities, and hydrogen‐bonded receptor cyano. Acrolein, a by‐product of lipid peroxidation, is also observed from the simulation data. The breaking of single bonds, including C‐O, C‐C, and C‐N, is observed in the simulation, as well as the destroying of crucial structural components of POPC, such as the base, glycerophosphate chain, and fatty acid chains, suggesting that the cell membrane structure is disrupted. Compared to the bases and glycerophosphate, the fatty acid chains are most destroyed under the action of ROS. The final oxidation products of POPC have also been revealed from the computational data. Additionally, the dosage effects on the final products are also discussed by adjusting the types and numbers of ROS in the simulation box. This study provides the detailed oxidative process of lipid oxidation of POPC induced by CAP and fundamental insights for optimizing CAP to effectively inactivate cancer cells.

Toll/interleukin-1 receptor-only genes contribute to immune responses in maize.

Proteins with Toll/interleukin-1 receptor (TIR) domains are widely distributed in both prokaryotes and eukaryotes, serving as essential components of immune signaling. Although monocots lack the major TIR-nucleotide-binding (NB)-leucine-rich repeat (LRR)-type (TNL) immune receptors, they possess a small number of TIR-only proteins, the function of which remains largely unknown. In the monocot maize (Zea mays), there are three conserved TIR-only genes in the reference genome, namely ZmTIR1 to ZmTIR3. A genome-wide scan for TIR genes and comparative analysis revealed that these genes exhibit low sequence diversity and do not show copy number variation among 26 diverse inbred lines. ZmTIR1 and ZmTIR3, but not ZmTIR2, specifically trigger cell death and defense gene expression when overexpressed in Nicotiana benthamiana leaves. These responses depend on the critical glutamic acid and cysteine residues predicted to be essential for TIR-mediated NADase and 2',3'-cAMP/cGMP synthetase activity, respectively, as well as the key TIR downstream regulator Enhanced Disease Susceptibility 1 (EDS1). Overexpression of ZmTIR3 in N. benthamiana produces signaling molecules, including 2'cADPR, 2',3'-cAMP and 2',3'-cGMP, a process that requires the enzymatic glutamic acid and cysteine residues of ZmTIR3. ZmTIR expression in maize is barely detectable under normal conditions, but is substantially induced by different pathogens. Importantly, the maize Zmtir3 knockout mutant exhibits enhanced susceptibility to the fungal pathogen Cochliobolus heterostrophus, highlighting the role of ZmTIR3 in maize immunity. Overall, our results unveil the function of the maize ZmTIRs. We propose that the pathogen-inducible ZmTIRs play an important role in maize immunity, likely through their enzymatic activity and via EDS1-mediated signaling.

Metaproteomics reveals metabolic activities potentially involved in bloom formation and succession during a mixed dinoflagellate bloom of Prorocentrum obtusidens and Karenia mikimotoi.

Understanding metabolic activities involved in bloom formation during a single-species algal bloom has improved greatly. However, little is known about metabolic activities during a multi-species algal bloom. Here, we investigated protein expression profiles at different bloom stages of a mixed dinoflagellate bloom caused by Karenia mikimotoi and Prorocentrum obtusidens (syn. Prorocentrum donghaiense) using a metaproteomic approach. Our results indicated that both P. obtusidens and K. mikimotoi cells highly expressed proteins associated with essential cellular metabolisms such as cell growth and nutrient acquisition before their respective bloom occurrence. P. obtusidens preferentially enhanced uptake and utilization of ammonium, amino acid and organophosphorus-like phospholipid at the early bloom stage, and expressed highly abundant chloroplast peridinin-chlorophyll a-binding protein at the early and the P. obtusidens-dominated bloom stages, indicating their important roles in preferential occurrence and maintenance of P. obtusidens bloom. While absorption and utilization of nutrients, especially ammonium, urea, cyanate, phospholipid, and nucleotide, as well as endocytosis, in K. mikimotoi cells, were enhanced. Notably, both species increased photosynthesis, energy generation, cell proliferation, cell motility and cell defense before their respective blooms, which were beneficial to dealing with adverse external stresses, enabling them to be more competitive and advantageous in complex environments. Interestingly, diatom groups (Skeletonema, Pseudo-nitzschia, and Thalassiosira) decreased uptake and utilization of ambient nutrients and cell proliferation during the bloom period. This study demonstrates that niche differentiation and functional complementarity among phytoplankton species regulate bloom formation and succession during the mixed bloom.

Methionine-Derived Fluorescent Probes Targeting Mitochondria: A Tool for Real-Time Oxidative Stress Monitoring in Live Cells.

Reactive oxygen species (ROS) play crucial roles in both cell signaling and defense mechanisms. Hypochlorous acid (HOCl), a strong oxidant, aids the immune response by damaging pathogens. In this study, we developed two pyridinium-based fluorophores PSSM and PSSE for selective hypochlorite detection. Out of these two fluorescent probes, PSSM shows a strong turn-on emission via a photoinduced electron transfer (PeT) mechanism, excellent mitochondrial localization, and rapid response to HOCl with high selectivity among reactive oxygen species by achieving a detection limit of 2.41 μM. It successfully detects both exogenous and endogenous HOCl in live cells, enabling the study of HOCl's role at the organelle level. Structural analysis of PSSM via thioether oxidation confirmed by HPLC, NMR and HRMS further supports its specificity. Confocal imaging and flow cytometry studies further highlights its utility in investigating oxidative stress, positioning this fluorophore as a valuable tool for monitoring HOCl imbalances in biological systems.

The Functional Identification of the CYP2E1 Gene in the Kidney of Lepus yarkandensis.

This study aims to identify the function of the cytochrome P450 2E1 (CYP2E1) gene in the kidneys of Lepus yarkandensis. CYP2E1 is a significant metabolic enzyme involved in the metabolism of various endogenous and exogenous compounds and is associated with the occurrence and progression of multiple diseases. Given L. yarkandensis's ability to survive in the extremely arid L. yarkandensis, we hypothesize that CYP2E1 in its kidneys plays a crucial role in adaptability. Through molecular cloning and sequence analysis, we discovered that the CYP2E1 gene of Lepus yarkandensis encodes a protein of 493 amino acids. The 493-amino acid protein encoded by the Lepus yarkandensis CYP2E1 gene shows 13 amino acid variation sites compared to the homologous protein in Oryctolagus cuniculus. The protein is primarily localized to the endoplasmic reticulum membrane and lacks transmembrane structures. In the yeast expression system, the heterologous expression of the CYP2E1 gene enhanced the yeast's tolerance to drought, salinity, and high temperatures, achieved by increasing antioxidant enzyme activity and reducing levels of oxidative stress markers. Additionally, this study identified a "Yeast Oxidative Stress Lethal Threshold (Yeast OSLT)" under specific stress conditions. Once this threshold is exceeded, the cell's antioxidant defense system can no longer maintain cellular homeostasis, leading to massive cell death. Although CYP2E1 did not change this threshold, it contributed to cell survival to some extent. These findings not only reveal the function of L. yarkandensis CYP2E1 in stress adaptation but also provide valuable molecular insights into its survival strategy in extreme environments.

M6A methyltransferase METTL3 promotes non-small-cell lung carcinoma progression by inhibiting the RIG-I-MAVS innate immune pathway

Our experimental study showed that METTL3 was highly expressed in NSCLC cells and promoted the growth of tumor cells. METTL3 takes N6-methyladenosine (m6A) as the main means of mRNA modification to control the expression and function of RIG-I-MAVS signalling pathway. RIG-I-MAVS constitute the first line frontier in the innate immune defense of human cells. Activation of RIG-I-MAVS signaling can inhibit tumor cell growth and activate the immune microenvironment. Our experimental data reveal that lung cancer cells utilize METTL3-mediated methylation modifications to inhibit the activation of RIG-I-MAVS signaling pathway and immune responses. Our work provides new ideas for biotherapy and immunotherapy.

Effects of Saprolegnia parasitica on pathological damage and metabolism of Epithelioma papulosum cyprini cell.

Saprolegniasis is a common fungal disease in aquaculture. It will form white flocculent hyphae on the skin of fish, and the hyphae may grow inward and penetrate into muscle tissue, which will reduce the immunity of the body and eventually lead to death. However, there are still some gaps in the mechanism of the fish body surface against the invasion of Saprolegnia. This study explored the defense mechanism of Epithelioma papulosum cyprini cell (EPC) in the process of Saprolegnia parasitica infection from the perspective of pathogenic bacteria and host cells, so as to provide a theoretical basis for further exploring the mechanism of host resistance to S. parasitica invasion. The EPC cell was used as the research object. The EPC cells were treated with 1×106 CFU/mL of S. parasitica for 0, 6, 12, 24, 48 and 72 h. Cell viability and cell membrane damage were detected, and the non-specific immune enzyme activity in the cells was detected. Based on the above research, the apoptosis genes and antioxidant genes in the cells were detected to analyze the effect of S. parasitica on the metabolism of the EPC cells. The results showed that with the prolongation of the co-culture time of S. parasitica and cells, the cell viability gradually decreased and the cell membrane integrity was destroyed, but at the same time, the activity of non-specific immune enzymes increased to resist the infection of S. parasitica. In addition, the detection of EPC apoptosis gene casp3a and CTSD showed that the relative content of casp3a gene increased significantly at 24 h and reached the maximum value of the culture time (P<0.05). The content of CTSD gene increased significantly at 12 h and reached the maximum value (P<0.05). The results of antioxidant immune genes serpinh1a and gpx1a were opposite to the structure of apoptotic genes. The content of serpinh1a and gpx1a genes decreased significantly at 12 h (P<0.05), but with the prolongation of culture time, the content increased significantly at 24 h and 48 h (P<0.05). After stimulation of EPC cells by S. parasitica, the differential metabolites were mainly concentrated in Lipids, Compounds with biological roles and Phytochemical compounds. The KEGG pathway mainly focused on ABC transporters, Glycerophospholipid metabolism, Cysteine and methionine metabolism, Glycine, serine and threonine metabolism, Purine metabolism. In general, S. parasitica can affect cell activity, destroy the cell membrane of EPC cells, and cause apoptosis. However, EPC cells can also resist the invasion of S. parasitica by regulating their own non-specific immunity and their own metabolites, thereby protecting the body from the infection of S. parasitica.

Isoquinolinequinone N-oxides with diverging mechanisms of action induce collateral sensitivity against multidrug resistant cancer cells.

Multidrug resistance (MDR) is a major challenge in cancer research. Collateral sensitizers, compounds that exploit the enhanced defense mechanisms of MDR cells as weaknesses, are a proposed strategy to overcome MDR. Our previous work reported the synthesis of two novel Isoquinolinequinone (IQQ) N-oxides that induce collateral sensitivity in MDR ABCB1-overexpressing non-small cell lung cancer (NSCLC) and colorectal cancer cells. Herein, we aimed to investigate underlying mechanisms of antitumor and collateral sensitivity activity of these compounds. We evaluated their effect on cancer cell viability, proliferation, cell cycle profile, and studied their cytotoxicity in non-tumorigenic cells. Their antitumor effect was further studied using NSCLC and colorectal cancer MDR spheroids. To understand underlying collateral sensitivity mechanisms, we assessed the effect on rhodamine-123 accumulation, ROS production, GSH/GSSG balance and expression of key proteins associated with metabolism and redox balance. Both compounds reduced the viability of MDR cells, as 2D cultures or as spheroids, without decreasing the growth of a human nontumorigenic cell line, and increased rhodamine-123 accumulation in MDR NCI-H460/R cells. Moreover, RK2 increased ROS, disrupted GSH balance, and altered expression of proteins associated with oxidative stress protection, particularly in NCI-H460/R cells. The collateral sensitivity effect of RK3 could not be attributed to redox balance disruption, but increased IDH1 expression following treatment suggests a potential metabolic shift in MDR cells. These findings highlight RK2 and RK3 as promising candidates for next stages of drug development. Their distinct mechanisms of action could lead to therapeutic solutions for MDR-related cancers, specifically linked to ABCB1 overexpression.

Salmonella multimutants enable efficient identification of SPI-2 effector protein function in gut inflammation and systemic colonization.

Salmonella enterica spp. rely on translocation of effector proteins through the SPI-2 encoded type III secretion system (T3SS) to achieve pathogenesis. More than 30 effectors contribute to manipulation of host cells through diverse mechanisms, but interdependency or redundancy between effectors complicates the discovery of effector phenotypes using single mutant strains. Here, we engineer six mutant strains to be deficient in cohorts of SPI-2 effector proteins, as defined by their reported function. Using various animal models of infection, we show that three principle phenotypes define the functional contribution of the SPI-2 T3SS to infection. Multimutant strains deficient for intracellular replication, for manipulation of host cell defences, or for expression of virulence plasmid effectors all showed strong attenuation in vivo, while mutants representing approximately half of the known effector complement showed phenotypes similar to the wild-type parent strain. By additionally removing the SPI-1 T3SS, we find cohorts of effector proteins that contribute to SPI-2 T3SS-driven enhancement of gut inflammation. Further, we provide an example of how iterative mutation can be used to find a minimal number of effector deletions required for attenuation, and thus establish that the SPI-2 effectors SopD2 and GtgE are critical for the promotion of gut inflammation and mucosal pathology. This strategy provides a powerful toolset for simultaneous parallel screening of all known SPI-2 effectors in a single experimental context, and further facilitates the identification of the responsible effectors, and thereby provides an efficient approach to study how individual effectors contribute to disease.

Crosstalk between miRNAs and signaling pathways in the development of drug resistance in breast cancer.

One of the biggest challenges of today's society is cancer, which imposes a significant financial, emotional and spiritual burden on human life. Breast cancer (BC) is one of the most common cancers that affects people in society, especially women, and due to advanced treatment strategies and primary prevention, it is still the second cause of cancer-related deaths in society. Various genetic and environmental factors are involved in the development of BC. MicroRNAs (miRNA)s are non-coding RNAs, that the degradation or inhibition of them plays an important role in the prevention or development of cancer by modulating many cellular pathways including apoptosis, drug resistance, and tumorigenesis. Drug resistance is one of the important defense mechanisms of cancer cells against anticancer drugs and is considered one of the main causes of cancer treatment failure. Different miRNAs, including mir-7, mir-21, mir-31, and mir-124 control different cell activities, including drug resistance, through different pathways, including PI3K/AKT/mTOR, TGF-β, STAT3, and NF-kB. Therefore, cell signaling pathways are one of the important factors that miRNAs control cellular activities. Hence, in this study, we decided to highlight an overview of the relationship between miRNAs and signaling pathways in the development of drug resistance in BC.

The quality of SIV-specific fCD8 T cells limits SIV RNA production in Tfh cells during antiretroviral therapy.

The attack and defense of infected cells and cytotoxic CD8 T cells occur in germinal centers in lymphoid tissue in chronic persistent HIV/SIV infection. Latently infected cells, the therapeutic target of HIV infection, accumulate in follicular helper T (Tfh) cells in lymphoid tissue; the impact of HIV-specific follicular CD8 (fCD8) T cells in lymphoid tissue on the latently infected cells remains unknown. We infected 15 cynomolgus macaques with SIVmac239 and examined the contribution of SIV-Gag-specific fCD8 T cells, defined by activation-induced markers (AIMs), to SIV-infected cells. Eight out of the 15 infected macaques served as progressors; a chronic phase combination antiretroviral therapy (cART) model was established for the eight macaques (progressors) with chronic persistent infection status, wherein cART was started in the chronic phase and discontinued after 27 weeks. Seven macaques that naturally controlled the viremia served as natural controllers. The frequency of SIV-Gag-specific fCD8 T cells was inversely correlated with the amount of cell-associated SIV-gag RNA in the Tfh only under cART or in the controllers but not in untreated progressors. scRNA-seq of SIV-Gag-specific fCD8 T cells in various conditions revealed that the gene expression pattern of SIV-Gag-specific fCD8 T cells in the controllers was closer to that of those under cART than the untreated progressors. Comparing the SIV-Gag-specific fCD8 T cells of those under cART to the controllers revealed their more exhausted and immunosenescent nature under cART. Improving the HIV/SIV-specific fCD8 T cells under cART by targeting those pathways might contribute to the development of potential curative strategies.IMPORTANCEWe infected cynomolgus macaques with SIVmac239 to establish an SIV-chronically infected cART model. We performed an in-depth characterization of Tfh and fCD8 T cells in three conditions-chronic stage of untreated, cART-treated, and natural controller cynomolgus macaques-by combining tissue section analysis and single-cell analyses of sorted cells. We revealed the inverse relationship between Tfh infection and SIV-Gag-specific fCD8 T cell frequencies as observed in HIV-infected individuals, thereby establishing the cynomolgus macaque as a relevant animal model to study the determinants of HIV/SIV persistence in lymphoid tissue. Additionally, scRNA-seq analysis of SIV-Gag-specific fCD8 T cells revealed an enrichment of exhausted or senescent transcriptomic signatures under cART. These data will provide the basic insights into virus-host CD8 T cell interactions, particularly within the follicular region, during latent HIV infection under ART.

Specific Transcriptional Regulation Controls Plant Organ-Specific Infection by the Oomycete Pathogen Phytophthora sojae.

The organs of a plant species vary in cell structure, metabolism and defence responses. However, the mechanisms that enable a single pathogen to colonise different plant organs remain unclear. Here we compared the transcriptome of the oomycete pathogen Phytophthora sojae during infection of roots versus leaves of soybeans. We found differences in the transcript levels of hundreds of pathogenicity-related genes, particularly genes encoding carbohydrate-active enzymes, secreted (effector) proteins, oxidoreductase-related proteins and transporters. To identify the key regulator for root-specific infection, we knocked out root-specific transcription factors (TFs) and found the mutants of PsBZPc29, which encodes a member of an oomycete-specific class of basic leucine zipper (bZIP) TFs, displayed reduced virulence on soybean roots but not on leaves. More than 60% of the root-specific genes showed reduced expression in the mutants during root infection. The results suggest that transcriptional regulation underlies the organ-specific infection by P. sojae, and that a bZIP TF plays a key role in root-specific transcriptional regulation.

IRE1α silences dsRNA to prevent taxane-induced pyroptosis in triple-negative breast cancer.

Chemotherapy is often combined with immune checkpoint inhibitor (ICIs) to enhance immunotherapy responses. Despite the approval of chemo-immunotherapy in multiple human cancers, many immunologically cold tumors remain unresponsive. The mechanisms determining the immunogenicity of chemotherapy are elusive. Here, we identify the ER stress sensor IRE1α as a critical checkpoint that restricts the immunostimulatory effects of taxane chemotherapy and prevents the innate immune recognition of immunologically cold triple-negative breast cancer (TNBC). IRE1α RNase silences taxane-induced double-stranded RNA (dsRNA) through regulated IRE1-dependent decay (RIDD) to prevent NLRP3 inflammasome-dependent pyroptosis. Inhibition of IRE1α in Trp53-/- TNBC allows taxane to induce extensive dsRNAs that are sensed by ZBP1, which in turn activates NLRP3-GSDMD-mediated pyroptosis. Consequently, IRE1α RNase inhibitor plus taxane converts PD-L1-negative, ICI-unresponsive TNBC tumors into PD-L1high immunogenic tumors that are hyper-sensitive to ICI. We reveal IRE1α as a cancer cell defense mechanism that prevents taxane-induced danger signal accumulation and pyroptotic cell death.

Defensive responses of most antioxidant genes in the freshwater dinoflagellate Palatinus apiculatus to cadmium stress and their implications

Photosynthetic dinoflagellates are one of the major microalgal taxa, playing essential roles in biogeochemical cycles and food webs in aquatic environments. Some freshwater dinoflagellates are known to be sensitive to environmental conditions, like water quality and contaminants; however, their molecular toxicological responses are insufficiently discovered. In the present study, we evaluated the physiological and transcriptomic responses of the freshwater dinoflagellate Palatinus apiculatus exposed to cadmium (Cd), focusing on stress-responsive genes. The cell number of P. apiculatus decreased significantly at Cd concentrations above 0.25 mg/L after 72 h, with an estimated EC50 value of 1.35 mg/L. In addition, we constructed 87,207 transcriptomic contigs from the P. apiculatus cells exposed to the Cd. Differential expression gene analysis showed that 21.0 % of total contigs were statistically significant, including 8647 up-regulated and 4195 down-regulated genes. Gene Ontology enrichment results revealed that genes responsive to stress and external stimuli were highly expressed in Cd-treated cells. Moreover, Cd significantly induced reactive oxygen species (ROS) production in P. apiculatus cells, and their patterns were similar to the expressions of certain antioxidant genes. Among the selected genes, GR expression levels were down-regulated, which may lead to the failure of cell defense against heavy metals. These results showed molecular defense pathways of the freshwater dinoflagellate P. apiculatus against the heavy metal that could be served as potential sensitive biomarkers for evaluating molecular toxicity in freshwater ecosystems.

BCL2 regulates antibacterial autophagy in the intestinal epithelium

Autophagy is a key innate immune defense mechanism in intestinal epithelial cells. Bacterial invasion of epithelial cells activates antibacterial autophagy through a process that requires the innate immune adaptor protein MYD88, yet how MYD88 signaling connects to the autophagy machinery is unknown. Here, we show that the mouse intestinal pathogen Salmonella enterica Serovar Typhimurium (Salmonella Typhimurium) triggers MYD88 signaling that regulates binding of the anti-autophagy factor B cell lymphoma 2 (BCL2) to the essential autophagy protein Beclin1 (BECN1) in small intestinal enterocytes, a key epithelial cell lineage. Salmonella infection activated the kinase c-Jun N-terminal protein kinase 1 (JNK1) downstream of MYD88. JNK1 induced enterocyte BCL2 phosphorylation, promoting dissociation of the inhibitory BCL2-BECN1 complex and releasing BECN1 to initiate autophagy. Mice with BCL2 phosphorylation site mutations that prevent BCL2-BECN1 dissociation showed increased Salmonella invasion of enterocytes and dissemination to extraintestinal sites. These findings reveal that BCL2 links MYD88 signaling to enterocyte autophagy initiation, providing mechanistic insight into how invading bacteria trigger autophagy in the intestinal epithelium.

The Effect of Exercise on Improving Respiratory Function and Physical Activity in Hospitalized Patients with COVID-19

Background: The outbreak of COVID-19 has been associated with various physical and psychological effects. The role of exercise in strengthening the immune system and reducing inflammation has already been proven. Moderate levels of exercise can enhance overall immunity. Exercise can improve intracellular metabolism and increase cell defense activity by improving inflammatory cytokines, immature B cells, and cytotoxic T cells. Therefore, exercise is known as a defense strategy against respiratory infections. Here the role of exercise in improving respiratory function and physical activity in hospitalized patients with COVID-19 was evaluated. Methods: The present study was performed as a randomized clinical trial on 90 hospitalized patients with COVID-19. Both groups received all routine treatments (medication, invasive or non-invasive ventilation, physiotherapy). Then, in the experimental group, standard exercises were provided to improve the patients’ physical condition and exercise capacity. After two weeks and one month later, all indices were measured again in two groups. Results: The results of the present study showed that exercise causes significant changes in indicators such as 6-Minute Walk Test (6MWT) (p=0.001), balance score (p=0.02), and Sf1 score (p=0.05) in two time periods before and after rehabilitation in two groups. Conclusion: Performing standard and defined exercise exercises for patients with the new coronavirus improves the physical activity and respiratory function of patients.

Identification of Novel Genomic Variants in COVID-19 Patients Using Whole-Exome Sequencing: Exploring the Plausible Targets of Functional Genomics.

Covid-19 caused by SARS-CoV-2 virus has emerged as an immense burden and an unparalleled global health challenge in recorded human history. The clinical characteristics and risk factors of COVID-19 exhibit considerable variability, leading to a spectrum of clinical severity. Moreover, the likelihood of exposure to the virus may differ based on comorbidity status as comorbid illnesses have mechanisms that can considerably increase mortality by reducing the body's ability to withstand injury. The mammalian target of rapamycin (mTOR) pathway is essential for orchestrating innate immune cell defense, including cytokine production and is dysregulated in severe Coronavirus Disease 2019 (COVID-19) individuals. Through genome-wide, association studies, numerous genetic variants in the human host have been identified that have a significant impact on the immune response to SARS-CoV-2. To identify potentially significant genetic variants in Covid-19 patients that could affect the risk, severity, and clinical outcome of the infection, this study has used whole-exome sequencing (WES) on the 16 COVID-19 patients with varying comorbidities and severity of the disease including fatal outcomes. Among them, 8 patients made a full recovery and were discharged, while 8 patients unfortunately did not survive due to the severity of the illness and majority of them were males. The study identified 10,204 variants in the patients. From 1120 variants, which were chosen for novel variant analysis using mutation, function prediction tools to identify deleterious variants that could affect normal gene function, 116 variants of 57 genes were found to be deleterious. These variants were further classified as likely pathogenic and variants of uncertain significance. The data showed that among the likely pathogenic variants five genes were identified in connection to immune response whereas two were related to respiratory system. The common variants associated with the covid-19 phenotype showed the top 10 significant genes identified in this study such as ERCC2, FBXO5, HTR3D, FAIM, DNAH17, MTOR, IGHMBP2, ZNF530, QSER1, and FOXRED2 with variant rs1057079 of the MTOR gene representing the highest odds ratio (1.7, p = 8.7e-04). The mammalian target of rapamycin (mTOR) pathway variant rs1057079 was reported with high odds ratio, may orchestrate innate immune cell defense, including cytokine production, and is dysregulated. This study concluded that the mTOR signaling gene variant (rs1057079) is associated with different degrees of covid-19 severity and is essential for orchestrating innate immune cell defense including cytokine production. Inhibiting mTOR and its corresponding deleterious immune responses with medicinal approaches may provide a novel avenue for treating severe COVID-19 illness. Besides the PPI network exhibited a significantly high local clustering coefficient of 0.424 (p = 0.000536), suggesting the presence of tightly knit functional modules. These findings enhance our comprehension of the intricate interactions between genetic factors and COVID-19 disease.

In Vivo Time-Resolved Fluorescence Detection of Liver Cancer Supported by Machine Learning.

One of the widely used optical biopsy methods for monitoring cellular and tissue metabolism is time-resolved fluorescence. The use of this method in optical liver biopsy has a high potential for studying the shift in energy-type production from oxidative phosphorylation to glycolysis and changes in the antioxidant defense of malignant cells. On the other hand, machine learning methods have proven to be an excellent solution to classification problems in medical practice, including biomedical optics. We aim to combine time-resolved fluorescence measurements and machine learning to automate the division of liver parenchyma and tumors (primary malignant, metastases and benign tumors) into classes. An optical biopsy was performed using a developed setup with a fine-needle optical probe in clinical conditions under ultrasound control. Fluorescence decays were recorded in a conditionally healthy liver and lesions during percutaneous needle biopsy. The labeled data set was created on the basis of the recorded fluorescence results and the histopathological classification of the biopsies obtained. Several machine learning methods were trained using different separation strategies of the training test set, and their respective accuracy was compared. Our results show that each of the tumor types had its own characteristic metabolic shifts recorded by the time-resolved fluorescence spectroscopy. The application of machine learning demonstrates a reliable separation of the liver and all tumor types into cancer and noncancer classes with sensitivity, specificity and corresponding accuracy greater than 0.91, 0.79 and 0.90, using the random forest method. We also show that our method is capable of giving a preliminary diagnosis of the type of liver tumor (primary malignant, metastases and benign tumors) with a sensitivity, specificity and accuracy of at least 0.80, 0.95 and 0.90. These promising results highlight its potential as a key tool in the future development of diagnostic and therapeutic strategies for liver cancers. Lasers Surg. Med. 00:00-00, 2024. 2024 Wiley Periodicals LLC.

Cannabidiol Enhances Mitochondrial Metabolism and Antioxidant Defenses in Human Intestinal Epithelial Caco-2 Cells.

The reintroduction of hemp production has resulted in increased consumption of cannabidiol (CBD) products, particularly CBD oil, yet their effects on intestinal health are not fully understood. Proper mitochondrial function and antioxidant defenses are vital for maintaining the intestinal epithelial barrier. AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptor gamma coactivator (PGC)1α are key mediators of mitochondrial metabolism. Using Caco-2 cells, we found that CBD oil promoted AMPK phosphorylation, upregulated differentiation markers, and enhanced PGC1α/SIRT3 mitochondrial signaling. CBD oil reduced reactive oxygen species production and increased antioxidant enzymes. Moreover, CBD oil also increased levels of citrate, malate, and succinate-key metabolites of the tricarboxylic acid cycle-alongside upregulation of pyruvate dehydrogenase and isocitrate dehydrogenase 1. Similarly, pure CBD induced metabolic and antioxidant signaling. CBD enhances mitochondrial metabolic activity and antioxidant defense in Caco-2 cells, making it a promising candidate for treating intestinal dysfunction.

PTD-FNK Alleviated LPS-Induced Oxidative Stress of Boar Testicular Sertoli Cells via Keap1-Nrf2 Pathway.

PTD-FNK, a synthetic anti-apoptotic protein, has been shown to potently alleviate cellular injuries. However, the effects of PTD-FNK on oxidative defense in boar testicular Sertoli cells (SCs) against oxidative injury has not been explored. In this study, we show that exposure of SCs to 100 mg/L lipopolysaccharide (LPS) for 12 h leads to decreased survival rate, superoxide dismutase (SOD) activity, and increased malondialdehyde (MDA). Treatment with 0.01 nmol/L PTD-FNK for 4 h significantly enhanced the activity of SOD, catalase (CAT), glutathione peroxidase (GSH-Px), and total antioxidant capacity (T-AOC) in SCs. Concurrently, PTD-FNK treatment effectively reduced the production of reactive oxygen species (ROS) and the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in SCs. Moreover, using His pull-down and LC-MS techniques, we identified PTD-FNK-interacting proteins and confirmed that this protective effect may be mediated by the regulation of the Keap1-Nrf2 signaling pathway by PTD-FNK. Therefore, PTD-FNK alleviates LPS-induced oxidative stress via the Keap1/Nrf2 pathway, providing novel insights for the development of therapeutic agents targeting testicular oxidative damage.