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Heliyon Jun 2024Modeling of proton exchange membrane (PEM) fuel cells is attracting more attention as fuel cell technology continues to develop. In this study, we considered a hybrid...
Using a three-dimensional computational fluid dynamics model and an agglomerate model to investigate the effect of varying agglomerate parameters and output voltages on proton exchange membrane fuel cell performance.
Modeling of proton exchange membrane (PEM) fuel cells is attracting more attention as fuel cell technology continues to develop. In this study, we considered a hybrid model that combines an agglomerate model based on the agglomeration of catalyst particles and the coverage-dependent kinetic equation of platinum oxide for ORR, and another 3D numerical model of a PEM fuel cell based on computational fluid dynamics (CFD). The obtained results from our developed models were validated with experimental results from literature. In fact, we investigated the effects of changing the agglomerate radius , the ionomer volume fraction within the agglomerate the effective agglomerate surface area , the distribution of the gases and the temperature on the cell performances. The results revealed that the cell performances are strongly influenced by changing and for medium and high current densities: The activation loss increases with increasing and decreasing . Also, increases with decreasing and increasing . In addition, the PEM fuel cell's power output is significantly enhanced when is decreased and is increased, the optimal power being obtained for values of and = 0.6. The numerical results also showed that decreasing the output voltage from 0.95V to 0.35V can accelerate the electrochemical reaction process.
PubMed: 38933966
DOI: 10.1016/j.heliyon.2024.e32277 -
Heliyon Jun 2024Colon cancer is a common gastrointestinal malignancy that ranks third in incidence among gastrointestinal cancers. Therefore, screening bioactive compounds for treatment...
Colon cancer is a common gastrointestinal malignancy that ranks third in incidence among gastrointestinal cancers. Therefore, screening bioactive compounds for treatment of colon cancer is urgently needed. L. (SO) has been demonstrated that the extractions or monomers possess potential anti-tumor effect. In this study, we firstly used cell membrane chromatography (CMC) and ultra-performance liquid chromatography coupled with (quadrupole) time-of-flight mass spectrometry (UHPLC-(Q) TOF-MS/MS) to identify a novel active ingredient, octyl gallate (OG), from SO methanol extract (SO-MtOH). HCT116 and SW620 cells lines were used for research, which showed OG presents great anti-colon cancer effect by inhibiting proliferation, inducing apoptosis, and repressing the migration and invasion. Furthermore, SW620 bearing athymic nude mice was used to investigate the potential antitumor activity , which exhibited OG treatment remarkably lessened the tumor volume. Mechanism studies showed that OG downregulated the PI3K/AKT/mTOR signaling axis and induced apoptosis by upregulating the Bax/Bcl-2 protein and the cleaved caspase-3, caspase-9. In conclusion, our research innovatively applied the method of CMC to intriguingly unearth the potential anti-colon cancer ingredient OG and demonstrated its the great antineoplastic activity, which provide a new insight for researchers efficiently developing the novel apoptosis-inducing compound for colon cancer therapy.
PubMed: 38933948
DOI: 10.1016/j.heliyon.2024.e32230 -
Frontiers in Cell and Developmental... 2024Lipids, the primary constituents of the cell membrane, play essential roles in nearly all cellular functions, such as cell-cell recognition, signaling transduction, and... (Review)
Review
Lipids, the primary constituents of the cell membrane, play essential roles in nearly all cellular functions, such as cell-cell recognition, signaling transduction, and energy provision. Lipid metabolism is necessary for the maintenance of life since it regulates the balance between the processes of synthesis and breakdown. Increasing evidence suggests that cancer cells exhibit abnormal lipid metabolism, significantly affecting their malignant characteristics, including self-renewal, differentiation, invasion, metastasis, and drug sensitivity and resistance. Prominent oncogenic signaling pathways that modulate metabolic gene expression and elevate metabolic enzyme activity include phosphoinositide 3-kinase (PI3K)/AKT, MAPK, NF-kB, Wnt, Notch, and Hippo pathway. Conversely, when metabolic processes are not regulated, they can lead to malfunctions in cellular signal transduction pathways. This, in turn, enables uncontrolled cancer cell growth by providing the necessary energy, building blocks, and redox potentials. Therefore, targeting lipid metabolism-associated oncogenic signaling pathways could be an effective therapeutic approach to decrease cancer incidence and promote survival. This review sheds light on the interactions between lipid reprogramming and signaling pathways in cancer. Exploring lipid metabolism as a target could provide a promising approach for creating anticancer treatments by identifying metabolic inhibitors. Additionally, we have also provided an overview of the drugs targeting lipid metabolism in cancer in this review.
PubMed: 38933330
DOI: 10.3389/fcell.2024.1399065 -
Journal of Molecular and Cellular... Jun 2024Heart failure remains one of the largest clinical burdens globally, with little to no improvement in the development of disease-eradicating therapeutics. Integrin...
Heart failure remains one of the largest clinical burdens globally, with little to no improvement in the development of disease-eradicating therapeutics. Integrin targeting has been used in the treatment of ocular disease and cancer, but little is known about its utility in the treatment of heart failure. Here we sought to determine whether the second generation orally available, αvβ3-specific RGD-mimetic, , was cardioprotective. Male mice were subjected to transverse aortic constriction (TAC) and treated with 50 μg/kg or volume-matched saline as Vehicle control. At 3 weeks post-TAC, echocardiography showed that treatment significantly restored cardiac function and structure indicating the protective effect of treatment in this model of heart failure. Importantly, treatment improved cardiac function giving improved fractional shortening, ejection fraction, heart weight and lung weight to tibia length fractions, together with partial restoration of Ace and Mme levels, as markers of the TAC insult. At a tissue level, reduced cardiomyocyte hypertrophy and interstitial fibrosis, both of which are major clinical features of heart failure. RNA sequencing identified that, mechanistically, this occurred with concomitant alterations to genes involved molecular pathways associated with these processes such as metabolism, hypertrophy and basement membrane formation. Overall, targeting αvβ3 with provides a novel strategy to attenuate pressure-overload induced cardiac hypertrophy and fibrosis, providing a possible new approach to heart failure treatment.
PubMed: 38933087
DOI: 10.1016/j.jmccpl.2024.100069 -
Frontiers in Microbiology 2024Rice blast, a prevalent and highly destructive rice disease that significantly impacts rice yield, is caused by the rice blast fungus. In the present study, a strain...
Rice blast, a prevalent and highly destructive rice disease that significantly impacts rice yield, is caused by the rice blast fungus. In the present study, a strain named MTC-8, identified as , was demonstrated has strong antagonistic activity against the rice blast fungus, , and . The potential biocontrol agents were identified using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis and chromatography. Further investigations elucidated the inhibitory mechanism of the isolated compound and demonstrated its ability to suppress spore germination, alter hyphal morphology, disrupt cell membrane integrity, and induce defense-related gene expression in rice. MTC-8 promoted plant growth and may lead to the development of a biocontrol agent that meets agricultural standards. Overall, the MTC-8 strain exerted beneficial effects on plant growth, immunity and disease resistance against rice blast fungus. In this study, we isolated and purified a bioactive substance from fermentation broth, and the results provide a foundation for the development and application of biopesticides. Elucidation of the inhibitory mechanism against rice blast fungus provides theoretical support for the identification of molecular targets. The successful development of a biocontrol agent lays the groundwork for its practical application in agriculture.
PubMed: 38933037
DOI: 10.3389/fmicb.2024.1422476 -
Vaccines May 2024At times of pandemics, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the situation demands rapid development and production...
At times of pandemics, such as the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, the situation demands rapid development and production timelines of safe and effective vaccines for delivering life-saving medications quickly to patients. Typical biologics production relies on using the lengthy and arduous approach of stable single-cell clones. Here, we used an alternative approach, a stable cell pool that takes only weeks to generate compared to a stable single-cell clone that needs several months to complete. We employed the membrane, envelope, and highly immunogenic spike proteins of SARS-CoV-2 to produce virus-like particles (VLPs) using the HEK293-F cell line as a host system with an economical transfection reagent. The cell pool showed the stability of protein expression for more than one month. We demonstrated that the production of SARS-CoV-2 VLPs using this cell pool was scalable up to a stirred-tank 2 L bioreactor in fed-batch mode. The purified VLPs were properly assembled, and their size was consistent with the authentic virus. Our particles were functional as they specifically entered the cell that naturally expresses ACE-2. Notably, this work reports a practical and cost-effective manufacturing platform for scalable SARS-CoV-2 VLPs production and chromatographic purification.
PubMed: 38932290
DOI: 10.3390/vaccines12060561 -
Viruses Jun 2024Experimental evolution studies, in which biological populations are evolved in a specific environment over time, can address questions about the nature of spontaneous... (Review)
Review
Experimental evolution studies, in which biological populations are evolved in a specific environment over time, can address questions about the nature of spontaneous mutations, responses to selection, and the origins and maintenance of novel traits. Here, we review more than 30 years of experimental evolution studies using the bacteriophage (phage) Φ6 cystovirus. Similar to many lab-studied bacteriophages, Φ6 has a high mutation rate, large population size, fast generation time, and can be genetically engineered or cryogenically frozen, which facilitates its rapid evolution in the laboratory and the subsequent characterization of the effects of its mutations. Moreover, its segmented RNA genome, outer membrane, and capacity for multiple phages to coinfect a single host cell make Φ6 a good non-pathogenic model for investigating the evolution of RNA viruses that infect humans. We describe experiments that used Φ6 to address the fitness effects of spontaneous mutations, the consequences of evolution in the presence of coinfection, the evolution of host ranges, and mechanisms and consequences of the evolution of thermostability. We highlight open areas of inquiry where further experimentation on Φ6 could inform predictions for pathogenic viruses.
Topics: Bacteriophage phi 6; Mutation; Host Specificity; Evolution, Molecular; Cystoviridae; Genome, Viral; Humans; Directed Molecular Evolution; Biological Evolution
PubMed: 38932268
DOI: 10.3390/v16060977 -
Viruses Jun 2024Human alphaherpesvirus 1 (HSV-1) is a significantly widespread viral pathogen causing recurrent infections that are currently incurable despite available treatment...
Human alphaherpesvirus 1 (HSV-1) is a significantly widespread viral pathogen causing recurrent infections that are currently incurable despite available treatment protocols. Studies have highlighted the potential of antimicrobial peptides sourced from venom, particularly those belonging to the mastoparan family, as effective against HSV-1. This study aimed to demonstrate the antiviral properties of mastoparans, including mastoparan-L [I, R], mastoparan-MO, and [I, R] mastoparan, against HSV-1. Initially, Vero cell viability was assessed in the presence of these peptides, followed by the determination of antiviral activity, mechanism of action, and dose-response curves through plaque assays. Structural analyses via circular dichroism and nuclear magnetic resonance were conducted, along with evaluating membrane fluidity changes induced by [I, R] mastoparan using fluorescence-labeled lipid vesicles. Cytotoxic assays revealed high cell viability (>80%) at concentrations of 200 µg/mL for mastoparan-L and mastoparan-MO and 50 µg/mL for [I, R] mastoparan. Mastoparan-MO and [I, R] mastoparan exhibited over 80% HSV-1 inhibition, with up to 99% viral replication inhibition, particularly in the early infection stages. Structural analysis indicated an α-helical structure for [I, R] mastoparan, suggesting effective viral particle disruption before cell attachment. Mastoparans present promising prospects for HSV-1 infection control, although further investigation into their mechanisms is warranted.
Topics: Herpesvirus 1, Human; Antiviral Agents; Animals; Vero Cells; Chlorocebus aethiops; Peptides; Wasp Venoms; Intercellular Signaling Peptides and Proteins; Cell Survival; Humans; Virus Replication
PubMed: 38932240
DOI: 10.3390/v16060948 -
Viruses May 2024Proteins of the Bcl-2 family regulate cellular fate via multiple mechanisms including apoptosis, autophagy, senescence, metabolism, inflammation, redox homeostasis, and... (Review)
Review
Proteins of the Bcl-2 family regulate cellular fate via multiple mechanisms including apoptosis, autophagy, senescence, metabolism, inflammation, redox homeostasis, and calcium flux. There are several regulated cell death (RCD) pathways, including apoptosis and autophagy, that use distinct molecular mechanisms to elicit the death response. However, the same proteins/genes may be deployed in multiple biochemical pathways. In apoptosis, Bcl-2 proteins control the integrity of the mitochondrial outer membrane (MOM) by regulating the formation of pores in the MOM and apoptotic cell death. A number of prosurvival genes populate the genomes of viruses including those of the pro-survival Bcl-2 family. Viral Bcl-2 proteins are sequence and structural homologs of their cellular counterparts and interact with cellular proteins in apoptotic and autophagic pathways, potentially allowing them to modulate these pathways and determine cellular fate.
Topics: Humans; Proto-Oncogene Proteins c-bcl-2; DNA Viruses; Autophagy; Apoptosis; Viral Proteins; Animals; Mitochondrial Membranes
PubMed: 38932171
DOI: 10.3390/v16060879 -
Viruses May 2024Repression of human cytomegalovirus (HCMV) immediate-early (IE) gene expression is a key regulatory step in the establishment and maintenance of latent reservoirs. Viral...
cGAS-STING-TBK1 Signaling Promotes Valproic Acid-Responsive Human Cytomegalovirus Immediate-Early Transcription during Infection of Incompletely Differentiated Myeloid Cells.
Repression of human cytomegalovirus (HCMV) immediate-early (IE) gene expression is a key regulatory step in the establishment and maintenance of latent reservoirs. Viral IE transcription and protein accumulation can be elevated during latency by treatment with histone deacetylase inhibitors such as valproic acid (VPA), rendering infected cells visible to adaptive immune responses. However, the latency-associated viral protein UL138 inhibits the ability of VPA to enhance IE gene expression during infection of incompletely differentiated myeloid cells that support latency. UL138 also limits the accumulation of IFNβ transcripts by inhibiting the cGAS-STING-TBK1 DNA-sensing pathway. Here, we show that, in the absence of UL138, the cGAS-STING-TBK1 pathway promotes both IFNβ accumulation and VPA-responsive IE gene expression in incompletely differentiated myeloid cells. Inactivation of this pathway by either genetic or pharmacological inhibition phenocopied UL138 expression and reduced VPA-responsive IE transcript and protein accumulation. This work reveals a link between cytoplasmic pathogen sensing and epigenetic control of viral lytic phase transcription and suggests that manipulation of pattern recognition receptor signaling pathways could aid in the refinement of MIEP regulatory strategies to target latent viral reservoirs.
Topics: Humans; Valproic Acid; Myeloid Cells; Signal Transduction; Membrane Proteins; Cytomegalovirus; Nucleotidyltransferases; Protein Serine-Threonine Kinases; Cytomegalovirus Infections; Virus Latency; Transcription, Genetic; Cell Differentiation; Gene Expression Regulation, Viral; Genes, Immediate-Early; Interferon-beta
PubMed: 38932169
DOI: 10.3390/v16060877