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Asian Pacific Journal of Cancer... Jun 2024Gastric cancer is a prevalent cancer type worldwide, and significant research efforts are focused on finding effective treatments. Recent studies have highlighted the...
OBJECTIVE
Gastric cancer is a prevalent cancer type worldwide, and significant research efforts are focused on finding effective treatments. Recent studies have highlighted the importance of plasma membrane carriers, particularly solute carriers, in cancer progression. The SLC16A family, notably the SLC16A13 gene, plays a critical role in cancer development and tumor growth. This study aims to explore the impact of reducing SLC16A13 expression in gastric cancer cells on their survival, proliferation, and metastatic potential.
METHODS
Gastric cancer cells (KATO2) were cultured in RPMI medium supplemented with 10% fetal bovine serum. The cells were then transfected with SLC16A13 si-RNA to lower gene expression. The effects of this si-RNA on cell death and apoptosis were assessed using MTT and flow cytometry assays. Cell migration capabilities were evaluated using the scratch test. Western blot and Real-Time PCR were employed to measure SLC16A13 expression levels and protein detection. Additionally, RT-PCR was used to analyze changes in genes related to apoptosis and cell migration.
RESULTS
The reduction of SLC16A13 expression following si-RNA transfection significantly increased apoptosis and cell death in the KATO2 cell line after 72 hours (P < 0.0001). Furthermore, the study revealed that decreased SLC16A13 expression did not impact cancer cell migration. Cell viability, assessed by MTT assay, showed a significant decrease at 48 and 72 hours post-transfection (P < 0.0001).
CONCLUSION
The findings indicate that targeting SLC16A13 can effectively increase cell death and apoptosis in gastric cancer cells, making it a viable therapeutic target.
Topics: Humans; Apoptosis; Stomach Neoplasms; Cell Movement; Cell Proliferation; Biomarkers, Tumor; Monocarboxylic Acid Transporters; Tumor Cells, Cultured; Gene Expression Regulation, Neoplastic; Cell Line, Tumor; RNA, Small Interfering
PubMed: 38918656
DOI: 10.31557/APJCP.2024.25.6.1953 -
Microbiology Spectrum Jun 2024The discovery of antimicrobials with novel mechanisms of action is crucial to tackle the foreseen global health crisis due to antimicrobial resistance. Bacterial...
UNLABELLED
The discovery of antimicrobials with novel mechanisms of action is crucial to tackle the foreseen global health crisis due to antimicrobial resistance. Bacterial two-component signaling systems (TCSs) are attractive targets for the discovery of novel antibacterial agents. TCS-encoding genes are found in all bacterial genomes and typically consist of a sensor histidine kinase (HK) and a response regulator. Due to the conserved Bergerat fold in the ATP-binding domain of the TCS HK and the human chaperone Hsp90, there has been much interest in repurposing inhibitors of Hsp90 as antibacterial compounds. In this study, we explore the chemical space of the known Hsp90 inhibitor scaffold 3,4-diphenylpyrazole (DPP), building on previous literature to further understand their potential for HK inhibition. Six DPP analogs inhibited HK autophosphorylation and had good antimicrobial activity against Gram-positive bacteria. However, mechanistic studies showed that their antimicrobial activity was related to damage of bacterial membranes. In addition, DPP analogs were cytotoxic to human embryonic kidney cell lines and induced the cell arrest phenotype shown for other Hsp90 inhibitors. We conclude that these DPP structures can be further optimized as specific disruptors of bacterial membranes providing binding to Hsp90 and cytotoxicity are lowered. Moreover, the X-ray crystal structure of resorcinol, a substructure of the DPP derivatives, bound to the HK CheA represents a promising starting point for the fragment-based design of novel HK inhibitors.
IMPORTANCE
The discovery of novel antimicrobials is of paramount importance in tackling the imminent global health crisis of antimicrobial resistance. The discovery of novel antimicrobials with novel mechanisms of actions, e.g., targeting bacterial two-component signaling systems, is crucial to bypass existing resistance mechanisms and stimulate pharmaceutical innovations. Here, we explore the possible repurposing of compounds developed in cancer research as inhibitors of two-component systems and investigate their off-target effects such as bacterial membrane disruption and toxicity. These results highlight compounds that are promising for further development of novel bacterial membrane disruptors and two-component system inhibitors.
PubMed: 38917423
DOI: 10.1128/spectrum.00146-24 -
Microbiology Spectrum Jun 2024Acetic acid bacteria are used in many industrial processes such as the production of vinegar, vitamin C, the antidiabetic drug miglitol, and various artificial...
Acetic acid bacteria are used in many industrial processes such as the production of vinegar, vitamin C, the antidiabetic drug miglitol, and various artificial flavorings. These industrially important reactions are primarily carried out by an arsenal of periplasmic-facing membrane-bound dehydrogenases that incompletely oxidize their substrates and shuttle electrons directly into the respiratory chain. Among these dehydrogenases, GOX in was predicted to be a pyrroloquinoline quinone-dependent dehydrogenase of unknown function. However, after multiple analysis by a number of labs, no dehydrogenase activity has been detected. Reanalysis of GOX1969 sequence and structure reveals similarities to BamB, which functions as a subunit of the β-barrel assembly machinery complex that is responsible for the assembly of β-barrel outer membrane proteins in Gram-negative bacteria. To test if the physiological function of GOX1969 is similar to BamB in , we introduced the gene into an ∆ mutant. Growth deficiencies in the ∆ mutant were restored when was expressed on the plasmid pGox1969. Furthermore, increased membrane permeability conferred by deletion was restored upon expression, which suggests a direct link between GOX1969 and a role in maintaining outer membrane stability. Together, this evidence strongly suggests that GOX1969 is functionally acting as a BamB in . As such, functional information on uncharacterized genes will provide new insights that will allow for more accurate modeling of acetic acid bacterial metabolism and further efforts to design rational strains for industrial use.IMPORTANCE is an industrially important member of the acetic acid bacteria. Experimental characterization of putative genes is necessary to identify targets for further engineering of rational acetic acid bacteria strains that can be used in the production of vitamin C, antidiabetic compounds, artificial flavorings, or novel compounds. In this study, we have identified an undefined dehydrogenase GOX1969 with no known substrate and defined structural similarities to outer membrane biogenesis protein BamB in K12. Furthermore, we demonstrate that GOX1969 is capable of complementing knockout phenotypes in K12. Taken together, these findings enhance our understanding of physiology and expand the list of potential targets for future industrial strain design.
PubMed: 38916353
DOI: 10.1128/spectrum.01060-24 -
Microbiology Spectrum Jun 2024Bacteria are involved in numerous interactions during infection and among host-associated microbial populations. serovar Typhimurium is a foodborne pathogen of great...
Bacteria are involved in numerous interactions during infection and among host-associated microbial populations. serovar Typhimurium is a foodborne pathogen of great importance as well as a model organism to study interactions within a microbial community. In this study, we found that . Typhimurium becomes tolerant to azithromycin when co-cultured with lactobacilli strains. Similarly, acidified media, from cell-free supernatant of lactobacilli cultures for instance, also induced the tolerance of . Typhimurium to azithromycin. The addition of membrane disruptors restored the normal sensitivity to azithromycin in acidified media, but not when lactobacilli were present. These results suggested that the acidification of the media led to modification in envelope homeostasis, but that a different mechanism promoted the tolerance to azithromycin in the presence of lactobacilli strains. To further understand how lactobacilli strains modify the sensitivity of . Typhimurium to azithromycin, a high-throughput assay was performed using the single-gene deletion collection of the . Typhimurium (1) in co-culture with and (2) in sterile acidic conditions (pH 5.5 media only). As expected, both screens identified genes involved in envelope homeostasis and membrane permeability. Our results also suggest that changes in the metabolism of . Typhimurium induce the tolerance observed in the presence of . Our results thus highlight two different mechanisms by which lactobacilli induce the tolerance of . Typhimurium to azithromycin.IMPORTANCEThis study provides valuable insights into the intricate interactions between bacteria during infections and within host-associated microbial communities. Specifically, it sheds light on the significant role of lactobacilli in inducing antibiotic tolerance in serovar Typhimurium, a critical foodborne pathogen and model organism for microbial community studies. The findings not only uncover the mechanisms underlying this antibiotic tolerance but also reveal two distinct pathways through which strains of lactobacilli might influence 's response to antibiotics. Understanding these mechanisms has the potential to enhance our knowledge of bacterial infections and may have implications for the development of strategies to combat antibiotic resistance in pathogens, such as . Furthermore, our results underscore the necessity to explore beyond the direct antimicrobial effects of antibiotics, emphasizing the broader microbial community context.
PubMed: 38916329
DOI: 10.1128/spectrum.03497-23 -
MBio Jun 2024causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs...
UNLABELLED
causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs available to combat this disease. In this manuscript, we show the host defense peptide mimetic brilacidin (BRI) as a promising antifungal drug against . BRI can affect the organization of the cell membrane, increasing the fungal cell permeability. We also investigated the effects of BRI against the model system by analyzing libraries of mutants grown in the presence of BRI. In , BRI also affects the cell membrane organization, but in addition the cell wall integrity pathway and calcium metabolism. experiments show BRI significantly reduces survival inside macrophages and partially clears lung infection in an immunocompetent murine model of invasive pulmonary cryptococcosis. We also observed that BRI interacts with caspofungin (CAS) and amphotericin (AmB), potentiating their mechanism of action against . BRI + CAS affects endocytic movement, calcineurin, and mitogen-activated protein kinases. Our results indicate that BRI is a novel antifungal drug against cryptococcosis.
IMPORTANCE
Invasive fungal infections have a high mortality rate causing more deaths annually than tuberculosis or malaria. Cryptococcosis, one of the most prevalent fungal diseases, is generally characterized by meningitis and is mainly caused by two closely related species of basidiomycetous yeasts, and . There are few therapeutic options for treating cryptococcosis, and searching for new antifungal agents against this disease is very important. Here, we present brilacidin (BRI) as a potential antifungal agent against . BRI is a small molecule host defense peptide mimetic that has previously exhibited broad-spectrum immunomodulatory/anti-inflammatory activity against bacteria and viruses. BRI alone was shown to inhibit the growth of , acting as a fungicidal drug, but surprisingly also potentiated the activity of caspofungin (CAS) against this species. We investigated the mechanism of action of BRI and BRI + CAS against . We propose BRI as a new antifungal agent against cryptococcosis.
PubMed: 38916308
DOI: 10.1128/mbio.01031-24 -
Frontiers in Plant Science 2024The tolerance to salinity stress is an intricate phenomenon at cellular and whole plant level that requires the knowledge of contributing physiological and biochemical...
The tolerance to salinity stress is an intricate phenomenon at cellular and whole plant level that requires the knowledge of contributing physiological and biochemical processes and the genetic control of participating traits. In this context, present study was conducted with objective to evaluate the physiological, biochemical, and genetic responses of different wheat genotypes including bread wheat (BW) and synthetic hexaploids (SHs) under saline and control environment. The experiment was conducted in two factorial arrangement in randomized complete block design (RCBD), with genotypes as one factor and treatments as another factor. A significant decline in physiological traits (chlorophyll, photosynthesis, stomatal conductance, transpiration, and cell membrane stability) was observed in all genotypes due to salt stress; however, this decline was higher in BW genotypes as compared to four SH genotypes. In addition, the biochemical traits including enzymes [superoxide dismutase, catalase, and peroxidase (POD)] activity, proline, and glycine betaine (GB) illustrated significant increase along with increase in the expression of corresponding genes (, , , , and ) due to salt stress in SHs as compared to BW. Correspondingly, highly overexpressed genes, , , and caused a significant decline in Na/K in SH as compared to BW genotypes under salt stress. Moreover, correlation analysis, principal component analysis (PCA), and heatmap analysis have further confirmed that the association and expression of physiological and biochemical traits varied significantly with salinity stress and type of genotype. Overall, the physiological, biochemical, and genetic evaluation proved SHs as the most useful stock for transferring salinity tolerance to other superior BW cultivars via the right breeding program.
PubMed: 38916034
DOI: 10.3389/fpls.2024.1336571 -
Frontiers in Chemistry 2024Numerous local herbal extract species have been investigated as potential medicinal ingredients due to their promising anti-cancer properties. However, the primary...
Numerous local herbal extract species have been investigated as potential medicinal ingredients due to their promising anti-cancer properties. However, the primary constraint of the class of plant flavonoids lies in their low solubility and limited membrane permeability, leading to chemical instability and restricted bioavailability that impede biomedical applications. In this study, we have developed an ideal nanozyme-Galazyme, comprising galangin-loaded copper Nanozyme coated by DSPE-PEG, which amplifies oxidative stress to induce apoptosis via the regulation of reactive oxygen species (ROS) generation and mitogen-activated protein kinase (MAPK) activation. Galazyme exhibited significant peroxidase mimetic activity, demonstrating its potential to generate ROS and elevate oxidative stress. Upon uptake by HepG-2 cells, Galazyme efficiently converts excess hydrogen peroxide (H2O2) into highly reactive •OH radicals and upregulates MAPK expression, leading to the activation of Bax and Caspase 3, thereby promoting irreversible tumor cell apoptosis. Both and results demonstrate that Galazyme inhibits tumor cell growth and induces apoptosis by generating ample ROS and activating the MAPK pathway. Our study offers novel evidence supporting the enhancement of Galazyme-induced apoptosis through the upregulation of Bax and Caspase 3, along with the elucidation of the interaction between MAPK and apoptosis.
PubMed: 38915904
DOI: 10.3389/fchem.2024.1426634 -
Frontiers in Endocrinology 2024Type 2 diabetes (T2D) is a polygenic metabolic disorder characterized by insulin resistance in peripheral tissues and impaired insulin secretion by the pancreas. While... (Review)
Review
Type 2 diabetes (T2D) is a polygenic metabolic disorder characterized by insulin resistance in peripheral tissues and impaired insulin secretion by the pancreas. While the decline in insulin production and secretion was previously attributed to apoptosis of insulin-producing β-cells, recent studies indicate that β-cell apoptosis rates are relatively low in diabetes. Instead, β-cells primarily undergo dedifferentiation, a process where they lose their specialized identity and transition into non-functional endocrine progenitor-like cells, ultimately leading to β-cell failure. The underlying mechanisms driving β-cell dedifferentiation remain elusive due to the intricate interplay of genetic factors and cellular stress. Understanding these mechanisms holds the potential to inform innovative therapeutic approaches aimed at reversing β-cell dedifferentiation in T2D. This review explores the proposed drivers of β-cell dedifferentiation leading to β-cell failure, and discusses current interventions capable of reversing this process, thus restoring β-cell identity and function.
Topics: Humans; Insulin-Secreting Cells; Cell Dedifferentiation; Diabetes Mellitus, Type 2; Animals; Cell Differentiation; Apoptosis; Insulin Secretion
PubMed: 38915897
DOI: 10.3389/fendo.2024.1414447 -
Frontiers in Cellular Neuroscience 2024Extracellular vesicles (EVs) are secreted by all cells in the CNS, including neurons and astrocytes. EVs are lipid membrane enclosed particles loaded with various...
Extracellular vesicles (EVs) are secreted by all cells in the CNS, including neurons and astrocytes. EVs are lipid membrane enclosed particles loaded with various bioactive cargoes reflecting the dynamic activities of cells of origin. In contrast to neurons, the specific role of EVs released by astrocytes is less well understood, partly due to the difficulty in maintaining primary astrocyte cultures in a quiescent state. The aim of this study was to establish a human serum-free astrocyte culture system that maintains primary astrocytes in a quiescent state to study the morphology, function, and protein cargoes of astrocyte-derived EVs. Serum-free medium with G5 supplement and serum-supplemented medium with 2% FBS were compared for the culture of commercially available human primary fetal astrocytes. Serum-free astrocytes displayed morphologies similar to astrocytes, and surprisingly, higher levels of astrocyte markers compared to astrocytes chronically cultured in FBS. In contrast, astrocyte and inflammatory markers in serum-free astrocytes were upregulated 24 h after either acute 2% FBS or cytokine exposure, confirming their capacity to become reactive. Importantly, this suggests that distinct signaling pathways are involved in acute and chronic astrocyte reactivity. Despite having a similar morphology, chronically serum-cultured astrocyte-derived EVs (ADEVs) were smaller in size compared to serum-free ADEVs and could reactivate serum-free astrocytes. Proteomic analysis identified distinct protein datasets for both types of ADEVs with enrichment of complement and coagulation cascades for chronically serum-cultured astrocyte-derived EVs, offering insights into their roles in the CNS. Collectively, these results suggest that human primary astrocytes cultured in serum-free medium bear similarities with quiescent astrocytes and the addition of serum induces multiple morphological and transcriptional changes that are specific to human reactive astrocytes and their ADEVs. Thus, more emphasis should be made on using multiple structural, molecular, and functional parameters when evaluating ADEVs as biomarkers of astrocyte health.
PubMed: 38915876
DOI: 10.3389/fncel.2024.1414142 -
Drug Design, Development and Therapy 2024Catalpol, as a natural medicine small-molecule drug, has been proven to have anti-inflammatory and antioxidant pharmacological effects.
OBJECTIVE
Catalpol, as a natural medicine small-molecule drug, has been proven to have anti-inflammatory and antioxidant pharmacological effects.
METHODS
The effect of catalpol on oxidative damage of mouse epidermal fibroblast L929 model and its mechanism were investigated by using hydrogen peroxide model, CCK8 method, flow cytometry, and Western blot.
RESULTS
The effect of catalpol on Nrf2/HO-1 signaling pathway was further studied to improve oxidative stress in cell models. The results showed that catalpol had no cytotoxicity to L929 cells, and inhibited the apoptosis of L929 cells after oxidative damage in a concentration-dependent manner, thus playing a role in cell protection. The oxidative damage of cells was inhibited by up-regulating the expression of the signature protein of Nrf2/HO-1 signaling pathway and inhibiting the interstitial formation of cells.
CONCLUSION
This study is a preliminary study on the protective function of catalpol against oxidation and apoptosis in dermal fibroblasts, which can provide a theoretical basis and drug guidance for promoting skin wound healing in the later stage.
Topics: Iridoid Glucosides; NF-E2-Related Factor 2; Fibroblasts; Oxidative Stress; Animals; Mice; Signal Transduction; Heme Oxygenase-1; Dose-Response Relationship, Drug; Apoptosis; Cells, Cultured; Hydrogen Peroxide; Antioxidants; Skin; Structure-Activity Relationship; Cell Line; Membrane Proteins
PubMed: 38915869
DOI: 10.2147/DDDT.S467569