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Microbiology Spectrum Jun 2024Tuberculosis (TB) is a leading cause of death among infectious diseases worldwide due to latent TB infection, which is the critical step for the successful pathogenic...
UNLABELLED
Tuberculosis (TB) is a leading cause of death among infectious diseases worldwide due to latent TB infection, which is the critical step for the successful pathogenic cycle. In this stage resides inside the host in a dormant and antibiotic-tolerant state. Latent TB infection can also lead to multisystemic diseases because invades virtually all organs, including ocular tissues. Ocular tuberculosis (OTB) occurs when the dormant bacilli within the ocular tissues reactivate, originally seeded by hematogenous spread from pulmonary TB. Histological evidence suggests that retinal pigment epithelium (RPE) cells play a central role in immune privilege and in protection from antibiotic effects, making them an anatomical niche for invading . RPE cells exhibit high tolerance to environmental redox stresses, allowing phagocytosed bacilli to maintain viability in a dormant state. However, the microbiological and metabolic mechanisms determining the interaction between the RPE intracellular environment and phagocytosed are largely unknown. Here, liquid chromatography-mass spectrometry metabolomics were used to illuminate the metabolic state within RPE cells reprogrammed to harbor dormant bacilli and enhance antibiotic tolerance. Timely and accurate diagnosis as well as efficient chemotherapies are crucial in preventing the poor visual outcomes of OTB patients. Unfortunately, the efficacy of current methods is highly limited. Thus, the results will lead to propose a novel therapeutic option to synthetically kill the dormant inside the RPE cells by modulating the phenotypic state of and laying the foundation for a new, innovative regimen for treating OTB.
IMPORTANCE
Understanding the metabolic environment within the retinal pigment epithelium (RPE) cells altered by infection with and mycobacterial dormancy is crucial to identify new therapeutic methods to cure ocular tuberculosis. The present study showed that RPE cellular metabolism is altered to foster intracellular to enter into the dormant and drug-tolerant state, thereby blunting the efficacy of anti-tuberculosis chemotherapy. RPE cells serve as an anatomical niche as the cells protect invading bacilli from antibiotic treatment. LC-MS metabolomics of RPE cells after co-treatment with HO and infection showed that the intracellular environment within RPE cells is enriched with a greater level of oxidative stress. The antibiotic tolerance of intracellular within RPE cells can be restored by a metabolic manipulation strategy such as co-treatment of antibiotic with the most downstream glycolysis metabolite, phosphoenolpyruvate.
PubMed: 38916325
DOI: 10.1128/spectrum.00788-24 -
Journal of Proteome Research Jun 2024Protein succinylation modification is a common post-translational modification (PTM) that plays an important role in bacterial metabolic regulation. In this study,...
Protein succinylation modification is a common post-translational modification (PTM) that plays an important role in bacterial metabolic regulation. In this study, quantitative analysis was conducted on the succinylated proteome of wild-type and florfenicol-resistant to investigate the mechanism of succinylation regulating antibiotic resistance. Bioinformatic analysis showed that the differentially succinylated proteins were mainly enriched in energy metabolism, and it was found that the succinylation level of phosphoenolpyruvate carboxyl kinase (PEPCK) was highly expressed in the florfenicol-resistant strain. Site-directed mutagenesis was used to mutate the lysine (K) at the succinylation site of PEPCK to glutamic acid (E) and arginine (R), respectively, to investigate the function of lysine succinylation of PEPCK in the florfenicol resistance of . The detection of site-directed mutagenesis strain viability under florfenicol revealed that the survival rate of the E mutant was significantly higher than that of the R mutant and wild type, indicating that succinylation modification of PEPCK protein may affect the resistance of to florfenicol. This study indicates the important role of PEPCK during antibiotic-resistance evolution and provides a theoretical basis for the prevention and control of vibriosis and the development of new antibiotics.
PubMed: 38904328
DOI: 10.1021/acs.jproteome.4c00085 -
International Journal of Biological... 2024Coenzyme Q (CoQ), a quinone derivative from , has antitumor capabilities. This study investigated the antitumor effect of noncytotoxic CoQ, which included NLRP3...
Coenzyme Q (CoQ), a quinone derivative from , has antitumor capabilities. This study investigated the antitumor effect of noncytotoxic CoQ, which included NLRP3 inflammasome inhibition, anti-EMT/metastasis, and metabolic reprogramming via HIF-1α inhibition, in HNSCC cells under normoxia and hypoxia. CoQ suppressed hypoxia-induced ROS-mediated HIF-1α expression in OECM-1 and SAS cells. Under normoxia and hypoxia, the inflammatory NLRP3, ASCcaspase-1, NFκB, and IL-1β expression was reduced by CoQ. CoQ reduced migration/invasion by enhancing epithelial marker E-cadherin and suppressing mesenchymal markers Twist, N-cadherin, Snail, and MMP-9, and MMP-2 expression. CoQ inhibited glucose uptake, lactate accumulation, GLUT1 levels, and HIF-1α-target gene (HK-2, PFK-1, and LDH-A) expressions that are involved in aerobic glycolysis. Notably, CoQ reduced ECAR as well as glycolysis, glycolytic capability, and glycolytic reserve and enhanced OCR, basal respiration, ATP generation, maximal respiration, and spare capacity in OECM-1 cells. Metabolomic analysis using LC-ESI-MS showed that CoQ treatment decreased the levels of glycolytic intermediates, including lactate, 2/3-phosphoglycerate, fructose 1,6-bisphosphate, and phosphoenolpyruvate, and increased the levels of TCA cycle metabolites, including citrate, isocitrate, and succinate. HIF-1α silencing reversed CoQ-mediated anti-metastasis (N-Cadherin, Snail, and MMP-9) and metabolic reprogramming (GLUT1, HK-2, and PKM-2) under hypoxia. CoQ prevents cancer stem-like characteristics (upregulated CD24 expression and downregulated CD44, ALDH1, and OCT4) under normoxia and/or hypoxia. Further, in IL-6-treated SG cells, CoQ attenuated fibrosis by inhibiting TGF-β and Collagen I expression and suppressed EMT by downregulating Slug and upregulating E-cadherin expression. Interesting, CoQ inhibited the growth of OECM-1 tumors in xenografted mice. Our results advocate CoQ for the therapeutic application against HNSCC.
Topics: Humans; NLR Family, Pyrin Domain-Containing 3 Protein; Hypoxia-Inducible Factor 1, alpha Subunit; Cell Line, Tumor; Epithelial-Mesenchymal Transition; Ubiquinone; Animals; Squamous Cell Carcinoma of Head and Neck; Mice; Inflammasomes; Warburg Effect, Oncologic; Mice, Nude; Head and Neck Neoplasms
PubMed: 38904007
DOI: 10.7150/ijbs.93943 -
Biomedicine & Pharmacotherapy =... Jun 2024To delve into the underlying mechanism of Salidroside (Sal) on the improvement of cognitive function in Parkinson's Disease (PD).
OBJECTIVE
To delve into the underlying mechanism of Salidroside (Sal) on the improvement of cognitive function in Parkinson's Disease (PD).
METHODS
The experimental mice were divided into Control group, Model group [injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)], and Model+Sal (low concentration, high concentration) group. Mouse hippocampal tissues were extracted for RNA sequencing to obtain the core pathway and core gene. Mouse plasma was prepared and analyzed by LC-MS to obtain differential metabolites. In vitro experiments were verified by immunofluorescence and lentiviral transduction.
RESULTS
ELISA signaled that Sal facilitated the reduction of neuronal damage and inflammatory reaction in mice. MPTP_Sal_Low and MPTP_Sal_High groups had high levels of glial cell derived neurotrophie factor (GDNF) expression. Differentially expressed genes (DEGs) in control group, MPTP group and MPTP_Sal_High group were identified by transcriptomic, which were classified to the mitogen-activated protein kinase (MAPK) signaling pathway, and the core gene Braf was obtained. Metabolomics manifested that the differential metabolites involved DL-tyrosine, adenosine, phosphoenolpyruvate, and L-tryptophan. In vitro experiments verified that Sal treatment inhibited the up-regulation of p-p38, p-c-Jun N-terminal kinase (JNK), and p-extracellular signal-regulated kinase (ERK) expression, and growth of neuronal protrusions. The OE-Braf group showed a significant up-regulation of the GDNF expression, a decrease in the expression of p-p38, p-JNK, and p-ERK, and a significant growth of neuronal protrusions.
CONCLUSION
Sal may exert its effects in PD through the Braf-mediated MAPK signaling pathway, which can increase GDNF expression and promote neuronal protrusion growth for the protection of neurological function and the improvement of cognitive function.
PubMed: 38901199
DOI: 10.1016/j.biopha.2024.116968 -
Current Microbiology Jun 2024Pyruvate (Pyr) is the end product of the glycolysis pathway. Pyr is also renewable and is further metabolized to produce formate, which is the precursor of H, via...
Pyruvate (Pyr) is the end product of the glycolysis pathway. Pyr is also renewable and is further metabolized to produce formate, which is the precursor of H, via pyruvate formate lyase (PFL) under anaerobic conditions. The formate is excluded and re-imported via the formate channel and is then converted to H via the formate hydrogenlyase (FHL) complex. In H producing marine vibrios, such as Vibrio tritonius and Vibrio porteresiae in the Porteresiae clade of the family Vibrionaceae, apparent but inefficient H production from Pyr has been observed. To elucidate the molecular mechanism of why this inefficient H production is observed in Pry-metabolized marine vibrio cells and how glycolysis affects those H productions of marine vibrios, the "Core Transcriptome" approach to find common gene expressions of those two major H producing Vibrio species in Pyr metabolism was first applied. In the Pyr-metabolized vibrio cells, genes for the "Phosphoenolpyruvate (PEP)-Pyruvate-Oxalate (PPO)" node, due to energy saving, and PhoB-, RhaR-, and DeoR-regulons were regulated. Interestingly, a gene responsible for oxalate/formate family antiporter was up-regulated in Pyr-metabolized cells compared to those of Glc-metabolized cells, which provides new insights into the uses of alternative formate exclusion mechanics due to energy deficiencies in Pyr-metabolized marine vibrios cells. We further discuss the contribution of the Embden-Meyerhof-Parnas (EMP) pathway to efficient H production in marine vibrios.
Topics: Hydrogen; Vibrio; Transcriptome; Glycolysis; Pyruvic Acid; Bacterial Proteins; Seawater; Gene Expression Regulation, Bacterial; Aquatic Organisms
PubMed: 38896159
DOI: 10.1007/s00284-024-03764-z -
Protein Science : a Publication of the... Jul 2024Rheostat positions, which can be substituted with various amino acids to tune protein function across a range of outcomes, are a developing area for advancing...
Rheostat positions, which can be substituted with various amino acids to tune protein function across a range of outcomes, are a developing area for advancing personalized medicine and bioengineering. Current methods cannot accurately predict which proteins contain rheostat positions or their substitution outcomes. To compare the prevalence of rheostat positions in homologs, we previously investigated their occurrence in two pyruvate kinase (PYK) isozymes. Human liver PYK contained numerous rheostat positions that tuned the apparent affinity for the substrate phosphoenolpyruvate (K) across a wide range. In contrast, no functional rheostat positions were identified in Zymomonas mobilis PYK (ZmPYK). Further, the set of ZmPYK substitutions included an unusually large number that lacked measurable activity. We hypothesized that the inactive substitution variants had reduced protein stability, precluding detection of K tuning. Using modified buffers, robust enzymatic activity was obtained for 19 previously-inactive ZmPYK substitution variants at three positions. Surprisingly, both previously-inactive and previously-active substitution variants all had K values close to wild-type. Thus, none of the three positions were functional rheostat positions, and, unlike human liver PYK, ZmPYK's K remained poorly tunable by single substitutions. To directly assess effects on stability, we performed thermal denaturation experiments for all ZmPYK substitution variants. Many diminished stability, two enhanced stability, and the three positions showed different thermal sensitivity to substitution, with one position acting as a "stability rheostat." The differences between the two PYK homologs raises interesting questions about the underlying mechanism(s) that permit functional tuning by single substitutions in some proteins but not in others.
Topics: Humans; Zymomonas; Pyruvate Kinase; Amino Acid Substitution; Protein Stability; Bacterial Proteins; Enzyme Stability; Liver; Phosphoenolpyruvate
PubMed: 38895978
DOI: 10.1002/pro.5075 -
International Journal of Molecular... May 2024Marine natural products constitute a great source of potential new antidiabetic drugs. The aim of this study was to evaluate the role of phosphoeleganin (PE), a...
Marine natural products constitute a great source of potential new antidiabetic drugs. The aim of this study was to evaluate the role of phosphoeleganin (PE), a polyketide purified from the Mediterranean ascidian , and its derivatives PE/2 and PE/3 on insulin sensitivity in human hepatocellular carcinoma (HepG2) cells. In our experiments, insulin stimulates the phosphorylation of its receptor (INSR) and AKT by 1.5- and 3.5-fold, respectively, whereas in the presence of PE, PE/2, and PE/3, the insulin induced INSR phosphorylation is increased by 2.1-, 2-, and 1.5-fold and AKT phosphorylation by 7.1-, 6.0-, and 5.1-fold, respectively. Interestingly, PE and PE/2 have an additive effect on insulin-mediated reduction of phosphoenolpyruvate carboxykinase (PEPCK) expression. Finally, PE and PE/2, but not PE/3, decrease interleukin 6 (IL6) secretion and expression before and after palmitic acid incubation, while in the presence of high glucose (HG), only PE reduces IL6. Levels of other cytokines are not significantly affected by PE and its derivates. All these data suggest that PE and its synthetic-derived compound, PE/2, significantly decrease IL6 and improve hepatic insulin signaling. As IL6 impairs insulin action, it could be hypothesized that PE and PE/2, by inhibiting IL6, may improve the hepatic insulin pathway.
Topics: Humans; Interleukin-6; Insulin; Liver Neoplasms; Carcinoma, Hepatocellular; Signal Transduction; Hep G2 Cells; Animals; Receptor, Insulin; Phosphorylation; Proto-Oncogene Proteins c-akt; Insulin Resistance; Antigens, CD
PubMed: 38892230
DOI: 10.3390/ijms25116039 -
Scientific Reports Jun 2024Mitochondrial phosphoenolpyruvate carboxykinase (PCK2), a mitochondrial isoenzyme, supports the growth of cancer cells under glucose deficiency conditions in vitro. This...
Mitochondrial phosphoenolpyruvate carboxykinase (PCK2), a mitochondrial isoenzyme, supports the growth of cancer cells under glucose deficiency conditions in vitro. This study investigated the role and potential mechanism of PCK2 in the occurrence and development of Hepatocellular carcinoma (HCC). The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and other databases distinguish the expression of PCK2 and verified by qRT-PCR and Western blotting. Kaplan-Meier was conducted to assess PCK2 survival in HCC. The potential biological function of PCK2 was verified by enrichment analysis and gene set enrichment analysis (GSEA). The correlation between PCK2 expression and immune invasion and checkpoint was found by utilizing Tumor Immune Estimation Resource (TIMER). Lastly, the effects of PCK2 on the proliferation and metastasis of hepatocellular carcinoma cells were evaluated by cell tests, and the expressions of Epithelial mesenchymal transformation (EMT) and apoptosis related proteins were detected. PCK2 is down-regulated in HCC, indicating a poor prognosis. PCK2 gene mutation accounted for 1.3% of HCC. Functional enrichment analysis indicated the potential of PCK2 as a metabolism-related therapeutic target. Subsequently, we identified several signaling pathways related to the biological function of PCK2. The involvement of PCK2 in immune regulation was verified and key immune checkpoints were predicted. Ultimately, after PCK2 knockdown, cell proliferation and migration were significantly increased, and N-cadherin and vimentin expression were increased. PCK2 has been implicated in immune regulation, proliferation, and metastasis of hepatocellular carcinoma, and is emerging as a novel predictive biomarker and metabolic-related clinical target.
Topics: Carcinoma, Hepatocellular; Liver Neoplasms; Humans; Prognosis; Cell Proliferation; Gene Expression Regulation, Neoplastic; Cell Line, Tumor; Phosphoenolpyruvate Carboxykinase (GTP); Epithelial-Mesenchymal Transition; Mitochondria; Male; Female; Apoptosis; Cell Movement; Biomarkers, Tumor; Middle Aged; Phosphoenolpyruvate Carboxykinase (ATP)
PubMed: 38890507
DOI: 10.1038/s41598-024-64907-7 -
Veterinary Research Jun 2024Bacteria utilize intercellular communication to orchestrate essential cellular processes, adapt to environmental changes, develop antibiotic tolerance, and enhance...
Bacteria utilize intercellular communication to orchestrate essential cellular processes, adapt to environmental changes, develop antibiotic tolerance, and enhance virulence. This communication, known as quorum sensing (QS), is mediated by the exchange of small signalling molecules called autoinducers. AI-2 QS, regulated by the metabolic enzyme LuxS (S-ribosylhomocysteine lyase), acts as a universal intercellular communication mechanism across gram-positive and gram-negative bacteria and is crucial for diverse bacterial processes. In this study, we demonstrated that in Streptococcus suis (S. suis), a notable zoonotic pathogen, AI-2 QS enhances galactose utilization, upregulates the Leloir pathway for capsular polysaccharide (CPS) precursor production, and boosts CPS synthesis, leading to increased resistance to macrophage phagocytosis. Additionally, our molecular docking and dynamics simulations suggest that, similar to S. pneumoniae, FruA, a fructose-specific phosphoenolpyruvate phosphotransferase system prevalent in gram-positive pathogens, may also function as an AI-2 membrane surface receptor in S. suis. In conclusion, our study demonstrated the significance of AI-2 in the synthesis of galactose metabolism-dependent CPS in S. suis. Additionally, we conducted a preliminary analysis of the potential role of FruA as a membrane surface receptor for S. suis AI-2.
Topics: Streptococcus suis; Galactose; Quorum Sensing; Virulence; Animals; Bacterial Capsules; Lactones; Streptococcal Infections; Homoserine; Polysaccharides, Bacterial
PubMed: 38886823
DOI: 10.1186/s13567-024-01335-5 -
Plant Physiology and Biochemistry : PPB Jun 2024The phosphoenolpyruvate carboxylase kinase of Medicago sativa L. (MsPPCK1) modulates the phosphorylation status and activity of the C4 pathway phosphoenolpyruvate...
Overexpression of phosphoenolpyruvate carboxylase kinase gene MsPPCK1 from Medicago sativa L. increased alkali tolerance of alfalfa by enhancing photosynthetic efficiency and promoting nodule development.
The phosphoenolpyruvate carboxylase kinase of Medicago sativa L. (MsPPCK1) modulates the phosphorylation status and activity of the C4 pathway phosphoenolpyruvate carboxylase enzyme, which is pivotal for photosynthetic carbon assimilation in plants. This study investigated the role of MsPPCK1 in alfalfa by creating transgenic plants overexpressing MsPPCK1 under the control of the CaMV35S promoter. The enhanced alkali tolerance of transgenic plants indicated an important role of MsPPCK1 gene in regulating plant alkali tolerance. Transgenic plants exhibited heightened antioxidant activity (SOD, POD, and CAT), reduced MDA, HO, OFR and REC% content, increased activity of key photosynthetic enzymes (PEPC, PPDK, NADP-ME, and NADP-MDH), and enhanced photosynthetic parameters (Pn, E, Gs, and Ci). Moreover, MsPPCK1 overexpression increased the content of organic acids (oxaloacetic, malic, citric, and succinic acids) in the plants. The upregulation of MsPPCK1 under rhizobial inoculation showcased its other role in nodule development. In transgenic plants, MsDMI2, MsEnod12, and MsNODL4 expression increased, facilitating root nodule development and augmenting plant nodulation. Accelerated root nodule growth positively influences plant growth and yield and enhances alfalfa resistance to alkali stress. This study highlights the pivotal role of MsPPCK1 in fortifying plant alkali stress tolerance and improving yield, underscoring its potential as a key genetic target for developing alkali-tolerant and high-yielding alfalfa varieties.
PubMed: 38879983
DOI: 10.1016/j.plaphy.2024.108764