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Microbiology Spectrum Jun 2024Due to fungal diseases that threaten immunocompromised patients, along with the limited availability of antifungal agents, there is an urgent need for new antifungal...
UNLABELLED
Due to fungal diseases that threaten immunocompromised patients, along with the limited availability of antifungal agents, there is an urgent need for new antifungal compounds to treat fungal infections. Here, we aimed to identify potential antifungal drugs from natural products using the fission yeast as a model organism since it shares many features with some pathogenic fungi. Here, we identified tubeimoside I (TBMS1), an extract from Chinese herbal medicine, that showed strong antifungal activity against . To gain insight into the underlying mechanism, we performed transcriptomics analyses of cells exposed to TBMS1. A significant proportion of the differential expressed genes were involved in cell wall organization or biogenesis. Additionally, TBMS1 treatment of cells resulted in pleiotropic phenotypes, including increased sensitivity to β-glucanase, enhanced calcineurin activity, translocation of GFP-Prz1 to the nucleus, as well as enhanced dephosphorylation of Prz1, suggesting that TBMS1 disrupted cell wall integrity of cells. Notably, calcofluor staining showed that abnormal deposits of cell wall materials were observed in the septum and cell wall of the TBMS1-treated cells, which were further corroborated by electron microscopy analysis. We also found that oxidative stress might be involved in the antifungal action of TBMS1. Moreover, we confirmed the antifungal activities of TBMS1 against several clinical isolates of pathogenic fungi. Collectively, our findings suggest that TBMS1, a novel antifungal compound, exerts its antifungal activity by targeting cell walls, which may pave the way for the development of a new class of antifungals.
IMPORTANCE
Fungal infections pose a serious threat to public health and have become an emerging crisis worldwide. The development of new antifungal agents is urgently needed. Here, we identified compound tubeimoside I (TBMS1) for the first time showing strong antifungal activity, and explored the underlying mechanisms of its antifungal action by using the model yeast . Notably, we presented multiple evidence that TBMS1 exerts its antifungal activity through targeting fungal cell walls. Moreover, we verified the antifungal activities of TBMS1 against several pathogenic fungi. Our work indicated that TBMS1 may serve as a novel antifungal candidate, which provides an important foundation for designing and developing new cell wall-targeting agents for combating life-threatening fungal infections.
Topics: Cell Wall; Schizosaccharomyces; Antifungal Agents; Triterpenes; Microbial Sensitivity Tests; Saponins; Schizosaccharomyces pombe Proteins
PubMed: 38651884
DOI: 10.1128/spectrum.04047-23 -
BioRxiv : the Preprint Server For... Apr 2024Alpha-synuclein (αsyn) is an intrinsically disordered protein that aggregates in the brain in several neurodegenerative diseases collectively called synucleinopathies....
Alpha-synuclein (αsyn) is an intrinsically disordered protein that aggregates in the brain in several neurodegenerative diseases collectively called synucleinopathies. Phosphorylation of αsyn at serine 129 (PSER129) was considered rare in the healthy human brain but is enriched in pathological αsyn aggregates and is used as a specific marker for disease inclusions. However, recent observations challenge this assumption by demonstrating that PSER129 results from neuronal activity and can be readily detected in the non-diseased mammalian brain. Here, we investigated experimental conditions under which two distinct PSER129 pools, namely endogenous-PSER129 and aggregated-PSER129, could be detected and differentiated in the mammalian brain. Results showed that in the wild-type (WT) mouse brain, perfusion fixation conditions greatly influenced the detection of endogenous-PSER129, with endogenous-PSER129 being nearly undetectable after delayed perfusion fixation (30-minute and 1-hour postmortem interval). Exposure to anesthetics (e.g., Ketamine or xylazine) before perfusion did not significantly influence endogenous-PSER129 detection or levels. In situ, non-specific phosphatase calf alkaline phosphatase (CIAP) selectively dephosphorylated endogenous-PSER129 while αsyn preformed fibril (PFF)-seeded aggregates and genuine disease aggregates (Lewy pathology and Papp-Lantos bodies in Parkinson's disease and multiple systems atrophy brain, respectively) were resistant to CIAP-mediated dephosphorylation. The phosphatase resistance of aggregates was abolished by sample denaturation, and CIAP-resistant PSER129 was closely associated with proteinase K (PK)-resistant αsyn (i.e., a marker of aggregation). CIAP pretreatment allowed for highly specific detection of seeded αsyn aggregates in a mouse model that accumulates non-aggregated-PSER129. We conclude that αsyn aggregates are impervious to phosphatases, and CIAP pretreatment increases detection specificity for aggregated-PSER129, particularly in well-preserved biological samples (e.g., perfusion fixed or flash-frozen mammalian tissues) where there is a high probability of interference from endogenous-PSER129. Our findings have important implications for the mechanism of PSER129-accumulation in the synucleinopathy brain and provide a simple experimental method to differentiate endogenous-from aggregated PSER129.
PubMed: 38645137
DOI: 10.1101/2023.11.20.567854 -
Scientific Reports Apr 2024Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Macrophage-mediated innate immune responses play a crucial role in tumor...
Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. Macrophage-mediated innate immune responses play a crucial role in tumor development. This study revealed the mechanism of SHP-1 in regulating HCC progression. SHP-1 inhibits tumour development in vivo. Increasing SHP-1 expression in macrophages promotes the expression of p-SHP-1, SHP2, and p-SHP-2. In macrophages GM-CSF recruits SHP-2 to the GM-CSF receptor GM-CSFR induces p-SHP-2 dephosphorylation. GM-CSF recruits p-SHP-2 for dephosphorylation by up-regulating HoxA10HOXA10 activates the transcription of TGFβ2 by interacting with tandem cis-elements in the promoter thereby regulating the proliferation and migration of liver cancer cells. GM-CSF inhibits SHP-1 regulation of p-SHP-1, SHP2, and p-SHP-2 in macrophages. Detailed studies have shown that SHP-1 regulates SHP2 expression, and SHP-1 and SHP2 are involved in macrophage M2 polarisation. SHP-1 inhibits HOXA10 and TGFβ2 which in turn regulates the expression of the migration-associated proteins, MMP2/9, and the migration of hepatocellular carcinoma cells. Overexpression of SHP-1 inhibits macrophage M2 polarisation via the p-STAT3/6 signalling pathway Classical markers arginase-1, CD206, CD163 and regulate the expression of M2 polarisation cytokines IL-4 and IL-10. In addition, hypoxia-induced ROS inhibited SHP-1 regulation by suppressing the expression of p-SHP-1. The combined effect of GM-CSF and ROS significantly increased p-HOXA10/TGFβ2 and macrophage M2 polarisation, and the regulatory effect of ROS was significantly suppressed by GM-CSF knockdown. These findings suggest that increasing the expression of tyrosine phosphatase SHP-1 can inhibit hepatocellular carcinoma progression by modulating the SHP2/GM-CSF pathway in TAM and thus inhibit the progression of hepatocellular carcinoma.
Topics: Carcinoma, Hepatocellular; Liver Neoplasms; Protein Tyrosine Phosphatase, Non-Receptor Type 6; Granulocyte-Macrophage Colony-Stimulating Factor; Protein Tyrosine Phosphatase, Non-Receptor Type 11; Humans; Animals; Macrophages; Mice; Signal Transduction; Disease Progression; Cell Line, Tumor; Cell Proliferation; Cell Movement; Gene Expression Regulation, Neoplastic
PubMed: 38644382
DOI: 10.1038/s41598-024-59725-w -
Stem Cell Research Jun 2024PPM1A is a member of the serine/threonine protein phosphatase family. It can bind to a variety of proteins to dephosphorylate them, and extensively regulates many life...
PPM1A is a member of the serine/threonine protein phosphatase family. It can bind to a variety of proteins to dephosphorylate them, and extensively regulates many life activities such as cell growth, cell stress, immune response, and tumor formation. Here we constructed a human induced pluripotent stem cell (hiPSC) line with knockout of PPM1A using CRISPR/Cas9-mediated gene targeting. This cell line exhibits normal karyotype, pluripotency, and trilineage differentiation potential, which could provide a useful cellular resource for exploring the mechanism of PPM1A in regulating downstream signaling pathways and explore the application of PPM1A in anti-tumor and anti-infection.
Topics: Humans; Induced Pluripotent Stem Cells; CRISPR-Cas Systems; Protein Phosphatase 2C; Cell Differentiation; Cell Line
PubMed: 38643711
DOI: 10.1016/j.scr.2024.103420 -
Microbiological Research Jul 2024Heme oxygenase HO-1 (HMOX) regulates cellular inflammation and apoptosis, but its role in regulation of autophagy in Mycoplasma bovis infection is unknown. The objective...
Heme oxygenase activates calcium release from the endoplasmic reticulum of bovine mammary epithelial cells to promote TFEB entry into the nucleus to reduce the intracellular load of Mycoplasma bovis.
Heme oxygenase HO-1 (HMOX) regulates cellular inflammation and apoptosis, but its role in regulation of autophagy in Mycoplasma bovis infection is unknown. The objective was to determine how the HO-1/CO- Protein kinase RNA-like endoplasmic reticulum kinase (PERK)-Ca- transcription factor EB (TFEB) signaling axis induces autophagy and regulates clearance of M. bovis by bovine mammary epithelial cells (bMECs). M. bovis inhibited autophagy and lysosomal biogenesis in bMECs and suppressed HO-1 protein and expression of related proteins, namely nuclear factor erythroid 2-related factor 2 (Nrf2) and Kelch-like ECH-associated protein 1 (keap1). Activation of HO-1 and its production of carbon monoxide (CO) were required for induction of autophagy and clearance of intracellular M. bovis. Furthermore, when HO-1 was deficient, CO sustained cellular autophagy. HO-1 activation increased intracellular calcium (Ca) and cytosolic localization activity of TFEB via PERK. Knockdown of PERK or chelation of intracellular Ca inhibited HO-1-induced M. bovis autophagy and clearance. M. bovis infection affected nuclear localization of lysosomal TFEB in the MiT/TFE transcription factor subfamily, whereas activation of HO-1 mediated dephosphorylation and intranuclear localization of TFEB, promoting autophagy, lysosomal biogenesis and autophagic clearance of M. bovis. Nuclear translocation of TFEB in HO-1 was critical to induce M. bovis transport and survival of infected bMECs. Furthermore, the HO-1/CO-PERK-Ca-TFEB signaling axis induced autophagy and M. bovis clearance, providing a viable approach to treat persistent M. bovis infections.
Topics: Animals; Cattle; Mycoplasma bovis; Autophagy; Epithelial Cells; Calcium; Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; Endoplasmic Reticulum; Mammary Glands, Animal; Cell Nucleus; Female; eIF-2 Kinase; Mycoplasma Infections; Lysosomes; Heme Oxygenase-1; Carbon Monoxide; Signal Transduction; NF-E2-Related Factor 2
PubMed: 38636241
DOI: 10.1016/j.micres.2024.127727 -
International Journal of Biological... 2024Colorectal cancer (CRC) remains one of the leading causes of cancer-related death worldwide. The poor prognosis of this malignancy is attributed mainly to the persistent...
Colorectal cancer (CRC) remains one of the leading causes of cancer-related death worldwide. The poor prognosis of this malignancy is attributed mainly to the persistent activation of cancer signaling for metastasis. Here, we showed that protein tyrosine phosphatase-like A domain containing 1 (PTPLAD1) is down-regulated in highly metastatic CRC cells and negatively associated with poor survival of CRC patients. Systematic analysis reveals that epithelial-to-mesenchymal transition (EMT) and mitochondrial fusion-to-fission (MFT) transition are two critical features for CRC patients with low expression of PTPLAD1. PTPLAD1 overexpression suppresses the metastasis of CRC and by inhibiting the Raf/ERK signaling-mediated EMT and mitofission. Mechanically, PTPLAD1 binds with PHB its middle fragment (141-178 amino acids) and induces dephosphorylation of PHB-Y259 to disrupt the interaction of PHB-Raf, resulting in the inactivation of Raf/ERK signaling. Our results unveil a novel mechanism in which Raf/ERK signaling activated in metastatic CRC induces EMT and mitochondrial fission simultaneously, which can be suppressed by PTPLAD1. This finding may provide a new paradigm for developing more effective treatment strategies for CRC.
Topics: Humans; Amino Acids; Colonic Neoplasms; Epithelial-Mesenchymal Transition; Mitochondrial Dynamics; Prohibitins; Signal Transduction; raf Kinases
PubMed: 38617530
DOI: 10.7150/ijbs.82361 -
Placenta Jun 2024Placenta-associated pregnancy complications, including pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are conditions postulated to originate from initial...
INTRODUCTION
Placenta-associated pregnancy complications, including pre-eclampsia (PE) and intrauterine growth restriction (IUGR) are conditions postulated to originate from initial failure of placentation, leading to clinical sequelae indicative of endothelial dysfunction. Vascular smooth muscle aberrations have also been implicated in the pathogenesis of both disorders via smooth muscle contractility and relaxation mediated by Myosin Light Chain Phosphatase (MLCP) and the oppositional contractile action of Myosin Light Chain Kinase. PPP1R12A is a constituent part of the MLCP complex responsible for dephosphorylation of myosin fibrils. We hypothesize that alternative splicing of micro-exons result in isoforms lacking the functional leucine zipper (LZ) domain which may give those cells expressing these alternative transcripts a tendency towards contraction and vasoconstriction.
METHODS
Expression was determined by qRT-PCR. Epigenetic profiling consisted of bisulphite-based DNA methylation analysis and ChIP for underlying histone modifications.
RESULTS
We identified several novel transcripts with alternative micro-exon inclusion that would produce LZ- PPP1R12A protein. qRT-PCR revealed some isoforms, including the PPP1R12A canonical transcript, are differentially expressed in placenta biopsies from PE and IUGR samples compared to uncomplicated pregnancies.
DISCUSSION
We propose that upregulation of PPP1R12A expression in complicated pregnancies may be due to enhanced promoter activity leading to increased transcription as a response to physiological stress in the placenta, which we show is independent of promoter DNA methylation.
Topics: Female; Humans; Pregnancy; Alternative Splicing; Fetal Growth Retardation; Placenta; Myosin-Light-Chain Phosphatase; Pre-Eclampsia; Exons; DNA Methylation; Adult
PubMed: 38615553
DOI: 10.1016/j.placenta.2024.04.005 -
Heliyon Apr 2024Non-alcoholic fatty liver disease (NAFLD) stands as a predominant chronic liver ailment globally, yet its pathogenesis remains elusive. This study aims to identify Hub...
BACKGROUND
Non-alcoholic fatty liver disease (NAFLD) stands as a predominant chronic liver ailment globally, yet its pathogenesis remains elusive. This study aims to identify Hub mitophagy-related genes (MRGs), and explore the underlying pathological mechanisms through which these hub genes regulate NAFLD.
METHODS
A total of 3 datasets were acquired from the GEO database and integrated to identify differentially expressed genes (DEGs) in NAFLD and perform Gene Set Enrichment Analysis (GSEA). By intersecting DEGs with MRGs, mitophagy-related differentially expressed genes (MRDEGs) were obtained. Then, hub MRGs with diagnostic biomarker capability for NAFLD were screened and a diagnostic prediction model was constructed and assessed using Nomogram, Decision Curve Analysis (DCA), and ROC curves. Functional enrichment analysis was conducted on the identified hub genes to explore their biological significance. Additionally, regulatory networks were constructed using databases. NAFLD was stratified into high and low-risk groups based on the Riskscore from the diagnostic prediction model. Furthermore, single-sample gene set enrichment analysis (ssGSEA) and CIBERSORT algorithms were employed to analyze immune cell infiltration patterns and the relationship between Hub MRGs and immune cells.
RESULTS
The integrated dataset comprised 122 NAFLD samples and 31 control samples. After screening, 18 MRDEGs were identified. Subsequently, six hub MRGs (NR4A1, PPP2R2A, P4HA1, TUBB6, DUSP1, NAMPT) with diagnostic potential were selected through WGCNA, logistic regression, SVM, RF, and LASSO models, all significantly downregulated in NAFLD samples compared to the control group. A diagnostic prediction model based on these six genes demonstrated robust predictive performance. Functional enrichment analysis of the six hub genes revealed involvement in processes such as protein phosphorylation or dephosphorylation. Correlation analysis demonstrated a significant association between hub MRGs and infiltrating immune cells.
CONCLUSION
We identified six hub MRGs in NAFLD and constructed a diagnostic prediction model based on these six genes, applicable for early NAFLD diagnosis. These genes may participate in regulating NAFLD progression through the modulation of mitophagy and immune activation. Our findings may contribute to subsequent clinical and basic research on NAFLD.
PubMed: 38601640
DOI: 10.1016/j.heliyon.2024.e28935 -
IScience Apr 2024To investigate the phosphorylation-based signaling and protein changes occurring early in epileptogenesis, the hippocampi of mice treated with pilocarpine were examined...
To investigate the phosphorylation-based signaling and protein changes occurring early in epileptogenesis, the hippocampi of mice treated with pilocarpine were examined by quantitative mass spectrometry at 4 and 24 h post-status epilepticus at vast depth. Hundreds of posttranscriptional regulatory proteins were the major early targets of increased phosphorylation. At 24 h, many protein level changes were detected and the phosphoproteome continued to be perturbed. The major targets of decreased phosphorylation at 4 and 24 h were a subset of postsynaptic density scaffold proteins, ion channels, and neurotransmitter receptors. Many proteins targeted by dephosphorylation at 4 h also had decreased protein abundance at 24 h, indicating a phosphatase-mediated weakening of synapses. Increased translation was indicated by protein changes at 24 h. These observations, and many additional indicators within this multiomic resource, suggest that early epileptogenesis is characterized by signaling that stimulates both growth and a homeostatic response that weakens excitability.
PubMed: 38600976
DOI: 10.1016/j.isci.2024.109534 -
The Biochemical Journal Apr 2024The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status. When activated by increases in ADP:ATP and/or AMP:ATP ratios (signalling energy deficit),...
The AMP-activated protein kinase (AMPK) is a sensor of cellular energy status. When activated by increases in ADP:ATP and/or AMP:ATP ratios (signalling energy deficit), AMPK acts to restore energy balance. Binding of AMP to one or more of three CBS repeats (CBS1, CBS3, CBS4) on the AMPK-γ subunit activates the kinase complex by three complementary mechanisms: (i) promoting α-subunit Thr172 phosphorylation by the upstream kinase LKB1; (ii) protecting against Thr172 dephosphorylation; (iii) allosteric activation. Surprisingly, binding of ADP has been reported to mimic the first two effects, but not the third. We now show that at physiologically relevant concentrations of Mg.ATP2- (above those used in the standard assay) ADP binding does cause allosteric activation. However, ADP causes only a modest activation because (unlike AMP), at concentrations just above those where activation becomes evident, ADP starts to cause competitive inhibition at the catalytic site. Our results cast doubt on the physiological relevance of the effects of ADP and suggest that AMP is the primary activator in vivo. We have also made mutations to hydrophobic residues involved in binding adenine nucleotides at each of the three γ subunit CBS repeats of the human α2β2γ1 complex and examined their effects on regulation by AMP and ADP. Mutation of the CBS3 site has the largest effects on all three mechanisms of AMP activation, especially at lower ATP concentrations, while mutation of CBS4 reduces the sensitivity to AMP. All three sites appear to be required for allosteric activation by ADP.
Topics: Adenosine Diphosphate; Adenosine Monophosphate; Humans; Allosteric Regulation; AMP-Activated Protein Kinases; Ligands; Phosphorylation; Adenosine Triphosphate; Enzyme Activation; Protein Binding
PubMed: 38592738
DOI: 10.1042/BCJ20240082