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1.
Cell ; 150(4): 685-96, 2012 Aug 17.
Article in English | MEDLINE | ID: mdl-22901803

ABSTRACT

Tumor-specific pyruvate kinase M2 (PKM2) is essential for the Warburg effect. In addition to its well-established role in aerobic glycolysis, PKM2 directly regulates gene transcription. However, the mechanism underlying this nonmetabolic function of PKM2 remains elusive. We show here that PKM2 directly binds to histone H3 and phosphorylates histone H3 at T11 upon EGF receptor activation. This phosphorylation is required for the dissociation of HDAC3 from the CCND1 and MYC promoter regions and subsequent acetylation of histone H3 at K9. PKM2-dependent histone H3 modifications are instrumental in EGF-induced expression of cyclin D1 and c-Myc, tumor cell proliferation, cell-cycle progression, and brain tumorigenesis. In addition, levels of histone H3 T11 phosphorylation correlate with nuclear PKM2 expression levels, glioma malignancy grades, and prognosis. These findings highlight the role of PKM2 as a protein kinase in its nonmetabolic functions of histone modification, which is essential for its epigenetic regulation of gene expression and tumorigenesis.


Subject(s)
Astrocytoma/metabolism , Carrier Proteins/metabolism , Cell Transformation, Neoplastic , Gene Expression Regulation, Neoplastic , Glioblastoma/metabolism , Histones/metabolism , Membrane Proteins/metabolism , Thyroid Hormones/metabolism , Animals , Astrocytoma/genetics , Cell Line , Cell Line, Tumor , Cyclin D1/genetics , Cyclin D1/metabolism , Epidermal Growth Factor/metabolism , Epigenesis, Genetic , Female , Glioblastoma/genetics , Humans , Mice , Mice, Nude , Neoplasm Transplantation , Proto-Oncogene Proteins c-myc/genetics , Transcription, Genetic , Transplantation, Heterologous , Thyroid Hormone-Binding Proteins
2.
Mol Cell ; 76(1): 148-162.e7, 2019 10 03.
Article in English | MEDLINE | ID: mdl-31447391

ABSTRACT

The rapid proliferation of cancer cells and dysregulated vasculature within the tumor leads to limited nutrient accessibility. Cancer cells often rewire their metabolic pathways for adaption to nutrient stress, and the underlying mechanism remains largely unknown. Glutamate dehydrogenase 1 (GDH1) is a key enzyme in glutaminolysis that converts glutamate to α-ketoglutarate (α-KG). Here, we show that, under low glucose, GDH1 is phosphorylated at serine (S) 384 and interacts with RelA and IKKß. GDH1-produced α-KG directly binds to and activates IKKß and nuclear factor κB (NF-κB) signaling, which promotes glucose uptake and tumor cell survival by upregulating GLUT1, thereby accelerating gliomagenesis. In addition, GDH1 S384 phosphorylation correlates with the malignancy and prognosis of human glioblastoma. Our finding reveals a unique role of α-KG to directly regulate signal pathway, uncovers a distinct mechanism of metabolite-mediated NF-κB activation, and also establishes the critical role of α-KG-activated NF-κB in brain tumor development.


Subject(s)
Brain Neoplasms/metabolism , Cell Proliferation , Energy Metabolism , Glioblastoma/metabolism , Glucose/metabolism , Glutamate Dehydrogenase/metabolism , Ketoglutaric Acids/metabolism , NF-kappa B/metabolism , Adolescent , Adult , Aged , Aged, 80 and over , Animals , Brain Neoplasms/genetics , Brain Neoplasms/pathology , Cell Line, Tumor , Cell Survival , Child , Female , Gene Expression Regulation, Neoplastic , Glioblastoma/genetics , Glioblastoma/pathology , Glucose/deficiency , Glucose Transporter Type 1/genetics , Glucose Transporter Type 1/metabolism , Glutamate Dehydrogenase/genetics , HEK293 Cells , Humans , I-kappa B Kinase/genetics , I-kappa B Kinase/metabolism , Male , Mice, Inbred BALB C , Mice, Nude , Middle Aged , NF-kappa B/genetics , Neoplasm Grading , Phosphorylation , Signal Transduction , Transcription Factor RelA/genetics , Transcription Factor RelA/metabolism , Young Adult
3.
Mol Cell ; 71(2): 201-215.e7, 2018 07 19.
Article in English | MEDLINE | ID: mdl-30029001

ABSTRACT

Macrophages are a dominant leukocyte population in the tumor microenvironment and actively promote cancer progression. However, the molecular mechanism underlying the role of macrophages remains poorly understood. Here we show that polarized M2 macrophages enhance 3-phosphoinositide-dependent protein kinase 1 (PDPK1)-mediated phosphoglycerate kinase 1 (PGK1) threonine (T) 243 phosphorylation in tumor cells by secreting interleukin-6 (IL-6). This phosphorylation facilitates a PGK1-catalyzed reaction toward glycolysis by altering substrate affinity. Inhibition of PGK1 T243 phosphorylation or PDPK1 in tumor cells or neutralization of macrophage-derived IL-6 abrogates macrophage-promoted glycolysis, proliferation, and tumorigenesis. In addition, PGK1 T243 phosphorylation correlates with PDPK1 activation, IL-6 expression, and macrophage infiltration in human glioblastoma multiforme (GBM). Moreover, PGK1 T243 phosphorylation also correlates with malignance and prognosis of human GBM. Our findings demonstrate a novel mechanism of macrophage-promoted tumor growth by regulating tumor cell metabolism, implicating the therapeutic potential to disrupt the connection between macrophages and tumor cells by inhibiting PGK1 phosphorylation.


Subject(s)
Macrophages/metabolism , Phosphoglycerate Kinase/genetics , Phosphoglycerate Kinase/metabolism , 3-Phosphoinositide-Dependent Protein Kinases/genetics , 3-Phosphoinositide-Dependent Protein Kinases/metabolism , Animals , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Carcinogenesis/metabolism , Cell Line, Tumor , Cell Proliferation , Cell Transformation, Neoplastic/metabolism , Cell Transformation, Neoplastic/pathology , Female , Glioblastoma/genetics , Glioblastoma/metabolism , Glioblastoma/pathology , Glycolysis , Humans , Macrophages/pathology , Mice , Mice, Nude , Multiple Myeloma/genetics , Multiple Myeloma/metabolism , Multiple Myeloma/pathology , Phosphorylation , Prognosis , Tumor Microenvironment
4.
Nature ; 571(7763): 127-131, 2019 07.
Article in English | MEDLINE | ID: mdl-31243371

ABSTRACT

Cancer metastasis is the primary cause of morbidity and mortality, and accounts for up to 95% of cancer-related deaths1. Cancer cells often reprogram their metabolism to efficiently support cell proliferation and survival2,3. However, whether and how those metabolic alterations contribute to the migration of tumour cells remain largely unknown. UDP-glucose 6-dehydrogenase (UGDH) is a key enzyme in the uronic acid pathway, and converts UDP-glucose to UDP-glucuronic acid4. Here we show that, after activation of EGFR, UGDH is phosphorylated at tyrosine 473 in human lung cancer cells. Phosphorylated UGDH interacts with Hu antigen R (HuR) and converts UDP-glucose to UDP-glucuronic acid, which attenuates the UDP-glucose-mediated inhibition of the association of HuR with SNAI1 mRNA and therefore enhances the stability of SNAI1 mRNA. Increased production of SNAIL initiates the epithelial-mesenchymal transition, thus promoting the migration of tumour cells and lung cancer metastasis. In addition, phosphorylation of UGDH at tyrosine 473 correlates with metastatic recurrence and poor prognosis of patients with lung cancer. Our findings reveal a tumour-suppressive role of UDP-glucose in lung cancer metastasis and uncover a mechanism by which UGDH promotes tumour metastasis by increasing the stability of SNAI1 mRNA.


Subject(s)
Lung Neoplasms/genetics , Lung Neoplasms/pathology , Neoplasm Metastasis/genetics , Neoplasm Metastasis/prevention & control , RNA Stability , Snail Family Transcription Factors/genetics , Uridine Diphosphate Glucose/metabolism , Animals , Cell Line, Tumor , Cell Movement , ELAV-Like Protein 1/deficiency , ELAV-Like Protein 1/genetics , ELAV-Like Protein 1/metabolism , Epithelial-Mesenchymal Transition , Female , Humans , Lung Neoplasms/enzymology , Lung Neoplasms/metabolism , Mice , Mice, Nude , Phosphotyrosine/metabolism , Prognosis , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Neoplasm/genetics , RNA, Neoplasm/metabolism , Snail Family Transcription Factors/biosynthesis , Uridine Diphosphate Glucose Dehydrogenase/chemistry , Uridine Diphosphate Glucose Dehydrogenase/genetics , Uridine Diphosphate Glucose Dehydrogenase/metabolism , Uridine Diphosphate Glucuronic Acid/metabolism
5.
PLoS Genet ; 18(9): e1010389, 2022 09.
Article in English | MEDLINE | ID: mdl-36121836

ABSTRACT

Phosphorothioation (PT), in which a non-bridging oxygen is replaced by a sulfur, is one of the rare modifications discovered in bacteria and archaea that occurs on the sugar-phosphate backbone as opposed to the nucleobase moiety of DNA. While PT modification is widespread in the prokaryotic kingdom, how PT modifications are distributed in the genomes and their exact roles in the cell remain to be defined. In this study, we developed a simple and convenient technique called EcoWI-seq based on a modification-dependent restriction endonuclease to identify genomic positions of PT modifications. EcoWI-seq shows similar performance than other PT modification detection techniques and additionally, is easily scalable while requiring little starting material. As a proof of principle, we applied EcoWI-seq to map the PT modifications at base resolution in the genomes of both the Salmonella enterica cerro 87 and E. coli expressing the dnd+ gene cluster. Specifically, we address whether the partial establishment of modified PT positions is a stochastic or deterministic process. EcoWI-seq reveals a systematic usage of the same subset of target sites in clones for which the PT modification has been independently established.


Subject(s)
Escherichia coli , Salmonella enterica , DNA/genetics , DNA Restriction Enzymes , DNA, Bacterial/genetics , Escherichia coli/genetics , High-Throughput Nucleotide Sequencing , Oxygen , Phosphates , Salmonella enterica/genetics , Sugars , Sulfur
6.
Anal Chem ; 96(24): 10028-10037, 2024 Jun 18.
Article in English | MEDLINE | ID: mdl-38853671

ABSTRACT

Nucleic acids play a pivotal role in the diagnosis of diseases. However, rapid, cost-efficient, and ultrasensitive identification of nucleic acid targets still represents a significant challenge. Herein, we describe an enzyme-free DNA amplification method capable of achieving accurate and ultrasensitive nucleic acid detection via DNA-templated click ligation chain reaction (DT-CLCR) catalyzed by a heterogeneous nanocatalyst made of Cu2O (hnCu2O). This hnCu2O-DT-CLCR method is built on two cross-amplifying hnCu2O-catalyzed DNA-templated azide-alkyne cycloaddition-driven DNA ligation reactions that boast a fast reaction rate and a high DNA ligation yield in minutes, enabling rapid exponential amplification of specific DNA targets. This newly developed hnCu2O-DT-CLCR-enabled DNA amplification strategy is further integrated with two signal reporting mechanisms to achieve low-cost and easy-to-use biosensors: an electrochemical sensor through the conjugation of a methylene blue redox reporter to a DNA probe used in hnCu2O-DT-CLCR and a colorimetric sensor through the incorporation of the split-to-intact G-quadruplex DNAzyme encoded into hnCu2O-DT-CLCR. Both sensors are able to achieve specific detection of the intended DNA target with a limit of detection at aM ranges, even when challenged in complex biological matrices. The combined hnCu2O-DT-CLCR and sensing strategies offer attractive universal platforms for enzyme-free and yet efficient detection of specific nucleic acid targets.


Subject(s)
Click Chemistry , Copper , DNA , Nucleic Acid Amplification Techniques , Copper/chemistry , DNA/chemistry , Catalysis , Humans , Biosensing Techniques/methods , Limit of Detection , DNA, Catalytic/chemistry , DNA, Catalytic/metabolism , Azides/chemistry , Colorimetry/methods , Electrochemical Techniques/methods , Cycloaddition Reaction
7.
J Clin Microbiol ; : e0015424, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38809033

ABSTRACT

The increasing use of ceftazidime-avibactam has led to the emergence of a wide range of ceftazidime-avibactam-resistant blaKPC-2 variants. Particularly, the conventional carbapenemase phenotypic assay exhibited a high false-negative rate for KPC-2 variants. In this study, three colloidal gold immunoassays, including the Gold Mountainriver CGI test, Dynamiker CGI test and NG-Test CARBA5, and GeneXpert Carba-R, were used to detect the presence of KPC-2 carbapenemase and its various variants in 42 Klebsiella pneumoniae strains. These strains covered blaKPC-2 (13/42) and 16 other blaKPC-2 variants including blaKPC-12 (1/42), blaKPC-23 (1/42), blaKPC-25 (1/42), blaKPC-33 (6/42), blaKPC-35 (1/42), blaKPC-44 (1/42), blaKPC-71 (1/42), blaKPC-76 (8/42), blaKPC-78 (1/42), blaKPC-79 (1/42), blaKPC-100 (1/42), blaKPC-127 (1/42), blaKPC-128 (1/42), blaKPC-144 (1/42), blaKPC-157 (2/42), and blaKPC-180 (1/42). For KPC-2 strains, all four assays showed 100% negative percentage agreement (NPA) and 100% positive percentage agreement (PPA) with sequencing results. For all 16 KPC-2 variants, GeneXpert Carba-R showed 100% NPA and 100% PPA, and the three colloidal gold immunoassays showed 100% NPA, while the PPAs of the Gold Mountainriver CGI test, Dynamiker CGI test, and NG-Test CARBA5 were 87.5%, 87.5%, and 68.8%, respectively. We also found a correlation between the mutation site in the amino acid of the variants and false-negative results by colloidal gold immunoassays. In conclusion, the GeneXpert Carba-R has been proven to be a reliable method in detecting KPC-2 and its variants, and the colloidal gold immunoassay tests offer a practical and cost-effective approach for their detection. For the sample with a negative result by a colloidal gold immunoassay test but not matching the drug-resistant phenotype, it is recommended to retest using another type of kit or the GeneXpert Carba-R assay, which can significantly improve the accuracy of detection.

8.
Nat Chem Biol ; 18(10): 1087-1095, 2022 10.
Article in English | MEDLINE | ID: mdl-35879546

ABSTRACT

Oncogenic Kras-activated pancreatic ductal adenocarcinoma (PDAC) cells highly rely on an unconventional glutamine catabolic pathway to sustain cell growth. However, little is known about how this pathway is regulated. Here we demonstrate that Kras mutation induces cellular O-linked ß-N-acetylglucosamine (O-GlcNAc), a prevalent form of protein glycosylation. Malate dehydrogenase 1 (MDH1), a key enzyme in the glutamine catabolic pathway, is positively regulated by O-GlcNAcylation on serine 189 (S189). Molecular dynamics simulations suggest that S189 glycosylation on monomeric MDH1 enhances the stability of the substrate-binding pocket and strengthens the substrate interactions by serving as a molecular glue. Depletion of O-GlcNAcylation reduces MDH1 activity, impairs glutamine metabolism, sensitizes PDAC cells to oxidative stress, decreases cell proliferation and inhibits tumor growth in nude mice. Furthermore, O-GlcNAcylation levels of MDH1 are elevated in clinical PDAC samples. Our study reveals that O-GlcNAcylation contributes to pancreatic cancer growth by regulating the metabolic activity of MDH1.


Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Acetylglucosamine/metabolism , Animals , Carcinoma, Pancreatic Ductal/genetics , Carcinoma, Pancreatic Ductal/pathology , Cell Line, Tumor , Glutamine/metabolism , Malate Dehydrogenase/metabolism , Mice , Mice, Nude , N-Acetylglucosaminyltransferases/genetics , N-Acetylglucosaminyltransferases/metabolism , Pancreatic Neoplasms/genetics , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Serine/metabolism , Pancreatic Neoplasms
9.
FASEB J ; 37(4): e22881, 2023 04.
Article in English | MEDLINE | ID: mdl-36934380

ABSTRACT

Obesity is a major contributing factor for metabolic-associated fatty liver disease (MAFLD). Fibroblast growth factor (FGF) 1 is the first paracrine FGF family member identified to exhibit promising metabolic regulatory properties capable of conferring glucose-lowering and insulin-sensitizing effect. This study explores the role and molecular underpinnings of FGF1 in obesity-associated hepatic steatosis. In a mouse high-fat diet (HFD)-induced MAFLD model, chronic treatment with recombinant FGF1(rFGF1) was found to effectively reduce the severity of insulin resistance, hyperlipidemia, and inflammation. FGF1 treatment decreased lipid accumulation in the mouse liver and palmitic acid-treated AML12 cells. These effects were associated with decreased mature form SREBF1 expression and its target genes FASN and SCD1. Interestingly, we uncovered that rFGF1 significantly induced IGFBP2 expression at both mRNA and protein levels in HFD-fed mouse livers and cultured hepatocytes treated with palmitic acid. Adeno-associated virus-mediated IGFBP2 suppression significantly diminished the therapeutic benefit of rFGF1 on MAFLD-associated phenotypes, indicating that IGFBP2 plays a crucial role in the FGF1-mediated reduction of hepatic steatosis. Further analysis revealed that rFGF1 treatment reduces the recruitment of DNA methyltransferase 3 alpha to the IGFBP2 genomic locus, leading to decreased IGFBP2 gene methylation and increased mRNA and protein expression. Collectively, our findings reveal FGF1 modulation of lipid metabolism via epigenetic regulation of IGFBP2 expression, and unravel the therapeutic potential of the FGF1-IGFBP2 axis in metabolic diseases associated with obesity.


Subject(s)
Fibroblast Growth Factor 1 , Insulin Resistance , Insulin-Like Growth Factor Binding Protein 2 , Non-alcoholic Fatty Liver Disease , Obesity , Animals , Mice , Diet, High-Fat/adverse effects , Disease Models, Animal , Epigenesis, Genetic , Fibroblast Growth Factor 1/pharmacology , Liver/metabolism , Mice, Inbred C57BL , Non-alcoholic Fatty Liver Disease/complications , Non-alcoholic Fatty Liver Disease/metabolism , Obesity/complications , Palmitic Acid/pharmacology , Insulin-Like Growth Factor Binding Protein 2/genetics , Recombinant Proteins/pharmacology , Lipid Mobilization
10.
Cell Commun Signal ; 22(1): 278, 2024 May 18.
Article in English | MEDLINE | ID: mdl-38762737

ABSTRACT

BACKGROUND: While de novo cholesterol biosynthesis plays a crucial role in chemotherapy resistance of colorectal cancer (CRC), the underlying molecular mechanism remains poorly understood. METHODS: We conducted cell proliferation assays on CRC cells with or without depletion of squalene epoxidase (SQLE), with or without 5-fluorouracil (5-FU) treatment. Additionally, a xenograft mouse model was utilized to explore the impact of SQLE on the chemosensitivity of CRC to 5-FU. RNA-sequencing analysis and immunoblotting analysis were performed to clarify the mechanism. We further explore the effect of SQLE depletion on the ubiquitin of NF-κB inhibitor alpha (IκBα) and (S)-2,3-epoxysqualene on the binding of IκBα to beta-transducin repeat containing E3 ubiquitin protein ligase (BTRC) by using immunoprecipitation assay. In addition, a cohort of 272 CRC patients were selected for our clinical analyses. RESULTS: Mechanistically, (S)-2,3-epoxysqualene promotes IκBα degradation and subsequent NF-κB activation by enhancing the interaction between BTRC and IκBα. Activated NF-κB upregulates the expression of baculoviral IAP repeat containing 3 (BIRC3), sustains tumor cell survival after 5-FU treatment and promotes 5-FU resistance of CRC in vivo. Notably, the treatment of terbinafine, an inhibitor of SQLE commonly used as antifungal drug in clinic, enhances the sensitivity of CRC to 5-FU in vivo. Additionally, the expression of SQLE is associated with the prognosis of human CRC patients with 5-FU-based chemotherapy. CONCLUSIONS: Thus, our finding not only demonstrates a new role of SQLE in chemoresistance of CRC, but also reveals a novel mechanism of (S)-2,3-epoxysqualene-dependent NF-κB activation, implicating the combined potential of terbinafine for 5-FU-based CRC treatment.


Subject(s)
Colorectal Neoplasms , Drug Resistance, Neoplasm , Fluorouracil , NF-kappa B , Squalene Monooxygenase , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/pathology , Colorectal Neoplasms/metabolism , Humans , Squalene Monooxygenase/metabolism , Squalene Monooxygenase/genetics , NF-kappa B/metabolism , Drug Resistance, Neoplasm/genetics , Drug Resistance, Neoplasm/drug effects , Animals , Fluorouracil/pharmacology , Fluorouracil/therapeutic use , Mice , Cell Line, Tumor , Mice, Nude , Mice, Inbred BALB C , Female , Male , Cell Proliferation/drug effects , NF-KappaB Inhibitor alpha/metabolism , NF-KappaB Inhibitor alpha/genetics , Xenograft Model Antitumor Assays
11.
EMBO Rep ; 23(11): e55099, 2022 11 07.
Article in English | MEDLINE | ID: mdl-36125406

ABSTRACT

Stimulator of interferon genes (STING) is an essential signaling protein that is located on the endoplasmic reticulum (ER) and triggers the production of type I interferons (IFN) and proinflammatory cytokines in response to pathogenic DNA. Aberrant activation of STING is linked to autoimmune diseases. The mechanisms underlying homeostatic regulation of STING are unclear. Here, we report that UNC13D, which is associated with familial hemophagocytic lymphohistiocytosis (FHL3), is a negative regulator of the STING-mediated innate immune response. UNC13D colocalizes with STING on the ER and inhibits STING oligomerization. Cellular knockdown and knockout of UNC13D promote the production of interferon-ß (IFN-ß) induced by DNA viruses, but not RNA viruses. Moreover, UNC13D deficiency also increases the basal level of proinflammatory cytokines. These effects are diminished by an inhibitor of STING signaling. Furthermore, the domains involved in the UNC13D/STING interaction on both proteins are mapped. Our findings provide insight into the regulatory mechanism of STING, the previously unknown cellular function of UNC13D and the potential pathogenesis of FHL3.


Subject(s)
Endoplasmic Reticulum , Interferon Type I , Endoplasmic Reticulum/metabolism , Signal Transduction , Immunity, Innate , Interferon-beta/genetics
13.
Mol Cell ; 61(5): 705-719, 2016 Mar 03.
Article in English | MEDLINE | ID: mdl-26942675

ABSTRACT

It is unclear how the Warburg effect that exemplifies enhanced glycolysis in the cytosol is coordinated with suppressed mitochondrial pyruvate metabolism. We demonstrate here that hypoxia, EGFR activation, and expression of K-Ras G12V and B-Raf V600E induce mitochondrial translocation of phosphoglycerate kinase 1 (PGK1); this is mediated by ERK-dependent PGK1 S203 phosphorylation and subsequent PIN1-mediated cis-trans isomerization. Mitochondrial PGK1 acts as a protein kinase to phosphorylate pyruvate dehydrogenase kinase 1 (PDHK1) at T338, which activates PDHK1 to phosphorylate and inhibit the pyruvate dehydrogenase (PDH) complex. This reduces mitochondrial pyruvate utilization, suppresses reactive oxygen species production, increases lactate production, and promotes brain tumorigenesis. Furthermore, PGK1 S203 and PDHK1 T338 phosphorylation levels correlate with PDH S293 inactivating phosphorylation levels and poor prognosis in glioblastoma patients. This work highlights that PGK1 acts as a protein kinase in coordinating glycolysis and the tricarboxylic acid (TCA) cycle, which is instrumental in cancer metabolism and tumorigenesis.


Subject(s)
Citric Acid Cycle , Glioblastoma/enzymology , Glycolysis , Mitochondria/enzymology , Phosphoglycerate Kinase/metabolism , Animals , Cell Hypoxia , Cell Line, Tumor , Cell Proliferation , Enzyme Activation , ErbB Receptors/genetics , ErbB Receptors/metabolism , Extracellular Signal-Regulated MAP Kinases/metabolism , Female , Glioblastoma/genetics , Glioblastoma/pathology , Humans , Mice, Nude , Mitochondria/pathology , Mutation , NIMA-Interacting Peptidylprolyl Isomerase , Peptidylprolyl Isomerase/genetics , Peptidylprolyl Isomerase/metabolism , Phosphoglycerate Kinase/genetics , Phosphorylation , Prognosis , Protein Binding , Protein Serine-Threonine Kinases/genetics , Protein Serine-Threonine Kinases/metabolism , Protein Transport , Proto-Oncogene Proteins B-raf/genetics , Proto-Oncogene Proteins B-raf/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Proto-Oncogene Proteins p21(ras)/metabolism , Pyruvate Dehydrogenase Acetyl-Transferring Kinase , Pyruvate Dehydrogenase Complex/genetics , Pyruvate Dehydrogenase Complex/metabolism , RNA Interference , Rats , Signal Transduction , Time Factors , Transfection
14.
Ecotoxicol Environ Saf ; 272: 116094, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38364759

ABSTRACT

Exposure to benzo[a]pyrene (B[a]P) has been linked to lung injury and carcinogenesis. Airway epithelial cells express the B[a]P receptor AHR, so B[a]P is considered to mainly target airway epithelial cells, whereas its potential impact on alveolar cells remains inadequately explored. Metformin, a first-line drug for diabetes, has been shown to exert anti-inflammatory and tissue repair-promoting effects under various injurious conditions. Here, we explored the effect of chronic B[a]P exposure on alveolar cells and the impact of metformin on B[a]P-induced lung injury by examining the various parameters including lung histopathology, inflammation, fibrosis, and related signal pathway activation. MLKL knockout (Mlkl-/-) and AT2-lineage tracing mice (SftpcCre-ERT2;LSL-tdTomatoflox+/-) were used to delineate the role of necroptosis in B[a]P-induced alveolar epithelial injury and repair. Mice receiving weekly administration of B[a]P for 6 weeks developed a significant alveolar damaging phenotype associated with pulmonary inflammation, fibrosis, and activation of the necroptotic cell death pathway. These effects were significantly relieved in MLKL null mice. Furthermore, metformin treatment, which were found to promote AMPK phosphorylation and inhibit RIPK3, as well as MLKL phosphorylation, also significantly alleviated B[a]P-induced necroptosis and lung injury phenotype. However, the protective efficacy of metformin was rendered much less effective in Mlkl null mice or by blocking the necroptotic pathway with RIPK3 inhibitor. Our findings unravel a potential protective efficacy of metformin in mitigating the detrimental effects of B[a]P exposure on lung health by inhibiting necroptosis and protecting AT2 cells.


Subject(s)
Benzo(a)pyrene , Lung Injury , Red Fluorescent Protein , Mice , Animals , Benzo(a)pyrene/toxicity , Protein Kinases/metabolism , Necroptosis , Lung Injury/chemically induced , Lung Injury/prevention & control , Fibrosis
15.
Ren Fail ; 46(1): 2334396, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38570195

ABSTRACT

OBJECTIVES: Calcium oxalate (CaOx) crystal deposition in acute kidney injury (AKI) patients is under recognized but impacts renal outcomes. This study investigates its determinants and effects. METHODS: We studied 814 AKI patients with native kidney biopsies from 2011 to 2020, identifying CaOx crystal deposition severity (mild: <5, moderate: 5-10, severe: >10 crystals per section). We assessed factors like urinary oxalate, citrate, urate, electrolytes, pH, tubular calcification index, and SLC26A6 expression, comparing them with creatinine-matched AKI controls without oxalosis. We analyzed how these factors relate to CaOx severity and their impact on renal recovery (eGFR < 15 mL/min/1.73 m2 at 3-month follow-up). RESULTS: CaOx crystal deposition was found in 3.9% of the AKI cohort (32 cases), with 72% due to nephrotoxic medication-induced tubulointerstitial nephritis. Diuretic use, higher urinary oxalate-to-citrate ratio induced by hypocitraturia, and tubular calcification index were significant contributors to moderate and/or severe CaOx deposition. Poor baseline renal function, low urinary chloride, high uric acid and urea nitrogen, tubular SLC26A6 overexpression, and glomerular sclerosis were also associated with moderate-to-severe CaOx deposition. Kidney recovery was delayed, with 43.8%, 31.2%, and 18.8% of patients having eGFR < 15 mL/min/1.73 m2 at 4, 12, and 24-week post-injury. Poor outcomes were linked to high urinary α1-microglobulin-to-creatinine (α1-MG/C) ratios and active tubular injury scores. Univariate analysis showed a strong link between this ratio and poor renal outcomes, independent of oxalosis severity. CONCLUSIONS: In AKI, CaOx deposition is common despite declining GFR. Factors worsening tubular injury, not just oxalate-to-citrate ratios, are key to understanding impaired renal recovery.


Subject(s)
Acute Kidney Injury , Calcinosis , Hyperoxaluria , Humans , Calcium Oxalate/chemistry , Creatinine/metabolism , Kidney/pathology , Hyperoxaluria/complications , Oxalates/metabolism , Acute Kidney Injury/pathology , Citrates/metabolism , Citric Acid
16.
Sensors (Basel) ; 24(9)2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38732893

ABSTRACT

An abnormal level of dopamine (DA), a kind of neurotransmitter, correlates with a series of diseases, including Parkinson's disease, Willis-Ekbom disease, attention deficit hyperactivity disorder, and schizophrenia. Hence, it is imperative to achieve a precise, rapid detection method in clinical medicine. In this study, we synthesized nanocomposite carbon aerogels (CAs) doped with iron and iron carbide, based on algae residue-derived biomass materials, using Fe(NO3)3 as the iron source. The modified glassy carbon electrode (GCE) for DA detection, denoted as CAs-Fe/GCE, was prepared through surface modification with this composite material. X-ray photoelectron spectroscopy and X-ray diffraction characterization confirmed the successful doping of iron into the as-prepared CAs. Additionally, the electrochemical behavior of DA on the modified electrode surface was investigated and the results demonstrate that the addition of the CAs-Fe promoted the electron transfer rate, thereby enhancing their sensing performance. The fabricated electrochemical DA biosensor exhibits an accurate detection of DA in the concentration within the range of 0.01~200 µM, with a detection limit of 0.0033 µM. Furthermore, the proposed biosensor is validated in real samples, showing its high applicability for the detection of DA in beverages.


Subject(s)
Biosensing Techniques , Carbon , Dopamine , Electrochemical Techniques , Electrodes , Iron , Biosensing Techniques/methods , Biosensing Techniques/instrumentation , Dopamine/analysis , Dopamine/chemistry , Carbon/chemistry , Iron/chemistry , Electrochemical Techniques/methods , Gels/chemistry , Limit of Detection , Photoelectron Spectroscopy , Nanocomposites/chemistry
17.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 41(6): 753-757, 2024 Jun 10.
Article in Zh | MEDLINE | ID: mdl-38818564

ABSTRACT

OBJECTIVE: To carry out genetic analysis on two families with carriers of small terminal translocations using karyotyping analysis and genomic copy number variation sequencing (CNV-seq). METHODS: Two couples undergoing prenatal diagnosis at the Tianjin Central Hospital of Obstetrics and Gynecology respectively on April 12, 2020 and December 17, 2021 were selected as the study subjects. With informed consent, amniotic fluid and peripheral blood samples were collected and subjected to conventional karyotyping and CNV-seq analysis for the detection of chromosomal microdeletion/duplications. RESULTS: Both couples had given births to children with chromosomal aberrations previously, and both fetuses were found to have abnormal karyotypes. CNV-seq showed that they had harbored microdeletion/duplications, and their mothers had both carried balanced translocations involving terminal fragments of chromosomes. CONCLUSION: For fetuses with small chromosomal segmental abnormalities, their parental origin should be traced, and the diagnosis should be confirmed with combined genetic techniques.


Subject(s)
DNA Copy Number Variations , Karyotyping , Prenatal Diagnosis , Humans , Prenatal Diagnosis/methods , Female , Pregnancy , Male , Adult , Chromosome Aberrations , Translocation, Genetic , Genetic Testing/methods , Chromosome Deletion
18.
Angew Chem Int Ed Engl ; : e202406650, 2024 May 31.
Article in English | MEDLINE | ID: mdl-38818631

ABSTRACT

Dispersion of single atoms (SAs) in the host is important for optimizing catalytic activity. Herein, we propose a novel strategy to tune oxygen vacancies in CeO2-X directionally anchoring the single atom platinum (PtSA), which is uniformly dispersed on the rGO. The catalyst's performance for the hydrogen evolution reaction (HER) can be enhanced by controlling different densities of CeO2-X in rGO. The PtSA performs best optimally densified and loaded on homogeneous and moderately densified CeO2-X/rGO (PtSA-M-CeO2-X/rGO). It exhibited high activity in HER with an overpotential of 25 mV at 0.5 M H2SO4 and 33 mV at 1 KOH than that of almost reported electrocatalysts. Furthermore, it exhibited stability for 90 hours at -100 mA cm-2 in 1 KOH and -150 mA cm-2 in 0.5 M H2SO4 conditions, respectively. Through comprehensive experiments and theoretical calculations, the suitable dispersion density of PtSA on the defects of CeO2-X with more active sites gives the potential for practical applications. This research paves the way for developing single-atom catalysts with exceptional catalytic activity and stability, holding promise in advanced green energy conversion through defects engineering.

19.
Small ; 19(41): e2302092, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37292041

ABSTRACT

Lithium-sulfur (Li-S) batteries are widely studied because of their high theoretical specific capacity and environmental friendliness. However, the further development of Li-S batteries is hindered by the shuttle effect of lithium polysulfides (LiPSs) and the sluggish redox kinetics. Since the adsorption and catalytic conversion of LiPSs mainly occur on the surface of the electrocatalyst, regulating the surface structure of electrocatalysts is an advisable strategy to solve the obstacles in Li-S batteries. Herein, CoP nanoparticles with high oxygen content on surface embedded in hollow carbon nanocages (C/O-CoP) is employed to functionalize the separators and the effect of the surface oxygen content of CoP on the electrochemical performance is systematically explored. Increasing the oxygen content on CoP surface can enhance the chemical adsorption to lithium polysulfides and accelerate the redox conversions kinetics of polysulfides. The cell with C/O-CoP modified separator can achieve the capacity of 1033 mAh g-1 and maintain 749 mAh g-1 after 200 cycles at 2 C. Moreover, DFT calculations are used to reveal the enhancement mechanism of oxygen content on surface of CoP in Li-S chemistry. This work offers a new insight into developing high-performance Li-S batteries from the perspective of surface engineering.

20.
FASEB J ; 36(9): e22488, 2022 09.
Article in English | MEDLINE | ID: mdl-35929441

ABSTRACT

DCBLD2 is a neuropilin-like transmembrane protein that is up-regulated during arterial remodeling in humans, rats, and mice. Activation of PDGFR-ß via PDGF triggers receptor phosphorylation and endocytosis. Subsequent activation of downstream signals leads to the stimulation of phenotypic conversion of VSMCs and arterial wall proliferation, which are common pathological changes in vascular remodeling diseases such as atherosclerosis, hypertension, and restenosis after angioplasty. In this study, we hypothesized that DCBLD2 regulates neointimal hyperplasia through the regulation of PDGFR-ß endocytosis of vascular smooth muscle cells (VSMCs) through Caveolin-1 (Cav-1). Compared with wild-type (WT) mice or control littermate mice, the germline or VSMC conditional deletion of the Dcbld2 gene resulted in a significant increase in the thickness of the tunica media in the carotid artery ligation. To elucidate the underlying molecular mechanisms, VSMCs were isolated from the aorta of WT or Dcbld2-/- mice and were stimulated with PDGF. Western blotting assays demonstrated that Dcbld2 deletion increased the PDGF signaling pathway. Biotin labeling test and membrane-cytosol separation test showed that after DCBLD2 was knocked down or knocked out, the level of PDGFR-ß on the cell membrane was significantly reduced, while the amount of PDGFR-ß in the cytoplasm increased. Co-immunoprecipitation experiments showed that after DCBLD2 gene knock-out, the binding of PDGFR-ß and Cav-1 in the cytoplasm significantly increased. Double immunofluorescence staining showed that PDGFR-ß accumulated Cav-1/lysosomes earlier than for control cells, which indicated that DCBLD2 gene knock-down or deletion accelerated the endocytosis of PDGF-induced PDGFR-ß in VSMCs. In order to confirm that DCBLD2 affects the relationship between Cav-1 and PDGFR-ß, proteins extracted from VSMCs cultured in vitro were derived from WT and Dcbld2-/- mice, whereas co-immunoprecipitation suggested that the combination of DCBLD2 and Cav-1 reduced the bond between Cav-1 and PDGFR-ß, and DCBLD2 knock-out was able to enhance the interaction between Cav-1 and PDGFR-ß. Therefore, the current results suggest that DCBLD2 may inhibit the caveolae-dependent endocytosis of PDGFR-ß by anchoring the receptor on the cell membrane. Based on its ability to regulate the activity of PDGFR-ß, DCBLD2 may be a novel therapeutic target for the treatment of cardiovascular diseases.


Subject(s)
Caveolin 1 , Muscle, Smooth, Vascular , Animals , Caveolin 1/genetics , Caveolin 1/metabolism , Cell Proliferation , Cells, Cultured , Endocytosis , Humans , Hyperplasia/metabolism , Membrane Proteins/metabolism , Mice , Muscle, Smooth, Vascular/metabolism , Myocytes, Smooth Muscle/metabolism , Rats , Receptor, Platelet-Derived Growth Factor beta/genetics , Receptor, Platelet-Derived Growth Factor beta/metabolism
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