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1.
J Infect Dis ; 2024 Apr 24.
Article in English | MEDLINE | ID: mdl-38655824

ABSTRACT

BACKGROUND: Hepatitis C virus (HCV) and hepatitis B virus (HBV) cause chronic hepatitis with important clinical differences. HCV causes hepatic steatosis and insulin resistance, while HBV confers increased risk of liver cancer. We hypothesised these differences may be due to virus-specific effects on mitochondrial function. METHODS: Seahorse technology was utilised to investigate effects of virus infection on mitochondrial function. Cell based assays were used to measure mitochondrial membrane potential and quantify pyruvate and lactate. Mass spectrometry was performed on mitochondria isolated from HBV expressing, HCV infected and control cells cultured with isotope-labelled amino acids, to identify proteins with different abundance. Altered expression of key mitochondrial proteins was confirmed by real time PCR and western blot. RESULTS: Reduced mitochondrial function and ATP production were observed with HCV infection and HBV expression. HCV impairs glycolysis and reduces expression of genes regulating fatty acid oxidation, promoting lipid accumulation. HBV causes lactate accumulation by increasing expression of lactate dehydrogenase A, which converts pyruvate to lactate. In HBV expressing cells there was marked enrichment of pyruvate dehydrogenase kinase, inhibiting conversion of pyruvate to acetyl-CoA and thereby reducing its availability for mitochondrial oxidative phosphorylation. CONCLUSIONS: HCV and HBV impair mitochondrial function and reduce ATP production. HCV reduces acetyl-CoA availability for energy production by impairing fatty acid oxidation, causing lipid accumulation and hepatic steatosis. HBV has no effect on fatty oxidation but reduces acetyl-CoA availability by disrupting pyruvate metabolism. This promotes lactic acidosis and oxidative stress, increasing the risk of disease progression and liver cancer.

2.
Blood ; 138(16): 1391-1405, 2021 10 21.
Article in English | MEDLINE | ID: mdl-33974080

ABSTRACT

We performed a phase 1 clinical trial to evaluate outcomes in patients receiving donor-derived CD19-specific chimeric antigen receptor (CAR) T cells for B-cell malignancy that relapsed or persisted after matched related allogeneic hemopoietic stem cell transplant. To overcome the cost and transgene-capacity limitations of traditional viral vectors, CAR T cells were produced using the piggyBac transposon system of genetic modification. Following CAR T-cell infusion, 1 patient developed a gradually enlarging retroperitoneal tumor due to a CAR-expressing CD4+ T-cell lymphoma. Screening of other patients led to the detection, in an asymptomatic patient, of a second CAR T-cell tumor in thoracic para-aortic lymph nodes. Analysis of the first lymphoma showed a high transgene copy number, but no insertion into typical oncogenes. There were also structural changes such as altered genomic copy number and point mutations unrelated to the insertion sites. Transcriptome analysis showed transgene promoter-driven upregulation of transcription of surrounding regions despite insulator sequences surrounding the transgene. However, marked global changes in transcription predominantly correlated with gene copy number rather than insertion sites. In both patients, the CAR T-cell-derived lymphoma progressed and 1 patient died. We describe the first 2 cases of malignant lymphoma derived from CAR gene-modified T cells. Although CAR T cells have an enviable record of safety to date, our results emphasize the need for caution and regular follow-up of CAR T recipients, especially when novel methods of gene transfer are used to create genetically modified immune therapies. This trial was registered at www.anzctr.org.au as ACTRN12617001579381.


Subject(s)
Immunotherapy, Adoptive/adverse effects , Lymphoma/etiology , Receptors, Antigen, T-Cell/therapeutic use , Aged , DNA Transposable Elements , Gene Expression Regulation, Neoplastic , Gene Transfer Techniques , Humans , Immunotherapy, Adoptive/methods , Leukemia, B-Cell/genetics , Leukemia, B-Cell/therapy , Lymphoma/genetics , Lymphoma, B-Cell/genetics , Lymphoma, B-Cell/therapy , Male , Receptors, Antigen, T-Cell/genetics , T-Lymphocytes/metabolism , Transcriptome , Transgenes
3.
Am J Hematol ; 98(1): 159-165, 2023 01.
Article in English | MEDLINE | ID: mdl-35560045

ABSTRACT

We designed a trial to simultaneously address the problems of graft versus host disease (GVHD), infection, and recurrence of malignancy after allogeneic stem cell transplantation. CD34+ stem cell isolation was used to minimize the development of acute and chronic GVHD. Two prophylactic infusions, one combining donor-derived cytomegalovirus, Epstein-Barr virus, and Aspergillus fumigatus specific T-cells and the other comprising donor-derived CD19 directed chimeric antigen receptor (CAR) bearing T-cells, were given 21-28 days after transplant. Two patients were transplanted for acute lymphoblastic leukemia from HLA identical siblings using standard doses of cyclophosphamide and total body irradiation without antilymphocyte globulin. Patients received no post-transplant immune suppression and were given no pre-CAR T-cell lymphodepletion. Neutrophil and platelet engraftment was prompt. Following adoptive T-cell infusions, there was rapid appearance of antigen-experienced CD8+ and to a lesser extent CD4+ T-cells. Tetramer-positive T-cells targeting CMV and EBV appeared rapidly after T-cell infusion and persisted for at least 1 year. CAR T-cell expansion occurred and persisted for up to 3 months. T-cell receptor tracking confirmed the presence of product-derived T-cell clones in blood targeting all three pathogens. Both patients are alive over 3 years post-transplant without evidence of GVHD or disease recurrence. Combining robust donor T-cell depletion with directed T-cell adoptive immunotherapy targeting infectious and malignant antigens permits independent modulation of GVHD, infection, and disease recurrence. The combination may separate GVHD from the graft versus tumor effect, accelerate immune reconstitution, and improve transplant tolerability.


Subject(s)
Epstein-Barr Virus Infections , Graft vs Host Disease , Hematopoietic Stem Cell Transplantation , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Humans , T-Lymphocytes , Epstein-Barr Virus Infections/complications , Epstein-Barr Virus Infections/therapy , Transplantation, Homologous , Treatment Outcome , Herpesvirus 4, Human , Graft vs Host Disease/etiology , Graft vs Host Disease/prevention & control , Stem Cell Transplantation , Immunotherapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/therapy
4.
Int J Mol Sci ; 24(10)2023 May 15.
Article in English | MEDLINE | ID: mdl-37240132

ABSTRACT

The hepatitis C virus (HCV) relies on cellular lipid pathways for virus replication and also induces liver steatosis, but the mechanisms involved are not clear. We performed a quantitative lipidomics analysis of virus-infected cells by combining high-performance thin-layer chromatography (HPTLC) and mass spectrometry, using an established HCV cell culture model and subcellular fractionation. Neutral lipid and phospholipids were increased in the HCV-infected cells; in the endoplasmic reticulum there was an ~four-fold increase in free cholesterol and an ~three-fold increase in phosphatidyl choline (p < 0.05). The increase in phosphatidyl choline was due to the induction of a non-canonical synthesis pathway involving phosphatidyl ethanolamine transferase (PEMT). An HCV infection induced expression of PEMT while knocking down PEMT with siRNA inhibited virus replication. As well as supporting virus replication, PEMT mediates steatosis. Consistently, HCV induced the expression of the pro-lipogenic genes SREBP 1c and DGAT1 while inhibiting the expression of MTP, promoting lipid accumulation. Knocking down PEMT reversed these changes and reduced the lipid content in virus-infected cells. Interestingly, PEMT expression was over 50% higher in liver biopsies from people infected with the HCV genotype 3 than 1, and three times higher than in people with chronic hepatitis B, suggesting that this may account for genotype-dependent differences in the prevalence of hepatic steatosis. PEMT is a key enzyme for promoting the accumulation of lipids in HCV-infected cells and supports virus replication. The induction of PEMT may account for virus genotype specific differences in hepatic steatosis.


Subject(s)
Fatty Liver , Hepatitis C, Chronic , Hepatitis C , Humans , Hepacivirus/genetics , Hepacivirus/metabolism , Transferases/metabolism , Hepatitis C/genetics , Fatty Liver/pathology , Virus Replication , Genotype , Cholesterol/metabolism , Phosphatidylcholines/metabolism , Phenotype , Phosphatidylethanolamine N-Methyltransferase/genetics
5.
Brain Behav Immun ; 94: 308-317, 2021 05.
Article in English | MEDLINE | ID: mdl-33422639

ABSTRACT

Although genetic variation is a major risk factor of neurodevelopmental disorders, environmental factors during pregnancy and early life are also important in disease expression. Animal models demonstrate that maternal inflammation causes fetal neuroinflammation and neurodevelopmental deficits, and brain transcriptomics of neurodevelopmental disorders in humans show upregulated differentially expressed genes are enriched in immune pathways. We prospectively recruited 200 sequentially referred children with tic disorders/obsessive-compulsive disorder (OCD), 100 autoimmune neurological controls, and 100 age-matched healthy controls. A structured interview captured the maternal and family history of autoimmune disease and other pro-inflammatory states. Maternal blood and published Tourette brain transcriptomes were analysed for overlapping enriched pathways. Mothers of children with tics/OCD had a higher rate of autoimmune disease compared with mothers of children with autoimmune neurological conditions (p = 0.054), and mothers of healthy controls (p = 0.0004). Autoimmunity was similarly elevated in first- and second-degree maternal relatives of children with tics/OCD (p < 0.0001 and p = 0.014 respectively). Other pro-inflammatory states were also more common in mothers of children with tics/OCD than controls (p < 0.0001). Upregulated differentially expressed genes in maternal autoimmune disease and Tourette brain transcriptomes were commonly enriched in innate immune processes. Pro-inflammatory states, including autoimmune disease, are more common in the mothers and families of children with tics/OCD. Exploratory transcriptome analysis indicates innate immune signalling may link maternal inflammation and childhood tics/OCD. Targeting inflammation may represent preventative strategies in pregnancy and treatment opportunities for children with neurodevelopmental disorders.


Subject(s)
Obsessive-Compulsive Disorder , Tic Disorders , Tics , Autoimmunity/genetics , Child , Female , Humans , Immunity, Innate/genetics , Infant, Newborn , Inflammation/genetics , Obsessive-Compulsive Disorder/genetics , Pregnancy , Transcriptome
6.
Int J Mol Sci ; 22(18)2021 Sep 15.
Article in English | MEDLINE | ID: mdl-34576118

ABSTRACT

Rett Syndrome (RTT) is an X linked neurodevelopmental disorder caused by mutations in the methyl-CpG-binding protein 2 (MECP2) gene, resulting in severe cognitive and physical disabilities. Despite an apparent normal prenatal and postnatal development period, symptoms usually present around 6 to 18 months of age. Little is known about the consequences of MeCP2 deficiency at a molecular and cellular level before the onset of symptoms in neural cells, and subtle changes at this highly sensitive developmental stage may begin earlier than symptomatic manifestation. Recent transcriptomic studies of patient induced pluripotent stem cells (iPSC)-differentiated neurons and brain organoids harbouring pathogenic mutations in MECP2, have unravelled new insights into the cellular and molecular changes caused by these mutations. Here we interrogated transcriptomic modifications in RTT patients using publicly available RNA-sequencing datasets of patient iPSCs harbouring pathogenic mutations and healthy control iPSCs by Weighted Gene Correlation Network Analysis (WGCNA). Preservation analysis identified core gene pathways involved in translation, ribosomal function, and ubiquitination perturbed in some MECP2 mutant iPSC lines. Furthermore, differential gene expression of the parental fibroblasts and iPSC-derived neurons revealed alterations in genes in the ubiquitination pathway and neurotransmission in fibroblasts and differentiated neurons respectively. These findings might suggest that global translational dysregulation and proteasome ubiquitin function in Rett syndrome begins in progenitor cells prior to lineage commitment and differentiation into neural cells.


Subject(s)
Gene Regulatory Networks , Proteasome Endopeptidase Complex/metabolism , Protein Biosynthesis/genetics , Rett Syndrome/genetics , Ubiquitin/metabolism , Cluster Analysis , Databases, Genetic , Fibroblasts/metabolism , Gene Expression Regulation , Humans , Induced Pluripotent Stem Cells/metabolism , Methyl-CpG-Binding Protein 2/chemistry , Methyl-CpG-Binding Protein 2/genetics , Methyl-CpG-Binding Protein 2/metabolism , Neurons/metabolism , Principal Component Analysis , Protein Domains , Ubiquitin/genetics
7.
Am J Hum Genet ; 101(2): 255-266, 2017 Aug 03.
Article in English | MEDLINE | ID: mdl-28777932

ABSTRACT

Breast cancer risk is strongly associated with an intergenic region on 11q13. We have previously shown that the strongest risk-associated SNPs fall within a distal enhancer that regulates CCND1. Here, we report that, in addition to regulating CCND1, this enhancer regulates two estrogen-regulated long noncoding RNAs, CUPID1 and CUPID2. We provide evidence that the risk-associated SNPs are associated with reduced chromatin looping between the enhancer and the CUPID1 and CUPID2 bidirectional promoter. We further show that CUPID1 and CUPID2 are predominantly expressed in hormone-receptor-positive breast tumors and play a role in modulating pathway choice for the repair of double-strand breaks. These data reveal a mechanism for the involvement of this region in breast cancer.


Subject(s)
Breast Neoplasms/genetics , Chromosomes, Human, Pair 11/genetics , Cyclin D1/genetics , DNA Repair/genetics , RNA, Long Noncoding/genetics , Cell Line, Tumor , Chromatin/metabolism , DNA Breaks, Double-Stranded , DNA Damage/genetics , Enhancer Elements, Genetic/genetics , Estrogens/metabolism , Female , Gene Expression Regulation, Neoplastic , Genetic Predisposition to Disease/genetics , Humans , MCF-7 Cells , Polymorphism, Single Nucleotide/genetics , Promoter Regions, Genetic/genetics , RNA Interference , RNA, Guide, Kinetoplastida/genetics , RNA, Small Interfering/genetics
8.
Trends Genet ; 32(10): 620-637, 2016 10.
Article in English | MEDLINE | ID: mdl-27592414

ABSTRACT

Although a considerable portion of eukaryotic genomes is transcribed as long noncoding RNAs (lncRNAs), the vast majority are functionally uncharacterised. The rapidly expanding catalogue of mechanistically investigated lncRNAs has provided evidence for distinct functional subclasses, which are now ripe for exploitation as a general model to predict functions for uncharacterised lncRNAs. By utilising publicly-available genome-wide datasets and computational methods, we present several developed and emerging in silico approaches to characterise and predict the functions of lncRNAs. We propose that the application of these techniques provides valuable functional and mechanistic insight into lncRNAs, and is a crucial step for informing subsequent functional studies.


Subject(s)
Genome , RNA, Long Noncoding/genetics , Computational Biology , Databases, Genetic , RNA, Long Noncoding/chemistry , RNA, Long Noncoding/isolation & purification
9.
Bioinformatics ; 34(6): 920-927, 2018 03 15.
Article in English | MEDLINE | ID: mdl-29092009

ABSTRACT

Motivation: The branchpoint element is required for the first lariat-forming reaction in splicing. However current catalogues of human branchpoints remain incomplete due to the difficulty in experimentally identifying these splicing elements. To address this limitation, we have developed a machine-learning algorithm-branchpointer-to identify branchpoint elements solely from gene annotations and genomic sequence. Results: Using branchpointer, we annotate branchpoint elements in 85% of human gene introns with sensitivity (61.8%) and specificity (97.8%). In addition to annotation, branchpointer can evaluate the impact of SNPs on branchpoint architecture to inform functional interpretation of genetic variants. Branchpointer identifies all published deleterious branchpoint mutations annotated in clinical variant databases, and finds thousands of additional clinical and common genetic variants with similar predicted effects. This genome-wide annotation of branchpoints provides a reference for the genetic analysis of splicing, and the interpretation of noncoding variation. Availability and implementation: Branchpointer is written and implemented in the statistical programming language R and is freely available under a BSD license as a package through Bioconductor. Contact: b.signal@garvan.org.au or t.mercer@garvan.org. Supplementary information: Supplementary data are available at Bioinformatics online.


Subject(s)
Genome, Human , Introns , Machine Learning , Molecular Sequence Annotation , RNA Splicing , Sequence Analysis, DNA/methods , Genetic Variation , Humans , Sensitivity and Specificity , Software
11.
Proc Natl Acad Sci U S A ; 112(52): 15898-903, 2015 Dec 29.
Article in English | MEDLINE | ID: mdl-26578815

ABSTRACT

We surveyed the "dark" proteome-that is, regions of proteins never observed by experimental structure determination and inaccessible to homology modeling. For 546,000 Swiss-Prot proteins, we found that 44-54% of the proteome in eukaryotes and viruses was dark, compared with only ∼14% in archaea and bacteria. Surprisingly, most of the dark proteome could not be accounted for by conventional explanations, such as intrinsic disorder or transmembrane regions. Nearly half of the dark proteome comprised dark proteins, in which the entire sequence lacked similarity to any known structure. Dark proteins fulfill a wide variety of functions, but a subset showed distinct and largely unexpected features, such as association with secretion, specific tissues, the endoplasmic reticulum, disulfide bonding, and proteolytic cleavage. Dark proteins also had short sequence length, low evolutionary reuse, and few known interactions with other proteins. These results suggest new research directions in structural and computational biology.


Subject(s)
Computational Biology/methods , Databases, Protein , Proteins/metabolism , Proteome/metabolism , Algorithms , Animals , Archaea/genetics , Archaea/metabolism , Bacteria/genetics , Bacteria/metabolism , Eukaryota/metabolism , Humans , Models, Molecular , Protein Conformation , Proteins/chemistry , Proteins/genetics , Proteome/chemistry , Proteome/genetics , Viruses/genetics , Viruses/metabolism
12.
Biochim Biophys Acta ; 1859(1): 16-22, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26297315

ABSTRACT

Over the last decade, long noncoding RNAs (lncRNAs) have emerged as a fundamental molecular class whose members play pivotal roles in the regulation of the genome. The observation of pervasive transcription of mammalian genomes in the early 2000s sparked a revolution in the understanding of information flow in eukaryotic cells and the incredible flexibility and dynamic nature of the transcriptome. As a molecular class, distinct loci yielding lncRNAs are set to outnumber those yielding mRNAs. However, like many important discoveries, the road leading to uncovering this diverse class of molecules that act through a remarkable repertoire of mechanisms, was not a straight one. The same characteristic that most distinguishes lncRNAs from mRNAs, i.e. their developmental-stage, tissue-, and cell-specific expression, was one of the major impediments to their discovery and recognition as potentially functional regulatory molecules. With growing numbers of lncRNAs being assigned to biological functions, the specificity of lncRNA expression is now increasingly recognized as a characteristic that imbues lncRNAs with great potential as biomarkers and for the development of highly targeted therapeutics. Here we review the history of lncRNA research and how technological advances and insight into biological complexity have gone hand-in-hand in shaping this revolution. We anticipate that as increasing numbers of these molecules, often described as the dark matter of the genome, are characterized and the structure-function relationship of lncRNAs becomes better understood, it may ultimately be feasible to decipher what these non-(protein)-coding genes encode. This article is part of a Special Issue entitled: Clues to long noncoding RNA taxonomy1, edited by Dr. Tetsuro Hirose and Dr. Shinichi Nakagawa.


Subject(s)
Gene Expression Regulation , Organ Specificity/genetics , RNA, Long Noncoding/genetics , Transcriptome/genetics , Animals , Cell Lineage/genetics , Conserved Sequence/genetics , Genome , Humans , RNA, Long Noncoding/biosynthesis , RNA, Messenger/genetics
13.
Nucleic Acids Res ; 43(Database issue): D168-73, 2015 Jan.
Article in English | MEDLINE | ID: mdl-25332394

ABSTRACT

Despite the prevalence of long noncoding RNA (lncRNA) genes in eukaryotic genomes, only a small proportion have been examined for biological function. lncRNAdb, available at http://lncrnadb.org, provides users with a comprehensive, manually curated reference database of 287 eukaryotic lncRNAs that have been described independently in the scientific literature. In addition to capturing a great proportion of the recent literature describing functions for individual lncRNAs, lncRNAdb now offers an improved user interface enabling greater accessibility to sequence information, expression data and the literature. The new features in lncRNAdb include the integration of Illumina Body Atlas expression profiles, nucleotide sequence information, a BLAST search tool and easy export of content via direct download or a REST API. lncRNAdb is now endorsed by RNAcentral and is in compliance with the International Nucleotide Sequence Database Collaboration.


Subject(s)
Databases, Nucleic Acid , RNA, Long Noncoding/physiology , Base Sequence , Conserved Sequence , Gene Expression , Humans , Internet , Proteins/genetics , RNA, Long Noncoding/chemistry , RNA, Long Noncoding/metabolism , Sequence Alignment
14.
EBioMedicine ; 104: 105156, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38768529

ABSTRACT

BACKGROUND: Kabuki syndrome (KS) is a genetic disorder caused by DNA mutations in KMT2D, a lysine methyltransferase that methylates histones and other proteins, and therefore modifies chromatin structure and subsequent gene expression. Ketones, derived from the ketogenic diet, are histone deacetylase inhibitors that can 'open' chromatin and encourage gene expression. Preclinical studies have shown that the ketogenic diet rescues hippocampal memory neurogenesis in mice with KS via the epigenetic effects of ketones. METHODS: Single-cell RNA sequencing and mass spectrometry-based proteomics were used to explore molecular mechanisms of disease in individuals with KS (n = 4) versus controls (n = 4). FINDINGS: Pathway enrichment analysis indicated that loss of function mutations in KMT2D are associated with ribosomal protein dysregulation at an RNA and protein level in individuals with KS (FDR <0.05). Cellular proteomics also identified immune dysregulation and increased abundance of other lysine modification and histone binding proteins, representing a potential compensatory mechanism. A 12-year-old boy with KS, suffering from recurrent episodes of cognitive decline, exhibited improved cognitive function and neuropsychological assessment performance after 12 months on the ketogenic diet, with concomitant improvement in transcriptomic ribosomal protein dysregulation. INTERPRETATION: Our data reveals that lysine methyltransferase deficiency is associated with ribosomal protein dysfunction, with secondary immune dysregulation. Diet and the production of bioactive molecules such as ketone bodies serve as a significant environmental factor that can induce epigenetic changes and improve clinical outcomes. Integrating transcriptomic, proteomic, and clinical data can define mechanisms of disease and treatment effects in individuals with neurodevelopmental disorders. FUNDING: This study was supported by the Dale NHMRC Investigator Grant (APP1193648) (R.D), Petre Foundation (R.D), and The Sydney Children's Hospital Foundation/Kids Research Early and Mid-Career Researcher Grant (E.T).


Subject(s)
DNA-Binding Proteins , Diet, Ketogenic , Face , Hematologic Diseases , Proteomics , Ribosomal Proteins , Vestibular Diseases , Vestibular Diseases/genetics , Vestibular Diseases/metabolism , Vestibular Diseases/diet therapy , Humans , Face/abnormalities , Male , Hematologic Diseases/metabolism , Hematologic Diseases/genetics , Hematologic Diseases/etiology , Hematologic Diseases/diet therapy , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Ribosomal Proteins/genetics , Ribosomal Proteins/metabolism , Child , Proteomics/methods , Female , Neoplasm Proteins/genetics , Neoplasm Proteins/metabolism , Gene Expression Regulation , Mutation , Transcriptome , Abnormalities, Multiple
15.
Sci Transl Med ; 16(741): eadj0133, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38569018

ABSTRACT

Transforming growth factor-ß (TGFß) drives fibrosis and disease progression in a number of chronic disorders, but targeting this ubiquitously expressed cytokine may not yield a viable and safe antifibrotic therapy. Here, we sought to identify alternative ways to inhibit TGFß signaling using human hepatic stellate cells and macrophages from humans and mice in vitro, as well as mouse models of liver, kidney, and lung fibrosis. We identified Mer tyrosine kinase (MERTK) as a TGFß-inducible effector of fibrosis that was up-regulated during fibrosis in multiple organs in three mouse models. We confirmed these findings in liver biopsy samples from patients with metabolic dysfunction-associated fatty liver disease (MAFLD). MERTK also induced TGFß expression and drove TGFß signaling resulting in a positive feedback loop that promoted fibrosis in cultured cells. MERTK regulated both canonical and noncanonical TGFß signaling in both mouse and human cells in vitro. MERTK increased transcription of genes regulating fibrosis by modulating chromatin accessibility and RNA polymerase II activity. In each of the three mouse models, disrupting the fibrosis-promoting signaling loop by reducing MERTK expression reduced organ fibrosis. Pharmacological inhibition of MERTK reduced fibrosis in these mouse models either when initiated immediately after injury or when initiated after fibrosis was established. Together, these data suggest that MERTK plays a role in modulating organ fibrosis and may be a potential target for treating fibrotic diseases.


Subject(s)
Liver , Protein-Tyrosine Kinases , Animals , Humans , Mice , c-Mer Tyrosine Kinase/metabolism , Disease Models, Animal , Fibrosis , Liver/metabolism , Protein-Tyrosine Kinases/metabolism , Transforming Growth Factor beta/metabolism
16.
JCI Insight ; 9(6)2024 Feb 13.
Article in English | MEDLINE | ID: mdl-38516885

ABSTRACT

CD4+Foxp3+ regulatory T cells (Tregs) play an essential role in suppressing transplant rejection, but their role within the graft and heterogeneity in tolerance are poorly understood. Here, we compared phenotypic and transcriptomic characteristics of Treg populations within lymphoid organs and grafts in an islet xenotransplant model of tolerance. We showed Tregs were essential for tolerance induction and maintenance. Tregs demonstrated heterogeneity within the graft and lymphoid organs of tolerant mice. A subpopulation of CD127hi Tregs with memory features were found in lymphoid organs, presented in high proportions within long-surviving islet grafts, and had a transcriptomic and phenotypic profile similar to tissue Tregs. Importantly, these memory-like CD127hi Tregs were better able to prevent rejection by effector T cells, after adoptive transfer into secondary Rag-/- hosts, than naive Tregs or unselected Tregs from tolerant mice. Administration of IL-7 to the CD127hi Treg subset was associated with a strong activation of phosphorylation of STAT5. We proposed that memory-like CD127hi Tregs developed within the draining lymph node and underwent further genetic reprogramming within the graft toward a phenotype that had shared characteristics with other tissue or tumor Tregs. These findings suggested that engineering Tregs with these characteristics either in vivo or for adoptive transfer could enhance transplant tolerance.


Subject(s)
T-Lymphocytes, Regulatory , Transplantation Tolerance , Animals , Mice , Forkhead Transcription Factors , Graft Rejection/prevention & control , Immune Tolerance , CD4-Positive T-Lymphocytes , Interleukin-7 Receptor alpha Subunit
17.
Life Sci Alliance ; 6(11)2023 11.
Article in English | MEDLINE | ID: mdl-37648284

ABSTRACT

Polo-like kinase 1 (PLK1) is a regulator of cell mitosis and cytoskeletal dynamics. PLK1 overexpression in liver cancer is associated with tumour progression, metastasis, and vascular invasion. Hepatitis C virus (HCV) NS5A protein stimulates PLK1-mediated phosphorylation of host proteins, so we hypothesised that HCV-PLK1 interactions might be a mechanism for HCV-induced liver cancer. We used a HCV cell-culture model (Jc1) to investigate the effects of virus infection on the cytoskeleton. In HCV-infected cells, a novel posttranslational modification in ß-actin was observed with phosphorylation at Ser239. Using in silico and in vitro approaches, we identified PLK1 as the mediating kinase. In functional experiments with a phosphomimetic mutant form of ß-actin, Ser239 phosphorylation influences ß-actin polymerization and distribution, resulting in increased cell motility. The changes were prevented by treating cells with the PLK1 inhibitor volasertib. In HCV-infected hepatocytes, increased cell motility contributes to cancer cell migration, invasion, and metastasis. PLK1 is an important mediator of these effects and early treatment with PLK1 inhibitors may prevent or reduce HCC progression, particularly in people with HCV-induced HCC.


Subject(s)
Carcinoma, Hepatocellular , Hepatitis C , Liver Neoplasms , Humans , Hepacivirus , Actins , Carcinoma, Hepatocellular/genetics , Liver Neoplasms/genetics , Cell Movement/genetics , Polo-Like Kinase 1
18.
Metabolism ; 144: 155583, 2023 07.
Article in English | MEDLINE | ID: mdl-37146900

ABSTRACT

Lean patients with MAFLD have an initial adaptive metabolic response characterised by increased serum bile acids and Farnesoid X Receptor (FXR) activity. How this adaptive response wanes resulting in an equal or perhaps worse long-term adverse outcome compared to patients with obese MAFLD is not known. We show that patients with lean MAFLD have endotoxemia while their macrophages demonstrate excess production of inflammatory cytokines in response to activation by Toll-like receptor (TLR) ligands when compared to healthy subjects. Alterations of the lean MAFLD macrophage epigenome drives this response and suppresses bile acids signalling to drive inflammation. Our data suggests that selectively restoring bile acids signalling might restore adaptive metabolic responses in patients with MAFLD who are lean.


Subject(s)
Endotoxemia , Non-alcoholic Fatty Liver Disease , Humans , Receptors, Cytoplasmic and Nuclear/genetics , Endotoxemia/genetics , Inflammation/genetics , Bile Acids and Salts , Epigenesis, Genetic
19.
Gynecol Oncol ; 124(3): 582-8, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22115852

ABSTRACT

OBJECTIVE: Altered DNA methylation patterns hold promise as cancer biomarkers. In this study we selected a panel of genes which are commonly methylated in a variety of cancers to evaluate their potential application as biomarkers for prognosis and diagnosis in high grade serous ovarian carcinoma (HGSOC); the most common and lethal subtype of ovarian cancer. METHODS: The methylation patterns of 10 genes (BRCA1, EN1, DLEC1, HOXA9, RASSF1A, GATA4, GATA5, HSULF1, CDH1, SFN) were examined and compared in a cohort of 80 primary HGSOC and 12 benign ovarian surface epithelium (OSE) samples using methylation-specific headloop suppression PCR. RESULTS: The genes were variably methylated in primary HGSOC, with HOXA9 methylation observed in 95% of cases. Most genes were rarely methylated in benign OSE, with the exception of SFN which was methylated in all HGSOC and benign OSE samples examined. Methylation of DLEC1 was associated with disease recurrence, independent of tumor stage and suboptimal surgical debulking (HR 3.5 (95% CI:1.10-11.07), p=0.033). A combination of the methylation status of HOXA9 and EN1 could discriminate HGSOC from benign OSE with a sensitivity of 98.8% and a specificity of 91.7%, which increased to 100% sensitivity with no loss of specificity when pre-operative CA125 levels were also incorporated. CONCLUSIONS: This study provides further evidence to support the feasibility of detecting altered DNA methylation patterns as a potential diagnostic and prognostic approach for HGSOC.


Subject(s)
Cystadenocarcinoma, Serous/genetics , DNA Methylation , Ovarian Neoplasms/genetics , Cohort Studies , Cystadenocarcinoma, Serous/pathology , Female , Homeodomain Proteins/genetics , Humans , Middle Aged , Neoplasm Grading , Ovarian Neoplasms/pathology , Polymerase Chain Reaction/methods , Survival Rate , Tumor Suppressor Proteins/genetics
20.
Front Neurosci ; 16: 999346, 2022.
Article in English | MEDLINE | ID: mdl-36590292

ABSTRACT

Neurodevelopmental disorders (NDDs), including autism-spectrum disorders (ASD) and Tourette syndrome (TS) are common brain conditions which often co-exist, and have no approved treatments targeting disease mechanisms. Accumulating literature implicates the immune system in NDDs, and transcriptomics of post-mortem brain tissue has revealed an inflammatory signal. We interrogated two RNA-sequencing datasets of ASD and TS and identified differentially expressed genes, to explore commonly enriched pathways through GO, KEGG, and Reactome. The DEGs [False Discovery Rate (FDR) <0.05] in the ASD dataset (n = 248) and the TS dataset (n = 156) enriched pathways involving inflammation, cytokines, signal transduction and cell signalling. Of the DEGs from the ASD and TS analyses, 23 were shared, all of which were up-regulated: interaction networks of the common protein-coding genes using STRING revealed 5 central up-regulated hub genes: CCL2, ICAM1, HMOX1, MYC, and SOCS3. Applying KEGG and Reactome analysis to the 23 common genes identified pathways involving the innate immune response such as interleukin and interferon signalling pathways. These findings bring new evidence of shared immune signalling in ASD and TS brain transcriptome, to support the overlapping symptoms that individuals with these complex disorders experience.

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