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1.
Blood ; 142(4): 382-396, 2023 07 27.
Article in English | MEDLINE | ID: mdl-37267508

ABSTRACT

Sickle cell disease (SCD) is a chronic hemolytic and systemic hypoxia condition with constant oxidative stress and significant metabolic alterations. However, little is known about the correlation between metabolic alterations and the pathophysiological symptoms. Here, we report that Nrf2, a master regulator of cellular antioxidant responses, regulates the production of the metabolite l-2-hydroxyglutarate (L2HG) to mediate epigenetic histone hypermethylation for gene expression involved in metabolic, oxidative, and ferroptotic stress responses in SCD. Mechanistically, Nrf2 was found to regulate the expression of L2HG dehydrogenase (L2hgdh) to mediate L2HG production under hypoxia. Gene expression profile analysis indicated that reactive oxygen species (ROS) and ferroptosis responses were the most significantly affected signaling pathways after Nrf2 ablation in SCD. Nrf2 silencing and L2HG supplementation sensitize human sickle erythroid cells to ROS and ferroptosis stress. The absence of Nrf2 and accumulation of L2HG significantly affect histone methylation for chromatin structure modification and reduce the assembly of transcription complexes on downstream target genes to regulate ROS and ferroptosis responses. Furthermore, pharmacological activation of Nrf2 was found to have protective effects against ROS and ferroptosis stress in SCD mice. Our data suggest a novel mechanism by which Nrf2 regulates L2HG levels to mediate SCD severity through ROS and ferroptosis stress responses, suggesting that targeting Nrf2 is a viable therapeutic strategy for ameliorating SCD symptoms.


Subject(s)
Anemia, Sickle Cell , Chromatin , Epigenesis, Genetic , Ferroptosis , Glutarates , NF-E2-Related Factor 2 , Ferroptosis/genetics , Glutarates/metabolism , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism , Anemia, Sickle Cell/genetics , Anemia, Sickle Cell/metabolism , Anemia, Sickle Cell/pathology , Chromatin/metabolism , Methylation , Alcohol Oxidoreductases/metabolism , Animals , Mice , Reactive Oxygen Species/metabolism , Transcription, Genetic , Gene Expression Profiling
2.
Kidney Int ; 105(2): 281-292, 2024 Feb.
Article in English | MEDLINE | ID: mdl-37923131

ABSTRACT

Lesion scores on procurement donor biopsies are commonly used to guide organ utilization for deceased-donor kidneys. However, frozen sections present challenges for histological scoring, leading to inter- and intra-observer variability and inappropriate discard. Therefore, we constructed deep-learning based models to recognize kidney tissue compartments in hematoxylin & eosin-stained sections from procurement needle biopsies performed nationwide in years 2011-2020. To do this, we extracted whole-slide abnormality features from 2431 kidneys and correlated with pathologists' scores and transplant outcomes. A Kidney Donor Quality Score (KDQS) was derived and used in combination with recipient demographic and peri-transplant characteristics to predict graft loss or assist organ utilization. The performance on wedge biopsies was additionally evaluated. Our model identified 96% and 91% of normal/sclerotic glomeruli respectively; 94% of arteries/arterial intimal fibrosis; 90% of tubules. Whole-slide features of Sclerotic Glomeruli (GS)%, Arterial Intimal Fibrosis (AIF)%, and Interstitial Space Abnormality (ISA)% demonstrated strong correlations with corresponding pathologists' scores of all 2431 kidneys, but had superior associations with post-transplant estimated glomerular filtration rates in 2033 and graft loss in 1560 kidneys. The combination of KDQS and other factors predicted one- and four-year graft loss in a discovery set of 520 kidneys and a validation set of 1040 kidneys. By using the composite KDQS of 398 discarded kidneys due to "biopsy findings", we suggest that if transplanted, 110 discarded kidneys could have had similar survival to that of other transplanted kidneys. Thus, our composite KDQS and survival prediction models may facilitate risk stratification and organ utilization while potentially reducing unnecessary organ discard.


Subject(s)
Deep Learning , Kidney Transplantation , Tissue and Organ Procurement , Humans , Kidney Transplantation/adverse effects , Retrospective Studies , Donor Selection , Kidney/pathology , Tissue Donors , Biopsy , Fibrosis , Graft Survival
3.
Kidney Int ; 101(2): 288-298, 2022 02.
Article in English | MEDLINE | ID: mdl-34757124

ABSTRACT

Interstitial fibrosis, tubular atrophy, and inflammation are major contributors to kidney allograft failure. Here we sought an objective, quantitative pathological assessment of these lesions to improve predictive utility and constructed a deep-learning-based pipeline recognizing normal vs. abnormal kidney tissue compartments and mononuclear leukocyte infiltrates. Periodic acid- Schiff stained slides of transplant biopsies (60 training and 33 testing) were used to quantify pathological lesions specific for interstitium, tubules and mononuclear leukocyte infiltration. The pipeline was applied to the whole slide images from 789 transplant biopsies (478 baseline [pre-implantation] and 311 post-transplant 12-month protocol biopsies) in two independent cohorts (GoCAR: 404 patients, AUSCAD: 212 patients) of transplant recipients to correlate composite lesion features with graft loss. Our model accurately recognized kidney tissue compartments and mononuclear leukocytes. The digital features significantly correlated with revised Banff 2007 scores but were more sensitive to subtle pathological changes below the thresholds in the Banff scores. The Interstitial and Tubular Abnormality Score (ITAS) in baseline samples was highly predictive of one-year graft loss, while a Composite Damage Score in 12-month post-transplant protocol biopsies predicted later graft loss. ITASs and Composite Damage Scores outperformed Banff scores or clinical predictors with superior graft loss prediction accuracy. High/intermediate risk groups stratified by ITASs or Composite Damage Scores also demonstrated significantly higher incidence of estimated glomerular filtration rate decline and subsequent graft damage. Thus, our deep-learning approach accurately detected and quantified pathological lesions from baseline or post-transplant biopsies and demonstrated superior ability for prediction of post-transplant graft loss with potential application as a prevention, risk stratification or monitoring tool.


Subject(s)
Deep Learning , Kidney Transplantation , Biopsy , Graft Rejection/pathology , Graft Survival , Humans , Kidney/pathology , Kidney Transplantation/adverse effects
4.
Blood ; 131(5): 558-562, 2018 02 01.
Article in English | MEDLINE | ID: mdl-29255069

ABSTRACT

The basic leucine zipper transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) plays a critical role in the cellular antioxidant response under oxidative stress conditions. In this study, we investigated the role of NRF2 in fetal hemoglobin expression and the pathophysiology of sickle cell disease (SCD) in a NRF2 knockout (SCD/NRF2-/-) transgenic mouse model. NRF2 loss impaired survival of SCD pups during gestation and in the first 2 months of life. Furthermore, fetal hemoglobin expression was inhibited during erythropoiesis in embryonic day 13.5 and embryonic day 18.5 fetal liver and adult spleen and bone marrow cells, respectively. Examination of peripheral red blood cells revealed an increase of reactive oxygen species (ROS) and sickling under hypoxic conditions. Loss of NRF2 function in SCD/NRF2-/- mice produced greater splenomegaly with red pulp expansion and obscured architecture. In addition, NRF2 knockout reduced the expression of its target antioxidant proteins, leading to increased levels of ROS, proinflammatory cytokines, and adhesion molecules in SCD mice. Genetic knockout of NRF2 demonstrates its role in developmentally regulated γ-globin gene expression and the ability to control oxidative stress and the phenotypic severity of SCD.


Subject(s)
Anemia, Sickle Cell/genetics , Anemia, Sickle Cell/pathology , NF-E2-Related Factor 2/physiology , Animals , Animals, Newborn , Disease Models, Animal , Disease Progression , Female , Gene Knockout Techniques , Male , Mice , Mice, Inbred C57BL , Mice, Transgenic , NF-E2-Related Factor 2/genetics , Oxidative Stress/genetics , Phenotype , gamma-Globins/genetics
5.
J Am Soc Nephrol ; 30(8): 1481-1494, 2019 08.
Article in English | MEDLINE | ID: mdl-31278196

ABSTRACT

BACKGROUND: In kidney transplant recipients, surveillance biopsies can reveal, despite stable graft function, histologic features of acute rejection and borderline changes that are associated with undesirable graft outcomes. Noninvasive biomarkers of subclinical acute rejection are needed to avoid the risks and costs associated with repeated biopsies. METHODS: We examined subclinical histologic and functional changes in kidney transplant recipients from the prospective Genomics of Chronic Allograft Rejection (GoCAR) study who underwent surveillance biopsies over 2 years, identifying those with subclinical or borderline acute cellular rejection (ACR) at 3 months (ACR-3) post-transplant. We performed RNA sequencing on whole blood collected from 88 individuals at the time of 3-month surveillance biopsy to identify transcripts associated with ACR-3, developed a novel sequencing-based targeted expression assay, and validated this gene signature in an independent cohort. RESULTS: Study participants with ACR-3 had significantly higher risk than those without ACR-3 of subsequent clinical acute rejection at 12 and 24 months, faster decline in graft function, and decreased graft survival in adjusted Cox analysis. We identified a 17-gene signature in peripheral blood that accurately diagnosed ACR-3, and validated it using microarray expression profiles of blood samples from 65 transplant recipients in the GoCAR cohort and three public microarray datasets. In an independent cohort of 110 transplant recipients, tests of the targeted expression assay on the basis of the 17-gene set showed that it identified individuals at higher risk of ongoing acute rejection and future graft loss. CONCLUSIONS: Our targeted expression assay enabled noninvasive diagnosis of subclinical acute rejection and inflammation in the graft and may represent a useful tool to risk-stratify kidney transplant recipients.


Subject(s)
Gene Expression Profiling , Graft Rejection/blood , Graft Rejection/diagnosis , Kidney Failure, Chronic/surgery , Kidney Transplantation/adverse effects , Adult , Aged , Biomarkers/metabolism , Biopsy , Female , Genomics , Graft Survival , Humans , Immunosuppressive Agents/therapeutic use , Inflammation , Kaplan-Meier Estimate , Kidney Failure, Chronic/blood , Kidney Failure, Chronic/mortality , Kidney Transplantation/mortality , Male , Middle Aged , Oligonucleotide Array Sequence Analysis , Prospective Studies , Risk Factors , Sequence Analysis, RNA
6.
Lancet ; 388(10048): 983-93, 2016 Sep 03.
Article in English | MEDLINE | ID: mdl-27452608

ABSTRACT

BACKGROUND: Chronic injury in kidney transplants remains a major cause of allograft loss. The aim of this study was to identify a gene set capable of predicting renal allografts at risk of progressive injury due to fibrosis. METHODS: This Genomics of Chronic Allograft Rejection (GoCAR) study is a prospective, multicentre study. We prospectively collected biopsies from renal allograft recipients (n=204) with stable renal function 3 months after transplantation. We used microarray analysis to investigate gene expression in 159 of these tissue samples. We aimed to identify genes that correlated with the Chronic Allograft Damage Index (CADI) score at 12 months, but not fibrosis at the time of the biopsy. We applied a penalised regression model in combination with permutation-based approach to derive an optimal gene set to predict allograft fibrosis. The GoCAR study is registered with ClinicalTrials.gov, number NCT00611702. FINDINGS: We identified a set of 13 genes that was independently predictive for the development of fibrosis at 1 year (ie, CADI-12 ≥2). The gene set had high predictive capacity (area under the curve [AUC] 0·967), which was superior to that of baseline clinical variables (AUC 0·706) and clinical and pathological variables (AUC 0·806). Furthermore routine pathological variables were unable to identify which histologically normal allografts would progress to fibrosis (AUC 0·754), whereas the predictive gene set accurately discriminated between transplants at high and low risk of progression (AUC 0·916). The 13 genes also accurately predicted early allograft loss (AUC 0·842 at 2 years and 0·844 at 3 years). We validated the predictive value of this gene set in an independent cohort from the GoCAR study (n=45, AUC 0·866) and two independent, publically available expression datasets (n=282, AUC 0·831 and n=24, AUC 0·972). INTERPRETATION: Our results suggest that this set of 13 genes could be used to identify kidney transplant recipients at risk of allograft loss before the development of irreversible damage, thus allowing therapy to be modified to prevent progression to fibrosis. FUNDING: National Institutes of Health.


Subject(s)
Gene Expression Profiling/methods , Graft Rejection/genetics , Kidney Transplantation/adverse effects , Renal Insufficiency, Chronic/genetics , Adolescent , Adult , Aged , Aged, 80 and over , Biopsy , Fibrosis/genetics , Fibrosis/prevention & control , Genetic Testing , Graft Rejection/prevention & control , Humans , Kidney/pathology , Male , Middle Aged , Prospective Studies , Young Adult
7.
Antioxidants (Basel) ; 13(3)2024 Mar 11.
Article in English | MEDLINE | ID: mdl-38539870

ABSTRACT

Sickle cell disease (SCD) is a pathophysiological condition of chronic hemolysis, oxidative stress, and elevated inflammation. The transcription factor Nrf2 is a master regulator of oxidative stress. Here, we report that the FDA-approved oral agent simvastatin, an inhibitor of hydroxymethyl-glutaryl coenzyme A reductase, significantly activates the expression of Nrf2 and antioxidant enzymes. Simvastatin also induces fetal hemoglobin expression in SCD patient primary erythroid progenitors and a transgenic mouse model. Simvastatin alleviates SCD symptoms by decreasing hemoglobin S sickling, oxidative stress, and inflammatory stress in erythroblasts. Particularly, simvastatin increases cellular levels of cystine, the precursor for the biosynthesis of the antioxidant reduced glutathione, and decreases the iron content in SCD mouse spleen and liver tissues. Mechanistic studies suggest that simvastatin suppresses the expression of the critical histone methyltransferase enhancer of zeste homolog 2 to reduce both global and gene-specific histone H3 lysine 27 trimethylation. These chromatin structural changes promote the assembly of transcription complexes to fetal γ-globin and antioxidant gene regulatory regions in an antioxidant response element-dependent manner. In summary, our findings suggest that simvastatin activates fetal hemoglobin and antioxidant protein expression, modulates iron and cystine/reduced glutathione levels to improve the phenotype of SCD, and represents a therapeutic strategy for further development.

8.
J Biol Chem ; 287(42): 35646-35657, 2012 Oct 12.
Article in English | MEDLINE | ID: mdl-22847003

ABSTRACT

ErbB2/Neu oncogene is overexpressed in 25% of invasive/metastatic breast cancers. We have found that deletion of heat shock factor Hsf1 in mice overexpressing ErbB2/Neu significantly reduces mammary tumorigenesis and metastasis. Hsf1(+/-)ErbB2/Neu(+) tumors exhibit reduced cellular proliferative and invasive properties associated with reduced activated ERK1/2 and reduced epithelial-mesenchymal transition (EMT). Hsf1(+/+)Neu(+) mammary epithelial cells exposed to TGFß show high levels of ERK1/2 activity and EMT; this is associated with reduced expression of E-cadherin and increased expression of Slug and vimentin, a mesenchymal marker. In contrast, Hsf1(-/-)Neu(+) or Hsf1(+/+)Neu(+) cells do not exhibit activated ERK1/2 and show reduced EMT in the presence of TGFß. The ineffective activation of the RAS/RAF/MEK/ERK1/2 signaling pathway in cells with reduced levels of HSF1 is due to the low levels of HSP90 in complex with RAF1 that are required for RAF1 stability and maturation. These results indicate a powerful inhibitory effect conferred by HSF1 downstream target genes in the inhibition of ErbB2-induced breast cancers in the absence of the Hsf1 gene.


Subject(s)
Cell Transformation, Neoplastic/metabolism , DNA-Binding Proteins/biosynthesis , Gene Expression Regulation, Neoplastic , MAP Kinase Signaling System , Mammary Neoplasms, Animal/metabolism , Receptor, ErbB-2/metabolism , Transcription Factors/biosynthesis , Animals , Cadherins/genetics , Cadherins/metabolism , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/pathology , DNA-Binding Proteins/genetics , Female , HSP90 Heat-Shock Proteins/genetics , HSP90 Heat-Shock Proteins/metabolism , Heat Shock Transcription Factors , Mammary Neoplasms, Animal/genetics , Mammary Neoplasms, Animal/pathology , Mice , Mice, Knockout , Mitogen-Activated Protein Kinase 3/genetics , Mitogen-Activated Protein Kinase 3/metabolism , Neoplasm Metastasis , Proto-Oncogene Proteins c-raf/genetics , Proto-Oncogene Proteins c-raf/metabolism , Receptor, ErbB-2/genetics , Transcription Factors/genetics , Transforming Growth Factor beta/genetics , Transforming Growth Factor beta/metabolism
9.
Sci Rep ; 13(1): 7503, 2023 May 09.
Article in English | MEDLINE | ID: mdl-37161003

ABSTRACT

Emergency capability assessment is a complex system with multiple factors, variables and levels. Incomplete and uncertain assess information often occurs during assessment. Based on this, a method combining D-number theory and fuzzy analytic Hierarchy process (FAHP) is proposed to study the emergency capacity of coal enterprises in Longdong area. On the basis of analyzing the limitation of D-S evidence theory, the D-number theory was optimized and improved. According to the principles of systematicness, feasibility, scientificity and timeliness, a hierarchical structure model of enterprise emergency capability assessment was constructed from the perspective of pre-incident, mid-incident and post-incident, which consisted of 4 first-level indicators and 18 s-level indicators. The weight and importance of the assessment index of emergency response capability are calculated by organically integrating the D-number preference relation with the hierarchy structure. Combined with the assessment results of experts, a quantitative analysis and evaluation of the emergency response capacity of a coal enterprise was conducted by using FAHP. The comprehensive score of the enterprise's emergency response capability was 80.45, and the level of emergency response capacity was "good". The research results show that the D-FAHP method has high reliability in evaluating the emergency response capability of coal enterprises, avoiding the impact of uncertain and incomplete information on the assessment results. This can not only effectively identify the weak links in emergency management, but also meet the emergency decision-making needs of enterprises in the emergency state, which has important guiding significance to improve the ability and level of enterprise emergency management.

10.
Mol Cancer Res ; 21(10): 1079-1092, 2023 10 02.
Article in English | MEDLINE | ID: mdl-37364049

ABSTRACT

Correlations between the oxidative stress response and metabolic reprogramming have been observed during malignant tumor formation; however, the detailed mechanism remains elusive. The transcription factor Nrf2, a master regulator of the oxidative stress response, mediates metabolic reprogramming in multiple cancers. In a mouse model of hepatocellular carcinoma (HCC), through metabolic profiling, genome-wide gene expression, and chromatin structure analyses, we present new evidence showing that in addition to altering antioxidative stress response signaling, Nrf2 ablation impairs multiple metabolic pathways to reduce the generation of acetyl-CoA and suppress histone acetylation in tumors, but not in tumor-adjacent normal tissue. Nrf2 ablation and dysregulated histone acetylation impair transcription complex assembly on downstream target antioxidant and metabolic regulatory genes for expression regulation. Mechanistic studies indicate that the regulatory function of Nrf2 is low glucose dependent, the effect of which is demolished under energy refeeding. Together, our results implicate an unexpected effect of Nrf2 on acetyl-CoA generation, in addition to its classic antioxidative stress response regulatory activity, integrates metabolic and epigenetic programs to drive HCC progression. IMPLICATIONS: This study highlights that Nrf2 integrates metabolic and epigenetic regulatory networks to dictate tumor progression and that Nrf2 targeting is therapeutically exploitable in HCC treatment.


Subject(s)
Carcinoma, Hepatocellular , Liver Neoplasms , Animals , Mice , Acetyl Coenzyme A/genetics , Acetyl Coenzyme A/metabolism , Carcinoma, Hepatocellular/pathology , Epigenesis, Genetic , Histones/metabolism , Liver Neoplasms/pathology , NF-E2-Related Factor 2/genetics , NF-E2-Related Factor 2/metabolism
11.
J Exp Med ; 203(4): 1067-80, 2006 Apr 17.
Article in English | MEDLINE | ID: mdl-16606672

ABSTRACT

The receptor for advanced glycation end products (RAGE) is a member of the immunoglobulin superfamily that has multiple ligands and is implicated in the pathogenesis of various diseases, including diabetic complications, neurodegenerative disorders, and inflammatory responses. However, the role of RAGE in normal physiology is largely undefined. Here, we present evidence for a role of RAGE in osteoclast maturation and function, which has consequences for bone remodeling. Mice lacking RAGE had increased bone mass and bone mineral density and decreased bone resorptive activity in vivo. In vitro-differentiated RAGE-deficient osteoclasts exhibited disrupted actin ring and sealing zone structures, impaired maturation, and reduced bone resorptive activity. Impaired signaling downstream of alphavbeta3 integrin was observed in RAGE(-/-) bone marrow macrophages and precursors of OCs. These results demonstrate a role for RAGE in osteoclast actin cytoskeletal reorganization, adhesion, and function, and suggest that the osteosclerotic-like phenotype observed in RAGE knockout mice is due to a defect in osteoclast function.


Subject(s)
Bone and Bones/physiology , Osteoclasts/physiology , Receptors, Immunologic/physiology , Actins/physiology , Animals , Bone and Bones/cytology , Bone and Bones/metabolism , Bone and Bones/pathology , Cell Adhesion/physiology , Cell Differentiation/physiology , Cells, Cultured , Cytoskeleton/physiology , Down-Regulation/physiology , Glycation End Products, Advanced , Integrin alphaVbeta3/antagonists & inhibitors , Integrin alphaVbeta3/biosynthesis , Integrin alphaVbeta3/physiology , Macrophage Colony-Stimulating Factor/antagonists & inhibitors , Macrophage Colony-Stimulating Factor/physiology , Macrophages/physiology , Mice , Mice, Inbred C57BL , Mice, Knockout , Osteoclasts/cytology , Osteoclasts/metabolism , Osteoclasts/pathology , Receptor for Advanced Glycation End Products , Receptors, Immunologic/deficiency , Receptors, Immunologic/genetics
12.
Blood ; 115(15): 3136-45, 2010 Apr 15.
Article in English | MEDLINE | ID: mdl-20065295

ABSTRACT

Neogenin, a deleted in colorectal cancer (DCC) family member, has been identified as a receptor for the neuronal axon guidance cues netrins and repulsive guidance molecules repulsive guidance molecules (RGM). RGMc, also called hemojuvelin (HJV), is essential for iron homeostasis. Here we provide evidence that neogenin plays a critical role in iron homeostasis by regulation of HJV secretion and bone morphogenetic protein (BMP) signaling. Livers of neogenin mutant mice exhibit iron overload, low levels of hepcidin, and reduced BMP signaling. Mutant hepatocytes in vitro show impaired BMP2 induction of Smad1/5/8 phosphorylation and hepcidin expression. Neogenin is expressed in liver cells in a reciprocal pattern to that of hepcidin, suggesting that neogenin functions in a cell nonautonomous manner. Further studies demonstrate that neogenin may stabilize HJV, a glycosylphosphatidylinositol-anchored protein that interacts with neogenin and suppresses its secretion. Taken together, our results lead the hypothesis that neogenin regulates iron homeostasis via inhibiting secretion of HJV, an inhibitor of BMP signaling, to enhance BMP signaling and hepcidin expression. These results reveal a novel mechanism underlying neogenin regulation of HJV-BMP signaling.


Subject(s)
Antimicrobial Cationic Peptides/metabolism , Bone Morphogenetic Protein 2/pharmacology , Homeostasis/drug effects , Iron/metabolism , Membrane Proteins/metabolism , Animals , Antimicrobial Cationic Peptides/genetics , Cation Transport Proteins/metabolism , Extracellular Space/drug effects , Extracellular Space/metabolism , GPI-Linked Proteins , Gene Expression Regulation/drug effects , Hemochromatosis Protein , Hep G2 Cells , Hepatocytes/drug effects , Hepatocytes/metabolism , Hepatocytes/pathology , Hepcidins , Humans , Iron Overload/genetics , Iron Overload/pathology , Liver/drug effects , Liver/metabolism , Liver/pathology , Membrane Proteins/deficiency , Membrane Proteins/genetics , Mice , Mice, Inbred C57BL , Mice, Mutant Strains , Phosphorylation/drug effects , Protein Transport/drug effects , Signal Transduction/drug effects , Smad Proteins/metabolism
13.
Nat Cell Biol ; 7(11): 1124-32, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16244667

ABSTRACT

Neurite extension is essential for wiring the nervous system during development. Although several factors are known to regulate neurite outgrowth, the underlying mechanisms remain unclear. Here, we provide evidence for a role of phosphatidylinositol transfer protein-alpha (PlTPalpha) in neurite extension in response to netrin-1, an extracellular guidance cue. PlTPalpha interacts with the netrin receptor DCC (deleted in colorectal cancer) and neogenin. Netrin-1 stimulates PlTPalpha binding to DCC and to phosphatidylinositol (5) phosphate [Pl(5)P], increases its lipid-transfer activity and elevates hydrolysis of phosphatidylinositol bisphosphate (PlP2). In addition, the stimulated PIP2 hydrolysis requires PlTPalpha. Furthermore, cortical explants of PlTPalpha mutant mice are defective in extending neurites in response to netrin-1. Commissural neurons from chicken embryos expressing a dominant-negative PlTPalpha mutant show reduced axon outgrowth. Morpholino-mediated knockdown of PlTPalpha expression in zebrafish embryos leads to dose-dependent defects in motor-neuron axons and reduced numbers of spinal-cord neurons. Taken together, these results identify a crucial role for PlTPalpha in netrin-1-induced neurite outgrowth, revealing a signalling mechanism for DCC/neogenin and PlTPalpha regulation.


Subject(s)
Chick Embryo/cytology , Nerve Growth Factors/physiology , Neurites/metabolism , Phospholipid Transfer Proteins/physiology , Tumor Suppressor Proteins/physiology , Animals , Cells, Cultured , Chick Embryo/metabolism , DCC Receptor , Humans , Lipid Metabolism/physiology , Membrane Proteins/metabolism , Membrane Proteins/physiology , Netrin-1 , Neurons/cytology , Neurons/metabolism , Phosphatidylinositol 4,5-Diphosphate/metabolism , Phospholipid Transfer Proteins/metabolism , Receptors, Cell Surface/metabolism , Signal Transduction/drug effects , Transfection , Tumor Suppressor Proteins/metabolism , Zebrafish/embryology , Zebrafish/physiology , Zebrafish Proteins
14.
Mol Immunol ; 46(4): 729-37, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19041137

ABSTRACT

Immunotherapy of rheumatoid arthritis (RA) using oral-dosed native chicken or bovine type II collagen (nCII) to induce specific immune tolerance is an attractive strategy. However, the majority of clinical trials of oral tolerance in human diseases including RA in recent years have been disappointing. Here, we describe a novel recombinant peptide rcCTE1-2 which contains only two tolerogenic epitopes (CTE1 and CTE2) of chicken type II collagen (cCII). These are the critical T-cell determinants for suppression of RA that were first developed and used to compare its suppressive effects with ncCII on the collagen-induced arthritis (CIA) model. The rcCTE1-2 was produced using the prokaryotic pET expression system and purified by Ni-NTA His affinity chromatography. Strikingly, our results showed clearly that rcCTE1-2 was as efficacious as ncCII at the dose of 50 microg/kg/d. This dose significantly reduced footpad swelling, arthritic incidence and scores, and deferred the onset of disease. Furthermore, rcCTE1-2 of 50 microg/kg/d could lower the level of anti-nCII antibody in the serum of CIA animals, decrease Th1-cytokine INF-gamma level, and increase Th3-cytokine TGF-beta(1) produced level by spleen cells from CIA mice after in vivo stimulation with ncCII. Importantly, rcCTE1-2 was even more potent than native cCII, which was used in the clinic for RA. Equally importantly, the findings that the major T-cell determinants of cCII that are also recognized by H-2(b) MHC-restricted T cells have not previously been reported. Taken together, these results suggest that we have successfully developed a novel recombinant peptide rcCTE1-2 that can induce a potent tolerogenic response in CIA.


Subject(s)
Arthritis, Experimental/therapy , Chickens/immunology , Collagen Type II/immunology , Epitopes, T-Lymphocyte/immunology , Epitopes/immunology , Recombinant Proteins/immunology , Animals , Antibodies/blood , Arthritis, Experimental/immunology , Arthritis, Experimental/pathology , Collagen Type II/biosynthesis , Collagen Type II/therapeutic use , Desensitization, Immunologic , Epitopes/metabolism , Epitopes, T-Lymphocyte/biosynthesis , Epitopes, T-Lymphocyte/therapeutic use , Female , Immune Tolerance/immunology , Immunotherapy , Interferon-gamma/biosynthesis , Interferon-gamma/immunology , Mice , Mice, Inbred Strains , Peptides/immunology , Peptides/therapeutic use , Recombinant Proteins/biosynthesis , Recombinant Proteins/therapeutic use , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Transforming Growth Factor beta/biosynthesis , Transforming Growth Factor beta/immunology
15.
Thorac Cancer ; 11(8): 2196-2208, 2020 08.
Article in English | MEDLINE | ID: mdl-32602212

ABSTRACT

BACKGROUND: Circular RNAs (circRNAs) have been closely implicated in competing endogenous RNA (ceRNA) network among human cancers including non-small cell lung cancer (NSCLC). However, the role of most circRNAs in NSCLC remains to be determined. Here, we aimed to investigate the role of hsa_circ_0007385 (circ_0007385) in NSCLC cells. METHODS: Expression of hsa_circ_0007385 (circ_0007385), miRNA (miR)-519d-5p and high-mobility group box 1 (HMGB1) was measured by real-time quantitative PCR and western blotting. Functional experiments were evaluated by cell counting kit (CCK)-8, flow cytometry, fluorescein active caspase-3 staining kit, transwell assays, western blotting, and xenograft experiment. The relationship among circ_0007385,miR-519d-5p and HMGB1 was testified by dual-luciferase reporter assay. Kaplan-Meiersurvival curve identified overall survival in NSCLC patients. RESULTS: circ_0007385 expression was higher in NSCLC tissues and cell lines, and was associated with poor overall survival. Silencing circ_0007385 could suppress cell proliferation, migration and invasion in A549 and H1975 cells, as well as cisplatin (DDP) resistance. Moreover, circ_0007385 silence retarded tumor growth of A549 cells in vivo. Molecularly, there was a direct interaction between miR-519d-3p and either circ_0007385 or HMGB1; expression of miR-519d-3p was downregulated in NSCLC tumors in a circ_0007385-correlated manner, and circ_0007385 could indirectly regulate HMGB1 via miR-519d-3p. Functionally, both inhibiting miR-519d-3p and restoring HMGB1 could overturn the suppressive effect of circ_0007385 knockdown on cell proliferation, migration, invasion, and DDP resistance. CONCLUSIONS: Collectively, circ_0007385 deletion could function anti-tumor role in NSCLC by suppressing malignant behaviors and DDP resistance in vitro and in vivo via circ_0007385/miR-519d-3p/HMGB1 axis. These outcomes might enhance our understanding of the molecular mechanisms underlying the malignant progression of NSCLC. KEY POINTS: SIGNIFICANT FINDINGS OF THE STUDY: circ_0007385 was upregulated in NSCLC tissues and cells, and was associated with poor overall survival. Silenced circ_0007385 suppressed NSCLC cell proliferation, migration, invasion, and DDP resistance in vitro, and tumor growth in vivo. circ_0007385 was upregulated in NSCLC tissues and cells, and was associated with poor overall survival. WHAT THIS STUDY ADDS: miR-519d-3p could directly interact with circ_0007385 and HMGB1 in NSCLC cells. A promising circ_0007385/miR-519d-3p/HMGB1 regulatory pathway was determined in NSCLC cells.


Subject(s)
Carcinoma, Non-Small-Cell Lung/drug therapy , Cisplatin/pharmacology , Lung Neoplasms/drug therapy , MicroRNAs/metabolism , RNA, Circular/metabolism , A549 Cells , Animals , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/metabolism , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line, Tumor , Drug Resistance, Neoplasm , Humans , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/pathology , Male , Mice , Mice, Inbred BALB C , Mice, Nude , MicroRNAs/genetics , RNA, Circular/genetics , Transfection , Xenograft Model Antitumor Assays
16.
Mol Cancer Res ; 18(3): 463-476, 2020 03.
Article in English | MEDLINE | ID: mdl-31744878

ABSTRACT

Deregulated oncogenic signaling linked to PI3K/AKT and mTORC1 pathway activation is a hallmark of human T-cell acute leukemia (T-ALL) pathogenesis and contributes to leukemic cell resistance and adverse prognosis. Notably, although the multiagent chemotherapy of leukemia leads to a high rate of complete remission, options for salvage therapy for relapsed/refractory disease are limited due to the serious side effects of augmenting cytotoxic chemotherapy. We report that ablation of HSF1, a key transcriptional regulator of the chaperone response and cellular bioenergetics, from mouse T-ALL tumors driven by PTEN loss or human T-ALL cell lines, has significant therapeutic effects in reducing tumor burden and sensitizing malignant cell death. From a mechanistic perspective, the enhanced sensitivity of T-ALLs to HSF1 depletion resides in the reduced MAPK-ERK signaling and metabolic and ATP-producing capacity of malignant cells lacking HSF1 activity. Impaired mitochondrial ATP production and decreased intracellular amino acid content in HSF1-deficient T-ALL cells trigger an energy-saving adaptive response featured by attenuation of the mTORC1 activity, which is coregulated by ATP, and its downstream target proteins (p70S6K and 4E-BP). This leads to protein translation attenuation that diminishes oncogenic signals and malignant cell growth. Collectively, these metabolic alterations in the absence of HSF1 activity reveal cancer cell liabilities and have a profound negative impact on T-ALL progression. IMPLICATIONS: Targeting HSF1 and HSF1-dependent cancer-specific anabolic and protein homeostasis programs has a significant therapeutic potential for T-ALL and may prevent progression of relapsed/refractory disease.


Subject(s)
Heat Shock Transcription Factors/metabolism , Mechanistic Target of Rapamycin Complex 1/metabolism , Precursor T-Cell Lymphoblastic Leukemia-Lymphoma/metabolism , Animals , Cell Line, Tumor , Disease Progression , Energy Metabolism , Female , Humans , Male , Mice , Signal Transduction
17.
Exp Biol Med (Maywood) ; 245(15): 1308-1318, 2020 09.
Article in English | MEDLINE | ID: mdl-32715783

ABSTRACT

IMPACT STATEMENT: Sickle cell disease is an inherited hemoglobin disorder that affects over 100,000 people in the United States causing high morbidity and early mortality. Although new treatments were recently approved by the FDA, only one drug Hydroxyurea induces fetal hemoglobin expression to inhibit sickle hemoglobin polymerization in red blood cells. Our laboratory previously demonstrated the ability of the NRF2 activator, dimethyl fumarate to induce fetal hemoglobin in the sickle cell mouse model. In this study, we investigated molecular mechanisms of γ-globin gene activation by NRF2. We observed the ability of NRF2 to modulate chromatin structure in the human ß-like globin gene locus of ß-YAC transgenic mice during development. Furthermore, an NRF2/TET3 interaction regulates γ-globin gene DNA methylation. These findings provide potential new molecular targets for small molecule drug developed for treating sickle cell disease.


Subject(s)
Chromosomes, Artificial, Yeast/metabolism , Epigenesis, Genetic , NF-E2-Related Factor 2/metabolism , gamma-Globins/genetics , Animals , Chromatin/metabolism , DNA/metabolism , DNA Methylation/genetics , Dioxygenases/metabolism , Erythroid Cells/metabolism , Erythropoiesis/genetics , Female , Genetic Loci , Humans , Male , Mice, Inbred C57BL , Mice, Transgenic , beta-Globins/metabolism
18.
JCI Insight ; 4(11)2019 06 06.
Article in English | MEDLINE | ID: mdl-31167967

ABSTRACT

Commonly available clinical parameters fail to predict early acute cellular rejection (EAR, occurring within 6 months after transplant), a major risk factor for graft loss after kidney transplantation. We performed whole-blood RNA sequencing at the time of transplant in 235 kidney transplant recipients enrolled in a prospective cohort study (Genomics of Chronic Allograft Rejection [GoCAR]) and evaluated the relationship of pretransplant transcriptomic profiles with EAR. EAR was associated with downregulation of NK and CD8+ T cell gene signatures in pretransplant blood. We identified a 23-gene set that predicted EAR in the discovery (n = 81, and AUC = 0.80) and validation (n = 74, and AUC = 0.74) sets. Exclusion of recipients with 5 or 6 HLA donor mismatches increased the AUC to 0.89. The risk score derived from the gene set was also significantly associated with acute cellular rejection after 6 months, antibody-mediated rejection and/or de novo donor-specific antibodies, and graft loss in a cohort of 154 patients, combining the validation set and additional GoCAR patients with surveillance biopsies between 6 and 24 months (n = 80) posttransplant. This 23-gene set is a potentially important new tool for determination of the recipient's immunological risk before kidney transplantation, and facilitation of an individualized approach to immunosuppressive therapy.


Subject(s)
Graft Rejection , Kidney Transplantation/adverse effects , Transcriptome/genetics , Adult , Biomarkers/blood , Biomarkers/metabolism , Female , Graft Rejection/diagnosis , Graft Rejection/epidemiology , Graft Rejection/genetics , Graft Rejection/metabolism , Humans , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Risk Assessment
19.
Sci China Life Sci ; 61(7): 815-825, 2018 07.
Article in English | MEDLINE | ID: mdl-29388039

ABSTRACT

Effective treatment of rheumatoid arthritis can be mediated by native chicken type II collagen (nCCII), recombinant peptide containing nCCII tolerogenic epitopes (CTEs), or a therapeutic DNA vaccine encoding the full-length CCOL2A1 cDNA. As recombinant CCII (rCCII) might avoid potential pathogenic virus contamination during nCCII preparation or chromosomal integration and oncogene activation associated with DNA vaccines, here we evaluated the importance of propeptide and telopeptide domains on rCCII triple helix molecular assembly. We constructed pC- and pN-procollagen (without N- or C-propeptides, respectively) as well as CTEs located in the triple helical domain lacking both propeptides and telopeptides, and expressed these in yeast Pichia pastoris host strain GS115 (his4, Mut+) simultaneously with recombinant chicken prolyl-4-hydroxylase α and ß subunits. Both pC- and pN-procollagen monomers accumulated inside P. pastoris cells, whereas CTE was assembled into homotrimers with stable conformation and secreted into the supernatants, suggesting that the large molecular weight pC-or pN-procollagens were retained within the endoplasmic reticulum whereas the smaller CTEs proceeded through the secretory pathway. Furthermore, resulting recombinant chicken type II collagen pCα1(II) can induced collagen-induced arthritis (CIA) rat model, which seems to be as effective as the current standard nCCII. Notably, protease digestion assays showed that rCCII could assemble in the absence of C- and N-propeptides or telopeptides. These findings provide new insights into the minimal structural requirements for rCCII expression and folding.


Subject(s)
Chickens/genetics , Collagen Type II/genetics , Collagen Type II/metabolism , Pichia/genetics , Animals , Arthritis, Rheumatoid/chemically induced , Arthritis, Rheumatoid/pathology , Cloning, Molecular , Collagen Type II/biosynthesis , Collagen Type II/chemistry , Disease Models, Animal , Peptides/chemistry , Peptides/genetics , Pichia/metabolism , Protein Engineering , Protein Folding , Rats , Recombinant Proteins/biosynthesis , Recombinant Proteins/chemistry , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , Transformation, Genetic
20.
Cell Metab ; 28(2): 228-242.e6, 2018 08 07.
Article in English | MEDLINE | ID: mdl-29887396

ABSTRACT

The inhibitory effects of cancer on T cell metabolism have been well established, but the metabolic impact of immunotherapy on tumor cells is poorly understood. Here, we developed a CD4+ T cell-based adoptive immunotherapy protocol that was curative for mice with implanted colorectal tumors. By conducting metabolic profiling on tumors, we show that adoptive immunotherapy profoundly altered tumor metabolism, resulting in glutathione depletion and accumulation of reactive oxygen species (ROS) in tumor cells. We further demonstrate that T cell-derived tumor necrosis factor alpha (TNF-α) can synergize with chemotherapy to intensify oxidative stress and tumor cell death in an NADPH (nicotinamide adenine dinucleotide phosphate hydrogen) oxidase-dependent manner. Reduction of oxidative stress, by preventing TNF-α-signaling in tumor cells or scavenging ROS, antagonized the therapeutic effects of adoptive immunotherapy. Conversely, provision of pro-oxidants after chemotherapy can partially recapitulate the antitumor effects of T cell transfer. These findings imply that reinforcing tumor oxidative stress represents an important mechanism underlying the efficacy of adoptive immunotherapy.


Subject(s)
Apoptosis/drug effects , CD4-Positive T-Lymphocytes/physiology , Colorectal Neoplasms , Immunotherapy, Adoptive/methods , Oxidative Stress/drug effects , Tumor Necrosis Factor-alpha/metabolism , Animals , Cell Line, Tumor , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/metabolism , Glutathione/metabolism , Mice , Mice, Inbred BALB C , NADPH Oxidases/metabolism , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Xenograft Model Antitumor Assays/methods
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