scholarly journals Cdx2 regulates immune cell infiltration in the intestine

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Simon Chewchuk ◽  
Sanzida Jahan ◽  
David Lohnes
Keyword(s):  
Intestinal Epithelium ◽  
Target Genes ◽  
Immune Cell ◽  
Cell Number ◽  
Macrophage Infiltration ◽  
Intestinal Homeostasis ◽  
Chronic Inflammatory Response ◽  
Complex Protein ◽  
Inflammatory Phenotype

AbstractThe intestinal epithelium is a unique tissue, serving both as a barrier against pathogens and to conduct the end digestion and adsorption of nutrients. As regards the former, the intestinal epithelium contains a diverse repertoire of immune cells, including a variety of resident lymphocytes, macrophages and dendritic cells. These cells serve a number of roles including mitigation of infection and to stimulate regeneration in response to damage. The transcription factor Cdx2, and to a lesser extent Cdx1, plays essential roles in intestinal homeostasis, and acts as a context-dependent tumour suppressor in colorectal cancer. Deletion of Cdx2 from the murine intestinal epithelium leads to macrophage infiltration resulting in a chronic inflammatory response. However the mechanisms by which Cdx2 loss evokes this response are poorly understood. To better understand this relationship, we used a conditional mouse model lacking all intestinal Cdx function to identify potential target genes which may contribute to this inflammatory phenotype. One such candidate encodes the histocompatability complex protein H2-T3, which functions to regulate intestinal iCD8α lymphocyte activity. We found that Cdx2 occupies the H3-T3 promoter in vivo and directly regulates its expression via a Cdx response element. Loss of Cdx function leads to a rapid and pronounced attenuation of H2-T3, followed by a decrease in iCD8α cell number, an increase in macrophage infiltration and activation of pro-inflammatory cascades. These findings suggest a previously unrecognized role for Cdx in intestinal homeostasis through H2-T3-dependent regulation of iCD8α cells.

scholarly journals Impact of Reduced ATGL-Mediated Adipocyte Lipolysis on Obesity-Associated Insulin Resistance and Inflammation in Male Mice

Endocrinology ◽  
2015 ◽  
Vol 156 (10) ◽  
pp. 3610-3624 ◽  
Author(s):  
Gabriele Schoiswohl ◽  
Maja Stefanovic-Racic ◽  
Marie N. Menke ◽  
Rachel C. Wills ◽  
Beth A. Surlow ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Target Genes ◽  
Immune Cell ◽  
Cell Infiltration ◽  
Peroxisome Proliferator ◽  
Immune Cell Infiltration ◽  
Lipid Uptake ◽  
Peroxisome Proliferator Activated Receptor ◽  
Triacylglycerol Hydrolysis

Emerging evidence suggests that impaired regulation of adipocyte lipolysis contributes to the proinflammatory immune cell infiltration of metabolic tissues in obesity, a process that is proposed to contribute to the development and exacerbation of insulin resistance. To test this hypothesis in vivo, we generated mice with adipocyte-specific deletion of adipose triglyceride lipase (ATGL), the rate-limiting enzyme catalyzing triacylglycerol hydrolysis. In contrast to previous models, adiponectin-driven Cre expression was used for targeted ATGL deletion. The resulting adipocyte-specific ATGL knockout (AAKO) mice were then characterized for metabolic and immune phenotypes. Lean and diet-induced obese AAKO mice had reduced adipocyte lipolysis, serum lipids, systemic lipid oxidation, and expression of peroxisome proliferator-activated receptor alpha target genes in adipose tissue (AT) and liver. These changes did not increase overall body weight or fat mass in AAKO mice by 24 weeks of age, in part due to reduced expression of genes involved in lipid uptake, synthesis, and adipogenesis. Systemic glucose and insulin tolerance were improved in AAKO mice, primarily due to enhanced hepatic insulin signaling, which was accompanied by marked reduction in diet-induced hepatic steatosis as well as hepatic immune cell infiltration and activation. In contrast, although adipocyte ATGL deletion reduced AT immune cell infiltration in response to an acute lipolytic stimulus, it was not sufficient to ameliorate, and may even exacerbate, chronic inflammatory changes that occur in AT in response to diet-induced obesity.

scholarly journals TM4SF5-mediated liver malignancy involves NK cell exhaustion-like phenotypes

2021 ◽  
Author(s):  
Hyunseung Sun ◽  
Eunmi Kim ◽  
Jihye Ryu ◽  
Hyejin Lee ◽  
Eun-Ae Shin ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Mouse Models ◽  
Immune Cell ◽  
Nk Cell ◽  
Cell Number ◽  
Liver Carcinogenesis ◽  
Liver Malignancy ◽  
Cell Exhaustion

AbstractAberrant extracellular matrix and immune cell alterations within the tumor microenvironment promote the pathological progression of liver carcinogenesis. Although transmembrane 4 L six family member 5 (TM4SF5) is involved in liver fibrosis and cancer, its mechanism avoiding immune surveillance during carcinogenesis remains unknown. We investigated how TM4SF5-mediated signaling caused immune evasion using in vitro primary cells and in vivo liver tissues from genetic or chemically induced mouse models. TM4SF5-transgenic and diethylnitrosamine (DEN)-induced liver cancer mouse models exhibited fibrotic and cancerous livers, respectively, with enhanced TM4SF5, pY705STAT3, collagen I, and laminin γ2 levels. These TM4SF5-mediated effects were abolished by TM4SF5 inhibitor, 4′-(p-toluenesulfonylamido)-4-hydroxychalcone (TSAHC). TM4SF5-dependent tumorigenesis involved natural killer (NK) cell exhaustion-like phenotypes including the reduction of NK cell number or function, which were blocked with TSAHC treatment. TM4SF5 expression in cancer cells downregulated stimulatory ligands and receptors for NK cell cytotoxicity, including SLAMF6, SLAMF7, MICA/B, and others. TM4SF5 suppression or inhibition reduced STAT3 signaling activity and recovered the receptor levels and NK cell surveillance, leading to reduced fibrotic and cancerous phenotypes, and longer survival. Altogether, these findings suggest that TM4SF5-mediated STAT3 activity for extracellular matrix modulation is involved in the progression of liver disease to HCC and that TM4SF5 appears to suppress NK cells during liver carcinogenesis.

scholarly journals DOT1L-Mediated H3K79 Methylation in Chromatin Is Dispensable for Wnt Pathway-Specific and Other Intestinal Epithelial Functions

2013 ◽  
Vol 33 (9) ◽  
pp. 1735-1745 ◽  
Author(s):  
Li-Lun Ho ◽  
Amit Sinha ◽  
Michael Verzi ◽  
Kathrin M. Bernt ◽  
Scott A. Armstrong ◽  
...  
Keyword(s):  
Stem Cells ◽  
Intestinal Epithelium ◽  
Target Genes ◽  
Intestinal Stem Cells ◽  
Intestinal Epithelial ◽  
Aberrant Expression ◽  
Genome Wide ◽  
Transcript Profiles ◽  
H3k79 Methylation

Methylation of H3K79 is associated with chromatin at expressed genes, though it is unclear if this histone modification is required for transcription of all genes. Recent studies suggest that Wnt-responsive genes depend particularly on H3K79 methylation, which is catalyzed by the methyltransferase DOT1L. Human leukemias carrying MLL gene rearrangements show DOT1L-mediated H3K79 methylation and aberrant expression of leukemogenic genes. DOT1L inhibitors reverse these effects, but their clinical use is potentially limited by toxicity in Wnt-dependent tissues such as intestinal epithelium. Genome-wide positioning of the H3K79me2 mark in Lgr5 + mouse intestinal stem cells and mature intestinal villus epithelium correlated with expression levels of all transcripts and not with Wnt-responsive genes per se . Selective Dot1l disruption in Lgr5 + stem cells or in whole intestinal epithelium eliminated H3K79me2 from the respective compartments, allowing genetic evaluation of DOT1L requirements. The absence of methylated H3K79 did not impair health, intestinal homeostasis, or expression of Wnt target genes in crypt epithelium for up to 4 months, despite increased crypt cell apoptosis. Global transcript profiles in Dot1l -null cells were barely altered. Thus, H3K79 methylation is not essential for transcription of Wnt-responsive or other intestinal genes, and intestinal toxicity is not imperative when DOT1L is rendered inactive in vivo .

scholarly journals Role of miRNAs shuttled by mesenchymal stem cell-derived small extracellular vesicles in modulating neuroinflammation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Debora Giunti ◽  
Chiara Marini ◽  
Benedetta Parodi ◽  
Cesare Usai ◽  
Marco Milanese ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Mode Of Action ◽  
Target Genes ◽  
Therapeutic Potential ◽  
Mapk Signaling ◽  
Target Cells ◽  
Inflammatory Phenotype ◽  
Lateral Sclerosis

AbstractMesenchymal stromal/stem cells (MSCs) are characterized by neuroprotective, immunomodulatory, and neuroregenerative properties, which support their therapeutic potential for inflammatory/neurodegenerative diseases, including multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS). One mode of action through which MSCs exert their immunomodulatory effects is release of extracellular vesicles that carry proteins, mRNAs, and microRNAs (miRNAs), which, once transferred, modify the function of target cells. We identified nine miRNAs significantly dysregulated in IFN-γ-primed MSCs, but present at different levels in their derived small extracellular vesicles (s-EV). We show that miR-467f and miR-466q modulate the pro-inflammatory phenotype of activated N9 microglia cells and of primary microglia acutely isolated from late symptomatic SOD1G93A mice, a murine ALS model, by downregulating Tnf and Il1b expression. Further analysis of the mode of action of miR-467f and miR-466q indicated that they dampen the pro-inflammatory phenotype of microglia by modulating p38 MAPK signaling pathway via inhibition of expression of their target genes, Map3k8 and Mk2. Finally, we demonstrated that in vivo administration of s-EV leads to decreased expression of neuroinflammation markers in the spinal cord of EAE-affected mice, albeit without affecting disease course. Overall, our data suggest that MSC-derived exosomes could affect neuroinflammation possibly through specific immunomodulatory miRNAs acting on microglia.

scholarly journals Men1 maintains exocrine pancreas homeostasis in response to inflammation and oncogenic stress

2020 ◽  
Vol 117 (12) ◽  
pp. 6622-6629 ◽  
Author(s):  
Amanda R. Wasylishen ◽  
Chang Sun ◽  
Gilda P. Chau ◽  
Yuan Qi ◽  
Xiaoping Su ◽  
...  
Keyword(s):  
Exocrine Pancreas ◽  
Molecular Mechanisms ◽  
Target Genes ◽  
Direct Evidence ◽  
Immune Cell ◽  
Cytokeratin 19 ◽  
Severe Damage ◽  
Oncogenic Stress ◽  
Genetic Mouse Models

A more comprehensive understanding of the molecular mechanisms underlying pancreatic diseases, including pancreatitis and cancer, is essential to improve clinical management. MEN1 has established roles in epigenetic regulation and tumor suppression in the endocrine pancreas; however, intriguing recent data suggest MEN1 may also function in the exocrine pancreas. Using physiologically relevant genetic mouse models, we provide direct evidence that Men1 is essential for exocrine pancreas homeostasis in response to inflammation and oncogenic stress. Men1 loss causes increased injury and impaired regeneration following acute caerulein-induced pancreatitis, leading to more severe damage, loss of the normal acinar compartment, and increased cytokeratin 19-positive metaplasias and immune cell infiltration. We further demonstrate the Men1 protein is stabilized in response to insult, and loss of Men1 is associated with the overexpression of proinflammatory Jund target genes, suggesting that loss of Men1-mediated repression of Jund activity is, at least in part, responsible for the impaired response. Finally, we demonstrate thatMen1loss significantly accelerates mutant Kras-dependent oncogenesis. Combined, this work establishes Men1 as an important mediator of pancreas homeostasis in vivo.

scholarly journals Cardiac macrophage subsets differentially regulate lymphatic network remodeling during pressure overload

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mathilde Bizou ◽  
Romain Itier ◽  
Mina Majdoubi ◽  
Dounia Abbadi ◽  
Estelle Pichery ◽  
...  
Keyword(s):  
Immune Cell ◽  
Pressure Overload ◽  
Gene Expression Signature ◽  
Cell Number ◽  
Cell Trafficking ◽  
Macrophage Subpopulations ◽  
Lymphatic Network ◽  
Macrophage Subsets

AbstractThe lymphatic network of mammalian heart is an important regulator of interstitial fluid compartment and immune cell trafficking. We observed a remodeling of the cardiac lymphatic vessels and a reduced lymphatic efficiency during heart hypertrophy and failure induced by transverse aortic constriction. The lymphatic endothelial cell number of the failing hearts was positively correlated with cardiac function and with a subset of cardiac macrophages. This macrophage population distinguished by LYVE-1 (Lymphatic vessel endothelial hyaluronic acid receptor-1) and by resident macrophage gene expression signature, appeared not replenished by CCR2 mediated monocyte infiltration during pressure overload. Isolation of macrophage subpopulations showed that the LYVE-1 positive subset sustained in vitro and in vivo lymphangiogenesis through the expression of pro-lymphangiogenic factors. In contrast, the LYVE-1 negative macrophage subset strongly expressed MMP12 and decreased the endothelial LYVE-1 receptors in lymphatic endothelial cells, a feature of cardiac lymphatic remodeling in failing hearts. The treatment of mice with a CCR2 antagonist during pressure overload modified the proportion of macrophage subsets within the pathological heart and preserved lymphatic network from remodeling. This study reports unknown and differential functions of macrophage subpopulations in the regulation of cardiac lymphatic during pathological hypertrophy and may constitute a key mechanism underlying the progression of heart failure.

scholarly journals Immune Dysregulation in HFpEF: A Target for Mesenchymal Stem/Stromal Cell Therapy

2020 ◽  
Vol 9 (1) ◽  
pp. 241 ◽  
Author(s):  
Ruxandra Sava ◽  
Carl Pepine ◽  
Keith March
Keyword(s):  
Heart Failure ◽  
Immune Cell ◽  
Therapeutic Option ◽  
Cell Types ◽  
Immune Dysregulation ◽  
Tissue Healing ◽  
Inflammatory Phenotype ◽  
Stromal Stem Cells

Over 26 million people worldwide suffer from heart failure, a disease associated with a 1 year mortality rate of 22%. Half of these patients present heart failure with preserved ejection fraction (HFpEF), for which there is no available therapy to improve prognosis. HFpEF is strongly associated with aging, inflammation, and comorbid burden, which are thought to play causal roles in disease development. Mesenchymal stromal/stem cells (MSCs) have potent immunomodulatory actions and promote tissue healing, thus representing an attractive therapeutic option in HFpEF. In this review, we summarize recent data suggesting that a two-hit model of immune dysregulation lies at the heart of the HFpEF. A first hit is represented by genetic mutations associated with clonal hematopoiesis of indeterminate potential (CHIP), which skew immune cells toward a pro-inflammatory phenotype, are associated with HFpEF development in animal models, and with immune dysregulation and risk of HF hospitalization in patients. A second hit is induced by cardiovascular risk factors, which cause subclinical cardiac dysfunction and production of danger signals. In mice, these attract proinflammatory macrophages, Th1 and Th17 cells into the myocardium, where they are required for the development of HFpEF. MSCs have been shown to reduce the pro-inflammatory activity of immune cell types involved in murine HFpEF in vitro, and to reduce myocardial fibrosis and improve diastolic function in vivo, thus they may efficiently target immune dysregulation in HFpEF and stop disease progression.

scholarly journals STAT3 and HIF1α cooperatively mediate the transcriptional and physiological responses to hypoxia

2021 ◽  
Author(s):  
Alberto Dinarello ◽  
Riccardo Massimiliano Betto ◽  
Chiara Cioccarelli ◽  
Linda Diamante ◽  
Giacomo Meneghetti ◽  
...  
Keyword(s):  
Molecular Mechanisms ◽  
Target Genes ◽  
Immune Cell ◽  
Large Fraction ◽  
Physiological Responses ◽  
Embryonic Stem ◽  
Knock Out ◽  
Two Factors ◽  
Cell Mobilization

STAT3 and HIF1α are two fundamental transcription factors involved in many merging properties, like angiogenesis, metabolism, and cell differentiation. Notably, under pathological conditions, the two factors have been shown to interact genetically, but both the molecular mechanisms underlying such interactions and their relevance under physiological conditions remains unclear. Here we report that STAT3 is required for the HIF1α-dependent response to hypoxia. In Stat3 knock-out pluripotent embryonic stem cells (ESCs), a large fraction of HIF1α target genes is not induced by hypoxia. Mechanistically, STAT3 does not regulate neither HIF1α expression nor stability, rather, it physically interacts with it in the nucleus. In vivo, we observed that both genetic and chemical inactivation of Stat3 blunted physiological responses to hypoxia, such as angiogenesis, erythropoiesis, and immune cell mobilization. Such defects were accompanied with faulty transcriptional activity of HIF1α. In sum, our data reveal that STAT3 and HIF1α cooperatively mediate the physiological response to hypoxia.

scholarly journals Creatine maintains intestinal homeostasis and protects against colitis

2017 ◽  
Vol 114 (7) ◽  
pp. E1273-E1281 ◽  
Author(s):  
Emre Turer ◽  
William McAlpine ◽  
Kuan-wen Wang ◽  
Tianshi Lu ◽  
Xiaohong Li ◽  
...  
Keyword(s):  
Immune Cell ◽  
Mammalian Target Of Rapamycin ◽  
Metabolic Stress ◽  
Recessive Model ◽  
Mucosal Barrier ◽  
Strongly Correlated ◽  
Intestinal Homeostasis ◽  
Rate Limiting Step ◽  
Phosphocreatine Shuttle

Creatine, a nitrogenous organic acid, replenishes cytoplasmic ATP at the expense of mitochondrial ATP via the phosphocreatine shuttle. Creatine levels are maintained by diet and endogenous synthesis from arginine and glycine. Glycine amidinotransferase (GATM) catalyzes the rate-limiting step of creatine biosynthesis: the transfer of an amidino group from arginine to glycine to form ornithine and guanidinoacetate. We screened 36,530 third-generation germline mutant mice derived from N-ethyl-N-nitrosourea–mutagenized grandsires for intestinal homeostasis abnormalities after oral administration of dextran sodium sulfate (DSS). Among 27 colitis susceptibility phenotypes identified and mapped, one was strongly correlated with a missense mutation in Gatm in a recessive model of inheritance, and causation was confirmed by CRISPR/Cas9 gene targeting. Supplementation of homozygous Gatm mutants with exogenous creatine ameliorated the colitis phenotype. CRISPR/Cas9-targeted (Gatmc/c) mice displayed a normal peripheral immune response and immune cell homeostasis. However, the intestinal epithelium of the Gatmc/c mice displayed increased cell death and decreased proliferation during DSS treatment. In addition, Gatmc/c colonocytes showed increased metabolic stress in response to DSS with higher levels of phospho-AMPK and lower levels of phosphorylation of mammalian target of rapamycin (phospho-mTOR). These findings establish an in vivo requirement for rapid replenishment of cytoplasmic ATP within colonic epithelial cells in the maintenance of the mucosal barrier after injury.

scholarly journals Oncostatin M Mediates Adipocyte Expression and Secretion of Stromal-Derived Factor 1

Biology ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 19
Author(s):  
Hardy Hang ◽  
Jennifer Bailey ◽  
Carrie Elks
Keyword(s):  
Adipose Tissue ◽  
Stromal Cells ◽  
Target Genes ◽  
Immune Cell ◽  
Tissue Homeostasis ◽  
Oncostatin M ◽  
Cytokines And Chemokines ◽  
Gene And Protein Expression ◽  
Cell Balance

Adipose tissue homeostasis depends on interactions between stromal cells, adipocytes, and the cytokines and chemokines they produce. The gp130 cytokine, oncostatin M (OSM), plays a role in adipose tissue homeostasis. Mice, lacking the OSM receptor (OSMR) in adipocytes (OsmrFKO mice), exhibit derangements in adipose tissue, insulin sensitivity, and immune cell balance. Here, we describe a possible role for the chemokine stromal-derived factor 1 (SDF-1) in these alterations. We treated 3T3-L1 adipocytes with OSM and observed a suppression of SDF-1 gene expression and protein secretion, an effect which was partially blunted by OSMR knockdown. However, OsmrFKO mice also exhibited decreased SDF-1 gene and protein expression in adipose tissue. These contrasting results suggest that the loss of adipocyte OSM–OSMR signaling in vivo may be indirectly affecting adipokine production and secretion by altering OSM target genes to ultimately decrease SDF-1 expression in the OsmrFKO mouse. We conclude that adipocyte OSM–OSMR signaling plays a role in adipose tissue SDF-1 production and may mitigate its effects on adipose tissue homeostasis.

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