0000000000181480
AUTHOR
Maria D. Barrachina
Efavirenz induces interactions between leucocytes and endothelium through the activation of Mac-1 and gp150,95
The potential cardiovascular (CV) toxicity associated with combined antiretroviral therapy (cART) has been attributed mainly to the nucleoside reverse transcriptase inhibitors abacavir and didanosine. However, the other two components of cART--non-nucleoside reverse transcriptase inhibitors (NNRTIs) and protease inhibitors (PIs)--may also be implicated, either directly or by influencing the action of the other drugs. This study evaluates the acute direct effects of the NNRTIs efavirenz and nevirapine and one of the most widely employed PIs, lopinavir, on leucocyte-endothelium interactions, a hallmark of CV disease.Drugs were analysed in vitro in human cells (interactions of peripheral blood…
Succinate receptor mediates intestinal inflammation and fibrosis.
Succinate, an intermediate of the tricarboxylic acid cycle, is accumulated in inflamed areas and its signaling through succinate receptor (SUCNR1) regulates immune function. We analyze SUCNR1 expression in the intestine of Crohn's disease patients and its role in murine intestinal inflammation and fibrosis. We show that both serum and intestinal succinate levels and SUCNR1 expression in intestinal surgical resections were higher in CD patients than in controls. SUCNR1 co-localized with CD86, CD206, and alpha-SMA(+) cells in human intestine and we found a positive and significant correlation between SUCNR1 and alpha-SMA expression. In human isolated fibroblasts from CD patients SUCNR1 expres…
Nitrergic modulation of gastrointestinal function during early endotoxemia.
After bacterial infection, the host reacts by signalling to the central nervous system where a cascade of physiologic, neuroendocrine and behavioural processes is orchestrated, collectively termed the acute phase response. Endotoxemia following Gram-negative bacterial infection induces a wide array of effects, including fever, loss of appetite and changes in gastrointestinal function that attempt to eliminate the challenge and restore homeostasis. Systemic administration of low doses of endotoxin (5-40 microg/kg) to rats is associated with changes in gastrointestinal motor function, inhibition of gastric acid secretion and increase in the gastric mucosal resistance to damage. These changes …
HIF-Overexpression and Pro-Inflammatory Priming in Human Mesenchymal Stromal Cells Improves the Healing Properties of Extracellular Vesicles in Experimental Crohn’s Disease
Extracellular vesicles (EVs) derived from mesenchymal stromal cells (MSCs) have therapeutic potential in the treatment of several immune disorders, including ulcerative colitis, owing to their regenerative and immunosuppressive properties. We recently showed that MSCs engineered to overexpress hypoxia-inducible factor 1-alpha and telomerase (MSC-T-HIF) and conditioned with pro-inflammatory stimuli release EVs (EVMSC-T-HIFC) with potent immunomodulatory activity. We tested the efficacy of EVMSC-T-HIFC to repolarize M1 macrophages (Mφ1) to M2-like macrophages (Mφ2-like) by analyzing surface markers and cytokines and performing functional assays in co-culture, including efferocytosis and T-cel…
THE VITAMIN D RECEPTOR TAQ I POLYMORPHISM IS ASSOCIATED WITH REDUCED VDR AND INCREASED PDIA3 PROTEIN LEVELS IN HUMAN INTESTINAL FIBROBLASTS
The synonymous single nucleotide polymorphism (SNP) rs731236, located in the vitamin D receptor (VDR) gene (Taq I) has been associated with both decreased levels of the protein in peripheral blood mononuclear cells and a fibrosis-related complication in Crohn´s disease (CD). Interactions between VDR and a protein-disulfide isomerase-associated 3 (PDIA3) in the regulation of extracellular matrix have been reported and we aim to analyze the relevance of the VDR genotypes and the effects of Vitamin D (VD) in the expression of VDR, PDIA3 and proliferation of intestinal fibroblasts. Human intestinal fibroblasts were isolated from the non-affected surgical resections of colorectal patients and cl…
Effects of Mn2+ on the responses induced by different spasmogens in the oestrogen-primed rat uterus
Abstract We investigated the effect of Mn 2+ on the mechanical responses evoked by high K + (60 mM) or low Na + (25 mM) solutions, oxytocin and neurokinin A in the oestrogen-primed rat uterus. In a Ca 2+ -free, Mn 2+ (0.54 mM)-containing solution, high K + or low Na + solutions produced contractions of smaller amplitude than those observed in a normal Ca 2+ (0.54 mM) solution, which were abolished by nifedipine (1 μM). Oxytocin (1 μM) and neurokinin A (1 μM, in the presence of phosphoramidon 1 μM) evoked nifedipine-insensitive contractile responses similar to (oxytocin) or smaller (neurokinin A) in amplitude than those observed in Ca 2+ (0.54 mM)-containing solution. In strips loaded with C…
Autophagy Stimulation as a Potential Strategy Against Intestinal Fibrosis
We recently observed reduced autophagy in Crohn’s disease patients and an anti-inflammatory effect of autophagy stimulation in murine colitis, but both anti- and pro-fibrotic effects are associated with autophagy stimulation in different tissues, and fibrosis is a frequent complication of Crohn’s disease. Thus, we analyzed the effects of pharmacological modulation of autophagy in a murine model of intestinal fibrosis and detected that autophagy inhibition aggravates, while autophagy stimulation prevents, fibrosis. These effects are associated with changes in inflammation and in collagen degradation in primary fibroblasts. Thus, pharmacological stimulation of autophagy may be useful against …
Induction of CD36 and thrombospondin-1 in macrophages by hypoxia-inducible factor 1 and its relevance in the inflammatory process.
Inflammation is part of a complex biological response of vascular tissue to pathogens or damaged cells. First inflammatory cells attempt to remove the injurious stimuli and this is followed by a healing process mediated principally by phagocytosis of senescent cells. Hypoxia and p38-MAPK are associated with inflammation, and hypoxia inducible factor 1 (HIF-1) has been detected in inflamed tissues. We aimed to analyse the role of p38-MAPK and HIF-1 in the transcriptional regulation of CD36, a class B scavenger receptor, and its ligand thrombospondin (TSP-1) in macrophages and to evaluate the involvement of this pathway in phagocytosis of apoptotic neutrophils. We have also assessed HIF-1α, p…
Profile of leukocyte-endothelial cell interactions induced in venules and arterioles by nucleoside reverse-transcriptase inhibitors in vivo.
Background There is controversy regarding cardiovascular (CV) toxicity of the nucleoside reverse-transcriptase inhibitors used to treat human immunodeficiency virus infection. Methods We evaluated the effects of nucleoside reverse-transcriptase inhibitors on leukocyte-endothelium interactions, a hallmark of CV diseases, in rat mesenteric vessels using intravital microscopy and in human arterial cells using a flow chamber system. Results Abacavir and didanosine increased rolling, adhesion and emigration in rat vessels. These effects were reversed with antibodies against Macrophage-1 antigen (Mac-1) or intercellular adhesion molecule 1 and were reproduced in human cells. Lamivudine, zidovudin…
CD16+ Macrophages Mediate Fibrosis in Inflammatory Bowel Disease.
Background and Aims Fibrosis is a common complication of Crohn's disease [CD], and is related to dysregulated tissular repair following inflammation, in which macrophages play a central role. We have previously observed that STAT6-/- mice present delayed mucosal recovery after 2,4,6-trinitrobenzenesulfonic acid [TNBS]-induced colitis due to a deficiency in reparatory interleukin-4 [IL4]/STAT6-dependent M2 macrophages, which can be reverted by the exogenous transfer of this cell type. In the present study, we analyse the role of STAT6-dependent macrophages in intestinal fibrosis. Methods Colitis was induced by weekly intra-rectal administration of TNBS [6 weeks] to STAT6-/- mice and wild-typ…
Role of Nitric Oxide in Gastrointestinal Inflammatory and Ulcerative Diseases: Perspective for Drugs Development
Nitric oxide is a ubiquitous molecule involved in a variety of biological processes. The specific action of NO depends on its enzymatic sources namely neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS) and inducible NOS (iNOS) and all three isoforms have been localized in the gastrointestinal tract. Constitutive synthesis of NO by nNOS or eNOS isoforms is involved in the maintaining of the gastrointestinal mucosal integrity through modulation of gastric mucosal blood flow, epithelial secretion and barrier function. However, large amounts of NO synthesized from the inducible isoform have been implicated in tissue injury in the gut during inflammatory reactions. In this review we p…
Stimulation of autophagy prevents intestinal mucosal inflammation and ameliorates murine colitis
Background and pourpose A defective autophagy is involved in the pathogenesis of inflammatory disorders such as IBD. Cross talk interactions between autophagy and inflammation have been reported and we analyse the effects of autophagy stimulators on murine colitis. Experimental approach Mice were treated with intrarectal administration of TNBS (3.5 mg/20 g BW) and body weight was measured every day and histological damage score analysed two or four days after treatment. Some mice received trehalose (3% in drinking water three weeks before TNBS administration) or a daily administration of rapamycin (1.25 mg/kg, i.p.), betanin (1g/kg, i.p.) or betanin + 3MA (10mg/kg, i.p.). Mucosal protein le…
Diminished Vitamin D Receptor Protein Levels in Crohn´s Disease Fibroblasts: Effects of Vitamin D
Vitamin D (VD) deficiency has been associated to Crohn´
iNOS-derived nitric oxide mediates the increase in TFF2 expression associated with gastric damage: role of HIF-1.
Trefoil (TFF) peptides are involved in gastrointestinal mucosal restitution. An hypoxia inducible factor 1 (HIF-1)-dependent induction of TFF genes has been reported in gastric epithelial cells. Nitric oxide (NO) is associated with mucosal damage and modulates HIF-1 activity. The aim of the present study was to analyze the role of iNOS-derived NO in HIF-1alpha stabilization and TFF gene expression in damaged gastric mucosa. Aspirin caused gastric injury that peaked 6 h after dosing and returned to normality at 24 h. iNOS mRNA expression occurs in the corpus in parallel with damage. Blockade of iNOS activity did not modify gastric lesions induced by aspirin but delayed mucosal healing. Aspir…
Role of central oxytocin in the inhibition by endotoxin of distension-stimulated gastric acid secretion
The gastric acid hyposecretory state associated with endotoxemia is mediated by a nervous reflex involving the central nervous system. The aim of the present study was to analyse the central effects of different peptides on distension-stimulated gastric acid secretion and the endogenous role of such peptides on the hyposecretory effects of endotoxin. The effect of an intracisternal (i.c.) administration of oxytocin, vasopressin, corticotropin releasing factor (CRF), bombesin, somatostatin and the opioid receptor agonist BW443C or an intravenous (i.v.) injection of a small dose of endotoxin on distension-stimulated gastric acid secretion was studied in the continuously perfused stomach of an…
The flesh ethanolic extract of Hylocereus polyrhizus exerts anti-inflammatory effects and prevents murine colitis
IBD is a chronic disorder of the gastrointestinal tract characterized by mucosal inflammation and epithelial damage. Biologic therapy has significantly improved the course of the disease but there are still a high percentage of patients that do not respond to current therapies. We aim to determine the effects of the flesh ethanolic extract of Hylocereus polyrhizus (EH) in a mice model of colitis induced by TNBS.Balb/c mice received TNBS (175 mg/kg, 100 μl, i.r.) and six and thirty hours later were administered with EH (1 g/kg, i.p.). Mice were weighted daily and after sacrificing (2 and 4 days after TNBS) we analyzed mucosal histology, myeloperoxidase activity (MPO), the expression of pro-i…
Endotoxin inhibits gastric emptying in rats via a capsaicin-sensitive afferent pathway.
The effects of endotoxin on gastric emptying of a solid nutrient meal and the neural mechanisms involved in such a response were investigated in conscious rats. The intraperitoneal (i.p.) administration of E. coli endotoxin (40 mug/kg) significantly reduced the 4-h rate of gastric emptying of a standard solid nutrient meal. Ablation of primary afferent neurons by systemic administration of high doses of capsaicin (20+30+50 mg/kg s.c.) to adult rats did not modify the rate of gastric emptying in control animals but prevented the delay in gastric transit induced by endotoxin. Local application of capsaicin to the vagus nerve rather than application of capsaicin to the celiac ganglion signific…
WNT2b activates epithelial-mesenchymal transition through FZD4: relevance in penetrating Crohns disease.
Abstract Background and Aims Epithelial-mesenchymal transition [EMT] has been related to fibrosis and fistula formation, common complications associated with Crohn´s disease [CD]. The WNT signalling pathway mediates EMT, and specific WNT/FZD interactions have been related to the activation of this process in several diseases. We aim to analyse the relevance of EMT and WNT ligands and receptors in the penetrating behaviour of CD. Methods Intestinal surgical resections were obtained from control and CD patients with a stenotic or penetrating behaviour. Fibrosis was determined by the histological analysis of collagen deposition and EMT by confocal microscopy. The expression of WNT ligands, inh…
Gastrin induces the interaction between human mononuclear leukocytes and endothelial cells through the endothelial expression of P-selectin and VCAM-1.
Gastric mucosal inflammation is frequently associated with hypergastrinemia, and a correlation exists between the level of gastrin and degree of gastritis. We have previously observed that gastrin promotes leukocyte-endothelial interactions and contributes to Helicobacter -induced inflammation in the rat mesentery. In the present study, we aimed to evaluate a possible proinflammatory activity of gastrin in humans. The interaction between human leukocytes [U-937 cells, peripheral blood polymorphonuclear (PMN), and peripheral blood mononuclear (PBMC) cells] and human umbilical vein endothelial cells (HUVEC) was analyzed in static and dynamic conditions. The endothelial expression of adhesion …
A cerebral nitrergic pathway modulates endotoxin-induced changes in gastric motility
1 This study analyses the neural pathway involved in the modulation of gastric motor function by stress. 2 Systemic administration of low doses of endotoxin (40 m gk g 71 , i.v.) prevents the increase in gastric tone induced by 2-deoxy-D-glucose (200 mg kg 71 , i.v., 2-DG) in urethane-anaesthetized rats. 3 Functional inhibition of aAerent neurones by systemic administration of capsaicin (20+30+50 mg kg 71 , i.m.) in adult rats prevented the inhibitory eAects of endotoxin. 4 Pre-treatment with the nitric oxide synthase (NOS) inhibitor, N G -nitro-L-arginine methyl ester (LNAME), both i.v. (10 mg kg 71 ) and i.c. (200 mg rat 71 ), prevented the inhibitory eAects of endotoxin on gastric tone i…
A Single Nucleotide Polymorphism in the Vitamin D Receptor Gene Is Associated With Decreased Levels of the Protein and a Penetrating Pattern in Crohn’s Disease
Background: Vitamin D signaling modulates inflammation through the vitamin D receptor (VDR). The synonymous single nucleotide polymorphism (SNP) rs731236, located in the VDR gene, has been associated with a higher risk of Crohn's disease (CD). We analyzed differences in VDR expression levels among CD patients who were homozygous for allelic variants in this SNP and their relevance for disease course. Methods: DNA was extracted from blood samples of CD patients, and SNP genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism. Fresh blood from patients was used to isolate peripheral blood mononuclear cells (PBMCs) or to determine the expression of adhesi…
Metabolite Sensing GPCRs: Promising Therapeutic Targets for Cancer Treatment?
G-protein-coupled receptors constitute the most diverse and largest receptor family in the human genome, with approximately 800 different members identified. Given the well-known metabolic alterations in cancer development, we will focus specifically in the 19 G-protein-coupled receptors (GPCRs), which can be selectively activated by metabolites. These metabolite sensing GPCRs control crucial processes, such as cell proliferation, differentiation, migration, and survival after their activation. In the present review, we will describe the main functions of these metabolite sensing GPCRs and shed light on the benefits of their potential use as possible pharmacological targets for cancer treat…
Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition)
Seuls les 100 premiers auteurs dont les auteurs INRA ont été entrés dans la notice. La liste complète des auteurs et de leurs affiliations est accessible sur la publication.; International audience; In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues…
ER stress in human hepatic cells treated with Efavirenz: Mitochondria again
Background & Aims ER stress is associated with a growing number of liver diseases, including drug-induced hepatotoxicity. The non-nucleoside analogue reverse transcriptase inhibitor Efavirenz, a cornerstone of the multidrug strategy employed to treat HIV1 infection, has been related to the development of various adverse events, including metabolic disturbances and hepatic toxicity, the mechanisms of which remain elusive. Recent evidence has pinpointed a specific mitochondrial effect of Efavirenz in human hepatic cells. This study assesses the induction of ER stress by Efavirenz in the same model and the implication of mitochondria in this process. Methods Primary human hepatocytes and Hep3B…
M2 Macrophages Activate WNT Signaling Pathway in Epithelial Cells: Relevance in Ulcerative Colitis
Macrophages, which exhibit great plasticity, are important components of the inflamed tissue and constitute an essential element of regenerative responses. Epithelial Wnt signalling is involved in mechanisms of proliferation and differentiation and expression of Wnt ligands by macrophages has been reported. We aim to determine whether the macrophage phenotype determines the expression of Wnt ligands, the influence of the macrophage phenotype in epithelial activation of Wnt signalling and the relevance of this pathway in ulcerative colitis. Human monocyte-derived macrophages and U937-derived macrophages were polarized towards M1 or M2 phenotypes and the expression of Wnt1 and Wnt3a was analy…
Indomethacin Disrupts Autophagic Flux by Inducing Lysosomal Dysfunction in Gastric Cancer Cells and Increases Their Sensitivity to Cytotoxic Drugs
AbstractNSAIDs inhibit tumorigenesis in gastrointestinal tissues and have been proposed as coadjuvant agents to chemotherapy. The ability of cancer epithelial cells to adapt to the tumour environment and to resist cytotoxic agents seems to depend on rescue mechanisms such as autophagy. In the present study we aimed to determine whether an NSAID with sensitizing properties such as indomethacin modulates autophagy in gastric cancer epithelial cells. We observed that indomethacin causes lysosomal dysfunction in AGS cells and promotes the accumulation of autophagy substrates without altering mTOR activity. Indomethacin enhanced the inhibitory effects of the lysosomotropic agent chloroquine on l…
Transcriptional up-regulation of nNOS in the dorsal vagal complex during low endotoxemia
The present study analyses the expression and distribution of neuronal nitric oxide synthase (nNOS) in the brainstem of animals pre-treated with Escherichia coli or Helicobacter pylori LPS, at doses that modulate gastric motor function. Systemic administration of H. pylori LPS prevented in a dose-dependent manner (5, 40 and 100 microg kg(-1), i.v.) the increase in intragastric pressure induced by 2-deoxy-D-glucose (200 mg kg(-1), i.v.) in urethane-anaesthetized rats. Quantitative analysis showed a significant increase in the amount of nNOS mRNA induced by E. coli or H. pylori LPS (2 h later), in a segment of the brainstem containing the dorsal vagal complex (DVC). Immunohistochemical studie…
Erratum
Author(s): Klionsky, DJ; Abdelmohsen, K; Abe, A; Abedin, MJ; Abeliovich, H; Arozena, AA; Adachi, H; Adams, CM; Adams, PD; Adeli, K; Adhihetty, PJ; Adler, SG; Agam, G; Agarwal, R; Aghi, MK; Agnello, M; Agostinis, P; Aguilar, PV; Aguirre-Ghiso, J; Airoldi, EM; Ait-Si-Ali, S; Akematsu, T; Akporiaye, ET; Al-Rubeai, M; Albaiceta, GM; Albanese, C; Albani, D; Albert, ML; Aldudo, J; Algul, H; Alirezaei, M; Alloza, I; Almasan, A; Almonte-Beceril, M; Alnemri, ES; Alonso, C; Altan-Bonnet, N; Altieri, DC; Alvarez, S; Alvarez-Erviti, L; Alves, S; Amadoro, G; Amano, A; Amantini, C; Ambrosio, S; Amelio, I; Amer, AO; Amessou, M; Amon, A; An, Z; Anania, FA; Andersen, SU; Andley, UP; Andreadi, CK; Andrieu-Ab…
Downregulation of nNOS and synthesis of PGs associated with endotoxin-induced delay in gastric emptying
A single intraperitoneal injection of endotoxin (40 μg/kg) significantly delayed gastric emptying of a solid nutrient meal. Blockade of nitric oxide synthase (NOS) with 30 mg/kg ip N G-nitro-l-arginine methyl ester or 20 mg/kg ip 7-nitroindazole [neuronal NOS (nNOS) inhibitor] significantly delayed gastric emptying in control animals but failed to modify gastric emptying in endotoxin-treated rats. Administration of 2.5, 5, and 10 mg/kg ip N 6-iminoethyl-l-lysine [inducible NOS (iNOS) inhibitor] had no effect in either experimental group. Indomethacin (5 mg/kg sc), NS-398 (cyclooxygenase-2 inhibitor; 10 mg/kg ip), and dexamethasone (10 mg/kg sc) but not quinacrine (20 mg/kg ip) significantl…
Succinate Activates EMT in Intestinal Epithelial Cells through SUCNR1: A Novel Protagonist in Fistula Development
The pathogenesis of Crohn&rsquo