Protective effect of thioredoxin upon NO-mediated cell injury in THP1 monocytic human cells.
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ABSTRACT:
SUBMITTER: Ferret PJ
PROVIDER: S-EPMC1220910 | biostudies-other | 2000 Mar
REPOSITORIES: biostudies-other
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Project description:AimsMonocytes play a significant role in the development of atherosclerosis. During the process of inflammation, circulating monocytes become activated in the blood stream. The consequent interactions of the activated monocytes with the blood flow and endothelial cells result in reorganization of cytoskeletal proteins, in particular of the microfilament structure, and concomitant changes in cell shape and mechanical behavior. Here we investigate the full elastic behavior of activated monocytes in relation to their cytoskeletal structure to obtain a better understanding of cell behavior during the progression of inflammatory diseases such as atherosclerosis.Methods and resultsThe recently developed Capillary Micromechanics technique, based on exposing a cell to a pressure difference in a tapered glass microcapillary, was used to measure the deformation of activated and non-activated monocytic cells. Monitoring the elastic response of individual cells up to large deformations allowed us to obtain both the compressive and the shear modulus of a cell from a single experiment. Activation by inflammatory chemokines affected the cytoskeletal organization and increased the elastic compressive modulus of monocytes with 73-340%, while their resistance to shape deformation decreased, as indicated by a 25-88% drop in the cell's shear modulus. This decrease in deformability is particularly pronounced at high strains, such as those that occur during diapedesis through the vascular wall.ConclusionOverall, monocytic cells become less compressible but more deformable upon activation. This change in mechanical response under different modes of deformation could be important in understanding the interplay between the mechanics and function of these cells. In addition, our data are of direct relevance for computational modeling and analysis of the distinct monocytic behavior in the circulation and the extravascular space. Lastly, an understanding of the changes of monocyte mechanical properties will be important in the development of diagnostic tools and therapies concentrating on circulating cells.
| S-EPMC3968036 | biostudies-literature
Project description:BackgroundThe aim of this study was to investigate the protective effect of 1α,25-dihydroxyvitamin D3 [1,25(OH)2D3] on effector CD4+ T cells or on inflammatory cytokine-induced injury in human renal proximal tubular epithelial cells (HRPTEpiC).MethodsFirst, we investigated the effect of 1,25(OH)2D3 on CD4+ T cell proliferation. Second, we examined the effect of 1,25(OH)2D3 on inflammatory cytokine secretion or fibrosis in HRPTEpiC induced by inflammatory cytokines or activated CD4+ T cells using ELISA and real-time PCR. Lastly, we compared urine inflammatory-cytokine (IL-6, IL-8) or KIM-1 levels in kidney transplant recipients low serum 25-hydroxyvitamin D (25(OH)D) group (< 20 ng/mL) (n = 40) and normal 25(OH)D group (n = 50).ResultsPre-incubation with 1,25(OH)2D3 significantly reduced the percentages of Th1 and Th17 cells compared to that of Th0 condition (P < 0.05 for each). In contrast, 1,25(OH)2D3 increased the proportion of Th2 and Treg cells in a dose-dependent manner (P < 0.05 for each). Treatment of HRPTEpiC with inflammatory cytokines (TNF-α, IL-17, and TGF-β) or effector CD4+ T cells resulted in increased production of IL-6, IL-8, or KIM-1 from HRPTEpiC in a dose-dependent manner. However, treatment with 1,25(OH)2D3 significantly reduced the level of these cytokines (P < 0.05 for all). Western blot analysis demonstrated that the mTOR/STAT3/ERK pathway was downregulated by 1,25(OH)2D3 in HRPTEpiC. Furthermore, the concentrations of urine IL-6/creatinine (P < 0.05) and Kim-1/creatinine (P < 0.05) were higher in the low 25(OH)D group than in the normal 25(OH)D group in kidney transplant recipients.ConclusionThe results of this study suggests that vitamin D may have a significant role in the regulation of inflammation in allograft tissue in kidney transplant recipients.Trial registrationAll participants provided written informed consent in accordance with the Declaration of Helsinki. This study was approved by the Institutional Review Board of Seoul St. Mary's Hospital (KC13TNMI0701).
| S-EPMC5330482 | biostudies-literature
Project description:Mechanical ventilation is an indispensable life-support treatment for acute respiratory failure in critically ill patients, which is generally believed to involve uncontrolled inflammatory responses. Oxytocin (OT) has been reported to be effective in animal models of acute lung injury. However, it is not clear whether Oxytocin has a protective effect on ventilator-induced lung injury (VILI). Therefore, in this study, we aimed to determine whether OT can attenuate VILI and explore the possible mechanism of this protection. To this end, a mouse VILI model was employed. Mice were pretreated with OT 30 min before the intraperitoneal injection of saline or nigericin and ventilation for 4 h, after which they were euthanized. Pathological changes, lung wet/dry (W/D) weight ratio, myeloperoxidase (MPO) activity, the levels of inflammatory cytokines [i.e., interleukin (IL)-1β, IL-6, and IL-18] in lung tissues and bronchoalveolar lavage fluid (BALF), and expression of NLRP3, Toll-like receptor 4 (TLR4), caspase-1, nuclear factor (NF)-κB, and GSDMD in lung tissues were measured. OT treatment could reduce pathological injury, the W/D ratio, and MPO activity in VILI mice. Our data also indicated that OT administration alleviated the expression of TLR4/My-D88 and the activation of NF-κB, NLRP3, and caspase-1 in lung tissues from the VILI mice model. Furthermore, OT also decreased the levels of IL-1β, IL-6, and IL-18 in the bronchoalveolar lavage fluid. Moreover, the OT administration may alleviate the activation of GSDMD partially through its effects on the NLRP3-mediated pathway. Collectively, OT exerted a beneficial effect on VILI by downregulating TLR4-and NLRP3-mediated inflammatory pathways.
| S-EPMC8558354 | biostudies-literature
Project description:Elevated reactive oxygen species (ROS) in type 2 diabetes cause cellular damage in many organs. Recently, the new class of glucose-lowering agents, SGLT-2 inhibitors, have been shown to reduce the risk of developing diabetic complications; however, the mechanisms of such beneficial effect are largely unknown. Here we aimed to investigate the effects of dapagliflozin on cell proliferation and cell death under oxidative stress conditions and explore its underlying mechanisms. Human proximal tubular cells (HK-2) were used. Cell growth and death were monitored by cell counting, water-soluble tetrazolium-1 (WST-1) and lactate dehydrogenase (LDH) assays, and flow cytometry. The cytosolic and mitochondrial (ROS) production was measured using fluorescent probes (H2DCFDA and MitoSOX) under normal and oxidative stress conditions mimicked by addition of H2O2. Intracellular Ca2+ dynamics was monitored by FlexStation 3 using cell-permeable Ca2+ dye Fura-PE3/AM. Dapagliflozin (0.1-10 μM) had no effect on HK-2 cell proliferation under normal conditions, but an inhibitory effect was seen at an extreme high concentration (100 μM). However, dapagliflozin at 0.1 to 5 μM showed remarkable protective effects against H2O2-induced cell injury via increasing the viable cell number at phase G0/G1. The elevated cytosolic and mitochondrial ROS under oxidative stress was significantly decreased by dapagliflozin. Dapagliflozin increased the basal intracellular [Ca2+]i in proximal tubular cells, but did not affect calcium release from endoplasmic reticulum and store-operated Ca2+ entry. The H2O2-sensitive TRPM2 channel seemed to be involved in the Ca2+ dynamics regulated by dapagliflozin. However, dapagliflozin had no direct effects on ORAI1, ORAI3, TRPC4 and TRPC5 channels. Our results suggest that dapagliflozin shows anti-oxidative properties by reducing cytosolic and mitochondrial ROS production and altering Ca2+ dynamics, and thus exerts its protective effects against cell damage under oxidative stress environment.
| S-EPMC7894948 | biostudies-literature
Project description:AimsPulmonary oxygen toxicity contributes to lung injury in newborn and adult humans. We previously reported that thioredoxin reductase (TrxR1) inhibition with aurothioglucose (ATG) attenuates hyperoxic lung injury in adult mice. The present studies tested the hypothesis that TrxR1 inhibition protects against the effects of hyperoxia via nuclear factor E2-related factor 2 (Nrf2)-dependent mechanisms.ResultsBoth pharmacologic and siRNA-mediated TrxR1 inhibition induced robust Nrf2 responses in murine-transformed Clara cells (mtCC). While TrxR1 inhibition did not alter the susceptibility of cells to the effects of hyperoxia, glutathione (GSH) depletion after TrxR1 inhibition markedly enhanced the hyperoxic susceptibility of cultured mtCCs. Finally, in vivo data revealed dose-dependent increases in the expression of the Nrf2 target gene NADPH:quinone oxidoreductase 1 (NQO1) in the lungs of ATG-treated adult mice.InnovationTrxR1 inhibition activates Nrf2-dependent antioxidant responses in mtCCs in vitro and in adult murine lungs in vivo, providing a plausible mechanism for the protective effects of TrxR1 inhibition in vivo.ConclusionGSH-dependent enzyme systems in mtCCs may be of greater importance for protection against hyperoxic exposure than are TrxR-dependent systems. The induction of Nrf2 activation via TrxR1 inhibition represents a novel therapeutic strategy that attenuates oxidant-mediated lung injury. Similar expression levels of TrxR1 in newborn and adult mouse or human lungs broaden the potential clinical applicability of the present findings to both neonatal and adult oxidant lung injury.
| S-EPMC3437047 | biostudies-literature
Project description:CD13 is a membrane-bound ectopeptidase, highly expressed on monocytes, macrophages, and dendritic cells. CD13 is involved in diverse functions, including degradation of peptide mediators, cellular adhesion, migration, viral endocytosis, signaling, and positive modulation of phagocytosis mediated by Fc?Rs and other phagocytic receptors. In this work, we explored whether besides acting as an accessory receptor, CD13 by itself is a primary phagocytic receptor. We found that hCD13 mediates efficient phagocytosis of large particles (erythrocytes) modified so as to interact with the cell only through CD13 in human macrophages and THP-1 monocytic cells. The extent of this phagocytosis is comparable with the phagocytosis mediated through the canonical phagocytic receptor Fc?RI. Furthermore, we demonstrated that hCD13 expression in the nonphagocytic cell line HEK293 is sufficient to enable these cells to internalize particles bound through hCD13. CD13-mediated phagocytosis is independent of other phagocytic receptors, as it occurs in the absence of Fc?Rs, CR3, and most phagocytic receptors. Phagocytosis through CD13 is independent of its enzymatic activity but is dependent on actin rearrangement and activation of PI3K and is partially dependent on Syk activation. Moreover, the cross-linking of CD13 with antibodies rapidly induced pSyk in human macrophages. Finally, we observed that antibody-mediated cross-linking of hCD13, expressed in the murine macrophage-like J774 cell line, induces production of ROS. These results demonstrate that CD13 is a fully competent phagocytic receptor capable of mediating internalization of large particles.
| S-EPMC7167067 | biostudies-literature
Project description:Accumulating evidence indicates that gut microbiota participates in the pathogenesis and progression of liver diseases. The severity of immune-mediated liver injury is associated with different microbial communities. Akkermansia muciniphila can regulate immunologic and metabolic functions. However, little is known about its effects on gut microbiota structure and function. This study investigated the effect of A. muciniphila on immune-mediated liver injury and potential underlying mechanisms. Twenty-two C57BL/6 mice were assigned to three groups (N = 7-8 per group) and continuously administrated A. muciniphila MucT or PBS by oral gavage for 14 days. Mouse feces were collected for gut microbiota analysis on the 15th day, and acute liver injury was induced by Concanavalin A (Con A, 15 mg/kg) injection through the tail vein. Samples (blood, liver, ileum, colon) were assessed for liver injury, systemic inflammation, and intestinal barrier function. We found that oral administration of A. muciniphila decreased serum ALT and AST and alleviated liver histopathological damage induced by Con A. Serum levels of pro-inflammatory cytokines and chemokines (IL-2, IFN-γ, IL-12p40, MCP-1, MIP-1a, MIP-1b) were substantially attenuated. A. muciniphila significantly decreased hepatocellular apoptosis; Bcl-2 expression increased, but Fas and DR5 decreased. Further investigation showed that A. muciniphila enhanced expression of Occludin and Tjp-1 and inhibited CB1 receptor, which strengthened intestinal barriers and reduced systemic LPS level. Fecal 16S rRNA sequence analysis indicated that A. muciniphila increased microbial richness and diversity. The community structure of the Akk group clustered distinctly from that of mice pretreated with PBS. Relative abundance of Firmicutes increased, and Bacteroidetes abundance decreased. Correlation analysis showed that injury-related factors (IL-12p40, IFN-γ, DR5) were negatively associated with specific genera (Ruminococcaceae_UCG_009, Lachnospiraceae_UCG_001, Akkermansia), which were enriched in mice pretreated with A. muciniphila. Our results suggested that A. muciniphila MucT had beneficial effects on immune-mediated liver injury by alleviating inflammation and hepatocellular death. These effects may be driven by the protective profile of the intestinal community induced by the bacteria. The results provide a new perspective on the immune function of gut microbiota in host diseases.
| S-EPMC5626943 | biostudies-literature
Project description:AimsAccumulating evidence indicates that oxidative stress is associated with inflammation, and the cellular redox status can determine the sensitivity and the final outcome in response to inflammatory stimuli. To control the redox balance, mammalian cells contain a variety of oxidoreductases belonging to the thioredoxin superfamily. The large number of these enzymes suggests a complex mechanism of redox regulation in mammals, but the precise function of each family member awaits further investigations.ResultsWe generated mice deficient in transmembrane thioredoxin-related protein (TMX), a transmembrane oxidoreductase in the endoplasmic reticulum (ER). When exposed to lipopolysaccharide (LPS) and d-(+)-galactosamine (GalN) to induce inflammatory liver injury, mutant mice were highly susceptible to the toxicants and developed severe liver damage. LPS-induced production of inflammatory mediators was equivalent in both wild-type and TMX(-/-) mice, whereas neutralization of the proinflammatory cytokine tumor necrosis factor-? suppressed the toxic effects of LPS/GalN in the mutant mice. Liver transcriptional profiles revealed enhanced activation of the p53-signaling pathway in the TMX(-/-) mice after LPS/GalN treatment. Furthermore, TMX deficiency also caused increased sensitivity to thioacetamide, which exerts its hepatotoxicity through the generation of reactive oxygen species.InnovationThe present study is the first to address the role of the oxidoreductase TMX in inflammatory liver injury. The phenotype of mice deficient in TMX suggests a functional link between redox regulation in the ER and susceptibility to oxidative tissue damage.ConclusionWe conclude that TMX plays a major role in host defense under the type of inflammatory conditions associated with oxidative stress.
| S-EPMC3584524 | biostudies-literature
Project description:Background and Objectives: Acetylsalicylic acid (ASA) is widely used for preventing cerebrovascular and cardiovascular diseases. Gastrointestinal (GI) tract injury is one of the major complications of aspirin use, potentially leading to severe GI bleeding. However, no drugs for preventing aspirin-induced small intestinal injury have been developed. The aim of this study was to establish a human experimental model for investigating aspirin-induced small intestinal mucosal injury. In addition, we evaluated the protective effect of Irsogladine against aspirin-induced small intestinal mucosal injury using human induced pluripotent stem cell-derived 2D monolayer crypt-villus structural small intestine (2D-hiPSC-SI). Materials and Methods: Human iPS cell-derived intestinal organoids were seeded and cultured in Air-liquid interface. The permeability of 2D-hiPSC-SI was evaluated using Lucifer yellow. Changes in structure and mucosal permeability of 2D-hiPSC-SI after addition of aspirin were confirmed over time, and changes in intestinal epithelium-related markers were evaluated by real-time qPCR and Immunofluorescence staining. The effect of Irsogladine on prevention of aspirin mucosal injury was examined by adding Irsogladine to the culture medium. Results: Cultured 2D-hiPSC-SI showed multi-lineage differentiation into small intestinal epithelium comprised of absorptive cells, goblet cells, enteroendocrine cells, and Paneth cells, which express CD10, MUC2, chromogranin A, and lysozyme, respectively. RNA in situ hybridization revealed intestinal stem cells that express Lgr5. ASA administration induced an increase in the mucosal permeability of 2D-hiPSC-SI. ASA-injured 2D-hiPSC-SI showed decreased mRNA expression of multi-lineage small intestinal cell markers as well as intestinal stem cell marker Lgr5. Administration of Irsogladine on the basal side of the 2D-hiPSC-SI resulted in significant increases in Mki67 and Muc2 mRNA expression by 2D-hiPSCs at 48 h compared with the control group. Administration of 400 µg/mL Irsogladine to the ASA-induced small intestinal injury model resulting in significantly decreased mucosal permeability of 2D-hiPSC-SI. In immunofluorescence staining, Irsogladine significantly increased the fluorescence intensity of MUC2 under normal conditions and administration of 400 µg/mL ASA. Conclusions: we established a novel ASA-induced small intestinal injury model using human iPSC-derived small intestine. Irsogladine maintains mucosal permeability and goblet cell differentiation against ASA-induced small intestinal injury.
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Project description:Human umbilical cord mesenchymal stromal cell-derived extracellular vesicles (HuMSC-EVs) can repair damaged tissues. The expression profile of circular RNAs (circRNAs) provides valuable insights into the regulation of the repair process and the exploration of the repair mechanism. AC16 cardiomyocytes were exposed to hypoxia/reoxygenation (H/R) injury and subsequently cultured with or without HuMSC-EVs (Group T and Group C, respectively). High-throughput RNA sequencing was implemented for the two groups. On the basis of the transcriptome data, gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway, and network analyses were carried out to determine the differential gene expression profiles between the two groups. After screening the circRNA database, the results were proved by quantitative real-time polymerase chain reaction. The survival rate of cardiomyocytes exposed to H/R was increased by treatment with HuMSC-EVs. RNA-seq analysis showed that 66 circRNAs were differentially expressed in cardiomyocytes in the co-cultured group. The cellular responses to hypoxia and to decreased oxygen levels were at the top of the GO upregulated list for the two groups, while the vascular endothelial growth factor signaling pathway, long-term potentiation, and the glucagon signaling pathway were at the top of the KEGG pathway upregulated list for the two groups. In the same samples, the 10 most aberrantly upregulated circRNAs were chosen for further verification of their RNA sequences. Seven of the 10 most aberrant circRNAs were significantly upregulated in the co-cultured group and in the HuMSC-EVs. Our results revealed that upregulated circRNAs were abundant during the repair of damaged cardiomyocytes by HuMSC-EVs, which provides a new perspective for the repair of H/R by HuMSC-EVs.
| S-EPMC7940380 | biostudies-literature