Macrophage adenosine monophosphate-activated protein kinase (AMPK) limits the development of experimental colitis. AMPK activation inhibits NADPH oxidase (NOX) 2 expression, reactive oxygen species ...(ROS) generation, and pro-inflammatory cytokine secretion in macrophages during inflammation, while increased NOX2 expression is reported in experimental models of colitis and inflammatory bowel disease (IBD) patients. Although there are reductions in AMPK activity in IBD, it remains unclear whether targeted inhibition of NOX2 in the presence of defective AMPK can reduce the severity of colitis. Here, we investigate whether the inhibition of NOX2 ameliorates colitis in mice independent of AMPK activation. Our study identified that VAS2870 (a pan-Nox inhibitor) alleviated dextran sodium sulfate (DSS)-induced colitis in macrophage-specific AMPKβ1-deficient (AMPKβ1
) mice. Additionally, VAS2870 blocked LPS-induced TLR-4 and NOX2 expression, ROS production, nuclear translocation of NF-κB, and pro-inflammatory cytokine secretion in bone marrow-derived macrophages (BMDMs) from AMPKβ1
mice, whereas sodium salicylate (SS; AMPK β1 activator) did not. Both VAS2870 and SS inhibited LPS-induced NOX2 expression, ROS production, and pro-inflammatory cytokine secretions in bone marrow-derived macrophages (BMDMs) from wildtype (AMPKβ1
) mice but only VAS2870 inhibited these effects of LPSs in AMPKβ1
BMDMs. Furthermore, in macrophage cells (RAW 264.7), both SS and VAS2870 inhibited ROS production and the secretion of pro-inflammatory cytokines and reversed the impaired autophagy induced by LPSs. These data suggest that inhibiting NOX2 can reduce inflammation independent of AMPK in colitis.
Oncostatin M (OSM), a pleiotropic cytokine of the gp130 cytokine family, has been implicated in chronic allergic inflammatory and fibrotic disease states associated with tissue eosinophilia. Mouse ...(m)OSM induces airway eosinophilic inflammation and interstitial pulmonary fibrosis in vivo and regulates STAT6 activation in vitro. To determine the requirement of STAT6 in OSM-induced effects in vivo, we examined wild-type (WT) and STAT6-knockout (STAT6(-/-)) C57BL/6 mouse lung responses to transient ectopic overexpression of mOSM using an adenoviral vector (AdmOSM). Intratracheal AdmOSM elicited persistent eosinophilic lung inflammation that was abolished in STAT6(-/-) mice. AdmOSM also induced pronounced pulmonary remodeling characterized by goblet cell hyperplasia and parenchymal interstitial fibrosis. Goblet cell hyperplasia was STAT6 dependent; however, parenchymal interstitial fibrosis was not. OSM also induced airway hyperresponsiveness in WT mice that was abolished in STAT6(-/-) mice. OSM stimulated an inflammatory signature in the lungs of WT mice that demonstrated STAT6-dependent regulation of Th2 cytokines (IL-4, IL-13), chemokines (eotaxin-1/2, MCP-1, keratinocyte chemoattractant), and extracellular matrix modulators (tissue inhibitor of matrix metalloproteinase-1, matrix metalloproteinase-13), but STAT6-independent regulation of IL-4Rα, total lung collagen, collagen-1A1, -1A2 mRNA, and parenchymal collagen and α smooth muscle actin accumulation. Thus, overexpression of mOSM induces STAT6-dependent pulmonary eosinophilia, mucous/goblet cell hyperplasia, and airway hyperresponsiveness but STAT6-independent mechanisms of lung tissue extracellular matrix accumulation. These results also suggest that eosinophil or neutrophil accumulation in mouse lungs is not required for OSM-induced lung parenchymal collagen deposition and that OSM may have unique roles in the pathogenesis of allergic and fibrotic lung disease.
In this article we discuss the novel pharmacological aspects of 5-HT3 receptor antagonists. Commonly used to counteract chemotherapy-induced emesis, these agents now appear to be reaching out for ...newer indications. Studies have reported neuroprotective and anti-inflammatory properties in vitro and in vivo. 5-HT3 receptor antagonists can modulate the immune-inflammatory axis through blockade of 5-HT3 receptors present on immune cells. We review evidence addressing the effects of these drugs on peripheral inflammatory diseases, including asthma, rheumatoid diseases, inflammatory bowel disease and sepsis in addition to diabetes and CNS disorders, including Alzheimer's disease (AD), seizure and stroke.
Microbes modify immunometabolism responses linking obesity and type 2 diabetes. Immunity helps maintain a host-microbe symbiosis, but inflammation can promote insulin resistance in tissues that ...control blood glucose. We were interested in compartmentalization of immune responses during obesity and show here that feeding mice an obesity-causing high-fat diet (HFD) decreased a marker of neutrophil activation and cytokines related to Th17 responses in the gut. A HFD decreased IL-17 and IL-21/22 in the ileum and colon, respectively. A HFD increased IL-17, IL-21/22 and other related Th17 responses in the liver. At the whole tissue level, there is divergence in gut and metabolic tissue Th17 cytokines during diet-induced obesity. Deletion of the bacterial peptidoglycan sensor NOD2 had relatively minor effects on these immune responses. We propose a model where diet-induced obesity promotes a permissive gut immune environment and sets the stage for host genetics to contribute to dysbiosis-driven metabolic tissue inflammation.
Background & Aims:
We established the concept that transient enteric infection may lead to persistent gut dysfunction, evident in vitro, in nematode-infected mice. The present study determined ...whether gut dysfunction in this model involves motor and sensory changes reminiscent of changes found in patients with postinfective irritable bowel syndrome (PI-IBS) and investigated underlying mechanisms.
Methods:
Mice infected up to 70 days previously with
Trichinella spiralis (
Tsp) underwent videofluoroscopy with image analysis to assess upper gastrointestinal motility. Pseudoaffective responses to colorectal distention (CRD) were assessed using a barostat and validated by single fiber recordings from spinal nerves during CRD. Tissues were examined at different time points for histology, immunohistochemistry, and cytokine analysis. Some mice received dexamethasone intraperitoneally on days 23–25 PI or
Tsp antigen orally on days 29, 43, and 57 PI.
Results:
From day 28 PI, no discernible inflammation was present in the gut. Frequency and propagation velocity of intestinal contractions decreased, and retroperistalsis increased at days 28 to 42 PI. CRD induced an allodynic and hyperalgesic response in PI mice, which was accompanied by increased single unit discharge. Gavage of
Tsp antigen induced T-cell responses and sustained gut dysfunction for 70 days PI. Administration of dexamethasone postinfection normalized dysmotility and visceral hyperalgesia.
Conclusions:
Long-lasting gut dysmotility and hyperalgesia develop in mice after transient intestinal inflammation. These changes are maintained by luminal exposure to antigen and reversed by corticosteroid treatment. The findings prompt consideration of this as a model of PI-IBS.
Mucins secreted by intestinal goblet cells are considered an important component of innate defense in a number of enteric infections, including many parasitic infections, but also likely provide ...protection against the gut microbiota. Nod proteins are intracellular receptors that play key roles in innate immune response and inflammation. Here, we investigated the role of Nod proteins in regulation of intestinal goblet cell response in naive mice and mice infected with the enteric parasite Trichuris muris. We observed significantly fewer periodic acid-Schiff (PAS)-stained intestinal goblet cells and less mucin (Muc2) in Nod1 and Nod2 double-knockout (Nod DKO) mice after T. muris infection than in wild-type (WT) mice. Expulsion of parasites from the intestine was significantly delayed in Nod DKO mice. Treatment of naive WT mice with Nod1 and Nod2 agonists simultaneously increased numbers of PAS-stained goblet cells and Muc2-expressing cells, whereas treatment with Nod1 or Nod2 separately had no significant effect. Stimulation of mucin-secreting LS174T cells with Nod1 and Nod2 agonists upregulated core 3 β1,3-N-acetylglucosaminyltransferase (C3GnT; an important enzyme in mucin synthesis) and MUC2. We also observed lower numbers of PAS-stained goblet cells and less Muc2 in germfree mice. Treatment with Nod1 and Nod2 agonists enhanced the production of PAS-stained goblet cells and Muc2 in germfree mice. These data provide novel information on the role of Nod proteins in goblet cell response and Muc2 production in relation to intestinal innate defense.
•Measles, mumps, rubella, and varicella-zoster (MMRV) immunity testing is important in occupational screening of healthcare workers and at-risk populations.•Multiplex fluorescent immunoassay (MFI) ...benefits from high throughput testing of multiple antibodies simultaneously.•Bio-Rad BioPlex 2200 MFI demonstrated good agreement with the Bio-Rad Evolis Twin Plus measles, mumps, and varicella-zoster (MMV) IgG assay and the Abbott Architect Rubella IgG assay.•This is the first report that includes imprecision analysis of the Bio-Rad BioPlex MMRV IgG assay against two EIA methods.
Measles, mumps, rubella, and varicella-zoster (MMRV) immunity testing is important in occupational screening of healthcare workers and at-risk populations.
The goal of this study was to compare the performance of the Bio-Rad BioPlex 2200 MMRV multiplex fluorescence immunoassay (MFI) against two enzyme immunoassay (EIA) methods: the Bio-Rad Evolis Twin Plus measles, mumps, and varicella-zoster (MMV) IgG assay and the Abbott Architect Rubella IgG assay.
Clinically uncharacterized serum specimens were obtained and analyzed using the Bio-Rad BioPlex assay and compared against the EIA methods.
The Bio-Rad BioPlex demonstrated total agreement of 85.5% (95% confidence interval (CI), 78.0 to 90.7%), 92.7% (95% confidence interval (CI), 86.7 to 96.1%), 92.4% (95% confidence interval (CI), 86.9 to 95.7%), and 98.8% (95% confidence interval (CI), 93.7 to 99.8%) for measles, mumps, varicella-zoster, and rubella, respectively, against the current EIA methods. Furthermore, precision testing agreed with the manufacturer's package insert in 10 of 13 pooled samples.
These data indicate that the Bio-Rad BioPlex has comparable performance to the EIA methods.
Lactobacillus plantarum strains are noted for their presence in the human gastrointestinal tract and are distinguished for their immunomodulatory actions and therapeutic applications. Despite the ...uncertainty in the underlining molecular mechanisms, recent evidence suggests that L. plantarum secretes immunomodulatory agents that alter immunological signaling cascades. Elaboration of these metabolic products from L. plantarum strain WCFS1 was demonstrated previously to correlate with the mid-log-stationary transition, perhaps consistent with secondary metabolite expression. Here, we present the metabolomic shifts revealed by principal component analysis that correspond to the mid-log-stationary transition of L. plantarum, and identify pyroglutamic (pyro) dipeptides within this transition as correlative with the immunomodulatory actions. Four of these (pyro-phenylalanine, pyro-leucine, pyro-isoleucine, pyro-tryptophan) were characterized and the two dominant members, pyro-phenylalanine and pyro-tryptophan, were directly interrogated for immunomodulatory activity through in vivo administration using C57BL/6 mice. Administration of these compounds resulted in decreased production of pro-inflammatory cytokine interferon (IFN)-gamma, which is of noted importance in gastrointestinal immune homeostasis.
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