Mycobacterium tuberculosis -Induced Upregulation of the COX-2/mPGES-1 Pathway in Human Macrophages Is Abrogated by Sulfasalazine

Macrophages are the primary human host cells of intracellular Mycobacterium tuberculosis ( M.tb ) infection, where the magnitude of inflammatory reactions is crucial for determining the outcome of infection. Previously, we showed that the anti-inflammatory drug sulfasalazine (SASP) significantly reduced the M.tb bactericidal burden and histopathological inflammation in mice. Here, we asked which genes in human inflammatory macrophages are affected upon infection with M.tb and how would potential changes impact the functional state of macrophages. We used a flow cytometry sorting system which can distinguish the dead and alive states of M.tb harbored in human monocyte-derived macrophages (MDM). We found that the expression of cyclooxygenase-2 and microsomal prostaglandin E 2 synthase (mPGES)-1 increased significantly in tagRFP + MDM which were infected with alive M.tb . After exposure of polarized M1-MDM to M.tb (H37Rv strain)-conditioned medium (MTB-CM) or to the M.tb -derived 19-kD antigen, the production of PGE 2 and pro-inflammatory cytokines increased 3- to 4-fold. Upon treatment of M1-MDM with SASP, the MTB-CM-induced expression of COX-2 and the release of COX products and cytokines decreased. Elevation of PGE 2 in M1-MDM upon MTB-CM stimulation and modulation by SASP correlated with the activation of the NF-κB pathway. Together, infection of human macrophages by M.tb strongly induces COX-2 and mPGES-1 expression along with massive PGE 2 formation which is abrogated by the anti-inflammatory drug SASP

Oregano essential oil modulates colonic homeostasis and intestinal barrier function in fattening bulls

Oregano essential oil (OEO) primarily contains phenolic compounds and can serve as a dietary supplement for fattening bulls. However, the precise molecular mechanism underlying this phenomenon remains largely elusive. Therefore, this study investigated the impact of adding OEO to diet on the integrity of the intestinal barrier, composition of the colonic microbiome, and production of microbial metabolites in fattening bulls. Our goal was to provide insights into the utilization of plant essential oil products in promoting gastrointestinal health and welfare in animals. We employed amplicon sequencing and metabolome sequencing techniques to investigate how dietary supplementation with OEO impacted the intestinal barrier function in bulls. The inclusion of OEO in the diet resulted in several notable effects on the colon of fattening bulls. These effects included an increase in the muscle thickness of the colon, goblet cell number, short-chain fatty acid concentrations, digestive enzyme activity, relative mRNA expression of intestinal barrier-related genes, and relative expression of the anti-inflammatory factor IL-10. Additionally, α-amylase activity and the relative mRNA expression of proinflammatory cytokines decreased. Moreover, dietary OEO supplementation increased the abundance of intestinal Bacteroides, Coprobacillus, Lachnospiraceae_UCG_001, and Faecalitalea. Metabolomic analysis indicated that OEO primarily increased the levels of 5-aminovaleric acid, 3-methoxysalicylic acid, and creatinine. In contrast, the levels of maltose, lactulose, lactose, and D-trehalose decreased. Correlation analysis showed that altered colonic microbes and metabolites affected intestinal barrier function. Taken together, these results demonstrate that OEO facilitates internal intestinal environmental homeostasis by promoting the growth of beneficial bacteria while inhibiting harmful ones

Intratracheal administration of adipose derived mesenchymal stem cells alleviates chronic asthma in a mouse model

Abstract Background Adipose-derived mesenchymal stem cell (ASCs) exerts immunomodulatory roles in asthma. However, the underlying mechanism remains unclear. The present study aimed to explore the effects and mechanisms of ASCs on chronic asthma using an ovalbumin (OVA)-sensitized asthmatic mouse model. Methods Murine ASCs (mASCs) were isolated from male Balb/c mice and identified by the expression of surface markers using flow cytometry. The OVA-sensitized asthmatic mouse model was established and then animals were treated with the mASCs through intratracheal delivery. The therapy effects were assessed by measuring airway responsiveness, performing immuohistochemical analysis, and examining bronchoalveolar lavage fluid (BALF). Additionally, the expression of inflammatory cytokines and lgE was detected by CHIP and ELISA, respectively. The mRNA levels of serum indices were detected using qRT-PCR. Results The mASCs grew by adherence with fibroblast-like morphology, and showed the positive expression of CD90, CD44, and CD29 as well as the negative expression of CD45 and CD34, indicating that the mASCs were successfully isolated. Administering mASCs to asthmatic model animals through intratracheal delivery reduced airway responsiveness, the number of lymphocytes (P < 0.01) and the expression of lgE (P < 0.01), IL-1β (P < 0.05), IL-4 (P < 0.001), and IL-17F (P < 0.001), as well as increased the serum levels of IL-10 and Foxp3, and the percentage of CD4 + CD25 + Foxp3+ Tregs in the spleen, and reduced the expression of IL-17 (P < 0.05) and RORγ. Conclusions Intratracheal administration of mASCs alleviated airway inflammation, improved airway remodeling, and relieved airway hyperresponsiveness in an OVA-sensitized asthma model, which might be associated with the restoration of Th1/Th2 cell balance by mASCs

Fungal and bacterial microbiome dysbiosis and imbalance of trans-kingdom network in asthma

Abstract Background Fungal and bacterial microbiota play an important role in development of asthma. We aim to characterize airway microbiome (mycobiome, bacteriome) and functional genes in asthmatics and controls. Methods Sputum microbiome of controls, untreated asthma patients and inhaled corticosteroid (ICS) receiving patients was detected using high throughput sequencing. Metagenomic sequencing was used to examine the functional genes of microbiome. Results 1. Mycobiome: α diversity was lower in untreated asthma group than that in controls. Mycobiome compositions differed among the three groups. Compared with controls, untreated asthma group has higher abundance of Wallemia, Mortierella and Fusarium. Compared with untreated asthma patients, ICS receiving patients has higher abundance of Fusarium and Mortierella, lower frequency of Wallemia, Alternaria and Aspergillus. 2. Bacteriome: α diversity was lower in untreated asthma group than that in controls. There are some overlaps of bacteriome compositions between controls and untreated asthma patients which were distinct from ICS receiving patients. Untreated asthma group has higher Streptococcus than controls. 3. Potential fungal and bacterial biomarkers of asthma: Trametes, Aspergillus, Streptococcus, Gemella, Neisseria, etc. 4. Correlation network: There are dense and homogenous correlations in controls but a dramatically unbalanced network in untreated asthma and ICS receiving patients, which suggested the existence of disease-specific inter-kingdom and intra-kingdom alterations. 5. Metagenomic analysis: functional pathways were associated with the status of asthma, microbiome and functional genes showed different correlations in different environment. Conclusion We showed mycobiome and bacteriome dysbiosis in asthma featured by alterations in biodiversity, community composition, inter-kingdom and intra-kingdom network. We also observed several functional genes associated with asthma

Autoantibody-Mediated Erythrophagocytosis Increases Tuberculosis Susceptibility in HIV Patients

HIV infection significantly increases TB susceptibility due to CD4 T-cell loss and macrophage dysfunction. Although it is relatively clear that CD4 T-cell loss represents a direct effect of HIV infection, the mechanism underlying how HIV infection dampens macrophage function is unknown. Here, we show that HIV infection enhances autoantibody-mediated erythrophagocytosis, which dampens macrophage bactericidal activity against TB by inhibiting HO-1-associated autophagy. Our findings reveal a novel mechanism explaining how HIV infection increases susceptibility to TB. We propose that DAT could be a potential measure to identify HIV patients who are at high TB risk and who would be suitable for anti-TB chemotherapy preventive treatment.Macrophage dysfunction is associated with increased tuberculosis (TB) susceptibility in patients with human immunodeficiency virus (HIV) infection. However, the mechanisms underlying how HIV infection impairs macrophage function are unclear. Here, we found that levels of autoantibodies against red blood cells (RBCs) were significantly elevated in patients with HIV as determined by direct antiglobulin test (DAT). DAT positivity was significantly associated with TB incidence in both univariate and multivariate analyses (odds ratio [OR] = 11.96 [confidence interval {CI}, 4.68 to 30.93] and 12.65 [3.33 to 52.75], respectively). Ex vivo analysis showed that autoantibodies against RBCs enhanced erythrophagocytosis and thus significantly impaired macrophage bactericidal function against intracellular Mycobacterium tuberculosis. Mechanistically, autoantibody-mediated erythrophagocytosis increased heme oxygenase-1 (HO-1) expression, which inhibited M. tuberculosis-induced autophagy in macrophages. Silencing ATG5, a key component for autophagy, completely abrogated the effect of erythrophagocytosis on macrophage bactericidal activity against M. tuberculosis. In conclusion, we have demonstrated that HIV infection increases autoantibody-mediated erythrophagocytosis. This process impairs macrophage bactericidal activity against M. tuberculosis by inhibiting HO-1-associated autophagy. These findings reveal a novel mechanism as to how HIV infection increases TB susceptibility