Yong-Qiang Ma

Spironolactone Attenuates Bleomycin-Induced Pulmonary Injury Partially via Modulating Mononuclear Phagocyte Phenotype Switching in Circulating and Alveolar Compartments

Background Recent experimental studies provide evidence indicating that manipulation of the mononuclear phagocyte phenotype could be a feasible approach to alter the severity and persistence of pulmonary injury and fibrosis. Mineralocorticoid receptor (MR) has been reported as a target to regulate macrophage polarization. The present work was designed to investigate the therapeutic potential of MR antagonism in bleomycin-induced acute lung injury and fibrosis. Methodology/Principal Findings We first demonstrated the expression of MR in magnetic bead-purified Ly6G-/CD11b+ circulating monocytes and in alveolar macrophages harvested in bronchoalveolar lavage fluid (BALF) from C57BL/6 mice. Then, a pharmacological intervention study using spironolactone (20mg/kg/day by oral gavage) revealed that MR antagonism led to decreased inflammatory cell infiltration, cytokine production (downregulated monocyte chemoattractant protein-1, transforming growth factor β1, and interleukin-1β at mRNA and protein levels) and collagen deposition (decreased lung total hydroxyproline content and collagen positive area by Masson’ trichrome staining) in bleomycin treated (2.5mg/kg, via oropharyngeal instillation) male C57BL/6 mice. Moreover, serial flow cytometry analysis in blood, BALF and enzymatically digested lung tissue, revealed that spironolactone could partially inhibit bleomycin-induced circulating Ly6Chi monocyte expansion, and reduce alternative activation (F4/80+CD11c+CD206+) of mononuclear phagocyte in alveoli, whereas the phenotype of interstitial macrophage (F4/80+CD11c-) remained unaffected by spironolactone during investigation. Conclusions/Significance The present work provides the experimental evidence that spironolactone could attenuate bleomycin-induced acute pulmonary injury and fibrosis, partially via inhibition of MR-mediated circulating monocyte and alveolar macrophage phenotype switching.

The Emerging Role of miR-223 in Platelet Reactivity: Implications in Antiplatelet Therapy.

Platelets are anuclear cells and are devoid of genomic DNA, but they are capable of de novo protein synthesis from mRNA derived from their progenitor cells, megakaryocytes. There is mounting evidence that microRNA (miRNA) plays an important role in regulating gene expression in platelets. miR-223 is the most abundant miRNAs in megakaryocytes and platelets. One of the miR-223-regulated genes is ADP P2Y12, a key target for current antiplatelet drug therapy. Recent studies showed that a blunted response to P2Y12 antagonist, that is, high on-treatment platelet reactivity (HTPR), is a strong predictor of major cardiovascular events (MACEs) in coronary heart disease (CHD) patients receiving antiplatelet treatment. Recent clinical cohort study showed that the level of circulating miR-223 is inversely associated with MACE in CHD patients. In addition, our recent data demonstrated that the level of both intraplatelet and circulating miR-223 is an independent predictor for HTPR, thus providing a link between miR-223 and MACE. These lines of evidence indicate that miR-223 may serve as a potential regulatory target for HTPR, as well as a diagnostic tool for identification of HTPR in clinical settings.

Th17/Treg Imbalance Induced by Dietary Salt Variation Indicates Inflammation of Target Organs in Humans.

The functions of T helper 17 (Th17) and regulatory T (Treg) cells are tightly orchestrated through independent differentiation pathways that are involved in the secretion of pro- and anti-inflammatory cytokines induced by high-salt dietary. However, the role of imbalanced Th17/Treg ratio implicated in inflammation and target organ damage remains elusive. Here, by flow cytometry analysis, we demonstrated that switching to a high-salt diet resulted in decreased Th17 cells and reciprocally increased Treg cells, leading to a decreased Th17/Treg ratio. Meanwhile, Th17-related pathway was down-regulated after one day of high salt loading, with the increase in high salt loading as shown by microarray and RT-PCR. Subsequently, blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) observed hypoxia in the renal medulla (increased R2* signal) during high-salt loading, which was regressed to its baseline level in a step-down fashion during low-salt feeding. The flow-mediated vasodilatation (FMD) of the branchial artery was significantly higher on the first day of high salt loading. Collectively, these observations indicate that a short-term increase in dietary salt intake could induce reciprocal switches in Th17/Treg ratio and related cytokines, which might be the underlying cellular mechanism of high-salt dietary induced end organ inflammation and potential atherosclerotic risk.

Proteomics analysis of human placenta reveals glutathione metabolism dysfunction as the underlying pathogenesis for preeclampsia

Hypertensive disorder in pregnancy (HDP) refers to a series of diseases that cause the hypertension during pregnancy, including HDP, preeclampsia (PE) and eclampsia. This study screens differentially expressed proteins of placenta tissues in PE cases using 2D LC-MS/MS quantitative proteomics strategy. A total of 2281 proteins are quantified, of these, 145 altering expression proteins are successfully screened between PE and control cases (p<0.05). Bioinformatics analysis suggests that these proteins are mainly involved in many biological processes, such as oxidation reduction, mitochondrion organization, and acute inflammatory response. Especially, the glutamine metabolic process related molecules, GPX1, GPX3, SMS, GGCT, GSTK1, NFκB, GSTT2, SOD1 and GCLM, are involved in the switching process from oxidized glutathione (GSSG) conversion to the reduced glutathione (GSH) by glutathione, mercapturic acid and arginine metabolism process. Results of this study revealed that glutathione metabolism disorder of placenta tissues may contribute to the occurrence of PE disease.

HO‑1 alleviates cholesterol‑induced oxidative stress through activation of Nrf2/ERK and inhibition of PI3K/AKT pathways in endothelial cells

Heme oxygenase‑1 (HO‑1), as an inducible and cytoprotective enzyme, has a protective effect against cellular oxidative stress. In the present study, cholesterol was used to induce lipid overload and increase reactive oxygen species (ROS), leading to oxidative stress in EA.hy926 cells. In the present study, western blotting and immunofluorescence analysis were used to detect the expression level of important molecules in the metabolism process of cholesterol. It was confirmed that cholesterol stimulation upregulated the expression of HO‑1 in a time‑dependent manner via the activation and translocation of nuclear factor erythroid 2‑related factor 2 (Nrf2), activation of the mitogen‑activated protein kinase (MAPK)/extracellular signal‑regulated kinase (ERK) signaling pathway and increasing intercellular Ca2+ ([Ca2+]i) concentration. The results showed that increasing the expression of HO‑1 decreased activation of the phosphoinositide 3‑kinase (PI3K)/AKT signaling pathway and inhibited the expression of c‑Myc. It was confirmed that cholesterol‑mediated oxidative damage in vascular endothelial cells induced an increase in the expression of HO‑1 via the activation of Nrf2 and the MAPK/ERK signaling pathway, and increasing the [Ca2+]i concentration. The overexpression of HO‑1 alleviated oxidative damage through inhibition of the PI3K/AKT signaling pathway and downregulation of the expression of c‑Myc.

Dynamic changes of mononuclear phagocytes in circulating, pulmonary alveolar and interstitial compartments in a mouse model of experimental silicosis

Abstract Context: Silicosis is a devastating, irreversible lung fibrosis condition exposed to crystalline silica. The mononuclear phagocyte system plays an important role in the pathogenesis of silicosis. Objective: The present study was aimed to explore the dynamic changes of mononuclear phagocytes in circulating, pulmonary alveolar and interstitial compartments in experimental silicosis model. Materials and methods: A mouse model of lung fibrosis was developed with crystalline silica particles (2 mg/40 μL via oropharyngeal instillation) using male C57BL/6 mice, and were killed on days 1, 3, 7, 14, and 28. The lung inflammation and fibrosis was investigated using hematoxylin–eosin staining and bronchoalveolar lavage fluid (BALF) analysis, Masson’s trichrome staining, and immunofluorescence. Circulating monocyte subsets (Ly6Chi and Ly6Clo), polarization state of BALF-derived alveolar macrophages (AMϕ) and lung interstitial macrophages (IMϕ, derived from enzymatically digested lung tissue) were analyzed by flow cytometry. Results: The percentage of Ly6Chi monocytes significantly increased on day 1 after silica exposure, which reached the peak level from day 7 till day 28. Moreover, M2 (alternative activation) AMϕ (PI − CD64 + CD206+) was dramatically and progressively increased from day 1 to day 28. A parallel increase in IMϕ with M2 polarization (PI-CD64 + CD11b + CD206+) was also observed from day 1 to day 28. Conclusion: Our data demonstrate a dynamic view of mononuclear phagocyte change in three compartments after silica challenge, which highlights the remodeling of mononuclear phagocyte system as a potential therapeutic target for silicosis.

Gut-dependent microbial translocation induces inflammation and cardiovascular events after ST-elevation myocardial infarction

BackgroundPost-infarction cardiovascular remodeling and heart failure are the leading cause of myocardial infarction (MI)-driven death during the past decades. Experimental observations have involved intestinal microbiota in the susceptibility to MI in mice; however, in humans, identifying whether translocation of gut bacteria to systemic circulation contributes to cardiovascular events post-MI remains a major challenge.ResultsHere, we carried out a metagenomic analysis to characterize the systemic bacteria in a cohort of 49 healthy control individuals, 50 stable coronary heart disease (CHD) subjects, and 100 ST-segment elevation myocardial infarction (STEMI) patients. We report for the first time higher microbial richness and diversity in the systemic microbiome of STEMI patients. More than 12% of post-STEMI blood bacteria were dominated by intestinal microbiota (Lactobacillus, Bacteroides, and Streptococcus). The significantly increased product of gut bacterial translocation (LPS and d-lactate) was correlated with systemic inflammation and predicted adverse cardiovascular events. Following experimental MI, compromised left ventricle (LV) function and intestinal hypoperfusion drove gut permeability elevation through tight junction protein suppression and intestinal mucosal injury. Upon abrogation of gut bacterial translocation by antibiotic treatment, both systemic inflammation and cardiomyocyte injury in MI mice were alleviated.ConclusionsOur results provide the first evidence that cardiovascular outcomes post-MI are driven by intestinal microbiota translocation into systemic circulation. New therapeutic strategies targeting to protect the gut barrier and eliminate gut bacteria translocation may reduce or even prevent cardiovascular events post-MI.

The influence of different anticoagulants and time-delayed sample processing and measurements on human monocyte subset and monocyte-platelet aggregate analyses

Measuring human monocyte subsets (CD14++CD16−, CD14++CD16+, and CD14 + CD16++) and subset‐specific monocyte‐platelet aggregates (MPA) is vulnerable to analytical bias due to unavailability of a standardized methodology. We aimed to address this issue by focusing on the impacts of time‐delayed sample processing and measurement between two commonly used anticoagulants.

Systemic Evaluation of Vascular Dysfunction by High-Resolution Sonography in an Nω-Nitro-l-Arginine Methyl Ester Hydrochloride–Induced Mouse Model of Preeclampsia-Like Symptoms

The purpose of this study was to evaluate vascular function, including arterial resistance and endothelial function, by high‐resolution sonography in an Nω‐nitro‐l‐arginine methyl ester hydrochloride (l‐NAME)‐induced mouse model of preeclampsia‐like symptoms.

Pseudolaric acid B attenuates atherosclerosis progression and inflammation by suppressing PPARγ-mediated NF-κB activation

Aims/objective: Atherosclerosis is a progressive disease of large arteries characterized with chronic inflammation and aberrant immune response. Pseudolaric acid B (PB) has been found to exert multiple effects by inhibiting inflammatory response. However, there is no comprehensive assessment of the effects of PB on atherosclerosis using relevant in vivo and in vitro models. Material and methods: Male ApoE−/− mice were treated with PB orally with a high fat diet (HFD) to clarify its anti‐atherosclerotic activities. RAW264.7 macrophage line, a well‐accepted cell model of atherosclerosis, was used to investigate anti‐inflammatory effects and molecular mechanisms of PB. Results: PB significantly attenuated atherosclerotic lesions by modulating plasma lipid profiles as well as inhibiting inflammatory responses in macrophages of atherosclerotic mice. Meanwhile, PB markedly suppressed the expression of pro‐inflammatory cytokines, and regulated cholesterol efflux related genes in oxidative low density lipoprotein (ox‐LDL)‐loaded macrophages. The cellular uptake of Dil‐labeled ox‐LDL was significantly inhibited by PB either. Moreover, the ability of PB to suppress nuclear factor kappa B (NF‐&kgr;B) and activate peroxisome proliferator‐activated receptor gamma (PPAR&ggr;) was confirmed using luciferase reporter assays. Conversely, the selective PPAR&ggr; antagonist GW9662 reversed the influence of PB in macrophages. Conclusion: Together, these findings indicate that PB exerts its protective effects on atherosclerosis by inhibiting macrophage‐mediated inflammatory response and cellular ox‐LDL uptake, and promoting cholesterol efflux by suppressing NF‐&kgr;B activation PPAR&ggr;‐dependently. Therefore, PB may be a promising agent for inflammatory and atherosclerotic diseases. HIGHLIGHTSWe have identified a novel action of Pseudolaric acid B (PB) on atherosclerosis.PB enhances cholesterol efflux related genes in lipid‐loaded macrophages, thereby reducing the cellular uptake of ox‐LDL.PB alleviates the progression of atherosclerosis through inhibiting inflammatory response both in vitro and in vivo.The mechanisms of PB might be related to the inhibition of NF‐&kgr;B activation via a PPAR‐&ggr;‐dependent manner.