ABSTRACT
INTRODUCTION: The CD163 is exclusively expressed by mononuclear phagocytes as a transmembrane protein, which synthesis is regulated by anti- and pro-inflammatory signals. After shedding from the cell surface it exists in body fluids as a soluble protein (sCD163) which exerts anti-inflammatory effects. AIM: To evaluate serum concentration and ex vivo production of sCD163 by peripheral blood mononuclear cells (PBMC) in asthmatic patients treated with inhaled (ICS) or oral corticosteroids (OCS). MATERIAL AND METHODS: The study was performed on 35 allergic asthma patients (AAs) including 15 treated with ICS (ICS-AAs), 10 with OCS (OCS-AAs), 10 during asthma exacerbation (EX-AAs) before OCS had been started and 13 non-atopic healthy subjects (HCs) as a control group. PBMC were cultured in vitro for up to 144 h. The concentration of sCD163 in serum and the culture supernatants was evaluated with ELISA. RESULTS: The greatest serum sCD163 concentration was demonstrated in EX-AAs, which was significantly greater than that in other studied subgroups. The concentration of sCD163 in PBMC culture supernatants was greater in AAs than in HCs (p = 0.006). Among individual asthma subgroups the greatest concentration of sCD163 was demonstrated in PBMC culture supernatants of OCS-AAs, which was significantly greater than in ICS-AAs (p < 0.001) and EX-AAs (p < 0.001), both being significantly greater than in HCs (p < 0.001). CONCLUSIONS: In AAs, enhanced capability of PBMCs to release sCD163 may be at least partially responsible for the anti-inflammatory effects of systemic corticosteroid therapy.
ABSTRACT
BACKGROUND: The CD163 is a marker of monocyte/macrophage anti-inflammatory function. Its soluble form (sCD163) also exert anti-inflammatory activities including inhibition of T cell proliferation. OBJECTIVE: To evaluate the effect of dexamethasone (Dx) and Dermatophagoides pteronyssinus (Dp) on ex vivo production of sCD163 by peripheral blood mononuclear cells (PBMCs). METHODS: PBMCs from 26 allergic asthma patients (AAs) and 12 non-atopic healthy controls (HCs) were cultured with Dp, Dx, Dp + Dx or without any stimulation for up to 144 h (T144). Concentration of sCD163, interleukin (IL) -6 and IL-10 in PMBC culture supernatants was evaluated using ELISA. The mRNA expression of CD163 by PBMCs was estimated using quantitative PCR (qPCR). RESULTS: At T144 the median concentration of CD163 in unstimulated PBMC cultures of AAs was greater than that in HCs (p = 0.008). Concomitant application of Dp and Dx resulted in a synergistic effect reflected by a dramatic increase of sCD163 concentration both in HCs (p = 0.0002) and AAs (p < 0.0001). Also a synergistic effect of Dp and Dx on CD163 mRNA expression was seen at T24 and T48 but not at T6 or T12. Among asthmatic patients the effect of Dx on sCD163 production was attenuated in severe in comparison to mild-to-moderate AAs (p = 0.0007). Moreover, Dp-induced production of IL-6 but not IL-10 was inhibited by Dx (p < 0.0001). Inhibition of IL-10 decreased sCD163 concentration by more than 50%. CONCLUSIONS: Dx-triggered upregulation of anti-inflammatory CD163 expression by monocytes is synergistic with endogenous mechanisms involved in the resolution of Dp-induced inflammation. This effect is impaired in severe asthma patients.
Subject(s)
Allergens/immunology , Antigens, CD/metabolism , Antigens, Dermatophagoides/immunology , Antigens, Differentiation, Myelomonocytic/metabolism , Dermatophagoides pteronyssinus/immunology , Dexamethasone/pharmacology , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/physiology , Receptors, Cell Surface/metabolism , Adult , Animals , Anti-Inflammatory Agents/pharmacology , Antigens, CD/genetics , Antigens, Differentiation, Myelomonocytic/genetics , Asthma/diagnosis , Asthma/etiology , Asthma/metabolism , Biomarkers , Cytokines/genetics , Cytokines/metabolism , Female , Gene Expression , Humans , Male , Middle Aged , Receptors, Cell Surface/genetics , Respiratory Function Tests , Young AdultABSTRACT
AIMS: l-Alpha-lysophosphatidylinositol (LPI) is an endogenous agonist of G protein-coupled receptor 55 (GPR55) which relaxes mesenteric arteries on activation. The aim of the present study was to determine the influence and underlying mechanisms of LPI-induced relaxation in human pulmonary arteries (hPAs). MAIN METHODS: Functional studies were performed in isolated hPAs using organ bath technique. The expression of GPR55 in hPAs and bronchioles was determined by real-time qPCR, Western blot analysis, and immunohistochemistry. KEY FINDINGS: LPI induced a concentration-dependent vasorelaxation in endothelium-intact hPAs. This effect was attenuated by the GPR55 antagonist CID16020046, the peroxisome proliferator-activated receptor-γ (PPARγ) antagonist GW9662, the putative endothelial cannabinoid receptor (CBe) antagonist O-1918 and the inhibitor of nitric oxide (NO) synthase (L-NAME). In addition, vasorelaxation was also attenuated by the presence of a high KCl concentration, selective blockers of small (KCa2.3; UCL1684), intermediate (KCa3.1; TRAM-34) and large conductance (KCa1.1; iberiotoxin) calcium-activated potassium channels and by endothelium denudation. However, vasorelaxation was not attenuated by the cannabinoid CB1 receptor antagonist AM251 or by the cyclooxygenase inhibitor indomethacin. SIGNIFICANCE: The study showed that the LPI-induced vasorelaxation was endothelium-dependent and mediated by GPR55, PPARγ and CBe receptors, occurred in a NO- and calcium-activated potassium channel-dependent manner in isolated hPAs. LPI seems to possess positive, hypotensive properties in pulmonary vascular bed.
Subject(s)
Lysophospholipids/pharmacology , Muscle Relaxation/drug effects , Muscle, Smooth, Vascular/drug effects , Pulmonary Artery/drug effects , Aged , Anilides/pharmacology , Anisoles/pharmacology , Azabicyclo Compounds/pharmacology , Benzoates/pharmacology , Bronchioles/drug effects , Bronchioles/metabolism , Cyclohexanes/pharmacology , Dose-Response Relationship, Drug , Endothelium, Vascular/drug effects , Enzyme Inhibitors/pharmacology , Female , Humans , In Vitro Techniques , Male , Middle Aged , Muscle, Smooth, Vascular/metabolism , NG-Nitroarginine Methyl Ester/pharmacology , PPAR gamma/antagonists & inhibitors , Potassium Channel Blockers/pharmacology , Pulmonary Artery/metabolism , Receptors, Cannabinoid , Receptors, G-Protein-Coupled/antagonists & inhibitors , Receptors, G-Protein-Coupled/biosynthesis , Receptors, G-Protein-Coupled/geneticsABSTRACT
INTRODUCTION: Chemokines have been shown to play an important role in tissue remodeling and fibrosis in the respiratory system. In this study we wanted to evaluate the mechanisms, which regulate the expression of selected chemokines by pulmonary fibroblasts in vitro. MATERIAL AND METHODS: Pulmonary fibroblasts were cultured with and without bacterial lipopolysaccharide (LPS) for 6 hours. In addition some of the cultures were pre-treated with histone deacetylase inhibitor Trichostatin A (TSA). Real-time PCR reaction was performed to estimate the expression of chemokines CCL2, CCL3 and CXCL8. RESULTS: In unstimulated cultures detectable expression of CCL2 and CXCL8 was observed, while CCL3 expression could not be detected. After stimulation with LPS, TSA and both agents together CCL2 expression rose by 1.52, 1.62 and 1.8 times in comparison to control cultures respectively. CXCL8 mRNA expression levels after stimulation with LPS, TSA and LPSTSA increased by 1.53, 1.91 and 2.4 times accordingly. CONCLUSION: Epigenetic mechanisms related to histone acetylation affects transcriptional regulation of CCL2 and CXCL8 expression by pulmonary fibroblasts. Those mechanisms may play a role in tissue repair and pathologic remodeling.