Cigarette smoke extract contributes to the inception and aggravation of asthmatic inflammation by stimulating innate immunity

Purpose@#Smoking is a risk factor for the development of asthma and worsens the long-term prognosis of asthma. This study investigated the effect of cigarette smoke extract (CSE) on innate immune cells such as innate lymphoid cells (ILCs) and macrophages in a murine model of induced asthma. @*Methods@#Six-week-old female BALB/C mice were exposed to ovalbumin (OVA) via an intranasal route with or without CSE for 8 weeks to establish a chronic murine asthma model. Airway hyperresponsiveness (AHR), airway inflammatory cells from bronchoalveolar lavage fluid, and the population of CD4 + T cells, ILCs, and macrophages in the lungs were studied to evaluate the effect of chronic CSE exposure on asthma. @*Results@#Mice intranasally exposed to CSE along with OVA treatment (CSE/OVA) had significantly enhanced AHR, eosinophilic inflammation, increased IL-13 and IL-17 producing CD4 + T cells compared to mice intranasally exposed to OVA only. On the contrary, the frequency of Foxp3 + in CD4 + T cells was reduced in the CSE/OVA group. CSE enhanced the dendritic cell (DC) population, especially MHCII + DC with antigen-presenting capacity. Among ILCs, the CSE/OVA group showed a significant increase of IL-13-producing type 2 ILCs, but not interferon-γ+ ILC1s and IL-17 + ILC3s. . Among macrophages, alveolar macrophage and Ym-1 and FIZZ1 positive M2 macrophage populations were significantly induced by CSE exposure alone and when combined with OVA treatment. @*Conclusion@#In this study, we showed that long-term exposure to cigarette smoke contributes to the inception and aggravation of asthmatic inflammation by enhancing DCs, ILC2, and M2 alveolar macrophage populations in the mouse model.

Antiasthmatic effect of atorvastatin via modulation of macrophage activation

Purpose@#Asthma is a chronic airway inflammatory disorder and is associated with macrophages. Statin, a well-known lipid-lowering agent, has recently been noted for its anti-inflammatory effect on macrophage. This study was designed to evaluate the antiasthmatic effect of atorvastatin via modulation of macrophage activation by using an animal model of allergic asthma. @*Methods@#Atorvastatin 40 mg/kg was given by gavage once a day for 3 days before challenge of ovalbumin (OVA); airway hyperresponsiveness (AHR), airway inflammatory cells, and cytokines were evaluated in the murine asthma model. The direct effect of atorvastatin on the activation of macrophages In vitro was determined using the alveolar macrophage cell line CRL-2456. @*Results@#Administration of atorvastatin reduced the numbers of total inflammatory cells, macrophages, and eosinophils as well as lung histology enhanced in the murine asthma model. AHR measured by enhanced pause was significantly reduced after atorvastatin administration in the murine asthma model (P< 0.05). Atorvastatin administration resulted in the reduction in serum OVA-specific IgE levels and the increase in serum OVA-specific IgG2a levels (P< 0.05). The mRNA levels of Ccr3, Il-17, and Muc5ac enhanced by OVA challenge were decreased by treatment with atorvastatin (P< 0.05). Along with these improvement in allergic inflammatory changes, the population of CD11c-CD206+ macrophages as well as the expression of Ym-1 and Relm-α in the lungs were reduced with atorvastatin (P< 0.05). In vitro test with CRL-2456 showed that atorvastatin reduced the expression of Cd206, Arg-1, and Fgf-2 induced by IL-4 stimulation (P< 0.05). @*Conclusion@#This study highlighted the antiasthmatic effect of atorvastatin on the suppression of M2 macrophage activation in allergic asthma.

Therapeutic effect of atorvastatin on interleukin-13-induced lung pathology

Purpose@#Asthma is a common chronic lung disease, in which interleukin (IL)-13 is implicated as a central regulator of IgE synthesis, mucus hypersecretion, airway hyperresponsiveness (AHR), and fibrosis. This study was designed to determine the anti-inflammatory effect of atorvastatin, a widely used lipid-lowering agent, on the IL-13-induced lung pathology through the modulation of macrophages. @*Methods@#Atorvastatin (40 mg/kg) was given to transgenic mice overexpressing IL-13 (IL-13 TG mice) and their wild type littermates by oral gavage for 2 weeks. AHR, numbers of inflammatory cells in the airway, and cytokine levels in IL-13 TG mice were measured.Using the alveolar macrophage cell line CRL-2456, the direct effect of atorvastatin on macrophages activated by recombinant IL-13 was assessed. @*Results@#Significant reduction in total leukocytes and alleviation of AHR were observed with administration of atorvastatin in IL-13 TG mice compared to those without atorvastatin treatment (P< 0.05). Atorvastatin administration resulted in upregulation of IL-10 in the lungs of IL-13 TG mice (P< 0.05). In addition, mRNA expression of connective tissue growth factor, fibronectin, and type III collagen as well as chord length enhanced by IL-13 overexpression were reduced by atorvastatin administration (P< 0.05). M2 macrophage markers, such as Ym-1 and CD206, were decreased, while M1 macrophage marker, inducible nitric oxide synthase, was increased upon atorvastatin treatment (P< 0.05). Administration of atorvastatin resulted in improved removal of apoptotic cells (P< 0.05). @*Conclusion@#The results of this study reveal a potential of atorvastatin as an effective antiasthmatic agent by reducing IL-13-induced lung inflammation via the modulation of macrophage polarization.