Induction of Murine Macrophage M2 Polarization by Cigarette Smoke Extract via the JAK2/STAT3 Pathway

Abstract

Cigarette smoking is a major pathogenic factor in lung cancer. Macrophages play an important role in host defense and adaptive immunity. These cells display diverse phenotypes for performing different functions. M2 type macrophages usually exhibit immunosuppressive and tumor-promoting characteristics. Although macrophage polarization toward the M2 phenotype has been observed in the lungs of cigarette smokers, the molecular basis of the process remains unclear. In this study, we evaluated the possible mechanisms for the polarization of mouse macrophages that are induced by cigarette smoking (CS) or cigarette smoke extract (CSE). The results showed that exposure to CSE suppressed the production of reactive oxygen species (ROS) and nitric oxide (NO) and down-regulated the phagocytic ability of Ana-1 cells. The CD163 expressions on the surface of macrophages from different sources were significantly increased in in vivo and in vitro studies. The M1 macrophage cytokines TNF-α, IL-12p40 and enzyme iNOS decreased in the culture supernatant, and their mRNA levels decreased depending on the time and concentration of CSE. In contrast, the M2 phenotype macrophage cytokines IL-10, IL-6, TGF-β1 and TGF-β2 were up-regulated. Moreover, phosphorylation of JAK2 and STAT3 was observed after the Ana-1 cells were treated with CSE. In addition, pretreating the Ana-1 cells with the STAT3 phosphorylation inhibitor WP1066 inhibited the CSE-induced CD163 expression, increased the mRNA level of IL-10 and significantly decreased the mRNA level of IL-12. In conclusion, we demonstrated that the M2 polarization of macrophages induced by CS could be mediated through JAK2/STAT3 pathway activation.

Experimental progressive emphysema in BALB/cJ mice as a model for chronic alveolar destruction in humans

“…Consistent with previous studies, we found that the susceptible BALB/cJ mice had a very marked and prolonged production of MMP-12 in the lung in response to elastase injury than the resistant C57BL/6J strain. The polarization of macrophages toward an M2 phenotype accompanied by MMP-12 elevation has also been observed in the hookworm infection model of emphysema (51), an acute ozone exposure model (74), the mouse cigarette smoke model (24,92), and possibly in human emphysema patients (42). Interestingly, in addition to the expression of signature M2 markers such as arg1 and fizz1, we also found elevated expression of iNOS, a typical marker for classical activated macrophages (M1 phenotype) both at baseline and after elastase insult in the BALB/cJ strain.…”

M2 polarized macrophages induced by CSE promote proliferation, migration, and invasion of alveolar basal epithelial cells

“…c o m / l o c a t e / i n t i m p penicillin and 100 μg/ml streptomycin at 37°C in a 5% CO 2 atmosphere. CSE was prepared as previously described [13]. THP-1 cells in exponential growth were plated at a density of 5 × 10 4 cells/ml in 6-well plates, 2 ml/well.…”

“…TAM infiltration has been associated with poor prognosis [7,8,12]. In our previous studies, we have demonstrated that cigarette smoke can induce M2 polarization of mouse macrophages both in vivo and in vitro [13]. However, the relationship between cigarette smoking, macrophage M2 polarization and lung cancer remains unclear.…”

Reduced phagocytic capacity of blood monocyte/macrophages in tuberculosis patients is further reduced by smoking

“…35 The removed cells (5×10 4 ) were suspended in 100µl PBS including 1% bovine serum albumin and incubated together with FITC-dextran (0.1mg/ml) at 37°C or 4°C for 2hrs as described previously. 36 Incubation was stopped by mixing with 2ml ice-cold PBS that include 1% human serum and 0.02% sodium azide. The cells were washed three times, with cold PBS and FACS Calibour flow cytometer (FACS Calibour, BD bioscience, USA) was used for analysis.…”