Carbocisteine attenuates TNF-α-induced inflammation in human alveolar epithelial cells in vitro through suppressing NF-κB and ERK1/2 MAPK signaling pathways

Abstract

Aim: We previously proven that carbocisteine, a conventional mucolytic drug, remarkably reduced the rate of acute exacerbations and improved the quality of life in the patients with chronic obstructive pulmonary disease. In this study we investigated the mechanisms underlying the anti-inflammatory effects of carbocisteine in human alveolar epithelial cells in vitro. Methods: Human lung adenocarcinoma cell line A549 was treated with TNF-α (10 ng/mL). Carbocisteine was administered either 24 h prior to or after TNF-α exposure. The cytokine release and expression were measured using ELISA and qRT-PCR. Activation of NF-κB was analyzed with Western blotting, immunofluorescence assay and luciferase reporter gene assay. The expression of ERK1/2 MAPK signaling proteins was assessed with Western blotting. Results: Carbocisteine (10, 100, 1000 µmol/L), administered either before or after TNF-α exposure, dose-dependently suppressed TNF-α-induced inflammation in A549 cells, as evidenced by diminished release of IL-6 and IL-8, and diminished mRNA expression of IL-6, IL-8, TNF-α, MCP-1 and MIP-1β. Furthermore, pretreatment with carbocisteine significantly decreased TNF-α-induced phosphorylation of NF-κB p65 and ERK1/2 MAPK, and inhibited the nuclear translocation of p65 subunit in A549 cells. In an NF-κB luciferase reporter system, pretreatment with carbocisteine dose-dependently inhibited TNF-α-induced transcriptional activity of NF-κB. Conclusion: Carbocisteine effectively suppresses TNF-α-induced inflammation in A549 cells via suppressing NF-κB and ERK1/2 MAPK signaling pathways.

The Protective Effects of a Synthetic Geranyl Acetophenone in a Cellular Model of TNF-α-Induced Pulmonary Epithelial Barrier Dysfunction

“…Alveolar epithelial barrier dysfunction is also attributed to increased expression or secretion of inflammatory mediators, such as chemokines and adhesion molecules by alveolar epithelial cells themselves, which further promote leukocyte adhesion and infiltration, causing edema [ 3 , 6 ]. TNF-α in particular, has been shown to enhance leukocyte adhesion by upregulating chemokines and adhesion molecules expression in alveolar epithelial cells, increasing barrier permeability and downregulating tight junctions expression [ 18 , 19 , 20 , 22 , 23 , 24 , 25 ]. The effects of TNF-α on lung epithelial barrier integrity and function are also supported by in vivo studies [ 26 , 27 , 28 ].…”

CARBOCISTEINE INHIBITS THE EXPRESSION OF Muc5b IN COPD MOUSE MODEL

“…Our findings indicated that carbocisteine conferred a dosedependent therapeutic effect, which was in agreement with our previous findings related to the anti-inflammatory actions of carbocisteine in vitro. 7,8 However, Hanaoka et al showed no significant differences between the two carbocisteine treatment groups. 10 Several explanations were likely to be responsible for such a difference.…”

“…Our previous studies showed that carbocisteine attenuated hydrogen peroxide and TNF-alpha-induced inflammation in vitro via suppressing NF-kB and ERK1/2 MAPK signaling pathways. 7,8 Additionally, IL-6 and IL-17 regulate Muc5b expression via the ERK signaling pathway, 35 and IL-1b and IL-17A mediate Muc5b expression by NF-kB-based transcriptional mechanism in vitro. 28 We hypothesized that carbocisteine may regulate Muc5b expression via suppressing NF-kB and ERK1/2 MAPK signaling pathways in COPD mice model, thereby affecting the progression of COPD.…”

“…Carbocisteine, a well-tolerated mucolytic agent, has been extensively used in COPD. 4,5 Carbocisteine has been shown to markedly prevent COPD exacerbations 6 and alleviate oxidative stress and inflammatory-induced injury in vitro [7][8][9] and in vivo. 10,11 Carbocisteine also altered mucus properties by balancing the fucose and sialic acid contents on mucins.…”

Negative Effects of SIGIRR on TRAF6 Ubiquitination in Acute Lung Injury In Vitro

“…After cell transfection, an NF- κ B firefly luciferase reporter was used to evaluate NF- κ B activity according to the manufacturer's instructions. First, the above cells were lysed in passive lysis buffer, and then, a dual-luciferase assay was used to quantify the luciferase activity [ 38 , 39 ].…”