Modulation of the airway smooth muscle phenotype in a murine asthma model and effects of nuclear factor-κB inhibition

Abstract

Objective: Phenotype modulation of airway smooth muscle (ASM) is a unique characteristic of asthma and is considered to regulate airway remodeling, airway hyperresponsiveness (AHR) and inflammation. The nuclear factor-κB (NF-κB) signaling pathway plays a crucial role in phenotypic modulation. Thus, models of acute and chronic asthma were established and pyrrolidine dithiocarbamate (PDTC), an NF-κB inhibitor was delivered by intraperitoneal injection. Methods: The Penh value was measured using the BUXCO WBP system. Lung tissues were subjected to histologic analysis. Phenotypic markers of ASM and COL1A1 mRNA levels were measured by RT-PCR. Expression levels of phosphorylated p65 (pP65) and α-SMA were detected by Western blot. Serum cytokine levels were quantified by RayBiotech ELISA array. Results: PDTC intervention decreased the Penh values in both the acute and chronic models. The ASM area and the airway collagen area were decreased in the PDTC intervention group. A decrease in phenotypic markers were detected in both the acute and chronic models in time-dependent manner, and PDTC intervention partially reversed the phenotypic modulation. The effect of PDTC intervention on systemic inflammation was also verified. Conclusion: These results revealed the existence of a dynamic ASM phenotype modulation procedure in asthma development and that targeting NF-κB by PDTC was effective to mitigate ASM phenotype modulation and major asthmatic pathological features.