Role of C-reactive protein in airway smooth muscle dysfunction relevant to obstructive lung disease.

Abstract

C-reactive protein (CRP), is an inflammation marker, often elevated in airways conditions such as asthma and COPD. This research investigated the impact of CRP on airway smooth muscle (ASM) cells, which are crucial in the airway remodelling and hyperresponsiveness which is observed in these conditions. By using primary human ASM cells, this study has shown that purified CRP reduced cell number, increased cell size and intracellular complexity, and maintained cell viability. However, these findings were not replicated with recombinant CRP, which lacks endotoxin, suggesting that endotoxin contamination in the purified CRP may have played a role. Lipopolysaccharide (LPS) treatment, an endotoxin component, resulted in increased intracellular complexity but did not completely replicate the other effects of purified CRP on ASM cells. Moreover, a CRP-neutralizing antibody did not reverse the changes induced by purified CRP, indicating the potential involvement of contaminants. The differences between purified and recombinant CRP highlight the challenges in isolating the true effects of CRP from those of other inflammatory agents. Future research will give priority to endotoxin removal or neutralization, using higher concentrations of both CRP and the neutralizing antibody. Additionally, the study will focus on exploring potential synergistic effects between CRP and LPS on ASM cells. Further investigations are needed to fully understand the role of CRP in the ASM dysfunction and the underlying mechanisms, including apoptosis, hypertrophy, and mediator secretion. In conclusion, this study suggests that CRP has the potential to contribute to ASM dysfunction but underscores the importance of strict experimental controls to distinguish its effects from potential contaminants like endotoxin. The research emphasizes the need for further exploration of the complex interplay between CRP, endotoxin, and ASM cells to elucidate their individual or combined contribution to ASM dysfunction in lung diseases.