Tiotropium Bromide Improves Neutrophilic Asthma by Recovering Histone Deacetylase 2 Activity
- Author:
Tai Joon AN
1
;
Ji Hye KIM
;
Jung HUR
;
Chan Kwon PARK
;
Jeong Uk LIM
;
Seohyun KIM
;
Chin Kook RHEE
;
Hyoung Kyu YOON
Author Information
- Publication Type:Original Article
- From:Journal of Korean Medical Science 2023;38(12):e91-
- CountryRepublic of Korea
- Language:English
-
Abstract:
Background:The value of tiotropium bromide (TIO) in neutrophilic asthma was meaningful in previous study. We hypothesized that TIO’s mechanism of action is associated with histone deacetylase 2 (HDAC2) activity, which is key for controlling the transcription of inflammatory cytokines and usually downregulated in neutrophilic asthma.
Methods:The effects of TIO and dexamethasone (DEX) on HDAC2 activity, nuclear factor kappa B (NF-κB), and C-X-C motif chemokine ligand 1 (CXCL1) were evaluated in neutrophilic asthma mouse model (C57BL, 6-week-old). An in-vitro study was conducted using primary human bronchial/tracheal epithelial (HBE) cells from asthma patients.Western blot analyses were performed for phospho-phospholipase Cγ-1 (PLCγ-1) and inositol trisphosphate (IP3 ) receptors (IP3 R) with treating lipopolysaccharide (LPS) and TIO.
Results:Ovalbumin was used to induce eosinophilic inflammation in this study. After neutrophilic asthma was induced by LPS (O+L group), HDAC2 activity was diminished with increased NF-κB activity and CXCL1 compared to the control group. TIO significantly improved NF-κB activity, CXCL1, and HDAC2 activity compared with the O+L group in in-vivo study (P < 0.05, each). Western blot analyses showed that LPS treated HBE cells from asthma patients increased PLCγ-1 and diminished IP3 receptor levels. After TIO treatment, recovery of IP3 R and improved PLCγ-1 levels were observed.
Conclusion:These results support the hypothesis that TIO modulates inflammation by recovering HDAC2 activity from the acetylcholine-stimulated inflammation cascade in neutrophilic asthma. The detailed inflammation cascade of recovering HDAC2 activity by TIO might be associated with PLCγ-1-IP3-IP3R mediated intracellular calcium ion pathway.
