Carbocisteine Improves Histone Deacetylase 2 Deacetylation Activity via Regulating Sumoylation of Histone Deacetylase 2 in Human Tracheobronchial Epithelial Cells

Abstract

Histone deacetylase (HDAC) 2 plays a vital role in modifying histones to mediate inflammatory responses, while HDAC2 itself is commonly regulated by post-translational modifications. Small ubiquitin-related modifier (SUMO), as an important PTM factor, is involved in the regulation of multiple protein functions. Our previous studies have shown that carbocisteine (S-CMC) reversed cigarette smoke extract (CSE)-induced down-regulation of HDAC2 expression/activity in a thiol/GSH-dependent manner and enhanced sensitivity of steroid therapy. However, the mechanism by which S-CMC regulates HDAC2 is worth further exploring. Our study aimed to investigate the relationships between HDAC2 sumoylation and its deacetylase activity under oxidative stress and the molecular mechanism of S-CMC to regulate HDAC2 activity that mediates inflammatory responses in human bronchial epithelial cells. We found that modification of HDAC2 by SUMO1 and SUMO2/3 occurred in 16HBE cells under physiological conditions, and CSE induced SUMO1 modification of HDAC2 in a dose and time-dependent manner. K462 and K51 of HDAC2 were the two major modification sites of SUMO1, and the K51 site mediated deacetylation activity and function of HDAC2 on histone H4 that regulates IL-8 secretion. S-CMC inhibited CSE-induced SUMO1 modification of HDAC2 in the presence of thiol/GSH, increased HDAC activity, and decreased IL-8 expression. Our study may provide novel mechanistic explanation of S-CMC to ameliorate steroid sensitivity treatment in chronic obstructive pulmonary disease.

Expression of histone deacetylase 2 in tracheal stenosis models and its relationship with tracheal granulation tissue proliferation

“…It may promote fibroblast proliferation and collagen synthesis, inhibit collagen fiber decomposition and facilitate the deposition of extracellular matrix, the formation of granulation tissue and fibrosis ( 49 ). In human tracheobronchial epithelial cells, carbocisteine, which is a mucoactive drug, reduced IL-8 expression by increasing HDAC2 activity ( 50 ). Erythromycin may increase the activity of HDAC2 via inhibiting the PI3K/Akt pathway and reducing the release of inflammatory factors, such as IL-8, thereby increasing the anti-inflammatory activity of budesonide ( 13 ).…”

“…In human THP-1 cells stimulated with lipopolysaccharide and primary human peripheral blood mononuclear cells, pre-treatment with the HDAC inhibitor trichostatin A or gene silencing of HDAC1 and HDAC2 inhibited the anti-inflammatory effects of isoflurane and increased the expression of TNF-α, IL-8 and interleukin-1β ( 51 ). These studies indicated that increasing the expression/activity of HDAC2 reduces the release of the inflammatory factor IL-8 and enhances the anti-inflammatory effect, while inhibiting the expression/activity of HDAC2 increases the release of the inflammatory factor IL-8 and aggravates the inflammatory response ( 13 , 50 , 51 ). A clinical study revealed that mechanical damage, which was triggered via tracheal intubation induced an increased expression of TGF-β, VEGF, and basic fibroblast growth factor, which resulted in enhanced expression of collagen type I and III, tracheal granulation hyperplasia and tracheal stenosis ( 52 ).…”

“…In a study of a rat COPD model, carbocisteine ameliorated the airway remodeling via increasing the HDAC2 expression/activity, including the airway epithelial and smooth muscle thickness, airway fibrosis and the α-smooth muscle antibody and TGF-β1 levels ( 53 ). Multiple lines of evidence have suggested that erythromycin and carbocisteine upregulate HDAC2 expression, reduce the release of inflammatory factors, such as IL-8, to achieve anti-inflammatory effects, decrease the expression of the fibrosis-related factors TGF-β1, VEGF, type I and III collagen and inhibit airway fibrosis ( 13 , 45 , 50 , 52 , 53 ).…”

CpG oligodeoxynucleotides attenuate RORγt-mediated Th17 response by restoring histone deacetylase-2 in cigarette smoke-exposure asthma

“…CSE preparation was performed as previous described, with minor modifications [ 26 ]. Briefly, one cigarette (each cigarette: nicotine, 1.0 mg; tar oil, 10 mg; carbon monoxide, 13 mg; Tobacco Hunan Industrial Corporation, China) was combusted, and the smoke was passed through 10 mL of serum-free culture medium at a rate of 5 min/cigarette.…”

CpG oligodeoxynucleotides attenuate RORγt-mediated Th17 response by restoring histone deacetylase-2 in cigarette smoke-exposure asthma

“…We analyzed the uorophore with the excitation at 360nm and emission at 460nm by using a uorescence plate reader. CSE preparation CSE preparation followed a previous report, with minor modi cations [23]. Brie y, one cigarette (per cigarette: nicotine, 1.0 mg; tar oil, 10 mg; carbon monoxide, 13 mg; Tobacco Hunan Industrial Corporation, China) was combusted, and the smoke was passed through 10 mL of serum-free culture medium at 5 min/cigarette.…”