CAPN5 attenuates cigarette smoke extract-induced apoptosis and inflammation in BEAS-2B cells

Herui Li; Yiming Ma; Tiao Li; Zihang Zeng; Lijuan Luo; Xiangming Liu; Yi Li; Yan Chen

doi:10.18332/tid/186183

CAPN5 attenuates cigarette smoke extract-induced apoptosis and inflammation in BEAS-2B cells

Tob Induc Dis. 2024 Apr 22:22. doi: 10.18332/tid/186183. eCollection 2024.

Authors

Herui Li^{1

2

3

4}, Yiming Ma^{1

2

3

4}, Tiao Li^{1

2

3

4}, Zihang Zeng^{1

2

3

4}, Lijuan Luo^{1

2

3

4}, Xiangming Liu^{1

2

3

4}, Yi Li⁵, Yan Chen^{1

2

3

4}

Affiliations

¹ Department of Respiratory Medicine, The Second Xiangya Hospital, Central South University, Changsha, China.
² Research Unit of Respiratory Diseases, Central South University, Changsha, China.
³ Clinical Medical Research Center for Respiratory and Critical Care Medicine in Hunan Province, Changsha, China.
⁴ Diagnosis and Treatment Center of Respiratory Disease, Central South University, Changsha, China.
⁵ Department of Infectious Disease, The Second Xiangya Hospital, Central South University, Changsha, China.

Abstract

Introduction: Apoptosis and chronic inflammation are the main phenotypes in chronic obstructive pulmonary disease (COPD) pathogenesis. Cigarette smoke exposure is the leading risk factor for COPD, which causes aberrant airway epithelial structure and function. As a non-classical calpain, the molecular function of calpain5 (CAPN5) in COPD remains unclear. This study investigated the role of CAPN5 in mediating cigarette smoke extract (CSE)-induced apoptosis and inflammation.

Methods: Immunohistochemistry (IHC) and Western blotting (WB) were performed to detect the location and expression of CAPN5. In vitro, BEAS-2B cells were transfected with CAPN5 siRNA or CAPN5 plasmid, followed by phosphate-buffered saline (PBS) or cigarette smoke extract (CSE) treatment. The protein expression levels of CAPN5, NF-κB p65, p-p65, IκBα, p-IκBα and apoptosis proteins (BCL-2, BAX) were measured by WB. Flow cytometry (FCM) was performed to analyze the cell apoptosis index.

Results: CAPN5 was mainly expressed in the airway epithelium and significantly decreased in the COPD-smoker and emphysema-mouse groups. Silencing CAPN5 significantly decreased the protein expression of BCL-2, IκBα, and increased p-p65 and BAX protein expression. Additionally, an increased apoptosis index was detected after silencing CAPN5. Moreover, overexpression of CAPN5 partly inhibited IκBα degradation and p65 activation, and reduced CSE-induced inflammation and apoptosis.

Conclusions: These combined results indicate that CAPN5 could protect against CSE-induced apoptosis and inflammation, which may provide a potential therapeutic target for smoking-related COPD.

Keywords: CAPN5; apoptosis; cigarette smoke; inflammation.

Grants and funding

FUNDING This work was supported by National Natural Science Foundation of China (No. 81873410, No. 82070646 and No. 82070049) and the National Key Clinical Specialty Construction Projects of China.