Author + information
- Received July 31, 2019
- Revision received September 27, 2019
- Accepted October 1, 2019
- Published online January 27, 2020.
- Huibing Liu, MSa,∗,
- Libo Wang, MSa,∗,
- Yating Pan, MDa,∗,
- Xuehui Wang, MD, PhDa,
- Yuan Ding, BSMb,
- Chaoyuan Zhou, MDc,
- Ajay M. Shah, MDd,
- Guoan Zhao, MD, PhDa,∗∗ ( and )
- Min Zhang, MD, PhDd,∗ ()
- aDepartment of Cardiology, First Affiliated Hospital of Xinxiang Medical University, Heart Center of Xinxiang Medical University, Henan, China
- bDepartment of Ultrasonography, First Affiliated Hospital of Xinxiang Medical University, Henan, China
- cDepartment of Thoracic Surgery, First Affiliated Hospital of Xinxiang Medical University, Henan, China
- dSchool of Cardiovascular Medicine & Sciences, King's College London British Heart Foundation Centre of Research Excellence, London, United Kingdom
- ↵∗Address for correspondence:
Dr. Min Zhang, School of Cardiovascular Medicine and Sciences, James Black Centre, King’s College London BHF Centre of Research Excellence, 125 Coldharbour Lane, London SE5 9NU, United Kingdom.
- ↵∗∗Dr. Guoan Zhao, Department of Cardiology, the First Affiliated Hospital of Xinxiang Medical University, Heart Center of Xinxiang Medical University, Henan 453100, China.
• The reactive oxygen species–generating enzyme Nox2 is up-regulated in the leaflets of both rabbit and human with CAVD.
• Nox2 is markedly induced in cultured porcine AVICs after osteogenic stimulation. Knockdown of endogenous Nox2 substantially suppressed AVIC calcification.
• Celastrol, a natural compound capable of inhibiting Nox2 activity, significantly decreased AVIC calcification in vitro, and mitigated the severity of aortic valve fibrosis, calcification, and stenosis in a rabbit model of CAVD in vivo.
• The protective effects of celastrol may, in part, involve the inhibition of Nox2-mediated glycogen synthase kinase 3 beta/β-catenin pathway.
This study sought to investigate whether reactive oxygen species (ROS)–generating reduced nicotinamide adenine dinucleotide phosphate oxidase 2 (Nox2) contributes to calcific aortic valve disease (CAVD) or whether celastrol, a natural Nox2 inhibitor, may provide potential therapeutic target for CAVD. CAVD is an active and cellular-driven fibrocalcific process characterized by differentiation of aortic valvular interstitial cells (AVICs) toward an osteogenic-like phenotype. ROS levels increase in calcified aortic valves, while the sources of ROS and their roles in the pathogenesis of CAVD are elusive. The roles of Nox2 and the effects of celastrol were studied using cultured porcine AVICs in vitro and a rabbit CAVD model in vivo. Nox2 proteins were significantly upregulated in human aortic valves with CAVD. In vitro, Nox2 was markedly induced upon stimulation of AVICs with osteogenic medium, along with the increases in ROS production and calcium nodule formation. Celastrol significantly decreased calcium deposition of AVICs by 35%, with a reduction of ROS generation. Knockdown of endogenous Nox2 substantially suppressed AVIC calcification by 39%, the inhibitory effect being similar to celastrol treatment. Mechanistically, either celastrol treatment or knockdown of Nox2 significantly inhibited glycogen synthase kinase 3 beta/β-catenin signaling, leading to attenuation of fibrogenic and osteogenic responses of AVICs. In a rabbit CAVD model, administration of celastrol significantly reduced aortic valve ROS production, fibrosis, calcification, and severity of aortic stenosis, with less left ventricular dilatation and better preserved contractile function. Upregulation of Nox2 is critically involved in CAVD. Celastrol is effective to alleviate CAVD, likely through the inhibition of Nox2-mediated glycogen synthase kinase 3 beta/β-catenin pathway in AVICs.
↵∗ Drs. Liu, Wang, and Pan contributed equally to this work and are joint first authors.
This study was supported by the National Natural Science Foundation of China (81470506), Key Scientific Research Project of Higher Education Institutions in Henan Province (18A320005), Key Research Project of the Heart Center of Xinxiang Medical University (2017360), Foundation and Frontier Technology Research Project in Henan Province (142300410191), and grants from British Heart Foundation (PG/17/39/33027 to Dr. Zhang, RG/13/11/30384 to Dr. Shah). The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
The authors attest they are in compliance with human studies committees and animal welfare regulations of the authors’ institutions and Food and Drug Administration guidelines, including patient consent where appropriate. For more information, visit the JACC: Basic to Translational Science author instructions page.
- Received July 31, 2019.
- Revision received September 27, 2019.
- Accepted October 1, 2019.