CDN1163 alleviates SERCA2 dysfunction-induced pulmonary vascular remodeling by inhibiting the phenotypic transition of pulmonary artery smooth muscle cells

ABSTRACT

Background and Purpose

Substitution of Cys⁶⁷⁴ (C674) in the sarcoplasmic/endoplasmic reticulum Ca²⁺ ATPase 2 (SERCA2) causes SERCA2 dysfunction which leads to activated inositol requiring enzyme 1 alpha (IRE1α) and spliced X-box binding protein 1 (XBP1s) pathway accelerating cell proliferation of pulmonary artery smooth muscle cells (PASMCs) followed by significant pulmonary vascular remodeling resembling human pulmonary hypertension. Based on this knowledge, we intend to investigate other potential mechanisms involved in SERCA2 dysfunction-induced pulmonary vascular remodeling.

Experimental Approach

Heterozygous SERCA2 C674S knock-in (SKI) mice of which half of cysteine in 674 was substituted by serine to mimic the partial irreversible oxidation of C674 were used. The lungs of SKI mice and their littermate wild-type mice were collected for PASMC culture, protein expression, and pulmonary vascular remodeling analysis.

Results

SERCA2 dysfunction increased intracellular Ca²⁺ levels, which activated Ca²⁺-dependent calcineurin (CaN) and promoted the nuclear translocation and protein expression of the nuclear factor of activated T-lymphocytes 4 (NFAT4) in an IRE1α/XBP1s pathway-independent manner. In SKI PASMCs, the scavenge of intracellular Ca²⁺ by BAPTA-AM or inhibition of CaN by cyclosporin A can prevent PASMC phenotypic transition. CDN1163, a SERCA2 agonist, suppressed the activation of CaN/NFAT4 and IRE1α/XBP1s pathways, reversed the protein expression of PASMC phenotypic transition markers and cell cycle-related proteins, and inhibited cell proliferation and migration when given to SKI PASMCs. Furthermore, CDN1163 ameliorated pulmonary vascular remodeling in SKI mice.

Conclusions and Implications

SERCA2 dysfunction promotes PASMC phenotypic transition and pulmonary vascular remodeling by multiple mechanisms, which could be improved by SERCA2 agonist CDN1163.

SUMMARY

‘What is already known’

• l The dysfunction of SERCA2 promotes PASMC hyperproliferation and pulmonary vascular remodeling through activation of the IRE1α/XBP1s pathway.

‘What this study adds’

• l The dysfunction of SERCA2 activates the Ca²⁺-dependent CaN-mediated NFAT4 pathway to promote the PASMC phenotypic transition.

• l Revitalization of SERCA2 suppresses PASMC phenotypic transition and pulmonary vascular remodeling caused by SERCA2 dysfunction.

‘Clinical significance’

• l SERCA2 dysfunction-induced pulmonary vascular remodeling involves more than one mechanism, implicating that more drugable targets are to be discovered.

• l SERCA2 is a potential therapeutic target for preventing pulmonary vascular remodeling.

KEYWORDS:

• Pulmonary hypertension
• SERCA2
• pulmonary vascular remodeling
• pulmonary artery smooth muscle cells; phenotypic transition
• calcineurin
• nuclear factor of activated T-lymphocytes

Acknowledgments

This work was supported by the National Natural Science Foundation of China (31571172 and 81870343, X.T., and 81700237, P.H.), Chongqing Natural Science Foundation (cstc2021jcyj-msxmX0043, X.T.), Special Research Assistant of the Chinese Academy of Sciences (W.Y.), Postdoctoral Research Program of Chongqing Human Resources and Social Security Bureau (W.Y.).

Disclosure statement

No potential conflict of interest was reported by the author(s).

Author contributions

Y.W., Z.Q., P. H., and X.T. participated in the research design and performed the data analysis and interpretation; Y.W., L.S., and X.T. wrote the manuscript; Y.W., Z.Q., Y.Q., C.H., X.H., X.L., and X.G. conducted the experiments. All authors reviewed and revised the final version of this manuscript and approved its submission.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Significance

We first report that the dysfunction of SERCA2 causes pulmonary vascular remodeling by promoting PASMC phenotypic transition via activation of CaN/NFAT4 pathway, which could be reversed by SERCA2 agonist CDN1163.

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/10641963.2023.2272062

Abbreviations

C674, Cys⁶⁷⁴; CaN, calcineurin; CDK, cyclin-dependent kinase; Col I, collagen type I; Col III, collagen type III; CsA, cyclosporin A; DAPI, 4,’6-diamidino-2-phenylindole; ECM, extracellular matrix; ECs, endothelial cells; IRE1α, inositol requiring enzyme 1 alpha; LV, left ventricle; NFAT, nuclear factor of activated T-lymphocytes; OPN, osteopontin; PA, pulmonary artery; PAH, pulmonary artery hypertension; PASMCs, pulmonary artery smooth muscle cells; PH, pulmonary hypertension; p-IRE1α, phosphorylated IRE1α; RV; right ventricle; RVEDP, right ventricular end diastolic pressure; RVSP, right ventricular systolic pressure; S, interventricular septum; S674, Ser⁶⁷⁴; SERCA, sarcoplasmic/endoplasmic reticulum calcium ATPase; SKI, SERCA2 C674S knock-in; SMA, smooth muscle actin; SMCs, smooth muscle cells; VVG, Verhoeff-Van Gieson; vWF, von Willebrand factor; WT, wild-type; XBP1s, spliced X-box binding protein 1

Additional information

Funding

The work was supported by the National Natural Science Foundation of China [31571172]; Chongqing Natural Science Foundation [cstc2021jcyj-msxmX0043]; Special Research Assistant of the Chinese Academy of Sciences Postdoctoral Research Program of Chongqing Human Resources and Social Security Bureau .