LncRNA ZFAS1 as a SERCA2a Inhibitor to Cause Intracellular Ca2+ Overload and Contractile Dysfunction in a Mouse Model of Myocardial Infarction.

Abstract

RATIONALE:

Ca2+ homeostasis-a critical determinant of cardiac contractile function-is critically regulated by SERCA2a (sarcoplasmic reticulum Ca2+-ATPase 2a). Our previous study has identified ZFAS1 as a new lncRNA biomarker of acute myocardial infarction (MI).

OBJECTIVE:

To evaluate the effects of ZFAS1 on SERCA2a and the associated Ca2+ homeostasis and cardiac contractile function in the setting of MI.

METHODS AND RESULTS:

ZFAS1 expression was robustly increased in cytoplasm and sarcoplasmic reticulum in a mouse model of MI and a cellular model of hypoxia. Knockdown of endogenous ZFAS1 by virus-mediated silencing shRNA partially abrogated the ischemia-induced contractile dysfunction. Overexpression of ZFAS1 in otherwise normal mice created similar impairment of cardiac function as that observed in MI mice. Moreover, at the cellular level, ZFAS1 overexpression weakened the contractility of cardiac muscles. At the subcellular level, ZFAS1 deleteriously altered the Ca2+ transient leading to intracellular Ca2+ overload in cardiomyocytes. At the molecular level, ZFAS1 was found to directly bind SERCA2a protein and to limit its activity, as well as to repress its expression. The effects of ZFAS1 were readily reversible on knockdown of this lncRNA. Notably, a sequence domain of ZFAS1 gene that is conserved across species mimicked the effects of the full-length ZFAS1. Mutation of this domain or application of an antisense fragment to this conserved region efficiently canceled out the deleterious actions of ZFAS1. ZFAS1 had no significant effects on other Ca2+-handling regulatory proteins.

CONCLUSIONS:

ZFAS1 is an endogenous SERCA2a inhibitor, acting by binding to SERCA2a protein to limit its intracellular level and inhibit its activity, and a contributor to the impairment of cardiac contractile function in MI. Therefore, anti-ZFAS1 might be considered as a new therapeutic strategy for preserving SERCA2a activity and cardiac function under pathological conditions of the heart.

• Authors: Ying Zhang, Lei Jiao, Lihua Sun, Yanru Li, Yuqiu Gao, Chaoqian Xu, Yingchun Shao, Mengmeng Li, Chunyan Li, Yanjie Lu, Zhenwei Pan, Lina Xuan, Yiyuan Zhang, Qingqi Li, Rui Yang, Yuting Zhuang, Yong Zhang, Baofeng Yang
• Journal: Circulation research (Circ Res) Vol. 122 Issue 10 Pg. 1354-1368 (05 11 2018) ISSN: 1524-4571 [Electronic] United States
• PMID: 29475982 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: © 2018 The Authors.

Chemical References

• NFATC Transcription Factors
• Nfatc2 protein, mouse
• Oligonucleotides, Antisense
• RNA, Long Noncoding
• RNA, Small Interfering
• Sarcoplasmic Reticulum Calcium-Transporting ATPases
• Calcium

Topics

• Animals
• Calcium (metabolism)
• Calcium Signaling
• Cell Hypoxia
• Conserved Sequence
• Cytoplasm (metabolism)
• Enzyme Induction
• Humans
• Mice
• Mice, Inbred C57BL
• Mutation
• Myocardial Contraction
• Myocardial Infarction (etiology, genetics, metabolism)
• Myocardial Ischemia (metabolism)
• Myocytes, Cardiac (metabolism)
• NFATC Transcription Factors (metabolism)
• Oligonucleotides, Antisense (genetics)
• RNA Interference
• RNA, Long Noncoding (biosynthesis, genetics)
• RNA, Small Interfering (genetics)
• Sarcoplasmic Reticulum (metabolism)
• Sarcoplasmic Reticulum Calcium-Transporting ATPases (antagonists & inhibitors, physiology)
• Transcriptional Activation