Overexpression of sarcoplasmic reticulum Ca2+-ATPase improves cardiac contractile function in hypothyroid mice

Wolfgang F. Bluhm, Markus Meyer, M. Richard Sayen, Eric A. Swanson, Wolfgang H. Dillmann

Research output: Contribution to journalArticlepeer-review

25 Scopus citations

Abstract

Objective: Prolonged cardiac contraction and relaxation in hypothyroidism are in part related to diminished expression of the gene coding for the calcium pump of the sarcoplasmic reticulum (SERCA2a). Therefore, we examined whether or not transgenic SERCA2a gene expression in mice may compensate for the cardiac effects of hypothyroidism. Methods: SERCA2a mRNA and protein were analyzed from hearts of euthyroid and hypothyroid mice of wild-type or SERCA2a transgene status. Contractile function was studied in isolated left ventricular papillary muscles. Results: We found significant decreases of SERCA2a mRNA and protein levels in hearts of hypothyroid wild-type mice in comparison with euthyroid wild-type mice (controls). Papillary muscles from hypothyroid wild-type mice showed significant increases in time to peak contraction and relaxation times compared with controls. In contrast, SERCA2a mRNA and protein levels were significantly higher in hypothyroid SERCA2a transgenic mice than in hypothyroid wild-type mice. The transgene led to a functional improvement by compensating for the prolonged contraction and relaxation of papillary muscles. Conclusions: Our murine model of hypothyroidism revealed decreases in SERCA2a gene expression accompanied by prolonged contraction and relaxation of papillary muscles, and an improvement of the contractile phenotype due to compensated SERCA2a gene expression in SERCA2a transgenic mice.

Original languageEnglish (US)
Pages (from-to)382-388
Number of pages7
JournalCardiovascular Research
Volume43
Issue number2
DOIs
StatePublished - Aug 1 1999
Externally publishedYes

Bibliographical note

Funding Information:
This study was supported by US Public Health Service grants DK-07494 (Dr. Bluhm), R01-HL-25022 (Dr. Dil-lmann) and R01-HL-52946 (Dr. Dillmann) from the National Institutes of Health, and by grant Me 1477 / 2-1 from the Deutsche Forschungsgemeinschaft (Dr. Meyer). We would like to thank Michele Bluhm for her assistance with the manuscript.

Keywords

  • Cardiomyopathy
  • Contractile function
  • E-C coupling
  • Gene expression
  • SR

Fingerprint

Dive into the research topics of 'Overexpression of sarcoplasmic reticulum Ca<sup>2+</sup>-ATPase improves cardiac contractile function in hypothyroid mice'. Together they form a unique fingerprint.

Cite this