| First Author | Duse DA | Year | 2024 |
| Journal | Basic Res Cardiol | Volume | 119 |
| Issue | 5 | Pages | 853-868 |
| PubMed ID | 39110173 | Mgi Jnum | J:359206 |
| Mgi Id | MGI:7782778 | Doi | 10.1007/s00395-024-01073-x |
| Citation | Duse DA, et al. (2024) Deficiency of the sphingosine-1-phosphate (S1P) transporter Mfsd2b protects the heart against hypertension-induced cardiac remodeling by suppressing the L-type-Ca(2+) channel. Basic Res Cardiol 119(5):853-868 |
| abstractText | The erythrocyte S1P transporter Mfsd2b is also expressed in the heart. We hypothesized that S1P transport by Mfsd2b is involved in cardiac function. Hypertension-induced cardiac remodeling was induced by 4-weeks Angiotensin II (AngII) administration and assessed by echocardiography. Ca(2+) transients and sarcomere shortening were examined in adult cardiomyocytes (ACM) from Mfsd2b(+/+) and Mfsd2b(-/-) mice. Tension and force development were measured in skinned cardiac fibers. Myocardial gene expression was determined by real-time PCR, Protein Phosphatase 2A (PP2A) by enzymatic assay, and S1P by LC/MS, respectively. Msfd2b was expressed in the murine and human heart, and its deficiency led to higher cardiac S1P. Mfsd2b(-/-) mice had regular basal cardiac function but were protected against AngII-induced deterioration of left-ventricular function as evidenced by ~ 30% better stroke volume and cardiac index, and preserved ejection fraction despite similar increases in blood pressure. Mfsd2b(-/-) ACM exhibited attenuated Ca(2+) mobilization in response to isoprenaline whereas contractility was unchanged. Mfsd2b(-/-) ACM showed no changes in proteins responsible for Ca(2+) homeostasis, and skinned cardiac fibers exhibited reduced passive tension generation with preserved contractility. Verapamil abolished the differences in Ca(2+) mobilization between Mfsd2b(+/+) and Mfsd2b(-/-) ACM suggesting that S1P inhibits L-type-Ca(2+) channels (LTCC). In agreement, intracellular S1P activated the inhibitory LTCC phosphatase PP2A in ACM and PP2A activity was increased in Mfsd2b(-/-) hearts. We suggest that myocardial S1P protects from hypertension-induced left-ventricular remodeling by inhibiting LTCC through PP2A activation. Pharmacologic inhibition of Mfsd2b may thus offer a novel approach to heart failure. |
