Low-dose dasatinib rescues cardiac function in Noonan syndrome
Jae-Sung Yi, Yan Huang, Andrea T. Kwaczala, Ivana Y. Kuo, Barbara E. Ehrlich, Stuart G. Campbell, Frank J. Giordano, Anton M. Bennett
Jae-Sung Yi, Yan Huang, Andrea T. Kwaczala, Ivana Y. Kuo, Barbara E. Ehrlich, Stuart G. Campbell, Frank J. Giordano, Anton M. Bennett
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Research Article Cardiology Therapeutics

Low-dose dasatinib rescues cardiac function in Noonan syndrome

Abstract

Noonan syndrome (NS) is a common autosomal dominant disorder that presents with short stature, craniofacial dysmorphism, and cardiac abnormalities. Activating mutations in the PTPN11 gene encoding for the Src homology 2 (SH2) domain-containing protein tyrosine phosphatase-2 (SHP2) causes approximately 50% of NS cases. In contrast, NS with multiple lentigines (NSML) is caused by mutations that inactivate SHP2, but it exhibits some overlapping abnormalities with NS. Protein zero-related (PZR) is a SHP2-binding protein that is hyper-tyrosyl phosphorylated in the hearts of mice from NS and NSML, suggesting that PZR and the tyrosine kinase that catalyzes its phosphorylation represent common targets for these diseases. We show that the tyrosine kinase inhibitor, dasatinib, at doses orders of magnitude lower than that used for its anticancer activities inhibited PZR tyrosyl phosphorylation in the hearts of NS mice. Low-dose dasatinib treatment of NS mice markedly improved cardiomyocyte contractility and functionality. Remarkably, a low dose of dasatinib reversed the expression levels of molecular markers of cardiomyopathy and reduced cardiac fibrosis in NS and NSML mice. These results suggest that PZR/SHP2 signaling is a common target of both NS and NSML and that low-dose dasatinib may represent a unifying therapy for the treatment of PTPN11-related cardiomyopathies.

Authors

Jae-Sung Yi, Yan Huang, Andrea T. Kwaczala, Ivana Y. Kuo, Barbara E. Ehrlich, Stuart G. Campbell, Frank J. Giordano, Anton M. Bennett

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Figure 5

Dasatinib reverses impaired Ca2+-contraction coupling in NS cardiomyocytes.

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Dasatinib reverses impaired Ca2+-contraction coupling in NS cardiomyocyt...
(A) Alexa488-conjugated wheat germ agglutinin (WGA) stain of left ventricles from postnatal vehicle- and dasatinib-treated WT and NS mice (D61G/+) at P56 (scale bar: 50 μm). The cross-sectional areas of each mouse group are summarized (n = 377 for vehicle-treated WT; n = 294 for vehicle-treated NS; n = 280 for dasatinib-treated WT; n = 345 for dasatinib-treated NS). (B) Cardiomyocytes were isolated from postnatal vehicle- or dasatinib-treated WT and NS mice (D61G/+). Cardiomyocytes were tested for Ca2+ excitation and sarcomere-contraction coupling under a real-time imaging system. Representative traces of cardiomyocyte dynamics for intracellular Ca2+ transients (top traces) and their corresponding sarcomere length shortening traces (bottom traces). Relative high magnitude of intracellular Ca2+ (Rmag Ca2+) and fractional sarcomeric shortening are summarized (n = 131 for vehicle-treated WT cells; n = 128 for vehicle-treated NS cells; n = 111 for dasatinib-treated WT cells; n = 162 for dasatinib-treated NS cells). (C) Heart tissue was isolated from postnatal vehicle- or dasatinib-treated WT and NS mice, and tissue lysates were immunoblotted with anti-SERCA2A, troponin I (TnI), troponin T (TnT), and tubulin antibodies. The ratio of SERCA2A, TnI, or TnT expression to tubulin were quantitated and normalized to the vehicle-treated WT group (n = 3 per group). Data represent mean ± SEM and were analyzed by 2-way ANOVA and Tukey’s multiple comparison test. *P < 0.05; ***P < 0.001.