Medicine and Health Sciences Commons^™

Orai1 Deficiency Leads To Heart Failure And Skeletal Myopathy In Zebrafish., Mirko Völkers, Nima Dolatabadi, Natalie Gude, Patrick Most, Mark A Sussman, David Hassel

Center for Translational Medicine Faculty Papers

Mutations in the store-operated Ca²⁺ entry pore protein ORAI1 have been reported to cause myopathies in human patients but the mechanism involved is not known. Cardiomyocytes express ORAI1 but its role in heart function is also unknown. Using reverse genetics in zebrafish, we demonstrated that inactivation of the highly conserved zebrafish orthologue of ORAI1 resulted in severe heart failure, reduced ventricular systolic function, bradycardia and skeletal muscle weakness. Electron microscopy of Orai1-deficient myocytes revealed progressive skeletal muscle instability with loss of myofiber integrity and ultrastructural abnormalities of the z-disc in both skeletal and cardiac muscle. Isolated Orai1-deficient cardiomyocytes showed loss …

Wnt Signaling Exerts An Antiproliferative Effect On Adult Cardiac Progenitor Cells Through Igfbp3., Angelos Oikonomopoulos, Konstantina-Ioanna Sereti, Frank Conyers, Michael Bauer, Annette Liao, Jian Guan, Dylan Crapps, Jung-Kyu Han, Hanhua Dong, Ahmad F Bayomy, Gabriel C Fine, Karen Westerman, Travis L Biechele, Randall T Moon, Thomas Force, Ronglih Liao

Center for Translational Medicine Faculty Papers

RATIONALE: Recent work in animal models and humans has demonstrated the presence of organ-specific progenitor cells required for the regenerative capacity of the adult heart. In response to tissue injury, progenitor cells differentiate into specialized cells, while their numbers are maintained through mechanisms of self-renewal. The molecular cues that dictate the self-renewal of adult progenitor cells in the heart, however, remain unclear.

OBJECTIVE: We investigate the role of canonical Wnt signaling on adult cardiac side population (CSP) cells under physiological and disease conditions.

METHODS AND RESULTS: CSP cells isolated from C57BL/6J mice were used to study the effects of canonical …