RT Journal Article SR Electronic T1 Peroxisomes contribute to intracellular calcium dynamics in cardiomyocytes and non-excitable cells JF Life Science Alliance JO Life Sci. Alliance FD Life Science Alliance LLC SP e202000987 DO 10.26508/lsa.202000987 VO 4 IS 9 A1 Sargsyan, Yelena A1 Bickmeyer, Uta A1 Gibhardt, Christine S A1 Streckfuss-Bömeke, Katrin A1 Bogeski, Ivan A1 Thoms, Sven YR 2021 UL http://www.life-science-alliance.org/content/4/9/e202000987.abstract AB Peroxisomes communicate with other cellular compartments by transfer of various metabolites. However, whether peroxisomes are sites for calcium handling and exchange has remained contentious. Here we generated sensors for assessment of peroxisomal calcium and applied them for single cell-based calcium imaging in HeLa cells and cardiomyocytes. We found that peroxisomes in HeLa cells take up calcium upon depletion of intracellular calcium stores and upon calcium influx across the plasma membrane. Furthermore, we show that peroxisomes of neonatal rat cardiomyocytes and human induced pluripotent stem cell–derived cardiomyocytes can take up calcium. Our results indicate that peroxisomal and cytosolic calcium signals are tightly interconnected both in HeLa cells and in cardiomyocytes. Cardiac peroxisomes take up calcium on beat-to-beat basis. Hence, peroxisomes may play an important role in shaping cellular calcium dynamics of cardiomyocytes.