Description
The anthracycline, doxorubicin (Dox), is widely used in oncology, but it may it may cause a cardiomyopathy which has dismal prognosis and cannot be effectively prevented. The secretome of multipotent human amniotic fluid-derived stem cells (hAFS) has previously been demonstrated to reduce ischemic cardiac damage. Here, it is shown that the hAFS conditioned medium (hAFS-CM) antagonizes senescence and apoptosis of cardiomyocytes and cardiac progenitor cells, two major features of Dox cardiotoxicity. Mechanistic studies with primary mouse neonatal cardiomyocytes reveal that hAFS-CM inhibition of Dox-elicited senescence and apoptosis is paralleled by decreased DNA damage and is associated with nuclear translocation of NF-kB and upregulation of a set of genes controlled by NF-kB, namely Il6 and Cxcl1, which promote cardiomyocyte survival, and Cyp1b1 and Abcb1, which encode for proteins involved in Dox metabolism and efflux, respectively. The PI3K/Akt signaling cascade, upstream of NF-kB, is potently activated by the hAFS-CM and pre-treatment with a PI3K inhibitor abrogates NF-kB accumulation into the nucleus, modulation of its target genes, and prevention of Dox-initiated senescence and apoptosis in response to the hAFS-CM. This work may lay the ground for the development of a stem cell-based paracrine therapy of chemotherapy-related cardiotoxicity.