Abstract. Doxorubicin (DOX) is widely used to treat patients suffering from cancer, but the usage for patients is limited because of the dose-dependent cardiotoxicity. We hypothesized that DOX induces apoptosis through caspase activation in cardiomyocytes, and we examined this hypothesis using both rat primary cultured cardiomyocytes and rat hearts from an animal model. Cardiomyocytes were treated with DOX for 24 h. The activity of caspase-3 was significantly increased by DOX treatment. In rats with DOX injected intravenously once a week for 5 weeks, left ventricular fractional shortening evaluated by echocardiography was significantly decreased at age 14 weeks, 2 weeks after the end of DOX-administration. At 16 weeks of age, endothelin-1 mRNA and atrial natriuretic peptide mRNA were also significantly increased, likewise, and TUNEL positive cells were significantly increased in the ventricles of DOX-treated rats. The activity of caspase-3 in the ventricles was also significantly increased compared to that of untreated rats at 16 weeks. However, the activity of caspase-8 and the expression level of Fas-ligand mRNA were comparable with those of the untreated rats. In conclusion, DOX induces apoptosis through the activation of caspase-3, suggesting that apoptosis has an important role in the progression of cardiomyopathy due to DOX.

No abstract

To understand the genetics of steroid-sensitive nephrotic syndrome (SSNS), we conducted a genome-wide association study in 987 childhood SSNS patients and 3,206 healthy controls with Japanese ancestry. Beyond known associations in the HLA-DR/DQ region, common variants in NPHS1-KIRREL2 (rs56117924, P[4.94E-20, odds ratio (OR) [1.90)

Our protocol was useful and safe for refractory NS. However, RTX administration four times might have been excessive in patients who had no relapse by 1 year after the initial RTX administration. Further investigation of the most appropriate method of RTX administration is required.