ABSTRACT
Aim To explore whether edaravone (EDA), a novel free radical scavenger, protects H9c2 cardiac cells against doxorubicin ( DOX )-induced car-diotoxicity. Methods H9c2 cells were treated with 5μmol·L-1 DOX to establish a model of DOX cardio-toxicity. Cell viability was examined by cell counter kit ( CCK-8 ) . Changes in morphology and amount of ap-optotic cells were detected by Hoechst 33258 staining;intracellular level of reactive oxygen species ( ROS ) was measured by DCFH-DA staining and photofluorog-raphy;mitochondrial membrane potential ( MMP) was observed by rhodamine 123 ( RH123 ) staining and photoflurograph; the expression level of caspase-3 was determined by Western blot assay. Results Pretreat-ment of H9 c2 cells with 20 , 40 and 80 μmol · L-1 EDA for 60 min markedly inhibited cytotoxicity in-duced by 5 μmol · L-1 DOX, respectively, as evi-denced by an increase in cell viability. The protective effect induced by 40 μmol · L-1 EDA was maximal. Pretreatment of H9 c2 cells with 40 μmol · L-1 EDA for 30 , 60 , 90 and 120 min significantly attenuated DOX-induced cytotoxicity, respectively, having a max-imal protection at 60 min. Furthermore, pretreatment of H9 c2 cells with 40 μmol · L-1 EDA for 60 min be-fore exposure to 5 μmol · L-1 DOX for 24 h obviously reduced cardiac injuries, as evidenced by decreases in the DOX-induced intracellular ROS generation, num-ber of apoptotic cells, and expression of cleaved caspase-3, as well as loss of MMP. Conclusions EDA can protect H9 c2 cardiac cells against DOX-in-duced cardiotoxicity, this protection may be associated with inhibition of ROS production and preservation of MMP.
ABSTRACT
<p><b>OBJECTIVE</b>To explore whether strontium ranelate (Sr) promotes osteoblast lineage differentiation of rat bone mesenchymal stem cells (BMSCs) through the bone morphogenetic protein-2 (BMP-2)/Smad signaling pathway.</p><p><b>METHODS</b>Cultured rat BMSCs were exposed to different concentrations of Sr, noggin (an inhibitor of BMP-2) or Smad1 siRNA. The activity of alkaline phosphatase (ALP) in the exposed cells was detected by colorimetry, and the formation of mineralized nodules was observed with alizarin red staining. The expressions of phosphorylated (p) Smad1/5/8 and Runt-related transcription factor 2 (Runx2) in the cells were detected by Western blotting.</p><p><b>RESULTS</b>Exposure to Sr at 0.1 to 10 mmol/L for 1 h markedly increased the expression of p-Smad1/5/8 in the BMSCs, and the increment was the most obvious following 1 mmol/L Sr exposure. Preconditioning with 100 ng/ml noggin for 2 h inhibited Sr-induced up-regulation of p-Smad1/5/8 expressions. Exposure of the cells to 0.1 to 5 mmol/L Sr for 6 h significantly enhanced Runx2 expression, and the peak enhancement occurred following 1 mmol/L Sr exposure. Transfection of the BMSCs with Smad1 siRNA decreased the basal level of Smad1/5/8 protein expression, and also inhibited Sr-induced up-regulation of p-Smad1/5/8 and Runx2 expressions as well as Sr-induced enhancement of ALP activity and formation of mineralized nodules.</p><p><b>CONCLUSION</b>The BMP-2/Smad pathway is involved in Sr-induced osteoblast differentiation of rat BMSCs.</p>