Antioxidant effects of Cirsium setidens extract on oxidative stress in human mesenchymal stem cells.

Human mesenchymal stem cells (MSCs) may be used in cell-based therapy to promote neovascularization for the treatment of ischemic diseases. However, high levels of reactive oxygen species (ROS) derived from the pathophysiological ischemic environment induce senescence and apoptosis of MSCs, resulting in reduced functionality and defective neovascularization. Therefore, the present study aimed to determine the protective effects of Cirsium setidens, a natural product, on oxidative stress­induced apoptosis in MSCs. The present study investigated for the change of ROS levels in MSCs using ROS assays. In addition, cell viability determined by MTT and TUNEL assays. Western blot analysis was performed to investigate the change of apoptosis­associated proteins in MSCs. Treatment of MSCs with hydrogen peroxide (H2O2; 200 µM) significantly increased intracellular ROS levels and cell death; however, pretreatment with C. setidens (100 µg/ml) suppressed H2O2­induced ROS generation and increased the survival of MSCs. H2O2­induced ROS production increased the levels of phosphorylated­p38 mitogen activated protein kinase, c­Jun N­terminal kinase, ataxia telangiectasia mutated and p53; these increases were inhibited by pretreatment with C. setidens. In addition, C. setidens inhibited ROS­induced apoptosis of MSCs by increasing the expression levels of the anti­apoptotic protein B­cell lymphoma 2 (BCL­2), and decreasing the expression levels of the proapoptotic protein BCL­2­associated X protein. These findings indicated that pretreatment of MSCs with C. setidens may prevent ROS­induced oxidative injury by regulating the oxidative stress­associated signaling pathway, and suppressing the apoptosis­associated signal pathway. Therefore, C. setidens may be developed as a beneficial broad­spectrum agent for enhancing the effectiveness of MSC transplantation in the treatment of ischemic diseases.

Fucoidan protects mesenchymal stem cells against oxidative stress and enhances vascular regeneration in a murine hindlimb ischemia model.

BACKGROUND: Mesenchymal stem cells (MSCs) have the potential to differentiate into multiple cell lineages. Given this potential for tissue regeneration, MSC-based therapeutic applications have been considered in recent years. However, ischemia-induced apoptosis has been reported to be one of the main causes of MSC death following transplantation. The primary objective of this study was to determine whether a natural antioxidant, fucoidan, could protect MSCs from ischemia-induced apoptosis in vitro and in vivo. Furthermore, we investigated the mechanism of action of fucoidan's anti-ischemic effect in MSCs. METHODS AND RESULT: Pre-treatment with fucoidan (10 µg/mL) suppressed the increase in H2O2-induced reactive oxygen species (ROS) levels and drastically reduced apoptotic cell death in MSCs. Fucoidan inhibited the activation of the pro-apoptotic proteins p38-mitogen-activated protein kinase (MAPK), Jun N-terminal kinase (JNK), and caspase-3, and augmented the expression of the anti-apoptosis protein cellular inhibitor of apoptosis (cIAP). Moreover, fucoidan significantly increased manganese superoxide dismutase (MnSOD) expression and decreased cellular ROS levels via the Akt pathway, resulting in enhanced cell survival. In a murine hindlimb ischemia model, transplanted fucoidan-treated MSCs showed significantly enhanced cell survival and proliferation in ischemic tissues. Functional recovery and limb salvage also remarkably improved in mice injected with fucoidan-stimulated MSCs compared with mice injected with non-stimulated MSCs. CONCLUSION: Taken together, these results show that fucoidan protects MSCs from ischemia-induced cell death by modulation of apoptosis-associated proteins and cellular ROS levels through regulation of the MnSOD and Akt pathways, suggesting that fucoidan could be powerful therapeutic adjuvant for MSC-based therapy in ischemic diseases.