Platelet-Derived Microparticles Increase Expression of hTERT in Umbilical Cord Mesenchymal Stem Cells

Introduction: Mesenchymal stem cells (MSCs) are widely studied due to their self- renewal potential and capacity to differentiate into multiple tissues. However, they have a limited life span of several divisions in vitro, which alters various cellular characteristics and reduces their application. Aim: We evaluated the effect of platelet-derived microparticles on gene expression of hTERT, one of the main factors involved in aging and cell longevity. Materials and methods: Umbilical cord MSCs were used for this study. Cells were characterized by evaluating morphology via inverted microscope and identifying associated surface markers using flow cytometry. Platelet-derived microparticles were prepared by centrifuging platelet bags at varying speeds, and their concen- trations were determined by Bradford assay. At 30% confluency, MSCs were treated with 50 μg/mL of microparticles for five days. Then, RNA was extracted and cDNA was synthesized. Quantitative expression of hTERT was assessed using real-time polymerase chain reaction (PCR). Results: Fibroblast-like cells were isolated from umbilical cord tissue and MSCs were identified by the presence of mesenchymal surface markers via flow cytometry. Real- time PCR showed that gene expression of hTERT increased by more than three times when treated with platelet-derived microparticles, in comparison to expression of the control group. Conclusion: We concluded that platelet-derived microparticles may be a potentially safe and effective method to increase hTERT gene expression in MSCs, ultimately prolonging their life span in vitro.