Effects of platelet rich plasma and platelet lysate on proliferation of rat bone marrow mesenchymal stem cells: A comparative study / 第二军医大学学报

ABSTRACT

Objective To compare the effects of platelet rich plasma (PRP) and platelet lysate (PL) on proliferation and cell cycle of cultured rat bone marrow stem cells (BMSCs). Methods BMSCs were obtained from twenty 4-week-old SD rats using the whole bone marrow isolation and cultivation method and were identified with flow cytometry. Blood samples were taken from the hearts of thirty 12-week-old SD rats and gradient centrifugation was used to prepare PRP, and PL was obtained after three times of centrifugation and repeated freezing and thawing. The third generation of BMSCs with good growth state were divided into seven groups according to different culture media ordinary complete medium (A group), 1% PRP-conditioned medium (B group), 1% PL-conditioned medium (C group), 5% PRP-conditioned medium (D group), 5% PL-conditioned medium (E group), 10% PRP-conditioned medium (F group), and 10% PL-conditioned medium (G group). The proliferation of BMSCs was assessed by MTT assay. The PCNA protein expression was assessed by immunofluorescence method. Cell cycle of BMSCs was tested by flow cytometry. Western blotting analysis was used to analyze CyclinD1 and p27 Kip1 protein expression of BMSCs. Results The proliferation of BMSCs was significantly promoted by 1 %, 5%, 10% PRP- and 1 %, 5%, 10% PL-conditioned media after cultured for 24 h, 48 h, and 72h in a time- and dose-dependent manner (P0. 05). Immunofluorescence assay showed that PRP and PL both significantly promoted PCNA protein expression in a dose-dependent manner (P0. 05). Western blotting analysisshowed that 5% PRP and 5% PL significantly up-regulated CyclinD1 and down-regulated the expression of p27 Kip1. Conclusion Different concentrations of PL and PRP can accelerate cell cycle progression of cultured rat BMSCs by up-regulation CyclinD1 and inhibiting p27 Kip1, promoting the proliferation of BMSCs in a time- and dose-dependent manner. PL and PRPat the same concentrationhave the same proliferation-promoting effect, indicating that PL may be used as an alternative of PRP to promote the repair of bone defects.