Liposomal Nanoparticle-Mediated miR-27b Influences Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells via Peroxisome Proliferator-Activated Receptor Gamma in a Microgravity Environment

This study was aimed at analyzing the effects of liposomal nanoparticle-based miR-27b on PPARγ and osteogenic differentiation of bone marrow mesenchymal stem cells under microgravity. The rat bone marrow mesenchymal stem cells were set as the research object, and the gyroscope was employed for simulation of microgravity. The cells were randomized into four groups, including the experimental group A (simulated microgravity+liposomal nanoparticle-mediated miR-27b transfection group), as well as the control groups: group B (simulated microgravity+negative control group), group C (simulated microgravity+transfection reagent group) and group D (normal gravity+liposomal nanoparticle-mediatedmiR-27b transfection group). After a two-week osteogenic induction in vitro, staining was performed to assess the lipogenesis rate of the samples. In addition, ALP activity and PPARγ mRNA level was detected. The number of alizarin staining-positive osteogenic nodules and ALP activity (0.21±0.44 King unit) in group A was significantly diminished compared to those in group B, C, and D. Moreover, its lipogenesis rate (9.31±1.02%) and PPARγ mRNA level (1.86±0.39) were significantly higher than those in group B, C, and D (P < 0.05). The number of alizarin staining-positive osteogenic nodules and ALP activity (0.96±0.18 King unit) in group D were significantly reduced in comparison with those in groups B and C, while the lipogenesis rate (4.86±0.77%) and PPARγ mRNA level (0.93±0.34) were significantly higher than those in group B and C (P < 0.05) without difference between group B and group C (P > 0.05). Under a microgravity condition, liposomal nanoparticle-mediated miR-27b can impede the differentiation of BMSCs into osteoblasts via regulating PPARγ signal transduction.