Effects of spheroid culture in a rotating bioreactor on secretion of inflammatory factors by human placenta-derived mesenchymal stem cells

Zhang Pingping; Liang Tingting; Fan Mingsong; Chen Li; Zhang Shichang

doi:10.12307/2024.177

Abstract：BACKGROUND:Spheroid culture of mesenchymal stem cells in bioreactors is an in vitro culture method to maintain their stemness properties and allow for large-scale expansion.Clarifying its effects on the immunoregulation effect of stem cells is beneficial for their clinical application. OBJECTIVE:To investigate the effects of spheroid culture in a rotating bioreactor on the secretion of inflammatory factors by human placenta-derived mesenchymal stem cells. METHODS:Placenta-derived mesenchymal stem cells isolated from human placenta tissue were cultured in two-dimensional culture or a rotating bioreactor culture.Cell morphology and proliferation ability were observed using inverted phase contrast microscopy,immunohistochemical staining,and CCK-8 assay.The gene expression and protein secretion of several inflammatory factors were detected by RT-qPCR and flow immunofluorescence assay. RESULTS AND CONCLUSION:(1)Mesenchymal stem cells cultured in a rotating bioreactor aggregated into multicellular spheroids,which gradually increased in number and volume.(2)The hematoxylin-eosin staining results showed that the mesenchymal stem cells cultured in the rotating bioreactor for 4 days were evenly distributed and had normal morphology in the spheroids.(3)Immunohistochemical staining results revealed many mesenchymal stem cells with Ki-67 positive in the spheroids.(4)The CCK-8 assay results exhibited that the viability of mesenchymal stem cells derived from spheroid culture was significantly higher than that of cells cultured in two-dimensional culture.(5)The results of RT-qPCR and flow immunofluorescence assay demonstrated that the gene expression and protein secretion(interleukin 1β,interleukin-4,interleukin-6,interleukin-8,interleukin-10,interleukin-17,tumor necrosis factor α and interferon α)of inflammatory factors derived from mesenchymal stem cells cultured in the rotating bioreactor were significantly higher than those in two-dimensional culture.(6)Our results indicate that spheroid culture in a rotating bioreactor can significantly elevate the secretion ability of various inflammatory factors by human placenta-derived mesenchymal stem cells,and enhance the immunoregulatory effect of human placenta-derived mesenchymal stem cells.