ABSTRACT
Objective:To investigate whether transplantation of gingival mesenchymal stem cells (GMSCs) can inhibit radiation-induced senescence of alveolar epithelial cells type Ⅱ (AECⅡ) and its role in the prevention of radiation-induced pulmonary fibrosis (RIPF).Methods:Mouse type Ⅱ alveolar epithelial cells (MLE12) were irradiated with 6 Gy X-rays and then co-cultured with GMSCs. The extent of cellular senescence of MLE12 cells was assessed by cell morphology, β-Gal staining, and senescence secretion-associated phenotype (SASP) assay. RIPF model was constructed by unilaterally irradiating the right chest of C57BL/6 mice with 17 Gy X-rays. GMSCs were transplanted 1 d after irradiation. At 180 d after irradiation, the pulmonary organ ratio, HE staining, and Masson staining were used to assess intra-pulmonary structure and interstitial collagen deposition in the lung. β-Gal immunohistochemistry and immunofluorescence co-localization with AECⅡ were measured to assess the degree of cellular senescence in the lung. The SASP expression changes in lung tissue were detected by qRT-PCR. The protein expressions in P53-P21 and P16 pathways were detected by Western blot assay. P21 expression in AECⅡ was detected by immunofluorescence co-localization assay.Results:GMSCs effectively inhibited radiation-induced senescence of MLE12 cells, reduced the ratio of radiation-elevated β-Gal positive cells by 11.8% ( t=6.72, P<0.05), and decreased the expressions of SASP (IL-6, IL-8, IL-1β) ( t=28.43, 28.43, 4.82, P<0.05). GMSCs transplantation improved the survival rate of irradiated mice, prevented radiation-induced alveolar structural collapse thickening and collagen deposition, reduced the number of senescent cells in the irradiated lung tissues by 23.9% ( t=21.83, P<0.05), and inhibited the expressions of SASP ( t=8.86, 20.63, P<0.05). GMSCs also inhibited the expression of P53-P21, P16-related proteins in MLE12 cells and lung tissues of mice after irradiation. Conclusions:GMSCs inhibit senescence-related P53-P21 and P16 pathways, prevent radiation-induced AECⅡ senescence, as well as the development of RIPF.
ABSTRACT
ABSTRACT@#The use of tooth-derived material as a scaffold has gained attention recently due to its ease of availability and bioactive properties. Hence, the objective of this study was to determine in vitro interaction of human gingival mesenchymal stem cells (hGMSCs) with human demineralised teeth matrix (hDTM) on osteogenic potential with or without osteogenic inducers. The hGMSCs were established and characterised on their morphology, proliferation, population doubling time (PDT), viability, colony-forming ability, expression of cell surface markers and adipogenic differentiation. Further, the effect of hDTM on the biocompatibility and osteogenic differentiation ability of hGMSCs was evaluated. The hGMSCs displayed a fibroblast-like appearance and exhibited a greater proliferative activity. The cells showed > 91% viability, and PDT varied between 39.34 hours and 62.59 hours. Further, hGMSCs indicated their propensity to form clusters/ colonies, and expressed the markers, such as CD29, CD44, CD73 and CD90, but were negative for CD34 and CD45. When treated with adipogenic induction medium, hGMSCs were able to exhibit the formation of neutral lipid vacuoles. The hGMSCs cultured with hDTM did not show any cytotoxic changes including morphology and viability. Mineralisation of calcium nodules was observed in hGMSCs when cultured in osteogenic induction (OI) medium as an indication of osteogenesis. hGMSCs when cultured with hDTM confirmed the presence of a mineralised matrix. Further, when the cells were cultured with hDTM along with OI, they showed slightly enhanced differentiation into osteocytes. In conclusion, hGMSCs were shown to be biocompatible with hDTM, and demonstrated their enhanced osteogenic potential in the presence of hDTM and osteogenic supplements.
Subject(s)
Mesenchymal Stem Cells , DentinABSTRACT
ABSTRACT@#The use of tooth-derived material as a scaffold has gained attention recently due to its ease of availability and bioactive properties. Hence, the objective of this study was to determine in vitro interaction of human gingival mesenchymal stem cells (hGMSCs) with human demineralised teeth matrix (hDTM) on osteogenic potential with or without osteogenic inducers. The hGMSCs were established and characterised on their morphology, proliferation, population doubling time (PDT), viability, colony-forming ability, expression of cell surface markers and adipogenic differentiation. Further, the effect of hDTM on the biocompatibility and osteogenic differentiation ability of hGMSCs was evaluated. The hGMSCs displayed a fibroblast-like appearance and exhibited a greater proliferative activity. The cells showed > 91% viability, and PDT varied between 39.34 hours and 62.59 hours. Further, hGMSCs indicated their propensity to form clusters/ colonies, and expressed the markers, such as CD29, CD44, CD73 and CD90, but were negative for CD34 and CD45. When treated with adipogenic induction medium, hGMSCs were able to exhibit the formation of neutral lipid vacuoles. The hGMSCs cultured with hDTM did not show any cytotoxic changes including morphology and viability. Mineralisation of calcium nodules was observed in hGMSCs when cultured in osteogenic induction (OI) medium as an indication of osteogenesis. hGMSCs when cultured with hDTM confirmed the presence of a mineralised matrix. Further, when the cells were cultured with hDTM along with OI, they showed slightly enhanced differentiation into osteocytes. In conclusion, hGMSCs were shown to be biocompatible with hDTM, and demonstrated their enhanced osteogenic potential in the presence of hDTM and osteogenic supplements.