Background: Systemic transplantation of stem cells from human exfoliated deciduous teeth (SHED) recovers bone loss in animal models of osteoporosis; however, the mechanisms underlying this remain unclear. Here, we hypothesized that trophic factors within SHED-releasing extracellular vesicles (SHED-EVs) rescue osteoporotic phenotype. Methods: EVs were isolated from culture supernatant of SHED. SHED-EVs were treated with or without ribonuclease and systemically administrated into ovariectomized mice, followed by the function of recipient bone marrow mesenchymal stem cells (BMMSCs) including telomerase activity, osteoblast differentiation, and sepmaphorine-3A (SEMA3A) secretion. Subsequently, human BMMSCs were stimulated by SHED-EVs with or without ribonuclease treatment, and then human BMMSCs were examined regarding the function of telomerase activity, osteoblast differentiation, and SEMA3A secretion. Furthermore, SHED-EV-treated human BMMSCs were subcutaneously transplanted into the dorsal skin of immunocompromised mice with hydroxyapatite tricalcium phosphate (HA/TCP) careers and analyzed the de novo bone-forming ability. Results: We revealed that systemic SHED-EV-infusion recovered bone volume in ovariectomized mice and improved the function of recipient BMMSCs by rescuing the mRNA levels of Tert and telomerase activity, osteoblast differentiation, and SEMA3A secretion. Ribonuclease treatment depleted RNAs, including microRNAs, within SHED-EVs, and these RNA-depleted SHED-EVs attenuated SHED-EV-rescued function of recipient BMMSCs in the ovariectomized mice. These findings were supported by in vitro assays using human BMMSCs incubated with SHED-EVs. Conclusion: Collectively, our findings suggest that SHED-secreted RNAs, such as microRNAs, play a crucial role in treating postmenopausal osteoporosis by targeting the telomerase activity of recipient BMMSCs.

Background: Systemic transplantation of stem cells from human exfoliated deciduous teeth (SHED) induces bone regeneration in animal models of osteoporosis; however, the mechanisms underlying this remain unclear. Here, we hypothesized that trophic factors within SHED-releasing extracellular vesicles (SHED-EVs) rescue osteoporotic phenotype.Methods: EVs were isolated from culture supernatant of SHED. SHED-EVs were treated with or without ribonuclease and systemically administrated into ovariectomized mice, followed by the measurement of bone regenerative function of recipient bone marrow mesenchymal stem cells (BMMSCs) including Tert expression. Subsequently, human BMMSCs were stimulated by SHED-EVs with or without ribonuclease treatment, and then human BMMSCs were examined osteogenic function in vitro and telomerase activity. Furthermore, SHED-EVs treated human BMMSCs were subcutaneously transplanted into dorsal skin of immunocompromised mice with hydroxyapatite tricalcium phosphate (HA/TCP) careers and analyzed the de novo bone forming ability.Results: We revealed that systemic SHED-EV-infusion recovered bone volume in ovariectomized mice and improved osteogenic function of recipient BMMSCs by rescuing the mRNA levels of Tert and telomerase activity. Ribonuclease treatment depleted RNAs, including microRNAs, within SHED-EVs and these RNA-depleted SHED-EVs attenuated SHED-EV-triggered bone regeneration and telomerase-mediated osteogenesis in the ovariectomized mice. These findings were supported by in vitro osteogenic assays using human BMMSCs incubated with SHED-EVs.Conclusion: Collectively, our findings suggest that SHED-secreted trophic factors, specifically microRNAs, play a crucial role in treating postmenopausal osteoporosis by targeting the telomerase activity of recipient BMMSCs.

Variations in osteoclast cell number are observed when osteoclast precursor cells are irradiated with atmospheric dielectric barrier discharge plasma. Active species generated by the oxygen plasma control the differentiation function of the osteoclast precursor cells. Long-lifetime active species such as H2O2 and NOx– dissolved in the culture medium decrease the osteoclast number due to the inactivation of the differentiation function of the osteoclast precursor cells. When short-lifetime active species such as O* and OH* make contact with the osteoclast precursor cells directly, the osteoclast number tends to increase. Short-lifetime active species induce the enhancement of the gene expression of NFATc1.

Background: Systemic transplantation of stem cells from human exfoliated deciduous teeth (SHED) recover bone loss in animal models of osteoporosis; however, the mechanisms underlying this remain unclear. Here, we hypothesized that trophic factors within SHED-releasing extracellular vesicles (SHED-EVs) rescue osteoporotic phenotype. Methods: EVs were isolated from culture supernatant of SHED. SHED-EVs were treated with or without ribonuclease and systemically administrated into ovariectomized mice, followed by the function of recipient bone marrow mesenchymal stem cells (BMMSCs) including telomerase activity, osteoblast differentiation, and sepmaphorine-3A (SEMA3A) secretion. Subsequently, human BMMSCs were stimulated by SHED-EVs with or without ribonuclease treatment, and then human BMMSCs were examined the function of telomerase activity, osteoblast differentiation, and SEMA3A secretion. Furthermore, SHED-EVs treated human BMMSCs were subcutaneously transplanted into dorsal skin of immunocompromised mice with hydroxyapatite tricalcium phosphate (HA/TCP) careers and analyzed the de novo bone forming ability.Results: We revealed that systemic SHED-EV-infusion recovered bone volume in ovariectomized mice and improved the function of recipient BMMSCs by rescuing the mRNA levels of Tert and telomerase activity, osteoblast differentiation, and SEMA3A secretion. Ribonuclease treatment depleted RNAs, including microRNAs, within SHED-EVs and these RNA-depleted SHED-EVs attenuated SHED-EV-rescued function of recipient BMMSCs in the ovariectomized mice. These findings were supported by in vitro assays using human BMMSCs incubated with SHED-EVs. Conclusion: Collectively, our findings suggest that SHED-secreted RNAs, such as microRNAs, play a crucial role in treating postmenopausal osteoporosis by targeting the telomerase activity of recipient BMMSCs.