Exosomes as biomimetic tools for stem cell differentiation: Applications in dental pulp tissue regeneration

Abstract

Achieving and maintaining safe and reliable lineage specific differentiation of stem cells is important for clinical translation of tissue engineering strategies. In an effort to circumvent the multitude of problems arising from the usage of growth factors and growth factor delivery systems, we have explored the use of exosomes as biomimetic tools to induce stem cell differentiation. Working on the hypothesis that cell-type specific exosomes can trigger lineage-specific differentiation of stem cells, we have evaluated the potential of exosomes derived from dental pulp cells cultured on under growth and odontogenic differentiation conditions to induce odontogenic differentiation of naïve human dental pulp stem cells (DPSCs) and human bone marrow derived stromal cells (HMSCs) in vitro and in vivo. Results indicate that the exosomes can bind to matrix proteins such as type I collagen and fibronectin enabling them to be tethered to biomaterials. The exosomes are endocytosed by both DPSCs and HMSCs in a dose-dependent and saturable manner via the caveolar endocytic mechanism and trigger the P38 mitogen activated protein kinase (MAPK) pathway. In addition, the exosomes also trigger the increased expression of genes required for odontogenic differentiation. When tested in vivo in a tooth root slice model with DPSCs, the exosomes triggered regeneration of dental pulp-like tissue. However, our results indicate that exosomes isolated under odontogenic conditions are better inducers of stem cell differentiation and tissue regeneration. Overall, our results highlight the potential exosomes as biomimetic tools to induce lineage specific differentiation of stem cells. Our results also show the importance of considering the source and state of exosome donor cells before a choice is made for therapeutic applications.

Dental Stem Cell-Derived Secretome/Conditioned Medium: The Future for Regenerative Therapeutic Applications

“…(Table 3). EXs derived from dental pulp MSCs demonstrated a potent stimulatory effect on odontoblastic differentiation in vitro and triggered regeneration of dental pulp-like tissue in vivo in an ectopic tooth transplantation model [155]. Dental pulp MSC-CM enhanced the proliferation and migration of the myoblast [156] and fibroblast [157] in vitro, which was confirmed in vivo in an ectopic tooth transplantation model [107].…”

“…On the other hand, dental pulp MSC-CM alone failed to induce odontoblastic differentiation in cells of nondental origin like myoblast [156]. The regenerated tissues by dental pulp MSC-CM demonstrated the expression of pulp tissue markers including syndecan 3, thyrotropinreleasing hormone-degrading enzyme, CXCL14, G-CSF, BDNF, neuropeptide Y, IL-1α, IL-6, IL-8, IL-16, MCP-1 [107], BMP2, BMP9, TGF-β, PDGF, runt-related transcription factor 2 (RUNX2), and dentin sialophosphoprotein [155] in addition to enamelysin as well as periodontal tissue markers, including periodontal ligament-associated protein (PLAP-1) and periostin [156].…”

Human bone marrow mesenchymal stem/stromal cell behaviour is coordinated via mechanically activated osteocyte-derived extracellular vesicles

“…Many of the proteins identified in this paper have also been identified in a proteomic analysis of osteoblast released EVs [31, 52]. A previous in vivo study has suggested a role for EVs in systemic signalling, demonstrating altered miRNA expression in EVs isolated from the plasma of osteocyte ablated mice and wild-type mice [24], while other studies have demonstrated the potential for EVs in therapeutics to enhance osteogenic gene expression [53], the use of drug loaded EVs for osteoporosis therapies [27], and the use of EVs for functionalisation of TE scaffolds to enhance bone regeneration [54, 55]. In addition to osteocyte derived MAEVs and the contents driving MSC osteogenesis, MAEVs may also act as sites for mineral nucleation, as has previously been demonstrated in osteoblast EVs [56, 57].…”

Comunicação exossomal na transdiferenciação de células-tronco em cocultivo com células neuronais

“…No caso das vesículas extracelulares (pequenas vesículas extracelularesexossomos, e grandes vesículas extracelulares-microvesículas), estas auxiliam na interação celular, participando das vias metabólicas celulares que mantêm o organismo em funcionamento (LANE et al, 2014;MAAS et al, 2017;. Essas vesículas podem carrear internamente microRNAs, RNA mensageiros, DNA e proteínas (DE GASSART et al, 2004;VLASSOV et al, 2012), que podem modular a célula receptora, induzindo à diferenciação celular (HUANG et al, 2016).…”

“…Há várias vias de comunicação celular, tais como: 1) a comunicação entre células próximas (sinal autócrino); 2) por meio de junções celulares (dependente do contato celular); 3) entre células relativamente próximas a células secretoras (sinal parácrino), por exemplo a comunicação via vesículas extracelulares (VE); 4) entre células distantes (sinal endócrino) (BOBRIE et al, 2011;BONAFEDE et al, 2016;CAMUSSI et al, 2011;DE GASSART et al, 2004;HUANG et al, 2016;VALADI et al, 2007;VLASSOV et al, 2012;.…”