Project description:Recent reports of directed reprogramming have raised questions about the stability of cell lineages. Here, we have addressed this issue, focusing upon skin-derived precursors (SKPs), a dermally-derived precursor cell. We show by lineage tracing that murine SKPs from dorsal skin originate from mesenchymal and not neural crest-derived cells. These mesenchymally-derived SKPs can, without genetic manipulation, generate functional Schwann cells, a neural crest cell type, and are highly similar at the transcriptional level to Schwann cells isolated from the peripheral nerve. This is not a mouse-specific phenomenon, since human SKPs that are highly similar at the transcriptome level can be made from facial (neural crest-derived) and foreskin (mesodermally-derived) dermis, and the mesodermally-derived SKPs can make myelinating Schwann cells. Thus, non-neural crest-derived mesenchymal precursors can differentiate into bona fide peripheral glia in the absence of genetic manipulation, suggesting that developmentally-defined lineage boundaries are more flexible than widely thought. We obtained 4 independent samples of neonatal human foreskin and 4 independent samples of discarded facial skin tissue from children less than two years old. Primary cells were isolated and cultured as SKPs and RNA was collected from those cultured samples. RNA samples deriving from these cells were analyzed on the Affymetrix Human Gene 2.0 ST Array.
Project description:Recent reports of directed reprogramming have raised questions about the stability of cell lineages. Here, we have addressed this issue, focusing upon skin-derived precursors (SKPs), a dermally-derived precursor cell. We show by lineage tracing that murine SKPs from dorsal skin originate from mesenchymal and not neural crest-derived cells. These mesenchymally-derived SKPs can, without genetic manipulation, generate functional Schwann cells, a neural crest cell type, and are highly similar at the transcriptional level to Schwann cells isolated from the peripheral nerve. This is not a mouse-specific phenomenon, since human SKPs that are highly similar at the transcriptome level can be made from facial (neural crest-derived) and foreskin (mesodermally-derived) dermis, and the mesodermally-derived SKPs can make myelinating Schwann cells. Thus, non-neural crest-derived mesenchymal precursors can differentiate into bona fide peripheral glia in the absence of genetic manipulation, suggesting that developmentally-defined lineage boundaries are more flexible than widely thought. We obtained 3 independent samples of nerve Schwann cells, SKP-derived Schwann cells, and Dorsal Trunk SKPs, each, from adult SD rats. Primary cells were isolated and cultured, and RNA was collected from those cultured samples. RNA samples deriving from these cells were analyzed on the Affymetrix Rat Gene 1.0 ST Array.
Project description:Recent reports of directed reprogramming have raised questions about the stability of cell lineages. Here, we have addressed this issue, focusing upon skin-derived precursors (SKPs), a dermally-derived precursor cell. We show by lineage tracing that murine SKPs from dorsal skin originate from mesenchymal and not neural crest-derived cells. These mesenchymally-derived SKPs can, without genetic manipulation, generate functional Schwann cells, a neural crest cell type, and are highly similar at the transcriptional level to Schwann cells isolated from the peripheral nerve. This is not a mouse-specific phenomenon, since human SKPs that are highly similar at the transcriptome level can be made from facial (neural crest-derived) and foreskin (mesodermally-derived) dermis, and the mesodermally-derived SKPs can make myelinating Schwann cells. Thus, non-neural crest-derived mesenchymal precursors can differentiate into bona fide peripheral glia in the absence of genetic manipulation, suggesting that developmentally-defined lineage boundaries are more flexible than widely thought.
Project description:Recent reports of directed reprogramming have raised questions about the stability of cell lineages. Here, we have addressed this issue, focusing upon skin-derived precursors (SKPs), a dermally-derived precursor cell. We show by lineage tracing that murine SKPs from dorsal skin originate from mesenchymal and not neural crest-derived cells. These mesenchymally-derived SKPs can, without genetic manipulation, generate functional Schwann cells, a neural crest cell type, and are highly similar at the transcriptional level to Schwann cells isolated from the peripheral nerve. This is not a mouse-specific phenomenon, since human SKPs that are highly similar at the transcriptome level can be made from facial (neural crest-derived) and foreskin (mesodermally-derived) dermis, and the mesodermally-derived SKPs can make myelinating Schwann cells. Thus, non-neural crest-derived mesenchymal precursors can differentiate into bona fide peripheral glia in the absence of genetic manipulation, suggesting that developmentally-defined lineage boundaries are more flexible than widely thought.
Project description:Schwann cells (SCs) are an absolute prerequisite for development of effective treatment of myelin disorders and nerve injuries. However, human sources of functional, myelinating SCs are extremely limited. Here, we have developed a novel, efficient strategy for producing directly an unlimited supply of functional human SCs via successful derivation of expandable Schwann cell precursors (SCPs) from human pluripotent stem cells (hPSCs) (hPSC-SCPs). Functional and molecular characteristics of SCs from hPSC-SCPs (hPSC-SCP-SCs) appeared to be similar to those of authentic Schwann cells. As a novel therapeutic target, transplanted hPSC-SCP-SCs effectively promoted axonal regeneration through directly myelinating regenerated-axons in sciatic nerve injured mice. Here, we present hPSC-SCPs and hPSC-SCP-SCs as an outstanding resource to use for investigating human Schwann cell pathology and biology and for translational approaches to PNS and CNS repair and regeneration.
Project description:Here, we asked whether we could identify pharmacological agents that enhance endogenous stem cell function to promote skin repair, focusing on SKPs (skin-derived precursors) a dermal precursor cell population. Libraries of compounds already used in humans were screened for their ability to enhance the self-renewal of human and rodent SKPs. We identified and validated 5 such compounds, and showed that two of them, alprostadil and trimebutine maleate, enhanced the repair of full thickness skin wounds in middle-aged mice. Moreover, SKPs isolated from drug-treated skin displayed long-term increases in self-renewal when cultured in basal growth medium without drugs. Both alprostadil and trimebutine maleate likely mediated increases in SKPs self-renewal by moderate hyperactivation of the MEK-ERK pathway. These findings identify candidates for potential clinical use in human skin repair, and provide support for the idea that pharmacological activation of endogenous tissue precursors represents a viable therapeutic strategy.
Project description:Here, we asked whether we could identify pharmacological agents that enhance endogenous stem cell function to promote skin repair, focusing on SKPs (skin-derived precursors) a dermal precursor cell population. Libraries of compounds already used in humans were screened for their ability to enhance the self-renewal of human and rodent SKPs. We identified and validated 5 such compounds, and showed that two of them, alprostadil and trimebutine maleate, enhanced the repair of full thickness skin wounds in middle-aged mice. Moreover, SKPs isolated from drug-treated skin displayed long-term increases in self-renewal when cultured in basal growth medium without drugs. Both alprostadil and trimebutine maleate likely mediated increases in SKPs self-renewal by moderate hyperactivation of the MEK-ERK pathway. These findings identify candidates for potential clinical use in human skin repair, and provide support for the idea that pharmacological activation of endogenous tissue precursors represents a viable therapeutic strategy.