@article{839197a39e004a999d988c759620b503,
title = "Engineering a haematopoietic stem cell niche by revitalizing mesenchymal stromal cells",
abstract = " Haematopoietic stem cells (HSCs) are maintained by bone marrow niches in vivo 1,2 , but the ability of niche cells to maintain HSCs ex vivo is markedly diminished. Expression of niche factors by Nestin-GFP + mesenchymal-derived stromal cells (MSCs) is downregulated upon culture, suggesting that transcriptional rewiring may contribute to this reduced HSC maintenance potential. Using an RNA sequencing screen, we identified five genes encoding transcription factors (Klf7, Ostf1, Xbp1, Irf3 and Irf7) that restored HSC niche function in cultured bone marrow-derived MSCs. These revitalized MSCs (rMSCs) exhibited enhanced synthesis of HSC niche factors while retaining their mesenchymal differentiation capacity. In contrast to HSCs co-cultured with control MSCs, HSCs expanded with rMSCs showed higher repopulation capacity and protected lethally irradiated recipient mice. Competitive reconstitution assays revealed an approximately sevenfold expansion of functional HSCs by rMSCs. rMSCs prevented the accumulation of DNA damage in cultured HSCs, a hallmark of ageing and replication stress. Analysis of the reprogramming mechanisms uncovered a role for myocyte enhancer factor 2c (Mef2c) in the revitalization of MSCs. These results provide insight into the transcriptional regulation of the niche with implications for stem cell-based therapies. ",
author = "Fumio Nakahara and Borger, {Daniel K.} and Qiaozhi Wei and Sandra Pinho and Maria Maryanovich and Zahalka, {Ali H.} and Masako Suzuki and Cruz, {Cristian D.} and Zichen Wang and Chunliang Xu and Boulais, {Philip E.} and Avi Ma{\textquoteright}ayan and Greally, {John M.} and Frenette, {Paul S.}",
note = "Funding Information: We thank C. Prophete and P. Ciero for technical assistance, L. Tesfa for assistance with cell sorting and S. Maqbool for RNA-seq. We thank L. Ding and S. J. Morrison for providing the Scf-GFP knock-in mice. We thank C.-J. Chang and E. E. Bouhassira for the FUWC-GW and pHIV-dTmt vectors. We thank T. Taniguchi (University of Tokyo, Japan) for the pCAGGS/Irf3 and pCAGGS/Irf7 vectors and S. Maeda (University of Kagoshima, Japan) for the pEF/Runx2 vectors. We thank J. F. Reidhaar-Olson and J. Shan for supplying overexpression and knockdown vectors. This work was supported by R01 grants from the US National Institutes of Health (NIH) (DK056638, HL069438, DK116312 and DK112976 to P.S.F., and U54HL127624 and U24CA224260 to A.M.). We are also grateful to the New York State Department of Health (NYSTEM Program) for shared facility (C029154) and research support (N13G-262) and the Leukemia and Lymphoma Society{\textquoteright}s Translational Research Program. F.N. was supported by the Postdoctoral Fellowship for Research Abroad from the Japan Society for the Promotion of Science (JSPS). D.K.B. is partially supported by a NIH Training Grant (T32 GM007288). M.M. is a New York Stem Cell Foundation (NYSCF) Druckenmiller fellow. A.H.Z. was supported by a NIH Training Grant (T32 NS007098) and by a National Cancer Institute (NCI) predoctoral MD/PhD fellowship (F30 CA203446). Funding Information: P.E.B. is supported by a postdoctoral fellowship from Fonds de recherche du Qu{\'e}bec-Sant{\'e} (FRQS).",
year = "2019",
month = may,
day = "1",
doi = "10.1038/s41556-019-0308-3",
language = "English (US)",
volume = "21",
pages = "560--567",
journal = "Nature Cell Biology",
issn = "1465-7392",
publisher = "Nature Publishing Group",
number = "5",
}