Human Vascular Progenitor Cells Can Guide Mesodermal Lineage Choice of Mesenchymal Stem and Progenitor Cells After Co-Transplantation In Vivo.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 939-939
Author(s):  
Andreas Reinisch ◽  
Nathalie Etchart ◽  
Nicole A Hofmann ◽  
Anna Ortner ◽  
Eva Rohde ◽  
...  

Abstract Abstract 939 Background: Multilineage differentiation potential of mesenchymal stem and progenitor cells (MSPCs) make them attractive candidates for tissue regeneration purposes. Guiding the differentiation of MSPCs towards single lineages would facilitate their application for targeted therapies in vivo. We have previously shown that MSPCs are essential for endothelial colony-forming progenitor cell (ECFC)-derived patent vessel formation in vivo*[Blood 2009; 113 (26):6716-25]. Preliminary data indicate that the ratio of co-applied cells can change mesenchymal lineage differentiation from vascular support towards either osteogenesis with subsequent bone marrow (BM) ingrowth or chondrogenesis. We hypothesized that environmental conditioning by ECFCs plays an instructive role during the developmental fate decision of MSPCs in vivo. Methods: MSPCs as well as ECFCs were isolated from adult BM, white adipose tissue (WAT), umbilical cord blood (UCB) and perivascular cord tissue**[J Vis Exp. 2009;(32) pii: 1525]. Proliferation potential and clonogenicity were monitored. Phenotype was analyzed by flow cytometry and immune cytochemistry. Cell function was studied in differentiation assays and during vascular network assembly in vitro. Models for in vivo human vessel as compared to bone, BM or cartilage formation were established in immune-deficient NSG mice (NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ). Non-invasive imaging was performed using computed tomography (CT), magnetic resonance (MRI) and near-infrared fluorescence imaging to elucidate the time course of heterotopic tissue development. Immune histochemistry was applied for morphologic studies of organogenesis. Results: Baseline analysis confirmed MSPC and ECFC purity, immune phenotype and sustained proliferation potential. We could show that human BM-derived MSPCs are capable of forming bone in vivo. Osteogenic differentiation and heterotopic ossicle formation was followed by attraction of mouse hematopoiesis and the establishment of entire murine BM including red and white blood cells and megakaryocytes within a human endosteal niche. Co-transplanted human ECFCs could instruct the MSPCs to differentiate also into pericytes or chondrocytes in vivo, depending on the applied MSPC/ECFC cell ratio. Non-invasive imaging and histological staining revealed that ectopic organogenesis had already started after 2–4 weeks and was stable during the observation period of 20 weeks. Non-BM-derived populations, although phenotypically identical, invariably lacked the capacity to build bone and marrow environment in this model in vivo. Conclusion: These data indicate that human ECFCs can instruct MSPCs and induce developmental fate decisions early in the time course of organ regeneration after transplantation. We suppose that effective regenerative stem cell therapy in vivo requires more than the injection of one single cell population. For vascular repair as compared to bone and marrow environment reconstitution our model is a promising tool to study the therapeutic applicability and risk profile of such ECFC/MSPC-based transplantation strategies. Disclosures: No relevant conflicts of interest to declare.

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 3593-3593
Author(s):  
Wei Du ◽  
Surya Amarachintha ◽  
Erden Ozlem ◽  
Qishen Pang

Abstract Members of the Fanconi anemia (FA) protein family are involved in DNA damage response. A common damage to DNA in vivo is oxidative stress, and compelling evidence suggests that FA cells are in an in vivo pro-oxidant state. In response to oncogenic activation, normal cells induce genetically encoding programs that prevent deregulated proliferation and thus protect multicellular organisms from cancer progression. How FA cells respond to oxidative DNA damage and oncogenic stress is largely unknown. By employing an in vivo stress-response model expressing the Gadd45b-luciferase transgene, we show here that hematopoietic stem and progenitor cells (HSPCs) from mice deficient for the FA gene Fanca or Fancc differentially responded to oxidative and oncogenic stresses. Compared to wild-type controls, Fanca-/- or Fancc-/- HSPCs exhibited a persistent response to oxidative stress. Mechanistically, we demonstrated that accumulation of unrepaired DNA damage, particularly in oxidative damage-sensitive genes, was responsible for the long-lasting response in FA HSPCs. In contrast, using two inducible models of oncogenic activation (LSL-K-rasG12D and MycER), we identify a short-lived response of FA HSPCs to oncogenic insults both in vitro and in vivo. Mechanistic studies revealed that loss of Fanca or Fancc impaired oncogenic stress-induced senescence (OIS), and genetic correction of Fanca or Fancc deficiency restored OIS in HSPCs. Furthermore, FA deficiency compromised K-rasG12D-induced arginine methylation of p53 mediated by the protein arginine methyltransferase 5 (PRMT5). Finally, forced expression of PRMT5 in HSPCs from LSL-K-rasG12D/CreER-Fanca-/- mice prolonged oncogenic response and delayed leukemia development in recipient mice. Taken together, our study demonstrates differential responses of HSPCs to oxidative and oncogenic stresses and identifies the FA pathway as an integral part of this versatile cellular mechanism. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 244-244
Author(s):  
Sneha Borikar ◽  
Vivek Philip ◽  
Jennifer J. Trowbridge

Abstract During aging, the hematopoietic compartment undergoes lineage skewing, biased toward myeloid differentiation at the expense of lymphoid differentiation. This skewing clinically presents as impaired adaptive immunity and an increased risk of myeloproliferative disorders. However, little is known of the regulatory mechanisms underlying these changes in differentiation potential due in part to the inadequacy of current analytic techniques to evaluate lineage potency of individual progenitor cells. Recent demonstration that long-lived hematopoietic progenitor cells drive steady-state hematopoiesis has shifted focus onto the progenitor cell compartment to understand clonal dynamics of native hematopoiesis. Here, we critically assess the functional and molecular alterations in the multipotent progenitor cell pool with aging at the single-cell level. We developed novel in vitro and in vivo assays to define the heterogeneity of the LMPP population and test cell-fate potential from single cells. Our results demonstrate, for the first time, distinct, intrinsic lineage potential of single in vitro LMPPs at the cellular and molecular level. We find that clonal alterations in the lymphoid-primed multipotent progenitor (LMPP) compartment contributes to the functional alterations in hematopoiesis observed during aging. Unbiased single-cell transcriptome analysis reveals that true multipotential clones and lymphoid-restricted clones are reduced with aging, while bipotential and myeloid-restricted clones are modestly expanded. Furthermore, myeloid-restricted clones gain myc driver signatures, molecularly identifying clones emerging during aging that are susceptible to transformation. Our study reveals that aging alters the clonal composition of multipotential progenitor cells, directly contributing to the global loss of the lymphoid compartment and increased susceptibility to myeloid transformation. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 34-35
Author(s):  
Fengjiao Wang ◽  
Jiahuan He ◽  
Yanni Ma ◽  
Sha Hao ◽  
Siqi Liu ◽  
...  

RNA editing, adenosine (A)-to-inosine (I), plays a vital role in many biological processes. Our previous study has demonstrated that the hematopoietic stem and progenitor cells (HSPCs) deficient in adenosine deaminase acting on RNA 1 (Adar1), an RNA-editing enzyme, cannot reconstitute the irradiated recipients in vivo and form colonies in vitro (Xufeng R et al, PNAS 2009). However, the overall profile of RNA editome in hematopoiesis has not been established and the underlying mechanism how RNA editing governs the function of HSPCs is poorly defined. In this study, we sorted 12 murine adult hematopoietic cell populations and performed RNA sequencing. We depicted the landscape of RNA editome in hematopoietic cells and identified 30,796 editing sites in total. The dynamic landscape of RNA editome comprised of stage/group-specific as well as house-keeping editing patterns. Notably, antizyme inhibitor 1 (Azin1) was uncovered to be highly edited in HSPCs. To understand whether edited Azin1 was required for functioning of HSPCs, we transduced c-Kit+ HSPCs with the lentivirus carrying Azin1 cDNAs with distinct editing frequencies. c-Kit+ cells transduced with fully edited Azin1 showed enhanced reconstitution, compared to that transduced with partially edited or non-edited Azin1. Specifically, inability of RNA editing in Azin1 blocked the differentiation of hematopoietic stem cells (HSCs) in vivo. Moreover, a similar finding was obtained when Azin1 was knocked down. In conclusion, RNA editing of Azin1 (i) results in amino acid change to induce AZIN1 translocation to the nucleus, (ii) enhances AZIN1 binding affinity for DEAD box polypeptide 1 (DDX1) to alter the DDX1 chromatin distribution, and (iii) changes the expression of multiple hematopoietic regulators to ultimately promote HSPC differentiation. This work provides a valuable resource for studying RNA editing and delineates an essential role of Azin1 RNA editing in HSPCs. Disclosures No relevant conflicts of interest to declare.


Blood ◽  
2010 ◽  
Vol 116 (17) ◽  
pp. 3197-3207 ◽  
Author(s):  
Kirsteen J. Campbell ◽  
Mary L. Bath ◽  
Marian L. Turner ◽  
Cassandra J. Vandenberg ◽  
Philippe Bouillet ◽  
...  

Abstract Diverse human cancers with poor prognosis, including many lymphoid and myeloid malignancies, exhibit high levels of Mcl-1. To explore the impact of Mcl-1 overexpression on the hematopoietic compartment, we have generated vavP-Mcl-1 transgenic mice. Their lymphoid and myeloid cells displayed increased resistance to a variety of cytotoxic agents. Myelopoiesis was relatively normal, but lymphopoiesis was clearly perturbed, with excess mature B and T cells accumulating. Rather than the follicular lymphomas typical of vavP-BCL-2 mice, aging vavP-Mcl-1 mice were primarily susceptible to lymphomas having the phenotype of a stem/progenitor cell (11 of 30 tumors) or pre-B cell (12 of 30 tumors). Mcl-1 overexpression dramatically accelerated Myc-driven lymphomagenesis. Most vavP-Mcl-1/ Eμ-Myc mice died around birth, and transplantation of blood from bitransgenic E18 embryos into unirradiated mice resulted in stem/progenitor cell tumors. Furthermore, lethally irradiated mice transplanted with E13 fetal liver cells from Mcl-1/Myc bitransgenic mice uniformly died of stem/progenitor cell tumors. When treated in vivo with cyclophosphamide, tumors coexpressing Mcl-1 and Myc transgenes were significantly more resistant than conventional Eμ-Myc lymphomas. Collectively, these results demonstrate that Mcl-1 overexpression renders hematopoietic cells refractory to many cytotoxic insults, perturbs lymphopoiesis and promotes malignant transformation of hematopoietic stem and progenitor cells.


mBio ◽  
2020 ◽  
Vol 11 (3) ◽  
Author(s):  
Cristina Bono ◽  
Alba Martínez ◽  
Javier Megías ◽  
Daniel Gozalbo ◽  
Alberto Yáñez ◽  
...  

ABSTRACT Toll-like receptor (TLR) agonists drive hematopoietic stem and progenitor cells (HSPCs) to differentiate along the myeloid lineage. In this study, we used an HSPC transplantation model to investigate the possible direct interaction of β-glucan and its receptor (dectin-1) on HSPCs in vivo. Purified HSPCs from bone marrow of B6Ly5.1 mice (CD45.1 alloantigen) were transplanted into dectin-1−/− mice (CD45.2 alloantigen), which were then injected with β-glucan (depleted zymosan). As recipient mouse cells do not recognize the dectin-1 agonist injected, interference by soluble mediators secreted by recipient cells is negligible. Transplanted HSPCs differentiated into macrophages in response to depleted zymosan in the spleens and bone marrow of recipient mice. Functionally, macrophages derived from HSPCs exposed to depleted zymosan in vivo produced higher levels of inflammatory cytokines (tumor necrosis factor alpha [TNF-α] and interleukin 6 [IL-6]). These results demonstrate that trained immune responses, already described for monocytes and macrophages, also take place in HSPCs. Using a similar in vivo model of HSPC transplantation, we demonstrated that inactivated yeasts of Candida albicans induce differentiation of HSPCs through a dectin-1- and MyD88-dependent pathway. Soluble factors produced following exposure of HSPCs to dectin-1 agonists acted in a paracrine manner to induce myeloid differentiation and to influence the function of macrophages derived from dectin-1-unresponsive or β-glucan-unexposed HSPCs. Finally, we demonstrated that an in vitro transient exposure of HSPCs to live C. albicans cells, prior to differentiation, is sufficient to induce a trained phenotype of the macrophages they produce in a dectin-1- and Toll-like receptor 2 (TLR2)-dependent manner. IMPORTANCE Invasive candidiasis is an increasingly frequent cause of serious and often fatal infections. Understanding host defense is essential to design novel therapeutic strategies to boost immune protection against Candida albicans. In this article, we delve into two new concepts that have arisen over the last years: (i) the delivery of myelopoiesis-inducing signals by microbial components directly sensed by hematopoietic stem and progenitor cells (HSPCs) and (ii) the concept of “trained innate immunity” that may also apply to HSPCs. We demonstrate that dectin-1 ligation in vivo activates HSPCs and induces their differentiation to trained macrophages by a cell-autonomous indirect mechanism. This points to new mechanisms by which pathogen detection by HSPCs may modulate hematopoiesis in real time to generate myeloid cells better prepared to deal with the infection. Manipulation of this process may help to boost the innate immune response during candidiasis.


2020 ◽  
Vol 42 ◽  
pp. 8-9
Author(s):  
B.Q. Oliveira ◽  
B.A.A.S. Lemos ◽  
L.F.B. Catto ◽  
M.F. Tellechea ◽  
P. Scheinberg ◽  
...  

2020 ◽  
Vol 26 (6) ◽  
pp. 794-803
Author(s):  
Emmanuelle Tancrède‐Bohin ◽  
Thérèse Baldeweck ◽  
Sébastien Brizion ◽  
Etienne Decencière ◽  
Steeve Victorin ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Dong Joon Lee ◽  
Yonsil Park ◽  
Wei-Shou Hu ◽  
Ching-Chang Ko

Osteogenic cells derived from rat multipotent adult progenitor cells (rMAPCs) were investigated for their potential use in bone regeneration. rMAPCs are adult stem cells derived from bone marrow that have a high proliferation capacity and the differentiation potential to multiple lineages. They may also offer immunomodulatory properties favorable for applications for regenerative medicine. rMAPCs were cultivated as single cells or as 3D aggregates in osteogenic media for up to 38 days, and their differentiation to bone lineage was then assessed by immunostaining of osteocalcin and collagen type I and by mineralization assays. The capability of rMAPCs in facilitating bone regeneration was evaluatedin vivoby the direct implantation of multipotent adult progenitor cell (MAPC) aggregates in rat calvarial defects. Bone regeneration was examined radiographically, histologically, and histomorphometrically. Results showed that rMAPCs successfully differentiated into osteogenic lineage by demonstrating mineralized extracellular matrix formationin vitroand induced new bone formation by the effect of rMAPC aggregatesin vivo. These outcomes confirm that rMAPCs have a good osteogenic potential and provide insights into rMAPCs as a novel adult stem cell source for bone regeneration.


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