Project description:Mesenchymal stromal cells (MSC) are multipotent cells with regenerative and immune-modulatory properties. Therefore, MSC have been proposed as a potential cell-therapy for bronchiolitis obliterans syndrome (BOS). On the other hand, there are publications demonstrating that MSC might be involved in the development of BOS. Despite limited knowledge regarding the functional role of tissue-resident lung-MSC, several clinical trials have been performed using MSC, particularly bone marrow (BM)-derived MSC, for various lung diseases. We aimed to compare lung-MSC with the well-characterized BM-MSC. Furthermore, MSC isolated from lung-transplanted patients with BOS were compared to patients without BOS. Our study show that lung-MSCs are smaller, possess a higher colony-forming capacity and have a different cytokine profile compared to BM-MSC. Utilizing gene expression profiling, 89 genes including lung-specific FOXF1 and HOXB5 were found to be significantly different between BM-MSC and lung-MSC. No significant differences in cytokine secretion or gene expression were found between MSC isolated from BOS patients compared recipients without BOS. These data demonstrate that lung-resident MSC possess lung-specific properties. Furthermore, these results show that MSC isolated from lung-transplanted patients with BOS do not have an altered phenotype compared to MSC isolated from good outcome recipients.
Project description:We describe the proteomic composition of the extracellular environment of fetal and adult hematopoietic progenitors by data-independent acquisition mass spectrometry analysis.
Project description:We used the NanoString mouse nCounter miRNA expression platform to compare the miRNA expression profiles of pro-B cells sorted from fetal liver and adult bone marrow in order to gain insight into changes in miRNA expression during B cell ontogeny. Fetal liver and adult bone marrow cells were harvested and FACS sorted for pro-B cells (B220+CD43+IgM-veCD19+CD24+). Total RNA was extracted and used for sample preparation and hybridization per manufacturer's instructions.
Project description:We used the NanoString mouse nCounter miRNA expression platform to compare the miRNA expression profiles of pro-B cells sorted from fetal liver and adult bone marrow in order to gain insight into changes in miRNA expression during B cell ontogeny.
Project description:We speculate that the genes that acquired mutations in liver cancer tissues might be preferentially and actively transcribed in hepatic lineage cells. Therefore, to examine whether the mutated genes in liver cancer tissues in mice were transcribed at relatively higher levels in liver-lineage cells compared with hematopoietic lineage cells, we aim to analyze and compare the gene expression profiles in the adult liver, fetal liver and bone marrow.
Project description:The gene expression of bone marrow cells of mice enriched for Gremlin1 vs control was measured (n=3). It is not known if endogenous adult mesenchymal stem cells (MSCs) exist.Following culture,perisinusoidal mesenchymal cells can clonally recapitulate the skeletal microenvironment, but this fails to confirm their endogenous lineage repertoire. Multipotential MSCs in vitro may be fate-restricted in vivo and specific perisinusoidal recombination does not trace bone or cartilage Reconciling in vitro MSCs with their in vivo potential has been challenging and remains untested outside of the bone. We prove that expression of the bone morphogenetic protein (BMP)-antagonist gremlin 1 (Grem1) identifies a population of self-renewing, multipotent bone, cartilage and stromal-primed MSCs in both health and healing that are completely distinct from the established Nes-GFP niche-supporting mesenchymal cells. Grem1 recombination also identifies small intestinal MSCs (siMSCs) that can be transplanted and clonally trace the self-renewing, multilineage periepithelial mesenchymal sheath. Our findings prove the existence of adult MSCs that are regionally and functionally distinct from perisinusoidal Nes-GFP cells. We also established that the mesenchyme undergoes ordered turnover outside of the bone and may help to preserve regional niches. Grem1 MSCs provide a new focus for investigating mesenchymal renewal and repair. a.Adult (6-8 weeks) Grem1;TdTomato mice were induced by oral tamoxifen and their bone marrow harvested by digestion sorted for Non-recombined CD45/CD31/Ter-119 triple negative bone marrow cells (n=3). b.Adult (6-8 weeks) Grem1;TdTomato mice were induced by oral tamoxifen and their bone marrow harvested by digestion sorted for Grem1 (n=3). Same mice as in a so that samples are matched.
Project description:The gene expression of bone marrow cells of mice enriched for Gremlin1 vs control was measured (n=3). It is not known if endogenous adult mesenchymal stem cells (MSCs) exist.Following culture,perisinusoidal mesenchymal cells can clonally recapitulate the skeletal microenvironment, but this fails to confirm their endogenous lineage repertoire. Multipotential MSCs in vitro may be fate-restricted in vivo and specific perisinusoidal recombination does not trace bone or cartilage Reconciling in vitro MSCs with their in vivo potential has been challenging and remains untested outside of the bone. We prove that expression of the bone morphogenetic protein (BMP)-antagonist gremlin 1 (Grem1) identifies a population of self-renewing, multipotent bone, cartilage and stromal-primed MSCs in both health and healing that are completely distinct from the established Nes-GFP niche-supporting mesenchymal cells. Grem1 recombination also identifies small intestinal MSCs (siMSCs) that can be transplanted and clonally trace the self-renewing, multilineage periepithelial mesenchymal sheath. Our findings prove the existence of adult MSCs that are regionally and functionally distinct from perisinusoidal Nes-GFP cells. We also established that the mesenchyme undergoes ordered turnover outside of the bone and may help to preserve regional niches. Grem1 MSCs provide a new focus for investigating mesenchymal renewal and repair.
Project description:Umbilical cord blood (CB) is a valuable source of stem cells for transplantation, but CB transplantations are frequently complicated by delayed platelet engraftment. The reasons underlying this are unclear. We hypothesized that CB- and peripheral-blood (PB)-derived megakaryocytes (MKs) respond differently to the adult hematopoietic microenvironment and to thrombopoietin (Tpo). To test this, we cultured CB- and PB-CD34(+) cells in adult bone marrow stromal conditioned media (CM) or unconditioned media (UCM) with increasing concentrations of recombinant Tpo and compared the effects of these conditions on CB-versus PB-MKs. PB-MKs reached highest ploidy in response to UCM + 100 ng/mL rTpo, and the addition of CM inhibited their maturation. In contrast, CB-MKs reached highest ploidy in CM without rTpo, and high rTpo concentrations (> 0.1 ng/mL) inhibited their maturation. This is the first evidence that human neonatal and adult MKs have substantially different biologic responses to Tpo and potentially to other cytokines.
Project description:The immune system develops in waves during ontogeny; it is initially populated by cells generated from fetal hematopoietic stem cells (HSCs) and later by cells derived from adult HSCs. Remarkably, the genetic programs that control these two distinct stem cell fates remain poorly understood. We report that Lin28b is specifically expressed in mouse and human fetal liver and thymus, but not in adult bone marrow or thymus. We demonstrate that ectopic expression of Lin28 reprograms hematopoietic stem/progenitor cells (HSPCs) from adult bone marrow, which endows them with the ability to mediate multilineage reconstitution that resembles fetal lymphopoiesis, including increased development of B-1a, marginal zone B, gamma/delta (γδ) T cells, and natural killer T (NKT) cells.
Project description:Fetal cartilage fully regenerates following injury while in adult mammals cartilage injury leads to osteoarthritis (OA). OA is characterized by cartilage breakdown and joint inflammation and associated with significant pain and socioeconomic costs. As no clinically satisfactory treatment is available to date, disease-modifying therapies aimed to achieve cartilage regeneration are urgently required. The inherent regeneration potential of fetal individuals may hold answers to this unmet need. Therefore, to characterize the differences in fetal and adult response to cartilage injury, we carried out histology and comprehensive proteome analyses on fetal (day 80/150-day gestation) and adult cartilage samples one (fetal samples) and three (adult and fetal samples) days after surgical induction of a full-thickness cartilage lesion. In addition, proteins secreted by inflamed fetal MSCs in vitro were compared with the in vivo response to injury to evaluate their therapeutic potential. Histology of synovial samples revealed the presence of neutrophils one day post injury (p.i.) and an influx of macrophages into the subsynovial tissue on day 3 p.i. in fetal samples. In contrast, adult synovial samples showed invasion of neutrophils on day 3 p.i. Activation and migration of Iba1+- macrophages of the synovial lining was observed both in fetal and adult animals. Comparative mass spectrometry revealed 57 proteins significantly up-regulated (> 2FC, FDR<0.05), and 67 proteins significantly down-regulated (<-2 FC) upon injury in adults. Neutrophil-related proteins and acute phase proteins were the two major upregulated protein groups in adult cartilage following injury compared to fetal sheep. In contrast, several immunomodulating proteins and growth factors were significantly higher expressed in the fetus than the adult. Comparison of the in vitro MSCs with the in vivo fetal proteome revealed shared upregulation of 17 proteins, which were considered to be of potential therapeutic interest. The results of this study support our molecular understanding of successful fetal cartilage healing and new therapeutic strategies to induce regeneration in adult articular cartilage by modulating the inflammatory environment. The shared protein upregulation in fetal cartilage in vivo and in fetal MSCS during in vitro inflammation supports the possible therapeutic potential of these factors in specific and fetal MSCs in general.