MT1-MMP Plays a Critical Role In the Modulation of Hematopoiesis.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3851-3851
Author(s):  
Chiemi Nishida ◽  
Beate Heissig ◽  
Yoshihiko Tashiro ◽  
Motoharu Seiki ◽  
Hiromitsu Nakauchi ◽  
...  
Keyword(s):  
Stromal Cell ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Critical Role ◽  
Cancer Drug ◽  
Hematopoietic Stem ◽  
Kit Ligand ◽  
Significant Difference ◽  
Stromal Cell Derived Factor

Abstract Abstract 3851 Specific niches, in which hematopoietic stem cells (HSCs) reside control the balance between HSC quiescence and self-renewal, yet little is known about the extrinsic signals provided by the niche and how these niche signals regulate such a balance. In the recent study, activation of the fibrinolytic pathway via matrix metalloproteinases (MMPs) including MMP-9 resulted in the release of kit ligand (KitL) in the BM niche. Membrane type 1-MMP (MT1-MMP) can activate MMP-9 in the process of mutual activation of MMP. It has already known that BM myeloablation with irradiation or anti-cancer drug induces MT1-MMP expression, but the role of MT1-MMP in hematopoiesis is not well-understood. We examined MT1-MMP deficient mice (MT1-MMP-/-) 12 days after birth. MT1-MMP-/- were suffering from pancytopenia, and are reduced numbers of bone marrow mononuclear cells (BMMCs), splenocytes and number of hematopoietic progenitor cells in the BM although the number of HSCs in BM showed no significant difference. BM cytospins from MT1-MMP-/- mice showed mild erythropoietic disturbance and severer impairment of myelopoiesis. Interestingly, a powerful hematopoietic factor, Kit-ligand (KitL) levels were significantly lower in MT1-MMP-/- mice than wild type. MT1-MMP knockdown by shRNA or/and siRNA impaired KitL expression and secretion in transfected stroma cells compared to Mock controls, demonstrating that reduced KitL plasma levels were due to impaired release/production and not due to reduced numbers of stromal cells in MT1-MMP-/-. Similarly, impaired proliferation and differentiation of MT1-MMP-/- BMMCs in vitro could be restored by exogenous sKitL. Others and we reported that BM ablation induces the production of stromal cell-derived factor-1 (SDF-1; CXCL12), which plays a key role in stem cell homing and B-cell lymphopoiesis. Reduced SDF-1 expression was observed in BMMCs of MT1-MMP-/- mice and genetic knockdown of MT1-MMP resulted in lower SDF-1 expression both on a transcriptional and protein level. BMMCs of MT1-MMP-/- showed a decrease in the percentage of mature B cells compare to controls. Knocking down of MT1-MMP in stromal cell reduced the number of adherent hematopoietic cells, but addition of rec. SDF-1 could reverse the phenotype. These results suggested stromal-derived MT1-MMP was functionally important to maintain HSC function in long-term cultures of WT HSCs. Thus, MT1-MMP is a critical modulator of hematopoiesis, as it alters the growth factor output of niche cells. Disclosures: No relevant conflicts of interest to declare.

Durable and Robust Fetal Globin Induction without Anemia in Rhesus Monkeys Following Autologous Hematopoietic Stem Cell Transplant with BCL11A Erythroid Enhancer Editing

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4632-4632 ◽  
Author(s):  
Selami Demirci ◽  
Jing Zeng ◽  
Yuxuan Wu ◽  
Naoya Uchida ◽  
Jackson Gamer ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Mononuclear Cells ◽  
Hematologic Toxicity ◽  
Cell Transplant ◽  
Post Transplantation ◽  
Hematopoietic Stem ◽  
Significant Difference ◽  
Hbf Induction

Elevated fetal hemoglobin (HbF, α2γ2) levels are clinically beneficial for patients with β-hemoglobinopathies. Editing of the erythroid-specific BCL11A enhancer induces HbF, inhibiting sickling and restoring globin chain balance in erythroid cells derived from hematopoietic stem and progenitor cells (HSPCs) from SCD and β-thalassemia patients respectively, without detectable genotoxicity or adverse effects on hematopoietic stem cell (HSC) function (Wu Y, Nat Med, 2019). Here, we sought to evaluate engraftment and HbF induction potential of erythroid-specific BCL11A enhancer edited CD34+ HSPCs in a non-human primate transplantation model in which hemoglobin switching is conserved. We targeted the erythroid-specific +58 DNAse I hypersensitive site of BCL11A, which has identical human and rhesus sequences at the spacer and protospacer adjacent motif (PAM) of the potent #1617 sgRNA. Ribonucleoprotein complex (RNP) composed of 3x-NLS SpCas9 protein and either BCL11A enhancer targeting (#1617) or AAVS1 targeting sgRNA was electroporated into rhesus CD34+ HSPCs (n=3). Following erythroid differentiation, substantial γ-globin expression (54-77%, p<0.01) was observed in BCL11A edited cells (81-85% indels) as compared to 19-25% and 15-24% for non-electroporated and AAVS1 edited cells, respectively, with no significant difference in red blood cell (RBC) enucleation efficiency (44-47%) among groups. We tested BCL11A enhancer editing with autologous HSC transplant in two cohorts, with two macaques per cohort. For cohort 1, we performed competitive engraftment of BCL11A enhancer and AAVS1 edited HSPCs to test long-term reconstitution. For cohort 2, we evaluated BCL11A enhancer editing alone to evaluate HbF induction and hematopoietic reconstitution. For each cohort, purified CD34+ HSPCs were electroporated with RNP one day after G-CSF and plerixafor mobilization and cultured for two days prior to cryopreservation. HSPCs were thawed and infused following 2×5 Gy total body irradiation. For cohort 1 (n=2, ZL25 and ZL22, 1.34-1.39×106 CD34+ HSPCs/kg), we observed reduced indel frequencies (8-41%) at early post-infusion time points compared to cell products (18-49%), suggesting indels in unfractionated HSPCs may overestimate those in engrafting cells and/or hematopoietic ablation was incomplete. From weeks 6 to 83, stable indel frequencies were detected in both BCL11A (~3-18%) and AAVS1 (~10-45%), suggesting no selective advantage for BCL11A enhancer edited, AAVS1 edited, or non-edited HSCs. For cohort 2 (BCL11A enhancer editing alone (n=2, ZM17 and ZM26, 1.78-6.06×106 CD34+ cells/kg), cell products showed improved editing with ~95% indels and ~65-78% γ-globin protein after in vitro erythroid culture. Animals engrafted with typical kinetics and displayed stable indel ratios up to 28 weeks post-transplantation. A significant correlation was detected between γ-globin level and indel frequency comparing all 4 transplanted animals and unedited controls (R2=0.76, p<0.01). In both edited and unedited animals γ-globin levels peaked in the first two months after transplantation and subsequently declined and plateaued. In ZM17 (~70% BCL11A enhancer indels at ~24 weeks), ~12% γ-globin was observed in peripheral blood (PB) at last measurement (compared to 0.5% γ-globin in RBC prior to transplant). In the same animal, editing ranged from 78-81% across all PB and bone marrow (BM) lineages (excluding CD3+ T-cells with 63% indels), including B-lymphoid, myeloid, erythroid, and HSPCs (in particular including 78% indels in CD71+ CD45- erythroblasts). Hemoglobin, hematocrit, and reticulocyte counts and peripheral smear appearance were all normal, suggesting no erythroid toxicity. Colony-forming ability of BM-derived mononuclear cells was similar in edited and control animals. In summary, we evaluated the clinical potential of autologous BCL11A erythroid enhancer editing in rhesus macaques. BCL11A enhancer edited HSCs can persist for at least 83 weeks post-transplant and provide therapeutic levels of HbF in peripheral RBCs without anemia or other apparent hematologic toxicity. Furthermore, these results emphasize input CD34+ HSPC dose and conditioning intensity as critical variables that influence gene editing following autologous HSCT. Overall, these findings support BCL11A erythroid enhancer genome editing as a promising strategy for therapeutic HbF induction. Disclosures Weiss: GlaxoSmithKline: Consultancy; Cellarity INC: Consultancy; Esperian: Consultancy; Beam Therapeutics: Consultancy; Rubius INC: Consultancy.

Innate Lymphoid Cell-Derived IL-22 Mediates Endogenous Thymic Repair Under the Control of IL-23

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 143-143
Author(s):  
Jarrod A Dudakov ◽  
Alan M Hanash ◽  
Lauren F. Young ◽  
Natalie V Singer ◽  
Mallory L West ◽  
...  
Keyword(s):  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Critical Role ◽  
Lymphoid Cells ◽  
Thymic Epithelial Cells ◽  
Immune Competence ◽  
Strong Negative Correlation ◽  
Hematopoietic Stem ◽  
Stimulation Of

Abstract Abstract 143 Despite being exquisitely sensitive to insult, the thymus is remarkably resilient in young healthy animals. Endogenous regeneration of the thymus is a crucial function that allows for renewal of immune competence following infection or immunodepletion caused by cytoreductive chemotherapy or radiation. However, the mechanisms governing this regeneration remain poorly understood. Thymopoiesis is a highly complex process involving cross-talk between developing thymocytes and their supporting non-hematopoietic stromal microenvironment, which includes highly specialized thymic epithelial cells (TECs) that are crucial for T cell development. IL-22 is a recently identified cytokine predominantly associated with maintenance of barrier function at mucosal surfaces. Here we demonstrate for the first time a critical role for IL-22 in endogenous thymic repair. Comparing IL-22 KO and WT mice we observed that while IL-22 deficiency was redundant for steady-state thymopoiesis, it led to a pronounced and prolonged loss of thymus cellularity following sublethal total body irradiation (SL-TBI), which included depletion of both thymocytes (p=0.0001) and TECs (p=0.003). Strikingly, absolute levels of IL-22 were markedly increased following thymic insult (p<0.0001) despite the significant depletion of thymus cellularity. This resulted in a profound increase in the production of IL-22 on a per cell basis (p<0.0001). These enhanced levels of IL-22 peaked at days 5 to 7 after SL-TBI, immediately following the nadir of thymic cellularity. This was demonstrated by a strong negative correlation between thymic cellularity and absolute levels of IL-22 (Fig 1a). In mucosal tissues the regulation of IL-22 production has been closely associated with IL-23 produced by dendritic cells (DCs) and ex vivo incubation of cells with IL-23 stimulates the production of IL-22. Following thymic insult there was a significant increase in the amount of IL-23 produced by DCs (Fig 1b) resulting in similar kinetics of intrathymic levels of IL-22 and IL-23. We identified a population of radio-resistant CD3−CD4+IL7Ra+RORg(t)+ thymic innate lymphoid cells (tILCs) that upregulate both their production of IL-22 (Fig 1c) and expression of the IL-23R (p=0.0006) upon exposure to TBI. This suggests that they are responsive to IL-23 produced by DCs in vivo following TBI and, in fact, in vitro stimulation of tILCs by IL-23 led to upregulation of Il-22 production by these cells (Fig 1d). We found expression of the IL-22Ra on cortical and medullary TECs (cTECs and mTECs, respectively), and uniform expression across both mature MHCIIhi mTEC (mTEChi) and immature MHCIIlo mTECs (mTEClo). However, in vitro stimulation of TECs with recombinant IL-22 led to enhanced TEC proliferation primarily in cTEC and mTEClo subsets (p=0.002 and 0.004 respectively). It is currently unclear if IL-22 acts as a maturation signal for mTECs, however, the uniform expression of IL-22Ra between immature mTEClo and mature Aire-expressing mTEChi, together with the preferential promotion of proliferation amongst mTEClo and cTEC seem to argue against IL-22 as a maturational signal but rather as promoter of proliferation, which ultimately leads to terminal differentiation of TECs. Of major clinical importance, administration of exogenous IL-22 led to enhanced thymic recovery (Fig. 1e) following TBI, primarily by promoting the proliferation of TECs. Consistent with this, the administration of IL-22 also led to significantly enhanced thymopoiesis following syngeneic BMT. Taken together these findings suggest that following thymic insult, and specifically the depletion of developing thymocytes, upregulation of IL-23 by DCs induces the production of IL-22 by tILCs and regeneration of the supporting microenvironment. This cascade of events ultimately leads to rejuvenation of the thymocyte pool (Fig. 1f). These studies not only reveal a novel pathway underlying endogenous thymic regeneration, but also identify a novel regenerative strategy for improving immune competence in patients whose thymus has been damaged from infection, age or cytoreductive conditioning required for successful hematopoietic stem cell transplantation. Finally, these findings may also provide an avenue of study to further understand the repair and regeneration of other epithelial tissues such as skin, lung and breast. Disclosures: No relevant conflicts of interest to declare.

Comparative Analysis on Cellular Components of Bone Marrow Microenvironment in Normal and Aberrant Hematopoiesis

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4808-4808
Author(s):  
Young-Ho Lee ◽  
Young-hee Kwon ◽  
Kyoujung Hwang ◽  
Hyunju Jun ◽  
Byungbae Park ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Conflicts Of Interest ◽  
T Cell Subsets ◽  
Hematopoietic Stem ◽  
Cd34 Cells ◽  
Significant Difference ◽  
Stromal Cell Derived Factor ◽  
And Control ◽  
Cellular Components

Abstract Abstract 4808 Background: It is now evident that hematopoietic stem cells (HSCs) reside preferentially at the endosteal region within the bone marrow (BM) where bone-lining osteoblasts are a key cellular component of the HSC niche that directly regulates HSC fate. We investigated the microenvironmental differences including osteoblastic activities and HSC components in myeloproliferative (chronic myeloid leukemia, CML) and hypogenerative disease (aplastic anemia, AA) as well as normal control (NC). Methods: The immunohistochemistry for osteonectin, osteocalcin, stromal cell derived factor (SDF, CXCL12), T cell, T helper/inducer cell, T suppressor/cytotoxic cell, hematopoietic stem/progenitor (CD34, CD117) and megakaryocytes was performed on BM biopsy specimens from 10 AA patients, 10 CML patients and 10 NC (lymphoma without BM involvement). The positive cells for immunohistochemical stainings except osteocalcin on each slide were calculated on 10 high power fields (HPF, ×400), and then corrected by the cellularity. The positive cells for osteocalcin were counted on the peritrabecular line on each slide, and then corrected by the mean length measured. Results: The CD34+ cells (p=0.012) and megakaryocytes (p<0.0001) were significantly lower in AA than in NC, but CD117+ cells was comparable in AA, CML, and control samples. The osteonectin+ cells (p=0.0003) were lower in CML than in AA and NC, however the osteocalcin+ cells showed wide variation (0-903/2035um) and no significant difference. The SDF+ cells (p<0.0001) was significantly higher in AA and very lower in CML, compared with NC. The counts for T cell and T cell subsets were significantly lower in CML than in NC, and higher in AA than in NC (p<0.0001). Conclusions: Cellular components of BM microenvironment in 2 hematologic diseases representative of myeloproliferation (CML) and hyporegeneration (AA) respectively are quite different. Further studies would be required to explore the role of these components for hematopoiesis and the rationale for therapeutic application. Disclosures: No relevant conflicts of interest to declare.

A Critical Role of Mir-9 in Myelopoesis and EVI1-Induced Leukemogenesis.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2332-2332
Author(s):  
Vitalyi Senyuk ◽  
Yunyuan Zhang ◽  
Yang Liu ◽  
Ming Ming ◽  
Jianjun Chen ◽  
...  
Keyword(s):  
Cell Transformation ◽  
Conflicts Of Interest ◽  
Critical Role ◽  
Ectopic Expression ◽  
Myeloid Differentiation ◽  
Dna Hypermethylation ◽  
Hematopoietic Stem

Abstract Abstract 2332 MicroRNA-9 (miR-9) is required for normal neurogenesis and organ development. The expression of miR-9 is altered in several types of solid tumors suggesting that it may have a function in cell transformation. However the role of this miR in normal hematopoiesis and leukemogenesis is unknown. Here we show that miR-9 is expressed at low levels in hematopoietic stem/progenitor cells (HSCs/HPCs), and that it is upregulated during hematopoietic differentiation. Ectopic expression of miR-9 strongly accelerates terminal myelopoiesis, while promoting apoptosis in vitro and in vivo. In addition, the inhibition of miR-9 in HPC with a miRNA sponge blocks myelopoiesis. EVI1, required for normal embryogenesis, and is considered an oncogene because inappropriate upregulation induces malignant transformation in solid and hematopoietic cancers. In vitro, EVI1 severely affects myeloid differentiation. Here we show that EVI1 binds to the promoter of miR-9–3 leading to DNA hypermethylation of the promoter as well as repression of miR-9. We also show that ectopic miR-9 reverses the myeloid differentiation block that is induced by EVI1. Our findings suggest that inappropriately expressed EVI1 delays or blocks myeloid differentiation, at least in part by DNA hypermethylation and downregulation of miR-9. It was previously reported that FoxOs genes inhibit myeloid differentiation and prevent differentiation of leukemia initiating cells. Here we identify FoxO3 and FoxO1 as new direct targets of miR-9 in hematopoietic cells, and we find that upregulation of FoxO3 in miR-9-positive cells reduces the acceleration of myelopoiesis. These results reveal a novel role of miR-9 in myelopoiesis and in the pathogenesis of EVI1-induced myeloid neoplasms. They also provide new insights on the potential chromatin-modifying role of oncogenes in epigenetic changes in cancer cells. Disclosures: No relevant conflicts of interest to declare.

Ezrin Regulates Hematopoietic Stem/Progenitor Cell Motility

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1282-1282
Author(s):  
Yi Zeng ◽  
Karl Staser ◽  
Keshav Mohan Menon ◽  
Su-jung Park ◽  
Muithi Mwanthi ◽  
...  
Keyword(s):  
Progenitor Cell ◽  
Conflicts Of Interest ◽  
Cell Contact ◽  
Wild Type ◽  
Hematopoietic Stem ◽  
Knock Out ◽  
Actin Organization ◽  
Stromal Cell Derived Factor ◽  
Cell Mobilization

Abstract Abstract 1282 Ezrin is a member of the ERM (ezrin, moesin and radixin) protein family that links plasma membrane proteins to the actin cytoskeleton. Ezrin in other in vitro cell systems has been hypothesized to participate in cell-cell contact and could have a role in stem/ progenitor cell mobilization and adhesion. To test this hypothesis, we crossed ezrinflox/flox mice with Mx1 cre transgenic mice to generate an inducible ezrin knock out mouse model. Inducible disruption of the ezrin gene in hematopoietic cells was achieved by the administration of polyIC. Ezrin knock out HSPCs exhibited a 30–40% decrease in baseline and chemokine stromal cell-derived factor-1 (SDF-1) stimulated motility in transwell migration assays in vitro. In addition, loss of ezrin led to a 60% decrease in the homing capacity of HSPCs in lethally irradiated recipient mice following transplantation. There was a 40–55% decrease in colony forming cells in peripheral blood and spleen of the mice following ezrin knock out, suggesting that ezrin knock out HSPCs may be deficient in egressing out of the bone marrow. To further understand the cause of the impaired motility of ezrin knock out HSPCs, we examined F-actin level of HSPCs at baseline and in response to SDF-1. Ezrin knock out HSPCs displayed 1.5 to 2 fold higher level of F-actin at baseline when compared with wild type cells. Following stimulation with SDF-1, wild type HSPCs that migrated to the bottom compartment of the transwell demonstrated a 2 time greater decrease in F-actin level when compared with ezrin knock out cells, suggesting that ezrin may participate in the regulation of F-actin depolymerization in HSPCs. In summary, we demonstrate that ezrin modulates HSPC migration and homing likely through its regulation on F-actin organization. Disclosures: No relevant conflicts of interest to declare.

Screen for Small Molecules Capable of Expanding Human Hematopoietic Stem Cell Ex Vivo

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 1919-1919
Author(s):  
Iman Hatem Fares ◽  
Jalila Chagraoui ◽  
Jana Krosl ◽  
Denis-Claude Roy ◽  
Sandra Cohen ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Ex Vivo ◽  
Fold Increase ◽  
Hematopoietic Stem ◽  
Cd34 Cells

Abstract Abstract 1919 Hematopoietic stem cell (HSC) transplantation is a life saving procedure whose applicability is restricted by the lack of suitable donors, by poor responsiveness to mobilization regimens in preparation of autologous transplantations, by insufficient HSC numbers in individual cord blood units, and by the inability to sufficiently amplify HSCs ex vivo. Characterization of Stemregenin (SR1), an aryl hydrocarbon receptor (AHR) antagonist that promotes HSC expansion, provided a proof of principle that low molecular weight (LMW) compounds have the ability to promote HSC expansion. To identify novel putative agonists of HSC self-renewal, we initiated a high throughput screen (HTS) of a library comprising more than 5,000 LMW molecules using the in vitro maintenance of the CD34+CD45RA- phenotype as a model system. Our study was based on the fact that mobilized peripheral blood-derived CD34+CD45RA- cells cultured in media supplemented with: stem cell factor, thrombopoietin, FLT3 ligand and interleukin 6, would promote the expansion of mononuclear cells (MNC) concomitant with a decrease in CD34+CD45RA- population and HSC depletion. LMW compounds preventing this loss could therefore act as agonists of HSC expansion. In a 384-well plate, 2000 CD34+cells were initially cultured/well in 50μl medium comprising 1μM test compounds or 0.1% DMSO (vehicle). The proportions of CD34+CD45RA− cells were determined at the initiation of experiment and after a 7-day incubation. Six of 5,280 LMW compounds (0.11%) promoted CD34+CD45RA− cell expansion, and seventeen (0.32%) enhanced differentiation as determined by the increase in proportions of CD34−CD45RA+ cells compared to control (DMSO). The 6 LMW compounds promoting expansion of the CD34+CD45RA− cell population were re-analyzed in a secondary screen. Four out of these 6 molecules suppressed the transcriptional activity of AHR, suggesting that these compounds share the same molecular pathway as SR1 in stimulating HSC expansion, thus they were not further characterized. The remaining 2 compounds promoted, similar to SR1 or better, a 10-fold and 35-fold expansion of MNC during 7 and 12-day incubations, respectively. The expanded cell populations comprised 65–75% of CD34+ cells compared to 12–30% determined for DMSO controls. During 12-day incubation with these compounds, the numbers of CD34+ cells increased ∼25-fold over their input values, or ∼ 6-fold above the values determined for controls. This expansion of CD34+ cells was associated with a ∼5-fold increase in the numbers of multilineage CFC (granulocyte, erythroid, monocyte, and megakaryocyte, or CFU-GEMM) compared to that found in DMSO control cultures. The ability of the 2 newly identified compounds to expand functional HSCs is currently being evaluated in vivo usingimmunocompromised mice. In conclusion, results of our initial screen suggest that other mechanism, besides inhibition of AhR, are at play for expansion of human HSC. Disclosures: No relevant conflicts of interest to declare.

Primary Bone Marrow-Derived MSC Subsets Have Distinct Wnt-Signatures Compared to Conventionally Cultured MSC and Differ in Their Capacity to Support Hematopoiesis in Vitro,

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 3414-3414 ◽  
Author(s):  
Marijke W Maijenburg ◽  
Marion Kleijer ◽  
Kim Vermeul ◽  
Erik P.J. Mul ◽  
Floris P.J. van Alphen ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bone Marrow ◽  
Wnt Signaling ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Cell Types ◽  
Hematopoietic Stem ◽  
Wnt Proteins

Abstract Abstract 3414 Mesenchymal stromal cells (MSC) are of promising therapeutic use to suppress immunogenic responses following transplantation, and to support expansion of hematopoietic stem- and progenitors cells (HSPC) from small transplants derived for instance from cord blood. Culture-expanded MSC produce a wide variety and quantity of Wnt-proteins and the crucial role of Wnt-signaling in the hematopoietic stem cell niche is well established. However, studies addressing Wnt-signaling in MSC have (i) only focused on culture-expanded MSC and (ii) did not discriminate between phenotypically distinct subpopulations which are present in bulk cultures of expanded MSC. Recently we identified three new subpopulations of MSC in human bone marrow (BM) based on expression of CD271 and CD146: CD271brightCD146−, CD271brightCD146+, CD271−CD146+. These fractions co-express the “classical” MSC markers CD90 and CD105 and lack expression of CD45 and CD34 (Maijenburg et al, Blood 2010, 116, 2590). We and others demonstrated that the adult BM-derived CD271brightCD146− and CD271brightCD146+ cells contain all colony forming units-fibroblasts (Maijenburg et al, Blood 2010, 116, 2590; Tormin et al, Blood 2010, 116, 2594). To investigate how these primary subsets functionally compare to conventional, culture-expanded MSC, we investigated their Wnt-signature and hematopoietic support capacity. To this end, we sorted CD271brightCD146− and CD271brightCD146+ cells from human adult BM (n=3) and compared their Wnt-signatures obtained by Wnt-PCR array to the profiles from cultured MSC from the same donors. Fifteen genes were consistently differentially expressed in the two sorted uncultured subsets compared to their conventionally cultured counterparts. Expression of CCND1, WISP1 and WNT5B was strongly increased, and WNT5A was only detected in the conventionally cultured MSC. In contrast, WNT3A was exclusively expressed by sorted primary CD271brightCD146− and CD271brightCD146+ cells, that also expressed higher levels of JUN, LEF1 and WIF1. The differences in Wnt (target)-gene expression between CD271brightCD146− and CD271brightCD146+ cells were more subtle. The Wnt-receptors LRP6 and FZD7 were significantly higher expressed in CD271brightCD146+ cells, and a trend towards increased expression in the same subset was observed for CTNNB1, WNT11 and MYC. When the sorted subsets were cultured for 14 days (one passage), the differences in Wnt-related gene expression between the subsets was lost and the expanded sorted cells acquired an almost similar Wnt-signature as the MSC cultured from BM mononuclear cells from the same donors. The cultured subsets lost the expression of Wnt3a and gained the expression of Wnt5a, similar to the unsorted MSC cultured from the same donors in parallel. Despite the loss of a distinct Wnt-signature, co-culture experiments combining the sorted MSC subsets with human HSPC revealed that CD271brightCD146+ cells have a significantly increased capacity to support HSPC in short-term co-cultures (2 weeks) compared to CD271brightCD146− cells (p<0.021, n=3), which was analyzed in hematopoietic colony assays following co-culture. In contrast, a trend towards better long-term hematopoietic support (co-culture for 6 weeks) was observed on CD271brightCD146− cells. In conclusion, we demonstrate for the first time that primary sorted uncultured MSC subsets have a distinct Wnt-signature compared to cultured unsorted MSC and display differences in hematopoietic support. As it was recently shown that CD271brightCD146− and CD271brightCD146+ MSC localize to separate niches in vivo (Tormin et al, Blood 2011), our data indicate that the two MSC subsets are not necessarily distinct cell types and that the different Wnt-signature may be a reflection of these distinct microenvironments. Cell culturing for only one passage dramatically changed the Wnt-signature of the sorted MSC subsets, indicating that Wnt-signaling in in vitro expanded MSC does not resemble the Wnt-signature in their tissue resident counterparts in vivo. Disclosures: No relevant conflicts of interest to declare.

Colony-Forming Unit Cell (CFU-C) Assays in Myelodysplastic Syndrome

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2874-2874
Author(s):  
Bing Li ◽  
Jinqin Liu ◽  
Shiqiang Qu ◽  
Robert Peter Gale ◽  
Ruixian Xing ◽  
...  
Keyword(s):  
Overall Survival ◽  
Scoring System ◽  
Conflicts Of Interest ◽  
Unit Cell ◽  
International Prognostic Scoring System ◽  
Hematopoietic Stem ◽  
Colony Forming Unit ◽  
Significant Difference

Abstract Introduction: The myelodysplastic syndromes (MDS) are a group of clonal diseases derived from hematopoietic stem cells (HSC). Colony-forming unit cell (CFU-C) assay is an effective method to study the number and the function of HSC in vitro. In this study, we focus on the characteristics and the prognostic value of CFU-C in patients with MDS. Patients and Method: CFU-C assays were performed according to the protocol of MethoCultTM H4435 Enriched (STEMCELL Technologies). A colony was defined as an aggregate of >40 cells. Clusters consisted of 4 to 40 cells. 560 consecutive newly-diagnosed, untreated subjects with MDS diagnosed from March, 2001 to April, 2013 were studied. All subjects were reclassified according to the 2008 WHO criteria. 535 subjects with evaluable cytogenetics were classified using the International Prognostic Scoring System (IPSS) and the revised International Prognostic Scoring System (IPSS-R) criteria. Follow-up data were available for 470£¨84%£©subjects. Median follow-up of survivors was 26 months (range, 1-170) months. Subjects receiving an allotransplants were censored in survival analyses. Erythroid and myeloid colonies were isolated from each subject with one cytogenetic abnormality such as del(5/5q-) or +8. Cytogenetic abnormalities of each colony were analyzed by fluorescence in situ hybridization (FISH). SPSS 17.0 software was used to make statistical analysis. Results: Frequencies of burst-forming units-erythroid (BFU-E), colony forming unit-erythroid (CFU-E) and colony forming unit-granulocytes/macrophages (CFU-G/M) were significantly lower than normals (P<0.05) (Table 1). Subjects classified as lower risk in IPSS and IPSS-R had significantly higher numbers of BFU-E and CFU-E (P<0.05) but similar numbers CFU-G/M and clusters-G/M compared with higher risk subjects (Table 2). In 11 subjects with del(-5/5q-) or +8 identified by G- and/or R-banding, both normal and abnormal CFU-Cs were identified in 8 subjects studied by FISH. A high ratio of cluster- to CFU-G/M (>0.6) was associated with poor-risk cytogenetics (Table 2) and with worse overall survival in univariable (Figure 1, P=0.001) and multivariable analyses (HR 1.748, [1.01-3.0]; P=0.046) after adjusting for IPSS. Conclusions: These data suggest abnormalities of proliferation and differentiation of erythroid and myeloid precursor cells in vitro parallel the ineffective hematopoiesis typical of MDS and may be useful in predicting outcomes of patients with MDS. Table 1. CFU-C in MDS subtypes N BFU-E CFU-E CFU-G/M N Ratio of cluster- to CFU-G/M RA 21 8 (0-44) 40 (0-134) 14 (0-127)1 6 0.25 (0.40-1.00) RT 4 18 (4-55) 75 (60-90)1 30 (18-70)1 2 2 RARS 27 12 (0-33) 35 (1-140) 12 (0-70)1 10 0.45 (0.17-0.80) RCMD 275 10 (0-80) 33 (0-178) 14 (0-100) 126 0.35 (0-0.83) RAEB1 112 10 (0-258) 32 (0-312) 14 (0-89) 53 0.47 (0-1.00) RAEB2 103 9 (0-46) 25 (0-120) 13 (0-72) 42 0.37 (0-1.00) MDS-U 15 4 (0-58) 25 (0-161) 10 (0-43) 3 2 Del(5q) 3 2 (2-4) 15 (0-20) 5 (5-41)1 1 2 1No significant difference compared with normals. 2Too few cases to analyze. Table 2. Associations between CFU-C and clinical and laboratory variables N BFU-E P CFU-E P CFU-G/M P Number Ratio of cluster- to CFU-GM P IPSS 0.064 0.006 0.361 0.089 Low 30 13 (0-44) 60 (0-169) 19 (0-45) 10 0.44 (0.24-0.70) Int-1 361 10 (0-258) 33 (0-312) 14 (0-127) 150 0.33 (0-1.00) Int-2 115 9 (0-61) 30 (0-137) 14 (0-72) 52 0.45 (0-1.00) High 29 7 (0-34) 21 (0-93) 12 (0-67) 12 0.44 (0-1.00) IPSS-R 0.003 0.003 0.125 0.209 Very low 7 16 (9-25) 30 (15-120) 18 (5-33) 2 0.29 (0.10-0.49) Low 130 14 (0-80) 42 (0-178) 17 (0-70) 48 0.31 (0-0.77) Intermediate 173 10 (0-66) 34 (0-161) 13 (0-127) 81 0.37 (0-1.00) High 139 9 (0-259) 29 (0-312) 11 (0-89) 51 0.33 (0-1.00) Very high 86 8 (0-61) 25 (0-137) 14 (0-91) 42 0.47 (0-1.00) Cytogenetics (IPSS) 0.867 0.055 0.290 0.007 Good 327 10 (0-258) 36 (0-312) 15 (0-89) 133 0.33 (0-1.00) Intermediate 133 10 (0-69) 30 (0-162) 12 (0-127) 63 0.45 (0-1.00) Poor 75 10 (0-61) 25 (0-137) 14 (0-91) 28 0.42 (0-1.00) Cytogenetics (IPSS-R) 0.990 0.090 0.676 0.022 Very good 7 11 (4-20) 48 (1-110) 14 (8-28) 2 0.49 (0.43-0.56) Good 324 10 (0-258) 35 (0-312) 15 (0-89) 132 0.33 (0-1.00) Intermediate 129 10 (0-69) 30 (0-162) 12 (0-127) 62 0.45 (0-1.00) Poor 27 10 (0-61) 35 (0-137) 16 (0-48) 8 0.36 (0.15-1.00) Very poor 48 11 (0-42) 22 (0-120) 14 (0-91) 20 0.53 (0-1.00) Figure 1. Overall survival in subjects with cluster- to CFU-G/M ratios ¡Ü or > 60%. Figure 1. Overall survival in subjects with cluster- to CFU-G/M ratios ¡Ü or > 60%. Disclosures No relevant conflicts of interest to declare.

scholarly journals Decreased Expression of PPARγ mRNA in Patients Correlates with aGVHD after Allo-HSCT

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 5776-5776
Author(s):  
Xiaojin Wu ◽  
Jubin Zhang ◽  
Shoubao Ma ◽  
Yuhan Ji ◽  
Shuangzhu Liu ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Hormone Receptors ◽  
Mononuclear Cells ◽  
Conflicts Of Interest ◽  
Ppar Gamma ◽  
Healthy Controls ◽  
Peripheral Blood Mononuclear ◽  
Hematopoietic Stem ◽  
Significant Difference

Abstract Background and objective: Peroxisome proliferator-activated receptor (PPAR)-gamma(γ) is a member of superfamily of nuclear hormone receptors and involved in the lipids metabolism, adipocyte differentiation, atherosclerosis and anti-inflammation. The role of PPARγ in acute graft versus host disease (aGVHD ) remains unclear. In this study, we aimed to investigate the role of PPARγ during aGVHD after allogenic hematopoietic stem cell transplantation (allo-HSCT ). Methods: 50 patients undering allo-HSCT and 20 healthy controls were enrolled in study. Peripheral blood (PB) of patients 30 days, 60 days, and 90 days were collected after allo-HSCT. We also collected PB samples at aGVHD onset and after aGVHD remission. Peripheral blood mononuclear cells (PBMCs) were isolated for real-time PCR to detect the mRNA expression of PPARγ, IFNγ, IL4, T-bet, GATA3, Foxp3, RORγt . Results: Expression of PPARγmRNA in healthy controls were significant lower than that in patients after allo-HSCT(P<0.05). At the onset of aGVHD, the expression of PPARγmRNA was significantly lower than that in non-GVHD and increased when remission (P<0.05). PPARγexpression in severe aGVHD (grade 3 to 4) was lower than mild aGVHD (grade 1 to 2) patients (P<0.05). Gender, age, graft type, and the kind of disease showed no significant difference in the aGVHD and non-GVHD patients. The expression of IFNγ and T-bet increased after aGVHD and were negatively correlated with PPARγmRNA expression. Conclusion: Our findings suggest that low expression of PPARγ is associated with aGVHD occurrence. PPARγ may be a useful indicator to predict aGVHD and follow-up. Disclosures No relevant conflicts of interest to declare.

Stromal Cell Regulation of Murine Hematopoietic Stem Cells.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 1566-1566
Author(s):  
Stefan Wohrer ◽  
Keegan Rowe ◽  
Heidi Mader ◽  
Claudia Benz ◽  
Michael R Copley ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Stromal Cell ◽  
Cultured Cells ◽  
Conflicts Of Interest ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Daughter Cells

Abstract Abstract 1566 Recent advances in purifying murine hematopoietic stem cells (HSCs) to near homogeneity (>20%) have made it possible to analyze their in vivo clonal growth, self-renewal and differentiation properties over prolonged periods and the effects of various manipulations on these key functional parameters. However, conditions that allow genetically unaltered HSCs to maintain their original functional properties over equivalent periods of prolonged proliferation in vitro have not yet been identified. Since initial studies showed that the UG26 stromal cell could support murine HSC maintenance for limited periods, we first asked whether the addition of cytokines that also maintain HSCs for short periods might synergize with UG26 cells to enable HSC expansion to occur. Limiting dilution transplants that used a 6-month read-out of reconstituted blood elements (>1%) showed that the addition of 100 ng/ml Steel Factor (SF) and 20 ng/ml IL-11 to cultures containing UG26 cells and single purified (50%) HSCs (EPCR+CD150+CD48-, ESLAM cells) consistently stimulated a 3–5 fold HSC expansion after 7 days (3 expts). Furthermore, the effect of the UG26 cells could be replaced by UG26 conditioned medium (CM) and, in the presence of the CM+SF/IL-11 cocktail, the HSCs showed sustained longterm in vivo lympho-myeloid reconstituting activity in both primary and secondary recipients. Under these conditions, every ESLAM cell isolated proliferated several times within 7 days, but individual analysis of paired daughter cells showed that most first divisions (13/42) were, nevertheless, asymmetrical in terms of the numbers and types of different lineages produced by each of the 2 daughter cells for at least 4 months, although occasional evidence of symmetry was obtained (2/42 divisions). Interestingly, these first divisions showed a biphasic curve with 75% of the cells dividing before and 25% after 48 hours - the late dividers being more highly enriched for HSCs (95% vs 20%). We next asked whether TGF-β might be an important factor in UG26 CM, since UG26 cells exert a strong cell cycle inhibitory effect, and produce abundant TGF-beta. Accordingly, we next analyzed the effect of adding a neutralizing anti-TGF-β antibody or replacing the CM with TGF-β in the same type of single HSC cultures by tracking the survival and division kinetics of the cells as well as measuring the repopulating activity of their in vitro progeny present after 7 days. Strikingly, the addition of anti-TGF-β to the CM+SF/IL-11 supplemented HSC cultures eliminated the late wave of first cell divisions and caused an accompanying loss of myeloid reconstituting ability in recipients transplanted with the cultured cells. Conversely, replacement of the CM with TGF-β restored a biphasic division kinetics curve to cultures supplemented with SF/IL-11 but no CM. However, this did not protect against the early 50% loss of cells by apoptosis. These findings provide evidence of a new role of TGF-β in preserving the integrity of HSC functionality in vitro, but suggest a requirement for other types of factors released by certain stromal cells to achieve sustained symmetrical HSC self-renewal in vitro. Disclosures: No relevant conflicts of interest to declare.

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