scholarly journals CXCR6 Expression Is Important for Retention and Circulation of ILC Precursors

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
Sylvestre Chea ◽  
Cécilie Possot ◽  
Thibaut Perchet ◽  
Maxime Petit ◽  
Ana Cumano ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Fetal Liver ◽  
Lymphoid Cells ◽  
Reporter Mice ◽  
Heterogeneous Expression ◽  
Embryonic Life ◽  
Partial Retention

Innate lymphoid cells are present at mucosal sites and represent the first immune barrier against infections, but what contributes to their circulation and homing is still unclear. UsingRag2−/−Cxcr6Gfp/+reporter mice, we assessed the expression and role of CXCR6 in the circulation of ILC precursors and their progeny. We identify CXCR6 expressing ILC precursors in the bone marrow and characterize their significant increase in CXCR6-deficient mice at steady state, indicating their partial retention in the bone marrow after CXCR6 ablation. Circulation was also impaired during embryonic life as fetal liver from CXCR6-deficient embryos displayed decreased numbers of ILC3 precursors. When injected, fetal CXCR6-deficient ILC3 precursors also fail to home and reconstitute ILC compartmentsin vivo. We show that adult intestinal ILC subsets have heterogeneous expression pattern of CXCR6, integrinα4β7, CD62L, CD69, and CD44, with ILC1 and ILC3 being more likely tissue resident lymphocytes. Intestinal ILC subsets were unchanged in percentages and numbers in both mice. We demonstrate that the ILC frequency is maintained due to a significant increase of ILC peripheral proliferation, as well as an increased proliferation of thein situILC precursors to compensate their retention in the bone marrow.

scholarly journals Bcl11b is essential for group 2 innate lymphoid cell development

2015 ◽  
Vol 212 (6) ◽  
pp. 875-882 ◽  
Author(s):  
Jennifer A. Walker ◽  
Christopher J. Oliphant ◽  
Alexandros Englezakis ◽  
Yong Yu ◽  
Simon Clare ◽  
...  
Keyword(s):  
Fetal Liver ◽  
Lymphoid Cells ◽  
Nippostrongylus Brasiliensis ◽  
Reporter Mice ◽  
Mucosal Surfaces ◽  
Gfp Reporter ◽  
Worm Expulsion ◽  
Group 2 ◽  
Cell Commitment

Group 2 innate lymphoid cells (ILC2s) are often found associated with mucosal surfaces where they contribute to protective immunity, inappropriate allergic responses, and tissue repair. Although we know they develop from a common lymphoid progenitor in the bone marrow (BM), the specific lineage path and transcriptional regulators that are involved are only starting to emerge. After ILC2 gene expression analysis we investigated the role of Bcl11b, a factor previously linked to T cell commitment, in ILC2 development. Using combined Bcl11b-tom and Id2-gfp reporter mice, we show that Bcl11b is expressed in ILC2 precursors in the BM and maintained in mature ILC2s. In vivo deletion of Bcl11b, by conditional tamoxifen-induced depletion or by Bcl11b−/− fetal liver chimera reconstitution, demonstrates that ILC2s are wholly dependent on Bcl11b for their development. Notably, in the absence of Bcl11b there is a concomitant expansion of the RORγt+ ILC3 population, suggesting that Bcl11b may negatively regulate this lineage. Using Nippostrongylus brasiliensis infection, we reveal that the absence of Bcl11b leads to impaired worm expulsion, caused by a deficit in ILC2s, whereas Citrobacter rodentium infection is cleared efficiently. These data clearly establish Bcl11b as a new factor in the differentiation of ILC2s.

scholarly journals Osteal Macrophages and Megakaryocytes Increase Adipogenesis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Nikhil Tewari ◽  
Deepa Kanagasabapathy ◽  
Rachel J. Blosser ◽  
Edward F. Srour ◽  
Angela Bruzzaniti ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Cell Sorting ◽  
Fetal Liver ◽  
Fold Increase ◽  
Wild Type ◽  
Bone Marrow Adipose Tissue ◽  
New Treatments

Bone marrow adipose tissue (MAT) increases with aging and contributes to low bone density and skeletal fractures. However, the cells and factors within the bone marrow (BM) that regulate adipogenesis remain poorly understood. In the current study, we examined the role of osteal macrophages (OMs) and megakaryocytes (MKs) on the regulation of adipogenesis. We cultured murine osteoblasts/osteoblast progenitors (OBs from hereon) derived from neonatal calvarial cells (CCs, a combination of OBs and OMs) or OBs isolated by fluorescence activated cell sorting (FACS) in the presence or absence of fetal liver derived murine MK. The cells underwent induced adipogenesis for 5-7 days by supplementation of media with insulin, indomethacin, and dexamethasone, and then the number of adipocytes was quantified.   We found that co-culturing MKs and OMs with OBs results in up to a 7.8-fold and 11.7-fold increase in adipocytes, respectively. We also elucidated that thrombopoietin (TPO), the major growth factor for MKs, inhibits adipogenesis in both OBs and CCs by approximately 60%. Similarly, we found that CCs and OBs derived from mice deficient in the TPO receptor, Mpl, had approximately 30% more adipocytes than their wild-type (WT) counterparts. Finally, in vitro findings were corroborated in vivo through quantification of MKs and adipocytes in mice in which MK number was elevated or reduced. Mice with significantly higher numbers of BM-residing MKs also had significantly higher numbers of BM-residing adipocytes. Because there is typically an inverse relationship between adipogenesis and osteogenesis, understanding ways to inhibit adipogenesis could lead to an increase in OB number and bone formation, which in turn could lead to new treatments for bone loss diseases such as osteoporosis.

A novel bone marrow frozen section assay for studying hematopoietic interactions in situ: the role of stromal bone marrow macrophages in erythroblast binding

1996 ◽  
Vol 109 (12) ◽  
pp. 2937-2945
Author(s):  
E. Barbe ◽  
I. Huitinga ◽  
E.A. Dopp ◽  
J. Bauer ◽  
C.D. Dijkstra
Keyword(s):  
Bone Marrow ◽  
Frozen Section ◽  
Differentiation Antigen ◽  
Intimate Contact ◽  
Neuraminidase Treatment ◽  
Antigen Present ◽  
Selective Depletion

Bone marrow macrophages are found in intimate contact with erythroblasts. Exact mechanisms and functions of this interaction are unclear. New insights into erythroblast binding were obtained using a newly developed bone marrow frozen section assay. This modified Woodruff and Stamper assay has some important advantages compared to other adhesion assays. Erythroblasts specifically adhered to bone marrow macrophages forming clusters, as appear in vivo. Selective depletion of bone marrow macrophages by intravenous injection of dichloromethyl-enediphosphonate resulted in a release of immature erythroid cells to the peripheral blood. Furthermore no erythroblasts adhered to bone marrow sections without macrophages. Evaluating the binding of erythroblasts to bone marrow macrophages we found that this binding is temperature and cation dependent. The receptor for erythroblasts present on macrophages recognizes a sialyated protein as ligand on erythroblasts, since neuraminidase treatment of erythroblasts resulted in a decrease in binding. A possible candidate for the erythroblast receptor on macrophages is the ED2 antigen. ED2 is a differentiation antigen present on resident macrophages that has some biochemical features characteristic of an adhesion molecule. Erythroblast binding to bone marrow was inhibited using a monoclonal antibody directed against ED2.

scholarly journals Role of bcl-2 in the Development of Lymphoid Cells From the Hematopoietic Stem Cell

Blood ◽  
1997 ◽  
Vol 89 (3) ◽  
pp. 853-862 ◽  
Author(s):  
Yumi Matsuzaki ◽  
Kei-ichi Nakayama ◽  
Keiko Nakayama ◽  
Takashi Tomita ◽  
Miu Isoda ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Hematopoietic Stem Cell ◽  
Fetal Liver ◽  
Lymphoid Cells ◽  
Mouse Bone Marrow ◽  
Chimeric Mouse ◽  
Hematopoietic Stem

Abstract To investigate the role of bcl-2 in lymphohematopoiesis, a long-term bone marrow reconstitution system was established. Transplantation of 1,000 c-Kit+ Sca-1+ and lineage markers negative cells from bcl-2−/− mouse bone marrow resulted in long-term reconstitution of nonlymphoid cells. However, T cells were totally absent and B-lymphocyte development was severely impaired at a very early stage of differentiation in the chimeric mouse. On the other hand, transplantation of day 14 fetal liver cells from bcl-2−/− mice resulted in generation of both T and B cells in the recipient, albeit transiently. These data suggest that bcl-2 plays a critical role in the development of lymphoid progenitor cells from the hematopoietic stem cell (HSC), but is not essential for the development of nonlymphoid cells and the self-renewal of HSC. In addition, lymphopoiesis from fetal liver HSC appears to be less dependent on bcl-2 than adult bone marrow HSC.

scholarly journals Posttranslational Modification in Megakaryocytes Regulates β1 Integrin Expression, Migration and Platelet Production in Vivo

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1435-1435
Author(s):  
Silvia Giannini ◽  
Max Adelman ◽  
Antonija Jurak Begonja ◽  
Karin M Hoffmeister
Keyword(s):  
Bone Marrow ◽  
Posttranslational Modification ◽  
Fetal Liver ◽  
Marrow Transplant ◽  
Β1 Integrin ◽  
Integrin Expression ◽  
Platelet Recovery ◽  
Platelet Production

Abstract Platelet recovery following bone marrow transplant and radiochemotherapy is crucial to prevent bleeding complications. Defects in glycosylation have been associated with decrease in blood platelet counts. However, the role of posttranslational modification in platelet production remains elusive. We here investigated the role of β1,4 galactosyltransferase 1 (β4GalT1), the key glycosyltransferase regulating lactosaminoglycan (LacNAc or βGal1,4 GlcNAc) expression by adding galactose (Gal) to terminal N-acetylglucosamine (GlcNAc), in platelet production. Stromal cell-derived factor 1 (SDF-1), but not thrombopoietin promotes megakaryocyte (MK) migration towards the bone marrow sinusoids, thereby increasing platelet production. SDF-1 (CXCL12) upregulated LacNAc expression in fetal liver wild type (WT), but not β4galt1-null megakaryocytes (MKs) lacking β4GalT1, suggesting that SDF-1 promotes LacNAc expression in vivo to regulate MK migration and platelet production. In support of this hypothesis, β4galt1-null mice had severe macrothrombocytopenia with increased bone marrow MK numbers, but normal platelet clearance. Ploidy, expression of the major glycoproteins (GPIbα/V/IX and αIIbβ3) and the surface expression of the SDF-1 receptor CXCR4 were normal in β4galt1-null bone marrow MKs. However, β4galt1-null bone marrow MKs had increased surface and total β1 integrin expression, as determined by flow cytometry, immunoblot and immunofluorescence. Mature CD42b/CD41 positive β4galt1-null MKs co-localized poorly with endoglin positive bone marrow sinusoids (49.9 ± 2.1 %), compared to WT MKs (72.4 ± 0.6 %). Expression of laminin, the major β1 integrin ligand, was upregulated in β4galt1-null MKs, suggesting that loss of LacNAc expression on β1 integrin increased its function. To exclude an extrinsic contribution to the failure of β4galt1-null MKs to migrate, β4galt1-null fetal liver (E14.5) hematopoietic cells (FLHCs) were transplanted in lethally irradiated WT mice. Transplanted β4galt1-null FLHCs restored bone marrow MKs, but failed to migrate to sinusoids and produce circulating platelets. In marked contrast, production of β4galt1-null white blood cells was normal. Together, our results suggest that SDF-1 upregulates β4GalT1-dependent LacNAc expression to promote MK migration and interaction with BM sinusoids, likely regulating MK β1 integrin expression and interaction with components of the extracellular matrix, specifically laminin. Understanding of the mechanisms regulating posttranslational modifications induced by various hematopoietic stimulating chemokines and cytokines will contribute to better platelet recovery following bone marrow transplant and radiochemotherapy. Disclosures No relevant conflicts of interest to declare.

Abstract 11664: The Identification and Hierarchy of Bone Marrow-Derived Artery-Resident Mesodermal Progenitor Cells and Their Dynamics in Atherosclerosis

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Hyun-Jai Cho ◽  
Hyun-Ju Cho ◽  
Yoo-Wook Kwon ◽  
Young-Bae Park ◽  
Hyo-Soo Kim
Keyword(s):  
Bone Marrow ◽  
Progenitor Cells ◽  
Peripheral Circulation ◽  
Humoral Factors ◽  
Cell Property ◽  
Apoe Ko Mice ◽  
Multiplex Cytokine ◽  
Developmental Hierarchy

Background: We recently identified bone marrow (BM)-derived artery resident calcifying progenitor cells. Sca-1+PDGFRα- cells may possess bipotent (osteoblastic/osteoclastic) characteristics. However, the nature of progenitor cells remains elusive. Hypothesis: We investigated developmental hierarchy of progenitor cells and in vivo dynamics in atherosclerosis. Methods and Results: We harvested cells from BM and artery of C57 mice. In BM, Lin-CD29+Sca-1+PDGFRα- cells showed hematopoietic potential and differentiated into osteoclasts (OC). They also possessed mesenchymal stem cell property including osteoblastic (OB) differentiation, suggesting that Sca-1+PDGFRα- cells could be mesodermal progenitor cells. Interestingly, BM-derived artery-resident, clonal Sca-1+PDGFRα- cells maintained bipotency but lost hematopoietic nature. In contrast, Sca-1+PDGFRα+ cells in BM and artery only showed unipotency (OB). When we overexpressed or knocked down PDGFRα, there was no alteration in OB or OC differentiation of Sca-1+PDGFRα- cells and no effect on OB differentiation of Sca-1+PDGFRα+ cells, indicating PDGFRα as a surface marker but not a functional player. In hyperlipidemic ApoE-KO mice compared with control, Sca-1+PDGFRα- cells were less mobilized from BM to peripheral circulation and less infiltrated into atherosclerotic plaque, whereas Sca-1+PDGFRα+ cells were not significantly affected. Multiplex cytokine assay of serum and artery revealed that IL-1β was significantly increased and IL-5 was markedly decreased in atherosclerotic mice. IL-1β decreased the migration of Sca-1+PDGFRα- cells by 5 folds compared with TNFα, and IL-5 increased the migration as much as TNFα. But the migration of Sca-1+PDGFRα+ cells was not altered. These data indicate that atherosclerosis-related humoral factors mainly regulated mesodermal progenitor cells’ dynamics. Conclusion: We demonstrate that Sca-1+PDGFRα- cell is a mesodermal progenitor cell that possesses both hematopoietic and mesenchymal potentials. In atherogenesis, the mobilization and infiltration of Sca-1+PDGFRα- progenitor cells were regulated by IL-1β and IL-5. These data provide a novel mechanism regarding the role of bipotent progenitor cells in atherosclerosis.

scholarly journals Effects of Nrf2 Deficiency on Bone Microarchitecture in an Experimental Model of Osteoporosis

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Lidia Ibáñez ◽  
María Luisa Ferrándiz ◽  
Rita Brines ◽  
David Guede ◽  
Antonio Cuadrado ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Bone Marrow ◽  
Bone Metabolism ◽  
Bone Microarchitecture ◽  
Related Factor ◽  
Mineral Density ◽  
Trabecular Bone Mineral Density ◽  
Bone Marrow Derived Cells

Objective. Redox imbalance contributes to bone fragility. We have evaluated the in vivo role of nuclear factor erythroid derived 2-related factor-2 (Nrf2), an important regulator of cellular responses to oxidative stress, in bone metabolism using a model of postmenopausal osteoporosis.Methods. Ovariectomy was performed in both wild-type and mice deficient in Nrf2 (Nrf2−/−). Bone microarchitecture was analyzed byμCT. Serum markers of bone metabolism were also measured. Reactive oxygen species production was determined using dihydrorhodamine 123.Results. Sham-operated or ovariectomized Nrf2−/−mice exhibit a loss in trabecular bone mineral density in femur, accompanied by a reduction in cortical area in vertebrae. Nrf2 deficiency tended to increase osteoblastic markers and significantly enhanced osteoclastic markers in sham-operated animals indicating an increased bone turnover with a main effect on bone resorption. We have also shown an increased production of oxidative stress in bone marrow-derived cells from sham-operated or ovariectomized Nrf2−/−mice and a higher responsiveness of bone marrow-derived cells to osteoclastogenic stimuli in vitro.Conclusion. We have demonstrated in vivo a key role of Nrf2 in the maintenance of bone microarchitecture.

The Role of Microbiology in Models of Dental Caries: Reaction Paper

1995 ◽  
Vol 9 (3) ◽  
pp. 255-269 ◽  
Author(s):  
G.H. Bowden
Keyword(s):  
Process Selection ◽  
Advantages And Disadvantages ◽  
Test Models ◽  
Plaque Development ◽  
In Vitro Systems ◽  
Selection Of

Models of the caries process have made significant contributions toward defining the roles of bacteria in caries. Microbiologists use a variety of in vitro systems to model aspects of the caries process. Also, in situ models in humans provide information on the microbiology of caries in vivo. These models do not involve the entire process leading to natural caries; consequently, the results from such studies are used to deduce the roles of bacteria in natural caries. Therefore, they can be described as Inferential Caries Models. In contrast, animal models and some clinical trials in humans involve natural caries and can be described as Complete Caries Models. Furthermore, these models are used in two distinct ways. They can be used as Exploratory Models to explore different aspects of the caries process, or as Test Models to determine the effects of anticaries agents. This dichotomy in approach to the use of caries models results in modification of the models to suit a particular role. For example, if we consider Exploratory Models, the in situ appliance in humans is superior to others for analyzing the microbiology of plaque development and demineralization in vivo. The chemostat and biofilm models are excellent for exploring factors influencing bacterial interactions. Both models can also be used as Test Models. The in situ model has been used to test the effects of fluoride on the microflora and demineralization, while the chemostat and biofilm models allow for the testing of antibacterial agents. Each model has its advantages and disadvantages and role in analysis of the caries process. Selection of the model depends on the scientific question posed and the limitations imposed by the conditions available for the study.

Carbonic anhydrase in the midgut of larvalAedes aegypti: cloning, localization and inhibition

2002 ◽  
Vol 205 (5) ◽  
pp. 591-602 ◽  
Author(s):  
Maria del Pilar Corena ◽  
Theresa J. Seron ◽  
Herm K. Lehman ◽  
Judith D. Ochrietor ◽  
Andrea Kohn ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Aedes Aegypti ◽  
Fruit Fly ◽  
Cellular Heterogeneity ◽  
Carbonic Anhydrases ◽  
Larval Midgut ◽  
Posterior Midgut

SUMMARYThe larval mosquito midgut exhibits one of the highest pH values known in a biological system. While the pH inside the posterior midgut and gastric caeca ranges between 7.0 and 8.0, the pH inside the anterior midgut is close to 11.0. Alkalization is likely to involve bicarbonate/carbonate ions. These ions are produced in vivo by the enzymatic action of carbonic anhydrase. The purpose of this study was to investigate the role of this enzyme in the alkalization mechanism, to establish its presence and localization in the midgut of larval Aedes aegypti and to clone and characterize its cDNA. Here, we report the physiological demonstration of the involvement of carbonic anhydrase in midgut alkalization. Histochemistry and in situ hybridization showed that the enzyme appears to be localized throughout the midgut, although preferentially in the gastric caeca and posterior regions with specific cellular heterogeneity. Furthermore, we report the cloning and localization of the first carbonic anhydrase from mosquito larval midgut. A cDNA clone from Aedes aegypti larval midgut revealed sequence homology to α-carbonic anhydrases from vertebrates. Bioinformatics indicates the presence of at least six carbonic anhydrases or closely related genes in the genome of another dipteran, the fruit fly Drosophila melanogaster. Molecular analyses suggest that the larval mosquito may also possess multiple forms.

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