CYP2C9-Catalyzed Metabolism of S-Warfarin to 7-Hydroxywarfarin in Vivo and in Vitro in Chimeric Mice with Humanized Liver

2008 ◽  
Vol 36 (12) ◽  
pp. 2429-2433 ◽  
Author(s):  
Tae Inoue ◽  
Kayoko Nitta ◽  
Kazumi Sugihara ◽  
Toru Horie ◽  
Shigeyuki Kitamura ◽  
...  
Keyword(s):  
Chimeric Mice

scholarly journals Chimeric Mice with Humanized Livers: A Unique Tool for in Vivo and in Vitro Enzyme Induction Studies

2013 ◽  
Vol 15 (1) ◽  
pp. 58-74 ◽  
Author(s):  
Masakazu Kakuni ◽  
Chihiro Yamasaki ◽  
Asato Tachibana ◽  
Yasumi Yoshizane ◽  
Yuji Ishida ◽  
...  
Keyword(s):  
Enzyme Induction ◽  
Chimeric Mice

scholarly journals Temporally chimeric mice reveal flexibility of circadian period-setting in the suprachiasmatic nucleus

2016 ◽  
Vol 113 (13) ◽  
pp. 3657-3662 ◽  
Author(s):  
Nicola J. Smyllie ◽  
Johanna E. Chesham ◽  
Ryan Hamnett ◽  
Elizabeth S. Maywood ◽  
Michael H. Hastings
Keyword(s):  
Gene Expression ◽  
Suprachiasmatic Nucleus ◽  
Feedback Loops ◽  
Chimeric Mice ◽  
Pacemaker Cells ◽  
Daily Behavior ◽  
New Perspective ◽  
Circadian Behavior

The suprachiasmatic nucleus (SCN) is the master circadian clock controlling daily behavior in mammals. It consists of a heterogeneous network of neurons, in which cell-autonomous molecular feedback loops determine the period and amplitude of circadian oscillations of individual cells. In contrast, circuit-level properties of coherence, synchrony, and ensemble period are determined by intercellular signals and are embodied in a circadian wave of gene expression that progresses daily across the SCN. How cell-autonomous and circuit-level mechanisms interact in timekeeping is poorly understood. To explore this interaction, we used intersectional genetics to create temporally chimeric mice with SCN containing dopamine 1a receptor (Drd1a) cells with an intrinsic period of 24 h alongside non-Drd1a cells with 20-h clocks. Recording of circadian behavior in vivo alongside cellular molecular pacemaking in SCN slices in vitro demonstrated that such chimeric circuits form robust and resilient circadian clocks. It also showed that the computation of ensemble period is nonlinear. Moreover, the chimeric circuit sustained a wave of gene expression comparable to that of nonchimeric SCN, demonstrating that this circuit-level property is independent of differences in cell-intrinsic periods. The relative dominance of 24-h Drd1a and 20-h non-Drd1a neurons in setting ensemble period could be switched by exposure to resonant or nonresonant 24-h or 20-h lighting cycles. The chimeric circuit therefore reveals unanticipated principles of circuit-level operation underlying the emergent plasticity, resilience, and robustness of the SCN clock. The spontaneous and light-driven flexibility of period observed in chimeric mice provides a new perspective on the concept of SCN pacemaker cells.

scholarly journals Detection of acute toxicity of aflatoxin B1 to human hepatocytes in vitro and in vivo using chimeric mice with humanized livers

PLoS ONE ◽  
2020 ◽  
Vol 15 (9) ◽  
pp. e0239540
Author(s):  
Yuji Ishida ◽  
Chihiro Yamasaki ◽  
Hiroko Iwanari ◽  
Hisahiko Yamashita ◽  
Yuko Ogawa ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Aflatoxin B1 ◽  
Human Hepatocytes ◽  
Chimeric Mice

scholarly journals A requirement for Notch1 distinguishes 2 phases of definitive hematopoiesis during development

Blood ◽  
2004 ◽  
Vol 104 (10) ◽  
pp. 3097-3105 ◽  
Author(s):  
Brandon K. Hadland ◽  
Stacey S. Huppert ◽  
Jyotshnabala Kanungo ◽  
Yingzi Xue ◽  
Rulang Jiang ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Fetal Liver ◽  
Es Cells ◽  
Es Cell ◽  
Chimeric Mice ◽  
Developmental Potential ◽  
Definitive Hematopoiesis

Abstract Notch1 is known to play a critical role in regulating fates in numerous cell types, including those of the hematopoietic lineage. Multiple defects exhibited by Notch1-deficient embryos confound the determination of Notch1 function in early hematopoietic development in vivo. To overcome this limitation, we examined the developmental potential of Notch1–/– embryonic stem (ES) cells by in vitro differentiation and by in vivo chimera analysis. Notch1 was found to affect primitive erythropoiesis differentially during ES cell differentiation and in vivo, and this result reflected an important difference in the regulation of Notch1 expression during ES cell differentiation relative to the developing mouse embryo. Notch1 was dispensable for the onset of definitive hematopoiesis both in vitro and in vivo in that Notch1–/– definitive progenitors could be detected in differentiating ES cells as well as in the yolk sac and early fetal liver of chimeric mice. Despite the fact that Notch1–/– cells can give rise to multiple types of definitive progenitors in early development, Notch1–/– cells failed to contribute to long-term definitive hematopoiesis past the early fetal liver stage in the context of a wild-type environment in chimeric mice. Thus, Notch1 is required, in a cell-autonomous manner, for the establishment of long-term, definitive hematopoietic stem cells (HSCs).

Interferon-Gamma Impairs the Self-Renewal of Hematopoietic Stem Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2351-2351
Author(s):  
Alexander M. de Bruin ◽  
Berend Hooibrink ◽  
Martijn A. Nolte
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Hematopoietic Stem Cells ◽  
Interferon Gamma ◽  
Chimeric Mice ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
The Impact

Abstract Abstract 2351 Regulation of hematopoiesis during stress situations, such as bacterial or viral infections, is crucial for the maintenance of sufficient numbers of cells in the blood. It has become clear that activated immune cells provide such feedback signals to the bone marrow. An important mediator in this respect is the pro-inflammatory cytokine Interferon-gamma (IFNγ), which is produced in the bone marrow by activated T cells during the course of an infection. As such, we have previously shown that T cell-derived IFNγ can directly influence the output of myeloid and erythroid cells. To address whether IFNγ can also influence the function of hematopoietic stem cells (HSCs), we cultured highly purified HSCs from murine bone marrow with or without IFNγ and found that IFNγ strongly reduced the absolute number of HSCs in these cultures, both phenotypically and functionally. We confirmed that the functional impact of IFNγ was due to a direct effect on HSCs and not mediated by more differentiated progenitors. In addition, IFNγ does not directly influence the quiescent state of purified HSC, nor their cell cycle entry. By labeling HSCs with CFSE, we found that IFNγ reduces HSC expansion in vitro by decreasing their proliferative capacity, but not their ability to differentiate. To investigate the impact of IFNγ on HSCs in vivo, we infected WT and IFNγ−/− mice with lymphocytic choriomeningitis virus (LCMV) and found that IFNγ severely impaired HSC recovery upon infection. Finally, to exclude indirect effects of IFNγ on other cell types we generated chimeric mice with bone marrow from both WT and IFNγR−/− mice. Infection of these mixed-chimeric mice with LCMV resulted in decreased recovery of WT HSCs, but not of IFNγR−/− HSCs in the same mouse, which formally demonstrates that IFNγ directly impairs the proliferation of HSCs in vivo. Based on these experiments we conclude that IFNγ reduces HSC self renewal both in vitro and in vivo. Importantly, we thereby challenge the current concept in literature that IFNγ would induce the proliferation of HSCs (Baldridge et al, Nature 2010). Our findings thus provide challenging new insight regarding the impact of immune activation on hematopoiesis and will contribute significantly to the scientific discussion concerning this process. Moreover, our data also provide an explanation for the occurrence of anemia and bone marrow failure in several human diseases in which IFNγ is chronically produced. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Genetic analysis of alpha 4 integrin functions in the development of mouse skeletal muscle.

1996 ◽  
Vol 135 (3) ◽  
pp. 829-835 ◽  
Author(s):  
J T Yang ◽  
T A Rando ◽  
W A Mohler ◽  
H Rayburn ◽  
H M Blau ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Muscle Development ◽  
Es Cells ◽  
Embryonic Stem ◽  
Chimeric Mice ◽  
Skeletal Muscle Development ◽  
Gene Encoding ◽  
Pure Cultures

It has been suggested, on the basis of immunolocalization studies in vivo and antibody blocking experiments in vitro, that alpha 4 integrins interacting with vascular cell adhesion molecule 1 (VCAM-1) are involved in myogenesis and skeletal muscle development. To test this proposal, we generated embryonic stem (ES) cells homozygous null for the gene encoding the alpha 4 subunit and used them to generate chimeric mice. These chimeric mice showed high contributions of alpha 4-null cells in many tissues, including skeletal muscle, and muscles lacking any detectable (< 2%) alpha 4-positive cells did not reveal any gross morphological abnormalities. Furthermore, assays for in vitro myogenesis using either pure cultures of alpha 4-null myoblasts derived from the chimeras or alpha 4-null ES cells showed conclusively that alpha 4 integrins are not essential for muscle cell fusion and differentiation. Taking these results together, we conclude that alpha 4 integrins appear not to play essential roles in normal skeletal muscle development.

scholarly journals In a fully H-2 incompatible chimera, T cells of donor origin can respond to minor histocompatibility antigens in association with either donor or host H-2 type.

1978 ◽  
Vol 148 (1) ◽  
pp. 84-92 ◽  
Author(s):  
P Matzinger ◽  
G Mirkwood
Keyword(s):  
T Cells ◽  
Chimeric Mice ◽  
Spleen Cells ◽  
Histocompatibility Antigens ◽  
Minor Histocompatibility Antigens ◽  
Radiation Chimeras ◽  
Cell Responses ◽  
Viral Antigens

Fully H-2 incompatible radiation chimeras were prepared using BALB congenic mice. Such chimeric mice were immunized in vivo against histocompatibility antigens of the C57BL/10Sn (B10) background in association with either of the parental H-2 haplotypes, and their spleen cells subsequently boosted in vitro with the same minor antigens. Strong H-2-restricted cytotoxic activity against minor antigens was detected, and the specificity of the restriction could be to the H-2 haplotype of the donor or the host depending on the cells used for priming or boosting. Cross priming could also be demonstrated in these mice. The results show that fully allogenic radiation chimeras can produce H-2-restricted T-cell responses to minor histocompatibility (H) antigens, and are discussed in relation to contrasting results recently obtained against viral antigens.

scholarly journals Syk, c-Src, the αvβ3 integrin, and ITAM immunoreceptors, in concert, regulate osteoclastic bone resorption

2007 ◽  
Vol 176 (6) ◽  
pp. 877-888 ◽  
Author(s):  
Wei Zou ◽  
Hideki Kitaura ◽  
Jennifer Reeve ◽  
Fanxin Long ◽  
Victor L.J. Tybulewicz ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Αvβ3 Integrin ◽  
Chimeric Mice ◽  
Signaling Complex ◽  
Skeletal Mass ◽  
Osteoclast Function ◽  
Activation Motif ◽  
Bone Resorbing Osteoclast

In this study, we establish that the tyrosine kinase Syk is essential for osteoclast function in vitro and in vivo. Syk−/− osteoclasts fail to organize their cytoskeleton, and, as such, their bone-resorptive capacity is arrested. This defect results in increased skeletal mass in Syk−/− embryos and dampened basal and stimulated bone resorption in chimeric mice whose osteoclasts lack the kinase. The skeletal impact of Syk deficiency reflects diminished activity of the mature osteoclast and not impaired differentiation. Syk regulates bone resorption by its inclusion with the αvβ3 integrin and c-Src in a signaling complex, which is generated only when αvβ3 is activated. Upon integrin occupancy, c-Src phosphorylates Syk. αvβ3-induced phosphorylation of Syk and the latter's capacity to associate with c-Src is mediated by the immunoreceptor tyrosine-based activation motif (ITAM) proteins Dap12 and FcRγ. Thus, in conjunction with ITAM-bearing proteins, Syk, c-Src, and αvβ3 represent an essential signaling complex in the bone-resorbing osteoclast, and, therefore, each is a candidate therapeutic target.

Differential Development of Donor Bone Marrow-Derived Thymocytes after Allogeneic in Utero Hematopoietic Cell Transplantation in the Murine Model

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5800-5800
Author(s):  
Yan Li ◽  
Jesse D Vrecenak ◽  
Haying Li ◽  
Michael A Conner ◽  
Aimee G Kim ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cells ◽  
Murine Model ◽  
Hematopoietic Cell Transplantation ◽  
Chimeric Mice ◽  
Thymocyte Development ◽  
Donor Bone Marrow ◽  
Donor Cells

Abstract Introduction In Utero Hematopoietic Cell Transplantation (IUHCT) is a promising therapeutic strategy for congenital hematopoietic disorders. While mixed allogeneic hematopoietic chimerism with associated donor specific tolerance is routinely achieved by a predominant mechanism of central deletion, the critical events of donor and host thymocyte development have not been determined. In this study, we utilized the murine model of allogeneic IUHCT to analyze donor and host thymocyte development in the context of normal immune ontogeny. Methods Bone marrow (BM) cells (10x106) from C57/BL6 (B6, H2kb) mice were injected intravenously into Balb/c (H2kd) fetuses at embryonic day 14 (E14). E14 B6 fetuses injected with GFP B6 BM were used as congeneic controls. At indicated postnatal ages the thymocytes were delineated by multi-color flow cytometry. Cell apoptosis and proliferation were determined by Annexin V staining and in vivo BrdU incorporation, respectively. T cell alloreactivity was assessed by in vitro and in vivo MLR. Results Our findings demonstrate that the thymic processing of donor BM-derived thymocytes differs significantly from host thymocyte processing and from thymocyte development in normal control mice. While the phenotypic development of host thymocytes remained comparable with that of normal control Balb/c mice, the four major subsets of donor thymocytes showed altered distribution, with significantly higher proportions of single positive (SP) cells, and a dramatically lower proportion of CD4+CD8+ double positive (DP) cells, compared to their host-derived counterparts and B6 controls. The extent of the alteration is directly related to both BM chimerism levels and age. Higher levels of chimerism and/or older age are associated with more profound alterations in donor thymocyte distribution. Moreover, DP cells of donor origin show higher apoptosis and lower proliferation than those of the host. Donor TCR gamma/delta cells in DN cells which do not require positive selection based on MHC recognition are relatively increased compared to the host. Moreover, compared with the naive mice and congeneic chimeric mice, the donor BM-derived thymocytes in the allogeneic chimeric mice show increased proportion of DN3 and decreased proportion of DN4, but increased TCRβ+ proportions in both DN3 and DN4 cells, indicating that donor BM-derived thymocyte development is impeded during DN to DP transition, resulting from a MHC-restriction associated mechanism. In addition, in allogeneic chimeric mice, both host and donor BM-derived T cells are tolerant to allogeneic antigens in in vivo and in vitro MLR. Conclusion Our data suggests that in an allogeneic IUHCT system the immune reconstitution of the donor bone marrow-derived thymocytes differs from that of the host cells and that of normal mice. The data supports a mechanism of impaired MHC based positive selection of donor cells by the predominantly host thymic stroma resulting in lack of progression of a higher proportion of donor cells from the DN to DP stage of thymocyte development. Taken together, although donor BM-derived T cells undergo differential thymic development, permanent host-donor two-way tolerance could be achieved in the allogeneic IUHCT mouse model. These findings add to our understanding of the requirements for tolerance induction after IUHCT and have important clinical implications in choosing an optimal donor for IUHCT. Disclosures No relevant conflicts of interest to declare.

Sign in / Sign up

Export Citation Format

Share Document