Over Expression of MN1 Confers Resistance to Chemotherapy In Vitro and In Vivo

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 969-969
Author(s):  
Timothy Pardee ◽  
Teresa Mascenik ◽  
Britt H. Bolemon ◽  
Guerry J Cook
Keyword(s):  
Bone Marrow ◽  
The United States ◽  
Genetic Alterations ◽  
T Test ◽  
Over Expression ◽  
Student’S T ◽  
Worse Prognosis ◽  
Student’S T Test

Abstract Abstract 969 Acute myeloid leukemia (AML) is an accumulation of immature myeloid precursors that leads to progressive marrow failure and death. This disease affects approximately 12,000 people per year in the United States, causing 9,000 deaths. Despite decades of active research the overall 5 year survival remains a dismal 30–40%. The backbone of initial therapy for the last 30 years is combination chemotherapy containing cytarabine (Ara-C) and an anthracycline. Resistance to these therapies is a major problem and most patients diagnosed with AML will ultimately die from resistant disease. AML is characterized by heterogeneous genetic alterations that can be used to delineate prognosis. Using standard karyotyping techniques patients can be divided into good, intermediate and poor prognostic categories. There is a clear link between these chromosomal aberrations and response to chemotherapy as complete remission rates are significantly different between groups. Patients with no detectable cytogenetic abnormality fall into an intermediate prognostic group with a very heterogeneous outcome. Recent work has begun to uncover submicroscopic genetic alterations that effect prognosis for these patients. These alterations can be mutations, over or under expression of a particular gene. The MN1 gene encodes a transcription co-factor first identified by its involvement in a balanced translocation in a patient with a meningioma. Since its initial description it has been found over-expressed in multiple AML patient samples. There are several reports that over-expression of MN1 confers a worse prognosis in AML. High MN1 expressers were less likely to achieve a remission and had a lower 3 year survival rate. Additionally, over expression of MN1 in murine bone marrow leads to AML in transplanted recipients and predicts for resistance to ATRA in elderly AML patients. However, the effect of MN1 over expression on response to standard chemotherapy is currently unknown. To answer this question we used a murine model of AML driven by MLL-ENL. AML blasts were infected with retroviral vectors that contained MN1 and a GFP reporter. Partially infected blast populations were then exposed to various concentrations of either Ara-C or doxorubicin and the ratio of GFP positive and negative cells was compared to untreated controls. When blasts were exposed to 150 nM Ara-C the GFP+ percentage went from 21.10 (+/− 0.5302) in the control samples to 35.68 (+/−1.230) in the treated samples. This result was even more profound when cells were treated with 15 ng/ml doxorubicin where the percentage went from 21.10 (+/− 0.5302) to 80.27 (+/−1.615). Both results were highly statistically significant by two tailed student's t test with p values of 0.004 and <0.0001 respectively. Consistent results were obtained in multiple different infections and with separately derived MLL-ENL lines. These data demonstrate that blasts expressing MN1 had an advantage when exposed to either Ara-C or doxorubicin although the effect was far more pronounced with doxorubicin exposure. MN1 expressing blasts were also resistant to the combination of Ara-C and doxorubicin. In order to determine if MN1 conferred resistance to Ara-C and doxorubicin in vivo we injected sublethally irradiated, Ly5.1+ C57Bl6 recipients with a partially infected population of blasts. Ly5.1+ animals do not express the Ly5.2 allele; thus, staining cells for Ly5.2 allows differentiation of leukemic cells from endogenous marrow. Eight days after injection of blasts animals were treated with 100 mg/kg Ara-C plus 3 mg/kg doxorubicin daily for 5 days or observed. On day 6 animals were sacrificed and bone marrow from bilateral femurs was harvested, stained for Ly5.2 and analyzed by flow cytometery. Animals treated with Ara-C plus doxorubicin had 90.58% (+/−0.6638) Ly5.2+, GFP+ blasts compared to 55.38% (+/−5.245) in control animals. This result was highly statistically significant with a p value of <0.0001 by two tailed student's t test. This observation was reproducible in a separately derived MLL-ENL driven cell line. These data suggest that over expression of MN1 in this murine AML model confers resistance to both Ara-C and doxorubicin in vitro and in vivo and provides a biological explanation for the clinical observation that it confers a worse prognosis. The mechanisms involved in this resistance are currently under study. Disclosures: No relevant conflicts of interest to declare.

Over Expression of MN1 Accelerates Leukemia Onset and Confers Resistance to Chemotherapy by Suppression of p53 and Bim

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 2501-2501
Author(s):  
Timothy Pardee
Keyword(s):  
Bone Marrow ◽  
Conflicts Of Interest ◽  
The United States ◽  
Retroviral Vectors ◽  
Genetic Alterations ◽  
P Value ◽  
Over Expression ◽  
Resistance To Chemotherapy ◽  
Worse Prognosis

Abstract Abstract 2501 Acute myeloid leukemia (AML) is an aggressive malignancy of immature myeloid precursors that leads to progressive marrow failure and death. This disease will affect approximately 12,950 people this year in the United States, causing 9,050 deaths. The most common treatment is combination chemotherapy containing cytarabine (Ara-C) and an anthracycline. Resistance to these therapies is a major problem and most patients diagnosed with AML will ultimately die from resistant disease. AML is a genetically diverse malignancy and karyotype can be used to delineate prognosis. There is a clear link between chromosomal abnormalities and resistance to chemotherapy as complete remission rates are significantly different between groups. Additionally, there are now multiple submicroscopic genetic alterations that have been found to effect prognosis. These alterations can be mutations, over or under expression of a particular gene. MN1 is a transcription co-factor and several studies have demonstrated its over-expression confers a worse prognosis. High MN1 expressers were less likely to achieve a remission and had lower 3 year survival rates. Additionally, over expression of MN1 in murine bone marrow leads to AML in transplanted recipients and predicts for resistance to ATRA in elderly AML patients. The effect of MN1 on response to standard chemotherapy is currently unknown. To determine the effect of MN1 expression on therapy response we infected murine MLL-ENL driven AML cells with retroviral vectors that expressed MN1. When partially infected populations were exposed to a titration of either Ara-C or doxorubicin MN1 expressing cells were significantly enriched compared to untreated controls. When cells were exposed to a titration of Ara-C the MN1 expressing cells were enriched up to1.69 fold and when exposed to doxorubicin were enriched up to 3.80 fold. Both results were highly statistically significant with p values of 0.004 and < 0.0001. Consistent results were obtained with repeated infections and with separately derived MLL-ENL lines. Additionally, MN1 was able to confer therapy resistance to anthracycline resistant Flt3-ITD expressing cells suggesting non-overlapping mechanisms. Purified populations of cells expressing MN1 were resistant to Ara-C when compared to the parental leukemia (IC50 175.6nM vs 67.28nM) and highly resistant to doxorubicin. Consistent with these results human OCI-AML3 cells expressing MN1were enriched by 1.6 fold when exposed to doxorubicin, a highly significant result with a p value of 0.0002. In contrast a control vector without MN1 was not significantly enriched. In vivo when mixed leukemia cells were injected into syngeniec recipients MN1 expressers were significantly enriched in the femoral bone marrow of treated animals compared to controls. Treated animals had 90.58% (+/−0.66) MN1 expressing blasts compared to 55.38% (+/−5.25) in controls. This result was highly statistically significant with a p value of < 0.0001. This observation was reproducible in a separately derived MLL-ENL driven cell line. Additionally, the engraftment of MLL-ENL and Flt3-ITD expressing cells was significantly increased by MN1 expression leading to shorter survival in recipient animals despite the already highly aggressive nature of the parental leukemia. When MN1 expressing cells were exposed to doxorubicin or Ara-C they displayed significantly lower Annexin V positivity consistent with an attenuated apoptotic response (3.65 vs 34.79, p=<0.0001). When we examined BH3 only family member induction following exposure to Ara-C and doxorubicin we found significantly decreased levels of Bim induction by QPCR in cells expressing MN1. Similarly, stabilization of p53 following treatment was blunted in MN1 expressers as was induction of its downstream targets p21 and MDM2. Importantly the amount of DNA damage induced by doxorubicin as assessed by γH2AX foci was not different between MN1 expressing cells and the parental leukemia. These data suggest that over expression of MN1 confers resistance to both Ara-C and doxorubicin in vitro and in vivo by suppression of Bim induction and p53 response. These observations suggest a biological explanation for the clinical observation that it confers a worse prognosis. Disclosures: No relevant conflicts of interest to declare.

18 EMBRYO AGGREGATION IN PIG IMPROVES CLONING EFFICIENCY AND EMBRYO QUALITY

2016 ◽  
Vol 28 (2) ◽  
pp. 139
Author(s):  
C. Buemo ◽  
A. Gambini ◽  
L. Moro ◽  
R. F. Y. Martin ◽  
D. Salamone
Keyword(s):  
In Vitro Culture ◽  
Dna Fragmentation ◽  
Embryo Development ◽  
Embryo Quality ◽  
T Test ◽  
Control Group ◽  
Reconstructed Embryo ◽  
Student’S T ◽  
Student’S T Test

In this study, we analysed the effects of the cloned embryo aggregation on in vitro embryo development and embryo quality by measuring blastocyst size and cell number, DNA fragmentation levels by TUNEL assay, and the relative expression of genes associated with pluripotency, apoptosis, trophoblast markers, and DNA methylation in the porcine. Cumulus-oocyte complexes were recovered from slaughterhouse ovaries by follicular aspiration. Maturation was performed in TCM for 42 to 48 h at 39°C and 5% CO2. After denudation by treatment with hyaluronidase, mature oocytes were stripped of the zona pellucida using a protease and then enucleated by micromanipulation; staining was performed with Hoëchst 33342 to observe metaphase II. Ooplasms were placed in phytohemagglutinin to permit different membranes to adhere between each other; the ooplasm membrane was adhered to a porcine fetal fibroblast from an in vitro culture. Adhered membranes of the donor cell nucleus and enucleated oocyte cytoplasm were electrofused through the use of an electric pulse (80 V for 30 μs). All reconstituted embryos were electrically activated using an electroporator in activation medium (0.3 M mannitol, 1.0 mM CaCl2, 0.1 mM MgCl2, and 0.01% polyvinyl alcohol) by a DC pulse of 1.2 kVcm for 80 μs. Then, embryos were incubated in 2 mM 6-DMAP for 3 h. In vitro culture of zona-free embryos was achieved in a well of wells system in 100 μL of SOF medium. Two experimental groups were used, one control group with a single reconstructed embryo per microwell (1×) and the other group placing 3 reconstructed embryo per microwell (3x aggregation group). Embryos were cultivated at 39°C in 5% O2, 5% CO2 for 7 days in SOF medium with a supplement of 10% fetal bovine serum on the fifth day. At Day 7, resulting blastocysts were classified according to their morphology and diameter to determine their quality. Our results showed that aggregation of 3× embryos increased blastocyst formation rate and blastocyst size of pig cloned embryos (Fisher’s test P < 0.05 and Student’s t-test P < 0.05, respectively). The DNA fragmentation levels in 3× aggregated cloned blastocysts were significantly decreased compared to 1x blastocyst (Student’s t-test P < 0.05). Levels of Oct4, Klf4, Igf2, Bax, and Dnmt1 transcripts were significantly higher in aggregated embryos, whereas Nanog levels were not affected. Transcripts of Cdx2 and Bcl-xl were essentially nondetectable (Student’s t-test P < 0.05). Our study suggests that embryo aggregation in the porcine may be beneficial for cloned embryo development and embryo quality, through a reduction in apoptotic levels and an improvement in cell reprogramming.

26 Drugs that Modify Epigenetics...What do they do to Porcine Clones?

2018 ◽  
Vol 30 (1) ◽  
pp. 152
Author(s):  
C. P. Buemo ◽  
A. Gambini ◽  
L. N. Moro ◽  
N. Canel ◽  
D. F. Salamone
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Electric Pulse ◽  
Donor Cell ◽  
T Test ◽  
Control Group ◽  
Developmental Rates ◽  
Student’S T ◽  
Student’S T Test

Although somatic cell nuclear transfer (SCNT) technology was developed more than 20 years ago, cloning efficiency remains low. Failures in the reprogramming of the donor cell result in embryos with aberrant epigenetic patterns and low developmental rates. In this study, we assessed whether the use the inhibitor of DNA (cytosine 5) methyltransferase 5-azacitidine (5Aza) combined with the MEK inhibitor in the MAPK pathway PD0325901 (PD) could improve SCNT efficiency in pigs. In vitro maturation of cumulus–oocyte complexes was performed in TCM for 44 h at 39°C under 5% CO2. Cumulus cells and zona pellucida was removed from matured oocytes, followed by enucleation of the metaphase plate previously stained with Hoëchst 33342. Each enucleated oocyte was attached to a donor cell by phytohemagglutinin treatment followed by an electric pulse of 80V for 30 μs. After fusion, reconstituted embryos were activated by an electric pulse followed by an incubation in 2 mM 6-DMAP for 3 h. Cloned embryos were cultured in vitro in a modified well-of-well system in SOF medium, where 3 cloned embryos were placed per microwell (3X). The experimental group 3X + drugs was exposed for the first 3 days to 1 μM PD and 1 μM 5Aza in SOF medium. After washing, embryos were cultured until Day 7 in regular SOF medium. The control group (3X) was cultured in regular SOF medium for 7 days. In vitro embryo developmental rates, gene expression, histone acetylation, and DNA methylation status were studied. The use of epigenetic modifying drugs significantly increased blastocyst rates (40.9% v. 29%; Fisher’s test, P < 0.05) and embryo size (41.46% v. 28.56%; Student’s t-test, P < 0.05) compared with the control group. Regarding gene expression, an increase of the relative expression of genes related to cell differentiation (Igf2 and Cdx2), antiapoptotic pathways (Bcl-xl) and DNA methylation modulation (Mapk1) was observed (P < 0.05). Pluripotency genes Oct4 and Nanog did not show differences between groups. The Bax proapoptotic gene significantly decreased its expression after drug treatment, as did the Klf4 gene (P < 0.05). Results were analysed by Student’s t-test. According to Histone H3K27ac, which is associated with enhancers or gene promoters, its marker was located mainly in the nuclear periphery respect to the control group with a uniform dispersion, indicating that the treatment could be activating certain genes by locating them near the periphery. Histone H3K4me1 was more uniformly localised throughout the nucleus in both groups. The intensity of the fluorescence was measured by quantitative confocal microscopy using a histogram produced by the ImageJ program (National Institutes of Health, Bethesda, MD, USA). Regarding DNA methylation by bisulphite sequencing, the 2 genes studied (Oct4 and DNMT1) showed a higher demethylation status for the treated group. Our results indicate that the combination of 5Aza+PD during early pre-implantation development dramatically increase blastocyst rates and embryo quality. This novel combination could be used as a strategy to improve the efficiency of SCNT in pigs and potentially other animals.

Angptl-4 Is Upregulated Under Inflammatory Conditions In The BM Of Mice, Expands Myeloid Progenitors and Accelerates Reconstitution Of Platelets After Myelosuppressive Therapy

Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3677-3677
Author(s):  
Anne Schumacher ◽  
Till Braunschweig ◽  
Bernd Denecke ◽  
Tim H. Brümmendorf ◽  
Patrick Ziegler
Keyword(s):  
Bone Marrow ◽  
Conflicts Of Interest ◽  
Myeloid Cell ◽  
Relative Increase ◽  
T Test ◽  
Gm Csf ◽  
Emergency Situations ◽  
Inflammatory Conditions

Abstract The concerted action of hematopoiesis supporting cytokines such as G-CSF, GM-CSF or IL-6 regulates hematopoiesis during steady state and emergency situations. Respective knockout mice show defects both in production and function of myelopoietic effector cells. However, alternative pathways are likely to exist as mice with single or combined deficiencies for G-CSF, GM-CSF, and IL-6 or G-CSF and GM-CSF are still able to mount reactive neutrophilia responses during inflammatory conditions. In order to identify pathways for inflammation induced enhancement of hematopoiesis as well as to find new cytokines, which enhance myeloid cell regeneration, we analyzed the bone marrow (BM) of lipopolysaccharide (LPS) and vehicle injected wild type (WT) mice (single IP- injection) by gene expression microarray. Focusing on the identification of genes encoding for secreted or membrane proteins, we found 83 candidates to be up- and 14 to be downregulated after LPS treatment. Among known candiates, we found angiopoietin-like 4 (Angptl-4) as a predominantly upregulated gene in the BM of LPS-treated WT-mice. Upregulation was confirmed by RT-PCR as well as by Elisa in the BM of LPS treated mice and bone marrow stromal cells (BMSC) were identified as candidate producer cells. Functionally, we found recombinant Angptl-4 to stimulate the proliferation of myeloid colony-forming units (CFU) in vitro. In mice, repeated injections of Angptl-4 increased BM progenitor cell frequency and this was paralleled by a relative increase in phenotypically defined granulocyte-macrophage progenitors (GMPs). Furthermore, in vivo treatment with Angptl-4 resulted in elevated platelet counts both in untreated animals and after myelosuppressive therapy. After lethal irradiation and transplantation of syngeneic BM cells repetitive injections of recombinant Angptl-4 for 5 consecutive days resulted in an accelerated reconstitution of platelets starting at day 8 after transplantation. The 50% pre-treatment platelet count was reached on day 14 in Angptl-4-treated animals as compared to day 21 for transplanted controls receiving no Angptl-4 (n=8; p=0.03, student´s T test). In contrast, transplantation of BM cells from Angptl-4 pre-treated donor mice had no effect on the recovery of platelets in this setting. The frequency of CD41lowCD61+ immature megakaryocytes was significantly increased in the BM of Angptl-4 injected as compared to control mice (27% vs 19% of total megakaryocytes; p= 0.008, student´s T test). Furthermore, bone marrow cytology revealed local accumulation of megakaryocytes carrying dysplastic features in Angptl-4 injected mice. In summary, our data suggest that Angptl-4 plays a complementary role on hematopoiesis during emergency situations like sepsis. The use of Angptl-4 in the setting of autologous stem cell transplantation could represent a potential approach to accelerate the reconstitution of megakaryopoiesis. Disclosures: No relevant conflicts of interest to declare.

scholarly journals In vitro study of marginal, internal and proximal adaptation of implant-supported single-crown CAD/CAM restorations

2020 ◽  
Vol 19 ◽  
pp. e207286
Author(s):  
Kamila Aguiar Figueiredo Alves ◽  
Janaina Emanuela Damasceno ◽  
Viviane Maia Barreto de Oliveira ◽  
Luiz Gustavo Cavalcanti Bastos ◽  
Andrea Nóbrega Cavalcanti
Keyword(s):  
Repeated Measures ◽  
T Test ◽  
Digital Impression ◽  
Single Crown ◽  
Significant Difference ◽  
Cad Cam ◽  
Student’S T ◽  
One Way Anova ◽  
Student’S T Test

Aim: This study evaluated the precision of a CAD/CAM system by measuring marginal, internal and proximal fits in implantsupported single-crown restorations. Methods: Ten models of the upper arch were made in which implants replaced the upper left premolars. For fabrication of the zirconia infrastructures, titanium bases (TiBase) were coded and scanned using a scan body. A second digital impression was made for the fabrication of prostheses. Silicone impression material was used to determine the internal clearance between the TiBase and infrastructure and between the infrastructure and crown, whose thickness was measured at three points [P1 (cervical), P2 (middle) and P3 (occlusal)] with a stereoscopic microscope at 70x and 100x magnification. One-way ANOVA for repeated measures and the Student t-test were used for the analysis of internal and marginal adaptation. Proximal contacts were analyzed qualitatively. Results: There was no significant difference between the teeth evaluated (Student’s t-test; p>0.05) or between the corresponding points evaluated in either tooth (one-way ANOVA; p>0.05). Analysis of the internal clearance between the infrastructure and crown demonstrated that all points were significantly different compared to the reference standardized at 100 μm (Student’s t-test p<0.0001). There was no significant difference between P1 and P2, with the thickness at these two points being lower than that obtained at P3 (one-way ANOVA, p<0.05). The proximal contacts did not coincide with the quality defined by the device. Conclusion: The system tested was unable to produce implantsupported single-crown ceramic restorations with marginal, internal and proximal fits matching the digital workflow, with the inferior fits requiring adjustment prior to cementation.

scholarly journals NR2F6 (EAR-2) Is a Novel Leukemia Oncogene Whose Cellular Function Is to Regulate Terminal Differentiation of Erythrocytes at the Proerythroblast Stage

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1337-1337
Author(s):  
Christine Victoria Ichim ◽  
Dzana Dervovic ◽  
David Koos ◽  
Marciano D. Reis ◽  
Alden Chesney ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Stem Cell ◽  
Cell Differentiation ◽  
Bone Marrow Cells ◽  
Erythroid Differentiation ◽  
Erythroid Progenitor ◽  
Over Expression ◽  
Marrow Cells

Abstract The leukemia stem cell model suggests that elucidation of the genes that regulate growth ability within the leukemia cell hierarchy will have important clinical relevance. We showed that the expression of NR2F6 (EAR-2), is greater in clonogenic leukemia single cells than in leukemia cells that do not divide, and that this gene is over-expressed in patients with acute myeloid leukemia and myelodysplastic syndrome. In vivo, overexpression of EAR-2 using a retroviral vector in a chimeric mouse model leads to a condition that resembles myelodysplastic syndrome with hypercellular bone marrow, increased blasts, abnormal localization of immature progenitors, morphological dysplasia of the erythroid lineage and a competitive advantage over wild-type cells, that eventually leads to AML in a subset of the mice, or after secondary-transplantation. Interestingly, animals transplanted with bone marrow that over-expresses EAR-2 develop leukemia that is preceded by expansion of the stem cell compartment in the transplanted mice—suggesting that EAR-2 is an important regulator of hematopoietic stem cell differentiation. Here we report that over-expression of EAR-2 also has a profound effect on the differentiation of erythroid progenitor cells both in vitro and in vivo. Studies of the roles of EAR-2 in normal primary bone marrow cells in vitro showed that overexpression of EAR-2 profoundly impaired differentiation along the erythroid lineage. EAR-2 over-expressing bone marrow cells formed 40% fewer BFU-E colonies, but had greatly extended replating capacity in colony assays. While knockdown of EAR-2 increased the number of cells produced per BFU-E colony 300%. Normal mice transplanted with grafts of purified bone marrow cells that over-expressed EAR-2 developed a rapidly fatal leukemia characterized by pancytopenia, enlargement of the spleen, and infiltration of blasts into the spleen, liver and peripheral blood. Sick animals had profound reduction of peripheral blood cell counts, particularly anemia with a 55% reduction in hemoglobin levels. Anemia was evident even on gross inspection of the blood and the liver in EAR-2 overexpressing animals. Analysis of the leukemic cells revealed an erythroblastic morphology, with the immunophenotype lineageneg, CD71high, TER119med. Hence, we wondered weather EAR-2 caused leukemia by arresting erythroid progenitor cell differentiation. Examination of the bone marrow of pre-leukemic animals showed a four-fold increase in cells with a pro-erythroblastic immunophenotype (CD71highTER119med , region I), and a four-fold decrease in orthochromatophilic erythroblasts (CD71lowTER119high , region IV). We observed no change in the numbers of basophilic erythroblasts (CD71highTER119high , region II) or late basophilic and polychromatophilic erythroblasts (CD71medTER119high, region III). These data suggests that over-expression of EAR-2 blocks erythroid cell differentiation at the pro-erythroblastic stage. Since EAR-2 over-expressing recipients died within 4 week, we wanted to definitively test whether animals had compromised radioprotection. We showed that decreasing the size of the bone marrow graft, reduced survival of the EAR-2 over-expressing cohort by a week, but had no effect on control animals proving that EAR-2 over-expression has a profound effect on erythropoietic reconstitution in vivo. Mechanistically, we show that DNA binding is necessary for EAR-2 function, and that EAR-2 functions in an HDAC-dependent manner, regulating expression of several genes. Pre-leukemic pro-erythroblastic cells (CD71highTER119med) that over-expressed EAR-2 had lower expression of genes involved in erythroid differentiation such as GATA1, EBF1, inhibitor of NFKB (NFKBia), ETV6, CEBP/a, LMO2, and Nfe2, and increased expression of GATA2, GLI1, ID1 and PU.1 than GFP control pro-erythroblasts. These data establish that EAR-2 is a novel oncogene whose cellular function is to regulate terminal differentiation of erythroid cells at the proerythroblastic (CD71highTER119med) stage by deregulating gene expression necessary for erythroid differentiation. Disclosures Ichim: Entest BioMedical: Employment, Equity Ownership, Patents & Royalties, Research Funding. Koos:Entest BioMedical: Employment, Equity Ownership, Patents & Royalties, Research Funding.

162 IMPROVED EMBRYO SURVIVAL AND QUALITY WITH EMCARE II

2006 ◽  
Vol 18 (2) ◽  
pp. 189
Author(s):  
A. Harvey ◽  
M. Lane ◽  
J. Thompson
Keyword(s):  
Calf Serum ◽  
Cell Number ◽  
Tunel Staining ◽  
Embryo Survival ◽  
Improved Outcomes ◽  
Student’S T ◽  
The Impact ◽  
Student’S T Test

Collection of embryos exposes them to a number of stresses, including light, air, and changes in temperature. Improvement of holding media to reduce the impact of handling stresses on the embryo during in vivo collection and transfer is therefore beneficial to ensure maintenance of viability following transfer. The aim of this study was to compare the effect of holding IVP-derived blastocysts at 25°C in Emcare I (ECMI, Emcare, Dallas, TX, USA) with those held in Emcare II (ECMII), a proprietry formulation designed to reduce in vitro-induced stress. In vitro-produced bovine embryos were generated using standard protocols. Blastocysts were randomly allocated to either ECMI or ECMII (ICPBio, Aukland, New Zealand) on Day 7 and were held at 25°C for a period of 24 h, after which they were cultured in Cook Bovine Blast (Cook Australia, Brisbane, Australia) supplemented with 10% fetal calf serum for 48 h. At 24 and 48 h, embryos were scored for hatching, and a cohort removed for TUNEL staining at each time point. Differences were analyzed by Student's t-test. At both 24- and 48-h culture, hatching rates tended to be higher for embryos held in ECMII than in ECMI (Table 1). The level of apoptosis at 48 h was reduced in blastocysts held in ECMII (P = 0.06). Moreover, the total cell number of hatched blastocysts at 48 h was significantly increased (1.5-fold) in those held in ECMII (P = 0.01). Results suggest that the formulation of ECMII improves the ability of IVP bovine blastocysts to re-expand and hatch following an imposed stress (25°C for 24 h). Furthermore, ECMII improves overall embryo quality through a reduction in the percentage of cells undergoing apoptosis as well as through increased cell numbers, evident 48 h following cessation of the stress. We suggest that Emcare II reduces the impact of (or increases the embryo's tolerance to and recovery from) an imposed stress, which, although severe in the present study, may provide improved outcomes following embryo transfer in field situations. Table 1. Hatching and apoptosis of blastocysts held at 25°C for 24 h in Emcare I or Emcare II This work was supported with funding by ICPBio (NZ).

74 EFFECT OF SIZE AND CULTURE PERIOD OF FROZEN–THAWED BOVINE TROPHOBLASTIC VESICLES ON INTERFERON-τ SECRETION

2014 ◽  
Vol 26 (1) ◽  
pp. 151
Author(s):  
Y. Hashiyada ◽  
H. Takahashi ◽  
D. Yamaguchi ◽  
K. Imai ◽  
M. Geshi
Keyword(s):  
Significant Positive Correlation ◽  
Culture Media ◽  
Fetal Bovine Serum ◽  
Calf Serum ◽  
Culture Period ◽  
Fetal Bovine ◽  
Student’S T ◽  
Student’S T Test

Frozen–thawed bovine trophoblastic vesicles (bTV) derived in vivo could secrete interferon-τ (IFN-τ) at the same level as fresh bTV on Days 4 to 6 after thawing. However, amounts of IFN-τ decreased following continuous in vitro culture (Hashiyada et al. 2012 38th IETS). Co-transfer of frozen–thawed bTV improved pregnancy rate of embryos due to the effects of IFN-τ secreted by bTV (Hashiyada et al. 2008 41th SSR). However, the relation between bTV size and IFN-τ secretion level during culture has not been well documented. The objective of present study was to characterise the concentration of IFN-τ related bTV volume and culture period after thawing of cryopreserved bTV. The bTV were prepared from Day 16 elongating blastocysts recovered nonsurgically. The dissected trophoblastic fragment, 1 to 1.5 mm in width, was cultured using TCM-199 supplemented with 20% (vol/vol) fetal bovine serum and 0.1 mM β-mercaptoethanol. Formed vesicles after 24 h of culture were cryopreserved using D-PBS supplemented with 20% calf serum and 1.8 M ethylene glycol. After thawing, bTV were cultured individually with 100 μL/well/day until Day 2 (i.e. the day of thawing was defined as Day 0), and thereafter changed to 200 μL/well/day to termination at Day 10. Collection of culture media and measurement of bTV diameter were performed before cryopreservation and after thawing for every day. Interferon-τ in collected media was measured by radioimmunoassay. The estimated bTV volume was calculated based on the diameter. Data were analysed by Student's t-test. Nine fresh bTV before cryopreservation were used to assess the IFN-τ secretion for 24 h in relation to bTV volume. A significant positive correlation was observed between secreted IFN-τ (mean ± s.e.M, 19.9 ± 3.1 ng mL–1) and bTV volume (1.49 ± 0.6 mm3, r = 0.91; P < 0.01). Initial IFN-τ secretion from bTV cultured for 24 h after thawing was significantly decreased compared with that before cryopreservation (29.1 ± 2.1 ng mL–1 and 58.4 ± 4.8 ng mL–1; P < 0.01, n = 27). In continuous culture of bTV (n = 8), IFN-τ secretion increased gradually from Day 2 (23.1 ± 9.0 ng mL–1) to Day 4 (32.2 ± 8.4 ng mL–1), and then maintained this level until Day 7 (33.4 ± 14.9 ng mL–1). However, this amount of IFN-τ tended to decrease on Day 8 (24.8 ± 5.0 ng mL–1), 9 (16.5 ± 4.4 ng mL–1), and 10 (12.0 ± 1.7 ng mL–1). Interferon-τ secretion from bTV on Day 9 and 10 was lower than that on Day 3, 4, 5, 6, and 8, respectively (P < 0.05). Volume of bTV increased also from Day 2 (0.2 ± 0.1 mm3) to Day 5, 6 (0.8 ± 0.3 mm3) and 7 (0.7 ± 0.2 mm3). However, bTV volumes shrank drastically on Day 8 (0.3 ± 0.1 mm3), 9, and 10 (0.2 ± 0.1 mm3). In comparison with bTV during culture, volumes on Day 4, 5, and 7 were greater than those on Day 2 and 3, and volumes on Day 6 and 7 were greater than on Day 8, 9, and 10 (P < 0.05). These results indicate that the dynamics of IFN-τ secretion reflected the expansion or reduction of bTV in continued culture after thawing. Interferon-τ secretion might be related to bTV volume. Moreover, we reconfirmed that cryopreserved bTV highly express IFN-τ during 4 to 7 days after thawing.

78 INTERFERON-τ SECRETION OF CRYOPRESERVED BOVINE TROPHOBLASTIC VESICLES DERIVED FROM IN VIVO

2012 ◽  
Vol 24 (1) ◽  
pp. 151
Author(s):  
Y. Hashiyada ◽  
H. Takahashi ◽  
K. Imai ◽  
M. Geshi
Keyword(s):  
Continuous Culture ◽  
Culture Media ◽  
Calf Serum ◽  
Measure Concentration ◽  
Fetal Bovine ◽  
The Mean ◽  
Student’S T ◽  
Student’S T Test

The co-transfer of bovine trophoblastic vesicles (bTVs) prepared from in vivo recovered conceptuses is known to promote the successful implantation of embryos, which expected lower viability, through the effects of interferon-τ (IFN-τ) secreted by bTVs. We have reported that the pregnancy rate was improved for co-transferred embryos with frozen-thawed bTVs using the direct-transfer technique (Hashiyada et al. 2008, 41st SSR). However, the IFN-τ secretion level from cryopreserved bTVs is not well known. The objective of the present study was to measure concentration of IFN-τ released from frozen-thawed bTVs individually cultured in vitro. bTVs were prepared from elongating blastocysts 3 to 20 mm in length, following superstimulatory treatment and recovered on Day 16 post-AI, by dissection using a surgical blade. Each trophoblastic fragment, 1 to 1.5 mm in width, was cultured in a well of a 96-well plate using TCM-199 supplemented with 20% (v/v) fetal bovine serum and 0.1 mM β-mercaptoethanol. Formed vesicles after 24 or 48 h of culture were cryopreserved using D-PBS supplemented with 20% calf serum, 1.5 M ethylene glycol (EG) and 0.1 M sucrose or 1.8 M EG. After thawing, each bTVs was cultured for 2 days to compare IFN-τ secretion between the 2 cryoprotectants. Furthermore, transition of IFN-τ level was assessed in continuous culture until Day 10 (the day of thawing was defined as Day 0). The volume of culture medium was 100 μL well–1 day–1 until Day 2 and thereafter changed to 200 μL well–1 day–1 until termination. Exchange and collection of culture media were performed on Day 1, 2, 4, 6, 8 and 10. Collected culture media were stored at –30°C until use. IFN-τ was measured by RIA (Takahashi et al. 2005 Theriogenology 63, 1050–1060). Data were analysed by Student's t-test. Initial IFN-τ secretion from bTVs before cryopreservation did not differ between 24 and 48 h of culture period to form vesicles, 44.0 ± 2.9 (mean ± standard error of the mean, n = 64) and 52.8 ± 6.4 ng mL–1 (n = 27), respectively. IFN-τ secretion was no difference between the 1.5 M EG group and the 1.8 M EG group on Day 1 (41.2 ± 4.9 ng mL–1, n = 42 and 30.4 ± 2.2 ng mL–1, n = 31) and on Day 2 (38.0 ± 5.4 and 38.2 ± 4.5 ng mL–1), respectively. In the continuous culture group (n = 28), IFN-τ secretion tended to increase from Day 2 (25.2 ± 3.4 ng mL–1) to Day 4 (51.8 ± 12.3 ng mL–1) and 6 (55.4 ± 13.3 ng mL–1) (P < 0.05). However, this amount of IFN-τ on Day 6 significantly decreased on Day 8 (25.6 ± 2.7 ng mL–1; P < 0.05) and Day 10 (15.5 ± 2.2 ng mL–1; P < 0.01), gradually. These results indicate that cryopreserved bTVs could secrete IFN-τ at the same level as fresh bTVs on Day 4 to 6 after thawing and then these amounts of IFN-τ significantly decrease in vitro.

Kinase-Inactivating Braf Mutation Drives Aneuploidy In Splenic Myeloid Cells by Deregulation of Craf

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3138-3138
Author(s):  
Tamihiro Kamata ◽  
Susan Giblett ◽  
Robert Hayward ◽  
Richard Marais ◽  
Catrin A Pritchard
Keyword(s):  
Kinase Activity ◽  
Myeloid Cells ◽  
T Test ◽  
Brdu Incorporation ◽  
Erk Pathway ◽  
Wild Type ◽  
Monocytic Cells ◽  
Student’S T ◽  
Student’S T Test

Abstract Abstract 3138 BRAF belongs to RAF family serine/threonine kinases regulating the downstream MEK/ERK pathway, and is known as an oncogene mutated in ∼7% of human cancers, including some hematopoietic neoplasms (e.g. childhood ALL, therapy-related AML, and Langerhans cell histiocytosis). Although most oncogenic BRAF mutants aberrantly activate the MEK/ERK pathway, D594BRAF mutant, which represents ∼1% of oncogenic BRAF mutants, lacks in vitro kinase activity and in vivo ERK-activating potential when ectopically expressed, implying that this mutant might contribute to tumorigenesis through MEK/ERK-independent mechanisms. Using a compound knock-in mouse model, we recently reported that kinase-inactive D594ABraf cooperates with oncogenic Kras to promote tumorigenesis through another Raf family kinase, Craf (Cell. 2010; 140(2):209-221). To further understand how the BrafD594A mutation contributes to tumorigenesis, we analyzed BrafD594A/+ mice retaining wild-type ras alleles. Braf D594A/+ mice developed splenomegaly at 100% penetrance within three months after birth, with increased CD11b+ splenic myeloid (monocytic) cells (mutants: 4.50 ×107/spleen, littermate controls: 0.96 ×107/spleen, p=0.003, student's t-test). In vivo BrdU incorporation assay revealed that CD11b+ cells in the mutant spleen were actively cycling compared to littermate wild-type controls (mutants: 35.0 +/&− 6.2%, controls: 14.5 +/&− 4.0%, p=0.027, student's t-test). The aberrant myeloid expansion was restricted to spleen, and there was no significant difference in bone marrow cellularity and differential cell count between the mutants and wild-type controls. Interestingly, DNA ploidy analysis of the mutant splenic CD11b+ cells frequently exhibited aneuploid populations. Clear aneuploid (hyperdiploid to near-triploid) peaks were detected in 4 out of 10 mutant spleens, while a minor aneuploid peak detected in only one out of 24 control spleens (p=0.007, chi-square test). Karyotyping of CD11b+ macrophages/monocytic cells developed from BrafD594A/+ splenocytes in culture also revealed that more than 70% of mitotic cells were aneuploid (hypodiploid 55.6%, hyperdiploid 12.6%, near-tetraploid 5.2%, in total 135 metaphases from 3 independent cultures on day 10). These data indicate that D594ABRaf promotes myeloid expansion with compromising chromosome stability, specifically in the splenic microenvironment. Craf kinase activity in BrafD594A/+ splenocytes was about 2.5 times higher than littermate wild-type controls, suggesting that D594ABraf could transactivate Craf even in the absence of oncogenic Ras. Craf was also found to be essential for D594ABraf-induced aneuploidy because pharmacological inhibition of Craf by sorafenib or reduced Craf protein expression by genetic modification (CrafD486A allele, Mol Cell. 2008; 31(6):862-72) rescued the aneuploidization of BrafD594A/+ splenic myeloid cells. Unexpectedly, increased ERK phosphorylation was also found in BrafD594A/+ splenocytes, suggesting that D594ABraf could activate the MEK/ERK pathway through Craf transactivation when endogenously expressed. However, MEK inhibition by UO126 rather facilitated tetraploidization of BrafD594A/+ splenocytes in culture without improving aneuploidy, and constitutive MEK/ERK activation introduced by BrafV600E mutation (Cancer Res. 2005; 65(24):11493-500) did not promote aneuploidization of splenocytes. Collectively, we conclude that Craf transactivation by kinase-inactive Braf promotes aneuploidization of splenic myeloid cells in a MEK/ERK-independent manner. These results shed light on the potential involvement of Craf in the pathogenesis of aneuploid myeloid neoplasms. Disclosures: No relevant conflicts of interest to declare.

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