Bone Morrow Cells Research Articles

Trp53-Loss in Hematopoietic Stem Cells Drives the Evolutionary Process of Leukemic Transformation in a Jak2V617F-Driven Myeloproliferative Neoplasms Mouse Model

Myeloproliferative neoplasms (MPNs) are clonal disorders resulting from genetic lesions in hematopoietic stem cells (HSCs). The development of post-MPN AML is treatment resistant and associated with very poor outcomes. This leukemic transformation is due to TP53 inactivation in approximately 50% of cases. Existing mouse models with double mutant Jak2V617F and Trp53 have demonstrated that Trp53-lossalone is sufficient to induce leukemic transformation in Jak2V617F-driven MPN. These models were generated either by crossing Jak2V617F transgenic mice with Trp53R172H knock-in or Trp53 knock-out mice, or by retroviral expression of Jak2V617F in Trp53 knock-out bone morrow (BM) cells. These germline mutated models do not accurately model the sequential somatic Trp53 mutations that arise in Jak2V617F MPN, or track their clonal expansion in vivo. Here, we used CRISPR-Cas9 to induce Trp53-loss in HSCs of Jak2V617F mice to generate a novel mouse model of high molecular risk MPN that transforms to AML. We isolated lineage -/low Sca1 +c-Kit + (LSK) cells from BM of donor mice expressing a conditional allele of mutant Jak2 from its endogenous locus ( Jak2fl-V617F) in combination with an inducible Cas9-IRES-GFP allele and CreER-fusion allele, both from the Rosa26 locus ( Rosa26CreER/lsl-Cas9-IRES-GFP). LSKs were transduced with lentivirus expressing a sgRNA targeting exon 4 of Trp53 (sgTrp53), located in the DNA-binding domain of Trp53. These transfected sgTrp53 LSKs, along with control groups transduced with either empty vector (EV) or a sgRNA targeting Catsper1 (sgCatsper1, off target cutting control), were transplanted into lethally irradiated recipients. Successful engraftment and CreER activity, induced by a 2-week period of Tamoxifen chow, were confirmed by flow cytometry. Validation of Trp53-editing was performed using amplicon sequencing, revealing the most common mutations were frameshift mutations. A subset of these frameshift mutations exhibited an extremely high frequency, conferring a selective advantage within the cell populations in sgTrp53 mice. We further examined the levels of p53 induced by nutlin-3a (an MDM2 inhibitor) in edited BM cells from three groups of mice and found that Trp53 editing leads to a reduction in p53 levels and prevents the loss of viability in response to MDM2 inhibition. This indicates that CRISPR-Cas9 mediated Trp53 mutations result in a loss of function. SgTrp53 mice recapitulated the evolution of leukemic transformation of MPN, showing a PV phenotype for 8 weeks post CreER activation, characterized by elevated hematocrit but normal leukocytes and platelet counts, consistent with the phenotype exhibited by the EV and sgCatsper1 recipients. Subsequently, after 12 weeks, this MPN phenotype transformed to acute leukemia. This disease progression was associated with significantly shortened survival of sgTrp53 recipients, compared to the sgCatsper1 or EV control groups. Histopathologic analysis further supported these findings, showing leukocytosis and the presence of immature blast cells in the PB, spleen and BM of sgTrp53 mice, whereas such cells were absent in the control groups. Notably, the frequency of blast cells was correlated with the frequency of Trp53 frameshift mutations, consistent with what has been reported in MPN patients. Additionally, CRISPR-Cas9 mediated Trp53-loss primarily affected the erythroid lineage, driving expansion of erythroblasts, megakaryocyte-erythroid progenitors (MEP), and Lineage -/low Sca1 -c-Kit + in sgTrp53 mice. The erythroblasts showed aberrant co-expression of CD41 and CD71. Through secondary transplants with unfractionated spleen cells, whole BM cells, or sorted MEP cell populations, we confirmed that the leukemia driven by CRISPR-cas9 mediated Trp53-loss in the Jak2V617F-driven PV is transplantable, and that the MEP compartment in leukemic sgTrp53 mice contains the leukemia initiation population. In total, we used CRISPR-Cas9 to induce Trp53-loss in HSCs of Jak2V617F mice, faithfully replicating the process of clonal expansion and evolution observed in the leukemic transformation of MPN. These mouse models of secondary AML are valuable for testing new therapies targeting disease initiating stem cells. Moreover, our models represent the distinct stages of MPN progression, offering a platform to evaluate preventive and therapeutic interventions at various stages of this disease.

Prognostic Relevance of Structural Maintenance of Chromosomes 4 Overexpression in Pediatric Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia (ALL) is the most common cancer in children. Abnormal expression of structural maintenance of chromosomes (SMC) 4 has been observed in multiple tumors and plays a vital role in cancer development. However, the association between SMC4 expression and clinical characteristics in Chinese childhood patients with ALL is unknown. Thus, this study aimed to investigate the relationship between SMC4 expression and clinical features and prognosis in these patients. Real-time quantitative polymerase chain reaction (PCR) was performed to detect the expression of SMC4 in Chinese pediatric ALL patients and in patients achieving complete remission (CR). Then, the relationships between SMC4 expression and clinical features, such as gender, age, white blood cell (WBC) count, French-American-British (FAB) classification, immunophenotype, fusion gene, prednisone response, and minimal residual disease (MRD) were determined. Furthermore, survival and prognostic factor analyses were carried out to examine the prognostic value of SMC4 expression. The expression level of SMC4 was significantly higher in bone morrow cells of newly diagnosed pediatric ALL patients than in those of healthy controls (p = 0.006), especially in B-cell precursor ALL (BCP ALL). Moreover, SMC4 expression was correlated with different clinical parameters. Furthermore, a decrease of SMC4 expression was detected in BCP ALL patients achieving CR. The high SMC4 expression group had both worse event-free survival rate and poorer overall survival rate. However, multivariate analysis showed that SMC4 expression was not an independently predictive factor of BCP ALL outcome. These results revealed that SMC4 expression in BM was associated with various clinical outcomes in pediatric patients with ALL, although it was not an independent outcome factor.

Methodology of Differentiation of Bone Marrow Cells into Megakaryocytes in Vitro

To explore the method for inducing the differentiation of bone marrow cells into megakaryocytes in vitro so as to use for evaluating the activity of traditional Chinese medicines. The bone marrow cells were separated from femurs and tibias of mice. The experiments were divided into 4 groups: control (no adding cytokines), TPO (adding 50 ng/ml TPO), TPO+SCF (50 ng/ml+50 ng/ml) and TPO+SCF+IL-6+IL-9 (50 ng/ml+50 ng/ml+20 ng/ml+20 ng/ml). The bone marrow cells in 4 groups were cultured in vitro for 6 d. Then the cell growth status was observed by the inverted microscopy, and the cell count was detected by using the automatic cell counter. The ratio and absolute count of megakaryocytes were detected by flow cytometry. Compared with control, three induction methods could stimulate the differentiation of bone marrow cells into megakaryocytes in vitro. TPO could slightly enhance the differentiation of bone marrow cells into megakaryocytes. Both the combination of TPO and SCF, and the combination of TPO, SCF, IL-6 and IL-9 could intensively stimulate proliferation of bone morrow cells and promote the differentiation of bone marrow cells into megakaryocytes. The addition of IL-6 and IL-9 could decrease the proliferation of non-megakaryocytes, but promote the differentiation of bone marrow cells into megakaryocytes. The optimized differentiation of bone marrow cells into megakaryocytes has been completed by co-induction regimen of TPO, SCF, IL-6 and IL-9, which can be used to screen and evaluate traditional Chinese medicines promoting formation of platelets.

Triflumuron induces genotoxicity in both mice bone marrow cells and human Colon cancer cell line

Triflumuron (TFM) is an insect growth regulator (IGR), an insecticide commonly used over the world. It is known for its several toxic manifestations, such as reprotoxicity, immunotoxicity and hematotoxicity, which could affect public health. However, studies that reveal its toxic effects on mammalians are limited. To reach this purpose, our study aimed to elucidate the eventual genotoxic effects of TFM in mice bone marrow cells and in HCT 116 cells after a short term exposition. TFM was administered intraperitoneally to Balb/C male mice at doses of 250, 350 and 500 mg/kg bw for 24 h. Genotoxicity was monitored in bone marrow cells using the comet test, the micronucleus test and the chromosome aberration assay. Our results showed that TFM induced DNA damages in a dose-dependent manner. This genotoxicity was confirmed also in vitro on human intestinal cells HCT 116 using the comet test. It was then asked whether this genotoxicity induced by TFM could be due to an oxidative stress. Thus, we found that TFM significantly decreased HCT 116 cell viability. In addition, it induced the generation of reactive oxygen species (ROS) followed by lipid peroxidation as revealed by the increase in the malondialdehyde (MDA) levels. Similarly, the activation of the antioxidant enzymes (catalase and superoxide dismutase) was also observed. Our results indicated that, in our experimental conditions, TFM had a genotoxic effect on bone morrow cells and in HCT 116 cells. Moreover, we demonstrated that this genotoxicity passes through an oxidative stress.

Gexia-Zhuyu Decoction Attenuates Carbon Tetrachloride-Induced Liver Fibrosis in Mice Partly via Liver Angiogenesis Mediated by Myeloid Cells.

BackgroundThis study aims to demonstrate the underlying correlation between the resolution of liver fibrosis induced by Gexia-Zhuyu decoction (GZD) treatment and myeloid cell-mediated angiogenesis.Material/MethodsA liver fibrosis mouse model induced by carbon tetrachloride (CCl4) intervention was employed in this study. Dynamics of blood liver function parameters were followed. The liver pathology was detected by Sirius Red and Masson staining. Matrix metalloproteinase (MMP) 2/9, tissue inhibitors of metalloproteinase (TIMP)-1/2, and vascular endothelial growth factor (VEGF)-A expression levels were measured. Bone marrow chimera mice were generated by transfer of bone morrow cells from green fluorescent protein (GFP)-knockin mice into irradiated wild-type mice, and were used it to visualize the role of myeloid cells on the fibrosis resolution induced by GZD treatment.ResultsThe result of Sirius Red and Masson staining and the dynamics of blood liver function parameters showed that 5 weeks of GZD treatment attenuated the severity of liver fibrosis with continual CCl4 administration. GZD treatment promoted the expression of MMP2/9 and repressed the heightened level of TIMP-1/2 in the recovery phase. More notably, the increased VEGF-A and augmented endothelial progenitor cells were observed in the liver and blood in mice that received GZD, and contributed to the remodeling of hepatic vascular though the CXCL12/CXCR4 axis. Then, chimera mice with GFP-positive bone marrow cells were used to show angiogenesis driven by GZD-induced myeloid cell motivation. We found that GZD facilitated myeloid cells binding to the vascular CXCR4 and induced the resolution of fibrosis.ConclusionsThis study shows that activation of myeloid cells induced by GZD administration accelerates the functional angiogenesis, which benefits the resolution of CCl4-induced liver fibrosis.

Gata4-Dependent Differentiation of c-Kit+-Derived Endothelial Cells Underlies Artefactual Cardiomyocyte Regeneration in the Heart.

Although c-Kit+ adult progenitor cells were initially reported to produce new cardiomyocytes in the heart, recent genetic evidence suggests that such events are exceedingly rare. However, to determine if these rare events represent true de novo cardiomyocyte formation, we deleted the necessary cardiogenic transcription factors Gata4 and Gata6 from c-Kit-expressing cardiac progenitor cells. Kit allele-dependent lineage tracing and fusion analysis were performed in mice following simultaneous Gata4 and Gata6 cell type-specific deletion to examine rates of putative de novo cardiomyocyte formation from c-Kit+ cells. Bone marrow transplantation experiments were used to define the contribution of Kit allele-derived hematopoietic cells versus Kit lineage-dependent cells endogenous to the heart in contributing to apparent de novo lineage-traced cardiomyocytes. A Tie2CreERT2 transgene was also used to examine the global impact of Gata4 deletion on the mature cardiac endothelial cell network, which was further evaluated with select angiogenesis assays. Deletion of Gata4 in Kit lineage-derived endothelial cells or in total endothelial cells using the Tie2CreERT2 transgene, but not from bone morrow cells, resulted in profound endothelial cell expansion, defective endothelial cell differentiation, leukocyte infiltration into the heart, and a dramatic increase in Kit allele-dependent lineage-traced cardiomyocytes. However, this increase in labeled cardiomyocytes was an artefact of greater leukocyte-cardiomyocyte cellular fusion because of defective endothelial cell differentiation in the absence of Gata4. Past identification of presumed de novo cardiomyocyte formation in the heart from c-Kit+ cells using Kit allele lineage tracing appears to be an artefact of labeled leukocyte fusion with cardiomyocytes. Deletion of Gata4 from c-Kit+ endothelial progenitor cells or adult endothelial cells negatively impacted angiogenesis and capillary network integrity.

Minimal Residual Disease in Multiple Myeloma Patients: Influence on Indicators of Progression Free Survival

Background. Induction, consolidation of response and maintenance therapy are very effective approaches in the treatment of patients with multiple myeloma (MM). However, the majority of patients will inevitably relapse despite achieving progressively higher complete response (CR) rates. Activation of residual clonal plasmatic cells is a cause of relapse disease. Therefore, the assessment of minimal residual disease (MRD) is a strong prognostic factor for progression-free survival (PFS).Aim. To estimate influence of MRD on PFS indicators in MM patients. Methods. We analyzed 28 patients with MM (median age 56 years, male/female - 1.8:1). 5-color flow cytometry was used for immunophenotyping of bone morrow cells as well as definition of primary tumor cells phenotype and detection of MRD. Such markers as CD38, CD138, CD45, CD19, CD20, CD27, CD56 and CD117 were used to identify clonal plasma cells. In addition, MRD was assessed by FISH analysis in patients with genetic abnormalities; CT-PET carried out to patients with the MRD-negative CR.Results. Patients had bortezomib- or lenalidomide-based programs of therapy. Autologous stem cell transplantation (ASCT) was carried out in 18 patients. Performing ASCT statistically significantly increased frequency of MRD-negative CR (p<.01). Before ASCT MRD-negative CR was reached in 3/28 (10,7%) patients. After ASCT 9/18 (50,0%) patients were transferred to the MRD-negative group (6/9 patients before ASCT had MRD-positive CR, 1/9 - MRD status did not change, 2/9 - stringent CR was reached). One patient with MRD-negative CR had CT-PET positive specific lesions. 19/28 (67,8%) patients were transferred to the MRD-positive group (9/19 patients had CR, 5/19 - VGPR, 5/19 - PR). The median PFS didn’t correlate with ASCT in general and the MRD-positive groups (р>.05). PFS in the MRD-negative group was better than in the MRD-positive group with CR (median was not reached vs median of 63.9 months, respectively; 2-year PFS was 100% vs 77%, respectively) (p=.0048). In addition, we analyzed the influence of CR in the MRD-positive group on PFS. Absence of CR is an inferior prognostic factor and is characterized by decrease of PFS in patients with MRD-positive status. The median PFS in the MRD-positive group with CR was 63.9 months and 26.0 months in the MRD-positive group without CR (VGPR and PR) (p=.049). Genetic abnormalities were detected in 7/26 (26.9%) patients before antimyeloma therapy: t(11;14) - in 5/26 (19.2%), del(13q) - in 3/26 (11.5%), t(4;14) - in 1/26 (3.8%), del(1p) - in 1/26 (3.8%). After treatment patients with CR (MRD-positive and MRD-negative) had normal genetic status by FISH. Only 1/7 patients with MRD-positive PR had residual clone with del(13q).Conclusion. Performing ASCT influences frequency of MRD-negative CR. The PFS indicators (median and 2-year PFS) were higher in the group of MM patients, who had MRD-negative status of the disease compared to than in the MRD-positive group. The FISH method had low sensitivity in detection of residual clone with genetic abnormalities, especially in patients with CR. DisclosuresShuvaev:BMS: Honoraria; Pfizer: Honoraria; Novartis pharma: Honoraria.

Functional Studies of Ex Vivo Expanded Hematopoietic Stem Cells in Mice and Monkeys

Hematopoietic stem cell (HSC) transplantation has been widely applied for the treatment of malignant blood diseases. However, obtaining sufficient HLA-matched stem/progenitors for cell transplantation is an obstacle for clinical applications.We reported here that an optimal cytokine cocktail in a modified IMDM basal medium was developed that contained stem cell factor, Flt-3 ligand, thrombopoietin, interleukin 3, G-CSF and GM-CSF. Up to 7.3 folds of expanded CD34+ cells with 66.3% CD34+ of whole cells were obtained after 4 days' culture from human umbilical cord blood. Colony-forming unit (CFU) assays showed that expanded CD34+ cells retained the same renewal ability as the pre-expanded counterparts. To test the repopulating ability of the expanded CD34+ in vivo, sixteen NOD/SCID mice were divided to four groups and injected with saline (group 1), 0.4 million pre-expanded CD34+ cells (group 2), 0.4 million 4-day expanded CD34+ cells (group 3), and 2.9 million expanded CD34+ cells (group 4), respectively. Multi-lineage differentiations in the peripheral blood were assessed by flow cytometry with antibodies against a panel of human cell surface markers. In week 3, human CD34+ cells were decreased below 1% in groups 2 and 3, and 1.717%±0.65% in group 4. Whereas, human CD45+ was increased up to 3.831%±1.54%, 3.108%±1.18% and 10.408%±3.27% for groups 2, 3 and 4, respectively. The other human CD41+, CD71+ and CD15+ were also increased in groups 2-4. No expression of any human cell lineage markers was detected in group 1, indicating that expanded human CD34+ cells possessed the repopulating viability of HSCs in vivo. Furthermore, in week 12, the human CD34+ cells were re-isolated from the bone morrow of the mice (one mouse from each group). The isolated human CD34+ cells were again transfused into new NOD/SCID mice for the secondary transplantation. In week 6, human CD45+, CD15+ and CD19+ were observed from the bone morrow cells of sacrificed mice. On the other hand, human CD45+, CD15+ and CD19+ were also detectable in bone morrow cells for all remaining mice in week 24, suggesting that the expanded CD34+ cells could be successfully engrafted into mice in a long term.In addition, the cytokine cocktail was further evaluated for its safety and efficacy in primates. The CD34+ cells were isolated from the peripheral blood of cynomolgus monkeys and expanded for about 8 folds were obtained on day 9. Harvested CD34+ cells were transducted with the gene of green fluorescent protein (GFP). These cynomolgus monkeys (n=11) were administered with cyclophosphamide via intravenous injection at a dose of 50 mg/kg/day for two days. The myelo-suppressed monkeys were randomly divided into three groups as follows: a control group treated with saline (n=3), a group with autologous CD34- cells (n=3), and a group treated with GFP-labeled, expanded autologous CD34+ cells (n=5), respectively. After autologous transplantation, routine blood tests and flow cytometry analysis were performed to determine the proportion of GFP+ cells in the peripheral blood.The flow cytometry analysis revealed that the white blood cells (WBC), neutrophil (NEU) and platelets (PLT) in peripheral blood of cynomolgus monkeys were completely recovered to the normal levels on days 12, 11 and 10 post autologous transplantation of expended CD34+ cells, respectively. For the control groups, WBC, NEU and PLT returned to the normal on days 22, 22 and 12 for the saline treatment and on days 20, 20 and 12 for the CD34- group, respectively. Similarly, the lymphocytes of cynomolgus monkeys were recovered completely on day 20 post autologous CD34+ cell transplantation compared with the saline control (day 25) and the CD34- group (day 22). On day 30 after the autologous transplantation, the GFP+ ratio in CD45+ populations was around 2% in the peripheral blood. GFP+ cells (ranging from 1.8% to 4.1%) were also detected in bone morrow of cynomolgus monkeys. All primates transplanted with the expanded autologous CD34+ cells have survived for 18 months without any noticeable abnormalities.In conclusion, our results indicate that expanded CD34+ cells can be safely and efficiently used for repopulating stem cell compartment in mice and primates, underscoring the potential applications in the clinic. Furthermore, the results from successful autologous transplantation of cynomolgus CD34+ cells strongly suggest a possible application for personalized treatment of blood diseases. DisclosuresQin:Biopharmagen. corp: Employment. Ren:Biopharmagen corp: Employment.

GNB1 Activating Mutations Promote Myeloid and Lymphoid Neoplasms Targetable By Combined PI3K/mTOR Inhibition

GNB1 encodes a beta subunit (Gβ) of heterotrimeric G proteins, which mediate signals downstream of G protein coupled receptors (GPCRs). We isolated a somatic mutant of GNB1 (K89E) by functional screening of a cDNA library derived from a blastic plasmacytoid dendritic cell neoplasm (BPDCN). A search of cancer genome databases identified recurrent mutations in GNB1 and the highly related protein GNB2. GNB1/2 K89E/T were found in B cell acute lymphoblastic leukemia (B-ALL) (1 case), follicular lymphoma (1) and myelodysplastic syndrome (MDS) (1) as well as BPDCN (1). Interestingly GNB1 K57E/T mutations were found only in myeloid diseases: [acute myeloid leukemia (2), atypical CML (2), polycythemia vera (1) and MDS (6)], while GNB1 I80N/T were found predominantly in B cell diseases [CLL (2), FL (2), DLBCL (1) and MDS (1)]. These mutated codons are all located on the GNB1 protein surface that is critical for interactions between Gβ and alpha subunits (Gα) or downstream effectors. Immunoprecipitation followed by mass spectrometry demonstrated that GNB1 K57E, I80T and K89E mutants failed to bind Gα, including GNAI2/3, GNA11/Q and GNA13 that are normally bound by wild-type (WT) GNB1. All mutations affecting these codons promoted cytokine-independent growth of human TF1 myeloid cells or mouse BaF3 lymphoid cells with activation of MEK/ERK and mTOR/PI3K pathways. Pertussis toxin treatment did not affect GNB1-dependent ERK activation or cell growth, implying a Gα-independent pathway. To investigate the function of GNB1 mutations in vivo, we performed a mouse bone marrow transplantation (BMT) experiment using wild-type and Cdkn2a-deficient donors. Loss of the cell cycle regulator CDKN2A is common in BPDCN, B-ALL, and several other hematologic malignancies. Bone marrow cells were isolated from 5-FU treated donor mice and infected with retrovirus expressing GNB1 WT, K57E, I80T or K89E. Transplantation of GNB1 mutant-expressing Cdkn2a-deficient bone marrow resulted in myeloid dendritic cell neoplasms that were CD11b+, CD11c+, CD19-, B220-, and CD3-. GNB1 mutants did not induce tumors in WT bone marrow after 12 months of observation suggesting that GNB1 requires additional cooperating mutations such as Cdkn2a loss. We performed the same BMT experiment using Cdkn2a-deficient bone morrow cells without 5-FU pretreatment. We found thatGNB1 I80T and K89E mutants induced a progenitor B cell ALL (CD11b-, CD11c-, CD19+, CD3-, TdT+). These data suggest that GNB1 mutations can promote tumorigenesis in more than one cell lineage, as observed in patients. In vivo treatment of the myeloid neoplasm with the dual PI3K/mTOR inhibitor BEZ235 suppressed GNB1-induced signaling and markedly increased survival. In several human tumors, we noted that GNB1 mutations co-occurred with oncogenic kinase alterations, including BCR/ABL, JAK2 V617F and BRAF V600K. Co-expression of patient-derived GNB1 alleles with the mutant kinases resulted in relative resistance to treatment with the corresponding kinase inhibitor in each context. Thus, GNB1 and GNB2 mutations confer transformation and targeted therapy resistance across a range of human tumors and may be targetable with inhibitors of PI3K/mTOR signaling. DisclosuresGotlib:Novartis Pharmaceuticals Corporation: Membership on an entity’s Board of Directors or advisory committees, Research Funding, Travel Support Other. Deininger:BMS, Novartis, Celgene, Genzyme, Gilead: Research Funding; BMS, ARIAD, Novartis, Incyte, Pfizer: Advisory Board, Advisory Board Other; BMS, ARIAD, Novartis, Incyte, Pfizer: Consultancy. Tyner:Constellation Pharmaceuticals: Research Funding.

Protective effect of cactus cladode extract against cisplatin induced oxidative stress, genotoxicity and apoptosis in balb/c mice: combination with phytochemical composition.

BackgroundCis-Platinum (II) (cis-diammine dichloroplatinum; CDDP) is a potent antitumor compound widely used for the treatment of many malignancies. An important side-effect of CDDP is nephrotoxicity. The cytotoxic action of this drug is often thought to induce oxidative stress and be associated with its ability to bind DNA to form CDDP–DNA adducts and apoptosis in kidney cells. In this study, the protective effect of cactus cladode extract (CCE) against CDDP-induced oxidative stress and genotoxicity were investigated in mice. We also looked for levels of malondialdehyde (MDA), catalase activity, superoxide dismutase (SOD) activity, chromosome aberrations (CA) test, SOS Chromotest, expressions of p53, bax and bcl2 in kidney and we also analyzed several parameters of renal function markers toxicity such as serum biochemical analysis.MethodsAdult, healthy balb/c (20–25 g) male mice aged of 4–5 weeks were pre-treated by intraperitonial administration of CCE (50 mg/Kg.b.w) for 2 weeks. Control animals were treated 3 days a week for 4 weeks by intraperitonial administration of 100 μg/Kg.b.w CDDP. Animals which treated by CDDP and CCE were divided into two groups: the first group was administrated CCE 2 hours before each treatment with CDDP 3 days a week for 4 weeks. The second group was administrated without pre-treatment with CCE but this extract was administrated 24 hours after each treatment with CDDP 3 days a week for 4 weeks.ResultsOur results showed that CDDP induced significant alterations in all tested oxidative stress markers. In addition it induced CA in bone morrow cells, increased the expression of pro-apoptotic proteins p53 and bax and decreased the expression of anti-apoptotic protein bcl2 in kidney. On the other hand, CDDP significantly increased the levels of urea and creatinine and decreased the levels of albumin and total protein.The treatment of CCE before or after treatment with CDDP showed, (i) a total reduction of CDDP induced oxidative damage for all tested markers, (ii) an anti-genotoxic effect resulting in an efficient prevention of chromosomal aberrations compared to the group treated with CDDP alone (iii) restriction of the effect of CDDP by differential modulation of the expression of p53 which is decreased as well as its associated genes such as bax and bcl2, (iiii) restriction of serums levels of creatinine, urea, albumin and total protein resuming its values towards near normal levels of control.ConclusionWe concluded that CCE is beneficial in CDDP-induced kidney dysfunction in mice via its anti-oxidant anti-genotoxic and anti-apoptotic properties against CDDP.

Abstract P034: Bone Marrow--Derived Cells Are Not an Essential Component in Cardiosphere Formation

Background: Cardiospheres (CS) are composed of heterogeneous population of cells but it is unknown whether bone marrow derived cells are an essential cell component in CS formation. Methods: Chimera mice were generated by transplantation of bone morrow cells from GFP transgenic mice to irradiated C57BL mice. Mice were randomized into 3 groups 5 months after transplantation: 1) myocardial infarction; 2) sham operated; 3) un-operated (n=5/group). Hearts were harvested 2-weeks post-surgery. Cardiac explants were cultured and putative cardiosphere forming cells (CFCs) (small cells migrating out from the explants) were collected 14 days later and reseeded on new culture dishes for CS formation. The number of CS from each heart was counted at 3 days. CS cell composition was analyzed by FACS. To further analyze the role of bone marrow derived CD45+ cells in forming CS, CD45+ cells was isolated from CFCs by CD45 antibody coated immunomagnetic beads. The number of CS formed from 1×10 5 putative CFCs, CFCs without CD45+ cells and CD45+ cells from CFCs (n=6-9/cell type) respectively were also counted at 3 days in culture. Results: Compared to sham (122± 23/heart) and un-operated hearts (18± 5/heart), infarcted hearts formed more CS (357± 64/heart, P&lt;0.01). In all groups, irrespective of any surgery, 18.4± 4.5% of cells in CS co-expressed GFP and CD45, indicating they originated in bone marrow. Low percentage of bone marrow stem/progenitor cells (3.9% Sca-1+GFP+CD45+ and 1% c-Kit+GFP+CD45+ cells) were detected in CS, but a high percentage of cells within CS were cardiac stem/progenitor cells (26.3± 9.4% cells were Sca-1+GFP-CD45-, 0.10± 0.04% c-Kit+GFP-CD45-). Depleting CD45+ cells from putative CFCs actually increased the formation of CS (67±10 CS/1×10 5 cells) compared to un-depleted CFCs (51± 6 CS/1×10 5 cells, P&lt;0.0001). Purified CD45+ cells from CFCs did not form CS in culture. Conclusion: Myocardial infarction increases the formation of CS in culture. Bone marrow derived CD45+ cells make up a small percentage of CS, but are not necessary for CS formation.

Hepatoprotective effect of cactus extract against carcinogenicity of benzo(a)pyrene on liver of Balb/C mice

The cactus Opuntia ficus-indica is a xerophyte plant it has an increasing interest of nutritional and pharmacological power. In the present study we choose cactus cladode extract (CCE) to investigate its efficacy against benzo(a)pyrene (BAP) a widespread environmental genotoxin classified as probably carcinogenic to humans witch induced liver injury. Our results using balb/c mice clearly showed that BAP induced significant alterations in all tested oxidative stress markers the malondialdehyde level (MDA), the catalase activity and the expression of the heat shock proteins (Hsp 70) and (Hsp 27) which increased. In addition, it induces deoxyriboNucleic acid (DNA) fragmentation in liver and chromosomal aberrations in bone morrow cells. Moreover it increases the expression of anti apoptotic proteins bcl2 and decrease the expression of bax. The treatment of CCE after or before treatment with BAP showed a total reduction of BAP induced oxidative damage for all tested markers, it showed also an antigenotoxic effect compared to the group treated with BAP alone, CCE was able to restrict the effect of BAP by differential modulation of the expression of p53 which is increased and its associated genes such as bax and bcl2. We concluded that CCE was effective in the protection against BAP hazards.

In vivo and in vitro effect of peptide HP-6 derived from donkey serum albumin on hematopoietic system

By bioinformatics method, the effect in hematopoietic system of bioactive peptide HP-6, which was obtained from donkey serum albumin and is one of the major protein components from donkey-hide gelatin, was investigated. Human bone marrow nucleated cells (hBMNCs) and murine bone marrow stromal cells (mBMSCs) were separated and cultured with different concentration of peptide HP-6 (0.000 15, 0.001 5, 0.015, 0.15, 1.5 micromol x L(-1)). The effect on promoting proliferation of cells related to hematopoiesis in bone morrow was detected and the ultrastructure of cells after treated by HP-6 was observed through transmission electron microscope. Hemorrhage anemia mouse model and anemia mouse model induced by cyclophosphamide were established, and randomly divided into peptide HP-6 groups which were administered respectively with different doses (1, 0.1, 0.01 mg x kg(-1)) by gavage, and control group which was administered with PBS by gavage. Peripheral blood components of all mice and bone morrow cells (BMC) number of mice induced by cyclophosphamide were evaluated. Peptide HP-6 could concentration-related promote the proliferation of hBMNCs and mBMSCs, hBMNCs got the highest reproduction rate of 152.11% and mBMSCs also got 63.52% with the concentration of 0.15 micromol x L(-1), then the reproduction rate decreased while the concentration kept increasing. The transmission electron microscope showed that ultrastructure of cells was normal after treated by HP-6.1 mg x kg(-1) peptide HP-6 significantly increased peripheral platelet and protected mouse morrow injured by cyclophoshamide. 0.1 mg x kg(-1) peptide HP-6 significantly increased peripheral platelet with relative growth rate of 77.65%, increased peripheral white blood cells count and peripheral red blood cells count, also could protect mouse peripheral blood after treated by chemotherapeutics. Peptide HP-6 could promote the proliferation of cells related to hematopoietic system, enhance mouse hemopoiesis function and the resistance to chemotherapeutic injury.

Tissue Distribution of Mesenchymal Stem Cell Marker Stro-1

Stro-1 is the best-known mesenchymal stem cell marker. However, despite its bone marrow origin, its localization in bone marrow has never been demonstrated. By immunofluorescence staining, we show here that ∼ 0.74% of nucleated bone marrow cells expressed Stro-1. We also found that ∼ 8.7% of CD34-expressing cells expressed Stro-1, and more than 20% of Stro-1-expressing cells did not express CD34. In adipose tissue Stro-1 expression was identified in the endothelium of arterioles and capillaries. Stro-1 was also localized in the endothelium of some but not all adipose tissue veins. Endothelial expression of Stro-1 was also identified in blood vessels in penis and in leg muscles, but not in other tested tissues. In these other tissues, Stro-1 was scantly expressed near but not in blood vessels. These variable and endothelial expression patterns of Stro-1 point to a need to re-examine published data that relied on Stro-1 as a mesenchymal stem cell marker.

Novel role of curcumin combined with bone marrow transplantation in reversing experimental diabetes: Effects on pancreatic islet regeneration, oxidative stress, and inflammatory cytokines

Therapeutic utility of bone marrow transplantation in diabetes is an attractive approach. However, the oxidative stress generated by hyperglycemia may hinder β-cell regeneration. The present study was undertaken to investigate the therapeutic potential of curcumin, a dietary spice with antioxidant activity, bone marrow transplantation, and their combined effects in the reversal of experimental diabetes. Diabetes was induced in mice by multiple low doses of streptozotocin. After the onset of diabetes, mice were treated with curcumin (10 mM; 100 μl/mouse, i.p., for 28 days) or received a single bone marrow transplantation (10 6 un-fractionated bone morrow cells), or both. Parameters of diabetes, integrity of pancreatic islets, pancreatic oxidative stress markers, and serum pro-inflammatory cytokines, were evaluated. Treatment with either curcumin or bone marrow transplantation significantly reversed streptozotocin-induced hyperglycemia/glucose intolerance, hypoinsulinemia, and damage of pancreatic islets. Interestingly, combination of curcumin and bone marrow transplantation elicited the most profound alleviation of such streptozotocin-evoked anomalies; including islet regeneration/insulin secretion. On the other hand, curcumin, either alone or combined with bone marrow transplantation, blunted the pancreatic lipid-peroxidation, up-regulated activities of the antioxidant enzymes, and suppressed serum levels of TNF-α and IL-1β. Curcumin and single bone marrow transplantation proved their therapeutic potential in reversing diabetes when used in combination. Curcumin, via its antioxidant and anti-inflammatory effects, evidently enhanced the ability of bone marrow transplantation to regenerate functional pancreatic islets. Hence, the use of natural antioxidants combined with other therapeutic regimens to induce pancreatic regeneration is a promising strategy in the management of diabetes.

Transplanted bone marrow stem cells relocate to infarct penumbra and co-express endogenous proliferative and immature neuronal markers in a mouse model of ischemic cerebral stroke

BackgroundSeveral studies demonstrate that neurogenesis may be induced or activated following vascular insults, which may be important for neuronal regeneration and functional recovery. Understanding the cellular mechanism underlying stroke-associated neurogenesis is of neurobiological as well as neurological/clinical relevance. The present study attempted to explore potential homing and early development of transplanted bone marrow stem cells in mouse forebrain after focal occlusion of the middle cerebral artery, an experimental model of ischemic stroke.ResultsBone marrow stem cells isolated from donor mice were confirmed by analysis of surface antigen profile, and were pre-labeled with a lipophilic fluorescent dye PKH26, and subsequently transfused into recipient mice with middle cerebral artery coagulation. A large number of PKH26-labeled cells were detected surrounding the infarct site, most of which colocalized with immunolabelings for the proliferating cell nuclear antigen (PCNA) and some also colocalized with the immature neuronal marker doublecortin (DCX) during 1-2 weeks after the bone marrow cells transfusion.ConclusionsThe present study shows that transplanted bone morrow cells largely relocate to the infarct penumbra in ischemic mouse cerebrum. These transplanted bone marrow cells appear to undergo a process of in situ proliferation and develop into putative cortical interneurons during the early phase of experimental vascular injury.

Prospective In Vivo Identification of Osteogenic Stem/Progenitor Cells from Bone Marrow-Derived Lin−/Sca-1+/CD45− Cells.

We previously developed an in vivo prospective assay for identification of non-cultured cells with MSC potential. Using this assay we identified a population of cells that were slowly cycling and of low density that were capable of multilineage differentiation both in vitro and in vivo (Z. Wang et al, Stem Cells. 2006 24(6):1573). Further characterization of these cells suggested that they resemble a homogenous population of rare Lin−/Sca-1+/CD45− cells that have the morphology and express several markers of undifferentiated embryonic-like stem cells. In vitro the Lin−/Sca-1+/CD45− cells may differentiate into cells from all three germ-layers (M. Kucia et al, Leukemia. 2007 21(2):297). To determine the in vivo fate of this population, we transplanted 500 or 5,000 Lin−/Sca-1+/CD45− cells from a GFP mouse into SCID mice in each group (n=3) immediately after cell sorting to evaluate tissue generation in vivo. At 4 weeks the regenerative potential of these populations was evaluated by micro-CT and histology, and cells were tracked by gross examination of the harvested tissues by fluorescent microscopy. The results showed that a large number of GFP+ cells are located in the implants, indicating that the transplanted cells maintain the ability to contribute to the generation of new tissue. Bone-like tissue was observed in the Lin−/Sca-1+/CD45− group with as low as 500-cells/implant, while 5,000 Lin−/Sca-1+/CD45− cells generated significantly larger mineralized tissue volume, which was confirmed by micro-CT. Lin−/Sca-1+/CD45+ cell only implantation did not form any mineralized tissue, however, while mixed with 2x106 whole bone morrow cells, positive mineralized tissue occurred. Whole bone marrow mixture also improve bone formation in Lin−/Sca-1+/CD45− cell implants compared the actual bone volumes measured by micro-CT. This study demonstrates that non-cultured BM-derived Lin−/Sca-1+/CD45− cells exhibit the capacity to form bone in vivo with as low as 500 cells/implant. Whole bone marrow mixtures can enhance the bone formation, presumably through the interaction of other populations cells. Based on these findings, it is proposed that non-cultured BM-derived Lin−/Sca-1+/CD45− cells are enriched osteogenic cells that can be applied to bone regeneration in vivo.

Comparison of genetic changes between interphase and metaphase nuclei in monitoring CML and APL treatment using DC-FISH technique

In leukemias, the monitoring techniques on the response after the treatment have clinical importance for evaluating new therapeutic approaches and identifying the risk of relapse. In this study, genetic changes before and after chemotherapy in interphase and metaphase nuclei of bone morrow of adults with provisional diagnosis of leukemia were compared to understand the molecular characterization and pathogenesis of the leukemia for the classification of diagnosis and prognosis. We examined bone morrow cells of 47 chronic myeloid leukemia (CML) cases (29 of 47 at the time of diagnosis, 31 of 47 after chemotherapy) with the bcr/abl translocation probes and of 10 acute promyelocytic leukemia (APL) cases (7 of 10 at the time of diagnosis, 4 of 10 after chemotherapy) with the PML/RAR_ translocation probes by using dual color-flourescence in situ hybridization (DC-FISH). For each case, 400 interphase nuclei and 11 to 25 metaphases nuclei were analysed. The ratios of translocations before and after chemotherapy were compared between interphase and metaphase nuclei. After chemotherapy, though, translocations were detected in interphase nuclei of 29 of the 31 CML and 4 of the 4 APL cases, these translocations were determined in metaphase nuclei of only 14 of the 31 CML and 1 of the 4 APL cases with very low ratios (p<0.01). The results showed that the rates of translocation positive interphase nuclei were higher than the rates of translocation positive metaphase nuclei (p<0.01) after chemotherapy, so there may be some factors effecting proliferative activity of metaphase formation in leukemias.

Nitric oxide inhibition decreases bleomycin-detectable iron in spleen, bone marrow cells and heart but not in liver in exercise rats.

The possible role of nitric oxide on the exercise-induced changes in bleomycin-detectable iron (BDI) in the liver, spleen, bone marrow cells and heart was investigated. Female Sprague-Dawley rats were randomly assigned to four groups: S1 (Sedentary), S2 (Sedentary + L-NAME [N-nitro-L-arginine methyl ester]), E1 (Exercise) and E2 (Exercise + L-NAME). Animals in the E1 and E2 swam for 2 h/day for 3 months. L-NAME in the drinking water (1 mg/ml) was administrated to rats in the S2 and E2 groups for the same period. At the end of the 3rd month, nitrite and nitrate (NOx), BDI and non-heme iron (NHI) contents in the liver, spleen, bone marrow cells and heart were measured. The ratio of BDI/NHI was calculated. The exercise induced a significant increase in NOx and BDI contents and/or BDI/NHI ratio in the spleen, bone morrow cells and heart. Treatment with L-NAME, an inhibitor of NOS, led to a significant decrease in NOx and an increase in BDI levels and BDI/NHI ratios in these tissues. The correlative analysis showed that there is significantly positive correlation between NOx levels and BDI contents and/or BDI/NHI ratios in the spleen, bone marrow cells and heart. These results suggest that the increased nitric oxide might be one of the reasons leading to the increased BDI levels in these tissues in the exercised rats. In contrast to the above tissues, in the liver, exercise led to a significant decrease rather than increase in BDI levels and BDI/NHI ratios with a significant increase in NOx contents. Treatment with L-NAME led to a significant increase in BDI levels and BDI/NHI ratios and a decrease in NOx contents in the tissue. These findings plus the results reported by others imply that nitric oxide might have an inhibitory effect on BDI in the liver.

In vivo effect of gamma ray pretreatment on sister-chromatid exchange induction by mitomycin C in murine bone marrow cells

The effect of gamma ray pretreatment on sister-chromatid exchange induction by mitomycin C (MMC) was determined in murine bone morrow cells in vivo. A 30% reduction in the expected SCE frequency was observed assuming an additive effect. These results support the prediction of the replicative model for SCE formation with regard to the interactions between mutagens, and confirm previous results focused on the adaptive response.