Chemokine system and tissue infiltration in aggressive NK-cell leukemia

NK cell-type lymphoproliferative disease of granular lymphocytes can be subdivided into aggressive NK-cell leukemia (ANKL) and chronic NK-cell lymphocytosis (CNKL). Hepatosplenomegaly is observed in ANKL patients, and hepatic failure is a common cause of death. Significant numbers of ANKL cells were pathologically observed in sinusoidal and interlobular regions of the liver, and in the splenic red pulp. In our previous study, ANKL cells were simultaneously positive for CXCR1 and CCR5. So, in order to elucidate the mechanism in the systemic migration of ANKL cells, we investigated the expression of the corresponding chemokines in ANKL compared with CNKL. The serum level of IL-8, MIP-1alpha and MIP-1beta was significantly elevated in ANKL patients, and ANKL cells were highly positive for IL-8, RANTES, MIP-1alpha and MIP-1beta according to intracellular staining and RT-PCR. These chemokines were also positively stained in hepatocytes. The interaction between Fas and Fas ligand (FasL) is supposed to be one of the mechanisms for liver dysfunction in ANKL. The serum concentration of soluble FasL was significantly high in ANKL patients, and ANKL cells expressed FasL protein in the cytoplasm. These results suggest that the chemokine system plays an important role in the transmigration of FasL-expressing ANKL cells.

A complex karyotype, including a three-way translocation generating a NUP98-HOXD13 transcript, in an infant with acute myeloid leukemia

We report the case of an infant with acute myeloblastic leukemia who had the abnormal karyotype 46,XX,t(2;11;9)(q31;p15;q22),t(6;11;15)(q21;q23;q22),t(8;10)(q13;q22). At relapse, a different three-way translocation emerged. Fluorescence in situ hybridization and a reverse transcription-polymerase chain reaction assay detected the NUP98-HOXD13 fusion gene in bone marrow cells of the patient at diagnosis and at relapse. Sequence analysis showed that exon 12 of NUP98 was fused in-frame with exon 2 of HOXD13. The patient had neither a rearrangement of the MLL gene nor aberrations for FLT3, KIT, NRAS, KRAS, or PTPN11. The NUP98-HOXD13 fusion transcript created by t(2;11;9)(q31;p15;q22) may play an important role in the leukemogenesis in this case.

Outcome of non-T-cell-depleted HLA-haploidentical hematopoietic stem cell transplantation from family donors in children and adolescents

Non-T-cell-depleted HLA-haploidentical hematopoietic stem cell transplantation (SCT) from family members has been reported, but its effectiveness and safety are not fully known. In this study, we examined the outcomes of 83 children and adolescents with nonmalignant (n = 11) or malignant (n = 72) disorders who underwent SCT mismatched at 2 or 3 HLA loci, either from the mother (n = 56), a noninherited maternal antigen (NIMA)-mismatched sibling (n = 14), or the father/a noninherited paternal antigen (NIPA)-mismatched sibling (n = 13). Engraftment was satisfactory. Severe (grade III-IV) acute graft-versushost disease (GVHD) was noted only in malignant disease, with an incidence of 21 of 64 evaluable patients. GVHD prophylaxis with a combination of tacrolimus and methotrexate was significantly associated with a lower risk of severe acute GVHD, compared with other types of prophylaxis (P = .04). Nine of 11 patients with nonmalignant disease and 29 of 72 patients with malignant disease were alive at a median follow-up of 26 months (range, 4-57 months). Outcomes were not significantly different among the 3 donor groups (mother versus NIMA-mismatched sibling versus father/NIPA-mismatched sibling) for the malignancy disorders. Our results indicate that non-T-cell-depleted HLA-haploidentical SCT may be feasible, with appropriate GVHD prophylaxis, for young recipients who lack immediate access to a conventional stem cell source.

In-crystal and surface charge transport of electric-field-induced carriers in organic single-crystal semiconductors

Gate-voltage dependence of carrier mobility is measured in high-performance field-effect transistors of rubrene single crystals by simultaneous detection of the longitudinal conductivity sigma(square) and Hall coefficient R(H). The Hall mobility mu(H) (identical with sigma(square)R(H)) reaches nearly 10 cm(2)/V s when relatively low-density carriers (<10(11) cm(-2)) distribute into the crystal. mu(H) rapidly decreases with higher-density carriers as they are essentially confined to the surface and are subjected to randomness of the amorphous gate insulators. The mechanism to realize high carrier mobility in the organic transistor devices involves intrinsic-semiconductor character of the high-purity organic crystals and diffusive bandlike carrier transport in the bulk.

Spontaneous improvement of hematologic abnormalities in patients having juvenile myelomonocytic leukemia with specific RAS mutations

Of 11 children with juvenile myelomonocytic leukemia (JMML) carrying RAS mutations (8 with NRAS mutations, 3 with KRAS2 mutations), 5 had a profound elevation in either or both the white blood cells and spleen size at diagnosis. Three patients had no or modest hepatosplenomegaly and mild leukocytosis at presentation but subsequently showed a marked increase in spleen size with or without hematologic exacerbation, for which nonintensive chemotherapy was initiated. The other three patients with NRAS or KRAS2 glycine to serine substitution received no chemotherapy, but hematologic improvement has been observed during a 2- to 4-year follow up. In the third group, all hematopoietic cell lineages analyzed had the RAS mutations at the time of hematologic improvement, whereas DNA obtained from the nails had the wild type. Additionally, numbers of circulating granulocyte-macrophage progenitors were significantly reduced during the clinical course. Thus, some patients with JMML with specific RAS mutations may have spontaneously improving disease.

A possible role for the production of multiple HLA antibodies in fatal platelet transfusion refractoriness after peripheral blood progenitor cell transplantation from the mother in a patient with relapsed leukemia

BACKGROUND

There has been controversy over whether HLA alloimmunization is a risk factor for platelet (PLT) transfusion refractoriness (PTR) in hematopoietic peripheral blood progenitor cell transplantation (HPBPCT).

STUDY DESIGN AND METHODS

Reported here is a boy with relapsed leukemia who developed fatal PTR after a peripheral blood progenitor cell transplantation (PBPCT) as a second HPBPCT from his mother. To elucidate the cause of PTR, a single-antigen assay (FlowPRA, One Lambda), a magnetic particles mixed passive hemagglutination test, and anti-human immunoglobulin-lymphocyte cytotoxicity test were performed on serum samples of the patient and his mother.

RESULTS

Although HLA Class I antibodies were absent in his serum sample before HPBPCT, the serum sample after the first bone marrow transplantation (BMT) reacted weakly with beads coated with multiple HLA Class I molecules. After PBPCT, the positive reaction markedly increased. Although HLA-B44 antibody emerged transiently after BMT, the apparent generation of antibodies against HLA-A2 and -A24 as well as HLA-B44 occurred after PBPCT. The continuous appearance of HLA Class I antibodies coincided with the duration of marked PTR after PBPCT. The patient, however, had no antibodies against PLT-specific glycoproteins. Unidentified HLA Class I-reactive antibodies were detected in maternal serum sample.

CONCLUSION

Although the patient appeared to be immunized to allogeneic HLA Class I molecules after BMT, profound HLA alloimmunization might have occurred after PBPCT in this case. It is possible that the administration of large numbers of immunocompetent cells sensitive to alloantigens at PBPCT causes the aberrant and persistent production of the HLA Class I antibodies.

Cooperative interaction between ETS1 and GFI1 transcription factors in the repression of Bax gene expression

The proto-oncoproteins ETS1 and growth factor independent-1 (GFI1) are implicated in cell growth and differentiation in various types of cells, and their deregulated expression is involved in malignant transformation. Here, we report that ETS1 and GFI1 interact and affect gene expression through their cross-talk. Co-immunoprecipitation analyses and glutathione-S-transferase pull-down assays revealed that ETS1 bound directly to GFI1 via its Ets domain, and GFI1 bound to ETS1 via its zinc-finger domain. Luciferase (Luc) assays using artificial reporters showed that GFI1 repressed ETS1-mediated transcriptional activation and ETS1 repressed GFI1-mediated transcriptional activation, in a dose-dependent manner. However, in the Bax promoter where the Ets- and Gfi-binding sites (EBS and GBS) are adjacent, ETS1 and GFI1 cooperatively reduced activation. Site-directed mutagenesis on the EBS and GBS of the Bax promoter showed that both binding sites were necessary for full repression. Chromatin immunoprecipitation analyses confirmed that an ETS1-GFI1 complex formed on the Bax promoter even when either EBS or GBS was mutated. Introduction of small interfering RNA against ETS1 and/or GFI1 enhanced endogenous Bax gene expression. Our results suggest that the interaction between ETS1 and GFI1 facilitates their binding to specific sites on the Bax promoter and represses Bax expression in vivo.

216 THE RELATIONSHIP BETWEEN OXYGEN CONSUMPTION RATE AND PREGNANCY RATE OF BOVINE EMBRYOS

A precise evaluation of embryo quality is important to estimate the suitability of embryo transfer to recipient animal. Recently, an objective evaluation method was reported for bovine embryos, in which the oxygen consumption of embryos can be noninvasively determined by scanning electrochemical microscopy (SECM) (Shiku et al. 2001 Anal. Chem. 73, 3751–3758). Trimarchi et al. (2000 Biol. Reprod. 62, 1866–1874) suggested that the oxygen consumption reflects the cell number and mitochondrial activity of embryos. The objectives of this study were (1) to examine the oxygen consumption of in vivo-derived embryos by SECM, (2) to investigate the relationship between oxygen consumption and morphological estimation of embryos, and (3) to assess the correlation among the oxygen consumption, embryo viability, and pregnancy rates. Fifty-six embryos were collected from Japanese Black cattle, which were superovulated with a total dose of 20 mg porcine FSH (FSH-R; Kawasaki Pharmaceutical Co., Ltd., Tokyo, Japan) followed by AI. The qualities of collected embryos at the stage of compacted morulae (CM), early blastocysts (EB), and blastocysts (BL) on Day 7 after AI were categorized as grade 1 and grade 2, according to the IETS manual (2002). The oxygen consumption rates of embryos were evaluated by SECM, as previously described by Abe et al. (2004 J. Mamm. Ova Res. 21). Embryos were frozen by programmable freezer in Dulbecco&apos;s PBS containing 1.5 M ethylene glycol, 0.1 M trehalose, and 20&percnt; calf serum. They were thawed by holding the straws in air for 8 s and then immersing them in a 30&deg;C water bath for 15 s. After thawing, the embryos were examined for oxygen consumption. Twenty-eight embryos were then cultured in TCM-199 supplemented with 20&percnt; fetal bovine serum and 0.1 mM &beta;-mercaptoethanol for 24 h to assess the viability of embryos by re-expansion of blastocole. The remaining 28 embryos were transferred to recipients. The pregnancy rates were determined by rectal palpation on Day 70. Data were analyzed by ANOVA. The consumption rates of BL embryos on Day 7 were significantly higher (P &lt; 0.05) than those of CM collected on the same day (0.84 vs. 1.29 &times; 10&minus;14 mol s&minus;1, respectively). A significant difference was also observed in consumption rates between grade 1 and 2 embryos at the BL stage (P &lt; 0.05). After freezing&ndash;thawing, the average oxygen consumption rates of embryos were 0.52 &times; 10&minus;14 mol s&minus;1 for CM (n &equals; 9), 0.67 &times; 10&minus;14 mol s&minus;1 for EB (n &equals; 8), and 0.96 &times; 10&minus;14 mol s&minus;1 for BL (n &equals; 11). The CM embryos with rates of &lt; 0.5 &times; 10&minus;14 mol s&minus;1 and the EB and BL embryos with those &lt; 0.6 &times; 10&minus;14 mol s&minus;1 did not show good morphological appearance after 24 h in culture. Pregnant animals were not obtained from embryos with rates &lt;0.5 &times; 10&minus;14 mol s&minus;1 for CM (n &equals; 5) and &lt;0.7 &times; 10&minus;14 mol s&minus;1 for EB (n &equals; 9). A high pregnancy rate (67&percnt;) was obtained from embryos with rates &gt;1.0 &times; 10&minus;14 mol s&minus;1 for BL (n &equals; 14). These results suggest that the measurement of oxygen consumption of embryos after embryo freezing and prior to embryo transfer may be useful for estimating embryo quality and suitability of embryo transfer.

Purification, Characterization and Cloning of Phospholipase D from Peanut Seeds

We purified phospholipase D (PLD) enzyme from peanut seeds, and the PLD enzyme eluted as two distinct peak fractions on Mono-Q chromatography, the first of which was characterized. N-terminal sequencing indicated that the N-terminus was blocked. The molecular mass of the purified enzyme was estimated to be 92 kDa by SDS-PAGE. The pH optimum of the enzyme was 5.0, and the Km value against its substrate phosphatidylcholine (PC), in the presence of 10 mM CaCl2 and 4 mM deoxycholate, was estimated to be 0.072 mM. The enzyme catalyzed two reactions, i.e., hydrolysis of PC generating phosphatidic acid (PA) and choline, and transphosphatidylation of the PA-moiety in the PC molecule to the acceptor glycerol, generating phosphatidylglycerol. Furthermore, we cloned two types of full-length cDNA, Ahpld1 and Ahpld2, each encoding distinct PLD molecules having 794 and 807 residues, respectively. The partial amino acid sequence of the purified PLD was consistent with the deduced sequence of AhPLD2.

Chromosomal change during 6-mercaptopurine (6-MP) therapy in juvenile myelomonocytic leukemia: the growth of a 6-MP-refractory clone that already exists at onset

Among 11 JMML children, two had an abnormal karyotype, and nine had a normal karyotype at onset. In one patient with trisomy 8 and four patients with a normal karyotype, a new clone with an aberrant karyotype emerged 1-14 months after 6-mercaptopurine (6-MP) therapy as shown by G-banding analyses. Fluorescence in situ hybridization disclosed that an abnormal clone existed in approximately 3-6% of bone marrow cells at onset or before 6-MP therapy in all the four cases examined, and increased to approximately 12-90% during the treatment. In culture with granulocyte-macrophage colony-stimulating factor, cytogenetically abnormal clones that proliferated during 6-MP therapy possessed significantly less sensitivity to the antimetabolite, compared with cells that decreased in numbers after the therapy. A PTPN11 mutation was detected in all of granulocyte-macrophage colonies irrespective of karyotypic aberration in one patient, whereas approximately 80% of erythroid colonies and 20% of mixed colonies possessed neither a PTPN11 mutation nor chromosomal abnormalities. The appearance of chromosomal aberrations shown by G-banding during 6-MP therapy in some JMML cases may result, in part, from the growth of a 6-MP-refractory clone that already exists at onset. It is possible that treatment with 6-MP promotes progression of the disease.

Four molecules of the 33 kDa haemagglutinin component of the Clostridium botulinum serotype C and D toxin complexes are required to aggregate erythrocytes

Normally, large-sized botulinum toxin complexes (L-TC) of serotype C and D are composed of a single neurotoxin, a single non-toxic non-haemagglutinin, two HA-70 molecules, four HA-33 molecules and four HA-17 molecules that assemble to form a 650 kDa L-TC. The 540 and 610 kDa TC species (designated here as L-TC2and L-TC3, respectively) were purified in addition to the 650 kDa L-TC from the culture supernatants of serotype D strains (D-4947 and D-CB16) and serotype C strains (C-6814 and C-Yoichi). The 650 kDa L-TC from D-4947, D-CB16 and C-6814 showed haemagglutination and erythrocyte-binding activity, but their L-TC2and L-TC3species had only binding activity. In contrast, every TC species from C-Yoichi having the C-terminally truncated variant of HA-33 exhibited neither haemagglutination activity nor erythrocyte-binding activity. Four strain-specific HA-33/HA-17 complexes were isolated from the 650 kDa L-TC of each strain. The 650 kDa HA-hybrid L-TCs were reconstituted by various combinations of isolated HA-33/HA-17 complexes and haemagglutination-negative L-TC2or L-TC3from each strain. HA-hybrid 650 kDa L-TC, including at least one HA-33/HA-17 complex derived from C-Yoichi, lost haemagglutination activity, leading to the conclusion that the binding of four HA-33 molecules is required for haemagglutination activity of botulinum L-TC. The results of the modelling approach indicated that the structure of a variant C-Yoichi HA-33 molecule reveals clear deformation of theβ-trefoil domain responsible for the carbohydrate recognition site.

Development of two cytogenetically abnormal clones from multipotential hematopoietic stem cells in a patient with juvenile myelomonocytic leukemia

We report a patient with juvenile myelomonocytic leukemia who had two cytogenetically independent clones at the time of diagnosis. Fluorescence in situ hybridization analyses showed that 42.5% of myeloperoxidase(+) cells and 27.3% of CD20(+) cells had three signals for chromosome 8, while 13.1% of myeloperoxidase(+) cells and 6.0% of CD20(+) cells had del (Y). However, a great majority of CD3(+) cells had no numerical aberration of the two chromosomes. The two karyotypically abnormal clones might have developed from multipotential hematopoietic stem cells with the potential to differentiate into myeloid and B-lymphoid lineages, but not T-lymphoid lineage.

Significance of chemokine receptor expression in aggressive NK cell leukemia

Natural killer (NK) cell-type lymphoproliferative diseases of granular lymphocytes can be subdivided into aggressive NK cell leukemia (ANKL) and chronic NK cell lymphocytosis (CNKL). One reason for the poor outcome in ANKL is leukemic infiltration into multiple organs. The mechanisms of cell trafficking associated with the chemokine system have been investigated in NK cells. To clarify the mechanism of systemic migration of leukemic NK cells, we enrolled nine ANKL and six CNKL cases, and analyzed the expression profiles and functions of chemokine receptors by flowcytometry and chemotaxis assay. CXCR1 was detected on NK cells in all groups, and CCR5 was positive in all ANKL cells. Proliferating NK cells were simultaneously positive for CXCR1 and CCR5 in all ANKL patients examined, and NK cells with this phenotype did not expand in CNKL patients or healthy donors. ANKL cells showed enhanced chemotaxis toward the ligands of these receptors. These results indicated that the chemokine system might play an important role in the pathophysiology of ANKL and that chemokine receptor profiling might be a novel tool for discriminating ANKL cells from benign NK cells.

Domino Liver Transplantation in Living Donors

Domino liver transplantation (DLT) has been developed as a method to expand the donor pool. In living donors DLT, the prime concern is to avoid any disadvantage to the donor and the first recipient. Seven DLTs were performed among 211 patients who underwent living donor liver transplantation. The domino recipients included six with hepatocellular carcinoma and one with citrullinemia. The domino grafts were obtained from patients with familial amyloid polyneuropathy (FAP) including the left liver in three cases and the right liver in four. Among the seven domino recipients, a 64-year-old woman with advanced hepatocellular carcinoma died of lung metastasis. The other six domino recipients are alive without FAP symptoms. In living donor liver transplantation, because the vessels of the graft from the first donor are not long enough for anastomosis, the hepatic vessels must be left as long as possible when removing the liver from the FAP patients in order to ensure sufficient safety for vascular reconstruction. With careful decision making during the procedure, such as where to divide the vessels in the FAP patients, DLT may help address the shortage of liver grafts.

Successful Unrelated Cord Blood Transplantation Using a Reduced-Intensity Conditioning Regimen in a 6-Month-Old Infant with Congenital Neutropenia Complicated by Severe Pneumonia

Here we report the first successful unrelated cord blood transplantation (CBT) using reduced-intensity conditioning for the 'treatment of congenital neutropenia in a 6-month-old infant with complications of severe pneumonia probably due to Staphylococcus aureus infection. Because the patient showed no response to treatment with granulocyte colony-stimulating factor and had a cytogenetic aberration, unrelated CBT with an HLA-DRB1 genotypic mismatch was performed. The number of infused cells was 15 x 10(7)/kg. The preparative regimen was fludarabine, cyclophosphamide, and 6 Gy of total body irradiation. Teicoplanin was administered for bacterial pneumonia. Neutrophil engraftment was achieved on day 41 and was followed by clinical improvement. The patient gradually caught up on growth and development after the CBT. Unrelated CBT using a reduced-intensity conditioning regimen may be an effective treatment for congenital neutropenia.

Conversion from tacrolimus to cyclosporine microemulsion therapy in liver transplant recipients

The calcineurin inhibitors cyclosporine and tacrolimus have distinct advantages and drawbacks. Therefore it is important to tailor their use to the patient's tolerance. In some patients, the need to ameliorate the adverse effects of tacrolimus may necessitate a switch to cyclosporine-based therapy. Rescue therapy with a cyclosporine microemulsion (Neoral)-based regimen for transplant patients intolerant of tacrolimus has been evaluated to assess the best method of switching and determine the initial and maintenance doses of Neoral in children and adults. Our aims were to evaluate not only these facets, but also the pharmacokinetics of Neoral in stable patients, including target 2-hour postdose blood concentrations (C2) of cyclosporine in liver transplant recipients. Eighteen liver transplant patients switched from tacrolimus to Neoral underwent a program of cyclosporine blood level monitoring. The conversions were conducted safely; the incidence of acute rejection episodes was low (11.1%). Statistical analysis showed that the C2 correlated with the area under the time-blood concentration curve of cyclosporine for 0 to 4 hours after dosing (R=0.970). We determined the maintenance doses of Neoral for pediatric and adult patients as well as the feasibility of C2 quantitated monitoring in liver transplantation.

STI571 inhibits growth and adhesion of human mast cells in culture

Stem cell factor (SCF)/c-kit system is critical for human mast cell development. We thus examined the effects of STI571, an inhibitor of the c-kit tyrosine kinase receptor, on the proliferation and function of human mast cells. STI571 at concentrations of 10(-6) M or higher almost completely abolished the SCF-dependent progeny generation from cord blood-derived cultured mast cells through an inhibition of the tyrosine phosphorylation of c-kit. The compound also suppressed the early phase of mast cell development. The extinction of mast cell growth induced by STI571 may be due largely to apoptosis according to the flow cytometric analysis and gel electrophoresis. Two-hour exposure to STI571 that failed to influence the total viable cell number suppressed adhesion of the cells to fibronectin in the presence of SCF without altering the expressions of integrin molecules. Our results may provide a fundamental insight for the clinical application of STI571 in allergic disorders.

Specific autoantibodies to platelet glycoproteins in Epstein-Barr virus-associated immune thrombocytopenia

In this study, we detected autoantibodies to platelet glycoproteins GPIIb/IIIa and GPIb/IX on platelets and in plasma in a patient with immune thrombocytopenia associated with Epstein-Barr virus-related infectious mononucleosis. In addition, we present our findings on the effectiveness of intravenous immunoglobulin therapy for immune thrombocytopenia associated with Epstein-Barr virus.

ARF tumor suppressor induces mitochondria-dependent apoptosis by modulation of mitochondrial Bcl-2 family proteins

A tumor suppressor gene product, ARF, sensitizes cells to apoptosis in the presence of appropriate collateral signals. In this study, we analyzed the mechanism of ARF-dependent apoptosis and demonstrated that ARF induces mitochondria-dependent apoptosis in p53 wild-type, ARF/p16-null cells. We also found that ARF evokes cytochrome c release from mitochondria, decreases mitochondrial membrane potential, and activates pro-caspase-9 to induce apoptosis. Our findings suggest that this apoptotic cellular modulation is brought about by up-regulation of the proapoptotic Bcl-2 family proteins Bax and Bim and down-regulation of antiapoptotic Bcl-2 in mitochondrial fractions. Additionally, ARF seems to down-regulate Bcl-2 in a p53-dependent manner while up-regulating Bax/Bim via a p53-independent pathway.

Analysis of long-chain polyprenols using supercritical fluid chromatography and matrix-assisted laser desorption ionization time-of-flight mass spectrometry

The separation of long-chain polyprenols was successfully achieved using supercritical fluid chromatography (SFC). Each 100-mer greater component was separated using tetrahydrofuran as a mobile phase modifier. The molecular mass distributions derived from SFC analyses agreed with the results of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analyses. The number-average molecular mass calculated by MALDI-TOF-MS data were also in accord with the results of quantitative 1H-NMR analysis of terminal groups. A combination of SFC and MALDI-TOF-MS analyses is a powerful tool for the elucidation of the complicated structures of natural polyprenols.

Replacement of nuclear protein by histone in pig sperm nuclei during in vitro fertilization

Sperm-specific nuclear protamines are dissociated before decondensation of sperm nuclei during fertilization in pigs. In the present study, replacement of nuclear protein by histone in boar spermatozoa during in vitro fertilization was evaluated by immunohistochemistry using anti-histone antibody. First, the specificity of the antibody used in this study was examined. Immunohistochemistry of the testes and epididymides indicated that somatic nuclei, but not elongated spermatids or maturing spermatozoa, were immunoreactive. Furthermore, immunoreaction was diminished after the antibody had been preincubated with unfractionated histone, indicating that the antibody was specific for the somatic nuclear histone. Immunohistochemistry of serial sections of oocytes, which were matured and co-cultured with boar spermatozoa for 2 to 6 h indicated that, at 2 to 3 h after insemination, penetrating sperm nuclei in the condensed state were not immunoreactive. At 4 to 5 h after insemination, some of the condensed sperm nuclei were immunoreactive in part or over the whole area of the nucleus, and all of the decondensing nuclei and male pronuclei were immunoreactive. At 6 h after insemination, the decondensing sperm nuclei and well-developed male pronuclei were immunoreactive. These results imply that, in pigs, remodelling of sperm nuclear protein from protamine to histone is initiated at the time of sperm penetration, before onset of decondensation and male pronuclear formation.

Replacement of nuclear protein by histone in pig sperm nuclei during in vitro fertilization

Sperm-specific nuclear protamines are dissociated before decondensation of sperm nuclei during fertilization in pigs. In the present study, replacement of nuclear protein by histone in boar spermatozoa during in vitro fertilization was evaluated by immunohistochemistry using anti-histone antibody. First, the specificity of the antibody used in this study was examined. Immunohistochemistry of the testes and epididymides indicated that somatic nuclei, but not elongated spermatids or maturing spermatozoa, were immunoreactive. Furthermore, immunoreaction was diminished after the antibody had been preincubated with unfractionated histone, indicating that the antibody was specific for the somatic nuclear histone. Immunohistochemistry of serial sections of oocytes, which were matured and co-cultured with boar spermatozoa for 2 to 6 h indicated that, at 2 to 3 h after insemination, penetrating sperm nuclei in the condensed state were not immunoreactive. At 4 to 5 h after insemination, some of the condensed sperm nuclei were immunoreactive in part or over the whole area of the nucleus, and all of the decondensing nuclei and male pronuclei were immunoreactive. At 6 h after insemination, the decondensing sperm nuclei and well-developed male pronuclei were immunoreactive. These results imply that, in pigs, remodelling of sperm nuclear protein from protamine to histone is initiated at the time of sperm penetration, before onset of decondensation and male pronuclear formation.

Synergism between stem cell factor and granulocyte-macrophage colony-stimulating factor on cell proliferation by induction of cyclins

Synergism between stem cell factor (SCF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to be essential for hematopoietic cell proliferation. Since HML-2 cells proliferate exponentially in the presence of SCF and GM-CSF together, we analyzed the molecular mechanism of the interaction between these two factors in the cells. An immediate-early gene product, c-myc, was additively upregulated in HML-2 cells by addition of a combination of SCF and GM-CSF. c-myc antisense oligonucleotides effectively suppressed cell proliferation and downregulated the induction of D3, E, A, and B cyclins in HML-2 cells stimulated with the two-factor combination. HML-2 cells arrested at the G0/G1 phase with SCF alone and expressed modest amounts of c-myc and cyclin D3, but not cyclin E. With GM-CSF treatment alone, the cells could not progress to the G2/M phase and expressed c-myc, cyclin D3 and cyclin E but not cyclins A or B. The addition of the counterpart cytokine resulted in cell cycle completion by induction of the deficient cyclins. Taken together, it appears that the induction of c-myc is an indispensable event in the proliferation of HML-2 cells and that the cytokines SCF and GM-CSF interact reciprocally for expression of all cyclins required for cell cycle progression.