Search PubMed⌕ Search

Biomedical subjects

Muneo Inaba

Publications and source records attributed to Muneo Inaba.

At least 19 recordsLinked to original sources
PubMed2005

Treatment of senile osteoporosis in SAMP6 mice by intra-bone marrow injection of allogeneic bone marrow cells.

A substrain of the senescence-accelerated mouse, SAMP6 (senescence-accelerated mouse prone 6), spontaneously develops osteoporosis early in life. Therefore, this strain is a useful animal model for developing new strategies for the treatment of osteoporosis in humans. We succeeded in treating osteoporosis in SAMP6 mice after the onset of this disease, using a newly developed method of bone marrow transplantation (BMT): Allogeneic bone marrow cells obtained from normal mouse strains were directly injected into the bone marrow cavity of irradiated SAMP6 mice (intra-bone marrow BMT [IBM-BMT]). After the treatment with IBM-BMT, hematolymphoid cells were completely reconstituted by donor-derived cells, and bone marrow stromal cells were also found to be of donor origin. The treated SAMP6 mice showed histologically-normal trabecular bone. In addition, bone mineral density and urinary deoxypiridinoline, a hallmark of bone destruction, were normalized. When the message levels of cytokines (tumor necrosis factor alpha, interleukin-6 [IL-6], IL-11, and receptor activator of nuclear factor-kappa B ligand [RANKL]) were examined, IL-11, RANKL (from bone marrow stromal cells), and IL-6 (from osteoclasts), which regulate bone remodeling, were restored to levels similar to those in normal B6 mice. These findings indicate that not only the hemopoietic system but also the bone marrow microenvironment were normalized after IBM-BMT, resulting in an amelioration of the imbalance between bone absorption and formation.

Amino Acids↗
PubMed2005

Neural cell adhesion molecule contributes to hemopoiesis-supporting capacity of stromal cell lines.

To clarify mechanisms underlying cell-to-cell interactions between hemopoietic stem cells (HSCs) and stromal cells, we established a stromal cell line (FMS/PA6-P) from day-16 fetal bone marrow (BM) adherent cells using an anti-PA6 monoclonal antibody (mAb) specific for BM stromal cells. Importantly, this FMS/PA6-P cell line, showing homogenous fibroblastic morphology, is absent from hematolymphoid and endothelial lineage markers and maintains a high level of expression of PA6 molecule, recognized by the anti-PA6 mAb, for approximately 20 passages. Further, the cell line expressing a high level of PA6 molecule has a better hemopoiesis-supporting capacity in vitro than other stromal cell lines such as PA6 and MS-5. In fact, the PA6 molecule is closely related to the hemopoiesis-supporting capacity of the stromal cells because the proliferation of HSCs was suppressed to a great extent by the anti-PA6 mAb. Affinity chromatography and mass peptide fingerprinting revealed that the protein reacting with the anti-PA6 mAb is neural cell adhesion molecule (NCAM). The frequencies of long-term cobblestone area-forming cells and long-term culture-initiating cells were significantly suppressed by repression of NCAM in the FMS/PA6-P cells using NCAM small interfering RNA. Our findings clearly indicate that NCAM functions on the maintenance of HSCs.

Animals↗
PubMed2005

Antioxidant mechanism of heme oxygenase-1 involves an increase in superoxide dismutase and catalase in experimental diabetes.

Increased heme oxygenase (HO)-1 activity attenuates endothelial cell apoptosis and decreases superoxide anion (O2-) formation in experimental diabetes by unknown mechanisms. We examined the effect of HO-1 protein and HO activity on extracellular SOD (EC-SOD), catalase, O2-, inducible nitric oxide synthase (iNOS), and endothelial nitric oxide synthase (eNOS) levels and vascular responses to ACh in control and diabetic rats. Vascular EC-SOD and plasma catalase activities were significantly reduced in diabetic compared with nondiabetic rats (P < 0.05). Upregulation of HO-1 expression by intermittent administration of cobalt protoporphyrin, an inducer of HO-1 protein and activity, resulted in a robust increase in EC-SOD but no significant change in Cu-Zn-SOD. Administration of tin mesoporphyrin, an inhibitor of HO-1 activity, decreased EC-SOD protein. Increased HO-1 activity in diabetic rats was associated with a decrease in iNOS but increases in eNOS and plasma catalase activity. On the other hand, aortic ring segments from diabetic rats exhibited a significant reduction in vascular relaxation to ACh, which was reversed with cobalt protoporphyrin treatment. These data demonstrate that an increase in HO-1 protein and activity, i.e., CO and bilirubin production, in diabetic rats brings about a robust increase in EC-SOD, catalase, and eNOS with a concomitant increase in endothelial relaxation and a decrease in O2-. These observations in experimental diabetes suggest that the vascular cytoprotective mechanism of HO-1 against oxidative stress requires an increase in EC-SOD and catalase.

Acetylcholine↗
PubMed2005

Treatment of streptozotocin-induced diabetes mellitus in rats by transplantation of islet cells from two major histocompatibility complex disparate rats in combination with intra bone marrow injection of allogeneic bone marrow cells.

BACKGROUND: We have established a new method for the transplantation of allogeneic pancreatic islets obtained from two different rat strains in combination with a newly developed bone marrow transplantation (BMT) method in which bone marrow cells (BMCs) are directly injected into the bone marrow cavity (intra bone marrow BMT [IBM-BMT]). METHODS: Streptozotocin-induced diabetic Brown Norway (BN: RT1A(n)) rats were injected with fludarabine, irradiated with 5.0 Gy x 2, and BMCs from two allogeneic rat strains, Fischer 344 (F344: RT1A(1)) and PVG (PVG: RT1A(c)), were then directly injected into the bone marrow cavity (IBM-BMT). Simultaneously, approximately 600 pancreatic islets (PIs) from F344 and PVG rats were mixed and transplanted into the liver by way of the portal vein. RESULTS: All the recipients thus treated showed normoglycemia 30 days after the treatment. Hematolymphoid cells were completely reconstituted with the two donor-type cells, and immunologic tolerance to F344 and PVG major histocompatibility complex (MHC) determinants were induced. CONCLUSIONS: The transplantation of PIs from two MHC-disparate donors was completely achieved in combination with IBM-BMT, resulting in the improvement of blood glucose levels and the amelioration of diabetes mellitus.

Animals↗
PubMed2005

Intra-bone marrow-bone marrow transplantation facilitates hemopoietic recovery including dendritic cells.

In this report, we provide evidence using a serial bone marrow transplantation (BMT) protocol that intra-bone marrow (IBM)-BMT (IBM-BMT) can efficiently reconstitute the hemopoietic system with cells of donor origin, in contrast to conventional intravenous (IV)-BMT (IV-BMT). Furthermore, the hematolymphoid system of secondary recipients that had received bone marrow cells (BMCs) from primary recipients treated with IBM-BMT recovered earlier than that of the secondary recipients of BMCs from primary recipients treated with IV-BMT. This was the case when the Lin-/c-kit+ progenitor cells of the secondary and tertiary recipients were examined. These findings indicate that IBM-BMT can facilitate the development of not only cells of various lineages but also the effective generation and, more importantly, the maintenance of the progenitor cells. Furthermore, we show that IBM-BMT can reconstitute the dendritic cell (DC) subsets (myeloid and lymphoid DCs), which are critical for the initiation of both adaptive and innate immune responses. The frequency of both myeloid and lymphoid DC subsets was approximately equal to that of normal age-matched untreated controls and, after second and third BMT, this ratio was close to that observed in the normal controls. However, the lymphoid DCs were clearly reduced in the secondary and tertiary recipients of BMCs from mice that had received IV-BMT. Therefore, the development of DC subsets is also normally maintained in the IBM-BMT group.

Animals↗
PubMed2005

Bone marrow transplantation as a strategy for the treatment of autoimmune hearing loss in MRL/Mp-lpr/lpr mice.

Sensorineural hearing loss (SNHL) has been reported to develop as a main part of or in combination with systemic and organ-specific autoimmune diseases. The aim of the current study is to treat autoimmune SNHL in MRL/Mp-lpr/lpr (MRL/lpr) mice, a murine model of systemic autoimmune disease, using allogeneic bone marrow transplantation (BMT), which replaces recipient bone marrow cells with bone marrow cells from a non-autoimmune-prone donor. The results indicate that BMT can be used to treat SNHL; cochlear pathology, serum autoantibodies and lupus nephritis are ameliorated. Therefore, it is conceivable that the autoimmune SNHL in the MRL/lpr mice results not from defects in the cochlea, including the stria vascularis, but from defects in the bone marrow, and BMT would therefore provide a curative effect on inner ear autoimmune dysfunction associated with systemic autoimmune diseases.

Acoustic Stimulation↗
PubMed2005

Antigen recognition and presentation by dendritic cells.

In this article we review the following important points in the antigen-presenting system: (1) the regulation of the expression of major histocompatibility complex (MHC) molecules, (2) the mechanism of cross-presentation, and (3) the interaction of antigen-presenting cells (APC) and T-cells. 1. The expression of MHC class I or class II molecules is regulated by the interaction of the MHC enhanceosome and the class II transactivator (CIITA). CIITA also regulates the gene expression of plexna-1, which encodes a semaphorin receptor, plexin-A1, that might be involved in the interaction with T-cells through an unknown ligand for plexin-A1. 2. Two pathways, a proteasome/TAP-independent pathway and a proteasome/TAP-dependent pathway, have now been identified in the cross-presentation. In the proteasome/TAP-dependent pathway, the translocon/Sec61 protein channel is an important element for the transport of antigenic peptides in phagosomes to the cytoplasm. 3. The integration of adhesion/costimulatory molecules and peptide-MHC complexes at the surface of APC creates the "immunological synapse" region, which potentiates the efficiency of APC-T-cell interactions. The peptide-MHC complexes preferentially reside in the "raft" structure or associate with tetraspanin family molecules.

Animals↗
PubMed2004

Plasmacytoid dendritic cells regulate Th cell responses through OX40 ligand and type I IFNs.

Dendritic cells (DCs) show a functional plasticity in determining Th responses depending on their maturational stage or on maturational signals delivered to the DCs. Human plasmacytoid DCs (PDCs) can induce either Th1- or Th2-type immune responses upon exposure to viruses or IL-3, respectively. In this study we have investigated the Th-polarizing capacity of PDCs after short (24-h) or long (72-h) culture with stimuli and have assessed the expression and function of OX40 ligand (OX40L) in PDC-mediated Th polarization in addition to type I IFN-dependent responses. IL-3-treated PDCs expressed OX40L, but produced almost no IFN-alpha in response to T cell stimulation (CD40 ligand or T cell interaction), resulting in the preferential priming of Th2 cells through OX40L-dependent mechanisms. Meanwhile, PDCs were rapidly endowed by viral infection (Sendai virus) with a high potency to develop IFN-gamma-producing Th cells depending on their capacity to residually produce IFN-alpha. Although Sendai virus-stimulated PDCs simultaneously expressed OX40L in their maturational process, the Th1-inducing effect of endogenous type I IFNs may overcome and thus conceal the OX40L-dependent Th2 responses. However, during maturation in response to Sendai virus over the longer 72-h period, the expression level of OX40L was up-regulated, whereas the residual IFN-alpha-producing ability was down-regulated, and consequently, the PDCs with prolonged Sendai virus stimulation induced Th2 responses to some extent. Thus, PDCs have the distinct means to dictate an appropriate response to environmental stimuli.

Cell Differentiation↗
PubMed2004

Heme oxygenase-1 prevents superoxide anion-associated endothelial cell sloughing in diabetic rats.

Heme oxygenase-1 (HO-1) represents a key defense mechanism against oxidative injury. Hyperglycemia has been linked to increased oxidative stress, leading to endothelial dysfunction, delayed cell replication, and enhanced apoptosis. The effect of streptozotocin (STZ)-induced diabetes on HO activity, HO-1 promoter activity, superoxide anion (O*-2, and the number of circulating endothelial cells was measured. The expression of HO-1/HO-2 protein was unchanged, but HO activity was decreased in aortas of diabetic rats compared with control (p < 0.05). High glucose decreased HO-1 promoter activity (p < 0.05). Hyperglycemia increased O*-2 and this increase was augmented with HO-1 inhibition and diminished with HO-1 upregulation (p < 0.05). Circulating endothelial cells were significantly higher in diabetic rats and were decreased or increased with administration of the HO-1 inducer (CoPP) or inhibitor (SnMP), respectively (p<0.05). In conclusion, HO-1 upregulation in diabetic rats brings about an increase in serum bilirubin, a reduction in O*-2 production, and a decrease in endothelial cell sloughing.

Animals↗
PubMed2004

Effect of ovarian hormones on periodical changes in immune resistance associated with estrous cycle in the beagle bitch.

In bitches, the onset of pyometra, an infection of the uterus, characteristically occurs in the first half of the diestrous stage in the estrous cycle, in which the blood concentration of progesterone peaks and that of estradiol-17beta is lowest. To investigate the immunological mechanisms governing stage-specific onset of pyometra, peripheral blood mononuclear cells (PBMNCs) were collected from beagle bitches during different stages of the estrous cycle and examined using various immunological assays. When we examined the proliferative response of PBMNCs to PYO-252, that is a clone of Escherichia coli isolated from the uterus of a dog afflicted with pyometra, the response of PBMNCs significantly decreased in the first half (day 10) of diestrus, but increased in proestrus/estrus. No significant differences were observed in the responses to concanavaline A between stages of the cycle. Throughout the estrous cycle, canine PBMNCs did not respond to lipopolysaccharide derived from E. coli. The response of PBMNCs collected in anestrus to PYO-252 was significantly enhanced upon the addition of estradiol-17beta to the culture. In contrast, these responses were significantly suppressed in the presence of progesterone. Progesterone progenitor or metabolite molecules, which have a low affinity for the progesterone receptor, did not affect proliferative responses. Expression of gamma interferon (IFNgamma) in response to PYO-252 was also significantly enhanced by estradiol-17beta, but suppressed by progesterone. This evidence suggests that in the first half of the diestrous stage, suppressed activity of cellular immunity results from increasing progesterone concentration and minimal estrogen release. This marked decrease of immune resistance allows the expansion of E. coli, which enter the uterine cavity through the loosened cervical canal during estrus, leading to pyometra onset.

Animals↗
PubMed2004

Bone marrow cells as an origin of immune-mediated hearing loss.

The MRL/lpr mouse, which is homozygous for the recessive lpr genes and has a mutation in the Fas gene encoding a cell-surface receptor for apoptosis, exhibits severe lymphadenopathy and develops systemic lupus erythematosus (SLE)-like disease. It has recently been reported that this mouse also manifests sensorineural hearing loss (SHL) with cochlear pathology at 20 weeks of age. We examined the effects of reconstituting severe combined immunodeficient (SCID) mice with MRL/lpr bone marrow on the development of SHL. These mice normally develop neither SHL nor cochlear pathology. Immune-mediated SHL and cochlear pathology did, indeed, occur following transfer of MRL/lpr bone marrow into SCID mice. These findings suggest that the development of SHL and cochlear pathology observed in MRL/lpr mice and in SCID mice receiving MRL/lpr bone marrow are the result of bone marrow defects rather than the result of a problem intrinsic to the cochlea.

Animals↗
PubMed2004

Enhancement of allogeneic hematopoietic stem cell engraftment and prevention of GVHD by intra-bone marrow bone marrow transplantation plus donor lymphocyte infusion.

We examined the effect of intra-bone marrow (IBM)-bone marrow transplantation (BMT) in conjunction with donor lymphocyte infusion (DLI) on the engraftment of allogeneic bone marrow cells (BMCs) in mice. Recipients that had received 6 Gy of radiation completely rejected donor BMCs, even when IBM-BMT was carried out. However, when BMCs were IBM injected and donor peripheral blood mononuclear cells (PBMNCs) were simultaneously injected intravenously (DLI), donor cell engraftment was observed 7 days after BMT and complete donor chimerism continued thereafter. It is of interest that the cells of recipient origin did not recover, and that the hematolymphoid cells, including progenitor cells (Lin-/c-kit+ cells) in the recipients, were fully reconstituted with cells of donor origin. The cells in the PBMNCs responsible for the donor BMC engraftment were CD8+. Recipients that had received 6 Gy of radiation, IBM-BMT, and DLI showed only a slight loss of body weight, due to radiation side effects, and had no macroscopic or microscopic symptoms of graft-versus-host disease. These findings suggest that IBM-BMT in conjunction with DLI will be a valuable strategy for allogeneic BMT in humans.

Animals↗
PubMed2004

Induction of tolerance in quadruple chimeric mice.

Human cord blood (CB) contains hematopoietic stem cells and progenitors. Because the major limitation to a widespread use of CB for transplantation lies in its limited volume, it is necessary to combine the CB from several donors. In this study, we show that lethally irradiated mice can be reconstituted with the injection of a mixture of T cell-depleted bone marrow cells (BMCs; total, 3 x 10(6)) obtained from three fully allogeneic mouse strains in two different mouse combinations. A higher survival rate was obtained in the triple injection group than in mice injected with BMCs (1 x10(6)) obtained from a single mouse strain. In the mixed chimeric mice, three kinds of donor-type and recipient-type cells were detected in all the hematopoietic organs 1 month after bone marrow transplantation (BMT). Mixed-lymphocyte reaction showed that the tolerance to both recipient-type and donor-type major histocompatibility complex determinants was induced in the chimeric mice. In the peripheral blood (PB) of these mice, only one type of cells from the three different donor strains became dominant in most chimeric mice and reached a stable level about 4 months after BMT. Polymerase chain reaction analyses, however, revealed that the skins from all the donors were accepted even when no cells with their phenotypes could be detected in the PB. These results suggest that both hemato-lymphoid reconstitution and stable tolerance to not only the recipient strain but also all the donor strains can be achieved in chimeric mice, indicating the possibility of mixed CB transplantation in humans.

Animals↗
PubMed2003

Successful allogeneic leg transplantation in rats in conjunction with intra-bone marrow injection of donor bone marrow cells.

BACKGROUND: We have recently established a new method for bone marrow transplantation (BMT) in mice: bone marrow cells are directly injected into the intra-bone marrow (IBM) cavity. IBM-BMT induces persistent donor-specific tolerance and enhances the rapid recovery or reconstitution of the hematolymphoid system of donor origin without any signs of graft-versus-host disease (GVHD) or graft failure. Furthermore, the prior injection of fludarabine can reduce the irradiation dose to the sublethal level (4.5 Gy x 2). Therefore, we hypothesize that IBM-BMT plus fludarabine is applicable to allogeneic leg transplantation in rats. METHODS: Brown Norway (BN; RT1An) rats were injected intravenously with 50 mg/kg of fludarabine phosphate, followed by sublethal fractionated irradiation (4.5 Gy x 2) 1 day before IBM-BMT. The hind limbs from Fischer 344 (F344; RT1Al) rats were transplanted on day 0, and bone marrow cells (3 x 10(7) cells/50 microL) obtained from the donor F344 rats were injected into the bone marrow cavity of the left tibias of the recipient BN rats. RESULTS: The hematolymphoid cells in the recipient BN rats were completely reconstituted by the cells of the donor F344 rats. The limbs transplanted from the donor F344 rats were accepted for >1 year without any clinical signs of rejection (10 of 10). The lymphocytes of the BN rats showed tolerance to both donor-type and recipient-type major histocompatibility complex determinants in mixed lymphocyte reaction, but showed a significant response to the third-party major histocompatibility complex determinants. CONCLUSIONS: Using a combination of the injection of fludarabine, low-dose irradiation, and IBM-BMT, we have succeeded in allogeneic limb transplantation without using any immunosuppressants after the operation. This strategy would be applicable to the transplantation of other vascularized organs in humans.

Animals↗
PubMed2003

Correlation between accelerated presbycusis and decreased immune functions.

The aim of the current study is to analyze the relationship between presbycusis and the immune system, which is affected by pathogenic environments, and to devise a strategy for the prevention of presbycusis using the SAMP1 mouse, an animal model for accelerated senescence that shows both immunological dysfunction and hearing loss caused by the impairment of spiral ganglion cells in the cochlea. When these mice were bred in different pathogenic environments, we found that the development of age-related diseases such as presbycusis was delayed in the mice bred under clean conditions. Prednisolone administration showed no significant prevention of the development of presbycusis in the mice, suggesting that autoimmune mechanisms are not involved in the acceleration of presbycusis. It is conceivable that pathogen-induced infections impose a severe stress on the host, impairing the host's immune functions. A reduction in the number of pathogens may therefore prevent the acceleration of the aging process. These findings suggest that not only the gene backgrounds but also immune functions affect the development of presbycusis in SAMP1 mice. Further studies into the relationship between systemic immune functions and the neuro-generation system may provide additional information about the treatment for age-related diseases.

Aging↗
PubMed2002

Marked increase in number of dendritic cells in autoimmune-prone (NZW x BXSB)F1 mice with age.

Here, we report that the number of CD11c(+)CD3(-) B220(-) cells increases in autoimmune-prone male (NZW x BXSB)F1 (W/BF1) mice with age. The CD11c(+)CD3(-)B220(-) cells from W/BF1 mice show a typical stellate shape and induce the proliferation of T cells. In the CD11c(+)CD3(-)B220(-) cells from W/BF1 mice, CD11b (Mac-1alpha), NK 1.1, and CD95 (Fas) are upregulated in comparison with normal mice, while the expression of CD8alpha, CD117 (c-kit), CD135 (Flk-2/Flt-3), and Sca-1 decreases. There is a significant increase in Flt-3L (FL) mRNA in the bone marrow of W/BF1 mice with age. Moreover, activated hemopoietic cells express high levels of FL. The injection of CD11c(+)CD3(-)B220(-) cells from old W/BF1 mice to young W/BF1 mice transiently induces autoimmune disease (thrombocytopenia). These results suggest that hyperproduction of FL from activated hemopoietic cells induces a dramatic increase in the number of dendritic cells in aged W/BF1 mice, followed by the acceleration of autoimmunity.

Animals↗
PubMed2002

Comparison of bone marrow cells harvested from various bones of cynomolgus monkeys at various ages by perfusion or aspiration methods: a preclinical study for human BMT.

Using cynomolgus monkeys, we have previously established a new method for harvesting bone marrow cells (BMCs) with minimal contamination of the BMCs with T cells from the peripheral blood. We originally conducted this new "perfusion method" in the long bones (the humerus, femur, and tibia) of cynomolgus monkeys. Here, we apply the perfusion method to obtain BMCs from the ilium of cynomolgus monkeys, since BMCs are usually collected from the ilium by the conventional aspiration method in humans. The perfusion method consists of two approaches: transverse iliac perfusion and longitudinal iliac perfusion. BMCs harvested by the perfusion method from the long bones and ilium were compared with those collected from the ilium by the aspiration method. The contamination of BMCs with peripheral blood, determined by the frequencies of CD4+ and CD8+ T cells, was significantly lower in BMCs obtained from the ilium or long bones by the perfusion method (CD4+ plus CD8+ T cells <4%) than in those obtained by the iliac aspiration method (CD4+ plus CD8+ T cells >20%). However, the numbers of immature myeloid cells, such as myeloblasts, promyelocytes, myelocytes, and metamyelocytes, were higher in BMCs obtained by the iliac perfusion method than in those obtained by the iliac aspiration method. The assays for in vitro colony-forming unit in culture revealed that progenitor activity was significantly higher in BMCs obtained by the perfusion method than in those obtained by the aspiration method. These findings suggest that the contamination of BMCs with peripheral blood is much less when using the perfusion method than when using the aspiration method. To determine the best site for harvesting BMCs by the perfusion method, age-dependent changes in BMCs harvested by the perfusion method from the long bones and ilium were examined. The numbers of BMCs varied in the long bones (humerus > femur > tibia) and showed age-dependent decreases, whereas they remained similar in the ilium of cynomolgus monkeys from 3 years to 6 years of age. However, in cynomolgus monkeys, BMC harvesting by the perfusion method from the ilium (but not from the long bones) is found to involve the risk of fat emboli, particularly when the BMCs are quickly perfused under high pressure. These findings suggest, even in humans, that the perfusion method is better than the aspiration method, and that the best site for collection of BMCs is the humerus.

Aging↗