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Biomedical subjects

Shigeru Takahashi

Publications and source records attributed to Shigeru Takahashi.

At least 19 recordsLinked to original sources

Amino acid limitation induces expression of ATF5 mRNA at the post-transcriptional level.

ATF5 is a transcription factor in the cAMP response element (CRE)-binding protein/activating transcription factor (CREB/ATF) family. We studied the effect of amino acid limitation on ATF5 mRNA levels in a mammalian cell line. Northern-blot analysis demonstrated that limitation of a single amino acid, glutamine, methionine, or leucine, resulted in increased ATF5 mRNA levels in HeLaS3 cells. This resulted, at least in part, from increased half-life of the ATF5 mRNA transcript. Cycloheximide inhibited the increase in ATF5 mRNA expression induced by glutamine limitation, indicating that it was dependent on de novo protein synthesis. Moreover, rapamycin had no effect on basal ATF5 mRNA expression or on increased expression induced by glutamine limitation. These results indicate that amino acid limitation regulates ATF5 mRNA expression during post-transcription in a rapamycin-independent manner. The potential role for ATF5 in protecting cells from amino acid-limitation is of considerable interest.

Activating Transcription Factors↗

Mineralization process during acellular cementogenesis in rat molars: a histochemical and immunohistochemical study using fresh-frozen sections.

This study was designed to detect tissue non-specific alkaline phosphatase (TNSALP) by Azo-dye staining, calcium by glyoxal bis (2-hydroxyanil) (GBHA) staining, bone sialoprotein (BSP) and osteopontin (OPN) by immunoperoxidase staining in developing rat molars, and also to discuss the mineralization process during acellular cementogenesis. To restrain a reduction in histochemical and immunohistochemical reactions, fresh-frozen undemineralized sections were prepared. Where the epithelial sheath was intact, TNSALP reaction was observed in the dental follicle, but not in the epithelial sheath. With the onset of dentin mineralization, the BSP- and OPN-immunoreactive, initial cementum layer appeared. At this point, cementoblasts had shown intense TNSALP reaction and GBHA reactive particles (=calcium-GBHA complex) appeared on the root surface. With further development, the reaction of TNSALP and GBHA became weak on the root surface. Previous studies have shown that the initial cementum is fibril-poor and that matrix vesicles and calciferous spherules appear on the root surface only during the initial cementogenesis. The findings mentioned above suggest that: during the initial cementogenesis, cementoblasts release matrix vesicles which result in calciferous spherules, corresponding to the GBHA reactive particles. The calciferous spherules trigger the mineralization of the initial cementum. After principal fiber attachment, mineralization advances along collagen fibrils without matrix vesicles.

Aging↗

Tissue preferential expression of estrogen receptor gene in the marine snail, Thais clavigera.

Sex steroid hormones have been widely detected in molluscs, and experiments have shown the importance of sex steroids in sex determination, gonadal tissue maturation and gametogenesis. Nevertheless, the signaling pathways of sex steroids in invertebrates have not yet been elucidated. In order to gain insights into the mechanism of sex steroid signaling in molluscs, we have, therefore, tried to isolate molluscan estrogen receptors from the prosobranch mollusc Thais clavigera. Cerebral ganglia of T. clavigera (Mollusca, Gastropoda, Prosobranchia) were subjected to RNA extraction, and degenerate primers for amino acid sequences conserved in vertebrate estrogen receptors were designed. PCR amplification using cerebral RNA and degenerate primers followed by 5'- and 3'-RACE identified the cDNA encoding T. clavigera estrogen receptor 1 (tcER1). The deduced amino acid sequence showed 93% identity in the DNA-binding domain and 72% identity in the ligand binding domain when compared to Aplysia estrogen receptor. Reporter gene assay revealed that tcER1 is constitutively active and unresponsive to estrogen. Quantitative analysis of the tcER1 mRNA level demonstrated the preferential expression in the ovary. Furthermore, cerebral ganglia expressed tcER1 at a high level in the spring followed by subsequent enlargement of the ovary in later seasons. These results suggest importance of tcER1 in the seasonal development of reproductive organs in T. clavigera.

Amino Acid Sequence↗

Regulation of heme oxygenase-1 gene expression through the phosphatidylinositol 3-kinase/PKC-zeta pathway and Sp1.

The molecular mechanisms involved in modulation of the antioxidant cell defence by survival signals remain largely unexplored. Here, we report a mechanistic connection between the survival signal elicited by nerve growth factor (NGF) and the antioxidant cell defence represented by heme oxygenase-1 (HO-1) at the level of a newly identified Sp1 site in the human ho1 proximal promoter. By using luciferase reporter constructs we identified a PI3K-responsive region containing a GC-box that resembled the response element for Sp1. Indeed, transfection of Sp1-deficient SL2 cells, electrophoretic mobility shift assays, the use of the GC-box binding drug mithramycin, and mutation of the GC-box provided evidence for a Sp1-like site in the PI3K-sensitive region. Then, we observed with the use of a Sp1-Gal4 chimera that PI3K regulates the transactivating capacity of Sp1. Cotransfection of active PI3K and PKC-zeta expression vectors resulted in substantial increase of Sp1 phosphorylation and in synergistic activation of both Sp1-Gal4 and endogenous Sp1. Moreover, these effects were mimicked by cotransfection of active MEK and ERK expression vectors and were blocked by the MEK inhibitor PD98059. Inhibition of HO-1 with Sn protoporphyrin IX and blockage of Sp-1-mediatied upregulation of HO-1 with mithramycin attenuated antioxidant and cytoprotective functions of NGF against hydrogen peroxide. This study elucidates how NGF contributes to protection of target cells against oxidative stress.

Animals↗

Prediction of transfusions in extremely low-birthweight infants in the erythropoietin era.

BACKGROUND: The purpose of the present paper was to detect the clinical factors most predictive of red blood cell (RBC) transfusion in extremely low-birthweight (ELBW) infants in the recombinant human erythropoietin era. METHODS: Between 1995 and 2000, 66 ELBW infants were admitted to a level III neonatal intensive care unit. Fifty-four of 66 infants were eligible for enrollment in the present study. Infants were treated with erythropoietin 200 IU/kg per dose s.c. twice a week with 4-6 mg/kg per day iron supplement. RESULTS: The mean gestational age and birthweight were 26.5 +/- 2.1 weeks and 776 +/- 134 g, respectively. Ten of 54 ELBW infants (18.5%) died during the first 21 days. Eight of 10 dead infants (80.0%) and 27 of 44 surviving infants (61.4%) received one or more RBC transfusions. The overall requirement for RBC transfusions in the surviving infants was 3.0 +/- 3.2 per infant/hospital course (range: 0-9) . There were significant differences in gestational weeks, birthweight, initial hemoglobin value, 5 min Apgar score, phlebotomy loss, phlebotomy loss/birthweight, duration of mechanical ventilation, duration of oxygen supplement, and incidence of both intraventricular hemorrhage and chronic lung disease between the transfused and non-transfused group. The predictive variables, initial hemoglobin level (odds ratio [OR] 2.61; 1 g/dL), birthweight (OR 3.00; 100 g), and gestational week (OR 1.89; 1 week), were found to be most predictive for transfusion on logistic regression analysis. CONCLUSION: ELBW infants are still the population at greatest risk for repeated blood transfusions after introduction of erythropoietin treatment. If labor develops, it is often impossible to extend the pregnancy period, therefore efforts should be made to increase hemoglobin level at birth.

Algorithms↗

Inhaled nitric oxide therapy might reduce the need for hyperventilation therapy in infants with persistent pulmonary hypertension of the newborn.

AIM: To determine whether inhaled nitric oxide might reduce the need for excessive respiratory alkalosis to maintain systemic oxygenation in infants with persistent pulmonary hypertension of the newborn (PPHN). MATERIALS AND METHODS: A retrospective historical cohort study of 34 infants with PPHN with oxygenation index (OI) of 25 or more, including 19 infants without inhaled nitric oxide (i-NO) therapy (control group) and 15 infants with inhaled nitric oxide therapy (i-NO group) was performed. The initial dose of 10 ppm of i-NO was administered and no responders received the maximum dose of 25 ppm. We evaluated the mortality rate and the change of OI index and PaCO(2) during the first 6 days. RESULTS: There were no significant differences in characteristics between groups. Two of 15 in the i-NO group and 6 of 19 infants in the control group died during the first 48 h. Baseline OI, PaCO(2) and arterial pH were similar in the two groups. OI in the i-NO group was significantly higher than in the control group between 12 and 96 h. PaCO(2) in the i-NO group was higher than in the control group between 24 and 144 h. CONCLUSION: i-NO therapy for PPHN might improve systemic oxygenation without excessive hypocapnia. However there was no reduction in duration of ventilation support or oxygen supply.

Administration, Inhalation↗

Features of the clear zone of odontoclasts in the Chinook salmon (Oncorhynchus tshawytscha).

This study aims to clarify the features of the clear zone of odontoclasts on shedding teeth of a teleost fish, Chinook salmon, Oncorhynchus tshawytscha (Walbaum), using a light microscope to determine the orientation between a cell body and a resorptive lacuna, followed by transmission electron microscopy. Ultrathin sections of LR White embedded material were incubated in rabbit anti-actin polyclonal antibody and then were incubated with 15 nm gold-conjugated goat anti-rabbit IgG. The clear zones of odontoclasts showed a variable structure with electron-dense structures on sections, but distinct clear zones were not always seen on odontoclasts. In odontoclasts sectioned in the direction perpendicularly to the surface of a resorptive lacuna, some cells showed a wide clear zone, but two types of clear zones were usually observed: a part composed of some cytoplasmic processes and one composed of several complicatedly interwoven processes. Gold particles were localized on the clear zones, especially in electron-dense structures; very few gold particles were detected in ruffled borders. These results show that the clear zone of odontoclasts in Chinook salmon contains actin. Our results suggest that the clear zone of an odontoclast in Chinook salmon is not always a wide annular structure.

Actins↗

Transcriptional coactivator PGC-1alpha regulates chondrogenesis via association with Sox9.

Chondrogenesis is a multistep pathway in which multipotential mesenchymal stem cells (MSC) differentiate into chondrocytes. The transcription factor Sox9 (SRY-related high mobility group-Box gene 9) regulates chondrocyte differentiation and cartilage-specific expression of genes, such as Col2a1 (collagen type II alpha1). However, Sox9 expression is detected not only in chondrogenic tissue but also in nonchondrogenic tissues, suggesting the existence of a molecular partner(s) required for Sox9 to control chondrogenesis and chondrogenic gene expression. Here, we report identification of peroxisome proliferator-activated receptor gamma co-activator 1alpha (PGC-1alpha) as a coactivator for Sox9 during chondrogenesis. Expression of PGC-1alpha is induced at chondrogenesis sites during mouse embryonic limb development and during chondrogenesis in human MSC cultures. PGC-1alpha directly interacts with Sox9 and promotes Sox9-dependent transcriptional activity, suggesting that PGC-1alpha acts as a transcriptional coactivator for Sox9. Consistent with this finding, PGC-1alpha disruption in MSC by small interfering RNA inhibits Col2a1 expression during chondrogenesis. Furthermore, overexpression of both PGC-1alpha and Sox9 induced expression of chondrogenic genes, including Col2a1, followed by chondrogenesis in the MSC and developing chick limb. Together, our results suggest a transcriptional mechanism for chondrogenesis that is coordinated by PGC-1alpha.

Animals↗

[Tuberculosis and human rights].

Tuberculosis (TB) patients must be hospitalized while the smear of sputum is positive because TB spreads through air. Cooperation of a patient is important in order to complete the treatment of TB. However, a small number of patients are noncooperative for the treatment and may sometimes refuse it. At this symposium, we discussed about whether we could restrict the human rights of noncooperative TB patients. Although the patients' human rights must be protected, we also have to protect the human rights of people who may receive TB infection. The balance of the both people's rights is fully considered in the TB control policy. It is epoch-making that the TB society took up the theme about the human rights' restriction of TB patients. Five speakers presented their papers from each position. There were presentations about the scientific evidence of isolation, the actual cases, the situation of the United States, and the legal view on the human rights' restriction of TB patients. The present situation and the legal problems in Japan became clear at this symposium. We need further discussion about the human rights' restriction of TB patients for the revision of the Tuberculosis Protection Act and have to obtain the national consensus on it. 1. The evidence for isolation: Emiko TOYODA (International Medical Center of Japan) To determine appropriate periods of respiratory isolation, available biological, clinical, and epidemiological issues and data were studied. Although absolute lack of infectiousness requires consecutive culture negative and it takes too long and impractical periods. There seems to be no established evidence for noncontagiousness after 2 to 3 weeks effective treatment. Practically conversion to 3 negative consecutive smear results may used as a surrogate for noninfectiousness, even though a small risk of transmission still be present. Chemical isolation has been more important and administration with DOT should be indicated to keep compliance. 2. Discontinued hospitalization in tuberculosis patient: Yoshiko KAWABE (National Hospital Organization Tokyo National Hospital) We investigated the background of tuberculosis patients who entered our hospital in 11 years from 1993 to 2003 and discontinued hospitalization. Out of 4,126 cases 76 cases (1.8 %) discontinued hospitalization. We classify three groups. One is self discharged group who leaved hospital without permission. Second is obligatory discharged group who were displaced for some trouble. Third is transferred group who were transferred to another hospital including mental hospital that have ward for tuberculosis. Major reasons were drinking during hospitalization, violence, roam because of dementia and major backgrounds were repeatedly noncompliant patients, homeless people, and suffering from senile dementia. We concluded we need some legal intervention for few cases who cannot continue hospitalization. 3. Tuberculosis control policy and human rights in public health center: Keiko FUJIWARA (Infection Diseases Control Division, Public Health Bureau, City of Yokohama) It is required for a success of the tuberculosis control policy to consider human rights. Patients' human rights should be respected, and surrounding people's human rights should also be respected. We sometimes see a tuberculosis patient who cannot continue tuberculosis treatment. A society as a whole has to share the recognition of tuberculosis as a social illness. The completion of tuberculosis treatment is not only the benefit of individual, but also it is very important as social defense. When we revise the tuberculosis control policy, we should think about both protecting a society from tuberculosis and protecting tuberculosis patients' human rights and obtain national consensus. 4. The mandatory TB control policy in the US: Hidenori MASUYAMA (Shibuya Dispensary, Japan Anti-TB Association) The mandatory TB control policy in the US was discussed. If the mandatory health policy would be applied, the following three criteria of human rights must be satisfied. 1. The health of others will be adversely affected without a mandatory program. 2. The mandatory program is the least restrictive alternative. 3. The mandatory program is implemented equitably without purposeful bias. For example, the mandatory DOT could not satisfy these criteria. Before applying the mandatory TB control policy in Japan, the TB patient's autonomy and social cooperation of TB therapy need to be considered. 5. Tuberculosis and guarantee of human rights: Shigeru TAKAHASHI (Graduate School of Law, Hitotsubashi University) In modern administrative Law the relations between Governments and peoples are regarded not as the facing relationships between Governments and the peoples, who submit to the interventions by Government, but as the triangle relationships between Governments, the peoples who submit to the interventions by Governments and the peoples who enjoy benefits from the interventions by Governments. When we make a new design of the Tuberculosis Protection Act, we must at first take considerations of the human rights of the tuberculosis patients from the view points of due Process of Law. And we must also take considerations of the human rights of the peoples who are threatened with the risks of tuberculosis infection.

Adult↗

Odontoclasts in the Chinook salmon differ from mammalian odontoclasts by exhibiting a great proportion of cells with high nuclei number.

Odontoclasts resorbing teeth are multinucleated cells. Previously, the authors have investigated the distribution of number of nuclei per human odontoclast and showed that the mean number of nuclei per cell is 5.3, the median is 4, and 93.8% of cells have 10 or fewer nuclei. Teleost odontoclasts have features similar to those of mammals; however, the distribution of number of nuclei per cell remains unknown. The present study aimed to examine the distribution of number of nuclei per odontoclast in a teleost fish, Chinook salmon, Oncorhynchus tshawytscha (Walbaum), and to clarify the difference of number of nuclei in odontoclasts between Chinook salmon and humans. The maxillae and mandibles of Chinook salmon were fixed, decalcified, and embedded in Epon 812. Specimens were serially sectioned into 0.5-microm semithin sections and examined by light microscopy. Cells possessing a brush border adjacent to a resorptive lacuna were identified as odontoclasts, and 246 odontoclasts were investigated to determine the distribution of nuclei per cell. The mean number of nuclei per cell was 21.8 and the median was 17; only 24.4% of odontoclasts had 10 or fewer nuclei, and 95.5% had 50 or fewer nuclei. These results suggest that the range for the number of nuclei per odontoclast in Chinook salmon is greater than that in humans.

Animals↗

HTLV-I env protein acts as a major antigen in patients with HTLV-I-associated arthropathy.

Our objective was to investigate the pathological mechanisms of HTLV-I (human T-cell leukemia virus type I)-associated chronic arthritis (HAAP) with respect to T-cell response to HTLV-I viral proteins. We examined T-cell clonality and the antigen recognized by T cells from the inflamed synovium of patients with HAAP by using histology, a single-strand conformation polymorphism (SSCP) analysis and T cell receptor (TCR) sequencing. The SSCP analysis showed oligoclonal expansion of T cells in the synovium, suggesting an antigen-mediated stimulation. In contrast, there was less clonal expansion in peripheral blood lymphocytes (PBL). The expression of HTLV-1 env and tax mRNA was detected in the affected synovium as well as in PBL. A number of T-cell clones in the synovium recognized HTLV-I env and tax proteins. Twenty-seven (24.9%) of 109 examined T-cell clones in the joints were HTLV-I env reactive, and 7 clones (6.4%) were HTLV-I tax reactive. Junctional sequence analysis of synovial T cells showed a lack of highly conserved amino acid motifs in the complementarity-determining region 3 (CDR3) of HTLV-I env and tax reactive T cells, suggesting that these cells recognized multiple T-cell epitopes on HTLV-I antigen. These findings suggest that HTLV-I env protein acts as a major antigen and may play a role in the development of arthropathy in patients with HAAP.

Amino Acid Sequence↗

Expression of heme oxygenase-1 is repressed by interferon-gamma and induced by hypoxia in human retinal pigment epithelial cells.

The retinal pigment epithelium (RPE) is essential for maintenance of photoreceptors and normally functions under conditions enriched with reactive oxygen species. RPE therefore expresses various defense enzymes against oxidative stress, including heme oxygenase-1 (HO-1). HO-1 catalyzes heme breakdown to release iron, carbon monoxide, and biliverdin, which is reduced to bilirubin, a potent radical scavenger. HO-1 expression is induced by various environmental factors, which has been established as a defense mechanism. To explore the hypothesis that the expression level of HO-1 is reduced in those RPE cells under certain conditions, we analyzed the effects of interferon-gamma and hypoxia, each of which represses the expression of HO-1 mRNA in other types of human cells. Expression levels of HO-1 mRNA were reduced by interferon-gamma in two human RPE cell lines, D407 and ARPE-19, which was consistently associated with the induction of mRNA for Bach1, a transcriptional repressor for the HO-1 gene. On the other hand, HO-1 and Bach1 mRNAs were induced by hypoxia in D407 cells but remained unchanged in ARPE-19 cells, suggesting that Bach1 is not a sole regulator for HO-1 expression. The hypoxia-mediated induction of HO-1 mRNA in D407 cells depends on gene transcription and protein synthesis, as judged by the effects of their inhibitors. The half-life of HO-1 mRNA did not change during hypoxia. Thus, hypoxia may increase transcription of the HO-1 gene through a certain protein factor in RPE cells. These results indicate that RPE cells maintain retinal homeostasis by repressing or inducing the expression of HO-1, depending on the microenvironment.

Basic-Leucine Zipper Transcription Factors↗

Autologous cord blood transfusion in an infant with a huge sacrococcygeal teratoma.

We describe a case of cord blood harvest for autologous transfusion in a neonate weighing 3,992 g with a giant sacrococcygeal teratoma. The umbilical vein was pierced with an 18-gauge needle, and placental blood was withdrawn into two 50-ml syringes filled with 4 ml of citrate-phosphate-dextrose solution. Resection of the sacrococcygeal teratoma was performed on day one. During the operation the infant lost 46 ml of whole blood, more than 15% of the estimated total blood volume, and thus underwent autologous transfusion with 27.8 ml of packed red cells obtained from autologous cord blood. Consequently, she could avoid homologous blood transfusion during the hospital stay. This case highlights the safety of this procedure, with no evidence of consumption coagulopathy, hemolysis or bacterial infection.

Blood Loss, Surgical↗

[Treatment results of peritoneal dissemination from gastric cancer by neoadjuvant intraperitoneal-systemic chemotherapy].

UNLABELLED: No standard treatment exists for peritoneal dissemination from gastric cancer. We reviewed our experience using a novel treatment consisting of peritonectomy and intraoperative chemo-hyperthermic peritoneal perfusion (CHPP). Records of all patients who underwent CHPP and cytoreductive surgery from 1992 to 2001 were reviewed. RESULTS: Data from 107 patients (average age, 52 years) were available. P3 dissemination was found in 72 patients, and 8 and 27 patients showed P1 or P2 dissemination, respectively. Peritoneal metastasis was synchronous in 75 and metachronous in 32 patients. All patients received CHPP after cytoreductive surgery. Peritonectomy was performed in 42 patients. Complete cytoreduction (CC-0) was achieved in 47 patients (44%). Peritonectomy, resulted in CC-0 in 69% (29/42), but CC-0 was achieved in 18 of 65 (28%) patients by ordinary surgical techniques. There were 23 postoperative complications (21%) after operation. The overall operative mortality was 2.8% (3/107). Median follow-up for the entire study group was 46 months. Seventeen patients (15%) were disease-free, and 90 patients were dead at the time of analysis. Eighty-seven deaths were related to progression of disease. The median survival of all patients was 16.2 months, with an actual 5-year survival of 6%. Median survival of CHPP plus ordinary cyoreduction was 12.0 months and that after CHPP and peritonectomy was 22.8 months. Completeness of cytoreduction and peritonectomy were significant prognostic factors on univariate analysis and 5-year survival rate was 27%. Lymph node status, grade of peritoneal dissemination (P1-2 vs P3), age (>60 years vs <60 years), tumor volume of dissemination (>2.5 cm vs <2.5 cm in diameter), and histologic type (differentiated vs. poorly differentiated type) did not affect survival. The cox proportional model demonstrated that completeness of cytoreduction was the strongest prognostic factor. Patients who had an incomplete resection had 2.8-fold higher risk of dying from disease than patients who underwent complete cytoreduction. The 5-year survival after complete cytoreduction was 12%, compared with 2% for incomplete resection. Four patients lived more than 5 years. Cytoreduction was incomplete in one 5-year survivor who showed complete response to CHPP. CONCLUSION: Complete cytoreduction using peritonectomy and CHPP may improve survival of patients with peritoneal dissemination from gastric cancer. This procedure is most appropriate for highly motivated patients who are committed to survive as long as possible.

Analysis of Variance↗

Transcriptional co-activators CREB-binding protein and p300 regulate chondrocyte-specific gene expression via association with Sox9.

Chondrocytes are critical components for the precise patterning of a developing skeletal framework and articular joint formation. Sox9 is a key transcription factor that is essential for chondrocyte differentiation and chondrocyte-specific gene expressions; however, the precise transcriptional activation mechanism of Sox9 is not fully understood. Here we demonstrate that Sox9 utilizes a cAMP-response element-binding protein (CREB)-binding protein (CBP)/p300 to exert its effects. Sox9 associates with CBP/p300 in the chondrosarcoma cell line SW1353 via its carboxyl termini activation domain in a cell type-specific manner. In promoter assays, CBP/p300 enhances Col2a1, which encodes cartilage-specific type II collagen gene promoter activity via Sox9. Chromatin immunoprecipitation shows that p300 is bound to the Col2a1 promoter region. Furthermore, the CBP/Sox9 complex disrupter peptide suppresses Col2a1 gene expression and chondrogenesis from mesenchymal stem cells. These data demonstrate that CBP and p300 function as co-activators of Sox9 for cartilage tissue-specific gene expression and chondrocyte differentiation.

Binding Sites↗

Tunica interna endothelial cell kinase expression and hematopoietic and angiogenic potentials in cord blood CD34+ cells.

Tunica interna endothelial cell kinase (TEK) is expressed in both hematopoietic and endothelial cells and plays a crucial role in hematopoiesis and angiogenesis in mouse development. In humans, however, little is known about the hematopoietic and angiogenic potentials of TEK-expressing cells in umbilical cord blood (CB) cells, which originate during the human fetal period. We therefore compared the hematopoietic and angiogenic abilities of CB CD34+TEK+ and CD34+TEK- cells by using a clonogenic assay and xenotransplantation into immunodeficient NOD/SCID mice. The results showed that colony-forming cells and cells capable of repopulating in NOD/SCID mice were present in both CD34+TEK+ and CD34+TEK- cells and that the hematopoietic activities of the cell types were similar. In contrast, the potential to differentiate into endothelial cells in vivo was greater in the CD34+TEK+ cells. All NOD/SCID mice engrafted with CD34+TEK+ cells had human CD31-expressing and VE-cadherin-expressing endothelial cells in the vessels of the ischemic muscles and/ or human endothelial cells expressing CD31, kinase-insert domain-containing receptor, and endothelial nitric oxide synthase in liver sinusoidal cells, whereas such endothelial cells were detected in only 3 of the 7 recipients engrafted with CD34+TEK- cells. This result has important implications in cell therapy using CB cells for treating hematopoietic disorders and vascular diseases.

Animals↗