Relationship between glucose transporter and changes in the absorptive system in small intestinal absorptive cells during the weaning process

In the present study, we investigated the changes in the localization of the glucose transporter GLUT2 and the fructose transporter GLUT5 in small intestinal absorptive cells during postnatal development, especially during the weaning period, using immunohistochemistry and confocal laser scanning microscopy. In the jejunum, GLUT2 was observed within the apical and basolateral membrane domain of absorptive cells, especially in the middle part of the villi. In the suckling rat ileum, GLUT2 was found within the apical and basolateral membrane domain of absorptive cells, but after 18 or 19 days after birth, GLUT2 was found mainly within the apical membrane domain. GLUT5 was observed within the apical membrane domain of absorptive cells in the suckling rat jejunum. In the 18- or 19-day-old rat jejunum, GLUT5 was localized within the apical and basolateral membrane domain of absorptive cells in the lower part of the villi, but after weaning, GLUT5 was found within the apical and basolateral membrane domain of absorptive cells throughout the entire villi. In the suckling rat ileum, there was little GLUT5 in the absorptive cells. In the 18- or 19-day-old rat ileum, GLUT5 was localized within the apical membrane domain of absorptive cells in the lower part of the villi, but after weaning, GLUT5 was observed mainly within the apical membrane domain of absorptive cells throughout the entire villi. These results suggest that the localization of glucose transporters corresponds with a shift from neonatal-suckling to weaned absorptive cells during postnatal development.     

Whole genome association study of rheumatoid arthritis using 27 039 microsatellites

A major goal of current human genome-wide studies is to identify the genetic basis of complex disorders. However, the availability of an unbiased, reliable, cost efficient and comprehensive methodology to analyze the entire genome for complex disease association is still largely lacking or problematic. Therefore, we have developed a practical and efficient strategy for whole genome association studies of complex diseases by charting the human genome at 100 kb intervals using a collection of 27,039 microsatellites and the DNA pooling method in three successive genomic screens of independent case-control populations. The final step in our methodology consists of fine mapping of the candidate susceptible DNA regions by single nucleotide polymorphisms (SNPs) analysis. This approach was validated upon application to rheumatoid arthritis, a destructive joint disease affecting up to 1% of the population. A total of 47 candidate regions were identified. The top seven loci, withstanding the most stringent statistical tests, were dissected down to individual genes and/or SNPs on four chromosomes, including the previously known 6p21.3-encoded Major Histocompatibility Complex gene, HLA-DRB1. Hence, microsatellite-based genome-wide association analysis complemented by end stage SNP typing provides a new tool for genetic dissection of multifactorial pathologies including common diseases.     

Seminoma in a postmenopausal woman with a Y;15 translocation in peripheral blood lymphocytes and a t(Y;15)/45,X Turner mosaic pattern in skin fibroblasts.

We report an unusual case of a 55 year old Japanese woman with a seminoma but relatively normal menses. The patient was a phenotypic female with late onset menarche (18 years of age), who was amenorrhoeic for the first year, followed by menses of one to three days' slight flow with dysmenorrhoea, but an otherwise normal menstrual history. A typical seminoma was removed from the left adnexal region and an immature testis was identified separately as an associated right adnexal mass. Repeated karyotypic studies on peripheral blood lymphocyte cultures showed only 46,X,-Y,t(Y;15)(q12;p13). Cytogenetic examination of the patient's younger brother, who had fathered three healthy children, showed an identical karyotype. Mosaicism of 46,X,-Y,t(Y;15)(q12;p13)/45,X cell lines was found in skin samples from the patient's elbow and genital regions, although there were no clinical stigmata of Turner syndrome. An androgen receptor binding assay of cultured genital skin fibroblasts was negative. Molecular analysis using Southern blot hybridisation, PCR, and direct DNA sequencing showed that neither the patient nor her brother had a detectable deletion or other abnormalities of Y chromosome sequences, including the SRY (sex determining region of the Y chromosome) gene sequence. These findings suggest that Turner mosaicism of the 45,X cell line may have contributed to this atypical presentation in an XY female, although we cannot exclude abnormalities of other genes related to sex differentiation.     

GATA3 abnormalities and the phenotypic spectrum of HDR syndrome

We report on GATA3 analysis and the phenotypic spectrum in nine Japanese families with the HDR syndrome (hypoparathyroidism, sensorineural deafness, and renal dysplasia) (MIM 146255). Fluorescence in situ hybridisation and microsatellite analyses showed heterozygous gross deletions including GATA3 in four families. Sequence analysis showed heterozygous novel mutations in three families: a missense mutation within the first zinc finger domain at exon 4 (T823A, W275R), an unusual mutation at exon 4 (900insAA plus 901insCCT or C901AACCCT) resulting in a premature stop at codon 357 with loss of the second zinc finger domain, and a nonsense mutation at exon 6 (C1099T, R367X). No GATA3 abnormalities were identified in the remaining two families. The triad of HDR syndrome was variably manifested by patients with GATA3 abnormalities. The results suggest that HDR syndrome is primarily caused by GATA3 haploinsufficiency and is associated with a wide phenotypic spectrum.


Keywords: GATA3; HDR syndrome; phenotypic spectrum; mutation analysis     

A novel human B-lymphocyte antigen shared with lymphoid dendritic cells: characterization by monoclonal antibody.

A novel cell-surface antigen (L25) expressed on human B cells was identified using a B cell-reactive monoclonal antibody (TB1-4D5). This L25 antigen was expressed on most B-lineage cells but not other cell types including thymocytes, T cells, granulocytes and monocytes. Thus, L25 existed on the majority of normal B cells present in the blood and lymphoid tissues, on cultured cell lines derived from normal and malignant B cells, and on neoplastic cells isolated from patients with B cell-derived malignancies. Though L25 was persistently expressed on B cells until 7 days after their activation with pokeweed mitogen (PWM), neither normal nor neoplastic plasma cells expressed L25. Moreover, L25 was present on cultured as well as freshly isolated leukaemic cells with common acute lymphatic leukaemia (CALL) antigen, which have been thought to correspond to the early B-cell ontogeny. Besides pan-B cell reactivity of TB1-4D5 antibody, it apparently cross-reacted with so-called dendritic or interdigitating cells located in the thymic-dependent areas of peripheral lymphoid organs, which have been presumably ascribed to those associated with accessory-cell function. Functional studies showed that anti-L25 (TB1-4D5) antibody had inhibitory effect on induction of immunoglobulin synthesis by PWM-stimulated B cells.     

Inherited partial duplication of chromosome No. 15

A boy with unusual facial appearance and mental retardation was found to have duplication for the distal half of the long arm of chromosome No. 15 and possibly deficiency for the distal end of the long arm of No. 21. The chromosome abnormality was inherited from his mother, who had a translocation involving chromosomes Nos. 15 and 21. Giemsa-banding localized the break point in chromosome No. 15 just distal to the intense band at the midportion of the long arm. The break point in chromosome No. 21 appeared to be at the distal end of the long arm. The difficulty encountered in cytogenetic analysis of the propositus with conventional staining, the importance of chromosome analysis of the parents, and the application of differential staining techniques are also presented.     

Origin of hematopoietic progenitors during embryogenesis

It has been widely accepted that hematopoietic and endothelial cell lineages diverge from a common progenitor referred to as the hemangioblast. Recently, analyses of the potential of progenitor cells purified from mouse embryos as well as embryonic stem cells differentiating in vitro resolved intermediate stages between mesodermal cells and committed precursors for hematopoietic and endothelial cell lineages. There are two distinct hematopoietic cell lineages which have different origins, i.e., primitive hematopoietic lineage derived from mesoderm or hemangioblasts and definitive hematopoietic lineage derived from endothelial cells. The endothelium is suggested to provide a milieu in which the definitive hematopoietic lineage acquires multiple potentials.     

Alloreactivity and mitogen-induced responses in allogeneic murine bone marrow chimeras

Alloreactive mixed lymphocyte reaction (MLR), mitogen-induced response (MR), and suppressor cells against these responses in murine bone marrow chimeras were examined, to clarify the mechanisms of immunological tolerance and immunodeficiency after bone marrow transplantation (BMT). Between 35 and 70 days after BMT, there was no response of spleen cells from allogeneic chimeras against host (C3H/He) and donor (BALB/c) cells, although responses against third party (C57BL/6) cells were detected, thus indicating that these allogeneic chimeras were immunologically tolerant. The activity of suppressor cells against alloreactive responses was increased 35 to 55 days after BMT, so that these suppressor cells appeared to be related to immunological tolerance. Some of the suppressor cells against alloreactive responses were Thy1+. Among them some were Lyt1+ or Lyt2+, and others were Lyt1+2+. Plastic dish non-adherent cells had slightly weaker suppressor activity than adherent cells. Proliferative responses to Con A, PHA, and PWM were decreased 13 to 15 days after BMT, and gradually increased. The responses to LPS differed from those to the former three mitogens, showing an enhanced response 21 to 25 days after BMT. The increased response to LPS did not appear to be simply due to the increased number of non-T cells in the spleen of allogeneic chimeras. The alloantigen specific suppressor cells may play an important role in the induction and maintenance of immunological tolerance, while the alloantigen nonspecific suppressor cells and suppressor cells against MRs may be related to immunodeficiency after BMT.     

Influence of culture method on the proliferation and osteogenic differentiation of human adipo-stromal cells in nonwoven fabrics

The initial attachment, proliferation, and osteogenic differentiation of stromal cells from human fat tissue were investigated in three-dimensional nonwoven fabrics prepared from polyethylene terephthalate (PET) fiber with different diameters. The largest number of cells initially attached was observed in the nonwoven fabrics prepared from PET fiber with a diameter of 22.0 microm, irrespective of fabric porosity. The number of cells attached was larger and the cells were distributed more homogeneously in the fabrics by the agitated seeding method than by the static seeding method. The culture method depended on the time profile of cell proliferation. Cell proliferation improved in the following order: stirred (spinner flask) culture method > agitated culture method > static culture method. In addition, cells proliferated homogeneously in fabrics by the stirred culture method. When evaluated as a measurement of cell osteogenic differentiation, the activity of alkaline phosphatase (ALP) was not influenced by the diameter of fabrics. The static culture method tended to enable cells to enhance ALP activity, in contrast with the stirred and agitated culture methods. It is concluded that fabric fiber diameter and culture method greatly affected the proliferation and differentiation of cells in nonwoven fabrics.     

Expression profiles of the duplicated matrix metalloproteinase-9 genes suggest their different roles in apoptosis of larval intestinal epithelial cells during Xenopus laevis metamorphosis.

Matrix metalloproteinases (MMPs) play a pivotal role in development and/or pathogenesis through degrading extracellular matrix (ECM) components. We have previously shown that Xenopus MMP-9 gene is duplicated. To assess possible roles of MMP-9 and MMP-9TH in X. laevis intestinal remodeling, we here analyzed their expression profiles by in situ hybridization and show that their expression is transiently up-regulated during thyroid hormone-dependent metamorphosis. Of interest, MMP-9TH mRNA is strictly localized in the connective tissue and most highly expressed just beneath the larval epithelium that begins to undergo apoptosis. On the other hand, cells expressing MMP-9 mRNA become first detectable in the connective tissue and then, after the start of epithelial apoptosis, also in the larval epithelium. These results strongly suggest that MMP-9TH is responsible in the larval epithelial apoptosis through degrading ECM components in the basal lamina, whereas MMP-9 is involved in the removal of dying epithelial cells during amphibian intestinal remodeling.