Review article
- Novel
neuroglial and glioglial relationships mediated by L-serine
metabolism (FURUYA, S.)
- Use
of a new adhesive film for the preparation of multi-purpose fresh-frozen sections
from hard tissues, whole-animals, insects and plants (KAWAMOTO, T.)
Original articles
- Morphological
and immunocytochemical characterization of cultured fibroblast-like cells derived
from adult human synovial membrane (VANDENABEELE, F.)
- Expression
of heme oxygenase-1 in rat ontogeny (WATANABE, T.)
- Differentiation
and proliferation of endocrine cells in the regenerating rat pancreas after 90%
pancreatectomy (HAYASHI, KY.)
- Atomic
force microscopy analysis of rolling circle amplification of plasmid DNA (MIZUTA,
R.)
- The
involvement of brain-derived neurotrophic factor (BDNF) in the regeneration of
periodontal Ruffini endings following transection of the inferior alveolar nerve
(HARADA, F.)
Summary
Title
Novel neuroglial and glioglial relationships mediated by
L-serine metabolism
Author
Shigeki Furuya and Masahiko Watanabe
Address
Neuronal Circuit Mechanisms Research Group, RIKEN Brain Science Institute, Wako,
Saitama, and Department of Anatomy, Hokkaido University School of Medicine, Sapporo,
Japan
Summary
L-Serine is a non-essential amino acid that can be synthesized
in the body. It derives from an intermediate of the glycolytic pathway, 3-phosphoglycerate,
and utilized for the syntheses of proteins, other amino acids, membrane lipids,
heme, and nucleotides. Emerging evidence indicates that L-serine
functions as a glia-derived trophic factor, which strongly promotes the survival
and differentiation of cultured neurons. L-Serine biosynthetic
enzyme 3-phosphoglycerate dehydrogenase (3PGDH) and small neutral amino acid transporter
ASCT1 have been revealed to be expressed preferentially in the radial glia-astrocyte
lineage and olfac-tory ensheathing glia of both adult and developing rodent brains.
In contrast, these biosynthetic and transporter molecules for L-serine
are faint or undetectable in neurons and phagocytic cells. In this review, we
summarize recent progress to propose that L-serine synthesis
in these glial cells and its supply to nearby neurons and other glia constitute
a novel metabolic unit in the brain. Based on these neuroglial and glioglial relationships,
glucose in neurons and phogocytes can be strategically used for energy production,
while a variety of L-serine-derived biomolecules required
for their proliferaton, survival, differentiation, and function are synthesized
in and supplied from the radial glia-astrocyte lineage and olfactory ensheathing
glia. A transient capillary expression of ASCT1 in fetal and neonatal brains further
suggests that, in addition to the glia-borne L-serine, an
active transport of blood-borne L-serine would play an essential
role in neural development.
Correspondence: Prof Masahiko Watanabe, Department of Anatomy, Hokkaido University
School of Medicine, Sapporo 060-8638, Japan.
Tel: +81-11-706-5032, Fax: +81-11-706-5031
E-mail: watamasa@med.hokudai.ac.jp
Title
Use of a new adhesive film for the preparation of multi-purpose
fresh-frozen sections from hard tissues, whole-animals, insects and plants
Author
Tadafumi Kawamoto
Address
Radioisotope Research Institute, Tsurumi University, School of Dental Medicine,
Yokohama, Japan
Summary
A method for preparing thin fresh-frozen sections from large samples and hard
tissues is described and the applications are shown. A new adhesive film is introduced
to produce the frozen sections. The sample is frozen in a cooled hexane or liquid
nitrogen, and then freeze-embedded with 4-5% carboxymethyl cellulose (CMC) in
the coolant. A specially prepared adhesive film is fastened to the cut surface
of the sample in order to support the section and cut slowly with a disposable
tungsten carbide blade. The adhesive film is made of a thin plastic film and an
adhesive before use. This method produces 2-μm thick fresh-frozen sections
from a large sample, bone or tooth. The "film-section" i. e. the section
attached to the adhesive film, can be used for many types of studies such as histology,
general histochemistry, enzyme histochemistry, immunohistochemistry, in situ hybridization,
elemental analysis, and autoradiography for water-soluble materials. Immunohistochemistry
and in situ hybridization can be carried out with nonfixed and undecalcified sections.
The section on the adhesive film can be transferred to a glass slide and mounted
under a cover slip, and stained sections can be examined with an optical microscope
at high magnification. This method is also useful for preparing frozen sections
from samples of fish, insects, and plants. Furthermore, samples of particular
areas can be collected from the film-section by means of a laser microdissection
technique.
The multiple possible applications of the adhesive film render it highly useful
for studies in biological and medico- dental fields.
Correspondence: Dr. Tadafumi Kawamoto, Radioisotope Research Institute, Tsurumi
University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama, 230-8501
Japan
Tel: +81-45-580-8448, Fax: +81-45-573-9599
E-mail: kawamoto-t@tsurumi-u.ac.jp
Title
Morphological and immunocytochemical characterization of
cultured fibroblast-like cells derived from adult human synovial membrane
Author
F. Vandenabeele, C. De Bari, M. Moreels, I. Lambrichts, F. Dell'Accio, P. L. Lippens
and F. P. Luyten
Address
Laboratory of Histology, Biomedical Research Institute-DWI, Limburgs Universitair
Centrum, Diepenbeek; and Laboratory for Skeletal Development and Joint Disorders,
Onderwijs & Navorsing, Katholieke Universiteit Leuven, Leuven, Belgium
Summary
The synovial membrane (SM) is a source of multipotent mesenchymal stem cells (MSCs),
which appeared microscopically to be a relatively homogeneous population of fibroblast-like
cells (FCs) in culture (De Bari et al., 2001). The aim of this study was
to investigate phenotypic characteristics of the SM-derived FCs (SD-FCs) that
could elucidate their origin inside the synovial tissue. Morphological characterization
of SD-FCs was assessed by electron microscopy and by expression of surfactant
protein A (SP-A). This study, yielded substantial evidence that SD-FCs show ultrastructural
and immunocytochemical features of type B synoviocytes; they contained characteristic
lamellar bodies (LBs) that are secreted by exocytosis. LB secretion ability was
maintained upon passaging (P3-P10). Immunocytochemistry showed that SD-FCs express
surfactant protein A (SP-A). Taken together, these results indicate that multipotent
SD-MSCs may originate from the synovial lining, having a phenotype highly similar
to that of type B synoviocytes. We believe our data highlight the potent ability
of type B synoviocytes to have a multilineage differentiation potential.
Correspondence: Frank Vandenabeele, MD, PhD, Laboratory of Histology, Biomedical
Research Institute-DWI, Limburgs Universitair Centrum, 3590 Diepenbeek, Belgium
Tel: + 32 11 268111, Fax: + 32 11 268199
E-mail: frank.vandenabeele@luc.ac.be
Title
Expression of heme oxygenase-1 in rat ontogeny
Author
Takaoki Watanabe, Go Hasegawa, Takashi Yamamoto, Katsuyoshi Hatakeyama, Makoto
Suematsu, and Makoto Naito
Address
Division of Cellular and Molecular Pathology, Division of Digestive and General
Surgery, Niigata University Graduate School of Medical and Dental Sciences, Niigata;
and Department of Biochemistry, School of Medicine, Keio University, Tokyo, Japan
Summary
Heme oxygenase (HO), the heme-degrading enzyme, plays an important role in heme
catabolism. Among three isozymes, HO-1 is an inducible form expressed mainly in
macrophages. In rat ontogeny, HO-1 immunoreactivity was detected in mononuclear
cells in the yolk sac at 10 days of gestation. HO-1-expressing cells were then
detected in the fetal liver and their numbers increased during the gestational
period. The numbers of HO-1-positive cells and HO-1 mRNA levels in the liver peaked
at 18 days of gestation. Most of the macrophages expressed both HO-1 and a macrophage
scavenger receptor. Macrophages in the fetal liver showed marked hemophagocytosis.
Macrophages in the lung, spleen, bone marrow, and other tissues also expressed
HO-1. HO-1 immunoreactivity was also observed in syncytial cells of the chorionic
villi, the endodermal layer of the yolk sac, and renal tubules of the fetus. Intestinal
mucosal epithelial cells expressed HO-1 after birth. These findings imply that
HO-1 is crucial for macrophages in heme catabolism from an early stage of ontogeny.
HO-1 expression in non-macrophagic cells may be required for other purposes such
as protection from oxidative stress and various stimuli.
Correspondence: Prof Makoto Naito, MD, Department of Cellular Function, Division
of Cellular and Molecular Pathology, Niigata University Graduate School of Medical
and Dental Sciences, Asahimachi-dori 1, Niigata 951-8510 Japan
Tel: +81-25-227-2102, Fax: +81-25-227-0761
E-mail: mnaito@med.niigata-u.ac.jp
Title
Differentiation and proliferation of endocrine cells in
the regenerating rat pancreas after 90% pancreatectomy
Author
Keiko Y. Hayashi, Hideaki Tamaki, Kimiya Handa, Tsuyoshi Takahashi, Akira Kakita,
and Shohei Yamashina
Address
Departments of Surgery and Anatomy, Kitasato University School of Medicine, Sagamihara,
Kanagawa, Japan
Summary
The transplantation of pancreatic tissue has been anticipated to serve as a radical
treatment for diabetes mellitus. However, the identification of the stem cells,
and elucidation of their differential lineage and controlling mechanisms are prerequisites
to ensure effective transplantation. We conducted an immunohistochemical study
to determine the proliferation and differentiation dynamics of pancreatic endocrine
cells in the rat pancreas 1 to 28 days after a 90% pancreatectomy.
Regeneration of endocrine cells started immediately after pancreatectomy. The
process of regeneration included the proliferation of preexisting islet cells
and neogenesis of endocrine cells from epithelial cells of the most peripheral
duct. Intercalated ductal cells and centroacinar cells were speculated to be the
major sources of neogenesis, from which islet tissue was formed. Glucagon cells
were the first endocrine cells differentiated, some of which transformed to insulin
cells by a mechanism of non-replication. These results indicate that endocrine
stem cells exist among the intercalated ductal and/ or centroacinar cells, and
these special regions should be utilized in transplantation for the successful
treatment of diabetes.
Correspondence: Prof. Shohei Yamashina, MD, Department of Anatomy, Kitasato University
School of Medicine, 1-15-1, Kitasato, Sagamihara, Kanagawa 228-8555, Japan
Tel: +81-42-778-8826, Fax: +81-42-778-9398
E-mail: yamasina@kitasato-u.ac.jp
Title
Atomic force microscopy analysis of rolling circle amplification
of plasmid DNA
Author
Ryushin Mizuta, Midori Mizuta and Daisuke Kitamura
Address
Research Institute for Biological Sciences, and Genome and Drug Research Center,
Tokyo University of Science, Noda, Chiba, Japan
Summary
Rolling circle amplification (RCA) of plasmid DNA using random hexamers and bacteriophage
phi29 DNA polymerase is an increasingly applied technique for amplifying template
DNA for DNA sequencing. We analyzed this RCA reaction at a single-molecular level
by atomic force microscopy (AFM) and found that multibranched amplified products
containing tandem repeats of a circle unit are formed within 1 h. We also used
the RCA product of a GFP expression vector for the protein expression in cells,
and found that the crude RCA product from one bacterial colony is sufficient for
the GFP expression. Thus, the RCA reaction is useful in amplifying DNA for both
DNA sequencing and protein expression.
Correspondence: Dr. Ryushin Mizuta, Research Institute for Biological Sciences,
Tokyo University of Science, 2669 Yamazaki, Noda, Chiba 278-0022, Japan
Phone: +81-4-7121-4072, Telex: +81-4-7121-4079
E-mail: mizuta@rs.noda.tus.ac.jp
Title
The involvement of brain-derived neurotrophic factor (BDNF)
in the regeneration of periodontal Ruffini endings following transection of the
inferior alveolar nerve
Author
Fumiko Harada, Natalia Hoshino, Kooji Hanada, Yoshiro Kawano, Yukako Atsumi, Satoshi
Wakisaka and Takeyasu Maeda
Address
Divisions of Oral Anatomy and Orthodontics, Department of Oral Biological Science,
Niigata University Graduate School of Medical and Dental Sciences, Niigata,; and
Department of Oral Anatomy and Developmental Biology, Osaka University Graduate
School of Dentistry, Suita, Japan
Summary
The present study employed immunohistochemistry for protein gene product 9.5 (PGP
9.5) to examine the regeneration process of Ruffini endings, the primary mechanoreceptor
in the periodontal ligament, in heterozygous mice with targeted disruption of
the brain-derived neurotrophic factor (BDNF) gene and their littermates, following
transection of the inferior alveolar nerve. When immunostained for PGP 9.5, periodontal
Ruffini endings appeared densely distributed in the periodontal ligament of the
heterozygous mice, but the density of the positively stained nerve fibers in the
ligament was 20% lower than that in the control littermates. At 3 days after surgery,
the PGP 9.5-positive neural elements had disappeared; they began to appear in
the periodontal ligament of both animals at 7 days. However, the recovery pattern
of the PGP 9.5-positive nerves differed between heterozygous and wild type mice,
typical periodontal Ruffini endings morphologically identical to those in the
control group appeared in the wild-type mice at 7 days, whereas such Ruffini endings
were detectable in the heterozygous mice at 28 days, though much smaller in number.
On day 28, when PGP 9.5-positive nerves were largely regenerated in wild type
mice, their distribution was much less dense in the ligament of the heterozygous
mice than in the non-treated heterozygous mice. The density of PGP 9.5-positive
nerve fibers was significantly lower in the heterozygous mice than in wild type
mice at any stage examined. These data showing that a reduced expression of BDNF
causes delayed regeneration of the periodontal Ruffini endings suggest the involvement
of BDNF in the regeneration process of these mechanoreceptors.
Correspondence: Takeyasu Maeda, DDS, PhD, Division of Oral Anatomy, Department
of Oral Biological Science, Niigata University Graduate School of Medical and
Dental Sciences, 2-5274 Gakkocho-dori, Niigata 951-8514, Japan
Tel: +81-25-227-2815, Fax: +81-25-223-6499
E-mail: maedat@dent.niigata-u.ac.jp
