Biomedical subjects

Shuji Toda

Publications and source records attributed to Shuji Toda.

26 records · Page 2Linked to original sources

PubMed2003

Mature adipocytes, but not preadipocytes, promote the growth of breast carcinoma cells in collagen gel matrix culture through cancer-stromal cell interactions.

Interaction between cancer and stromal cells is critical for tumour cell growth and invasion. It has recently been suggested that mature adipocytes, a specific type of stromal cell that is abundant in the breast, affect the biological behaviour of some epithelial cell types. However, the nature of the interaction between mature adipocytes and breast cancer cells remains unclear. The present study has examined the effects of mature rat adipocytes, as the main cell type in adipose tissue, on the growth, apoptosis, and cell adhesion of breast carcinoma cell lines [human oestrogen receptor (ER)-positive cell lines MCF-7, ZR75-1, and T47-D; and the ER-negative mouse cell line MMT 060562] by analysing bromodeoxyuridine (BrdU) uptake, apoptotic indices, and immunohistochemical expression of E-cadherin. As a reference, the effects of rat preadipocytes (immature adipocytes) on the behaviour of the cell lines were examined. The cell lines were cultured in a three-dimensional collagen gel matrix with mature adipocytes or preadipocytes. Mature adipocytes significantly promoted BrdU uptake by all cell lines other than MMT 060562 cells. Preadipocytes decreased the uptake of T47-D cells and had no effect on that of MCF-7, ZR75-1 or MMT 060562 cells. Mature adipocytes or preadipocytes did not affect the apoptotic indices of any of the cell lines. Mature adipocytes did not influence E-cadherin expression in any of the cell lines, but preadipocytes clearly promoted E-cadherin expression by MCF-7 and T47-D cells, but not by R75-1 and MMT 060562 cells. These data suggest that mature adipocytes may be involved in the mechanisms regulating the growth of breast cancer mass through their growth-promoting effect on ER-positive tumour cells.

Adipocytes↗

PubMed2003

Foveolar differentiation of mouse gastric mucosa in vitro.

We report a novel method that allows the culture of highly differentiated gastric surface mucous cells. Isolated mouse gastric epithelial cells and fibroblasts were co-cultured in a three-dimensional collagen gel system, and the reconstructed mucosal surface treated with an air-liquid interface. Cultured cells were examined by histology, immunohistochemistry, and electron microscopy. Isolated epithelial cells were positive for MUC5AC, and showed immature mucous cell features (pre-pit cell stage) on cell-free collagen gel. However, when given fibroblastic support, the epithelial cells differentiated into mature surface mucous cells (pit cell stage), and showed a tall columnar cell shape, basal round nuclei, and mucus-filled cytoplasm. In the fine structure, the cells showed junctional complexes, basal lamina, and glycogen and secretary granules. Further treatment by the air-liquid interface environment modified the differentiated state of the pit cells (pit top cell stage); resulting in the expression of cathepsin E, the disappearance of glycogen granules and the apical accumulation of secretory granules along with an increase in apoptotic cells. This culture model should provide a useful tool for studying gastric epithelial cell biology and various diseases of the gastric mucosa.

Animals↗

PubMed2003

Coculture of endothelial cells and mature adipocytes actively promotes immature preadipocyte development in vitro.

Adipose tissue consists of mature adipocytes and endothelial cells, which are all supported by the extracellular matrix. Adipose tissue development is closely associated with angiogenesis. However, the adipocyte-endothelial cell interaction is unclear. To address this issue, we examined the effects of endothelial cells on the growth, apoptosis, and differentiation of mature adipocytes in three-dimensional collagen gel culture of the adipocytes with or without rat lung endothelial (RLE) cells. Spindle-shaped preadipocytes, an immature type of adipocyte, developed more actively around the adhesion sites of RLE cells to mature adipocytes in the coculture (rate of preadipocytes: 18.9+/-4.3%) than in the culture of adipocytes alone (2.0+/-5.1%). With respect to growth, RLE cells induced about a three-fold increase in bromodeoxyuridine uptake of mature adipocytes alone, while RLE cells did not influence the uptake of preadipocytes. RLE cells also did not affect the apoptotic indices by immunohistochemistry for single-stranded DNA in mature adipocytes or preadipocytes. These phenomena were not reproduced by RLE cell-conditioned medium, or by certain endothelial cell-produced cytokines. Our in vitro study is the first demonstration that endothelial RLE cells promote the active development of preadipocytes together with increased growth of mature adipocytes. These results suggest that endothelial cells are involved in the enlargement mechanism of adipose tissue mass through their direct adhesion to mature adipocytes.

Adipocytes↗

PubMed2002

A new organotypic culture of thyroid tissue maintains three-dimensional follicles with C cells for a long term.

Thyroid follicles embedded in extracellular matrix (ECM) seem to be supplied enough oxygen by a dense network of capillaries in vivo. Air exposure (AE) causes cells to increase oxygen availability in vitro. We speculated that three-dimensional (3D) environment of ECM together with AE may be applied to a thyroid tissue-organotypic culture, simply simulating such a microenvironment of follicles. To address the issue, we performed 3D collagen gel culture of minced thyroid tissues with or without AE. Most follicles in the tissues without AE died within 7 days. In culture with AE, most of the follicles with calcitonin-positive C cells were kept for over one month. Immunohistochemistry showed that thyrocytes displayed thyroglobulin, thyrotropin receptor, thyroid transcription factor-1 (TTF-1), and pendrin, which are all crucial for thyroid function. C cells expressed calcitonin gene-related peptide and TTF-1. Our study is the first demonstration that 3D collagen gel culture with AE retains 3D thyroid follicles with C cells for a long term. This suggests that ECM and oxygen supply together may be crucial for maintenance of 3D follicle structure and function. Our method will possibly open a new path to the study of thyrocyte-C cell interaction and thyroid biology.

Adenosine Triphosphate↗

PubMed2002

Effects of irradiation on biological behavior of carcinoma cells under carcinoma-stromal cell interaction and air-liquid interface: a possible model for testing radiosensitivity of carcinoma of the upper aerodigestive tract using a collagen gel culture system.

Carcinoma-stromal cell interaction and air-liquid interface (ALI) constitute a specific microenvironment that modulates the biological behavior of carcinoma cells of the upper aerodigestive tract. Although radiotherapy is a useful tool for treating carcinomas of this organ, effects of irradiation on carcinoma cells under carcinoma-stromal cell interaction and ALI are unclear. To address this issue, we examined the effects of irradiation on the proliferation and apoptosis of squamous cell carcinoma cell lines (KB and HEp-2), using three-dimensional collagen gel culture with both carcinoma-stromal cell interaction and ALI. During the second week after irradiation with or without the two factors mentioned above, bromodeoxyuridin (BrdU) uptake and apoptosis of KB, and HEp-2 cell types decreased and increased, respectively. After this stage, the carcinoma cells with these two factors actively re-proliferated together with increased BrdU uptake and decreased apoptosis, whereas the magnitude of these parameters was considerably lower in culture without these factors. We applied our method to carcinoma tissues obtained from several clinical cases. At the same stage, the irradiated carcinoma cells replicated the phenomena observed in cell lines. The data indicate that carcinoma-stromal cell interaction and ALI together promote the re-proliferation of irradiated carcinoma cells and their decreased apoptosis, suggesting that our method is a possible model for testing radiosensitivity of carcinomas in a more physiological condition.

Adipose Tissue↗

PubMed2002

Expression of PDS/Pds, the Pendred syndrome gene, in endometrium.

Expression of the Pendred syndrome gene (PDS/Pds) is thought to be responsible for the iodide transport in the thyroid as well as the formation and function of the inner ear. Its mRNA is also expressed in the kidney and placenta. We report here that PDS and its encoded protein (pendrin) are also expressed in the endometrium. The RNA levels of rat PDS in the endometrium and kidney were much higher than those of the thyroid, opposite of the pattern of RNA expression in humans. In human endometrium, pendrin localization changed from the basal to apical surfaces of the epithelium during progression of the menstrual cycle. This suggests a possible role for pendrin in cationic ion transport required to maintain the physiological function of the endometrium. Since there is no evidence of endometrial abnormalities in patients with Pendred syndrome, it suggests the existence of a compensatory mechanisms for pendrin's function in the uterus.

Animals↗

PubMed2002

[A case of hypertrophic spinal pachymeningitis associated with MPO-ANCA].

A 71-year-old man was admitted to our hospital, because of subacute progressive back pain and thoracic transverse myelopathy. Magnetic resonance imaging showed thickening with gadolinium enhancement of dura mater at the T1-T6 vertebrate levels. A dura biopsy specimen revealed fibrous thickening of the dura with the inflammatory changes, and diagnosis of hypertrophic spinal pachymeningitis was made. The cerebrospinal fluid (CSF) contained high titer of myeloperoxydase anti-neutrophil cytoplasmic antidody (MPO-ANCA), indicating that the antibody synthesized intrathecally. After treatment with oral prednisolone, 60 mg daily for a month, thickness of the dura and the CSF MPO-ANCA improved dramatically. This is the first report of hypertrophic pachymeningitis associated with MPO-ANCA localized exclusively in the spine. This report suggests that intrathecal MPO-ANCA synthesis is an index of disease activity as well as a diagnostic hallmark. Early corticosteroid therapy is recommended in this disorder.

Administration, Oral↗

PubMedDate not supplied

Effects of extracellular matrices on F9 teratocarcinoma stem cells: a crucial role of type IV collagen in the early stage of differentiation of F9 stem cells.

F9 teratocarcinoma stem cells treated with retinoic acid (RA) differentiate into visceral endoderm, and this process affects the expression of some extracellular matrix (ECM) proteins. As the direct influence of ECM molecules on the differentiation of F9 stem cells has not been studied, we investigated the effects of various ECM proteins on the early differentiation of these cells. Monolayers of F9 stem cells were cultured on dishes coated with various ECM, such as type I or IV collagen, fibronectin, or laminin. They aggregated and formed spheroid bodies in the absence of RA only on type IV collagen. The outer layer cells of the spheroid bodies exhibited numerous microvilli, junctional complexes and mature cell organelles. Alpha-fetoprotein was positive in the outer layer cells. A small amount of laminin was detected in the matrix of the spheroid bodies. These data suggest that type IV collagen promoted the early stage of the differentiation of F9 stem cells without RA. The other ECM molecules failed to induce them to form spheroid bodies. The reversibility of the structure of the spheroid bodies to a monolayer was also examined. When the spheroid bodies were reseeded only on fibronectin- or laminin-coated culture dishes, they broke down and the cells spread to the surface in the absence of RA. The differentiation of F9 stem cells induced by type IV collagen seemed to be reversible and to take place at an early stage of their morphogenesis. These findings suggest that type IV collagen plays an important role in early embryogenesis.

Animals↗