The stack of the golgi apparatus

One hundred years have passed since the discovery of "the internal reticular apparatus" by Camillo GOLGI. Investigations into the structure and function of the "Golgi apparatus" have raised more and more challenging issues for cell biologists. After long debate, many new findings have accumulated in the last 10 years as a result of the availability of elegant new genetic, biochemical and morphological tools. This, in turn, has raised many new questions to be solved. In addition, numerous new findings have led to some confusion on the understanding of the Golgi apparatus. This review article deals with several modern aspects of vesicular transport versus cisternal maturation. Disruption of the stacked structure in mitotic and drug-induced conditions is also discussed to demonstrate the importance of structural integrity in the Golgi apparatus.     

Increased expression levels of integrin alphavbeta5 on scleroderma fibroblasts

Integrin alphavbeta5 is a receptor for vitronectin, a plasma glycoprotein that is also distributed in extracellular matrix of various tissues. Matrix-bound vitronectin has the potential to stabilize the active form of plasminogen activator inhibitor-1, resulting in the inhibition of the plasmin-mediated pericellular proteolytic cascade. In this study, we compared the levels of alphavbeta5 and matrix-bound vitronectin between normal and scleroderma fibroblasts and investigated the association with fibrosis. We demonstrated that alphavbeta5 was up-regulated on scleroderma fibroblasts. The up-regulated alphavbeta5 contributed to the increase in vitronectin-binding ability in scleroderma fibroblasts, which led to the vitronectin-dependent activation of plasminogen activator inhibitor-1. In immunohistochemistry, the alphav and beta5 subunits were stained strongly on scleroderma fibroblasts and the amount of vitronectin was increased in the pericellular matrix of those cells. The transient overexpression of alphavbeta5 on normal fibroblasts enhanced the human alpha2(I) collagen promoter activity through Sp-1 and Smad3 as well as the vitronectin-dependent plasminogen activator inhibitor-1 activity. This effect on the promoter activity was also observed in the absence of vitronectin and completely disappeared in the presence of anti-alphavbeta5 antibody. These results indicate that the up-regulated alphavbeta5 may contribute to the phenotypical alteration of scleroderma fibroblasts, while at the same time suppressing the plasmin-mediated pericellular proteolytic cascade.     

Graphic and movie illustrations of human prenatal development and their application to embryological education based on the human embryo specimens in the Kyoto collection.

Morphogenesis in the developing embryo takes place in three dimensions, and in addition, the dimension of time is another important factor in development. Therefore, the presentation of sequential morphological changes occurring in the embryo (4D visualization) is essential for understanding the complex morphogenetic events and the underlying mechanisms. Until recently, 3D visualization of embryonic structures was possible only by reconstruction from serial histological sections, which was tedious and time-consuming. During the past two decades, 3D imaging techniques have made significant advances thanks to the progress in imaging and computer technologies, computer graphics, and other related techniques. Such novel tools have enabled precise visualization of the 3D topology of embryonic structures and to demonstrate spatiotemporal 4D sequences of organogenesis. Here, we describe a project in which staged human embryos are imaged by the magnetic resonance (MR) microscope, and 3D images of embryos and their organs at each developmental stage were reconstructed based on the MR data, with the aid of computer graphics techniques. On the basis of the 3D models of staged human embryos, we constructed a data set of 3D images of human embryos and made movies to illustrate the sequential process of human morphogenesis. Furthermore, a computer-based self-learning program of human embryology is being developed for educational purposes, using the photographs, histological sections, MR images, and 3D models of staged human embryos.     

Neoplastic and non-neoplasti mediate trophoblasts: An immunohistochemical an structural study

Five cases of non-molar trophoblastic disease including one placental site trophoblastic tumor (PSTT), two exaggerated placental sites and two choriocarcinomas were compared with each other and with normal chorionic villi and placental site. This involved light microscopic, immunohistochemical and ultrastructural studies. Comparison of PSTT with choriocarcinoma suggested that the former represented a neoplastic transformation of placental site intermediate trophoblast. The PSTT showed a characteristic immunohistochemical distribution of human placental lactogen and human chorionic gonadotropin, resembling that of the placental site intermediate trophoblast. Placental site trophoblastic tumor cells were also characterized ultrastructurally by prominent perinuclear filaments, abundant rough endoplasmic reticulum, or both. Infiltrating intermediate trophoblasts in exaggerated placental sites were similar to PSTT cells rather than normal placental site intermediate trophoblasts. However cells with vacuolated cytoplasm or spindle-shaped intermediate trophoblastic ceils were observed more frequently in the PSTT than the exaggerated placental sites. The intermediate trophoblastic cells in the choriocarcinomas showed a morphologically transitional form from cytotrophoblastic cell to syncytiotrophoblastic cell, but did not share unique ultra-structural similarities with placental site intermediate trophoblasts.     

The frequency of type 2 CD8+ T cells is increased in peripheral blood from patients with psoriasis vulgaris

Studies have suggested that psoriasis vulgaris is mediated by type 1 T cells. In this study, we examined both chemokine receptor expression and intracellular cytokine production by circulating T cells to check the type 1/type 2 balance in psoriasis. CCR4⁺ and CXCR3⁺ T cells predominantly produced interleukin-4 and interferon-, respectively. The frequency of interferon--producing cells and that of CXCR3⁺ cells in circulating CD4⁺ T cells were similar for psoriatic patients and healthy control subjects. By contrast, the frequency of CCR4⁺CD8⁺ T cells and CCR4/CXCR3 ratio in circulating CD8⁺ T cells were significantly higher in psoriatic patients than in healthy control subjects. Analysis of intracellular cytokine production also indicated relative increase of type 2 CD8⁺ T (Tc2) cells in peripheral blood from psoriatic patients. The frequency of circulating Tc2 cells directly correlated with Psoriasis Area and Severity Index. Immunohistochemical analysis showed that not only CXCR3⁺CD8⁺ T cells but also a similar number of CCR4⁺CD8⁺ T cells infiltrated the psoriatic epidermis and dermis. Our findings suggest an increase in Tc2 cell number in blood from psoriatic patients, and the association of Tc2 cells with inflammation in psoriasis.     

Immunization with recombinant surface antigen P50 of Babesia gibsoni expressed in insect cells induced parasite growth inhibition in dogs

This is a report of a vaccine trial directed against Babesia gibsoni infection in dogs with the use of the recombinant antigen P50. Dogs immunized with P50 showed partial protection manifested as a significantly low level of parasitemia. The results indicated that P50 is a primary vaccine candidate molecule against canine B. gibsoni infection.     

Characterization and localization of side population cells in mouse skin

Recently, the detection of side population (SP) cells, which have the ability to strongly efflux Hoechst 33342 fluorescence dye, has attracted attention as a method of stem cell isolation. We identified SP cells from mouse skin using the same method as from bone marrow. This population almost completely disappeared after treatment with the calcium channel blocker verapamil. SP cells were mainly localized in the epidermis, with a few in the dermis. The ratio of SP cells decreased as the mouse became older. Surface marker analysis revealed that the sorted SP cells expressed alpha6-integrin, beta1-integrin, Sca-1, keratin 14, and keratin 19, which are proliferating and progenitor cell markers, at levels higher than in non-SP cells, while they expressed E-cadherin, CD34, and CD71 at lower levels. The expression of breast cancer resistance protein 1 (BCRP1), which participates in dye efflux, was expressed at high levels at both the protein and mRNA level in sorted SP cells. Immunohistochemical analysis showed that BCRP1 was expressed in the basal layers and hair bulge regions of mouse skin. BCRP1 mRNA was found in basal layers and hair follicles of newborn skin by in situ hybridization. These results indicate that the localization of BCRP1-positive cells is compatible with that of keratinocyte stem cells. Based on the close relationship between BCRP1 and the SP cell phenotype, we conclude that keratinocyte stem cells are closely related to the SP- or BCRP1-positive cells.     

Estrogen receptor-associated expression of keratinocyte growth factor and its possible role in the inhibition of apoptosis in human breast cancer

Although estrogen is known to play a crucial role in the pathogenesis of breast cancer, the molecular mechanisms underlying the action of estrogen remain elusive. In the present study, we focused on keratinocyte growth factor (KGF) and its receptor (KGFR) in the pathogenesis of breast cancer, as a growth factor mediating estrogen action, since significant roles of KGF were demonstrated in various steroid hormone-dependent tissues. First, using paraffin-embedded specimens from 42 breast cancer patients, we examined expression patterns of KGF and KGFR by both immunohistochemistry using newly generated antibodies and nonradioactive in situ hybridization with T-T dimerized synthetic oligonucleotide probes. We next compared the results with the expression of estrogen receptor (ER) alpha and beta, proliferative activity and apoptotic frequency (TUNEL staining). Also, the similar approaches were taken to analyze the expression and role of KGF in ER-positive (MCF7, ZR-75-1) and ER-negative (SK-BR-3, MDA-MB-231) human breast cancer cell lines in vitro. In the surgical specimens, KGF was expressed in cancer cells as well as stromal cells in 19/42 cases (45%), while KGFR was found in cancer cells in 24/42 cases (57%). The distribution of protein and mRNA in the analysis of both KGF and KGFR expression generally coincided. Moreover, KGF expression was closely associated with the expression of ER alpha, and the coexpression of KGF and KGFR significantly correlated with lower TUNEL index, but not with proliferative activity. In accordance with the in vivo findings, KGF expression was detected only in ER alpha-positive MCF7 and ZR-75-1 cells in vitro. And more importantly, we found the inhibitory effect of KGF upon the induction of apoptosis by anticancer drugs in MCF7 cells. Collectively, our results indicate that ER alpha may be involved in KGF expression, and that KGF may play antiapoptotic roles, rather than mitogenic, in human breast cancer.     

Effect of endurance training on muscle fiber type composition and capillary supply in rat diaphragm

Summary Muscle fiber type composition and capillary supply in rat diaphragm were investigated after 14 weeks of endurance training: body weight and muscle fiber area were significantly decreased, the muscle fiber type composition, capillary to fiber ratio and number of capillaries around each fiber type were unchanged, and the capillary density and number of capillaries around each fiber relative to fiber type areas were significantly increased. These small fiber areas and increased capillary supplies in the trained rats would facilitate oxygen transport to all parts of the muscle fiber during exercise. It is concluded that the changes observed in the trained rat diaphragm appear to enhance the capacity for oxidative metabolism.     

Prevention of endotoxin shock by an antibody against leukocyte integrin {beta}2 through inhibiting production and action of TNF

Septic shock remains a serious disorder associated with highmortality. Accumulating evidence indicates that TNF is a majorand essential mediator of endotoxin shock. We report here thatadministration of an antibody against CD18 dramatically reducedendotoxin-induced shock inrabbits as revealed by preventionof severe hypotension, metabolic acidosis and a pathologicalchange suggestive of disseminated intravascular coagulationwith concomitant inhibition of elevation of plasma TNF activity.The anti-CD18 antibody also inhibited the hypotension inducedby administering recombinant TNF. Furthermore, an antibody againsta ligand for CD18 complexes, intercellular adhesion molecule-1,also prevented TNF-induced shock as well as endotoxin shockinrabbits. These observations suggest that adhesion of leukocytesto endothelium may be of primary importance in the action ofTNF as well as in the production of TNF in vivo and that theantibody against adhesion molecules could be of therapeuticbenefit in life-threatening septic shock in humans.