[Show abstract][Hide abstract] ABSTRACT: The immunoreactivity and protein expression of olfactory marker protein (OMP) and tyrosine hydroxylase (TH) in the main olfactory bulb (MOB) of the dog during normal ageing was investigated. OMP immunolabelling was observed only in nerve bundles of the olfactory nerve (ONL) and glomerular layers (GL) and there was no OMP expression within cell bodies of any layer. TH immunolabelling was detected in all layers of the MOB except for the ONL. Most of the neurons expressing TH were distributed in the juxtaglomerular region and had a morphological appearance consistent with periglomerular, external tufted or superficial short axon cells. Dendrites of TH-immunoreactive neurons were closely apposed to OMP-immunoreactive nerve bundles within the glomeruli. There was no significant age-related loss of OMP and TH immunoreactivity and protein concentrations of these molecules were consistent in dogs of different ages. These results suggest that olfactory signal transduction to the GL via axons of olfactory receptor neurons remains unchanged during ageing in the dog.
[Show abstract][Hide abstract] ABSTRACT: The expression of calbindin D-28k (CB), calretinin (CR), substance P (SP) and calcitonin gene-related peptide (CGRP) in the stomach myenteric plexus of the Korean native goat stomach was investigated by immunohistochemistry. The results demonstrated the presence of nerve fibers and cell bodies immunoreactive (IR) to CB, CR, SP and CGRP. In tissues of rumen, reticulum, omasum and abomasum, some distinct neuronal populations could be distinguished according to their morphologic and neuronal chemical properties: Dogiel type I cells which have irregular lamellar dendrites and a single axon, Dogiel type II cells which have large ovoid cell bodies and several long axon-like processes, and small filamentous interneurons. CB-, CR-, SP- and CGRP-IR neurons and fibers were observed in the myenteric plexus of stomach, and varicose nerve fiber immunostained to SP and CGRP also were found in the muscle layer. In myenteric plexus of the stomach, CB- and SP-positive neurons were characterized by Dogiel type II and CR-IR neurons were classified Dogiel type I with lamellar dendrites, and immunoreactivity of CGRP was very weak in the somata. SP- and CGRP-IR nerve fibers formed dense networks within the myenteric ganglia. SP-IR cell bodies and their fibers were found in the myenteric plexus, and the immunoreactivity and number of cell bodies were more than CB-, CR-, and CGRP-IR neurons. These results suggest that SP, CGRP, CB and CR in the myenteric neurons of Korean native goat stomach may have play an important role in the dynamic movement.(Support contributed by: Korean Research Foundation 2003-015-E00195).
[Show abstract][Hide abstract] ABSTRACT: Somatostatin is found in the olfactory system, including the main olfactory bulb (MOB), and is thought to be one of the neuroactive substances for olfaction. However, somatostatin immunoreactivity in the olfactory system has not been determined during ageing. Hence, we examined the age-related changes of somatostatin-immunoreactive (IR) neurones in the rat MOB over a period of 2 years, at the following various ageing stages: post-natal month 1 (PM 1), PM 3, PM 6, PM 12 and PM 24. In PM 1 group, a few somatostatin-IR neurones were detected in the granule cell layer (GCL), and had slender or oval somata and short processes. At PM 3, somatostatin-IR neurones were observed in the glomerular, external plexiform and GCL. The size of somatostatin-IR somata was larger than that at PM 1. In PM 6 group, the number and size of somatostatin-IR neurones increased, and their processes became longer while running in various directions. At PM 12, somatostatin-IR neurones increased in number, and their processes became markedly longer than those at PM 6. At this stage, somatostatin-IR neurones had multipolar somata, and were the largest in size. In PM 24 group, somatostatin-IR neurones were most numerous. However, the processes of somatostatin-IR neurones were shorter than those at PM 12. This study suggests that the increased number of somatostatin-IR neurones in the MOB of aged rats may play a role to compensate for any decrease of olfactory function.
[Show abstract][Hide abstract] ABSTRACT: In the present study, the temporal and spatial alterations of adrenocorticotropic hormone (ACTH) immunoreactivity in the gerbil hippocampus after 5 min transient forebrain ischemia were investigated as followed up 7 days after ischemic insult, and the effects of ACTH after ischemic insult were also investigated 4 days after ischemic insult. The ectopic expression of ACTH (1-24 fragments) immunoreactive neurons in the cornus ammonis 1 (CA1) region of hippocampus and hilar region of the dentate gyrus 1 day after the ischemic insult was observed. Judging from the double immunofluorescence study, these neurons contain GABA. Four days after ischemic insult, the ACTH immunoreactivity was localized in CA1 pyramidal cells and glia near the stratum pyramidale, which normally do not express ACTH. In addition, in the saline-treated groups, the percentage of the detected Cresyl Violet positive neurons was 11.2% compared with the sham-operated group 4 and 7 days after ischemic insult. In these groups, the OX-42 immunoreactive microglia were detected in the strata pyramidale, oriens and radiatum. However, in the Org2766 (analog of ACTH)-treated group, 57.8% neurons compared with the sham-operated group were stained with Cresyl Violet 4 and 7 days after ischemic insult. In these groups, the OX-42 immunoreactive microglia were significantly reduced in the stratum pyramidale. These results suggest that transient forebrain ischemia may provoke selective ectopic and enhanced expression of ACTH in the hippocampus, and further suggest that ACTH plays an important role in reducing the ischemic damage.
[Show abstract][Hide abstract] ABSTRACT: Recent in vitro and in vivo studies have shown that glucocorticoids have a profound influence on the survival of hippocampal neurones, and that the depletion of glucocorticoids as a result of adrenalectomy (ADX) reduces nerve growth factor levels in the hippocampus. It is also believed that ADX is associated with the seizure susceptibility of the Mongolian gerbil. In the present study, the choronological changes of c-jun immunoreactivity were investigated after ADX in the hippocampal formations in the seizure-prone gerbil model. In the sham hippocampus, c-jun immunoreactivity was not observed in the neurones of the hippocampus proper and dentate gyrus. C-jun immunoreactive neurones appeared 3 h after ADX in the neurones of the CA1 area and dentate gyrus, and these immunoreactivities peaked 24 h after ADX and then gradually decreased. These results suggest that, in the adrenalectomized gerbil, c-jun may be expressed in the neurones of the hippocampus in compensation for glucocorticoid deficit. The result of enhanced c-jun expression of the hippocampal formation provides anatomical support for the hypothesis that c-jun may play a role in the reduction of seizure activity.
[Show abstract][Hide abstract] ABSTRACT: We report upon the distribution of galanin-immunoreactive (GAL-IR) cells in the lumbar dorsal root ganglia (DRG) of the rat, and upon the distribution of GAL-IR cells, which also contain calcitonin gene-related peptide (CGRP)-, substance P (SP)- and somatostatin (SOM)-immunoreactivity. Neuropeptide-immunoreactive lumbar DRG cells were 55.8% for CGRP, 12.7% for SP, and 6.5% for GAL in lumbar DRG cells. There was no significant difference between the right and left DRGs (L1-L6) for any neuropeptide-immunoreactive cell (P < 0.01). In terms of size distribution, CGRP-immunoreactive cells were identified below 1500 microm2, and SP-, and GAL-IR cells below 600 microm2. Neuropeptide immunoreactive cells showed various immunoreactivities in the cytoplasm according to each neuropeptide. CGRP and SP immunoreactive cells were colocalized with GAL immunoreactive cells in the serial sections about 83.3 and 60% respectively, but SOM colocalizing with GAL-IR cells were not in evidence. The current results confirm and extend previous results, and show that neuropeptides can coexist in single sensory neurones of the rat DRG. In addition, our results demonstrate that the normal distribution of some neurotransmitters modulating sensory action in Wistar Kyoto rat, make this model more prone to develop neuropathic pain than Sprague-Dawley rat.
[Show abstract][Hide abstract] ABSTRACT: Neuropeptide Y (NPY) is located in the olfactory system, including the olfactory bulb, and is thought to be one of the main neurotransmitters for olfaction. Thus, we examined age-related changes of NPY-immunoreactive (IR) neurons in the rat anterior olfactory nucleus (AON) at various aging stages over a period of 2 years; postnatal months 1 (PM 1), PM 6, PM 12 and PM 24. NPY-IR neurons in the AON were present in the lateral and medial subdivisions at PM 1 and at PM 6 were distributed in all subdivisions of the AON. Prior to PM 12, the NPY-IR neurons showed a tendency to change from bipolar cells with short processes into multipolar cells with long processes. Moreover, the population of NPY-IR neurons and nerve fibers in the AON increased in proportion to age. In particular, the number of NPY-IR neurons increased about 6-fold between PM 1 and PM 3. At PM 24, the number of NPY-IR neurons was much smaller than that at PM 12 and somal size had decreased. It is therefore suggested that the dramatic increase in the number and size of the NPY-IR neurons between PM 1 and PM 3 may be associated with sexual maturation and that the decrease in the number and cell size of the NPY-IR neurons at PM 24 may underlie age-related changes in the olfactory process.
Journal of Neurocytology 01/2002; 30(12):967-72. DOI:10.1023/A:1021880405862 · 1.94 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Hodgkin's and Reed-Sternberg (H-RS) cells are morphological hallmarks of Hodgkin's disease (HD). So far, several characteristics frequently seen in H-RS cells from different origins have been described, such as the high expression of Epstein-Barr virus latent membrane protein 1 (LMP1), the elevation of NF-kappaB activity, and the aberrant expression of molecules such as CD15, CD30, and CD99. Despite extensive studies on the nature of H-RS cells, the molecular mechanism by which H-RS cells are generated remained elusive. Recently, the forced down-regulation of CD99 was reported to induce typical H-RS phenotypes in vitro in a B cell line. Furthermore, it was revealed that LMP1 markedly reduces the CD99 expression at the transcriptional level. Since the presence of LMP1 is known to be associated with the H-RS cell formation, the data provide a possibility of linkage between LMP1 and HD via CD99, thus suggesting that, at least in part, the loss of CD99 may play a critical role in the pathogenic sequence to the formation of H-RS cells in HD. In this review, the role of CD99 in the generation of H-RS cells and its molecular mechanism will be suggested.
Leukemia and Lymphoma 09/2001; 42(4):587-94. DOI:10.3109/10428190109099318 · 2.89 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Epstein-Barr virus (EBV)-encoded latent membrane protein-1 (LMP1) is highly expressed in Hodgkin and Reed-Sternberg (H-RS) cells from patients with EBV-associated Hodgkin disease. It was previously demonstrated that CD99 can be negatively regulated by LMP1 at the transcriptional level, and the decreased expression of CD99 in a B lymphocyte cell line generates H-RS-like cells. In this study, detailed dissection of the CD99 promoter region was performed to search regulatory factor(s) involved in the expression of the gene. Using various mutant constructs containing deletions in the promoter region, it was revealed that the maximal promoter activity was retained on 5'-deletion to the position -137 from the transcriptional initiation site. Despite the presence of multiple putative Sp1-binding sites in the promoter region, the site located at -95 contributes heavily as a positive cis-acting element to its basal promoter activity. However, on examination of the involvement of the positive-acting Sp1-binding site of the promoter for the repressive activity of LMP1, it appeared to be dispensable. Instead, the repressive effect was mapped to the nuclear factor (NF)-kappaB activation domains in the cytoplasmic carboxyl terminus of LMP1 despite the absence of the NF-kappaB consensus sequences in the CD99 promoter region. Furthermore, the decreased CD99 promoter activity by LMP1 was markedly restored when NF-kappaB activity was inhibited. Taken together, these data suggest that Sp1 activates, whereas LMP1 represses, transcription from the CD99 promoter through the NF-kappaB signaling pathway, and they might aid in the understanding of the molecular mechanisms of viral pathogenesis in EBV-positive Hodgkin disease. (Blood. 2001;97:3596-3604)
[Show abstract][Hide abstract] ABSTRACT: The down-regulation of surface expression of MHC class I molecules has recently been reported in the CD99-deficient lymphoblastoid B cell line displaying the characteristics of Hodgkin's and Reed-Sternberg phenotype. Here, we demonstrate that the reduction of MHC class I molecules on the cell surface is primarily due to a defect in the transport from the Golgi complex to the plasma membrane. Loss of CD99 did not affect the steady-state expression levels of mRNA and protein of MHC class I molecules. In addition, the assembly of MHC class I molecules and the transport from the endoplasmic reticulum to the cis-Golgi occurred normally in the CD99-deficient cells, and no difference was detected between the CD99-deficient and the control cells in the pattern and degree of endocytosis. Instead, the CD99-deficient cells displayed the delayed transport of newly synthesized MHC class I molecules to the plasma membrane, thus causing accumulation of the molecules within the cells. The accumulated MHC class I molecules in the CD99-deficient cells were colocalized with alpha-mannosidase II and gamma-adaptin in the Golgi compartment. These results suggest that CD99 may be associated with the post-Golgi trafficking machinery by regulating the transport to the plasma membrane rather than the endocytosis of surface MHC class I molecules, providing a novel mechanism of MHC class I down-regulation for immune escape.
The Journal of Immunology 02/2001; 166(2):787-94. DOI:10.4049/jimmunol.166.2.787 · 4.92 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To induce proper immune responses, T lymphocytes require two types of stimuli, antigen-specific and costimulatory signals. Among costimulatory molecules, CD28-engagement promotes the survival and proliferation of both naive and memory T cells. In addition, it is now believed that Fas may play a role in T cell activation in the human system. It is, however, controversial whether Fas can act as a costimulatory signal in the murine system. Thus, we investigated fundamental differences in the capacity to induce proliferation of T cells between Fas and CD28 in mice. Fas-mediated T cell proliferation was observed only with a full mitogenic dose of anti-CD3 antibodies, whereas CD28 engagement was able to enhance T cell proliferation in the presence of a suboptimal level of anti-CD3 antibody. Furthermore, Fas-engaged T cells showed faster response in the upregulation of CD25 and CD69 expression than CD28-engaged ones. Here, we report that Fas might play a role in mature T cell activation in the mouse system through a different mechanism from that in CD28 costimulation.
Molecules and Cells 01/2001; 10(6):642-6. DOI:10.1007/s10059-000-0642-z · 2.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To attempt a rigorous definition of the structure of the accessory spleen (AS) in the Chinese hamster, we examined twenty-one animals, and found AS in 5 animals (23.8%), which were over 7-month-old. The AS had no connection with the main spleen and was seen as a dark red oval organ (0.7 mm x 1.5 mm), which was embedded in the adipose tissue near the tail of the pancreas. It was demarcated from the adipose tissue and some pancreatic tissue. The organ was encapsulated by thin collagenous connective tissue and smooth muscle fibers, and contained lymphatic nodules, reticular fibers, nodular central arterioles, macrophages and megakaryocytes. Notably the incidence of AS appeared to increase with age in the Chinese hamsters.
Journal of Veterinary Science 01/2001; 1(2):73-5. · 1.16 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In most tissues, apoptosis plays a pivotal role in normal development and for regulating cell number, thus inappropriate apoptosis underlies a variety of diseases. Caspase-3 is one of a family of caspases that are mainly involved in the apoptotic signal transduction pathway, where caspase-3 acts as an effect molecule to proteolytically cleave intracellular substrates that are necessary for maintaining cell survival. Recent evidences show that apoptotic cell death can be blocked by inhibiting caspase-3, suggesting its inhibitors have potential to be therapeutic drugs for the diseases related with inappropriate apoptosis. We have established a screening system to search caspase-3 inhibitors from chemical libraries stocked in our institute. The enzyme assay is configured entirely in 96-well format, which is easily adapted for high throughput screening. Before performing mass screening, 80 in-house compounds were screened as a preliminary experiment, and we found that morin hydrate inhibited caspase-3 by 66.4% at the final concentration of 20 microM.
Archives of Pharmacal Research 07/2000; 23(3):246-51. DOI:10.1007/BF02976454 · 2.05 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Anaplastic myeloma is a rare but distinct, biologically aggressive variant of myeloma which usually results from dedifferentiation or anaplastic transformation of the myeloma cells. The molecular mechanisms that determine the biologic behavior of anaplastic myeloma and effective treatment modalities have not been well known due to lack of in vitro models. In the present study, we have developed an anaplastically transformed mutant from a human myeloma-derived cell line. In the process of long-term culture of the myeloma-derived IM-9 cell line in low serum and nutrient conditions, an adherent mutant line was developed and named IM-9/AD. This mutant cell line displayed several characteristics resembling anaplastic myeloma such as: 1, large cells with large vesicular nucleus and prominent nucleolus, multinuclearity and high mitotic figures; 2, loss of leukocyte-associated antigens; and 3, higher tumorigenecity in scid mice than its parental cell line. This newly developed mutant cell line may serve as a readily available in vitro model to investigate the biology of anaplastic myeloma.
Molecules and Cells 01/2000; 9(6):657-61. · 2.09 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Recently we reported that the down-regulation of CD99 (Mic2) is a primary requirement for the generation of Hodgkin's and Reed-Sternberg (H-RS) cells seen in Hodgkin's disease. In this study, we provide evidence that the down-regulation of CD99 is induced by high expression of Epstein-Barr virus (EBV) latent membrane protein 1 (LMP-1), which is highly expressed in H-RS cells of EBV-associated Hodgkin's disease. To investigate the effect of LMP-1 on the expression of CD99 in vitro, we established a stable cell line by transfecting an SV40-early promoter driven-LMP-1 expression construct into a neoplastic lymphoblastoid B cell line, IM9, in which the level of endogenous LMP-1 expression is almost negligible. In this cell line, the overexpression of LMP-1 led to the down-regulation of CD99 and the acquisition of morphological and functional characteristics of H-RS cells indistinguishable from those in lymph nodes of Hodgkin's disease patients and in CD99-deficient B cells. In addition, induced LMP-1 expression in an EBV-negative B cell clone, BJAB, directly caused the down-regulation of surface CD99 expression. Northern and Western analysis data, showing that overexpression of LMP-1 negatively influenced the expression of CD99, were supported by experiments in which a CD99 promoter-driven luciferase promoter reporter construct transfected into 293T cells was down-regulated when LMP-1 was coexpressed. Therefore, our data strongly suggest that the EBV LMP-1 protein plays a pivotal role in the down-regulation of CD99 via transcriptional regulation, which leads to the generation of the H-RS cells. (Blood. 2000;95:294-300)
[Show abstract][Hide abstract] ABSTRACT: Angiogenin is a potent angiogenic factor secreted by cultured tumor cells and is found in various normal organs and tissues. The ovary is one of the adult organs in which angiogenesis normally occurs during the female reproductive cycle. In this study, we examined whether angiogenin protein is localized and if angiogenin mRNA is expressed in the normal bovine ovary by immunohistochemistry using polyclonal rabbit anti-bovine angiogenin IgG and by in situ hybridization using bovine angiogenin probe, respectively. The localization and mRNA expression of angiogenin in the ovarian follicle and in the corpus luteum were different in their developmental stages. The intensities of immunoreactivities and angiogenin transcripts in the follicle increased from the primordial to the tertiary (or Graafian) follicle. The early corpus luteum contained strong immunoreactivities and mRNA expression of angiogenin but these intensities weakened during regression. The results suggest that angiogenin is involved in morphological changes and angiogenesis in the ovary.
Biochemical and Biophysical Research Communications 05/1999; 257(1):182-6. DOI:10.1006/bbrc.1999.0359 · 2.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: We employed the retrograde neural tracing method using the pseudorabies virus bartha strain (PRV-Ba) to investigate the projection from accessory trigeminal nucleus (Acc5) or accessary facial nucleus (Acc7) to hypoglossal nucleus (HP). After injection of PRV-Ba into the bellies of the digastric muscle, the PRV-Ba containing neurones were observed in Acc5 of the cranial belly injected rats and Acc7 of caudal belly injected rats ipsilaterally, but not in HP. These results suggest that Acc5 and Acc7 may not project to HP and that movements of the digastric muscle are not related to cooperation with tongue movements during mastication.
[Show abstract][Hide abstract] ABSTRACT: Pericellular arborization is reported to be the self-regulating structure in sensory ganglia. Although the calcitonin gene-related peptide (CGRP) or substance P (SP) immunoreactive pericellular arborization appeared in the sensory ganglia, there was no available information that CGRP and SP colocalize in this structure. As the attempts to resolve the question described above, the present study was undertaken to identify the coexistence of CGRP and SP in pericellular arborizations of the goat nodose and trigeminal ganglia by double immunohistochemistry. As the results show, CGRP immunoreactivity was present in every pericellular arborization containing SP immunoreactivity in trigeminal ganglia, however, pericellular network containing CGRP or SP immunoreactivity was not present in nodose ganglia. Unexpectedly, a few small satellite elements were observed to contain intense CGRP and SP immunoreactivity at the periphery of CGRP and SP immunoreactive neurones in nodose ganglia. Therefore, these results suggest that CGRP and SP coexist in pericellular arborizations, and that satellite cell as well as pericellular arborization may be involved in intraganglionic regulation of goat sensory ganglia.
[Show abstract][Hide abstract] ABSTRACT: Programmed cell death (PCD) is a prominent feature of the development of the immune and nervous systems. In both systems, widespread PCD occurs in primitive progenitor cells during development. In this study, we demonstrated that Ewing's sarcoma (ES) cells, undifferentiated neural precursors, underwent apoptosis upon engagement of CD99 with anti-CD99 monoclonal antibody. Apoptosis via CD99 occurred only in the undifferentiated state of ES cells, but not in differentiated ES cells. CD99-induced apoptosis in ES cells appeared to require de novo synthesis of RNA and protein as well as caspase activation. Cyclosporin A, known to be a potent inhibitor of both calcineurin activation and mitochondrial permeability transition pore opening, inhibited CD99-mediated apoptosis, whereas FK-506, a specific calcineurin inhibitor, did not, indicating the induction of CD99-mediated apoptosis through a calcineurin-independent pathway. Furthermore, the dying cells displayed the reduction of mitochondrial transmembrane potential (delta psi m). These results suggest that CD99 engagement induce CsA-inhibitable mitochondrial permeability transition pore opening, followed by a reduction of delta psi m and caspase activation, thereby leading to apoptosis. Based on these results, we suggest the possible involvement of CD99 in the apoptotic processes that occur during nervous system development and also its application in immunotherapeutic trials for ES cases.
American Journal Of Pathology 01/1999; 153(6):1937-45. DOI:10.1016/S0002-9440(10)65707-0 · 4.59 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In the present study, we performed the retrograde tracing method using the neurotropic pseudorabies virus bartha strain (PRV-Ba) and immunohistochemistry against CGRP, to identify whether CGRP exists in the gastric monosynaptic vagal circuit between dorsal motor nucleus of vagus nerve (DMV) and nucleus tractus solitarius (NTS). At the results, PRV immunoreactive neurons were found in both DMV and NTS. However, CGRP-immunoreactive cells were present only in NTS, which contained no double-labeled neurons for PRV and CGRP. These results suggest that CGRP may not have a neuronal function in gastric vagal circuit of rat.