• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.29 no.1
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• pp.105-117
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• 1999

Purpose: Ionizing radiations have been reported as an apoptosis initiating stimulus in various cells and it has established that sustained elevations in [Ca/sup 2+/] can lead to DNA fragmentation by Ca/sup 2+/-dependent endonucleases, ultimately resulting in apoptotic cell death. The previous experiments have been reported by using primarily thymocytes and lymphocytes and the change of [Ca/sup 2+/] was measured only by minutes or hours respectively. We need to evaluate [Ca/sup 2+/] in both several minutes and hours after irradiation of radiation of radiation therapy and verify the apoptotic cells. Materials and Methods: We have measured [Ca/sup 2+/] in human gingival epitheloid cancer cell with 10Gy irradiation, at minutely intervals and hourly intervals using digitized video-intensified fluorescence microscopy and the fluorescent Ca/sup 2+/ indicator dye, fura-2. In order to find out that the transient rise in [Ca/sup 2+/] could induced apoptosis, cells were incubated for 1 hour at 37℃ with TdT enzyme, rinsed and resuspended containing fluorescence and observed under a confocal fluorescence microscope. MTT assay was done to determine cell activity and LDH assay was done to determine the amount of necrotic cells. Results: After irradiation, the transient and temporal increasing of [Ca/sup 2+/] in the KB cells was founded. Though, there was no change in the intracellular [Ca/sup 2+/] at 30 minutes and 2 hours after irradiation. We could detect of DNA fragmented cells at 4 hours after 10Gy irradiated cells. There were no significant differences between 4 hour, 1 day, 3 day cells. There were no significant differences in MTT and LDH assay between the irradiated group and the control group after 4 hours and 1 day. Though after 3 days there were differences in MTT and LDH assay between the irradiated group was significantly decreased than the control group, in LDH assay the number of necrotic cell death of the irradiated was higher than the control group. Conclusion: In KB cells there were incipient and temporal increasing of the [Ca/sup 2+/] with 10Gy irradiation and the apoptosis was founded from 4 hours later which was earlier than seeing of the change of the amount of the cellular ability and necrosis.

• Journal of Life Science
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• v.17 no.7 s.87
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• pp.923-930
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• 2007

Thymus can regenerate to its normal mass within 14 days after acute involution induced by cyclophosphamide (CY) in adult rat. Despite the established role of Wnt pathways in the process of thymus development, they have not yet been associated with the regeneration of adult thymus. The purpose of this study was to investigate whether Wnt7b, which is expressed in developing thymic epithelial cells rather than in thymocytes, is modulated during thymic regeneration in adult rat. Here, we show that Wnt7b expression was up-regulated in the regenerating thymus. Cells immunolabeled for the Wnt7b were identified as macrophages. Furthermore, Wnt7b gene expression was decreased by the treatment of receptor activator of NF-kappaB ligand (RANKL). Taken together, our results demonstrate that Wnt7b gene expression was increased in macrophages during thymic regeneration and negatively regulated by RANKL.

• YAKHAK HOEJI
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• v.35 no.3
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• pp.174-181
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• 1991

These experiments were conducted to investigate the effects of glycyrrhizin(GL) and glycyrrhetinic acid(GA) on histamine synthesis, lymphocyte blastogenesis in C57BL/6J mice splenocytes, IL-1 production, $Ca^{2+}$ uptake by macrophage-like P388D$_{1}$ cells and plaque forming cell assay against SRBC. Histamine contents, lymphocyte blastogenesis, IL-1 activity, $Ca^{2+}$ uptake and plaque forming cell were determined by enzyme isotope method, [sup 3/H]-thymidine incorporation, C3H/HeJ mouse thymocytes proliferation, the addition of 5 $\mu$Ci/ml $^{45}$Ca$^{2+}$ to P388D$_{1}$, cell suspension and assay to sheep red blood cell, respectively. Cytotoxicity, which was expressed as 50% mortality, was occurred by the addition of GL(10$^{-3}$M) and GA(10$^{-4}$M). Histamine production in mouse spleen cell culture was significantly increased by the addition of 0.25 $\mu\textrm{g}$/ml of Con A, after 48 hour incubation. Con A dependent T-lymphocyte proliferation was also enhanced by the addition of 0.25 .mu.g/ml of Con A. The effects of GL on histamine contents and T-lymphocyte proliferation were significantly decreased at high dose (10$^{-5}$M), while IL-1 activity was remarkably suppressed by 10$^{-8}$~10$^{-4}$M of GL. $Ca^{2+}$ uptake was not changed, but antibody production was increased by GL(10 mg/kg). GA inhibited histamine contents at 10$^{-9}$~10$^{-7}$ and depressed Con A (0.25 $\mu\textrm{g}$/ml) dependent T-lymphocyte proliferation at 10$^{-7}$~10$^{-5}$M of GA, but increased suboptimal dose (Con A 0.1 $\mu\textrm{g}$/ml) at 10$^{-9}$~10$^{-7}$M of GA. IL-1 activity was suppressed by 10$^{-8}$~10$^{-4}$M of GA and $Ca^{2+}$ uptake was enhanced by 10$^{-9}$~10$^{-6}$ of GA, but antibody production was not changed by GA. From the above results, it is suggested that GL and GA have immuno-regulatory action. GL decreased cell-mediated immune response, and increased humoral immune response at high dose. On the other hand, low dose of GA enhanced cell-mediated immune response, while high doses of GA decreased humoral immune reaction.

• IMMUNE NETWORK
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• v.20 no.5
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• pp.43.1-43.11
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• 2020

Capicua (CIC) is a transcriptional repressor that regulates several developmental processes. CIC deficiency results in lymphoproliferative autoimmunity accompanied by expansion of CD44^hiCD62L^lo effector/memory and follicular Th cell populations. Deletion of Cic alleles in hematopoietic stem cells (Vav1-Cre-mediated knockout of Cic) causes more severe autoimmunity than that caused by the knockout of Cic in CD4⁺CD8⁺ double positive thymocytes (Cd4-Cre-mediated knockout of Cic). In this study, we compared splenic CD4⁺ T cell activation and proliferation between whole immune cell-specific Cic-null (Cic^f/f;Vav1-Cre) and T cell-specific Cic-null (Cic^f/f;Cd4-Cre) mice. Hyperactivation and hyperproliferation of CD4⁺ T cells were more apparent in Cic^f/f;Vav1-Cre mice than in Cic^f/f;Cd4-Cre mice. Cic^f/f;Vav1-Cre CD4⁺ T cells more rapidly proliferated and secreted larger amounts of IL-2 upon TCR stimulation than did Cic^f/f;Cd4-Cre CD4⁺ T cells, while the TCR stimulation-induced activation of the TCR signaling cascade and calcium flux were comparable between them. Mixed wild-type and Cic^f/f;Vav1-Cre bone marrow chimeras also exhibited more apparent hyperactivation and hyperproliferation of Cic-deficient CD4⁺ T cells than did mixed wild-type and Cic^f/f;Cd4-Cre bone marrow chimeras. Taken together, our data demonstrate that CIC deficiency at the beginning of T cell development endows peripheral CD4⁺ T cells with enhanced T cell activation and proliferative capability.