• Animal cells and systems
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• 제16권6호
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• pp.438-446
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• 2012

In 1964, Susumu Ohno, an evolutionary biologist, hypothesized that the size of X chromosome was conserved in mammalian evolution, and that this was based on chromosomal length. Today, unlike Ohno's method which was based on estimated lengths, we know the exact lengths of some mammalian sequences. The aim of this study was to reanalyze Ohno's hypothesis. In mammalian species, variation in the length of the X chromosome is greater than in the autosomes; however, this variation is not statistically significant. This means that differences in chromosomal length occur equally in the X chromosome and in the autosomes. Interspersed nuclear elements and genetic rearrangements were analyzed to maintain the same variance between the length of the X chromosome and the autosomes. The X chromosome contained fewer short interspersed elements (SINEs) (0.90 on average); however, it did contain more long interspersed elements (LINEs) than did autosomes (1.56 on average). An overall correlation of LINEs and SINEs with genetic rearrangements was observed; however, synteny breaks were more closely associated with LINEs in the autosomes, and with SINEs in the X chromosome. These results suggest that the chromosome-specific activities of LINEs and SINEs result in the same variance between the lengths of the X chromosome and the autosomes. This is based on the function of interspersed nuclear elements, such as LINEs, which can inactivate the X chromosome and the reliance of non-autonomous SINEs on LINEs for transposition.

• Journal of Korean Neurosurgical Society
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• 제38권2호
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• pp.121-125
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• 2005

Objective : Many recent reports have shown that the mature mammalian brain harbors multipotent stem cells, rendering the brain capable of generating new neurons and glia throughout life. Harvested stem cells from an adult rat are transplanted in order to evaluate the cell survival and differentiation. Methods : Using a percoll gradient with a high speed centrifugation method, we isolate neural stem/progenitor cells were isolated from the subventricular zone[SVZ] of a syngeneic adult Fisher 344 rats brain. For 14days expansion, the cultured cells comprised of a heterogeneous population with the majority of cells expressing nestin and/or GFAP. After expanding the SVZ cells in the presence of basic fibroblast growth factor-2, and transplanting then into the hippocampus of normal rats, the survival and differentiation of those cells were examined. For transplantation, the cultured cells were labeled with BrdU two days prior to use. In order to test their survival, the cells were transplanted into the dorsal hippocampus of normal adult Fisher 344 rats. Results : The preliminary data showed that at 7days after transplantation, BrdU+ transplanted cells were observed around the injection deposition sites. Immuno-fluorescent microscopy revealed that the cells co-expressed BrdU+ and neuronal marker ${\beta}$-tubulin III. Conclusion : The data demonstrate that the in vitro expanded SVZ cells can survive in a heterotypic environment and develop a neuronal phenotype in the neurogenic region. However more research will be needed to examine the longer survival time points and quantifying the differentiation in the transplanted cells in an injured brain environment.

• Animal cells and systems
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• 제5권3호
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• pp.253-262
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• 2001

Ligand-receptor clustering event is the most important step in leukocyte adhesion and spreading on endothelial cells. Intercellular adhesion molecule-1 (ICAM-1) has been shown to enhance leukocyte adhesion, but the molecular event during the process of adhesion is unclear. To visualize the dynamics of ICAM-1 movement during adhesion, we have engineered stable Chinese hamster ovary cell lines expressing ICAM-1 fused to a green fluorescent protein (IC1_GFP/CHO) and examined them under the fluorescence microscopy. The transfection of IC1_GFP alone in these cells was sufficient to support the adhesion of K562 cells that express $\alpha$L$\beta$2 (LFA-1) integrin stimulated by CBR LFA-1/2 mAb. This phenomenon was mediated by ICAM-1-LFA-1 interactions, as an mAb that specifically inhibits ICAM-1-LFA-1 interaction (RRl/l) completely abolished the adhesion of LFA-1＊ cells to IC1_ GFP/CHO cells. We found that the characteristic of adhesion was followed almost immediately (~10 min) by the rapid accumulation of ICAM-1 on CHO cells at a tight interface between the two cells. Interestingly, ICI_GFP/CHO cells projected plasma membrane and encircled approximately half surface of LFA-1+ cells, as defined by confocal microscopy. This unusual phenomenon was also confirmed on HUVEC after adhesion of LFA-1＊ cells. Neither cytochalasin D nor 2,3-butanedione 2-monoxime an inhibitor of myosin light chain kinase blocked LFA-1-mediated ICAM-1 clustering, indicating that actin cytoskeleton and myosin-dependent contractility are not necessary for ICAM-1 clustering. Taken together, we suggest that leukocyte adhesion to endothelial cells induces specialized form of ICAM-1 clustering that is distinct from immunological synapse mediated by T cell interaction with antigen presenting cells.

• Journal of Microbiology and Biotechnology
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• 제10권3호
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• pp.394-398
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• 2000

A methanol extract of the root of Peucedanum japonicum, used as a medicinal herb, showed an inhibitory effect on mammalian topoisomerase I activity. The methanol extract was suspended in ethyl acetate, and a topoisomerase I inhibitor in the organic soluble fraction was then isolated by silica gel and thin layer chromatography. The topoisomerase I inhibitory compound was indentified as falcarindiol based on the analysis of EI-MS, $^1$H and \ulcornerC NMR spectroscopy. This inhibitory showed cytotoxicity against human leukemia Jurkat T and HL60 cells with an IC\ulcorner value of 7 $\mu\textrm{g}$/ml. These results suggest the possibility of falcarindiol as a new anticancer agent which can be expected to have a synergistic effect on other anticancer drugs. In addition, the present data show that falcarindiol has antifungal, yet not antibacterial, activity.

• BMB Reports
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• 제42권9호
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• pp.580-585
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• 2009

Dimethyl sulfoxide (DMSO) is widely used in chemistry and biology as a solvent and as a cryoprotectant. It is also used as a pharmaceutical agent for the treatment of interstitial cystitis and rheumatoid arthritis. Previous reports described DMSO as being reduced by methionine-S-sulfoxide reductase (MsrA). However, little is known about the DMSO reduction capability of methionine-R-sulfoxide reductase (MsrB) or its effect on the catalysis of methionine sulfoxide reduction. We show that mammalian MsrB2 and MsrB3 were unable to reduce DMSO. This compound inhibited MsrB2 activity but did not inhibit MsrB3 activity. We further determined that DMSO functions as an inhibitor of MsrA and MsrB2 in the reduction of methionine sulfoxides via different inhibition mechanisms. DMSO competitively inhibited MsrA activity but acted as a non-competitive inhibitor of MsrB2 activity. Our study also demonstrated that DMSO inhibits in vivo methionine sulfoxide reduction in yeast and mammalian cells.

• Journal of Embryo Transfer
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• 제26권4호
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• pp.287-296
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• 2011

Mammalian fertilization is a complex cascade process consisting of sperm migration through the female reproductive tract, physiological changes to sperm such as sperm capacitation and acrosome reaction, and sperm-egg interaction in the oviduct in vivo. On the other hand, in vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the body: in vitro. IVF has been used for a variety of purposes in reproductive biotechnology for human and animals. The discovery of sperm capacitation in 1951 promoted the development of IVF technology. In the initial stage of IVF, sperm capacitation in preincubation medium was shown to be essential to fuse with eggs. Besides, sperms should detour some of the in vivo regulations for IVF. This review introduces a general mammalian fertilization process, including sperm capacitation, removal of cumulus matrix, acrosome reaction, and sperm-egg fusion and focuses on the roles of key biochemical molecules, signal mechanisms, and genes involved during IVF and novel results of sperm-oocyte interaction elucidated in various gene-knockout mice models.

• Ocean and Polar Research
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• 제30권4호
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• pp.467-472
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• 2008

Antarctic krill has a strong proteolytic enzyme system, which comes from a combination of several proteases. This powerful activity can be easily detected by krill's superior post mortem autolysis. Mammalian skin consists of epidermis and dermal connective tissue, and functions as a barrier against threatening environments. A clot in a wound site of the skin should be removed for successful skin regeneration. Epithelial cells secrete proteases to dissolve the clot. In previous studies Antarctic krill proteases were purified and characterized. The proteolytic enzymes from Antarctic krill showed higher activity than mammalian enzymes. It has been suggested that these krill clean up the necrotic skin wound to induce a natural healing ability. The enzymes exhibited additional possibilities for several other biomedical applications, including dental plaque controlling agent and healing agent for corneal alkali burn. Considering that these versatile activities come from a mixture of several enzymes, discovering other proteolytic enzymes could be another feasible way to enhance the activity if they can be used together with krill enzymes. Molecular cloning of the krill proteases should be carried out to study and develop the applications. This review introduces possible roles of the unique Antarctic krill proteases, with basic information and suggestion for the development of an application to skin regeneration.

• BMB Reports
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• 제44권9호
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• pp.584-589
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• 2011

The mammalian ste20-like kinase (MST) pathway is important in the regulation of apoptosis and cell cycle and emerges as a novel tumor suppressor pathway. MST-induced phosphorylation of Salvador homolog 1 (SAV1), which is a scaffold protein, has not been evaluated in detail. We performed a mass spectrometric analysis of the SAV1 protein that was co-expressed with MST2. Phosphorylation was detected at Thr-26, Ser-27, Ser-36 and Ser-269. Although single or double mutations had little effects, the mutation of all four residues in SAV1 to Ala (SAV1-4A) had inhibitory effects on the MST pathway. MST2-mediated induction of SAV1-4A protein levels, SAV1-4A interaction with MST2 and the self-dimerization of SAV1-4A were weaker compared to those of wild-type SAV1. SAV1-4A inhibited MST2- and K-RasG12V-induced cell death of MCF7 cells. These results suggest that MST-mediated phosphorylation of four residues within SAV1 may be important in the induction of cell death by the MST pathway.

• Reproductive and Developmental Biology
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• 제38권1호
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• pp.21-34
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• 2014

The majority of early embryonic mortality in pregnancy occurs during the peri-implantation stage, suggesting that this period is important for conceptus viability and the establishment of pregnancy. Successful establishment of pregnancy in all mammalian species depends on the orchestrated molecular events that transpire at the conceptus-uterine interface during the peri-implantation period. This maternal-conceptus interaction is especially crucial in pigs because in them non-invasive epitheliochorial placentation occurs, in which the pre-implantation phase is prolonged. During the pre-implantation period, conceptus survival and the establishment of pregnancy are known to depend on the developing conceptus receiving an adequate supply of histotroph, which contains a wide range of nutrients and growth factors. Evidence links growth factors including epidermal growth factor (EGF), insulin-like growth factor-I (IGF-I), vascular endothelial growth factor (VEGF), and colony-stimulating factor 2 (CSF2) to embryogenesis or implantation in various mammalian species; however, in the case of pig, little is known about such functions of these growth factors, especially their regulatory mechanisms at the maternal-conceptus interface. Our research group has presented evidence for promising growth factors affecting cellular activities of primary porcine trophectoderm (pTr) cells, and we have identified potential intracellular signaling pathways responsible for the activities induced by these factors. Therefore, this review focuses on promising growth factors at the maternal-conceptus interface regulating the development of the porcine conceptus and playing pivotal roles in implantation events during early pregnancy in pigs.

• Molecules and Cells
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• 제25권2호
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• pp.317-321
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• 2008

Members of the large family of Asb proteins are ubiquitously expressed in mammalian tissues; however, the roles of individual Asb and their function in the developmental testes have not been reported. In this report, we isolated a murine Asb4 from mouse testis. Northern blot analysis revealed that mAsb-4 was expressed only in testes and produced in a stage-specific manner during spermatogenesis. It was expressed in murine testes beginning in the fourth week after birth and extending into adulthood. Pachytene spermatocytes had the highest level of expression. Interestingly, the human homologue of mAsb-4, ASB-4 (hASB-4) was also expressed in human testis. These results suggest that ASB-4 plays pivotal roles in mammalian testis development and spermatogenesis.