• BMB Reports
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• v.48 no.7
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• pp.371-372
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• 2015

MicroRNAs (miRNAs) can regulate the expression of genes that are involved in multiple cellular pathways. However, their targets and mechanism of action associated with the autophagy pathway are not fully investigated yet. EWSR1 (EWS RNA-Binding Protein 1/Ewing Sarcoma Break Point Region 1) gene encodes a RNA/DNA binding protein that is ubiquitously expressed and plays roles in numerous cellular processes. Recently, our group has shown that EWSR1 deficiency leads to developmental failure and accelerated senescence via processing of miRNAs, but its role in the regulation of autophagy remains elusive. In this context, we further investigated and found that EWSR1 deficiency triggers the activation of the DROSHA-mediated microprocessor complex and increases the levels of miR125a and miR351, which directly target Uvrag. Interestingly, the miR125a- and miR351-targeted reduction of Uvrag led to the inhibition of autophagy in both ewsr1 knockout (KO) MEFs and ewsr1 KO mice. In summary, our study demonstrates that EWSR1 is associated with the posttranscriptional regulation of Uvrag via miRNA processing. The regulation of autophagy pathway in miRNAs-Uvrag-dependent manner provides a novel mechanism of EWSR1 deficiency-related cellular dysfunction. [BMB Reports 2015; 48(7): 371-372]

• Molecules and Cells
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• v.21 no.3
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• pp.389-394
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• 2006

Human seven-in-absentia (SIAH)-interacting protein (SIP) is a component of the E3 ligase complex targeting beta-catenin for destruction. Arabidopsis has one SIP protein (AtSIP) with 32% amino acid sequence identity to SIP. To investigate the functions of AtSIP, we isolated an atsip knockout mutant, and generated transgenic plants overexpressing AtSIP. The growth rates and morphologies of the atsip and transgenic plants were indistinguishable from those of wild type. However, atsip plants were more susceptible to Pseudomonas syringae infection, and the transgenic plants overexpressing AtSIP were more resistant. Consistent with this, RNA blot analysis showed that the AtSIP gene is strongly induced by wounding and hydrogen peroxide treatment. In addition, when plants were infected with P. syringae, AtSIP was transiently induced prior to PR-1 induction. These observations show that Arabidopsis AtSIP plays a role in resistance to pathogenic infection.

• Molecules and Cells
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• v.37 no.9
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• pp.685-690
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• 2014

Osteoclasts are large polykaryons that have the unique capacity to degrade bone and are generated by the differentiation of myeloid lineage progenitors. To identify the genes involved in osteoclast development, we performed microarray analysis, and we found that carboxypeptidase E (CPE), a prohormone processing enzyme, was highly upregulated in osteoclasts compared with their precursors, bone marrow-derived macrophages (BMMs). Here, we demonstrate a novel role for CPE in receptor activator of NF-${\kappa}B$ ligand (RANKL)-induced osteoclast differentiation. The overexpression of CPE in BMMs increases the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinuclear osteoclasts and the expression of c-Fos and nuclear factor of activated T cells c1 (NFATc1), which are key regulators in osteoclastogenesis. Furthermore, employing CPE knockout mice, we show that CPE deficiency attenuates osteoclast formation. Together, our data suggest that CPE might be an important modulator of RANKL-induced osteoclast differentiation.

• Korean Journal of Veterinary Research
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• v.45 no.4
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• pp.517-525
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• 2005

This study was performed to evaluate using wild-type (WT) and $C{\times}32$ knockout (KO) mice if lack of cell to cell communication by connexin 32 gap junction enhances the benzene-induced hematotoxicity and hemopoietic tumor development. The WT and $C{\times}32$ KO mice were exposed to 300 ppm of benzene for 6 hours/day, 5 days/week for a total of 26 weeks by inhalation, and then sacrificed to evaluate the toxicities of hemopoietic organs or allowed to live out their life span to evaluate the hemopoietic tumor incidence. The significant increase and decrease of organ weight were respectively noted in spleen and thymus of both WT and $C{\times}32$ KO mice without significant difference between the genotypes. Histopathologically, benzene exposure for 26 weeks induced the morphological changes in hemopoietic organs, characterized by fat cell accumulation in the bone marrow and extramedullary hemopoiesis in the spleen. The fat cell accumulation was, compared with that of WT mice, considerably exacerbated in the $C{\times}32$ KO mice. However, no significant difference was observed in the changes of hematological values and bone marrow cellularity as well as in the onset and incidence of hemopoietic tumors between WT and $C{\times}32$ KO mice. In conclusion, this study indicated little significant role of the cellular communication by $C{\times}32$ gap junction in the action mechanism of benzene hematotoxicity and leukemogenicity.

• Molecules and Cells
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• v.25 no.3
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• pp.438-445
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• 2008

Leaf senescence is a highly regulated genetic process that constitutes the last stage of plant development and provides adaptive fitness by relocating metabolites from senescing leaves to reproducing seeds. Characterization of various senescence mutants, mostly in Arabidopsis, and genome-wide analyses of gene expression, have identified a wide array of regulatory components, including transcription factors and enzymes as well as signaling molecules mediating growth hormones and environmental stress responses. In this work we demonstrate that a membrane-associated NAC transcription factor, NTL9, mediates osmotic stress signaling in leaf senescence. The NTL9 gene is induced by osmotic stress. Furthermore, activation of the dormant, membrane-associated NTL9 is elevated under the same conditions. A series of senescence-associated genes (SAGs) were upregulated in transgenic plants overexpressing an activated form of NTL9, and some of them were slightly but reproducibly downregulated in a T-DNA insertional NTL9 knockout mutant. These observations indicate that NTL9 mediates osmotic stress responses that affect leaf senescence, providing a genetic link between intrinsic genetic programs and external signals in the control of leaf senescence.

• Molecules and Cells
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• v.24 no.2
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• pp.247-254
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• 2007

Improvement in the pharmacokinetic properties of short interfering RNAs (siRNAs) is a prerequisite for the therapeutic application of RNA interference technology. When injected into mice as unmodified siRNAs complexed to DOTAP/Chol-based cationic liposomes, all 12 tested siRNA duplexes caused a strong induction of cytokines including interferon ${\alpha}$, indicating that the immune activation by siRNA duplexes is independent of sequence context. When modified by various combinations of 2'-OMe, 2'-F, and phosphorothioate substitutions, introduction of as little as three 2'-OMe substitutions into the sense strand was sufficient to suppress immune activation by siRNA duplexes, whereas the same modifications were much less efficient at inhibiting the immune response of single stranded siRNAs. It is unlikely that Toll-like receptor 3 (TLR3) signaling is involved in immune stimulation by siRNA/liposome complexes since potent immune activation by ds siRNAs was induced in TLR3 knockout mice. Together, our results indicate that chemical modification of siRNA provides an effective means to avoid unwanted immune activation by therapeutic siRNAs. This improvement in the in vivo properties of siRNAs should greatly facilitate successful development of siRNA therapeutics.

• IMMUNE NETWORK
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• v.13 no.6
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• pp.289-294
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• 2013

Lipocalin-2 (LCN2) is an acute-phase protein induced by injury, infection, or other inflammatory stimuli. LCN2 binds small hydrophobic ligands and interacts with cell surface receptor to regulate diverse cellular processes. The role of LCN2 as a chemokine inducer in the central nervous system (CNS) has been previously reported. Based on the previous participation of LCN2 in neuroinflammation, we investigated the role of LCN2 in formalin-induced nociception and pathological pain. Formalin-induced nociceptive behaviors (licking/biting) and spinal microglial activation were significantly reduced in the second or late phase of the formalin test in Lcn2 knockout mice. Likewise, antibody-mediated neutralization of spinal LCN2 attenuated the mechanical hypersensitivity induced by peripheral nerve injury in mice. Taken together, our results suggest that LCN2 can be therapeutically targeted, presumably for both prevention and reversal of acute inflammatory pain as well as pathological pain.

• Animal cells and systems
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• v.2 no.2
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• pp.153-164
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• 1998

Cytokines regulate proliferation, differentiation and functions of haemotopoietic cells. Each cytokine possesses a variety of activities on various target cells (pleiotropy) and various cytokines have similar and overlapping activities on the same target cells (redundancy). The nature of these cytokine activities predicts unique feature of cytokine receptors, namely, cytokine has multiple receptors, different cytokines share a common receptor, and different cytokine receptors are linked to common signaling pathways. cDNA cloning of genes for cytokine receptors revealed distinct sets of receptor family with different structural features. The cytokine receptor superfamily consists of a largest family, and contains more than twenty cytokine receptor subunits. This receptor has common structural features in both extracellular and intracellular regions without tyrosine kinase domain. Another striking feature of the receptor is to share common subunit of multiple cytokines, which partly explains the redundancy of activities of some cytokines. Recent studies revealed detailed signaling events of the cytokine receptor, the primary activation of JAK and subsequent phosphorylation of tyrosine residues of receptor, and various cellular proteins. Many SH2 containing adapter proteins play an important role in cytokine signals, and this system has similarities with tyrosine kinase receptor signal transduction. STAT may mainly account for cytokine specific functions as suggested by knockout mice studies. It is of importance to note that cytokine activates multiple signaling pathways and the balance and combination of related signaling events may determine the specificity of functions of cytokines.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.72-78
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• 2008

Metal stamping is widely used in the mass-production process of the automobile. During the stamping process, air may be trapped between the draw die and the panel and/or between the punch and the panel. Air pocket rapidly not only increases forming load in the final stage, but also deforms the product just formed by compressive air inside the air pocket in knockout process. To prevent these problems air bent holes are drilled in the die to exhaust the trapped air but all processes associated with air bent holes are performed by empirical know-how of workers in the field due to lack of researches. Therefore this study developed an automated design system for predicting the shape and position, and volume of air pocket on the draw die by using the AutoLISP language under AutoCAD circumstance. The system is able to display the shape of air pocket occurred in the draw die and to calculate automatically its volume by strokes. So it makes a stepping stone to calculate theoretical size of an air bent hole and numbers according to it by predicting and analyzing the position and volume of air pocket. Results obtained from the system enable the designers or manufacturers of the stamping die to be more efficient in this field.

• Development and Reproduction
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• v.8 no.2
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• pp.69-75
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• 2004

It has been known for many years that administration of estrogen, a so-called female hormone, has harmful effects on male fertility. However, studies employing transgenic mice deficient in estrogen receptors reveal substantial roles for estrogen in male fertility. The aim of this article is to review and summarize the current knowledge on the estrogen receptor localization in male reproductive organs including male germ cells of rodents. Also, informations about the mice models with disrupted estrogen signaling and associated phenotypes will be provided.