• Korean Journal of Microbiology
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• v.53 no.4
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• pp.286-291
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• 2017

In eukaryotic cells, histone modification is an important mechanism to regulate the chromatin structure. The methylation of the fourth lysine on histone H3 (H3K4) by Set1 complex is one of the various well-known histone modifications. Set1 complex has seven subunits including Swd2, which is known to be important for H2B ubiquitination dependent on H3K4 methylation. Swd2 was reported to regulate Set1's methyltransferase activity by binding to near RNA recognition motif (RRM) domain of Set1 and to act as a component of CPF (Cleavage and Polyadenylation Factors) complex involved in RNA 3' end processing. According to the recent reports, two functions of Swd2 work independently of each other and the lethality of Swd2 knockout strain was known to be caused by its function as a component of CPF complex. In this study, we found that Swd2 could influence the Set1's stability as well as histone methyltransferase activity through the association with RRM domain of Set1. Also, we found that ${\Delta}swd2$ mutant bearing truncated-Set1, which cannot interact with Swd2, lost its lethality and grew normally. These results suggest that the dual functions of Swd2 in H3K4 methylation and RNA 3' end processing are not independent in Saccharomyces cerevisiae.

• Journal of Life Science
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• v.33 no.1
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• pp.102-113
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• 2023

This review discusses the cellular and molecular mechanisms by which the endometrial estrogen and progesterone receptors regulate local estrogen production, expression of the specific estrogen receptors, progesterone resistance, inflammatory responses and the differentiation and survival of endometriotic cells in endometrial inflammation. The epigenetic aberrations of endometrial stromal cells play an important role in the pathogenesis and progression of endometriosis. In particular, differential methylation of the estrogen receptor genes changes in the stromal cells the dominancy of estrogen receptor from ERα into ERβ, and results in the abnormal estrogen responses including inflammation, progesterone resistance and the disturbance of retinoid synthesis. These stromal cells also stimulate local estrogen production in response to PGE2 and the SF-1 mediated induction of steroidogenic enzyme expression, and the increased estradiol then feeds back into the ERβ to repeat the vicious inflammatory cycle through the activation of COX-2. In addition, high levels of ERβ expression may also change the chromatin structure of endometrial mesenchymal stem cells, and together with the repeated menstrual cycles can induce formation of the endometriotic tissue. The cascade of these serial events then leads to cell adhesion, angiogenesis and survival of the differentiation-disregulated stromal cells through the action of inflammatory factors such as ERβ-mediated estrogen, TNF-α and TGF-β1. Therefore, understanding of the dynamic hormonal changes during the menstrual cycle and the corresponding signal transduction mechanisms of the related nuclear receptors in endometrium would provide new insights for treating inflammatory diseases such as the endometriosis.

• Applied Microscopy
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• v.38 no.3
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• pp.175-183
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• 2008

Liver regeneration is a result of highly coordinated proliferation of hepatocytes and non-parenchymal liver cells. At this process, induction of metallothionein (MT), which is low molecular and cysteine rich, has been reported. The present study was carried to find the ultrastructure of hepatocytes and determine the expression of MT in regenerating rat liver after partial hepatectomy. As a result, the remnant liver after PH grew fast from 1 day until 7 days. Various changes were morphologically observed. Disintegration of cell plates and liver lobule appeared shortly after PH. And hepatocytes showed the rapid proliferation, characterized by high nuclear cytoplasmic ratio, weak intercellular junctional complexes, chromatin condensation, increase of ribosomes and mitochondria, and temporary increase of lipid droplets. Finally, remodeling of the liver lobule was completed through the rearrangement of blood vessels and cell plates by 7 days after PH. On histochemistry, immunoreactivity indicating the presence of MT appeared moderately throughout the cytoplasm of control rat hepatocyte. After PH, positive reactions for MT increased at the cytoplasm and the nucleus. These results suggest that the remnant liver cells immediately entered cell proliferation and increase of MT expression after PH. It is thought that MT protein might be associated with transfer of some factors needed to cell division from the cytoplasm to the nucleus for regeneration of the liver after PH.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.1
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• pp.35-43
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• 1996

The appearance of the primordial germ cells (PGC's), early gonadogenesis, sex differentiation and sex ratio of the embryo in the viviparous teleost, Ditrema temmincki were investigated by using photomicroscopy. The PGC's were first observed in the fibrous mesenchymal tissue located between the early alimentary tract and the dorsal body wall in the late embryonic development stage. During the period from the hatching to the individual total length (TL) of 4.0 mm the PGC's were evenly distributed in the fibrous mesenchymal tissue between alimentary tract and body wall. But the period of TL 5.0 mm mesenchymal tissue separated from the dorsal body wall, the PGC's moved to the posterior mesenchymal tissue and formed the primitive gonad. During the early gonadogenesis, differentiation of the testis and ovary were distinguished from the arrangement of the germ cells and somatic cells. Gonad of embryo in TL 10.0 mm can be separated into the ovary and testis by external morphology. The testis had a separated form which was consisted with two lobes, and the ovary had a fused form in half-posterior part. In the testicular differentiation of the embryo, histological pattern of the seminiferous tubule appeared when TL of the embryo was to be 25.0 mm, for the seminal vesicle was formed In the individual TL of 30.0mm. The testis of the embryo with TL of 45.0 mm was similar to that of the adult fish in the external and internal structures. In the ovarian differentiation, formation of the ovigerous folds and the ovarian cavity were clearly observed when the TL reached to 30.0 mm. The ovary from the individual with TL of 60.0 mm was differentiated into a similar ovary as seen in the adult fish in the external and internal structure. Right before parturition the total length of the individual was approximately 63.0 mm of which the individual embryo has an ovary containing the oocytes in the chromatin nucleolus stage, or a testis containing the spermatogonia, respectively. And the embryonic sex ratio of female to male was 1.65 : 1. Ditrema temmincki is dioecism and the pattern of sex differentiation is belonged to a differentiation type.

• The Korean Journal of Pharmacology
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• v.32 no.1
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• pp.113-123
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• 1996

It has been well known that polyamines ensure the stability of chromatin structure and the fidelity of DNA transcription. This study was carried out to evaluate the effect of polyamines on the apoptosis of mouse thymocytes induced by dexamethasone and polyamine synthesis inhibitors. 1) In the histological death findings of thymocytes double-stained with acridine orange and ethidium bromide, the apoptotic and the necrotic fractions (AF; NF) in the control group were $9.4{\pm}4.2%$ and $4.5{\pm}5.3%$, respectively. Dexamethasone $(3\;{\times}\;10^{-8}\;M:\;DX)$ in creased AF upto $52.0{\pm}8.1%$ and did not change NF, but A23187 $(5\;{\times}\;10^{-7}\;M:\;A2)$ increased AF and NF upto $45.0{\pm}8.9%$ and $20.5{\pm}10.6%$, respectively. 2) The thymocyte viability was significantly reduced by DX, DHEA $(1\;{\times}\;10^{-4}\;M)$, A2, DFMO $(1\;{\times}\;10^{-4}\;M)$, and $MGBG\;(1\;{\times}\;10^{-4}\;M)$, respectively. It was, however, little affected by $aminoguanidine\;(1\;{\times}\;10^{-4}\;M:\;AG)$, $putrescine\;(1\;{\times}\;10^{-5}\;M:\;PT)$, $spermidine\;(1\;{\times}\;10^{-5}\;M:\;SD)$, and $spermine\;(1\;{\times}\;10^{-5}\;M:\;SM)$. 3) The genomic DNA of mouse thymocyte was markedly fragmented by DX and A2, respectively, and to a lesser extent, by DHEA, but was little affected by MGBG, DFMO, AG, and each of polyamines. 4) The DX induced reduction of thymocyte viability was moderately attenuated by DHEA, but little affected by DFMO, MGBC, and AG. However, SM significantly attenuated the viability reduction induced by A2 as well as DX. 5) The thymocyte viability reduction by MGBG and DFMO was significantly attenuated by only SM among three polyamines applied in this study. 6) The thymocyte viability redution by combined treatments of DX with DFMO and MGBG, respectively, was significantly attenuated by SM, and moderately by PT. But the viability reduction by combined treatment of DX with AG or DHEA was not affected by polyamines. These results suggest that polyamines, particularly spermine, might play the inhibitory role in thymocyte apoptosis and the inhibitory effect can be ascribed in part to the increase of polyamine uptake by thymocytes pretreated with DFMO and MGBG.