• BMB Reports
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• 제49권4호
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• pp.197-198
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• 2016

Although three different research groups have reported successful derivations of human somatic cell nuclear transfer-derived embryonic stem cell (SCNT-ESC) lines using fetal, neonatal and adult fibroblasts, the extremely poor development of cloned embryos has hindered its potential applications in regenerative medicine. Recently, however, our group discovered that the severe methylation of lysine 9 in Histone H3 in a human somatic cell genome was a major SCNT reprogramming barrier, and the overexpression of KDM4A, a H3K9me3 demethylase, significantly improved the blastocyst formation of SCNT embryos. In particular, by applying this new approach, we were able to produce multiple SCNT-ES cell lines using oocytes obtained from donors whose eggs previously failed to develop to the blastocyst stage. Moreover, the success rate was closer to 25%, which is comparable to that of IVF embryos, so that our new human SCNT method seems to be a practical approach to establishing a pluripotent stem cell bank for the general public as well as for individual patients.

• 생명과학회지
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• 제30권12호
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• pp.1092-1100
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• 2020

Six-transmembrane epithelial antigen of prostate 4 (Steap4)는 철과 구리를 환원하여 철과 구리의 세포내 유입에 관여하는 금속 환원효소로, 구리 철의 항상성 뿐만 아니라 염증, 포도당 대사, 지질 대사에도 중요한 역할을 한다. 최근에 Steap4가 지방세포의 분화를 촉진한다는 보고가 발표되었으나, 이에 관련된 분자적 기전에 대해서는 알려지지 않았다. 그래서, 본 연구에서는 Steap4에 의한 지방세포분화 촉진에 관련된 기전을 연구하였다. 이를 위해 3T3-L1 백색지방세포, 불멸화된 갈색지방세포(iBA) 및 생쥐의 배아 섬유아 세포인 C3H10T1/3 세포에서 Steap4을 감소시킨 후 지방세포분화 초기단계에 관련된 신호들을 분석하였다. Steap4을 shRNA로 감소시켰을 때 지방세포분화 초기 단계에서 3종류 지방세포의 세포 증식이 억제되었으며, 세포주기 관련 단백질인 cyclin A, cyclin D 그리고 cdk2의 발현은 감소하는 반면 세포주기 저해 단백질인 p21과 p27의 발현은 증가하였다. 또한 세포주기 관련 신호인 p38, ERK 그리고 Akt의 활성화는 억제되었다. 한편 지방세포분화 초기 단계에 관여하는 지방세포분화 전사인자들을 분석하였을 때, Steap4의 감소는 지방세포분화 활성 전사 인자인 C/EBPβ, KLF4의 발현을 저해하는 반면, 지방세포분화 억제 전사 인자인 KLF2, KLF3 그리고 GATA2의 발현은 증가시켰다. 또한 Steap4의 과발현은 C/EBPβ promoter에 존재하는 전사억제 히스톤 표지자인 H3K9me2과 H3K27me3을 감소시켰다. 따라서, 이상의 결과를 종합하면 Steap4는 지방세포분화 초기단계인 mitotic clonal expansion을 촉진하고 지방세포분화 전사인자들의 발현을 조절함으로써, 지방세포분화를 촉진시킴을 알 수 있었다.

• 약학회지
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• 제43권3호
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• pp.378-384
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• 1999

Retinoic acid (RA) and dibutyryl cyclic AMP (dbcAMP) induce the differentiation of the multipotent embryonic carcinoma cell line, F9 cells, into parietal endoderm like cell. The F9 cells are highly proliferative doubling approximately 12 hourse. S Phase is predominant, lasting 10 hours and G2/M phase occupies most of the remaining cycle (2 hours) and G1 phase is nearly non-existent. In this study, we showed the effect of RA and dbcAMPon the cell cycle associated molecules (especially around G1 phase) during F9 cell differentiation. Differentiation of F9 cells was induced by the combined addition of RA ($10^{-7}M$) and dbcAMP (0.5mM), and cells were harvested daily up to 4 days. Flow cytometric analysis showed the prolongation of G1 phase around 30 hours after induction. Western blot analysis revealed that the amount of cyclin D1 and cdk2 were increased at day 4. However, histone H1 kinase activity of cdk2 was decreased. These data strongly suggest that RA and dbcAMP induce the growth arrest of F9 cells at G1 phase by decreasing the activity of cdk2, although they have increased the protein contents of cyclin D1 and cdk2. The reason for the discrepancy between the H1 kinase activity and protein contents are not clear yet.

• Molecules and Cells
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• 제43권11호
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• pp.945-952
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• 2020

Hypoxia induces the expression of several genes through the activation of a master transcription factor, hypoxia-inducible factor (HIF)-1α. This study shows that hypoxia strongly induced the expression of two carboxypeptidases (CP), CPA4 and CPE, in an HIF-1α-dependent manner. The hypoxic induction of CPA4 and CPE gene was accompanied by the recruitment of HIF-1α and upregulation in the active histone modification, H3K4me3, at their promoter regions. The hypoxic responsiveness of CPA4 and CPE genes was observed in human adipocytes, human adipose-derived stem cells, and human primary fibroblasts but not mouse primary adipocyte progenitor cells. CPA4 and CPE have been identified as secreted exopeptidases that degrade and process other secreted proteins and matrix proteins. This finding suggests that hypoxia changes the microenvironment of the obese hypoxic adipose tissue by inducing the expression of not only adipokines but also peptidases such as CPA4 and CPE.

• The Korean Journal of Physiology and Pharmacology
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• 제14권6호
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• pp.435-440
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• 2010

Valproic acid (VPA) is a well-known anti-epileptic and mood stabilizing drug. A growing number of reports demonstrate that VPA is neuroprotective against various insults. Despite intensive efforts to develop new therapeutics for stroke over the past two decades, all treatments have thus far failed to show clinical effect because of treatment-limiting side effects of the drugs. Therefore, a safety-validated drug like VPA would be an attractive candidate if it has neuroprotective effects against ischemic insults. The present study was undertaken to examine whether pre- and post-insult treatments with VPA protect against brain infarct and neurological deficits in mouse transient (tMCAO) and permanent middle cerebral artery occlusion (pMCAO) models. In the tMCAO (2 hr MCAO and 22 hr reperfusion) model, intraperitoneal injection of VPA (300 mg/kg, Lp.) 30 min prior to MCAO significantly reduced the infarct size and the neurological deficit. VPA treatment immediately after reperfusion significantly reduced the infarct size. The administration of VPA at 4 hr after reperfusion failed to reduce the infarct size and the neurological deficit. In the pM CAO model, treatment with VPA (300 mg/kg, i.p.) 30 min prior to MCAO significantly attenuated the infarct size, but did not affect the neurological deficit. Western blot analysis of acetylated H3 and H4 protein levels in extracts from the ischemic cortical area showed that treatment with VPA increased the expression of acetylated H3 and H4 at 2 hrs after MCAO. These results demonstrated that treatment with VPA prior to ischemia attenuated ischemic brain damage in both mice tMCAO and pMCAO models and treatment with VPA immediately after reperfusion reduced the infarct area in the tMCAO model. VPA could therefore be evaluated for clinical use in stroke patients.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권4호
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• pp.243-249
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• 2010

Tissue engineered bone (TEB) can replace an autogenous bone graft requiring an secondary operation site as well as avoid complications like inflammation or infection from xenogenic or synthetic bone graft. Adult mesenchymal stem cells (MSC) for TEB are considered to have various ranges of differentiation capacity or multipotency by the donor site and age. This study examined the effect of age on proliferation capacity, differentiation capacity and bone morphogenetic protein-2 (BMP-2) responsiveness of human bone marrow stromal cells (hBMSC) according to the age. In addition, to evaluate the effect on enhancement for osteoblast differentiation, the hBMSC were treated with Trichostatin A (TSA) and 5-Azacitidine (5-AZC) which was HDAC inhibitors and methyltransferase inhibitors respectively affecting chromatin remodeling temporarily and reversibly. The young and old group of hBMSC obtained from the iliac crest from total 9 healthy patients, showed similar proliferation capacity. Cell surface markers such as CD34, CD45, CD90 and CD105 showed uniform expression regardless of age. However, the young group showed more prominent transdifferentiation capacity with adipogenic differentiation. The osteoblast differentiation capacity or BMP responsiveness was low and similar between young and old group. TSA and 5-AZC showed potential for enhancing the BMP effect on osteoblast differentiation by increasing the expression level of osteogenic master gene, such as DLX5, ALP. More study will be needed to determine the positive effect of the reversible function of HDAC inhibitors or methyltransferase inhibitors on enhancing the low osteoblast differentiation capacity of hBMSC.

• Molecules and Cells
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• 제41권5호
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• pp.444-453
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• 2018

Aberrations in histone modifications are being studied in mixed-lineage leukemia (MLL)-AF9-driven acute myeloid leukemia (AML). In this study, we focused on the regulation of the differentiation of the MLL-AF9 type AML cell line THP-1. We observed that, upon phorbol 12-myristate 13-acetate (PMA) treatment, THP-1 cells differentiated into monocytes by down-regulating Aurora kinase A (AURKA), resulting in a reduction in H3S10 phosphorylation. We revealed that the AURKA inhibitor alisertib accelerates the expression of the H3K27 demethylase KDM6B, thereby dissociating AURKA and YY1 from the KDM6B promoter region. Using Flow cytometry, we found that alisertib induces THP-1 differentiation into monocytes. Furthermore, we found that treatment with the KDM6B inhibitor GSK-J4 perturbed the PMA-mediated differentiation of THP-1 cells. Thus, we discovered the mechanism of AURKA-KDM6B signaling that controls the differentiation of THP-1 cells, which has implications for biotherapy for leukemia.

• 생명과학회지
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• 제25권11호
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• pp.1214-1222
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• 2015

본 연구는 난소 제거 수술을 시행하여 폐경기를 유도시킨 뒤 고지방 식이를 섭취한 쥐에게서 나타난 신체 변화에 있어 운동과 갈근/지황 섭취에 의한 개선 효과를 관찰하고, 그러한 효과가 골격근에서의 후성 유전적 발현 변화에 의한 것임을 규명하고자 하였다. 8주령의 쥐(rat, n=60)의 난소를 제거한 뒤 고지방 식이를 유도하면서 트레드밀 운동(exercise)을 실시하는 그룹과 비운동(sedentary) 그룹으로 나누었다. 두 그룹을 각각 estradiol, 갈근과 지황의 3:1 복합물(HT051), 그리고 물 섭취 군으로 다시 나누어 총 8주간 경구 투여를 함께 실시하였다. 그 결과 운동 그룹과 갈근/지황 섭취 그룹에서 체중이 유의하게 감소하였고, 가자미근과 족저근의 근질량 또한 운동 그룹과 갈근/지황 섭취 그룹에서 유의하게 증가하였다. 한편, 가자미근에서 물을 섭취하며 운동하지 않은 그룹의 H3K9 아세틸화가 억제 되었고 H3K9의 메틸화에는 변화가 없었다. 족저근의 경우 운동 그룹에서 H3K9 아세틸화가 현저하게 눈에 띄었고, 반대로 메틸화는 줄어든 것이 관찰되었다. 나아가 H3K9의 아세틸화와 메틸화를 조절하는 대표적인 효소 중 HDAC4, HDAC5, G9a 유전자의 mRNA 발현양을 정량한 결과, 가자미근에서는 모두 유의한 차이가 없었고 족저근에서 운동 한 그룹의 HDAC5와 G9a 유전자의 mRNA 발현양이 유의하게 감소하였지만 HDAC4의 mRNA는 차이가 없었다. 또한 운동과 갈근/지황의 상호작용 효과는 나타나지 않았다. 본 연구를 통하여 운동과 갈근/지황 섭취가 체중 감소, 근질량 증가에 영향을 미치고, 이러한 현상은 히스톤 H3K9 부분의 아세틸화와 메틸화에 의한 유전자 발현 조절이 그 기전으로 작용한다는 것을 알 수 있었다.

• Animal cells and systems
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• 제13권4호
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• pp.381-389
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• 2009

Using the DDRT-PCR, a series of differentially expressed genes in human primary cervical cancer was isolated. Among the 250 PCR amplimers, 88 gene fragments were confirmed by reverse Northern hybridization. Homology searches indicated that 26 out of 88 were previously known genes including calmodulin, human BBC1, histone H3.3, a series of ribosomal proteins (RPL19, RPS19, and RPS12), translation initiation factor (eIF-4AI), lactoferrin, integrin ${\alpha}6$, cell-surface antigens (CD9 and CD59), transcription factor (mbp-1), and mitochondrial proteins. Several unknown clones showed sequence homology with known genes. Furthermore, six of the unknown genes showed identical sequence with expressed sequence tags (EST) of unknown function. Differential expression patterns of identified genes were further examined and confirmed with multiple pairs of cervical cancer samples using Northern hybridization. Our profiling of differentially expressed genes may provide useful information about the underlying genetic alterations in human cervical carcinoma and diagnostic markers for this disease. The precise roles of these genes in cancer development remain to be elucidated.

• Parasites, Hosts and Diseases
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• 제57권5호
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• pp.489-497
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• 2019

Cystic echinococcosis (CE), a zoonotic disease caused by Echinococcus granulosus at the larval stage, predominantly develops in the liver and lungs of intermediate hosts and eventually results in organ malfunction or even death. The interaction between E. granulosus and human body is incompletely understood. Exosomes are nanosized particles ubiquitously present in human body fluids. Exosomes carry biomolecules that facilitate communication between cells. To the best of our knowledge, the role of exosomes in patients with CE is not reported. Here, we isolated exosomes from the sera of patients with CE (CE-exo) and healthy donors and subjected them to liquid chromatography-tandem mass spectrometry analysis. Proteomic analysis identified 49 proteins specifically expressed in CE-exo, including 4 proteins of parasitic origin. The most valuable parasitic proteins included tubulin alpha-1C chain and histone H4. And 8 proteins were differentially regulated in CE-exo (fold change>1.5), as analyzed with bioinformatic methods such as annotation and functional enrichment analyses. These findings may improve our understanding about the interaction between E. granulosus and human body, and may contribute to the diagnosis and prevention of CE.