Genome-wide screening and identification of novel proteolytic cleavage targets of caspase-8 and -10 in vitro.

Bae, Seunghee,Ha, Tae-Su,Yoon, Youngmin,Lee, Joonyoung,Cha, Hwa Jun,Yoo, Hoesook,Choe, Tae-Boo,Li, Shunhua,Sohn, Insook,Kim, Ji-Young,Kim, Cha-Soon,Jin, Hyeon-Ok,Lee, Hyung-Chahn,Park, In-Chul,Kim, Ch D.A. Spandidos 2008 International journal of molecular medicine Vol.21 No.3

<P>Apoptosis executed by the mammalian caspase family plays a fundamental role in cellular homeostasis. Deregulation of this process is associated with several human diseases. The multimerization of ligand-induced death receptors results in the recruitment of the death inducing signaling complex and autocatalytic activation of initiator caspases, including caspase-8 and -10. However, it is still unclear how initiator caspases trigger and control the early apoptotic signaling pathways, partly because the downstream proteolytic cleavage targets of the initiator caspases are not completely known. Although it is known that a number of proteins are cleaved by various members of the caspase family, the identification of specific cleavage substrates of the initiator caspases 8 and 10, has been hindered by a lack of systematic and broadly applicable strategies for substrate identification. In the present study we constructed a mouse cDNA library and used it to perform a systematic, genome-wide screen for novel in vitro substrates of caspase-8 and -10. From this, we successfully identified six putative caspase substrates, including five novel proteins (ABCF1, AKAP1, CPE, DOPEY1 and GOPC1) that may be targeted specifically by the initiator caspases 8 and 10 during the early stages of apoptosis. These findings may provide useful information for elucidating the apoptotic signaling pathways downstream of the death receptors.</P>

Effects of Er-Miao-San extracts on TNF-alpha-induced <i>MMP-1</i> expression in human dermal fibroblasts

Bae, Seunghee,Jung, Younjung,Choi, Yeong Min,Li, Shunhua BioMed Central 2015 BIOLOGICAL RESEARCH Vol.48 No.1

<P><B>Background</B></P><P>Various health benefits have been attributed to Er-Miao-San (EMS), a traditional Chinese herbal formulation that contains equal amounts of cortex phellodendri (<I>Phellodendron amurense</I> Ruprecht) and rhizoma atractylodis (<I>Atractylodes lancea</I> D.C). However, its effect on the anti-inflammatory activity in human dermal fibroblasts (HDFs) and the mechanism underlying this effect are unknown.</P><P><B>Results</B></P><P>This study investigated the effects of EMS on TNF-α-induced <I>MMP-1</I> expression in HDFs. Our data show that EMS inhibited TNF-α-induced <I>MMP-1</I> expression in a concentration-dependent manner. Interestingly, EMS maintained IκB content without inhibiting the phosphorylation of MAPKs, which are well-established upstream kinases of NF-κB. Moreover, EMS reduced the level of nuclear p65 protein in HDFs. Luciferase assay revealed that EMS inhibits the transcriptional activity of NF-κB by stabilizing IκB. Our results show that EMS exerts its anti-inflammatory effect by inhibiting NF-κB-regulated genes such as <I>IL-1β</I> and <I>IL-8</I>. Moreover, EMS effectively inhibited TNF-α-induced expression of <I>MMP-1</I> via the NF-κB pathway.</P><P><B>Conclusions</B></P><P>Taken together, our data suggest that EMS could potentially be used as an anti-inflammatory and anti-aging treatment.</P>

Resveratrol alters microRNA expression profiles in A549 human non-small cell lung cancer cells

Bae, Seunghee,Lee, Eun-Mee,Cha, Hwa Jun,Kim, Karam,Yoon, Yeongmin,Lee, Hyunjin,Kim, Jongran,Kim, Yu-Jeong,Lee, Hong Ghi,Jeung, Hoi-Kyung,Min, Yoo Hong,An, Sungkwan Springer-Verlag 2011 Molecules and cells Vol.32 No.3

Altered microRNA expression profiles are involved in resistance to low-dose ionizing radiation in the absence of BMI1 in human dermal fibroblasts.

Bae, Seunghee,Kim, Karam,Cha, Hwa Jun,Choi, Yeongmin,Shin, Shang Hun,An, In-Sook,Lee, Jae Ho,Song, Jie-Young,Yang, Kwang Hee,Nam, Seon Young,An, Sungkwan Lychnia 2014 International journal of oncology Vol.45 No.4

<P>The polycomb group RING finger protein, B-cell?specific moloney murine leukemia virus integration site?1 (BMI1), has emerged as a key regulator of cell proliferation, cell cycle, cell immortalization, chemoresistance and radioresistance. Although the radioresistant effect of BMI1 has been thoroughly investigated, the effectiveness of this factor on low-dose radiation (LDR) resistance has not been explored. Here, we demonstrate that BMI1 is not critical for altering cell viability or cell growth in response to LDR, but BMI1 changes cellular gene expression profiles in response to LDR. Normal human dermal fibroblasts (NHDFs) stably expressing BMI1 short hairpin RNA (shRNA) did not exhibit changes in cell viability or cell cycle distribution assays following exposure to 0.1?Gy of γ-radiation. However, microRNA (miRNA) microarrays revealed that a lack of BMI1 leads to changes in miRNA expression in response to LDR. Bioinformatics analyses demonstrated that predicted target genes of the altered miRNAs are functionally involved in both negative and positive regulation of cell growth, cell proliferation, cell cycle and apoptosis. Therefore, these results indicate that low radiosensitivity even in the absence of the radioresistant factor BMI1 is related with the altered miRNA expression profiles in NHDF.</P>

Identification of Anti-skin Aging Components Derived from Microalgae

Seunghee BAE 한국생물공학회 2020 한국생물공학회 학술대회 Vol.2020 No.10

Development of a high-throughput screening system for identification of novel reagents regulating DNA damage in human dermal fibroblasts

Bae, Seunghee,An, In-Sook,An, Sungkwan Walter de Gruyter GmbH 2015 Acta pharmaceutica Vol.65 No.3

<B>Abstract</B><P>Ultraviolet (UV) radiation is a major inducer of skin aging and accumulated exposure to UV radiation increases DNA damage in skin cells, including dermal fibroblasts. In the present study, we developed a novel DNA repair regulating material discovery (DREAM) system for the high-throughput screening and identification of putative materials regulating DNA repair in skin cells. First, we established a modified lentivirus expressing the luciferase and hypoxanthine phosphoribosyl transferase (HPRT) genes. Then, human dermal fibroblast WS-1 cells were infected with the modified lentivirus and selected with puromycin to establish cells that stably expressed luciferase and HPRT (DREAM-F cells). The first step in the DREAM protocol was a 96-well-based screening procedure, involving the analysis of cell viability and luciferase activity after pretreatment of DREAM-F cells with reagents of interest and post-treatment with UVB radiation, and <I>vice versa</I>. In the second step, we validated certain effective reagents identified in the first step by analyzing the cell cycle, evaluating cell death, and performing HPRT-DNA sequencing in DREAM-F cells treated with these reagents and UVB. This DREAM system is scalable and forms a time-saving high-throughput screening system for identifying novel anti-photoaging reagents regulating DNA damage in dermal fibroblasts.</P>

Oridonin protects HaCaT keratinocytes against hydrogen peroxide-induced oxidative stress by altering microRNA expression

BAE, SEUNGHEE,LEE, EUN-JIN,LEE, JAE HO,PARK, IN-CHUL,LEE, SU-JAE,HAHN, HYUNG JIN,AHN, KYU JOONG,AN, SUNGKWAN,AN, IN-SOOK,CHA, HWA JUN UNKNOWN 2014 INTERNATIONAL JOURNAL OF MOLECULAR MEDICINE Vol.33 No.1

microRNAs (miRNAs) have been shown to function as primary regulators of a variety of biological processes, including proliferation, differentiation and apoptosis in human keratinocytes. However, the biological significance of miRNAs in the defense against oxidative stress in keratinocytes remains to be elucidated. In this study, we demonstrate that oridonin, a diterpenoid compound isolated from Rabdosia rubescens with established antioxidant properties, protects HaCaT human keratinocytes from oxidative stress induced by exposure to hydrogen peroxide (H2O2). Our data demonstrate that low doses of oridonin (1-5 M) protect keratinocytes against H2O2-induced apoptosis in a concentration- and time-dependent manner. Moreover, as shown by our results, oridonin markedly decreased H2O2-induced reactive oxygen species production in HaCaT cells. Oridonin mediated these effects by altering miRNA expression. Bioinformatics analysis identified several putative target genes of the differentially expressed miRNAs. Assessment of their gene ontology annotation revealed that these target genes are likely involved in cell growth and inhibition of apoptosis. Thus, the data from this study establish a role for miRNAs in mediating oridonin-induced protective effects against oxidative stress in human keratinocytes.

H2AX의 BRCA1 NLS domain과 BARD1 BRCT domain 각각과의 in vitro 상호 결합

배승희(Seunghee Bae),이선미(Sun-Mi Lee),김수미(Sumi Kim),최태부(Tae-Boo Choe),김차순(Cha Soon Kim),성기문(Ki-Moon Seong),진영우(Young-Woo Jin),안성관(Sungkwan An) 한국생물공학회 2009 KSBB Journal Vol.24 No.4

본 연구에서는 H2AX의 생리학적인 기능 및 분자세포 생물학적 기전 해석에 대한 보다 명확한 정보를 제시하고자, H2AX 관련 단백질들을 literature review 및 생물정보학적인 기술을 이용하여 최적의 결합 단백질체를 40개를 예측하고, 이들 가운데 상호작용 가능성이 높은 BRCA1 와 BARD1 단백질을 선별하여 in vitro 결합실험을 통해 이를 증명하였다. 이들 두 가지의 유전자를 발굴하여, 클로닝하였다. 클로닝된 유전자를 이용하여 두 가지 단백질을 발현 및 정제하였으며, 단백질들의 자체적인 구조에 의한 결합능력을 판단하기 위해 in vitro binding assay법을 실시하였다. 단백질의 구조적 안정과 비특이적 결합을 억제하는 detergent만이 포함된 상태에서, 구조학적 및 물리학적 상호 결합의 유무를 판정할 수 있게 하였으며, BRCA1과 BARD1은 모두 H2AX에 결합함을 확인하였다. 이런 실험 결과를 바탕으로 각각의 단백질에 대해 H2AX와의 최적 결합 부위를 알아내기 위해 각 유전자의 domain을 생물정 보학적으로 분석하였다. 이에 RING domain, NES, NLS 및 BRCT domain에 해당하는 유전자 부분을 새로 클로닝하여, 다시 in vitro 결합실험 및 실험결과에 대한 literature review를 통한 분석을 실시한 결과, H2AX는 BRCA1의 NLS, BARD1의 BRCT domain 부분과 결합하는 것을 확인하였다. H2AX에 대한 BRCA1과 BARD1과의 결합은 DNA repair에 있어 BRCA1의 NLS와 BARD1의 BRCT domain을 통해 H2AX foci의 관련 세포 신호전달 기전에 중요한 역할을 하여 전체적으로 genomic stability에 영향을 미칠 가능성이 농후할 것으로 사료된다. H2AX, a crucial component of chromatin, is implicated in DNA repair, cell cycle check point and tumor suppression. The aim of this study was to identify direct binding partners of H2AX to regulate cellular responses to above mechanisms. Literature reviews and bioinformatical tools were attempted intensively to find binding partners of H2AX, which resulted in identifying two potential proteins, breast cancer-1 (BRCA1) and BRCA1-associated RING domain 1 (BARD1). Although it has been reported in vivo that BRCA1 co-localizes with H2AX at the site of DNA damage, their biochemical mechanism for H2AX were however only known that the complex monoubiquitinates histone monomers, including unphosphorylated H2AX in vitro. Therefore, it is important to know whether the complex directly interacts with H2AX, and also which regions of these are specifically mediated for the interaction. Using in vitro GST pull-down assay, we present here that BRCA1 and BARD1 directly bind to H2AX. Moreover, through combinational approaches of domain analysis, fragment clonings and in vitro binding assay, we revealed molecular details of the BRCA1-H2AX and BARD1-H2AX complex. These data provide the potential evidence that each of the BRCA1 nuclear localization signal (NLS) and BARD1 BRCA1 C-terminal (BRCT) repeat domain is the novel mediator of H2AX recognition.

Molecular Identification of Cr(VI) Removal Mechanism on Vivianite Surface

Bae, Sungjun,Sihn, Youngho,Kyung, Daeseung,Yoon, Sunho,Eom, Taedaehyeong,Kaplan, Ugras,Kim, Hyungjun,Schä,fer, Thorsten,Han, Seunghee,Lee, Woojin American Chemical Society 2018 Environmental science & technology Vol.52 No.18

<P>Experimental and theoretical studies were conducted to identify the molecular-scale reaction mechanism for Cr(VI) removal by a ferrous phosphate mineral, vivianite. The surface-normalized rate constant for Cr(VI) removal in a vivianite suspension at pH 7 was higher than those obtained for other Fe(II)-containing minerals (i.e., magnetite and pyrite). The highest rate constant was obtained at pH 5, which was 35- and 264-times higher than those obtained at pH 7 and 9, respectively, indicating the dramatic acceleration of removal kinetics with decreasing pH of suspension. The X-ray photoelectron spectroscopy (XPS) and X-ray absorption near-edge structure (XANES) spectroscopy revealed that Cr(VI) removal involved reduction of Cr(VI) to Cr(III) coupled with oxidation of Fe(II) to Fe(III) on the vivianite surface. In addition, the density functional theory (DFT)-optimized structure of the Cr(VI)-vivianite complex was consistent with that obtained from extended X-ray absorption fine structure (EXAFS) spectroscopy and revealed the transformation of vivianite to amorphous Fe(III) phosphate. We also demonstrated that both Cr(VI) species, HCrO<SUB>4</SUB>̅ and CrO<SUB>4</SUB><SUP>2-</SUP>, can effectively bind to the vivianite surface, particularly on the Fe sites having 6 neighboring Fe molecules with 4 H<SUB>2</SUB>O and 2 PO<SUB>4</SUB> moieties. Our results show that Cr(VI) is readily reduced to Cr(III) by vivianite via adsorption and inner-sphere complexation, suggesting that in anoxic iron-phosphate-enriched environments, vivianite may significantly influence the fate and transport of Cr(VI).</P> [FIG OMISSION]</BR>

VLM을 이용한 모핑 플랩 형상의 공력해석

고승희(Seunghee Ko),배재성(Jaesung Bae),김학봉(Harkbong Kim),노진호(Jinho Rho),구교남(Kyonam Koo),안석민(Seokmin Ahn) 항공우주시스템공학회 2013 항공우주시스템공학회 학술대회 발표집 Vol.2013 No.5