Prostaglandin A₂-induced Apoptosis is Not Inhibited by Heme Oygenase-1 in U2OS Cells

Kyoung-Won Ko(고경원),Sun-Young Lee(이선영),Ji-Hyun Ahn(안지현),Jaetaek Kim(김재택),In-Kyung Kim(김인경),Ho-Shik Kim(김호식) 한국생명과학회 2008 생명과학회지 Vol.18 No.11

Prostaglandin A₂ (PGA₂)는 사람 골육종 세포인 U2OS 세포주에서 apoptosis와 heme oxygenase (HO)-1의 발현을 함께 유도하였다. PGA₂에 의한 apoptosis는 HO-1의 과도한 발현이나 HO-1에 대한 small interfering RNA에 의한 발현저하에 의하여 변동되지 않았으나 H₂O₂에 의한 세포사망은 HO-1의 발현 수준에 반비례하여 변동되었다. 또한 thiol antioxidant인 N-acetyl-L-cysteine (NAC)은 PGA₂에 의한 세포사망과 HO-1의 발현 증가를 모두 차단하였지만, non-thiol antioxidant인 butylated hydroxyanisole (BHA)과 ascorbic acid는 세포사망과 HO-1의 발현 유도를 차단하지 않았다. 이와 같은 결과들은 PGA₂는 산화성 손상에 의해서가 아니라 PGA₂의 thiol-reactivity에 의하여 apoptosis와 HO-1의 발현을 유도하며, HO-1의 발현은 PGA₂에 의한 apoptosis와는 독립적인 현상이거나 기능적으로 apoptosis 유도의 하부에 위치하고 apoptosis의 진행에는 기여하지 않을 것이라는 것을 시사해 준다. Prostaglandin A₂ (PGA₂), one of cyclopentenone PGs, induced both apoptosis and heme oxygenase (HO)-1 expression in U2OS cells. PGA₂-induced apoptosis was not perturbed by either over-expression or knock-down of HO-1, whereas H₂O₂-induced cell death was inversely modulated by the expression level of HO-1. In addition, N-acetyl-L-cysteine (NAC), a thiol antioxidant, blocked both apoptosis and HO-1 expression induced by PGA₂. But, non-thiol antioxidants like butylated hydorxyanisole (BHA) and ascorbic acid did not block either apoptosis or HO-1-induction. Taken together, these results suggest that PGA₂ induces both apoptosis and HO-1 expression, which are critically related to the thiol-reactivity of PGA₂, but not oxidative stress, and HO-1 expression may be independent or functionally located downstream of apoptosis by PGA₂ without contribution to apoptosis progression.

PGA2-induced HO-1 attenuates G2M arrest by modulating GADD45α expression

Yun-Jeong Choe,고경원,Hyein Lee,이선영,Byung-Chul Kim,Ho-Shik Kim,Ho-Shik Kim 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.4

Prostaglandin (PG) A2, a cyclopentenone PG, arrested the growth of U2OS cells in the G2M phase. While inducing G2M arrest, PGA2 increased the expression of heme oxygenase-1 (HO-1) at the level of transcription along with the accumulation of ROS and the activation of MAPKs including JNK, p38MAPK, and ERK1/2. Among the MAPKs, the inhibition of p38MAPK by a specific chemical inhibitor SB203580, or by RNA interference, but not JNK or ERK1/2, attenuated the PGA2-induced transcription of HO-1. Nacetylcysteine (NAC), a ROS scavenger, prevented PGA2-induced G2M arrest, p38MAPK activation and transcriptional induction of HO-1. PGA2 also stimulated GADD45α expression at the level of transcription, and the knockdown of GADD45α repressed PGA2- induced G2M arrest. Finally, the knockdown of the HO-1 protein elevated PGA2-induced GADD45α expression as well as G2M arrest. Collectively, these results suggest that PGA2 causes an increase in ROS accumulation which initiates both HO-1 transcription via p38MAPK, and G2M arrest via GADD45α transcription, and HO-1 attenuates G2M arrest by modulating the expression of GADD45α.

Nutlin-3 induces HO-1 expression by activating JNK in a transcription-independent manner of p53

CHOE, YUN-JEONG,LEE, SUN-YOUNG,KO, KYUNG WON,SHIN, SEOK JOON,KIM, HO-SHIK Spandidos Publications 2014 International journal of oncology Vol.44 No.3

A recent study reported that p53 can induce HO-1 by directly binding to the putative p53 responsive element in the HO-1 promoter. In this study, we report that nutlin-3, a small molecule antagonist of HDM2, induces the transcription of HO-1 in a transcription-independent manner of p53. Nutlin-3 induced HO-1 expression at the level of transcription in human cancer cells such as U2OS and RKO cells. This induction of HO-1 did not occur in SAOS cells in which p53 was mutated and was prevented by knocking down the p53 protein using p53 siRNA transfection, but not by PFT-alpha, an inhibitor of the transcriptional activity of p53. Accompanying HO-1 expression, nutlin-3 stimulated the accumulation of ROS and the phosphorylation of MAPKs such as JNK, p38 MAPK and ERK1/2. Nutlin-3-induced HO-1 expression was suppressed by TEMPO, a ROS scavenger, and chemical inhibitors of JNK and p38 MAPK but not ERK1/2. In addition, nutlin-3-induced phosphorylation of JNK but not p38 MAPK was inhibited by TEMPO. Notably, the levels of nutlin-3-induced ROS were correlated with the mitochondrial translocation of p53 and this induction was prevented by PFT-beta, an inhibitor of the mitochondrial translocation of p53. Consistent with the effect of the ROS scavenger and MAPK inhibitors, PFT-beta reduced HO-1 expression and the phosphorylation of JNK induced by nutlin-3. In the experiments of analyzing cell death, the knockdown of HO-1 augmented nutlin-3-induced apoptosis. Collectively, these results suggest that nutlin-3 induces HO-1 expression via the activation of both JNK which is dependent on ROS generated by p53 translocated to the mitochondria and p38 MAPK which appears to be stimulated by a ROS-independent mechanism, and this HO-1 induction may inhibit nutlin-3-induced apoptosis, constituting a negative feedback loop of p53-induced apoptosis.

PGA2-induced expression of HO-1 is mediated by transcriptional upregulation of Nrf2

Sang-sun Lee,Yun-Jeong Choe,Hyein Lee,Sun-Young Lee,Ho-Shik Kim 대한독성 유전단백체 학회 2019 Molecular & cellular toxicology Vol.15 No.2

Backgrounds: Prostaglandin (PG) A2 reportedly stimulated expression of heme oxygenase (HO)-1 at the level of transcription via the activation of p38MAPK. Details of the mechanism, however, have not been provided, and this includes identification of the transcription factors responsible for PGA2-induced HO-1 expression. Herein is described an analysis of the role of nuclear factor erythroid 2 related factor 2 (Nrf2) and how PGA2 increases the activity of Nrf2 during PGA2-induced HO-1 expression. Methods: Expressions of HO-1 and Nrf2 were analyzed at the levels of both mRNA and protein. Nrf2 siRNA, SB203580, an inhibitor of p38MAPK, and scavengers of reactive oxygen species (ROS) were used to identify the effects of Nrf2, p38MAPK and ROS on PGA2-induced HO-1 expression. Results: Although SB203580 suppressed PGA2-induced HO-1 expression, genetic activation of p38MAPK could not stimulate the transcription of HO-1. Cycloheximide (CHX), an inhibitor of protein translation, almost completely prevented PGA2-induced increase of HO-1 transcription, but it did not prevent the phosphorylation of p38MAPK, which suggests that both de novo protein synthesis and p38MAPK activity are required to induce the transcription of HO-1 in response to PGA2 treatment. In addition, PGA2 increased the level of both Nrf2 mRNA and protein in a dose-dependent manner. Knockdown of Nrf2 using small interfering RNA (siRNA) suppressed PGA2-induced HO-1 expression. The PGA2-induced transcription of Nrf2 was prevented by ROS scavengers such as n-acetyl-l-cysteine and tempol but not CHX. Furthermore, siRNA against p38MAPK did not change the level of nuclear Nrf2 protein. Conclusion: These findings suggest that PGA2 induces HO-1 transcription via an increase in Nrf2 protein, the transcription of which is initiated by an accumulation of ROS that is independent of the p38MAPK activation pathway.

PGA2 induces the expression of HO-1 by activating p53 in HCT116 cells

Hyein Lee,Sang-Sun Lee,Ji-Young Park,Yun-Jeong Choe,이선영,Ho-Shik Kim,H.-S. Kim 대한독성 유전단백체 학회 2017 Molecular & cellular toxicology Vol.13 No.2

Prostaglandin (PG) A2 which is a cytotoxic PG, was reported to induce the expression of heme oxygenase (HO)-1 via activation of p38MAPK to keep U2OS cells from cell cycle arrest in G2M phase. The expression of HO-1 is primarily regulated at the level of transcription. But the transcription factors that are responsible for PGA2-induced HO-1 expression were not clarified yet. Here, we report that PGA2-induced transcription of HO-1 is mediated by p53, a tumor suppressive transcription factor. In HCT116 cells, PGA2 treatment led to the phosphorylation of p53 and an increase of p21WAF1 transcription as well as the activation of HO-1 transcription. Knocking p53 down via RNA interference or inhibiting the p53’s transcriptional activity by pifithrin-α treatment led to suppression of the increase in the level of both HO-1 expression and activity of HO-1 promoter. Pretreatment of NU- 7441, a chemical inhibitor of DNA-activated protein kinase (DNA-PK), prevented both the PGA2-induced phosphorylation of p53 and an increase of HO-1 transcription. In addition, N-acetyl-l-cysteine, a scavenger of reactive oxygen species (ROS), also mimicked the effect of NU-7441 on the PGA2-induced activation of p53 and HO-1 transcription. Collectively, these results suggest that PGA2 induces the expression of HO-1 via activation of p53, which is mediated by the ROSDNA- PK pathway.

Protective Effects of Hyperoside against Carbon Tetrachloride-Induced Liver Damage in Mice

Choi, Jun-Ho,Kim, Dong-Wook,Yun, Nari,Choi, Jae-Sue,Islam, Md. Nurul,Kim, Yeong-Shik,Lee, Sun-Mee American Chemical Society and American Society of 2011 Journal of natural products Vol.74 No.5

<P>In this study, the hepatoprotective effects of hyperoside (<B>1</B>), a flavonoid glycoside isolated from <I>Artemisia capillaris</I>, have been examined against carbon tetrachloride (CCl<SUB>4</SUB>)-induced liver injury. Mice were treated intraperitoneally with vehicle or <B>1</B> (50, 100, and 200 mg·kg<SUP>−1</SUP>) 30 min before and 2 h after CCl<SUB>4</SUB> (20 μL·kg<SUP>−1</SUP>) injection. Levels of serum aminotransferases were increased 24 h after CCl<SUB>4</SUB> injection, and these increases were attenuated by <B>1</B>. Histological analysis showed that <B>1</B> prevented portal inflammation, centrizonal necrosis, and Kupffer cell hyperplasia. Lipid peroxidation was increased and hepatic glutathione content was decreased significantly after CCl<SUB>4</SUB> treatment, and these changes were reduced by administration of <B>1</B>. Protein and mRNA expression of tumor necrosis factor-α (TNF-α), inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and heme oxygenase-1 (HO-1) and nuclear protein expression of nuclear factor erythroid 2-related factor 2 (Nrf2) significantly increased after CCl<SUB>4</SUB> injection. Compound <B>1</B> suppressed TNF-α, iNOS, and COX-2 protein and mRNA expression and augmented HO-1 protein and mRNA expression and Nrf2 nuclear protein expression. These results suggest that <B>1</B> has protective effects against CCl<SUB>4</SUB>-induced acute liver injury, and this protection is likely due to enhancement of the antioxidative defense system and suppression of the inflammatory response.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jnprdf/2011/jnprdf.2011.74.issue-5/np200001x/production/images/medium/np-2011-00001x_0006.gif'></P>

조혈모세포이식 후 발생한 주폐포자층 폐렴에 대한 고찰

주지현,최정현,이동건,백지연,고윤호,이혜정,김세희,신호진,박윤희,박지영,김유진,신완식,김춘추 대한감염학회 2001 감염 Vol.33 No.4

Background : Pneumocytitis cainii pneumonia (PCP) can occur in immunocompromised hosts especially such as AIDS or cancer patients. Although recent research had focused on PCP in AIDS patients, few studies have described the clinical presentations of PCP in recipients of stem cell transplantation (SCT). We evaluated the clinical manifestations of PCP in SCT patients admitted at St. Mary's hospital, Seoul, Korea. Methods : The medical records of 17 PCP patients undergoing SCT between Feb. 1998 and Feb. 2000 were reviewed. The diagnosis of PCP was confirmed through the demonstration of Pneumocytitis cainii via either cytology of brochoalveolar lavage (BAL) or histological technique of lung biopsy. CMV disease and CMV infection were confirmed by BAL culture and antigenemia respectively . Results : Seventeen patients were all recipients of allogeneic SCT and 7 of 17 patients were performed non-sibling SCT. Patients presented with symptoms including brief period (4 ∼23 days) of fever (76%), dyspnea (70%), cough (64%), and signs such as rare(58.8%), Sixteen patients (94%) had been receiving immunosuppressive agent such as cyclosporine A (64%) or Fk506 (35%) without PCP prophylaxis. Eleven patients (64%) were treated with corticosteroid with mean dose of 16 mg/day prednisolone and mean duration of 4.6 months after post-SCT period. Twelve patients were co-infected with CMV. Another co-infected miCroorganisms were Pseudomonas aeruginosa, Mycobacterium tuberculosis, herpes simplex virus, parainfluenza virus, Average duration of treatment with trimethoprim-sulfamethoxazole (TMP/SMX) was 21 ±9 days. Four patients died, and three of them were related with PCP. Conclusion : PCP developed frequently in patients who were taking immunosuppressive drug due to graft versus host disease or were not taking TMP/SMX prophylaxis. High risk patients showing fever, cough, or dyspnea should be considered to take early bronchoscopic intervention for detection of PCP. When treat for PCP, it also be considered to the possibility of coinfection such as CMV. (Korean J Infect Dis 33:273∼279, 2001)

ESPI를 이용한 복합재료 구조물의 결함 검출

김경석,정성균,강진식,장호섭 한국비파괴검사학회 2001 한국비파괴검사학회지 Vol.21 No.3

본 논문에서는 ESPI 시스템을 이용하여 복합재료 구조물의 인위, 자연 결함을 검출하였다. 복합재료 구조물에서의 ESPI의 적용성을 알아보기 위해 복합재료 적층판 시험편, 하니컴 구조물 시험편, 접착조인트 시험편을 사용하였다. 결함을 검출하기 위해 시편의 표면변형을 쉽게 발생시킬 수 있는 열하중법을 선택하였다. 실험경과는 ESPI를 이용하여 복합재료 구조물의 결함을 쉽게 검출할 수 있고, 다른 여러 복합재료 구조물의 결함의 검출에도 적용할 수 있음을 확인하였다. In this paper, artificial and real defects(delamination and debond) in composite structures were detected by using ESPI system. There types of specimens, that is, composite laminates, honeycomb structures, and adhesive joints, were used to study the applicability of ESPI to composite structures. To detect defects in specimens, we selected thermal loading method that can easily induce the surface deformation of specimen. Experimental results show that defects in composite structures could be easily detected by ESPI. Moreover, it shows that ESPI could be usefully applied to the detection of defects of defects in various composite structures.

EPR 및 NMR 분광법에 의한 LHRH 금속착물의 연구

김대성,원호식 한양대학교 이학기술연구소 2000 이학기술연구지 Vol.2 No.

Luteinizing Hormone Releasing Hormone(LHRH) is composed of 10 amino acids, and is best known as a neurotransmitter. Because of the 80% homology in animals, much more concerns have focused on the substances that have similar functions or can control LHRH. Ni, Cu, Zn-LHRH complexes were synthesized. Complexations were monitored by 1H, 13C-NMR chemical shifts and final products were identified by ESI-Mass spectrum. Solution-state structure determination of LHRH was accomplished by using NMR results and NMR-based distance geometry(DG). Interproton distances from nuclear Overhauser effect spectroscopy (NOESY) were utilized for the molecular structure determination. Results were compared with previous structures obtained from energy minimization and other spectroscopic methods. Structure obtained in this study has a cyclic conformation which is similar to that of energy minimized, and exhibits a specific α-helical turn with residue numbers (2~7) out of 10 amino acids. EPR studies of Ni, Cu-LHRH complexes exhibit that they have same binding sites with the distorted 4-coordination like Zn-LHRH complex. Luteinizing Hormone Releasing Hormone(LHRH)는 신경전달 물질로서 10개의 아미노산으로서 이루어져 있다. 고등동물에서 80% 정도 동종성을 가지고 있어, 유사한 기능을 가지고 있거나 LHRH를 조절할 수 있는 물질에 관심이 집중되고 있다. 본 연구에서는 Ni, Cu, Zn-LHRH 착물을 합성하였다. 1H, 13C-NMR 신호변화를 이용하여 착물 형성과정을 추적하였고 ESI-Mass 실험에 의해 합성된 착물의 형성을 확인하였다. 핵자기공명 실험의 결과 및 distance geometry(DG)를 이용하여 Zn-LHRH의 액상상태 3차원구조를 구하였다. Nuclear Overhauser effect 분광법(NOESY)에서 얻어진 수소쌍들의 거리 정보를 분자구조 결정에 사용하였다. 얻어진 구조를 기존의 에너지 계산법 및 분광학적인 방법에 의해 예측된 구조에 대한 연구결과와 비교하였다. 본 연구에서 얻어진 구조는 10개의 아미노산중 잔기서열 2~7범위에서 α-나선 구조로 특이한 회전을 나타내고 있고, 에너지 계산에 의해 얻어진 구조와 유사한 고리 형태를 이루고 있다. EPR 실험을 통하여 예측된 Ni, Cu-LHRH 금속착물의 구조를 예측하였는데 뒤틀린 4배위 형태인 Zn-LHRH의 결합부와 같은 위치에서 각각 뒤틀린 4배위 형태의 구조를 하고 있음이 확인되었다.

한양대학교 (안산 캠퍼스) 주변 담수호의 수질분석

김용건,원호식,경진범,김동국,홍태기 漢陽大學校 環境科學硏究所 2000 環境科學論文集 Vol.21 No.-

본 연구의 목적은 한양대학교(안산캠퍼스) 주변 호수들의 수질과 물의 오염 상태를 조사하기 위해서이다. 수질은 물의 온도, pH 화학적 산소 요구량(CODMn), 총 질소(T-N), 총 인(T-P), 부유물질(SS), 그리고 중금속(Zn, Cd, Pb, Cu, As, Cr(VI), Hg)을 측정했다. 호수들의 수질등급은 환경처에 의해 평가된 등급V보다 더 낮았다. 한양대학교(안산캠퍼스) 주변의 모든 저수지들은 생활폐수, 그리고 산업폐수의 유입으로 이미 심각하게 오염되어 있다. 그러나 중금속의 오염은 관찰되지 않았다. 만약 폐수의 처리가 확립되지 않는다면 한양대학교 주변 저수지들의 수질은 더욱악화될것으로 사료된다. The objective of this study was to investigate the water quality and status of water pollution in the lakes around Hanyang University (Ansan campus). Water quality was determined by monitoring water temperature, pH, chemical oxygen demand(CODMn), total nitrogen (T-N), total Phosphorus (T-P), suspended solids (SS), heavy metals (Zn, Cd, Pb, Cu, As, Cr(VI) and Hg). The level of water quality of lakes was lower than the level V estimated by the Enviroment Ministry. All of the reserviors around Hanyang University (Ansan campus) had been already seriously polluted by inflow of wastewater from residents, animal husbandries and industries. However, heavy metal pollution was not observed. It is recommended to establish plans for water quality improvement for the reserviors around Hanyang University before it gets worse.