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.

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.

Heme oxygenase-1 (HO-1)/carbon monoxide (CO) axis suppresses RANKL-induced osteoclastic differentiation by inhibiting redox-sensitive NF-κB activation

( Sun-uk Bak ),( Suji Kim ),( Hae-jun Hwang ),( Jung-a Yun ),( Wan-sung Kim ),( Moo-ho Won ),( Ji-yoon Kim ),( Kwon-soo Ha ),( Young-guen Kwon ),( Young-myeong Kim ) 생화학분자생물학회(구 한국생화학분자생물학회) 2017 BMB Reports Vol.50 No.2

Heme oxygenase (HO-1) catalyzes heme to carbon monoxide (CO), biliverdin/bilirubin, and iron and is known to prevent the pathogenesis of several human diseases. We assessed the beneficial effect of heme degradation products on osteoclastogenesis induced by receptor activator of NF-κB ligand (RANKL). Treatment of RAW264.7 cells with CORM-2 (a CO donor) and bilirubin, but not with iron, decreased RANKLinduced osteoclastogenesis, with CORM-2 having a more potent anti-osteogenic effect. CORM-2 also inhibited RANKLinduced osteoclastogenesis and osteoclastic resorption activity in marrow-derived macrophages. Treatment with hemin, a HO-1 inducer, strongly inhibited RANKL-induced osteoclastogenesis in wild-type macrophages, but was ineffective in HO-1^+/-cells. CORM-2 reduced RANKL-induced NFATc1 expression by inhibiting IKK-dependent NF-κB activation and reactive oxygen species production. These results suggest that CO potently inhibits RANKL-induced osteoclastogenesis by inhibiting redox-sensitive NF-κB-mediated NFATc1 expression. Our findings indicate that HO-1/CO can act as an antiresorption agent and reduce bone loss by blocking osteoclast differentiation. [BMB Reports 2017; 50(2): 103-108]

Carbon monoxide prevents TNF-α-induced eNOS downregulation by inhibiting NF-κB-responsive miR-155-5p biogenesis

Choi, Seunghwan,Kim, Joohwan,Kim, Ji-Hee,Lee, Dong-Keon,Park, Wonjin,Park, Minsik,Kim, Suji,Hwang, Jong Yun,Won, Moo-Ho,Choi, Yoon Kyung,Ryoo, Sungwoo,Ha, Kwon-Soo,Kwon, Young-Guen,Kim, Young-Myeong Nature Publishing Group 2017 Experimental and molecular medicine Vol.49 No.11

<P>Heme oxygenase-1-derived carbon monoxide prevents inflammatory vascular disorders. To date, there is no clear evidence that HO-1/CO prevents endothelial dysfunction associated with the downregulation of endothelial NO synthesis in human endothelial cells stimulated with TNF-α. Here, we found that the CO-releasing compound CORM-2 prevented TNF-α-mediated decreases in eNOS expression and NO/cGMP production, without affecting eNOS promoter activity, by maintaining the functional activity of the <I>eNOS</I> mRNA 3′-untranslated region. By contrast, CORM-2 inhibited MIR155HG expression and miR-155-5p biogenesis in TNF-α-stimulated endothelial cells, resulting in recovery of the 3′-UTR activity of <I>eNOS</I> mRNA, a target of miR-155-5p. The beneficial effect of CORM-2 was blocked by an NF-κB inhibitor, a miR-155-5p mimic, a HO-1 inhibitor and siRNA against HO-1, indicating that CO rescues TNF-α-induced eNOS downregulation through NF-κB-responsive miR-155-5p expression via HO-1 induction; similar protective effects of ectopic HO-1 expression and bilirubin were observed in endothelial cells treated with TNF-α. Moreover, heme degradation products, except iron and <I>N</I>-acetylcysteine prevented H<SUB>2</SUB>O<SUB>2</SUB>-mediated miR-155-5p biogenesis and eNOS downregulation. These data demonstrate that CO prevents TNF-α-mediated eNOS downregulation by inhibiting redox-sensitive miR-155-5p biogenesis through a positive forward circuit between CO and HO-1 induction. This circuit may play an important preventive role in inflammatory endothelial dysfunction associated with human vascular diseases.</P>

크론병에 대한 CoPPLX의 방어효과에 대한 연구

이호학,김유림,문창기,이재일,양병윤,김종수,이정민,정재혁,안석진,박상준,김윤권,김소연,김영중,조민구,최영자,장성조 圓光大學校 醫科學硏究所 2005 圓光醫科學 Vol.20 No.1

춘천시민의 종의 진동 및 음향 특성

김석현,김태형,김윤호,한영호 강원대학교 산업기술연구소 2006 産業技術硏究 Vol.26 No.A

The Chun-cheon Citizen's Bell was cast in memory of hosting the 2010 world leasure conference and a striking ceremony was held at the city hall on December 31, 2005. In this study, vibration and sound of the bell are measured and the property of the magnificent sound of the bell is scientifically investigated. Frequency components making the sound are identified and how the frequency components decrease with time is observed using waterfall plot(3-dimensional frequency spectrum). Beat characteristics of the hum(1st frequency) and the fundamental(2nd frequency)are examined by experiment. Directivity of the sound radiation of the bell is examined by measuring the vibration and sound in several directions. Duration of the vibration and the sound is estimated using damping ratio.

심근 허혈-재관류 백서 모델에서 mitogen-activated protein kinase 활성화에 대한 α-lipoic acid의 효과

김연경,박은미,최준호,윤경호,유남진,이은미,김남호,정진원,김민선,박병림,오석규 圓光大學校 醫科學硏究所 2006 圓光醫科學 Vol.21 No.1

Disruption of rsmA Gene of Pectobacterium carotovorum subsp. carotovorum LY34 and Effect on Pathogenicity

Kim, Min Keun,Kang, Tae Ho,Kim, Sung Kyum,Jeong, Yu Seok,Yun, Han Dae,Kim, Hoon The Korean Society for Applied Biological Chemistr 2012 Applied Biological Chemistry (Appl Biol Chem) Vol.55 No.6

The rsmA gene was cloned from soft-rot bacterium Pectobacterium carotovorum subsp. carotovorum LY34 (Pcc LY34), and its role in pathogenicity was investigated by marker exchange mutagenesis. From a cosmid library of Pcc LY34 genomic DNA, a positive clone carrying the rsmA gene was selected, and the gene was cloned by polymerase chain reaction (PCR) amplification. The gene is 186 bp in size and encodes a protein of 62 amino acids with a predicted molecular mass of 6,839 Da. The calculated pI of the RsmA is 8.16. The phylogenetic tree showed that the RsmA of Pcc LY34 appeared genetically identical to the CsrA of Pectobacterium atrosepticum SCRI1043 (100% identity) and similar to the CsrA of Yersinia pestis KIM10+(98.3%). The gene was disrupted by the $Km^r$ gene, and the cells became mutated (i.e., $RsmA^-$ mutant). The pathogenicity test revealed that the disease rating of the $RsmA^-$ mutant only differed slightly from that of the wild type on a slice of potato tuber and a Chinese cabbage stalk. These results suggest that RsmA is not an essential factor for the pathogenicity of Pcc LY34 and that the rsmA gene of Pcc LY34 is not completely derepressed in the $RsmA^-$ mutant for virulence-related genes, contrary to the results of Erwinia carotovora subsp. carotovora $RsmA^-$ mutant, which proved hypervirulent for celery petioles. These results showed that the microenvironmental conditions of the host and/or strain of pathogen are important for the coordination of virulence gene expression.