Inhibitory effect of α-terpinyl acetate on cytochrome P450 2B6 enzymatic activity

Lee, Yejin,Park, Hyoung-Goo,Kim, Vitchan,Cho, Myung-A.,Kim, Harim,Ho, Thien-Hoang,Cho, Kyoung Sang,Lee, Im-Soon,Kim, Donghak Elsevier Pub. Co 2018 Chemico-biological interactions Vol.289 No.-

<P><B>Abstract</B></P> <P>Human cytochrome P450 2B6 is an important hepatic enzyme for the metabolism of xenobiotics and clinical drugs. Recently, more attention has been paid to P450 2B6 because of the increasing number of drugs it metabolizes. It has been known to interact with terpenes, the major constituents of the essential oils used for various medicinal purposes. In this study, the effect of monoterpenes on P450 2B6 catalytic activity was investigated. Recombinant P450 2B6 was expressed in <I>Escherichia coli</I> and purified using Ni-affinity chromatography. The purified P450 2B6 enzyme displayed bupropion hydroxylation activity in gas-mass spectrometry (GC-MS) analysis with a <I>k</I> <SUB>cat</SUB> of 0.5 min<SUP>−1</SUP> and a <I>K</I> <SUB>m</SUB> of 47 μM. Many terpenes displayed the type I binding spectra to purified P450 2B6 enzyme and α-terpinyl acetate showed strong binding affinity with a <I>K</I> <SUB>d</SUB> value of 5.4 μM. In GC-MS analysis, P450 2B6 converted α-terpinyl acetate to a putative oxidative product. The bupropion hydroxylation activity of P450 2B6 was inhibited by α-terpinyl acetate and its IC<SUB>50</SUB> value was 10.4 μM α-Terpinyl acetate was determined to be a competitive inhibitor of P450 2B6 with a <I>K</I> <SUB>i</SUB> value of 7.6 μM. The molecular docking model of the binding site of the P450 2B6 complex with α-terpinyl acetate was constructed. It showed the tight binding of α-terpinyl acetate in the active site of P450 2B6, which suggests that it could be a competitive substrate for P450 2B6.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Recombinant P450 2B6 was expressed and purified. </LI> <LI> Purified P450 2B6 displayed the bupropion hydroxylation activity. </LI> <LI> Terpenes displayed the typical type I binding spectra to P450 2B6. </LI> <LI> α-Terpinyl acetate showed strong binding affinity to P450 2B6. </LI> <LI> α-Terpinyl acetate is a competitive inhibitor of P450 2B6 to bupropion. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Endoribonucleolytic Cleavage of m⁶A-Containing RNAs by RNase P/MRP Complex

Park, Ok Hyun,Ha, Hongseok,Lee, Yujin,Boo, Sung Ho,Kwon, Do Hoon,Song, Hyun Kyu,Kim, Yoon Ki Elsevier 2019 Molecular cell Vol.74 No.3

<P><B>Summary</B></P> <P> <I>N</I> <SUP>6</SUP>-methyladenosine (m<SUP>6</SUP>A) is the most abundant internal modification in RNAs and plays regulatory roles in a variety of biological and physiological processes. Despite its important roles, the molecular mechanism underlying m<SUP>6</SUP>A-mediated gene regulation is poorly understood. Here, we show that m<SUP>6</SUP>A-containing RNAs are subject to endoribonucleolytic cleavage via YTHDF2 (m<SUP>6</SUP>A reader protein), HRSP12 (adaptor protein), and RNase P/MRP (endoribonucleases). We demonstrate that HRSP12 functions as an adaptor to bridge YTHDF2 and RNase P/MRP, eliciting rapid degradation of YTHDF2-bound RNAs. Transcriptome-wide analyses show that m<SUP>6</SUP>A RNAs that are preferentially targeted for endoribonucleolytic cleavage have an HRSP12-binding site and a RNase P/MRP-directed cleavage site upstream and downstream of the YTHDF2-binding site, respectively. We also find that a subset of m<SUP>6</SUP>A-containing circular RNAs associates with YTHDF2 in an HRSP12-dependent manner and is selectively downregulated by RNase P/MRP. Thus, our data expand the known functions of RNase P/MRP to endoribonucleolytic cleavage of m<SUP>6</SUP>A RNAs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> m<SUP>6</SUP>A-containing RNAs are degraded by an endoribonucleolytic cleavage pathway </LI> <LI> A YTHDF2-HRSP12-RNase P/MRP axis contributes to m<SUP>6</SUP>A-mediated RNA decay </LI> <LI> An interaction between YTHDF2 and RNase P/MRP is bridged by HRSP12 </LI> <LI> m<SUP>6</SUP>A-containing circular RNAs are degraded by the YTHDF2-HRSP12-RNase P/MRP pathway </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>[DISPLAY OMISSION]</P>

Reciprocal negative regulation between the tumor suppressor protein p53 and B cell CLL/lymphoma 6 (BCL6) via control of caspase-1 expression

Kim, Min-Kyeong,Song, Ji-Yang,Koh, Dong-In,Kim, Jin Young,Hatano, Masahiko,Jeon, Bu-Nam,Kim, Min-Young,Cho, Su-Yeon,Kim, Kyung-Sup,Hur, Man-Wook American Society for Biochemistry and Molecular Bi 2019 The Journal of biological chemistry Vol.294 No.1

<P>Even in the face of physiological DNA damage or expression of the tumor suppressor protein p53, B cell CLL/lymphoma 6 (BCL6) increases proliferation and antagonizes apoptotic responses in B cells. BCL6 represses <I>TP53</I> transcription and also appears to inactivate p53 at the protein level, and additional findings have suggested negative mutual regulation between BCL6 and p53. Here, using <I>Bcl6</I><SUP>−/−</SUP> knockout mice, HEK293A and HCT116 <I>p53</I><SUP>−/−</SUP> cells, and site-directed mutagenesis, we found that BCL6 interacts with p53 and thereby inhibits acetylation of Lys-132 in p53 by E1A-binding protein p300 (p300), a modification that normally occurs upon DNA damage–induced cellular stress and whose abrogation by BCL6 diminished transcriptional activation of p53 target genes, including that encoding caspase-1. Conversely, we also found that BCL6 protein is degraded via p53-induced, caspase-mediated proteolytic cleavage, and the formation of a BCL6–p53–caspase-1 complex. Our results suggest that p53 may block oncogenic transformation by decreasing BCL6 stability via caspase-1 up-regulation, whereas aberrant BCL6 expression inactivates transactivation of p53 target genes, either by inhibiting p53 acetylation by p300 or repressing <I>TP53</I> gene transcription. These findings have implications for B cell development and lymphomagenesis.</P>

HDAC6 deacetylates p53 at lysines 381/382 and differentially coordinates p53-induced apoptosis

Ryu, Hyun-Wook,Shin, Dong-Hee,Lee, Dong Hoon,Choi, Junjeong,Han, Gyoonhee,Lee, Kang Young,Kwon, So Hee Elsevier 2017 Cancer letters Vol.391 No.-

<P><B>Abstract</B></P> <P>HDAC6-selective inhibitors represent promising new cancer therapeutic agents, but their precise mechanisms of action are not well understood. In particular, p53's role in HDAC6 inhibitor-induced effects has not been fully elucidated. In this study, we show that an HDAC6-selective inhibitor, A452, increased wild-type p53 levels by destabilizing MDM2, but decreased mutant p53 by inducing MDM2 and inhibiting Hsp90-mutant p53 complex formation. Interestingly, HDAC6 levels inversely correlated with p53 acetylation at lysines 381/382 associated with p53 functional activation. A452 blocked HDAC6 nuclear localization, resulting in increased levels of acetylated p53 at Lys381/382. HDAC6 bound to the C-terminal region of p53 via its deacetylase domain. A452 disrupted the HDAC6-Hsp90 chaperone machinery via Hsp90 acetylation and degradation. Furthermore, it chemosensitized cancer cells to the Hsp90 inhibitor 17-AAG. Overall, silencing of HDAC6 showed similar effects. These findings suggest that the anticancer action of HDAC6 inhibitors requires p53 and Hsp90 and targeting of HDAC6 may represent a new therapeutic strategy for cancers regardless of p53's mutation status.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HDAC6 deacetylates p53 at lysine 381/382. </LI> <LI> A452 increases wild-type p53 levels by destabilizing MDM2. </LI> <LI> A452 decreases mutant p53 levels by inhibiting Hsp90-mutp53 complex formation. </LI> <LI> HDAC6 levels inversely correlate with p53 acetylation. </LI> <LI> A452 disrupts HDAC6-Hsp90 chaperone machinery via Hsp90 acetylation and degradation. </LI> </UL> </P>

Four unreported types of glycans containing mannose-6-phosphate are heterogeneously attached at three sites (including newly found Asn 233) to recombinant human acid alpha-glucosidase that is the only approved treatment for Pompe disease

Park, Heajin,Kim, Jihye,Lee, Young Kwang,Kim, Wooseok,You, Seung Kwan,Do, Jonghye,Jang, Yeonjoo,Oh, Doo-Byung,Il Kim, Jae,Kim, Ha Hyung Academic Press 2018 Biochemical and biophysical research communication Vol. No.

<P><B>Abstract</B></P> <P>Myozyme is a recombinant human acid alpha-glucosidase (rhGAA) that is currently the only drug approved for treating Pompe disease, and its low efficacy means that a high dose is required. Mannose-6-phosphate (M6P) glycosylation on rhGAA is a key factor influencing lysosomal enzyme targeting and the efficacy of enzyme replacement therapy (ERT); however, its complex structure and relatively small quantity still remain to be characterized. This study investigated M6P glycosylation on rhGAA using liquid chromatography (LC)–electrospray ionization (ESI)–high-energy collisional dissociation (HCD) tandem mass spectrometry (MS/MS). The glycans released from rhGAA were labeled with procainamide to improve mass ionization efficiency and the sensitivity of MS/MS. The relative quantities (%) of 78 glycans were obtained, and 1.0% of them were glycans containing M6P (M6P glycans). These were categorized according to their structure into 4 types: 3 newly found ones, comprising high-mannose-type M6P glycans capped with <I>N</I>-acetylglucosamine (GlcNAc) (2 variants, 17.5%), hybrid-type M6P glycans (2 variants, 11.2%), and hybrid-type M6P glycans capped with GlcNAc (3 variants, 6.9%), as well as high-mannose-type M6P glycans (3 variants, 64.4%). HCD-MS/MS spectra identified six distinctive M6P-derived oxonium ions. The glycopeptides obtained from protease-digested rhGAA were analyzed using nano-LC-ESI-HCD-MS/MS, and the extracted-ion chromatograms of M6P-derived oxonium ions confirmed three M6P glycosylation sites comprising Asn 140, Asn 233 (newly found), and Asn 470 attached heterogeneously to nine M6P glycans (two types), eight M6P glycans (four types), and seven M6P glycans (two types), respectively. This is the first study of rhGAA to differentiate M6P glycans and identify their attachment sites, despite rhGAA already being an approved drug for Pompe disease.</P> <P><B>Highlights</B></P> <P> <UL> <LI> M6P glycosylation is a key factor for lysosomal enzyme targeting and efficacy of ERT. </LI> <LI> M6P glycosylation on rhGAA, the only ERT for Pompe disease, was not fully reported. </LI> <LI> This study investigated M6P glycosylation on rhGAA using LC-ESI-HCD-MS/MS. </LI> <LI> All M6P glycans constitute 1.0% of the 78 glycans of rhGAA. </LI> <LI> Four types of ten M6P glycans and their three attachment sites are newly identified. </LI> </UL> </P>

자궁경부암을 유발하는 HPV E6 단백질에 의한 p73 단백질의 불활성화 : p53과 무관한 E6의 새로운 기능

남궁성은(Sung Eun Namkoong),김승조(Seung Jo Kim),김은주(Eun Joo Kim),엄수종(Soo Jong Um),박종섭(Jong Sup Park) 대한산부인과학회 1998 Obstetrics & Gynecology Science Vol.41 No.11

Objective: Human papillomavirus (HPV) is strongly implicated as a causative agent in the etiology of cervical cancer. Of its gene products, E6 and E7 oncoproteins play major roles by inactivation of cellular p53 and pRb tumor suppressor proteins, respectively. However, it has been recently suggested that p53 and/or pRb-independent functions of E6 and E7 are involved in cervical carcinogenesis. The purpose of this study is to identify novel a cellular target, p73, of E6 and to determine how E6 inactivates p73 function, Methods: The interaction between E6 and p73 were identified by the yeast two-hybrid assay in vivo and the GST pull-down assay in vitro. The function of the interaction was determined by transient transfections using p21 promoter-CAT reporter plasmid. The molecular mechanism underlying the functional significance of the interaction was further assessed by in vivo and in vitro protein degradation assays, and gel mobility shift assays. Results: Yeast two-hybrid and GST pull-down assays indicate a physical interaction between p73 and either HPV-16 or HPV-11 E6 proteins in vivo and in vitro, respectively. Transactivation domain (amino acid residues 1-49) is found to be absolutely required for this interaction. Transient co-expression of E6 significantly inhibits the p73-mediated activation of p21 promoter in a p53-defective C33A cell line. Using Ga14-p73 fusion protein, we demonstrate that E6 inhibition of p73 transactivation function is independent of sequence-specific DNA binding, which is confirmed by direct electrophoretic mobility shift assay. Moreover, E6 inhibits p73 function by interfering with the activity of the amino-terminal activation domain. The protein degradation assays in vivo and in vitro indicate that p73, unlike p53, is not susceptible to E6-dependent proteolysis. Conclusion: Throughout this study, we identified p73 as a novel cellular target of HPV-E6 protein and found that E6 binds p73 through the amino-terminal transactivation domain, and inhibits its transactivation function independent of the protein degradation and DNA binding. These overall results, consequently, suggest that in addition to the inactivation of p53, the functional interference of p73 by HPV-E6 may, at least in part, contribute to E6-mediated cellular transformation.

A study on the regulatory effect of p-38 MAP kinase on nitric oxide and interleukin-6 in osteoblasts

Lee, Kyung-Won,Lee, Doe-Hoon,Kang, Kyung-Hwa,Kim, Sang-Cheol 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.3

치아이동 시 발생하는 골흡수에서 이미 여러 cytokine의 중요성이 강조된 바 있으며 이 가운데 interleukin-6는 구강 및 연골조직 등에서 많은 연구의 초점이 되어 왔으나 확실한 기전은 아직까지 정확ㅚ 확립되어 있지 못하다. 골흡수 시조골세포에서 유리되는 , Interleukn-6 (IL-6)와 nitric oxide(NO) 등이 골흡수의 조절자로 최근 대두되고 있으며 Mitogen-activated protein kinase (MAPK)의 활성화로 인해 염증성 cytokine등이 유리될 수 있음이 최근 macrophage 등에서 증명된 바 있다. 그러므로 치아이동을 비롯한 구강 내 여러 염증의 조건에서 골흡수의 대표인자인 IL-6 및 NO 유리가 MAPK 등의 활성 등을 통해 조절될 수 있는 가능성을 시사하고 있다. 본 연구에서 조골세포 특징을 대부분 가지고 있는 조골세포주, MC3TE1에서 p-38 MAP kinase을 매개로 NO와 IL-6가 유리됨을 확인하고자 하였다. 10% Fetal Bovine Serum이 첨가된 -MEM 배양액으로 배양한 조골세포주인 MC3TE1 세포에 tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ) 및 lipopolysacchalide(LPS)등의 단독처리 시 NO와 IL-6의 증가는 확인되지 않았으나 TNF-α/IFN-γ 혹은 LPS/IFN-γ 등의 처치시 NO와 IL-6의 유의한 증가를 보였으며, NO 발현에 직접 관여하는 inducible nitric oxide synthase (iNOS)와 IL-6 단백질 및 mRNA의 발현을 관찰하였다. 또한 specific p=38 MAP kinase inhibitor 인 SB203580의 NO와 IL-6의 생성을 조절하고 있음을 시사하여 주고 있다. TNF-α/IFN-γ 혹은 LPS/IFN-γ 처치시 p-38 MAP Kinase의 활성을 관찰하였으나 단독 처치 시 역시 p-38 MAP Kinase의 활성을 확인함으로써 NO와 IL-6생성기전에는 p-38 MAP Kinase이외에 다른 인자 역시 관여하고 있음을 보여주고 있다. 본 연구에서는 치아 등의 골조직의 구성 세포인 조골세포에서 NO와 IL-6유리를 확인하였으며, 또한 이들의 생성기전중의 하나로 p-38 MAP Kinase가 transcription 단계에서 관여하고 있음을 확인하였다. Tooth movement is the result of bone metabolism in the periodontium, where various cytokines take important roles. Interleukin-6(Ⅱ-6) and nitrous oxide (NO) were reported to be secreted from osteoblasts in the process of bone resorption. The mechanism of the process has not been clearly understood, but the activation of mitogen-activated protein kinase (MAPK) was known to be an important process in the releas of the inflammatory cytokines in macrophages. In this regard, to prove the role of MAPK in the release of IL-6 and NO in MC3T3E-1 osteoblasts, Northern blot analysis, Western blot analysis and immune complex kinase assay were used. As a result, the treatment of MC3T3E-1 osteoblast cultures with combined interferon-γ(IFN-γ), lipopolysaccharide (LPS) and tumor necrosis factor-α(TNF-α) induces expressions of inducible nitric oxide synthase (iNOS) and IL-6, resulting in sustained releases of large amounts of NO and IL-6. However, IFN-γ,LPS, and TNF-α individually induce a non-detectable or small amount of NO and IL-6 in MC3T3E-1 osteoblasts. The role of MAPK activation in the early intracellular signal transduction involved in iNOS and IL-6 transcription in the combined agents- Stimulated osteoblasts has been investigated. The p38 MAPK pathway is specifically involved in the combined agents-induced NO and IL-6 release, since NO and IL-6 release in the presence of a specific inhibitor of p38 MAPK, 4-(4-fluorophenyl)-2-(4-metylsulfinylphenyl)-5-(4-pyridyl)imidazole) (SB203580), were sighnificantly diminished. In contrast, PD98059, a specific inhibitor of MEK1, had no effect on NO and IL-6 release. Northern blot analysis showed that the p38 MAPK pathway controlled the iNOS and IL-6 transcription level. These data suggest that p38 MAPK play an important role in the secretion of NO and IL-6 in LPS/IFNγ-or TNF-α/IFN-γ treated MC3T3E-1 osteoblasts.

자궁경부종양의 진행 과정에 따른 HPV 16/18의 E6/E7과 p53 및 Rb 단백의 발현에 관한 연구

장기홍(KH Jang),이규완(KW Lee),염범우(BW Yeom) 대한산부인과학회 1998 Obstetrics & Gynecology Science Vol.41 No.4

Human papillomavirus (HPV) infection in women is known to be a causative factor in the initiation and progression of uterine cervical cancer by producing proteins in host cells to effect transformation and immortalization at the cellular level resulting in cancerous tumor growth. Among the types of the HPV, type 16 and type 18 are classified as high risk types because they are frequently found in cervical lesions with high grade dysplasias and invasive carcinomas. However, it is impossible to ascertain by host histologic or cellular changes which type of HPV is infected. The HPV genome is composed of six open reading frames (ORF`s) named as E1, E2, E4, E5, E6, and E7 in the early region, of which the E6 and E7 ORF`s interact with tumor suppressor proteins p53 and retinoblastoma (Rb) gene products repectively, and stimulate the cell cycle. In this study, immunohistochemical staining of E6, E7, p53, and Rb proteins was conducted to determine the rate of expression of HPV oncoproteins, correlation with the tumor supressor proteins, and relationship in dysplasia and invasive uterine cervical cancer. Sixty cases of carcinoma in situ (CIS) and invasive cacinoma were immunohistochemically stained, and the results obtained were as follows: 1) p53 was positive in 5 of 17 cases (29.4%) of CIS, in 6 of 8 cases of microinvasive carcinoma (75.0%), and in 17 of 25 cases of invasive carcinoma (68.0%), showing significantly different p53 protein expression between the dysplasia and invasive cancer groups (p=0.007). 2) Rb protein was positive in 12 of 17 cases (70.6%) of CIS, in 4 of 8 cases of microinvasive carcinoma (50.0%), and in only 5 of 25 cases of invasive carcinoma (20.0%), showing that there was significantly different Rb protein expression between the CIS and invasive cancer groups (p=0.003). 3) E6 protein of HPV type 16/18 was expressed in 6 of 17 cases (35.3%) of CIS, in 4 of 8 cases of microinvasive carcinoma (50.0%), and in 15 of 25 cases of invasive carcinoma (60.0%), but there was no significant difference in expression between the CIS and invasive cancer groups (p=0.136). 4) E7 protein of HPV type 16/18 was expressed in 12 of 17 cases (70.6%) of CIS, in 7 of 8 cases of microinvasive carcinoma (87.5%), and in 23 of 25 cases of invasive carcinoma (92.0%), but there was no significant difference in expression between the CIS and invasive cancer groups (p=0.063). 5) There was no statistical significance between HPV type 16/18 E6 protein and p53 protein expression (p=0.07). 6) There was also no statistical significance between HPV type 16/18 E7 protein and Rb protein expression (p=0.19). The above results suggest that limited action by mutation of the tumor suppressor genes p53 and Rb seems to play a role in the progression of uterine cervical cancer, and E6 and E7 proteins may also play a role. However, this study was unable to reveal a significant role of p53 and Rb protiens in adenocarcinoma of the uterine cervix, and it is recommended that further studies should be undertaken.

P2Y6 수용체 길항제의 파골세포 분화 촉진 효과 규명

노아롱새미(A Long Sae Mi Noh),문미란(Mi ran Moon),임미정(Mi jung Yim) 대한약학회 2015 약학회지 Vol.59 No.5

P2Y receptors, a type of P2 receptor family, are G-protein coupled receptors and 8 subtypes have been char-acterized (P2Y1, P2Y2, P2Y4, P2Y6, P2Y11-14). Recently, several studies have shed light on the role of P2Y receptors in bone biology. Among them, little is known on the role of P2Y6 receptor on osteoclast differentiation. Thus, we investigated the role of P2Y6 receptor on osteoclastogenesis using P2Y6 receptor selective antagonist, MRS 2578. When osteoblasts and bone marrow cells were co-cultured in the presence of VitD3 and PGE2, P2Y6 antagonist increased the formation of TRAP positive osteoclasts. To elucidate the target cells of P2Y6 antagonist, we first checked the effect of MRS 2578 on osteoblasts. Treatment of MRS 2578 did not affect OPG : RANKL mRNA ratio in osteoblasts. Next, we checked the effects of P2Y6 antagonist on osteoclast precursors using mouse bone marrow macrophages (BMMs). Addition of MRS 2578 increased the number of osteoclasts in RANKL-treated BMMs. Although P2Y6 antagonist had no effect on RANKL-induced NFATc1, c-Fos and MafB expression levels, it significantly stimulated RANKL-induced Blimp1 mRNA expression in BMMs. Taken together, these data indicate that P2Y6 antagonist increases osteoclast formation by upregulation of Blimp1 expression.

유산소 훈련에 의한 노화 쥐의 심장근 합성 반응 변화

권형태(HyeongTaeKwon),김효정(HyoJeongKim) 한국체육학회 2013 한국체육학회지 Vol.52 No.6

이 연구는 장기간의 유산소 훈련 수행이 노화 쥐의 심장근 합성 반응에 미치는 영향을 검증하기 위해 수행되었다. 총 56마리의 노화 쥐(100 주령)를 훈련 집단(n=28)과 비훈련 집단(n=28)으로 구분하였으며 훈련 집단은 12주간 주 5일, 매회 1시간 동안 75∼80% VO2max (15 m/min, 15% 경사도)의 강도로 트레드밀을 이용한 유산소 훈련을 실시하였다. 훈련이 종료된 후, 두 집단 모두 동일한 강도의 일회성 유산소 운동을 1시간 동안 수행시킨 후 회복기 시점별(운동직후, 운동 후 1시간, 운동 후 3시간)로 좌심실 근육에서 심근 합성 신호를 일으키는 단백질의 인산화 수준을 평가하였다. 실험을 통해 체중에 대한 상대적 심장무게(HW/BW ratio)가 비훈련 집단에 비해 훈련 집단에서 9.4%(3.66±0.4 mg/g, p=.008) 더 무거워진 긍정적 결과를 나타냈다. 비훈련 집단은 안정 시에 비해 일회성 운동 수행후 Akt(30%, p<.05), mTOR(64%, p<.05) 및 p70S6K(82%, p<.05)가 증가하였으며, 운동후 회복기의 인산화 수준은 비훈련 집단보다 훈련 집단에서 Akt(87%, p=.001), mTOR(32%, p=.01), p70S6K(25%, p=.009), 및 4E-BP1( 35%, p=.005)의 활성이 더 증가한 것으로 나타났다. 또한, 훈련 집단은 안정 시에도 Akt(156%, p=.001), mTOR(58%, p=.001), p70S6K(98%, p=.001), 4E-BP1(103%, p=.001) 및 AMPK(51%, p=.001) 활성이 비훈련 집단 보다 높은 것으로 나타났다. 이러한 결과는 고강도의 유산소 훈련이 노화 쥐의 좌심실 근세포에서 성장 반응을 유발함으로써 심장의 생리적 기능향상에 기여하는 긍정적 변화를 제시하고 있다. This study was performed to determine the effect of intense endurance training on cardiac muscle protein synthesis in aged rats. Male Sprague-Dawley rats (100 wk) were randomly assigned into control (n=28) and training (n=28) groups. Training group ran on the rodent treadmill for 1 hour at the level of 15m/min, on a 15% incline (75∼80% VO2max) for 12 weeks (5d/w). Muscle samples were obtained from left ventricular muscle before and during the recovery period (immediately, 1hr, and 3hr after running) with the single bout of acute exercise (1hr) following endurance training. Phosphorylation of related proteins were analyzed by SDS-PAGE and western blotting. From the results of this study, the HW/BW ratio, indicator of cardiac hypertrophy, in training group was increased by 9.4 % (3.66±0.4 mg/g, p=.008) than control group. We also confirmed Akt(30%, p<.05), mTOR(64%, p<.05) and p70S6K(82%, p<.05) in control group were significantly increased with the intensive acute running. The mean changes of Akt(87%, p=.001), mTOR(32%, p=.01), p70S6K(25%, p=.009), and 4E-BP1(35%, p=.005) phosphorylation with the training during the recovery period were higher in training group than control group. The changes of resting Akt(156%, p<.05), mTOR(58%, p<.05), p70S6K(98%, p<.05), 4E-BP1(103%, p<.05) and AMPK(51%, p<.05) phosphorylation were higher in training group than control group. This study demonstrates that high intensity aerobic exercise activates the Akt/mTOR signal pathway of the left ventricular muscle, as well as long-term high intensity endurance training may induce physiological growth of the heart in aged rats.