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In vitro antiviral activity of Coxsackievirus B3 3C protease inhibitor
In vitro antiviral activity of Coxsackievirus B3 3C protease inhibitor Eun-Seok Jeon a,∗ , Soo-Hyeon Yun a , hyun Mi Song a , Eun-Seon Ju a , Sang Hoon Lee a , Myeong-Chan Cho b , Dong Ju Choi c , Jae-Joong Kim d , Kyu Hyung Ryu e a Cardiac and Vascular Center, Samsung Medical Center, South Korea b Cardiology, Chungbuk National University Hospital, South Korea c Cardiology, Seoul National University Hospital, South Korea d Cardiology, Asan Medical Center, Ulsan Medical University, South Korea e Cardiovascular Center, Kunkook University Hospital, South Korea
Objective: Coxsackievirus B3 is a primary cause of viral myocarditis. The viral genome encodes a single polyprotein that undergoes a series of proteolytic events to produce several viral proteins. Most of this proteolytic processing is catalyzed by the 3C protease, which is a cysteine protease that cleaves the viral polyprotein encoded by the viral genome. We investigated the potential for chemotherapeutic use of CVB 3CPI. Methods and results: We determined Km value (1.5 × 10−4 M) and substrate specificity of CVB 3CP, yielding a consensus sequence of Pro-Ala-X- (Pro/Phe)Gln ¡e´ Gly-(Glu/Asp/Pro). Since human rhinovirus (HRV) 3CP and CVB 3CP are similar in their catalytic structures, we have synthesized derivatives of an existing peptidomimetic inhibitor of HRV 3CP. One distinct aspect of CVB 3CP is the presence of a Tyr residue at the S2¡¯ pocket. Therefore, we substituted the ethyl group at the P2¡¯ location of the HRV 3CP inhibitor with hydrophobic aromatic rings that can interact preferentially with the Tyr residue. The resulting derivatives showed dramatically increased inhibitory activities against CVB 3CP. Antiviral activity of CVB 3CPI derivative in vitro was evaluated by measurement of cell cytotoxic effect in dose dependent manner. In GFP expression, 3CPI inhibited the proliferation of GFP-H3, which is replication competent virus. GFP expression decreased in high dose of 3CPI. Also we observed that 3CPI inhibited cleavage of viral capsid protein (VP2/VP4) and viral proliferation by Western blotting assay. Conclusion: 3CPI, protein structure-based drug, inhibited activity of 3C protease and were not observed cytopathic effect in high dose. Consequently, 3CPI inhibited the proliferation of CVB3. It could be used as a novel therapeutic agent for CVB3-induced myocarditis. doi:10.1016/j.hlc.2007.11.057
Poster Presentations
S23
Changes of NT proBNP correlated with the regression of left ventricular hypertrophy in patients with aortic valve replacement Eun-Seok Jeon a,∗ , Sang-Hoon Lee a , Seung-Woo Park a , Duk-Kyung Kim a , Dong Ju Choi b , Myeong-Chan Cho c , Kyu Hyung Ryu d a Cardiac and Vascular Center, Samsung Medical Center, South
Korea b Cardiology, Seoul National University Hospital, South Korea c Cardiology, Chungbuk National University Hospital, South Korea d Cardiovascular Center, Kunkook University Hospital, South Korea Background and methods: B-type natriuretic peptide (BNP, NT-proBNP) is a cardiac neurohormone secreted from the ventricular myocardium in a response to ventricular volume overload and/or pressure overload. Clinically, aortic stenosis (AS) or regurgitation (AR) is typical of pressure overload or volume overload, respectively. However, the differences of NT-proBNP levels in patients with aortic valvular disease due to volume-overload (aortic regurgitation, AR) or pressure-overload (aortic stenosis, AS) have not been identified. And it has not been identified either when or whether the elevated NT-proBNP returns to normal levels after correction of AS or AR by aortic valve replacement (AVR). In this study, we measured both preoperative (within 1 month before AVR) and pre-discharge (12 „b7 days after AVR) NT-proBNP levels by Elecsys 2010 (Roche Diagnostics, Manheim, Germany) and echocardiography whether the reverse remodeling happens in patients after AVR (AS = 75, AR = 53). Results: Preoperative NT-proBNP levels were not statistically different between groups (AS vs. AR, 1222 „b 216 vs. 1847 „b 461, p = 0.127). Preoperative LV mass indices (LVMI) were significantly increased in AR (250 „b 11 vs. 321 „b 12 gm/m2, p = 0.001). Postoperative NT-proBNP and LVMI were significantly decreased in both groups. However, the changes of NT-proBNP and LVMI before and after AVR were not statistically correlated in AR (r = 0.007, p = 0.962). In contrast, in AS after AVR, the changes of NT-proBNP were positively correlated with those of LVMI (r = 0.335, P = 0.007) Conclusion: In summary, when the pressure overload and volume overload had been completely removed in patients with AS or AR by AVR, the reverse cardiac remodeling process was starting in a month. And the reverse remodeling could be identified by the measurement of sequential NT-ProBNP levels. Therefore, it may be possible that preoperative NT-proBNP levels can be used as a useful biomarker to predict a reversible cardiac remodeling after AVR. doi:10.1016/j.hlc.2007.11.058
POSTER PRESENTATIONS
Heart, Lung and Circulation 2008;17S:S4–S53
Objective: Coxsackievirus B3 is a primary cause of viral myocarditis. The viral genome encodes a single polyprotein that undergoes a series of proteolytic events to produce several viral proteins. Most of this proteolytic processing is catalyzed by the 3C protease, which is a cysteine protease that cleaves the viral polyprotein encoded by the viral genome. We investigated the potential for chemotherapeutic use of CVB 3CPI. Methods and results: We determined Km value (1.5 × 10−4 M) and substrate specificity of CVB 3CP, yielding a consensus sequence of Pro-Ala-X- (Pro/Phe)Gln ¡e´ Gly-(Glu/Asp/Pro). Since human rhinovirus (HRV) 3CP and CVB 3CP are similar in their catalytic structures, we have synthesized derivatives of an existing peptidomimetic inhibitor of HRV 3CP. One distinct aspect of CVB 3CP is the presence of a Tyr residue at the S2¡¯ pocket. Therefore, we substituted the ethyl group at the P2¡¯ location of the HRV 3CP inhibitor with hydrophobic aromatic rings that can interact preferentially with the Tyr residue. The resulting derivatives showed dramatically increased inhibitory activities against CVB 3CP. Antiviral activity of CVB 3CPI derivative in vitro was evaluated by measurement of cell cytotoxic effect in dose dependent manner. In GFP expression, 3CPI inhibited the proliferation of GFP-H3, which is replication competent virus. GFP expression decreased in high dose of 3CPI. Also we observed that 3CPI inhibited cleavage of viral capsid protein (VP2/VP4) and viral proliferation by Western blotting assay. Conclusion: 3CPI, protein structure-based drug, inhibited activity of 3C protease and were not observed cytopathic effect in high dose. Consequently, 3CPI inhibited the proliferation of CVB3. It could be used as a novel therapeutic agent for CVB3-induced myocarditis. doi:10.1016/j.hlc.2007.11.057
Poster Presentations
S23
Changes of NT proBNP correlated with the regression of left ventricular hypertrophy in patients with aortic valve replacement Eun-Seok Jeon a,∗ , Sang-Hoon Lee a , Seung-Woo Park a , Duk-Kyung Kim a , Dong Ju Choi b , Myeong-Chan Cho c , Kyu Hyung Ryu d a Cardiac and Vascular Center, Samsung Medical Center, South
Korea b Cardiology, Seoul National University Hospital, South Korea c Cardiology, Chungbuk National University Hospital, South Korea d Cardiovascular Center, Kunkook University Hospital, South Korea Background and methods: B-type natriuretic peptide (BNP, NT-proBNP) is a cardiac neurohormone secreted from the ventricular myocardium in a response to ventricular volume overload and/or pressure overload. Clinically, aortic stenosis (AS) or regurgitation (AR) is typical of pressure overload or volume overload, respectively. However, the differences of NT-proBNP levels in patients with aortic valvular disease due to volume-overload (aortic regurgitation, AR) or pressure-overload (aortic stenosis, AS) have not been identified. And it has not been identified either when or whether the elevated NT-proBNP returns to normal levels after correction of AS or AR by aortic valve replacement (AVR). In this study, we measured both preoperative (within 1 month before AVR) and pre-discharge (12 „b7 days after AVR) NT-proBNP levels by Elecsys 2010 (Roche Diagnostics, Manheim, Germany) and echocardiography whether the reverse remodeling happens in patients after AVR (AS = 75, AR = 53). Results: Preoperative NT-proBNP levels were not statistically different between groups (AS vs. AR, 1222 „b 216 vs. 1847 „b 461, p = 0.127). Preoperative LV mass indices (LVMI) were significantly increased in AR (250 „b 11 vs. 321 „b 12 gm/m2, p = 0.001). Postoperative NT-proBNP and LVMI were significantly decreased in both groups. However, the changes of NT-proBNP and LVMI before and after AVR were not statistically correlated in AR (r = 0.007, p = 0.962). In contrast, in AS after AVR, the changes of NT-proBNP were positively correlated with those of LVMI (r = 0.335, P = 0.007) Conclusion: In summary, when the pressure overload and volume overload had been completely removed in patients with AS or AR by AVR, the reverse cardiac remodeling process was starting in a month. And the reverse remodeling could be identified by the measurement of sequential NT-ProBNP levels. Therefore, it may be possible that preoperative NT-proBNP levels can be used as a useful biomarker to predict a reversible cardiac remodeling after AVR. doi:10.1016/j.hlc.2007.11.058
POSTER PRESENTATIONS
Heart, Lung and Circulation 2008;17S:S4–S53