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Abstract
Forkhead box O1 (FoxO1) is a multifunctional initiator, mediator, and repressor of autoimmune diseases in an organ- or disease-specific manner. However, the role of FoxO1 in the salivary gland has not yet been elucidated. In this study, we discovered that FoxO1 and aquaporin 5 (AQP5) are both significantly downregulated in the patients with primary Sjögren syndrome, an autoimmune disease accompanying salivary gland dysfunction. Pharmacologic or genetic perturbation of FoxO1 in the rat salivary gland acinar cell line, SMG-C6, induced a significant downregulation of AQP5 expression, as observed in clinical specimens. There was a strong correlation between FoxO1 and AQP5 expression because FoxO1 is a direct regulator of AQP5 expression in salivary gland acinar cells through its interaction with the promoter region of AQP5. Serial injection of a FoxO1 inhibitor into mice induced a reduction of AQP5 expression in submandibular glands and, consequently, hyposalivation, which is one of the major clinical symptoms of primary Sjögren syndrome. However, there was no sign of inflammation or cell damage in the submandibular glands harvested from mice treated with the FoxO1 inhibitor. In conclusion, our findings indicate that FoxO1 in salivary gland tissue acts as a direct regulator of AQP5 expression. Thus, downregulation of FoxO1 observed in primary Sjögren syndrome is a putative mechanism for hyposalivation without the involvement of previously reported soluble factors in primary Sjögren syndrome patient sera.
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Affiliation(s)
- S M Lee
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - S W Lee
- Department of Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - M Kang
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - J K Choi
- Department of Oral Medicine, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - K Park
- Department of Physiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Republic of Korea
| | - J S Byun
- Department of Oral Medicine, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
| | - D Y Kim
- Department of Pharmacology, School of Dentistry, Kyungpook National University, Daegu, Republic of Korea
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2
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Babinchak WM, Haider R, Dumm BK, Sarkar P, Surewicz K, Choi JK, Surewicz WK. The role of liquid-liquid phase separation in aggregation of the TDP-43 low-complexity domain. J Biol Chem 2019; 294:6306-6317. [PMID: 30814253 DOI: 10.1074/jbc.ra118.007222] [Citation(s) in RCA: 188] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 02/26/2019] [Indexed: 12/14/2022] Open
Abstract
Pathological aggregation of the transactive response DNA-binding protein of 43 kDa (TDP-43) is associated with several neurodegenerative disorders, including ALS, frontotemporal dementia, chronic traumatic encephalopathy, and Alzheimer's disease. TDP-43 aggregation appears to be largely driven by its low-complexity domain (LCD), which also has a high propensity to undergo liquid-liquid phase separation (LLPS). However, the mechanism of TDP-43 LCD pathological aggregation and, most importantly, the relationship between the aggregation process and LLPS remains largely unknown. Here, we show that amyloid formation by the LCD is controlled by electrostatic repulsion. We also demonstrate that the liquid droplet environment strongly accelerates LCD fibrillation and that its aggregation under LLPS conditions involves several distinct events, culminating in rapid assembly of fibrillar aggregates that emanate from within mature liquid droplets. These combined results strongly suggest that LLPS may play a major role in pathological TDP-43 aggregation, contributing to pathogenesis in neurodegenerative diseases.
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Affiliation(s)
- W Michael Babinchak
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Raza Haider
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Benjamin K Dumm
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Prottusha Sarkar
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Krystyna Surewicz
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Jin-Kyu Choi
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
| | - Witold K Surewicz
- From the Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106
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Chung JO, Lee SB, Jeong KH, Song JH, Kim SK, Joo KM, Jeong HW, Choi JK, Kim JK, Kim WG, Shin SS, Shim SM. Quercetin and fisetin enhanced the small intestine cellular uptake and plasma levels of epi-catechins in in vitro and in vivo models. Food Funct 2018; 9:234-242. [PMID: 29168878 DOI: 10.1039/c7fo01576c] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Quercetin and fisetin, known as catechol-containing flavonoids, could positively affect the absorption of catechins due to their strong affinity for catechol-O-methyl transferase (COMT), which can methylate and cause the excretion of catechins. The current study examined the effect of quercetin and fisetin on the absorption of epi-catechins (ECs) by using a Caco-2 cell line and an in vivo model. The intestinal transport of total catechins by Caco-2 cells was enhanced from 1.3- to 1.6-fold and 1.4- to 1.7-fold by adding quercetin and fisetin, respectively, compared to the control. It was even higher in the treatment with a mixture of quercetin and fisetin. While EC had the highest value of intestinal transport (169% of the control) in 10% quercetin treatment, EGC (235%), EGCG (244%), and ECG (242%) were significantly transported in the treatment with a 5% mixture of quercetin and fisetin (p < 0.05). In an in vivo pharmacokinetic study, the values of the area under the plasma concentration-time curve (AUC, ng h mL-1) were also higher in rats orally administered EGCG with 10% quercetin (365.5 ± 25.5) or 10% fisetin (825.3 ± 46.7) than in those administered EGCG only (111.3 ± 13.1). Methylated quercetin and methylated fisetin were determined to be m/z 317.24 and m/z 301.25 [M + H]+ with their own product ions, respectively. The results indicate that quercetin or fisetin is superior to ECs for methylation by COMT.
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Affiliation(s)
- Jin-Oh Chung
- Vital Beautie Research Institute, Amorepacific R&D Center, Yongin-si, Gyeonggi-do 17074, Republic of Korea
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4
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Choi EH, Lee DY, Kim S, Chung JO, Choi JK, Joo KM, Jeong HW, Kim JK, Kim WG, Shim SM. Influence of flavonol-rich excipient food (onion peel and Dendropanax morbifera) on the bioavailability of green tea epicatechins in vitro and in vivo. Food Funct 2018; 8:3664-3674. [PMID: 28914949 DOI: 10.1039/c7fo01173c] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The impacts of onion peel (OP) and Dendropanax morbifera (DM), as excipient foods rich in flavonols, on the digestive recovery, intestinal absorption, and pharmacokinetics of GT epicatechins were studied via an in vitro digestion model system with Caco-2 cells and an in vivo study. The digestive stability of total epicatechins recovered from GT upon the addition of 2% DM was up to 1.12 times higher than that observed with OP. The combined effects of OP and DM, which were observed with 2% OP + DM in a ratio of 1 : 4 (w : w), significantly increased (by a factor of 1.31) the digestive recovery of total epicatechins (p < 0.05). Remarkable cellular uptakes of EC (185.36%) and ECG (188.08%) were found with 4% OP + DM (4 : 1, w : w), and those of EGC (112.30%) and EGCG (136.27%) were obtained with 2% OP + DM (4 : 1, w : w) and 1% OP + DM (1 : 1, w : w), respectively. The peak plasma concentrations of total epicatechins from GT, GT + 5% OP, GT + 5% DM, and GT + 2% OP + 2% DM were 1044.78 ± 609.10, 2267.18 ± 3734.38, 1270.35 ± 547.59, and 714.53 ± 499.27 ng mL-1, respectively. The Cmax value of total epicatechins in rats orally administrated with GT with 5% OP was found to be approximately twice of that obtained with GT alone. The co-ingestion of GT with flavonol-rich excipient foods possibly enhances the absorption of epicatechins because flavonols act as not only enhancers of digestive stability but also modulators of the biotransformation of epicatechins. The results obtained from the current study suggest that the absorption of GT catechins can vary depending upon the kinds and doses of excipient foods co-ingested.
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Affiliation(s)
- Eun-Hye Choi
- Department of Food Science and Technology, Sejong University, 98 Gunja-dong, Gwangjin-gu, Seoul 143-747, Republic of Korea.
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5
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Tiao J, Feng R, Bird S, Choi JK, Dunham J, George M, Gonzalez-Rivera TC, Kaufman JL, Khan N, Luo JJ, Micheletti R, Payne AS, Price R, Quinn C, Rubin AI, Sreih AG, Thomas P, Okawa J, Werth VP. The reliability of the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) among dermatologists, rheumatologists and neurologists. Br J Dermatol 2016; 176:423-430. [PMID: 28004387 DOI: 10.1111/bjd.15140] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/13/2016] [Indexed: 11/30/2022]
Abstract
BACKGROUND Previous studies have shown that skin disease in dermatomyositis (DM) is best assessed using the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI). Although the CDASI has been validated for use by dermatologists, it has not been validated for use by other physicians such as rheumatologists and neurologists, who also manage patients with DM and assess skin activity in clinical trials. OBJECTIVES To assess the reliability of the CDASI among dermatologists, rheumatologists and neurologists. METHODS Fifteen patients with cutaneous DM were assessed using the CDASI and the Physician Global Assessment (PGA) by five dermatologists, five rheumatologists and five neurologists. RESULTS The mean CDASI activity scores for dermatologists, rheumatologists and neurologists were 21·0, 21·8 and 20·8, respectively. These mean scores were not different among the specialists. The CDASI damage score means for dermatologists, rheumatologists and neurologists were 5·3, 7·0 and 4·8, respectively. The mean scores between dermatologists and rheumatologists were significantly different, but the means between dermatologists and neurologists were not. The intraclass correlation coefficients (ICCs) for interrater reliability for CDASI activity and damage were good to excellent for dermatologists and rheumatologists, and moderate to excellent for neurologists. The ICCs for intrarater reliability for CDASI activity and damage were excellent for dermatologists and rheumatologists and moderate to excellent for neurologists. The PGA displayed lower interrater and intrarater reliability relative to the CDASI. CONCLUSIONS Our results confirm the reliability of the CDASI when used by dermatologists and rheumatologists. The data for its use by neurologists were not as robust.
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Affiliation(s)
- J Tiao
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A.,Corporal Michael J. Crescenz Veterans Affairs Medical Center (Philadelphia), Philadelphia, PA, U.S.A
| | - R Feng
- Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania, Philadelphia, PA, U.S.A
| | - S Bird
- Department of Neurology Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - J K Choi
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A.,Corporal Michael J. Crescenz Veterans Affairs Medical Center (Philadelphia), Philadelphia, PA, U.S.A
| | - J Dunham
- Division of Rheumatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - M George
- Division of Rheumatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - T C Gonzalez-Rivera
- Division of Rheumatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A.,Department of Neurology, GlaxoSmithKline USA, Philadelphia, PA, U.S.A
| | - J L Kaufman
- Department of Neurology Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - N Khan
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A.,Corporal Michael J. Crescenz Veterans Affairs Medical Center (Philadelphia), Philadelphia, PA, U.S.A
| | - J J Luo
- Department of Neurology, Temple University School of Medicine, Philadelphia, PA, U.S.A
| | - R Micheletti
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - A S Payne
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - R Price
- Department of Neurology Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - C Quinn
- Department of Neurology Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - A I Rubin
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - A G Sreih
- Division of Rheumatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - P Thomas
- Division of Rheumatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - J Okawa
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A
| | - V P Werth
- Department of Dermatology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, U.S.A.,Corporal Michael J. Crescenz Veterans Affairs Medical Center (Philadelphia), Philadelphia, PA, U.S.A
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6
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Kim CJ, Choi WS, Jung Y, Kiem S, Seol HY, Woo HJ, Choi YH, Son JS, Kim KH, Kim YS, Kim ES, Park SH, Yoon JH, Choi SM, Lee H, Oh WS, Choi SY, Kim NJ, Choi JP, Park SY, Kim J, Jeong SJ, Lee KS, Jang HC, Rhee JY, Kim BN, Bang JH, Lee JH, Park S, Kim HY, Choi JK, Wi YM, Choi HJ. Surveillance of the Middle East respiratory syndrome (MERS) coronavirus (CoV) infection in healthcare workers after contact with confirmed MERS patients: incidence and risk factors of MERS-CoV seropositivity. Clin Microbiol Infect 2016; 22:880-886. [PMID: 27475739 PMCID: PMC7128923 DOI: 10.1016/j.cmi.2016.07.017] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 07/11/2016] [Accepted: 07/16/2016] [Indexed: 01/16/2023]
Abstract
Given the mode of transmission of Middle East respiratory syndrome (MERS), healthcare workers (HCWs) in contact with MERS patients are expected to be at risk of MERS infections. We evaluated the prevalence of MERS coronavirus (CoV) immunoglobulin (Ig) G in HCWs exposed to MERS patients and calculated the incidence of MERS-affected cases in HCWs. We enrolled HCWs from hospitals where confirmed MERS patients had visited. Serum was collected 4 to 6 weeks after the last contact with a confirmed MERS patient. We performed an enzyme-linked immunosorbent assay (ELISA) to screen for the presence of MERS-CoV IgG and an indirect immunofluorescence test (IIFT) to confirm MERS-CoV IgG. We used a questionnaire to collect information regarding the exposure. We calculated the incidence of MERS-affected cases by dividing the sum of PCR-confirmed and serology-confirmed cases by the number of exposed HCWs in participating hospitals. In total, 1169 HCWs in 31 hospitals had contact with 114 MERS patients, and among the HCWs, 15 were PCR-confirmed MERS cases in study hospitals. Serologic analysis was performed for 737 participants. ELISA was positive in five participants and borderline for seven. IIFT was positive for two (0.3%) of these 12 participants. Among the participants who did not use appropriate personal protective equipment (PPE), seropositivity was 0.7% (2/294) compared to 0% (0/443) in cases with appropriate PPE use. The incidence of MERS infection in HCWs was 1.5% (17/1169). The seroprevalence of MERS-CoV IgG among HCWs was higher among participants who did not use appropriate PPE.
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Affiliation(s)
- C-J Kim
- Department of Internal Medicine, Division of Infectious Diseases, Ewha Womans University School of Medicine, South Korea
| | - W S Choi
- Division of Infectious Diseases, Department of Internal Medicine, Korea University College of Medicine, Seoul, South Korea
| | - Y Jung
- Department of Internal Medicine, Konyang University Hospital, South Korea
| | - S Kiem
- Department of Internal Medicine, Inje University Haeundae Paik Hospital, South Korea
| | - H Y Seol
- Department of Internal Medicine, Good GangAn Hospital, South Korea
| | - H J Woo
- Department of Internal Medicine, Hallym University Dongtan Sacred Heart Hospital, South Korea
| | - Y H Choi
- Department of Internal Medicine, Ajou University Hospital, South Korea
| | - J S Son
- Department of Internal Medicine, Kyung Hee University Hospital at Gangdong, South Korea
| | - K-H Kim
- Department of Internal Medicine, Pusan National University Hospital, South Korea
| | - Y-S Kim
- Division of Infectious Diseases, Department of Internal Medicine, Chungnam National University School of Medicine, South Korea
| | - E S Kim
- Department of Internal Medicine, Seoul National University Bundang Hospital, South Korea
| | - S H Park
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Daejeon St. Mary's Hospital, South Korea
| | - J H Yoon
- Department of Internal Medicine, Eulji University Hospital, South Korea
| | - S-M Choi
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Yeouido St. Mary's Hospital, South Korea
| | - H Lee
- Division of Infectious Diseases, Dong-A University Hospital, South Korea
| | - W S Oh
- Department of Internal Medicine, Kangwon National University Hospital, South Korea
| | - S-Y Choi
- Department of Neurology, Dae Cheong Hospital, South Korea
| | - N-J Kim
- Department of Internal Medicine, Seoul National University Hospital, South Korea
| | - J-P Choi
- Department of Internal Medicine, Seoul Medical Center, South Korea
| | - S Y Park
- Department of Internal Medicine, Hallym University Kangdong Sacred Heart Hospital, South Korea
| | - J Kim
- Department of Internal Medicine, Hanyang University Guri Hospital, South Korea
| | - S J Jeong
- Department of Internal Medicine, Gangnam Severance Hospital, South Korea
| | - K S Lee
- Department of Internal Medicine, Myongji Hospital, South Korea
| | - H C Jang
- Department of Internal Medicine, Chonnam National University Hospital, South Korea
| | - J Y Rhee
- Department of Internal Medicine, Dankook University Hospital, South Korea
| | - B-N Kim
- Department of Internal Medicine, Inje University Sanggye Paik Hospital, South Korea
| | - J H Bang
- Department of Internal Medicine, Borame Medical Center, South Korea
| | - J H Lee
- Department of Internal Medicine, Wonkwang University Hospital, South Korea
| | - S Park
- Department of Family Medicine, Seobuk Hospital Seoul Metropolitan Government, South Korea
| | - H Y Kim
- Department of Internal Medicine, Wonju Severance Christian Hospital, South Korea
| | - J K Choi
- Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Bucheon St. Mary's Hospital, South Korea
| | - Y-M Wi
- Department of Internal Medicine, Samsung Changwon Hospital, South Korea
| | - H J Choi
- Department of Internal Medicine, Division of Infectious Diseases, Ewha Womans University School of Medicine, South Korea.
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Scott-McKean JJ, Surewicz K, Choi JK, Ruffin VA, Salameh AI, Nieznanski K, Costa ACS, Surewicz WK. Soluble prion protein and its N-terminal fragment prevent impairment of synaptic plasticity by Aβ oligomers: Implications for novel therapeutic strategy in Alzheimer's disease. Neurobiol Dis 2016; 91:124-131. [PMID: 26949218 DOI: 10.1016/j.nbd.2016.03.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/25/2016] [Accepted: 03/02/2016] [Indexed: 10/22/2022] Open
Abstract
The pathogenic process in Alzheimer's disease (AD) appears to be closely linked to the neurotoxic action of amyloid-β (Aβ) oligomers. Recent studies have shown that these oligomers bind with high affinity to the membrane-anchored cellular prion protein (PrP(C)). It has also been proposed that this binding might mediate some of the toxic effects of the oligomers. Here, we show that the soluble (membrane anchor-free) recombinant human prion protein (rPrP) and its N-terminal fragment N1 block Aβ oligomers-induced inhibition of long-term potentiation (LTP) in hippocampal slices, an important surrogate marker of cognitive deficit associated with AD. rPrP and N1 are also strikingly potent inhibitors of Aβ cytotoxicity in primary hippocampal neurons. Furthermore, experiments using hippocampal slices and neurons from wild-type and PrP(C) null mice (as well as rat neurons in which PrP(C) expression was greatly reduced by gene silencing) indicate that, in contrast to the impairment of synaptic plasticity by Aβ oligomers, the cytotoxic effects of these oligomers, and the inhibition of these effects by rPrP and N1, are independent of the presence of endogenous PrP(C). This suggests fundamentally different mechanisms by which soluble rPrP and its fragments inhibit these two toxic responses to Aβ. Overall, these findings provide strong support to recent suggestions that PrP-based compounds may offer new avenues for pharmacological intervention in AD.
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Affiliation(s)
- Jonah J Scott-McKean
- Division of Pediatric Neurology, Department of Pediatrics, Cleveland, OH, USA 44116
| | | | - Jin-Kyu Choi
- Department of Physiology and Biophysics, Cleveland, OH, USA 44116
| | - Vernon A Ruffin
- Department of Physiology and Biophysics, Cleveland, OH, USA 44116
| | - Ahlam I Salameh
- Department of Physiology and Biophysics, Cleveland, OH, USA 44116
| | - Krzysztof Nieznanski
- Department of Biochemistry, Nencki Institute of Experimental Biology, 02-093Warsaw, Poland
| | - Alberto C S Costa
- Division of Pediatric Neurology, Department of Pediatrics, Cleveland, OH, USA 44116.,Department of Psychiatry, Case Western Reserve University, Cleveland, OH, USA 44116
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Williams TL, Choi JK, Surewicz K, Surewicz WK. Soluble Prion Protein Binds Isolated Low Molecular Weight Amyloid-β Oligomers Causing Cytotoxicity Inhibition. ACS Chem Neurosci 2015; 6:1972-80. [PMID: 26466138 DOI: 10.1021/acschemneuro.5b00229] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A growing number of observations indicate that soluble amyloid-β (Aβ) oligomers play a major role in Alzheimer's disease. Recent studies strongly suggest that at least some of the neurotoxic effects of these oligomers are mediated by cellular, membrane-anchored prion protein and that Aβ neurotoxicity can be inhibited by soluble recombinant prion protein (rPrP) and its fragments. However, the mechanism by which rPrP interacts with Aβ oligomers and prevents their toxicity is largely unknown, and studies in this regard are hindered by the large structural heterogeneity of Aβ oligomers. To overcome this difficulty, here we used photoinduced cross-linking of unmodified proteins (PICUP) to isolate well-defined oligomers of Aβ42 and characterize these species with regard to their cytotoxicity and interaction with rPrP, as well the mechanism by which rPrP inhibits Aβ42 cytotoxicity. Our data shows that the addition of rPrP to the assembling Aβ42 results in a shift in oligomer size distribution, decreasing the population of toxic tetramers and higher order oligomers and increasing the population of nontoxic (and possibly neuroprotective) monomers. Isolated oligomeric species of Aβ42 are cytotoxic to primary neurons and cause permeation of model lipid bilayers. These toxic effects, which are oligomer size-dependent, can be inhibited by the addition of rPrP, and our data suggest potential mechanisms of this inhibitory action. This insight should help in current efforts to develop PrP-based therapeutics for Alzheimer's disease.
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Affiliation(s)
- Thomas L. Williams
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Jin-Kyu Choi
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Krystyna Surewicz
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Witold K. Surewicz
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, United States
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9
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Ahn JI, Lee ST, Park JH, Kim JY, Park JH, Choi JK, Lee G, Lee ES, Lim JM. In vitro-growth and Gene Expression of Porcine Preantral Follicles Retrieved by Different Protocols. Asian-Australas J Anim Sci 2014; 25:950-5. [PMID: 25049649 PMCID: PMC4092981 DOI: 10.5713/ajas.2010.10355] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Revised: 07/26/2011] [Accepted: 12/08/2010] [Indexed: 12/03/2022]
Abstract
This study was conducted to determine how the isolation method of the porcine preantral follicles influenced the following follicular growth in vitro. Mechanical and enzymatical isolations were used for retrieving the follicles from prepubertal porcine ovaries, and in vitro-growth of the follicles and the expression of folliculogenesis-related genes were subsequently monitored. The enzymatic retrieval with collagenase treatment returned more follicles than the mechanical retrieval, while the percentage of morphologically normal follicles was higher with mechanical retrieval than with enzymatic retrieval. After 4 days of culture, mechanically retrieved, preantral follicles yielded more follicles with normal morphology than enzymatically retrieved follicles, which resulted in improved follicular growth. The mRNA expression of FSHR, LHR Cx43, DNMT1 and FGFR2 genes was significantly higher after culture of the follicles retrieved mechanically. These results suggest that mechanical isolation is a better method of isolating porcine preantral follicles that will develop into competent oocytes in in vitro culture.
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Affiliation(s)
- J I Ahn
- Department of Animal Biotechnology, Kangwon National University, Chunchon 200-701, Korea
| | - S T Lee
- Department of Animal Biotechnology, Kangwon National University, Chunchon 200-701, Korea
| | - J H Park
- Department of Animal Biotechnology, Kangwon National University, Chunchon 200-701, Korea
| | - J Y Kim
- School of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chunchon 200-701, Korea
| | - J H Park
- Department of Animal Biotechnology, Kangwon National University, Chunchon 200-701, Korea
| | - J K Choi
- Department of Animal Biotechnology, Kangwon National University, Chunchon 200-701, Korea
| | - G Lee
- School of Dentistry, Seoul National University, Seoul 110-742, Korea
| | - E S Lee
- School of Veterinary Medicine and Institute of Veterinary Science, Kangwon National University, Chunchon 200-701, Korea
| | - J M Lim
- Department of Animal Biotechnology, Kangwon National University, Chunchon 200-701, Korea
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Choi JK, Kim BS, Choi IY, Cho SE, Shin HD. First Report of Powdery Mildew Caused by Golovinomyces artemisiae on Artemisia annua in Korea. Plant Dis 2014; 98:1010. [PMID: 30708899 DOI: 10.1094/pdis-01-14-0055-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Artemisia annua L., known as sweet wormwood or sweet annie, is native to temperate Asia, but is naturalized throughout the world. It produces artemisinin, a potent antimalarial drug that is also effective in treating other parasitic diseases (4). In August 2013, hundreds of plants showing typical symptoms of powdery mildew were found in Seoul (37°36'29.4″ N 127°02'38.3″ E), Korea. Powdery mildew colonies first appeared as thin white patches, which progressed to abundant hyphal growth on both sides of the leaves, stems, and inflorescence. As symptoms continued to develop, the leaves became distorted and turned purplish-gray. Severe infections caused leaf withering and premature senescence. The same symptoms were found on sweet wormwoods in Nonsan (36°09'55.3″ N 127°01'07.1″ E) and Chuncheon (37°52'27.4″ N 127°43'10.0″ E), Korea. Voucher specimens were deposited in the Korea University Herbarium (KUS). Appressoria on the mycelium were nipple-shaped or occasionally lobed. Conidiophores were cylindrical, measured 120 to 230 × 10 to 12.5 μm, and produced 2 to 4 immature conidia in chains with a sinuate outline, followed by 2 to 3 cells. Foot-cells of conidiophores were straight, cylindrical, and 54 to 100 μm long. Conidia were hyaline, ellipsoid to barrel-shaped, measured 30 to 40 × 15 to 20 μm (length/width ratio of 1.5 to 2.1), lacked distinct fibrosin bodies, and showed reticulate wrinkling of the outer walls. Germ tubes were produced on the perihilar position of conidia. Primary conidia were apically rounded, basally subtruncate, and generally smaller than the secondary conidia. No chasmothecia were observed. The structures described above were typical of the powdery mildew Euoidium anamorph of the genus Golovinomyces, and the fungus measurements were similar to those of G. artemisiae (Grev.) V.P. Heluta (3). The complete internal transcribed spacer (ITS) region of rDNA from KUS-F27763 was amplified with primers ITS1/ITS4 and sequenced. The resulting sequence of 624 bp was deposited in GenBank (Accession No. KJ136112). The obtained ITS sequence shared >99% similarity with G. artemisiae on A. princeps and A. montana from Japan (AB077659 and AB077649) and A. argyi from China (KF056818). Pathogenicity was confirmed through inoculation by gently dusting conidia onto leaves of five healthy potted plants. Five non-inoculated plants served as controls. Inoculated plants developed symptoms after 5 days, whereas the control plants remained symptomless. The fungus present on the inoculated plants was identical morphologically to that originally observed on diseased plants. Powdery mildews of A. annua caused by G. artemisiae have been reported in Japan, China, the Russian Far East, and Romania (1,2). To our knowledge, this is the first report of powdery mildew caused by G. artemisiae on A. annua in Korea. Since sweet wormwood production was only recently started on a commercial scale in Korea, powdery mildew infections pose a serious threat to the production of this plant, especially in organic farming where chemical control options are limited. References: (1) K. Amano. Host Range and Geographical Distribution of the Powdery Mildew Fungi. Japan Scientific Societies Press, Tokyo, 1986. (2) U. Braun. The Powdery Mildews (Erysiphales) of Europe. G. Fischer Verlag, Jena, 1995. (3) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht, 2012. (4) P. J. Weathers et al. Phytochem. Rev. 10:173, 2011.
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Affiliation(s)
- J K Choi
- Gangwondo Agricultural Research and Extension Services, Chuncheon 200-150, Korea
| | - B S Kim
- Department of Plant Science, Gangneung-Wonju National University, Gangneung 210-702, Korea
| | - I Y Choi
- Jeollabuk-do Agricultural Research and Extension Services, Iksan 570-704, Korea
| | - S E Cho
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea
| | - H D Shin
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea
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Choi JK, Kim BS, Hong SH, Cho SE, Shin HD. First Report of Powdery Mildew Caused by Golovinomyces sonchicola on Ixeris chinensis in Korea. Plant Dis 2014; 98:999. [PMID: 30708886 DOI: 10.1094/pdis-11-13-1132-pdn] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ixeris chinensis (Thunb.) Nakai, known as Chinese ixeris, is distributed from Siberia to Japan, including Korea, Taiwan, and China. The whole plant has been used in folk medicine in Asia (4). In Korea, the plants of Chinese ixeris have been gathered and used as a wild root vegetable. During summer to autumn of 2011, Chinese ixeris leaves were found to be heavily infected with a powdery mildew in several locations of Korea. Symptoms first appeared as thin white colonies, which subsequently developed into abundant hyphal growth on both sides of the leaves, leading to drying of the leaves. The same symptoms on Chinese ixeris leaves were continuously observed in 2012 and 2013. Voucher specimens (n = 10) were deposited at Korea University Herbarium (KUS). Hyphal appressoria were moderately lobed or nipple-shaped. Conidiophores arose from the lateral part of the hyphae, measured 100 to 270 × 10 to 12.5 μm, and produced 2 to 6 immature conidia in chains with a sinuate outline. Basal parts of foot-cells in conidiophores were curved. Conidia were barrel-shaped to ellipsoid, measured 26 to 36 × 13 to 19 μm (length/width ratio = 1.7 to 2.4), lacked fibrosin bodies, and showed reticulate wrinkling of the outer walls. Primary conidia were ovate with conical-obtuse apex and subtruncate base. Germ tubes were produced on the perihilar position of conidia. Chasmothecia were not observed. The morphological characteristics were typical of the Euoidium type anamorph of the genus Golovinomyces, and the fungus measurements and structures were consistent with those of G. sonchicola U. Braun & R.T.A. Cook (1). To confirm the identification, internal transcribed spacer (ITS) region of rDNA sequences from a representative material (KUS-F26212) was amplified using primers ITS5/P3 and sequenced (3). The resulting 416-bp sequence was deposited in GenBank (Accession No. KF819857). A GenBank BLAST search revealed that the isolate showed >99% sequence similarity with those of G. cichoracearum from Sonchus spp. (e.g., AB453762, AF011296, JQ010848, etc.). G. sonchicola is currently confined to G. cichoracearum s. lat. on Sonchus spp., based on molecular sequence analyses (1). Pathogenicity was confirmed through inoculation by gently pressing a diseased leaf onto leaves of five healthy potted Chinese ixeris. Five non-inoculated plants served as controls. Inoculated plants developed symptoms after 6 days, whereas the controls remained symptomless. The fungus present on the inoculated plants was identical morphologically to that originally observed on diseased plants. Powdery mildew infections of I. chinensis associated with Golovinomyces have been known in China (2). To our knowledge, this is the first report of powdery mildew disease caused by G. sonchicola on I. chinensis in Korea. Farming of Chinese ixeris has recently started on a commercial scale in Korea. Though no statistical data are available, we postulate the cultivation area in Korea to be approximately 200 ha, mostly growing without chemical controls. Occurrence of powdery mildews poses a potential threat to safe production of this vegetable, especially in organic farming. References: (1) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht, 2012. (2) F. L. Tai. Bull. Chinese Bot. Sci. 2:16, 1936. (3) S. Takamatsu et al. Mycol. Res. 113:117, 2009. (4) S. J. Zhang et al. J. Nat. Prod. 69:1425, 2006.
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Affiliation(s)
- J K Choi
- Gangwondo Agricultural Research and Extension Services, Chuncheon 200-150, Korea
| | - B S Kim
- Department of Plant Science, Gangneung-Wonju National University, Gangneung 210-702, Korea
| | - S H Hong
- Institute of Environment and Ecology, Korea University, Seoul 136-701, Korea
| | - S E Cho
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea
| | - H D Shin
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea
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Choi JK, Kim JH, Cho SE, Shin HD. First Report of Powdery Mildew Caused by Erysiphe cruciferarum on Garden Cress in Korea. Plant Dis 2013; 97:998. [PMID: 30722545 DOI: 10.1094/pdis-01-13-0001-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Garden cress (Lepidium sativum L.), belonging to the family Brassicaceae, is an edible herb with peppery flavor and aroma (2). This plant was recently introduced and is cultivated as an edible green under organic farming in Korea. In September 2012, seedlings showing typical symptoms of powdery mildew were found in greenhouses in Pyeongchang County, Korea. Symptoms first appeared as thin white colonies, which progressed to abundant growth on the leaves and stems. Infected herbs were unmarketable mainly due to signs of senescence and withering of leaves and mostly abandoned without becoming harvested. Two samples of diseased leaves were deposited in the Korea University Herbarium (KUS Accession Nos. F27137 and F27150). Appressoria on the mycelium were well-developed, lobed, and solitary or in opposite pairs. Conidiophores were unbranched, cylindrical, 88 to 120 × 8.5 to 10 μm, and composed of 3 to 4 cells. Foot-cells of conidiophores were straight to sub-straight, cylindric, 22 to 42 μm long, and generally equal to or shorter than the upper cells. Singly produced conidia were oblong to cylindrical or oval, 34 to 52 × 14 to 18 μm with a length/width ratio of 2.2 to 3.3, with angular/rectangular wrinkling of outer walls, and no distinct fibrosin bodies. Germ tubes were produced on the perihilar position of conidia. No chasmothecia were found. These structures are typical of the powdery mildew Pseudoidium anamorph of the genus Erysiphe. The specific measurements match with those of E. cruciferarum Opiz ex L. Junell as previously described (1). To confirm the identification, the complete internal transcribed spacer (ITS) region of rDNA from KUS-F27150 was amplified with primers ITS5 and P3 and directly sequenced (4). The resulting 554-bp sequence was deposited in GenBank (Accession No. KC414675). The amplified ITS sequence shared >99% similarity with the sequences of E. cruciferarum on several brassicaceous hosts (EU140958, FJ548627, and GU721075). Pathogenicity was confirmed through inoculation by gently dusting conidia onto leaves of five healthy potted garden cress plants. Five non-inoculated plants served as controls. Inoculated plants were isolated from non-inoculated plants in separate rooms in a greenhouse at 18 to 24°C. Inoculated plants developed signs and symptoms after 8 days, whereas the control plants remained symptomless. The fungus present on the inoculated plants was morphologically identical to that originally observed on diseased plants, fulfilling Koch's postulates. Previously, the disease was reported in several European countries and southeastern Asia (Lebanon, Israel, Iran, Iraq, India, and China) (3). To our knowledge, this is the first report of powdery mildew caused by E. cruciferarum on garden cress in Korea. Since garden cress production was only recently started on a commercial scale in Korea, powdery mildew infections pose a serious threat to the production of this herb, especially in organic farming where chemical control options are limited. References: (1) U. Braun and R. T. A. Cook. Taxonomic Manual of the Erysiphales (Powdery Mildews), CBS Biodiversity Series No.11. CBS, Utrecht, 2012. (2) S. Choudhary et al. Indian J. Agric. Sci. 80:752, 2010. (3) D. F. Farr and A. Y. Rossman. Fungal Databases, Syst. Mycol. Microbiol. Lab., Online publication. ARS, USDA. Retrieved December 2, 2012. (4) S. Takamatsu et al. Mycol. Res. 113:117, 2009.
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Affiliation(s)
- J K Choi
- Gangwon Agricultural Research and Extension Services, Chuncheon 200-150, Korea
| | - J H Kim
- Gangwon Agricultural Research and Extension Services, Chuncheon 200-150, Korea
| | - S E Cho
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea. Financially supported by a Korea University Grant to HDS in 2012
| | - H D Shin
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea. Financially supported by a Korea University Grant to HDS in 2012
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Dung MX, Choi JK, Jeong HD. Newly synthesized silicon quantum dot-polystyrene nanocomposite having thermally robust positive charge trapping. ACS Appl Mater Interfaces 2013; 5:2400-2409. [PMID: 23510254 DOI: 10.1021/am400356r] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Striving to replace the well known silicon nanocrystals embedded in oxides with solution-processable charge-trapping materials has been debated because of large scale and cost effective demands. Herein, a silicon quantum dot-polystyrene (SiQD-PS) nanocomposite (NC) was synthesized by post-functionalization of hydrogen-terminated silicon quantum dots (H-SiQDs) with styrene using a thermally induced surface-initiated polymerization approach. The NC contains two miscible components: PS and SiQD@PS which, respectively, are polystyrene and polystyrene chains-capped SiQDs. Spin-coated films of the nanocomposite on various substrate were thermally annealed at different temperatures and subsequently used to construct metal-insulator-semiconductor (MIS) devices and thin film field-effect transistors (TFTs) having a structure of p-Si++/SiO2/NC/pentacene/Au source-drain. Capacitance-voltage (C-V) curves obtained from the MIS devices exhibit a well-defined counterclockwise hysteresis with negative fat band shifts, which was stable over a wide range of curing temperatures (50-250 °C). The positive charge trapping capability of the NC originates from the spherical potential well structure of the SiQD@PS component while the strong chemical bonding between SiQDs and polystyrene chains accounts for the thermal stability of the charge trapping property. The transfer curve of the transistor was controllably shifted to the negative direction by varying applied gate voltage. Thereby, this newly synthesized and solution processable SiQD-PS nanocomposite is applicable as charge trapping materials for TFT based memory devices.
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Affiliation(s)
- Mai Xuan Dung
- Nanomaterials and Interface Laboratory, Department of Chemistry, Chonnam National University, 500-757 Gwangju, Republic of Korea
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Jeon YC, Choi JK, Choi EK, Carp RI, Kim YS. Pathological characterization of TgElk mice injected with brain homogenate from elk with chronic wasting disease. J Vet Sci 2013; 14:21-6. [PMID: 23388435 PMCID: PMC3615228 DOI: 10.4142/jvs.2013.14.1.21] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 04/19/2012] [Indexed: 11/30/2022] Open
Abstract
Chronic wasting disease (CWD) is classified as a transmissible spongiform encephalopathy or prion disease that affects cervids. CWD has been reported in 15 US states, two Canadian provinces, and in imported elk on several farms in Korea. This study was conducted to examine the molecular biological and pathogenic characteristics of a CWD-associated prion isolated in Korea. The epidemiological origin of this pathogen was also determined. Homozygous TgElk mice were infected with a CWD-affected elk brain pool prepared from the brain of an imported Canadian elk. We measured the incubation time of the pathogen, neuropathological changes by immunohistochemical staining, the pattern(s) of scrapie prion protein (PrPSc) deposition, and PrPSc protein profiles by Western blotting. We found that TgElk mice infected with brain homogenate from the elk suffering from CWD showed incubation times, vacuolar degeneration, and PrPSc accumulation similar to those previously reported in the literature. Our results suggest that homozygous TgElk mice efficiently transmit CWD with short incubation times and that this animal can serve a valuable research model and reliable in vivo diagnostic tool.
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Affiliation(s)
- Yong-Chul Jeon
- Ilsong Institute of Life Science, Hallym University, Anyang 431-060, Korea
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Jung CH, Choi JK, Yang Y, Koh HJ, Heo P, Yoon KJ, Kim S, Park WS, Shing HJ, Kweon DH. A botulinum neurotoxin-like function of Potentilla chinensis extract that inhibits neuronal SNARE complex formation, membrane fusion, neuroexocytosis, and muscle contraction. Pharm Biol 2012; 50:1157-1167. [PMID: 22881141 DOI: 10.3109/13880209.2012.661743] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
CONTEXT Botulinum neurotoxins (BoNTs) are popularly used to treat various diseases and for cosmetic purposes. They act by blocking neurotransmission through specific cleavage of soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. Recently, several polyphenols were shown to interfere with SNARE complex formation by wedging into the hydrophobic core interface, thereby leading to reduced neuroexocytosis. OBJECTIVE In order to find industrially-viable plant extract that functions like BoNT, 71 methanol extracts of flowers were screened and BoNT-like activity of selected extract was evaluated. MATERIALS AND METHODS After evaluating the inhibitory effect of 71 flower methanol extracts on SNARE complex formation, seven candidates were selected and they were subjected to SNARE-driven membrane fusion assay. Neurotransmitter release from neuronal PC12 cells and SNARE complex formation inside the cell was also evaluated. Finally, the effect of one selected extract on muscle contraction and digit abduction score was determined. RESULTS The extract of Potentilla chinensis Ser. (Rosaceae)(Chinese cinquefoil) flower inhibited neurotransmitter release from neuronal PC12 cells by approximately 90% at a concentration of 10 μg/mL. The extract inhibited neuroexocytosis by interfering with SNARE complex formation inside cells. It reduced muscle contraction of phrenic nerve-hemidiaphragm by approximately 70% in 60 min, which is comparable to the action of the Ca²⁺-channel blocker verapamil and BoNT type A. DISCUSSION AND CONCLUSION While BoNT blocks neuroexocytosis by cleaving SNARE proteins, the Potentilla chinensis extract exhibited the same activity by inhibiting SNARE complex formation. The extract paralyzed muscle as efficiently as BoNT, suggesting the potential versatility in cosmetics and therapeutics.
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Affiliation(s)
- Chang-Hwa Jung
- School of Life Science and Biotechnology and Center for Human Interface Nano Technology, Sungkyunkwan University, Gyeonggi-do, Korea
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Abstract
The pathogenesis of Alzheimer disease appears to be strongly linked to the aggregation of amyloid-β (Aβ) peptide and, especially, formation of soluble Aβ1-42 oligomers. It was recently demonstrated that the cellular prion protein, PrP(C), binds with high affinity to these oligomers, acting as a putative receptor that mediates at least some of their neurotoxic effects. Here we show that the soluble (i.e. glycophosphatidylinositol anchor-free) prion protein and its N-terminal fragment have a strong effect on the aggregation pathway of Aβ1-42, inhibiting its assembly into amyloid fibrils. Furthermore, the prion protein prevents formation of spherical oligomers that normally occur during Aβ fibrillogenesis, acting as a potent inhibitor of Aβ1-42 toxicity as assessed in experiments with neuronal cell culture. These findings may provide a molecular level foundation to explain the reported protective action of the physiologically released N-terminal N1 fragment of PrP(C) against Aβ neurotoxicity. They also suggest a novel approach to pharmacological intervention in Alzheimer disease.
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Affiliation(s)
- Krzysztof Nieznanski
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, USA
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Myung IS, Choi JK, Wu JM, Lee JY, Yoo HL, Shim HS. Bacterial Stripe of Hog Millet Caused by Acidovorax avenae subsp. avenae, a New Disease in Korea. Plant Dis 2012; 96:1222. [PMID: 30727087 DOI: 10.1094/pdis-03-12-0320-pdn] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In July 2011, bacterial stripe was observed on a commercial field of hog millet (Panicum miliaceum L.) in Chuncheon, Korea, with a disease incidence of 37% in the field. Symptoms on leaves included reddish-brown, long, narrow stripes that varied in length and were sharply delineated by uninfected adjacent vascular bundles. Eleven bacterial isolates (BC3107, BC3214 to BC3223) were recovered on trypticase soy agar from lesions surface sterilized in 70% ethanol for 1 min. The isolates, all obtained from different plants, were gram negative, oxidase positive, aerobic rods with two to four flagella. The isolates produced circular, cream-colored, nonfluorescent, butyrous colonies with entire margins on King's B medium. Using the Biolog Microbial Identification System, Version 4.2 (Biolog Inc., Hayward, CA), the isolates were identified as Acidovorax avenae subsp. avenae with Biolog similarity indices ranging from 0.52 to 0.72 after 24 hr. Characters for differentiating between Acidovorax spp. were tested according to Schaad et al. (2). The isolates were positive for gelatin liquefaction, nitrate reduction, lipase production, utilization of D-mannitol, sodium citrate, and alkaline in litmus milk. The isolates were negative for utilization of D-arabitol and did not amplify with PCR primer sets Aaaf5, Aaaf3/Aaar2, and Aacf2/Aacr2. Colonies were V-, V+, and V+ for utilization of D-fucose, maltose, and ethanol, respectively. Regions of the 16S rRNA (rrs) and the IGS were sequenced to aid in the identification of the isolates using reported PCR primer sets (1,4). A 1,426 bp fragment of the rrs region shared 100% similarity with all strains of A. avenae available in GenBank. Pathogenicity tests were separately performed for the 11 isolates in different greenhouses located in Suwon (National Academy of Agricultural Science), and Chuncheon (Gangwondo Agricultural Research and Extension Services) in Korea. Pathogenicity was confirmed by clip inoculation with sterilized scissors dipped into cell suspensions containing 105 CFU/ml on three 8-day-old leaves of hog millet (two plants per isolate), rice (Oryza sativa L. cv. Hopyeong), and sweet corn (Zea mays L. cv. Daehak) in a greenhouse maintained at 28 to 32°C and 90% relative humidity. The isolates induced similar symptoms as those originally observed on hog millet 5 days after inoculation. No symptoms were observed on the control plants (hog millet, rice, and sweet corn), which were clipped with scissors dipped in sterilized distilled water. The identity of bacteria reisolated from the stripes on inoculated leaves was confirmed by analyzing sequences of the 16S-23S rRNA intergenic spacer region (IGS) (1). On the basis of physiological, pathological, and sequence data, the isolates were identified as A. avenae subsp. avenae. To our knowledge, this is the first report of bacterial stripe of hog millet caused by A. avenae subsp. avenae in Korea. The spread of the bacterial disease is expected to have a significant economic impact on hog millet culture in the fields of Gangwon Province in Korea. Nucleotide sequence data reported are available under accession numbers JQ743877 to JQ743887 for rrs of BC 3207 and BC3214 to BC3223, and JQ743877 to JQ743887 for IGS of BC3207 and BC3214 to BC3223. References: (1) T. Barry et al. The PCR Methods Appl. 1:51, 1991. (2) N. W. Schaad et al. Syst, Appl. Microbiol. 31: 434, 2008. (3) K. Tamura et al. Mol. Biol. Evol. 28:2731, 2011. (4) W. G. Weisburg et al. J. Bacteriol. 173: 697, 1991.
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Affiliation(s)
- I S Myung
- Crop Protection, National Academy of Agricultural Science (NAAS), Rural Development Administration (RDA), Suwon 441-707, Korea
| | - J K Choi
- Agricultural Environment Research Division, Gangwondo Agricultural Research and Extension Services, Chuncheon 200-939, Korea
| | - J M Wu
- Crop Protection, NAAS, RDA, Suwon 441-707, Korea
| | - J Y Lee
- Crop Protection, NAAS, RDA, Suwon 441-707, Korea
| | - H L Yoo
- Crop Protection, NAAS, RDA, Suwon 441-707, Korea
| | - H S Shim
- Crop Protection, NAAS, RDA, Suwon 441-707, Korea
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Ahn DG, Choi JK, Taylor DR, Oh JW. Biochemical characterization of a recombinant SARS coronavirus nsp12 RNA-dependent RNA polymerase capable of copying viral RNA templates. Arch Virol 2012; 157:2095-104. [PMID: 22791111 PMCID: PMC7086750 DOI: 10.1007/s00705-012-1404-x] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2012] [Accepted: 05/24/2012] [Indexed: 11/26/2022]
Abstract
The severe acute respiratory syndrome coronavirus (SARS-CoV) RNA genome is replicated by a virus-encoded RNA replicase, the key component of which is the nonstructural protein 12 (nsp12). In this report, we describe the biochemical properties of a full-length recombinant SARS-CoV nsp12 RNA-dependent RNA polymerase (RdRp) capable of copying viral RNA templates. The purified SARS-CoV nsp12 showed both primer-dependent and primer-independent RNA synthesis activities using homopolymeric RNA templates. The RdRp activity was strictly dependent on Mn2+. The nsp12 preferentially copied homopolymeric pyrimidine RNA templates in the absence of an added oligonucleotide primer. It was also able to initiate de novo RNA synthesis from the 3’-ends of both the plus- and minus-strand genome of SARS-CoV, using the 3’-terminal 36- and 37-nt RNA, respectively. The in vitro RdRp assay system established with a full-length nsp12 will be useful for understanding the mechanisms of coronavirus replication and for the development of anti-SARS-CoV agents.
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Affiliation(s)
- Dae-Gyun Ahn
- Department of Biotechnology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 Korea
| | - Jin-Kyu Choi
- Department of Biotechnology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 Korea
| | - Deborah R. Taylor
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892 USA
| | - Jong-Won Oh
- Department of Biotechnology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 Korea
- Translational Research Center for Protein Function Control, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 Korea
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Cho SE, Park JH, Choi JK, Shin HD. First Report of Zonate Leaf Spot of Glycine max Caused by Cristulariella moricola in Korea. Plant Dis 2012; 96:906. [PMID: 30727372 DOI: 10.1094/pdis-01-12-0028-pdn] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Soybean (Glycine max (L.) Merr.) is native to East Asia including Korea and is widely grown and consumed as an edible seed. In August 2011, following a prolonged period of cool and moist weather, zonate leaf spots were observed in local soybean (cultivar unknown) planted in a mountainous area of Goseong, central Korea. A voucher specimen was collected and entered at the Korea University herbarium (KUS-F26049). Initial symptoms included grayish green-to-grayish brown spots without border lines. As the lesions enlarged, they coalesced, leading to leaf blight and premature defoliation. Sporophores on the leaf lesions were dominantly hypophyllous, rarely epiphyllous, solitary, erect, easily detachable, and as long as 750 μm. The upper portion of the sporophores consisted of a pyramidal head that was ventricose, 275 to 500 μm long, and 80 to 160 μm wide. The fungus was isolated from leaf lesions and maintained on potato dextrose agar (PDA). Sclerotia were produced on PDA after 4 to 5 weeks at 18°C without light, but conidia were not observed in culture. The morphological and cultural characteristics were consistent with those of Cristulariella moricola (Hino) Redhead (2,3). An isolate was preserved in the Korean Agricultural Culture Collection (KACC46401). Genomic DNA was extracted with the DNeasy Plant Mini DNA Extraction Kit (Qiagen Inc., Valencia, CA). The complete internal transcribed spacer (ITS) region of rDNA was amplified with the primers ITS1/ITS4 and sequenced. The resulting sequence of 453 bp was deposited in GenBank (Accession No. JQ036182). A BLAST search in GenBank revealed that the sequence showed an exact match with that of C. moricola from Acer negundo (JQ036181) and >99% similarity with that of Grovesinia pyramidalis, teleomorph of C. moricola from Juglans sp. (Z81433). To determine the pathogenicity of the fungus, sporophores with the pyramidal head were carefully detached from a lesion on the naturally infected leaflet with fine needles. Each sporophore was transferred individually onto four places of six detached healthy soybean leaflets. The leaflets were placed in humid chambers at 100% relative humidity and incubated at 16 to 20°C (4). Symptoms were observed after 2 days on all inoculated leaflets (one to four lesions/leaflet). The lesions enlarged rapidly and reached ~20 mm diameter in a week. A number of sporulating structures and immature sclerotia were formed on the abaxial surface of the leaf 2 weeks after inoculation. The pathogen was reisolated from lesions on the inoculated leaflets, confirming Koch's postulates. No symptoms were observed on the control leaflets kept in humid chambers for 2 weeks. C. moricola was known to cause zonate leaf spots and defoliation on a wide range of woody and annual plants (1), but not on G. max. To our knowledge, this is the first report of Cristulariella infection in cultivated soybeans. Since the infections may be limited to the mountainous area with low night temperature and high humidity, economic losses seem to be negligible. However, the disease could be a potential threat to the safe production of soybeans in areas with prolonged periods of cool and moist weather. References: (1) D. F. Farr and A. Y. Rossman. Fungal Databases. Systematic Mycology and Microbiology Laboratory, ARS, USDA. Retrieved from http://nt.arsgrin.gov/fungaldatabases/ , January 7, 2012. (2) H. B. Lee and C. J. Kim. Plant Dis. 86:440, 2002. (3) S. A. Redhead. Can. J. Bot. 53:700, 1975. (4) H. J. Su and S. C. Leu. Plant Dis. 67:915, 1983.
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Affiliation(s)
- S E Cho
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea
| | - J H Park
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea
| | - J K Choi
- Gangwon Agricultural Research and Extension Services, Chuncheon 200-150, Korea
| | - H D Shin
- Division of Environmental Science and Ecological Engineering, Korea University, Seoul 136-701, Korea
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Affiliation(s)
- Jin-Kyu Choi
- a Port and Airport Research Institute, 3-1-1 Nagase, Yokosuka, Kanagawa 239-0826, Japan
| | - Tetsuya Shiraishi
- b Port and Airport Research Institute, 3-1-1 Nagase, Yokosuka, Kanagawa 239-0826, Japan
| | - Toshinari Tanaka
- c Port and Airport Research Institute, 3-1-1 Nagase, Yokosuka, Kanagawa 239-0826, Japan
| | - Hiroshi Sakai
- d Port and Airport Research Institute, 3-1-1 Nagase, Yokosuka, Kanagawa 239-0826, Japan
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Affiliation(s)
- Jin-Kyu Choi
- a Technology Research Institute of Osaka Prefecture, 2-7-1 Ayumino, Izumi, Osaka 594-1157, Japan
| | - Choong Sik Park
- b Technology Research Institute of Osaka Prefecture, 2-7-1 Ayumino, Izumi, Osaka 594-1157, Japan
| | - Takahiro Kitagawa
- c Technology Research Institute of Osaka Prefecture, 2-7-1 Ayumino, Izumi, Osaka 594-1157, Japan
| | - Kotaro Nakatani
- d Technology Research Institute of Osaka Prefecture, 2-7-1 Ayumino, Izumi, Osaka 594-1157, Japan
| | - Haruo Sugii
- e Technology Research Institute of Osaka Prefecture, 2-7-1 Ayumino, Izumi, Osaka 594-1157, Japan
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Choi JK, Jang S, Kim KJ, Sohn H, Jeong HD. Observation of Negative Charge Trapping and Investigation of Its Physicochemical Origin in Newly Synthesized Poly(tetraphenyl)silole Siloxane Thin Films. J Am Chem Soc 2011; 133:7764-85. [DOI: 10.1021/ja1108112] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Jin-Kyu Choi
- Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea
| | - Seunghyun Jang
- Department of Chemistry, Chosun University, Gwangju 501-759, Republic of Korea
| | - Ki-Jeong Kim
- Pohang Accelerator Laboratory, Pohang University of Science and Technology, Pohang 790-784, Republic of Korea
| | - Honglae Sohn
- Department of Chemistry, Chosun University, Gwangju 501-759, Republic of Korea
| | - Hyun-Dam Jeong
- Department of Chemistry, Chonnam National University, Gwangju 500-757, Republic of Korea
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Ahn DG, Lee W, Choi JK, Kim SJ, Plant EP, Almazán F, Taylor DR, Enjuanes L, Oh JW. Interference of ribosomal frameshifting by antisense peptide nucleic acids suppresses SARS coronavirus replication. Antiviral Res 2011; 91:1-10. [PMID: 21549154 PMCID: PMC4728714 DOI: 10.1016/j.antiviral.2011.04.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 03/09/2011] [Accepted: 04/19/2011] [Indexed: 02/09/2023]
Abstract
The programmed −1 ribosomal frameshifting (−1 PRF) utilized by eukaryotic RNA viruses plays a crucial role for the controlled, limited synthesis of viral RNA replicase polyproteins required for genome replication. The viral RNA replicase polyproteins of severe acute respiratory syndrome coronavirus (SARS-CoV) are encoded by the two overlapping open reading frames 1a and 1b, which are connected by a −1 PRF signal. We evaluated the antiviral effects of antisense peptide nucleic acids (PNAs) targeting a highly conserved RNA sequence on the – PRF signal. The ribosomal frameshifting was inhibited by the PNA, which bound sequence-specifically a pseudoknot structure in the −1 PRF signal, in cell lines as assessed using a dual luciferase-based reporter plasmid containing the −1 PRF signal. Treatment of cells, which were transfected with a SARS-CoV-replicon expressing firefly luciferase, with the PNA fused to a cell-penetrating peptide (CPP) resulted in suppression of the replication of the SARS-CoV replicon, with a 50% inhibitory concentration of 4.4 μM. There was no induction of type I interferon responses by PNA treatment, suggesting that the effect of PNA is not due to innate immune responses. Our results demonstrate that −1 PRF, critical for SARS-CoV viral replication, can be inhibited by CPP-PNA, providing an effective antisense strategy for blocking −1 PRF signals.
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Affiliation(s)
- Dae-Gyun Ahn
- Department of Biotechnology and Translational Research Center for Protein Function Control, Yonsei University, Seoul, Republic of Korea
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Abstract
Epigenetics is the study of regulatory mechanisms that are not accompanied by the action of genetic elements. Recently, a system-wide extension of epigenetics has been driven by the rapid evolution of genomics technology. This means not simply profiling multiple genes together as gene expression microarrays, but also factoring in the crosstalk among various epigenetic components and extending our focus to relatively uncharted genomic areas, including intergenic and intragenic regions. Although this exciting extension provides many interesting research topics as described in this review, the future expansion of epigenomics to cover multiple samples will offer an even more profound opportunity for systems biology research.
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Affiliation(s)
- J K Choi
- KAIST, Department of Bio and Brain Engineering, Daejeon, Republic of Korea.
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Mohapatra P, Dung MX, Choi JK, Jeong SH, Jeong HD. Effects of Curing Temperature on the Optical and Charge Trap Properties of InP Quantum Dot Thin Films. B KOREAN CHEM SOC 2011. [DOI: 10.5012/bkcs.2011.32.1.263] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Jang C, Choi JK, Kim E, Park ES, Wasco W, Buxbaum JD, Kim YS, Choi EK. Calsenilin is degraded by the ubiquitin-proteasome pathway. Biochem Biophys Res Commun 2011; 405:180-5. [PMID: 21216226 DOI: 10.1016/j.bbrc.2010.12.137] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2010] [Accepted: 12/31/2010] [Indexed: 01/12/2023]
Abstract
Calsenilin, a neuronal calcium binding protein that has been shown to have multiple functions in the cell, interacts with presenilin 1 (PS1) and presenilin 2 (PS2), represses gene transcription and binds to A-type voltage-gated potassium channels. In addition, increased levels of calsenilin are observed in the brains of Alzheimer's disease and epilepsy patients. The present study was designed to investigate the molecular mechanism of calsenilin degradation pathways in cultured cells. Here, we demonstrate that inhibition of the ubiquitin-proteasomal pathway (UPP) but not lysosomal pathway markedly increased the expression levels of calsenilin. Immunofluorescence analysis revealed that following proteasomal inhibition calsenilin accumulated in the endoplasmic reticulum (ER) and Golgi, while lysosomal inhibition had no effect on calsenilin localization. In addition, we found the change of subcellular localization of PS1 from diffuse pattern to punctuate staining pattern in the ER and perinuclear region in the presence of calsenilin. These findings suggest that calsenilin degradation is primarily mediated by the UPP and that impairment in the UPP may contribute to the involvement of calsenilin in disease-associated neurodegeneration.
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Affiliation(s)
- Changhwan Jang
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea
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Choi JK, Jeon YC, Lee DW, Oh JM, Lee HP, Jeong BH, Carp RI, Koh YH, Kim YS. A Drosophila model of GSS syndrome suggests defects in active zones are responsible for pathogenesis of GSS syndrome. Hum Mol Genet 2010; 19:4474-89. [PMID: 20829230 DOI: 10.1093/hmg/ddq379] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
We have established a Drosophila model of Gerstmann-Sträussler-Scheinker (GSS) syndrome by expressing mouse prion protein (PrP) having leucine substitution at residue 101 (MoPrP(P101L)). Flies expressing MoPrP(P101L), but not wild-type MoPrP (MoPrP(3F4)), showed severe defects in climbing ability and early death. Expressed MoPrP(P101L) in Drosophila was differentially glycosylated, localized at the synaptic terminals and mainly present as deposits in adult brains. We found that behavioral defects and early death of MoPrP(P101L) flies were not due to Caspase 3-dependent programmed cell death signaling. In addition, we found that Type 1 glutamatergic synaptic boutons in larval neuromuscular junctions of MoPrP(P101L) flies showed significantly increased numbers of satellite synaptic boutons. Furthermore, the amount of Bruchpilot and Discs large in MoPrP(P101L) flies was significantly reduced. Brains from scrapie-infected mice showed significantly decreased ELKS, an active zone matrix marker compared with those of age-matched control mice. Thus, altered active zone structures at the molecular level may be involved in the pathogenesis of GSS syndrome in Drosophila and scrapie-infected mice.
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Affiliation(s)
- Jin-Kyu Choi
- Ilsong Institute of Life Science, Hallym University, 1605-4 Gwanyangdong Dongangu, Anyang, Gyeonggi-Do, Republic of Korea
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Shin KM, Park JH, Kil HK, Kang SS, Kim IS, Hong SJ, Choi JK. Caudal epidural block in children: comparison of needle insertion parallel with caudal canal versus conventional two-step technique. Anaesth Intensive Care 2010; 38:525-9. [PMID: 20514963 DOI: 10.1177/0310057x1003800318] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
This study compared the technique of inserting the needle for caudal epidural blockade in a single pass parallel to the caudal canal versus the conventional technique of approaching the caudal canal with the needle at a steeper angle. Seventy-five patients, aged 0 to 72 months, scheduled for urological surgery were prospectively enrolled in this study. Patients were randomly divided into two groups: a conventional method group (caudal block performed with conventional needle insertion, n=40) and a new method group (needle inserted into the skin at an angle of 200 and into the caudal space without redirection, n=35). Two anaesthetists (A, B) performed the caudal blocks. For anaesthetist A, the mean time required (standard deviation) to perform needle insertion in the conventional method group was 2.2 (0.8) minutes and in the new method group 1.1 (0.7) minutes (P = 0.03). For anaesthetist B the mean time (standard deviation) to perform needle insertion in the conventional method group was 2.1 (1.1) minutes and in the new method group 1.3 (0.8) minutes (P = 0.04). Successful block was considered as first pass placement of the needle in the caudal canal confirmed (after placement) by ultrasound imaging, and the absence of a bloody tap. Subcutaneous placement of the needle after the first attempt occurred in two cases in the conventional method group and three cases in the new method group. Bloody tap occurred in four cases, all in the conventional method group and none in the new method group. When required, the second pass was successful in all cases.
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Affiliation(s)
- K M Shin
- Department of Anesthesiology and Pain Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea
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Choi JK, Kim KM, Yeom MH, Cho HY, Lee HJ, Park MK, Jeong KC, Lee BI, Noh MS, Lee CH. Antinociceptive Effects of Alpinia katsumadai via Cyclooxygenase-2 Inhibition. Biomol Ther (Seoul) 2010. [DOI: 10.4062/biomolther.2010.18.2.159] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Choi JK, Jang S, Sohn H, Jeong HD. Tuning of Refractive Indices and Optical Band Gaps in Oxidized Silicon Quantum Dot Solids. J Am Chem Soc 2009; 131:17894-900. [DOI: 10.1021/ja9065656] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Jin-Kyu Choi
- Department of Chemistry, Chonnam National University, Gwangju-si 500-757, Korea, and Department of Chemistry, Chosun University, Gwangju-si 501-759, Korea
| | - Seunghyun Jang
- Department of Chemistry, Chonnam National University, Gwangju-si 500-757, Korea, and Department of Chemistry, Chosun University, Gwangju-si 501-759, Korea
| | - Honglae Sohn
- Department of Chemistry, Chonnam National University, Gwangju-si 500-757, Korea, and Department of Chemistry, Chosun University, Gwangju-si 501-759, Korea
| | - Hyun-Dam Jeong
- Department of Chemistry, Chonnam National University, Gwangju-si 500-757, Korea, and Department of Chemistry, Chosun University, Gwangju-si 501-759, Korea
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Sanchez PV, Perry RL, Sarry JE, Perl AE, Murphy K, Swider CR, Bagg A, Choi JK, Biegel JA, Danet-Desnoyers G, Carroll M. A robust xenotransplantation model for acute myeloid leukemia. Leukemia 2009; 23:2109-17. [PMID: 19626050 DOI: 10.1038/leu.2009.143] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Xenotransplantation of human acute myeloid leukemia (AML) in immunocompromised animals has been critical for defining leukemic stem cells. However, existing immunodeficient strains of mice have short life spans and low levels of AML cell engraftment, hindering long-term evaluation of primary human AML biology. A recent study suggested that NOD/LtSz-scid IL2Rgammac null (NSG) mice have enhanced AML cell engraftment, but this relied on technically challenging neonatal injections. Here, we performed extensive analysis of AML engraftment in adult NSG mice using tail vein injection. Of the 35 AML samples analyzed, 66% showed bone marrow engraftment over 0.1%. Further, 37% showed high levels of engraftment (>10%), with some as high as 95%. A 2-44-fold expansion of AML cells was often seen. Secondary and tertiary recipients showed consistent engraftment, with most showing further AML cell expansion. Engraftment did not correlate with French-American-British subtype or cytogenetic abnormalities. However, samples with FLT3 mutations showed a higher probability of engraftment than FLT3 wild type. Importantly, animals developed organomegaly and a wasting illness consistent with advanced leukemia. We conclude that the NSG xenotransplantation model is a robust model for human AML cell engraftment, which will allow better characterization of AML biology and testing of new therapies.
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Affiliation(s)
- P V Sanchez
- Department of Medicine, Division of Hematology and Oncology, University of Pennsylvania, Philadelphia, PA, USA
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Kang SM, Choi JK, Kim SJ, Kim JH, Ahn DG, Oh JW. Regulation of hepatitis C virus replication by the core protein through its interaction with viral RNA polymerase. Biochem Biophys Res Commun 2009; 386:55-9. [PMID: 19501052 PMCID: PMC7092928 DOI: 10.1016/j.bbrc.2009.05.129] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2009] [Accepted: 05/29/2009] [Indexed: 01/12/2023]
Abstract
The hepatitis C virus (HCV) core protein is a structural component of the nucleocapsid and has been shown to modulate cellular signaling pathways by interaction with various cellular proteins. In the present study, we investigated the role of HCV core protein in viral RNA replication. Immunoprecipitation experiments demonstrated that the core protein binds to the amino-terminal region of RNA-dependent RNA polymerase (RdRp), which encompasses the finger and palm domains. Direct interaction between HCV RdRp and core protein led to inhibition of RdRp RNA synthesis activity of in vitro. Furthermore, over-expression of core protein, but not its derivatives lacking the RdRp-interacting domain, suppressed HCV replication in a hepatoma cell line harboring an HCV subgenomic replicon RNA. Collectively, our results suggest that the core protein, through binding to RdRp and inhibiting its RNA synthesis activity, is a viral regulator of HCV RNA replication.
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Affiliation(s)
- Su-Min Kang
- Department of Biotechnology, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul 120-749, Republic of Korea
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Lee K, Lee J, Bae WK, Choi JK, Kim HJ, Cho B. Efficacy of low-calorie, partial meal replacement diet plans on weight and abdominal fat in obese subjects with metabolic syndrome: a double-blind, randomised controlled trial of two diet plans - one high in protein and one nutritionally balanced. Int J Clin Pract 2009; 63:195-201. [PMID: 19196357 DOI: 10.1111/j.1742-1241.2008.01965.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
BACKGROUND Little is known about the relative efficacy of high-protein vs. conventional diet plans that include partial meal replacements on body fat loss in obese subjects with metabolic syndrome. OBJECTIVE We aimed to evaluate the efficacy of two low-calorie diets with partial meal replacement plans-a high-protein plan (HP) and a nutritionally balanced conventional (C) plan-on reducing obesity in obese subjects with metabolic syndrome. DESIGN In a 12-week, double-blind study, we randomised 75 participants to either the HP- or the C-plan group. We recorded key metrics at 0 and 12 weeks. RESULTS The overall mean weight loss was 5 kg in the HP-plan group and 4.9 kg in the C-plan group (p = 0.72). Truncal fat mass decreased 1.6 kg in the HP-plan group (p < 0.05) and 1.5 kg in the C-plan group (p < 0.05), while whole body fat mass decreased 2.5 kg in the HP-plan group (p < 0.05) and 2.3 kg in the C-plan group (p < 0.05). Between-group losses did not differ significantly for truncal (p = 0.52) or whole body (p = 0.77) fat mass. Among subjects with > or = 70% dietary compliance, however, truncal and whole body fat mass decreased more in the HP-plan group (Delta 2.2 kg and Delta 3.5 kg respectively) than in the C-plan group (Delta 1.3 kg and Delta 2.3 [corrected] kg respectively) (p < 0.05). CONCLUSION The HP- and C-plans had a similar effect on weight and abdominal fat reduction, but the HP-plan was more effective in reducing body fat among compliant subjects.
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Affiliation(s)
- K Lee
- Health Promotion Center, Seoul National University Bundang Hospital, Seongnam, Korea
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Jang B, Kim E, Choi JK, Jin JK, Kim JI, Ishigami A, Maruyama N, Carp RI, Kim YS, Choi EK. Accumulation of citrullinated proteins by up-regulated peptidylarginine deiminase 2 in brains of scrapie-infected mice: a possible role in pathogenesis. Am J Pathol 2008; 173:1129-42. [PMID: 18787103 DOI: 10.2353/ajpath.2008.080388] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Peptidylarginine deiminases (PADs), which are a group of posttranslational modification enzymes, are involved in protein citrullination (deimination) by the conversion of peptidylarginine to peptidylcitrulline in a calcium concentration-dependent manner. Among the PADs, PAD2 is widely distributed in various tissues and is the only type that is expressed in brain. To elucidate the involvement of protein citrullination by PAD2 in the pathogenesis of brain-specific prion diseases, we examined the profiles of citrullinated proteins using the brains of scrapie-infected mice as a prion disease model. We found that, compared with controls, increased levels of citrullinated proteins of various molecular weights were detected in different brain sections of scrapie-infected mice. In support of this data, expression levels of PAD2 protein as well as its enzyme activity were significantly increased in brain sections of scrapie-infected mice, including hippocampus, brain stem, and striatum. Additionally, the expression levels of PAD2 mRNA were increased during scrapie infection. Moreover, PAD2 immunoreactivity was increased in scrapie-infected brains, with staining detected primarily in reactive astrocytes. Using two-dimensional electrophoresis and matrix-assisted laser desorption/ionization-time of flight mass spectrometry, various citrullinated proteins were identified in the brains of scrapie-infected mice, including glial fibrillary acidic protein, myelin basic protein, enolases, and aldolases. This study suggests that accumulated citrullinated proteins and abnormal activation of PAD2 may function in the pathogenesis of prion diseases and serve as potential therapeutic targets.
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Affiliation(s)
- Byungki Jang
- Ilsong Institute of Life Science, Hallym University, Anyang, Republic of Korea
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Kasprzycka M, Zhang Q, Witkiewicz A, Marzec M, Potoczek M, Liu X, Wang HY, Milone M, Basu S, Mauger J, Choi JK, Abrams T, Hou S, Rook AH, Vonderheid E, Woetmann A, Odum N, Wasik MA. Gamma c-signaling cytokines induce a regulatory T cell phenotype in malignant CD4+ T lymphocytes. J Immunol 2008; 181:2506-12. [PMID: 18684941 PMCID: PMC2586884 DOI: 10.4049/jimmunol.181.4.2506] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study, we demonstrate that malignant mature CD4(+) T lymphocytes derived from cutaneous T cell lymphomas (CTCL) variably display some aspects of the T regulatory phenotype. Whereas seven cell lines representing a spectrum of primary cutaneous T cell lymphoproliferative disorders expressed CD25 and TGF-beta, the expression of FOXP3 and, to a lesser degree, IL-10 was restricted to two CTCL cell lines that are dependent on exogenous IL-2. IL-2, IL-15, and IL-21, all of which signals through receptors containing the common gamma chain, induced expression of IL-10 in the IL-2-dependent cell lines as well as primary leukemic CTCL cells. However, only IL-2 and IL-15, but not IL-21, induced expression of FOXP3. The IL-2-triggered induction of IL-10 and FOXP3 expression occurred by signaling through STAT3 and STAT5, respectively. Immunohistochemical analysis of the CTCL tissues revealed that FOXP3-expressing cells were common among the CD7-negative enlarged atypical and small lymphocytes at the early skin patch and plaque stages. Their frequency was profoundly diminished at the tumor stage and in the CTCL lymph node lesions with or without large cell transformation. These results indicate that the T regulatory cell features are induced in CTCL T cells by common gamma chain signaling cytokines such as IL-2 and do not represent a fully predetermined, constitutive phenotype independent of the local environmental stimuli to which these malignant mature CD4(+) T cells become exposed.
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MESH Headings
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD4-Positive T-Lymphocytes/pathology
- Cell Line, Tumor
- Cytokines/physiology
- Disease Progression
- Forkhead Transcription Factors/biosynthesis
- Humans
- Immunophenotyping
- Interleukin Receptor Common gamma Subunit/physiology
- Interleukin-10/metabolism
- Interleukin-15/physiology
- Interleukin-2/physiology
- Interleukin-2 Receptor alpha Subunit/biosynthesis
- Leukemia, T-Cell/immunology
- Leukemia, T-Cell/metabolism
- Leukemia, T-Cell/pathology
- Lymphoma, T-Cell, Cutaneous/immunology
- Lymphoma, T-Cell, Cutaneous/metabolism
- Lymphoma, T-Cell, Cutaneous/pathology
- Signal Transduction/immunology
- Skin Neoplasms/immunology
- Skin Neoplasms/metabolism
- Skin Neoplasms/pathology
- T-Lymphocytes, Regulatory/immunology
- T-Lymphocytes, Regulatory/metabolism
- T-Lymphocytes, Regulatory/pathology
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Affiliation(s)
- M Kasprzycka
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - Q Zhang
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - A Witkiewicz
- Department of Pathology, Jefferson Medical College, Philadelphia, PA
| | - M Marzec
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - M Potoczek
- Department of Pathology, Jefferson Medical College, Philadelphia, PA
| | - X Liu
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - HY Wang
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - M Milone
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - S Basu
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - J Mauger
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - JK Choi
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - T Abrams
- Lankenau Institute for Medical Research, Wynnewood, PA
| | - S Hou
- Department of Pathology, Drexel University, Philadelphia, PA
| | - AH Rook
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA
| | - E Vonderheid
- Department of Dermatology, John Hopkins University, Baltimore, MD
| | - A Woetmann
- Institute of Molecular Biology, University of Copenhagen, Copenhagen, Denmark
| | - N Odum
- Institute of Molecular Biology, University of Copenhagen, Copenhagen, Denmark
| | - MA Wasik
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
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42
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Lee HP, Choi JK, Shin HY, Jeon YC, Jeong BH, Kim JI, Carp RI, Kim YS. P4-235: Altered expression of type 1 inositol 1,4,5 trisphosphate receptor in the Ngsk PRNP deficient mice. Alzheimers Dement 2008. [DOI: 10.1016/j.jalz.2008.05.2303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Hyun-Pil Lee
- Ilsong Institute of Life Science, Hallym University; Anyang Republic of Korea
| | - Jin-Kyu Choi
- Ilsong Institute of Life Science, Hallym University; Anyang Republic of Korea
| | - Hae-Young Shin
- Ilsong Institute of Life Science, Hallym University; Anyang Republic of Korea
| | - Yong-Chul Jeon
- Ilsong Institute of Life Science, Hallym University; Anyang Republic of Korea
| | - Byung-Hoon Jeong
- Ilsong Institute of Life Science, Hallym University; Anyang Republic of Korea
| | - Jae-Il Kim
- Department of Physiology & Biophysics; Case Western Reserve University; Cleveland OH USA
| | - Richard I. Carp
- New York State Institute for Basic Research in Developmental Disabilities; Staten Island NY USA
| | - Yong-Sun Kim
- Ilsong Institute of Life Science, Hallym University; Anyang Republic of Korea
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43
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Hong JS, Ohnishi S, Masuta C, Choi JK, Ryu KH. Infection of soybean by cucumber mosaic virus as determined by viral movement protein. Arch Virol 2007; 152:321-8. [PMID: 17006598 DOI: 10.1007/s00705-006-0847-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2006] [Accepted: 08/07/2006] [Indexed: 11/24/2022]
Abstract
To characterize the host range determinant of the soybean strain of Cucumber mosaic virus (CMV) we analyzed a series of pseudorecombinants and chimeric viruses between infectious transcripts from two soybean strains (CMV-SC and CMV-SD) and an ordinary strain (CMV-Y). CMV-Y could not infect soybeans, even locally. Systemic infection of the two soybean-adapted soybean isolates on soybean plants mapped to RNA3. Chimeric RNA3s from between CMV-SC and CMV-Y, and chimeric RNA3s from between CMV-SC and CMV-SD, were made and inoculated onto wild soybean Iwate and soybean cv. Tsurunoko. The 3a region determined the viral systemic movement in the plants. In the wild soybean ecotype Hyougo, cell-to-cell movement of two different CMV soybean strains, one of which infects systemically while the other does not, in the inoculated leaves were almost the same, suggesting that the resistance of soybean operates at the level of long-distance movement. Our results clearly suggest that movement protein is a host determinant of CMV soybean strains.
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Affiliation(s)
- J S Hong
- Plant Virus GenBank, Division of Environment and Life Sciences, Seoul Women's University, Seoul, Republic of Korea
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44
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Choi JK, Park SJ, Jun YC, Oh JM, Jeong BH, Lee HP, Park SN, Carp RI, Kim YS. Generation of monoclonal antibody recognized by the GXXXG motif (glycine zipper) of prion protein. Hybridoma (Larchmt) 2006; 25:271-7. [PMID: 17044782 DOI: 10.1089/hyb.2006.25.271] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
To develop monoclonal antibodies (MAbs) to react with normal prion protein (PrPC) and abnormal isoform of prion protein (PrPSc), PrPSc was isolated from brains of 263 K scrapie-infected hamsters and immunized to PrP knockout mice. We developed two hybridomas, 3F10 and 1C5 (IgG1), of which epitope mappings were screened by using glutathione S-transferase (GST) fusion proteins of recombinant hamster prion protein and suitable peptides. 3F10 showed a high affinity for hamster and mouse PrP and was demonstrated to recognize the residues 137-151. 1C5 recognizes the region 119-130 corresponding to the GXXXG motif, the glycine zipper region, conserved in all mammals. In the immunohistochemical analysis, the positive staining for PrPSc was observed in the extracellular compartment of scrapie-infected brains but not in the normal brains. However, in Western blot, these antibodies recognized both normal and abnormal prion proteins. These results suggested that the developed mouse MAbs are specific to prion protein and can recognize abnormal prion protein more effectively than normal prion protein in immunohistochemistry. Therefore, these antibodies could be utilized as a useful reagent for the analysis of biochemical, structural, and functional properties between PrPC and PrPSc.
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Affiliation(s)
- Jin-Kyu Choi
- Ilsong Institute of Life Science, College of Medicine, Hallym University, Kyeonggi-Do, Republic of Korea
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45
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Choi EK, Kim EA, Choi JK, Park ES, Ishigami A, Kim YS. P4–122: Abnormal accumulation of citrullinated proteins in scrapie–infected mouse brain. Alzheimers Dement 2006. [DOI: 10.1016/j.jalz.2006.05.1861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Eun-Kyoung Choi
- Ilsong Institute of Life Science, Hallym UniversityAnyangKyonggi-doRepublic of Korea
| | - Eun-Ah Kim
- Ilsong Institute of Life Science, Hallym UniversityAnyangKyonggi-doRepublic of Korea
| | - Jin-Kyu Choi
- Ilsong Institute of Life Science, Hallym UniversityAnyangKyonggi-doRepublic of Korea
| | - Eun-Su Park
- Ilsong Institute of Life Science, Hallym UniversityAnyangKyonggi-doRepublic of Korea
| | | | - Yong-Sun Kim
- Ilsong Institute of Life Science, Hallym UniversityAnyangKyonggi-doRepublic of Korea
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46
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Ahn HI, Yoon JY, Hong JS, Yoon HI, Kim MJ, Ha JH, Rhie MJ, Choi JK, Park WM, Ryu KH. The complete genome sequence of pepper severe mosaic virus and comparison with other potyviruses. Arch Virol 2006; 151:2037-45. [PMID: 16699829 DOI: 10.1007/s00705-006-0776-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2006] [Accepted: 04/04/2006] [Indexed: 11/26/2022]
Abstract
The complete nucleotide sequence of pepper severe mosaic virus (PepSMV) was determined. The viral genome consisted of 9890 nucleotides, excluding a poly (A) tract at the 3' end of the genome. The PepSMV RNA genome encoded a single polyprotein of 3085 amino acid residues, resulting in ten functionally distinct potyviral proteins. The lengths of the 5' nontranslated region (NTR) and the 3' NTR were 164 and 468 nucleotides, respectively. The genome organization of the virus was typical for members of the genus Potyvirus in the family Potyviridae. The coat protein amino acid sequence identity between PepSMV and the other 45 potyviruses ranged from 53.4 to 79.7%. Sequence alignments and phylogenetic analyses of the potyviral polyprotein sequences revealed that PepSMV was the closest to potato virus Y (PVY) and closely related to members of the PVY subgroup. Our genome sequence data clearly confirmed that PepSMV belongs to a separate species in the genus Potyvirus.
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Affiliation(s)
- H I Ahn
- Plant Virus GenBank, Division of Environmental and Life Sciences, Seoul Women's University, Seoul, Republic of Korea
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47
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Abstract
This study was undertaken to examine the photocatalytic degradation of explosives hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) with a circular photocatalytic reactor, using a UV lamp as a light source and TiO2 as a photocatalyst. The effects of various parameters, such as the RDX or HMX concentration, the amount of TiO, and the initial pH, on the photocatalytic degradation rates of explosives were examined. In the presence of both UV light and TiO2 RDX and HMX were more effectively degraded than with either UV or TiO2 alone. The degradation rates were found to obey pseudo-first-order kinetics represented by the Langmuir-Hinshelwood model. Increases in the RDX and HMX degradation rates were obtained with decreasing initial concentrations of the explosives. The RDX and HMX degradation rates were higher at pH 7 than at either pH 3 or pH 11. A dose of approximately 0.7 g l(-1) of TiO2 degraded HMX more rapidly than did higher or lower TiO2 doses. RDX (20 mg l(-1)) photocatalysis resulted in an approximately 20% decrease in TOC, and HMX (5 mg l(-1)) photocatalysis resulted in a 60%, decrease in TOC within 150 minutes. A trace amount of formate was produced as an intermediate that was further mineralized by RDX or HMX photocatalysis. The nitrogen byproducts from the photocatalysis of RDX and HMX were mainly NO3- with NO2-, and NH4+. The total nitrogen recovery was about 60% from RDX (20 mg l(-1)), and 70% from HMX (5 mg l(-1)), respectively. Finally, a mechanism for RDX/HMX photocatalysis was proposed, along with supporting qualitative and quantitative evidence.
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Affiliation(s)
- J K Choi
- Institute of Health and Environment, School of Public Health, Seoul National University, Seoul 110-799, Republic of Korea
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48
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Choi JK, Lee HP, Choi EK, Jin JK, Lee HG, Wasco W, Buxbaum JD, Carp RI, Kim YS. Increased Expression of Calsenilin in the Brains of Scrapie-infected Mice. Ann N Y Acad Sci 2006. [DOI: 10.1111/j.1749-6632.2001.tb05682.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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49
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Abstract
We investigated the expression, activation and distribution of c-Jun N-terminal kinases (JNKs), p38 mitogen-activated protein kinases (p38 MAPKs) and extracellular signal-regulated kinases (ERKs), using western blotting and immunohistochemistry, in the brains of hamsters infected with 263K scrapie agent, to clarify the role of these kinases in the pathogenesis of prion disease. The immunoblot analysis demonstrated that activation of JNK, p38 MAPK and ERK in whole brain homogenates was increased in infected animals. Phosphorylation of cAMP/calcium responsive element binding protein (CREB), a downstream transcription factor of active ERK, was significantly increased in scrapie-infected hamsters. The immunohistochemical study showed that active ERK was enhanced in infected hamsters compared with controls. Active ERK immunoreactivity was observed within neurons in the dentate gyrus and in glial fibrillary acidic protein (GFAP)-positive reactive astrocytes of infected animals. The expression level of c-Jun mRNA as well as protein, a substrate of active JNK, was increased in infected animals. A significant increase in JNK activity upon glutathione S-transferase (GST)-c-Jun was observed in infected compared with control animals. Phospho-c-Jun immunoreactivity was observed only in neurons of the thalamus in infected groups. These findings indicated that the JNK pathway was activated in the scrapie-infected group. The chronological activation of MAPKs using immunoblot analysis indicates that the kinases are sequentially activated during the pathophysiology of prion disease. Taken together, these results lend credence to the notion that MAPK pathways are dysregulated in prion disease, and also indicate an active role for this pathway in disease pathogenesis.
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Affiliation(s)
- Hyun-Pil Lee
- Ilsong Institute of Life Science, Hallym University, Anyang, Kyeonggi-Do, Republic of Korea
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50
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Abstract
C-terminal Src Kinase (Csk) is a cytoplasmic tyrosine kinase that phosphorylates a critical tyrosine residue in each of the Src family kinases to inhibit their activities. To investigate the possible regulation of spermatogenesis by Src-Csk loop, the postnatal changes in the expression of Csk were examined in mouse testes. Semiquantitative RT-PCR analysis revealed that Csk mRNA increased during neonatal development and peaked at 2 weeks of age. Following the decrease during pubertal development, Csk expression re-increased in adult testes. In Western blot, immature testes showed higher expression of Csk protein than the pubertal or adult testes. In immature testis, Csk immunoreactivity was largely found in the Sertoli cell and there was no visible difference in the Csk immunoreactivity among the seminiferous tubules. In adult testis, however, a differential Csk immunoreactivity was found among the seminiferous tubules. Intense signal was found in the adluminal cytoplasm of the Sertoli cells bearing the post-meiotic differentiating germ cells, suggesting that Csk may participate in the remodeling of seminiferous tubule during late phase of spermatogenesis. Csk immunoreactivity was also found in the Leydig cells, suggesting the possible regulation of Leydig cell function. Src-Csk loop may participate in the differentiation of the seminiferous epithelia and Leydig cells in mouse testis.
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Affiliation(s)
- M C Gye
- Department of Life Science, College of Natural Sciences, Hanyang University, Seoul, Korea.
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