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Cao J, Zheng HS, Zhang R, Xu YP, Pan H, Li S, Liu C, Cheng TC. Dimmed gene knockout shortens larval growth and reduces silk yield in the silkworm, Bombyx mori. Insect Mol Biol 2023; 32:26-35. [PMID: 36082617 DOI: 10.1111/imb.12810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 08/30/2022] [Indexed: 06/15/2023]
Abstract
The bHLH domain transcription factor, Bombyx mori-derived dimmed (Bmdimm), is directly regulated by the JH-BmMet/BmSRC-BmKr-h1 pathway and plays a key role in regulating the expression of FibH, which codes the main component of silk protein. However, the other roles of Bmdimm in silk protein synthesis remain unclear. Here, we established a Bmdimm knockout (KO) line containing a 7-bp deletion via CRISPR/Cas9 system, which led to the absence of the bHLH domain. The expression level of silk protein genes and silk yield decreased significantly in the Bmdimm KO line. Moreover, knocking out Bmdimm led to shortened larval stages and significant weight loss in larvae and adults. Bmdimm was found to be highly expressed in the silk gland, but it was also expressed in the fat body. The expression level of Bmkr-h1 in the fat body was significantly downregulated in the Bmdimm KO line. Exogenous JHA treatment upregulated Bmkr-h1 and rescued the phenotype of larval growth in the Bmdimm KO line. In conclusion, knocking out Bmdimm led to a shortened larval stage via the inhibition of Bmkr-h1 expression, then reduced silk yield. These findings help to elucidate the regulatory mechanism of fibroin synthesis and larval development in silkworms.
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Affiliation(s)
- Jun Cao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Hong-Sheng Zheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Ran Zhang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Yong-Ping Xu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Huan Pan
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Shan Li
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
| | - Chun Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
| | - Ting-Cai Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Cancer Center, Medical Research Institute, Southwest University, Chongqing, China
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Cheng TC, Arnold ADA, Chow JC, Shun-Shin MJSS, Howard JPH, Keene DK, Ali NA, Miyazawa AM, Varnava AV, Kanagaratnam PK, Ng FSN, Peters NSP, Francis DPF, Whinnett ZIW. His resynchronization therapy produces more physiological ventricular repolarisation compared with biventricular pacing. Europace 2021. [DOI: 10.1093/europace/euab116.441] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abstract
Funding Acknowledgements
Type of funding sources: Foundation. Main funding source(s): British Heart Foundation
BACKGROUND
Biventricular pacing (BVP) is known to shorten activation time in patients with heart failure and left bundle branch block (LBBB) but its effects on repolarisation are not well studied. His bundle pacing (HBP) can correct LBBB to deliver cardiac resynchronization therapy (HBP-CRT), producing more physiological ventricular activation time and pattern than BVP. It is not known whether this translates to more physiological repolarisation, and if so whether the effect is mediated through its effects on activation.
PURPOSE
We measured the effects of HBP-CRT and BVP on left ventricular repolarisation using non-invasive epicardial mapping (ECGI).
METHODS
Patients were recruited in two groups. 1) Patients scheduled for clinically indicated BVP procedures for heart failure with LBBB, 2) Individuals with narrow QRS, normal ventricular function and intact conduction systems. Using non-invasive electrocardiographic imaging, we identified patients with LBBB in whom HBP shortened ECGI-derived left ventricular (LV) activation time by >10ms. We compared the effects of HBP and BVP on ECGI-derived dispersion of LV repolarisation times and activation-recovery intervals (a surrogate for action potential duration).
RESULTS
21 patients in whom HBP shortened LV activation time by >10ms and an equal number of individuals with narrow intrinsic QRS were recruited. LV repolarisation dispersion was reduced by HBP-CRT (-42.0 ms, 95% confidence interval (CI): -52.3 to -31.7 ms, p <0.001) but not by BVP (11.9 ms, 95% CI: -6.24 to 30.1 ms, p = 0.182). The mean within-patient change in LV repolarisation dispersion from BVP to HBP-CRT was -56.5 ms (95% CI: -70.5 to -42.5 ms, p < 0.001). LV repolarisation dispersion with HBP-CRT was not different from individuals with narrow intrinsic QRS (2.75 ms, 95% CI: -16.2 to 21.7 ms, p = 0.981). The magnitude of reduction in LV repolarisation dispersion with HBP-CRT from intrinsic LBBB appeared similar to the magnitude of LV activation time shortening (-54.9 ms, 95% CI: -68.2 to -41.6 ms, p < 0.001). However, LV activation-recovery interval dispersion was also reduced by HBP-CRT (-44.3 ms, 95% CI: -69.2 to -19.3 ms, p < 0.001). Repolarisation mapping demonstrated normalisation of repolarisation pattern by HBP-CRT.
CONCLUSIONS
HBP-CRT can normalise repolarisation dispersion, producing more physiological repolarisation compared with BVP, which does not resolve the repolarisation abnormality of LBBB. HBP-CRT improves repolarisation through both activation resynchronization and modulation of action-potential duration. If these acute results translate to longer term outcomes, HBP-CRT may reduce the risk of ventricular arrhythmias in heart failure with LBBB to a greater extent than BVP. Abstract Figure. Epicardial Repolarisation Maps
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Affiliation(s)
- TC Cheng
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - ADA Arnold
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - JC Chow
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - MJS-S Shun-Shin
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - JPH Howard
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - DK Keene
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - NA Ali
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - AM Miyazawa
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - AV Varnava
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - PK Kanagaratnam
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - FSN Ng
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - NSP Peters
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - DPF Francis
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
| | - ZIW Whinnett
- National Heart and Lung Institute Imperial College, London, United Kingdom of Great Britain & Northern Ireland
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Pi GL, Bi JP, He HP, Li Y, Cheng TC, Li YP. [The protective effect of optimized target delineation in intensity modulated radiation therapy on swallowing function in patients with different TNM staging of nasopharyngeal carcinoma]. Lin Chung Er Bi Yan Hou Tou Jing Wai Ke Za Zhi 2018; 32:617-620. [PMID: 29798149 DOI: 10.13201/j.issn.1001-1781.2018.08.015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Indexed: 11/12/2022]
Abstract
Objective:To investigate the protective effect of optimized target delineation in intensity modulated radiation therapy(IMRT) on swallowing function in patients with different TNM staging of nasopharyngeal carcinoma.Method:Fifty patients with nasopharyngeal carcinoma were enrolled in this study. They were randomly divided into 25 cases of experimental group and 25 cases of control group by random number table and received IMRT treatment. Patients in control group only received routine delineation of target areas, the patients in experimental group were given the delineation of the relevant parts of the swallowing on the basis of the control group.And then, the degree of dysphagia, xerostomia, weight loss, and quality of life were assessed in the two groups of patients during and after IMRT.Result:There was no significant change in the degree of dysphagia in stage Ⅱ patients during radiotherapy, but the degree of dysphagia in stage Ⅲ and Ⅳ patients increased with the increase of radiotherapy time. After the end of radiotherapy, there was no significant change in the degree of dysphagia in the control group of patients. Compared with the 0th week after the end of radiotherapy, the stage Ⅱ patients in experimental group showed significant improvement in week 12(P<0.05), while the stage Ⅲ and Ⅳ patients showed significant improvement in week 24 after radiotherapy(P<0.05). The degree of xerostomia of two groups of patients continued to increase with varying degrees during and after IMRT(P<0.05 or P<0.01). The weight of the two groups of patients during radiotherapy continued to decrease with the increase of radiotherapy time,and gradually recovered after the end of radiotherapy.And in the experimental group, the weight loss was significantly lower in week 12 and week 24 than in the control group (P<0.05). During radiotherapy, the quality of life scores of the two groups became lower and lower with the increase of radiotherapy time compared with the 0th week of radiotherapy. After the end of radiotherapy, the quality of life began to gradually improve, and in week 24 after the end of radiotherapy, the quality of life of the experimental group of patients was significantly higher than that of the control group (P<0.05).Conclusion:During radiotherapy of patients with nasopharyngeal carcinoma, the structural organs associated with swallowing function are given individualized target delineation can reduce the occurring of dysphagia due to radiotherapy and improve the quality of life of patients after radiotherapy.
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Affiliation(s)
- G L Pi
- Head and Neck Radiotherapy Ward 1, Hubei Cancer Hospital, Wuhan, 430079, China
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Edney LC, Haji Ali Afzali H, Cheng TC, Karnon J. Mortality reductions from marginal increases in public spending on health. Health Policy 2018; 122:892-899. [PMID: 29759682 DOI: 10.1016/j.healthpol.2018.04.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [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: 08/09/2017] [Revised: 04/20/2018] [Accepted: 04/21/2018] [Indexed: 10/17/2022]
Abstract
There is limited empirical evidence of the nature of any relationship between health spending and health outcomes in Australia. We address this by estimating the elasticity of health outcomes with respect to public healthcare spending using an instrumental variable (IV) approach to account for endogeneity of healthcare spending to health outcomes. Results suggest that, based on the conditional mean, a 1% increase in public health spending was associated with a 2.2% (p < 0.05) reduction in the number of standardised Years of Life Lost (YLL). Sensitivity analyses and robustness checks supported this conclusion. Further exploration using IV quantile regression indicated that marginal returns on public health spending were significantly greater for areas with poorer health outcomes compared to areas with better health outcomes. On average, marginal increases in public health spending reduce YLL, but areas with poorer health outcomes have the greatest potential to benefit from the same marginal increase in public health spending compared to areas with better health outcomes. Understanding the relationship between health spending and outcomes and how this differs according to baseline health outcomes can help meet dual policy objectives to improve the productivity of the healthcare system and reduce inequity.
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Affiliation(s)
- L C Edney
- School of Public Health, University of Adelaide, Level 9, Adelaide Health and Medical Sciences Building, The University of Adelaide, 5005, Australia.
| | - H Haji Ali Afzali
- School of Public Health, University of Adelaide, Level 9, Adelaide Health and Medical Sciences Building, The University of Adelaide, 5005, Australia
| | - T C Cheng
- School of Economics, University of Adelaide, Level 4, 10 Pulteney Street, The University of Adelaide, 5005, Australia
| | - J Karnon
- School of Public Health, University of Adelaide, Level 9, Adelaide Health and Medical Sciences Building, The University of Adelaide, 5005, Australia
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Cheung TK, Cheng TC, Wong LY. Willingness for deceased organ donation under different legislative systems in Hong Kong: population-based cross-sectional survey. Hong Kong Med J 2018; 24:119-127. [PMID: 29633715 DOI: 10.12809/hkmj176831] [Citation(s) in RCA: 2] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
INTRODUCTION Under the current opt-in system, the deceased organ donation rate remains low in Hong Kong. An opt-out system and an opt-in system combined with organ allocation priority (ie, priority to donors as transplant recipients) have been proposed to encourage willingness among the general population towards deceased organ donation. This study aimed to compare willingness, and its determinants, across these three legislative systems. METHODS A random telephone survey of Hong Kong permanent residents aged ≥18 years was conducted between August and October 2016 using an anonymous questionnaire. Willingness towards deceased organ donation was compared between the legislative systems with McNemar's test. Determinants of willingness were tested by logistic regression. RESULTS The proportion of those willing to consider deceased organ donation under the current opt-in system would significantly increase after combining it with allocation priority (64.5% vs 73.4%; P=0.018). "Fairness or reciprocity" was the major reported reason underlying the increase. In contrast, willingness would decrease after introducing the opt-out system (60.1%), although not significantly (P=0.336). The reduction might be attributable to a "belief of being forced to donate". Under the allocation priority system, reduced willingness to donate was associated with advanced age, lower educational attainment, and lower monthly household income. Under the opt-out system, reduced willingness was associated with being married, having a lower household income, and distrust of local government. CONCLUSIONS An opt-in system with allocation priority could induce willingness to donate, whereas an opt-out system may reduce willingness. The findings have implications for policy-making and promotion of organ donation.
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Affiliation(s)
- T K Cheung
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
| | - T C Cheng
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
| | - L Y Wong
- The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong
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Cheng TC, Long RW, Wu YQ, Guo YB, Liu DL, Peng L, Li DQ, Yang DW, Xu X, Liu FX, Xia QY. Identification and characterization of toxins in the venom gland of the Chinese bird spider, Haplopelma hainanum, by transcriptomic analysis. Insect Sci 2016; 23:487-499. [PMID: 26678257 DOI: 10.1111/1744-7917.12305] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 12/02/2015] [Indexed: 06/05/2023]
Abstract
Tarantula venoms provide a model system for studying toxin selectivity, structure-activity relationships and molecular evolution of peptide toxins. Previous studies have identified a large number of peptide toxins in the venom of the Chinese bird spider Haplopelma hainanum, generally regarded as a highly venomous spider. However, the lack of available RNA-seq transcriptomic and genomic data is an obstacle to understanding its venom at the molecular level. In this study, we investigated the venom gland transcriptome of H. hainanum by RNA-seq, in the absence of an available genomic sequence. We identified 201 potential toxins among 57 181 de novo assembled transcripts, including knottins, Kunitz-type toxins, enzymes and other proteins. We systematically identified most of the knottins and Kunitz-type toxins, some of which showed strongly biased expression in the venom gland, including members of the huwentoxin-1, huwentoxin-2 and magi-1 families. We also discovered several novel potential toxins. These data demonstrate the high molecular and structural diversity in the venom toxins of H. hainanum. This study offers a useful strategy for exploring the complex components of spider venoms.
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Affiliation(s)
- Ting-Cai Cheng
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Ren-Wen Long
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Yu-Qian Wu
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - You-Bing Guo
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Duo-Lian Liu
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Li Peng
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
| | - Dai-Qin Li
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Dai-Wen Yang
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Xin Xu
- College of Life Sciences, Hunan Normal University, Changsha, China
- College of Life Sciences, Hubei University, Wuhan, China
| | - Feng-Xiang Liu
- College of Life Sciences, Hubei University, Wuhan, China
| | - Qing-You Xia
- State Key Laboratory of Silkworm Genome Biology, College of Biotechnology, Southwest University, Chongqing, China
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Hua XT, Ma XJ, Xue RJ, Cheng TC, Wang F, Xia QY. Characterization of the Bombyx mori Cecropin A1 promoter regulated by IMD pathway. Insect Sci 2016; 23:297-304. [PMID: 25684679 DOI: 10.1111/1744-7917.12210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/18/2015] [Indexed: 06/04/2023]
Abstract
Cecropin A1 (CecA1) promoter from Bombyx mori was cloned and characterized to provide insight into the transcriptional control of this antimicrobial peptide gene upon immune challenges. Reporter gene assays demonstrated that both Escherichia coli and lipopolysaccharide could induce expression in BmE cells but B. bombyseptieus or peptidoglycan failed, and the induction pattern of the reporter gene was coincident with the endogenous CecA1. Analysis of deletion and mutation constructs revealed that the regulatory region was the κB motif located between -176 and -166, and no other predicted elements on CecA1 promoter affected its inducibility. Insertion of additional κB motifs increased the activity of CecA1 promoter. Furthermore, binding of Relish to κB motif was confirmed by electrophoretic mobility shift assay. These findings indicate the regulatory mechanism of CecA1 expression in IMD pathway and suggest an approach of engineering antimicrobial peptide promoter with enhanced activities that may lead to broad applications.
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Affiliation(s)
- Xiao-Ting Hua
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
| | - Xiao-Juan Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
| | - Ren-Ju Xue
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
| | - Ting-Cai Cheng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
| | - Fei Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
| | - Qing-You Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, 400716, China
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Zhao XM, Liu C, Jiang LJ, Li QY, Zhou MT, Cheng TC, Mita K, Xia QY. A juvenile hormone transcription factor Bmdimm-fibroin H chain pathway is involved in the synthesis of silk protein in silkworm, Bombyx mori. J Biol Chem 2015; 290:972-86. [PMID: 25371208 PMCID: PMC4294524 DOI: 10.1074/jbc.m114.606921] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 11/03/2014] [Indexed: 01/16/2023] Open
Abstract
The genes responsible for silk biosynthesis are switched on and off at particular times in the silk glands of Bombyx mori. This switch appears to be under the control of endogenous and exogenous hormones. However, the molecular mechanisms by which silk protein synthesis is regulated by the juvenile hormone (JH) are largely unknown. Here, we report a basic helix-loop-helix transcription factor, Bmdimm, its silk gland-specific expression, and its direct involvement in the regulation of fibroin H-chain (fib-H) by binding to an E-box (CAAATG) element of the fib-H gene promoter. Far-Western blots, enzyme-linked immunosorbent assays, and co-immunoprecipitation assays revealed that Bmdimm protein interacted with another basic helix-loop-helix transcription factor, Bmsage. Immunostaining revealed that Bmdimm and Bmsage proteins are co-localized in nuclei. Bmdimm expression was induced in larval silk glands in vivo, in silk glands cultured in vitro, and in B. mori cell lines after treatment with a JH analog. The JH effect on Bmdimm was mediated by the JH-Met-Kr-h1 signaling pathway, and Bmdimm expression did not respond to JH by RNA interference with double-stranded BmKr-h1 RNA. These data suggest that the JH regulatory pathway, the transcription factor Bmdimm, and the targeted fib-H gene contribute to the synthesis of fibroin H-chain protein in B. mori.
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Affiliation(s)
- Xiao-Ming Zhao
- From the State Key Laboratory of Silkworm Genome Biology and Key Sericultural Laboratory of the Ministry of Agriculture, College of Bio-Technology, Southwest University, Chongqing 400716 and the Research Institute of Applied Biology, Shanxi University, Taiyuan, Shanxi 030006, China
| | - Chun Liu
- From the State Key Laboratory of Silkworm Genome Biology and Key Sericultural Laboratory of the Ministry of Agriculture, College of Bio-Technology, Southwest University, Chongqing 400716 and
| | - Li-Jun Jiang
- From the State Key Laboratory of Silkworm Genome Biology and Key Sericultural Laboratory of the Ministry of Agriculture, College of Bio-Technology, Southwest University, Chongqing 400716 and
| | - Qiong-Yan Li
- From the State Key Laboratory of Silkworm Genome Biology and Key Sericultural Laboratory of the Ministry of Agriculture, College of Bio-Technology, Southwest University, Chongqing 400716 and
| | - Meng-Ting Zhou
- From the State Key Laboratory of Silkworm Genome Biology and Key Sericultural Laboratory of the Ministry of Agriculture, College of Bio-Technology, Southwest University, Chongqing 400716 and
| | - Ting-Cai Cheng
- From the State Key Laboratory of Silkworm Genome Biology and Key Sericultural Laboratory of the Ministry of Agriculture, College of Bio-Technology, Southwest University, Chongqing 400716 and
| | - Kazuei Mita
- From the State Key Laboratory of Silkworm Genome Biology and
| | - Qing-You Xia
- From the State Key Laboratory of Silkworm Genome Biology and Key Sericultural Laboratory of the Ministry of Agriculture, College of Bio-Technology, Southwest University, Chongqing 400716 and
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Young JW, Cheng TC, Bandyopadhyay B, Duncan MA. IR photodissociation spectroscopy of H7(+), H9(+), and their deuterated analogues. J Phys Chem A 2013; 117:6984-90. [PMID: 23374094 DOI: 10.1021/jp312630x] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cluster ions of H7(+)/D7(+) and H9(+)/D9(+) produced in a supersonic molecular beam with a pulsed discharge source are mass selected and studied with infrared laser photodissociation spectroscopy. Photodissociation occurs by the loss of H2 (D2) from each cluster, producing resonances in the 2000-4500 cm(-1) region. Vibrational patterns indicate that these ions consist of an H3(+) (D3(+)) core ion solvated by H2 (D2) molecules. There is no evidence for the shared proton structure seen previously for H5(+). The H3(+) ion core vibrational bands are weakened and broadened significantly, presumably by enhanced rates of intramolecular vibrational relaxation. Computational studies at the DFT/B3LYP or MP2 levels of theory (including scaling) are adequate to reproduce qualitative details of the vibrational spectra, but neither provides quantitative agreement with vibrational frequencies.
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Affiliation(s)
- J W Young
- Department of Chemistry, University of Georgia, Athens, Georgia 30602, USA
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Abstract
The Argonaute protein family is a highly conserved group of proteins, which have been implicated in RNA silencing in both plants and animals. Here, four members of the Argonaute family were systemically identified based on the genome sequence of Bombyx mori. Based on their sequence similarity, BmAgo1 and BmAgo2 belong to the Ago subfamily, while BmAgo3 and BmPiwi are in the Piwi subfamily. Phylogenetic analysis reveals that silkworm Argonaute family members are conserved in insects. Conserved amino acid residues involved in recognition of the 5' end of the small RNA guide strand and of the conserved (aspartate, aspartate and histidine [DDH]) motif present in their PIWI domains suggest that these four Argonaute family members may have conserved slicer activities. The results of microarray expression analysis show that there is a low expression level for B. mori Argonaute family members in different tissues and different developmental stages, except for BmPiwi. All four B. mori Argonaute family members are upregulated upon infection with B. mori nucleopolyhedrovirus. The complete coding sequence of BmPiwi, the homolog of Drosophila piwi, was cloned and its expression occurred mainly in the area where spermatogonia and spermatocytes appear. Our results provide an overview of the B. mori Argonaute family members and suggest that they may have multiple roles. In addition, this is also the first report, to our knowledge, of the response of RNA silencing machinery to DNA virus infection in insects.
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Affiliation(s)
- Gen-Hong Wang
- State Key Laboratory of Silkworm Genome Biology, School of Biotechnology, Southwest, Chongqing, China
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Abstract
In this paper, we present a selective and differential medium, termed Vibrio alginolyticus (VAL) agar, developed for the isolation and identification of V. alginolyticus. The presence of bile salts, high salinity and high incubation temperature allows the selective growth of moderately halophilic Vibrio species. Differentiation of bacteria is achieved by identifying species capable of sucrose fermentation, made visible by the pH indicator bromocresol purple. In this study, all of the 26 strains of V. alginolyticus and only three of the 99 strains representing 30 species (including 19 Vibrio species) other than V. alginolyticus were able to grow in the VAL medium. The remaining three strains could be further differentiated from V. alginolyticus according to colour or the diameter of colonies produced on VAL agar plates. Colonies isolated from shellfish rearing water and infected shrimp through the use of VAL agar plates were all positively identified as V. alginolyticus by conventional tests and 16S rDNA sequencing. The testing of specificity and differentiation capability of VAL shows the potential of the agar as a medium for the primary isolation of V. alginolyticus from pathological and environmental samples.
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Affiliation(s)
- C-I Chang
- Aquaculture Division, Fisheries Research Institute, Council of Agriculture, Keelung, Taiwan.
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Lin TC, Truong TK, Chen SH, Wang LJ, Cheng TC. Simplified 2-D cubic spline interpolation scheme using direct computation algorithm. IEEE Trans Image Process 2010; 19:2913-2923. [PMID: 20494853 DOI: 10.1109/tip.2010.2050723] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
It has been shown that the 2-D cubic spline interpolation (CSI) proposed by Truong et al. is one of the best algorithms for image resampling or compression. Such a CSI algorithm together with the image coding standard, e.g., JPEG, can be used to obtain a modified image codec while still maintaining a good quality of the reconstructed image for higher compression ratios. In this paper, a fast direct computation algorithm is developed to improve the computational efficiency of the original FFT-based 2-D CSI methods. In fact, this algorithm computes the 2-D CSI directly without explicitly calculating the complex division usually needed in the FFT or Winograd discrete Fourier transform (WDFT) algorithm. In addition, this paper describes a novel way to derivate the 2-D CSI from the 1-D CSI by using the row-column method. This new fast 2-D CSI provides a regular and simple structure based upon linear correlations. Therefore, it can be implemented by the use of a modification of Kung’s pipeline structure and is naturally suitable for VLSI implementations. Experimental results show that the proposed new fast 2-D CSI algorithm can achieve almost the same CSI performance with much fewer arithmetic operations in comparison with existing efficient algorithms.
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Zhao P, Wang GH, Dong ZM, Duan J, Xu PZ, Cheng TC, Xiang ZH, Xia QY. Genome-wide identification and expression analysis of serine proteases and homologs in the silkworm Bombyx mori. BMC Genomics 2010; 11:405. [PMID: 20576138 PMCID: PMC2996933 DOI: 10.1186/1471-2164-11-405] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [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: 11/28/2009] [Accepted: 06/24/2010] [Indexed: 11/23/2022] Open
Abstract
Background Serine proteases (SPs) and serine proteases homologs (SPHs) are a large group of proteolytic enzymes, with important roles in a variety of physiological processes, such as cell signalling, defense and development. Genome-wide identification and expression analysis of serine proteases and their homologs in the silkworm might provide valuable information about their biological functions. Results In this study, 51 SP genes and 92 SPH genes were systematically identified in the genome of the silkworm Bombyx mori. Phylogenetic analysis indicated that six gene families have been amplified species-specifically in the silkworm, and the members of them showed chromosomal distribution of tandem repeats. Microarray analysis suggests that many silkworm-specific genes, such as members of SP_fam12, 13, 14 and 15, show expression patterns that are specific to tissues or developmental stages. The roles of SPs and SPHs in resisting pathogens were investigated in silkworms when they were infected by Escherichia coli, Bacillus bombysepticus, Batrytis bassiana and B. mori nucleopolyhedrovirus, respectively. Microarray experiment and real-time quantitative RT-PCR showed that 18 SP or SPH genes were significantly up-regulated after pathogen induction, suggesting that SP and SPH genes might participate in pathogenic microorganism resistance in B. mori. Conclusion Silkworm SP and SPH genes were identified. Comparative genomics showed that SP and SPH genes belong to a large family, whose members are generated mainly by tandem repeat evolution. We found that silkworm has species-specific SP and SPH genes. Phylogenetic and microarray analyses provide an overview of the silkworm SP and SPHs, and facilitate future functional studies on these enzymes.
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Affiliation(s)
- Ping Zhao
- The Key Sericultural Laboratory of Agricultural Ministry, Southwest University, Chongqing 400715, PR China
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14
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Abstract
Electron field emission from a single nanoemitter is a barrier tunneling, quantum mechanical process that can, therefore, be described by the well-known Fowler-Nordheim (FN) equation. At high emission current densities, however, the space charge caused by the cathode may affect the current density-voltage (J-V) characteristics predicted by the FN theory. In this study, we theoretically investigated the effect of space charge on FE nanodevices, including diode and triode structures. The J-V characteristics of FE nanodevices were obtained by analytically (diode structures) or numerically (triode structures) solving the coupled FN equation and Poisson's equation. We discuss the behavior of FE nanodiodes and nanotriodes displaying different geometries, dimensions and work functions of their emitter materials. In the high current density region, space charge plays an important role in FE nanodevices; the threshold current density of space-charge limitation is related to the electric field distributions. Besides, our theoretical results are in good agreement with the experimental results reported previously.
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Affiliation(s)
- P Y Chen
- Sky-watcher Telescope and Optics Corp., Richmond, British Columbia V7A5C8, Canada.
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15
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Cheng TC, Zhang YL, Liu C, Xu PZ, Gao ZH, Xia QY, Xiang ZH. Identification and analysis of Toll-related genes in the domesticated silkworm, Bombyx mori. Dev Comp Immunol 2008; 32:464-75. [PMID: 17499357 DOI: 10.1016/j.dci.2007.03.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2007] [Revised: 03/15/2007] [Accepted: 03/19/2007] [Indexed: 05/15/2023]
Abstract
Silkworm (Bombyx mori), a model system for Lepidoptera, has contributed enormously to the study of insect immunology especially in humoral immunity. But little is known about the molecular mechanism of immune response in the silkworm. Toll receptors are a group of evolutionarily ancient proteins, which play a crucial role in the innate immunity of both insects and vertebrates. In human, Toll-like receptors (TLRs) are the typical pattern recognition receptors for different kinds of pathogen molecules. Toll-related receptors in Drosophila, however, were thought to function as cytokine receptors in immune response and embryogenesis. We have identified 11 putative Toll-related receptors and two Toll analogs in the silkworm genome. Phylogenetic analysis of insect Toll family and human TLRs showed that BmTolls is grouped with Drosophila Tolls and Anopheles Tolls. These putative proteins are typical transmembrane receptors flanked by the extracellular leucine-rich repeat (LRR) domain and the cytoplasmic TIR domain. Structural prediction of the TIR domain alignment found five stranded sheets and five helices, which are alternatingly joined. Microarray data indicated that BmToll and BmToll-2 were expressed with remarkable enrichment in the ovary, suggesting that they might play a role in the embryogenesis. However, the enriched expression of BmToll-2 and -4 in the midgut suggested that the proteins they encode may be involved in immune defense. Testis-specific expression of BmToll-10 and -11 and BmToLK-2 implies that these may be involved in sex-specific biological functions. The RT-PCR results indicated that 10 genes were induced or suppressed with different degrees after their immune system was challenged by different invaders. Expression profiles of BmTolls and BmToLKs reported here provide insight into their role in innate immunity and development.
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Affiliation(s)
- Ting-Cai Cheng
- College of Life Science, Southwest University, Chongqing 400716, China
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16
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Chuang FT, Chen PY, Cheng TC, Chien CH, Li BJ. Improved field emission properties of thiolated multi-wall carbon nanotubes on a flexible carbon cloth substrate. Nanotechnology 2007; 18:395702. [PMID: 21730427 DOI: 10.1088/0957-4484/18/39/395702] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
In this paper we report the observation of enhanced field emission properties from thiolated multi-wall carbon nanotubes (MWCNTs) produced by a simple and effective two-step chemical surface modification technique. This technique implements carboxylation and thiolation on the MWCNTs synthesized by microwave plasma chemical vapor deposition (MPCVD) on the flexible carbon cloth substrate. The resulting thiolated MWCNTs were found to have a very low threshold field value of 1.25 V µm(-1) and a rather high field enhancement factor of 1.93 × 10(4), which are crucial for applications in versatile vacuum microelectronics.
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Affiliation(s)
- F T Chuang
- Department of Material Science and Engineering, National Chiao-Tung University, Hsinchu 30050, Taiwan, Republic of China
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17
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Xu HF, Xia QY, Liu C, Cheng TC, Zhao P, Duan J, Zha XF, Liu SP. Identification and characterization of piggyBac-like elements in the genome of domesticated silkworm, Bombyx mori. Mol Genet Genomics 2006; 276:31-40. [PMID: 16685528 DOI: 10.1007/s00438-006-0124-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [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: 12/01/2005] [Accepted: 03/27/2006] [Indexed: 11/26/2022]
Abstract
piggyBac is a short inverted terminal repeat (ITR) transposable element originally discovered in Trichoplusia ni. It is currently the preferred vector of choice for enhancer trapping, gene discovery and identifying gene function in insects and mammals. Many piggyBac-like sequences have been found in the genomes of phylogenetically species from fungi to mammals. We have identified 98 piggyBac-like sequences (BmPBLE1-98) from the genome data of domesticated silkworm (Bombyx mori) and 17 fragments from expressed sequence tags (ESTs). Most of the BmPBLE1-98 probably exist as fossils. A total of 21 BmPBLEs are flanked by ITRs and TTAA host dinucleotides, of which 5 contain a single ORF, implying that they may still be active. Interestingly, 16 BmPBLEs have CAC/GTG not CCC/GGG as the characteristic residues of ITRs, which is a surprising phenomenon first observed in the piggyBac families. Phylogenetic analysis indicates that many BmPBLEs have a close relation to mammals, especially to Homo sapiens, only a few being grouped with the T. ni piggyBac element. In addition, horizontal transfer was probably involved in the evolution of the piggyBac-like elements between B. mori and Daphnia pulicaria. The analysis of the BmPBLEs will contribute to our understanding of the characteristic of the piggyBac family and application of piggyBac in a wide range of insect species.
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Affiliation(s)
- Han-Fu Xu
- The Key Sericultural Laboratory of Agricultural Ministry of China, Southwest University, Chongqing, 400716, China
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18
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Abstract
Malignant mesothelioma of the tunica vaginalis is rare, and is usually not diagnosed until surgery is undertaken. Reports on the ultrasound features of this tumour are limited. We present an unusual case with ultrasound features mimicking an adenomatoid tumour.
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Affiliation(s)
- C W Mak
- Department of Diagnostic Radiology, Chi-Mei Foundation Medical Center, 901 Chung Hwa Road, Yung Kang, Tainan, Taiwan, Republic of China
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19
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Cheng TC, Xia QY, Liu C, Zhao P, Zha XF, Xu HF, Xiang ZH. [Three Bombyx mori genes, chi, gluE and fruA, encode proteins homologous to microorganism and primary analysis of horizontal gene transfer]. Yi Chuan Xue Bao 2004; 31:1082-8. [PMID: 15552042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
According to the analysis of large scale EST sequencing of silkworm, Bombyx mori, we found that chi, glue and fruA of silkworm have very high homology at amino acid level and closely phylogenetic relative with that of microorganism, but lower similarity with genes of eelworm (Caenorhabditis elegans), fruitfly (Drosophila melanogaster), mosquito (Anopheles gambiae) and other relative insects, respectively. It indicates that each of them is likely to have common ancestor with that of microorganism. Namely, microbial genes were likely transferred to silkworm by horizontal gene transfer, instead of the vertical inheritance in evolutionary manner.
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Affiliation(s)
- Ting-Cai Cheng
- Key Laboratory of Sericulture of the Agricultural Ministry of China, Southwest Agricultural University, Chongqing 400716, China.
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20
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Cheng TC, Xia QY, Qian JF, Liu C, Lin Y, Zha XF, Xiang ZH. Mining single nucleotide polymorphisms from EST data of silkworm, Bombyx mori, inbred strain Dazao. Insect Biochem Mol Biol 2004; 34:523-530. [PMID: 15147754 DOI: 10.1016/j.ibmb.2004.02.004] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2004] [Accepted: 02/19/2004] [Indexed: 05/24/2023]
Abstract
We made use of 81,635 expressed sequence tags (ESTs) derived from 12 different cDNA libraries of the silkworm, Bombyx mori, inbred strain Dazao (P50), to identify high-quality candidate single nucleotide polymorphisms (SNPs). By PHRAP assembling, 12,980 contigs containing 11,537 contigs assembled by more than one read were obtained, and 101 candidate SNPs and 27 single base insertions/deletions were identified from 117 contigs assembled from 1576 high-quality reads base-called with PHRED and screened on the basis of the neighborhood quality standard (NQS). Simultaneously, we also predicted 40 SNPs in coding regions (cSNPs), of which 26 were predicted to lead to amino acid non-synonymous variations and 14 synonymous substitutions. Also, the 1.66:1 ratio of transition/transversion is different from that of other insects. As the first SNP analysis of a Lepidoptera, B. mori, the single nucleotide polymorphic density is estimated to be 1.3 x 10(-3) by sequence diversity. This analysis shows that expressed sequences from multiple libraries may provide an abundant source of comparative reads to mine for cSNPs from the silkworm genome.
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Affiliation(s)
- Ting-Cai Cheng
- The Key Sericultural Laboratory of Agricultural Ministry, Southwest Agricultural University, Chongqing 400716, China
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21
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Chen CH, Tzeng CC, Cheng TC, Chiu AW. Angiomyolipoma of kidney as a part of tuberous sclerosis complex. J Postgrad Med 2003; 49:278-9. [PMID: 14597797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/27/2023] Open
Affiliation(s)
- C H Chen
- Division of Urology, Department of Surgery, Department of Pathology, Chi Mei Medical Center, Tainan, Taiwan
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22
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Fan EW, Cheng TC, Chiu AW, Lin H. Pyonephrosis and urinary retention secondary to a large Gartner's duct cyst associated with single ectopic ureter in a pregnant woman. BJU Int 2002; 89:136-7. [PMID: 11849179 DOI: 10.1046/j.1464-4096.2001.00935.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- E W Fan
- Division of Urology, Department of Surgery, Chi-Mei Foundation Hospital, Tainan, Taiwan, ROC
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23
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Said JW, Hoyer KK, French SW, Rosenfelt L, Garcia-Lloret M, Koh PJ, Cheng TC, Sulur GG, Pinkus GS, Kuehl WM, Rawlings DJ, Wall R, Teitell MA. TCL1 oncogene expression in B cell subsets from lymphoid hyperplasia and distinct classes of B cell lymphoma. J Transl Med 2001; 81:555-64. [PMID: 11304575 DOI: 10.1038/labinvest.3780264] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Activation of the TCL1 oncogene has been implicated in T cell leukemias/lymphomas and recently was associated with AIDS diffuse large B cell lymphomas (AIDS-DLBCL). Also, in nonmalignant lymphoid tissues, antibody staining has shown that mantle zone B cells expressed abundant Tcl1 protein, whereas germinal center (GC; centrocytes and centroblasts) B cells showed markedly reduced expression. Here, we analyze isolated B cell subsets from hyperplastic tonsil to determine a more precise pattern of Tcl1 expression with development. We also examine multiple B cell lines and B lymphoma patient samples to determine whether different tumor classes retain or alter the developmental pattern of expression. We show that TCL1 expression is not affected by Epstein-Barr virus (EBV) infection and is high in naïve B cells, reduced in GC B cells, and absent in memory B cells and plasma cells. Human herpesvirus-8 infected primary effusion lymphomas (PEL) and multiple myelomas are uniformly TCL1 negative, whereas all other transformed B cell lines tested express moderate to abundant TCL1. This observation supports the hypothesis that PEL, like myeloma, usually arise from post-GC stages of B cell development. Tcl1 protein is also detected in most naïve/GC-derived B lymphoma patient samples (23 of 27 [85%] positive), whereas most post-GC-derived B lymphomas lack expression (10 of 41 [24%] positive). These data indicate that the pattern of Tcl1 expression is distinct between naïve/GC and post-GC-derived B lymphomas (P < 0.001) and that the developmental pattern of expression is largely retained. However, post-GC-derived AIDS-DLBCL express TCL1 at a frequency equivalent to naïve/GC-derived B lymphomas in immune-competent individuals (7 of 9 [78%] positive), suggesting that TCL1 down-regulation is adversely affected by severe immune system dysfunction. These findings demonstrate that TCL1 expression in B cell lymphoma usually reflects the stage of B cell development from which they derive, except in AIDS-related lymphomas.
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MESH Headings
- B-Lymphocyte Subsets/metabolism
- Cell Line, Transformed
- Cell Transformation, Viral
- DNA-Binding Proteins/metabolism
- Down-Regulation
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Neoplastic
- Herpesvirus 4, Human/pathogenicity
- Humans
- Hyperplasia/genetics
- Hyperplasia/metabolism
- Lymphoma, AIDS-Related/genetics
- Lymphoma, AIDS-Related/metabolism
- Lymphoma, B-Cell/classification
- Lymphoma, B-Cell/genetics
- Lymphoma, B-Cell/metabolism
- Lymphoma, Large B-Cell, Diffuse/metabolism
- Multiple Myeloma/genetics
- Multiple Myeloma/metabolism
- Palatine Tonsil/immunology
- Proto-Oncogene Proteins/biosynthesis
- Proto-Oncogene Proteins/genetics
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-bcl-6
- RNA, Messenger/biosynthesis
- Transcription Factors/metabolism
- Tumor Cells, Cultured
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Affiliation(s)
- J W Said
- Department of Pathology, University of California at Los Angeles School of Medicine, 90095-1732, USA
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Abstract
Conditions were developed to cryopreserve cells from pronase-dissociated atria and ventricles of eastern oysters (Crassostrea virginica). The effect of three concentrations (5, 10, 15%) of the cryoprotectants (dimethyl sulfoxide, glycerol, and propylene glycol), three thawing temperatures (25, 45, 75 degrees C), and three cooling rates (slow, medium, fast) were compared. Cells were frozen at -80 degrees C and plunged in liquid nitrogen. Thawed cells were seeded in 96-well plates and primary cultures were evaluated after 3 d by measuring the metabolic activity using a tetrazolium compound, 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium, and by comparing the relative spreading of cells between treatments. The best conditions for freezing and thawing of cells for each cryoprotectant were selected and a final study was performed to compare cryoprotectants. For this final study, we measured the number of cells and their viability 3 d after thawing, in addition to determining cell metabolic activity and cell spreading. Primary cultures of cells fozen without cryoprotectant and of nonfrozen cells were used as controls in all studies. Atrial cells were best cryopreserved with glycerol at a concentration of 10%, a medium cooling rate, and thawing at 45 degrees C. After thawing, atrial cells showed 53+/-5% of the metabolic activity, 84+/-5% of the number, and 92+/-2% of the viability of nonfrozen cells. For ventricular cells, 10% glycerol, a medium cooling rate, and thawing at 25 degrees C yielded the best results. The thawed ventricular cells showed 83+/-5% of the metabolic activity, 91+/-5% of the number, and 96+/-2% of the viability of nonfrozen cells.
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Affiliation(s)
- T C Cheng
- Department of Veterinary Science, Louisiana State University Agricultural Center, Baton Rouge 70803, USA
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25
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Chang WC, Hsieh YY, Cheng TC, Chang CC, Tsai HD, Lee MS. Effect of methylglyoxal on mouse embryogenesis. Chang Gung Med J 2001; 24:251-7. [PMID: 11413883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
BACKGROUND Methylglyoxal (MG), a highly active and mutagenetic compound, has been found widely in a variety of foods and beverages. We investigated the effect of MG on mouse embryo development in-vitro. METHODS Two-cell mouse embryos were divided into six groups according to the MG concentration in the culture medium: Group 1 (control group). 0 mM; Group 2, 10(-4) mM; Group 3, 10(-3) mM; Group 4, 10(-2) mM; Group 5, 10(-1) mM; Group 6, 1 mM. Embryo development and cleavage were compared every day for 5 days. RESULTS The percentages of embryos reaching blastocyst/hatching stages were as follows: Group 1, 66.8%/34.2%; Group 2, 67.9%/38.7%; Group 3, 56.2%/31.5%; Group 4, 39.4%/14.1%; Group 5, 11.4%/10.2%; Group 6, 0%/0%. Higher MG concentrations (> or = 10(-2) mM) were associated with morphological aberrations and blocked development of embryos. CONCLUSION The cutoff value of MG concentration on the mouse embryo development in-vitro is 10(-2) mM. An increased risk of embryotoxicity occurs with MG concentrations > or = 10(-2) mM in vitro. There were no significant effects on the growth rate at MG concentrations of 10(-3) and 10(-4) mM.
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Affiliation(s)
- W C Chang
- Department of Obstetrics and Gynecology, China Medical College Hospital, Taichung, Taiwan, R.O.C
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26
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Hill CM, Li WS, Cheng TC, DeFrank JJ, Raushel FM. Stereochemical specificity of organophosphorus acid anhydrolase toward p-nitrophenyl analogs of soman and sarin. Bioorg Chem 2001; 29:27-35. [PMID: 11300693 DOI: 10.1006/bioo.2000.1189] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Organophosphorus acid anhydrolase (OPAA) catalyzes the hydrolysis of p-nitrophenyl analogs of the organophosphonate nerve agents, sarin and soman. The enzyme is stereoselective toward the chiral phosphorus center by displaying a preference for the R(P)-configuration of these analogs. OPAA also exhibits an additional preference for the stereochemical configuration at the chiral carbon center of the soman analog. The preferred configuration of the chiral carbon center is dependent upon the configuration at the phosphorus center. The enzyme displays a two- to four-fold preference for the R(P)-enantiomer of the sarin analog. The k(cat)/K(m) of the R(P)-enantiomer is 250 M(-1) s(-1), while that of the S(P)-enantiomer is 110 M(-1) s(-1). The order of preference for the stereoisomers of the soman analog is R(P)S(C) > R(P)R(C) > S(P)R(C) > S(P)S(C). The k(cat)/K(m) values are 36,300 M(-1)s(-1), 1250 M(-1) s(-1), 80 M(-1) s(-1) and 5 M(-1) s(-1), respectively. The R(P)S(C)-isomer of the soman analog is therefore preferred by a factor of 7000 over the S(P)S(C)-isomer.
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Affiliation(s)
- C M Hill
- Department of Chemistry, Texas A&M University, College Station, Texas 77842-3021, USA
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27
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Petrikovics I, Cheng TC, Papahadjopoulos D, Hong K, Yin R, DeFrank JJ, Jaing J, Song ZH, McGuinn WD, Sylvester D, Pei L, Madec J, Tamulinas C, Jaszberenyi JC, Barcza T, Way JL. Long circulating liposomes encapsulating organophosphorus acid anhydrolase in diisopropylfluorophosphate antagonism. Toxicol Sci 2000; 57:16-21. [PMID: 10966507 DOI: 10.1093/toxsci/57.1.16] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [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: 11/13/2022] Open
Abstract
These studies are focused on antagonizing organophosphorous (OP) intoxications by a new conceptual approach using recombinant enzymes encapsulated within sterically stabilized liposomes to enhance diisopropylfluorophosphate (DFP) degradation. The OP hydrolyzing enzyme, organophosphorous acid anhydrolase (OPAA), encapsulated within the liposomes, was employed either alone or in combination with pralidoxime (2-PAM) and/or atropine. The recombinant OPAA enzyme, from the ALTEROMONAS: strain JD6, has high substrate specificity toward a wide range of OP compounds, e.g., DFP, soman, and sarin. The rate of DFP hydrolysis by liposomes containing OPAA (SL)* was measured by determining the changes in fluoride-ion concentration using a fluoride ion-selective electrode. This enzyme carrier system serves as a biodegradable protective environment for the OP-metabolizing enzyme (OPAA), resulting in an enhanced antidotal protection against the lethal effects of DFP. Free OPAA alone showed some antidotal protection; however, the protection with 2-PAM and/or atropine was greatly enhanced when combined with (SL)*.
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Affiliation(s)
- I Petrikovics
- Department of Medical Pharmacology and Toxicology, Texas A&M University, College of Medicine, College Station, Texas 77843-1114, USA
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28
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Hill CM, Wu F, Cheng TC, DeFrank JJ, Raushel FM. Substrate and stereochemical specificity of the organophosphorus acid anhydrolase from Alteromonas sp. JD6.5 toward p-nitrophenyl phosphotriesters. Bioorg Med Chem Lett 2000; 10:1285-8. [PMID: 10866401 DOI: 10.1016/s0960-894x(00)00213-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The enzyme OPAA hydrolyzes p-nitrophenyl phosphotriesters bearing substituents at the phosphorus center ranging in size from methyl to phenyl. The enzyme exhibits stereoselectivity toward the hydrolysis of chiral substrates with a preference for the Sp enantiomer.
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Affiliation(s)
- C M Hill
- Department of Chemistry, Texas A&M University, College Station 77843, USA
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29
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Petrikovics I, McGuinn WD, Sylvester D, Yuzapavik P, Jiang J, Way JL, Papahadjopoulos D, Hong K, Yin R, Cheng TC, DeFrank JJ. In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism. Drug Deliv 2000; 7:83-9. [PMID: 10892408 DOI: 10.1080/107175400266641] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [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: 10/16/2022] Open
Abstract
This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.
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Affiliation(s)
- I Petrikovics
- Department of Medical Pharmacology and Toxicology, Texas A&M University, College of Medicine, College Station 77843-1114, USA
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Cheng TC, Ramakrishnan V, Chan SI. Purification and characterization of a cobalt-activated carboxypeptidase from the hyperthermophilic archaeon Pyrococcus furiosus. Protein Sci 1999; 8:2474-86. [PMID: 10595552 PMCID: PMC2144183 DOI: 10.1110/ps.8.11.2474] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
A novel metallocarboxypeptidase (PfuCP) has been purified to homogeneity from the hyperthermophilic archaeon, Pyrococcus furiosus, with its intended use in C-terminal ladder sequencing of proteins and peptides at elevated temperatures. PfuCP was purified in its inactive state by the addition of ethylenediaminetetraacetic acid (EDTA) and dithiothreitol (DTT) to purification buffers, and the activity was restored by the addition of divalent cobalt (K, = 24 +/- 4 microM at 80 degrees C). The serine protease inhibitor phenylmethylsulfonyl fluoride (PMSF) had no effect on the activity. The molecular mass of monomeric PfuCP is 59 kDa as determined by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 58 kDa by SDS-PAGE analysis. In solution, PfuCP exists as a homodimer of approximately 128 kDa as determined by gel filtration chromatography. The activity of PfuCP exhibits a temperature optimum exceeding 90 degrees C under ambient pressure, and a narrow pH optimum of 6.2-6.6. Addition of Co2+ to the apoPfuCP at room temperature does not alter its far-UV circular dichroism (CD) or its intrinsic fluorescence spectrum. Even when the CoPfuCP is heated to 80 degrees C, its far-UV CD shows a minimal change in the global conformation and the intrinsic fluorescence of aromatic residues shows only a partial quenching. Changes in the intrinsic fluorescence appear essentially reversible with temperature. Finally, the far-UV CD and intrinsic fluorescence data suggest that the overall structure of the holoenzyme is extremely thermostable. However, the activities of both the apo and holo enzyme exhibit a similar second-order decay over time, with 50% activity remaining after approximately 40 min at 80 degrees C. The N-blocked synthetic dipeptide, N-carbobenzoxy-Ala-Arg (ZAR), was used in the purification assay. The kinetic parameters at 80 degrees C with 0.4 mM CoCl2 were: Km, 0.9 +/- 0.1 mM; Vmax, 2,300 +/- 70 U mg(-1); and turn over number, 600 +/- 20 s(-1). Activity against other ZAX substrates (X = V, L, I, M, W, Y, F, N, A, S, H, K) revealed a broad specificity for neutral, aromatic, polar, and basic C-terminal residues. This broad specificity was confirmed by the C-terminal ladder sequencing of several synthetic and natural peptides, including porcine N-acetyl-renin substrate, for which we have observed (by MALDI-TOF MS) stepwise hydrolysis by PfuCP of up to seven residues from the C-terminus: Ac-Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu-Leu-Val-Tyr-Ser.
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Affiliation(s)
- T C Cheng
- Noyes Laboratories, Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena 91125, USA
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Huang CC, Cheng TC, Chang HH, Chang CC, Chen CI, Liu J, Lee MS. Birth after the injection of sperm and the cytoplasm of tripronucleate zygotes into metaphase II oocytes in patients with repeated implantation failure after assisted fertilization procedures. Fertil Steril 1999; 72:702-6. [PMID: 10521114 DOI: 10.1016/s0015-0282(99)00309-x] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [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: 11/24/2022]
Abstract
OBJECTIVE To assess the technique of injecting a single sperm and cytoplasm obtained from tripronucleate zygotes into metaphase II oocytes for the treatment of patients with repeated implantation failure after intracytoplasmic sperm injection or IVF. DESIGN Clinical study. SETTING Private infertility clinic. PATIENT(S) Patients with repeated implantation failure after intracytoplasmic sperm injection or IVF. INTERVENTION(S) The metaphase II oocytes of recipients were injected with their husbands' spermatozoa and cytoplasm aspirated from the tripronucleate zygotes of donors. MAIN OUTCOME MEASURE(S) Fertilization after cytoplasm and sperm injection, embryo development, and successful pregnancy. RESULT(S) In total, 62 metaphase II oocytes from nine recipients were injected. Of the 62 injected oocytes, 3 (5%) degenerated and 43 (69%) had two pronuclei 18 hours after injection. Thirty-nine oocytes with two pronuclei cleaved to the two-cell to six-cell stage after another 24 hours of culture. All cleaved embryos were transferred into the uteruses of recipients. Four clinical pregnancies occurred in four recipients. No abnormal chromosomes were observed after amniocentesis and karyotyping in all pregnancies. Five healthy infants were born. CONCLUSION(S) Injection of the cytoplasm of tripronucleate zygotes may enhance the clinical pregnancy rate in patients with repeated implantation failure after intracytoplasmic sperm injection or IVF.
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Affiliation(s)
- C C Huang
- Infertility Clinic, Lee Women's Hospital, Taichung, Taiwan, Republic of China
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32
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Abstract
Enzymes catalyzing the hydrolysis of highly toxic organophosphorus compounds (OPs) are classified as organophosphorus acid anhydrolases (OPAA; EC 3.1.8.2). Recently, the genes encoding OPAA from two species of Alteromonas were cloned and sequenced. Sequence and biochemical analyses of the cloned genes and enzymes have established Alteromonas OPAAs to be prolidases (E.C. 3.4.13.9), a type of dipeptidase hydrolyzing dipeptides with a prolyl residue in the carboxyl-terminal position (X-Pro). Alteromonas prolidases hydrolyze a broad range of G-type chemical warfare (CW) nerve agents. Efforts to over-produce a prolidase from A. sp.JD6.5 with the goal of developing strategies for long-term storage and decontamination have been successfully achieved. Large-scale production of this G-agent degrading enzyme is now feasible with the availability of an over-producing recombinant cell line. Use of this enzyme for development of a safe and non-corrosive decontamination system is discussed.
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Affiliation(s)
- T C Cheng
- Environmental Technology Team, US Army Edgewood Research, Development and Engineering Center, Aberdeen, MD 21010, USA.
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33
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Affiliation(s)
- T C Cheng
- United States Army Edgewood Research, Development, and Engineering Center, Aberdeen Proving Ground, Maryland 21010, USA
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Affiliation(s)
- J H Chang
- Department of Urology, National Cheng-Kung University Hospital, Tainan, Taiwan, ROC
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35
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Abstract
The Russian-VX (R-VX) is the principle V-type nerve agent in the chemical warfare (CW) arsenal of the Former Soviet Union. We here report the enzymatic hydrolysis of the P-S bond of Russian-VX by organophosphorus hydrolase (OPH) from Pseudomonas diminuta. While the Michaelis constant, K(m) for R-VX (474 microM), was similar to that for VX (434 microM), the Vmax for R-VX (2.1 mumoles/mg/min) was about four-fold higher compared to that for VX (0.56 mumoles/mg/min). A 50% inhibition in the rate of the enzymatic hydrolysis of R-VX was observed in the presence of 0.5% ethanol, isoamyl-alcohol, or isopropanol. The presence of acetonitrile, diethylene glycol, or methanol had marginal effects. These results comprise the first demonstration of enzymatic detoxification of R-VX.
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Affiliation(s)
- V K Rastogi
- GEO-Centers, Inc./ERDEC, Aberdeen Proving Ground, Maryland 21010, USA.
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Chang CP, Liu RS, Yu SM, Wynchank S, Chu LS, Shiau HY, Cheng TC. Clinical evaluation of the bone marrow imaging agent 99Tcm-phytate in the detection of bone metastases. Nucl Med Commun 1996; 17:1030-4. [PMID: 9004298 DOI: 10.1097/00006231-199612000-00005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 02/03/2023]
Abstract
The aims of this study were to assess whether 99Tcm-phytate can detect metastatic skeletal lesions, and to compare it with 99Tcm-methylene diphosphonate (99Tcm-MDP) and 99Tcm-labelled human serum albumin nanocolloids (99Tcm-NC). Twenty-four patients with multiple bony metastases, investigated by 99Tcm-MDP whole-body scintigraphy, underwent 99Tcm-phytate bone marrow imaging. A separate bone marrow scintigram with 99Tcm-NC was performed in 20 of the patients. All of the metastatic lesions detected on the 99Tcm-phytate scintigrams exhibited photon-abundant foci only. Most of the 99Tcm-phytate scintigrams detected fewer metastatic lesions than the corresponding bone scintigrams. Visual comparison of the 99Tcm-NC images showed that 13 of 20 99Tcm-NC images were superior to the 99Tcm-phytate images in the detection of metastatic involvement of the skeleton. Thus 99Tcm-phytate should not be used as a bone marrow imaging agent for the detection of skeletal metastases.
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Affiliation(s)
- C P Chang
- Department of Nuclear Medicine, Taipei Veterans General Hospital, National Defense Medical Center, Taiwan, Republic of China
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37
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Abstract
Crocetin, a carotenoid isolated from the seeds of Gardenia jasminoides, was found to be a potent inhibitor of tumor promotion induced by 12-O-tetradecanoylphorbol-13-acetate (TPA) in mouse skin. When mouse fibroblast NIH/3T3 cells were treated with TPA alone, protein kinase C (PKC) translocated from the cytosolic fraction to the particulate fraction. Pretreatment with 60 and 120 microM crocetin for 15 min inhibited the TPA-induced PKC activity in the particulate fraction by 50% and 66%, respectively, but did not affect the level of PKC protein. Crocetin also reduced the level of TPA-stimulated phosphorylation of cellular proteins. Cells pretreated with crocetin (120 microM) had 55% less PKC [3H]phorbol dibutyrate-binding capacity. Suppression of TPA (100 ng/mL)-induced c-jun and c-fos gene expression was also observed in the mouse fibroblast cells pretreated with crocetin (30, 60, and 120 microM). Our results provided a basis for understanding the inhibitory effect of crocetin on TPA-mediated tumor promotion.
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Affiliation(s)
- C J Wang
- Institute of Biochemistry, Chung Shan Medical and Dental College, Taichung, Taiwan, Republic of China
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38
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Benton HP, Cheng TC, MacDonald MH. Use of adverse conditions to stimulate a cellular stress response by equine articular chondrocytes. Am J Vet Res 1996; 57:860-5. [PMID: 8725814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To determine the response of equine articular cartilage cells to heat and calcium stresses. DESIGN Analysis of newly synthesized, [35S]methionine-labeled proteins after treatment of isolated primary equine chondrocytes. PROCEDURE Primary cultures of equine articular chondrocytes were incubated at temperatures ranging from 37 to 42 C for heat stress experiments or incubated in the presence or absence of the intracellular calcium pump inhibitor, thapsigargin, for calcium stress experiments. Patterns of new protein synthesis were determined by incubating with [35S]methionine followed by separation of proteins by use of one- or two-dimensional gel electrophoresis and visualization of labeled proteins by use of fluorography. RESULTS Equine chondrocytes cultured at temperature of 42 C had increased synthesis of specific proteins, compared with the profile of protein synthesis in control chondrocytes cultured at 37 C. These changes were characteristic of the heat shock stress response described in a number of other mammalian cell-types. Equine chondrocytes cultured in the presence of thapsigargin also had increased synthesis of specific proteins. Two-dimensional gel electrophoresis of these newly synthesized proteins revealed the changes to be consistent with the induction of the glucose-regulated protein family of stress proteins. CONCLUSIONS Changes in the pattern of new protein synthesis can be induced in differentiated equine articular chondrocytes by heat shock or calcium stress. These responses are characteristic of a widely described mammalian stress response that has been postulated to be involved in cellular protective mechanisms. The ability of equine chondrocytes to mount a robust stress response may be important in the processes of tissue damage and recovery in articular joints of horses.
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Affiliation(s)
- H P Benton
- Department of Anatomy, Physiology, and Cell Biology, School of Veterinary Medicine, University of California, Davis 95616, USA
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39
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Cheng TC, Harvey SP, Chen GL. Cloning and expression of a gene encoding a bacterial enzyme for decontamination of organophosphorus nerve agents and nucleotide sequence of the enzyme. Appl Environ Microbiol 1996; 62:1636-41. [PMID: 8633861 PMCID: PMC167937 DOI: 10.1128/aem.62.5.1636-1641.1996] [Citation(s) in RCA: 104] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Organophosphorus acid (OPA) anhydrolase enzymes have been found in a wide variety of prokaryotic and eukaryotic organisms. Interest in these enzymes has been prompted by their ability to catalyze the hydrolysis of toxic organophosphorus cholinesterase-inhibiting compounds, including pesticides and chemical nerve agents. The natural substrates for these enzymes are unknown. The gene (opaA) which encodes an OPA anhydrolase (OPAA-2) was isolated from an Alteromonas sp. strain JD6.5 EcoRI-lambda ZAPII chromosomal library expressed in Escherichia coli and identified by immunodetection with anti-OPAA-2 serum. OPA anhydrolase activity expressed by the immunopositive recombinant clones was demonstrated by using diisopropylfluorophosphate (DFP) as a substrate. A comparison of the recombinant enzyme with native, purified OPAA-2 showed they had the same apparent molecular mass (60 kDa), antigenic properties, and enzyme activity against DFP and the chemical nerve agents sarin, soman, and O-cyclohexyl methylphosphonofluoridate. The gene expressing this activity was found in a 1.74-kb PstI-HindIII fragment of the original 6.1-kb EcoRI DNA insert. The nucleotide sequence of this PstI-HindIII fragment revealed an open reading frame of 1,551 nucleotides, coding for a protein of 517 amino acid residues. Amino acid sequence comparison of OPAA-2 with the protein database showed that OPAA-2 is similar to a 647-amino-acid sequence produced by an open reading frame which appears to be the E. coli pepQ gene. Further comparison of OPAA-2, the E. coli PepQ protein sequence, E. coli aminopeptidase P, and human prolidase showed regions of different degrees of similarity or functionally conserved amino acid substitutions. These findings, along with preliminary data confirming the presence of prolidase activity expressed by OPAA-2, suggest that the OPAA-2 enzyme may, in nature, be used in peptide metabolism.
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Affiliation(s)
- T C Cheng
- U.S. Army Edgewood Research, Development and Engineering Center, Research and Technology Directorate, Aberdeen Proving Ground, Maryland 21010, USA.
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40
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Yu H, Bruno JG, Cheng TC, Calomiris JJ, Goode MT, Gatto-Menking DL. A comparative study of PCR product detection and quantitation by electro-chemiluminescence and fluorescence. J Biolumin Chemilumin 1995; 10:239-45. [PMID: 8533605 DOI: 10.1002/bio.1170100407] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Amplification and detection of target DNA sequences are made possible in a polymerase chain reaction (PCR) by using a mixture of biotinylated and ruthenium(II) trisbipyridal (Ru(bpy)3(2+))-end-labelled primers. In this way, biotin for capture and Ru(bpy)3(2+) for detection are directly incorporated into the PCR product obviating subsequent probe hybridization. PCR of a bacterial DNA template from Alteromonas species strain JD6.5 using a cocktail of biotin- and Ru(bpy)3(2+)-labelled primers amplified a 1 kilobase region. Serial dilution of PCR product followed by magnetic separation with Streptavidin (SA)-coated magnetic beads and an electrochemiluminescence (ECL) assay using the semi-automated QPCR System 5000 demonstrated sensitive (pg range) DNA detection. ECL assay of probe hybridization to a human immunodeficiency virus (HIV) sequence also produced pg level sensitivity. Quantitative DNA determination by ECL assay correlated well with visual detection of DNA in electrophoretic gels. However, DNA detection by ECL assay was 10 to 100 times more sensitive than conventional ethidium bromide staining. The combination of DNA-based magnetic separation with ECL assay provides a very sensitive and rapid method of quantitating DNA which, owing to its rapid and facile nature, may have many applications in the research, environmental monitoring, industrial and clinical fields.
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Affiliation(s)
- H Yu
- Optech Corporation, San Antonio, TX 78229, USA
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41
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Cheng TC, Tsai TC, Lin GJ. Successful medical treatment for staphylococcal vertebral osteomyelitis complicated by spinal epidural abscess, psoas abscess and meningitis: a case report. Gaoxiong Yi Xue Ke Xue Za Zhi 1995; 11:295-9. [PMID: 7602668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
A 42 year-old farmer was transferred to our hospital for recently exaggerated lower back pain. Neurological examination revealed an L4 radiculopathy on the right side. Meningitis developed after admission. MRI showed L4-5 osteomyelitis and discitis with contiguous spinal epidural abscess and right psoas abscess. Blood culture and CSF culture both grew Staphylococcus aureus. Because the patient refused to receive a drainage procedure, we gave him antibiotics which resulted in a favorable outcome.
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Affiliation(s)
- T C Cheng
- Department of Urology, Chi-Mei Foundation Hospital, Taiwan, Republic of China
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42
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Cheng TC, Tseng BS, Merlie JP, Klein WH, Olson EN. Activation of the myogenin promoter during mouse embryogenesis in the absence of positive autoregulation. Proc Natl Acad Sci U S A 1995; 92:561-5. [PMID: 7831329 PMCID: PMC42781 DOI: 10.1073/pnas.92.2.561] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [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: 01/27/2023] Open
Abstract
Myogenin, a member of the MyoD family of helix-loop-helix proteins, can induce myogenesis in a wide range of cell types. In addition to activating muscle structural genes, members of the MyoD family can autoactivate their own and cross-activate one another's expression in transfected cells. This has led to the hypothesis that autoregulatory loops among these factors provide a mechanism for amplifying and maintaining the muscle-specific gene expression program in vivo. Here, we make use of myogenin-null mice to directly test this hypothesis. To investigate whether the myogenin protein autoregulates the myogenin gene during embryogenesis, we introduced a myogenin-lacZ transgene into mice harboring a null mutation at the myogenin locus. Despite a severe deficiency of skeletal muscle in myogenin-null neonates, the myogenin-lacZ transgene was expressed normally in myogenic cells throughout embryogenesis. These results show that myogenin is not required for regulation of the myogenin gene and argue against the existence of a myogenin autoregulatory loop in the embryo.
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Affiliation(s)
- T C Cheng
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030
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43
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Cheng TC, Benton HP. The intracellular Ca(2+)-pump inhibitors thapsigargin and cyclopiazonic acid induce stress proteins in mammalian chondrocytes. Biochem J 1994; 301 ( Pt 2):563-8. [PMID: 8043004 PMCID: PMC1137118 DOI: 10.1042/bj3010563] [Citation(s) in RCA: 26] [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] [Indexed: 01/28/2023]
Abstract
Primary cultures of mammalian articular chondrocytes respond to treatment with the intracellular Ca(2+)-pump inhibitors thapsigargin (TG) and cyclopiazonic acid by specific changes in protein synthesis consistent with a stress response. Two-dimensional gel electrophoresis of newly synthesized proteins confirmed that the response was consistent with the induction of glucose-regulated proteins. The effects of low-dose TG (10 nM), measured by changes in [35S]methionine labelling of newly synthesized proteins, can first be observed by 10 h and are maximal by 24 h. The pattern of changes induced by TG is shared with cyclopiazonic acid, but effects of both perturbants differ significantly from changes induced by heat shock. Upon removal of TG, normal protein synthesis is restored by 48 h. Immunoblots showed increased concentrations of the stress proteins HSP90, HSP72/73 and HSP60 in chondrocytes treated with TG, but induction of newly synthesized heat-shock proteins by TG was not apparent on [35S]methionine-labelled gels. The alterations in protein synthesis induced by Ca(2+)-pump inhibitors were unaffected by BAPTA-AM loading, which clamped cytosolic Ca2+ at resting levels. We conclude that inhibition of intracellular Ca(2+)-pump activity can elicit a stress response, which has important implications for the interpretation of chronic use of Ca(2+)-pump inhibitors. In particular, the activation of the cellular shock response should be considered in interpreting the regulation of protein synthesis and cell survival by Ca(2+)-pump inhibitors such as TG.
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Affiliation(s)
- T C Cheng
- Department of Anatomy, Physiology and Cell Biology, School of Veterinary Medicine, University of California, Davis 95616
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44
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Merlie JP, Mudd J, Cheng TC, Olson EN. Myogenin and acetylcholine receptor alpha gene promoters mediate transcriptional regulation in response to motor innervation. J Biol Chem 1994; 269:2461-7. [PMID: 8300573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Several genes expressed in skeletal muscle are transcriptionally repressed by electrical activity arising from motor innervation and are rapidly induced following denervation. Among these are genes encoding the subunits of the nicotinic acetylcholine receptor (AChR) and the myogenic helix-loop-helix protein myogenin, which activates muscle-specific genes. To understand how electrical activity arising from motor innervation is converted into a transcriptional response, we have attempted to localize cis-acting sequences in the AChR alpha subunit and myogenin genes sufficient to direct activity-dependent transcription. Here we show that an 111-base pair and a 335-base pair region from the promoters of the AChR alpha subunit and myogenin genes, respectively, can confer activity-dependent regulation to a linked reporter gene in transgenic mice. The presence of binding sites for myogenic helix-loop-helix proteins in both of these regulatory regions is consistent with the hypothesis that these myogenic regulators serve as nuclear targets for the signaling cascade through which motor innervation leads to changes in gene transcription in skeletal muscle.
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Affiliation(s)
- J P Merlie
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, St. Louis, Missouri 63110
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45
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Leibham D, Wong MW, Cheng TC, Schroeder S, Weil PA, Olson EN, Perry M. Binding of TFIID and MEF2 to the TATA element activates transcription of the Xenopus MyoDa promoter. Mol Cell Biol 1994; 14:686-99. [PMID: 8264638 PMCID: PMC358418 DOI: 10.1128/mcb.14.1.686-699.1994] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Members of the MyoD family of helix-loop-helix proteins control expression of the muscle phenotype by regulating the activity of subordinate genes. To investigate processes that control the expression of myogenic factors and regulate the establishment and maintenance of the skeletal muscle phenotype, we have analyzed sequences necessary for transcription of the maternally expressed Xenopus MyoD (XMyoD) gene. A 3.5-kb DNA fragment containing the XMyoDa promoter was expressed in a somite-specific manner in injected frog embryos. The XMyoDa promoter was active in oocytes and cultured muscle cells but not in fibroblasts or nonmuscle cell lines. A 58-bp fragment containing the transcription initiation site, a GC-rich region, and overlapping binding sites for the general transcription factor TFIID and the muscle-specific factor MEF2 was sufficient for muscle-specific transcription. Transcription of the minimal XMyoDa promoter in nonmuscle cells was activated by expression of Xenopus MEF2 (XMEF2) and required binding of both MEF2 and TFIID to the TATA motif. These results demonstrate that the XMyoDa TATA motif is a target for a cell-type-specific regulatory factor and suggests that MEF2 stabilizes and amplifies XMyoDa transcription in mesodermal cells committed to the muscle phenotype.
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Affiliation(s)
- D Leibham
- Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030
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46
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Cheng TC, Harvey SP, Stroup AN. Purification and Properties of a Highly Active Organophosphorus Acid Anhydrolase from
Alteromonas undina. Appl Environ Microbiol 1993; 59:3138-40. [PMID: 16349054 PMCID: PMC182420 DOI: 10.1128/aem.59.9.3138-3140.1993] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A highly active organophosphorus acid anhydrolase from
Alteromonas undina
was purified to homogeneity and found to be composed of a single polypeptide chain with a molecular weight of 53,000. With diisopropylfluorophosphate as a substrate, the purified enzyme has a specific activity of ∼575 μmol/min/mg of protein. The enzyme has optimum activity at pH 8.0 and 55�C and is stimulated by sulfhydryl reducing agents and manganese. It is capable of rapidly hydrolyzing a wide range of nerve agents and several chromogenic phosphinates.
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Affiliation(s)
- T C Cheng
- U.S. Army Chemical and Biological Defense Agency, Edgewood Research, Development and Engineering Center, Research and Technology Directorate, Aberdeen Proving Ground, Maryland 21010-5423
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47
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Abstract
Expression of the myogenic helix-loop-helix (HLH) protein myogenin in muscle cell precursors within somites and limb buds is among the earliest events associated with myogenic lineage determination in vertebrates. Mutations in the myogenin promoter that abolish binding sites for myogenic HLH proteins or myocyte enhancer factor-2 (MEF-2) suppressed transcription of a linked lacZ transgene in subsets of myogenic precursors in mouse embryos. These results suggest that myogenic HLH proteins and MEF-2 participate in separable regulatory circuits leading to myogenin transcription and provide evidence for positional regulation of myogenic regulators in the embryo.
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Affiliation(s)
- T C Cheng
- Department of Biochemistry and Molecular Biology, University of Texas M.D. Anderson Cancer Center, Houston 77030
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DeFrank JJ, Beaudry WT, Cheng TC, Harvey SP, Stroup AN, Szafraniec LL. Screening of halophilic bacteria and Alteromonas species for organophosphorus hydrolyzing enzyme activity. Chem Biol Interact 1993; 87:141-8. [PMID: 8393735 DOI: 10.1016/0009-2797(93)90035-w] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Previously, a G-type nerve agent degrading enzyme activity was found in a halophilic bacterial isolate designated JD6.5. This organism was tentatively identified as an unknown species of the genus Alteromonas. In order to determine whether this type of enzyme activity was common in other species of Alteromonas, a screening program was initiated. A number of Alteromonas species and five halophilic bacterial isolates were cultured and their crude cell extracts screened for hydrolytic activity against several organophosphorus chemical agents and other related compounds. The samples were also screened for cross-reactivity with a monoclonal antibody raised against the purified enzyme from JD6.5 and for hybridization with a DNA probe based on its N-terminal amino acid sequence A wide spectrum of activities and reactivities were seen, suggesting a significant heterogeneity between the functionally similar enzymes that are present in these bacterial species. Enzymes of the type described here have considerable potential for the decontamination and demilitarization of chemical warfare agents.
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Affiliation(s)
- J J DeFrank
- Biochemical Decontamination Team, U.S. Army Edgewood Research, Development and Engineering Center, Aberdeen Proving Ground, MD 21010-5423
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Cheng TC, Hanley TA, Mudd J, Merlie JP, Olson EN. Mapping of myogenin transcription during embryogenesis using transgenes linked to the myogenin control region. J Biophys Biochem Cytol 1992; 119:1649-56. [PMID: 1334962 PMCID: PMC2289748 DOI: 10.1083/jcb.119.6.1649] [Citation(s) in RCA: 62] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
During vertebrate embryogenesis, the muscle-specific helix-loop-helix protein myogenin is expressed in muscle cell precursors in the developing somite myotome and limb bud before muscle fiber formation and is further upregulated during myogenesis. We show that cis-acting DNA sequences within the 5' flanking region of the mouse myogenin gene are sufficient to direct appropriate temporal, spatial, and tissue-specific transcription of myogenin during mouse embryogenesis. Myogenin-lacZ transgenes trace the fate of embryonic cells that activate myogenin transcription and suggest that myogenic precursor cells that migrate from the somite myotome to the limb bud are committed to a myogenic fate in the absence of myogenin transcription. Activation of a myogenin-lacZ transgene can occur in limb bud explants in culture, indicating that signals required for activation of myogenin transcription are intrinsic to the limb bud and independent of other parts of the embryo. These results reveal multiple populations of myogenic precursor cells during development and suggest the existence of regulators other than myogenic helix-loop-helix proteins that maintain cells in the early limb bud in the myogenic lineage.
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Affiliation(s)
- T C Cheng
- Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030
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Edmondson DG, Cheng TC, Cserjesi P, Chakraborty T, Olson EN. Analysis of the myogenin promoter reveals an indirect pathway for positive autoregulation mediated by the muscle-specific enhancer factor MEF-2. Mol Cell Biol 1992; 12:3665-77. [PMID: 1324403 PMCID: PMC360220 DOI: 10.1128/mcb.12.9.3665-3677.1992] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Transcriptional cascades that specify cell fate have been well described in invertebrates. In mammalian development, however, gene hierarchies involved in determination of cell lineage are not understood. With the recent cloning of the MyoD family of myogenic regulatory factors, a model system has become available with which to study the dynamics of muscle determination in mammalian development. Myogenin, along with other members of the MyoD gene family, possesses the apparent ability to redirect nonmuscle cells into the myogenic lineage. This ability appears to be due to the direct activation of an array of subordinate or downstream genes which are responsible for formation and function of the muscle contractile apparatus. Myogenin-directed transcription has been shown to occur through interaction with a DNA consensus sequence known as an E box (CANNTG) present in the control regions of numerous downstream genes. In addition to activating the transcription of subordinate genes, members of the MyoD family positively regulate their own expression and cross-activate one another's expression. These autoregulatory interactions have been suggested as a mechanism for induction and maintenance of the myogenic phenotype, but the molecular details of the autoregulatory circuits are undefined. Here we show that the myogenin promoter contains a binding site for the myocyte-specific enhancer-binding factor, MEF-2, which can function as an intermediary of myogenin autoactivation. Since MEF-2 can be induced by myogenin, these results suggest that myogenin and MEF-2 participate in a transcriptional cascade in which MEF-2, once induced by myogenin, acts to amplify and maintain the myogenic phenotype by acting as a positive regulator of myogenin expression.
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Affiliation(s)
- D G Edmondson
- Department of Biochemistry and Molecular Biology, University of Texas M. D. Anderson Cancer Center, Houston 77030
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