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Tsai YT, Lo WL, Chen PY, Ko CY, Chuang JY, Kao TJ, Yang WB, Chang KY, Hung CY, Kikkawa U, Chang WC, Hsu TI. Reprogramming of arachidonate metabolism confers temozolomide resistance to glioblastoma through enhancing mitochondrial activity in fatty acid oxidation. J Biomed Sci 2022; 29:21. [PMID: 35337344 PMCID: PMC8952270 DOI: 10.1186/s12929-022-00804-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Accepted: 03/21/2022] [Indexed: 01/10/2023] Open
Abstract
Background Sp1 is involved in the recurrence of glioblastoma (GBM) due to the acquirement of resistance to temozolomide (TMZ). Particularly, the role of Sp1 in metabolic reprogramming for drug resistance remains unknown. Methods RNA-Seq and mass spectrometry were used to analyze gene expression and metabolites amounts in paired GBM specimens (primary vs. recurrent) and in paired GBM cells (sensitive vs. resistant). ω-3/6 fatty acid and arachidonic acid (AA) metabolism in GBM patients were analyzed by targeted metabolome. Mitochondrial functions were determined by Seahorse XF Mito Stress Test, RNA-Seq, metabolome and substrate utilization for producing ATP. Therapeutic options targeting prostaglandin (PG) E2 in TMZ-resistant GBM were validated in vitro and in vivo. Results Among the metabolic pathways, Sp1 increased the prostaglandin-endoperoxide synthase 2 expression and PGE2 production in TMZ-resistant GBM. Mitochondrial genes and metabolites were obviously increased by PGE2, and these characteristics were required for developing resistance in GBM cells. For inducing TMZ resistance, PGE2 activated mitochondrial functions, including fatty acid β-oxidation (FAO) and tricarboxylic acid (TCA) cycle progression, through PGE2 receptors, E-type prostanoid (EP)1 and EP3. Additionally, EP1 antagonist ONO-8713 inhibited the survival of TMZ-resistant GBM synergistically with TMZ. Conclusion Sp1-regulated PGE2 production activates FAO and TCA cycle in mitochondria, through EP1 and EP3 receptors, resulting in TMZ resistance in GBM. These results will provide us a new strategy to attenuate drug resistance or to re-sensitize recurred GBM. Supplementary Information The online version contains supplementary material available at 10.1186/s12929-022-00804-3.
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Affiliation(s)
- Yu-Ting Tsai
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan, 110
| | - Wei-Lun Lo
- Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taipei, 110, Taiwan.,Department of Neurosurgery, Shuang Ho Hospital, Taipei Medical University, Taipei, 110, Taiwan.,TMU Research Center of Neuroscience, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan
| | - Pin-Yuan Chen
- School of Medicine, Chang Gung University, Taoyuan City, 33302, Taiwan.,Department of Neurosurgery, Keelung Chang Gung Memorial Hospital, Keelung, 204, Taiwan.,Department of Neurosurgery, Linkou Chang Gung Memorial Hospital, Taoyuan, 333, Taiwan
| | - Chiung-Yuan Ko
- TMU Research Center of Neuroscience, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan.,Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, 110, Taiwan.,Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan.,Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan.,TMU Research Center of Cancer Translational Medicine, Taipei, 110, Taiwan
| | - Jian-Ying Chuang
- TMU Research Center of Neuroscience, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan.,Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, 110, Taiwan.,Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan.,Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan.,TMU Research Center of Cancer Translational Medicine, Taipei, 110, Taiwan
| | - Tzu-Jen Kao
- TMU Research Center of Neuroscience, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan.,Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, 110, Taiwan.,Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan.,Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan.,TMU Research Center of Cancer Translational Medicine, Taipei, 110, Taiwan
| | - Wen-Bing Yang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan, 110.,TMU Research Center of Neuroscience, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan
| | - Kwang-Yu Chang
- National Institute of Cancer Research, National Health Research Institutes, Tainan, 704, Taiwan
| | - Chia-Yang Hung
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope, Duarte, CA, 91010, USA
| | - Ushio Kikkawa
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan, 110
| | - Wen-Chang Chang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan, 110. .,TMU Research Center of Neuroscience, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan.
| | - Tsung-I Hsu
- TMU Research Center of Neuroscience, Taipei Medical University, 250 Wu-Hsing Street, Taipei, Taiwan. .,Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, 110, Taiwan. .,Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan. .,Ph.D. Program in Medical Neuroscience, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, 110, Taiwan. .,TMU Research Center of Cancer Translational Medicine, Taipei, 110, Taiwan. .,National Institute of Cancer Research, National Health Research Institutes, Tainan, 704, Taiwan.
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2
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Adamus T, Hung CY, Yu C, Kang E, Hammad M, Flores L, Nechaev S, Zhang Q, Gonzaga JM, Muthaiyah K, Swiderski P, Aboody KS, Kortylewski M. Glioma-targeted delivery of exosome-encapsulated antisense oligonucleotides using neural stem cells. Mol Ther Nucleic Acids 2022; 27:611-620. [PMID: 35036069 PMCID: PMC8752899 DOI: 10.1016/j.omtn.2021.12.029] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 12/17/2021] [Indexed: 12/20/2022]
Abstract
Tropism of neural stem cells (NSCs) to hypoxic tumor areas provides an opportunity for the drug delivery. Here, we demonstrate that NSCs effectively transport antisense oligonucleotides (ASOs) targeting oncogenic and tolerogenic signal transducer and activator of transcription 3 (STAT3) protein into glioma microenvironment. To enable spontaneous, scavenger receptor-mediated endocytosis by NSCs, we used previously described CpG-STAT3ASO conjugates. Following uptake and endosomal escape, CpG-STAT3ASO colocalized with CD63+ vesicles and later with CD63+CD81+ exosomes. Over 3 days, NSCs secreted exosomes loaded up to 80% with CpG-STAT3ASO. Compared to native NSC exosomes, the CpG-STAT3ASO-loaded exosomes potently stimulated immune activity of human dendritic cells or mouse macrophages, inducing nuclear factor κB (NF-κB) signaling and interleukin-12 (IL-12) production. Using orthotopic GL261 tumors, we confirmed that NSC-mediated delivery improved oligonucleotide transfer from a distant injection site into the glioma microenvironment versus naked oligonucleotides. Correspondingly, the NSC-delivered CpG-STAT3ASO enhanced activation of glioma-associated microglia. Finally, we demonstrated that NSC-mediated CpG-STAT3ASO delivery resulted in enhanced antitumor effects against GL261 glioma in mice. Peritumoral injections of 5 × 105 NSCs loaded ex vivo with CpG-STAT3ASO inhibited subcutaneous tumor growth more effectively than the equivalent amount of oligonucleotide alone. Based on these results, we anticipate that NSCs and NSC-derived exosomes will provide a clinically relevant strategy to improve delivery and safety of oligonucleotide therapeutics for glioma treatment.
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Affiliation(s)
- Tomasz Adamus
- Department of Immuno-Oncology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Chia-Yang Hung
- Department of Immuno-Oncology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Chunsong Yu
- Department of Immuno-Oncology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Elaine Kang
- Department of Immuno-Oncology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Mohamed Hammad
- Department of Developmental and Stem Cell Biology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Linda Flores
- Department of Developmental and Stem Cell Biology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Sergey Nechaev
- Department of Immuno-Oncology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Qifang Zhang
- Department of Immuno-Oncology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Joanna Marie Gonzaga
- Department of Developmental and Stem Cell Biology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Kokilah Muthaiyah
- DNA/RNA Synthesis Laboratory, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Piotr Swiderski
- DNA/RNA Synthesis Laboratory, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Karen S Aboody
- Department of Developmental and Stem Cell Biology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
| | - Marcin Kortylewski
- Department of Immuno-Oncology, Beckman Research Institute at City of Hope Comprehensive Cancer Center, Duarte, CA 91010, USA
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Lin HY, Liao KH, Ko CY, Chen GY, Hsu SP, Hung CY, Hsu TI. 17β-estradiol induces temozolomide resistance through NRF2-mediated redox homeostasis in glioblastoma. Free Radic Biol Med 2021; 172:430-440. [PMID: 34186205 DOI: 10.1016/j.freeradbiomed.2021.06.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/17/2021] [Accepted: 06/23/2021] [Indexed: 11/23/2022]
Abstract
Glioblastoma multiforme (GBM) is the most fatal cancer among brain tumors, and the standard treatment of GBM patients is surgical tumor resection followed by radiotherapy and temozolomide (TMZ) chemotherapy. However, tumors always recur due to the developing drug resistance. It has been shown that neurosteroids, including dehydroepiandrosterone and 17β-estradiol, are synthesized in TMZ-resistant GBM tumors. Therefore, we sought to explore the possible role of 17β-estradiol in the development of drug resistance in GBM. Bioinformatics analysis revealed that aromatase/cytochrome P450 19A1 expression was gradually increased in the development from normal, astrocytoma to GBM. The level of 17β-estradiol was significantly increased in TMZ-resistant cells characterized by ultra performance liquid chromatography-tandem mass spectrometry. Furthermore, 17β-estradiol attenuated TMZ-induced cell death and reduced reactive oxygen species production by mitochondria. In addition, 17β-estradiol attenuated oxidative stress by increasing the expression of superoxide dismutase 1/2, catalase, and nuclear factor erythroid 2-related factor (NRF) 2. We found that NRF2 expression was essential for the induction of drug resistance by 17β-estradiol through the reduction of oxidative stress in GBM.
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Affiliation(s)
- Hong-Yi Lin
- The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institute, Taipei, Taiwan
| | - Kuo-Hsing Liao
- Department of Neurosurgery, Wan Fang Hospital, Taipei Medical University, Taiwan; Division of Critical Medicine, Department of Emergency and Critical Medicine, Wan Fang Hospital, Taipei Medical University, Taiwan; Department of Neurotraumatology and Intensive Care, Taipei Neuroscience Institute, Taipei Medical University, Taiwan; Division of Neurosurgery, Department of Surgery, School of Medicine, College of Medicine, Taipei Medical University, Taiwan
| | - Chiung-Yuan Ko
- The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institute, Taipei, Taiwan; Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; TMU Research Center of Neuroscience, Taipei Medical University, Taipei, Taiwan
| | - Guan-Yuan Chen
- Graduate Institute of Forensic Medicine, National Taiwan University, Taipei, Taiwan
| | - Sung-Po Hsu
- Department of Physiology, School of Medicine, Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Chia-Yang Hung
- Department of Immuno-Oncology, Beckman Research Institute, City of Hope, Duarte, CA, USA
| | - Tsung-I Hsu
- The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institute, Taipei, Taiwan; Graduate Institute of Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan; TMU Research Center of Neuroscience, Taipei Medical University, Taipei, Taiwan; TMU Research Center of Cancer Translational Medicine, Taipei Medical University, Taipei, Taiwan.
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4
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Hsu TI, Wang YC, Hung CY, Yu CH, Su WC, Chang WC, Hung JJ. Positive feedback regulation between IL10 and EGFR promotes lung cancer formation. Oncotarget 2018; 7:20840-54. [PMID: 26956044 PMCID: PMC4991496 DOI: 10.18632/oncotarget.7894] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 01/29/2016] [Indexed: 01/20/2023] Open
Abstract
The role of IL10 in the tumorigenesis of various cancer types is still controversial. Here, we found that increased IL10 levels are correlated with a poor prognosis in lung cancer patients. Moreover, IL10 levels were significantly increased in the lungs and serum of EGFRL858R- and Kras4bG12D-induced lung cancer mice, indicating that IL10 might facilitate lung cancer tumorigenesis. IL10 knockout in EGFRL858R and Kras4bG12D mice inhibited the development of lung tumors and decreased the levels of infiltrating M2 macrophages and tumor-promoting Treg lymphocytes. We also showed that EGF increases IL10 expression by enhancing IL10 mRNA stability, and IL10 subsequently activates JAK1/STAT3, Src, PI3K/Akt, and Erk signaling pathways. Interestingly, the IL10-induced recruitment of phosphorylated Src was critical for inducing EGFR through the activation of the JAK1/STAT3 pathway, suggesting that Src and JAK1 positively regulate each other to enhance STAT3 activity. Doxycycline-induced EGFRL858R mice treated with gefitinib and anti-IL10 antibodies exhibited poor tumor formation. In conclusion, IL10 and EGFR regulate each other through positive feedback, which leads to lung cancer formation.
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Affiliation(s)
- Tsung-I Hsu
- Center for Infection Disease and Signal Research, College of Medicine, Tainan, Taiwan.,Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.,The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, Taiwan
| | - Yi-Chang Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chia-Yang Hung
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Chun-Hui Yu
- Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Wu-Chou Su
- Department of Internal Medicine, College of Medicine and Hospital, National Cheng Kung University, Tainan, Taiwan
| | - Wen-Chang Chang
- Center for Infection Disease and Signal Research, College of Medicine, Tainan, Taiwan.,Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.,The Ph.D. Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University and National Health Research Institutes, Taipei, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jan-Jong Hung
- Center for Infection Disease and Signal Research, College of Medicine, Tainan, Taiwan.,Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
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5
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Tsui KL, Hung CY, Kam CW. A Manikin Study to Compare Video-Optical Intubation Stylet versus Macintosh Laryngoscope Used by Novice in Normal and Simulated Difficult Airway Intubation. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790801500302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Objective To compare Macintosh laryngoscope with video-optical intubation stylet on rates and time durations of successful tracheal intubation in normal and simulated difficult airway. Design Crossover experimental study. Setting Intubation training laboratory. Methods A group of novices (58 medical students) attempted intubation on manikin under normal and simulated difficult airway (grade 3 larygnoscopic view) settings using both Macintosh laryngoscope and video-optical intubation stylet. The success rate, duration to intubate and occurrence of complications (oesophageal intubation and incisor breakage) when using the two different devices were measured and compared. The time results were analysed by paired t-test and categorical results by chi square test or Fisher's exact test. Results The success rate to intubate difficult airway using video-optical intubation stylet (0.92) was significantly higher than using Macintosh laryngoscope (0.59) (p=0.002). The mean time taken to intubate difficult airway using video-optical intubation stylet was significantly shorter than using Macintosh laryngoscope by 10.90 seconds (p=0.004). Oesophageal intubation rate was significantly higher when using Macintosh laryngoscope to intubate difficult airway compared to video-optical intubation stylet (p=0.002). There was no significant difference on the rate of incisor breakage between the two instruments. Conclusions Novice can learn to use both Macintosh laryngoscope and video-optical intubation stylet to intubate successfully after a short training. Video-optical intubation stylet is an effective “Plan B” instrument because it shortens the duration and increases the rate of successful intubation in difficult airway situations.
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6
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Hung CY, Ng P, Yau HH, Kam CW. Two Pregnant Women Presenting with Umbilical Cord Prolapse. HONG KONG J EMERG ME 2017. [DOI: 10.1177/102490790301000108] [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: 11/17/2022] Open
Abstract
Cord prolapse is an obstetric emergency as delay in management is associated with significantly increased neonatal morbidity and mortality. If the accident occurred outside the hospital, many babies would be dead or severely asphyxiated upon arrival in the hospital. The role of Accident & Emergency (A&E) department is to arrive at this diagnosis promptly and deliver appropriate intervention. Immediate cesarean delivery is the treatment of choice. The clinical presentations of two cases with umbilical cord prolapse presenting to our A&E department within two weeks were described. The pathophysiology, risk factors, diagnosis, management as well as outcome were discussed.
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Affiliation(s)
| | | | | | - CW Kam
- Tuen Mun Hospital, Accident and Emergency Department, Ching Chung Koon Road, Tuen Mun, N.T., Hong Kong
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Abstract
Acute gastroenteritis represents a frequent cause of morbidity among children in Hong Kong. Despite the large number of potential etiologic agents, principles of management of gastroenteritis are uniform and aim to prevent the two major complications - dehydration and malnutrition. A review of the literature was performed. Selected articles were appraised, graded, and synthesised qualitatively. Statements on recommendations were generated. Current evidence emphasises the use of oral rehydration and the early reintroduction of age-appropriate foods. Apart from these two, important aspects of management reviewed included laboratory investigations, role of anti-diarrhoeal agents, and use of antimicrobial agents. Criteria for admission of high-risk children are also addressed.
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8
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Abstract
This study evaluated the resuscitation outcome of adult patients presenting with non-traumatic out-of-hospital cardiac arrest (OHCA) to a regional hospital in Hong Kong. Out of 876 patients of non-traumatic OHCA, 12.7% survived to hospital admission. Only 0.5% of the 876 patients survived to hospital discharge and at one year after discharge. The number needed to treat (NNT) for prehospital asystolic cardiac arrest to have one survival to discharge was 795.
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9
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Hung CY, Wang YC, Chuang JY, Young MJ, Liaw H, Chang WC, Hung JJ. Nm23-H1-stabilized hnRNPA2/B1 promotes internal ribosomal entry site (IRES)-mediated translation of Sp1 in the lung cancer progression. Sci Rep 2017; 7:9166. [PMID: 28831131 PMCID: PMC5567229 DOI: 10.1038/s41598-017-09558-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 07/24/2017] [Indexed: 12/20/2022] Open
Abstract
Our recent studies have indicated that specificity protein-1 (Sp1) accumulates substantially in the early stage of lung cancer but is partially decreased in the late stages, which is an important factor in the progression of the cancer. In this study, we found that Nm23-H1 and hnRNPA2/B1 could be recruited to the 5'UTR of Sp1 mRNA. In investigating the clinical relevance of Nm23-H1/Sp1 levels, we found a positive correlation between lung cancer patients with poor prognosis and low levels of Sp1 and Nm23-H1, suggesting an association between Nm23-H1/Sp1 levels and survival rate. Knockdown of Nm23-H1 inhibits lung cancer growth but increases lung cancer cell malignancy, which could be rescued by overexpression of Sp1, indicating that Nm23-H1-induced Sp1 expression is critical for lung cancer progression. We also found that Nm23-H1 increases the protein stability of hnRNPA2/B1and is thereby co-recruited to the 5'UTR of Sp1 mRNA to regulate cap-independent translational activity. Since the Sp1 level is tightly regulated during lung cancer progression, understanding the molecular mechanisms underlying the regulation by Nm23-H1/hnRNPA2B1 of Sp1 expression in the various stages of lung cancer will be beneficial for lung cancer therapy in the future.
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Affiliation(s)
- Chia-Yang Hung
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Yi-Chang Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Jian-Ying Chuang
- The PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Ming-Jer Young
- Department of Biotechnology and Bioindustry Science, National Cheng Kung University, Tainan, Taiwan
- Center for Infection Disease and Signal Transduction, National Cheng Kung University, Tainan, Taiwan
| | - Hungjiun Liaw
- Department of Life Sciences, National Cheng Kung University, Tainan, Taiwan
| | - Wen-Chang Chang
- The PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Jan-Jong Hung
- Department of Biotechnology and Bioindustry Science, National Cheng Kung University, Tainan, Taiwan.
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
- Center for Infection Disease and Signal Transduction, National Cheng Kung University, Tainan, Taiwan.
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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10
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Valdes G, Scheuermann R, Hung CY, Olszanski A, Bellerive M, Solberg TD. A mathematical framework for virtual IMRT QA using machine learning. Med Phys 2017; 43:4323. [PMID: 27370147 DOI: 10.1118/1.4953835] [Citation(s) in RCA: 121] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
PURPOSE It is common practice to perform patient-specific pretreatment verifications to the clinical delivery of IMRT. This process can be time-consuming and not altogether instructive due to the myriad sources that may produce a failing result. The purpose of this study was to develop an algorithm capable of predicting IMRT QA passing rates a priori. METHODS From all treatment, 498 IMRT plans sites were planned in eclipse version 11 and delivered using a dynamic sliding window technique on Clinac iX or TrueBeam Linacs. 3%/3 mm local dose/distance-to-agreement (DTA) was recorded using a commercial 2D diode array. Each plan was characterized by 78 metrics that describe different aspects of their complexity that could lead to disagreements between the calculated and measured dose. A Poisson regression with Lasso regularization was trained to learn the relation between the plan characteristics and each passing rate. RESULTS Passing rates 3%/3 mm local dose/DTA can be predicted with an error smaller than 3% for all plans analyzed. The most important metrics to describe the passing rates were determined to be the MU factor (MU per Gy), small aperture score, irregularity factor, and fraction of the plan delivered at the corners of a 40 × 40 cm field. The higher the value of these metrics, the worse the passing rates. CONCLUSIONS The Virtual QA process predicts IMRT passing rates with a high likelihood, allows the detection of failures due to setup errors, and it is sensitive enough to detect small differences between matched Linacs.
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Affiliation(s)
- G Valdes
- Radiation Oncology Department, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19123
| | - R Scheuermann
- Radiation Oncology Department, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19123
| | - C Y Hung
- Radiation Oncology Department, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19123
| | - A Olszanski
- Radiation Oncology Department, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19123
| | - M Bellerive
- Radiation Oncology Department, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19123
| | - T D Solberg
- Radiation Oncology Department, Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19123
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11
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Hsu TI, Chen YJ, Hung CY, Wang YC, Lin SJ, Su WC, Lai MD, Kim SY, Wang Q, Qian K, Goto M, Zhao Y, Kashiwada Y, Lee KH, Chang WC, Hung JJ. A novel derivative of betulinic acid, SYK023, suppresses lung cancer growth and malignancy. Oncotarget 2016; 6:13671-87. [PMID: 25909174 PMCID: PMC4537041 DOI: 10.18632/oncotarget.3701] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Accepted: 03/02/2015] [Indexed: 12/25/2022] Open
Abstract
Herein, we evaluated the anti-cancer effect and molecular mechanisms of a novel betulinic acid (BA) derivative, SYK023, by using two mouse models of lung cancer driven by KrasG12D or EGFRL858R. We found that SYK023 inhibits lung tumor proliferation, without side effects in vivo or cytotoxicity in primary lung cells in vitro. SYK023 triggered endoplasmic reticulum (ER) stress. Blockage of ER stress in SYK023-treated cells inhibited SYK023-induced apoptosis. In addition, we found that the expression of cell cycle-related genes, including cyclin A2, B1, D3, CDC25a, and CDC25b decreased but, while those of p15INK4b, p16INK4a, and p21CIP1 increased following SYK023 treatment. Finally, low doses of SYK023 significantly decreased lung cancer metastasis in vitro and in vivo. Expression of several genes related to cell migration, including synaptopodin, were downregulated by SYK023, thereby impairing F-actin polymerization and metastasis. Therefore, SYK023 may be a potentially therapeutic treatment for metastatic lung cancer.
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Affiliation(s)
- Tsung-I Hsu
- Center for Infection Disease and Signal Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Ying-Jung Chen
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Chia-Yang Hung
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Yi-Chang Wang
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Sin-Jin Lin
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan
| | - Wu-Chou Su
- Department of Internal Medicine, College of Medicine and Hospital, National Cheng Kung University, Tainan, Taiwan
| | - Ming-Derg Lai
- Center for Infection Disease and Signal Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Biochemistry and Molecular Biology, College of Medicine, National Cheng Kung University, Tainan, Taiwan
| | - Sang-Yong Kim
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Qiang Wang
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Keduo Qian
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Masuo Goto
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Yu Zhao
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - Yoshiki Kashiwada
- Laboratory of Pharmacognosy, Graduate School of Pharmaceutical Sciences, The University of Tokushima, Tokushima, Japan
| | - Kuo-Hsiung Lee
- Natural Products Research Laboratories, UNC Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA.,Chinese Medicine Research and Development Center, China Medical University and Hospital, Taichung, Taiwan
| | - Wen-Chang Chang
- Center for Infection Disease and Signal Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jan-Jong Hung
- Center for Infection Disease and Signal Research, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng Kung University, Tainan, Taiwan.,Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Department of Pharmacology, College of Medicine, National Cheng Kung University, Tainan, Taiwan.,Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
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12
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Özçakar L, Kara M, Chang KV, Tok F, Hung CY, Akkaya N, Wu CH, Çarli AB, Hsiao MY, Tekin L, Wang TG, Ulaşlı AM, Chen WS, De Muynck M. EURO-MUSCULUS/USPRM. Basic scanning protocols for knee. Eur J Phys Rehabil Med 2015; 51:641-646. [PMID: 26351105] [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: 06/05/2023]
Abstract
In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned knee structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.
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Affiliation(s)
- L Özçakar
- Department of Physical and Rehabilitation Medicine, Hacettepe University Medical School, Ankara, Turkey -
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13
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Özçakar L, Kara M, Chang KV, Akkaya N, Hung CY, Tok F, Wu CH, Çarli AB, Hsiao MY, Tekin L, Wang TG, Ulaşlı AM, Chen WS, De Muynck M. EURO-MUSCULUS/USPRM. Basic scanning protocols for hip. Eur J Phys Rehabil Med 2015; 51:635-640. [PMID: 26351107] [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: 06/05/2023]
Abstract
In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned hip structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.
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Affiliation(s)
- L Özçakar
- Department of Physical and Rehabilitation Medicine, Hacettepe University Medical School, Ankara, Turkey -
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14
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Özçakar L, Kara M, Chang KV, Bayram Çarli A, Hung CY, Tok F, Wu CH, Akkaya N, Hsiao MY, Tekin L, Wang TG, Ulaşlı AM, Chen WS, De Muynck M. EURO-MUSCULUS/USPRM. Basic Scanning Protocols for Ankle and foot. Eur J Phys Rehabil Med 2015; 51:647-653. [PMID: 26351106] [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: 06/05/2023]
Abstract
In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned ankle/foot structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.
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Affiliation(s)
- L Özçakar
- Department of Physical and Rehabilitation Medicine, Hacettepe University Medical School, Ankara, Turkey -
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15
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Özçakar L, Kara M, Chang KV, Hung CY, Tekın L, Ulaşlı AM, Wu CH, Tok F, Hsıao MY, Akkaya N, Wang TG, Çarli AB, Chen WS, De Muynck M. EURO-MUSCULUS/USPRM Basic Scanning Protocols for elbow. Eur J Phys Rehabil Med 2015; 51:485-489. [PMID: 26158916] [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: 06/04/2023]
Abstract
In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned elbow structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.
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Affiliation(s)
- L Özçakar
- Department of Physical and Rehabilitation Medicine, Hacettepe University Medical School, Ankara, Turkey -
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16
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Chang KV, Hung CY, Han DS, Chen WS, Wang TG, Chien KL. Corrigendum. Early versus delayed passive range of motion exercise for arthroscopic rotator cuff repair: a meta-analysis of randomized controlled trials. Am J Sports Med 2015; 43:NP26. [PMID: 26232461 DOI: 10.1177/0363546515596940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Chang KV, Hung CY, Han DS, Chen WS, Wang TG, Chien KL. Early versus delayed passive range of motion exercise for arthroscopic rotator cuff repair: a meta-analysis of randomized controlled trials. Am J Sports Med. 2015;43(5):1265-1273. (Original DOI: 10.1177/0363546514544698 )
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17
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Özçakar L, Kara M, Chang KV, Ulaşlı AM, Hung CY, Tekin L, Wu CH, Tok F, Hsiao MY, Akkaya N, Wang T, Çarli AB, Chen WS, De Muynck M. EURO-MUSCULUS/USPRM Basic Scanning Protocols for wrist and hand. Eur J Phys Rehabil Med 2015; 51:479-484. [PMID: 26158917] [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: 06/04/2023]
Abstract
In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned wrist/hand structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.
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Affiliation(s)
- L Özçakar
- Department of Physical and Rehabilitation Medicine, Hacettepe University Medical School, Ankara, Turkey -
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18
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Özçakar L, Kara M, Chang KV, Tekin L, Hung CY, Ulaülı AM, Wu CH, Tok F, Hsiao MY, Akkaya N, Wang TG, Çarli AB, Chen WS, De Muynck M. EURO-MUSCULUS/USPRM Basic Scanning Protocols for shoulder. Eur J Phys Rehabil Med 2015; 51:491-496. [PMID: 26158915] [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: 06/04/2023]
Abstract
In this protocol, the patient/probe positionings, anatomical drawings and ultrasound images of commonly scanned shoulder structures are described. This practical guide is prepared (with an international consensus of several expert physiatrists) to serve as a uniform/standard approach especially for beginner sonographers.
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Affiliation(s)
- L Özçakar
- Department of Physical and Rehabilitation Medicine, Hacettepe University Medical School, Ankara, Turkey -
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19
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Koenighofer M, Hung CY, McCauley JL, Dallman J, Back EJ, Mihalek I, Gripp KW, Sol-Church K, Rusconi P, Zhang Z, Shi GX, Andres DA, Bodamer OA. Mutations in RIT1 cause Noonan syndrome - additional functional evidence and expanding the clinical phenotype. Clin Genet 2015; 89:359-66. [PMID: 25959749 DOI: 10.1111/cge.12608] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [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: 03/24/2015] [Revised: 04/05/2015] [Accepted: 05/05/2015] [Indexed: 12/24/2022]
Abstract
RASopathies are a clinically heterogeneous group of conditions caused by mutations in 1 of 16 proteins in the RAS-mitogen activated protein kinase (RAS-MAPK) pathway. Recently, mutations in RIT1 were identified as a novel cause for Noonan syndrome. Here we provide additional functional evidence for a causal role of RIT1 mutations and expand the associated phenotypic spectrum. We identified two de novo missense variants p.Met90Ile and p.Ala57Gly. Both variants resulted in increased MEK-ERK signaling compared to wild-type, underscoring gain-of-function as the primary functional mechanism. Introduction of p.Met90Ile and p.Ala57Gly into zebrafish embryos reproduced not only aspects of the human phenotype but also revealed abnormalities of eye development, emphasizing the importance of RIT1 for spatial and temporal organization of the growing organism. In addition, we observed severe lymphedema of the lower extremity and genitalia in one patient. We provide additional evidence for a causal relationship between pathogenic mutations in RIT1, increased RAS-MAPK/MEK-ERK signaling and the clinical phenotype. The mutant RIT1 protein may possess reduced GTPase activity or a diminished ability to interact with cellular GTPase activating proteins; however the precise mechanism remains unknown. The phenotypic spectrum is likely to expand and includes lymphedema of the lower extremities in addition to nuchal hygroma.
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Affiliation(s)
- M Koenighofer
- Department of Otorhinolaryngology, Medical University of Vienna, Vienna, Austria
| | - C Y Hung
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Dr. John T. Macdonald Foundation Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL, USA.,Harvard Medical School, Boston, MA, USA
| | - J L McCauley
- Dr. John T. Macdonald Foundation Department of Human Genetics, Miller School of Medicine, University of Miami, Miami, FL, USA.,John P. Hussman Institute for Human Genomics, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - J Dallman
- Department of Biology, University of Miami, Miami, FL, USA
| | - E J Back
- Department of Biology, University of Miami, Miami, FL, USA
| | - I Mihalek
- Bioinformatics Institute A*STAR Singapore, Singapore
| | - K W Gripp
- Division of Medical Genetics, Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - K Sol-Church
- Department of Pediatrics, Division of Pediatric Cardiology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - P Rusconi
- Department of Pediatrics, Division of Pediatric Cardiology, Miller School of Medicine, University of Miami, Miami, FL, USA
| | - Z Zhang
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - G-X Shi
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - D A Andres
- Department of Molecular and Cellular Biochemistry, College of Medicine, University of Kentucky, Lexington, KY, USA
| | - O A Bodamer
- Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
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20
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Hung CY, Yang WB, Wang SA, Hsu TI, Chang WC, Hung JJ. Nucleolin enhances internal ribosomal entry site (IRES)-mediated translation of Sp1 in tumorigenesis. Biochim Biophys Acta 2014; 1843:2843-54. [PMID: 25173817 DOI: 10.1016/j.bbamcr.2014.08.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2013] [Revised: 07/14/2014] [Accepted: 08/20/2014] [Indexed: 11/24/2022]
Abstract
Our previous study indicated that specificity protein-1 (Sp1) is accumulated during hypoxia in an internal ribosomal entry site (IRES)-dependent manner. Herein, we found that the Sp1 was induced strongly at the protein level, but not in the mRNA level, in lung tumor tissue, indicating that translational regulation might contribute to the Sp1 accumulation during tumorigenesis. A further study showed that the translation of Sp1 was dramatically induced through an IRES-dependent pathway. RNA immunoprecipitation analysis of proteins bound to the 5'-untranslated region (5'-UTR) of Sp1 identified interacting protein - nucleolin. Knockdown of nucleolin significantly inhibited IRES-mediated translation of Sp1, suggesting that nucleolin positively facilitates Sp1 IRES activation. Further analysis of the interaction between nucleolin and the 5'-UTR of Sp1 mRNA revealed that the GAR domain was important for IRES-mediated translation of Sp1. Moreover, gefitinib, and LY294002 and MK2206 compounds inhibited IRES-mediated Sp1 translation, implying that activation of the epithelial growth factor receptor (EGFR) pathway via Akt activation triggers the IRES pathway. In conclusion, EGFR activation-mediated nucleolin phosphorylated at Thr641 and Thr707 was recruited to the 5'-UTR of Sp1 as an IRES trans-acting factor to modulate Sp1 translation during lung cancer formation.
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Affiliation(s)
- Chia-Yang Hung
- Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
| | - Wen-Bin Yang
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience in Biotechnology, National Cheng-Kung University, Tainan, Taiwan
| | - Shao-An Wang
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience in Biotechnology, National Cheng-Kung University, Tainan, Taiwan
| | - Tsung-I Hsu
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan; Institute of Bioinformatics and Biosignal Transduction, College of Bioscience in Biotechnology, National Cheng-Kung University, Tainan, Taiwan; Center for Infection Disease and Signal Transduction, National Cheng-Kung University, Tainan, Taiwan
| | - Wen-Chang Chang
- Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan
| | - Jan-Jong Hung
- Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan, Taiwan; Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan; Institute of Bioinformatics and Biosignal Transduction, College of Bioscience in Biotechnology, National Cheng-Kung University, Tainan, Taiwan; Center for Infection Disease and Signal Transduction, National Cheng-Kung University, Tainan, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei, Taiwan.
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21
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Wang SA, Hung CY, Chuang JY, Chang WC, Hsu TI, Hung JJ. Phosphorylation of p300 increases its protein degradation to enhance the lung cancer progression. Biochim Biophys Acta 2014; 1843:1135-49. [PMID: 24530506 DOI: 10.1016/j.bbamcr.2014.02.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/01/2013] [Revised: 01/21/2014] [Accepted: 02/02/2014] [Indexed: 01/05/2023]
Abstract
p300 is a transcription cofactor for a number of nuclear proteins. Most studies of p300 have focused on the regulation of its function, which primarily includes its role as a transcription co-factor for a number of nuclear proteins. In this study, we found that p300 was highly phosphorylated and its level was decreased during mitosis and tumorigenesis. In vitro and in vivo experiments aimed showed that cyclin-dependent kinase 1 (CDK1) and ERK1/2 phosphorylated p300 on Ser1038 and Ser2039. Mutations of Ser1038 and Ser2039 increased p300 protein stability and levels. Inhibition of p300 degradation by blocking its phosphorylation decreased the proliferation and metastasis activity of lung cancer cells, indicating that p300 acts as a tumor suppressor in lung cancer tumorigenesis. Investigation of the molecular mechanism showed that blocking p300 phosphorylation disrupted chromatin condensation and the increased the acetylation of histone H3. Analysis of cell cycle progression in HA-p300-S2A-expressing cells by flow cytometry showed that the p300 mutants arrested the cells at S-phase or delayed the mitotic entry and exit. The expression of several important oncogenes, MMP-9, vimentin, β-catenin, N-cadherin and c-myc, was negatively regulated by p300. In conclusion, during lung tumorigenesis, a phosphorylation-mediated decrease in p300 level enhanced oncogene expression during interphase and decreased histone H3 acetylation during mitosis, which promoted lung cancer progression.
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Affiliation(s)
- Shao-An Wang
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan
| | - Chia-Yang Hung
- Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan 701, Taiwan
| | - Jian-Ying Chuang
- Neural Regenerative Medicine, College of Medical Sciences and Technology, Taipei Medical University, Taipei 11031, Taiwan
| | - Wen-Chang Chang
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan; Department of Pharmacology, National Cheng-Kung University, Tainan 701, Taiwan; Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan 701, Taiwan; Center for Infectious Disease and Signal Transduction, National Cheng-Kung University, Tainan 701, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan
| | - Tsung-I Hsu
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan; Center for Infectious Disease and Signal Transduction, National Cheng-Kung University, Tainan 701, Taiwan
| | - Jan-Jong Hung
- Institute of Bioinformatics and Biosignal Transduction, College of Bioscience and Biotechnology, National Cheng-Kung University, Tainan 701, Taiwan; Department of Pharmacology, National Cheng-Kung University, Tainan 701, Taiwan; Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan 701, Taiwan; Center for Infectious Disease and Signal Transduction, National Cheng-Kung University, Tainan 701, Taiwan; Graduate Institute of Medical Sciences, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
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22
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Kan WC, Wang JJ, Sun YM, Hung CY, Chu CC, Chien CC. The comorbidity scoring systems for predicting survival in elderly dialysis patients and additional management strategies. ACTA ACUST UNITED AC 2013. [DOI: 10.13172/2053-0293-1-2-762] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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23
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Hung CY, Hu HC, Chang CH, Huang CC, Kao KC. Outcomes of early delivery in pregnant patients with acute respiratory distress syndrome. Crit Care 2012. [PMCID: PMC3363530 DOI: 10.1186/cc10719] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Poon WL, Hung CY, Nakano K, Randall DJ. An in vivo study of common carp (Cyprinus carpio L.) liver during prolonged hypoxia. Comp Biochem Physiol Part D Genomics Proteomics 2007; 2:295-302. [PMID: 20483301 DOI: 10.1016/j.cbd.2007.05.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2007] [Revised: 05/08/2007] [Accepted: 05/11/2007] [Indexed: 10/23/2022]
Abstract
Hypoxia induced apoptosis has been studied extensively in many mammalian cell lines but there are only a few studies using whole animal models. We investigated the response of the intact liver to hypoxia in a hypoxia tolerant fish, the carp (Cyprinus carpio, L). We exposed carp to hypoxia for up to 42 days, using oxygen level (0.5 mgO(2)/L) that were slightly higher than the critical oxygen level of carp. There was extensive DNA damage in liver cells, especially during the first week of exposure, indicated by a massive TUNEL signal. However there was no change in cell proliferation, cell number or size, no increase in caspase-3 activity, no increase in single stranded DNA and this, combined with a number of other observations, led us to conclude there was no increase in apoptosis in the liver during hypoxia. There was up-regulation of some anti-apoptotic genes and proteins (Bcl-2, HSP70, p27) and down-regulation of some pro-apoptotic genes (Tetraspanin 5 and Cell death activator). The cells appeared to enter cell cycle arrest, presumably to allow repair of damaged DNA. As there was no change in cell proliferation and cell number, the damaged cells were not entering apoptosis and must have recovered during prolonged hypoxia.
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Affiliation(s)
- W L Poon
- Department of Biology and Chemistry, City University of Hong Kong, Kowloon, Hong Kong, S.A.R., China
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25
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Shih M, Lee WS, Chang-Chien GP, Wang LC, Hung CY, Lin KC. Dry deposition of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in ambient air. Chemosphere 2006; 62:411-6. [PMID: 15964055 DOI: 10.1016/j.chemosphere.2005.04.064] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 03/07/2005] [Accepted: 04/17/2005] [Indexed: 05/03/2023]
Abstract
The PCDD/Fs in the ambient air associated with concentration and dry deposition flux of four seasons were characterized in rural area. The mean PCDD/F concentrations were 0.342, 0.221, 0.675, 0.741 pg m(-3) and the mean I-TEQ values were 0.027, 0.016, 0.024, 0.063 pg m(-3) in spring, summer, fall and winter, respectively. Ambient air in winter was higher by a factor of 3.4 and 3.9 for PCDD/F concentration and I-TEQ, respectively, than in summer. The study area is located in a Tropical region. Hence, domestic heating is not found in this area and is not responsible for the elevated winter concentration in comparison to other studies. A smooth plate with a sharp leading edge that is pointed into the wind by a wind vane was used for measuring dry deposition flux of PCDD/Fs. Atmospheric dry deposition fluxes of total PCDD/Fs were 140, 116, 137, and 207 pg m(-2)day(-1) in spring, summer, fall, and winter, respectively, and averaged approximately 150 pg m(-2)day(-1). The total dry deposition flux was found to decrease as the temperature increased. Calculated dry deposition velocities of total PCDD/Fs were 0.45, 0.52, 0.32 and 0.39 cm s(-1) in spring, summer, fall, and winter, respectively, and averaged 0.42 cm s(-1).
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Affiliation(s)
- Minliang Shih
- Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, No. 60, Section 1, Erh-Jen Rd., Tainan 717, Taiwan, ROC.
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26
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Abstract
Coccidioides is a fungal pathogen of humans which can cause a life-threatening respiratory disease in immunocompetent individuals. Recurrent epidemics of coccidioidal infections in Southwestern United States has raised the specter of awareness of this soil-borne microbe, particularly among residents of Arizona and Southern California, and has galvanized research efforts to develop a human vaccine against coccidioidomycosis. In this review, we discuss the rationale for such a vaccine, examine the features of host innate and acquired immune response to Coccidioides infection, describe strategies used to identify and evaluate vaccine candidates, and provide an update on progress toward development of a vaccine against this endemic pathogen.
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Affiliation(s)
- G T Cole
- Department of Microbiology and Immunology, Medical College of Ohio, Toledo, Ohio 43614, USA
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27
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Abstract
Coccidioides posadasii is a dimorphic fungal pathogen which grows as a filamentous saprobe in the soil and multicellular parasitic form in host lung tissue. Studies of gene expression profiles during saprobic and parasitic phase development can provide clues about morphogenetic regulation and may lead to the discovery of molecular targets for novel antifungal drugs. Suppression-subtractive hybridization (SSH) and quantitative real-time polymerase chain reaction (QRT-PCR) were used to identify and quantify differential gene expression during in vitro growth of Coccidioides. DNA fragments obtained from the subtraction of cDNA pools derived from the saprobic and parasitic phase RNA preparations were each cloned into an appropriate vector and subjected to sequence analysis. Semi-quantitative, reverse transcription polymerase chain reaction (RT-PCR) experiments were first conducted to assess whether these inserts represented differentially expressed genes. Nucleotide sequences of the partial and full-length genes selected by RT-PCR were obtained by genome walking and rapid amplification of cDNA ends (RACE) methods. QRT-PCR analysis of the expression of these genes during saprobic and parasitic cell growth was then conducted using DNA standard curves normalized to a constitutively expressed control gene. Four C. posadasii genes whose expression is essentially restricted to the parasitic cycle were discovered using this approach. These genes include homologues of OPS1 (encodes opsin-related protein), MDR1 (multidrug resistance protein), ALDR1 (aldehyde reductase), and PSP1 (hypothetical lipid transporter/flippase protein). The combined applications of SSH and QRT-PCR permit global analysis of gene expression patterns in C. posadasii.
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Affiliation(s)
- N Delgado
- Department of Microbiology and Immunology Medical College of Ohio, Toledo, Ohio 43614-5806, USA
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Cole GT, Hung CY. The parasitic cell wall of Coccidioides immitis. Med Mycol 2002; 39 Suppl 1:31-40. [PMID: 11800267] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023] Open
Abstract
Coccidioides immitis is a human respiratory pathogen characterized by a parasitic cycle that is unique among fungi that cause systemic mycoses. Biochemical, molecular and immunological studies of the cell wall of C. immitis have focused on three distinct events of parasitic cell differentiation: isotropic growth, segmentation and endosporulation. Current investigations of each developmental phase in vitro include the identification, expression analysis, and disruption of synthase and hydrolase genes that are suspected to have key roles in morphogenesis. Temporal expression of families of beta-glucosidase and chitinase genes are of particular interest because their products may participate in wall modification during both isotropic growth and endosporulation and, thereby, represent potential molecular targets for novel antifungal drugs. Furthermore, our immunological studies of these and other isolated parasitic cell-wall components have resulted in the identification of antigens with demonstrated impact on host response to coccidioidal infection. C. immitis has proved to be an excellent model for fungal cell-wall research.
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Affiliation(s)
- G T Cole
- Department of Microbiology and Immunology, Medical College of Ohio, Toledo 43614-5806, USA.
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Li K, Yu JJ, Hung CY, Lehmann PF, Cole GT. Recombinant urease and urease DNA of Coccidioides immitis elicit an immunoprotective response against coccidioidomycosis in mice. Infect Immun 2001; 69:2878-87. [PMID: 11292702 PMCID: PMC98238 DOI: 10.1128/iai.69.5.2878-2887.2001] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [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: 11/20/2022] Open
Abstract
Coccidioides immitis antigens which stimulate a T helper cell 1 (Th1) pathway of host immune response are considered to be essential components of a vaccine against coccidioidomycosis. Recombinant urease (rURE) and recombinant heat shock protein 60 (rHSP60) of C. immitis were expressed in Escherichia coli and tested as vaccine candidates in BALB/c mice. A synthetic oligodeoxynucleotide which contained unmethylated CpG dinucleotides and was previously shown to enhance a murine Th1 response was used as an immunoadjuvant. T cells isolated from the spleens and lymph nodes of the rURE- and rHSP60-immune mice showed in vitro proliferative responses to the respective recombinant protein, but only those T lymphocytes from rURE-immunized mice revealed markedly elevated levels of expression of selected Th1-type cytokine genes. BALB/c mice immunized subcutaneously with rURE and subsequently challenged by the intraperitoneal (i.p.) route with a lethal inoculum of C. immitis arthroconidia demonstrated a significant reduction in the level of C. immitis infection compared to control animals. rHSP60 was much less effective as a protective antigen. Evaluation of cytokine gene expression in lung tissue and levels of recombinant urease-specific immunoglobulins (immunoglobulin G1 [IgG1] versus IgG2a) in murine sera at 12 days after challenge provided additional evidence that immunization with rURE stimulated a Th1 response to the pathogen. Urease was further evaluated by expression of the URE gene in a mammalian plasmid vector (pSecTag2A.URE) which was used to immunize mice by the intradermal route. In this case, 82% of the vector construct-immunized animals survived more than 40 days after i.p. infection, compared to only 10% of the mice immunized with the vector alone. In addition, 87% of the pSecTag2A.URE-immunized survivors had sterile lungs and spleens. These data support the need for further evaluation of the C. immitis urease as a candidate vaccine against coccidioidomycosis.
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Affiliation(s)
- K Li
- Department of Microbiology and Immunology, Medical College of Ohio, Toledo, Ohio 43614-5806, USA
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Hung CY, Yu JJ, Lehmann PF, Cole GT. Cloning and expression of the gene which encodes a tube precipitin antigen and wall-associated beta-glucosidase of Coccidioides immitis. Infect Immun 2001; 69:2211-22. [PMID: 11254576 PMCID: PMC98148 DOI: 10.1128/iai.69.4.2211-2222.2001] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [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: 11/20/2022] Open
Abstract
We report the structure and expression of the Coccidioides immitis BGL2 gene which encodes a previously characterized 120-kDa glycoprotein of this fungal respiratory pathogen. The glycoprotein is recognized by immunoglobulin M tube precipitin (TP) antibody present in sera of patients with coccidioidomycosis, a reaction which has been used for serodiagnosis of early coccidioidal infection. The deduced amino acid sequence of BGL2 shows 12 potential N glycosylation sites and numerous serine-threonine-rich regions which could function as sites for O glycosylation. In addition, the protein sequence includes a domain which is characteristic of family 3 glycosyl hydrolases. Earlier biochemical studies of the purified 120-kDa TP antigen revealed that it functions as a beta-glucosidase (EC 3.2.1.21). Its amino acid sequence shows high homology to several other reported fungal beta-glucosidases which are members of the family 3 glycosyl hydrolases. Results of previous studies have also suggested that the 120-kDa beta-glucosidase participates in wall modification during differentiation of the parasitic cells (spherules) of C. immitis. In this study we showed that expression of the BGL2 gene is elevated during isotropic growth of spherules and the peak of wall-associated BGL2 enzyme activity correlates with this same phase of parasitic cell differentiation. These data support our hypothesis that the 120-kDa beta-glucosidase plays a morphogenetic role in the parasitic cycle of C. immitis.
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Affiliation(s)
- C Y Hung
- Department of Microbiology and Immunology, Medical College of Ohio, Toledo, Ohio 43614-5806, USA
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Reichard U, Hung CY, Thomas PW, Cole GT. Disruption of the gene which encodes a serodiagnostic antigen and chitinase of the human fungal pathogen Coccidioides immitis. Infect Immun 2000; 68:5830-8. [PMID: 10992492 PMCID: PMC101544 DOI: 10.1128/iai.68.10.5830-5838.2000] [Citation(s) in RCA: 38] [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] [Received: 04/19/2000] [Accepted: 07/21/2000] [Indexed: 11/20/2022] Open
Abstract
Disruption of genes in medically important fungi has proved to be a powerful tool for evaluation of putative virulence factors and identification of potential protein targets for novel antifungal drugs. Chitinase has been suggested to play a pivotal role in autolysis of the parasitic cell wall of Coccidioides immitis during the asexual reproductive cycle (endosporulation) of this systemic pathogen. Two chitinase genes (CTS1 and CTS2) of C. immitis have been cloned. Preliminary evidence has suggested that expression of CTS1 is markedly increased during endospore formation. The secreted CTS1 chitinase has also been shown to react with patient anti-Coccidioides complement-fixing (CF) antibody and is a valuable aid in the serodiagnosis of coccidioidomycosis. To examine the role of CTS1 in the morphogenesis of parasitic cells, the CTS1 gene was disrupted by a single, locus-specific crossover event. This resulted in homologous integration of a pAN7.1 plasmid construct that contained a 1.1-kb fragment of the chitinase gene into the chromosomal DNA of C. immitis. Results of Southern hybridizations, immunoblot analyses of culture filtrates using both CTS1-specific murine antiserum and serum from a patient with confirmed coccidioidal infection, an immunodiffusion test for CF antigenicity, and substrate gel electrophoresis assays of chitinase activity confirmed that the CTS1 gene was disrupted and nonfunctional. This is the first report of a successful targeted gene disruption in C. immitis. However, loss of CTS1 function had no effect on virulence or endosporulation. Comparative assays of chitinase activity in the parental and Deltacts1 strains suggested that the absence of a functional CTS1 gene can be compensated for by elevated expression of the CTS2 gene. Current investigations are focused on disruption of CTS2 in the Deltacts1 host to further evaluate the significance of chitinase activity in the parasitic cycle of C. immitis.
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Affiliation(s)
- U Reichard
- Department of Microbiology and Immunology, Medical College of Ohio, Toledo, Ohio 43614, USA
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Hung CY, Ampel NM, Christian L, Seshan KR, Cole GT. A major cell surface antigen of Coccidioides immitis which elicits both humoral and cellular immune responses. Infect Immun 2000; 68:584-93. [PMID: 10639421 PMCID: PMC97180 DOI: 10.1128/iai.68.2.584-593.2000] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [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: 11/20/2022] Open
Abstract
Multinucleate parasitic cells (spherules) of Coccidioides immitis isolates produce a membranous outer wall component (SOW) in vitro which has been reported to be reactive with antibody from patients with coccidioidal infection, elicits a potent proliferative response of murine immune T cells, and has immunoprotective capacity in a murine model of coccidioidomycosis. To identify the antigenic components of SOW, the crude wall material was first subjected to Triton X-114 extraction, and a water-soluble fraction derived from this treatment was examined for protein composition and reactivity in humoral and cellular immunoassays. Protein electrophoresis revealed that the aqueous fraction of three different isolates of C. immitis each contained one or two major glycoproteins (SOWgps), distinguished by their molecular sizes, which ranged from 58 to 82 kDa. The SOWgps, however, showed identical N-terminal amino acid sequences, and each was recognized by sera from patients with C. immitis infection. Antibody raised against the purified 58-kDa glycoprotein (SOWgp58) of the Silveira isolate was used for Western blot and immunolocalization analyses. Expression of SOWgp was shown to be parasitic phase specific, and the antigen was localized to the membranous SOW. The water-soluble fraction of SOW and the purified SOWgp58 were tested for the ability to stimulate proliferation of human peripheral monocytic cells (PBMC). The latter were obtained from healthy volunteers with positive skin test reaction to spherulin, a parasitic-phase antigen of C. immitis, and from volunteers who showed no skin test reaction to the same antigen. The SOW preparations stimulated proliferation of PBMC from skin test-positive but not skin test-negative donors, and the activated cells secreted gamma interferon, which is indicative of a T helper 1 pathway of immune response. Results of this study suggest that SOWgp is a major parasitic cell surface-expressed antigen that elicits both humoral and cellular immune responses in patients with coccidioidal infection.
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Affiliation(s)
- C Y Hung
- Department of Microbiology and Immunology, Medical College of Ohio, Toledo, Ohio 43614, USA
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Abstract
The ornithine decarboxylase (ODC) gene of the human respiratory fungal pathogen, Coccidioides immitis (Ci) was cloned, sequenced, chromosome-mapped, and expressed in Escherichia coli (Ec). The genomic, cDNA and translated sequences are presented. Transformation of an ODC null mutant strain of Ec (EWH 319) with the Ci ODC gene was conducted to confirm function of the protein encoded by the fungal gene. Activity of the enzyme by the bacterial transformant was inhibited by 1, 4-diamino-2-butanone (DAB), a known inhibitor of eukaryotic ODC. Temporal expression of the Ci ODC gene during the parasitic cell cycle is constitutive, based on results of RT PCR. However, results of enzyme activity assays of cell homogenates obtained at different stages of parasitic cell development in vitro showed that the functional protein is present only during periods of isotropic growth and segmentation, and these morphogenetic events can be arrested by the addition of DAB. The observed absence of a difference in steady-state mRNA transcript amounts, and the developmentally correlated variation in levels of enzyme activity, suggest a translational or post-translational mechanism of ODC regulation. Since no PEST sequence was detected in the Ci ODC, enzyme regulation by programmed protein degradation as reported for many other eukaryotic ODCs may not occur in this case. ODC activity appears to play a key role in the morphogenesis of Ci, and the enzyme could be a rational target for therapy of disseminated coccidioidomycosis.
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MESH Headings
- Amino Acid Sequence
- Base Sequence
- Blotting, Southern
- Coccidioides/drug effects
- Coccidioides/enzymology
- Coccidioides/genetics
- DNA, Fungal/chemistry
- DNA, Fungal/genetics
- DNA, Fungal/isolation & purification
- Escherichia coli/enzymology
- Escherichia coli/genetics
- Gene Expression
- Gene Expression Regulation, Developmental
- Gene Expression Regulation, Fungal
- Genes, Fungal/genetics
- Molecular Sequence Data
- Mutation
- Ornithine Decarboxylase/genetics
- Ornithine Decarboxylase Inhibitors
- Putrescine/analogs & derivatives
- Putrescine/pharmacology
- Recombinant Fusion Proteins/genetics
- Sequence Alignment
- Sequence Analysis, DNA
- Sequence Homology, Amino Acid
- Transformation, Genetic
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Affiliation(s)
- L Guevara-Olvera
- Department of Microbiology and Immunology, Medical College of Ohio, Toledo 43614-5806, USA
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Abstract
OBJECTIVE The objectives of the study were to confirm the validity of using oscillometric measurement of MAP in the left lateral position to identify those at high risk for developing pregnancy-induced hypertension (PIH), and to assess and compare the efficacy of prophylaxis with low-dose aspirin or calcium supplementation in high-risk patients. STUDY DESIGN A prospective study in pregnancy; 500 normotensive, primigravid Chinese women were recruited in the second trimester of pregnancy on the basis of 80 mm Hg > or = MAP < 106 mm Hg in the antenatal clinic. They were then screened by Dinamap in a research setting, measuring MAP in the left lateral position after rest and using a cutoff value of 60 mm Hg for inclusion in the randomized study. Randomization was divided into three groups: control, low-dose aspirin, and calcium supplementation. After delivery, patients were classified as either having remained normotensive or having developed PIH, with or without proteinuria. RESULTS The incidence of both proteinuric and nonproteinuric PIH was significantly lower in patients screened out as low risk than in those selected as high risk using a critical value of 60 mm Hg for left lateral MAP (p < 0.05). The incidence of proteinuric PIH was significantly lower in patients given low-dose aspirin than in the control group (p < 0.05). However, the confidence intervals for the effect were wide, comparable with aspirin having no effect or leading to a 16-fold reduction in the risk of preeclampsia. For those given calcium supplementation, the reduction was not significant. There was no significant difference in the incidence of nonproteinuric PIH between the control group and the two groups receiving prophylaxis. CONCLUSION Oscillometric measurement of second-trimester left lateral MAP is a valid predictor of proteinuric PIH. Low-dose aspirin may offer a degree of protection from proteinuric PIH in these high-risk women. Calcium supplementation was not shown to significantly reduce the incidence of PIH.
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Affiliation(s)
- M S Rogers
- Faculty of Medicine, Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
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Mills WB, Lew CS, Hung CY. Sensitivity of concentration and risk predictions in the PRESTO and MMSOILS multimedia models: regression technique assessment. Risk Anal 1999; 19:511-525. [PMID: 10765419 DOI: 10.1023/a:1007013015263] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This paper describes the application of two multimedia models, PRESTO and MMSOILS, to predict contaminant migration from a landfill that contains an organic chemical (methylene chloride) and a radionuclide (uranium-238). Exposure point concentrations and human health risks are predicted, and distributions of those predictions are generated using Monte Carlo techniques. Analysis of exposure point concentrations shows that predictions of uranium-238 in groundwater differ by more than one order of magnitude between models. These differences occur mainly because PRESTO simulates uranium-238 transport through the groundwater using a one-dimensional algorithm and vertically mixes the plume over an effective mixing depth, whereas MMSOILS uses a three-dimensional algorithm and simulates a plume that resides near the surface of the aquifer. A sensitivity analysis, using stepwise multiple linear regression, is performed to evaluate which of the random variables are most important in producing the predicted distributions of exposure point concentrations and health risks. The sensitivity analysis shows that the predicted distributions can be accurately reproduced using a small subset of the random variables. Simple regression techniques are applied, for comparison, to the same scenarios, and results are similar. The practical implication of this analysis is the ability to distinguish between important versus unimportant random variables in terms of their sensitivity to selected endpoints.
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Affiliation(s)
- W B Mills
- Tetra Tech, Inc., Lafayette, California 94549, USA
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Hung CY, Lin Y, Zhang M, Pollock S, Marks MD, Schiefelbein J. A common position-dependent mechanism controls cell-type patterning and GLABRA2 regulation in the root and hypocotyl epidermis of Arabidopsis. Plant Physiol 1998; 117:73-84. [PMID: 9576776 PMCID: PMC35023 DOI: 10.1104/pp.117.1.73] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/1997] [Accepted: 01/26/1998] [Indexed: 05/18/2023]
Abstract
A position-dependent pattern of epidermal cell types is produced during root development in Arabidopsis thaliana. This pattern is reflected in the expression pattern of GLABRA2 (GL2), a homeobox gene that regulates cell differentiation in the root epidermis. GL2 promoter::GUS fusions were used to show that the TTG gene, a regulator of root epidermis development, is necessary for maximal GL2 activity but is not required for the pattern of GL2 expression. Furthermore, GL2-promoter activity is influenced by expression of the myc-like maize R gene (35S::R) in Arabidopsis but is not affected by gl2 mutations. A position-dependent pattern of cell differentiation and GL2-promoter activity was also discovered in the hypocotyl epidermis that was analogous to the pattern in the root. Non-GL2-expressing cell files in the hypocotyl epidermis located outside anticlinal cortical cell walls exhibit reduced cell length and form stomata. Like the root, the hypocotyl GL2 activity was shown to be influenced by ttg and 35S::R but not by gl2. The parallel pattern of cell differentiation in the root and hypocotyl indicates that TTG and GL2 participate in a common position-dependent mechanism to control cell-type patterning throughout the apical-basal axis of the Arabidopsis seedling.
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Affiliation(s)
- C Y Hung
- Department of Biology, University of Michigan, Ann Arbor, Michigan 48109-1048, USA
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Abstract
The formation of the root epidermis in Arabidopsis thaliana provides a simple model to study mechanisms underlying patterning in plants. In this paper we have analyzed the relationships between cell fate specification and the pattern of cell division that occur in the root epidermis. Using clonal analysis, the two cell types of the developing root epidermis, trichoblasts and atrichoblasts, were distinguished by different rates of cell division, highest in trichoblasts. This character appears to be dependent on TTG which controls epidermal cell fate specification. The ability of epidermal cells to undergo longitudinal divisions which are involved in the control of the radial symmetry was shown to be controlled in a cell-specific manner by TTG. The control of the rate and the orientation of cell division in the root meristem epidermal layer thus appear to be under the control of cell fate specification mechanisms.
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Affiliation(s)
- F Berger
- John Innes Centre, Norwich, United Kingdom.
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Hung CY, Ko YG, Thompson GA. Temperature-induced alteration of inositolphosphorylceramides in the putative glycosylated lipid precursors of Tetrahymena mimbres glycosylphosphatidylinositol-anchored proteins. Biochem J 1995; 307 ( Pt 1):107-13. [PMID: 7717964 PMCID: PMC1136751 DOI: 10.1042/bj3070107] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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: 01/26/2023]
Abstract
Tetrahymena species contain relatively prominent glycosylphosphatidylinositol (GPI)-anchored proteins as well as their putative precursor phosphatidylinositol (PI) glycans. We have characterized the lipid components of the two principal T. mimbres PI glycans. Following their purification by preparative TLC, the PI glycans were hydrolysed in methanolic HCl or NaOH, and resulting lipids were analysed by chromatography and mass spectrometry. The two PI glycans contained nearly identical lipid moieties having long-chain bases with N-linked fatty acids. The predominant long-chain base, 3-O-methylsphinganine, was first assumed to be O-methylated as an artifact of hydrolysis, but subsequently, on the basis of control experiments, it was shown to be naturally occurring. PI glycans from cells grown at 28 degrees C contained primarily palmitic acid (79%) and some stearic acid (11%), whereas the principal PI glycan from 38 degrees C-grown T. mimbres contained 65% stearic acid. In 15 degrees C-grown cells stearic acid accounted for only 2% of ceramide-bound fatty acids and was almost totally replaced by palmitic acid (95%). The distributions of fatty acids bound to T. mimbres GPI-anchored proteins [Ko, Hung and Thompson (1995) Biochem. J. 307, 115-121] were similar but not identical to those of the PI glycans described here. Temperature-induced specification of the lipid components of mature T. mimbres GPI-anchored proteins appears to be established both at the level of PI-glycan synthesis and the level of PI-glycan utilization for protein attachment.
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Affiliation(s)
- C Y Hung
- Department of Botany, University of Texas, Austin 78713, USA
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Ko YG, Hung CY, Thompson GA. Temperature regulation of the Tetrahymena mimbres glycosylphosphatidylinositol-anchored protein lipid composition. Biochem J 1995; 307 ( Pt 1):115-21. [PMID: 7717965 PMCID: PMC1136752 DOI: 10.1042/bj3070115] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
By incubating Tetrahymena mimbres cells with [3H]myristic acid, [3H]ethanolamine, [3H]inositol, and [3H]mannose, proteins having apparent molecular masses of 23 and 63 kDa were identified as the cells' principal glycosylphosphatidylinositol (GPI)-anchored proteins. These proteins accounted for as much as 2-5% of the whole cell proteins, with the higher levels being recovered from non-growing cells. The two proteins, gpi 23 and gpi 63, were purified to near homogeneity through Triton X-114/water partitioning followed by preparative SDS/PAGE. The lipid components of the GPI anchors were determined by chemical and enzymic hydrolysis. Both proteins were anchored by ceramides, with the principal long-chain base being C18 sphinganine containing an O-methyl group at the 3 position. O-Methylation was shown not to be an artifact of hydrolysis. When T. mimbres was cultured at 15 degrees C, the ceramide fatty acid component of the GPI anchors was principally palmitic acid (75% in gpi 23 and 76% in gpi 63). GPI anchors from 28 degrees C-grown cells contained mainly stearic acid (79% in gpi 23 and 70% in gpi 63). Temperature change had little effect on the long-chain-base composition. The direction of temperature-induced lipid change in the protein-bound anchors was the same as found in the inositolphosphorylceramide putative precursors of the protein anchors described in the accompanying paper [Hung, Ko and Thompson (1995) Biochem. J. 307, 107-113], but the detailed fatty acid compositions of the precursors and the protein-bound lipids were quite different. The precise metabolic regulation of anchor lipid chain length supports the concept that composition of the lipid anchor is important in the function and/or metabolism of the anchored protein.
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Affiliation(s)
- Y G Ko
- Department of Botany, University of Texas, Austin 78713, USA
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Hung CY, Lai YK, Feng TY, Chen CC. Chloroplast segregation in somatic hybrids of Nicotiana plumbaginifolia and N. sylvestris having different ratios of parental nuclear genomes. Plant Cell Rep 1993; 13:83-86. [PMID: 24196292 DOI: 10.1007/bf00235295] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/1993] [Revised: 08/24/1993] [Indexed: 06/02/2023]
Abstract
Fusion of mesophyll protoplasts of haploid Nicotiana plumbaginifolia (P) and N. sylvestris (S) resulted in the production of somatic hybrid plants of various ploidy levels. Analysis of the restriction fragment patterns of chloroplast DNA from 118 plants belonging to genome constitutions PS, PPS, PSS, and PPSS revealed that two had a pattern corresponding to a mixture of parental DNA while all the others had the pattern of either N. plumbaginifolia or N. sylvestris. In the latter case, the ratio of the two parental types fits 1∶1 in all the four genome constitutions studied. Since the protoplasts used in the fusion experiment were physiologically similar and the hybrid cells were not deliberately selected, these results suggest that chloroplast segregation in the somatic hybrids is independent of the chloroplast input of the fusion partners and the nuclear background of the fusion products.
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Affiliation(s)
- C Y Hung
- Department of Botany, National Taiwan University, Taipei, Taiwan, Republic of China
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Patterson E, Burow RD, Hung CY, Scherlag BJ. Coronary vascular injury after transient coronary artery occlusion. J Transl Med 1993; 69:471-82. [PMID: 8231114] [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] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
BACKGROUND Microvascular function was examined in dog hearts subjected to transient coronary artery occlusion. EXPERIMENTAL DESIGN Temporary coronary artery occlusion (15 or 30 minutes) followed by prolonged reperfusion (24 to 72 hours) was performed in dogs. Myocardial blood flow (radioactive microspheres), vascular permeability (human serum albumin uptake), and apparent vascular volume (radioactively labeled erythrocytes) were used as measures of vascular function. Myeloperoxidase was used as a measure of leukocyte uptake. Free radical formation was measured by electron spin resonance using a spin trapping agent (phenyl N-tert-butylnitrone). RESULTS A 30-minute occlusion followed by reperfusion produced prolonged hyperemia, increased vascular permeability, increased apparent vascular volume, and increased leukocyte uptake. Extravasation of red blood cells and carbon black was present within the coronary artery distribution. The altered vascular function was temporally correlated with prolonged leukocyte uptake and free radical production, returning to control values only at 72 hours. A 15-minute occlusion increased vascular permeability at 24 hours, without altering myocardial blood flow or apparent vascular volume. Transmural myocardial leukocyte accumulation after a 15-minute occlusion was minimal in the absence of myocardial infarction or other histologic alterations. Active free radical formation was minimal at 24 hours, with a return of vascular permeability to control values at 48 hours. CONCLUSIONS The data demonstrate prolonged dysfunction of the coronary microvasculature after a transient 30-minute occlusion of the left anterior descending coronary artery. The prolonged injury is associated temporally with leukocyte uptake and free radical formation in the presence of minimal infarction. A transient 15-minute occlusion produces a different pattern of vascular dysfunction with an abbreviated duration (24 hours), not associated with myocardial necrosis, extensive leukocyte uptake, nor prolonged free radical formation.
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Affiliation(s)
- E Patterson
- Department of Pharmacology, University of Oklahoma Health Sciences Center, Oklahoma City
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Kao YY, Hung CY, To KY, Chen CC. Mendelian inheritance of streptomycin resistance in Nicotiana plumbaginifolia. Plant Cell Rep 1991; 10:388-391. [PMID: 24221729 DOI: 10.1007/bf00232607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/1991] [Revised: 07/30/1991] [Indexed: 06/02/2023]
Abstract
In a previous study two haploid streptomycin-resistant clones of Nicotiana plumbaginifolia were isolated. The chromosome number of one of these clones has now been doubled through leaf-midvein culture and the resultant diploids were characterized genetically. Our results show that streptomycin resistance in this clone is conditioned by a recessive nuclear gene. Haploid protoplasts of this streptomycin-resistant mutant were selected for chlorate resistance. All clones obtained from the selection were deficient in nitrate reductase activity in addition to resistance to streptomycin. Genetic analysis of progeny of one of these clones revealed that the genes for streptomycin resistance and for the apoenzyme of nitrate reductase are unlinked.
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Affiliation(s)
- Y Y Kao
- Department of Botany, National Taiwan University, Taipei, Taiwan, Republic of China
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Brockman HE, de Serres FJ, Hung CY, Ong T. Effect of the uvs-2 allele of Neurospora crassa on the mutagenic potency of two N-hydroxylaminopurines and 2-aminopurine in the ad-3 forward-mutation test. Mutat Res 1989; 218:1-11. [PMID: 2526296 DOI: 10.1016/0921-8777(89)90040-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The mutagenic potencies of 3 purine analogs were determined in the ad-3 forward-mutation test in growing cultures of heterokaryon 59 (H-59), a nucleotide excision repair-deficient (uvs-2/uvs-2) 2-component heterokaryon of Neurospora crassa. Two N-hydroxylaminopurines, 2-amino-6-N-hydroxylaminopurine (AHA) and 6-N-hydroxylaminopurine (HAP), were potent and strong mutagens, respectively, whereas 2-aminopurine (AP) was a moderate mutagen. Dose-response curves showed that AHA and HAP were about equally mutagenic at low doses but that AHA was more mutagenic than HAP at high doses. Comparison of these results in H-59 with our earlier results in heterokaryon 12 (H-12) of N. crassa, which is identical to H-59 except for being DNA-repair-proficient (uvs-2+/uvs-2+), shows that the defect in nucleotide excision repair due to uvs-2 has little or no effect on the mutagenic potencies of these 3 purine analogs. Therefore, the nucleotide excision-repair pathway in N. crassa that is deficient in H-59 does not appear to have a major role in the repair of pre-mutational lesions induced by these 3 purine analogs. On the other hand, based on the controls of these experiments, the frequency of spontaneous ad-3 mutants was 4 greater in H-59 than in H-12. This result suggests that the nucleotide excision-repair pathway in N. crassa that is inactivated by the uvs-2 mutation has a major role in the repair of lesions that would lead to spontaneous mutation at the ad-3+ region if they were not repaired.
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Affiliation(s)
- H E Brockman
- Department of Biological Sciences, Illinois State University, Normal 61761
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Abstract
The effects of soman (pinacolyl methylphosphonofluoridate), an organophosphorus cholinesterase inhibitor, on vascular contractility were examined on helically cut central ear arteries (CEA) or superior mesenteric arteries (M) from New Zealand White rabbits. Concentrations of soman up to 20 microM added cumulatively to arterial strips did not alter their resting tension. Concentrations of soman up to 10 microM also did not alter the tension responses to cumulatively added norepinephrine (NE), histamine, potassium (KCl), or serotonin (5-HT). Concentration-response curves obtained to each agonist initially, or 2 h later, did not differ in artery strips from control rabbits and those from rabbits given soman at 5 micrograms/kg sc daily for 7 d. Changes in responses to NE between the two time periods did differ in arteries from soman-treated and control rabbits in both the CEA and M, and to histamine in the M. Soman at 10 microM potentiated contractions to single concentrations of agonists in most cases. Soman at 10 microM also further increased the tension of strips already contracted by the agonists. Thus, although soman did not alter the concentration-response curves of the agonists at contracting rabbit arteries, it potentiated contractions to single concentrations of agonists both when added before the agonist and when added at the peak of the agonist-induced contraction. It also altered the rate of change with time of both M and CEA in responses to NE of artery strips from rabbits given soman at 5 micrograms/kg daily for 7 d.
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Affiliation(s)
- C Y Hu
- College of Pharmacy, University of Oklahoma, Oklahoma City 73190
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de Serres FJ, Brockman HE, Hung CY. Effect of the homokaryotic state of the uvs-2 allele in Neurospora crassa on formaldehyde-induced killing and ad-3 mutation. Mutat Res 1988; 199:235-42. [PMID: 2966296 DOI: 10.1016/0027-5107(88)90251-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Formaldehyde was tested for its killing and mutagenic activities in the ad-3 forward-mutation test in Neurospora crassa. The test was conducted in 3 two-component heterokaryons (dikaryons) of N. crassa in order to determine the effect of the uvs-2 allele, which causes a defect in nucleotide excision repair, on formaldehyde-induced killing and the induction of ad-3 mutants. These dikaryons were homokaryotic for uvs-2+ (H-12), homokaryotic for usv-2 (H-59), and heterokaryotic for uvs-2 (H-71). Formaldehyde induced killing and ad-3 mutants in H-12, but the presence of uvs-2 in the homokaryotic state (H-59) resulted in a 9-fold increase in killing and a 40-fold increase in the induction of ad-3 mutants. This increased sensitivity to formaldehyde-induced killing and mutation conferred by uvs-2 in the homokaryotic state (H-59 vs. H-12) is similar to that noted by others in Escherichia coli. Salmonella typhimurium and Saccharomyces cerevisiae. The dikaryon heterokaryotic for uvs-2 (H-71) has the same sensitivity to formaldehyde-induced ad-3 mutation as H-12, indicating that uvs-2 is recessive to uvs-2+.
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Affiliation(s)
- F J de Serres
- Center for Life Sciences and Toxicology, Research Triangle Institute, Research Triangle Park, NC 27709
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Brockman HE, de Serres FJ, Ong TM, Hung CY. Two N-hydroxylaminopurines are highly mutagenic in the ad-3 forward-mutation test in growing cultures of heterokaryon 12 of Neurospora crassa. Mutat Res 1987; 177:61-75. [PMID: 2950320 DOI: 10.1016/0027-5107(87)90022-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
3 purine analogs were tested for their mutagenic activities in the ad-3 forward-mutation test in heterokaryon 12 (H-12) of Neurospora crassa. In growing cultures of H-12, the N-hydroxylaminopurines 2-amino-6-N-hydroxylaminopurine (AHA) and 6-N-hydroxylaminopurine (HAP) are potent and strong mutagens, respectively, whereas 2-aminopurine (AP) is a weak mutagen. AHA and HAP are about equally mutagenic at low doses, but AHA is more mutagenic than HAP at high doses. Despite their potent mutagenicity in growing cultures, AHA and HAP are not mutagenic in nongrowing conidia under the conditions of our experiments. AHA is the most potent mutagen tested in the ad-3 forward-mutation test in N. crassa. At the highest dose tested (30 micrograms/ml), it gave an ad-3 mutant frequency of 0.7 X 10(-2), about a 12,000-fold increase over the average spontaneous ad-3 mutant frequency. The potent mutagenicity of AHA may make it (and possibly HAP) especially useful for obtaining specific-locus mutations in other organisms.
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Hung CY, Burow RD, Scherlag BJ, Basmadjian GP, Lazzara R. New method for measuring myocardial blood flow by high resolution scintigraphy in the excised dog heart. J Nucl Med 1986; 27:1586-92. [PMID: 3760983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The standard method for measuring myocardial blood flow (MBF) with radioactive microspheres requires processing of selected tissue samples usually from the excised heart, and consequent loss of exact relation to myocardial morphology. A computer-based image processing method was developed by using [99mTc]microspheres (mean particle size 20 microns) for quantitative analysis of MBF in 25 dogs. A computer-controlled gamma camera was used to obtain the images of radioactive microsphere distribution in transaxial slices of the ex vivo heart. Any portion of these slice images could be quantitated by using a computer program based on modification of the formula for determining MBF by the standard microsphere method. Regional myocardial perfusion calculated by this technique correlated well with values obtained with reference microspheres (r = 0.96) over a broad range of MBF. The results show that our new method, accurately and with high resolution, delineated zones of differing MBF and confirmed the increase of MBF in surviving myocardium with healing.
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Brockman HE, de Serres FJ, Hung CY. Effect of the homokaryotic or heterokaryotic state of the uvs-2 allele in Neurospora crassa on mitomycin C-induced killing and ad-3 mutation. Mutat Res 1985; 150:193-202. [PMID: 3158811 DOI: 10.1016/0027-5107(85)90115-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Mitomycin C (MC) was tested for its killing and mutagenic activities in the ad-3 forward-mutation test in Neurospora crassa. The test was conducted in 4 dikaryons of N. crassa in order to determine the effect of the uvs-2 allele, which causes a defect in nucleotide excision repair, on MC-induced killing and ad-3 mutation. These dikaryons were homokaryotic for uvs-2+ (H-12), homokaryotic for uvs-2 (H-59), and heterokaryotic for uvs-2/uvs-2+ (H-70 and H-71). MC induced killing and ad-3 mutation in H-12, but the presence of uvs-2 in the homokaryotic state (H-59) resulted in a great increase in the killing and mutagenic activities of MC. This increased sensitivity to MC-induced killing and mutation conferred by uvs-2 in the homokaryotic state (H-59 vs. H-12) is a different effect than that noted by others for a defect in nucleotide excision-repair in Escherichia coli and Salmonella typhimurium or in human cells. The dikaryons heterokaryotic for uvs-2/uvs-2+ had the same sensitivity to MC as H-12, indicating that for MC-induced killing and ad-3 mutation uvs-2 is recessive to uvs-2+.
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de Serres FJ, Brockman HE, Hung CY, Overton LK. Mutagenicity of 2-aminopurine, 6-N-hydroxylaminopurine, and 2-amino-N6-hydroxyadenine in Neurospora crassa. Basic Life Sci 1985; 31:381-9. [PMID: 3158304 DOI: 10.1007/978-1-4613-2449-2_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
These data from our experiments with 3 purine analogs reveal striking differences in mutagenic potency. It seems highly likely that these analogs substitute readily for adenine and that they cause mutations in the main part, and in the case of AHA perhaps predominantly, by mispairing with cytosine. The most potent mutagens are those with the hydroxylamino group at the C6 position (AHA and HAP). Of these, the most potent is the analog with an amino group in the C2 position (AHA). The most interesting aspect of the present studies is their implications for other eukaryotic organisms. We have determined that AHA, which was shown to be a potent mutagen in bacteria [11], is an extremely potent mutagen in a eukaryotic organism. AHA is active at relatively low concentrations, and it gives rise to point mutations that appear to arise predominantly by AT----GC base-pair transitions. AHA should be an extremely useful genetic probe for studies on higher eukaryotic organisms. Its potency and specificity make it an unusual mutagen that can be expected to produce specific-locus mutants at high frequency with the genetic damage confined to the boundaries of the gene. These characteristics should make it useful not only for studies of specific-locus mutations and sex-linked recessive lethal mutations in Drosophila but also for specific-locus studies in mammalian cells in culture and in the whole animal. In these latter systems, it is extremely time consuming and sometimes impossible to distinguish between point mutations and multilocus deletions. The use of AHA as a mutagen in these systems should provide a useful new approach to genetic fine structure analysis.
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van Zeeland AA, Mohn GR, Aaron CS, Glickman BW, Brendel M, de Serres FJ, Hung CY, Brockman HE. Molecular dosimetry of the chemical mutagen ethyl methanesulfonate. Quantitative comparison of the mutagenic potency in Neurospora crassa and Saccharomyces cerevisiae. Mutat Res 1983; 119:45-54. [PMID: 6218404 DOI: 10.1016/0165-7992(83)90036-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Extending previous work with E. coli and mammalian cells in culture, forward-mutation frequencies induced by ethyl methanesulfonate (EMS) were quantitatively compared in Neurospora crassa and Saccharomyces cerevisiae under standardized conditions. Concomitantly, the actual dose to DNA was measured by determining the amount of radioactivity bound to DNA after treatment with tritium-labeled EMS. After exposure to EMS (2.5-50 mM), alkylation levels in N. crassa and S. cerevisiae were similar to those previously determined in E. coli and cultured mammalian cells. Consistently, there was a slightly less than proportional increase of the DNA alkylation level with the exposure concentration of the mutagen. Forward mutagenesis induced in yeast and N. crassa showed exponential kinetics with exponents of 1.5 and 2.6, respectively. These results are similar to those previously reported with E. coli, which differed from the results with cultured mammalian cells, where a linear dose-effect relationship between exposure and genetic effect was observed. These differences may reflect differences in the fate of EMS-induced adducts by cellular DNA repair systems, but are not due to initial differences in DNA alkylation levels. The fate and persistence of specific DNA adducts potentially responsible for pre-mutagenic changes are under investigation.
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