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Baek K, Kim D, Kim J, Kang BM, Park H, Park S, Shin HE, Lee MH, Maharjan S, Kim M, Kim S, Park MS, Lee Y, Kwon HJ. Analysis of SARS-CoV-2 omicron mutations that emerged during long-term replication in a lung cancer xenograft mouse model. Virus Genes 2024:10.1007/s11262-024-02067-6. [PMID: 38587722 DOI: 10.1007/s11262-024-02067-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/12/2024] [Indexed: 04/09/2024]
Abstract
SARS-CoV-2 Omicron has the largest number of mutations among all the known SARS-CoV-2 variants. The presence of these mutations might explain why Omicron is more infectious and vaccines have lower efficacy to Omicron than other variants, despite lower virulence of Omicron. We recently established a long-term in vivo replication model by infecting Calu-3 xenograft tumors in immunodeficient mice with parental SARS-CoV-2 and found that various mutations occurred majorly in the spike protein during extended replication. To investigate whether there are differences in the spectrum and frequency of mutations between parental SARS-CoV-2 and Omicron, we here applied this model to Omicron. At 30 days after infection, we found that the virus was present at high titers in the tumor tissues and had developed several rare sporadic mutations, mainly in ORF1ab with additional minor spike protein mutations. Many of the mutant isolates had higher replicative activity in Calu-3 cells compared with the original SARS-CoV-2 Omicron virus, suggesting that the novel mutations contributed to increased viral replication. Serial propagation of SARS-CoV-2 Omicron in cultured Calu-3 cells resulted in several rare sporadic mutations in various viral proteins with no mutations in the spike protein. Therefore, the genome of SARS-CoV-2 Omicron seems largely stable compared with that of the parental SARS-CoV-2 during extended replication in Calu-3 cells and xenograft model. The sporadic mutations and modified growth properties observed in Omicron might explain the emergence of Omicron sublineages. However, we cannot exclude the possibility of some differences in natural infection.
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Affiliation(s)
- Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Jinsoo Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Bo Min Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Heedo Park
- Department of Microbiology, Institute for Viral Diseases, Vaccine Innovation Center, College of Medicine, Korea University, Seoul, 02841, Republic of Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Ha-Eun Shin
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Myeong-Heon Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Suyeon Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, Institute for Viral Diseases, Vaccine Innovation Center, College of Medicine, Korea University, Seoul, 02841, Republic of Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Hyung-Joo Kwon
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea.
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, 24252, Republic of Korea.
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Kim D, Kim M, Kim J, Baek K, Park H, Park S, Kang BM, Kim S, Kim MJ, Mostafa MN, Maharjan S, Shin HE, Lee MH, Il Kim J, Park MS, Kim YS, Choi EK, Lee Y, Kwon HJ. A mouse xenograft long-term replication yields a SARS-CoV-2 Delta mutant with increased lethality. J Med Virol 2024; 96:e29459. [PMID: 38345153 DOI: 10.1002/jmv.29459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 12/26/2023] [Accepted: 01/16/2024] [Indexed: 02/15/2024]
Abstract
We recently established a long-term SARS-CoV-2 infection model using lung-cancer xenograft mice and identified mutations that arose in the SARS-CoV-2 genome during long-term propagation. Here, we applied our model to the SARS-CoV-2 Delta variant, which has increased transmissibility and immune escape compared with ancestral SARS-CoV-2. We observed limited mutations in SARS-CoV-2 Delta during long-term propagation, including two predominant mutations: R682W in the spike protein and L330W in the nucleocapsid protein. We analyzed two representative isolates, Delta-10 and Delta-12, with both predominant mutations and some additional mutations. Delta-10 and Delta-12 showed lower replication capacity compared with SARS-CoV-2 Delta in cultured cells; however, Delta-12 was more lethal in K18-hACE2 mice compared with SARS-CoV-2 Delta and Delta-10. Mice infected with Delta-12 had higher viral titers, more severe histopathology in the lungs, higher chemokine expression, increased astrocyte and microglia activation, and extensive neutrophil infiltration in the brain. Brain tissue hemorrhage and mild vacuolation were also observed, suggesting that the high lethality of Delta-12 was associated with lung and brain pathology. Our long-term infection model can provide mutant viruses derived from SARS-CoV-2 Delta and knowledge about the possible contributions of emergent mutations to the properties of new variants.
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Affiliation(s)
- Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jinsoo Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Heedo Park
- Department of Microbiology, Vaccine Innovation Center College of Medicine, Institute for Viral Diseases, Korea University, Seoul, Republic of Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Bo Min Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Suyeon Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Mo-Jong Kim
- Ilsong Institute of Life Science, Hallym University, Seoul, Republic of Korea
| | - Mohd Najib Mostafa
- Ilsong Institute of Life Science, Hallym University, Seoul, Republic of Korea
- Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Republic of Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Ha-Eun Shin
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Myeong-Heon Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Jin Il Kim
- Department of Microbiology, Vaccine Innovation Center College of Medicine, Institute for Viral Diseases, Korea University, Seoul, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, Vaccine Innovation Center College of Medicine, Institute for Viral Diseases, Korea University, Seoul, Republic of Korea
| | - Yong-Sun Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
- Ilsong Institute of Life Science, Hallym University, Seoul, Republic of Korea
| | - Eun-Kyoung Choi
- Ilsong Institute of Life Science, Hallym University, Seoul, Republic of Korea
- Department of Biomedical Gerontology, Graduate School of Hallym University, Chuncheon, Republic of Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Hyung-Joo Kwon
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
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Kim D, Kim J, Kim M, Park H, Park S, Maharjan S, Baek K, Kang BM, Kim S, Park MS, Lee Y, Kwon HJ. Analysis of spike protein variants evolved in a novel in vivo long-term replication model for SARS-CoV-2. Front Cell Infect Microbiol 2023; 13:1280686. [PMID: 38029235 PMCID: PMC10655031 DOI: 10.3389/fcimb.2023.1280686] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction The spectrum of SARS-CoV-2 mutations have increased over time, resulting in the emergence of several variants of concern. Persistent infection is assumed to be involved in the evolution of the variants. Calu-3 human lung cancer cells persistently grow without apoptosis and release low virus titers after infection. Methods We established a novel in vivo long-term replication model using xenografts of Calu-3 human lung cancer cells in immunodeficient mice. Virus replication in the tumor was monitored for 30 days and occurrence of mutations in the viral genome was determined by whole-genome deep sequencing. Viral isolates with mutations were selected after plaque forming assays and their properties were determined in cells and in K18-hACE2 mice. Results After infection with parental SARS-CoV-2, viruses were found in the tumor tissues for up to 30 days and acquired various mutations, predominantly in the spike (S) protein, some of which increased while others fluctuated for 30 days. Three viral isolates with different combination of mutations produced higher virus titers than the parental virus in Calu-3 cells without cytopathic effects. In K18-hACE2 mice, the variants were less lethal than the parental virus. Infection with each variant induced production of cross-reactive antibodies to the receptor binding domain of parental SARS-CoV-2 S protein and provided protective immunity against subsequent challenge with parental virus. Discussion These results suggest that most of the SARS-CoV-2 variants acquired mutations promoting host adaptation in the Calu-3 xenograft mice. This model can be used in the future to further study SARS-CoV-2 variants upon long-term replication in vivo.
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Affiliation(s)
- Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jinsoo Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Heedo Park
- Department of Microbiology, Institute for Viral Diseases, Vaccine Innovation Center, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Bo Min Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Suyeon Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, Institute for Viral Diseases, Vaccine Innovation Center, College of Medicine, Korea University, Seoul, Republic of Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Hyung-Joo Kwon
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
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Kim D, Kim J, An S, Kim M, Baek K, Kang BM, Maharjan S, Kim S, Hwang SY, Park IG, Park S, Suh JG, Park MS, Noh M, Lee Y, Kwon HJ. In vitro and in vivo suppression of SARS-CoV-2 replication by a modified, short, cell-penetrating peptide targeting the C-terminal domain of the viral spike protein. J Med Virol 2023; 95:e28626. [PMID: 36856164 DOI: 10.1002/jmv.28626] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/07/2023] [Accepted: 02/26/2023] [Indexed: 03/02/2023]
Abstract
Peptides are promising therapeutic agents for COVID-19 because of their specificity, easy synthesis, and ability to be fine-tuned. We previously demonstrated that a cell-permeable peptide corresponding to the SARS-CoV-2 Spike C-terminal domain (CD) inhibits the interaction between viral spike and nucleocapsid proteins that results in SARS-CoV-2 replication in vitro. Here, we used docking studies to design R-t-Spike CD(D), a more potent short cell-penetrating peptide composed of all D-form amino acids and evaluated its inhibitory effect against the replication of SARS-CoV-2 S clade and other variants. R-t-Spike CD(D) was internalized into Vero cells and Calu-3 cells and suppressed the replication of SARS-CoV-2 S clade, delta variant, and omicron variant with higher potency than the original peptide. In hemizygous K18-hACE2 mice, intratracheal administration of R-t-Spike CD(D) effectively delivered the peptide to the trachea and lungs, whereas intranasal administration delivered the peptide mostly to the upper respiratory system and stomach, and a small amount to the lungs. Administration by either route reduced viral loads in mouse lungs and turbinates. Furthermore, intranasally administered R-t-Spike CD(D) mitigated pathological change in the lungs and increased the survival of mice after infection with the SARS-CoV-2 S clade or delta variant. Our data suggest that R-t-Spike CD(D) has potential as a therapeutic agent against SARS-CoV-2 infection. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Seungchan An
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Bo Min Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Suyeon Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Seok Young Hwang
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul, Republic of Korea
| | - In Guk Park
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Jun Gyo Suh
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, College of Medicine, and the Institute for Viral Diseases, Korea University, Seoul, Republic of Korea
| | - Minsoo Noh
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul, Republic of Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Hyung-Joo Kwon
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
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Kim J, Kim D, Baek K, Kim M, Kang BM, Maharjan S, Park S, Choi JK, Kim S, Kim YK, Park MS, Lee Y, Kwon HJ. Production of a Monoclonal Antibody to the Nucleocapsid Protein of SARS-CoV-2 and Its Application to ELISA-Based Detection Methods with Broad Specificity by Combined Use of Detector Antibodies. Viruses 2022; 15:28. [PMID: 36680068 PMCID: PMC9866944 DOI: 10.3390/v15010028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 12/12/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022] Open
Abstract
The coronavirus disease 2019 pandemic, elicited by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is ongoing. Currently accessible antigen-detecting rapid diagnostic tests are limited by their low sensitivity and detection efficacy due to evolution of SARS-CoV-2 variants. Here, we produced and characterized an anti-SARS-CoV-2 nucleocapsid (N) protein-specific monoclonal antibody (mAb), 2A7H9. Monoclonal antibody 2A7H9 and a previously developed mAb, 1G10C4, have different specificities. The 2A7H9 mAb detected the N protein of S clade, delta, iota, and mu but not omicron, whereas the 1G10C4 antibody recognized the N protein of all variants under study. In a sandwich enzyme-linked immunosorbent assay, recombinant N protein bound to the 1G10C4 mAb could be detected by both 1G10C4 and 2A7H9 mAbs. Similarly, N protein bound to the 2A7H9 mAb was detected by both mAbs, confirming the existence of dimeric N protein. While the 1G10C4 mAb detected omicron and mu with higher efficiency than S clade, delta, and iota, the 2A7H9 mAb efficiently detected all the strains except omicron, with higher affinity to S clade and mu than others. Combined use of 1G10C4 and 2A7H9 mAb resulted in the detection of all the strains with considerable sensitivity, suggesting that antibody combinations can improve the simultaneous detection of virus variants. Therefore, our findings provide insights into the development and improvement of diagnostic tools with broader specificity and higher sensitivity to detect rapidly evolving SARS-CoV-2 variants.
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Affiliation(s)
- Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Bo Min Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Jun-Kyu Choi
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Suyeon Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Yong Kyun Kim
- Division of Infectious Diseases, Department of Internal Medicine, Hallym University Sacred Heart Hospital, College of Medicine, Hallym University, Anyang 14068, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, College of Medicine, and the Institute for Viral Diseases, Korea University, Seoul 02841, Republic of Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Hyung-Joo Kwon
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
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Baek K, Maharjan S, Akauliya M, Thapa B, Kim D, Kim J, Kim M, Kang M, Kim S, Bae JY, Lee KW, Park MS, Lee Y, Kwon HJ. Comparison of vaccination efficacy using live or ultraviolet-inactivated influenza viruses introduced by different routes in a mouse model. PLoS One 2022; 17:e0275722. [PMID: 36215268 PMCID: PMC9550053 DOI: 10.1371/journal.pone.0275722] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 09/22/2022] [Indexed: 11/18/2022] Open
Abstract
Influenza is a major cause of highly contagious respiratory illness resulting in high mortality and morbidity worldwide. Annual vaccination is an effective way to prevent infection and complication from constantly mutating influenza strains. Vaccination utilizes preemptive inoculation with live virus, live attenuated virus, inactivated virus, or virus segments for optimal immune activation. The route of administration also affects the efficacy of the vaccination. Here, we evaluated the effects of inoculation with ultraviolet (UV)-inactivated or live influenza A virus strains and compared their effectiveness and cross protection when intraperitoneal and intramuscular routes of administration were used in mice. Intramuscular or intraperitoneal inoculation with UV-inactivated Influenza A/WSN/1933 provided some protection against intranasal challenge with a lethal dose of live Influenza A/WSN/1933 but only when a high dose of the virus was used in the inoculation. By contrast, inoculation with a low dose of live virus via either route provided complete protection against the same intranasal challenge. Intraperitoneal inoculation with live or UV-inactivated Influenza A/Philippines/2/1982 and intramuscular inoculation with UV-inactivated Influenza A/Philippines/2/1982 failed to produce cross-reactive antibodies against Influenza A/WSN/1933. Intramuscular inoculation with live Influenza A/Philippines/2/1982 induced small amounts of cross-reactive antibodies but could not suppress the cytokine storm produced upon intranasal challenge with Influenza A/WSN/1993. None of the tested inoculation conditions provided observable cross protection against intranasal challenge with a different influenza strain. Taken together, vaccination efficacy was affected by the state and dose of the vaccine virus and the route of administration. These results provide practical data for the development of effective vaccines against influenza virus.
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Affiliation(s)
- Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Madhav Akauliya
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Bikash Thapa
- Department of Biomedical Science, Hallym University, Chuncheon, Republic of Korea
| | - Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Mijeong Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Suyeon Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
| | - Joon-Yong Bae
- Department of Microbiology, College of Medicine, and the Institute for Viral Diseases, Korea University, Seoul, Republic of Korea
| | - Keun-Wook Lee
- Department of Biomedical Science, Hallym University, Chuncheon, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, College of Medicine, and the Institute for Viral Diseases, Korea University, Seoul, Republic of Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, Republic of Korea
| | - Hyung-Joo Kwon
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, Republic of Korea
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, Republic of Korea
- * E-mail:
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Kim D, Maharjan S, Kang M, Kim J, Park S, Kim M, Baek K, Kim S, Suh JG, Lee Y, Kwon HJ. Differential effect of SARS-CoV-2 infection on stress granule formation in Vero and Calu-3 cells. Front Microbiol 2022; 13:997539. [PMID: 36081788 PMCID: PMC9445554 DOI: 10.3389/fmicb.2022.997539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Accepted: 08/04/2022] [Indexed: 12/05/2022] Open
Abstract
Stress granule formation is induced by numerous environmental stressors, including sodium arsenite treatment and viral infection. Accordingly, stress granules can inhibit viral propagation and function as part of the antiviral host response to numerous viral infections. Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antagonizes stress granule formation, in part, via interaction between SARS-CoV-2 nucleocapsid (N) protein and Ras-GTPase-activating SH3-domain-binding protein 1 (G3BP1). However, it is unclear whether there are differential effects in different cell types. In this study, we assessed interaction between the N protein of SARS-CoV-2 S clade and G3BP1/2 in Vero and Calu-3 cells and investigated the effect of various SARS-CoV-2 strains on sodium arsenite-induced stress granule formation. Our data show that SARS-CoV-2 S clade N protein interacts with both G3BP1 and G3BP2 more strongly in Calu-3 vs. Vero cells. Consistent with this observation, infection with SARS-CoV-2 S clade induces stress granule formation in Vero but not in Calu-3 cells. However, infection with SARS-CoV-2 S clade, as well as other SARS-CoV-2 variants, inhibits sodium arsenite-induced stress granule formation in both cell lines. Taken together, our results show differential effects of SARS-CoV-2 infection on stress granule formation that is dependent on host cell type, rather than virus strain type.
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Affiliation(s)
- Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Mijeong Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Suyeon Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Jun Gyo Suh
- Department of Medical Genetics, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea
- *Correspondence: Younghee Lee,
| | - Hyung-Joo Kwon
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
- Hyung-Joo Kwon,
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Kim J, Hwang SY, Kim D, Kim M, Baek K, Kang M, An S, Gong J, Park S, Kandeel M, Lee Y, Noh M, Kwon HJ. Abiraterone Acetate Attenuates SARS-CoV-2 Replication by Interfering with the Structural Nucleocapsid Protein. Biomol Ther (Seoul) 2022; 30:427-434. [PMID: 35548881 PMCID: PMC9424333 DOI: 10.4062/biomolther.2022.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 03/13/2022] [Revised: 04/01/2022] [Accepted: 04/14/2022] [Indexed: 12/02/2022] Open
Abstract
The drug repurposing strategy has been applied to the development of emergency COVID-19 therapeutic medicines. Current drug repurposing approaches have been directed against RNA polymerases and viral proteases. Recently, we found that the inhibition of the interaction between the SARS-CoV-2 structural nucleocapsid (N) and spike (S) proteins decreased viral replication. In this study, drug repurposing candidates were screened by in silico molecular docking simulation with the SARS-CoV-2 structural N protein. In the ChEMBL database, 1994 FDA-approved drugs were selected for the in silico virtual screening against the N terminal domain (NTD) of the SARS-CoV-2 N protein. The tyrosine 109 residue in the NTD of the N protein was used as the center of the ligand binding grid for the docking simulation. In plaque forming assays performed with SARS-CoV-2 infected Vero E6 cells, atovaquone, abiraterone acetate, and digoxin exhibited a tendency to reduce the size of the viral plagues without affecting the plaque numbers. Abiraterone acetate significantly decreased the accumulation of viral particles in the cell culture supernatants in a concentration-dependent manner. In addition, abiraterone acetate significantly decreased the production of N protein and S protein in the SARS-CoV-2-infected Vero E6 cells. In conclusion, abiraterone acetate has therapeutic potential to inhibit the viral replication of SARS-CoV-2.
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Affiliation(s)
- Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Seok Young Hwang
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Mijeong Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Seungchan An
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Junpyo Gong
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Mahmoud Kandeel
- Department of Biomedical Sciences, College of Veterinary Medicine, King Faisal University, Al-hofuf 31982, Saudi Arabia.,Department of Pharmacology, Faculty of Veterinary Medicine, Kafrelshikh University, Kafrelshikh 33516, Egypt
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Minsoo Noh
- College of Pharmacy, Natural Products Research Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Hyung-Joo Kwon
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea.,Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
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9
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Kim J, Kim M, Kim D, Park S, Kang M, Baek K, Choi JK, Maharjan S, Akauliya M, Lee Y, Kwon HJ. Targeting the Interaction Between Spike Protein and Nucleocapsid Protein for Suppression and Detection of Human Coronavirus OC43. Front Immunol 2022; 13:835333. [PMID: 35359936 PMCID: PMC8960273 DOI: 10.3389/fimmu.2022.835333] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 12/15/2021] [Accepted: 02/18/2022] [Indexed: 01/09/2023] Open
Abstract
Human coronavirus OC43 (HCoV-OC43) is the coronavirus most associated with "common colds", infections of the upper respiratory tract. Previously, we reported that direct interactions of nucleocapsid (N) protein and C-terminal domain of Spike protein (Spike CD) are essential for replication of SARS-CoV-2 and MERS-CoV. Thus, we developed a novel ELISA-based strategy targeting these specific interactions to detect SARS-CoV-2 and MERS-CoV. Here, we investigated whether the same principles apply to HCoV-OC43. We discovered that the S protein of HCoV-OC43 interacts with N protein and that cell penetrating Spike CD peptide inhibits virus protein expression and replication of HCoV-OC43. The interaction between HCoV-OC43 S and N proteins were recapitulated with a recombinant HCoV-OC43 Spike CD fusion protein and a recombinant HCoV-OC43 N fusion protein in vitro. By producing an anti-HCoV-OC43 N protein-specific monoclonal antibody, we established a virus detection system based on the interaction between recombinant Spike CD and N protein of HCoV-OC43. We suggest that the interaction between Spike CD and N protein is conserved in coronaviruses and therefore could be a target for therapeutics against both novel coronavirus and its variants.
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Affiliation(s)
- Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea
| | - Mijeong Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Jun-Kyu Choi
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Madhav Akauliya
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea,*Correspondence: Younghee Lee, ; Hyung-Joo Kwon,
| | - Hyung-Joo Kwon
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea,Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea,*Correspondence: Younghee Lee, ; Hyung-Joo Kwon,
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10
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Kim D, Kim J, Park S, Kim M, Baek K, Kang M, Choi JK, Maharjan S, Akauliya M, Lee Y, Kwon HJ. Production of SARS-CoV-2 N Protein-Specific Monoclonal Antibody and Its Application in an ELISA-Based Detection System and Targeting the Interaction Between the Spike C-Terminal Domain and N Protein. Front Microbiol 2021; 12:726231. [PMID: 34950112 PMCID: PMC8688357 DOI: 10.3389/fmicb.2021.726231] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 06/16/2021] [Accepted: 11/09/2021] [Indexed: 01/04/2023] Open
Abstract
SARS-CoV-2 infections continue to spread quickly by human-to-human transmission around the world. Therefore, developing methods to rapidly detect SARS-CoV-2 with high sensitivity are still urgently needed. We produced a monoclonal antibody that specifically detects the N protein of SARS-CoV-2 and recognizes N protein in cell lysates of SARS-CoV-2-infected Vero cells but not in cell lysates of MERS-CoV- or HCoV-OC43-infected Vero cells. This antibody recognized N protein in SARS-CoV-2 clades S, GR, and GH and recognized N protein in all the SARS-CoV-2 clades to ∼300 pfu. Previously, we reported that the coronavirus N protein interacts with the C-terminal domain of the spike protein (Spike CD). In this study, we developed an ELISA-based "bait and prey" system to confirm the interaction between SARS-CoV-2 Spike CD and N protein using recombinant fusion proteins. Furthermore, this system can be modified to quantitatively detect SARS-CoV-2 in culture media of infected cells by monitoring the interaction between the recombinant Spike CD fusion protein and the viral N protein, which is captured by the N protein-specific antibody. Therefore, we conclude that our N protein-specific monoclonal antibody and our ELISA-based bait and prey system could be used to diagnose SARS-CoV-2 infections.
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Affiliation(s)
- Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Mijeong Kang
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Jun-Kyu Choi
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea
| | - Sony Maharjan
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Madhav Akauliya
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju, South Korea
| | - Hyung-Joo Kwon
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon, South Korea.,Department of Microbiology, College of Medicine, Hallym University, Chuncheon, South Korea
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11
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Park BK, Kim J, Park S, Kim D, Kim M, Baek K, Bae JY, Park MS, Kim WK, Lee Y, Kwon HJ. MERS-CoV and SARS-CoV-2 replication can be inhibited by targeting the interaction between the viral spike protein and the nucleocapsid protein. Theranostics 2021; 11:3853-3867. [PMID: 33664866 PMCID: PMC7914343 DOI: 10.7150/thno.55647] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Accepted: 01/19/2021] [Indexed: 12/20/2022] Open
Abstract
Background: The molecular interactions between viral proteins form the basis of virus production and can be used to develop strategies against virus infection. The interactions of the envelope proteins and the viral RNA-binding nucleocapsid (N) protein are essential for the assembly of coronaviruses including the Middle East respiratory syndrome coronavirus (MERS-CoV). Methods: Using co-immunoprecipitation, immunostaining, and proteomics analysis, we identified a protein interacting with the spike (S) protein in the cells infected with MERS-CoV or SARS-CoV-2. To confirm the interaction, synthetic peptides corresponding to the C-terminal domain of the S protein (Spike CD) were produced and their effect on the interaction was investigated in vitro. In vivo effect of the Spike CD peptides after cell penetration was further investigated using viral plaque formation assay. Phylogeographic analyses were conducted to deduce homology of Spike CDs and N proteins. Results: We identified a direct interaction between the S protein and the N protein of MERS-CoV that takes place during virus assembly in infected cells. Spike CD peptides of MERS-CoV inhibited the interaction between the S and N proteins in vitro. Furthermore, cell penetration by the synthetic Spike CD peptides inhibited viral plaque formation in MERS-CoV-infected cells. Phylogeographic analyses of Spike CDs and N proteins showed high homology among betacoronavirus lineage C strains. To determine if Spike CD peptides can inhibit the replication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), we used the same strategy and found that the SARS-CoV-2 Spike CD peptide inhibited virus replication in SARS-CoV-2-infected cells. Conclusions: We suggest that the interaction between the S protein and the N protein can be targeted to design new therapeutics against emerging coronaviruses, including SARS-CoV-2.
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Affiliation(s)
- Byoung Kwon Park
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Jinsoo Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Sangkyu Park
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Dongbum Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Minyoung Kim
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Kyeongbin Baek
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Joon-Yong Bae
- Department of Microbiology, College of Medicine, and the Institute for Viral Diseases, Korea University, Seoul 02841, Republic of Korea
| | - Man-Seong Park
- Department of Microbiology, College of Medicine, and the Institute for Viral Diseases, Korea University, Seoul 02841, Republic of Korea
| | - Won-Keun Kim
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Younghee Lee
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 28644, Republic of Korea
| | - Hyung-Joo Kwon
- Institute of Medical Science, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
- Department of Microbiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
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12
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Yun S, Baek K, Shin H, Kang H. WT1-specific cytotoxic T lymphocytes induced by activated B cells as apc. Cytotherapy 2019. [DOI: 10.1016/j.jcyt.2019.03.352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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13
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Baek K, Choi Y. The microbiology of oral lichen planus: Is microbial infection the cause of oral lichen planus? Mol Oral Microbiol 2017; 33:22-28. [PMID: 28869787 DOI: 10.1111/omi.12197] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/25/2017] [Indexed: 12/15/2022]
Abstract
Oral lichen planus (OLP) is a variant of lichen planus (LP), a common chronic mucocutaneous inflammatory disease. Cutaneous lesions of LP are self-limiting, but OLP lesions are non-remissive, alternating periods of exacerbation and quiescence, and only symptomatic treatments exist for OLP. The precise etiology and pathogenesis of OLP are hardly understood, which is a major obstacle to the development of new therapeutics for this disease. OLP is considered a T-cell-mediated inflammatory disease. Although various antigens have been considered, what actually triggers the inflammatory response of T cells is unknown. Suggested predisposing factors include genetic factors, stress, trauma, and infection. The aim of this review was to determine whether microbial infection can cause OLP. We first reviewed the association between OLP and microbial factors, including viral, fungal, and bacterial infections. In addition, each microbial factor associated with OLP was assessed by modified guidelines of Fredricks and Relman to determine whether it establishes a causal relationship. In conclusion, no microbial factor yet fulfills the guidelines to establish the causality of OLP. By focusing on the unclarified issues, however, the potential roles of microbial factors in the pathogenesis of OLP will be soon elucidated.
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Affiliation(s)
- K Baek
- Department of Immunology and Molecular Microbiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea
| | - Y Choi
- Department of Immunology and Molecular Microbiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea
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14
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Abstract
Periodontitis is caused by dysbiotic subgingival bacterial communities that may lead to increased bacterial invasion into gingival tissues. Although shifts in community structures associated with transition from health to periodontitis have been well characterized, the nature of bacteria present within the gingival tissue of periodontal lesions is not known. To characterize microbiota within tissues of periodontal lesions and compare them with plaque microbiota, gingival tissues and subgingival plaques were obtained from 7 patients with chronic periodontitis. A sequencing analysis of the 16S rRNA gene revealed that species richness and diversity were not significantly different between the 2 groups. However, intersubject variability of intratissue communities was smaller than that of plaque communities. In addition, when compared with the plaque communities, intratissue communities were characterized by decreased abundance of Firmicutes and increased abundance of Fusobacteria and Chloroflexi. In particular, Fusobacterium nucleatum and Porphyromonas gingivalis were highly enriched within the tissue, composing 15% to 40% of the total bacteria. Furthermore, biofilms, as visualized by alcian blue staining and atomic force microscopy, were observed within the tissue where the degradation of connective tissue fibers was prominent. In conclusion, very complex bacterial communities exist in the form of biofilms within the gingival tissue of periodontal lesions, which potentially serve as a reservoir for persistent infection. This novel finding may prompt new research on therapeutic strategies to treat periodontitis.
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Affiliation(s)
- K Baek
- 1 Department of Immunology and Molecular Microbiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea
| | - S Ji
- 2 Department of Periodontology, Anam Hospital, Korea University, Seoul, Korea.,3 Department of Periodontology, Institute of Oral Health Science, Ajou University School of Medicine, Suwon, Korea
| | - Y Choi
- 1 Department of Immunology and Molecular Microbiology, School of Dentistry and Dental Research Institute, Seoul National University, Seoul, Korea
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15
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Baek K, Doñamayor N, Morris LS, Strelchuk D, Mitchell S, Mikheenko Y, Yeoh SY, Phillips W, Zandi M, Jenaway A, Walsh C, Voon V. Impaired awareness of motor intention in functional neurological disorder: implications for voluntary and functional movement. Psychol Med 2017; 47:1624-1636. [PMID: 28183377 PMCID: PMC5964459 DOI: 10.1017/s0033291717000071] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 01/03/2017] [Accepted: 01/04/2017] [Indexed: 11/29/2022]
Abstract
BACKGROUND Functional neurological disorders (FNDs), also known as conversion disorder, are unexplained neurological symptoms unrelated to a neurological cause. The disorder is common, yet poorly understood. The symptoms are experienced as involuntary but have similarities to voluntary processes. Here we studied intention awareness in FND. METHOD A total of 26 FND patients and 25 healthy volunteers participated in this functional magnetic resonance study using Libet's clock. RESULTS FND is characterized by delayed awareness of the intention to move relative to the movement itself. The reporting of intention was more precise, suggesting that these findings are reliable and unrelated to non-specific attentional deficits. That these findings were more prominent with aberrant positive functional movement symptoms rather than negative symptoms may be relevant to impairments in timing for an inhibitory veto process. Attention towards intention relative to movement was associated with lower right inferior parietal cortex activity in FND, a region early in the processing of intention. During rest, aberrant functional connectivity was observed with the right inferior parietal cortex and other motor intention regions. CONCLUSIONS The results converge with observations of low inferior parietal activity comparing involuntary with voluntary movement in FND, emphasizing core deficiencies in intention. Heightened precision of this impaired intention is consistent with Bayesian theories of impaired top-down priors that might influence the sense of involuntariness. A primary impairment in voluntary motor intention at an early processing stage might explain clinical observations of slowed effortful voluntary movement, heightened self-directed attention and underlie functional movements. These findings further suggest novel therapeutic targets.
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Affiliation(s)
- K. Baek
- Department of Psychiatry,
University of Cambridge, Cambridge,
UK
| | - N. Doñamayor
- Department of Psychiatry,
University of Cambridge, Cambridge,
UK
| | - L. S. Morris
- Behavioural and Clinical Neurosciences
Institute, Cambridge, UK
| | - D. Strelchuk
- Department of Psychiatry,
University of Cambridge, Cambridge,
UK
| | - S. Mitchell
- Department of Psychiatry,
University of Cambridge, Cambridge,
UK
| | - Y. Mikheenko
- Department of Psychiatry,
University of Cambridge, Cambridge,
UK
| | - S. Y. Yeoh
- School of Clinical Medicine, University of
Cambridge, Cambridge, UK
| | - W. Phillips
- Department of Clinical Neurosciences,
Addenbrooke's Hospital, Cambridge,
Cambridge, UK
| | - M. Zandi
- Department of Clinical Neurosciences,
Addenbrooke's Hospital, Cambridge,
Cambridge, UK
- Department of Molecular Neuroscience,
UCL Institute of Neurology, London,
UK
- National Hospital for Neurology and
Neurosurgery, UCLH NIHR Biomedical Research Centre,
London, UK
| | - A. Jenaway
- Cambridgeshire and Peterborough NHS Foundation
Trust, Cambridge, UK
| | - C. Walsh
- Department of Psychiatry,
University of Cambridge, Cambridge,
UK
- Department of Clinical Neurosciences,
Addenbrooke's Hospital, Cambridge,
Cambridge, UK
| | - V. Voon
- Department of Psychiatry,
University of Cambridge, Cambridge,
UK
- Behavioural and Clinical Neurosciences
Institute, Cambridge, UK
- Cambridgeshire and Peterborough NHS Foundation
Trust, Cambridge, UK
- NIHR Biomedical Research Council,
Cambridge, Cambridge, UK
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16
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Baek K, Morris LS, Kundu P, Voon V. Disrupted resting-state brain network properties in obesity: decreased global and putaminal cortico-striatal network efficiency. Psychol Med 2017; 47:585-596. [PMID: 27804899 PMCID: PMC5426347 DOI: 10.1017/s0033291716002646] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 09/09/2016] [Accepted: 09/13/2016] [Indexed: 12/31/2022]
Abstract
BACKGROUND The efficient organization and communication of brain networks underlie cognitive processing and their disruption can lead to pathological behaviours. Few studies have focused on whole-brain networks in obesity and binge eating disorder (BED). Here we used multi-echo resting-state functional magnetic resonance imaging (rsfMRI) along with a data-driven graph theory approach to assess brain network characteristics in obesity and BED. METHOD Multi-echo rsfMRI scans were collected from 40 obese subjects (including 20 BED patients) and 40 healthy controls and denoised using multi-echo independent component analysis (ME-ICA). We constructed a whole-brain functional connectivity matrix with normalized correlation coefficients between regional mean blood oxygenation level-dependent (BOLD) signals from 90 brain regions in the Automated Anatomical Labeling atlas. We computed global and regional network properties in the binarized connectivity matrices with an edge density of 5%-25%. We also verified our findings using a separate parcellation, the Harvard-Oxford atlas parcellated into 470 regions. RESULTS Obese subjects exhibited significantly reduced global and local network efficiency as well as decreased modularity compared with healthy controls, showing disruption in small-world and modular network structures. In regional metrics, the putamen, pallidum and thalamus exhibited significantly decreased nodal degree and efficiency in obese subjects. Obese subjects also showed decreased connectivity of cortico-striatal/cortico-thalamic networks associated with putaminal and cortical motor regions. These findings were significant with ME-ICA with limited group differences observed with conventional denoising or single-echo analysis. CONCLUSIONS Using this data-driven analysis of multi-echo rsfMRI data, we found disruption in global network properties and motor cortico-striatal networks in obesity consistent with habit formation theories. Our findings highlight the role of network properties in pathological food misuse as possible biomarkers and therapeutic targets.
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Affiliation(s)
- K. Baek
- Department of Psychiatry,
University of Cambridge, Addenbrooke's
Hospital, Cambridge CB2 0QQ, UK
| | - L. S. Morris
- Department of Psychiatry,
University of Cambridge, Addenbrooke's
Hospital, Cambridge CB2 0QQ, UK
- Behavioural and Clinical Neurosciences Institute,
University of Cambridge, Cambridge CB2 0QQ,
UK
| | - P. Kundu
- Departments of Radiology and Psychiatry,
Icahn School of Medicine at Mount Sinai, New York
City, NY 10029, USA
| | - V. Voon
- Department of Psychiatry,
University of Cambridge, Addenbrooke's
Hospital, Cambridge CB2 0QQ, UK
- Behavioural and Clinical Neurosciences Institute,
University of Cambridge, Cambridge CB2 0QQ,
UK
- Cambridgeshire and Peterborough NHS Foundation
Trust, Cambridge CB21 5EF, UK
- NIHR Cambridge Biomedical Research
Centre, Cambridge CB2 0QQ, UK
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17
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Juergens P, Augello M, Baek K, Deibel W, Baetscher C, Segesser M, Cattin P, Zeilhofer H. Execution of midfacial osteotomies with a cold ablation robot-guided laser osteotome. Int J Oral Maxillofac Surg 2017. [DOI: 10.1016/j.ijom.2017.02.699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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18
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Metzger CE, Baek K, Swift SN, De Souza MJ, Bloomfield SA. Exercise during energy restriction mitigates bone loss but not alterations in estrogen status or metabolic hormones. Osteoporos Int 2016; 27:2755-2764. [PMID: 27129456 DOI: 10.1007/s00198-016-3590-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [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: 11/30/2015] [Accepted: 04/04/2016] [Indexed: 01/26/2023]
Abstract
UNLABELLED Energy restriction causes bone loss, increasing stress fracture risk. The impact of exercise during energy restriction on bone and endocrine factors is examined. Exercise with energy restriction did not influence endocrine factors, but did mitigate some bone loss seen with energy restriction in sedentary rats. INTRODUCTION Chronic dietary energy restriction (ER) leads to bone loss and increased fracture risk. Strictly controlled trials of long-term ER with and without vigorous exercise are required to determine whether exercise loading can counterbalance ER-induced bone loss. The aim of this current project is to elucidate the impact of exercise and ER on bone mass, estrogen status, and metabolic hormones. METHODS Twenty-four virgin female Sprague-Dawley rats (n = 8/group) were divided into three groups-ad libitum fed + exercise (Adlib + EX), 40 % energy restricted + exercise (ER + EX), and 40 % energy restricted + sedentary (ER + SED). Energy availability between ER groups was equal. Treadmill running was performed 4 days/week at 70 % VO2max for 12 weeks. RESULTS Fat and lean mass and areal bone mineral density (aBMD) were lower after 12 weeks (p < 0.05) for ER + EX vs Adlib + EX, but ER + EX aBMD was higher than ER + SED (p < 0.0001). Serum leptin and a urinary estrogen metabolite, estrone-1-glucuronide (E1G), were lower at week 12 (p = 0.0002) with ER, with no impact of exercise. Serum insulin-like growth factor I (IGF-I) declined (p = 0.02) from baseline to week 12 in both ER groups. ER + EX exhibited higher cortical volumetric bone mineral density (vBMD) at the midshaft tibia (p = 0.006) vs ER + SED. CONCLUSION Exercise during ER mitigated some, but not all, of the bone loss observed in sedentary ER rats, but had little impact on changes in urinary E1G and serum IGF-I and leptin. These data highlight the importance of both adequate energy intake and the mechanical loading of exercise in maintaining bone mass.
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Affiliation(s)
- C E Metzger
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, USA
| | - K Baek
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, USA
- Department of Pharmacology, College of Dentistry and Research of Oral Science, Gangneung-Wonju National University, Gangwondo, Korea
| | - S N Swift
- Division of Dietary Supplement Programs, Federal Drug Administration, College Park, MD, USA
- Department of Nutrition & Food Science, Texas A&M University, College Station, TX, USA
| | - M J De Souza
- Departments of Kinesiology and Physiology, The Pennsylvania State University, State College, PA, USA
| | - S A Bloomfield
- Department of Health & Kinesiology, Texas A&M University, College Station, TX, USA.
- Departments of Kinesiology and Physiology, The Pennsylvania State University, State College, PA, USA.
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Lee YM, Yang JY, Baek K, Han SJ, Shin SC, Hwang CY, Hong SG, Lee HK. Pseudorhodobacter psychrotolerans sp. nov., a psychrotolerant bacterium isolated from terrestrial soil, and emended description of the genus Pseudorhodobacter. Int J Syst Evol Microbiol 2016; 66:1068-1073. [DOI: 10.1099/ijsem.0.000841] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Y. M. Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
- School of Biological Sciences, College of Natural Science, Seoul National University, 599 Gwanak-ro, Gwanak-gu, Seoul 151-747, Republic of Korea
| | - J. Y. Yang
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - K. Baek
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - S. J. Han
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - S. C. Shin
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - C. Y. Hwang
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - S. G. Hong
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - H. K. Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
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Hwang CY, Lee I, Cho Y, Lee YM, Baek K, Jung YJ, Yang YY, Lee T, Rhee TS, Lee HK. Rhodococcus aerolatus sp. nov., isolated from subarctic rainwater. Int J Syst Evol Microbiol 2014; 65:465-471. [PMID: 25385992 DOI: 10.1099/ijs.0.070086-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A Gram-stain-positive, rod-shaped and non-motile strain, designated PAMC 27367(T), was isolated from rainwater collected on the Bering Sea. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Rhodococcus. Phylogenetic analyses revealed that strain PAMC 27367(T) formed a robust clade with the type strains of Rhodococcus rhodnii, Rhodococcus aetherivorans and Rhodococcus ruber with 16S rRNA gene sequence similarities of 96.3 %, 95.8 % and 95.5 %, respectively. Cells of the strain grew optimally at 25 °C and at pH 6.5-7.0 in the presence of 0-2 % (w/v) sea salts. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and three unknown phospholipids. The major cellular fatty acids (>10 %) were iso-C16 : 0, C17 : 1ω8c and 10-methyl C17 : 0. Cell wall analysis showed that strain PAMC 27367(T) contained meso-diaminopimelic acid. The genomic DNA G+C content was 77.1 mol%. Based on the phylogenetic, chemotaxonomic and phenotypic data presented here, we propose a novel species with the name Rhodococcus aerolatus sp. nov., with PAMC 27367(T) ( = KCTC 29240(T) = JCM 19485(T)) as the type strain.
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Affiliation(s)
- C Y Hwang
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - I Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - Y Cho
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - Y M Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - K Baek
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - Y-J Jung
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - Y Y Yang
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - T Lee
- Department of Environmental Science, Hankuk University of Foreign Studies, 81 Oedae-ro, Yongin-si, Gyeonggi-do 449-791, Republic of Korea
| | - T S Rhee
- Division of Polar Ocean Environment, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
| | - H K Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 406-840, Republic of Korea
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Kwon A, Park HJ, Baek K, Lee HL, Park JC, Woo KM, Ryoo HM, Baek JH. Suberoylanilide hydroxamic acid enhances odontoblast differentiation. J Dent Res 2012; 91:506-12. [PMID: 22447851 DOI: 10.1177/0022034512443367] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Previous studies have shown that histone deacetylase (HDAC) inhibitors stimulate osteoblast differentiation in vitro and bone formation in vivo. However, the effects of HDAC inhibitors on odontoblasts have not been elucidated. Therefore, in this study, we examined the effect of suberoylanilide hydroxamic acid (SAHA), an HDAC inhibitor, on odontoblast differentiation using an MDPC23 odontoblast-like cell line. SAHA significantly enhanced matrix mineralization and the expression levels of odontoblast marker genes. SAHA increased the expression levels of nuclear factor I/C (Nfic) and dentin sialophosphoprotein (Dspp). Nfic bound directly to the Dspp promoter and stimulated Dspp transcription. SAHA increased both basal and Nfic-induced Dspp promoter activity. SAHA-induced Dspp promoter activity disappeared when mutations were introduced within the Nfic binding element of the Dspp promoter. Nfic knockdown by siRNA blocked SAHA stimulation of Dspp expression. These results indicate that SAHA enhances odontoblast differentiation and that SAHA increases Dspp expression, at least in part, by increasing the expression level of Nfic.
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Affiliation(s)
- A Kwon
- Department of Molecular Genetics, School of Dentistry and Dental Research Institute, Seoul National University, 28 Yeongun-dong, Jongno-gu, Seoul 110-749, Republic of Korea
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22
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Baek K, Chae JH, Jeong J. The effect of repetitive transcranial magnetic stimulation on fear extinction in rats. Neuroscience 2011; 200:159-65. [PMID: 21989475 DOI: 10.1016/j.neuroscience.2011.09.050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2010] [Revised: 09/26/2011] [Accepted: 09/26/2011] [Indexed: 11/18/2022]
Abstract
Facilitating fear extinction is clinically important to improve the efficacy of current exposure therapies for the treatment of anxiety disorders, such as post-traumatic stress disorder (PTSD). The aim of this study was to determine if repeated transcranial magnetic stimulation (rTMS) facilitates fear extinction in rats, especially when paired with exposure to a conditioned stimulus (CS). Thirty-five rats were conditioned to a tone CS by pairing the tone with an electric foot shock as an aversive unconditioned stimulus (US). We assessed the effects of 10 Hz rTMS before fear extinction (experiment 1) and rTMS paired with CS during extinction (experiment 2) on the following day. Fear responses of the rats were estimated using the level of freezing upon tone stimulus and were compared between the rTMS and corresponding sham groups. The rats treated with rTMS before fear extinction showed no difference in freezing time when compared with the sham group. However, the rats treated with rTMS paired with CS during extinction showed significantly less freezing behavior than the sham group, and this enhancement of fear extinction remained after 24 h without further stimulation. This finding suggests that high-frequency rTMS paired with trauma-reminding stimuli enhances fear extinction and that rTMS in conjunction with exposure therapy is potentially useful for facilitating extinction memory in the treatment of PTSD.
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Affiliation(s)
- K Baek
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
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Baek K, Kim J, Um J, Park S, Lee J, Park J, Park Y, Lim H, Kang W. Prognostic factors in patients with advanced hepatocellular carcinoma treated with sorafenib: A comparison with previously known prognostic models. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.4_suppl.323] [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: 11/20/2022] Open
Abstract
323 Background: Sorafenib, a multiple-targeted tyrosine kinase inhibitor, is now the treatment of choice for systemic therapy of patients with advanced hepatocellular carcinoma (HCC). Herein we present the clinical characteristics and outcomes of patients with advanced HCC who were treated with sorafenib. Methods: Data of 201 sorafenib-treated, metastatic HCC patients were collected from a single institution tumor registry. The primary and secondary endpoints were overall survival (OS) and failure-free survival (FFS). Results: Chronic hepatitis B was the predominant cause of HCC (84%).Of 162 evaluable patients, four partial responses were recorded. With a median follow-up of 15.7 months, the median FFS and OS were 2.5 months (95% confidence interval [CI], 2.3-2.7 months) and 5.3 months (95% CI, 4.4-6.3 months), respectively. In multivariate analysis, the prognostic factors associated with FFS were the presence of ascites, portal venous thrombosis, serum alpha- fetoprotein (AFP) ≥400 ng/mL, albumin, bilirubin, tumor size and number, and performance status. Likewise, the presence of ascites, portal venous thrombosis, tumor size and number, performance status, and baseline levels of AFP, albumin and bilirubin were significantly related with OS. After adjusting for performance status, the Cancer of the Liver Italian Program (CLIP) scoring system and Okuda stages can better predict the hazard of failure or death than Child-Pugh classification. Conclusions: Our results suggest that CLIP scores or Okuda stages, along with performance status, can be useful in stratifying patients with advanced HCC treated with sorafenib. No significant financial relationships to disclose.
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Affiliation(s)
- K. Baek
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - J. Kim
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - J. Um
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - S. Park
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - J. Lee
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - J. Park
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - Y. Park
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - H. Lim
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
| | - W. Kang
- Sungkyunkwan University, Samsung Medical Center, Seoul, South Korea; Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea
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Kim E, Choi Y, Lee S, Seo Y, Yoon J, Baek K. Characterization of the Drosophila melanogaster retinin gene encoding a cornea-specific protein. Insect Mol Biol 2008; 17:537-543. [PMID: 18828839 DOI: 10.1111/j.1365-2583.2008.00822.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Two-dimensional analysis of head extracts from Drosophila melanogaster identified the four eye-specific protein spots corresponding to the retinin protein. The retinin protein spots were specifically stained with phosphoprotein-specific dye, suggesting that the retinin protein undergoes post-translational modification by phosphorylation. Northern blot analysis showed that the retinin gene begins to be expressed during the late stage of puparium formation during development. Analysis of the N-terminal sequence and expression of the retinin gene in S2 suggest that retinin is a secretory protein. Transgenic flies with knockdown expression of the retinin gene by RNA interference (RNAi) were established. However, no significant phenotypic changes in eye structure or phototransduction were observed in the transgenic flies. Western blot analysis and immunohistochemical studies of D. melanogaster eyes suggest that retinin is a cornea-specific protein.
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MESH Headings
- Amino Acid Sequence
- Animals
- Animals, Genetically Modified
- Base Sequence
- Blotting, Northern
- Blotting, Western
- Cell Line
- Cornea/metabolism
- Drosophila Proteins/chemistry
- Drosophila Proteins/genetics
- Drosophila Proteins/metabolism
- Drosophila melanogaster/cytology
- Drosophila melanogaster/genetics
- Electrophoresis, Gel, Two-Dimensional
- Eye Proteins/chemistry
- Eye Proteins/genetics
- Eye Proteins/metabolism
- Gene Expression Regulation, Developmental
- Genes, Insect
- Genome
- Molecular Sequence Data
- Organ Specificity
- Protein Processing, Post-Translational
- Protein Transport
- RNA Interference
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
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Affiliation(s)
- E Kim
- Department of Life Science and Biotechnology, Kyung Hee University, Yongin, 446-701, Korea
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Rhee Y, Kang M, Min Y, Byun D, Chung Y, Ahn C, Baek K, Mok J, Kim D, Kim D, Kim H, Kim Y, Myoung S, Kim D, Lim SK. Effects of a combined alendronate and calcitriol agent (Maxmarvil) on bone metabolism in Korean postmenopausal women: a multicenter, double-blind, randomized, placebo-controlled study. Osteoporos Int 2006; 17:1801-7. [PMID: 17019520 DOI: 10.1007/s00198-006-0200-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Accepted: 01/11/2006] [Indexed: 12/01/2022]
Abstract
INTRODUCTION A randomized, double-blind, prospective, 24-week clinical trial was performed to evaluate the effects of a combinative agent, Maxmarvil, of calcitriol (0.5 mug) and alendronate (5 mg) on bone metabolism in postmenopausal women. METHODS A total of 217 postmenopausal women with osteoporosis were enrolled; 199 patients were randomly assigned to one of two treatment groups (Maxmarvil group or alfacalcidol group). None of the patients were vitamin-D-deficient, as assessed by serum 25-hydroxyvitamin D (25(OH)D), nor had they received any drugs affecting bone metabolism before enrollment. Bone mineral densities (BMD) of L1-L4 and the femur were measured by dual-energy X-ray absorptiometry (DXA) at the initial assessment and after 6 months of treatment. Serum biochemical assays, including serum calcium, 24-h urinary calcium excretion, and bone turnover markers (both bone-specific alkaline phosphatase [bsALP] and urine N-telopeptide [NTx]), were performed at the baseline and after 3 and 6 months of treatment. RESULTS In the Maxmarvil group, the BMD of the lumbar spine increased up to 2.42+/-0.5% from the baseline after 6 months (p<0.05). On the other hand, the change in BMD in the alfacalcidol group was 0.28+/-0.5% after 6 months. There was no significant difference in femoral BMD between the two groups. The levels of bsALP and NTx were significantly lower in the Maxmarvil group than in the alfacalcidol group (-22.04+/-3.9% vs. -11.42+/-2.8% [p<0.05] and -25.46+/-5.2% vs. 1.24+/-6.2% [p<0.001], respectively). Interestingly, there was a significantly smaller amount of 24-h urinary calcium in the Maxmarvil group (p<0.05). CONCLUSIONS Our study demonstrates that a combination of calcitriol and alendronate is quite effective in preventing bone loss, with the advantage of lesser hypercalciuric effect of calcitriol in the postmenopausal osteoporotic women.
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Affiliation(s)
- Y Rhee
- Department of Internal Medicine, Endocrine Research Institute, College of Medicine, Yonsei University, #134 Shinchon-Dong, Seodaemun-Gu, Seoul 120-752, South Korea
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Baek K, Feliciano M, Wang A, Rosenwaks Z, Palermo G. P-1006. Fertil Steril 2006. [DOI: 10.1016/j.fertnstert.2006.07.1404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Baek K, Rosenwaks Z, Poppas D, Palermo G. O-45. Fertil Steril 2006. [DOI: 10.1016/j.fertnstert.2006.07.055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Dragisic K, Baek K, Fasouliotis S, Rosenwaks Z, Spandorfer S. Metformin Usage in PCOS Patients Undergoing IVF Does Not Improve Outcome When Utilizing a Dual Suppression Stimulation Protocol. Fertil Steril 2005. [DOI: 10.1016/j.fertnstert.2005.07.831] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Baek K, Feliciano M, Neri Q, Rosenwaks Z, Palermo G. Platelet-Activating Factor: Not a Panacea for Sluggish Sperm. Fertil Steril 2005. [DOI: 10.1016/j.fertnstert.2005.07.1178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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33
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Baek K, Sajda P. A probabilistic network model of the influence of local figure-ground representations on the perception of motion. J Vis 2005. [DOI: 10.1167/5.8.842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Baek K, Sulit M, Ezcurra D, Davis O, Rosenwaks Z. Reducing the Risk of Multiples While Maintaining Pregnancy Rates After Controlled Ovarian Hyperstimulation Intrauterine Insemination Cycles. Fertil Steril 2005. [DOI: 10.1016/j.fertnstert.2005.07.718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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35
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Baek K, Takeuchi T, Neri Q, Wang A, Rosenwaks Z, Palermo G. Extended culture conditions affect ICSI fertilization and pregnancy characteristics. Fertil Steril 2004. [DOI: 10.1016/j.fertnstert.2004.07.574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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36
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Baek K, Neri Q, Wang A, Takeuchi T, Rosenwaks Z, Palermo G. Proportional oocyte nuclear maturation in relation to ICSI outcome. Fertil Steril 2004. [DOI: 10.1016/j.fertnstert.2004.07.597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Kim BK, Baek K, Yang JW. Simultaneous removal of nitrate and phosphate using cross-flow micellar-enhanced ultrafiltration (MEUF). Water Sci Technol 2004; 50:227-234. [PMID: 15537011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The feasibility of cross-flow micellar-enhanced ultrafiltration (MEUF) was investigated to remove nitrate and phosphate simultaneously. At the above critical micelle concentration (CMC), a cationic surfactant added in wastewater forms micelles, which have positive charge on their surface. Anionic contaminants such as nitrate and phosphate can be bound on the micelles by electrostatic interaction, and the micelle-pollutants complex is removed effectively by ultrafiltration. In this study, a cross-flow MEUF system was designed and investigated the feasibility of MEUF for field application. A cationic surfactant, cetylpyridinium chloride (CPC), was used, and the synthetic wastewater was treated by the polyacrylonitrile membranes with molecular weight cut-off (MWCO) of 30,000 Da and 10,000 Da. With the molar ratio of CPC to total pollutants of > 3, > 86% of nitrate and > 91% of phosphate were removed, respectively, and > 97% of CPC was also rejected. The flux was maintained 20-30% of the flux of distilled water. Therefore, it is feasible to remove nitrate and phosphate simultaneously using the cross-flow MEUF system.
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Affiliation(s)
- B K Kim
- Department of Chemical and Biomolecular Engineering, Korea Advanced Institute of Science and Technology, Guseong-dong, Yuseong-gu, Daejeon, Republic of Korea
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Park H, Seong C, Jang J, Yoon J, Han K, Cho NY, Baek K. Promoter analysis of the Drosophila melanogaster gene encoding the pterin 4alpha-carbinolamine dehydratase. Mol Cells 2001; 12:233-8. [PMID: 11710527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023] Open
Abstract
Pterin-4alpha-carbinolamine dehydratase (PCD) is a key enzyme in the regeneration pathway of tetrahydrobiopterin. Previously, we isolated and reported the Drosophila melanogaster gene encoding PCD. In the present study, we isolated and characterized the Drosophila virilis gene encoding PCD. The Drosophila virilis PCD gene has two introns and an open reading frame to encode a protein of 101 amino acids. The amino acid sequence of Drosophila virilis PCD shows a 83% homology to that of the Drosophila melanogaster PCD protein. From the alignment of the nucleotide sequence in the 5'-flanking region of the Drosophila melanogaster and Drosophila virilis PCD genes, we found four conserved sequences. Using a transient transfection assay, we showed that one of the conserved sequences (-127 to approximately -115) is critical for expression, also the minimal promoter region between -127 and +51 is necessary for the efficient expression of Drosophila melanogaster PCD.
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Affiliation(s)
- H Park
- Department and Institute of Genetic Engineering, Kyung Hee University, Yongin, Korea
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Oh Y, Lee S, Yoon J, Han K, Baek K. Promoter analysis of the Drosophila melanogaster gene encoding transcription elongation factor TFIIS. Biochim Biophys Acta 2001; 1518:276-81. [PMID: 11311940 DOI: 10.1016/s0167-4781(01)00203-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The promoter region of the Drosophila melanogaster TFIIS gene was characterized by transient expression assay. Serial deletion analysis of the promoter region showed that the promoter region between -112 and +113 is required for the efficient expression of the D. melanogaster TFIIS gene. The results also suggest that the DNA fragments between -112 and -54 and between +94 and +113 contain the vital elements for the expression. The importance of these fragments was further substantiated by the findings that the sequences in these fragments of the D. melanogaster TFIIS gene are conserved in the 5'-flanking regions of the Drosophila virilis TFIIS gene. The comparison of the nucleotide sequences in the 5'-flanking region of the D. melanogaster and D. virilis TFIIS genes revealed that the three regions, -85--59, +76-+126, and the vicinity of the transcription initiation site of the D. melanogaster TFIIS gene, are conserved. It is very interesting that the long downstream DNA between +76 and +126 is highly conserved with 90% identities between the two species. The downstream promoter region between +94 and +113 of the D. melanogaster TFIIS gene was further analyzed by transient expression and band mobility shift assays. The results obtained suggest that the region between +94 and +113 is probably recognized by nuclear factors and that the sequence (+98)AGTAAACAACAT(+109) seems to make a great contribution to promoter activity of the D. melanogaster TFIIS gene.
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Affiliation(s)
- Y Oh
- Department and Institute of Genetic Engineering, Kyung Hee University, Yongin City 449-701, South Korea
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40
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Park JS, Kim YT, Chung HY, Baek K, Jang YJ. Primary structures and chain dominance of anti-DNA antibodies. Mol Cells 2001; 11:55-63. [PMID: 11266121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Using several anti-DNA autoantibodies, we analyzed the relative involvement of heavy and light chains in their interactions with DNA. We previously obtained eight hybridomas producing monoclonal anti-DNA autoantibodies by fusing spleen cells from an MRL-lpr/lpr mouse with myeloma cells. The chain dominance was analyzed by UV cross-linking experiments, in which the antibodies were covalently cross-linked with radioisotope-labeled oligonucleotides by short-wavelength UV-light, and the cross-linked H and L chains were analyzed by SDS-PAGE and densitometric scanning. Among these, three were found to be heavy chain dominant antibodies in which heavy chains are dominantly involved in DNA binding. The other five were co-dominant antibodies in which both heavy and light chains are involved in DNA binding. To determine the factor(s) that can explain the chain dominance in DNA binding, we determined the amino acid sequences of the variable regions of both heavy (VH) and light (VL) chains of all eight monoclonal antibodies. By analyzing the data, we were able to draw the following conclusions: (1) The arginine residues are found in the CDR3 regions of both VH and VL of the co-dominant antibodies; whereas, the same residues are found only in the CDR3s of VH, but not in VL, of the heavy chain dominant antibodies. (2) The net charges of the V regions affect the chain dominance. From the results of this study it is suggested that the presence of arginine residue in CDR3 is a critical factor in determining chain-dominance, as well as DNA binding of anti-DNA antibodies in general.
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Affiliation(s)
- J S Park
- Laboratory of Immunology, Institute for Medical Science, Ajou University School of Medicine, Suwon, Korea
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Choi T, Cho N, Oh Y, Yoo M, Matsukage A, Ryu Y, Han K, Yoon J, Baek K. The DNA replication-related element (DRE)-DRE-binding factor (DREF) system may be involved in the expression of the Drosophila melanogaster TBP gene. FEBS Lett 2000; 483:71-7. [PMID: 11033359 DOI: 10.1016/s0014-5793(00)02085-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The TATA box binding protein (TBP) is a general transcription factor required for initiation by all three eukaryotic RNA polymerases. Previously, we found that the promoter region of the Drosophila melanogaster TBP gene contains three sequences similar to the DNA replication-related element (DRE) (5'-TATCGATA). In the present study, we found that the DRE-like sequences are also present in the promoter of the Drosophila virilis TBP gene, suggesting a role for these sequences in TBP expression. Band mobility shift assays revealed that oligonucleotides containing sequences similar to the DRE of D. melanogaster TBP gene promoter form specific complexes with a factor in a Kc cell nuclear extract and with recombinant DRE-binding factor (DREF). Furthermore, these complexes were either supershifted or diminished by monoclonal antibodies to DREF. Transient luciferase assays demonstrated that induction of mutations in two DRE-related sequences at positions -223 and -63 resulted in an extensive reduction of promoter activity. Thus, the DRE-DREF system appears to be involved in the expression of the D. melanogaster TBP gene.
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Affiliation(s)
- T Choi
- Department of Molecular Biology, College of Natural Science, Pusan National University, Pusan 609-735, South Korea
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42
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Abstract
We have isolated and characterized a Drosophila melanogaster gene encoding the sepiapterin reductase (SR). The gene does not have introns. The 5'- and 3'-RACE analysis, which determined the transcription start point (tsp) and polyadenylation site, respectively, showed that the gene produces single mRNA species. The potential promoter region lacks distinct TATAAA or CCAAT box consensus sequences. RNA blot analysis revealed that the gene encodes a 1.4kb transcript that could be detected throughout development and in both heads and bodies of adults. The Drosophila SR gene maps to 15A on the X chromosome.
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Affiliation(s)
- C Seong
- Department and Institute of Genetic Engineering, Kyung Hee University, 449-701, Yongin City, South Korea
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Yoon J, Ben-Ami HC, Hong YS, Park S, Strong LL, Bowman J, Geng C, Baek K, Minke B, Pak WL. Novel mechanism of massive photoreceptor degeneration caused by mutations in the trp gene of Drosophila. J Neurosci 2000; 20:649-59. [PMID: 10632594 PMCID: PMC6772429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/1999] [Revised: 10/14/1999] [Accepted: 10/21/1999] [Indexed: 02/15/2023] Open
Abstract
The Drosophila trp gene encodes a light-activated Ca(2+) channel subunit, which is a prototypical member of a novel class of channel proteins. Previously identified trp mutants are all recessive, loss-of-function mutants characterized by a transient receptor potential and the total or near-total loss of functional TRP protein. Although retinal degeneration does occur in these mutants, it is relatively mild and slow in onset. We report herein a new mutant, Trp(P365), that does not display the transient receptor potential phenotype and is characterized by a substantial level of the TRP protein and rapid, semi-dominant degeneration of photoreceptors. We show that, in spite of its unusual phenotypes, Trp(P365) is a trp allele because a Trp(P365) transgene induces the mutant phenotype in a wild-type background, and a wild-type trp transgene in a Trp(P365) background suppresses the mutant phenotype. Moreover, amino acid alterations that could cause the Trp(P365) phenotype are found in the transmembrane segment region of the mutant channel protein. Whole-cell recordings clarified the mechanism underlying the retinal degeneration by showing that the TRP channels of Trp(P365) are constitutively active. Although several genes, when mutated, have been shown to cause retinal degeneration in Drosophila, the underlying mechanism has not been identified for any of them. The present studies provide evidence for a specific mechanism for massive degeneration of photoreceptors in Drosophila. Insofar as some human homologs of TRP are highly expressed in the brain, a similar mechanism could be a major contributor to degenerative disorders of the brain.
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Affiliation(s)
- J Yoon
- Institute of Genetic Engineering and Natural Sciences, Department of Genetic Engineering, KyungHee University, Yongin City, Kyungki-Do, 449-701 Korea
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Oh Y, Lee C, Baek K, Kim W, Yoon J, Han K, Cho N. An element with palindromic structure is required for the expression of TBP (TATA box-binding protein) gene in Drosophila melanogaster. Mol Cells 1999; 9:673-7. [PMID: 10672937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
Previously we showed that the 5'-flanking regions between -261 and -207 of the Drosophila melanogaster TBP (TATA box binding protein) gene is important for its expression. We further made serial deletion mutants in this region and analyzed their promoter activities using the transient transfection assay. We found that the 16 bp deletion from -261 to -245 greatly reduces the promoter activity of the Drosophila TBP gene. The 16 bp DNA element contains half of a 11 bp long palindromic sequence, CTTTT-GAAAAG. Disruption of the palindromic sequence by site-directed mutagenesis severely affected promoter activity. In addition, the electrophoretic mobility shift assay showed that the oligonucleotide containing the palindromic sequence can make specific DNA/protein complexes when it was mixed with the Drosophila nuclear extract, suggesting that it interacts with nuclear protein(s). Our data suggest that the palindromic sequence has a critical role in the expression of the Drosophila TBP gene.
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Affiliation(s)
- Y Oh
- Department and Institute of Genetic Engineering, Kyung Hee University, Yongin, Korea
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Hwang KY, Cho CS, Kim SS, Baek K, Kim SH, Yu YG, Cho Y. Crystallization and preliminary x-ray analysis of glutamate racemase from Aquifex pyrophilus, a hyperthermophilic bacterium. Acta Crystallogr D Biol Crystallogr 1999; 55:927-8. [PMID: 10089337 DOI: 10.1107/s0907444999000608] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Glutamate racemase catalyzes the reversible reaction of L-glutamate to D-glutamate, an essential component of the bacterial cell wall. Glutamate racemase from Aquifex pyrophilus has been crystallized by the hanging-drop vapor-diffusion method using polyethylene glycol 6000 as a precipitant. The crystals belong to space group P6122 or P6522 with unit-cell parameters a = b = 72.1, c = 185.02 A. The asymmetric unit contains one molecule, corresponding to a Vm value of 2.35 A3 Da-1. Complete data sets from a native and a mercury-derivative crystal have been collected at 2.0 and 2.3 A resolution, respectively, using a synchrotron-radiation source.
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Affiliation(s)
- K Y Hwang
- Structural Biology Center, Korea Institute of Science and Technology, Cheongryang, Seoul, South Korea
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Hahn BS, Cho SY, Wu SJ, Chang IM, Baek K, Kim YC, Kim YS. Purification and characterization of a serine protease with fibrinolytic activity from Tenodera sinensis (praying mantis). Biochim Biophys Acta 1999; 1430:376-86. [PMID: 10082965 DOI: 10.1016/s0167-4838(99)00024-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mantis egg fibrolase (MEF) was purified from the egg cases of Tenodera sinensis using ammonium sulfate fractionation, gel filtration on Bio-Gel P-60 and affinity chromatography on DEAE Affi-Gel blue gel. The protease was assessed homogeneous by SDS-polyacrylamide gel electrophoresis and has a molecular mass of 31500 Da. An isoelectric point of 6.1 was determined by isoelectric focusing. Amino acid sequencing of the N-terminal region established a primary structure composed of Ala-Asp-Val-Val-Gln-Gly-Asp-Ala-Pro-Ser. MEF readily digested the Aalpha- and Bbeta-chains of fibrinogen and more slowly the gamma-chain. The nonspecific action of the enzyme results in extensive hydrolysis of fibrinogen and fibrin releasing a variety of fibrinopeptide. The enzyme is inactivated by Cu2+ and Zn2+ and inhibited by PMSF and chymostatin, yet elastinal, aprotinin, TLCK, TPCK, EDTA, EGTA, cysteine, beta-mercaptoethanol, iodoacetate, E64, benzamidine and soybean trypsin inhibitor do not affect activity. Antiplasmin was not sensitive to MEF but antithrombin III inhibited the enzymatic activity of MEF. Among chromogenic protease substrates, the most sensitive to MEF hydrolysis was benzoyl-Phe-Val-Arg-p-nitroanilide with maximal activity at pH 7.0 and 30 degrees C. MEF preferentially cleaved the oxidized B-chain of insulin between Leu15 and Tyr16. D-Dimer concentrations increased on incubation of cross-linked fibrin with MEF, indicating the enzyme has a strong fibrinolytic activity.
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Affiliation(s)
- B S Hahn
- Natural Products Research Institute, Seoul National University, 28 Yeonkun-Dong, Jongno-Ku, Seoul 110-460, South Korea
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Cho N, Oh Y, Hwang SY, Han D, Park SP, Yoon J, Han K, Baek K. Promoter analysis of the Drosophila genes encoding TFIIB and TATA box-binding protein. Mol Cells 1998; 8:770-6. [PMID: 9895133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
We have analyzed the 5'-flanking regions of the Drosophila genes encoding the TFIIB and TATA box-binding proteins (TBP) and mapped the regulatory regions required for their efficient expression. We found that the 500 bp long region (-439 to +60) and the 401 bp long region (-261 to +138) are required for the efficient expression of TFIIB and TBP genes, respectively. In the TFIIB promoter region, the upstream DNA between -439 and -280 and the downstream DNA between +8 and +60 are necessary for the stimulation of promoter activity. The upstream DNA between -439 and -280 stimulates transcription in an orientation dependent manner. In the TBP promoter region, the upstream DNA between -261 and -207, and the downstream DNA between +15 and +138 are necessary for the stimulation of promoter activity. The upstream DNA (-261 to -207) required for TBP promoter activity contains a 11 bp long palindromic sequence and a DNA replication-related element sequence. Particularly, we could find that the downstream promoter regions of TFIIB and TBP genes contain the conserved nucleotide sequences, suggesting the presence of a common regulatory mechanism for the expression of these two genes.
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Affiliation(s)
- N Cho
- Department of Microbiology, Taejon University, Korea
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48
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Baek G, Yoon S, Jeon MJ, Han S, Yim J, Baek K, Yoon J, Han K. An analysis of two tandem promoters of the Drosophila purple gene. Mol Cells 1998; 8:685-90. [PMID: 9895120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
We have analyzed two tandem promoters, separated by only about 400 bp, of the purple (pr) gene of Drosophila melanogaster, by fusing them to the firefly luciferase reporter gene and employing a transient expression assay with Drosophila S2 cells. Both the distal promoter and the proximal promoter were found to function in S2 cells and an about 700 bp long region (-270 to +421), containing both promoters, was sufficient to effect maximal promoter activity. When the two promoters were analyzed separately, the distal promoter was found to be much stronger in its function than the proximal promoter. At least three different kinds of cis elements near the transcription start site appear to play crucial roles in driving constitutive expression from the distal promoter. On the other hand, only a single cis element, which may play a role in tissue-specific expression, appears to be important for the activity of the proximal promoter in S2 cells. We propose that the clustering of important cis elements near the transcription start sites may be responsible for the selective regulation of the two tandem promoters.
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Affiliation(s)
- G Baek
- Department of Genetic Engineering, Hallym University, Chunchon, Korea
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49
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Kim B, Shortridge RD, Seong C, Oh Y, Baek K, Yoon J. Molecular characterization of a novel Drosophila gene which is expressed in the central nervous system. Mol Cells 1998; 8:750-7. [PMID: 9895130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023] Open
Abstract
We have isolated and characterized a novel Drosophila melanogaster gene (noe) that is specifically and abundantly expressed in the central nervous system (CNS). The gene, which maps to 74B on the left arm of third chromosome, encodes a protein of 74 amino acids with no significant similarity to known protein sequences. The deduced amino acid sequence of the gene product is rich in basic amino acids, especially the lysine, and contains five potential phosphorylation sites. The noe gene lacks introns and seems to produce two transcripts by alternative polyadenylations. The promoter region deduced from 5'-RACE analysis contains a sequence similar to the TATA-box consensus sequence. RNA blot analysis detected 1.0 kb noe transcripts that are expressed from the third-instar larval stage to the adult stage and which are predominantly found in the adult heads. In situ hybridizations to tissue sections showed that the gene is abundantly expressed in neuronal cell bodies as well as in the neurophiles of adult and larval CNS (brain, optic lobe, and thoracic ganglia of adults and larval brain).
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Affiliation(s)
- B Kim
- Institute of Genetic Engineering and Natural Sciences, Department of Genetic Engineering, Kyung Hee University, Yongin City, Korea
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50
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Hahn BS, Baek K, Kim WS, Lee CS, Chang IL, Kim YS. Molecular cloning of capillary permeability-increasing enzyme-2 from Agkistrodon caliginosus (Korean viper). Toxicon 1998; 36:1887-93. [PMID: 9839672 DOI: 10.1016/s0041-0101(98)00109-3] [Citation(s) in RCA: 8] [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: 11/29/2022]
Abstract
The gene of capillary permeability-increasing enzyme-2 (CPI enzyme-2) was cloned from the cDNA library of Agkistrodon caliginosus and its nucleotide sequence was determined. Its sequence indicates that CPI enzyme-2 is synthesized as a pre-zymogen of 258 amino acid residues, including a putative secretory signal peptide of 18 amino acids and a proposed zymogen peptide of 6 amino acids. The amino terminal sequence deduced from the cDNA sequence was exactly consistent with that of CPI enzyme-2 except for the substitution of an amino acid (Gly27-->Ser). The open reading frame is very similar to those of plasminogen activator and thrombin-like proteases cloned from other snakes. The clone encoding CPI enzyme-2 belongs to the serine protease family. The active site of the enzyme is highly conserved at His41, Asp86 and Ser180. Its possible glycosylation sites, Asn-X-Thr/Ser, are located at amino acid residues 20-22, 55-57, 79-81 and 97-99.
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Affiliation(s)
- B S Hahn
- Natural Products Research Institute, Seoul National University, South Korea
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