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Makioka D, Inada M, Awano M, Saito E, Shinoda T, Abe S, Yoshimura T, Müller M, Sasagawa T, Ito E. Quantification of HPV16 E7 Oncoproteins in Urine Specimens from Women with Cervical Intraepithelial Neoplasia. Microorganisms 2024; 12:1205. [PMID: 38930587 PMCID: PMC11205804 DOI: 10.3390/microorganisms12061205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/03/2024] [Accepted: 06/13/2024] [Indexed: 06/28/2024] Open
Abstract
We present the validity of using an ultrasensitive enzyme-linked immunosorbent assay (ELISA) for quantifying high-risk human papillomavirus (HPV) 16 E7 oncoproteins in urine specimens as a noninvasive method of analyzing the oncogenic activity of HPV. Some reports claim that the oncogenic activity of HPV is a more relevant clinical indicator than the presence of HPV DNA for estimating malignant potential. In the present study, urine containing HPV16 and related types were selected by uniplex E6/E7 polymerase chain reaction and classified according to the pathologic diagnosis of cervical intraepithelial neoplasia (CIN) in cervical biopsy specimens. Our ultrasensitive ELISA was able to detect attomole levels of HPV16 E7 oncoproteins, and it detected HPV16-positive SiHa cells at >500 cells/mL without detecting HPV18-positive cells. Our ELISA results showed E7 oncoproteins in 80% (4/5) of urine specimens from women with HPV16-positive CIN1, 71% (5/7) of urine specimens from CIN2 patients, and 38% (3/8) of urine specimens from CIN3 patients. Some urine specimens with undetectable E7 oncoproteins were thought to be negative for live HPV 16-positive cells or in an inactivated state of infection. These results provide the basis for assessing oncogenic activity by quantifying E7 oncoproteins in patient urine.
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Affiliation(s)
- Daiki Makioka
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan; (D.M.); (M.I.); (M.A.); (E.S.); (T.S.); (S.A.)
| | - Mikio Inada
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan; (D.M.); (M.I.); (M.A.); (E.S.); (T.S.); (S.A.)
| | - Masayuki Awano
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan; (D.M.); (M.I.); (M.A.); (E.S.); (T.S.); (S.A.)
| | - Ema Saito
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan; (D.M.); (M.I.); (M.A.); (E.S.); (T.S.); (S.A.)
| | - Takuya Shinoda
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan; (D.M.); (M.I.); (M.A.); (E.S.); (T.S.); (S.A.)
| | - Satoko Abe
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan; (D.M.); (M.I.); (M.A.); (E.S.); (T.S.); (S.A.)
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Tobetsu 061-0293, Hokkaido, Japan;
| | - Martin Müller
- Tumorvirus-Specific Vaccination Strategies, Deutsche Krebsforschungszentrum (DKFZ), 69120 Heidelberg, Germany;
| | - Toshiyuki Sasagawa
- Department of Obstetrics and Gynecology, Kanazawa Medical University, Uchinada 920-0293, Ishikawa, Japan
| | - Etsuro Ito
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan; (D.M.); (M.I.); (M.A.); (E.S.); (T.S.); (S.A.)
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
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2
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Chen PK, Chang JH, Ke LY, Kao JK, Chen CH, Yang RC, Yoshimura T, Ito E, Tsai JJ. Advanced Detection Method for Dengue NS1 Protein Using Ultrasensitive ELISA with Thio-NAD Cycling. Viruses 2023; 15:1894. [PMID: 37766300 PMCID: PMC10534902 DOI: 10.3390/v15091894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 09/03/2023] [Accepted: 09/06/2023] [Indexed: 09/29/2023] Open
Abstract
Dengue fever, a mosquito-borne disease in tropical and subtropical climates caused by the dengue virus (DENV), has become a major social and economic burden in recent years. However, current primary detection methods are inadequate for early diagnosis of DENV because they are either time-consuming, expensive, or require training. Non-structural protein 1 (NS1) is secreted during DENV infection and is thus considered a suitable biomarker for the development of an early detection method. In the present study, we developed a detection method for the NS1 protein based on a previously reported thio-NAD cycling ELISA (i.e., ultrasensitive ELISA) and successfully achieved a LOD of 1.152 pg/mL. The clinical diagnosis potential of the detection system was also evaluated by using 85 patient specimens, inclusive of 60 DENV-positive and 25 DENV-negative specimens confirmed by the NAAT method. The results revealed 98.3% (59/60) sensitivity and 100% (25/25) specificity, which was in almost perfect agreement with the NAAT data with a kappa coefficient of 0.972. The present study demonstrates the diagnostic potential of using an ultrasensitive ELISA as a low-cost, easy-to-use method for the detection of DENV compared with NAAT and could be of great benefit in low-income countries.
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Affiliation(s)
- Po-Kai Chen
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (P.-K.C.); (J.-H.C.)
| | - Jyun-Hao Chang
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (P.-K.C.); (J.-H.C.)
| | - Liang-Yin Ke
- Department of Medical Laboratory Science and Biotechnology, College of Health Sciences, Kaohsiung Medical University, Kaohsiung 80708, Taiwan;
| | - Jun-Kai Kao
- Frontier Molecular Medical Research Center in Children, Changhua Christian Children’s Hospital, Changhua 50006, Taiwan; (J.-K.K.); (R.-C.Y.)
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung 402204, Taiwan;
| | - Chang-Hua Chen
- Department of Post-Baccalaureate Medicine, College of Medicine, National Chung Hsing University, Taichung 402204, Taiwan;
- Changhua Christian Hospital, Changhua 50006, Taiwan
| | - Rei-Cheng Yang
- Frontier Molecular Medical Research Center in Children, Changhua Christian Children’s Hospital, Changhua 50006, Taiwan; (J.-K.K.); (R.-C.Y.)
- Kaohsiung Medical University Chung-Ho Memorial Hospital, Kaohsiung 80756, Taiwan
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Science University of Hokkaido, Hokkaido 061-0293, Japan;
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (P.-K.C.); (J.-H.C.)
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| | - Jih-Jin Tsai
- Tropical Medicine Center, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan
- School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
- Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Medical University Hospital, Kaohsiung 80756, Taiwan
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3
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Campion EM, Walls D, Loughran ST. Protein Quantitation and Analysis of Purity. Methods Mol Biol 2023; 2699:305-347. [PMID: 37647005 DOI: 10.1007/978-1-0716-3362-5_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
The accurate quantitation of proteins and an analysis of their purity is essential in numerous areas of scientific research and is a critical factor in many clinical applications. The large number and variety of techniques employed for this purpose is therefore not surprising. The selection of a suitable assay is dependent on such factors as the level of sensitivity required, the presence of interfering agents, and the composition of the protein itself. In this chapter, protocols for the most commonly used protein determination methodologies are outlined, including an overview of the highly sensitive real-time quantitative immuno-polymerase chain reaction assay. In addition, an approach to validate the UV protein absorption assay is outlined, which can be applied to any procedure for method validation.
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Affiliation(s)
- Eva M Campion
- Department of Life Science, Faculty of Science, Atlantic Technological University, Ash Lane, Sligo, Ireland.
| | - Dermot Walls
- School of Biotechnology, Dublin City University, Glasnevin, Dublin, Ireland
| | - Sinéad T Loughran
- Department of Life and Health Sciences, Dundalk Institute of Technology, Dundalk Co. Louth, Ireland
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Yamura S, Kawada N, Yamakado S, Kyosei Y, Watabe S, Yoshimura T, Murase Y, Mitarai S, Ito E. Non-amplification nucleic acid detection with thio-NAD cycling. J Microbiol Methods 2023; 204:106647. [PMID: 36496031 DOI: 10.1016/j.mimet.2022.106647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 12/12/2022]
Abstract
The PCR technique is indispensable in biology and medicine, but some difficulties are associated with its use, including false positive or false negative amplifications. To avoid these issues, a non-amplification nucleic acid detection protocol is needed. In the present study, we propose a method in which nucleic-acid probe hybridization is combined with thio-NAD cycling to detect nucleic acids without amplification. We report our application of this method for the detection of the gene of MPT64 in Mycobacterium tuberculosis. Two different cDNA probes targeted the mpt64 gene: the first probe was used to immobilize the mpt64 gene, and the second probe, linked with alkaline phosphatase (ALP), was hybridized to a target sequence in the mpt64 gene. A substrate was then hydrolyzed by ALP, and a cycling reaction was conducted by a dehydrogenase with its co-factors (thio-NAD and NADH). The single-stranded DNA, double-stranded DNA, plasmid DNA for the mpt64 gene, and whole genome of M. tuberculosis var. BCG were detected at the level of 105-106 copies/assay, whereas the non-tuberculosis mycobacteria (e.g., M. avium, M. intracellulare, M. kansasii, and M. abscessus) were below the limits of detection. The present method enables us to avoid the errors inherent in nucleic acid amplification methods.
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Affiliation(s)
- Sou Yamura
- Department of Biology, Waseda University, Shinjuku, Tokyo, Japan
| | - Naoki Kawada
- Department of Biology, Waseda University, Shinjuku, Tokyo, Japan
| | | | - Yuta Kyosei
- Department of Biology, Waseda University, Shinjuku, Tokyo, Japan
| | - Satoshi Watabe
- Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo, Japan
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Tobetsu, Hokkaido, Japan
| | - Yoshiro Murase
- The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Tokyo, Japan
| | - Satoshi Mitarai
- The Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association, Kiyose, Tokyo, Japan
| | - Etsuro Ito
- Department of Biology, Waseda University, Shinjuku, Tokyo, Japan; Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo, Japan; Graduate Institute of Medicine, Kaohsiung Medical University, Sanmin, Kaohsiung, Taiwan.
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Gastric Cancer Cell-Derived Exosomal GRP78 Enhances Angiogenesis upon Stimulation of Vascular Endothelial Cells. Curr Issues Mol Biol 2022; 44:6145-6157. [PMID: 36547080 PMCID: PMC9776843 DOI: 10.3390/cimb44120419] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/03/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
Exosomes containing glucose-regulated protein 78 (GRP78) are involved in cancer malignancy. GRP78 is thought to promote the tumor microenvironment, leading to angiogenesis. No direct evidence for this role has been reported, however, mainly because of difficulties in accurately measuring the GRP78 concentration in the exosomes. Recently, exosomal GRP78 concentrations were successfully measured using an ultrasensitive ELISA. In the present study, GRP78 concentrations in exosomes collected from gastric cancer AGS cells with overexpression of GRP78 (OE), knockdown of GRP78 (KD), or mock GRP78 (mock) were quantified. These three types of exosomes were then incubated with vascular endothelial cells to examine their effects on endothelial cell angiogenesis. Based on the results of a tube formation assay, GRP78-OE exosomes accelerated angiogenesis compared with GRP78-KD or GRP78-mock exosomes. To investigate the mechanisms underlying this effect, we examined the Ser473 phosphorylation state ratio of AKT, which is involved in the angiogenesis process, and found that AKT phosphorylation was increased by GRP78-OE exosome application to the endothelial cells. An MTT assay showed that GRP78-OE exosome treatment increased the proliferation rate of endothelial cells, and a wound healing assay showed that this treatment increased the migration capacity of the endothelial cells. These findings demonstrated that GRP78-containing exosomes promote the tumor microenvironment and induce angiogenesis.
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Ultrasensitive Detection of GRP78 in Exosomes and Observation of Migration and Proliferation of Cancer Cells by Application of GRP78-Containing Exosomes. Cancers (Basel) 2022; 14:cancers14163887. [PMID: 36010879 PMCID: PMC9405752 DOI: 10.3390/cancers14163887] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/08/2022] [Accepted: 08/10/2022] [Indexed: 11/17/2022] Open
Abstract
Simple Summary Cancer cells release exosomes to their surrounding cells, and it is believed that trace amounts of proteins included in exosomes promote cancer stemness. In the present study, we note 78-kDa glucose-regulated protein (GRP78), which is involved in cancer progression, and present the protocol for measurements of trace amounts of GRP78 in exosomes released from cultured gastric cancer cells using an ultrasensitive ELISA with thio-NAD cycling. We found that when high-GRP78-containing exosomes were incubated with cultured cancer cells, these cells increased their stemness, for example, an increase in indices of both an MTT assay and a wound healing assay. The technique for quantifying proteins in exosomes described here will advance our understanding of cancer stemness progression via exosomes. Abstract Cancer cells communicate with each other via exosomes in the tumor microenvironment. However, measuring trace amounts of proteins in exosomes is difficult, and thus the cancer stemness-promoting mechanisms of exosomal proteins have not been elucidated. In the present study, we attempted to quantify trace amounts of 78-kDa glucose-regulated protein (GRP78), which is involved in cancer progression, in exosomes released from cultured gastric cancer cells using an ultrasensitive ELISA combined with thio-NAD cycling. We also evaluated the cancer stemness-promoting effects by the application of high-GRP78-containing exosomes to cultured gastric cancer cells. The ultrasensitive ELISA enabled the detection of GRP78 at a limit of detection of 0.16 pg/mL. The stemness of cancer cultured cells incubated with high-GRP78-containing exosomes obtained from GRP78-overexpressed cells was increased on the basis of both an MTT assay and a wound healing assay. Our results demonstrated that the ultrasensitive ELISA has strong potential to measure trace amounts of proteins in exosomes. Further, exosomes with a high concentration of GRP78 promote the cancer stemness of surrounding cells. The technique for quantifying proteins in exosomes described here will advance our understanding of cancer stemness progression via exosomes.
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Iha K, Tsurusawa N, Tsai HY, Lin MW, Sonoda H, Watabe S, Yoshimura T, Ito E. Ultrasensitive ELISA detection of proteins in separated lumen and membrane fractions of cancer cell exosomes. Anal Biochem 2022; 654:114831. [DOI: 10.1016/j.ab.2022.114831] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Revised: 06/29/2022] [Accepted: 07/21/2022] [Indexed: 12/31/2022]
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Dong B, He Z, Li Y, Xu X, Wang C, Zeng J. Improved Conventional and New Approaches in the Diagnosis of Tuberculosis. Front Microbiol 2022; 13:924410. [PMID: 35711765 PMCID: PMC9195135 DOI: 10.3389/fmicb.2022.924410] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 05/06/2022] [Indexed: 02/05/2023] Open
Abstract
Tuberculosis (TB) is a life-threatening infectious disease caused by Mycobacterium tuberculosis (M. tuberculosis). Timely diagnosis and effective treatment are essential in the control of TB. Conventional smear microscopy still has low sensitivity and is unable to reveal the drug resistance of this bacterium. The traditional culture-based diagnosis is time-consuming, since usually the results are available after 3–4 weeks. Molecular biology methods fail to differentiate live from dead M. tuberculosis, while diagnostic immunology methods fail to distinguish active from latent TB. In view of these limitations of the existing detection techniques, in addition to the continuous emergence of multidrug-resistant and extensively drug-resistant TB, in recent years there has been an increase in the demand for simple, rapid, accurate and economical point-of-care approaches. This review describes the development, evaluation, and implementation of conventional diagnostic methods for TB and the rapid new approaches for the detection of M. tuberculosis.
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Affiliation(s)
- Baoyu Dong
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Zhiqun He
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China
| | - Xinyue Xu
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Chuan Wang
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
| | - Jumei Zeng
- West China School of Public Health and West China Fourth Hospital, Sichuan University, Chengdu, China
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Tsurusawa N, Chang J, Namba M, Makioka D, Yamura S, Iha K, Kyosei Y, Watabe S, Yoshimura T, Ito E. Modified ELISA for Ultrasensitive Diagnosis. J Clin Med 2021; 10:5197. [PMID: 34768717 PMCID: PMC8585087 DOI: 10.3390/jcm10215197] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/03/2021] [Accepted: 11/05/2021] [Indexed: 12/11/2022] Open
Abstract
An enzyme-linked immunosorbent assay (ELISA) can be used for quantitative measurement of proteins, and improving the detection sensitivity to the ultrasensitive level would facilitate the diagnosis of various diseases. In the present review article, we first define the term 'ultrasensitive'. We follow this with a survey and discussion of the current literature regarding modified ELISA methods with ultrasensitive detection and their application for diagnosis. Finally, we introduce our own newly devised system for ultrasensitive ELISA combined with thionicotinamide adenine dinucleotide cycling and its application for the diagnosis of infectious diseases and lifestyle-related diseases. The aim of the present article is to expand the application of ultrasensitive ELISAs in the medical and biological fields.
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Affiliation(s)
- Naoko Tsurusawa
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
| | - Jyunhao Chang
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
| | - Mayuri Namba
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
| | - Daiki Makioka
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
| | - Sou Yamura
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
| | - Kanako Iha
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
| | - Yuta Kyosei
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
| | - Satoshi Watabe
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan;
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, 1757 Kanazawa, Ishikari-Tobetsu 061-0293, Hokkaido, Japan;
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (N.T.); (J.C.); (M.N.); (D.M.); (S.Y.); (K.I.); (Y.K.)
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan;
- Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
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Kyosei Y, Namba M, Makioka D, Kokubun A, Watabe S, Yoshimura T, Sasaki T, Shioda T, Ito E. Ultrasensitive Detection of SARS-CoV-2 Spike Proteins Using the Thio-NAD Cycling Reaction: A Preliminary Study before Clinical Trials. Microorganisms 2021; 9:microorganisms9112214. [PMID: 34835340 PMCID: PMC8619787 DOI: 10.3390/microorganisms9112214] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 10/03/2021] [Accepted: 10/22/2021] [Indexed: 12/17/2022] Open
Abstract
To help control the global pandemic of coronavirus disease 2019 (COVID-19), we developed a diagnostic method targeting the spike protein of the virus that causes the infection, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We applied an ultrasensitive method by combining a sandwich enzyme-linked immunosorbent assay (ELISA) and the thio-nicotinamide adenine dinucleotide (thio-NAD) cycling reaction to quantify spike S1 proteins. The limit of detection (LOD) was 2.62 × 10−19 moles/assay for recombinant S1 proteins and 2.6 × 106 RNA copies/assay for ultraviolet B-inactivated viruses. We have already shown that the ultrasensitive ELISA for nucleocapsid proteins can detect ultraviolet B-inactivated viruses at the 104 RNA copies/assay level, whereas the nucleocapsid proteins of SARS-CoV-2 are difficult to distinguish from those in conventional coronaviruses and SARS-CoV. Thus, an antigen test for only the nucleocapsid proteins is insufficient for virus specificity. Therefore, the use of a combination of tests against both spike and nucleocapsid proteins is recommended to increase both the detection sensitivity and testing accuracy of the COVID-19 antigen test. Taken together, our present study, in which we incorporate S1 detection by combining the ultrasensitive ELISA for nucleocapsid proteins, offers an ultrasensitive, antigen-specific test for COVID-19.
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Affiliation(s)
- Yuta Kyosei
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (D.M.); (A.K.)
| | - Mayuri Namba
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (D.M.); (A.K.)
| | - Daiki Makioka
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (D.M.); (A.K.)
| | - Ayumi Kokubun
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (D.M.); (A.K.)
| | - Satoshi Watabe
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan;
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Hokkaido 061-0293, Japan;
| | - Tadahiro Sasaki
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; (T.S.); (T.S.)
| | - Tatsuo Shioda
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan; (T.S.); (T.S.)
| | - Etsuro Ito
- Department of Biology, Waseda University, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (D.M.); (A.K.)
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo 169-8555, Japan;
- Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
- Correspondence:
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11
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Iha K, Kyosei Y, Namba M, Makioka D, Yamura S, Watabe S, Yoshimura T, Ito E. Zeptomole Detection of an Enzyme by a Simple Colorimetric Method. ANAL SCI 2021; 37:1469-1472. [PMID: 33746140 DOI: 10.2116/analsci.21n009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An enzyme immunoassay, in which an enzyme (e.g., alkaline phosphatase, ALP) is conjugated with an antibody, is a precise and simple protein detection method. Precise measurements of enzymes at low concentrations allow for ultrasensitive protein detection. The application of a phosphorylated substrate to ALP, followed by using a dephosphorylated substrate in thionicotinamide-adenine dinucleotide cycling, provides a simple and precise quantification of ALP. We describe a protocol for detecting ALP at the zeptomole level using a simple colorimetric method.
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Affiliation(s)
- Kanako Iha
- Department of Biology, Waseda University
| | | | | | | | - Sou Yamura
- Department of Biology, Waseda University
| | - Satoshi Watabe
- Waseda Research Institute for Science and Engineering, Waseda University
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido
| | - Etsuro Ito
- Department of Biology, Waseda University.,Waseda Research Institute for Science and Engineering, Waseda University.,Graduate Institute of Medicine, Kaohsiung Medical University
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12
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Kyosei Y, Namba M, Yamura S, Watabe S, Yoshimura T, Sasaki T, Shioda T, Ito E. Improved Detection Sensitivity of an Antigen Test for SARS-CoV-2 Nucleocapsid Proteins with Thio-NAD Cycling. Biol Pharm Bull 2021; 44:1332-1336. [PMID: 34148926 DOI: 10.1248/bpb.b21-00387] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Antigen tests for infectious diseases are inexpensive and easy-to-use, but the limit of detection (LOD) is generally higher than that of PCR tests, which are considered the gold standard. In the present study, we combined a sandwich enzyme-linked immunosorbent assay (ELISA) with thionicotinamide-adenine dinucleotide (thio-NAD) cycling to improve the LOD of antigen tests for coronavirus disease 2019 (COVID-19). For recombinant nucleocapsid proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the LOD of our ELISA with thio-NAD cycling was 2.95 × 10-17 moles/assay. When UV-irradiated inactive SARS-CoV-2 was used, the minimum detectable virions corresponding to 2.6 × 104 RNA copies/assay were obtained using our ELISA with thio-NAD cycling. The assay volume for each test was 100 µL. The minimum detectable value was smaller than that of the latest antigen test using a fluorescent immunoassay for SARS-CoV-2, indicating the validity of our detection system for COVID-19 diagnosis.
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Affiliation(s)
| | | | - Sou Yamura
- Department of Biology, Waseda University
| | - Satoshi Watabe
- Waseda Research Institute for Science and Engineering, Waseda University
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido
| | - Tadahiro Sasaki
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University
| | - Tatsuo Shioda
- Department of Viral Infections, Research Institute for Microbial Diseases, Osaka University
| | - Etsuro Ito
- Department of Biology, Waseda University.,Waseda Research Institute for Science and Engineering, Waseda University.,Graduate Institute of Medicine, Kaohsiung Medical University
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13
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Kyosei Y, Yamura S, Namba M, Yoshimura T, Watabe S, Ito E. Antigen tests for COVID-19. Biophys Physicobiol 2021; 18:28-39. [PMID: 33954080 PMCID: PMC8049777 DOI: 10.2142/biophysico.bppb-v18.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 02/05/2021] [Indexed: 12/20/2022] Open
Abstract
PCR diagnosis has been considered as the gold standard for coronavirus disease 2019 (COVID-19) and other many diseases. However, there are many problems in using PCR, such as non-specific (i.e., false-positive) and false-negative amplifications, the limits of a target sample volume, deactivation of the enzymes used, complicated techniques, difficulty in designing probe sequences, and the expense. We, thus, need an alternative to PCR, for example an ultrasensitive antigen test. In the present review, we summarize the following three topics. (1) The problems of PCR are outlined. (2) The antigen tests are surveyed in the literature that was published in 2020, and their pros and cons are discussed for commercially available antigen tests. (3) Our own antigen test on the basis of an ultrasensitive enzyme-linked immunosorbent assay (ELISA) is introduced. Finally, we discuss the possibility that our antigen test by an ultrasensitive ELISA technique will become the gold standard for diagnosis of COVID-19 and other diseases.
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Affiliation(s)
- Yuta Kyosei
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan
| | - Sou Yamura
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan
| | - Mayuri Namba
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari, Hokkaido 061-0293, Japan
| | - Satoshi Watabe
- Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555, Japan
| | - Etsuro Ito
- Department of Biology, Waseda University, Shinjuku, Tokyo 162-8480, Japan.,Waseda Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555, Japan.,Graduate Institute of Medicine, Kaohsiung Medical University, Sanmin, Kaohsiung 80756, Taiwan
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14
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Wang WH, Takeuchi R, Jain SH, Jiang YH, Watanuki S, Ohtaki Y, Nakaishi K, Watabe S, Lu PL, Ito E. A novel, rapid (within hours) culture-free diagnostic method for detecting live Mycobacterium tuberculosis with high sensitivity. EBioMedicine 2020; 60:103007. [PMID: 32949995 PMCID: PMC7501073 DOI: 10.1016/j.ebiom.2020.103007] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/26/2020] [Accepted: 09/01/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Nucleic acid amplification tests (NAATs) are widely used to diagnose tuberculosis (TB), but cannot discriminate live bacilli from dead bacilli. Live bacilli can be isolated by culture methods, but this is time-consuming. We developed a de novo TB diagnostic method that detects only live bacilli with high sensitivity within hours. METHODS A prospective study was performed in Taiwan from 2017 to 2018. Sputum was collected consecutively from 1102 patients with suspected TB infection. The sputum was pretreated and heated at 46°C for 1 h to induce the secretion of MPT64 protein from live Mycobacterium tuberculosis. MPT64 was detected with our ultrasensitive enzyme-linked immunosorbent assay (ELISA) coupled with thionicotinamide-adenine dinucleotide (thio-NAD) cycling. We compared our data with those obtained using a culture test (MGIT), a smear test (Kinyoun staining), and a NAAT (Xpert). FINDINGS The limit of detection for MPT64 in our culture-free ultrasensitive ELISA was 2.0 × 10-19 moles/assay. When the criterion for a positive response was set as an absorbance value ≥17 mAbs, this value corresponded to ca. 330 CFU/mL in the culture method - almost the same high-detection sensitivity as the culture method. To confirm that MPT64 is secreted from only live bacilli, M. bovis BCG was killed using 8 μg/mL rifampicin and then heated. Following this procedure, our method detected no MPT64. Our rapid ultra-sensitive ELISA-based method required only 5 h to complete. Comparing the results of our method with those of culture tests for 944 specimens revealed a sensitivity of 86.9% (93/107, 95% CI: 79.0-92.7%) and a specificity of 92.0% (770/837, 95% CI: 89.9-93.7%). The performance data were not significantly different (McNemar's test, P = 0.887) from those of the Xpert tests. In addition, at a ≥1+ titer in the smear test, the positive predictive value of our culture-free ultrasensitive ELISA tests was in a good agreement with that of the culture tests. Furthermore, our culture-free ultrasensitive ELISA test had better validity for drug effectiveness examination than Xpert tests because our test detected only live bacilli. INTERPRETATION Our culture-free ultrasensitive ELISA method detects only live TB bacilli with high sensitivity within hours, allowing for rapid diagnosis of TB and monitoring drug efficacy. FUNDING Matching Planner Program from JST (VP29117939087), the A-STEP Program from JST (AS3015096U), Waseda University grants for Specific Research Projects (2017A-015 and 2019C-123), the Precise Measurement Technology Promotion Foundation to E.I.
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Affiliation(s)
- Wen-Hung Wang
- Division of Infectious Disease, Department of Internal Medicine, Kaohsiung Medical University Hospital, 100 TzYou 1st Rd., Kaohsiung 80756, Taiwan
| | - Rikiya Takeuchi
- R&D Department, TAUNS Laboratories, Inc., 761-1 Kamishima, Izunokuni, Shizuoka 410-2325, Japan
| | - Shu-Huei Jain
- Division of Infectious Disease, Department of Internal Medicine, Kaohsiung Medical University Hospital, 100 TzYou 1st Rd., Kaohsiung 80756, Taiwan
| | - Yong-Huang Jiang
- R&D Department, TAUNS Laboratories, Inc., 761-1 Kamishima, Izunokuni, Shizuoka 410-2325, Japan
| | - Sonoko Watanuki
- R&D Department, TAUNS Laboratories, Inc., 761-1 Kamishima, Izunokuni, Shizuoka 410-2325, Japan
| | - Yoshiharu Ohtaki
- R&D Department, TAUNS Laboratories, Inc., 761-1 Kamishima, Izunokuni, Shizuoka 410-2325, Japan
| | - Kazunari Nakaishi
- R&D Headquarters, TAUNS Laboratories, Inc., 761-1 Kamishima, Izunokuni, Shizuoka 410-2325, Japan; Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Satoshi Watabe
- R&D Headquarters, TAUNS Laboratories, Inc., 761-1 Kamishima, Izunokuni, Shizuoka 410-2325, Japan; Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Po-Liang Lu
- Division of Infectious Disease, Department of Internal Medicine, Kaohsiung Medical University Hospital, 100 TzYou 1st Rd., Kaohsiung 80756, Taiwan; College of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd., Kaohsiung 80756, Taiwan.
| | - Etsuro Ito
- Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan; Graduate Institute of Medicine, Kaohsiung Medical University, 100 Shih-Chuan 1st Rd., Kaohsiung 80756, Taiwan; Department of Biology, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan.
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15
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Kyosei Y, Namba M, Yamura S, Takeuchi R, Aoki N, Nakaishi K, Watabe S, Ito E. Proposal of De Novo Antigen Test for COVID-19: Ultrasensitive Detection of Spike Proteins of SARS-CoV-2. Diagnostics (Basel) 2020; 10:E594. [PMID: 32823866 PMCID: PMC7459804 DOI: 10.3390/diagnostics10080594] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 08/03/2020] [Accepted: 08/12/2020] [Indexed: 12/13/2022] Open
Abstract
Polymerase chain reaction (PCR)-based antigen tests are technically difficult, time-consuming, and expensive, and may produce false negative results requiring follow-up confirmation with computed tomography. The global coronavirus disease 2019 (COVID-19) pandemic has increased the demand for accurate, easy-to-use, rapid, and cost-effective antigen tests for clinical application. We propose a de novo antigen test for diagnosing COVID-19 using the combination of sandwich enzyme-linked immunosorbent assay and thio-nicotinamide adenine dinucleotide (thio-NAD) cycling. Our test takes advantage of the spike proteins specific to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The limit of detection of our test was 2.3 × 10-18 moles/assay. If the virus has ~25 spike proteins on its surface, our method should detect on the order of 10-20 moles of virus/assay, corresponding to ~104 copies of the virus RNA/assay. The detection sensitivity approaches that of PCR-based assays because the average virus RNA load used for PCR-based assays is ~105 copies per oro- or naso-pharyngeal swab specimen. To our knowledge, this is the first ultrasensitive antigen test for SARS-CoV-2 spike proteins that can be performed with an easy-to-use microplate reader. Sufficient sensitivity can be achieved within 10 min of thio-NAD cycling. Our antigen test allows for rapid, cost-effective, specific, ultrasensitive, and simultaneous multiple measurements of SARS-CoV-2, and has broad application for the diagnosis for COVID-19.
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Affiliation(s)
- Yuta Kyosei
- Department of Biology, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (S.Y.)
| | - Mayuri Namba
- Department of Biology, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (S.Y.)
| | - Sou Yamura
- Department of Biology, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (S.Y.)
| | - Rikiya Takeuchi
- Research and Development Department, TAUNS Laboratories, Inc., 245-1 Doniwa, Shimizu, Sunto, Shizuoka 411-0903, Japan; (R.T.); (N.A.); (S.W.)
| | - Noriko Aoki
- Research and Development Department, TAUNS Laboratories, Inc., 245-1 Doniwa, Shimizu, Sunto, Shizuoka 411-0903, Japan; (R.T.); (N.A.); (S.W.)
| | - Kazunari Nakaishi
- Quality Headquarters, TAUNS Laboratories, Inc., 761-1 Kamishima, Izunokuni, Shizuoka 410-2325, Japan;
- Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Satoshi Watabe
- Research and Development Department, TAUNS Laboratories, Inc., 245-1 Doniwa, Shimizu, Sunto, Shizuoka 411-0903, Japan; (R.T.); (N.A.); (S.W.)
- Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
| | - Etsuro Ito
- Department of Biology, Waseda University, 2-2 Wakamatsucho, Shinjuku, Tokyo 162-8480, Japan; (Y.K.); (M.N.); (S.Y.)
- Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555, Japan
- Graduate Institute of Medicine, Kaohsiung Medical University, No. 100 Shiquan 1st Rd., Sanmin, Kaohsiung 80756, Taiwan
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16
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Abstract
Accurate, rapid and simple detection methods are required to facilitate early diagnosis of various disorders including infectious and lifestyle diseases as well as cancer. These detection approaches reduce the window of infection, i.e., the period between infection and reliable detection. Optimally, these methods should target protein as an indicator of pathogenic microbes as well as other biomarkers. For example, although nucleic acid is easily detected by polymerase chain reaction (PCR), these markers are also present in dead microbes, and, in the case of mRNA, it is not known whether this target was successfully translated. Accordingly, early diagnostic approaches require the development of ultrasensitive protein detection methods. In this chapter, we introduce an ultrasensitive enzyme-linked immunosorbent assay (ELISA) which combines a traditional sandwich-based immunoassay with thionicotinamide adenine dinucleotide (thio-NAD) cycling. The performance characteristics of this unique approach are reviewed as well as its potential role in providing a novel and ultrasensitive diagnostic tool in the clinical laboratory.
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Affiliation(s)
- Etsuro Ito
- Department of Biology, Waseda University, Tokyo, Japan; Waseda Research Institute for Science and Engineering, Waseda University, Tokyo, Japan; Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
| | - Kanako Iha
- Department of Biology, Waseda University, Tokyo, Japan
| | - Teruki Yoshimura
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Sapporo, Hokkaido, Japan
| | - Kazunari Nakaishi
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo, Japan; R&D Headquarters, TAUNS Laboratories, Inc., Izunokuni, Japan
| | - Satoshi Watabe
- Waseda Research Institute for Science and Engineering, Waseda University, Tokyo, Japan; R&D Headquarters, TAUNS Laboratories, Inc., Izunokuni, Japan
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17
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Ultrasensitive enzyme-linked immunosorbent assay for the detection of MPT64 secretory antigen to evaluate Mycobacterium tuberculosis viability in sputum. Int J Infect Dis 2020; 96:244-253. [PMID: 32353548 DOI: 10.1016/j.ijid.2020.04.059] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 04/16/2020] [Accepted: 04/18/2020] [Indexed: 12/16/2022] Open
Abstract
OBJECTIVES This study examined Mycobacterium tuberculosis (MTB)-secreted MPT64 as a surrogate of bacterial viability for the diagnosis of active pulmonary TB (PTB) and for follow-up treatment. METHODS In this proof-of-concept prospective study, 50 PTB patients in the Tokyo metropolitan region, between 2017 and 2018, were consecutively included and 30 healthy individuals were also included. Each PTB patient submitted sputum on days 0, 14 and 28 for diagnosis and follow-up, and each healthy individual submitted one sputum sample. The following were performed: smear microscopy, Xpert MTB/RIF, MGIT and solid culture, and MPT64 detection on the sputum samples. Ultrasensitive ELISA (usELISA) was used to detect MPT64. The receiver operating characteristic analyses for diagnosis and follow-up revealed the optimal cut-off value of MPT64 absorbance for detecting culture positivity at multiple intervals. RESULTS The sensitivity of MPT64 for diagnosing PTB was 88.0% (95% CI 75.7-95.5) and the specificity was 96.7% (95% CI 82.8-99.9). The specificity of MPT64 for predicting negative culture results on day 14 was 89.5% (95% CI 66.9-98.7). The sensitivity of MPT64 for predicting positive culture results on day 28 was 81.0% (95% CI 58.1-94.6). CONCLUSIONS This study revealed that MPT64 is useful for diagnosing active PTB in patients and predicting treatment efficacy at follow-up.
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18
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Singh P, Bharti, Kumar R, Bhalla V. Gold nanoparticle triggered siloxane formation for polymerization based amplification in enzyme free visual immunoassay. Anal Chim Acta 2019; 1078:151-160. [PMID: 31358213 DOI: 10.1016/j.aca.2019.06.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 06/06/2019] [Accepted: 06/07/2019] [Indexed: 12/11/2022]
Abstract
Herein, we report a new signal amplification scheme for quantitative biochemical analysis based on gold nanoparticle (GNPs) catalyzed polymerization of transparent silane solution to milky white and turbid siloxane. Using immunoassay as a proof of concept, GNP labeled immunoprobe was used to bind captured antigen and catalyse the polymerization reaction allowing sensitive biochemical investigation. The polymerization reaction was optimized for standard 96 well polystyrene microtiter plates and we discovered that sodium lactate acts as an enhancer in the polymerization reaction as it reduces detection time to merely 30 min. The sensing strategy was applied to detection and quantification of Salmonella Typhimurium in water and egg samples and the platform showed excellent visibly quantifiable analytical response up to 100 cells mL-1. Furthermore, clinical utility and potential of the method was validated by detecting Vi capsular polysaccharide (Vi antigen) responsible for typhoidal Salmonellosis in human serum in sandwich format with a detection limit of 1 ng mL-1. The method serves as the first report towards nanoparticle triggered polymerization for development of rapid and low cost quantitative biochemical assay.
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Affiliation(s)
- Pargat Singh
- UIET-Panjab University, Sector-25, Chandigarh, India; CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh, India
| | - Bharti
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh, India
| | - Rajesh Kumar
- UIET-Panjab University, Sector-25, Chandigarh, India
| | - Vijayender Bhalla
- CSIR-Institute of Microbial Technology, Sector 39A, Chandigarh, India.
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19
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Ito E, Shima R, Yoshioka T. A novel role of oxytocin: Oxytocin-induced well-being in humans. Biophys Physicobiol 2019; 16:132-139. [PMID: 31608203 PMCID: PMC6784812 DOI: 10.2142/biophysico.16.0_132] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 07/27/2019] [Indexed: 12/19/2022] Open
Abstract
We review the involvement of a small molecule, oxytocin, in various effects of physical stimulation of somatosensory organs, mindfulness meditation, emotion and fragrance on humans, and then propose a hypothesis that complex human states and behaviors, such as well-being, social bonding, and emotional behavior, are explained by oxytocin. We previously reported that oxytocin can induce pain relief and described the possibility how oxytocin in the dorsal horn and/or the dorsal root ganglion relieves joint and muscle pain. In the present article, we expand our research target from the physical analgesic effects of oxytocin to its psychologic effects to upregulate well-being and downregulate stress and anxiety. For this purpose, we propose a “hypothalamic-pituitary-adrenal (HPA) axis-oxytocin model” to explain why mindfulness meditation, placebo, and fragrance can reduce stress and anxiety, resulting in contentment. This new proposed model of HPA axis-oxytocin in the brain also provides a target to address other questions regarding emotional behaviors, learning and memory, and excess food intake leading to obesity, aimed at promoting a healthy life.
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Affiliation(s)
- Etsuro Ito
- Department of Biology, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan.,Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
| | - Rei Shima
- Department of Biology, Waseda University, Shinjuku-ku, Tokyo 162-8480, Japan
| | - Tohru Yoshioka
- Graduate Institute of Medicine, School of Medicine, Kaohsiung Medical University, Kaohsiung 80756, Taiwan
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20
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Ultrasensitive ELISA Developed for Diagnosis. Diagnostics (Basel) 2019; 9:diagnostics9030078. [PMID: 31323782 PMCID: PMC6787603 DOI: 10.3390/diagnostics9030078] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Revised: 07/04/2019] [Accepted: 07/16/2019] [Indexed: 01/18/2023] Open
Abstract
For the diagnosis of disease, the ability to quantitatively detect trace amounts of the causal proteins from bacteria/viruses as biomarkers in patient specimens is highly desirable. Here we introduce a simple, rapid, and colorimetric assay as a de novo, ultrasensitive detection method. This ultrasensitive assay consists of a sandwich enzyme-linked immunosorbent assay (ELISA) and thionicotinamide-adenine dinucleotide (thio-NAD) cycling, forming an ultrasensitive ELISA, in which the signal substrate (i.e., thio-NADH) accumulates in a triangular manner, and the accumulated thio-NADH is measured at its maximum absorption wavelength of 405 nm. We have successfully achieved a limit of detection of ca. 10−18 moles/assay for a target protein. As an example of infectious disease detection, HIV-1 p24 could be measured at 0.0065 IU/assay (i.e., 10−18 moles/assay), and as a marker for a lifestyle-related disease, adiponectin could be detected at 2.3 × 10−19 moles/assay. In particular, despite the long-held belief that the trace amounts of adiponectin in urine can only be detected using a radioisotope, our ultrasensitive ELISA was able to detect urinary adiponectin. This method is highly versatile because simply changing the antibody enables the detection of various proteins. This assay system requires only the measurement of absorbance, thus it requires equipment that is easily obtained by medical facilities, which facilitates diagnosis in hospitals and clinics. Moreover, we describe an expansion of our ultrasensitive ELISA to a non-amplification nucleic acid detection method for nucleic acids using hybridization. These de novo methods will enable simple, rapid, and accurate diagnosis.
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21
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Immunochromatographic detection of MPB64 secreted from active BCG by heating: toward same-day diagnosis of tuberculosis. Biotechniques 2019; 66:240-242. [DOI: 10.2144/btn-2019-0020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
We propose a new detection method for a tuberculosis-specific protein, MPB64, obtained from active bacillus Calmette-Guérin (BCG) by heating. When BCG was included in solution at a concentration >2.75 × 104 CFU/ml, our method for collecting MPB64 through heating active BCG combined with an immunochromatographic assay detected active bacilli within 2.5 h. By contrast, a culture test, which is the gold standard for tuberculosis diagnosis, does not provide results for between 1 week and 2 months. The rapid tests based on PCR have some drawbacks, for example they detect DNA from both active and latent (or even dead) tubercle bacilli. Therefore, our method may pave the way toward detecting only active tubercle bacilli at a reasonable cost and providing same-day diagnosis.
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22
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Yamakado S, Cho H, Inada M, Morikawa M, Jiang YH, Saito K, Nakaishi K, Watabe S, Takagi H, Kaneda M, Nakatsuma A, Ninomiya M, Imachi H, Arai T, Yoshimoto T, Murao K, Chang JH, Chen SM, Shih YC, Zeng MJ, Ke LY, Chen CH, Yoshimura T, Miura T, Ito E. Urinary adiponectin as a new diagnostic index for chronic kidney disease due to diabetic nephropathy. BMJ Open Diabetes Res Care 2019; 7:e000661. [PMID: 31245009 PMCID: PMC6557464 DOI: 10.1136/bmjdrc-2019-000661] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 04/18/2019] [Accepted: 05/03/2019] [Indexed: 12/24/2022] Open
Abstract
OBJECTIVE The chronic kidney disease (CKD) is widely diagnosed on the basis of albuminuria and the glomerular filtration rate. A more precise diagnosis of CKD, however, requires the assessment of other factors. Urinary adiponectin recently attracted attention for CKD assessment, but evaluation is difficult due to the very low concentration of urinary adiponectin in normal subjects. RESEARCH DESIGN AND METHODS We developed an ultrasensitive ELISA coupled with thionicotinamide-adenine dinucleotide cycling to detect trace amounts of proteins, which allows us to measure urinary adiponectin at the subattomole level. We measured urinary adiponectin levels in 59 patients with diabetes mellitus (DM) and 24 subjects without DM (normal) to test our hypothesis that urinary adiponectin levels increase with progression of CKD due to DM. RESULTS The urinary adiponectin levels were 14.88±3.16 (ng/mg creatinine, mean±SEM) for patients with DM, and 3.06±0.33 (ng/mg creatinine) for normal subjects. The threshold between them was 4.0 ng/mg creatinine. The urinary adiponectin levels increased with an increase in the CKD risk. Furthermore, urinary adiponectin mainly formed a medium-molecular weight multimer (a hexamer) in patients with DM, whereas it formed only a low-molecular weight multimer (a trimer) in normal subjects. That is, the increase in urinary adiponectin in patients with DM led to the emergence of a medium-molecular weight form in urine. CONCLUSIONS Our new assay showed that urinary adiponectin could be a new diagnostic index for CKD. This assay is a non-invasive test using only urine, thus reducing the patient burden.
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Affiliation(s)
| | - Hiroki Cho
- Department of Biology, Waseda University, Shinjuku, Tokyo, Japan
| | - Mikio Inada
- Department of Biology, Waseda University, Shinjuku, Tokyo, Japan
| | - Mika Morikawa
- R&D Headquarters, TAUNS Laboratories, Izunokuni, Shizuoka, Japan
| | - Yong-Huang Jiang
- R&D Headquarters, TAUNS Laboratories, Izunokuni, Shizuoka, Japan
| | - Kenji Saito
- R&D Headquarters, TAUNS Laboratories, Izunokuni, Shizuoka, Japan
| | | | - Satoshi Watabe
- R&D Headquarters, TAUNS Laboratories, Izunokuni, Shizuoka, Japan
| | - Hitomi Takagi
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa, Japan
| | - Mugiho Kaneda
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa, Japan
| | - Akira Nakatsuma
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa, Japan
| | - Masaki Ninomiya
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Kagawa, Japan
| | - Hitomi Imachi
- Faculty of Medicine, Kagawa University, Miki, Kagawa, Japan
| | - Takeshi Arai
- Faculty of Medicine, Kagawa University, Miki, Kagawa, Japan
| | | | - Koji Murao
- Faculty of Medicine, Kagawa University, Miki, Kagawa, Japan
| | - Jyun-Hao Chang
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Shih-Min Chen
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Yi-Chen Shih
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Min-Jing Zeng
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Liang-Yin Ke
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Chu-Huang Chen
- Lipid Science and Aging Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Teruki Yoshimura
- Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Hokkaido, Japan
| | - Toshiaki Miura
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Hokkaido, Japan
| | - Etsuro Ito
- Department of Biology, Waseda University, Shinjuku, Tokyo, Japan
- Graduate Institute of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
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23
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Aonuma H, Totani Y, Kaneda M, Nakamura R, Watanabe T, Hatakeyama D, Dyakonova VE, Lukowiak K, Ito E. Effects of 5-HT and insulin on learning and memory formation in food-deprived snails. Neurobiol Learn Mem 2018; 148:20-29. [DOI: 10.1016/j.nlm.2017.12.010] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2017] [Revised: 12/08/2017] [Accepted: 12/29/2017] [Indexed: 01/20/2023]
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24
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Development and validation of an electrochemiluminescent ELISA for quantitation of oral insulin tregopil in diabetes mellitus serum. Bioanalysis 2017; 9:975-986. [PMID: 28692306 DOI: 10.4155/bio-2017-0020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
AIM Tregopil, a novel PEGylated human insulin is in clinical development for oral delivery in diabetes treatment. The aim of the study was to develop and validate a sensitive and specific ELISA method for quantitating Tregopil in diabetes subjects on basal Glargine, since most commercially available insulin kits either do not detect Tregopil or show significant reactivity to Glargine. METHODS An electrochemiluminescent ELISA was developed and validated for Tregopil quantitation in diabetes serum. RESULTS The method has a LLOQ of 0.25 ng/ml, shows minimum cross-reactivity to Glargine and was successfully tested using a subset of samples from Tregopil-dosed Type 1 diabetes mellitus patients. CONCLUSION The ELISA method is sensitive and can be used to support accurate measurement of Tregopil with no cross-reactivity to Glargine and its metabolites in clinical studies.
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25
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Watabe S, Morikawa M, Kaneda M, Nakaishi K, Nakatsuma A, Ninomiya M, Yoshimura T, Miura T, Ito E. Ultrasensitive detection of proteins and sugars at single-cell level. Commun Integr Biol 2016; 9:e1124201. [PMID: 27064305 PMCID: PMC4802808 DOI: 10.1080/19420889.2015.1124201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 11/18/2015] [Accepted: 11/18/2015] [Indexed: 11/10/2022] Open
Abstract
Each cell produces its own responses even if it appears identical to other cells. To analyze these individual cell characteristics, we need to measure trace amounts of molecules in a single cell. Nucleic acids in a single cell can be easily amplified by polymerase chain reaction, but single-cell measurement of proteins and sugars will require de novo techniques. In the present study, we outline the techniques we have developed toward this end. For proteins, our ultrasensitive enzyme-linked immunosorbent assay (ELISA) coupled with thionicotinamide-adenine dinucleotide cycling can detect proteins at subattomoles per assay. For sugars, fluorescence correlation spectroscopy coupled with glucose oxidase-catalyzed reaction allows us to measure glucose at tens of nM. Our methods thus offer versatile techniques for single-cell-level analyses, and they are hoped to strongly promote single-cell biology as well as to develop noninvasive tests in clinical medicine.
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Affiliation(s)
| | - Mika Morikawa
- R&D Headquarters, TAUNS Laboratories, Inc., Izunokuni, Japan; Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
| | - Mugiho Kaneda
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University , Sanuki, Japan
| | | | - Akira Nakatsuma
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University , Sanuki, Japan
| | - Masaki Ninomiya
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University , Sanuki, Japan
| | - Teruki Yoshimura
- Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido , Ishikari-Tobetsu, Japan
| | - Toshiaki Miura
- Graduate School of Pharmaceutical Sciences, Hokkaido University , Sapporo, Japan
| | - Etsuro Ito
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University , Sanuki, Japan
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26
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Immunoreactive insulin in diabetes mellitus patient sera detected by ultrasensitive ELISA with thio-NAD cycling. Biotechniques 2015; 59:359, 361-7. [PMID: 26651515 DOI: 10.2144/000114355] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 08/17/2015] [Indexed: 11/23/2022] Open
Abstract
To minimize patient suffering, the smallest possible volume of blood should be collected for diagnosis and disease monitoring. When estimating insulin secretion capacity and resistance to insulin in diabetes mellitus (DM), increasing insulin assay immunosensitivity would reduce the blood sample volume required for testing. Here we present an ultrasensitive ELISA coupled with thio-NAD cycling to measure immunoreactive insulin in blood serum. Only 5 μL of serum was required for testing, with a limit of detection (LOD) for the assay of 10(-16) moles/assay. Additional recovery tests confirmed this method can detect insulin in sera. Comparisons between a commercially available immunoreactive insulin kit and our ultrasensitive ELISA using the same commercially available reference demonstrated good data correlation, providing further evidence of assay accuracy. Together, these results demonstrate our ultrasensitive ELISA could be a powerful tool in the diagnosis and treatment of not only DM but also many other diseases in the future.
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27
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Morikawa M, Naito R, Mita K, Watabe S, Nakaishi K, Yoshimura T, Miura T, Hashida S, Ito E. Subattomole detection of adiponectin in urine by ultrasensitive ELISA coupled with thio-NAD cycling. Biophys Physicobiol 2015; 12:79-86. [PMID: 27493857 PMCID: PMC4736831 DOI: 10.2142/biophysico.12.0_79] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Accepted: 10/28/2015] [Indexed: 01/31/2023] Open
Abstract
Adiponectin is a hormone secreted from adipocytes, and it demonstrates antidiabetic, anti-atherosclerotic, antiobesity and anti-inflammatory effects. However, the patterns of change in urinary adiponectin levels in various diseases remain unknown, because only trace amounts of the hormone are present in urine. In the present study, we applied an ultrasensitive ELISA coupled with thio-NAD cycling to measure urinary adiponectin levels. Spikeand-recovery tests using urine confirmed the reliability of our ultrasensitive ELISA. The limit of detection for adiponectin in urine was 2.3×10−19 moles/assay (1.4 pg/mL). The urinary adiponectin concentration ranged between 0.04 and 5.82 ng/mL in healthy subjects. The pilot study showed that the urinary adiponectin levels, which were corrected by the creatinine concentration, were 0.73±0.50 (ng/mg creatinine, N=6) for healthy subjects, versus 12.02±3.85 (ng/mg creatinine, N=3) for patients with diabetes mellitus (DM). That is, the urinary adiponectin levels were higher (P<0.05) in DM patients than in healthy subjects. Further, these urinary adiponectin levels tended to increase with the progression of DM accompanied with nephropathy. Our method is thus expected to provide a simple, rapid and reasonably priced test for noninvasive monitoring of the progression of DM without the requirement of special tools.
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Affiliation(s)
- Mika Morikawa
- R&D Headquarters, TAUNS Laboratories, Inc., Shizuoka 410-2325, Japan; Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa 769-2193, Japan
| | - Rina Naito
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa 769-2193, Japan
| | - Koichi Mita
- Faculty of Science and Engineering, Tokushima Bunri University, Kagawa 769-2193, Japan
| | | | - Kazunari Nakaishi
- R&D Headquarters, TAUNS Laboratories, Inc., Shizuoka 410-2325, Japan
| | - Teruki Yoshimura
- Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Hokkaido 061-0293, Japan
| | - Toshiaki Miura
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Hokkaido 060-0812, Japan
| | - Seiichi Hashida
- Institute for Health Sciences, Tokushima Bunri University, Tokushima 770-8514, Japan
| | - Etsuro Ito
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Kagawa 769-2193, Japan
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28
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Function of insulin in snail brain in associative learning. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2015; 201:969-81. [PMID: 26233474 DOI: 10.1007/s00359-015-1032-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2015] [Revised: 07/23/2015] [Accepted: 07/24/2015] [Indexed: 12/23/2022]
Abstract
Insulin is well known as a hormone regulating glucose homeostasis across phyla. Although there are insulin-independent mechanisms for glucose uptake in the mammalian brain, which had contributed to a perception of the brain as an insulin-insensitive organ for decades, the finding of insulin and its receptors in the brain revolutionized the concept of insulin signaling in the brain. However, insulin's role in brain functions, such as cognition, attention, and memory, remains unknown. Studies using invertebrates with their open blood-vascular system have the promise of promoting a better understanding of the role played by insulin in mediating/modulating cognitive functions. In this review, the relationship between insulin and its impact on long-term memory (LTM) is discussed particularly in snails. The pond snail Lymnaea stagnalis has the ability to undergo conditioned taste aversion (CTA), that is, it associatively learns and forms LTM not to respond with a feeding response to a food that normally elicits a robust feeding response. We show that molluscan insulin-related peptides are up-regulated in snails exhibiting CTA-LTM and play a key role in the causal neural basis of CTA-LTM. We also survey the relevant literature of the roles played by insulin in learning and memory in other phyla.
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29
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Nakatsuma A, Kaneda M, Kodama H, Morikawa M, Watabe S, Nakaishi K, Yamashita M, Yoshimura T, Miura T, Ninomiya M, Ito E. Detection of HIV-1 p24 at Attomole Level by Ultrasensitive ELISA with Thio-NAD Cycling. PLoS One 2015; 10:e0131319. [PMID: 26098695 PMCID: PMC4476629 DOI: 10.1371/journal.pone.0131319] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 06/01/2015] [Indexed: 01/12/2023] Open
Abstract
To reduce the window period between HIV-1 infection and the ability to diagnose it, a fourth-generation immunoassay including the detection of HIV-1 p24 antigen has been developed. However, because the commercially available systems for this assay use special, high-cost instruments to measure, for example, chemiluminescence, it is performed only by diagnostics companies and hub hospitals. To overcome this limitation, we applied an ultrasensitive ELISA coupled with a thio-NAD cycling, which is based on a usual enzyme immunoassay without special instruments, to detect HIV-1 p24. The p24 detection limit by our ultrasensitive ELISA was 0.0065 IU/assay (i.e., ca. 10-18 moles/assay). Because HIV-1 p24 antigen is thought to be present in the virion in much greater numbers than viral RNA copies, the value of 10-18 moles of the p24/assay corresponds to ca. 103 copies of the HIV-1 RNA/assay. That is, our ultrasensitive ELISA is chasing the detection limit (102 copies/assay) obtained by PCR-based nucleic acid testing (NAT) with a margin of only one different order. Further, the detection limit by our ultrasensitive ELISA is less than that mandated for a CE-marked HIV antigen/antibody assay. An additional recovery test using blood supported the reliability of our ultrasensitive ELISA.
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Affiliation(s)
- Akira Nakatsuma
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
| | - Mugiho Kaneda
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
| | - Hiromi Kodama
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
| | - Mika Morikawa
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
- TAUNS Laboratories, Inc., Izunokuni, Japan
| | | | | | | | - Teruki Yoshimura
- Faculty of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Ishikari-Tobetsu, Japan
| | - Toshiaki Miura
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | - Masaki Ninomiya
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
| | - Etsuro Ito
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki, Japan
- * E-mail:
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30
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Ito E, Yamagishi M, Hatakeyama D, Watanabe T, Fujito Y, Dyakonova V, Lukowiak K. Memory block: a consequence of conflict resolution. ACTA ACUST UNITED AC 2015; 218:1699-704. [PMID: 25883377 DOI: 10.1242/jeb.120329] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Accepted: 04/05/2015] [Indexed: 11/20/2022]
Abstract
Food deprivation for 1 day in the pond snail Lymnaea stagnalis before aversive classical conditioning results in optimal conditioned taste aversion (CTA) and long-term memory (LTM) formation, whereas 5-day food deprivation before training does not. We hypothesize that snails do in fact learn and form LTM when trained after prolonged food deprivation, but that severe food deprivation blocks their ability to express memory. We trained 5-day food-deprived snails under various conditions, and found that memory was indeed formed but is overpowered by severe food deprivation. Moreover, CTA-LTM was context dependent and was observed only when the snails were in a context similar to that in which the training occurred.
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Affiliation(s)
- Etsuro Ito
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Miki Yamagishi
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Dai Hatakeyama
- Laboratory of Functional Biology, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Japan
| | - Takayuki Watanabe
- Laboratory of Neurocybernetics, Research Institute for Electronic Science, Hokkaido University, Sapporo 060-0812, Japan
| | - Yutaka Fujito
- Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, Sapporo 060-8556, Japan
| | - Varvara Dyakonova
- Laboratory of Comparative Physiology, Institute for Developmental Biology, RAS, Moscow 119909, Russia
| | - Ken Lukowiak
- Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada, T2N 4N1
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31
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An increase in insulin is important for the acquisition conditioned taste aversion in Lymnaea. Neurobiol Learn Mem 2014; 116:132-8. [PMID: 25451307 DOI: 10.1016/j.nlm.2014.10.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 09/30/2014] [Accepted: 10/20/2014] [Indexed: 11/21/2022]
Abstract
Conditioned taste aversion (CTA) in Lymnaea is brought about by pairing a sucrose solution (the conditioned stimulus, CS) with an electric shock (the unconditioned stimulus, US). Following repeated CS-US pairings, CTA occurs and it is consolidated into long-term memory (LTM). The best CTA is achieved, if snails are food-deprived for 1 day before training commences. With a longer period of food deprivation (5 days), learning and memory formation does not occur. It has been hypothesized that the levels of insulin in the central nervous system (CNS) are very important for CTA to occur. To test his hypothesis, we injected insulin directly into 5-day food-deprived snails. The injection of insulin, as expected, resulted in a decrease in hemolymph glucose concentration. Consistent with our hypothesis with insulin injection, learning and memory formation of CTA occurred. That is, the 'insulin spike' is more important than an increase in hemolymph glucose concentration for CTA-LTM. If we injected an insulin receptor antibody into the snails before the insulin injection, learning was formed but memory formation was not, which is consistent with our previous study. Therefore, a rise in the insulin concentration (i.e., insulin spike) in the CNS is considered to be a key determining factor in the process of CTA-LTM.
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