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Fu Y, Tao L, Wang X, Wang B, Qin W, Song L. PGC-1α participates in regulating mitochondrial function in aged sarcopenia through effects on the Sestrin2-mediated mTORC1 pathway. Exp Gerontol 2024; 190:112428. [PMID: 38604253 DOI: 10.1016/j.exger.2024.112428] [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: 02/19/2024] [Revised: 04/07/2024] [Accepted: 04/08/2024] [Indexed: 04/13/2024]
Abstract
BACKGROUND Mitochondrial dysregulation in skeletal myocytes is considered a major factor in aged sarcopenia. In this study, we aimed to study the effects of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α) on Sestrin2-mediated mechanistic target of rapamycin complex 1 (mTORC1) in aged skeletal muscles. METHODS C2C12 myoblasts were stimulated by 50 μM 7β-hydroxycholesterol (7β-OHC) to observe the changes of DNA damage, mitochondrial membrane potential (Δψm), mitochondrial ROS and PGC-1α protein. The PGC-1α silence in the C2C12 cells was established by siRNA transfection. The levels of DNA damage, Δψm, mitochondrial ROS, Sestrin2 and p-S6K1/S6K1 proteins were observed after the PGC-1α silence in the C2C12 cells. Recombinant Sestrin2 treatment was used to observe the changes of DNA damage, Δψm, mitochondrial ROS and p-S6K1/S6K1 protein in the 7β-OHC-treated or PGC-1α siRNA-transfected C2C12 cells. Wild-type (WT) mice and muscle-specific PGC-1α conditional knockout (MKO) mice, including young and old, were used to analyse the effects of PGC-1α on muscle function and the levels of Sestrin2 and p-S6K1 in the white gastrocnemius muscles. Recombinant Sestrin2 was administrated to analyse its effects on muscle function in the old WT mice and old MKO mice. RESULTS 7β-OHC treatment induced DNA damage, mitochondrial dysfunction and decrease of PGC-1α protein in the C2C12 cells. PGC-1α silence also induced DNA damage and mitochondrial dysfunction in the C2C12 cells. Additionally, PGC-1α silence or 7β-OHC treatment decreased the levels of Sestrin2 and p-S6K1/S6K1 protein in the C2C12 cells. Recombinant Sestrin2 treatment significantly improved the DNA damage and mitochondrial dysfunction in the 7β-OHC-treated or PGC-1α siRNA-transfected C2C12 cells. At the same age, muscle-specific PGC-1α deficiency aggravated aged sarcopenia and decreased the levels of Sestrin2 and p-S6K1 in the white gastrocnemius muscles when compared to the WT mice. Recombinant Sestrin2 treatment improved muscle function and increased p-S6K1 levels in the old two genotypes. CONCLUSION This research demonstrates that PGC-1α participates in regulating mitochondrial function in aged sarcopenia through effects on the Sestrin2-mediated mTORC1 pathway.
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Affiliation(s)
- Yimin Fu
- Geriatric Medicine Department, Yantai Yuhuangding Hospital, Yantai 264000, China
| | - Lei Tao
- Department of Rheumatology&Immunology, the Second Affiliated Hospital of Shandong First Medical University, Tai'an 271000, China
| | - Xiaojun Wang
- Geriatric Medicine Department, Yantai Yuhuangding Hospital, Yantai 264000, China
| | - Binyou Wang
- Department of Geriatrics, Second People's Hospital of Chengdu, Chengdu 610000, China
| | - Weilin Qin
- Department of Geriatrics, Qinghai Provincial People's Hospital, Xi'ning 810001, China.
| | - Lei Song
- Geriatric Medicine Department, Yantai Yuhuangding Hospital, Yantai 264000, China.
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Saito M, Kitamura M, Ide Y, Nguyen MH, Le BD, Mai AT, Miyashiro D, Mayama S, Umemura K. An Efficient Method of Observing Diatom Frustules via Digital Holographic Microscopy. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2022; 28:1-5. [PMID: 36124414 DOI: 10.1017/s1431927622012508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Herein, we propose a convenient method to enable pretreatment of target objects using digital holographic microscopy (DHM). As a test sample, we used diatom frustules (Nitzschia sp.) as the target objects. In the generally used sample preparation method, the frustule suspension is added dropwise onto a glass substrate or into a glass chamber. While our work confirms good observation of purified frustules using the typical sample preparation method, we also demonstrate a new procedure to observe unseparated structures of frustules prepared by baking them on a mica surface. The baked frustules on the mica surface were transferred to a glass chamber with 1% sodium dodecyl sulfate solution. In this manner, the unseparated structures of the diatom frustules were clearly observed. Furthermore, metal-coated frustules prepared by sputtering onto them on a mica surface were also clearly observed using the same procedure. Our method can be applied for the observation of any target object that is pretreated on a solid surface. We expect our proposed method to be a basis for establishing DHM techniques for microscopic observations of biomaterials.
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Affiliation(s)
- Makoto Saito
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - Masaki Kitamura
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - Yuki Ide
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
| | - Minh Hieu Nguyen
- VNU University of University of Science, 334 Nguyen Trai, Thanh Xuan, Hanoi, Vietnam
| | - Binh Duong Le
- National Center for Technological Progress, 25 Le Thanh Tong, Hoan Kiem, Hanoi, Vietnam
| | - Anh Tuan Mai
- VNU University of Engineering and Technology, 144 Xuan Thuy, Cau Giay, Hanoi, Vietnam
| | - Daisuke Miyashiro
- ScienceCafe MC2 Co., Ltd., 3-88 Hanasaki-Cho, Yokohama Naka-ku, Kanagawa 231-0063, Japan
| | - Shigeki Mayama
- Tokyo Diatomology Labo, 2-3-2 Nukuikitamachi, Koganei, Tokyo 184-0015, Japan
| | - Kazuo Umemura
- Biophysics Section, Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo 162-8601, Japan
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Guan Y, Chen R, Sun G, Liu Q, Liu J, Yu J, Lin C, Duan J, Wang J. Crawling and adhesion behavior of Halamphora sp. based on different parts of Folium Sennae-like film: Evaluation of analytical methods for anti-diatom experimental results. Micron 2021; 152:103178. [PMID: 34801958 DOI: 10.1016/j.micron.2021.103178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Revised: 10/30/2021] [Accepted: 11/02/2021] [Indexed: 10/19/2022]
Abstract
Anti-diatom testing is a basic method to evaluate the anti-fouling performance of coatings. Many existing results of anti-diatom performances are evaluated based on their attachment number or coverage area, ignoring the influence of the crawling and adhesion behavior of diatoms on the analysis results. Here, a Folium Sennae-like film with multiple structural units was prepared by considering the influence of diatom attachment behaviors on the analysis results. The anti-diatom performances of different parts (divided and called four parts: edge, surface, cross striation, and vertical pattern) on the Folium Sennae-like film were evaluated using the counting and area methods. Obviously, the anti-diatom performance of the Folium Sennae-like film was superior to that of epoxy resin without structure. Under equal areas, the average numbers of diatoms on the cross striation and the vertical pattern were similar to the surface. It was found that the attachment behavior of Halamphora sp. is affected by microstructure units, rather than the combined structure of which the scale is much larger than that of diatoms. Meanwhile, the average attachment area for the unit number of diatoms was calculated. The diatom attachment area without microstructure, surface, cross striation, or vertical pattern was 81.751, 106.950, 73.904, and 84.376 μm2, respectively. Moreover, the static and dynamic motion behaviors of Halamphora sp. were studied, and the theory for Halamphora sp. attachment was modeled in three dimensions. The variable morphology of Halamphora sp. lead to inaccurate results for diatom analyses based on the counting and area methods, which is summarized here. This study discusses the evaluation method of coatings by anti-diatom performance, further promoting the research of diatoms in the field of antifouling.
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Affiliation(s)
- Yu Guan
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China
| | - Rongrong Chen
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China; Shandong Key Laboratory of Corrosion Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Gaohui Sun
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China
| | - Qi Liu
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China
| | - Jingyuan Liu
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China
| | - Jing Yu
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China
| | - Cunguo Lin
- State Key Laboratory for Marine Corrosion and Protection, Luoyang Ship Material Research Institute, Qingdao, 266101, China
| | - Jizhou Duan
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China; Key Lab Marine Environm Corros & Biofouling, Chinese Academy of Sciences Institute of Oceanology, Qingdao, 266071, China
| | - Jun Wang
- Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin, 150001, China.
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Hamano R, Shoumura S, Takeda Y, Yamazaki T, Hirayama K, Hanada Y, Mayama S, Takemura M, Lin HJ, Umemura K. Sinking of Four Species of Living Diatom Cells Directly Observed by a "Tumbled" Optical Microscope. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2021; 27:1-7. [PMID: 34294188 DOI: 10.1017/s1431927621012150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
The study of the sinking phenomenon of diatom cells, which have a slightly larger specific gravity (~1.3) compared to that of water, is an important research topic for understanding photosynthetic efficiency. In this study, we successfully demonstrated the observation of the sinking behaviors of four different species of diatom using a homemade “tumbled” optical microscope. A homemade 1 mm3 microchamber was employed to decrease the effects of convection currents. In the microchamber, diatom cells were basically settled in a linear manner without floating, although some of the cells were rotated during their sinking. Sinking speeds of the four species of diatom cells, Nitzschia sp., Pheodactylum tricornutum, Navicula sp., and Odontella aurita, were 0.81 ± 5.56, 3.03 ± 10.17, 3.29 ± 7.39, and 11.22 ± 21.42 μm/s, respectively, based on the automatic tracking analysis of the centroids of each cell. Manual analysis of a vector between two longitudinal ends of the cells (two-point analysis) was effective for quantitatively characterizing the rotation phenomenon; therefore, angles and angular velocities of rotating cells were well determined as a function of time. The effects of the cell shapes on sinking velocity could be explained by simulation analysis using the modified Stokes’ law proposed by Miklasz et al.
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Affiliation(s)
- Ryo Hamano
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Shingo Shoumura
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Yuto Takeda
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Tokio Yamazaki
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Kota Hirayama
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Yasutaka Hanada
- Graduate School of Science and Technology, Hirosaki University, 3 Bunkyo-cho, Hirosaki, Aomori036-8561, Japan
| | - Shigeki Mayama
- Advanced Support Center for Science Teachers, Tokyo Gakugei University, 4-1-1 Nukui-kita-machi, Koganei, Tokyo184-8511, Japan
| | - Masaharu Takemura
- Laboratory of Biology, Institute of Arts and Sciences, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
| | - Han-Jia Lin
- Department of Bioscience and Biotechnology, Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung20224, Taiwan
| | - Kazuo Umemura
- Department of Physics, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku, Tokyo162-8601, Japan
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