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Miyaki T, Homma N, Kawasaki Y, Kishi M, Yamaguchi J, Kakuta S, Shindo T, Sugiura M, Oliva Trejo JA, Kaneda H, Omotehara T, Takechi M, Negishi-Koga T, Ishijima M, Aoto K, Iseki S, Kitamura K, Muto S, Amagasa M, Hotchi S, Ogura K, Shibata S, Sakai T, Suzuki Y, Ichimura K. Ultrastructural analysis of whole glomeruli using array tomography. J Cell Sci 2024; 137:jcs262154. [PMID: 39171439 DOI: 10.1242/jcs.262154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 08/09/2024] [Indexed: 08/23/2024] Open
Abstract
The renal glomerulus produces primary urine from blood plasma by ultrafiltration. The ultrastructure of the glomerulus is closely related to filtration function and disease development. The ultrastructure of glomeruli has mainly been evaluated using transmission electron microscopy; however, the volume that can be observed using transmission electron microscopy is extremely limited relative to the total volume of the glomerulus. Consequently, observing structures that exist in only one location in each glomerulus, such as the vascular pole, and evaluating low-density or localized lesions are challenging tasks. Array tomography (AT) is a technique used to analyze the ultrastructure of tissues and cells via scanning electron microscopy of serial sections. In this study, we present an AT workflow that is optimized for observing complete serial sections of the whole glomerulus, and we share several analytical examples that use the optimized AT workflow, demonstrating the usefulness of this approach. Overall, this AT workflow can be a powerful tool for structural and pathological evaluation of the glomerulus. This workflow is also expected to provide new insights into the ultrastructure of the glomerulus and its constituent cells.
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Affiliation(s)
- Takayuki Miyaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Nozomi Homma
- Department of Nephrology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Yuto Kawasaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Mami Kishi
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Junji Yamaguchi
- Laboratory of Morphology and Image Analysis, Research Core Facilities , Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Soichiro Kakuta
- Laboratory of Morphology and Image Analysis, Research Core Facilities , Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Tomoko Shindo
- Electron Microscope Laboratory, Keio University School of Medicine, Tokyo 160-0016, Japan
| | - Makoto Sugiura
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Juan Alejandro Oliva Trejo
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Hisako Kaneda
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Takuya Omotehara
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Masaki Takechi
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Takako Negishi-Koga
- Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
- Department of Community Medicine and Research for Bone and Joint Diseases, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Muneaki Ishijima
- Department of Medicine for Orthopedics and Motor Organ, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
- Department of Community Medicine and Research for Bone and Joint Diseases, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Kazushi Aoto
- Central Laboratory, Graduate School of Biomedical and Health Sciences , Hiroshima University, Hiroshima 734-8551, Japan
| | - Sachiko Iseki
- Department of Molecular Craniofacial Embryology and Oral Histology, Graduate School of Medical and Dental Sciences , Tokyo Medical and Dental University, Tokyo 113-8510, Japan
| | - Kosuke Kitamura
- Department of Urology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Satoru Muto
- Department of Urology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Mao Amagasa
- Department of Human Pathology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Shiori Hotchi
- Department of Human Pathology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Kanako Ogura
- Department of Human Pathology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Shinsuke Shibata
- Electron Microscope Laboratory, Keio University School of Medicine, Tokyo 160-0016, Japan
- Division of Microscopic Anatomy, Graduate School of Medical and Dental Sciences , Niigata University, Niigata City 951-8510, Japan
| | - Tatsuo Sakai
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Yusuke Suzuki
- Department of Nephrology, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
| | - Koichiro Ichimura
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
- Laboratory of Morphology and Image Analysis, Research Core Facilities , Juntendo University Graduate School of Medicine, Tokyo 113-8421, Japan
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Murase S, Mantani Y, Ohno N, Shimada A, Nakanishi S, Morishita R, Yokoyama T, Hoshi N. Regional differences in the ultrastructure of mucosal macrophages in the rat large intestine. Cell Tissue Res 2024; 396:245-253. [PMID: 38485763 DOI: 10.1007/s00441-024-03883-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 02/25/2024] [Indexed: 04/28/2024]
Abstract
We previously clarified the histological characteristics of macrophages in the rat small intestine using serial block-face scanning electron microscopy (SBF-SEM). However, the regional differences in the characteristics of macrophages throughout the large intestine remain unknown. Here, we performed a pilot study to explore the regional differences in the ultrastructure of mucosal macrophages in the large intestine by using SBF-SEM analysis. SBF-SEM analysis conducted on the luminal side of the cecum and descending colon revealed macrophages as amorphous cells possessing abundant lysosomes and vacuoles. Macrophages in the cecum exhibited a higher abundance of lysosomes and a lower abundance of vacuoles than those in the descending colon. Macrophages with many intraepithelial cellular processes were observed beneath the intestinal superficial epithelium in the descending colon. Moreover, macrophages in contact with nerve fibers were more prevalent in the cecum than in the descending colon, and a subset of them surrounded a nerve bundle only in the cecum. In conclusion, the present pilot study suggested that the quantity of some organelles (lysosomes and vacuoles) in macrophages differed between the cecum and the descending colon and that there were some region-specific subsets of macrophages like nerve-associated macrophages in the cecum.
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Affiliation(s)
- Shota Murase
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, Hyogo, 657-8501, Japan
| | - Youhei Mantani
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, Hyogo, 657-8501, Japan.
| | - Nobuhiko Ohno
- Department of Anatomy, Division of Histology and Cell Biology, Jichi Medical University, School of Medicine, Shimotsuke, Tochigi, 329-0498, Japan
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8787, Japan
| | - Asaka Shimada
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, Hyogo, 657-8501, Japan
| | - Satoki Nakanishi
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, Hyogo, 657-8501, Japan
| | - Rinako Morishita
- Laboratory of Histophysiology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, Hyogo, 657-8501, Japan
| | - Toshifumi Yokoyama
- Laboratory of Animal Molecular Morphology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, Hyogo, 657-8501, Japan
| | - Nobuhiko Hoshi
- Laboratory of Animal Molecular Morphology, Department of Bioresource Science, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai-Cho, Nada-Ku, Kobe, Hyogo, 657-8501, Japan
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Masoudi E, Soleimani M, Zarinfard G, Homayoun M, Bakhtiari M. The effects of chitosan-loaded JQ1 nanoparticles on OVCAR-3 cell cycle and apoptosis-related gene expression. Res Pharm Sci 2024; 19:53-63. [PMID: 39006975 PMCID: PMC11244706 DOI: 10.4103/1735-5362.394820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 10/14/2023] [Accepted: 01/02/2024] [Indexed: 07/16/2024] Open
Abstract
Background and purpose Ovarian cancer is the deadliest gynecological cancer. Bromodomain and extra terminal domain (BET) proteins play major roles in the regulation of gene expression at the epigenetic level. Jun Qi (JQ1) is a potent inhibitor of BET proteins. Regarding the short half-life and poor pharmacokinetic profile, JQ1 was loaded into newly developed nano-carriers. Chitosan nanoparticles are one of the best and potential polymers in cancer treatment. The present study aimed to build chitosan-JQl nanoparticles (Ch-J-NPs), treat OVCAR-3 cells with Ch-J-NPs, and evaluate the effects of these nanoparticles on cell cycle and apoptosis-associated genes. Experimental approach Ch-J-NPs were synthesized and characterized. The size and morphology of Ch-J-NPs were defined by DLS and FE-SEM techniques. OVCAR-3 cells were cultured and treated with Ch-J-NPs. Then, IC50 was measured using MTT assay. The groups were defined and cells were treated with IC50 concentration of Ch-J-NPs, for 48 h. Finally, cells in different groups were assessed for the expression of genes of interest using quantitative RT-PCR. Findings/Results IC50 values for Ch-J-NPs were 5.625 μg/mL. RT-PCR results demonstrated that the expression of genes associated with cell cycle activity (c-MYC, hTERT, CDK1, CDK4, and CDK6) was significantly decreased following treatment of cancer cells with Ch-J-NPs. Conversely, the expression of caspase-3, and caspase-9 significantly increased. BAX (pro-apoptotic) to BCL2 (anti-apoptotic) expression ratio, also increased significantly after treatment of cells with Ch-J-NPs. Conclusion and implications Ch-J-NPs showed significant anti-cell cyclic and apoptotic effects on OVCAR-3 cells.
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Affiliation(s)
- Ehsan Masoudi
- Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mitra Soleimani
- Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Giti Zarinfard
- Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mansour Homayoun
- Department of Anatomical Sciences, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Mohammad Bakhtiari
- Department of Anatomical Sciences, School of Medicine, Behbahan University of Medical Sciences, Behbahan, Iran
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Li XY, Chen HR, Kuang DD, Pan LH, Li QM, Luo JP, Zha XQ. Laminaria japonica polysaccharide attenuates podocyte epithelial-mesenchymal transformation via TGF-β1-mediated Smad3 and p38MAPK pathways. Int J Biol Macromol 2023; 241:124637. [PMID: 37121417 DOI: 10.1016/j.ijbiomac.2023.124637] [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: 12/03/2022] [Revised: 04/14/2023] [Accepted: 04/24/2023] [Indexed: 05/02/2023]
Abstract
In the present work, we explored the interventional effect and potential mechanism of a purified Laminaria japonica polysaccharide (LJP61A) on podocyte epithelial-mesenchymal transition (EMT) in TGF-β1-induced podocytes and adriamycin-treated mice. Results showed that compared to the model groups, LJP61A significantly up-regulated the levels of epithelial markers (Nephrin, WT-1, podocin) and down-regulated the levels of mesenchymal markers (α-SMA, FN1) in vitro and in vivo, thus preventing EMT-like morphological changes of podocytes, proteinuria and kidney injury. Smad3 and p38MAPK are two central pathways mediating podocyte EMT activated by TGF-β1. We found that LJP61A suppressed TGF-β1-induced activation of Smad3, Smad4 and p38MAPK in vitro and in vivo. Moreover, the inhibitory actions of LJP61A on podocyte EMT were synergistically strengthened by Smad3 inhibitor SIS3 and p38MAPK inhibitor SB203580. Taken together, these findings revealed that LJP61A could prevent podocyte EMT, which might be related to the inhibition of TGF-β1-mediated Smad3 and p38MAPK pathways.
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Affiliation(s)
- Xue-Ying Li
- Engineering Research Centre of Bioprocess of Ministry of Education, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; School of Food and Biological Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China
| | - Hao-Ran Chen
- Engineering Research Centre of Bioprocess of Ministry of Education, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; School of Food and Biological Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China
| | - Dan-Dan Kuang
- Engineering Research Centre of Bioprocess of Ministry of Education, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; School of Food and Biological Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China
| | - Li-Hua Pan
- Engineering Research Centre of Bioprocess of Ministry of Education, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; School of Food and Biological Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China
| | - Qiang-Ming Li
- Engineering Research Centre of Bioprocess of Ministry of Education, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; School of Food and Biological Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China
| | - Jian-Ping Luo
- Engineering Research Centre of Bioprocess of Ministry of Education, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; School of Food and Biological Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China
| | - Xue-Qiang Zha
- Engineering Research Centre of Bioprocess of Ministry of Education, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; School of Food and Biological Engineering, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China; Key Laboratory of Metabolism and Regulation for Major Disease of Anhui Higher Education Institutes, Hefei University of Technology, No. 193 Tunxi Road, Hefei 230009, People's Republic of China.
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Gerlach GF, Imseis ZH, Cooper SL, Santos AN, O’Brien LL. Mapping of the podocin proximity-dependent proteome reveals novel components of the kidney podocyte foot process. Front Cell Dev Biol 2023; 11:1195037. [PMID: 37325559 PMCID: PMC10262054 DOI: 10.3389/fcell.2023.1195037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 05/03/2023] [Indexed: 06/17/2023] Open
Abstract
Introduction: The unique architecture of glomerular podocytes is integral to kidney filtration. Interdigitating foot processes extend from the podocyte cell body, wrap around fenestrated capillaries, and form specialized junctional complexes termed slit diaphragms to create a molecular sieve. However, the full complement of proteins which maintain foot process integrity, and how this localized proteome changes with disease, remain to be elucidated. Methods: Proximity-dependent biotin identification (BioID) enables the identification of spatially localized proteomes. To this end, we developed a novel in vivo BioID knock-in mouse model. We utilized the slit diaphragm protein podocin (Nphs2) to create a podocin-BioID fusion. Podocin-BioID localizes to the slit diaphragm, and biotin injection leads to podocyte-specific protein biotinylation. We isolated the biotinylated proteins and performed mass spectrometry to identify proximal interactors. Results and Discussion: Gene ontology analysis of 54 proteins specifically enriched in our podocin-BioID sample revealed 'cell junctions,' 'actin binding,' and 'cytoskeleton organization' as top terms. Known foot process components were identified, and we further uncovered two novel proteins: the tricellular junctional protein Ildr2 and the CDC42 and N-WASP interactor Fnbp1l. We confirmed that Ildr2 and Fnbp1l are expressed by podocytes and partially colocalize with podocin. Finally, we investigated how this proteome changes with age and uncovered a significant increase in Ildr2. This was confirmed by immunofluorescence on human kidney samples and suggests altered junctional composition may preserve podocyte integrity. Together, these assays have led to new insights into podocyte biology and support the efficacy of utilizing BioID in vivo to interrogate spatially localized proteomes in health, aging, and disease.
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Affiliation(s)
| | | | | | | | - Lori L. O’Brien
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
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Ahmadian E, Eftekhari A, Atakishizada S, Valiyeva M, Ardalan M, Khalilov R, Kavetskyy T. Podocytopathy: The role of actin cytoskeleton. Biomed Pharmacother 2022; 156:113920. [DOI: 10.1016/j.biopha.2022.113920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 10/12/2022] [Accepted: 10/24/2022] [Indexed: 11/02/2022] Open
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Doi K, Kimura H, Matsunaga YT, Fujii T, Nangaku M. Glomerulus-on-a-Chip: Current Insights and Future Potential Towards Recapitulating Selectively Permeable Filtration Systems. Int J Nephrol Renovasc Dis 2022; 15:85-101. [PMID: 35299832 PMCID: PMC8922329 DOI: 10.2147/ijnrd.s344725] [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: 10/16/2021] [Accepted: 02/14/2022] [Indexed: 01/27/2023] Open
Abstract
Glomerulopathy, characterized by a dysfunctional glomerular capillary wall, results in proteinuria, leading to end-stage renal failure and poor clinical outcomes, including renal death and increased overall mortality. Conventional glomerulopathy research, including drug discovery, has mostly relied on animal experiments because in-vitro glomerulus models, capable of evaluating functional selective permeability, was unavailable in conventional in-vitro cell culture systems. However, animal experiments have limitations, including time- and cost-consuming, multi-organ effects, unstable reproducibility, inter-species reliability, and the social situation in the EU and US, where animal experiments have been discouraged. Glomerulus-on-a-chip, a new in-vitro organ model, has recently been developed in the field of organ-on-a-chip research based on microfluidic device technology. In the glomerulus-on-a-chip, the podocytes and endothelial cells are co-cultured in a microfluidic device with physical stimuli that mimic the physiological environment to enhance cell function to construct a functional filtration barrier, which can be assessed by permeability assays using fluorescently labeled molecules including inulin and albumin. A combination of this glomerulus-on-a chip technology with the culture technology to induce podocytes and endothelial cells from the human pluripotent stem cells could provide an alternative organ model and solve the issue of animal experiments. Additionally, previous experiments have verified the difference in the leakage of albumin using differentiated podocytes derived from patients with Alport syndrome, such that it could be applied to intractable hereditary glomerulopathy models. In this review, we provide an overview of the features of the existing glomerulus-on-a-chip systems, focusing on how they can address selective permeability verification tests, and the challenges they involved. We finally discuss the future approaches that should be developed for solving those challenges and allow further improvement of glomerulus-on-a-chip technologies.
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Affiliation(s)
- Kotaro Doi
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
| | - Hiroshi Kimura
- Department of Mechanical Engineering, School of Engineering, Tokai University, Kanagawa, Japan
| | | | | | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
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8
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Qu C, Roth R, Puapatanakul P, Loitman C, Hammad D, Genin GM, Miner JH, Suleiman HY. Three-Dimensional Visualization of the Podocyte Actin Network Using Integrated Membrane Extraction, Electron Microscopy, and Machine Learning. J Am Soc Nephrol 2022; 33:155-173. [PMID: 34758982 PMCID: PMC8763187 DOI: 10.1681/asn.2021020182] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2021] [Accepted: 10/19/2021] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Actin stress fibers are abundant in cultured cells, but little is known about them in vivo. In podocytes, much evidence suggests that mechanobiologic mechanisms underlie podocyte shape and adhesion in health and in injury, with structural changes to actin stress fibers potentially responsible for pathologic changes to cell morphology. However, this hypothesis is difficult to rigorously test in vivo due to challenges with visualization. A technology to image the actin cytoskeleton at high resolution is needed to better understand the role of structures such as actin stress fibers in podocytes. METHODS We developed the first visualization technique capable of resolving the three-dimensional cytoskeletal network in mouse podocytes in detail, while definitively identifying the proteins that comprise this network. This technique integrates membrane extraction, focused ion-beam scanning electron microscopy, and machine learning image segmentation. RESULTS Using isolated mouse glomeruli from healthy animals, we observed actin cables and intermediate filaments linking the interdigitated podocyte foot processes to newly described contractile actin structures, located at the periphery of the podocyte cell body. Actin cables within foot processes formed a continuous, mesh-like, electron-dense sheet that incorporated the slit diaphragms. CONCLUSIONS Our new technique revealed, for the first time, the detailed three-dimensional organization of actin networks in healthy podocytes. In addition to being consistent with the gel compression hypothesis, which posits that foot processes connected by slit diaphragms act together to counterbalance the hydrodynamic forces across the glomerular filtration barrier, our data provide insight into how podocytes respond to mechanical cues from their surrounding environment.
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Affiliation(s)
- Chengqing Qu
- Department of Mechanical Engineering, National Science Foundation Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri
| | - Robyn Roth
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri
| | | | - Charles Loitman
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Dina Hammad
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Guy M. Genin
- Department of Mechanical Engineering, National Science Foundation Science and Technology Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, Missouri
| | - Jeffrey H. Miner
- Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, Missouri,Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
| | - Hani Y. Suleiman
- Division of Nephrology, Washington University School of Medicine, St. Louis, Missouri
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9
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Doi K, Kimura H, Wada T, Tanaka T, Hiromura K, Saleem MA, Inagi R, Nangaku M, Fujii T. A novel method for successful induction of interdigitating process formation in conditionally immortalized podocytes from mice, rats, and humans. Biochem Biophys Res Commun 2021; 570:47-52. [PMID: 34271436 DOI: 10.1016/j.bbrc.2021.07.029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 07/08/2021] [Indexed: 11/29/2022]
Abstract
Formation of processes in podocytes is regarded as the hallmark of maturity and normal physical condition for the cell. There are many accumulated findings about molecular mechanisms that cause retraction of podocyte processes; however, there is little knowledge of the positive mechanisms that promote process formation in vitro, and most previous reports about this topic have been limited to low-density cultures. Here, we found that process formation can be induced in 100% confluent cultures of conditionally immortalized podocytes in mouse, rat, and human species by combining serum depletion and Y-27632 ROCK inhibitor supplementation on the scaffold of laminin-521(L521). We noted the cytoskeletal reorganization of the radial extension pattern of vimentin filaments and downregulation of actin stress fiber formation under that condition. We also found that additional standard amount of serum, depletion of ROCK inhibitor, or slight mismatch of the scaffold as laminin-511(L511) hinder process formation. These findings suggest that the combination of reduced serum, podocyte-specific scaffold, and intracellular signaling to reduce the overexpression of ROCK are required factors for process formation.
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Affiliation(s)
- Kotaro Doi
- Institute of Industrial Science, The University of Tokyo, 153-8503, Japan
| | - Hiroshi Kimura
- Department of Mechanical Engineering, School of Engineering, Tokai University, Japan
| | - Takehiko Wada
- Division of Nephrology, Endocrinology and Metabolism, Tokai University School of Medicine, Japan
| | - Tetsuhiro Tanaka
- Department of Nephrology and Endocrinology, Faculty of Medicine, The University of Tokyo, Japan
| | - Keiju Hiromura
- Department of Nephrology and Rheumatology, Gunma University Graduate School of Medicine, Japan
| | - Moin A Saleem
- University of Bristol, And Bristol Royal Hospital for Children, UK
| | - Reiko Inagi
- Division of Chronic Kidney Disease Pathophysiology the University of Tokyo Graduate School of Medicine, Japan
| | - Masaomi Nangaku
- Department of Nephrology and Endocrinology, Faculty of Medicine, The University of Tokyo, Japan
| | - Teruo Fujii
- Institute of Industrial Science, The University of Tokyo, 153-8503, Japan.
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10
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Kawasaki Y, Hosoyamada Y, Miyaki T, Yamaguchi J, Kakuta S, Sakai T, Ichimura K. Three-Dimensional Architecture of Glomerular Endothelial Cells Revealed by FIB-SEM Tomography. Front Cell Dev Biol 2021; 9:653472. [PMID: 33777962 PMCID: PMC7991748 DOI: 10.3389/fcell.2021.653472] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 02/04/2021] [Indexed: 11/29/2022] Open
Abstract
Focused-ion beam-scanning electron microscopic (FIB-SEM) tomography enables easier acquisition of a series of ultrastructural, sectional images directly from resin-embedded biological samples. In this study, to clarify the three-dimensional (3D) architecture of glomerular endothelial cells (GEnCs) in adult rats, we manually extracted GEnCs from serial FIB-SEM images and reconstructed them on an Amira reconstruction software. The luminal and basal surface structures were clearly visualized in the reconstructed GEnCs, although only the luminal surface structures could be observed by conventional SEM. The luminal surface visualized via the reconstructed GEnCs was quite similar to that observed through conventional SEM, indicating that 3D reconstruction could be performed with high accuracy. Thus, we successfully described the 3D architecture of normal GEnCs in adult rats more clearly and precisely than ever before. The GEnCs were found to consist of three major subcellular compartments, namely, the cell body, cytoplasmic ridges, and sieve plates, in addition to two associated subcellular compartments, namely, the globular protrusions and reticular porous structures. Furthermore, most individual GEnCs made up a “seamless” tubular shape, and some of them formed an autocellular junction to make up a tubular shape. FIB-SEM tomography with reconstruction is a powerful approach to better understand the 3D architecture of GEnCs. Moreover, the morphological information revealed in this study will be valuable for the 3D pathologic evaluation of GEnCs in animal and human glomerular diseases and the structural analysis of developmental processes in the glomerular capillary system.
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Affiliation(s)
- Yuto Kawasaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yasue Hosoyamada
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Department of Nutrition, Faculty of Health Care Sciences, Chiba Prefectural University of Health Sciences, Chiba, Japan
| | - Takayuki Miyaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Junji Yamaguchi
- Laboratory of Morphology and Image Analysis, Research Support Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Soichiro Kakuta
- Laboratory of Morphology and Image Analysis, Research Support Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tatsuo Sakai
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Koichiro Ichimura
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan.,Laboratory of Morphology and Image Analysis, Research Support Center, Juntendo University Graduate School of Medicine, Tokyo, Japan
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11
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Miyaki T, Kawasaki Y, Matsumoto A, Kakuta S, Sakai T, Ichimura K. Nephrocytes are part of the spectrum of filtration epithelial diversity. Cell Tissue Res 2020; 382:609-625. [PMID: 33191456 PMCID: PMC7683493 DOI: 10.1007/s00441-020-03313-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Accepted: 09/24/2020] [Indexed: 12/15/2022]
Abstract
The excretory system produces urine by ultrafiltration via a filtration epithelium. Podocytes are widely found as filtration epithelial cells in eucoelomates. In some animal taxa, including insects and crustaceans, nephrocytes serve to separate toxic substances from the body fluid, in addition to podocytes. Drosophila nephrocytes have been recently utilized as a model system to study podocyte function and disease. However, functionality and cellular architecture are strikingly different between Drosophila nephrocytes and eucoelomate podocytes, and the phylogenetic relationship between these cells remains enigmatic. In this study, using focused-ion beam-scanning electron microscopy (FIB-SEM) tomography, we revealed three-dimensional architecture of decapod nephrocytes with unprecedented accuracy—they filled an enormous gap, which can be called “missing link,” in the evolutionary diversity of podocytes and nephrocytes. Thus, we concluded that nephrocytes are part of the spectrum of filtration epithelial diversity in animal phylogeny.
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Affiliation(s)
- Takayuki Miyaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yuto Kawasaki
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Akira Matsumoto
- Department of Biology, Juntendo University School of Medicine, Inzai, Chiba, Japan
| | - Soichiro Kakuta
- Laboratory of Morphology and Image Analysis, Center for Biomedical Research Resources, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Tatsuo Sakai
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Koichiro Ichimura
- Department of Anatomy and Life Structure, Juntendo University Graduate School of Medicine, Tokyo, Japan. .,Laboratory of Morphology and Image Analysis, Center for Biomedical Research Resources, Juntendo University Graduate School of Medicine, Tokyo, Japan.
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12
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Wrede C, Hegermann J, Mühlfeld C. Novel cell contact between podocyte microprojections and parietal epithelial cells analyzed by volume electron microscopy. Am J Physiol Renal Physiol 2020; 318:F1246-F1251. [PMID: 32249613 DOI: 10.1152/ajprenal.00097.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Podocytes are highly specialized cells with a clear cell polarity. It is known that in health and disease, microvilli protrude from the apical surface of the podocytes into the urinary space. As a basis to better understand the podocyte microprojections/microvilli, the present study analyzed their spatial localization, extension, and contact site with parietal epithelial cells (PECs). Using different electron microscopic (EM) techniques, we analyzed renal corpuscles of healthy young adult male C57BL/6 mice fixed by vascular perfusion. Serial block-face scanning EM was used to visualize entire corpuscles, focused ion beam scanning EM was performed to characterize microprojection/microvilli-rich regions at higher magnification, and transmission EM of serial sections was used to analyze the contact zone between podocyte microprojections and PECs. Numerous microprojections originating from the primary processes of podocytes were present in the urinary space in all regions of the corpuscle. They often reached the apical surface of the PEC but did not make junctional contacts. At high resolution, it was observed that the glycocalyx of both cells was in contact. Depending on the distance between podocytes and PECs, these microprojections had a stretched or coiled state. The present study shows that microprojections/microvilli of podocytes are a physiological feature of healthy mouse kidneys and are frequently in contact with the apical surface of PECs, thus spanning the urinary space. It is proposed that podocyte microprojections serve mechanosensory or communicative functions between podocytes and PECs.
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Affiliation(s)
- Christoph Wrede
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
| | - Jan Hegermann
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
| | - Christian Mühlfeld
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany.,Research Core Unit Electron Microscopy, Hannover Medical School, Hannover, Germany
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