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Bend, Push, Stretch: Remarkable Structure and Mechanics of Single Intermediate Filaments and Meshworks. Cells 2021; 10:cells10081960. [PMID: 34440729 PMCID: PMC8394331 DOI: 10.3390/cells10081960] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 12/11/2022] Open
Abstract
The cytoskeleton of the eukaryotic cell provides a structural and functional scaffold enabling biochemical and cellular functions. While actin and microtubules form the main framework of the cell, intermediate filament networks provide unique mechanical properties that increase the resilience of both the cytoplasm and the nucleus, thereby maintaining cellular function while under mechanical pressure. Intermediate filaments (IFs) are imperative to a plethora of regulatory and signaling functions in mechanotransduction. Mutations in all types of IF proteins are known to affect the architectural integrity and function of cellular processes, leading to debilitating diseases. The basic building block of all IFs are elongated α-helical coiled-coils that assemble hierarchically into complex meshworks. A remarkable mechanical feature of IFs is the capability of coiled-coils to metamorphize into β-sheets under stress, making them one of the strongest and most resilient mechanical entities in nature. Here, we discuss structural and mechanical aspects of IFs with a focus on nuclear lamins and vimentin.
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Tang S, Di G, Hu S, Liu Y, Dai Y, Chen P. AQP5 regulates vimentin expression via miR-124-3p.1 to protect lens transparency. Exp Eye Res 2021; 205:108485. [PMID: 33582182 DOI: 10.1016/j.exer.2021.108485] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 01/27/2021] [Accepted: 01/29/2021] [Indexed: 12/18/2022]
Abstract
The pathogenesis of congenital cataract (CC), a major disease associated with blindness in infants, is complex and diverse. Aquaporin 5 (AQP5) represents an essential membrane water channel. In the present study, whole exome sequencing revealed a novel heterozygous missense mutation of AQP5 (c.152 T > C, p. L51P) in the four generations of the autosomal dominant CC (adCC) family. By constructing a mouse model of AQP5 knockout (KO) using the CRISPR/Cas9 technology, we observed that the lens of AQP5-KO mice showed mild opacity at approximately six months of age. miR-124-3p.1 expression was identified to be downregulated in the lens of AQP5-KO mice as evidenced by qRT-PCR analysis. A dual luciferase reporter assay confirmed that vimentin was a target gene of miR-124-3p.1. Organ-cultured AQP5-KO mouse lenses were showed increased opacity compared to those of WT mice, and vimentin expression was upregulated as determined by RT-PCR, western blotting, and immunofluorescence staining. After miR-124-3p.1 agomir was added, the lens opacity in WT mice and AQP5-KO mice decreased, accompanied by the downregulation of vimentin. AQP5-L51P increased vimentin expression of in human lens epithelial cells. Therefore, a missense mutation in AQP5 (c.152 T > C, p. L51P) was associated with adCC, and AQP5 could participate in the maintenance of lens transparency by regulating vimentin expression via miR-124-3p.1.
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Affiliation(s)
- Suzhen Tang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Guohu Di
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China; Institute of Stem Cell Regeneration Medicine, School of Basic Medicine, Qingdao University, Qingdao, 266071, China
| | - Shaohua Hu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Yaning Liu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China
| | - Yunhai Dai
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University & Shandong Academy of Medical Sciences, Qingdao, China.
| | - Peng Chen
- Department of Human Anatomy, Histology and Embryology, School of Basic Medicine, Qingdao University, Qingdao, 266071, Shandong Province, China; Institute of Stem Cell Regeneration Medicine, School of Basic Medicine, Qingdao University, Qingdao, 266071, China.
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García-Posadas L, Diebold Y. Three-Dimensional Human Cell Culture Models to Study the Pathophysiology of the Anterior Eye. Pharmaceutics 2020; 12:E1215. [PMID: 33333869 PMCID: PMC7765302 DOI: 10.3390/pharmaceutics12121215] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/11/2020] [Accepted: 12/13/2020] [Indexed: 02/07/2023] Open
Abstract
In recent decades, the establishment of complex three-dimensional (3D) models of tissues has allowed researchers to perform high-quality studies and to not only advance knowledge of the physiology of these tissues but also mimic pathological conditions to test novel therapeutic strategies. The main advantage of 3D models is that they recapitulate the spatial architecture of tissues and thereby provide more physiologically relevant information. The eye is an extremely complex organ that comprises a large variety of highly heterogeneous tissues that are divided into two asymmetrical portions: the anterior and posterior segments. The anterior segment consists of the cornea, conjunctiva, iris, ciliary body, sclera, aqueous humor, and the lens. Different diseases in these tissues can have devastating effects. To study these pathologies and develop new treatments, the use of cell culture models is instrumental, and the better the model, the more relevant the results. Thus, the development of sophisticated 3D models of ocular tissues is a significant challenge with enormous potential. In this review, we present a comprehensive overview of the latest advances in the development of 3D in vitro models of the anterior segment of the eye, with a special focus on those that use human primary cells.
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Affiliation(s)
- Laura García-Posadas
- Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, 47011 Valladolid, Spain;
| | - Yolanda Diebold
- Instituto de Oftalmobiología Aplicada (IOBA), Universidad de Valladolid, 47011 Valladolid, Spain;
- Centro de Investigación Biomédica en Red de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Instituto de Salud Carlos III, 28029 Madrid, Spain
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Young LK, Jarrin M, Saunter CD, Quinlan RA, Girkin JM. Non-invasive in vivo quantification of the developing optical properties and graded index of the embryonic eye lens using SPIM. BIOMEDICAL OPTICS EXPRESS 2018; 9:2176-2188. [PMID: 29760979 PMCID: PMC5946780 DOI: 10.1364/boe.9.002176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 03/22/2018] [Accepted: 03/23/2018] [Indexed: 06/08/2023]
Abstract
Graded refractive index lenses are inherent to advanced visual systems in animals. By understanding their formation and local optical properties, significant potential for improved ocular healthcare may be realized. We report a novel technique measuring the developing optical power of the eye lens, in a living animal, by exploiting the orthogonal imaging modality of a selective plane illumination microscope (SPIM). We have quantified the maturation of the lenticular refractive index at three different visible wavelengths using a combined imaging and ray tracing approach. We demonstrate that the method can be used with transgenic and vital dye labeling as well as with both fixed and living animals. Using a key eye lens morphogen and its inhibitor, we have measured their effects both on lens size and on refractive index. Our technique provides insights into the mechanisms involved in the development of this natural graded index micro-lens and its associated optical properties.
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Affiliation(s)
- Laura K Young
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, South Road, Durham, DH1 3LE, UK
- Joint first authors
| | - Miguel Jarrin
- Biophysical Sciences Institute, Durham University, South Road, Durham, DH1 3LE, UK
- Department of Biosciences, Durham University, Upper Mountjoy, Stockton Road, Durham, DH1 3LE, UK
- Joint first authors
| | - Christopher D Saunter
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, South Road, Durham, DH1 3LE, UK
| | - Roy A Quinlan
- Biophysical Sciences Institute, Durham University, South Road, Durham, DH1 3LE, UK
- Department of Biosciences, Durham University, Upper Mountjoy, Stockton Road, Durham, DH1 3LE, UK
| | - John M Girkin
- Department of Physics, Durham University, South Road, Durham, DH1 3LE, UK
- Biophysical Sciences Institute, Durham University, South Road, Durham, DH1 3LE, UK
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