Name: Author Spotlight: Advancing Lens Biomechanics Research Through a Novel Protocol for Imaging Complex Interdigitations and Protein Staining
Uploaded: 2023-06-09T14:50:00
Description: Watch this Scientific Journal Video about Advancing Lens Biomechanics Research Through a Novel Protocol for Imaging Complex Interdigitations and Protein Staining at JoVE.com

Este trabalho foi financiado pelo processo R01 EY032056 (para CC) do Instituto Nacional de Olhos. Os autores agradecem à Dra. Theresa Fassel e Kimberly Vanderpool do Scripps Research Core Microscopy Facility por sua assistência com as imagens do microscópio eletrônico.

Os camundongos foram cuidados com base em um protocolo animal aprovado pelo Comitê Institucional de Cuidados e Uso de Animais da Indiana University Bloomington. Os camundongos utilizados para gerar dados representativos foram animais controle (selvagem) no fundo C57BL6/J, fêmeas e com 8-12 semanas de idade. Camundongos machos e fêmeas podem ser usados para este experimento, já que é muito improvável que o sexo dos camundongos afete o resultado do experimento.
1. Dissecção e desca...

Immunofluorescence Staining of Membrane Interdigitations in Lens Fiber Cells

<ol>
	<li>Lovicu, F. J., McAvoy, J. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+factor+regulation+of+lens+development.">Growth factor regulation of lens development.</a> Developmental Biology. 280 (1), 1-14 (2005).</li><li>Kuszak, J., Alcala, J., Maisel, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+surface+morphology+of+embryonic+and+adult+chick+lens-fiber+cells.">The surface morphology of embryonic and adult chick lens-fiber cells.</a> The American Journal of Anatomy. 159 (4), 395-410 (1980).</li><li>Kuszak, J. 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V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Square+arrays+and+their+role+in+ridge+formation+in+human+lens+fibers.">Square arrays and their role in ridge formation in human lens fibers.</a> Journal of Ultrastructure Research. 86 (3), 228-245 (1984).</li><li>Taylor, V. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Morphology+of+the+normal+human+lens.">Morphology of the normal human lens.</a> Investigative Ophthalmology &amp; Visual Science. 37 (7), 1396-1410 (1996).</li><li>Vrensen, G. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aging+of+the+human+eye+lens-a+morphological+point+of+view.">Aging of the human eye lens-a morphological point of view.</a> Comparative Biochemistry and Physiology. Part A, Physiology. 111 (4), 519-532 (1995).</li><li>Vrensen, G. F., Duindam, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Maturation+of+fiber+membranes+in+the+human+eye+lens.+Ultrastructural+and+Raman+microspectroscopic+observations.">Maturation of fiber membranes in the human eye lens. Ultrastructural and Raman microspectroscopic observations.</a> Ophthalmic Research. 27, 78-85 (1995).</li><li>Willekens, B., Vrensen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+three-dimensional+organization+of+lens+fibers+in+the+rabbit.+A+scanning+electron+microscopic+reinvestigation.">The three-dimensional organization of lens fibers in the rabbit. A scanning electron microscopic reinvestigation.</a> Albrecht von Graefe's Archive for Clinical and Experimental Opthalmology. 216 (4), 275-289 (1981).</li><li>Willekens, B., Vrensen, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+three-dimensional+organization+of+lens+fibers+in+the+rhesus+monkey.">The three-dimensional organization of lens fibers in the rhesus monkey.</a> Graefe's Archive for Clinical and Experimental Ophthalmology. 219 (3), 112-120 (1982).</li><li>Zhou, C. J., Lo, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Association+of+clathrin,+AP-2+adaptor+and+actin+cytoskeleton+with+developing+interlocking+membrane+domains+of+lens+fibre+cells.">Association of clathrin, AP-2 adaptor and actin cytoskeleton with developing interlocking membrane domains of lens fibre cells.</a> Experimental Eye Research. 77 (4), 423-432 (2003).</li><li>Kuwabara, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+maturation+of+the+lens+cell:+a+morphologic+study.">The maturation of the lens cell: a morphologic study.</a> Experimental Eye Research. 20 (5), 427-443 (1975).</li><li>Weeber, H. A., Eckert, G., Pechhold, W., vander Heijde, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stiffness+gradient+in+the+crystalline+lens.">Stiffness gradient in the crystalline lens.</a> Graefe's Archive for Clinical and Experimental Ophthalmology. 245 (9), 1357-1366 (2007).</li><li>Weeber, H. A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dynamic+mechanical+properties+of+human+lenses.">Dynamic mechanical properties of human lenses.</a> Experimental Eye Research. 80 (3), 425-434 (2005).</li><li>Weeber, H. A., vander Heijde, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+relationship+between+lens+stiffness+and+accommodative+amplitude.">On the relationship between lens stiffness and accommodative amplitude.</a> Experimental Eye Research. 85 (5), 602-607 (2007).</li><li>Heys, K. R., Cram, S. L., Truscott, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Massive+increase+in+the+stiffness+of+the+human+lens+nucleus+with+age:+the+basis+for+presbyopia.">Massive increase in the stiffness of the human lens nucleus with age: the basis for presbyopia.</a> Molecular Vision. 10, 956-963 (2004).</li><li>Heys, K. R., Friedrich, M. G., Truscott, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Presbyopia+and+heat:+changes+associated+with+aging+of+the+human+lens+suggest+a+functional+role+for+the+small+heat+shock+protein,+alpha-crystallin,+in+maintaining+lens+flexibility.">Presbyopia and heat: changes associated with aging of the human lens suggest a functional role for the small heat shock protein, alpha-crystallin, in maintaining lens flexibility.</a> Aging Cell. 6 (6), 807-815 (2007).</li><li>Glasser, A., Campbell, M. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biometric,+optical+and+physical+changes+in+the+isolated+human+crystalline+lens+with+age+in+relation+to+presbyopia.">Biometric, optical and physical changes in the isolated human crystalline lens with age in relation to presbyopia.</a> Vision Research. 39 (11), 1991-2015 (1999).</li><li>Pierscionek, B. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-related+response+of+human+lenses+to+stretching+forces.">Age-related response of human lenses to stretching forces.</a> Experimental Eye Research. 60 (3), 325-332 (1995).</li><li>Biswas, S. K., Lee, J. E., Brako, L., Jiang, J. X., Lo, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gap+junctions+are+selectively+associated+with+interlocking+ball-and-sockets+but+not+protrusions+in+the+lens.">Gap junctions are selectively associated with interlocking ball-and-sockets but not protrusions in the lens.</a> Molecular Vision. 16, 2328-2341 (2010).</li><li>Lo, W. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Aquaporin-0+targets+interlocking+domains+to+control+the+integrity+and+transparency+of+the+eye+lens.">Aquaporin-0 targets interlocking domains to control the integrity and transparency of the eye lens.</a> Investigative Ophthalmology &amp; Visual Science. 55 (3), 1202-1212 (2014).</li><li>Cheng, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tropomyosin+3.5+protects+the+F-actin+networks+required+for+tissue+biomechanical+properties.">Tropomyosin 3.5 protects the F-actin networks required for tissue biomechanical properties.</a> Journal of Cell Science. 131 (23), (2018).</li><li>Cheng, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tropomodulin+1+regulation+of+actin+is+required+for+the+formation+of+large+paddle+protrusions+between+mature+lens+fiber+cells.">Tropomodulin 1 regulation of actin is required for the formation of large paddle protrusions between mature lens fiber cells.</a> Investigative Ophthalmology &amp; Visual Science. 57 (10), 4084-4099 (2016).</li><li>Kuszak, J. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+development+of+lens+sutures.">The development of lens sutures.</a> Progress in Retinal and Eye Research. 14 (2), 567-591 (1995).</li><li>Bassnett, S., Costello, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+cause+and+consequence+of+fiber+cell+compaction+in+the+vertebrate+lens.">The cause and consequence of fiber cell compaction in the vertebrate lens.</a> Experimental Eye Research. 156, 50-57 (2017).</li><li>Biswas, S., Son, A., Yu, Q., Zhou, R., Lo, W. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Breakdown+of+interlocking+domains+may+contribute+to+formation+of+membranous+globules+and+lens+opacity+in+ephrin-A5(-/-)+mice.">Breakdown of interlocking domains may contribute to formation of membranous globules and lens opacity in ephrin-A5(-/-) mice.</a> Experimental Eye Research. 145, 130-139 (2016).</li><li>Blankenship, T., Bradshaw, L., Shibata, B., Fitzgerald, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+specializations+emerging+late+in+mouse+lens+fiber+cell+differentiation.">Structural specializations emerging late in mouse lens fiber cell differentiation.</a> Investigative Ophthalmology &amp; Visual Science. 48 (7), 3269-3276 (2007).</li><li>Cheng, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Age-related+changes+in+eye+lens+biomechanics,+morphology,+refractive+index+and+transparency.">Age-related changes in eye lens biomechanics, morphology, refractive index and transparency.</a> Aging. 11 (24), 12497-12531 (2019).</li><li>Cheng, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=EphA2+affects+development+of+the+eye+lens+nucleus+and+the+gradient+of+refractive+index.">EphA2 affects development of the eye lens nucleus and the gradient of refractive index.</a> Investigative Ophthalmology &amp; Visual Science. 63 (1), 2 (2022).</li><li>Cheng, C., Gokhin, D. S., Nowak, R. B., Fowler, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sequential+application+of+glass+coverslips+to+assess+the+compressive+stiffness+of+the+mouse+lens:+strain+and+morphometric+analyses.">Sequential application of glass coverslips to assess the compressive stiffness of the mouse lens: strain and morphometric analyses.</a> Journal of Visualized Experiments. (111), e53986 (2016).</li><li>Forrester, J. V., Dick, A. D., McMenamin, P. G., Roberts, F., Pearlman, E., Saunders, W. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anatomy+of+the+eye+and+orbit.">Anatomy of the eye and orbit.</a> The Eye (Fourth Edition). , 1 (2016).</li><li>Cheng, C., Nowak, R. B., Fowler, V. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+lens+actin+filament+cytoskeleton:+Diverse+structures+for+complex+functions.">The lens actin filament cytoskeleton: Diverse structures for complex functions.</a> Experimental Eye Research. 156, 58-71 (2017).</li><li>Goldberg, M. W., Fiserova, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunogold+labeling+for+scanning+electron+microscopy.">Immunogold labeling for scanning electron microscopy.</a> Methods in Molecular Biology. 1474, 309-325 (2016).</li><li>Goldberg, M. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High-resolution+scanning+electron+microscopy+and+immuno-gold+labeling+of+the+nuclear+lamina+and+nuclear+pore+complex.">High-resolution scanning electron microscopy and immuno-gold labeling of the nuclear lamina and nuclear pore complex.</a> Methods in Molecular Biology. 1411, 441-459 (2016).</li><li>Hermann, R., Walther, P., Muller, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunogold+labeling+in+scanning+electron+microscopy.">Immunogold labeling in scanning electron microscopy.</a> Histochemistry and Cell Biology. 106 (1), 31-39 (1996).</li><li>Gokhin, D. 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Este protocolo demonstrou os métodos de fixação, preservação e imunomarcação que preservam fielmente a morfologia da membrana 3D de feixes ou células de fibras do cristalino singular de várias profundidades no cristalino. As fibras coradas do cristalino são comparadas com preparações de MEV que têm sido usadas há muito tempo para estudar a morfologia das células das fibras do cristalino. Os resultados mostram estruturas de membrana comparáveis entre as duas preparações. A ME continua sendo o padrão-our...

O cristalino é um tecido límpido e ovoide, na câmara anterior do olho, composto por dois tipos celulares, células epiteliais efibras1 (Figura 1). Existe uma monocamada de células epiteliais que recobre o hemisfério anterior do cristalino. As células fibrosas são diferenciadas das células epiteliais e compõem a maior parte do cristalino. As células fibrosas altamente especializadas sofrem uma programação de alongamento, diferenciação e maturação, marcada por distintas mudanças na morfologia da membrana celular da periferia do cristalino para o centro do cristalino2,3,4,5,6,7,8,9,10,11,12 , também conhecido como núcleo do cristalino. A função do cristalino de focalizar a luz vinda de várias distâncias para a retina depende de suas propriedades biomecânicas, incluindo rigidez e elasticidade 13,14,15,16,17,18,19. As complexas interdigitações das fibras do cristalino foram hipotetizadas 20,21 e recentemente mostraram-se importantes para a rigidez do cristalino 22,23.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/65638/65638fig01.jpg"> Figura 1: Diagramas de anatomia do cristalino e imagens representativas de microscopia eletrônica de varredura (MEV) das fibras do cristalino. O desenho mostra uma visão longitudinal (anterior a posterior de cima para baixo) da monocamada anterior de células epiteliais (sombreada em azul claro) e uma massa volumosa de células de fibra do cristalino (branco). O centro da lente (sombreado em rosa) é conhecido como núcleo e compreende células de fibra altamente compactadas. À direita, um desenho animado de seção transversal revela a forma de célula hexagonal alongada das fibras da lente que são embaladas em um padrão de favo de mel. As células de fibra têm dois lados largos e quatro lados curtos. Imagens SEM representativas ao longo da parte inferior mostram as interdigitações complexas da membrana entre as células de fibra da lente em diferentes profundidades da lente. A partir da direita, as fibras de lente recém-formadas na periferia da lente têm pequenas saliências ao longo dos lados curtos e bolas e soquetes ao longo do lado largo (caixas vermelhas). Durante a maturação, as fibras do cristalino desenvolvem grandes domínios de remo que são decorados por pequenas saliências ao longo dos lados curtos (caixas azuis). As células de fibras maduras possuem grandes domínios de pás ilustrados por pequenas saliências. Esses domínios de intertravamento são importantes para as propriedades biomecânicas das lentes. As células de fibra no núcleo do cristalino têm menos pequenas saliências ao longo de seus lados curtos e têm interdigitações complexas de língua e sulco (caixas roxas). Os lados largos da célula exibem uma morfologia de membrana globular. O desenho foi modificado de22,32 e não desenhado em escala. Barra de escala = 3 μm. <a href="https://www.jove.com/files/ftp_upload/65638/65638fig01large.jpg" target="_blank">Clique aqui para ver uma versão maior desta figura.</a>
A lente cresce pela adição de conchas de novas células de fibra sobrepostas às gerações anteriores de fibras24,25. As células de fibra têm uma forma de seção transversal hexagonal alongada com dois lados largos e quatro lados curtos. Essas células se estendem do polo anterior ao posterior do cristalino e, dependendo da espécie, as fibras do cristalino podem ter vários milímetros de comprimento. Para suportar a estrutura dessas células alongadas e magras, interdigitações especializadas ao longo dos lados largos e curtos criam estruturas interligadas para manter a forma da lente e as propriedades biomecânicas. Alterações na forma da membrana celular durante a diferenciação e maturação das células fibrosas têm sido extensivamente documentadas por estudos de microscopia eletrônica (ME)2,3,4,5,6,7,8,9,10,20,26,27,28,29 . As células de fibra recém-formadas têm bolas e soquetes ao longo de seus lados largos com saliências muito pequenas ao longo de seus lados curtos, enquanto as fibras maduras têm saliências e pás interligadas ao longo de seus lados curtos. As fibras nucleares exibem interdigitações de língua e sulco e morfologia da membrana globular. Pouco se sabe sobre as proteínas necessárias para essas complexas membranas interligadas. Estudos prévios sobre a localização de proteínas em células fibrosas basearam-se em cortes de tecido do cristalino, que não permitem uma visualização clara da arquitetura celular complexa.
Este trabalho criou e aperfeiçoou um novo método para fixar células de fibras simples e em feixes de lentes para preservar a morfologia complexa e permitir a imunomarcação de proteínas na membrana celular e dentro do citoplasma. Este método preserva fielmente a arquitetura da membrana celular, comparável aos dados de estudos de EM, e permite a coloração com anticorpos primários para proteínas específicas. Temos previamente imunomarcadas fibras corticais do cristalino em fase de diferenciação ematuração22,23. Neste protocolo, há também um novo método para corar células de fibra do núcleo do cristalino. Este protocolo abre as portas para a compreensão dos mecanismos de formação e mudanças nas interdigitações da membrana durante a maturação das células fibrosas e compactação do núcleo do cristalino.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr >
			<td >100% Triton X-100</td>
			<td >FisherScientific</td>
			<td >BP151-500</td>
			<td ></td>
		</tr>
		<tr >
			<td >60mm plate</td>
			<td >FisherScientific</td>
			<td >FB0875713A</td>
			<td></td>
		</tr>
		<tr >
			<td >16% paraformaldehyde</td>
			<td >Electron Microscopy Sciences</td>
			<td >15710</td>
			<td></td>
		</tr>
		<tr >
			<td >10X phosphate buffered saline</td>
			<td >ThermoFisher</td>
			<td >70011-044</td>
			<td></td>
		</tr>
		<tr >
			<td >1X phosphate buffered saline</td>
			<td >ThermoFisher</td>
			<td >14190136</td>
			<td></td>
		</tr>
		<tr >
			<td >48-well plate</td>
			<td >CytoOne</td>
			<td >CC7672-7548</td>
			<td></td>
		</tr>
		<tr >
			<td >Cover slips (22 x 40 mm)</td>
			<td >FisherScientific</td>
			<td >12-553-467</td>
			<td></td>
		</tr>
		<tr >
			<td >Curved tweezers</td>
			<td >World Precision Instruments</td>
			<td >501981</td>
			<td></td>
		</tr>
		<tr >
			<td >Dissection microscope</td>
			<td >Carl Zeiss</td>
			<td >Stereo Discovery V8</td>
			<td></td>
		</tr>
		<tr >
			<td >Fine tip straight tweezers</td>
			<td >Electron Microscopy Sciences</td>
			<td >72707-01</td>
			<td></td>
		</tr>
		<tr >
			<td >Fisherbrand Superfrost Plus Microscope Slides</td>
			<td >FisherScientific</td>
			<td >12-550-15</td>
			<td></td>
		</tr>
		<tr >
			<td >LSM 800 confocal microscope with Airyscan (63X) and Zen 3.5 Software</td>
			<td >Carl Zeiss</td>
			<td ></td>
			<td></td>
		</tr>
		<tr >
			<td >Nail polish</td>
			<td ></td>
			<td ></td>
			<td></td>
		</tr>
		<tr >
			<td >Normal donkey serum</td>
			<td >Jackson ImmunoResearch</td>
			<td >017-000-121</td>
			<td></td>
		</tr>
		<tr >
			<td >Phalloidin (rhodamine)</td>
			<td >ThermoFisher</td>
			<td >R415</td>
			<td></td>
		</tr>
		<tr >
			<td >Primary antibody</td>
			<td ></td>
			<td ></td>
			<td></td>
		</tr>
		<tr >
			<td >Scalpel Feather Disposable, steril, No. 11</td>
			<td >VWR</td>
			<td >76241-186</td>
			<td></td>
		</tr>
		<tr >
			<td >Secondary antibody</td>
			<td ></td>
			<td ></td>
			<td></td>
		</tr>
		<tr >
			<td >Straight forceps</td>
			<td >World Precision Instruments</td>
			<td >11252-40</td>
			<td></td>
		</tr>
		<tr >
			<td >Thermo Scientific&#160;Nunc MicroWell MiniTrays (dissection tray)</td>
			<td >FisherScientific</td>
			<td >12-565-154</td>
			<td></td>
		</tr>
		<tr >
			<td >Ultra-fine scissors</td>
			<td >World Precision Instruments</td>
			<td >501778</td>
			<td></td>
		</tr>
		<tr >
			<td >VECTASHIELD Antifade Mounting Medium with DAPI</td>
			<td >Vector Laboratories</td>
			<td >H-1200</td>
			<td></td>
		</tr>
		<tr >
			<td >Wheat germ agglutinin (fluorescein)</td>
			<td >Vector Laboratories</td>
			<td >FL-1021-5</td>
			<td></td>
		</tr>
	</tbody>
</table>

preparation and immunofluorescence staining of bundles and single fiber cells from the cortex and nucleus of the eye lens

O cristalino é um órgão transparente e elipsoide na câmara anterior do olho que muda de forma para focalizar finamente a luz na retina para formar uma imagem clara. A maior parte desse tecido é composta por células fibrosas especializadas e diferenciadas que possuem secção transversal hexagonal e se estendem dos polos anterior para posterior do cristalino. Essas células longas e magras são fortemente opostas às células vizinhas e têm interdigitações complexas ao longo do comprimento da célula. As estruturas intertravadas especializadas são necessárias para as propriedades biomecânicas normais do cristalino e têm sido extensivamente descritas usando técnicas de microscopia eletrônica. Este protocolo demonstra o primeiro método para preservar e imunomanchar singular, bem como feixes de células de fibra de lente de camundongo para permitir a localização detalhada de proteínas dentro dessas células de forma complexa. Os dados representativos mostram a coloração das células periféricas, diferenciadoras, maduras e de fibras nucleares em todas as regiões do cristalino. Este método pode ser potencialmente utilizado em células de fibras isoladas de lentes de outras espécies.

The lens is a clear and ovoid tissue in the anterior chamber of the eye that is made up of two cell types, epithelial and fiber cells1 (Figure 1). There is a monolayer of epithelial cells that covers the anterior hemisphere of the lens. Fiber cells are differentiated from epithelial cells and make up the bulk of the lens. The highly specialized fiber cells undergo an elongation, differentiation, and maturation programming, marked by distinct changes in cell membrane morphology from the lens periphery to the lens center2,3,4,5,6,7,8,9,10,11,12, also known as the lens nucleus. The function of the lens to fine-focus light coming from various distances onto the retina depends on its biomechanical properties, including stiffness and elasticity13,14,15,16,17,18,19. The complex interdigitations of lens fibers have been hypothesized20,21 and recently shown to be important for lens stiffness22,23.
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/65638/65638fig01.jpg" /> 
Figure 1: Lens anatomy diagrams and representative scanning electron microscopy (SEM) images from lens fibers. The cartoon shows a longitudinal (anterior to posterior from top to bottom) view of the anterior monolayer of epithelial cells (shaded in light blue) and a bulk mass of lens fiber cells (white). The center of the lens (shaded in pink) is known as the nucleus and comprises highly compacted fiber cells. On the right, a cross-section cartoon reveals the elongated hexagon cell shape of lens fibers that are packed into a honeycomb pattern. Fiber cells have two broad sides and four short sides. Representative SEM images along the bottom show the complex membrane interdigitations between lens fiber cells at different depths of the lens. From the right, newly formed lens fibers at the lens periphery have small protrusions along the short sides and balls-and-sockets along the broad side (red boxes). During maturation, lens fibers develop large paddle domains that are decorated by small protrusions along the short sides (blue boxes). Mature fiber cells possess large paddle domains illustrated by small protrusions. These interlocking domains are important for lens biomechanical properties. Fiber cells in the lens nucleus have fewer small protrusions along their short sides and have complex tongue-and-groove interdigitations (purple boxes). The broad sides of the cell display a globular membrane morphology. The cartoon was modified from22,32 and not drawn to scale. Scale bar = 3 &#181;m. <a href="https://www.jove.com/files/ftp_upload/65638/65638fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
The lens grows by adding shells of new fiber cells overlaid on top of previous generations of fibers24,25. Fiber cells have an elongated, hexagonal cross section shape with two broad sides and four short sides. These cells extend from the anterior to the posterior pole of the lens, and depending on the species, the lens fibers can be several millimeters in length. To support the structure of these elongated and skinny cells, specialized interdigitations along the broad and short sides create interlocking structures to maintain the lens shape and biomechanical properties. Changes in cell membrane shape during fiber cell differentiation and maturation have been extensively documented by electron microscopy (EM) studies2,3,4,5,6,7,8,9,10,20,26,27,28,29. Newly formed fiber cells have balls-and-sockets along their broad sides with very small protrusions along their short sides, while mature fibers have interlocking protrusions and paddles along their short sides. Nuclear fibers display tongue-and-groove interdigitations and globular membrane morphology. Little is known about the proteins that are required for these complex interlocking membranes. Previous studies on protein localization in fiber cells have relied on lens tissue sections, which do not allow clear visualization of the complex cell architecture.
This work has created and perfected a novel method to fix single and bundles of lens fiber cells to preserve the complex morphology and to allow immunostaining for proteins at the cell membrane and within the cytoplasm. This method faithfully preserves cell membrane architecture, comparable to data from EM studies, and allows staining with primary antibodies for specific proteins. We have previously immunostained cortical lens fibers undergoing differentiation and maturation22,23. In this protocol, there is also a new method to stain fiber cells from the lens nucleus. This protocol opens the door to understanding the mechanisms for formation and changes in membrane interdigitations during fiber cell maturation and lens nucleus compaction.

Author Spotlight: Advancing Lens Biomechanics Research Through a Novel Protocol for Imaging Complex Interdigitations and Protein Staining 

Preparo e Coloração por Imunofluorescência de Feixes e Células Monofibrais do Córtex e Núcleo do Cristalino Ocular

The lens is a transparent ellipsoid organ in the anterior chamber of the eye, and is responsible for fine focusing of light onto the retina to create a clear image. The function of the lens relies on its biomechanical properties, complex interdigitations between the lens fiber cells has recently been shown to be important for lens stiffness. While the specialized morphology of lens fiber cells has been previously described by electron microscopy, little is known about the proteins that are required for these interlocking membranes.Previous studies have relied on lens tissue sections, which do not allow clear visualization of complex cell architecture. We have created and perfected a novel technique to faithfully preserve the complex membrane interdigitations between lens fiber cells for staining and confocal microscopy imaging of specific proteins. In this protocol, there is also a new method for staining the fiber cells from the center of the lens, which is also known as the lens nucleus.This method opens the door to understanding fiber cell differentiation and maturation by studying the mechanisms of formation and changes in membrane interdigitations.

As células de fibras do cristalino são preparadas a partir do córtex do cristalino (fibras diferenciadoras e fibras maduras) e do núcleo, e as células são coradas com faloidina para F-actina e WGA para a membrana celular. Uma mistura de feixes de células ou fibras de lente única (Figura 3) são observadas e imageadas. A partir do córtex do cristalino, encontram-se dois tipos de células (Figura 3A). As células de fibra diferenciadoras na periferia do c...

Watch this Scientific Journal Video about Advancing Lens Biomechanics Research Through a Novel Protocol for Imaging Complex Interdigitations and Protein Staining at JoVE.com

Este protocolo descreve métodos para preparar células de fibras periféricas, maduras e nucleares do cristalino ocular para coloração por imunofluorescência para estudar interdigitações complexas célula-célula e a arquitetura da membrana.

The lens is a transparent and ellipsoid organ in the anterior chamber of the eye that changes shape to finely focus light onto the retina to form a clear ...

O cristalino é um órgão elipsoide transparente na câmara anterior do olho, e é responsável pelo foco fino da luz na retina para criar uma imagem clara. A função da lente depende de suas propriedades biomecânicas, interdigitações complexas entre as células de fibra da lente têm se mostrado recentemente importantes para a rigidez da lente. Embora a morfologia especializada das células de fibras do cristalino tenha sido previamente descrita por microscopia eletrônica, pouco se sabe sobre as proteínas necessárias para essas membranas interligadas.Estudos prévios basearam-se em cortes de tecido do cristalino, que não permitem a visualização clara da arquitetura celular complexa. Criamos e aperfeiçoamos uma nova técnica para preservar fielmente as complexas interdigitações de membrana entre as células de fibras do cristalino para coloração e imagens de microscopia confocal de proteínas específicas. Nesse protocolo, há também um novo método para colorir as células de fibra do centro da lente, que também é conhecido como núcleo do cristalino.Este método abre as portas para a compreensão da diferenciação e maturação das células fibrosas, estudando os mecanismos de formação e mudanças nas interdigitações de membrana.