Name: sequential application of glass coverslips to assess the compressive stiffness of the mouse lens: strain and morphometric analyses
Uploaded: 2016-05-03T12:00:00
Description: Watch this Scientific Journal Video about Sequential Application of Glass Coverslips to Assess the Compressive Stiffness of the Mouse Lens: Strain and Morphometric Analyses at JoVE.com

This work was supported by National Eye Institute Grant R01 EY017724 (VMF) and National Institute of Arthritis and Musculoskeletal and Skin Diseases Grant K99 AR066534 (DSG).

所有动物的程序均按照建议的指南中照顾和实验动物使用由卫生和批准议定书下国家研究院​​的机构动物护理和使用委员会在斯克里普斯研究所进行。 1.解剖镜<ol><li>根据健康“指南实验动物的护理和使用”的国家机构和认可机构使用动物的协议安乐死的建议只。 </li><li>去核的使用弯钳小鼠眼球。按压围绕与镊子眼组织带来的眼睛从插座中，然后从与镊子插座摘去眼。在...

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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> Exp Eye Res. 80 (3), 425-434 (2005).</li><li>Fisher, R. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Elastic+properties+of+the+human+lens.">Elastic properties of the human lens.</a> Exp Eye Res. 11 (1), 143 (1971).</li><li>Krueger, R. R., Sun, X. K., Stroh, J., Myers, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Experimental+increase+in+accommodative+potential+after+neodymium:+yttrium-aluminum-garnet+laser+photodisruption+of+paired+cadaver+lenses.">Experimental increase in accommodative potential after neodymium: yttrium-aluminum-garnet laser photodisruption of paired cadaver lenses.</a> Ophthalmology. 108 (11), 2122-2129 (2001).</li><li>Burd, H. J., Wilde, G. S., Judge, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+improved+spinning+lens+test+to+determine+the+stiffness+of+the+human+lens.">An improved spinning lens test to determine the stiffness of the human lens.</a> Exp Eye Res. 92 (1), 28-39 (2011).</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=Presbyopia+and+the+optical+changes+in+the+human+crystalline+lens+with+age.">Presbyopia and the optical changes in the human crystalline lens with age.</a> Vision Res. 38 (2), 209-229 (1998).</li><li>Pau, H., Kranz, 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+increasing+sclerosis+of+the+human+lens+with+age+and+its+relevance+to+accommodation+and+presbyopia.">The increasing sclerosis of the human lens with age and its relevance to accommodation and presbyopia.</a> Graefes Arch Clin Exp Ophthalmol. 229 (3), 294-296 (1991).</li><li>Hollman, K. W., O'Donnell, M., Erpelding, T. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mapping+elasticity+in+human+lenses+using+bubble-based+acoustic+radiation+force.">Mapping elasticity in human lenses using bubble-based acoustic radiation force.</a> Exp Eye Res. 85 (6), 890-893 (2007).</li><li>Baradia, H., Nikahd, N., Glasser, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mouse+lens+stiffness+measurements.">Mouse lens stiffness measurements.</a> Exp Eye Res. 91 (2), 300-307 (2010).</li><li>Gokhin, D. S., 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=Tmod1+and+CP49+synergize+to+control+the+fiber+cell+geometry,+transparency,+and+mechanical+stiffness+of+the+mouse+lens.">Tmod1 and CP49 synergize to control the fiber cell geometry, transparency, and mechanical stiffness of the mouse lens.</a> PLoS One. 7 (11), e48734 (2012).</li><li>Sindhu Kumari, S., 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=Role+of+Aquaporin+0+in+lens+biomechanics.">Role of Aquaporin 0 in lens biomechanics.</a> Biochem Biophys Res Commun. , (2015).</li><li>Fudge, D. S., 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=Intermediate+filaments+regulate+tissue+size+and+stiffness+in+the+murine+lens.">Intermediate filaments regulate tissue size and stiffness in the murine lens.</a> Invest Ophthalmol Vis Sci. 52 (6), 3860-3867 (2011).</li><li>Kuszak, J. R., Mazurkiewicz, M., Zoltoski, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Computer+modeling+of+secondary+fiber+development+and+growth:+I.+Nonprimate+lenses.">Computer modeling of secondary fiber development and growth: I. Nonprimate lenses.</a> Mol Vis. 12, 251-270 (2006).</li><li>Scarcelli, G., Kim, P., Yun, S. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+measurement+of+age-related+stiffening+in+the+crystalline+lens+by+Brillouin+optical+microscopy.">In vivo measurement of age-related stiffening in the crystalline lens by Brillouin optical microscopy.</a> Biophys J. 101 (6), 1539-1545 (2011).</li></ol>

使用这种方法来衡量镜片硬度时，有几个关键因素。 （ - 8.5°8）相对于所述腔室（θ）的底部第一，盖玻片在略微倾斜的角度施加到透镜。这将适用于负载的非常小的组分平展，而不是轴​​向。然而，这种赤道负载可以忽略不计，因为罪θ≈0.1 19。如果此方法适于大透镜，盖玻片到腔室的底部的角将需要被测量以确定赤道负载是否应计入应变计算。其次，它是重要的，以允许透镜到加?...

The lens is a transparent and avascular organ in the anterior chamber of the eye that is responsible for fine focusing of light onto the retina. A clear basement membrane, called the lens capsule, surrounds a bulk of elongated fiber cells covered by an anterior monolayer of epithelial cells1,2. Life-long growth of the lens depends on the continuous proliferation and differentiation of epithelial cells at the lens equator into new fiber cells that are added onto previous generations of fiber cells in a concentric manner2. Over time, lens fiber cells undergo compaction, resulting in a rigid center in the middle of the lens called the nucleus1. Accommodation, defined as a dioptric change in the optical power of the eye, occurs in humans when the ciliary muscles contract to deform the lens and allow a true increase in optical power to focus on near objects3-5. In the unaccommodated eye, the lens is held in a relatively flattened state due to tension from zonular fibers. When the ciliary muscles contract, the tension on the lens is released, leading to decreased lens equatorial diameter and increased axial thickness. Age-related changes in the lens cause presbyopia, a progressive loss of lens accommodation, which leads to the need for reading glasses. 
Several studies have linked presbyopia to age-related increase in the intrinsic stiffness of the lens6-11. Stiffness is defined as the resistance of an elastic object to deform under applied load. A variety of methods have been used to examine stiffness of human lenses, including spin compression12-14, actuator compression15, probe indentation16, dynamic mechanical analysis 6,10 and bubble-based acoustic radiation force17. While mouse lenses do not accommodate or develop presbyopia, mouse models for lens pathologies are valuable tools because mice are less expensive than larger animals, well characterized genetically and undergo accelerated age-related changes due to rapid aging. A handful of studies have examined mouse lens stiffness with compression methods and demonstrated changes in lens stiffness due to aging or targeted genetic disruptions18-21. Thus, mouse lenses are good models for studying age-related changes in lens stiffness. 
This protocol describes a simple and inexpensive, yet precise and reproducible, compression method for determining mouse lens stiffness based on application of glass coverslips onto the lens in conjunction with photographing the lens through a dissection microscope and mirror. This method yields robust strain and morphometric data with an easily fabricated and assembled apparatus. The representative results confirm that mouse lenses increase in stiffness with age.

<table border="0" cellpadding="0" cellspacing="0" width="811">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:361px;">Fine tip straight forceps</td>
			<td style="width:139px;">Fine Scientific Tools</td>
			<td style="width:119px;">11252-40</td>
			<td style="width:193px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Microdissection scissors, straight edge</td>
			<td style="width:139px;">Fine Scientific Tools</td>
			<td style="width:119px;">15000-00</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Curved forceps</td>
			<td style="width:139px;">Fine Scientific Tools</td>
			<td style="width:119px;">11272-40</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Seizing forceps</td>
			<td style="width:139px;">Hammacher</td>
			<td style="width:119px;">HSC 702-93</td>
			<td>Optional</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Dissection dish</td>
			<td style="width:139px;">Fisher Scientific</td>
			<td style="width:119px;">12565154</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">60mm petri dish</td>
			<td style="width:139px;">Fisher Scientific</td>
			<td style="width:119px;">0875713A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">1X phosphate buffered saline (PBS)</td>
			<td style="width:139px;">Life Technologies</td>
			<td style="width:119px;">14190</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">18mm x 18mm glass coverslips</td>
			<td style="width:139px;">Fisher Scientific</td>
			<td style="width:119px;">12-542A</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Measurement chamber with divots to hold lenses</td>
			<td style="width:139px;"></td>
			<td style="width:119px;"></td>
			<td>Custom-made (see Figure 1)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Right-angle mirror</td>
			<td style="width:139px;">Edmund Optics</td>
			<td style="width:119px;">45-591</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Light source</td>
			<td style="width:139px;">Schott/Fostec</td>
			<td style="width:119px;">8375</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Illuminated dissecting microscope</td>
			<td style="width:139px;">Olympus</td>
			<td style="width:119px;">SZX-ILLD100</td>
			<td>With SZ-PT phototube</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Digital camera</td>
			<td style="width:139px;">Nikon</td>
			<td style="width:119px;">Coolpix 990</td>
			<td></td>
		</tr>
	</tbody>
</table>

sequential application of glass coverslips to assess the compressive stiffness of the mouse lens: strain and morphometric analyses

眼透镜是透明的器官，折射和光聚焦，以形成在视网膜上的清晰图像。在人类中，睫状肌收缩变形的透镜，从而增加在透镜“光功率集中于附近的物体，被称为住宿的方法。在镜头的刚度与年龄相关的变化都与老花眼​​，在适应镜头的能力降低，以及由此延伸，需要老花镜。尽管鼠标镜头不适合或开发老花眼，小鼠模型可以为理解镜头病症的宝贵基因工具，并在小鼠中观察到加速老化能够在镜头年龄相关的变化研究。这个协议表明用于确定鼠标透镜刚度，用玻璃盖玻片依次施加压缩负荷增大到透镜的简单，精确和成本效益的方法。有代表性的数据证实，鼠标透镜随着年龄的增长变得更硬，像人类的镜头。这种方法是高度可重复的，并且可以潜在地扩大到从较大的动物机械地测试镜片。

刚度和2-，4-和8个月大的小鼠的镜片的尺寸进行了测量。小鼠从TSRI动物育种设施获得的纯C57BL6菌株背景所有野生型动物，并且每一个透镜装载有1至10个盖玻片。轴向和赤道株计算为通过测量透镜的轴向和赤道直径在加入每个盖玻片的后，再归一直径为相应的卸载每个直径变化的施加载荷的功能。从每个年龄八个透镜进行了测试，结果表示为平均值±标准误差。如图先前...

Watch this Scientific Journal Video about Sequential Application of Glass Coverslips to Assess the Compressive Stiffness of the Mouse Lens: Strain and Morphometric Analyses at JoVE.com

Sequential Application of Glass Coverslips to Assess the Compressive Stiffness of the Mouse Lens: Strain and Morphometric Analyses

盖玻片序贯应用评估鼠标透镜的抗压刚度：应变和形态分析

Age-related increases in eye lens stiffness are linked to presbyopia. This protocol describes a simple, cost-effective method for measuring mouse lens stiffness. Mouse lenses, like human lenses, become stiffer with age. This method is precise and can be adapted for lenses from larger animals.

The eye lens is a transparent organ that refracts and focuses light to form a clear image on the retina. In humans, ciliary muscles contract to deform the ...

The overall goal of this procedure is to evaluate the compressive stiffness and geometry of mouse lenses using a simple and inexpensive approach. This method can answer key questions in the lens field. Such as how different genetic and experimental perturbations affect lens biomechanical properties.The main advantages of this technique are that it is precise, reproducible, and does not require expensive or specialized equipment. This method provides insight into the properties on mouse lenses, with potential application to larger model organisms such as rats and rabbits. Visualization of the method is critical because lens dissection and coverslip application steps are difficult to learn without demonstration.Demonstrating the procedure will be Catherine Cheng, a post doc from my laboratory. Begin the dissection using curved forceps to depress the tissue around the eye of a euthanized mouse bringing the eye out of the socket. Then, remove the eye and place it in a dissection dish containing fresh PBS under a dissecting microscope.Cut off the optic nerve as close to the eyeball as possible. And gently and carefully insert fine, straight tweezers into the eyeball through the hole where the optic nerve exits the posterior of the organ. Carefully make an incision with scissors from the posterior to the edge of the cornea, taking care not to damage the lens.Continue the incision along the junction between the cornea and the sclera, at least halfway around the eyeball. And gently push on the cornea to remove the lens from the eye through the opening. Then, use fine tipped straight forceps to carefully remove any large debris that is still attached to the lens.And visually confirm that the lens is free of damage. At least two hours before starting the stiffness measurements, use an analytical balance to weigh at least 10 cover slips from the same box. Determine the average weight of the cover slips.Then, pre wet the cover slips and a right angle mirror in room temperature PBS. While the materials are being hydrated, fill the measurement chamber with 65 to 75 milliliters of PBS. And place the chamber under a dissecting microscope set to a 30 X magnification, with illumination from the bottom and a fiber optic light source on the left and right sides.When the cover slips are ready, place the right angle mirror into the chamber at a constant distance from the divot that will be used to hold the lens. Next, using curved forceps, carefully transfer the dissected lenses to the measurement chamber. Set the power optic power supply to 80%of the maximum light intensity, and adjust the power supply output based on the ambient lighting, user preference, and picture quality as needed.Obtain top view images of the unloaded lenses from directly overhead of the chamber. Then, take a picture of the mirror edge in focus, followed by a side view image of the unloaded lens through the mirror outside of the divot. Then, place a lens into the divot, and confirm that the lens is seated securely and straight within the divot on it's anterior or posterior pole.Take a photo of the lens in the mirror. Then, gently place a cover slip onto the lens. After two minutes, take another side view image of the loaded lens.Continue adding cover slips, obtaining side view images two minutes after the addition of each cover slip, until the total of 10 cover slips have been applied. Then, remove all of the cover slips, wait a final two minutes, and obtain side view images of the lens inside and outside of the divot. And a top view image of the lens outside the divot.To determine the lens nucleus size, place a lens into a clean petri dish filled with PBS and use fine, straight forceps to gently decapsulate the lens. To off the cortical fiber cells, roll the lens between gloved fingers. Next, gently rinse the lens nucleus in the PBS and place the nucleus back into the measurement chamber.Acquire an image of the lens nucleus through the right angle mirror. Finally, to analyze the images, use the appropriate image analysis software to measure the equatorial and axial diameters of the lenses before and after each loading step. Measure the diameter of each lens nucleus as well.In this representative experiment, the stiffness and dimensions of two, four, and eight month old mouse lenses were measured and the axial and equatorial strains were calculated. The axial strain is a logarithmic function of applied load with a statistically significant, age dependent decrease in the axial and equatorial strains under the maximum applied load, indicating that the mouse lens stiffens with age. The image data collected during this experiment were also used to determine several other lens morphological characteristics.As expected, the axial and equatorial diameters, and the lens volume, increased with age. The aspect ratio indicates that the lens has a slightly larger equatorial diameter than axial diameter. And this parameter did not change with age.The diameter, volume, and fraction of the lens nucleus increase with age, suggesting that the lens nucleus remodels to increase in relative size as the lens ages. Once mastered, this technique can be completed in 30 to 45 minutes per lens, if performed properly. While attempting this procedure, it's important to position the lens evenly inside the divot, and to allow the lens to stress relax for two minutes between each additional cover slip.After watching this video, you should have a good understanding of how to assess the compressive stiffness, and morphometrics of mouse lenses using the sequential application of cover slips. This precise, simple, and inexpensive technique paves the way for lens researchers to explore the biomechanical effects of gene mutations in mice.

Research

JoVE Journal

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在斑马鱼和镜头移植在眼突变分析中的应用

The lens plays an important role in the development of the optic cup[1,2]. Using the zebrafish as a model organism, questions regarding lens development ...

科研

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纯化 M。 magneticum应变AMB - 1磁小体相关蛋白MamAΔ41

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眼内容剜除小鼠玻璃体和视网膜蛋白质组分析

While the mouse retina has emerged as an important genetic model for inherited retinal disease, the mouse vitreous remains to be explored. The vitreous is ...

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生物物理检测探头相间细胞核的力学性能：基材应变的应用和微针操纵

In most eukaryotic cells, the nucleus is the largest organelle and is typically 2 to 10 times stiffer than the surrounding cytoskeleton; consequently, the ...

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诱导多能干细胞来源于小鼠的生成

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also ...

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测量的刚度<em&gt;离体</em&gt;鼠标主动脉用原子力显微镜

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a ...

A Morphometric and Cellular Analysis Method for the Murine Mandibular Condyle

小鼠下颌骨髁突的形态学及细胞分析方法

The temporomandibular joint (TMJ) has the capacity to adapt to external stimuli, and loading changes can affect the position of condyles, as well as the ...

A Simple Method for Isolation of Soybean Protoplasts and Application to Transient Gene Expression Analyses

大豆原生质体分离的简易方法及其在瞬态基因表达分析中的应用

Soybean (Glycine max (L.) Merr.) is an important crop species and has become a legume model for the studies of genetic and biochemical pathways. ...

Measurement of Liver Stiffness Using Atomic Force Microscopy Coupled with Polarization Microscopy

使用原子力显微镜结合偏振显微镜测量肝硬度

Matrix stiffening has been recognized as one of the key drivers of the progression of liver fibrosis. It has profound effects on various aspects of cell ...