Plazmid Vinculin-GFP Michael Davidson, Florida Eyalet Üniversitesi, Tallahassee, Florida&#39;daki bir hediye plazmid Ulusal Sağlık Enstitüleri, Ulusal Diş ve Kraniofasial Araştırma Enstitüsü, Bethesda, Maryland ve aktin-MRFP Kenneth Yamada bir hediye oldu. Bu çalışma, NSF Kariyer Ödülü # 0747334 ve AHA-Milli SDG # 0835205N Andreea Trache tarafından desteklenen oldu.

1. Entegre Mikroskop Sistemi Genel Bakış Bu çalışmalar için kullanılan mikroskop sistemi 1 ayrıntılı tarif edilmiştir. Kısaca, TIRF eki (Olympus, Center Valley, PA) ile ters bir Olympus IX-81 mikroskop ile birlikte CSU-22 Yokogawa tarama kafası (Yokogawa Elektrik A.Ş., Japonya). Bioscope SZ atomik kuvvet mikroskobu (Veeco Instruments Inc, Santa Barbara, CA), optik ters mikroskop üstüne monte edilir ve tüm sistemi bir araştırma notu optik tablonun üst (Newport, Irvine, CA) üzerine yerleştirilir. Konfokal montaj dönen disk tarayıcı, dış filtre çarkı ve EMCCD kamera (Roper Bilimsel Photometrics, Tucson, AZ) oluşan katı titreşim sönümleme için gerekli bir silikon pad üzerine yerleştirilen alüminyum taban plakası ile bağlantılıdır. Konfokal tarayıcı oluklu bir yaka ile AFM ölçümleri sırasında mikroskop ayrılabilir bir flanş ile mikroskop ile bağlanır dönen disk tarayıcı hiçbir titreşim AFM ölçümleri etkileyecektir. Bir Argon-Kripton lazer (Spectra Fizik, Mountain View, CA), sırasıyla TIRF ve konfokal görüntüleme modları için uyarma kaynağı olarak kullanılır ve alternatif TIRF eki veya tarama kafası lazer sağlayan iki optik fiberler akuple edilebilir . İki bilgisayar sisteminin kontrolü: Slidebook yazılımı optik görüntüleme kontrolleri ve NanoScope yazılım AFM kontrol. 2. Hücre Kültürü Canlı hücreler, belirli proteinlere karşı hedeflenen GFP yapıları ifade mekanik stimülasyonu deneyi 24 saat önce bir bardak alt hücre kültürü çanak konulmalıdır. Deney günü, fenol red-free orta ile hücre kültür ortamı değiştirin. Hücre kültürü çanak manyetik bir yaka ile AFM sahne üzerine monte edilmiştir. 3. AFM İpucu hazırlanması ve Mikroskop Set-up 2 mikron ile özelleştirilmiş AFM ucu, cam boncuk DPBS beş kez yıkanmış ve daha sonra 5 dakika avidin (1 mg / ml) ile inkübe, DPBS beş kez tekrar yıkanır ve daha sonra 1 mg / ml biotinilated ile 5 dakika inkübe olacak biotinilated fibronektin. Sonunda 2 ucu, beş kez daha yıkanarak AFM tarayıcı üzerine monte edilmiş ve daha sonra koruyucu silikon etek sahibinin etrafında alınacaktır olacak. Görüş alanının merkezinde AFM ucu hizalamak için video görüntüleme için mikroskop ayarlayın. Konsolun en sonunda lazer ışını koyarak optik kolu hizalayın ve sonra tek hücre görüntüleme için uygun bir yüksek büyütme amacı hedefi değiştirmek. Ucu sürekli bahar, deney başlamadan önce belirlenmelidir. Bu parametre NanoScope yazılım mevcuttur termal ayar yöntemi kullanılarak ölçülür. Floresans görüntüleme için izin EMCCD kamera, video kamera geçin. Sonra, bir hücre seçin ve bu belirli bir hücre ile temas AFM ucu getirmek. Hücre yüzeyi ile temas AFM noktada oluşturmak için güçlü bir odak yapışma için gerekli 20 dakika bekleme süresinden sonra, mekanik stimülasyonu prosedürü başlayacak. 4. Canlı Hücre Mekanik Uyarım 3-4 TIRF görüntüleme odak yapışıklıklar görselleştirilmesi ve ölçülmesi için tercih edilen bir yöntem olacak, ve dönen disk konfokal görüntüleme 5 hücre gövdesi boyunca aktin hücre iskeletinin görselleştirmek için kullanılacaktır. AFM 6 sıvı temas modunda görüntüleme kullanılır. Hücre TIRF veya konfokal görüntü mekanik stimülasyonu işlemine başlamadan önce alınacaktır. (1-1,5 saat) bir süre içinde her 3-5 dakikada bir ayrık adımlarla yukarı doğru hareket olacaktır Fonksiyonlu AFM prob mekanik stimülasyonu ile indüklenen olacaktır. Hücre reaktif-yanıt yüksekliği görüntü, görüntü temsil eden 1 sn bir birim zamanda her satırı bir dizi olarak NanoScope yazılım sürekli olarak kaydedilecektir. AFM veri elde edilirken, operatör sonraki çekme için uygun zamanlama her zaman AFM ucu z-pozisyon belirlemek için izler. Her mekanik stimülasyonu sonra sürekli AFM veriler elde edilirken, Slidebook yazılımı hücre TIRF veya konfokal görüntü elde etmek mümkündür. Aktin hücre iskeleti ve odak yapışıklıklar yeniden yapılanma gösteren filmler optik görüntü oluşturmak için off-line işlenebilir. Ayrıca, her görüntü hücre alanı, spesifik protein alanı belirlemek ve genel hücre morfolojisi analiz etmek için kantitatif olarak işlenmiş olabilir. Deneyin sonunda AFM ucu hücre ve AFM ucunun hassasiyeti çekilen NanoScope yazılım ölçülecektir. Deney çok gürültüye duyarlı! Eski sırasında dokunmadan herhangi bir konuşmaya ya da mikroskopdeneyimlemek önemlidir kaçınılmalıdır. AFM ölçümlerde gürültü en aza indirmek için, dönen disk konfokal mikroskop de çiftli olmalıdır. Hücre yüzeyi ve AFM ucu arasında güçlü bir fokal adezyon oluşturmak için bekleme süresi, kullanılan hücre tipi ve ucunda matris kaplamalı bağlı olarak değişebilir. 5. Temsilcisi Sonuçlar <img src="/files/ftp_upload/2072/2072fig1.jpg" alt="Şekil 1" /> Şekil 1. Aktin-MRFP ve vinculin-GFP ile transfekte aynı damar düz kas hücre (VSMC) tarafından görüntülenmiş oldu: (A) apikal hücre yüzeyinde AFM, (B) bazal hücre yüzeyinde TIRF; ve (C) iplik disk konfokal mikroskopi hücre gövdesi boyunca konfokal görüntü 3-D bir yığın maksimum projeksiyon olarak gösterilmiştir . AFM ve TIRF veya dönen disk konfokal görüntüler arasında iyi örtüşür, (D) ve (E), sırasıyla gösterilmiştir . Görüntü boyutu 64 x 50 mikron. <img src="/files/ftp_upload/2072/2072fig2.jpg" alt="Şekil 2" /> Şekil 2. Bir vasküler düz kas aktin-MRFP ile transfekte mekanik AFM tarafından uyarılan ve iplik disk konfokal mikroskopi tarafından görüntülendi oklar aktin liflerinin gösterir: (a) kalınlaşmasına / Polimerize, (b) depolymerize / kaybolurken, veya (c) nedeniyle bir araya toplamak aktin yeniden yapılanma. Beyaz kesik çizgiler hücrenin üstündeki AFM ucu temsil eder. Görüntü boyutu 91 x 91 mikron.

<ol>
	<li>Trache, A., Lim, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Integrated+microscopy+for+real-time+imaging+of+mechanotransduction+studies+in+live+cells.">Integrated microscopy for real-time imaging of mechanotransduction studies in live cells.</a> J Biomed Opt. 14, 034024-03 (2009).</li><li>Trache, A., Meininger, G. A., Coico, R., Kowalik, T., Quarles, J. M., Stevenson, B., Taylor, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atomic+Force+Microscopy.">Atomic Force Microscopy.</a> Current Protocols in Microbiology. , 2.1-2.17 (2008).</li><li>Axelrod, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+imaging+of+surface+fluorescence+with+very+high+aperture+microscope+objectives.">Selective imaging of surface fluorescence with very high aperture microscope objectives.</a> J Biomed Opt. 6, 6-13 (2001).</li><li>Trache, A., Meininger, G. A., Coico, R., Kowalik, T., Quarles, J. M., Stevenson, B., Taylor, R. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Total+Internal+Reflection+Fluorescence+Microscopy.">Total Internal Reflection Fluorescence Microscopy.</a> Current Protocols in Microbiology. , 2.1-2.22 (2008).</li><li>Inoue, S., Inoue, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct-view+high-speed+confocal+scanner:+the+CSU-10.">Direct-view high-speed confocal scanner: the CSU-10.</a> Methods Cell Biol. 70, 87-127 (2002).</li><li>Binnig, G., Quate, C. F., Gerber, C. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Atomic+force+microscope.">Atomic force microscope.</a> Phys Rev Lett. 56, 930-933 (1986).</li><li>Stamenovi&#263;, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytoskeletal+mechanics+in+airway+smooth+muscle+cells.">Cytoskeletal mechanics in airway smooth muscle cells.</a> Respir Physiol Neurobiol. 163, 25-32 (2008).</li><li>Gunst, S. J., Tang, D. D., Opazo Saez, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytoskeletal+remodeling+of+the+airway+smooth+muscle+cell:+a+mechanism+for+adaptation+to+mechanical+forces+in+the+lung.">Cytoskeletal remodeling of the airway smooth muscle cell: a mechanism for adaptation to mechanical forces in the lung.</a> Respir Physiol Neurobiol. 137, 151-168 (2003).</li><li>Worth, N. F., Rolfe, B. E., Song, J., Campbell, G. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vascular+smooth+muscle+cell+phenotypic+modulation+in+culture+is+associated+with+reorganization+of+contractile+and+cytoskeletal+proteins.">Vascular smooth muscle cell phenotypic modulation in culture is associated with reorganization of contractile and cytoskeletal proteins.</a> Cell Motility and the Cytoskeleton. 49, 130-145 (2001).</li><li>Romer, H. R., Birukov, K. G., Garcia, J. G. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focal+Adhesions:+paradigm+for+a+signaling+nexus.">Focal Adhesions: paradigm for a signaling nexus.</a> Circulation Research. 98, 606-616 (2006).</li><li>Opazo Saez, A., Zhang, W., Wu, Y., Turner, C. E., Tang, D. D., Gunst, 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=Tension+development+during+contractile+stimulation+of+smooth+muscle+requires+recruitment+of+paxillin+and+vinculin+to+the+membrane.">Tension development during contractile stimulation of smooth muscle requires recruitment of paxillin and vinculin to the membrane.</a> Am J Physiol Cell Physiol. 286, C433-C447 (2004).</li><li>Alenghat, F. J., Ingber, D. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanotransduction:+all+signals+point+to+cytoskeleton,+matrix+and+integrins.">Mechanotransduction: all signals point to cytoskeleton, matrix and integrins.</a> Sciences STKE. 119, pe6-pe6 (2002).</li><li>Zamir, E., Geiger, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molecular+complexity+and+dynamics+of+cell-matrix+adhesions.">Molecular complexity and dynamics of cell-matrix adhesions.</a> J Cell Sci. 114, 3583-3590 (2001).</li><li>Geiger, B., Bershdsky, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assembly+and+mechanosensory+function+of+focal+contacts.">Assembly and mechanosensory function of focal contacts.</a> Curr Opin Cell Biol. 13, 584-592 (2001).</li><li>Sastry, S. K., Burridge, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Focal+Adhesions:+a+nexus+for+intracellular+signaling+and+cytoskeletal+dynamics.">Focal Adhesions: a nexus for intracellular signaling and cytoskeletal dynamics.</a> Exp Cell Res. 261, 25-36 (2000).</li><li>Orr, A. W., Helmke, B. P., Blackman, B. R., Schwartz, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanisms+of+mechanotransduction.">Mechanisms of mechanotransduction.</a> Dev Cell. 10, 11-20 (2006).</li></ol>

Sitoiskelet 7-10 ve odak yapışıklıklar 11-16, montajı, dağıtmak ve hücreleri göç veya mekanik güç, 17 cevap olarak teslim dinamik yapılardır . Hücre büyümesi, hayatta kalma ve gen ekspresyonu düzenlenmesinde önemli işlevleri var. Kendi özel dağıtım ve dinamikleri bilmek hücreleri matrisi ve kendi aralarında nasıl iletişim daha iyi anlaşılmasını sağlar. Bu yeni mikroskop sistemi yapışık herhangi bir canlı hücreler molekül...

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">	
		
		<div>
		<table border="1">
		<thead>
		<tr>
		<th>Material Name</th>
		<th>Type</th>
		<th>Company</th>
		<th>Catalogue Number</th>
		<th>Comment</th>
		</tr>
		</thead>
		<tbody>
		
<tr>
<td>AFM tip</td>
<td>&nbsp;</td>
<td>Novascan Technologies</td>
<td>&nbsp;</td>
<td>2 micron Borosilicate bead, 0.01N/m, Biotin Surface</td>
</tr>
<tr>
<td>avidin</td>
<td>&nbsp;</td>
<td>Sigma Aldrich</td>
<td>A9275</td>
<td>1mg/mL in DPBS</td>
</tr>
<tr>
<td>Fibronectin</td>
<td>&nbsp;</td>
<td>Sigma Aldrich</td>
<td>F4759</td>
<td>1 mg/mL</td>
</tr>
<tr>
<td>DPBS</td>
<td>&nbsp;</td>
<td>Invitrogen</td>
<td>21600-051</td>
<td>&nbsp;</td>
<tr>
<td>Amaxa transfection kit for Smooth Muscle Cells</td>
<td>&nbsp;</td>
<td>Lonza</td>
<td>VPI-1004</td>
<td>&nbsp;</td>
<tr>
<td>Mattek glass bottom dishes</td>
<td>&nbsp;</td>
<td>MatTek Corporation</td>
<td>P60G-1.5-30-F</td>
<td>Sterile 60mm Falcon dishes with glass bottom coverslip no. 1.5</td>
</tr>		</tbody>
		</table>
		</div>

live cell response to mechanical stimulation studied by integrated optical and atomic force microscopy

Canlı hücreler mekanik kuvvetlerin anlamda mekanizmasını anlamak ve alt hücresel düzeyde yüksek mekansal ve zamansal çözünürlüğe sahip hücrelerin davranışını araştırmak için tepki ve çevreleriyle uyum nasıl yeni bir teknoloji geliştirildi. Böylece, bir atomik kuvvet mikroskobu (AFM), toplam iç yansıma floresan (TIRF) mikroskopi ve hızlı dönen disk (FSD) konfokal mikroskobu ile entegre edildi. Entegre bir sistem, gerçek zamanlı mekanik uyarılması hücre yanıtları doğrudan optik görüntüleme sağlayan geniş yapışık herhangi bir canlı hücreler moleküler dinamik çalışmaların geniş bir aralığında uygulanabilir. Aktin filamentler ve odak yapışıklıklar önemli düzenlenmesi nedeniyle apikal hücre yüzeyinde hücre gövdesi boyunca hücresel yapıya değişikliklerin neden olduğu yerel mekanik stimülasyonu gösterildi. Bu yenilikçi teknikler, mekanik güç, cevap canlı hücre yeniden yapılanma ve dinamikleri anlamak için yeni bilgiler sağlayacaktır. Ayrıntılı bir protokol ve temsil eden bir veri mekanik stimülasyonu göstermek için canlı hücre yanıtı verildikleri ayarlayın.

Watch this Scientific Journal Video about Live Cell Response to Mechanical Stimulation Studied by Integrated Optical and Atomic Force Microscopy at JoVE.com

Live Cell Response to Mechanical Stimulation Studied by Integrated Optical and Atomic Force Microscopy

Bu kağıt kültürü canlı hücreleri mekanik uyarılması için entegre bir atom operasyon okuyucu kuvvet optik görüntüleme mikroskop öğretmeyi hedefliyor. Bir adım-adım protokol sunulmuştur. Mekanik stimülasyonu canlı hücre yanıtı gösteren bir temsilci veri seti sunulmaktadır.

Tümleşik Optik ve Atomik Kuvvet Mikroskobu eğitimi Mekanik Uyarım Canlı Hücre Tepki

To understand the mechanism by which living cells sense mechanical forces, and how they respond and adapt to their environment, a new technology able to ...

live-cell-response-to-mechanical-stimulation-studied-integrated

Research

JoVE Journal

Biology

11.2K Görüntüleme.  Texas A&M Health Science Center. Bu kağıt kültürü canlı hücreleri mekanik uyarılması için entegre bir atom operasyon okuyucu kuvvet optik görüntüleme mikroskop öğretmeyi hedefliyor. Bir adım-adım protokol sunulmuştur. Mekanik stimülasyonu canlı hücre yanıtı gösteren bir temsilci veri seti sunulmaktadır.

Video: Live Cell Response to Mechanical Stimulation Studied by Integrated Optical and Atomic Force Microscopy

Phase Contrast and Differential Interference Contrast (DIC) Microscopy

Phase-contrast microscopy is often used to produce contrast for transparent, non light-absorbing, biological specimens. The technique was discovered by Zernike, in 1942, who received the Nobel prize for his achievement. DIC microscopy, introduced in the late 1960s, has been popular in biomedical research because it highlights edges of specimen structural detail, provides high-resolution optical sections of thick specimens including tissue cells, eggs, and embryos and does not suffer from the  phase halos  typical of phase-contrast images. This protocol highlights the principles and practical applications of these microscopy techniques.

Phase Contrast and Differential Interference Contrast DIC Microscopy

This protocol highlights the principles and practical applications of Phase and Differential Interference Contrast (DIC) Microscopy

Faz Kontrast ve Diferansiyel Girişim Kontrast (DIC) Mikroskopi

Phase-contrast microscopy is often used to produce contrast for transparent, non light-absorbing, biological specimens. The technique was discovered by ...

Biyoloji

Presynaptically Silent Synapses Studied with Light Microscopy

Synaptic plasticity likely underlies the nervous system's ability to learn and remember and may also represent an adaptability that prevents otherwise damaging insults from becoming neurotoxic.  We have been studying a form of presynaptic plasticity that is interesting in part because it is expressed as a digital switching on and off of a presynaptic terminal s ability to release vesicles containing the neurotransmitter glutamate.  Here we demonstrate a protocol for visualizing the activity status of presynaptic terminals in dissociated cell cultures prepared from the rodent hippocampus.  The method relies on detecting active synapses using staining with a fixable form of the styryl dye FM1-43, commonly used to label synaptic vesicles.  This staining profile is compared with immunostaining of the same terminals with an antibody directed against the vesicular glutamate transporter 1 (vGluT-1), a stain designed to label all glutamate synapses regardless of activation status.   We find that depolarizing stimuli induce presynaptic silencing.  The population of synapses that is silent under baseline conditions can be activated by prolonged electrical silencing or by activation of cAMP signaling pathways.

Glutamatergic synapses can switch from an active mode to a silent mode. We demonstrate that presynaptic activity status in dissociated culture of rodent neurons is visualized using a fixable form of the FM1-43 dye to visualize active synapses and immunostaining with vGluT-1 antibody to visualize all glutamate synapses.

Işık Mikroskop ile İncelenen Presynaptically Sessiz Sinapslar

Synaptic plasticity likely underlies the nervous system's ability to learn and remember and may also represent an adaptability that prevents otherwise ...

Micro-Mechanical Characterization of Lung Tissue Using Atomic Force Microscopy

Matrix stiffness strongly influences growth, differentiation and function of adherent cells1-3. On the macro scale the stiffness of tissues and organs within the human body span several orders of magnitude4. Much less is known about how stiffness varies spatially within tissues, and what the scope and spatial scale of stiffness changes are in disease processes that result in tissue remodeling. To better understand how changes in matrix stiffness contribute to cellular physiology in health and disease, measurements of tissue stiffness obtained at a spatial scale relevant to resident cells are needed. This is particularly true for the lung, a highly compliant and elastic tissue in which matrix remodeling is a prominent feature in diseases such as asthma, emphysema, hypertension and fibrosis. To characterize the local mechanical environment of lung parenchyma at a spatial scale relevant to resident cells, we have developed methods to directly measure the local elastic properties of fresh murine lung tissue using atomic force microscopy (AFM) microindentation. With appropriate choice of AFM indentor, cantilever, and indentation depth, these methods allow measurements of local tissue shear modulus in parallel with phase contrast and fluorescence imaging of the region of interest. Systematic sampling of tissue strips provides maps of tissue mechanical properties that reveal local spatial variations in shear modulus. Correlations between mechanical properties and underlying anatomical and pathological features illustrate how stiffness varies with matrix deposition in fibrosis. These methods can be extended to other soft tissues and disease processes to reveal how local tissue mechanical properties vary across space and disease progression.

The stiffness of the extracellular matrix strongly influences multiple behaviors of adherent cells. Matrix stiffness varies spatially throughout a tissue, and undergoes modification in various disease conditions. Here we develop methods to characterize spatial variations in stiffness in normal and fibrotic mouse lung tissue using atomic force microscopy microindentation.

Atomik Kuvvet Mikroskobu kullanarak Akciğer Doku Mikro-Mekanik Karakterizasyonu

Matrix stiffness strongly influences growth, differentiation and function of adherent cells1-3.  On the macro scale the stiffness of tissues and organs ...

Sample Preparation for Single Virion Atomic Force Microscopy and Super-resolution Fluorescence Imaging

Immobilization of virions to glass surfaces is a critical step in single virion imaging. Here we present a technique&#160;adopted from single molecule imaging assays which allows adhesion of single virions to glass surfaces with specificity. This preparation is based on grafting the surface of the glass with a mixture of PLL-g-PEG and PLL-g-PEG-Biotin, adding a layer of avidin, and finally creating virion anchors through attachment of biotinylated virus specific antibodies. We have applied this technique across a range of experiments including atomic force microscopy (AFM) and super-resolution fluorescence imaging. This sample preparation method results in a control adhesion of the virions to the surface.

The attachment of virions to a surface is a requirement for single virion imaging by Super-resolution fluorescence imaging or atomic force microscopy (AFM). Here we demonstrate a sample preparation method for controlled adhesion of virions to glass surfaces suitable for use in AFM and super-resolution fluorescence imaging.

Tek Virion Atomik Kuvvet Mikroskopisi ve Süper Çözünürlüklü Floresan Görüntüleme için Numune Hazırlama

Immobilization of virions to glass surfaces is a critical step in single virion imaging. Here we present a technique&#160;adopted from single molecule ...

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

Arterial stiffening is a significant risk factor and biomarker for cardiovascular disease and a hallmark of aging. Atomic force microscopy (AFM) is a versatile analytical tool for characterizing viscoelastic mechanical properties for a variety of materials ranging from hard (plastic, glass, metal, etc.) surfaces to cells on any substrate. It has been widely used to measure the stiffness of cells, but less frequently used to measure the stiffness of aortas. In this paper, we will describe the procedures for using AFM in contact mode to measure the ex vivo elastic modulus of unloaded mouse arteries. We describe our procedure for isolation of mouse aortas, and then provide detailed information for the AFM analysis. This includes step-by-step instructions for alignment of the laser beam, calibration of the spring constant and deflection sensitivity of the AFM probe, and acquisition of force curves. We also provide a detailed protocol for data analysis of the force curves.

Measuring the Stiffness of Ex Vivo Mouse Aortas Using Atomic Force Microscopy

We present detailed protocols for isolation of aortas from mouse and measurement of their elastic modulus using atomic force microscopy.

sertliği ölçme<em&gt; Ex Vivo</emAtomik Kuvvet Mikroskobu Kullanma&gt; Fare aorta

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

Analyzing Cell Surface Adhesion Remodeling in Response to Mechanical Tension Using Magnetic Beads

Mechanosensitive cell surface adhesion complexes allow cells to sense the mechanical properties of their surroundings. Recent studies have identified both force-sensing molecules at adhesion sites, and force-dependent transcription factors that regulate lineage-specific gene expression and drive phenotypic outputs. However, the signaling networks converting mechanical tension into biochemical pathways have remained elusive. To explore the signaling pathways engaged upon mechanical tension applied to cell surface receptor, superparamagnetic microbeads can be used. Here we present a protocol for using magnetic beads to apply forces to cell surface adhesion proteins. Using this approach, it is possible to investigate not only force-dependent cytoplasmic signaling pathways by various biochemical approaches, but also adhesion remodeling by magnetic isolation of adhesion complexes attached to the ligand-coated beads. This protocol includes the preparation of ligand-coated superparamagnetic beads, and the application of define tensile forces followed by biochemical analyses. Additionally, we provide a representative sample of data demonstrating that tension applied to integrin-based adhesion triggers adhesion remodeling and alters protein tyrosine phosphorylation.

Cell surface adhesions are central in mechanotransduction, as they transmit mechanical tension and initiate the signaling pathways involved in tissue homeostasis and development. Here, we present a protocol for dissecting the biochemical pathways that are activated in response to tension, using ligand-coated magnetic microbeads and force application to adhesion receptors.

Manyetik Boncuk Kullanarak Mekanik Gerilim Cevabı Hücre Yüzey Yapışma Modelleme Analizi

Mechanosensitive cell surface adhesion complexes allow cells to sense the mechanical properties of their surroundings. Recent studies have identified both ...

Glucose Uptake Measurement and Response to Insulin Stimulation in In Vitro Cultured Human Primary Myotubes

Skeletal muscle is the largest glucose deposit in mammals and largely contributes to glucose homeostasis. Assessment of insulin sensitivity of muscle cells is of major relevance for all studies dedicated to exploring muscle glucose metabolism and characterizing metabolic alterations. In muscle cells, glucose transporter type 4 (GLUT4) proteins translocate to the plasma membrane in response to insulin, thus allowing massive entry of glucose into the cell. The ability of muscle cells to respond to insulin by increasing the rate of glucose uptake is one of the standard readouts to quantify muscle cell sensitivity to insulin. Human primary myotubes are a suitable in vitro model, as the cells maintain many features of the donor phenotype, including insulin sensitivity. This in vitro model is also suitable for the test of any compounds that could impact insulin responsiveness. Measurements of the glucose uptake rate in differentiated myotubes reflect insulin sensitivity.
In this method, human primary muscle cells are cultured in vitro to obtain differentiated myotubes, and glucose uptake rates with and without insulin stimulation are measured. We provide a detailed protocol to quantify passive and active glucose transport rates using radiolabeled [3H] 2-deoxy-D-Glucose ([3H]2dG). Calculation methods are provided to quantify active basal and insulin-stimulated rates, as well as stimulation fold.

Glucose Uptake Measurement and Response to Insulin Stimulation in In Vitro Cultured Human Primary Myotubes

In this method, human primary muscle cells are cultured in vitro to obtain differentiated myotubes and glucose uptake rates are measured. We provide a detailed protocol to quantify rates in basal and insulin-stimulated states using radiolabeled [3H] 2-deoxy-D-Glucose.

Glikoz Alımı Ölçümü ve İnsülin Uyarıcısına Yanıt<em&gt; In vitro</em&gt; Kültürlü İnsan Primer Miyotları

Skeletal muscle is the largest glucose deposit in mammals and largely contributes to glucose homeostasis. Assessment of insulin sensitivity of muscle ...

Assessment of Dictyostelium discoideum Response to Acute Mechanical Stimulation

Chemotaxis, or migration up a gradient of a chemoattractant, is the best understood mode of directed migration. Studies using social amoeba Dictyostelium discoideum revealed that a complex signal transduction network of parallel pathways amplifies the response to chemoattractants, and leads to biased actin polymerization and protrusion of a pseudopod in the direction of a gradient. In contrast, molecular mechanisms driving other types of directed migration, for example, due to exposure to shear flow or electric fields, are not known. Many regulators of chemotaxis exhibit localization at the leading or lagging edge of a migrating cell, as well as show transient changes in localization or activation following global stimulation with a chemoattractant. To understand the molecular mechanisms of other types of directed migration we developed a method that allows examination of cellular response to acute mechanical stimulation based on brief (2 - 5 s) exposure to shear flow. This stimulation can be delivered in a channel while imaging cells expressing fluorescently-labeled biosensors to examine individual cell behavior. Additionally, cell population can be stimulated in a plate, lysed, and immunoblotted using antibodies that recognize active versions of proteins of interest. By combining both assays, one can examine a wide array of molecules activated by changes in subcellular localization and/or phosphorylation. Using this method we determined that acute mechanical stimulation triggers activation of the chemotactic signal transduction and actin cytoskeleton networks. The ability to examine cellular responses to acute mechanical stimulation is important for understanding the initiating events necessary for shear flow-induced motility. This approach also provides a tool for studying the chemotactic signal transduction network without the confounding influence of the chemoattractant receptor.

Assessment of Dictyostelium discoideum Response to Acute Mechanical Stimulation

Here we describe methods for assessing cellular response to acute mechanical stimulation. In the microscopy-based assay, we examine localization of fluorescently-labeled biosensors following brief stimulation with shear flow. We also test activation of various proteins of interest in response to acute mechanical stimulation biochemically.

Dictyostelium discoideum yanıt-e doğru akut mekanik stimülasyon değerlendirilmesi

Chemotaxis, or migration up a gradient of a chemoattractant, is the best understood mode of directed migration. Studies using social amoeba Dictyostelium ...

Protrusion Force Microscopy: A Method to Quantify Forces Developed by Cell Protrusions

In numerous biological contexts, animal cells need to interact physically with their environment by developing mechanical forces. Among these, traction forces have been well-characterized, but there is a lack of techniques allowing the measurement of the protrusion forces exerted by cells orthogonally to their substrate. We designed an experimental setup to measure the protrusion forces exerted by adherent cells on their substrate. Cells plated on a compliant Formvar sheet deform this substrate and the resulting topography is mapped by atomic force microscopy (AFM) at the nanometer scale. Force values are then extracted from an analysis of the deformation profile based on the geometry of the protrusive cellular structures. Hence, the forces exerted by the individual protruding units of a living cell can be measured over time. This technique will enable the study of force generation and its regulation in the many cellular processes involving protrusion. Here, we describe its application to measure the protrusive forces generated by podosomes formed by human macrophages.

Here, we detail the experimental techniques used to evaluate the protrusion forces that podosomes apply on a compliant film, from the preparation of the film to the automated analysis of topographical images.

Çıkıntı kuvvet mikroskobu: Hücre çıkıntılar tarafından geliştirilen kuvvetleri ölçmek için bir yöntem

In numerous biological contexts, animal cells need to interact physically with their environment by developing mechanical forces. Among these, traction ...

Characterizing Mechanical Properties of Primary Cell Wall in Living Plant Organs Using Atomic Force Microscopy

The mechanical properties of the primary cell walls determine the direction and rate of plant cell growth and, therefore, the future size and shape of the plant. Many sophisticated techniques have been developed to measure these properties; however, atomic force microscopy (AFM) remains the most convenient for studying cell wall elasticity at the cellular level. One of the most important limitations of this technique has been that only superficial or isolated living cells can be studied. Here, the use of atomic force microscopy to investigate the mechanical properties of primary cell walls belonging to the internal tissues of a plant body is presented. This protocol describes measurements of the apparent Young&#39;s modulus of cell walls in roots, but the method can also be applied to other plant organs. The measurements are performed on vibratome-derived sections of plant material in a liquid cell, which allows (i) avoiding the use of plasmolyzing solutions or sample impregnation with wax or resin, (ii) making the experiments fast, and (iii) preventing dehydration of the sample. Both anticlinal and periclinal cell walls can be studied, depending on how the specimen was sectioned. Differences in the mechanical properties of different tissues can be investigated in a single section. The protocol describes the principles of study planning, issues with specimen preparation and measurements, as well as the method of selecting force-deformation curves to avoid the influence of topography on the obtained values of elastic modulus. The method is not limited by sample size but is sensitive to cell size (i.e., cells with a large lumen are difficult to examine).

Studies of cell wall biomechanics are essential for understanding plant growth and morphogenesis. The following protocol is proposed to investigate thin primary cell walls in the internal tissues of young plant organs using atomic force microscopy.

Canlı Bitki Organlarında Primer Hücre Duvarının Mekanik Özelliklerinin Atomik Kuvvet Mikroskobu Kullanılarak Karakterize Edilmesi

The mechanical properties of the primary cell walls determine the direction and rate of plant cell growth and, therefore, the future size and shape of the ...