Name: three-dimensional reconstruction of the vascular architecture of the passive clarity-cleared mouse ovary
Uploaded: 2017-12-10T14:00:00
Description: Watch this Scientific Journal Video about Three-dimensional Reconstruction of the Vascular Architecture of the Passive CLARITY-cleared Mouse Ovary at JoVE.com

This study was supported by grants from the Chinese Special Fund for Postdocs (No. 2014T70392 to YF), the National Natural Science Foundation of China (No. 81673766 to YF), the New Teacher Priming Fund, the Zuoxue Foundation of Fudan University, and the Development Project of Shanghai Peak Disciplines-Integrative Medicine (20150407).

All procedures involving animal subjects followed the guidelines of the Animal Ethics Committee at Shanghai Medical College, Fudan University (Approval number 20160225-013).
1. Preparation of the Transparent Mouse Ovary
<ol>
	<li>Preparation of the solutions
	<ol>
		<li>Prepare phosphate-buffered saline (PBS) solution (1 M, pH 7.6) with 0.1% Triton X-100 (PBST). To make 1 L of 10x PBS stock solution, mix 87 g of NaCl, 3.1 g of NaH2PO4 &#183; 2H2</s...

<ol>
	<li>Brown, H. M., Russell, D. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+and+lymphatic+vasculature+in+the+ovary:+development,+function+and+disease.">Blood and lymphatic vasculature in the ovary: development, function and disease.</a> Hum Reprod Update. 20 (1), 29-39 (2014).</li><li>McFee, R. M., 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=Inhibition+of+vascular+endothelial+growth+factor+receptor+signal+transduction+blocks+follicle+progression+but+does+not+necessarily+disrupt+vascular+development+in+perinatal+rat+ovaries.">Inhibition of vascular endothelial growth factor receptor signal transduction blocks follicle progression but does not necessarily disrupt vascular development in perinatal rat ovaries.</a> Biol Reprod. 81 (5), 966-977 (2009).</li><li>Coveney, D., Cool, J., Oliver, T., Capel, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Four-dimensional+analysis+of+vascularization+during+primary+development+of+an+organ,+the+gonad.">Four-dimensional analysis of vascularization during primary development of an organ, the gonad.</a> Proc Natl Acad Sci U S A. 105 (20), 7212-7217 (2008).</li><li>Tomer, R., Ye, L., Hsueh, B., Deisseroth, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advanced+CLARITY+for+rapid+and+high-resolution+imaging+of+intact+tissues.">Advanced CLARITY for rapid and high-resolution imaging of intact tissues.</a> Nat Protoc. 9 (7), 1682-1697 (2014).</li><li>Schindelin, J., 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=Fiji:+an+Open+Source+platform+for+biological+image+analysis.">Fiji: an Open Source platform for biological image analysis.</a> Nat Methods. 9 (7), 676-682 (2012).</li><li>Cao, G., Fehrenbach, M. L., Williams, J. T., Finklestein, J. M., Zhu, J. X., Delisser, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Angiogenesis+in+platelet+endothelial+cell+adhesion+molecule-1-null+mice.">Angiogenesis in platelet endothelial cell adhesion molecule-1-null mice.</a> Am J Pathol. 175 (2), 903-915 (2009).</li><li>Manni, L., Holm&#228;ng, A., Lundeberg, T., Aloe, L., Stener-Victorin, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ovarian+expression+of+alpha+(1)-+and+beta+(2)-adrenoceptors+and+p75+neurotrophin+receptors+in+rats+with+steroid-induced+polycystic+ovaries.">Ovarian expression of alpha (1)- and beta (2)-adrenoceptors and p75 neurotrophin receptors in rats with steroid-induced polycystic ovaries.</a> Auton Neurosci. 118 (1 - 2), 79-87 (2005).</li><li>Chourasia, T. K., Chaube, R., Singh, V., Joy, K. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Annual+and+periovulatory+changes+in+tyrosine+hydroxylase+activity+in+the+ovary+of+the+catfish+Heteropneustes+fossilis.">Annual and periovulatory changes in tyrosine hydroxylase activity in the ovary of the catfish Heteropneustes fossilis.</a> Gen Comp Endocrinol. 166 (1), 111-116 (2010).</li><li>Feng, Y., 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=CLARITY+reveals+dynamics+of+ovarian+follicular+architecture+and+vasculature+in+three-dimensions.">CLARITY reveals dynamics of ovarian follicular architecture and vasculature in three-dimensions.</a> Sci Rep. 7, 44810 (2017).</li><li>Tainaka, K., Kuno, A., Kubota, S. I., Murakami, T., Ueda, H. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemical+principles+in+tissue+clearing+and+staining+protocols+for+whole-body+cell+profiling.">Chemical principles in tissue clearing and staining protocols for whole-body cell profiling.</a> Annu Rev Cell Dev Biol. 32, 713-741 (2016).</li><li>Liang, H., Schofield, E., Paxinos, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Imaging+Serotonergic+Fibers+in+the+Mouse+Spinal+Cord+Using+the+CLARITY/CUBIC+Technique.">Imaging Serotonergic Fibers in the Mouse Spinal Cord Using the CLARITY/CUBIC Technique.</a> J Vis Exp. (108), e53673 (2016).</li><li>Yang, B., 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=Single-cell+phenotyping+within+transparent+intact+tissue+through+whole-body+clearing.">Single-cell phenotyping within transparent intact tissue through whole-body clearing.</a> Cell. 158 (4), 945-958 (2014).</li><li>Phillips, J., Laude, A., Lightowlers, R., Morris, C. M., Turnbull, D. M., Lax, N. Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+passive+CLARITY+and+immunofluorescent+labelling+of+multiple+proteins+in+human+cerebellum:+understanding+mechanisms+of+neurodegeneration+in+mitochondrial+disease.">Development of passive CLARITY and immunofluorescent labelling of multiple proteins in human cerebellum: understanding mechanisms of neurodegeneration in mitochondrial disease.</a> Sci Rep. 6, 26013 (2016).</li><li>Roberts, D. G., Johnsonbaugh, H. B., Spence, R. D., MacKenzie-Graham, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optical+clearing+of+the+mouse+central+nervous+system+using+passive+CLARITY.">Optical clearing of the mouse central nervous system using passive CLARITY.</a> J Vis Exp. (112), (2016).</li><li>Woo, J., Lee, M., Seo, J. M., Park, H. S., Cho, Y. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+the+optical+transparency+of+rodent+tissues+by+modified+PACT-based+passive+clearing.">Optimization of the optical transparency of rodent tissues by modified PACT-based passive clearing.</a> Exp Mol Med. 48 (12), e274 (2016).</li><li>Chung, 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=Structural+and+molecular+interrogation+of+intact+biological+systems.">Structural and molecular interrogation of intact biological systems.</a> Nature. 497 (7449), 332-337 (2013).</li><li>Chung, A. S., Ferrara, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Developmental+and+pathological+angiogenesis.">Developmental and pathological angiogenesis.</a> Annu Rev Cell Dev Biol. 27, 563-584 (2011).</li><li>Rodgers, R. J., Irving-Rodgers, H. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Formation+of+the+ovarian+follicular+antrum+and+follicular+fluid.">Formation of the ovarian follicular antrum and follicular fluid.</a> Biol Reprod. 82 (6), 1021-1029 (2010).</li><li>Siu, M. K. Y., Cheng, C. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+blood-follicle+barrier+(BFB)+in+disease+and+in+ovarian+function.">The blood-follicle barrier (BFB) in disease and in ovarian function.</a> Adv Exp Med Biol. 763, 186-192 (2014).</li><li>Dodt, H. U., 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=Ultramicroscopy:+three-dimensional+visualization+of+neuronal+networks+in+the+whole+mouse+brain.">Ultramicroscopy: three-dimensional visualization of neuronal networks in the whole mouse brain.</a> Nat Methods. 4, 331-336 (2007).</li><li>Hama, H., 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=Scale:+a+chemical+approach+for+fluorescence+imaging+and+reconstruction+of+transparent+mouse+brain.">Scale: a chemical approach for fluorescence imaging and reconstruction of transparent mouse brain.</a> Nat Neurosci. 14, 1481-1488 (2011).</li><li>Erturk, 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=Three-dimensional+imaging+of+solvent-cleared+organs+using+3DISCO.">Three-dimensional imaging of solvent-cleared organs using 3DISCO.</a> Nat Protoc. 7, 1983-1995 (2012).</li><li>Kuwajima, T., 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=Clear(T):+a+detergent-+and+solvent-free+clearing+method+for+neuronal+and+non-neuronal+tissue.">Clear(T): a detergent- and solvent-free clearing method for neuronal and non-neuronal tissue.</a> Development. 140, 1364-1368 (2013).</li><li>Ke, M. T., Fujimoto, S., Imai, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=SeeDB:+a+simple+and+morphology-preserving+optical+clearing+agent+for+neuronal+circuit+reconstruction.">SeeDB: a simple and morphology-preserving optical clearing agent for neuronal circuit reconstruction.</a> Nat Neurosci. 16, 1154-1161 (2013).</li><li>Lai, H. M., 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=Rationalisation+and+validation+of+an+acrylamide-free+procedure+in+three-dimensional+histological+imaging.">Rationalisation and validation of an acrylamide-free procedure in three-dimensional histological imaging.</a> PLOS ONE. 11, e0158628 (2016).</li><li>Susaki, E. 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=Whole-brain+imaging+with+single-cell+resolution+using+chemical+cocktails+and+computational+analysis.">Whole-brain imaging with single-cell resolution using chemical cocktails and computational analysis.</a> Cell. 157, 726-739 (2014).</li><li>Tainaka, 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=Whole-body+imaging+with+single-cell+resolution+by+tissue+decolorization.">Whole-body imaging with single-cell resolution by tissue decolorization.</a> Cell. 159, 911-924 (2014).</li><li>Liu, A. K. L., Lai, H. M., Chang, R. C. C., Gentleman, 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=Free-of-acrylamide+SDS-based+tissue+clearing+(FASTClear):+A+novel+protocol+of+tissue+clearing+for+three-dimensional+visualisation+of+human+brain+tissues.">Free-of-acrylamide SDS-based tissue clearing (FASTClear): A novel protocol of tissue clearing for three-dimensional visualisation of human brain tissues.</a> Neuropathol Appl Neurobiol. 43, 346-351 (2016).</li><li>Xu, N., 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=Fast+free-of-acrylamide+clearing+tissue+(FACT)-an+optimized+new+protocol+for+rapid,+high-resolution+imaging+of+three-dimensional+brain+tissue.">Fast free-of-acrylamide clearing tissue (FACT)-an optimized new protocol for rapid, high-resolution imaging of three-dimensional brain tissue.</a> Sci Rep. 7, 9895 (2017).</li><li>Migone, F. F., Cowan, R. G., Williams, R. M., Gorse, K. J., Zipfel, W. R., Quirk, 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=In+vivo+imaging+reveals+an+essential+role+of+vasoconstriction+in+rupture+of+the+ovarian+follicle+at+ovulation.">In vivo imaging reveals an essential role of vasoconstriction in rupture of the ovarian follicle at ovulation.</a> Proc Natl Acad Sci U S A. 113, 2294-2299 (2016).</li><li>Malki, S., Tharp, M. E., Bortvin, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+whole-mount+approach+for+accurate+quantitative+and+spatial+assessment+of+fetal+oocyte+dynamics+in+mice.">A whole-mount approach for accurate quantitative and spatial assessment of fetal oocyte dynamics in mice.</a> Biol Reprod. 93 (113), (2015).</li></ol>

In the current study, we present 3D imaging to evaluate the relationships between capillaries and individual growing follicles. In our previous work using the same protocol 9, we studied the roles of large vasculature, interactions between follicles, and the location of follicles in intact mouse ovaries. The passive CLARITY approach allowed us to study micro- and macro-vasculatures, folliculogenesis, and the interrelationships between the corpora lutea and follicles as well as to reconstruct the o...

The follicle is the fundamental structural and functional unit of the ovary, and its development is highly related to the vasculature within the ovary. Blood vessels supply nutrition and hormones to the follicles and thus play important roles in the growth and maturation of follicles1.
A combination of technologies, including selective blood vessel markers, transgenic mouse models, and pharmaceutical development, have increased our knowledge about ovarian vascular networks, angiogenesis, and the function of blood vessels in folliculogenesis. The ovary is known as an active organ because it remodels various tissues and vascular networks during folliculogenesis and ovulation. Such active remodeling in the size and structure of vessels is required for the biological function of developing and recruiting follicles.
Traditional histological and histomorphometric methods using ovarian sections and immunolabeling of blood vessels are limited to two-dimensional (2D) images2. With the development of three-dimensional (3D) reconstruction technologies, 2D images of tissue slices can be overlapped to make a 3D structure, but this method still has some limitations &#8212; sectioning of the tissue can destroy the microstructures, some parts of the tissue are often missing, and significant labor is involved in making 3D reconstructions from images obtained from slices. Whole-tissue 3D imaging with confocal microscopy can overcome many of these limitations, but these methods are limited to the evaluation of angiogenesis in the embryonic ovary3. Using whole tissue clearing methods such as CLARITY4 can increase the visualized volume so as to solve these problems in postnatal and adult ovaries, and such methods provide optical clearance of the ovary without any structural deformations. Imaging of the 3D architecture of the intact ovary provides an accurate image database for image analysis software, such as the Imaris software package used in this work.
Remodeling of the ovary throughout adulthood is part of a dynamic physiological system, and this makes the ovary an excellent model for investigations into the regulation of angiogenesis. Furthermore, evaluating the role of ovarian blood vessels in pathologic conditions of the female reproductive system such as polycystic ovary syndrome or ovarian cancers can be studied through whole ovarian tissue imaging. The development of the passive CLARITY method and the use of advanced image analysis software have provided detailed spatial information on the relationships between blood vessels and ovarian structures such as follicles.

<table border="0" cellpadding="0" cellspacing="0" width="1664">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Acrylamide</td>
			<td style="width:189px;">Vetec</td>
			<td style="width:127px;">v900845</td>
			<td style="width:861px;">http://www.sigmaaldrich.com/catalog/product/vetec/v900845</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Alexa Flour 488 (Dilution 1:50)&#160;</td>
			<td style="width:189px;">Life Technologies</td>
			<td style="width:127px;">A11039</td>
			<td style="width:861px;">https://www.thermofisher.com/antibody/product/Goat-anti-Chicken-IgY-H-L-Secondary-Antibody-Polyclonal/A-11039</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Alexa Flour 594 (Dilution 1:50)</td>
			<td style="width:189px;">Life Technologies</td>
			<td style="width:127px;">A11012</td>
			<td style="width:861px;">https://www.thermofisher.com/antibody/product/Goat-anti-Rabbit-IgG-H-L-Cross-Adsorbed-Secondary-Antibody-Polyclonal/A-11012</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Bisacrylamide</td>
			<td style="width:189px;">Amresco</td>
			<td style="width:127px;">172</td>
			<td style="width:861px;">http://www.amresco-inc.com/BIS-ACRYLAMIDE-0172.cmsx</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Black wall glass bottom dish (Willco-Dish)</td>
			<td style="width:189px;">Ted Pella</td>
			<td style="width:127px;">14032</td>
			<td style="width:861px;">http://www.tedpella.com/section_html/706dish.htm#black_wall</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Boric acid</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">10004818</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=10004818</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:487px;">Disodium hydrogen phosphate dodecahydrate (Na2HPO4 12H2O)</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">10020318</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=10020318</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">FocusClear</td>
			<td style="width:189px;">Celexplorer</td>
			<td style="width:127px;">FC-102</td>
			<td style="width:861px;">http://www.celexplorer.com/product_list.asp?MainType=107&#38;BRDarea=1</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Parafilm</td>
			<td style="width:189px;">Bemis</td>
			<td style="width:127px;">PM996</td>
			<td style="width:861px;">http://www.parafilm.com/products</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Paraformaldehyde</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">80096618</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=80096618</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">PECAM1/CD31, platelet-endothelial cell adhesion molecule 1 (Dilution 1:10)</td>
			<td style="width:189px;">Abcam</td>
			<td style="width:127px;">ab28364</td>
			<td style="width:861px;">http://www.abcam.com/cd31-antibody-ab28364.html</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Photoinitiator VA044</td>
			<td style="width:189px;">Wako</td>
			<td style="width:127px;">va-044/225-02111</td>
			<td style="width:861px;">http://www.wako-chem.co.jp/specialty/waterazo/VA-044.htm</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Sodium azide</td>
			<td style="width:189px;">Sigma</td>
			<td style="width:127px;">S2002</td>
			<td style="width:861px;">http://www.sigmaaldrich.com/catalog/product/sial/s2002?lang=en&#38;region=US</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Sodium chloride (NaCl)</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">10019318</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=10019318</td>
		</tr>
		<tr height="25">
			<td height="25" style="height:25px;width:487px;">Sodium dihydrogen phosphate dihydrate (NaH2PO4 2H2O)</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">20040718</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=20040718</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Sodium dodecyl sulfate</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">30166428</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=30166428</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Sodium hydroxide (NaOH)</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">10019718</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=10019718</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:487px;">Triton X-100</td>
			<td style="width:189px;">Sinopharm Chemical Reagent</td>
			<td style="width:127px;">30188928</td>
			<td style="width:861px;">http://en.reagent.com.cn/enshowproduct.jsp?id=30188928</td>
		</tr>
		<tr height="22">
			<td height="22" style="height:22px;width:487px;">Tyrosine hydroxylase (TH, Dilution 1:50)</td>
			<td style="width:189px;">Abcam</td>
			<td style="width:127px;">ab76442</td>
			<td style="width:861px;">http://www.abcam.com/tyrosine-hydroxylase-phospho-s40-antibody-ab51206.html</td>
		</tr>
	</tbody>
</table>

three-dimensional reconstruction of the vascular architecture of the passive clarity-cleared mouse ovary

The ovary is the main organ of the female reproductive system and is essential for the production of female gametes and for controlling the endocrine system, but the complex structural relationships and three-dimensional (3D) vasculature architectures of the ovary are not well described. In order to visualize the 3D connections and architecture of blood vessels in the intact ovary, the first important step is to make the ovary optically clear. In order to avoid tissue shrinkage, we used the hydrogel fixation-based passive CLARITY (Clear Lipid-exchanged Acrylamide-hybridized Rigid Imaging/ Immunostaining/In situ-hybridization-compatible Tissue Hydrogel) protocol method to clear an intact ovary. Immunostaining, advanced multiphoton confocal microscopy, and 3D image-reconstructions were then used for the visualization of ovarian vessels and follicular capillaries. Using this approach, we showed a significant positive correlation (P &#60;0.01) between the length of the follicular capillaries and volume of the follicular wall.

We adapted the passive CLARITY method into a quick and simple method for passive ovary clearing while preserving the follicular and vascular architecture and obtaining the highest fluorescent signal from labeled markers of vessels and follicles. The 3D architecture of the follicular vasculature was determined by immunostaining for CD31, a marker for endothelial cells6. CD31 staining in the ovaries of adult mice was traced using the Filament algorithm and showed int...

Watch this Scientific Journal Video about Three-dimensional Reconstruction of the Vascular Architecture of the Passive CLARITY-cleared Mouse Ovary at JoVE.com

Three-dimensional Reconstruction of the Vascular Architecture of the Passive CLARITY-cleared Mouse Ovary

Here we present an adaptation of the passive CLARITY and 3D reconstruction method for visualization of the ovarian vasculature and follicular capillaries in intact mouse ovaries.

The ovary is the main organ of the female reproductive system and is essential for the production of female gametes and for controlling the endocrine ...

The overall goal of this protocol is to provide a complete three-dimensional view of the capillary distribution in mouse ovarian follicles and show their relationships. The ovary is an essential organ in reproduction and in endocrinology. Count each different developmental stage of follicle and the somatic cells.In addition, unlike other organs, ovary does not show the repeated branching of the functional unit. The local vascular system may be together with the nervous system are also capable of undergoing major changes in each menstrual cycle in adult females. Applying the passive clarity in the ovary allows us to see the overall distribution and the connection among those cells and follicles in the ovary.The most of the one key of this measure is that it has the least effect on the ovary, and accounts for the clearing of various markers. Through the reconstruction of the microscopic image we provided a map of the ovary. Some details of the vessels, neurons, and follicles can be observed clearly.For image analysis, some options of Imaris were used to evaluate the relationships between the ovary and the structures. Prepare profusion solutions according to the article instruction and keep them on ice. Anesthetize the mice and make sure the mouse has no toe pinch response.Spray ethanol, make an incision on the right atrium, then instantly profuse the left ventricle with 20ml of ice cold PBS at the speed of 10ml per minute to flush out the blood. Then profuse the animal with cold Hydrogel Solution with the same speed. Collect the ovaries as well as the uterus to maintain the integrity of ovarian morphology.Transfer the separated ovaries to the cold Hydrogel Solution. Under a stereo microscope remove the fatty tissues around the ovary. For better result of tissue fixation, we recommend removing of ovarian bursa.Keep the ovaries in Hydrogel Solution for three days. After three days, transfer the ovaries into a glass tube and fill the tube with fresh Hydrogel Solution. Stretch the parafilm over the top of the tube and then wrap another parafilm around the neck of the tube.Ensure there are no bubbles between the parafilm and the Hydrogel Solution. Place the glass tube on a shaker incubator at 37 degrees Centigrade for two hours until gel forms. Carefully remove the excess gel around the ovaries with a paper filter.Put the ovaries in a 15ml tube and fill the tube with 10ml of clearing solution. Place the tube on a shaker incubator at 37 degrees Centigrade for at least two months. Change the clearing solution every day in the first three days and then weekly until the ovary becomes cleared.All immunostaining procedures are done at 37 degrees Centigrade on a shaker. First, wash the ovary in PBST for 24 hours. Second incubate ovary in primary antibody diluted by PBST for two days.Third, wash off the primary antibodies with PBST buffer. Fourth, incubate the ovary with the desired secondary antibody in PBST for two days. Fifth, wash off the secondary antibodies with PBST.Sixth, transfer the ovary into a refractive index matching solution for RI homogenization. Check the visual transparency, when the ovary has been fully clarified it can be imaged. First, prepare a clean glass bottom dish.Make a putty cylinder and shape it into a horseshoe shape. Press the outer edge tightly onto glass slide to make a sealed space. The height of the putty should be a little higher than the ovary.Move the ovary carefully to the center and add mounting solution. Push a dish over the putty and use two putty pieces for fix it. When the ovary is ready to image, Nikon confocal microscope with 16X lens can be selected to image it.For imaging with confocal microscope, first choose the lens in the Ni-E panel. In the panel acquisition, select the number of channels. First, use Eye Port tab and XY controller joystick to move the tissue to the center of field through checking by microscope eyepieces.Second, after turning off the shutter light, click live tab to adjust the laser power, HV, and offset for each channel. In the panel Z Intensity Correction adjust acquisition for top layer, click the plus button to define the top, move the lens down lens and set appropriate HV and laser power to the bottom of tissue and add the lowest layer information click To ND to synchronize the setting with the panel and the acquisition. And in acquisition, first set the number of scanning steps.Click the tabs of Z and large image. Second, go to the scan large image window to define the size of field according to the border of the tissue. Third, back to the ND acquisition to input the size of the scanning fields and choose the overlap within 10 and 50%Then click run Z correction and wait for the imaging process.First use imagic to open the original NIS file. Click image button, choose color and display channels, then click file, choose image sequences and separately save them as tiff files. Second, use Imaris to open one of the tiff files.Click edit button and choose the add channels to add the rest. The name and color can be changed in the display adjustment. The thickness of the tissue should also be corrected in image properties.Third, click edit button and choose Crop 3D to cut the extra part. First, click the filament button and click next. Go to the slice panel, find a tracing vessel and distance, then back to the Surpass, input the static and click next.Second, adjust the starting and set point threshold. In the camera panel, choose the select, press shift and click on the point to remove the extra part. Third, choose the highest threshold and click next.Don't select detects points and go next. Some excess part can be removed in edit panel. The color can be edited by clicking the color.Ovarian vasculature 3D architecture was investigated following immunostaining CD31. The 3D structure can be either observed by slices through other slices or by entirety through volume rendering. CD 31 is staining of adult mouse follicular vasculature was done.Through the reconstruction of capillaries by the filaments, we could show relationship between the individual follicles and their capillaries. The ovary, like a woman, is always active and interchangeable. However, due to the limitation of traditional histological analysis, it's very hard to describe the relationships among such complex constituents.The newly developed method, passive clarity may help up us to overcome the optical obstacle, keep the integrity of the whole tissues, and provide the functional clues.

three-dimensional-reconstruction-vascular-architecture-passive

Research

JoVE Journal

Biology

Hi-C: A Method to Study the Three-dimensional Architecture of Genomes.

The three-dimensional folding of chromosomes compartmentalizes the genome and and can bring distant functional elements, such as promoters and enhancers, into close spatial proximity 2-6. Deciphering the relationship between chromosome organization and genome activity will aid in understanding genomic processes, like transcription and replication. However, little is known about how chromosomes fold. Microscopy is unable to distinguish large numbers of loci simultaneously or at high resolution. To date, the detection of chromosomal interactions using chromosome conformation capture (3C) and its subsequent adaptations required the choice of a set of target loci, making genome-wide studies impossible 7-10.
We developed Hi-C, an extension of 3C that is capable of identifying long range interactions in an unbiased, genome-wide fashion. In Hi-C, cells are fixed with formaldehyde, causing interacting loci to be bound to one another by means of covalent DNA-protein cross-links. When the DNA is subsequently fragmented with a restriction enzyme, these loci remain linked. A biotinylated residue is incorporated as the 5' overhangs are filled in. Next, blunt-end ligation is performed under dilute conditions that favor ligation events between cross-linked DNA fragments. This results in a genome-wide library of ligation products, corresponding to pairs of fragments that were originally in close proximity to each other in the nucleus. Each ligation product is marked with biotin at the site of the junction. The library is sheared, and the junctions are pulled-down with streptavidin beads. The purified junctions can subsequently be analyzed using a high-throughput sequencer, resulting in a catalog of interacting fragments.
Direct analysis of the resulting contact matrix reveals numerous features of genomic organization, such as the presence of chromosome territories and the preferential association of small gene-rich chromosomes. Correlation analysis can be applied to the contact matrix, demonstrating that the human genome is segregated into two compartments: a less densely packed compartment containing open, accessible, and active chromatin and a more dense compartment containing closed, inaccessible, and inactive chromatin regions. Finally, ensemble analysis of the contact matrix, coupled with theoretical derivations and computational simulations, revealed that at the megabase scale Hi-C reveals features consistent with a fractal globule conformation.

The Hi-C method allows unbiased, genome-wide identification of chromatin interactions (1). Hi-C couples proximity ligation and massively parallel sequencing. The resulting data can be used to study genomic architecture at multiple scales: initial results identified features such as chromosome territories, segregation of open and closed chromatin, and chromatin structure at the megabase scale.

The three-dimensional folding of chromosomes compartmentalizes the genome and and can bring distant functional elements, such as promoters and enhancers, ...

Generation of Mice Derived from Induced Pluripotent Stem Cells

The production of induced pluripotent stem cells (iPSCs) from somatic cells provides a means to create valuable tools for basic research and may also produce a source of patient-matched cells for regenerative therapies. iPSCs may be generated using multiple protocols and derived from multiple cell sources. Once generated, iPSCs are tested using a variety of assays including immunostaining for pluripotency markers, generation of three germ layers in embryoid bodies and teratomas, comparisons of gene expression with embryonic stem cells (ESCs) and production of chimeric mice with or without germline contribution2. Importantly, iPSC lines that pass these tests still vary in their capacity to produce different differentiated cell types2. This has made it difficult to establish which iPSC derivation protocols, donor cell sources or selection methods are most useful for different applications.
The most stringent test of whether a stem cell line has sufficient developmental potential to generate all tissues required for survival of an organism (termed full pluripotency) is tetraploid embryo complementation (TEC)3-5. Technically, TEC involves electrofusion of two-cell embryos to generate tetraploid (4n) one-cell embryos that can be cultured in vitro to the blastocyst stage6. Diploid (2n) pluripotent stem cells (e.g. ESCs or iPSCs) are then injected into the blastocoel cavity of the tetraploid blastocyst and transferred to a recipient female for gestation (see Figure 1). The tetraploid component of the complemented embryo contributes almost exclusively to the extraembryonic tissues (placenta, yolk sac), whereas the diploid cells constitute the embryo proper, resulting in a fetus derived entirely from the injected stem cell line.
Recently, we reported the derivation of iPSC lines that reproducibly generate adult mice via TEC1. These iPSC lines give rise to viable pups with efficiencies of 5-13%, which is comparable to ESCs3,4,7 and higher than that reported for most other iPSC lines8-12. These reports show that direct reprogramming can produce fully pluripotent iPSCs that match ESCs in their developmental potential and efficiency of generating pups in TEC tests. At present, it is not clear what distinguishes between fully pluripotent iPSCs and less potent lines13-15. Nor is it clear which reprogramming methods will produce these lines with the highest efficiency. Here we describe one method that produces fully pluripotent iPSCs and "all- iPSC" mice, which may be helpful for investigators wishing to compare the pluripotency of iPSC lines or establish the equivalence of different reprogramming methods.

Generating induced pluripotent stem cell (iPSC) lines produces lines of differing developmental potential even when they pass standard tests for pluripotency. Here we describe a protocol to produce mice derived entirely from iPSCs, which defines the iPSC lines as possessing full pluripotency1.

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

An Analytical Tool that Quantifies Cellular Morphology Changes from Three-dimensional Fluorescence Images

The most common software analysis tools available for measuring fluorescence images are for two-dimensional (2D) data that rely on manual settings for inclusion and exclusion of data points, and computer-aided pattern recognition to support the interpretation and findings of the analysis. It has become increasingly important to be able to measure fluorescence images constructed from three-dimensional (3D) datasets in order to be able to capture the complexity of cellular dynamics and understand the basis of cellular plasticity within biological systems. Sophisticated microscopy instruments have permitted the visualization of 3D fluorescence images through the acquisition of multispectral fluorescence images and powerful analytical software that reconstructs the images from confocal stacks that then provide a 3D representation of the collected 2D images. Advanced design-based stereology methods have progressed from the approximation and assumptions of the original model-based stereology1 even in complex tissue sections2. Despite these scientific advances in microscopy, a need remains for an automated analytic method that fully exploits the intrinsic 3D data to allow for the analysis and quantification of the complex changes in cell morphology, protein localization and receptor trafficking. 
Current techniques available to quantify fluorescence images include Meta-Morph (Molecular Devices, Sunnyvale, CA) and Image J (NIH) which provide manual analysis. Imaris (Andor Technology, Belfast, Northern Ireland) software provides the feature MeasurementPro, which allows the manual creation of measurement points that can be placed in a volume image or drawn on a series of 2D slices to create a 3D object. This method is useful for single-click point measurements to measure a line distance between two objects or to create a polygon that encloses a region of interest, but it is difficult to apply to complex cellular network structures. Filament Tracer (Andor) allows automatic detection of the 3D neuronal filament-like however, this module has been developed to measure defined structures such as neurons, which are comprised of dendrites, axons and spines (tree-like structure). This module has been ingeniously utilized to make morphological measurements to non-neuronal cells3, however, the output data provide information of an extended cellular network by using a software that depends on a defined cell shape rather than being an amorphous-shaped cellular model. To overcome the issue of analyzing amorphous-shaped cells and making the software more suitable to a biological application, Imaris developed Imaris Cell. This was a scientific project with the Eidgen&ouml;ssische Technische Hochschule, which has been developed to calculate the relationship between cells and organelles. While the software enables the detection of biological constraints, by forcing one nucleus per cell and using cell membranes to segment cells, it cannot be utilized to analyze fluorescence data that are not continuous because ideally it builds cell surface without void spaces. To our knowledge, at present no user-modifiable automated approach that provides morphometric information from 3D fluorescence images has been developed that achieves cellular spatial information of an undefined shape (Figure 1). 
We have developed an analytical platform using the Imaris core software module and Imaris XT interfaced to MATLAB (Mat Works, Inc.). These tools allow the 3D measurement of cells without a pre-defined shape and with inconsistent fluorescence network components. Furthermore, this method will allow researchers who have extended expertise in biological systems, but not familiarity to computer applications, to perform quantification of morphological changes in cell dynamics.

We developed a software platform that utilizes Imaris Neuroscience, ImarisXT and MATLAB to measure the changes in morphology of an undefined shape taken from three-dimensional confocal fluorescence of single cells. This novel approach can be used to quantify changes in cell shape following receptor activation and therefore represents a possible additional tool for drug discovery.

The most common software analysis tools available for measuring fluorescence images are for two-dimensional (2D) data that rely on manual settings for ...

Using High Resolution Computed Tomography to Visualize the Three Dimensional Structure and Function of Plant Vasculature

High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique with sub-micron resolution capability that is now being used to evaluate the structure and function of plant xylem network in three dimensions (3D) (e.g. Brodersen et al. 2010; 2011; 2012a,b). HRCT imaging is based on the same principles as medical CT systems, but a high intensity synchrotron x-ray source results in higher spatial resolution and decreased image acquisition time. Here, we demonstrate in detail how synchrotron-based HRCT (performed at the Advanced Light Source-LBNL Berkeley, CA, USA) in combination with Avizo software (VSG Inc., Burlington, MA, USA) is being used to explore plant xylem in excised tissue and living plants. This new imaging tool allows users to move beyond traditional static, 2D light or electron micrographs and study samples using virtual serial sections in any plane. An infinite number of slices in any orientation can be made on the same sample, a feature that is physically impossible using traditional microscopy methods.
Results demonstrate that HRCT can be applied to both herbaceous and woody plant species, and a range of plant organs (i.e. leaves, petioles, stems, trunks, roots). Figures presented here help demonstrate both a range of representative plant vascular anatomy and the type of detail extracted from HRCT datasets, including scans for coast redwood (Sequoia sempervirens), walnut (Juglans spp.), oak (Quercus spp.), and maple (Acer spp.) tree saplings to sunflowers (Helianthus annuus), grapevines (Vitis spp.), and ferns (Pteridium aquilinum and Woodwardia fimbriata). Excised and dried samples from woody species are easiest to scan and typically yield the best images. However, recent improvements (i.e. more rapid scans and sample stabilization) have made it possible to use this visualization technique on green tissues (e.g. petioles) and in living plants. On occasion some shrinkage of hydrated green plant tissues will cause images to blur and methods to avoid these issues are described. These recent advances with HRCT provide promising new insights into plant vascular function.

High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique that can be used to study the structure and function of plant vasculature in 3D. We demonstrate how HRCT facilitates exploration of xylem networks across a wide range of plant tissues and species.

High resolution x-ray computed tomography (HRCT) is a non-destructive diagnostic imaging technique with sub-micron resolution capability that is now being ...

Slide Preparation Method to Preserve Three-dimensional Chromatin Architecture of Testicular Germ Cells

During testicular germ cell differentiation, the structure of nuclear chromatin dynamically changes. The following describes a method designed to preserve the three-dimensional chromatin arrangement of testicular germ cells found in mice; this method has been termed as the three-dimensional (3D) slide method. In this method, testicular tubules are directly treated with a permeabilization step that removes cytoplasmic material, followed by a fixation step that fixes nuclear materials. Tubules are then dissociated, the cell suspension is cytospun, and cells adhere to slides. This method improves sensitivity towards detection of subnuclear structures and is applicable for immunofluorescence, DNA, and RNA fluorescence in situ hybridization (FISH) and the combination of these detection methods. As an example of a possible application of the 3D slide method, a Cot-1 RNA FISH is shown to detect nascent RNAs. The 3D slide method will facilitate the detailed examination of spatial relationships between chromatin structure, DNA, and RNA during testicular germ cell differentiation.

The material here describes a method developed to preserve the three-dimensional chromatin structure of testicular germ cells. This has been termed the three-dimensional (3D) slide method. This method improves sensitivity for detection of subnuclear structures and is applicable for immunofluorescence, DNA, and RNA fluorescence in situ hybridization (FISH).

During testicular germ cell differentiation, the structure of nuclear chromatin dynamically changes. The following describes a method designed to preserve ...

Isolation and Primary Culture of Mouse Aortic Endothelial Cells

The vascular endothelium is essential to normal vascular homeostasis. Its dysfunction participates in various cardiovascular disorders. The mouse is an important model for cardiovascular disease research. This study demonstrates a simple method to isolate and culture endothelial cells from the mouse aorta without any special equipment. To isolate endothelial cells, the thoracic aorta is quickly removed from the mouse body, and the attached adipose tissue and connective tissue are removed from the aorta. The aorta is cut into 1 mm rings. Each aortic ring is opened and seeded onto a growth factor reduced matrix with the endothelium facing down. The segments are cultured in endothelial cell growth medium for about 4 days. The endothelial sprouting starts as early as day 2. The segments are then removed and the cells are cultured continually until they reach confluence. The endothelial cells are harvested using neutral proteinase and cultured in endothelial cell growth medium for another two passages before being used for experiments. Immunofluorescence staining indicated that after the second passage the majority of cells were double positive for Dil-ac-LDL uptake, Lectin binding, and CD31 staining, the typical characteristics of endothelial cells. It is suggested that cells at the second to third passages are suitable for in vitro and in vivo experiments to study the endothelial biology. Our protocol provides an effective means of identifying specific cellular and molecular mechanisms in endothelial cell physiopathology.

The vascular endothelial cells play a significant role in many important cardiovascular disorders. This article describes a simple method to isolate and expand endothelial cells from the mouse aorta without using any special equipment. Our protocol provides an effective means of identifying mechanisms in endothelial cell physiopathology.

The vascular endothelium is essential to normal vascular homeostasis. Its dysfunction participates in various cardiovascular disorders. The mouse is an ...

Isolation of Murine Coronary Vascular Smooth Muscle Cells

While the isolation and culture of vascular smooth muscle cells (VSMCs) from large vessels is well established, we sought to isolate and culture VSMCs from the coronary circulation. Hearts with intact aortic arches were removed and perfused via retrograde Langendorff with digestion solution containing 300 Units/ml of collagenase type II, 0.1 mg/ml soybean trypsin inhibitor and 1 M CaCl2. The perfusates were collected at 15 min intervals for 90 min, pelleted by centrifugation, resuspended in plating media, and plated on tissue culture dishes. VSMCs were characterized by presence of SM22&#945;, &#945;-SMA, and vimentin. One of the main advantages of using this technique is the ability to isolate VSMCs from the coronary circulation of mice. Although the small number of cells obtained can limit some of the applications for which the cells can be utilized, isolated coronary VSMCs can be used in a variety of well-established cell culture techniques and assays. Studies investigating VSMCs from genetically modified mice can provide further information about structure-function and signaling processes associated with vascular pathologies.

The purpose of this protocol is to demonstrate the isolation and culture techniques of murine primary vascular smooth muscle cells (VSMCs) from the coronary circulation. Once VSMCs have been isolated, they can be used for many standard culture techniques.

While the isolation and culture of vascular smooth muscle cells (VSMCs) from large vessels is well established, we sought to isolate and culture VSMCs ...

FRET Imaging in Three-dimensional Hydrogels

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly employ two-dimensional (2D) culture, which does not mimic the three-dimensional (3D) cellular microenvironment. A method to perform quenched emission FRET imaging using conventional widefield epifluorescence microscopy of cells within a 3D hydrogel environment is presented. Here an analysis method for ratiometric FRET probes that yields linear ratios over the probe activation range is described. Measurement of intracellular cyclic adenosine monophosphate (cAMP) levels is demonstrated in chondrocytes under forskolin stimulation using a probe for EPAC1 activation (ICUE1) and the ability to detect differences in cAMP signaling dependent on hydrogel material type, herein a photocrosslinking hydrogel (PC-gel, polyethylene glycol dimethacrylate) and a thermoresponsive hydrogel (TR-gel). Compared with 2D FRET methods, this method requires little additional work. Laboratories already utilizing FRET imaging in 2D can easily adopt this method to perform cellular studies in a 3D microenvironment. It can further be applied to high throughput drug screening in engineered 3D microtissues. Additionally, it is compatible with other forms of FRET imaging, such as anisotropy measurement and fluorescence lifetime imaging (FLIM), and with advanced microscopy platforms using confocal, pulsed, or modulated illumination.

F&#246;rster resonance energy transfer (FRET) imaging is a powerful tool for real-time cell biology studies. Here a method for FRET imaging cells in physiologic three-dimensional (3D) hydrogel microenvironments using conventional epifluorescence microscopy is presented. An analysis for ratiometric FRET probes that yields linear ratios over the activation range is described.

Imaging of F&#246;rster resonance energy transfer (FRET)&#160;is a powerful tool for examining cell biology in real-time. Studies utilizing FRET commonly ...

Adipo-Clear: A Tissue Clearing Method for Three-Dimensional Imaging of Adipose Tissue

Adipose tissue plays a central role in energy homeostasis and thermoregulation. It is composed of different types of adipocytes, as well as adipocyte precursors, immune cells, fibroblasts, blood vessels, and nerve projections. Although the molecular control of cell type specification and how these cells interact have been increasingly delineated, a more comprehensive understanding of these adipose-resident cells can be achieved by visualizing their distribution and architecture throughout the whole tissue. Existing immunohistochemistry and immunofluorescence approaches to analyze adipose histology rely on thin paraffin-embedded sections. However, thin sections capture only a small portion of tissue; as a result, the conclusions can be biased by what portion of tissue is analyzed. We have therefore developed an adipose tissue clearing technique, Adipo-Clear, to permit comprehensive three-dimensional visualization of molecular and cellular patterns in whole adipose tissues. Adipo-Clear was adapted from iDISCO/iDISCO+, with specific modifications made to completely remove the lipid stored in the tissue while preserving native tissue morphology. In combination with light-sheet fluorescence microscopy, we demonstrate here the use of the Adipo-Clear method to obtain high-resolution volumetric images&#160;of an entire adipose tissue.

Due to the high lipid content, adipose tissue has been challenging to visualize using traditional histological methods. Adipo-Clear is a tissue clearing technique that allows robust labeling and high-resolution volumetric fluorescent imaging of adipose tissue. Here, we describe the methods for sample preparation, pretreatment, staining, clearing, and mounting for imaging.

Adipose tissue plays a central role in energy homeostasis and thermoregulation. It is composed of different types of adipocytes, as well as adipocyte ...

Evaluating the Angiogenetic Properties of Ovarian Cancer Stem-Like Cells using the Three-Dimensional Co-Culture System, NICO-1

Cancer stem cells (CSCs) reside in a supportive niche, constituting a microenvironment comprised of adjacent stromal cells, vessels, and extracellular matrix. The ability of CSCs to participate in the development of endothelium constitutes an important characteristic that directly contributes to the general understanding of the mechanisms of tumorigenesis and tumor metastasis. The purpose of this work is to establish a reproducible methodology to investigate the tumor-initiation capability of ovarian cancer stem cells (OCSCs). Herein, we examined the neovascularization mechanism between endothelial cells and OCSCs along with the morphological changes of endothelial cells using the in vitro co-culture model NICO-1. This protocol allows visualization of the neovascularization step surrounding the OCSCs in a time course manner. The technique can provide insight regarding the angiogenetic properties of OCSCs in tumor metastasis.

Ovarian cancer stem cells (OCSC) are responsible for cancer initiation, recurrence, therapeutic resistance, and metastasis. The OCSC vascular niche is considered to promote self-renewal of OCSCs, leading to chemoresistance. This protocol provides the basis for establishing a reproducible OCSC vascular niche model in vitro.

Cancer stem cells (CSCs) reside in a supportive niche, constituting a microenvironment comprised of adjacent stromal cells, vessels, and extracellular ...