Name: lumican extraction from amniotic membrane and determination of its storage temperature
Uploaded: 2022-10-14T14:30:00
Description: Watch this Scientific Journal Video about Lumican Extraction from Amniotic Membrane and Determination of its Storage Temperature at JoVE.com

The authors have no competing financial interests.

All the experimental procedures were approved by the Institutional Review Board (Project No. CEI-2020/06/04). The AM was obtained from the Instituto de Oftalmologia Conde de Valenciana amnion bank (from deidentified human subjects), which is prepared as described by Ch&#225;vez-Garc&#237;a et al.17.
1. Preparation of the amniotic membrane extract
<ol>
	<li>Obtain 100 mg of AM from the amnion bank. 
	NOTE: According to a previous report, 50 mg of ...

<ol>
	<li>Jirsova, K., Jones, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amniotic+membrane+in+ophthalmology:+properties,+preparation,+storage+and+indications+for+grafting-a+review.">Amniotic membrane in ophthalmology: properties, preparation, storage and indications for grafting-a review.</a> Cell and Tissue Banking. 18 (2), 193-204 (2017).</li><li>Witherel, C., Yu, T., Concannon, M., Dampier, W., Spiller, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Immunomodulatory+effects+of+human+cryopreserved+viable+amniotic+membrane+in+a+pro-inflammatory+environment+in+vitro.">Immunomodulatory effects of human cryopreserved viable amniotic membrane in a pro-inflammatory environment in vitro.</a> Cellular and Molecular Bioengineering. 10 (5), 451-462 (2017).</li><li>Ruiz-Ca&#241;ada, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amniotic+membrane+stimulates+cell+migration+by+modulating+transforming+growth+factor-&#946;+signalling.">Amniotic membrane stimulates cell migration by modulating transforming growth factor-&#946; signalling.</a> Journal of Tissue Engineering and Regenerative Medicine. 12 (3), 808-820 (2017).</li><li>Yeh, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Soluble+lumican+glycoprotein+purified+from+human+amniotic+membrane+promotes+corneal+epithelial+wound+healing.">Soluble lumican glycoprotein purified from human amniotic membrane promotes corneal epithelial wound healing.</a> Investigative Opthalmology &amp; Visual Science. 46 (2), 479 (2005).</li><li>Navas, 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=Anti-Inflammatory+and+anti-fibrotic+effects+of+human+amniotic+membrane+mesenchymal+stem+cells+and+their+potential+in+corneal+repair.">Anti-Inflammatory and anti-fibrotic effects of human amniotic membrane mesenchymal stem cells and their potential in corneal repair.</a> Stem Cells Translational Medicine. 7 (12), 906-917 (2018).</li><li>Maga&#241;a-Guerrero, F., Dom&#237;nguez-L&#243;pez, A., Mart&#237;nez-Aboytes, P., Buentello-Volante, B., Garfias, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Human+amniotic+membrane+mesenchymal+stem+cells+inhibit+neutrophil+extracellular+traps+through+TSG-6.">Human amniotic membrane mesenchymal stem cells inhibit neutrophil extracellular traps through TSG-6.</a> Scientific Reports. 7, 12426 (2017).</li><li>Garfias, Y., Zaga-Clavellina, V., Vadillo-Ortega, F., Osorio, M., Jimenez-Martinez, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amniotic+membrane+is+an+immunosuppressor+of+peripheral+blood+mononuclear+cells.">Amniotic membrane is an immunosuppressor of peripheral blood mononuclear cells.</a> Immunological Investigations. 40 (2), 183-196 (2010).</li><li>Koob, 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=Biological+properties+of+dehydrated+human+amnion/chorion+composite+graft:+implications+for+chronic+wound+healing.">Biological properties of dehydrated human amnion/chorion composite graft: implications for chronic wound healing.</a> International Wound Journal. 10 (5), 493-500 (2013).</li><li>Miyagi, H., Thomasy, S., Russell, P., Murphy, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+role+of+hepatocyte+growth+factor+in+corneal+wound+healing.">The role of hepatocyte growth factor in corneal wound healing.</a> Experimental Eye Research. 166, 49-55 (2018).</li><li>Chen, S., Mienaltowski, M., Birk, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+corneal+stroma+extracellular+matrix+assembly.">Regulation of corneal stroma extracellular matrix assembly.</a> Experimental Eye Research. 133, 69-80 (2015).</li><li>Karamanou, K., Perrot, G., Maquart, F., Br&#233;zillon, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lumican+as+a+multivalent+effector+in+wound+healing.">Lumican as a multivalent effector in wound healing.</a> Advanced Drug Delivery Reviews. 129, 344-351 (2018).</li><li>Theocharis, 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=Cell-matrix+interactions:+focus+on+proteoglycan-proteinase+interplay+and+pharmacological+targeting+in+cancer.">Cell-matrix interactions: focus on proteoglycan-proteinase interplay and pharmacological targeting in cancer.</a> FEBS Journal. 281 (22), 5023-5042 (2014).</li><li>Saika, 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+lumican+in+the+corneal+epithelium+during+wound+healing.">Role of lumican in the corneal epithelium during wound healing.</a> Journal of Biological Chemistry. 275 (4), 2607-2612 (2000).</li><li>Dom&#237;nguez-L&#243;pez, 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=Amniotic+membrane+conditioned+medium+(AMCM)+reduces+inflammatory+response+on+human+limbal+myofibroblast,+and+the+potential+role+of+lumican.">Amniotic membrane conditioned medium (AMCM) reduces inflammatory response on human limbal myofibroblast, and the potential role of lumican.</a> Molecular Vision. 27, 370-383 (2021).</li><li>Vij, N., Roberts, L., Joyce, S., Chakravarti, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lumican+regulates+corneal+inflammatory+responses+by+modulating+Fas-Fas+Ligand+signaling.">Lumican regulates corneal inflammatory responses by modulating Fas-Fas Ligand signaling.</a> Investigative Opthalmology &amp; Visual Science. 46 (1), 88 (2005).</li><li>Mahbod, 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=Amniotic+membrane+extract+preparation:+What+is+the+best+method.">Amniotic membrane extract preparation: What is the best method.</a> Journal of Ophthalmic and Vision Research. 9 (3), 314-319 (2014).</li><li>Ch&#225;vez-Garc&#237;a, C., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ophthalmic+indications+of+amniotic+membrane+transplantation+in+Mexico:+an+eight+years+Amniotic+Membrane+Bank+experience.">Ophthalmic indications of amniotic membrane transplantation in Mexico: an eight years Amniotic Membrane Bank experience.</a> Cell and Tissue Banking. 17 (2), 261-268 (2015).</li><li>Stenn, K. S., Link, R., Moellmann, G., Madri, J., Kuklinska, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dispase,+a+neutral+protease+from+Bacillus+polymyxa,+is+a+powerful+fibronectinase+and+type+IV+collagenase.">Dispase, a neutral protease from Bacillus polymyxa, is a powerful fibronectinase and type IV collagenase.</a> Journal of Investigative Dermatology. 93 (2), 287-290 (1989).</li><li>Bhatnagar, B. S., Bogner, R. H., Pikal, M. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protein+stability+during+freezing:+separation+of+stresses+and+mechanisms+of+protein+stabilization.">Protein stability during freezing: separation of stresses and mechanisms of protein stabilization.</a> Pharmaceutical Development and Technology. 12 (5), 505-523 (2007).</li><li>McClain, A. K., McCarrel, T. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+effect+of+four+different+freezing+conditions+and+time+in+frozen+storage+on+the+concentration+of+commonly+measured+growth+factors+and+enzymes+in+equine+platelet-rich+plasma+over+six+months.">The effect of four different freezing conditions and time in frozen storage on the concentration of commonly measured growth factors and enzymes in equine platelet-rich plasma over six months.</a> BMC Veterinary Research. 15 (1), 292 (2019).</li><li>Tamhane, 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=Evaluation+of+amniotic+membrane+transplantation+as+an+adjunct+to+medical+therapy+as+compared+with+medical+therapy+alone+in+acute+ocular+burns.">Evaluation of amniotic membrane transplantation as an adjunct to medical therapy as compared with medical therapy alone in acute ocular burns.</a> Ophthalmology. 112 (11), 1963-1969 (2005).</li><li>Shtein, R., 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=Autologous+serum-based+eye+drops+for+treatment+of+ocular+surface+disease.">Autologous serum-based eye drops for treatment of ocular surface disease.</a> Ophthalmology. 127 (1), 128-133 (2020).</li><li>Shahriari, H., Tokhmehchi, F., Reza, M., Hashemi, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+the+effect+of+amniotic+membrane+suspension+and+autologous+serum+on+alkaline+corneal+epithelial+wound+healing+in+the+rabbit+model.">Comparison of the effect of amniotic membrane suspension and autologous serum on alkaline corneal epithelial wound healing in the rabbit model.</a> Cornea. 27 (10), 1148-1150 (2008).</li><li>Schuerch, K., Baeriswyl, A., Frueh, B., Tappeiner, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+of+amniotic+membrane+transplantation+for+the+treatment+of+corneal+ulcers.">Efficacy of amniotic membrane transplantation for the treatment of corneal ulcers.</a> Cornea. 39 (4), 479-483 (2019).</li><li>Chen, 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=Amniotic+membrane+transplantation+for+persistent+corneal+ulcers+and+perforations+in+acute+fungal+keratitis.">Amniotic membrane transplantation for persistent corneal ulcers and perforations in acute fungal keratitis.</a> Cornea. 25 (5), 564-572 (2006).</li><li>Guo, Q., 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=A+comparison+of+the+effectiveness+between+amniotic+membrane+homogenate+and+transplanted+amniotic+membrane+in+healing+corneal+damage+in+a+rabbit+model.">A comparison of the effectiveness between amniotic membrane homogenate and transplanted amniotic membrane in healing corneal damage in a rabbit model.</a> Acta Ophthalmologica. 89 (4), 315-319 (2011).</li><li>Sabater, A., Perez, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Amniotic+membrane+use+for+management+of+corneal+limbal+stem+cell+deficiency.">Amniotic membrane use for management of corneal limbal stem cell deficiency.</a> Current Opinion in Ophthalmology. 28 (4), 363-369 (2017).</li><li>Ahmad, 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=Autolysis+of+bovine+skin,+its+endogenous+proteases,+protease+inhibitors+and+their+effects+on+quality+characteristics+of+extracted+gelatin.">Autolysis of bovine skin, its endogenous proteases, protease inhibitors and their effects on quality characteristics of extracted gelatin.</a> Food Chemistry. 265, 1-8 (2018).</li><li>Mullegama, S. 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In this study, the presence of lumican was analyzed in the AME and its direct correlation with its stability under different storage conditions. Interestingly, when the total protein concentration in AME was quantified, protein concentration increased after storage. Evidence suggests three mechanisms that could change protein concentration in frozen storage: cold denaturation, the frozen concentration of solutes, and ice-induced partial unfolding of protein structure19. The freezing process could ...

One of the most used treatments for corneal affections is amniotic membrane transplantation; however, in recent years, new proposals have emerged for using various components of amniotic tissue as alternative and adjuvant treatments. Among the most studied components of AM are those obtained from the AM extract (AME)1,2,3,4,5,6,7. AM contains multiple soluble factors such as antiangiogenic proteins, interleukins (IL), tissue inhibitors of metalloproteinases (TIMPs), anti-inflammatory proteins mediated by TSG-6 that inhibit neutrophil extracellular traps, growth factors: epidermal growth factor (EGF), transforming growth factor (TGF) (alpha and beta), keratinocyte growth factor (KGF), hepatocyte growth factor (HGF), and lumican, which maintains corneal transparency by regulating collagen fibrillogenesis1,2,3,4,5,6,7,8,9.
Lumican is a small leucine-rich proteoglycan (SLRP), one of the main extracellular components of interstitial collagenase in the corneal stroma matrix, responsible for organizing collagen fibers and maintaining corneal transparency4,10,11. Proteoglycans are molecules in the extracellular matrix (ECM), which are the main ones in carrying out cell signaling and maintaining intracellular homeostasis12. ECM proteins have been reported to drive the cellular processes of proliferation, differentiation, and migration during wound healing11.
Evidence indicates the possible participation of lumican in the process of corneal re-epithelialization. Saika et al., in a study, showed that after a corneal injury, lumican could be detected in corneal keratocytes between the first 8 h and up to 3 days after injury. Presenting the highest concentration of lumican on the second and third day, this proteoglycan is subsequently undetectable on the seventh day13. These data suggest the participation of lumican in the activation of the corneal re-epithelialization process. On the other hand, in another study, it was reported that the absence of lumican delays re-epithelialization; interestingly, adding lumican could accelerate the re-epithelialization process4,11,13. Likewise, a recent study has reported that lumican can modulate the inflammatory functions of corneal limbus fibroblasts14, which suggests a role for lumican as a modulator of the inflammatory, antifibrotic and re-epithelializing response. Similarly, lumican can modulate the corneal response by interacting with signaling molecules such as Fas-FasL. Also, the absence of lumican in a knockout Lum-/- mouse model demonstrated that the lack of lumican signaling prevents adequate corneal repair15.
Primarily, this method aims to demonstrate a feasible and approachable way to extract lumican from AM. With this advantageous method of lumican extraction, it is possible to obtain similar concentrations of proteins, decreasing the processing time and making it more convenient for investigators compared to the previous studies16. Furthermore, this AME lumican could be used as an adjuvant for corneal repair and re-epithelialization processes.

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>1 N H2SO4 stop solution</td>
			<td>R&#38;D Systems</td>
			<td>DY994</td>
			<td></td>
		</tr>
		<tr>
			<td>100 &#956;L micropipette</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>1000 &#956;L micropipette</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>15 mm Petri dish</td>
			<td>Symlaboratorios</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>18 G Needle (1.2 mm x 40 mm)</td>
			<td>BD Becton Dickinson&#160;</td>
			<td>305211</td>
			<td></td>
		</tr>
		<tr>
			<td>2 mL microcentrifuge tube</td>
			<td>Eppendorf</td>
			<td>Z606340</td>
			<td></td>
		</tr>
		<tr>
			<td>20 mL plastic syringe&#160;</td>
			<td>BD Becton Dickinson&#160;</td>
			<td>302562</td>
			<td></td>
		</tr>
		<tr>
			<td>20 &#956;L micropipette</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>20-200 &#956;L micropipette</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>5 mL microcentrifuge tube</td>
			<td>Eppendorf</td>
			<td>30119401</td>
			<td></td>
		</tr>
		<tr>
			<td>96-well microplate</td>
			<td>SARSTEDT</td>
			<td>821581</td>
			<td></td>
		</tr>
		<tr>
			<td>Aluminum foil</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Amniotic membrane</td>
			<td>Instituto de Oftalmologia Conde de Valenciana Amnion Bank</td>
			<td></td>
			<td>100 mg</td>
		</tr>
		<tr>
			<td>Balanced salt solution</td>
			<td>Bausch + Lomb</td>
			<td>BSS-403802</td>
			<td></td>
		</tr>
		<tr>
			<td>Beaker</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>BioRender&#160;</td>
			<td>BioRender</td>
			<td></td>
			<td>figures design&#160;</td>
		</tr>
		<tr>
			<td>Compact Rocker</td>
			<td>BioRad</td>
			<td>970822DD</td>
			<td>Mod. 5202SD-BIO</td>
		</tr>
		<tr>
			<td>complete, EDTA-free, Protease inhibitor 
			cocktail tablets</td>
			<td>Roche</td>
			<td>11 873 580 001</td>
			<td>Protease Inhibitor</td>
		</tr>
		<tr>
			<td>Daiggner vortex Genie 2</td>
			<td>A.Daigger &#38; Co. , INC</td>
			<td>22220A</td>
			<td></td>
		</tr>
		<tr>
			<td>Dispase II</td>
			<td>Gibco</td>
			<td>17105-041</td>
			<td></td>
		</tr>
		<tr>
			<td>ELISA plate spectrometer</td>
			<td>Thermo Labsystems&#160;</td>
			<td>35401106</td>
			<td>Multiscan</td>
		</tr>
		<tr>
			<td>Freezer</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>GraphPad Prism&#160;</td>
			<td>GraphPad Software, Inc</td>
			<td>version 9</td>
			<td>statistical analysis and graphic program&#160;</td>
		</tr>
		<tr>
			<td>Human lumican DuoSet ELISA kit</td>
			<td>R&#38;D Systems</td>
			<td>DY2846-05</td>
			<td>includes human Lumican capture antibody</td>
		</tr>
		<tr>
			<td>Incubator&#160;</td>
			<td>Forma Scientific&#160;</td>
			<td>3326 S/N 36481-7002</td>
			<td></td>
		</tr>
		<tr>
			<td>Inverted light Microscope</td>
			<td>Olympus&#160;</td>
			<td>6A13921</td>
			<td>to confirm de-epithelialization&#160; Mod.CK2</td>
		</tr>
		<tr>
			<td>Laminar flow hood</td>
			<td>Forma Scientific&#160;</td>
			<td>14753-567</td>
			<td>Mod.1184</td>
		</tr>
		<tr>
			<td>Liquid nitrogen</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Mortar</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Multi-channel pipettor</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Nitrogen Tank</td>
			<td>Thermo Scientific</td>
			<td></td>
			<td>Mod. Biocan 20</td>
		</tr>
		<tr>
			<td>Paper towels</td>
			<td>N/A</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>Phosphate-buffered saline</td>
			<td>R&#38;D Systems</td>
			<td>DY006</td>
			<td></td>
		</tr>
		<tr>
			<td>Pierce Modified Lowry Protein Assay Kit</td>
			<td>Thermo Scientific</td>
			<td>23240</td>
			<td></td>
		</tr>
		<tr>
			<td>Plate sealers</td>
			<td>R&#38;D Systems</td>
			<td>DY992</td>
			<td></td>
		</tr>
		<tr>
			<td>Reagent diluent</td>
			<td>R&#38;D Systems</td>
			<td>DY995</td>
			<td>1% BSA in PBS, pH 7.2-7.4, 0.2 &#956;m filtered</td>
		</tr>
		<tr>
			<td>Refrigerated centrifuge</td>
			<td>centurion scientific Ltd&#160;</td>
			<td>15877</td>
			<td>Mod. K2015R</td>
		</tr>
		<tr>
			<td>Rubber policeman cell scraper</td>
			<td>NEST</td>
			<td>710001</td>
			<td>for mechanical de-epithelialization</td>
		</tr>
		<tr>
			<td>Scalpel knife</td>
			<td>Braun</td>
			<td>BB521</td>
			<td>No. 10 or 21</td>
		</tr>
		<tr>
			<td>Streptavidin-HRP 40-fold concentrated&#160;</td>
			<td>R&#38;D Systems</td>
			<td>part 893975</td>
			<td></td>
		</tr>
		<tr>
			<td>Substrate tetramethylbenzidine (TMB) solution</td>
			<td>R&#38;D Systems</td>
			<td>DY999</td>
			<td></td>
		</tr>
		<tr>
			<td>Toothed tweezers</td>
			<td>Invent Germany</td>
			<td>6b</td>
			<td>inox&#160;</td>
		</tr>
		<tr>
			<td>Ultrapure water</td>
			<td>PISA</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Wash buffer</td>
			<td>R&#38;D Systems</td>
			<td>WA126</td>
			<td>0.05% Tween 20 in PBS, pH 7.2-7.4</td>
		</tr>
	</tbody>
</table>

lumican extraction from amniotic membrane and determination of its storage temperature

Lumican is a small leucine-rich proteoglycan in the human amniotic membrane (AM) that promotes corneal epithelialization and the organization of collagen fibers, maintaining corneal transparency. In the present work, a method for protein extraction from AM to obtain lumican is proposed. Additionally, the stability of lumican in the AM extract (AME) stored at different temperatures and time periods is evaluated. 100 mg of AM were thawed and mechanical de-epithelialized. The de-epithelialized AM was frozen and crushed until a fine powder was obtained, which was solubilized with 2.5 mL of saline buffer with protease inhibitors and centrifuged for protein extraction. The supernatant was collected and stored at -20 &#176;C, 4 &#176;C, and room temperature (RT) for 6, 12, 20, and 32 days. Afterward, lumican was quantified in each AME. This technique allows an accessible and acquirable protocol for lumican extraction from AM. Lumican concentration was affected by storage time and temperature conditions. Lumican in the AME of 12 days stored at -20 &#176;C and 4 &#176;C was significantly higher than other AME. This lumican extraction could be useful for developing treatments and pharmaceutical solutions. Further studies are needed to determine the uses of AME lumican in re-epithelialization and wound healing process.

Results are reported as the mean value &#177; standard deviation (SD). Student&#39;s t-tests and analysis of variance (ANOVA) were performed. P-values &#60; 0.05 was considered statistically significant. Statistical analysis was performed using statistics software (see Table of Materials).
The total protein quantity in the AME was affected by time and storage conditions. The basal protein concentration was similar among all AME; the range of total protein was...

Watch this Scientific Journal Video about Lumican Extraction from Amniotic Membrane and Determination of its Storage Temperature at JoVE.com

Lumican Extraction from Amniotic Membrane and Determination of its Storage Temperature

The present protocol describes the extraction of lumican from the amniotic membrane (AM) and their storing conditions as AM extract (AME) at -20 &#176;C, 4 &#176;C, and room temperature (RT) for 6, 12, 20, and 32 days to quantify its proteins and lumican concentration.

Lumican is a small leucine-rich proteoglycan in the human amniotic membrane (AM) that promotes corneal epithelialization and the organization of collagen ...

This method aims to demonstrate a straightforward technique for protein extraction, useful for the obtaintion of bountiful proteins and other factors. This technique could be used to extract other factors and proteins present in the amniotic membrane and also, to obtain proteins from other sources such as animals and vegetal tissues. Begin by thawing 100 milligrams of the amniotic membrane obtained from the amnion bank.Once thawed, add 10 milliliters of the sterile balanced salt solution to a Petri dish and wash the membrane for two minutes. Then, remove the used balanced salt solution into a beaker and repeat the process until no trace of glycerol medium is visible in the Petri dish. Next, add 10 milliliters of dispase II to the membrane and incubate at 37 degrees Celsius and 5%carbon dioxide for 30 minutes.At the end of the incubation, perform a mechanical de-epithelialization with a rubber policeman cell scraper. Then, visualize the membrane under an inverted microscope to confirm de-epithelialization. Next, wash the de-epithelialized amniotic membrane with the sterile balanced salt solution as demonstrated earlier, and place it in a two-milliliter microcentrifuge tube.Then, immerse the tube containing the membrane in liquid nitrogen for 40 minutes. Post freezing with liquid nitrogen, manually grind the membrane for two to three minutes in a mortar, pre-chilled at minus 85 degrees Celsius, until a fine powder is obtained. Next, add 2.5 milliliters of protease inhibitor solution and solubilize the finely-powdered membrane.Clean the mortar walls with the help of a scalpel knife and transfer the mixture to a five-milliliter tube. Vortex the tube for 30 seconds. Then, homogenize the tissue mixture by first centrifuging at 34 G for 20 minutes at four degrees Celsius, and immediately centrifuging it again at 3, 360 G for 20 minutes at four degrees Celsius.At the end of centrifugation, collect the supernatant, which is the amniotic membrane extract, in a new tube. Then, aliquot 0.7 milliliters in a different two-milliliter microcentrifuge tube for various time points and temperatures. The total protein quantity and lumican concentration in the amniotic membrane extract were affected by time and storage conditions.Basal protein concentration was similar among all the amniotic membrane extracts. However, a significantly high protein concentration was noted in the extract stored for 32 days at four degrees Celsius and 20 days at minus 20 degrees Celsius. Lumican in the amniotic membrane extract was significantly higher in the sample stored for a period of 12 days compared with the samples stored for 30, 20, and six days at four and minus 20 degrees Celsius.These results suggested that the appropriate storage time and temperature to achieve the highest concentration of lumican is 12 days at minus 20 degrees Celsius. Exercise utmost care while grounding the frozen amniotic membrane. The grounding should be gentle as it could fall out from the mortar.Further studies are needed to determine the role of amniotic membrane extract lumican in corneal epithelial cells and to determine the ideal dose of lumican for corneal re-epithelialization.

lumican-extraction-from-amniotic-membrane-determination-its-storage

Research

JoVE Journal

Medicine

Technique of Subnormothermic Ex Vivo Liver Perfusion for the Storage, Assessment, and Repair of Marginal Liver Grafts

The success of liver transplantation has resulted in a dramatic organ shortage. In most transplant regions 20-30% of patients on the waiting list for liver transplantation die without receiving an organ transplant or are delisted for disease progression. One strategy to increase the donor pool is the utilization of marginal grafts, such as fatty livers, grafts from older donors, or donation after cardiac death (DCD). The current preservation technique of cold static storage is only poorly tolerated by marginal livers resulting in significant organ damage. In addition, cold static organ storage does not allow graft assessment or repair prior to transplantation.
These shortcomings of cold static preservation have triggered an interest in warm perfused organ preservation to reduce cold ischemic injury, assess liver grafts during preservation, and explore the opportunity to repair marginal livers prior to transplantation. The optimal pressure and flow conditions, perfusion temperature, composition of the perfusion solution and the need for an oxygen carrier has been controversial in the past.
In spite of promising results in several animal studies, the complexity and the costs have prevented a broader clinical application so far. Recently, with enhanced technology and a better understanding of liver physiology during ex vivo perfusion the outcome of warm liver perfusion has improved and consistently good results can be achieved.
This paper will provide information about liver retrieval, storage techniques, and isolated liver perfusion in pigs. We will illustrate a) the requirements to ensure sufficient oxygen supply to the organ, b) technical considerations about the perfusion machine and the perfusion solution, and c) biochemical aspects of isolated organs.

Technique of Subnormothermic Ex Vivo Liver Perfusion for the Storage, Assessment, and Repair of Marginal Liver Grafts

Marginal grafts, such as fatty livers, grafts from older donors, or livers retrieved after cardiac death (DCD) tolerate conventional, cold static storage only poorly. We developed a novel model of subnormothermic ex vivo liver perfusion for preservation, assessment, and repair of marginal liver grafts prior to transplantation.

The success of liver transplantation has resulted in a dramatic organ shortage. In most transplant regions 20-30% of patients on the waiting list for ...

Modeling Encephalopathy of Prematurity Using Prenatal Hypoxia-ischemia with Intra-amniotic Lipopolysaccharide in Rats

Encephalopathy of prematurity (EoP) is a term that encompasses the central nervous system (CNS) abnormalities associated with preterm birth. To best advance translational objectives and uncover new therapeutic strategies for brain injury associated with preterm birth, preclinical models of EoP must include similar mechanisms of prenatal global injury observed in humans and involve multiple components of the maternal-placental-fetal system. Ideally, models should produce a similar spectrum of functional deficits in the mature animal and recapitulate multiple aspects of the pathophysiology. To mimic human systemic placental perfusion defects, placental underperfusion and/or chorioamnionitis associated with pathogen-induced inflammation in early preterm birth, we developed a model of prenatal transient systemic hypoxia-ischemia (TSHI) combined with intra-amniotic lipopolysaccharide (LPS). In pregnant Sprague Dawley rats, TSHI via uterine artery occlusion on embryonic day 18 (E18) induces a graded placental underperfusion defect associated with increasing CNS damage in the fetus. When combined with intra-amniotic LPS injections, placental inflammation is increased and CNS damage is compounded with associated white matter, gait and imaging abnormalities. Prenatal TSHI and TSHI+LPS prenatal insults meet several of the criteria of an EoP model including recapitulating the intrauterine insult, causing loss of neurons, oligodendrocytes and axons, loss of subplate, and functional deficits in adult animals that mimic those observed in children born extremely preterm. Moreover, this model allows for the dissection of inflammation induced by divergent injury types.

Encephalopathy of prematurity encompasses the central nervous system abnormalities associated with injury from preterm birth. This report describes a clinically relevant rat model of in utero transient systemic hypoxia-ischemia and intra-amniotic lipopolysaccharide administration (LPS) that mimics chorioamnionitis, and the related impact of infectious stimuli and placental underperfusion on CNS development.

Encephalopathy of prematurity (EoP) is a term that encompasses the central nervous system (CNS) abnormalities associated with preterm birth. To best ...

Using an Ingestible Telemetric Temperature Pill to Assess Gastrointestinal Temperature During Exercise

Exercise results in an increase in core body temperature (Tc), which may reduce exercise performance and eventually can lead to the development of heat-related disorders. Therefore, accurate measurement of Tc during exercise is of great importance, especially in athletes who have to perform in challenging ambient conditions. In the current literature a number of methods have been described to measure the Tc (esophageal, external tympanic membrane, mouth or rectum). However, these methods are suboptimal to measure Tc during exercise since they are invasive, have a slow response or are influenced by environmental conditions. Studies described the use of an ingestible telemetric temperature pill as a reliable and valid method to assess gastrointestinal temperature (Tgi), which is a representative measurement of Tc. Therefore, the goal of this study was to provide a detailed description of the measurement of Tgi using an ingestible telemetric temperature pill. This study addresses important methodological factors that must be taken into account for an accurate measurement. It is recommended to read the instructions carefully in order to ensure that the ingestible telemetric temperature pill is a reliable method to assess Tgi at rest and during exercise.

This study describes an accurate, reliable and non-invasive technique to continuously measure gastrointestinal temperature during exercise. The ingestible telemetric temperature pill is suitable to measure gastrointestinal temperature in laboratory settings as well as in field based settings.

Exercise results in an increase in core body temperature (Tc), which may reduce exercise performance and eventually can lead to the development of ...

Esophageal Heat Transfer for Patient Temperature Control and Targeted Temperature Management

Controlling patient temperature is important for a wide variety of clinical conditions. Cooling to normal or below normal body temperature is often performed for neuroprotection after ischemic insult (e.g. hemorrhagic stroke, subarachnoid hemorrhage, cardiac arrest, or other hypoxic injury). Cooling from febrile states treats fever and reduces the negative effects of hyperthermia on injured neurons. Patients are warmed in the operating room to prevent inadvertent perioperative hypothermia, which is known to cause increased blood loss, wound infections, and myocardial injury, while also prolonging recovery time. There are many reported approaches for temperature management, including improvised methods that repurpose standard supplies (e.g., ice, chilled saline, fans, blankets) but more sophisticated technologies designed for temperature management are typically more successful in delivering an optimized protocol. Over the last decade, advanced technologies have developed around two heat transfer methods: surface devices (water blankets, forced-air warmers) or intravascular devices (sterile catheters requiring vascular placement). Recently, a novel device became available that is placed in the esophagus, analogous to a standard orogastric tube, that provides efficient heat transfer through the patient&#39;s core. The device connects to existing heat exchange units to allow automatic patient temperature management via a servo mechanism, using patient temperature from standard temperature sensors (rectal, Foley, or other core temperature sensors) as the input variable. This approach eliminates vascular placement complications (deep venous thrombosis, central line associated bloodstream infection), reduces obstruction to patient access, and causes less shivering when compared to surface approaches. Published data have also shown a high degree of accuracy and maintenance of target temperature using the esophageal approach to temperature management. Therefore, the purpose of this method is to provide a low-risk alternative method for controlling patient temperature in critical care settings.

This study presents a novel method to provide efficient patient temperature control for cooling or warming patients. A single use, triple lumen device is placed into the esophagus, analogous to a standard orogastric tube, and connects to existing heat exchange units to perform automatic patient temperature management.

Controlling patient temperature is important for a wide variety of clinical conditions. Cooling to normal or below normal body temperature is often ...

Microelectrode Impalement Method to Record Membrane Potential from a Cannulated Middle Cerebral Artery

Membrane potential (Vm) of vascular smooth muscle cells determines vessel tone and thus blood flow to an organ. Changes in the expression and function of ion channels and electrogenic pumps that regulate Vm in disease conditions could potentially alter Vm, vascular tone, and blood flow. Thus, a basic understanding of electrophysiology and the methods necessary to accurately record Vm in healthy and diseased states are essential. This method will allow modulating Vm using different pharmacological agents to restore Vm. Although there are several methods, each with its advantages and disadvantages, this article provides protocols to record Vm from cannulated resistance vessels such as the middle cerebral artery using the microelectrode impalement method. Middle cerebral arteries are allowed to gain myogenic tone in a myograph chamber, and the vessel wall is impaled using high resistance microelectrodes. The Vm signal is collected through an electrometer, digitized, and analyzed. This method provides an accurate reading of the Vm of a vessel wall without damaging the cells and without changing the membrane resistance.

The primary goal of this article is to provide details of how to record membrane potential (Vm) from the middle cerebral artery using the microelectrode impalement method. The cannulated middle cerebral artery is equilibrated to gain myogenic tone, and the vessel wall is impaled using high resistance microelectrodes.

Membrane potential (Vm) of vascular smooth muscle cells determines vessel tone and thus blood flow to an organ. Changes in the expression and function of ...

Chemiluminescence-based Assays for Detection of Nitric Oxide and its Derivatives from Autoxidation and Nitrosated Compounds

Nitric oxide (NO) activity in vivo is the combined results of its direct effects, the action of its derivatives generated from NO autoxidation, and the effects of nitrosated compounds. Measuring NO metabolites is essential to studying NO activity both at vascular levels and in other tissues, especially in the experimental settings where exogenous NO is administered. Ozone-based chemiluminescence assays allow precise measurements of NO and NO metabolites in both fluids (including plasma, tissue homogenates, cell cultures) and gas mixtures (e.g., exhaled breath). NO reacts with ozone to generate nitrogen dioxide in an excited state. The consequent light emission allows photodetection and the generation of an electric signal reflecting the NO content of the sample. Aliquots from the same sample can be used to measure specific NO metabolites, such as nitrate, nitrite, S-nitrosothiols, and iron-nitrosyl complexes. In addition, NO consumed by cell-free hemoglobin is also quantified with chemiluminescence analysis. An illustration of all these techniques is provided.

Here, we present protocols for detecting nitric oxide and its biologically relevant derivatives using chemiluminescence-based assays with high sensitivity.

Nitric oxide (NO) activity in vivo is the combined results of its direct effects, the action of its derivatives generated from NO autoxidation, and the ...

Dynamic Continuous Blood Extraction from Rat Heart via Noninvasive Microdialysis Technique

Dynamic analysis of blood components is of great importance in understanding cardiovascular diseases and their related diseases, such as myocardial infarction, arrhythmia, atherosclerosis, cardiogenic pulmonary edema, pulmonary embolism, and cerebral embolism. At the same time, it is urgent to break through the continuous heart blood sampling technique in live rats to evaluate the effectiveness of distinctive ethnic medicine therapy. In this study, a blood microdialysis probe was implanted in the right jugular vein of rats in a precise and noninvasive surgical procedure. Cardiac blood samples were then collected at a rate of 2.87 nL/min to 2.98 mL/min by connecting to an online microdialysis sample collection system. Even more momentously, the acquired blood samples can temporarily be stored in microdialysis containers at 4 &#176;C. The microdialysis-based online continuous blood collection program from rat heart has greatly guaranteed the quality of blood samples, advancing and invigorating the scientific rationality of the research on systemic cardiovascular diseases and evaluating ethnomedicine therapy from the perspective of hematology.

Dynamic Continuous Blood Extraction from Rat Heart via Noninvasive Microdialysis Technique

The present protocol describes a simple and efficient method for the real-time and dynamic collection of rat heart blood using the microdialysis technique.

Dynamic analysis of blood components is of great importance in understanding cardiovascular diseases and their related diseases, such as myocardial ...

Economical Diatom DNA Extraction Using a Modified Kit

Extraction of Diatom DNA from Water Samples and Tissues

Diatom testing is an essential auxiliary means in forensic practice to determine whether the corpse drowned in water and to infer the drowning location. Diatom testing is also an important research content in the field of the environment and plankton. The diatom molecular biology testing technology, which focuses on diatom DNA as the primary research object, is a new method of diatom testing. Diatom DNA extraction is the basis of diatom molecular testing. At present, the kits commonly used for diatom DNA extraction are expensive, which increases the cost of carrying out related research. Our laboratory improved the general whole blood genomic DNA rapid extraction kit and obtained a satisfactory diatom DNA extraction effect, thus providing an alternative economical and affordable DNA extraction solution based on glass beads for related research. The diatom DNA extracted using this protocol could satisfy many downstream applications, such as PCR and sequencing.

Author Spotlight: Diatom Testing for Forensic Drowning Examination 

This article describes a protocol for diatom DNA extraction using a modified common DNA extraction kit.

Diatom testing is an essential auxiliary means in forensic practice to determine whether the corpse drowned in water and to infer the drowning location. ...

Protein Extraction from Human Tear Using Schirmer Strip

Begin by cutting and discarding the front end of the Schirmer strip containing the dried human tears beyond the zero millimeter mark. Then cut the strip into one millimeter intervals and place the pieces in a 1.5 milliliter micro centrifuge tube. Next, add 100 microliters of lysis buffer to the micro centrifuge tube.Vortex it at 1000 RPM at room temperature for one hour in a thermo mixer. After brief centrifugation, transfer the supernatant to a new 1.5 milliliter micro centrifuge tube. Using clean forceps, move the strips into 200 microliter pipette tips.Place the tips back into the same micro centrifuge tube, then centrifuge it for maximum sample recovery. Measure the protein concentration using bicinchoninic acid or a compatible protein assay.

Novel Retina Protection Assay for Diabetic Retinopathy Pathogenesis Study

An Assay to Detect Protection of the Retinal Vasculature from Diabetes-Related Death in Mice

Diabetic retinopathy (DR) is a complex and progressive ocular disease characterized by two distinct phases in its pathogenesis. The first phase involves the loss of protection from diabetes-induced damage to the retina, while the second phase centers on the accumulation of this damage. Traditional assays primarily focus on evaluating capillary degeneration, which is indicative of the severity of damage, essentially addressing the second phase of DR. However, they only indirectly provide insights into whether the protective mechanisms of the retinal vasculature have been compromised. To address this limitation, a novel approach was developed to directly assess the retina's protective mechanisms - specifically, its resilience against diabetes-induced insults like oxidative stress and cytokines. This protection assay, although initially designed for diabetic retinopathy, holds the potential for broader applications in both physiological and pathological contexts. In summary, understanding the pathogenesis of diabetic retinopathy involves recognizing the dual phases of protection loss and damage accumulation, with this innovative protection assay offering a valuable tool for research and potentially extending to other medical conditions.

Author Spotlight: Understanding Retinal Vessel Resilience and Disease Progression

A protection assay was developed to monitor the retinal vasculature's resilience to death from diabetes/diabetic retinopathy-related insults such as oxidative stress and cytokines.

Diabetic retinopathy (DR) is a complex and progressive ocular disease characterized by two distinct phases in its pathogenesis. The first phase involves ...