This work was supported in part by a Scientist Development Grant from the American Heart Association (14SDG18160021 to YD), the US NIH R01 grants HL 81753 and HL 107304 to XX, and the Mayo Foundation to XX.

All procedures described here were performed in accordance with the Guide for the Care and Use of Laboratory Animals (National Academies Press. 2011), and they were approved by the Mayo Clinic Institutional Animal Care and Use Committee.
1. Adult Zebrafish Preparation
<ol>
	<li>Set up sufficient breeding pairs in crossing tanks to acquire at least twice as many as the total fish needed for DOX injection. If comparing fish with different genetic backgrounds, breed all fish within the same wee...

<ol>
	<li>Octavia, 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=Doxorubicin-induced+cardiomyopathy:+from+molecular+mechanisms+to+therapeutic+strategies.">Doxorubicin-induced cardiomyopathy: from molecular mechanisms to therapeutic strategies.</a> J Mol Cell Cardiol. 52 (6), 1213-1225 (2012).</li><li>Singal, P. K., Iliskovic, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doxorubicin-induced+cardiomyopathy.">Doxorubicin-induced cardiomyopathy.</a> N Engl J Med. 339 (13), 900-905 (1998).</li><li>Angsutararux, P., Luanpitpong, S., Issaragrisil, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Chemotherapy-Induced+Cardiotoxicity:+Overview+of+the+Roles+of+Oxidative+Stress.">Chemotherapy-Induced Cardiotoxicity: Overview of the Roles of Oxidative Stress.</a> Oxid Med Cell Longev. , 795602 (2015).</li><li>Ichikawa, 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=Cardiotoxicity+of+doxorubicin+is+mediated+through+mitochondrial+iron+accumulation.">Cardiotoxicity of doxorubicin is mediated through mitochondrial iron accumulation.</a> J Clin Invest. 124 (2), 617-630 (2014).</li><li>Zhang, Y. W., Shi, J., Li, Y. J., Wei, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cardiomyocyte+death+in+doxorubicin-induced+cardiotoxicity.">Cardiomyocyte death in doxorubicin-induced cardiotoxicity.</a> Arch Immunol Ther Exp (Warsz). 57 (6), 435-445 (2009).</li><li>Sawyer, D. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Anthracyclines+and+heart+failure.">Anthracyclines and heart failure.</a> N Engl J Med. 368 (12), 1154-1156 (2013).</li><li>Zhang, 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=Identification+of+the+molecular+basis+of+doxorubicin-induced+cardiotoxicity.">Identification of the molecular basis of doxorubicin-induced cardiotoxicity.</a> Nat Med. 18 (11), 1639-1642 (2012).</li><li>Dodd, D. 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=Doxorubicin+cardiomyopathy+is+associated+with+a+decrease+in+calcium+release+channel+of+the+sarcoplasmic+reticulum+in+a+chronic+rabbit+model.">Doxorubicin cardiomyopathy is associated with a decrease in calcium release channel of the sarcoplasmic reticulum in a chronic rabbit model.</a> J Clin Invest. 91 (4), 1697-1705 (1993).</li><li>Mitry, M. A., Edwards, J. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doxorubicin+induced+heart+failure:+Phenotype+and+molecular+mechanisms.">Doxorubicin induced heart failure: Phenotype and molecular mechanisms.</a> Int J Cardiol Heart Vasc. 10, 17-24 (2016).</li><li>Aminkeng, F., 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+coding+variant+in+RARG+confers+susceptibility+to+anthracycline-induced+cardiotoxicity+in+childhood+cancer.">A coding variant in RARG confers susceptibility to anthracycline-induced cardiotoxicity in childhood cancer.</a> Nat Genet. 47 (9), 1079-1084 (2015).</li><li>Deng, 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=Dystrophin-deficiency+increases+the+susceptibility+to+doxorubicin-induced+cardiotoxicity.">Dystrophin-deficiency increases the susceptibility to doxorubicin-induced cardiotoxicity.</a> Eur J Heart Fail. 9 (10), 986-994 (2007).</li><li>Leong, S. L., Chaiyakunapruk, N., Lee, S. 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F., Nesser, M. E., Thompson, D. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dexrazoxane+in+the+prevention+of+doxorubicin-induced+cardiotoxicity.">Dexrazoxane in the prevention of doxorubicin-induced cardiotoxicity.</a> Ann Pharmacother. 28 (9), 1063-1072 (1994).</li><li>Adams, J. W., 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=Enhanced+Galphaq+signaling:+a+common+pathway+mediates+cardiac+hypertrophy+and+apoptotic+heart+failure.">Enhanced Galphaq signaling: a common pathway mediates cardiac hypertrophy and apoptotic heart failure.</a> Proc Natl Acad Sci U S A. 95 (17), 10140-10145 (1998).</li><li>Bowles, N. E., Bowles, K. R., Towbin, J. 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E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Etiologies+of+cardiomyopathy+and+heart+failure.">Etiologies of cardiomyopathy and heart failure.</a> Nat Med. 5 (3), 266-267 (1999).</li><li>Liu, 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=Visnagin+protects+against+doxorubicin-induced+cardiomyopathy+through+modulation+of+mitochondrial+malate+dehydrogenase.">Visnagin protects against doxorubicin-induced cardiomyopathy through modulation of mitochondrial malate dehydrogenase.</a> Sci Transl Med. 6 (266), 266ra170 (2014).</li><li>Asimaki, 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=Identification+of+a+new+modulator+of+the+intercalated+disc+in+a+zebrafish+model+of+arrhythmogenic+cardiomyopathy.">Identification of a new modulator of the intercalated disc in a zebrafish model of arrhythmogenic cardiomyopathy.</a> Sci Transl Med. 6 (240), 240ra274 (2014).</li><li>Ding, 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=Haploinsufficiency+of+target+of+rapamycin+attenuates+cardiomyopathies+in+adult+zebrafish.">Haploinsufficiency of target of rapamycin attenuates cardiomyopathies in adult zebrafish.</a> Circ Res. 109 (6), 658-669 (2011).</li><li>Sun, X., 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=Cardiac+hypertrophy+involves+both+myocyte+hypertrophy+and+hyperplasia+in+anemic+zebrafish.">Cardiac hypertrophy involves both myocyte hypertrophy and hyperplasia in anemic zebrafish.</a> PLoS One. 4 (8), e6596 (2009).</li><li>Sun, 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=Activation+of+the+Nkx2.5-Calr-p53+signaling+pathway+by+hyperglycemia+induces+cardiac+remodeling+and+dysfunction+in+adult+zebrafish.">Activation of the Nkx2.5-Calr-p53 signaling pathway by hyperglycemia induces cardiac remodeling and dysfunction in adult zebrafish.</a> Dis Model Mech. 10 (10), 1217-1227 (2017).</li><li>Yang, J., Shah, S., Olson, T. M., Xu, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modeling+GATAD1-Associated+Dilated+Cardiomyopathy+in+Adult+Zebrafish.">Modeling GATAD1-Associated Dilated Cardiomyopathy in Adult Zebrafish.</a> J Cardiovasc Dev Dis. 3 (1), (2016).</li><li>Ding, 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=Trapping+cardiac+recessive+mutants+via+expression-based+insertional+mutagenesis+screening.">Trapping cardiac recessive mutants via expression-based insertional mutagenesis screening.</a> Circ Res. 112 (4), 606-617 (2013).</li><li>Ding, 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=A+modifier+screen+identifies+DNAJB6+as+a+cardiomyopathy+susceptibility+gene.">A modifier screen identifies DNAJB6 as a cardiomyopathy susceptibility gene.</a> JCI Insight. 2 (8), (2017).</li><li>Kinkel, M. D., Eames, S. C., Philipson, L. H., Prince, V. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intraperitoneal+injection+into+adult+zebrafish.">Intraperitoneal injection into adult zebrafish.</a> J Vis Exp. (42), (2010).</li><li>Wang, L. W., 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=Standardized+echocardiographic+assessment+of+cardiac+function+in+normal+adult+zebrafish+and+heart+disease+models.">Standardized echocardiographic assessment of cardiac function in normal adult zebrafish and heart disease models.</a> Dis Model Mech. 10 (1), 63-76 (2017).</li><li>Desai, V. G., 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=Development+of+doxorubicin-induced+chronic+cardiotoxicity+in+the+B6C3F1+mouse+model.">Development of doxorubicin-induced chronic cardiotoxicity in the B6C3F1 mouse model.</a> Toxicol Appl Pharmacol. 266 (1), 109-121 (2013).</li><li>Zhu, W., Shou, W., Payne, R. M., Caldwell, R., Field, L. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+mouse+model+for+juvenile+doxorubicin-induced+cardiac+dysfunction.">A mouse model for juvenile doxorubicin-induced cardiac dysfunction.</a> Pediatr Res. 64 (5), 488-494 (2008).</li><li>Chatterjee, K., Zhang, J., Honbo, N., Karliner, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doxorubicin+cardiomyopathy.">Doxorubicin cardiomyopathy.</a> Cardiology. 115 (2), 155-162 (2010).</li><li>Bang, 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=Cardiac+fibroblast-derived+microRNA+passenger+strand-enriched+exosomes+mediate+cardiomyocyte+hypertrophy.">Cardiac fibroblast-derived microRNA passenger strand-enriched exosomes mediate cardiomyocyte hypertrophy.</a> J Clin Invest. 124 (5), 2136-2146 (2014).</li><li>Rassaf, T., Kelm, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Protection+from+diabetic+cardiomyopathy+-+putative+role+of+the+retinoid+receptor-mediated+signaling.">Protection from diabetic cardiomyopathy - putative role of the retinoid receptor-mediated signaling.</a> J Mol Cell Cardiol. 59, 179-180 (2013).</li><li>Wahbi, 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=Dilated+cardiomyopathy+in+patients+with+mutations+in+anoctamin+5.">Dilated cardiomyopathy in patients with mutations in anoctamin 5.</a> Int J Cardiol. 168 (1), 76-79 (2013).</li><li>Zhou, M. D., Sucov, H. M., Evans, R. M., Chien, K. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retinoid-dependent+pathways+suppress+myocardial+cell+hypertrophy.">Retinoid-dependent pathways suppress myocardial cell hypertrophy.</a> Proc Natl Acad Sci U S A. 92 (16), 7391-7395 (1995).</li><li>Hershman, D. 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=Doxorubicin,+cardiac+risk+factors,+and+cardiac+toxicity+in+elderly+patients+with+diffuse+B-cell+non-Hodgkin's+lymphoma.">Doxorubicin, cardiac risk factors, and cardiac toxicity in elderly patients with diffuse B-cell non-Hodgkin's lymphoma.</a> J Clin Oncol. 26 (19), 3159-3165 (2008).</li><li>Silber, J. H., Barber, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Doxorubicin-induced+cardiotoxicity.">Doxorubicin-induced cardiotoxicity.</a> N Engl J Med. 333 (20), 1359-1360 (1995).</li><li>Von Hoff, D. D., 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=Risk+factors+for+doxorubicin-induced+congestive+heart+failure.">Risk factors for doxorubicin-induced congestive heart failure.</a> Ann Intern Med. 91 (5), 710-717 (1979).</li><li>Pugach, E. K., Li, P., White, R., Zon, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Retro-orbital+injection+in+adult+zebrafish.">Retro-orbital injection in adult zebrafish.</a> J Vis Exp. (34), (2009).</li><li>Zang, L., Morikane, D., Shimada, Y., Tanaka, T., Nishimura, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+novel+protocol+for+the+oral+administration+of+test+chemicals+to+adult+zebrafish.">A novel protocol for the oral administration of test chemicals to adult zebrafish.</a> Zebrafish. 8 (4), 203-210 (2011).</li><li>Collymore, C., Rasmussen, S., Tolwani, R. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Gavaging+adult+zebrafish.">Gavaging adult zebrafish.</a> J Vis Exp. (78), (2013).</li></ol>

To model a progressive DIC, the dose of 20 mg/kg DOX was determined experimentally as the highest dose that does not cause significant fish death during 1 wpi but still results in fish death and the reduction of cardiac function after 4 wpi (Figure 3 and Figure 4C). This dose is comparable to those frequently used in rodent DIC models (15-25 mg/kg) and to the limit cumulative dose in humans (550 mg/m2, which is equivalent to 15 mg/kg)<sup class="xref"...

Doxorubicin (DOX), also named Adriamycin, has been developed as an anti-neoplastic drug since the 1960s1,2. It is now still actively used as an important chemotherapeutic drug for a broad spectrum of tumors. However, clinical application of DOX was hampered by its dose-dependent toxicities, especially cardiotoxicity characterized by variable symptoms ranging from asymptomatic electrocardiographic changes to pericarditis and decompensated cardiomyopathy1,2. To date, at least three major hypotheses have been raised to explain DIC, including activated reactive oxygen species (ROS)1,3,4,5, inhibition of topoisomerase II-&#946; (TOP2&#946;)6,7, and modulation of intracellular calcium release1,8,9. Accumulating evidence also suggests genetic predisposition as a pivotal risk factor for DIC10,11,12,13. Gene identities related to these DIC predispositions, however, remain largely unknown. Dexrazoxane is the only adjuvant agent approved by the US Food and Drug Administration (FDA) to treat DIC, but with limited implementation14,15,16, underscoring the need to identify additional therapeutic strategies. Animal models of DIC are therefore explored for these purposes. Owing to their accessibility and simplicity, mechanistic studies on DIC models could potentially have broader impacts on other types of cardiomyopathies: common pathogenesis might be shared among cardiomyopathies of different etiologies, especially at later pathological stages17,18,19,20.
In addition to rodent models of DIC, zebrafish DIC models with higher throughput have been developed to facilitate the discovery of both new genetic factors and therapeutics. An embryonic DIC model has been established in the transparent zebrafish embryos for screening therapeutic compounds21. Given that the cardiomyopathies are adult onset diseases with a progressive pathogenesis, adult zebrafish cardiomyopathy models have been developed22,23,24,25,26. We generated the first acquired model for cardiomyopathy resulting from chronic anemia24, followed by DIC as the second acquired cardiomyopathy model in adult zebrafish23. We found that injection of a single bolus of DOX into adult zebrafish induces cardiotoxicity that consists of an acute phase roughly within 1 week post-injection (wpi), followed by a chronic phase of cardiomyopathy up to 6 months post-injection. While haploinsufficiency of the mechanistic target of rapamycin(mtor) ameliorates cardiomyopathy at the chronic phase, it exaggerates fish mortality at the acute phase, underscoring the value of the adult DIC model to discern stage-dependent mechanisms23. We further demonstrated that the adult DIC model can be used to stress a collection of zebrafish insertional cardiac (ZIC) mutants that are being generated via a transposon-based insertional mutagenesis approach27. A pilot screen identified 3 known cardiomyopathy genes as well as DnaJ (Hsp40) homolog, subfamily B, and member 6b (dnajb6b) as new DIC susceptibility genes28. Therefore, the generation of the adult DIC model in zebrafish led to a new methodology that systematically enables identification of genetic modifiers for DIC, which complements the existing genome-wide association study (GWAS) and quantitative trait locus (QTL) analysis.
During the generation and implementation of the adult zebrafish DIC model, we noticed significant variations among different researchers and/or even among different injections performed by the same investigator. The longitudinal nature of the model imposes challenges to registering results from different investigators and to the sequential troubleshooting process. To facilitate the use of this simple cardiomyopathy-inducing stress method by the research community, we describe our protocol in detail, present two types of IP injection, and discuss considerations to reduce variations among different researchers.

<table>
	<tbody>
		<tr>
			<td>Crossing tank</td>
			<td>Aquaneering</td>
			<td>ZHCT100</td>
			<td>Fish breeding</td>
		</tr>
		<tr>
			<td>Incubator</td>
			<td>ThermoFisher</td>
			<td></td>
			<td>Maintaining embryo</td>
		</tr>
		<tr>
			<td>3 L medium tank</td>
			<td>Aquaneering</td>
			<td>ZT280</td>
			<td>Maintaining fish</td>
		</tr>
		<tr>
			<td>Paramecia</td>
			<td>Carolina</td>
			<td>131560</td>
			<td>Food for juvenile fish</td>
		</tr>
		<tr>
			<td>Live hatched brine shrimp</td>
			<td>in house</td>
			<td></td>
			<td>Food for adult fish</td>
		</tr>
		<tr>
			<td>Doxorubicin hydrochloride</td>
			<td>Sigma</td>
			<td>D1515-10MG</td>
			<td></td>
		</tr>
		<tr>
			<td>1.5 ml safe-lock tube</td>
			<td>Eppendorf</td>
			<td>No. 022363204</td>
			<td>For drug storage</td>
		</tr>
		<tr>
			<td>Aluminum foil paper</td>
			<td>Fisher</td>
			<td>1213104</td>
			<td>For preventing light exposure</td>
		</tr>
		<tr>
			<td>Proteinase K</td>
			<td>Roche</td>
			<td>No. 03115887001</td>
			<td>For dechorionating embryo</td>
		</tr>
		<tr>
			<td>Hank&#39;s balanced salt solution (HBBS)</td>
			<td>ThermoFisher</td>
			<td>14025076</td>
			<td>Vehicle for DOX</td>
		</tr>
		<tr>
			<td>100 mm petri dish</td>
			<td>Falcon</td>
			<td>431741</td>
			<td></td>
		</tr>
		<tr>
			<td>10 &#956;L NanoFil micro-syringe</td>
			<td>WPI</td>
			<td>NANOFIL</td>
			<td>For injection</td>
		</tr>
		<tr>
			<td>34 gauge needle&#160;</td>
			<td>WPI</td>
			<td>NF34BV-2</td>
			<td>For injection</td>
		</tr>
		<tr>
			<td>Tricaine</td>
			<td>Argent</td>
			<td>MS-222</td>
			<td>Anesthetizing fish</td>
		</tr>
		<tr>
			<td>96 well plate</td>
			<td>Costar</td>
			<td>3539</td>
			<td>For embryo drug treatment</td>
		</tr>
		<tr>
			<td>Transfer pipette</td>
			<td>Bel-art product</td>
			<td>F37898</td>
			<td>For transfering embryo</td>
		</tr>
	</tbody>
</table>

a doxorubicin-induced cardiomyopathy model in adult zebrafish

The genetically accessible adult zebrafish (Danio rerio) has been increasingly used as a vertebrate model for understanding human diseases such as cardiomyopathy. Because of its convenience and amenability to high throughput genetic manipulations, the generation of acquired cardiomyopathy models, such as the doxorubicin-induced cardiomyopathy (DIC) model in adult zebrafish, is opening the doors to new research avenues, including discovering cardiomyopathy modifiers via forward genetic screening. Different from the embryonic zebrafish DIC model, both initial acute and later chronic phases of cardiomyopathy can be determined in the adult zebrafish DIC model, enabling the study of stage-dependent signaling mechanisms and therapeutic strategies. However, variable results can be obtained with the current model, even in the hands of experienced investigators. To facilitate future implementation of the DIC model, we present a detailed protocol on how to generate this DIC model in adult zebrafish and describe two alternative ways of intraperitoneal (IP) injection. We further discuss options on how to reduce variations to obtain reliable results and provide suggestions on how to appropriately interpret the results.

Here, two methods to perform IP injection to model DIC in adult zebrafish are presented. While using the classic, established IP injection method29, it was noted that the injected DOX solution (red color) could sometimes ooze out from the location where the needle penetrated. The alternative IP injection uses a different location for needle penetration that is 3-4 mm away from the peritoneum where the DOX is released (Figure 1A), which...

Watch this Scientific Journal Video about A Doxorubicin-induced Cardiomyopathy Model in Adult Zebrafish at JoVE.com

A Doxorubicin-induced Cardiomyopathy Model in Adult Zebrafish

A method to generate a doxorubicin-induced cardiomyopathy model in adult zebrafish (Danio rerio) is described here. Two alternative ways of intraperitoneal injection are presented and conditions to reduce variations among different experimental groups are discussed.

The genetically accessible adult zebrafish (Danio rerio) has been increasingly used as a vertebrate model for understanding human diseases such as ...

This method can help determine key factors affecting viral agents during the development of an adaptive model for ensocycline induced catatoxicity. The main advantage of this technique is that it is a simple ensocycline induced catatoxicity model which can be used for high-throughput genetic and drug-based screenings. When making DOX stock solution, thoroughly dissolve the DOX powder in deionized water until absolutely no clumps are visible.For quality control testing, collect a wild-type Zebra fish embryos from at least two pair of fish in two separate collections. Manually dechorionate the embryos 24 hours post-fertilization using fine needles. After the dechorionation, refresh the embryo water and remove any dead embryos.Each collection of embryos must have at least 36 embryos for a quality control test. Now, dilute the stock DOX solution in fresh embryo water to a final concentration of 100 micromolar. Prepare at least 100 microliters per three embryos.Mix the dilution using a vortex. The final dilution should have a light red color. Next, load the wells of a 96 well plate with 100 microliters of diluted DOX solution.Prepare one well per three embryos. Then, transfer the embryos to the wells using a plastic transfer pipette. While transferring embryos, keep the embryos close to the end of the pipette tip.Then, put the pipette tip into solution and allow the embryos to swim naturally into the well. Do not eject the embryos with solution as this will alter the DOX concentration. 48 hours post-fertilization, refresh the DOX solution.At this time, look under 10X magnification to identify dead embryos, which have no heartbeat and identify embryos with edema. Be quick to count and remove any dead embryos, otherwise the remaining embryos in the well will also die. Repeat the dead count at 72 hours post-fertilization.If there is at least 25%death then the DOX solution has a good drug efficacy and can be used for the experiment. Prior to injecting the fish with DOX, fast the fish for 24 hours. Next, group the fish.While anesthetized, use a clean filter paper to dry each fish and measure its body weight. Make groups of fish that are all within 10%of the same body weight, so each group can be injected with the same dose of DOX. Next, calculate the working concentration of DOX for each group so that each group is injected with five microliters of solution and receives the same dose of DOX by body weight.Then, dilute the stock of DOX in 1X HBSS. Mix the dilution with a vortex and then pulse spin the dilution to keep it cooled together in the tube. For the injection, prepare an injecting platform.In a clean, 100 milliliter Petri dish, place a sponge. With the aid of a dissection microscope, cut a cavity into the sponge to hold one fish. Four centimeters usually works.Next, unto a 34-gage needle, attach a 10 microliter microsyringe. Then, rinse the needle with one 1X HBSS to remove any bubbles or blocks from the syringe and tubing. Now, briefly anesthetize the adult fish with tricaine.Then, soak the sponge in the embryo water with tricaine and transfer a fish onto the sponge with its abdomen up for the injection. Now, intraperitoneally inject DOX solution by quickly inserting the needle at a 45 degree angle into the midline between the pelvic fins about one to two millimeters deep. Then, slowly release all of the DOX solution.Before retracting the needle, wait five seconds. Alternatively, the fish can be positioned laterally, with the anterior to the right. Then, inject at the lateral line above the pelvic fin, with the bevel up pointing towards seven o'clock at a 45 degree angle and three to four millimeters deep.If either method for injection was successful, there will be a red tint in the belly. After the injection, quickly transfer the fish to a clean crossing tank filled with fresh system water where it can recover. Then, rinse the needle with HBSS and proceed to the inject the next fish.Later, return the injected fish to a system with running circulation, but separate from the main system to avoid cross-contamination. For the next 24 hours, continue to fast the fish. Over the first week post-injection, be certain to check the fish daily and remove any dead fish.When using the classic belly-up IP injection method, it was noted that the injected DOX solution could sometimes ooze out from the location where the needle penetrated. The alternative lateral IP injection effectively prevented the leakage. Injection of DOX dosed at 50 milligrams per kilogram led to severe toxicity where the majority of fish died within one week.However, at a lower dose of 20 milligrams per kilogram, the injected Zebra fish could be maintained for chronic observation. With the alternative injection, there was no fish death during the first two weeks, and only about 10%death at four weeks. The classic method for injection at the same dose led to about 30%dead by four weeks.Next, transgenic fish with a casper background expressing DsRed and cardiomyocytes were used to assess the progression of cardiac dysfunction in the DIC model. Their red heart could be viewed at both the systolic and diastolic stages under a fluorescent microscope. After injection of 20 milligrams per kilogram of DOX using the alternative lateral injection method, ventricular function decline was detected beginning after four weeks.Once mastered, delivery of Doxorubicin with either technique can be performed on about 30 to 50 fish an hour. Following this procedure, other methods like echocardiography, electrocardiography or ex vivo heart function essay can be performed in order to profile heart function of this DIC model at different stages. While attempting this procedure, it is important to remember to use freshly prepared Doxorubicin and to test its drug efficacy after long-term storage, before the injection.Also, always handle Doxorubicin taking the appropriate safety precautions.

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9.6K ビュー.  Mayo Clinic Graduate School of Biomedical Sciences. This method can help determine key factors affecting viral agents during the development of an adaptive model for ensocycline induced catatoxicity. The main advantage of this technique is that it is a simple ensocycline induced catatoxicity model which can be used for high-throughput genetic and drug-based screenings. When making DOX stock solution, thoroughly dissolve the DOX powder in deionized water until absolutely no clumps are visible.For quality control testing, collect a wild-t...

ビデオ: A Doxorubicin-induced Cardiomyopathy Model in Adult Zebrafish

A method to generate a doxorubicin-induced cardiomyopathy model in adult zebrafish (Danio rerio) is described here. Two alternative ways of intraperitoneal injection are presented and conditions to reduce variations among different experimental groups are...

zebrafish cardiomyopathy model: drug-induced cardiotoxicity

This video describes the technique of creating a zebrafish cardiomyopathy model with minimal variations among experimental groups and in the sample, we create zebrafish cardiomyopathy model using the drug...

Zebrafish Cardiomyopathy Model: Drug-Induced Cardiotoxicity

an intraperitoneal injection technique in adult zebrafish that minimizes body damage and associated mortality

Author Spotlight: Novel Intraperitoneal Injection Method for Zebrafish Cardiotoxicity Models

A new intraperitoneal (IP) injection method in adult zebrafish is described. When handling toxic compounds such as doxorubicin, this procedure is more effective than the two previously reported IP methods. The technique is designed to be easily adopted by researchers with limited experience in the zebrafish...

Optimized Intraperitoneal Injection for Compound Delivery in Adult Zebrafish

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An Intraperitoneal Injection Technique in Adult Zebrafish that Minimizes Body Damage and Associated Mortality

intrathoracic injection for the study of adult zebrafish heart

Intrathoracic Injection for the Study of Adult Zebrafish Heart

This method relies on the injection of 0.5&#8722;3 &#956;L of solution into the thorax of adult zebrafish. The procedure efficiently delivers proteins and chemical compounds into the proximity of the zebrafish heart without damaging the organ. The approach is suitable for testing effects of exogenous factors on various tissues of the...

a doxorubicin-induced murine model of dilated cardiomyopathy in vivo

A Doxorubicin-Induced Murine Model of Dilated Cardiomyopathy In Vivo

Described is a protocol to establish a Doxorubicin-induced dilated cardiomyopathy (DCM) model in mice via long-term intraperitoneal injection of...

modified intraperitoneal injection of doxorubicin into adult zebrafish

Modified Intraperitoneal Injection of Doxorubicin into Adult Zebrafish

tachycardia-induced cardiomyopathy as a chronic heart failure model in swine

Tachycardia-Induced Cardiomyopathy As a Chronic Heart Failure Model in Swine

Here, we present a protocol to produce tachycardia-induced cardiomyopathy in swine. This model represents a potent way to study the hemodynamics of progressive chronic heart failure and the effects of applied...

acute kidney injury model induced by cisplatin in adult zebrafish

Acute Kidney Injury Model Induced by Cisplatin in Adult Zebrafish

This protocol describes the procedures to induce Acute Kidney Injury (AKI) in adult zebrafish using cisplatin as a nephrotoxic agent. We detailed the steps to evaluate the reproducibility of the technique and two techniques to analyze inflammation and cell death in the renal tissue, flow cytometry and TUNEL,...

locomotor assessment of 6-hydroxydopamine-induced adult zebrafish-based parkinson's disease model

Locomotor Assessment of 6-Hydroxydopamine-induced Adult Zebrafish-based Parkinson&#039;s Disease Model

The present protocol describes the intracerebroventricular (ICV) injection of adult zebrafish with neurotoxic 6-hydroxydopamine (6-OHDA) at the ventral diencephalon (Dn) and the assessment of the impairment and subsequent recovery of swimming behavior postlesion by using the open tank test, which is accompanied by analysis using a video tracking...

Locomotor Assessment of 6-Hydroxydopamine-induced Adult Zebrafish-based Parkinson's Disease Model

kidney regeneration in adult zebrafish by gentamicin induced injury

Kidney Regeneration in Adult Zebrafish by Gentamicin Induced Injury

Here we present a reliable method to study adult kidney regeneration by inducing acute kidney injury by gentamicin injection. We show that injury is dependent on gentamicin dosage and environmental temperature using in situ hybridization to label lhx1a+ developing new nephrons.

a scalable model to study the effects of blunt-force injury in adult zebrafish

A Scalable Model to Study the Effects of Blunt-Force Injury in Adult Zebrafish

We modified the Marmarou weight drop model for adult zebrafish to examine a breadth of pathologies following blunt-force traumatic brain injury (TBI) and the mechanisms underlying subsequent neuronal regeneration. This blunt-force TBI model is scalable, induces a mild, moderate, or severe TBI, and recapitulates injury heterogeneity observed in human...

a mouse 5/6th nephrectomy model that induces experimental uremic cardiomyopathy

A Mouse 5/6th Nephrectomy Model That Induces Experimental Uremic Cardiomyopathy

This manuscript provides a detailed two-step surgical procedure to perform mouse 5/6th partial nephrectomy (PNx) with pole ligation. Four weeks after surgery, in comparison with sham-operated mice, the PNx mice developed impaired renal function, anemia, cardiac hypertrophy, cardiac fibrosis, and decreased heart systolic and diastolic...

A Mouse 5/6th Nephrectomy Model That Induces Experimental Uremic Cardiomyopathy

partial hepatectomy in adult zebrafish

Partial Hepatectomy in Adult Zebrafish

This protocol describes the procedure for removing the ventral lobe of the liver in adult zebrafish to enable the study of liver...

a cryoinjury model for studying skeletal muscle regeneration of the caudal peduncle in adult zebrafish

Author Spotlight: A Cryoinjury Model for Studying Skeletal Muscle Regeneration of the Caudal Peduncle in Adult Zebrafish  

This protocol describes a cryoinjury model to induce profound damage of several caudal myomeres in adult zebrafish. This method provides a new approach for studying skeletal muscle regeneration after severe loss of tissue in non-mammalian vertebrates.

A Cryoinjury Model for Studying Skeletal Muscle Regeneration of the Caudal Peduncle in Adult Zebrafish

m&#252;ller glia cell activation in a laser-induced retinal degeneration and regeneration model in zebrafish

M&amp;#252;ller Glia Cell Activation in a Laser-induced Retinal Degeneration and Regeneration Model in Zebrafish

The zebrafish is a popular animal model to study mechanisms of retinal degeneration/regeneration in vertebrates. This protocol describes a method to induce localized injury disrupting the outer retina with minimal damage to the inner retina. Subsequently, we monitor in vivo the retinal morphology and the M&#252;ller glia response throughout retinal...

M&#252;ller Glia Cell Activation in a Laser-induced Retinal Degeneration and Regeneration Model in Zebrafish

oral intubation of adult zebrafish: a model for evaluating intestinal uptake of bioactive compounds

Oral Intubation of Adult Zebrafish: A Model for Evaluating Intestinal Uptake of Bioactive Compounds

The protocol describes intubating adult zebrafish with a biologic; then dissecting and preparing the intestine for cytometry, confocal microscopy and qPCR. This method allows administration of bioactive compounds to monitor intestinal uptake and the local immune stimulus evoked. It&#160;is relevant for testing the intestinal dynamics of oral...

gavaging adult zebrafish

Gavaging Adult Zebrafish

The increasing use of zebrafish as an animal model requires the development of effective methods for the delivery of known quantities of compounds and solutions. The gavage procedure described below allows for the oral delivery of precise volumes of solution reliably, safely and efficiently to adult...

quantifying vibrio cholerae colonization and diarrhea in the adult zebrafish model

Quantifying Vibrio cholerae Colonization and Diarrhea in the Adult Zebrafish Model

Zebrafish are a natural Vibrio cholerae host and can be used to recapitulate and study the entire infectious cycle from colonization to transmission. Here, we demonstrate how to assess V. cholerae colonization levels and quantify diarrhea in...

Quantifying Vibrio cholerae Colonization and Diarrhea in the Adult Zebrafish Model

neurotoxicity assessment in adult danio rerio using a battery of behavioral tests in a single tank

Author Spotlight: Assessment of Environmental and Drug-Induced Behavioral Changes in Adult Zebrafish 

Here, we present a comprehensive behavioral test battery, including the novel tank, Shoaling, and social preference tests, to effectively determine the potential neurotoxic effects of chemicals (e.g., methamphetamine and glyphosate) on adult zebrafish using a single tank. This method is relevant to neurotoxicity and environmental...

Behavioral Test Battery to Assess Neurotoxic Effects in Adult Zebrafish

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Induction of Myocardial Infarction in Adult Zebrafish Using Cryoinjury

The mammalian heart is incapable of significant regeneration following an acute injury such as myocardial infarction1. By contrast, urodele amphibians and teleost fish retain a remarkable capacity for cardiac regeneration with little or no scarring throughout life2,3. It is not known why only some non-mammalian vertebrates can recreate a complete organ from remnant tissues4,5. To understand the molecular and cellular differences between regenerative responses in different species, we need to use similar approaches for inducing acute injuries.
In mammals, the most frequently used model to study cardiac repair has been acute ischemia after a ligation of the coronary artery or tissue destruction after cryoinjury6,7. The cardiac regeneration in newts and zebrafish has been predominantly studied after a partial resection of the ventricular apex2,3. Recently, several groups have established the cryoinjury technique in adult zebrafish8-10. This method has a great potential because it allows a comparative discussion of the results obtained from the mammalian and non-mammalian species.
Here, we present a method to induce a reproducible disc-shaped infarct of the zebrafish ventricle by cryoinjury. This injury model is based on rapid freezing-thawing tissue, which results in massive cell death of about 20% of cardiomyocytes of the ventricular wall. First, a small incision was made through the chest with iridectomy scissors to access the heart. The ventricular wall was directly frozen by applying for 23-25 seconds a stainless steel cryoprobe precooled in liquid nitrogen. To stop the freezing of the heart, fish water at room temperature was dropped on the tip of the cryoprobe. The procedure is well tolerated by animals, with a survival rate of 95%.
To characterize the regenerative process, the hearts were collected and fixed at different days after cryoinjury. Subsequently, the specimen were embedded for cryosectioning. The slides with sections were processed for histological analysis, in situ hybridization and immunofluorescence. This undertaking enhances our understanding of the factors that are required for the regenerative plasticity in the zebrafish, and provide new insights into the machinery of cardiac regeneration. A conceptual and molecular understanding of heart regeneration in zebrafish will impact both developmental biology and regenerative medicine.

Zebrafish represents a valuable model to study the mechanisms of heart regeneration in vertebrates. Here, we present a protocol for induction of a heart infarct in adult zebrafish using cryoinjury. This method results in massive cell death within 20% of the ventricular wall, similar to that observed in mammalian infarcts.

The mammalian heart is incapable of significant regeneration following an acute injury such as myocardial infarction1. By contrast, urodele amphibians and ...

Assessing Teratogenic Changes in a Zebrafish Model of Fetal Alcohol Exposure

Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, including mental retardation due to disordered and damaged brain development. Fetal alcohol spectrum disorder (FASD) is a term used to cover a continuum of birth defects that occur due to maternal alcohol consumption, and occurs in approximately 4% of children born in the United States. With 50% of child-bearing age women reporting consumption of alcohol, and half of all pregnancies being unplanned, unintentional exposure is a continuing issue2. In order to best understand the damage produced by ethanol, plus produce a model with which to test potential interventions, we developed a model of developmental ethanol exposure using the zebrafish embryo. Zebrafish are ideal for this kind of teratogen study3-8. Each pair lays hundreds of eggs, which can then be collected without harming the adult fish. The zebrafish embryo is transparent and can be readily imaged with any number of stains. Analysis of these embryos after exposure to ethanol at different doses and times of duration and application shows that the gross developmental defects produced by ethanol are consistent with the human birth defect. Described here are the basic techniques used to study and manipulate the zebrafish FAS model.

In order to understand the molecular mechanisms of the ethanol-induced developmental damage, we have developed a zebrafish model of ethanol exposure and are exploring the physical, cellular, and genetic alterations that occur after ethanol exposure1. We then seek to find potential interventions and rapidly test them in this animal model.

Fetal alcohol syndrome (FAS) is a severe manifestation of embryonic exposure to ethanol. It presents with characteristic defects to the face and organs, ...

Screening for Melanoma Modifiers using a Zebrafish Autochthonous Tumor Model

Genomic studies of human cancers have yielded a wealth of information about genes that are altered in tumors1,2,3. A challenge arising from these studies is that many genes are altered, and it can be difficult to distinguish genetic alterations that drove tumorigenesis from that those arose incidentally during transformation. To draw this distinction it is beneficial to have an assay that can quantitatively measure the effect of an altered gene on tumor initiation and other processes that enable tumors to persist and disseminate. Here we present a rapid means to screen large numbers of candidate melanoma modifiers in zebrafish using an autochthonous tumor model4 that encompasses steps required for melanoma initiation and maintenance. A key reagent in this assay is the miniCoopR vector, which couples a wild-type copy of the mitfa melanocyte specification factor to a Gateway recombination cassette into which candidate melanoma genes can be recombined5. The miniCoopR vector has a mitfa rescuing minigene which contains the promoter, open reading frame and 3'-untranslated region of the wild-type mitfa gene. It allows us to make constructs using full-length open reading frames of candidate melanoma modifiers. These individual clones can then be injected into single cell Tg(mitfa:BRAFV600E);p53(lf);mitfa(lf)zebrafish embryos. The miniCoopR vector gets integrated by Tol2-mediated transgenesis6 and rescues melanocytes. Because they are physically coupled to the mitfa rescuing minigene, candidate genes are expressed in rescued melanocytes, some of which will transform and develop into tumors. The effect of a candidate gene on melanoma initiation and melanoma cell properties can be measured using melanoma-free survival curves, invasion assays, antibody staining and transplantation assays.

A rapid way to screen for melanoma modifiers using a zebrafish autochthonous tumor model is presented. It takes advantage of the miniCoopR vector which allows for expression of candidate melanoma genes in melanocytes. A method to obtain melanoma-free survival curves, an invasion assay, a protocol for antibody staining of scale melanocytes and a melanoma transplantation assay are described.

Genomic studies of  human cancers have yielded a wealth of information about genes that are altered  in tumors1,2,3. A challenge arising from these ...

A Zebrafish Model of Diabetes Mellitus and Metabolic Memory

Diabetes mellitus currently affects 346 million individuals and this is projected to increase to 400 million by 2030. Evidence from both the laboratory and large scale clinical trials has revealed that diabetic complications progress unimpeded via the phenomenon of metabolic memory even when glycemic control is pharmaceutically achieved. Gene expression can be stably altered through epigenetic changes which not only allow cells and organisms to quickly respond to changing environmental stimuli but also confer the ability of the cell to "memorize" these encounters once the stimulus is removed. As such, the roles that these mechanisms play in the metabolic memory phenomenon are currently being examined.
We have recently reported the development of a zebrafish model of type I diabetes mellitus and characterized this model to show that diabetic zebrafish not only display the known secondary complications including the changes associated with diabetic retinopathy, diabetic nephropathy and impaired wound healing but also exhibit impaired caudal fin regeneration. This model is unique in that the zebrafish is capable to regenerate its damaged pancreas and restore a euglycemic state similar to what would be expected in post-transplant human patients. Moreover, multiple rounds of caudal fin amputation allow for the separation and study of pure epigenetic effects in an in vivo system without potential complicating factors from the previous diabetic state. Although euglycemia is achieved following pancreatic regeneration, the diabetic secondary complication of fin regeneration and skin wound healing persists indefinitely. In the case of impaired fin regeneration, this pathology is retained even after multiple rounds of fin regeneration in the daughter fin tissues. These observations point to an underlying epigenetic process existing in the metabolic memory state. Here we present the methods needed to successfully generate the diabetic and metabolic memory groups of fish and discuss the advantages of this model.

Metabolic memory is the phenomenon by which diabetic complications persist and progress unimpeded even after euglycemia is achieved pharmaceutically. Here we describe a diabetes mellitus zebrafish model which is unique in that it allows for the examination of the mitotically transmissible epigenetic components of metabolic memory in vivo.

Diabetes mellitus currently affects 346 million individuals and this is projected to increase to 400 million by 2030. Evidence from both the laboratory ...

A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation. Defects of the PCP pathway have been found to cause kidney cyst formation. Our paper describes a method for developing a zebrafish cystic kidney disease model by knockdown of the wnt5a gene with wnt5a antisense morpholino (MO) oligonucleotides. Tg(wt1b:GFP) transgenic zebrafish were used to visualize kidney structure and kidney cysts following wnt5a knockdown. Two distinct antisense MOs (AUG - and splice-site) were used and both resulted in curly tail down phenotype and cyst formation after wnt5a knockdown. Injection of mouse Wnt5a mRNA, resistant to the MOs due to a difference in primary base pair structure, rescued the abnormal phenotype, demonstrating that the phenotype was not due to &#8220;off-target&#8221; effects of the morpholino. This work supports the validity of using a zebrafish model to study wnt5a function in the kidney.

A Possible Zebrafish Model of Polycystic Kidney Disease: Knockdown of wnt5a Causes Cysts in Zebrafish Kidneys

We describe a method of generating a possible zebrafish model of polycystic kidney disease. We used Tg(wt1b:GFP) fish to visualize kidney structure. Knockdown of wnt5a was by morpholino injection. Pronephric cyst formation after wnt5a knockdown was observed in this GFP transgenic zebrafish.

Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The ...

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment methods. Here, we present such a model by tachycardia-induced cardiomyopathy, which can be produced by rapid cardiac pacing in swine.
A single pacing lead is introduced transvenously into fully anaesthetized healthy swine, to the apex of the right ventricle, and fixated. Its other end is then tunneled dorsally to the paravertebral region. There, it is connected to an in-house modified heart pacemaker unit that is then implanted in a subcutaneous pocket. 
After 4 - 8 weeks of rapid ventricular pacing at rates of 200 - 240 beats/min, physical examination revealed signs of severe heart failure - tachypnea, spontaneous sinus tachycardia, and fatigue. Echocardiography and X-ray showed dilation of all heart chambers, effusions, and severe systolic dysfunction. These findings correspond well to decompensated dilated cardiomyopathy and are also preserved after the cessation of pacing.
This model of tachycardia-induced cardiomyopathy can be used for studying the pathophysiology of progressive chronic heart failure, especially hemodynamic changes caused by new treatment modalities like mechanical circulatory supports. This methodology is easy to perform and the results are robust and reproducible.

Here, we present a protocol to produce tachycardia-induced cardiomyopathy in swine. This model represents a potent way to study the hemodynamics of progressive chronic heart failure and the effects of applied treatment.

A stable and reliable model of chronic heart failure is required for many experiments to understand hemodynamics or to test effects of new treatment ...

Isometric Contractility Measurement of the Mouse Mesenteric Artery Using Wire Myography

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and drugs. It is widely used in many studies on the physiological functions of vascular smooth muscle, the pathogenesis of vascular diseases such as hypertension, and the development of smooth muscle relaxant drugs. The mouse is a widely used model animal with a large pool of disease models and genetically modified strains. We introduced this method to measure the isometric contraction of mouse mesenteric artery in detail. A 1.4-mm segment of mouse mesenteric resistance artery was isolated and mounted on a myograph chamber by passing two steel wires through its lumen. After equilibration and normalization steps, the vessel segment was potentiated by a high-K+ solution twice prior to the contraction assay. As an example of the application of this method in drug development, we measured the relaxant effect of a novel natural substance, neoliensinine, isolated from a Chinese herb, embryos of the lotus seed (Nelumbo nucifera Gaertn.) on mouse mesenteric arteries. The vessel segments mounted on the myograph chamber were stimulated with a high-K+ solution. When the force tension reached a stable sustained phase, cumulative doses of neoliensinine were added to the chamber. We found that neoliensinine had a dose-dependent relaxant effect on smooth muscle contraction, thus suggesting that it bears potential activity against hypertension. In addition, as the vessel segment can survive at least 4 hours after mounting and maintain contractility induced by the high-K+ solution for many times, we suggest that the wire myograph system may be used for the time-consuming process of drug screening.

The wire myograph technique is used to investigate vascular smooth muscle functions and screen new drugs. We report a detailed protocol for measuring the isometric contractility of the mouse mesenteric artery and for screening new relaxants of vascular smooth muscle.

The wire myograph technique is used to assess the contractility of vascular smooth muscles in response to depolarization, GPCR agonists/inhibitors and ...

Murine Myocardial Infarction Model using Permanent Ligation of Left Anterior Descending Coronary Artery

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine models of MI with permanent ligation of left-anterior descending (LAD) coronary artery closely mimics MI in humans. Murine models benefit from the extensive genetic engineering available nowadays. Here we propose a reproducible murine surgical model of myocardial infarction by permanent LAD coronary ligation. Our technique comprises anesthesia with ketamine/xylazine that can be rapidly reversed by administration of an antagonist, intubation without tracheotomy for mechanical-assisted ventilation, ventilation with application of extrinsic positive end-expiratory pressure (PEEP) to avoid alveolar collapse, a thoracotomy method limiting to the minimum surgical lesions made to skeletal muscles, and lung inflation without thoracentesis. This method is sparsely invasive, reproducible and reduces post-surgery mortality and complications.

Herein we describe a surgical procedure showing how to achieve permanent ligation of the left-anterior descending coronary artery in mice. This model is of high relevance to investigate the pathophysiology of myocardial infarction and the concomitant biological processes.

Myocardial infarction (MI) and acute coronary diseases are among the most prominent causes of death in population with western lifestyle. The murine ...

Dilated cardiomyopathy (DCM) refers to a spectrum of heterogeneous myocardial disorders characterized by ventricular dilation and depressed cardiac performance in the absence of hypertension, valvular, congenital, or ischemic heart diseases, and which may be related to infection, autoimmune or metabolic abnormalities, or family inheritance. It can progress into congestive heart failure with a poor prognosis. Doxorubicin (Dox) is widely employed as a chemotherapeutic drug, but its use is limited because it causes DCM-like changes of the myocardium. Its myocardial toxicity is attributed to oxidative stress, chronic inflammation, and cardiomyocyte apoptosis. A model of DCM exploiting these Dox-induced DCM symptoms has not been established.

Described is a protocol to establish a Doxorubicin-induced dilated cardiomyopathy (DCM) model in mice via long-term intraperitoneal injection of Doxorubicin.

Dilated cardiomyopathy (DCM) refers to a spectrum of heterogeneous myocardial disorders characterized by ventricular dilation and depressed cardiac ...

Cisplatin is commonly used as chemotherapy. Although it has positive effects in cancer-treated individuals, cisplatin can easily accumulate in the kidney due to its low molecular weight. Such accumulation causes the death of tubular cells and can induce the development of Acute Kidney Injury (AKI), which is characterized by a quick decrease in kidney function, tissue damage, and immune cells infiltration. If administered in specific doses cisplatin can be a useful tool as an AKI inducer in animal models. The zebrafish has appeared as an interesting model to study renal function, kidney regeneration, and injury, as renal structures conserve functional similarities with mammals. Adult zebrafish injected with cisplatin shows decreased survival, kidney cell death, and increased inflammation markers after 24 h post-injection (hpi). In this model, immune cells infiltration and cell death can be assessed by flow cytometry and TUNEL assay. This protocol describes the procedures to induce AKI in adult zebrafish by intraperitoneal cisplatin injection and subsequently demonstrates how to collect the renal tissue for flow cytometry processing and cell death TUNEL assay. These techniques will be useful to understand the effects of cisplatin as a nephrotoxic agent and will contribute to the expansion of AKI models in adult zebrafish. This model can also be used to study kidney regeneration, in the search for compounds that treat or prevent kidney damage and to study inflammation in AKI. Moreover, the methods used in this protocol will improve the characterization of tissue damage and inflammation, which are therapeutic targets in kidney-associated comorbidities.

This protocol describes the procedures to induce Acute Kidney Injury (AKI) in adult zebrafish using cisplatin as a nephrotoxic agent. We detailed the steps to evaluate the reproducibility of the technique and two techniques to analyze inflammation and cell death in the renal tissue, flow cytometry and TUNEL, respectively.

Cisplatin is commonly used as chemotherapy. Although it has positive effects in cancer-treated individuals, cisplatin can easily accumulate in the kidney ...