Name: adeno-associated virus-mediated delivery of crispr for cardiac gene editing in mice
Uploaded: 2018-08-02T13:00:00
Description: Watch this Scientific Journal Video about Adeno-Associated Virus-Mediated Delivery of CRISPR for Cardiac Gene Editing in Mice at JoVE.com

R.H. is supported by US National Institutes of Health grants (R01HL116546 and R01 AR064241).

The animals used in this protocol were maintained at The Ohio State University Laboratory Animal Resources in accordance with animal use guidelines. All animal studies were authorized by the Institutional Animal Care, Use, and Review Committee of the Ohio State University.
1. Design and Cloning of gRNAs into the CRISPR Vector
<ol>
	<li>Select 2 gRNAs targeting dystrophin intron 20 and intron 23 (i20 and i23) for SaCas9: i20: 5&#39;-GGGCGTTGAAATTCTCATTAC CAGAGT and i23: 5&#39;-CACCGA...

<ol>
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E., 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=Muscle-specific+CRISPR/Cas9+dystrophin+gene+editing+ameliorates+pathophysiology+in+a+mouse+model+for+Duchenne+muscular+dystrophy.">Muscle-specific CRISPR/Cas9 dystrophin gene editing ameliorates pathophysiology in a mouse model for Duchenne muscular dystrophy.</a> Nat Commun. 8, 14454 (2017).</li><li>Hoffman, E. P., Brown, R. H., Kunkel, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dystrophin:+the+protein+product+of+the+Duchenne+muscular+dystrophy+locus.">Dystrophin: the protein product of the Duchenne muscular dystrophy locus.</a> Cell. 51, 919-928 (1987).</li><li>Nowak, K. J., Davies, K. 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R., Lloyd-Puryear, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Report+of+MDA+muscle+disease+symposium+on+newborn+screening+for+Duchenne+muscular+dystrophy.">Report of MDA muscle disease symposium on newborn screening for Duchenne muscular dystrophy.</a> Muscle Nerve. 48, 21-26 (2013).</li><li>Spurney, C. 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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=Eteplirsen.">Eteplirsen.</a> Hosp Pharm. 52, 302-305 (2017).</li><li>Sicinski, P., 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=The+molecular+basis+of+muscular+dystrophy+in+the+mdx+mouse:+a+point+mutation.">The molecular basis of muscular dystrophy in the mdx mouse: a point mutation.</a> Science. 244, 1578-1580 (1989).</li><li>Xu, 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=CRISPR-mediated+Genome+Editing+Restores+Dystrophin+Expression+and+Function+in+mdx+Mice.">CRISPR-mediated Genome Editing Restores Dystrophin Expression and Function in mdx Mice.</a> Molecular therapy : the journal of the American Society of Gene Therapy. 24, 564-569 (2016).</li><li>El Refaey, 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=In+Vivo+Genome+Editing+Restores+Dystrophin+Expression+and+Cardiac+Function+in+Dystrophic+Mice.">In Vivo Genome Editing Restores Dystrophin Expression and Cardiac Function in Dystrophic Mice.</a> Circ Res. 121, 923-929 (2017).</li><li>Tabebordbar, 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=In+vivo+gene+editing+in+dystrophic+mouse+muscle+and+muscle+stem+cells.">In vivo gene editing in dystrophic mouse muscle and muscle stem cells.</a> Science. 351, 407-411 (2016).</li><li>Pozsgai, E. R., Griffin, D. A., Heller, K. N., Mendell, J. R., Rodino-Klapac, L. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=beta-Sarcoglycan+gene+transfer+decreases+fibrosis+and+restores+force+in+LGMD2E+mice.">beta-Sarcoglycan gene transfer decreases fibrosis and restores force in LGMD2E mice.</a> Gene therapy. 23, 57-66 (2016).</li><li>Chicoine, L. 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=Plasmapheresis+eliminates+the+negative+impact+of+AAV+antibodies+on+microdystrophin+gene+expression+following+vascular+delivery.">Plasmapheresis eliminates the negative impact of AAV antibodies on microdystrophin gene expression following vascular delivery.</a> Mol Ther. 22, 338-347 (2014).</li><li>Chicoine, L. 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=Vascular+delivery+of+rAAVrh74.MCK.GALGT2+to+the+gastrocnemius+muscle+of+the+rhesus+macaque+stimulates+the+expression+of+dystrophin+and+laminin+alpha2+surrogates.">Vascular delivery of rAAVrh74.MCK.GALGT2 to the gastrocnemius muscle of the rhesus macaque stimulates the expression of dystrophin and laminin alpha2 surrogates.</a> Mol Ther. 22, 713-724 (2014).</li><li>Vouillot, L., Thelie, A., Pollet, 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+T7E1+and+surveyor+mismatch+cleavage+assays+to+detect+mutations+triggered+by+engineered+nucleases.">Comparison of T7E1 and surveyor mismatch cleavage assays to detect mutations triggered by engineered nucleases.</a> G3. 5, 407-415 (2015).</li><li>Tsai, S. 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In this protocol, we detail all the steps necessary to achieve in vivo cardiac gene editing in postnatal mice using rAAVrh.74-mediated delivery of SaCas9 and two gRNAs. As previously noted, this approach can be used to restore dystrophin expression in dystrophic mice as described in our work27, but it could also enable rapid reverse genetics studies of cardiac-related genes in mice without the lengthy process of the traditional knockout approach to generate and breed knockout mouse models...

The clustered, regularly interspaced, short palindromic repeat (CRISPR) technology represents the most recent advancement in genome engineering and has revolutionized the current practice of genetics in cells and organisms. CRISPR-based genome editing utilizes a single guide RNA (gRNA) to direct a CRISPR-associated endonuclease such as CRISPR-associated protein 9 (Cas9) and Cpf1 to a genomic DNA target that is complementary in sequence to the protospacer encoded by the gRNA with a specific protospacer adjacent motif (PAM)1,2. The PAM varies depending on the bacterial species of the Cas9 or Cpf1 gene. The most commonly used Cas9 nuclease derived from Streptococcus pyogenes (SpCas9) recognizes a PAM sequence of NGG that is found directly downstream of the target sequence in the genomic DNA, on the non-target strand. At the target site, the Cas9 and Cpf1 proteins generate a double-strand break (DSB), which is then repaired via intrinsic cellular DNA repair mechanisms including non-homologous end joining (NHEJ) and homology-directed repair (HDR) pathways3,4. In the absence of a DNA template for homologous recombination, the DSB is primarily repaired by the error-prone NHEJ pathway, which can result in insertions or deletions (indels) of nucleotides causing frameshift mutations if the DSB were created in the coding region of a gene5,6. Thus, the CRISPR system has been widely used to engineer loss-of-function mutations in various cellular models and whole organisms, in order to investigate the function of a gene. Moreover, the catalytically inactive Cas9 and Cpf1 have been developed to transcriptionally and epigenetically modulate the expression of target genes7,8.
More recently, both SpCas9 and SaCas9 (derived from Staphylococcus aureus) have been packaged into recombinant adeno-associated virus (rAAV) vectors for postnatal gene correction in the animal model of human diseases, particularly, Duchenne muscular dystrophy (DMD)9,10,11,12,13,14,15. DMD is a fatal X-linked recessive disease caused by mutations in the DMD gene, which encodes dystrophin protein16,17, affecting approximately one in 3500 male births according to newborn screening18,19. It is characterized by progressive muscle weakness and wasting. The DMD patients usually lose the ability to walk between 10 and 12 years of age and die of respiratory and/or cardiac failure by the age of 20-30 years20. Notably, cardiomyopathy develops in &#62;90% of DMD patients and represents the leading cause of death in DMD patients21,22. Although Deflazacort (an anti-inflammation drug) and Eteplirsen (an exon skipping medicine for skipping exon 51) have recently been approved for DMD by Food and Drug Administration (FDA)23,24, none of these treatments correct the genetic defect at the genomic DNA level. The mdx mouse, which carries a point mutation at exon 23 of the dystrophin gene, has been widely used as a DMD model25. Furthermore, we previously demonstrated that the functional dystrophin expression was restored by in-frame deletion of the genomic DNA covering exons 21, 22 and 23 in skeletal muscles of mdx mice using intramuscular Ad-SpCas9/gRNA delivery9, and in the heart muscles of mdx/utrophin+/- mice using intravenous and intraperitoneal rAAVrh.74-SaCas9/gRNA delivery26.
In this protocol, we describe in detail every step in postnatal cardiac gene editing to restore dystrophin in mdx/utrophin+/- mice using rAAVrh.74-SaCas9/gRNA vectors, from gRNA design to dystrophin analysis in the heart muscle sections.

<table>
	<tbody>
		<tr>
			<td>Alexa Fluor 555 goat anti-rabbit IgG</td>
			<td>Thermo Fisher Scientific</td>
			<td>A-21428</td>
			<td></td>
		</tr>
		<tr>
			<td>Benzonase Nuclease</td>
			<td>Sigma-Aldrich</td>
			<td>E1014</td>
			<td></td>
		</tr>
		<tr>
			<td>Bio Safety Cabinets</td>
			<td>Thermo Fisher Scientific</td>
			<td>1347</td>
			<td>1300 Series A2 Class II, Type A2</td>
		</tr>
		<tr>
			<td>BsaI</td>
			<td>New England BioLabs Inc</td>
			<td>RO535S</td>
			<td></td>
		</tr>
		<tr>
			<td>Competent cells</td>
			<td>Agilent Technologies</td>
			<td>200314</td>
			<td></td>
		</tr>
		<tr>
			<td>Cell culture dishes, 150mm</td>
			<td>Nest Scientific USA</td>
			<td>715001</td>
			<td></td>
		</tr>
		<tr>
			<td>Cryostat</td>
			<td>Leica Biosystems</td>
			<td></td>
			<td>Leica CM3050S</td>
		</tr>
		<tr>
			<td>DMEM</td>
			<td>Thermo Fisher Scientific</td>
			<td>MT10017CV</td>
			<td>Corning cellgro</td>
		</tr>
		<tr>
			<td>Dystrophin antibody</td>
			<td>Spring Bioscience</td>
			<td>E2660</td>
			<td></td>
		</tr>
		<tr>
			<td>Fast-Ion Midi Plasmdi Kits</td>
			<td>IBI Scientific</td>
			<td>IB47111</td>
			<td></td>
		</tr>
		<tr>
			<td>FBS</td>
			<td>Thermo Fisher Scientific</td>
			<td>26-140-079</td>
			<td></td>
		</tr>
		<tr>
			<td>Filter Unit, 0.45&#956;m</td>
			<td>Thermo Fisher Scientific</td>
			<td>166-0045</td>
			<td></td>
		</tr>
		<tr>
			<td>GoTaq Master Mixes</td>
			<td>Promega</td>
			<td>M7122</td>
			<td></td>
		</tr>
		<tr>
			<td>High-speed plasmid mini kit</td>
			<td>IBI Scientific</td>
			<td>IB47102</td>
			<td></td>
		</tr>
		<tr>
			<td>Horse serum</td>
			<td>Abcam</td>
			<td>ab139501</td>
			<td></td>
		</tr>
		<tr>
			<td>Isotemp 2239 Water Bath</td>
			<td>Thermo Fisher Scientific</td>
			<td>15-460-11Q</td>
			<td></td>
		</tr>
		<tr>
			<td>Isotemp Heat Block</td>
			<td>Thermo Fisher Scientific</td>
			<td>11-718</td>
			<td></td>
		</tr>
		<tr>
			<td>Inverted confocal microscope</td>
			<td>Carl Zeiss Microscopy, LLC</td>
			<td></td>
			<td>LSM 780</td>
		</tr>
		<tr>
			<td>LightCycler 480 instrument</td>
			<td>Roche</td>
			<td>5015243001</td>
			<td>LightCycler 480 Instrument II</td>
		</tr>
		<tr>
			<td>Large Capacity Centrifuge</td>
			<td>Thermo Fisher Scientific</td>
			<td>46-910</td>
			<td>Thermo Scientific Sorvall RC 6 Plus</td>
		</tr>
		<tr>
			<td>Microcentrifuge</td>
			<td>Thermo Fisher Scientific</td>
			<td>75002445</td>
			<td>Sorvall Legend Micro 21R</td>
		</tr>
		<tr>
			<td>Nanodrop spectrophotometers</td>
			<td>Thermo Scientific</td>
			<td>ND2000CLAPTOP</td>
			<td>NanoDrop&#8482; 2000/2000c</td>
		</tr>
		<tr>
			<td>Oligos for i20-F</td>
			<td>Integrated DNA Technologies</td>
			<td></td>
			<td>CACCgGGCGTTGAAATTCTCATTAC</td>
		</tr>
		<tr>
			<td>Oligos for i20-R</td>
			<td>Integrated DNA Technologies</td>
			<td></td>
			<td>AAAC GTAATGAGAATTTCAACGCCc;</td>
		</tr>
		<tr>
			<td>Oligos for i23-F</td>
			<td>Integrated DNA Technologies</td>
			<td></td>
			<td>CACCgCACCGATGAGAGGGAAAGGTC</td>
		</tr>
		<tr>
			<td>Oligos for i23-R</td>
			<td>Integrated DNA Technologies</td>
			<td></td>
			<td>GACCTTTCCCTCTCATCGGTGc</td>
		</tr>
		<tr>
			<td>Oligos</td>
			<td>Integrated DNA Technologies</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>OptiPrep Density Gradient Medium</td>
			<td>Sigma-Aldrich</td>
			<td>D1556-250ML</td>
			<td></td>
		</tr>
		<tr>
			<td>OptiMEM</td>
			<td>Thermo Fisher Scientific</td>
			<td>31985070</td>
			<td></td>
		</tr>
		<tr>
			<td>PEG8000</td>
			<td>Sigma-Aldrich</td>
			<td>89510-1kg-F</td>
			<td></td>
		</tr>
		<tr>
			<td>Polyethylenimine</td>
			<td>Polysciences</td>
			<td>23966</td>
			<td></td>
		</tr>
		<tr>
			<td>Proteinase K</td>
			<td>Sigma-Aldrich</td>
			<td>P2308</td>
			<td></td>
		</tr>
		<tr>
			<td>Quick-Seal centrifuge tube</td>
			<td>Beckman Coulter Inc</td>
			<td>342414</td>
			<td></td>
		</tr>
		<tr>
			<td>QIAquick Gel Extraction kit</td>
			<td>Qiagen</td>
			<td>28704</td>
			<td></td>
		</tr>
		<tr>
			<td>Radiant SYBR Green Hi-ROX qPCR Kits</td>
			<td>Alkali Scientific</td>
			<td>QS2005</td>
			<td></td>
		</tr>
		<tr>
			<td>RevertAid RT Reverse Transcription Kit</td>
			<td>Thermo Fisher Scientific</td>
			<td>K1691</td>
			<td></td>
		</tr>
		<tr>
			<td>Rotor</td>
			<td>Beckman Coulter Inc</td>
			<td>337922</td>
			<td>Type 70Ti</td>
		</tr>
		<tr>
			<td>T4 DNA ligase</td>
			<td>New England BioLabs Inc</td>
			<td>M0202S</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermal Cycler</td>
			<td>Bio-rad</td>
			<td>1861096</td>
			<td></td>
		</tr>
		<tr>
			<td>TRIzol Reagent</td>
			<td>Thermo Fisher Scientific</td>
			<td>15596026</td>
			<td></td>
		</tr>
		<tr>
			<td>Ultracentrifuge</td>
			<td>Beckman Coulter Inc</td>
			<td>8043-30-1192</td>
			<td>Optima le-80k</td>
		</tr>
		<tr>
			<td>Ultra centrifugal filter unit</td>
			<td>MilliporeSigma</td>
			<td>UFC510096</td>
			<td></td>
		</tr>
		<tr>
			<td>VECTASHIELD Mounting Medium with DAPI</td>
			<td>Vector Laboratories, Inc</td>
			<td>H-1200</td>
			<td></td>
		</tr>
	</tbody>
</table>

adeno-associated virus-mediated delivery of crispr for cardiac gene editing in mice

The clustered, regularly interspaced, short, palindromic repeat (CRISPR) system has greatly facilitated genome engineering in both cultured cells and living organisms from a wide variety of species. The CRISPR technology has also been explored as novel therapeutics for a number of human diseases. Proof-of-concept data are highly encouraging as exemplified by recent studies that demonstrate the feasibility and efficacy of gene editing-based therapeutic approach for Duchenne muscular dystrophy (DMD) using a murine model. In particular, intravenous and intraperitoneal injection of the recombinant adeno-associated virus (rAAV) serotype rh.74 (rAAVrh.74) has enabled efficient cardiac delivery of the Staphylococcus aureus CRISPR-associated protein 9 (SaCas9) and two guide RNAs (gRNA) to delete a genomic region with a mutant codon in exon 23 of mouse Dmd gene. This same approach can also be used to knock out the gene-of-interest and study their cardiac function in postnatal mice when the gRNA is designed to target the coding region of the gene. In this protocol, we show in detail how to engineer rAAVrh.74-CRISPR vector and how to achieve highly efficient cardiac delivery in neonatal mice.

The efficacy of the gRNAs to induce the deletion of the target genomic DNA region should be evaluated in cell cultures before packaging into rAAV for in vivo studies. To this end, the gRNAs and SaCas9-expressing constructs were electroporated into C2C12 cells and the genomic DNA was analyzed by PCR with the primers flanking the target sites (Figure 1). A PCR product of ~500 bp indicates successful deletion of the target genomic DNA resulting from gene editing...

Watch this Scientific Journal Video about Adeno-Associated Virus-Mediated Delivery of CRISPR for Cardiac Gene Editing in Mice at JoVE.com

Adeno-Associated Virus-Mediated Delivery of CRISPR for Cardiac Gene Editing in Mice

Here we provide a detailed protocol to carry out in vivo cardiac gene editing in mice using recombinant Adeno-Associated Virus(rAAV)-mediated delivery of CRISPR. This protocol offers a promising therapeutic strategy to treat dystrophic cardiomyopathy in Duchenne muscular dystrophy and can be used to generate cardiac-specific knockout in postnatal mice.

The clustered, regularly interspaced, short, palindromic repeat (CRISPR) system has greatly facilitated genome engineering in both cultured cells and ...

The overall goal of this in vivo cardiac gene editing protocol is to restore dystrophin expression in the heart of dystrophic mice using recombinant adeno-associated virus rh. 74 with CRISPR SaCas9 and guide RNA vectors. This method can help answer key questions in the muscular dystrophy field, such as whether gene editing is a reliable therapeutic strategy to treat the root cause of the cardiomyopathy associated with Duchenne's muscular dystrophy.The main advantage of these techniques are the expression of the corrected dystrophin gene is under its endogenous regulatory control, and this rescue effect is permanent. The implication of this technique extends toward treatment of other genetic disease where correction of mutant gene can be achieved by CRISPR Cas9 gene editing technology. This method not only provides insight into dystrophin restoration in the dystrophic heart, but it can also be used to knock out the gene of interest for reverse genetic studies.Demonstrating the procedure will be Yandi Gao, a technician from our laboratory. The proper design of the guide RNAs, or gRNAs, is critical to the success of this protocol. Select two gRNAs targeting dystrophin intron 20 and intron 23 for the Staphylococcus aureus CRISPR-associated protein nine.The protospacer adjacent motif sequence for each gRNA is underlined and italicized. To anneal the gRNA oligonucleotides, set up a reaction containing 100 micromoles per liter of the gRNA oligonucleotides in 1x annealing buffer. Use the following PCR parameters:95 degrees Celsius for 10 minutes, 90 cycles of 95 to 59 degrees Celsius with a 0.4 degree Celsius decrease per cycle for 20 seconds, 90 cycles of 59 to 32 degrees Celsius with a 0.3 degree Celsius decrease per cycle for 20 seconds, and 20 cycles of 32 to 26 degrees Celsius with a 0.3 degree Celsius decrease per cycle for 20 seconds.Next, prepare to ligate the annealed gRNA oligonucleotides into the CRISP vector in one reaction. Add the following to a tube:one microliter of 50 nanograms per microliter CRISPR vector, one microliter of annealed oligonucleotides, 1.5 microliters of 10x T4 DNA ligase buffer, 0.5 microliters of T4 DNA ligase, one microliter of Bsal, and 10 microliters of double-distilled water. Run the following reaction in a thermocycler:five cycles of 37 degrees Celsius for five minutes and 16 degrees Celsius for 10 minutes, 37 degrees Celsius for 20 minutes, and 80 degrees Celsius for five minutes.Transform the 15-microliter ligation product into 30 microliters of competent cells, and plate the cells on a agar plate containing 100 microgram per milliliter of ampicillin. Culture at 37 degrees Celsius for 24 hours. On the following day, pick five to 10 colonies from the agar plate and culture in LB medium containing 100 microgram per milliliter of ampicillin at 37 degrees Celsius and 250 rpm for three to four hours.To screen the colonies by PCR, prepare reactions that each contain 10 microliters of PCR master mix, eight microliters of double-distilled water, one microliter of E.coli culture, one microliter of U6-forward primer, and one microliter of i20 or i23 gRNA reverse primer. Use the following PCR cycling parameters:95 degrees Celsius for five minutes, followed by 35 cycles of 95 degrees Celsius for 30 seconds, 61 degrees Celsius for 30 seconds, and 72 degrees Celsius for 30 seconds. Once the positive clones have been identified, prepare a five-milliliter culture of each positive clone by adding four milliliters of fresh LB medium containing 100 microgram per milliliter ampicillin and culturing at 37 degrees Celsius and 250 rpm overnight.On the following day, purify the plasmid DNA using the appropriate plasmid extraction kit. The plasmid is subsequently verified by Sanger sequencing with the U6-forward primer. To test the gene editing efficacy of the plasmids, culture C2C12 cells in DMEM supplemented with 10%FBS and 1%Pen-Strep until the cells reach approximately 70%confluency.Electroporate a total of five micrograms of SaCas9/gRNA plasmid mixture in one-to-one molar ratio into C2C12 cells according to the manufacturer's protocol. 48 hours post-transfection, harvest the C2C12 cells, and extract genomic DNA as described in the text protocol. Use the genomic DNA as template to perform PCR for the mouse dystrophin locus.Set up reactions containing the forward primer, the reverse primer, the green PCR master mix, double-distilled water, and 100 nanograms of genomic DNA. Use the same PCR conditions as for screening positive clones. Prior to starting this procedure, prepare the recombinant adeno-associated virus, or rAAV, as described in the text protocol.Administer day three mdx mouse pups with viral particles systemically via an intraperitoneal injection. Allow the mice to recover, and place them back into their home cages. At 10 weeks after rAAV administration, collect tissues from the mice.Snap-freeze the tissues for genomic DNA and RNA extraction, and use cooled isopentane in liquid nitrogen to freeze tissues with optimal cutting temperature compound for cryosectioning. Begin the immunofluorescence staining protocol by fixing the frozen tissue sections with 4%paraformaldehyde at room temperature for five minutes. After 15 minutes, wash the tissue sections two times with PBS.Incubate with blocking solution at room temperature for one hour. Next, incubate with the anti-dystrophin primary antibody at four degrees Celsius overnight. On the following morning, wash the slides with PBS, and then incubate with fluorescent secondary antibodies at room temperature for one hour.Mount the slides using mounting medium with DAPI, and image with an inverted confocal microscope. The efficacy of the gRNAs to induce the deletion of the target genomic DNA region in cell cultures was evaluated by PCR. A PCR product of approximately 500 base pairs indicates successful deletion of the target genomic DNA resulting from gene editing, while the control cells should not yield a band.Once the efficacy of the gRNAs has been confirmed in cell cultures, the gRNAs are packaged into rAAV. The rAAV viral particles are purified and the purity analyzed by SDS-PAGE. The presence of only three bands corresponding to the three capsid proteins indicates high purity.These representative immunofluorescence images of heart sections of wild type, mdx, and mdx mice treated with AAV SaCas9 gRNA systemically show that AAV SaCas9 gRNA restores dystrophin expression in dystrophic mice. After watching this video, you should have a good understanding of how to achieve in vivo cardiac gene editings in postnatal mice using rAAV rh. 74-mediated delivery of SaCas9 and gRNAs.

adeno-associated-virus-mediated-delivery-crispr-for-cardiac-gene

Research

JoVE Journal

Medicine

Establishment and Propagation of Human Retinoblastoma Tumors in Immune Deficient Mice

Culturing retinoblastoma tumor cells in defined stem cell media gives rise to primary tumorspheres that can be grown and maintained for only a limited time. These cultured tumorspheres may exhibit markedly different cellular phenotypes when compared to the original tumors. Demonstration that cultured cells have the capability of forming new tumors is important to ensure that cultured cells model the biology of the original tumor. 
Here we present a protocol for propagating human retinoblastoma tumors in vivo using Rag2-/- immune deficient mice. Cultured human retinoblastoma tumorspheres of low passage or cells obtained from freshly harvested human retinoblastoma tumors injected directly into the vitreous cavity of murine eyes form tumors within 2-4 weeks. These tumors can be harvested and either further passaged into murine eyes in vivo or grown as tumorspheres in vitro. Propagation has been successfully carried out for at least three passages thus establishing a continuing source of human retinoblastoma tissue for further experimentation. 
Wesley S. Bond and Lalita Wadhwa are co-first authors.

A method is described to propagate human retinoblastoma tumors in mice. Tumor cells are directly injected into the eyes of immune deficient mice. Secondary tumors have been successfully established using both cells directly harvested from human tumors and cultured tumorspheres.

Culturing retinoblastoma tumor cells in defined stem cell media gives rise to primary tumorspheres that can be grown and maintained for only a limited ...

An Orthotopic Bladder Cancer Model for Gene Delivery Studies

Bladder cancer is the second most common cancer of the urogenital tract and novel therapeutic approaches that can reduce recurrence and progression are needed. The tumor microenvironment can significantly influence tumor development and therapy response. It is therefore often desirable to grow tumor cells in the organ from which they originated. This protocol describes an orthotopic model of bladder cancer, in which MB49 murine bladder carcinoma cells are instilled into the bladder via catheterization. Successful tumor cell implantation in this model requires disruption of the protective glycosaminoglycan layer, which can be accomplished by physical or chemical means. In our protocol the bladder is treated with trypsin prior to cell instillation. Catheterization of the bladder can also be used to deliver therapeutics once the tumors are established. This protocol describes the delivery of an adenoviral construct that expresses a luciferase reporter gene. While our protocol has been optimized for short-term studies and focuses on gene delivery, the methodology of mouse bladder catheterization has broad applications.

Implantation of cancer cells into the organ of origin can serve as a useful preclinical model to evaluate novel therapies. MB49 bladder carcinoma cells can be grown within the bladder following intravesical instillation. This protocol demonstrates catheterization of the mouse bladder for the purpose of tumor implantation and adenoviral delivery.

Bladder cancer is the second most common cancer of the urogenital tract and novel therapeutic approaches that can reduce recurrence and progression are ...

Using Adeno-associated Virus as a Tool to Study Retinal Barriers in Disease

M&#252;ller cells are the principal glial cells of the retina. Their end-feet form the limits of the retina at the outer and inner limiting membranes (ILM), and in conjunction with astrocytes, pericytes and endothelial cells they establish the blood-retinal barrier (BRB). BRB limits material transport between the bloodstream and the retina while the ILM acts as a basement membrane that defines histologically the border between the retina and the vitreous cavity. Labeling M&#252;ller cells is particularly relevant to study the physical state of the retinal barriers, as these cells are an integral part of the BRB and ILM. Both BRB and ILM are frequently altered in retinal disease and are responsible for disease symptoms.
There are several well-established methods to study the integrity of the BRB, such as the Evans blue assay or fluorescein angiography. However these methods do not provide information on the extent of BRB permeability to larger molecules, in nanometer range. Furthermore, they do not provide information on the state of other retinal barriers such as the ILM. To study BRB permeability alongside retinal ILM, we used an AAV based method that provides information on permeability of BRB to larger molecules while indicating the state of the ILM and extracellular matrix proteins in disease states. Two AAV variants are useful for such study: AAV5 and ShH10. AAV5&#160;has a natural tropism for photoreceptors but it cannot get across to the outer retina when administered into the vitreous when the ILM is intact (i.e., in wild-type retinas). ShH10 has a strong tropism towards glial cells and will selectively label M&#252;ller glia in both healthy and diseased retinas. ShH10 provides more efficient gene delivery in retinas where ILM is compromised. These viral tools coupled with immunohistochemistry and blood-DNA analysis shed light onto the state of retinal barriers in disease.

To investigate the blood-retinal barrier permeability and the inner limiting membrane integrity in animal models of retinal disease, we used several adeno-associated virus (AAV) variants as tools to label retinal neurons and glia. Virus mediated reporter gene expression is then used as an indicator of retinal barrier permeability.

M&#252;ller cells are the principal glial cells of the retina. Their end-feet form the limits of the retina at the outer and inner limiting membranes ...

Development of an Alpha-synuclein Based Rat Model for Parkinson's Disease via Stereotactic Injection of a Recombinant Adeno-associated Viral Vector

In order to study the molecular pathways of Parkinson&#39;s disease (PD) and to develop novel therapeutic strategies, scientific investigators rely on animal models. The identification of PD-associated genes has led to the development of genetic PD models. Most transgenic &#945;-SYN mouse models develop gradual &#945;-SYN pathology but fail to display clear dopaminergic cell loss and dopamine-dependent behavioral deficits. This hurdle was overcome by direct targeting of the substantia nigra with viral vectors overexpressing PD-associated genes. Local gene delivery using viral vectors provides an attractive way to express transgenes in the central nervous system. Specific brain regions can be targeted (e.g. the substantia nigra), expression can be induced in the adult setting and high expression levels can be achieved. Further, different vector systems based on various viruses can be used. The protocol outlines all crucial steps to perform a viral vector injection in the substantia nigra of the rat to develop a viral vector-based alpha-synuclein animal model for Parkinson&#39;s disease.

Development of an Alpha-synuclein Based Rat Model for Parkinson&#039;s Disease via Stereotactic Injection of a Recombinant Adeno-associated Viral Vector

This manuscript describes how viral vector-mediated local gene delivery provides an attractive way to express transgenes in the central nervous system. The protocol outlines all crucial steps to perform a viral vector injection in the substantia nigra of the rat to develop a viral vector-based animal model for Parkinson's disease.

In order to study the molecular pathways of Parkinson&#39;s disease (PD) and to develop novel therapeutic strategies, scientific investigators rely on ...

Myocardial Infarction in Neonatal Mice, A Model of Cardiac Regeneration

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and regeneration, and to define new targets for therapeutics. For decades, models of complete heart regeneration existed in amphibians and fish, but a mammalian counterpart was not available. The recent discovery of a postnatal window during which mice possess regenerative capabilities has led to the establishment of a mammalian model of cardiac regeneration. A surgical model of mammalian cardiac regeneration in the neonatal mouse is presented herein. Briefly, postnatal day 1 (P1) mice are anesthetized by isoflurane and placed on an ice pad to induce hypothermia. After the chest is opened, and the left anterior descending coronary artery (LAD) is visualized, a suture is placed around the LAD to inflict myocardial ischemia in the left ventricle. The surgical procedure takes 10-15 min. Visualizing the coronary artery is crucial for accurate suture placement and reproducibility. Myocardial infarction and cardiac dysfunction are confirmed by triphenyl-tetrazolium chloride (TTC) staining and echocardiography, respectively. Complete regeneration 21 days post myocardial infarction is verified by histology. This protocol can be used to as a tool to elucidate mechanisms of mammalian cardiac regeneration after myocardial infarction.

This protocol describes a highly reproducible model of cardiac regeneration by surgical induction of myocardial infarction in the left ventricle of postnatal day 1 mice. The method involves induction of hypothermic anesthesia and ligation of the left anterior descending coronary artery.

Myocardial infarction induced by coronary artery ligation has been used in many animal models as a tool to study the mechanisms of cardiac repair and ...

Posterior Semicircular Canal Approach for Inner Ear Gene Delivery in Neonatal Mouse

Inner ear gene therapy offers great promise as a potential treatment for hearing loss and dizziness. One of the critical determinants of the success of inner ear gene therapy is to find a delivery method which results in consistent transduction efficiency of targeted cell types while minimizing hearing loss. In this study, we describe the posterior semicircular canal approach as a viable method for inner ear gene delivery in neonatal mice. We show that gene delivery through the posterior semicircular canal is able to perfuse the entire inner ear. The easy anatomic identification of the posterior semicircular canal, as well as minimal manipulation of the temporal bone required, make this surgical approach an attractive option for inner ear gene delivery.

In this study, we describe the posterior semicircular canal approach as a reliable method for inner ear gene delivery in neonatal mice. We show that gene delivery through the posterior semicircular canal is able to perfuse the entire inner ear.

Inner ear gene therapy offers great promise as a potential treatment for hearing loss and dizziness. One of the critical determinants of the success of ...

Intratracheal Administration of Dry Powder Formulation in Mice

In the development of inhalable dry powder formulations, it is essential to evaluate their biological activities in preclinical animal models. This paper introduces a noninvasive method of intratracheal delivery of dry powder formulation in mice. A dry powder loading device that consists of a 200 &#181;L gel loading pipette tip connected to an 1 mL syringe via a three-way stopcock is presented. A small amount of dry powder (1-2 mg) is loaded into the pipette tip and dispersed by 0.6 mL of air in the syringe. Because pipette tips are disposable and inexpensive, different dry powder formulations can be loaded into different tips in advance. Various formulations can be evaluated in the same animal experiment without device cleaning and dose refilling, thereby saving time and eliminating the risk of cross-contamination from residual powder. The extent of powder dispersion can be inspected by the amount of powder remaining in the pipette tip. A protocol of intubation in mouse with a custom-made light source and a guiding cannula is included. Proper intubation is one of the key factors that influences the intratracheal delivery of dry powder formulation to the deep lung region of the mouse.

Dry powder formulations for inhalation have great potential in treating respiratory diseases. Before entering human studies, it is necessary to evaluate the efficacy of the dry powder formulation in preclinical studies. A simple and noninvasive method of the administration of dry powder in mice through the intratracheal route is presented.

In the development of inhalable dry powder formulations, it is essential to evaluate their biological activities in preclinical animal models. This paper ...

Subconjunctival Administration of Adeno-associated Virus Vectors in Small Animal Models

Ocular diseases include a wide range of inherited genetic and acquired disorders that are appealing targets for local drug delivery due to their relative ease of accessibility via multiple administration routes. Subconjunctival (SCJ) injections offer advantages over other intraocular administration routes as they are simple, safe, and usually performed in an outpatient setting. SCJ injections in small animals usually require the assistance of an operating microscope due to the size of the eye. Previous work has demonstrated that SCJ injection of specific adeno-associated virus (AAV) serotypes is a valid gene delivery strategy for targeted transduction of the ocular surface, eye muscle, cornea, and optic nerve, providing a potential approach for the treatment of many ocular diseases.
Herein, a detailed protocol is presented for SCJ injections in a mouse model using an injection system consisting of a programmable infusion/withdrawal syringe pump (which allows for consistent and precise injection speed and pressure) and a gastight removable syringe coupled with microinjection needles. The injection system is also adaptable for other intraocular administration routes such as intrastromal, intracameral, intravitreal, and subretinal injections in small animals. Although the delivery of adeno-associated viral vectors for ocular gene therapy studies is described, the protocol herein can also be adapted for a variety of ophthalmic solutions in small animal models. The key practical steps in the administration route, setup for the injection platform, preparation of the injection, and tips from direct experience will be discussed in detail. In addition, common validation techniques for AAV delivery confirmation to the desired tissues will also be briefly discussed.

In this manuscript, subconjunctival injection is demonstrated as a valid vector delivery method for ocular tissues in mice using an injection system consisting of an infusion/withdrawal syringe pump and a gastight removable syringe coupled with microinjection needles. This injection system is also adaptable for other intraocular administration routes.

Ocular diseases include a wide range of inherited genetic and acquired disorders that are appealing targets for local drug delivery due to their relative ...

AAV Isolation by Double Iodixanol Density Gradient Centrifugation

Suspension Culture Production and Purification of Adeno-Associated Virus by Iodixanol Density Gradient Centrifugation for In Vivo Applications

This protocol describes recombinant adeno-associated virus (rAAV) production and purification by iodixanol density gradient centrifugation, a serotype-agnostic method of purifying AAV first described in 1999. rAAV vectors are widely used in gene therapy applications to deliver transgenes to various human cell types. In this work, the recombinant virus is produced by transfection of Expi293 cells in suspension culture with plasmids encoding the transgene, vector capsid, and adenoviral helper genes. Iodixanol density gradient centrifugation purifies full AAV particles based on particle density. Additionally, three steps are included in this now-ubiquitous methodology in order to increase total virus yield, decrease the risk of precipitation due to contaminating proteins, and further concentrate the final virus product, respectively: precipitation of viral particles from cell media using a solution of polyethylene glycol (PEG) and sodium chloride, the introduction of a second round of iodixanol density gradient centrifugation, and buffer exchange via a centrifugal filter. Using this method, it is possible to consistently achieve titers in the range of 1012 viral particles/mL of exceptional purity for in vivo use.

Author Spotlight: Efficient Adeno-Associated Virus Isolation for Pre-Clinical Applications

Adeno-associated virus is produced in suspension cell culture and purified by double iodixanol density gradient centrifugation. Steps are included to increase total virus yield, decrease the risk of virus precipitation, and further concentrate the final virus product. Expected final titers reach 1012 viral particles/mL and are suitable for pre-clinical in vivo use.