This work was partially supported by JSPS KAKENHI (Grant No. 21K08233). We thank Edanz (https://jp.edanz.com/ac) for editing drafts of this manuscript.

All animal experimental protocols were approved by the animal ethics committee of Jichi Medical University and performed in accordance with Use and Care of Experimental Animals guidelines from the Jichi Medical University Guide for Laboratory Animals. Here, we demonstrated miRNA mimic delivery to the kidney resulting in its overexpression using UUO mice. This study was approved by the Ethics Committee of Jichi Medical University [Approval Nos. 19-12 for renal fibrosis, 17-024 for acute kidney infection (AKI), and 19-11 f...

<ol>
	<li>Mohr, A. M., Mott, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Overview+of+microRNA+biology.">Overview of microRNA biology.</a> Seminars in Liver Disease. 35 (1), 3-11 (2015).</li><li>Bushati, N., Cohen, S. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=microRNA+functions.">microRNA functions.</a> Annual Review of Cell and Developmental Biology. 23, 175-205 (2007).</li><li>Simpson, K., Wonnacott, A., Fraser, D. J., Bowen, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=microRNAs+in+diabetic+nephropathy:+From+biomarkers+to+therapy.">microRNAs in diabetic nephropathy: From biomarkers to therapy.</a> Current Diabetes Reports. 16 (3), 35 (2016).</li><li>Yheskel, M., Patel, V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Therapeutic+microRNAs+in+polycystic+kidney+disease.">Therapeutic microRNAs in polycystic kidney disease.</a> Current Opinion in Nephrology and Hypertension. 26 (4), 282-289 (2017).</li><li>Lv, 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=Therapeutic+potential+of+microRNAs+for+the+treatment+of+renal+fibrosis+and+CKD.">Therapeutic potential of microRNAs for the treatment of renal fibrosis and CKD.</a> Physiological Genomics. 50 (1), 20-34 (2018).</li><li>Dykxhoorn, D. M., Lieberman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+silent+revolution:+RNA+interference+as+basic+biology,+research+tool,+and+therapeutic.">The silent revolution: RNA interference as basic biology, research tool, and therapeutic.</a> Annual Review of Medicine. 56, 401-423 (2005).</li><li>Dykxhoorn, D. M., Palliser, D., Lieberman, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+silent+treatment:+siRNAs+as+small+molecule+drugs.">The silent treatment: siRNAs as small molecule drugs.</a> Gene Therapy. 13 (6), 541-552 (2006).</li><li>Stewart, S. 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=Lentivirus-delivered+stable+gene+silencing+by+RNAi+in+primary+cells.">Lentivirus-delivered stable gene silencing by RNAi in primary cells.</a> RNA. 9 (4), 493-501 (2003).</li><li>Deng, 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=Klotho+gene+delivery+ameliorates+renal+hypertrophy+and+fibrosis+in+streptozotocin-induced+diabetic+rats+by+suppressing+the+Rho-associated+coiled-coil+kinase+signaling+pathway.">Klotho gene delivery ameliorates renal hypertrophy and fibrosis in streptozotocin-induced diabetic rats by suppressing the Rho-associated coiled-coil kinase signaling pathway.</a> Molecular Medicine Reports. 12 (1), 45-54 (2015).</li><li>Zhou, 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=Suppressor+of+cytokine+signaling+(SOCS)+2+attenuates+renal+lesions+in+rats+with+diabetic+nephropathy.">Suppressor of cytokine signaling (SOCS) 2 attenuates renal lesions in rats with diabetic nephropathy.</a> Acta Histochemica. 116 (5), 981-988 (2014).</li><li>Tenenbaum, L., Lehtonen, E., Monahan, P. E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evaluation+of+risks+related+to+the+use+of+adeno-associated+virus-based+vectors.">Evaluation of risks related to the use of adeno-associated virus-based vectors.</a> Current Gene Therapy. 3 (6), 545-565 (2003).</li><li>Lukashev, A. N., Zamyatnin, A. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Viral+vectors+for+gene+therapy:+Current+state+and+clinical+perspectives.">Viral vectors for gene therapy: Current state and clinical perspectives.</a> Biochemistry. Biokhimiia. 81 (7), 700-708 (2016).</li><li>Morishita, 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=Delivery+of+microRNA-146a+with+polyethylenimine+nanoparticles+inhibits+renal+fibrosis+in+vivo.">Delivery of microRNA-146a with polyethylenimine nanoparticles inhibits renal fibrosis in vivo.</a> International Journal of Nanomedicine. 10, 3475-3488 (2015).</li><li>Ishii, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MicroRNA+expression+profiling+in+diabetic+kidney+disease.">MicroRNA expression profiling in diabetic kidney disease.</a> Translational Research: The Journal of Laboratory and Clinical. 237, 31-52 (2021).</li><li>Aomatsu, 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=MicroRNA+expression+profiling+in+acute+kidney+injury.">MicroRNA expression profiling in acute kidney injury.</a> Translational Research: The Journal of Laboratory and Clinical. (21), 00283-00288 (2021).</li><li>Lungwitz, U., Breunig, M., Blunk, T., Gopferich, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polyethylenimine-based+non-viral+gene+delivery+systems.">Polyethylenimine-based non-viral gene delivery systems.</a> European Journal of Pharmceutics and Biopharmaceutics. 60 (2), 247-266 (2005).</li><li>Swami, 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=A+unique+and+highly+efficient+nonviral+DNA/siRNA+delivery+system+based+on+PEI-bisepoxide+nanoparticles.">A unique and highly efficient nonviral DNA/siRNA delivery system based on PEI-bisepoxide nanoparticles.</a> Biochemical and Biophysical Research Communications. 362 (4), 835-841 (2007).</li><li>Kaneko, 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=Detection+of+microRNA+expression+in+the+kidneys+of+immunoglobulin+a+nephropathic+mice.">Detection of microRNA expression in the kidneys of immunoglobulin a nephropathic mice.</a> Journal of Visualized Experiments: JoVE. (161), e61535 (2020).</li><li>Yanai, 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=Quantitative+real-time+PCR+evaluation+of+microRNA+expressions+in+mouse+kidney+with+unilateral+ureteral+obstruction.">Quantitative real-time PCR evaluation of microRNA expressions in mouse kidney with unilateral ureteral obstruction.</a> Journal of Visualized Experiments: JoVE. (162), e61383 (2020).</li><li>Aomatsu, 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=A+quantitative+detection+method+for+microRNAs+in+the+kidney+of+an+ischemic+kidney+injury+mouse+model.">A quantitative detection method for microRNAs in the kidney of an ischemic kidney injury mouse model.</a> Journal of Visualized Experiments: JoVE. (163), e61378 (2020).</li><li>Kushibiki, T., Nagata-Nakajima, N., Sugai, M., Shimizu, A., Tabata, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+anti-fibrotic+activity+of+plasmid+DNA+expressing+small+interference+RNA+for+TGF-beta+type+II+receptor+for+a+mouse+model+of+obstructive+nephropathy+by+cationized+gelatin+prepared+from+different+amine+compounds.">Enhanced anti-fibrotic activity of plasmid DNA expressing small interference RNA for TGF-beta type II receptor for a mouse model of obstructive nephropathy by cationized gelatin prepared from different amine compounds.</a> Journal of Controlled Release: Official Journal of the Controlled Release Society. 110 (3), 610-617 (2006).</li><li>Xia, Z., 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=Suppression+of+renal+tubulointerstitial+fibrosis+by+small+interfering+RNA+targeting+heat+shock+protein+47.">Suppression of renal tubulointerstitial fibrosis by small interfering RNA targeting heat shock protein 47.</a> American Journal of Nephrology. 28 (1), 34-46 (2008).</li><li>Tanaka, T., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=In+vivo+gene+transfer+of+hepatocyte+growth+factor+to+skeletal+muscle+prevents+changes+in+rat+kidneys+after+5/6+nephrectomy.">In vivo gene transfer of hepatocyte growth factor to skeletal muscle prevents changes in rat kidneys after 5/6 nephrectomy.</a> American Journal of Transplantation: Official Journal of the American Society of Transplantation and the American Society of Transplant Surgeons. 2 (9), 828-836 (2002).</li><li>Hamar, 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=Small+interfering+RNA+targeting+Fas+protects+mice+against+renal+ischemia-reperfusion+injury.">Small interfering RNA targeting Fas protects mice against renal ischemia-reperfusion injury.</a> Proceedings of the National Academy of Sciences of the United States of America. 101 (41), 14883-14888 (2004).</li><li>Ma, 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=Xenon+preconditioning+protects+against+renal+ischemic-reperfusion+injury+via+HIF-1alpha+activation.">Xenon preconditioning protects against renal ischemic-reperfusion injury via HIF-1alpha activation.</a> Journal of the American Society of Nephrology: JASN. 20 (4), 713-720 (2009).</li><li>Wei, 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=Short+hairpin+RNA+knockdown+of+connective+tissue+growth+factor+by+ultrasound-targeted+microbubble+destruction+improves+renal+fibrosis.">Short hairpin RNA knockdown of connective tissue growth factor by ultrasound-targeted microbubble destruction improves renal fibrosis.</a> Ultrasound in Medicine and Biology. 42 (12), 2926-2937 (2016).</li></ol>

The authors declare that they have no conflicts of interest.

Using the protocol presented in this manuscript, PEI-NPs can deliver miRNA mimics to the kidney to induce overexpression of target miRNAs, resulting in treatment effects in in vivo mouse models of several renal diseases, including renal fibrosis, diabetic kidney disease, and AKI.
The method to prepare the complex of PEI-NPs and miRNA mimic is very simple. The positively charged surface of PEI-NPs entraps the miRNA mimic when they are just mixed13,<su...

miRNAs, small noncoding RNAs (21-25 bases) that are not translated into proteins, inhibit lots of target messenger RNAs (mRNAs) by destabilizing them and inhibiting their translation in various kidney diseases1,2. Therefore, gene therapy employing exogenous artificially synthesized miRNA mimics or inhibitors is a potential new option for inhibiting the development of many kidney diseases3,4,5.
Despite the promise of miRNA mimics or inhibitors for gene therapy, delivery to target organs remains a big hurdle for in vivo experiments to develop their clinical potential. Because artificially synthesized miRNA mimics or inhibitors are subject to immediate degradation by serum RNase, their half-life is shortened upon systemic administration in vivo6. Additionally, the efficiency of miRNA mimics or inhibitors to cross the plasma membrane and transfect cytoplasm is generally much lower without appropriate vectors7,8. These lines of evidence suggest that the development of the miRNA mimics or inhibitors delivery system for the kidney is required, to enable their use in clinical settings and make them a new treatment option for patients with various kidney diseases.
Viral vectors have been used as carriers to deliver exogenous miRNA mimics or inhibitors to the kidney9,10. Although they have been developed for biosafety and transfection efficacy, viral vectors may still cause an interferon response and/or genetic instability11,12. To overcome these concerns, we developed an miRNA mimics delivery system for the kidney using polyethylenimine nanoparticles (PEI-NPs), a nonviral vector, in several mouse models of kidney disease13,14,15.
PEI-NPs are linear polymer-based NPs that can effectively deliver oligonucleotides, including miRNA mimics, to the kidney, and are considered preferable for preparing nonviral vectors because of their long-term safety and biocompatibility13,16,17.
This study demonstrates the effects of systematic exogenous miRNA mimics delivery with PEI-NPs via tail vein injection in renal fibrosis model mice produced by unilateral ureter obstruction (UUO). Additionally, we demonstrate the effects of systematic exogenous miRNA mimic delivery with PEI-NPs via tail vein injection in diabetic kidney disease model mice (db/db mice: C57BLKS/J Iar -+Leprdb/+Leprdb) and acute kidney injury model mice produced by renal ischemia-reperfusion injury (IRI).

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>4&#8217;,6-diamidino-2-phenylindole for staining to nucleus</td>
			<td>Thermo Fisher Scientific</td>
			<td>D-1306</td>
			<td></td>
		</tr>
		<tr>
			<td>Buffer RPE</td>
			<td>Qiagen</td>
			<td>79216</td>
			<td>Wash buffer 2</td>
		</tr>
		<tr>
			<td>Buffer RWT</td>
			<td>Qiagen</td>
			<td>1067933</td>
			<td>Wash buffer 1</td>
		</tr>
		<tr>
			<td>Control-miRNA-mimic (artificially synthesized miRNA)</td>
			<td>Thermo Fisher Scientific</td>
			<td>Not assigned</td>
			<td>5&#8217;-UUCUCCGAACGUGUCACGUTT- 3&#8217; (sense) 
			5&#8217;-ACGUGACACGUUCGGAGAATT-3&#8242; (antisense)</td>
		</tr>
		<tr>
			<td>Cy3-labeled double-strand oligonucleotides</td>
			<td>Takara Bio Inc.</td>
			<td>MIR7900</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescein-labeled Lotus tetragonolobus lectin</td>
			<td>Vector Laboratories Inc</td>
			<td>FL-1321</td>
			<td></td>
		</tr>
		<tr>
			<td>In vivo-jetPEI</td>
			<td>Polyplus</td>
			<td>101000021</td>
			<td></td>
		</tr>
		<tr>
			<td>MicroAmp Optical 96-well reaction plate for qRT-PCR</td>
			<td>Thermo Fisher Scientific</td>
			<td>4316813</td>
			<td>96-well reaction plate</td>
		</tr>
		<tr>
			<td>MicroAmp Optical Adhesive Film</td>
			<td>Thermo Fisher Scientific</td>
			<td>4311971</td>
			<td>Adhesive film for 96-well reaction plate</td>
		</tr>
		<tr>
			<td>miRNA-146a-5p mimic (artificially synthesized miRNA)</td>
			<td>Thermo Fisher Scientific</td>
			<td>Not assigned</td>
			<td>5&#8217;-UGAGAACUGAAUUCCAUGGGU 
			UT-3&#8242; (sense) 5&#8217;-CCCAUGGAAUUCAGUUCUCAUU -3&#8242; (antisense)</td>
		</tr>
		<tr>
			<td>miRNA-146a-5p primer</td>
			<td>Qiagen</td>
			<td>MS00001638</td>
			<td>Not available because Qiagen has changed qRT-PCR kits (from miScript miRNA PCR system to miRCURY LNA miRNA PCR System from May 2021)</td>
		</tr>
		<tr>
			<td>miRNA-181b-5p mimic (artificially synthesized miRNA)</td>
			<td>Gene design</td>
			<td>Not assigned</td>
			<td>5&#8217;-AACAUUCAUUGCUGUCGGUGG 
			GUU-3&#8217;</td>
		</tr>
		<tr>
			<td>miRNA-181b-5p primer</td>
			<td>Qiagen</td>
			<td>MS00006083</td>
			<td>Not available because Qiagen has changed qRT-PCR kits (from miScript miRNA PCR system to miRCURY LNA miRNA PCR System from May 2021)</td>
		</tr>
		<tr>
			<td>miRNA-5100-mimic (artificially synthesized miRNA)</td>
			<td>Gene design</td>
			<td>Not assigned</td>
			<td>5&#8217;-UCGAAUCCCAGCGGUGCCUCU -3&#8242;</td>
		</tr>
		<tr>
			<td>miRNA-5100-primer</td>
			<td>Qiagen</td>
			<td>MS00042952</td>
			<td>Not available because Qiagen has changed qRT-PCR kits (from miScript miRNA PCR system to miRCURY LNA miRNA PCR System from May 2021)</td>
		</tr>
		<tr>
			<td>miRNeasy Mini kit</td>
			<td>Qiagen</td>
			<td>217004</td>
			<td>Membrane anchored spin column in a 2.0-mL collection tube</td>
		</tr>
		<tr>
			<td>miScript II RT kit</td>
			<td>Qiagen</td>
			<td>218161</td>
			<td>Not available because Qiagen has changed qRT-PCR kits (from miScript miRNA PCR system to miRCURY LNA miRNA PCR System from May 2021)</td>
		</tr>
		<tr>
			<td>miScript SYBR Green PCR kit</td>
			<td>Qiagen</td>
			<td>218073</td>
			<td>Not available because Qiagen has changed qRT-PCR kits (from miScript miRNA PCR system to miRCURY LNA miRNA PCR System from May 2021)</td>
		</tr>
		<tr>
			<td>QIA shredder</td>
			<td>Qiagen</td>
			<td>79654</td>
			<td>Biopolymer spin columns in a 2.0-mL collection tube</td>
		</tr>
		<tr>
			<td>QIAzol Lysis Reagent</td>
			<td>Qiagen</td>
			<td>79306</td>
			<td>Phenol/guanidine-based lysis reagent</td>
		</tr>
		<tr>
			<td>QuantStudio 12K Flex Flex Real-Time PCR system</td>
			<td>Thermo Fisher Scientific</td>
			<td>4472380</td>
			<td>Real-time PCR instrument</td>
		</tr>
		<tr>
			<td>QuantStudio 12K Flex Software version 1.2.1.</td>
			<td>Thermo Fisher Scientific</td>
			<td>4472380</td>
			<td>Real-time PCR instrument software</td>
		</tr>
		<tr>
			<td>RNase-free water</td>
			<td>Qiagen</td>
			<td>129112</td>
			<td></td>
		</tr>
		<tr>
			<td>RNU6-2 primer</td>
			<td>Qiagen</td>
			<td>MS00033740</td>
			<td>Not available because Qiagen has changed qRT-PCR kits (from miScript miRNA PCR system to miRCURY LNA miRNA PCR System from May 2021)</td>
		</tr>
		<tr>
			<td>Tissue-Tek OCT (Optimal Cutting Temperature Compound)</td>
			<td>Sakura Finetek Japan Co.,Ltd.</td>
			<td>Not assigned</td>
			<td></td>
		</tr>
	</tbody>
</table>

delivery of exogenous artificially synthesized mirna mimic to the kidney using polyethylenimine nanoparticles in several kidney disease mouse models

microRNAs&#160;(miRNAs), small noncoding RNAs (21-25 bases) that are not translated into proteins, inhibit lots of target messenger RNAs (mRNAs) by destabilizing and inhibiting their translation in various kidney diseases. Therefore, alternation of miRNA expression by exogenous artificially synthesized miRNA mimics is a potentially useful treatment option for inhibiting the development of many kidney diseases. However, because serum RNAase immediately degrades systematically administered exogenous miRNA mimics in vivo, delivery of miRNA to the kidney remains a challenge. Therefore, vectors that can protect exogenous miRNA mimics from degradation by RNAase and significantly deliver them to the kidney are necessary. Many studies have used viral vectors to deliver exogenous miRNA mimics or inhibitors to the kidney. However, viral vectors may cause an interferon response and/or genetic instability. Therefore, the development of viral vectors is also a hurdle for the clinical use of exogenous miRNA mimics or inhibitors. To overcome these concerns regarding viral vectors, we developed a nonviral vector method to deliver miRNA mimics to the kidney using tail vein injection of polyethylenimine nanoparticles (PEI-NPs), which led to significant overexpression of target miRNAs in several mouse models of kidney disease.

The target miRNAs for renal fibrosis, diabetic nephropathy, and AKI described below were selected based on the microarray, qRT-PCR, and/or database research for gene therapy applications. For further details, refer to the previous publications13,14,15.
Delivery and effects of miRNA-146a-5p-mimic using PEI-NPs in renal fibrosis mice13 
Fluo...

Watch this Scientific Journal Video about Delivery of Exogenous Artificially Synthesized miRNA Mimic to the Kidney Using Polyethylenimine Nanoparticles in Several Kidney Disease Mouse Models at JoVE.c

Delivery of Exogenous Artificially Synthesized miRNA Mimic to the Kidney Using Polyethylenimine Nanoparticles in Several Kidney Disease Mouse Models

Here, we deliver exogenous artificially synthesized miRNA mimics to the kidney via tail vein injection of a nonviral vector and polyethylenimine nanoparticles in several kidney disease mouse models. This led to significant overexpression of target miRNA in the kidney, resulting in inhibited progression of kidney disease in several mouse models.

microRNAs&#160;(miRNAs), small noncoding RNAs (21-25 bases) that are not translated into proteins, inhibit lots of target messenger RNAs (mRNAs) by ...

This method can help answer key questions in therapy of microRNA to the kidney, which remains a challenge. The main advantage of this technique is that it's enabled the therapy of microRNA mimics to the kidney without causing an interferon response or genetic instability. Begin by dissolving 10 microliters of PEI-NPs in 90 microliters of 5%glucose solution in a 1.5-milliliter microcentrifuge tube.Then vortex the tube gently and spin down. Mix 50 microliters of artificially synthesized miRNAs dissolved in 100 micromolar of nuclease-free water with 50 micromolar of 10%glucose solution in 1.5-milliliter microcentrifuge tubes. Vortex the tube gently and spin down.This process yields miRNA dissolved in 5%glucose solution. Then mix 100 microliters of PEI-NPs in 5%glucose solution and 100 microliters of miRNA mimic in 5%glucose solution. Vortex the tube gently and spin down.Incubate the mixture for 15 minutes at room temperature to prepare a stable complex of PEI-NPs miRNA mimic. Dissolve two microliters of PEI-NPs in 98 microliters of 10%glucose solution in a 1.5-milliliter microcentrifuge tube. Vortex the tube gently and spin down.Then add 100 microliters of Cy3-labeled miRNA mimic to 100 microliters of PEI-NPs in 10%glucose solution and vortex the tube gently. Incubate the mixture for 15 minutes at room temperature to prepare a stable complex of PEI-NPs-Cy3-labeled-miRNA-mimic. Place the UUO mouse headfirst in a 50-milliliter centrifuge tube without anesthesia and then place the tail through a prepared hole in the cap.Fill a one-milliliter syringe with a 30-gauge needle with 200 microliters of PEI-NPs-Cy3-labeled-miRNA-mimic complex and inject the complex via the tail vein of the mouse. Next, make an incision into the skin, muscles, and ribs with surgical scissors and forceps to expose the heart. After making an incision into the right atrium, inject PBS into the left ventricle until the kidney color changes to pale yellow.This indicates that the whole mouse body is perfused with PBS. After collecting the kidneys, remove the renal capsules, and wash them twice with PBS. Embed the kidney tissue samples in OCT compound and freeze them in liquid nitrogen.Use a cryostat to prepare sections and mount the sections onto silane-coated glass slides. Fix them with 4%paraformaldehyde and gently wash the slides twice with PBS. Finally, visualize the fluorescence staining by fluorescence microscopy at 100x and 400x magnification and appropriate imaging software.The representative image shows the structure of the PEI-NPs-miRNA-mimic complex. The delivery and effects of miRNA-146a-5p-mimic using PEI-NPs in renal fibrosis are depicted in these images. Fluorescent microscopy analysis showed that tail-vein injection of PEI-NPs could deliver the miRNA mimic to the tubulointerstitial space.In renal fibrosis mice produced by UUO, this included renal tubular cells which do not have a regular form in the kidney and the glomerulus. qRT-PCR analysis showed that injection of PEI-NPs-miRNA-146a-5p-mimic induced significant overexpression of miRNA-146a-5p in the kidney. The histological analysis with Sirius red staining is shown here.Fluorescent microscopy analysis showed that tail-vein injection of PEI-NPs could deliver miRNA mimic to the glomerulus and tubulointerstitial space in kidneys of diabetic kidney model mice in vivo. In addition, the qRT-PCR analysis showed that injection of PEI-NPs-miRNA-181b-5p-mimic induced significant overexpression of miRNA-181b-5p in the kidney. Histological analysis with Periodic acid-Schiff staining showed that injection of PEI-NPs-miRNA-181b-5p-mimic once per week from 10 to 20 weeks of age inhibited the progression of diabetic kidney disease in mice.Delivery and effects of PEI-NPs-miRNA-5100-mimic in acute kidney injury model mice produced by ischemia reperfusion injury are shown here. The data of the fluorescent microscopy analysis qRT-PCR analysis to evaluate the overexpression effects of miRNA-5100 following injection of PEI-NPs-miRNA-5100-mimic and the histological analysis of hematoxylin-eosin stained kidney are depicted in these images. PEI-NPs injected via the tail vein two days before the ischemia reperfusion injury, or IRI, procedure prevent acute kidney injury progression induced by IRI.When performing this technique, prepare five-micrometer thick sections which include as much kidney tissue as possible. You can also prepare seven-micrometer thick sections.

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Research

JoVE Journal

Medicine

1.4K Views.  Jichi Medical University. Questo metodo può aiutare a rispondere a domande chiave nella terapia del microRNA al rene, che rimane una sfida. Il vantaggio principale di questa tecnica è che ha permesso la terapia dei microRNA imitando il rene senza causare una risposta all'interferone o instabilità genetica. Iniziare sciogliendo 10 microlitri di PEI-NPs in 90 microlitri di soluzione di glucosio al 5% in una provetta da microcentrifuga da 1,5 millilitri.Quindi vortice delicatamente il tubo e girare verso il bas...

Video: Delivery of Exogenous Artificially Synthesized miRNA Mimic to the Kidney Using Polyethylenimine Nanoparticles in Several Kidney Disease Mouse Models