Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Nephrol. Sep 7, 2018; 7(5): 108-116
Published online Sep 7, 2018. doi: 10.5527/wjn.v7.i5.108
Unique interstitial miRNA signature drives fibrosis in a murine model of autosomal dominant polycystic kidney disease
Ameya Patil, William E Sweeney Jr, Cynthia G Pan, Ellis D Avner
Ameya Patil, William E Sweeney Jr, Cynthia G Pan, Ellis D Avner, Children’s Research Institute; Children’s’ Hospital Health System of Wisconsin and the Medical College of Wisconsin, Milwaukee, WI 53226, United States
Author contributions: Patil A, Sweeney Jr WE, Pan CG and Avner ED all equally contributed to the conception and design of this study, analysis, and interpretation of data; all authors drafted the article and made critical revisions related to the intellectual content of the manuscript, and approved the final version of the article to be published.
Supported by the Children’s Research Institute, the Lillian Goldman Charitable Trust; Amy P Goldman Foundation; and Ellsworth Family and Children’s Foundation of Children’s’ Hospital and Health System of Wisconsin.
Institutional animal care and use committee statement: All animal experiments are conducted in accordance with policies of the NIH Guide for the Care and Use of Laboratory Animals and the Institutional Animal Care and Use Committee (IACUC) of the Medical College of Wisconsin. The IACUC at the Medical College of Wisconsin is properly appointed according to PHS policy IV.A.3.a and is qualified through the experience and expertise of its members to oversee the Institution’s animal care and use program. The Animal Welfare Assurance for the Medical College of Wisconsin is A3102-01. Specific protocols used in this study were approved by the Medical College of Wisconsin IACUC (approved protocols are AUA 4278 and AUA 4179).
Conflict-of-interest statement: The authors have no conflict of interest to declare. Conflict of Interest in Research statements is on file with the institution as per Medical College of Wisconsin policy #RS.GN.020.
Data sharing statement: Data sets and statistical methods are available upon request from the corresponding author
ARRIVE guidelines statement: The manuscript was revised according to the ARRIVE guidelines.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Ameya P Patil, MD, Assistant Professor, Department of Pediatrics, Medical College of Wisconsin, Children’s Research Institute, Children’s’ Hospital Health System of Wisconsin, Children’s Corporate Center, Suite 510, Mailstop CCC C510, 999 North 92nd Street, Milwaukee, WI 53226, United States. appatil@mcw.edu
Telephone: +1-414-9555773 Fax: +1-414-3377105
Received: April 21, 2018
Peer-review started: April 21, 2018
First decision: May 16, 2018
Revised: May 25, 2018
Accepted: July 31, 2018
Article in press: August 1, 2018
Published online: September 7, 2018
Processing time: 139 Days and 13 Hours
Abstract
AIM

To delineate changes in miRNA expression localized to the peri-cystic local microenvironment (PLM) in an orthologous mouse model of autosomal dominant polycystic kidney disease (ADPKD) (mcwPkd1(nl/nl)).

METHODS

We profiled miRNA expression in the whole kidney and laser captured microdissection (LCM) samples from PLM in mcwPkd1(nl/nl) kidneys with Qiagen miScript 384 HC miRNA PCR arrays. The three times points used are: (1) post-natal (PN) day 21, before the development of trichrome-positive areas; (2) PN28, the earliest sign of trichrome staining; and (3) PN42 following the development of progressive fibrosis. PN21 served as appropriate controls and as the reference time point for comparison of miRNA expression profiles.

RESULTS

LCM samples revealed three temporally upregulated miRNAs [2 to 2.75-fold at PN28 and 2.5 to 4-fold (P ≤ 0.05) at PN42] and four temporally downregulated miRNAs [2 to 2.75 fold at PN28 and 2.75 to 5-fold (P ≤ 0.05) at PN42]. Expression of twenty-six miRNAs showed no change until PN42 [six decreased (2.25 to 3.5-fold) (P ≤ 0.05) and 20 increased (2 to 4-fold) (P ≤ 0.05)]. Many critical miRNA changes seen in the LCM samples from PLM were not seen in the contralateral whole kidney.

CONCLUSION

Precise sampling with LCM identifies miRNA changes that occur with the initiation and progression of renal interstitial fibrosis (RIF). Identification of the target proteins regulated by these miRNAs will provide new insight into the process of fibrosis and identify unique therapeutic targets to prevent or slow the development and progression of RIF in ADPKD.

Keywords: Inflammation; End-stage renal disease; Cysts; Autosomal dominant polycystic kidney disease; miRNA; Renal interstitial fibrosis

Core tip: An essential and consistent histologic feature of progressive autosomal dominant polycystic kidney disease (ADPKD) is interstitial inflammation and fibrosis. This study investigated miRNA expression in local peri-cystic areas between cysts that become fibrotic as the disease progresses. This study identifies a critical limitation to whole organ transcriptomic approaches and demonstrates that laser capture microdissection (LCM) provides a means to overcome the dilutional factor of whole organ miRNA analysis. The precision of LCM provides a unique miRNA signature, which identifies novel molecular and therapeutic targets that initiate and drive interstitial fibrosis in ADPKD.