Satellite cell-derived exosome-mediated delivery of microRNA-23a/27a/26a cluster ameliorates renal tubulointerstitial fibrosis in diabetic nephropathy
Authors: Ji Jialing , Zhang Aiqing 
Published: May 2023

Objective: Renal tubulointerstitial fibrosis (TIF) is the final convergent pathway of diabetic nephropathy (DN), yet no effective targeted therapies currently can prevent the progression of TIF. Here, as a novel and more effective gene therapy approach, the microRNA (miRNA) clusters provide a method to tackle this issue. Methods: Differentially expressed miRNAs in the serum of DN patients were identified by miRNA sequencing (miRNA-seq). We engineered a kidney targeting exosomes (Exos) vector that contained Lamp2b, an exosomal membrane protein gene fused with rabies virus glycoprotein (RVG) peptide. We transfected this vector into muscle satellite cells and then transduced these cells with adenovirus that expresses miR-23a/27a/26a cluster to manufacture the resultant Exos denoted as RVG-miR-23a/27a/26a-Exos. Db/db mice were injected by tail vein with RVG-miR-23a/27a/26a-Exos and the biodistribution of Exos in db/db mice was imaged by the IVIS. RNA sequencing (RNA-seq) and bioinformatic analysis were performed to explore downstream targets of miRNAs. Results: MiRNA-seq results showed that a total of 23 differentially expressed miRNAs with fold-change >2.0 and p value <0.05 were identified (six downregulated and seventeen upregulated) in serum samples from patients with DN, among which miR-23a, miR-26a, and miR-27a were significantly decreased. Then, it was confirmed that miR-23a, miR-26a and miR-27a expression in the serum of patients with DN were reduced by 47%, 57% and 38%, respectively. Moreover, Pearson's correlation analysis showed that miR-23a, miR-26a and miR-27a had strong negative correlation with TIF and renal function decline. Then, we combined miR-23a, miR-26a and miR-27a as an artificially engineered cluster and successfully engineered RVG-miR-23a/27a/26a cluster loaded exosomes derived from muscle satellite cells, which not only enhanced the stability of miR-23a/27a/26a cluster, but also efficiently delivered more miR-23a/27a/26a cluster homing to injured kidney. More importantly, treatment with RVG-miR-23a/27a/26a-Exos significantly ameliorated tubular injury and TIF in mice with DN. Mechanistically, we showed that miR-23a/27a/26a-Exos could potentiate antifibrotic effects by regulating miRNA cluster-targeting Lpp simultaneously, as well as miR-27a-targeting Zbtb20 and miR-26a-targeting Klhl42, respectively. Conclusions: We established a novel kidney-targeting Exo-based delivery system by manipulating the miRNA-23a/27a/26a cluster to ameliorate TIF in DN effectively, providing a promising therapeutic strategy for DN. This work was supported by the National Natural Science Foundation of China (Nos. 81970664, 82000648, 82070735); the Natural Science Foundation of Jiangsu Province (Nos. BK20211385, BK20200363); the 789 Outstanding Talent Program of SAHNMU (Nos. 789ZYRC202080119, 789ZYRC202090251) and the Science and Technology Development Foundation of Nanjing Medical University (No. NMUB2020049). This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.