WANG BO, WISE ANDREA F, HUUSKES BROOKE M, RICARDO SHARON D Monash University Introduction: MicroRNA (miR), including miR-let7, is highly effective at reducing

renal fibrosis and reversing progression of disease in rodent models. However, the advancement of miR therapies is hampered by difficulties in delivering miR in a robust and sustainable manner. Thus, it is imperative to develop an efficient delivery method for targeting miR to injured kidneys to exert their anti-fibrotic function. Mesenchymal stem cells (MSC) have demonstrated a strong safety profile in both completed and numerous ongoing clinical trials. The ability of MSC to transfer molecules and organelles suggests their potential usefulness as delivery vehicle for therapeutic miR treatment that is an innovative approach. Methods: C57BL6/J mice underwent 40 mins check details of unilateral ischemia/reperfusion

(IR) injury and were injected with GFP+/luciferase+ MSCs or PBS and imaged from 0–7 days using whole body bioluminescence imaging for cell tracing. miR-let7c modified MSCs were generated and characterised and miR expression assayed with Taqman microRNA assay. The miR-let7c-MSCs were co-cultured with NRK52E, a kidney proximal tubular cell line, using a Transwell system with/without TGF-β1 for 72 hours, and the expression of fibrotic genes assessed using qPCR. Results: Following IR, MSCs homed to the injured kidney where Metformin molecular weight they remained for up to 3 days. miR-let7c was successfully engineered and expressed in MSCs. The modified miR-let7c-MSCs maintained a normal karyotype and proliferative ability, but importantly

produced miR-let7c into the exogenous environment through exosome delivery. MSC-delivered miR-let7c was endocytosed into NRK52E cells, confirmed by the up-regulation of miR-let7c expression and fluorescent microscopy. After 3 days co-culturing, the miR-let7c-MSCs strongly inhibited the up-regulation of TGF-β type I receptor (TGBR1), a specific target of miR-let7c, and reduced a-smooth muscle actin and collagen mRNA expression, when NRK52E cells were treated with TGF-β1. Conclusion: MSCs home to the injured kidney in mice with IR injury. In vitro studies show that miR-let7c produced from modified MSC can be endocytosed into kidney epithelial cells leading to the inhibition of fibrotic genes and TGBR1 induced by TGF-β1. This data will pave the way for the application of miR, or siRNA, as an innovative Pyruvate dehydrogenase lipoamide kinase isozyme 1 RNAi therapeutic strategy for renal disease therapy, but may also offer promise for other degenerative chronic disorders. YAMANAKA SHUICHIRO1,2, YOKOTE SHINYA1, KATSUOKA YUICHI2, IZUHARA LUNA2, OGURA MAKOTO1, YOKOO TAKASHI1 1Department of Internal Medicine, Division of Nephrology and Hypertension; 2Division of Regenerative Medicine Introduction: We have previously demonstrated that mesenchymal stem cells (MSCs) differentiate into functional kidney cells capable of urine and erythropoietin production, indicating that MSCs may be used for kidney regeneration.