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Polycystic kidney disease is a complex clinical entity which comprises a group of genetic diseases that leads to renal cyst development. We evaluated the most suitable housekeeping genes for microRNA expression by RT-qPCR analyses of kidney tissues in Pkd1-deficient mouse models from a panel of five candidates genes (miR-20a, miR-25, miR-26a, miR-191 and U6) and 3 target genes (miR-17, miR-21 and let-7a) using samples from kidneys of cystic mice (Pkd1 flox/flox :Nestin cre , CY), non-cystic controls (Pkd1 flox/flox , NC), Pkd1-haploinsufficient (Pkd1 +/- , HT), wild-type controls (Pkd1 +/+ , WT), severely cystic mice (Pkd1 V/V , SC), wild-type controls (CO). The stability of the candidate genes was investigated using NormFinder, GeNorm, BestKeeper, DataAssist, and RefFinder software packages and the comparative ΔCt method. The analyses identified miR-26a as the most stable housekeeping gene for all kidney samples, miR-20a for CY and NC, miR-20a and miR-26a for HT and WT, and miR-25 and miR-26a for SC and CO. Expression of miR-21 was upregulated in SC compared to CO and trends of miR-21 upregulation and let-7a downregulation in CY and HT compared to its control kidneys, when normalized by different combinations of miR-20a, miR-25 and miR-26a. Our findings established miR-20a, miR-25, and miR-26a as the best housekeeping genes for miRNA expression analyses by RT-qPCR in kidney tissues of Pkd1-deficient mouse models.

Acute kidney injury is mostly reversible, and hepatocyte growth factor (HGF) has a relevant role in the tissue repair. MicroRNA (miR)-26a is an endogenous modulator of HGF. The role of miR-26a in the kidney repair process was evaluated in Wistar rats submitted to an acute kidney injury model of rhabdomyolysis induced by glycerol (6 mL/kg). Animals were evaluated 3, 12, 48, 96, and 120 hours after glycerol injection. Serum creatinine (SCr) and gene expression of HGF, c-met, signal transducer and activator of transcription 3 (STAT3), and miR-26a were estimated. Also, tubular NK52E cells were transfected with anti-miR26a and stimulated with Fe 3+ for 24 hours to mimic the effects of myoglobin in vitro. SCr was highest after 48 hours. After 96 hours, SCr started to decrease, characterizing the recovery phase, with normalization after 120 hours. HGF expression increased during the onset phase (3 hours), with a low relationship with miR-26a. In contrast, in the recovery phase, the increase in miR-26a was coincident with HGF messenger RNA suppression, suggesting that in the recovery phase, miR-26a may have a role in HGF modulation. Fe 3+ induced cellular death after 3 hours and proliferation after 24 hours. There was no correlation between miR-26a and STAT3 during the death phase; however, during the proliferation phase, an increase in STAT3 was paralleled with a decrease in miR-26a. miR-26a silencing induced increases in cell viability and the phosphorylated form of STAT3 protein expression in cells receiving Fe 3+ . In conclusion, miR-26a may have a key role in modulating HGF levels after its proliferative effects have been triggered., (© 2018 Wiley Periodicals, Inc., A Wiley.)