FIG. 8.

Study of endogenous miR-375 expression in freshly isolated rat islets. Rat islets were isolated as described in research design and methods. Islets were maintained overnight in Ham's F10 containing 1.8 g/l glucose supplemented with 300 mg/l glutamine, 100 mg/l streptomycin, 75 mg/l penicillin, 0.5% (wt/vol) BSA, and 2% (vol/vol) FCS. Thereafter, islets were treated with either 5, 10, or 20 mmol/l glucose for 2 h (A) or 72 h (B). RNA extracts were reverse-transcribed and analyzed by quantitative RT-PCR for miR-375 precursor. Expression of miR-375 precursor was normalized to the U6 transcript level. Results are means ± SE (n = 3/condition). *P < 0.05, **P < 0.005. Freshly isolated islets from Wistar (n = 5) and GK rats (n = 6) were prepared as previously described. RNA extracts were analyzed by quantitative RT-PCR for pre-miR-375 (C), pre-miR-124a2 (D), and insulin mRNA (E). Results are means ± SE (n = 5 for Wistar and n = 6 for GK), *P < 0.05.