Downregulation of miR-375 level induces BDNF expression and elicits pain-like behavior and spinal neuronal sensitization partly dependent on JAK2 expression. (A) qRT-PCR results show that miR-375 level is downregulated after injection with miR-375 antagomir at days 2 and 5. (B) Administration of miR-375 antagomir markedly decreases paw withdrawal latency (PWL) at days 2 and 5 after injection. (C and D) JAK2 mRNA and protein levels were examined by qRT-PCR and Western blot analysis after miR-375 antagomir injection. (E and F) Pre- (E) or posttreatment (F) of JAK2 siRNA 2 days before or after miR-375 antagomir administration alleviates miR-375-antagomir-induced decline of PWL. (G–J) Pre- (G and H) or posttreatment (I and J) of JAK2 siRNA 2 days before or after miR-375 antagomir administration alleviates miR-375-antagomir-induced increase of BDNF. (K) Delivery of TrkB-Fc, 2 days after miR-375-antagomir injection, alleviates miR-375-induced PWL reduction in a time-dependent manner. (L) p-STAT3 and STAT3 levels were detected by Western blot assays after miR-375 antagomir injection. Data were presented as mean ± SD; *P<0.05, **P<0.01 vs. control; ##P<0.01 vs. NC + miR-375 antagomir.
Abbreviations: BDNF, brain-derived neurotrophic factor; JAK2, Janus kinase 2; mRNA, messenger RNA; NC, negative control; PBS, phosphate buffered saline; qRT-PCR, quantitative real-time polymerase chain reaction; siRNA, small-interfering RNA; SD, standard deviation; STAT3, signal transducer and activator of transcription 3; TrkB-Fc, tyrosine receptor kinase B-Fc.