Along the same lines, DRGs from mice injected intrathecally with miRNA mimics showed a strong expression of targeted miRNAs in comparison to corresponding non-targeting mimics (examples with overexpression of miR-370-3p miR-370-3p miR-370-3ph their respective mimics in compandson miRNA-291b-5p miRNA-291b-5p miRNA-291b-5pig 2, panel D; p < 0.05 twithailed theirt).
Overexpression of let-7e by miRNA mimics resulted in the downregulation of TLR4 expression in mouse peritoneal macrophages, and inhibition of let-7e by antisense miRNA led to the upregulation of TLR4 expression [ 62].
These gain-of-function studies employed either transfection of synthetic mature miRNA mimics [ 31], or plasmid encoded pre-miRNAs, that were pieced together from mature CHO miRNAs and ectopic flanking and loop sequences from mouse ("artificial chimeric miRNA construct") [ 32].
MiRNA mimics and inhibitors for miR-153 and miR-31 were also mouse-specific and were obtained from Qiagen (Catalog # MSY0000163-miR-153 mimic, MIN0000163-miR-153 inhibitor, MSY0000538-miR-31 mimic, MIN0000538-miR-31 inhibitor).
Mouse ameloblast-like LS8 cells [ 19, 20] were used as the host cells for exogenous miRNA mimics, miRNA inhibitors and luciferase reporter vectors in the luciferase reporter assay.
To gain more insights into the in vivo stability of miRNA mimics, we injected 125 mpk of miR-29b mimic and sacrificed the mice 1, 2, 4, or 7 days later.
Indeed, Trang et al (2011) showed that systemically delivered synthetic miRNA mimics complexed with NLE are preferentially targeted to lung tumors and show a therapeutic benefit in mouse models of lung cancer.
The C.elegans miR-67 mimic was selected as suitable negative control due to its minimal sequence identity with mouse miRNAs and the confirmed absence of detectable effects on examined mouse miRNA functions (www.http://dharmacon.gelifesciences.com/).
(c) Overexpression of miRNAs using miRNA mimics on human embryonic kidney cells (HEK293).
Thirteen genes were downregulated by three of the four miRNA mimics.
