Figure 6.

TDMD of miR-7 by OIP5-AS1 affects myoblast fusion. (A) Schematic of fusion assays. AB678 cells were labeled by expression of enhanced green fluorescent protein (EGFP) or red fluorescent protein mCherry following lentivirus infection. Further silencing of OIP5-AS1 or overexpression of miR-7 or corresponding controls was carried out on EGFP-labeled AB678 cells. Equal numbers of EGFP-labeled or mCherry-labeled AB678 cells were then mixed and placed in differentiation medium for 72 h. (B) As described in panel (A), EGFP-labeled AB678 cells were transfected with Ctrl miR (left) or miR-7 mimic (right) and further mixed with mCherry-labeled AB678. The fusion ability was monitored by representative confocal images, homologous fusion (EGFP+ only or mCherry+ only) and heterologous syncytia (both EGFP+ and mCherry+). (C) As described in panel (A), EGFP-labeled AB678 cells were transfected with Ctrl siRNA (left) or OIP5-AS1-directed siRNA (right) and further mixed with mCherry-labeled AB678. The fusion ability was monitored by representative confocal images of homologous fusion (EGFP+ only or mCherry+ only) and heterologous syncytia (both EGFP+ and mCherry+). (D, E) Heterologous fusion indices were quantified for panels (B) and (C) after assessing five separate fields per experiment. Scale bar: 100 μm. Data in panels (D) and (E) represent the means ± SEM from at least three independent experiments. Significance was established using Student’s t-test. ***P < 0.001.