[High activity level of miR-206 discovered in BHK21 cells by high-throughput miRNA activity profiling]

Activities of 58 miRNAs for BHK21, HEK293, and Vero cell lines were screened using the high-throughput miRNA activity profiling method. miR-206 activity was found specifically high in BHK21. Considering miR-206 was recognized as a muscle-specific miRNA, we further detected the expression and activity level of miR-206 in BHK21 cells, with myoblast cells C2C12 as positive control and HEK293 cells as negative control. Then, we induced BHK21 by culturing with medium containing 2% horse serum (HS) and tested expression level of slow skeletal myosin heavy chain (MHC), activity and expression levels of miR-206, and expression level of Connexin43 (Cx43) which was reported negatively regulated by miR-206. Results demonstrated that activity and expression levels of miR-206 were both higher in BHK21 cells than in C2C12 cells. After induction of HS, MHC expression level was increased in BHK21 cells. The activity and expression levels of miR-206 were further enhanced. The Cx43 expression level was decreased. These results suggested that BHK21 had the characters of myoblast cells. In conclusion, we firstly discovered that miR-206 activity was specifically high in BHK21 cells, suggesting that BHK21 cells were derived from interstitial cells other than parenchyma cells of kidney from miRNA point of view. Our study also indicated that BHK21 cells were able to be used as models in vitro for research of miR-206 function.