The authors go on to show that expogenous expression of miR-98 lowers PGRMC1 abundance levels (a more apt description than the fuzzy description of “PGRMC1 downregulation”, which could be by a number of mechanisms as discussed below).
In response the authors have made minimal changes to the manuscript, effectively restricted to rewording the title, and several minor text changes. Unfortunately, the authors have been unable to demonstrate the direct involvement of PGRMC1 downregulation in decidualization. Since this is the main publishable finding, the results as they stand do not merit publication. The authors mention technical difficulties in establishing ESCs that express miRNA-resistant PGRMC1. This may be due to stable plasmid selection conditions, which may affect the differentiation status of the ESC cells. It would be possible to introduce an expression cassette via a lentiviral vector at MOI 1. An inducible vector may be advisable, such as tetracycline, IPTG, or other available systems. Such vectors typically include fluorescent protein reporters, enabling discrimination between infected and non-infected cells in one plate, or population separation by FACS.