I was not able to find any data regarding SOX2, OCT4 and NANOG gene expression of rat bone marrow mesenchymal stem cell. If you can, please share with me :)
The article entitled "The Three-Dimensional Collagen Scaffold Improves the Stemness of Rat Bone Marrow Mesenchymal Stem Cells" (by Han et al) contains information about the expression of these 3 genes (Sox2, Oct4 and Nanog) in cultured rat MSCs.
Pay attention to the isoforms especially for OCT4 and NANOG. False positive are a difficult trap. You may look at Liedtke 2008 papers for example of OCT4 isoforms.
We only have data from human Bone marrow Mesenchymal Stromal Cells from children where was observed a very low expression of all three genes. You may have a look at the publication "The role of children’s bone marrow mesenchymal stromal cells in the
ex vivo expansion of autologous and allogeneic hematopoietic stem cells" Cell Biology International 2015 Apr 24. doi: 10.1002/cbin.10483. [Epub ahead of print]