RNA-Seq reveals plant microRNAs regulating expression in mammals
from The Scientist
Chen-Yu Zhang, a molecular biologist at Nanjing University in China, hypothesized that exogenous microRNAs, such as those ingested through the consumption of milk, could also be found circulating in the serum of mammals. To test this idea, Zhang and his team of researchers sequenced the blood microRNAs of 31 healthy human subjects and searched for the presence of plant microRNAs. Because plant microRNAs are structurally different from those of mammals, they react differently to oxidizing agents, and the researchers were able to differentiate the two by treating them with sodium periodate, which oxidizes mammal but not plant microRNAs.
To their surprise, they found about 40 types of plant microRNAs circulating in the subjects’ blood—some of which were found in concentrations that were comparable to major endogenous human microRNAs—and that these exogenous plant microRNAs are primarily acquired orally, through food intake.
L. Zhang, et. al. (2011) Exogenous plant MIR168a specifically targets mammalian LDLRAP1: evidence of cross-kingdom regulation by microRNA. Cell Research [Epub ahead of print]. [abstract]