There has always been a fascination with the importance of food to its consumers. Food is the main source of energy input and also one of the main factors that keep the organism alive. Curiously, is there a link between food and heritable information? If there is, what is its effect on the organism and through what way is it expressed? Recently, scientists have been interested in the origin of microRNA or miRNA and some of those scientists suggested that they come from external sources, such as ingested food. MicroRNA are short strands of nucleotides that fasten to complementary messenger RNA (mRNA) which then stops those genes from their specific processes (Hodge 2011).
Chen-Yu Zhang and his team from Nanjing University examined the aspect of miRNA transferring to mammals specifically by plant constituents. The experiment took blood samples from healthy cows and humans as a source of analysis for evidence and to reassure that the miRNA was not already from the body, sodium periodate was used as an oxidising agent (Jabr 2011). The results indicated approximately thirty different miRNA which came from plants such as wheat, broccoli and cabbage and they represented about 5% of all miRNA in mammals (Vaucheret & Chupeau 2011). These RNA strands gave a surprising reaction to the scientists as it survived all processes to reach the organism’s bloodstream which include being cooked and digested in the animal’s stomach by the strong acid hydrochloric acid. Two types of miRNA which seemed to be present in high numbers in the blood samples are MIR168a and MIR156a and these two stands of nucleotides were also existent in the liver and intestines of rodents. As the miRNA were matched with human and rat genomes, about roughly fifty of those genes were complimentary with MIR168a and MIR156a. One of those vital genes which coded for a protein that helps the removal of LDL (Low Density Lipoprotein) or “bad cholesterol” from the body was called exon 4 LDLRAP1 mRNA. (Adams 2011) When a mice was injected with a dose of MIR168a, the cholesterol levels increased. This indicated that the miRNA had destroyed the protein’s function as it could not properly perform its designated action of LDL removal.
Another similar study conducted by French scientists Herve Vaucheret and Yves Chupeau explored the way miRNA was being transported through by the body (2011). They found that the RNA nucleotide strands were being shipped to other places by microvesicles. These microvesicles received the miRNA from epithelial cells in the intestines which had compacted them beforehand.
Overall, the conduction of these two and other experiments by scientists all over the world has helped explain the function and importance of miRNA. With such further research and study, the genetics side of science may well be fully discovered and with such comes hope for treatment of diseases and gene-related illnesses for the future.
Adams, P, 2011, We Incorporate Genetic Information From Food, viewed 19 March 2012, <http://www.popsci.com.au/science/health/we-incorporate-genetic-information-from-food- we-eat>.
Hodge, A-M, 2011, Food We Eat Might Control Our Genes, viewed 19 March 2012, <http:// www.scientificamerican.com/article.cfm?id=vitamins-minerals-and-microrna>.
Jabr, F 2011, Eating your greens alters your genes, viewed 19 March 2012, <http:// www.newscientist.com/article/mg21128323.100-eating-your-greens-alters-your- genes.html?full=true>.
Vaucheret, H & Chupeau, Y 2011, ʻIngested plant miRNAs regulate gene expression in animalsʼ, Cell Research, vol. 22, pp. 3-5.
By Hue Kim Thi Vo.