Our previous studies have demonstrated that stable microRNAs (miRNAs) in mammalian serum and plasma are actively secreted from tissues and cells and can serve as a novel class of biomarkers for diseases, and act as signaling molecules in intercellular communication. Here, we report the surprising finding that exogenous plant miRNAs are present in the sera and tissues of various animals and that these exogenous plant miRNAs are primarily acquired orally, through food intake. MIR168a is abundant in rice and is one of the most highly enriched exogenous plant miRNAs in the sera of Chinese subjects. Functional studies in vitro and in vivo demonstrated that MIR168a could bind to the human/mouse low-density lipoprotein receptor adapter protein 1 (LDLRAP1) mRNA, inhibit LDLRAP1 expression in liver, and consequently decrease LDL removal from mouse plasma. These findings demonstrate that exogenous plant miRNAs in food can regulate the expression of target genes in mammals.
植物的miRNA可以直接调控动物基因的表达,miRNA进入人体的途径是食物.所以今后对食品的营养评价可能就不是糖、氨基酸、蛋白质等那么简单了,miRNA也应该在考虑中。植物中哪些miRNA对人有正面影响,哪些miRNA对人有负面影响需要进一步评估,或许会产生一个新的研究领域。当然要进行食用的转基因产品也需要重新进行评估,评估是否会产生对人体有不利影响的miRNA.