Reversed Expression of Aging-Related Molecules by Transfection of Circulatory Biomarkers from Whole Blood and Exosomes

Abstract

Molecular changes during aging have been identified to understand the mechanism of aging progress, and also to use determine the status of aging progress. We investigated that changes in miRNA expression in the whole blood and exosomes of mice. The molecules selected as circulatory biomarkers from whole blood and exosomes were tried to induce reversed expression of aging-related molecules in tissues, and proposed to cause systemic reverse of aging in vivo. Through next generation sequencing analysis, we selected 27 differentially expressed miRNAs in whole blood of mice during aging. The most recognized function involved was liver steatosis, a type of non-alcoholic fatty liver disease (NAFLD). Among 27 miRNAs, six were predicted to be involved in NAFLD, miR-16-5p, miR-17-5p, miR-21a-5p, miR-30c-5p, miR-103-3p, and miR-130a-3p. The expression of the genes associated in the network of these miRNAs, Bcl2, Ppara, E2f1, E2f2, Akt, Ccnd1, and Smad2/3, was also altered in the liver of aged mice. Following transfection of these miRNAs into old mice, levels of transfected miRNAs in liver increased, and expression of Mre11a, p16INK4a, and Mtor, reported to be aging-associated molecules, was also reversed in the livers. In exosomes from 12-month-old mice, mmu-miR-126-5p and mmu-miR-466c-5p levels were decreased and mmu-miR-184-3p and mmu-miR-200b-5p levels were increased significantly, compared to those of 3-month-old mice. In the aged tissues injected with young exosomes, mmu-miR-126b-5p levels were reversed in the lungs and liver. Expression changes in aging-associated molecules in young exosome-injected mice were obvious: p16Ink4A, MTOR, and IGF1R were significantly downregulated in the lungs and/or liver of old mice. In addition, telomerase-related genes such as Men1, Mre11a, and Tnks were significantly upregulated in the liver of old mice after injection of young exosomes. Therefore, the identified molecules in whole blood and exosome might induce a reverse-regulation of aging-associated pathways. This study provides preliminary data on reverse-aging, which could be applied further for treatments of adult diseases.