This chapter describes one of the most reliable quantitative assays to test the silencing of a possible target gene by a specific miRNA using a luciferase reporter gene. The experimental procedure first consists in cloning both the wild-type and mutated forms of the 3'UTR of the miRNA predicted mRNA target downstream of a firefly luciferase reporter. Next, each construct is co-transfected together with the miRNA into HeLa cells, and the reporter expression is monitored. Changes in luciferase levels will indicate whether or not a miRNA can bind to the UTR and regulate its expression.
The pattern of psychosocial impact of disease in German IBD patients is largely congruent with the one observed in the USA and Canada, but shows some specific differences. The a priori unexpected finding that active coping was associated with poor HRQOL in active IBD status illustrates the importance of considering different determinants of HRQOL in terms of their mutual interaction.
Objective Decreased expression of collagen type II in favour of collagen type I or X is one hallmark of chondrocyte phenotype changes in osteoarthritic (OA) cartilage. MicroRNA- (miR-) 29b was previously shown to target collagens in several tissues. We studied whether it could contribute to collagen imbalance in chondrocytes with an impaired phenotype. Methods After preliminary microarrays screening, miR-29b levels were measured by RT- quantitative PCR in in vitro models of chondrocyte phenotype changes (IL-1β challenge or serial subculturing) and in chondrocytes from OA and non-OA patients. Potential miR-29b targets identified in silico in 3′-UTRs of collagens mRNAs were tested with luciferase reporter assays. The impact of premiR-29b overexpression in ATDC5 cells was studied on collagen mRNA levels and synthesis (Sirius red staining) during chondrogenesis. Results MiR-29b level increased significantly in IL-1β-stimulated and weakly in subcultured chondrocytes. A 5.8-fold increase was observed in chondrocytes from OA versus non-OA patients. Reporter assays showed that miR-29b targeted COL2A1 and COL1A2 3′-UTRs although with a variable recovery upon mutation. In ATDC5 cells overexpressing premiR-29b, collagen production was reduced while mRNA levels increased. Conclusions By acting probably as a posttranscriptional regulator with a different efficacy on COL2A1 and COL1A2 expression, miR-29b can contribute to the collagens imbalance associated with an abnormal chondrocyte phenotype.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.