the possible envolvement of microRNA-29a in the regulation of mitochondrial encoded genes in beta-cells: mulig involvering af mikroRNA-29a i reguleringen af mitokondrielt kodede gener i beta-celler

Amina Rukhsar Khawaja & Berit Juul Aarre

Studenteropgave: Semesterprojekt


Type 2 diabetes is characterized by reduced function of the beta cells, which in turn results in reduced insulin se-cretion. Prior, it has been observed that mikroRNA-29a, which is up regulated by increased blood glucose, is in-volved in decreased insulin secretion by regulating the nuclear encoded subunits in the mitochondrial electron transport chain. Recently two foreign laboratories have detected microRNAs in the mitochondria. In this study we examine whether microRNA-29a also has a regulatory effect on mitochondrial encoded subunits of the electron transport chain. We manually searched for potential microRNA-29a target-sites in the mitochondrial genome fol-lowed by experimental validation of the target-sites. This was done by cloning the target sequences into a vector in the 3'UTR of the luciferase gene. Then the target vectors were co-transfected with either microRNA-29a or a negative control into mammalian cells, and the luciferase activity was measured by a luciferase-assay, as re-duced luciferase activity will tell whether the microRNA-29a has bound and thus down regulated the gene expres-sion. In this study we have identified potential target sites in the genes for NADH-dehydrogenase 6 (ND6) and D-loop. ND6 is a subunit of complex I in the electron transport chain whose function is receiving the electrons from NADH and passing them to the enzyme Q10. D-loop is a noncoding region that has a function in the over-all transcription of the entire mitochondrial genome. But whether these targets are actual targets, is unknown since the experimental validation didn’t go as expected. It is concluded that there as something new has been found possible target-sites in the mitochondrial genome for microRNA-29a in ND6 and D-loop. But further experi-ments are necessary to confirm these target-sites.

UddannelserBasis - Naturvidenskabelig Bacheloruddannelse, (Bachelor uddannelse) Basis
Udgivelsesdato25 maj 2012


  • mitokondrier
  • elektron transport kæden
  • mikroRNA
  • betaceller
  • diabetes
  • miR-29a