Nextbigfuture covered the UCLA work a few days ago
SENS describes the promise for life extension
The UCLA group's approach is highly promising. Their work builds upon and may potentially supersede several previous approaches to the problem of mitochondrial mutations that occur as a result of the degenerative aging process, including allotopic protein expression,(6) its optimization using an MTS,(3-5) and the exploitation of the multiprotein RNA import complex (RIC) of the protozoal parasite Leishmania tropica(7) (which the investigators characterize as "requir[ing] the introduction of nonnative tRNAs with foreign protein factors or the transfer of a large multisubunit aggregate into cells, which is of low efficiency and difficult to reproduce in desirable disease-relevant settings"(2)).
As compared to allotopic protein expression, an RNA-based approach has the theoretical advantage of abrogating the difficulties encountered thus far with the mitochondrial import of large and hydrophobic proteins. But as we suggested in discussion of their earlier, more discovery-phase research, allotopic protein and RNA approaches are not mutually exclusive: different mitochondrially-encoded proteins could be either allotopically expressed, or their mRNAs generated allopically and imported for in situ translation, depending on the ease or efficiency of each approach for the protein in question. The use of a dual-track approach might be speculated to have an additional advantage, in avoiding any hypothetical "saturation" of the relevant mitochondrial import machinery (PNPase or TIM/TOM complex) if only one approach is used for all 13 mitochondrially-encoded proteins.