Inactivation of DGCR8/pash-1 in nematode reduces lifespan apparently due to accelerated aging. This intervention abrogates (lin-14 mutation and jnk-1(OE)) and suppresses (eat-2 and glp-1 mutants) several lifespan extending interventions, but not that conferred insulin-like signalling inhibition (daf-2 mutant) .
Assuming that miRNA normally silences aging genes and then these aging genes become ectopic expressed ( i.e. pash-1 inactivation) they subsequently program the animal to be at a later age, before they can be silenced again.
Another explanation might be that something gets non-harmonic in this mutant animals and can not be restored.