Tanycyte plasticity in the hypothalamus with the regulation of energy balance

Humans have a limited capacity for tissue regeneration. While we are able to regenerate portions of the kidney, liver, blood, hair and skin cells, we lack the ability to regenerate limbs or larger, more complex organs. Other organisms however, such as zebrafish, are endowed with the capacity to regenerate nearly all complex tissues, including appendages. Using the adult zebrafish (Danio rerio) as a model organism, we investigated the role of the miR-181b in the caudal fin during the regenerative process. Our findings reveal that miR-181b is upregulated during regeneration and its spatial expression is enriched in the regenerating blastema, the defining tissue of appendage regeneration. Importantly, depletion of miR-181b activity with antisense locked-nucleic-acid oligonucleotides inhibited regeneration by ~40% in comparison to scrambled control treated fins. Defective regeneration was accompanied with a robust suppression of blastema cell proliferation and defects in cell patterning. My findings suggest a model whereby miR-181b activation promotes blastema proliferation and tissue outgrowth.