Functional genomic screening during somatic cell reprogramming identifies Dkk3 as a roadblock of organ regeneration

Somatic cell reprogramming toward induced pluripotency can partly erase disease- and aging-associated phenotypes. Factors relevant to this process might also impact organ regeneration. Here, we identified Dickkopf 3 (Dkk3) as a roadblock of organ regeneration using combined transcription-factor-induced reprogramming and RNA-interference techniques as a screening assay. Genetic loss of Dkk3 enhanced the generation of induced pluripotent stem cells but did not hinder de novo derivation of embryonic stem cells and three-germ layer differentiation. Organoid derivation assays from intestine, liver, and pancreas of Dkk3 knock out mice did not reveal colony formation differences, while in vivoinjury induced DKK3 expression in wild type animals, respectively. Accordingly, Dkk3 null mice displayed less liver damage at time of regeneration upon CCl₄-induced acute liver failure. Similarly, recovery from experimental pancreatitis was accelerated albeit the extend of initial damage level was similar. Regeneration onset occurred in the acinar compartment accompanied by virtually abolished canonical Wnt-signaling in the Dkk3 null animals. Mechanistic analysis identified the downregulation of the Hedgehog (Hh) repressor Gli3 as a trigger of increased Hh-signaling upon Dkk3 loss. In contrast, treating knockout mice with a Hh inhibitor worsened improved pancreatic regeneration. Collectively, our data reveal Dkk3 as a roadblock toward pluripotency and regeneration to establish a direct, previously unacknowledged link between DKK3-/canonical Wnt- and Hh-signaling.

Publication History

Article published online:
08 September 2020