Functional Genomic Screening During Somatic Cell Reprogramming Identifies DKK3 as a Roadblock of Organ Regeneration.

Frank Arnold,Amar Deep Sharma,Eugen Zizer,Ronan Russell,Rupert Oellinger,Roland Rad,Markus M Lerch,Hans A Kestler,Johann Gout,Johann M Kraus,Wendy Bergmann,Ninel Azoitei,Alexander Kleger,Lukas Perkhofer,Thomas Seufferlein,Umesh Tharehalli,Michael Ott,Dharini Srinivasan,André Lechel,Pallavi U Mahaddalkar,Qiong Lin,Xiaowei Zhong,Stefan Liebau,Patrick Hermann ,Alica Beutel ,Nora Daiß ,Sarah–Fee Katz ,Florian Weiß ,Élodie Roger

doi:10.1002/advs.202100626

Abstract

Somatic cell reprogramming and tissue repair share relevant factors and molecular programs. Here, Dickkopf‐3 (DKK3) is identified as novel factor for organ regeneration using combined transcription‐factor‐induced reprogramming and RNA‐interference techniques. Loss of Dkk3 enhances the generation of induced pluripotent stem cells but does not affect de novo derivation of embryonic stem cells, three‐germ‐layer differentiation or colony formation capacity of liver and pancreatic organoids. However, DKK3 expression levels in wildtype animals and serum levels in human patients are elevated upon injury. Accordingly, Dkk3‐null mice display less liver damage upon acute and chronic failure mediated by increased proliferation in hepatocytes and LGR5+ liver progenitor cell population, respectively. Similarly, recovery from experimental pancreatitis is accelerated. Regeneration onset occurs in the acinar compartment accompanied by virtually abolished canonical‐Wnt‐signaling in Dkk3‐null animals. This results in reduced expression of the Hedgehog repressor Gli3 and increased Hedgehog‐signaling activity upon Dkk3 loss. Collectively, these data reveal Dkk3 as a key regulator of organ regeneration via a direct, previously unacknowledged link between DKK3, canonical‐Wnt‐, and Hedgehog‐signaling.

Highlights

IntroductionReprogramming of somatic cells to induced pluripotent stem cells (iPSC) upon ectopic expression of the four Yamanaka factors (OCT3/4, KLF4, SOX2, and c-MYC) represents a tremendous advance in disease modeling, regenerative medicine, and drug development.[1,2,3] Generation of patientspecific iPSCs complemented with lineagespecific differentiation can provide important insights into disease pathogenesis to leverage a resource for potential rescue strategies,[4,5,6,7] but can eliminate age- and disease-specific phenotypes.[8]
Generation of patientspecific induced pluripotent stem cells (iPSC) complemented with lineagespecific differentiation can provide important insights into disease pathogenesis to leverage a resource for potential rescue strategies,[4,5,6,7] but can eliminate age- and disease-specific phenotypes.[8]
Our study reveals that Dkk3 loss results in increased numbers of iPSCs during somatic reprogramming of mouse embryonic fibroblasts (MEF) without affecting pluripotency levels

Summary

Introduction

Reprogramming of somatic cells to induced pluripotent stem cells (iPSC) upon ectopic expression of the four Yamanaka factors (OCT3/4, KLF4, SOX2, and c-MYC) represents a tremendous advance in disease modeling, regenerative medicine, and drug development.[1,2,3] Generation of patientspecific iPSCs complemented with lineagespecific differentiation can provide important insights into disease pathogenesis to leverage a resource for potential rescue strategies,[4,5,6,7] but can eliminate age- and disease-specific phenotypes.[8].

Results

Discussion

Conclusion