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

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.

Dickkopf-3: An Update on a Potential Regulator of the Tumor Microenvironment

“…In this context, Dkk3 knockout increased recovery rates by limiting canonical Wnt signaling and increasing Hedgehog (Hh) signaling during pancreatic regeneration. These effects have been proposed to involve a reduction in the expression of the transcriptional repressor Gli3 [ 73 ]. The same study reported a similar scenario in the context of liver regeneration, leading the authors to propose that Dkk3 functions as a roadblock in liver and pancreas repair/regeneration upon injury [ 73 ].…”

“…These effects have been proposed to involve a reduction in the expression of the transcriptional repressor Gli3 [ 73 ]. The same study reported a similar scenario in the context of liver regeneration, leading the authors to propose that Dkk3 functions as a roadblock in liver and pancreas repair/regeneration upon injury [ 73 ]. Dkk-3 activation of non-canonical Wnt/β-catenin-independent signaling involving c-JUN N-terminal kinase (JNK) increases the secretion of inflammatory factors, such as TNF-α and IL-1β, in the brain, suggesting a neuroprotective mechanism [ 74 ] Furthermore, Dkk-3 is a factor required for smooth muscle cell differentiation [ 74 ]; the absence of Dkk-3 may therefore contribute to accelerating blood vessel inflammation and subsequent atherosclerotic plaque formation.…”

“…The role of Dkk-3 in orchestrating the quiescence and/or the differentiation of stem/progenitor cells has been investigated in prostate, breast, pancreatic, liver, and oral submucosal diseases [ 73 , 85 , 86 , 87 ]. Over the last decade, it has been of interest to identify the genes of somatic cells involved in re-programming to improve organogenesis for tissue engineering [ 88 ].…”

Functional Genomic Screening in Human Pluripotent Stem Cells Reveals New Roadblocks in Early Pancreatic Endoderm Formation

“…Functional genomic screening using gain-and loss-offunction technologies was successfully used to identify gene networks governing human embryonic stem cell behavior [24]. Our own group recently reported Dickkopf-3 (DKK3) as a novel factor for organ regeneration using combined transcription-factor-induced reprogramming and RNA interference techniques [25]. However, RNA interference screening during pancreatic endoderm formation has not been explored.…”

Dickkopf Homolog 3 (DKK3) as a Prognostic Marker in Lupus Nephritis: A Prospective Monocentric Experience

“…These proteins are essential regulators of embryomorphic pathways that are reactivable in response to tissue damage and are involved in epithelial-mesenchymal transition and fibrosis through various molecular mechanisms [ 1 , 2 , 3 ]. In particular, DKK3 is expressed in different organs, such as the heart, liver, eyes, uterus, embryo, placenta, blood, and pancreatic β cells [ 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. DKK3 has been described as a pleiotropic protein implicated in several cellular pathways involved in the cell cycle and differentiation.…”