Reducing YAP expression in Pkd1 mutant mice does not improve the cystic phenotype

Area of Science:

• Cellular biology
• Molecular biology
• Genetics

Background:

• The Hippo pathway regulates organ size and its effectors, YAP/TAZ, are implicated in disease.
• Aberrant Hippo pathway activation was previously observed in autosomal-dominant polycystic kidney disease (ADPKD).
• This suggested a potential role for YAP/TAZ in ADPKD progression.

Purpose of the Study:

• To investigate the role of YAP/TAZ in ADPKD progression.
• To determine if down-regulating YAP levels could be a therapeutic strategy for ADPKD.

Main Methods:

• Utilized antisense oligonucleotides (ASOs) to down-regulate Yap expression in a mouse model of ADPKD.
• Assessed the impact of Yap knockdown on cyst formation and growth.
• Analyzed the expression of YAP/TAZ downstream targets and other signaling pathways (WNT, TGF-β).

Main Results:

• Yap levels were efficiently reduced in the kidneys of ADPKD mice using ASOs.
• No significant effect on cyst formation or growth was observed after Yap knockdown.
• Expression of YAP/TAZ targets remained unchanged, while WNT and TGF-β targets (Myc, Acta2, Vim) increased.

Conclusions:

• Down-regulating YAP levels is not an effective strategy for modulating polycystic kidney disease progression.
• The Hippo pathway's role in ADPKD may be independent of YAP/TAZ activity, or other pathways compensate.
• Further research is needed to identify viable therapeutic targets for ADPKD.