Pde8b haploinsufficiency in mice is associated with modest adrenal defects, impaired steroidogenesis, and male infertility, unaltered by concurrent PKA or Wnt activation.

PDE8B, PRKAR1A and the Wnt/β-catenin signaling are involved in endocrine disorders. However, how PDEB8B interacts with both Wnt and protein kinase A signaling in vivo remains unknown. We created a novel Pde8b knockout mouse line (Pde8b^-/-); Pde8b haploinsufficient (Pde8b^+/-) mice were then crossed with mice harboring: (1) constitutive beta-catenin activation (Pde8b^+/-;ΔCat) and (2) Prkar1a haploinsufficieny (Pde8b^+/-;Prkar1a^+/-). Adrenals and testes from mice (3-12-mo) were evaluated in addition to plasma corticosterone, aldosterone and Dkk3 concentrations, and the examination of expression of steroidogenesis-, Wnt- and genes. Pde8b^-/- male mice were infertile with down-regulation of the Wnt/β-catenin pathway which did not change significantly in the Pde8b^+/-;ΔCat mice. Prkar1a haploinsufficiency also did not change the phenotype significantly. In vitro studies showed that PDE8B knockdown upregulated the Wnt pathway and increased proliferation in CTNNB1-mutant cells, whereas it downregulated the Wnt pathway in PRKAR1A-mutant cells. These data support an overall weak, if any, role for PDE8B in adrenocortical tumorigenesis, even when co-altered with Wnt signaling or upregulation; on the other hand, PDE8B appears to play a significant role in male fertility.

KEYWORDS: {{ getKeywords(articleDetailText.words) }}