Mapping the dynamic expression of Wnt11 and the lineage contribution of Wnt11-expressing cells during early mouse development

Abstract

Planar cell polarity (PCP) signaling is an evolutionarily conserved mechanism that coordinates polarized cell behavior to regulate tissue morphogenesis during vertebrate gastrulation, neurulation and organogenesis. In Xenopus and zebrafish, PCP signaling is activated by non-canonical Wnts such as Wnt11, and detailed understanding of Wnt11 expression has provided important clues on when, where and how PCP may be activated to regulate tissue morphogenesis. To explore the role of Wnt11 in mammalian development, we established a Wnt11 expression and lineage map with high spatial and temporal resolution by creating and analyzing a tamoxifen-inducible Wnt11-CreER BAC (bacterial artificial chromosome) transgenic mouse line. Our short- and long-term lineage tracing experiments indicated that Wnt11-CreER could faithfully recapitulate endogenous Wnt11 expression, and revealed for the first time that cells transiently expressing Wnt11 at early gastrulation were fated to become specifically the progenitors of the entire endoderm. During mid-gastrulation, Wnt11-CreER expressing cells also contribute extensively to the endothelium in both embryonic and extraembryonic compartments, and the endocardium in all chambers of the developing heart. In contrast, Wnt11-CreER expression in the myocardium starts from late-gastrulation, and occurs in three transient, sequential waves: first in the precursors of the left ventricular (LV) myocardium from E7.0 to 8.0; subsequently in the right ventricular (RV) myocardium from E8.0 to 9.0; and finally in the superior wall of the outflow tract (OFT) myocardium from E8.5 to 10.5. These results provide formal genetic proof that the majority of the endocardium and myocardium diverge by mid-gastrulation in the mouse, and suggest a tight spatial and temporal control of Wnt11 expression in the myocardial lineage to coordinate with myocardial differentiation in the first and second heart field progenitors to form the LV, RV and OFT. The insights gained from this study will also guide future investigations to decipher the role of non-canonical Wnt/ PCP signaling in endoderm development, vasculogenesis and heart formation.

Wnt11 regulates cardiac chamber development and disease during perinatal maturation

“…Among the major pathways enriched in the P3 poorly preserved modules, we found that 27 out of 58 Wnt-related genes were regulated in a chamber-specific manner, including components from the canonical and noncanonical signaling pathways (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35). Remarkably, established inhibitors of canonical β-catenindependent signaling (Wif1, Dkk3, and Sost1) were upregulated in RVs compared with LVs, while several members of the noncanonical Wnt11 signaling (Wnt11, Wnt5a, Ror2, Sfrp5, and Rock2) were enriched in RVs.…”

“…The noncanonical Wnt11 is a relatively new and underexplored member of the Wnt family, and its role in postnatal heart maturation or disease has not been reported. It was previously shown that Wnt11 is required for proper cardiogenesis, myocardium development, and outflow tract morphogenesis (27)(28)(29), while a recent study also implicated Wnt11 in reducing heart scaring after infarction (41). Our current report proves, to our knowledge for the first time, that endogenous Wnt11-mediated signaling directly regulates neonatal CMC proliferation.…”

“…Among the different developmental signals (21)(22)(23), Wnt signaling pathways play prominent roles in cardiac precursor's commitment, cell proliferation, differentiation, and fate (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35).Actions by the Wnt family molecules can be classified into the canonical Wnt/β-catenin-dependent pathway and the noncanonical pathway, which is generally β-catenin independent, and its function can be mediated by 2 distinct modules of the noncanonical signaling: (a) the planar cell polarity (PCP) pathway; and (b) the Wnt/ Ca 2+ pathway, which involves calmodulin-dependent kinase II (CamKII), protein kinase C (PKC), and calcineurin. These factors may coordinate important cellular signaling processes including regulating the expression of key cell cycle regulators.…”

“…Although substantial overlap exists between the different Wnt signaling pathways during heart development, existing evidence has revealed a critical role of noncanonical Wnt11 in orchestrating early development (24)(25)(26)(27)(28)(29)(30)(31)(32)(33)(34)(35). Wnt11 expression is dynamically regulated in a temporal-spatial manner (28), playing important roles in myocardial development, including the second heart field (SHF) derivatives and the outflow tract.…”

“…Wnt11 expression is dynamically regulated in a temporal-spatial manner (28), playing important roles in myocardial development, including the second heart field (SHF) derivatives and the outflow tract. Wnt11-null mouse fetuses developed conotruncal defects including pulmonary stenosis and double-outlet RV (DORV) (29).…”