Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2025.06.01.657323

Wnt11 Positively Regulates Neonatal Cardiomyocyte Maturation at the Interphase of Life via Frizzled 4 Receptor

Kang, X.·Moci, J.·Wolf, C.·Touma, M.
View original source ↗Export metadata ↓

Abstract

Congenital heart defects (CHDs) affect 1% of live births and remain the leading cause of infant morbidity and early mortality. While most studies focus on the genetic basis of CHDs, relatively little is known about the interplay between intrinsic signaling and external environmental factors in the progression of CHDs after birth during the perinatal circulatory transition window when environmental stress factors are prevalent. We recently explored such interplay through a newly identified gene-environment regulatory circuit involving Wnt11 signaling and systemic hypoxia. Specifically, we demonstrated that activation of the Wnt11/Rb1 axis is critical for normal chamber-specific development after birth. This regulatory switch is disrupted by systemic hypoxia more robustly in the right ventricle (RV) than the left ventricle (LV), leading to enhanced neonatal cardiomyocyte cell cycle activity in an RV-specific manner, resulting in delayed maturation and attenuation of ventricular patterning in response to systemic hypoxia stress in the neonatal heart. Furthermore, we found that the Wnt11/Rb1 axis is also inactivated in infantile hearts with cyanotic CHDs, such as tetralogy of Fallot (TOF), potentially contributing to hypoxia-associated RV abnormalities in this context. However, the molecular players of this signaling cascade in neonatal cardiomyocyte remain largely unknown. Herein, we report that Frizzled 4 (Fzd4) acts as a specific upstream receptor for Wnt11 in neonatal cardiomyocytes. Specifically, Fzd4 exhibited an expression pattern like Wnt11 in neonatal heart perinatal circulatory transition under normal and hypoxemic environments. Furthermore, Fzd4 loss in neonatal cardiomyocytes stimulated cardiomyocyte cell cycle activity and disrupted the Wnt11-Rb1 signaling axis mirroring the impact of the Wnt11-deficient cardiomyocyte phenotype. Finally, co-immunoprecipitation analysis confirmed the Wnt11-Fzd4 binding in isolated neonatal cardiomyocytes and intact hearts. These results demonstrate that Fzd4 is a specific and required upstream receptor for the Wnt11-Rb1 signaling activity in the neonatal heart and provides mechanistic insights into the essential role of Wnt11 as a key positive regulator of neonatal cardiomyocyte transition from proliferative to mature phenotype at the interphase of life.

Explore related subjects

cell biologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Kang, X., Moci, J., Wolf, C., Touma, M.. 2025-06-03. Wnt11 Positively Regulates Neonatal Cardiomyocyte Maturation at the Interphase of Life via Frizzled 4 Receptor. https://doi.org/10.1101/2025.06.01.657323

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Unraveling the metabolic landscape of alkaptonuria through a human-relevant in vitro liver disease model

Alkaptonuria (AKU) is a rare inherited metabolic disorder of tyrosine catabolism caused by a deficient homogentisate 1,2-dioxygenase (HGD) enzyme. This results in the accumulation of homogentisic acid (HGA), driving a progressive multisystem pathology characterized by debilitating early-onset osteoarthritis due to connective tissue degeneration. While previous in vitro studies have primarily relied on exogenous HGA exposure in osteoarticular cell models, the direct metabolic consequences of endogenous HGD deficiency within its native hepatic context remain poorly understood. Here, we established the first human-relevant HGD knockout hepatic in vitro model using a universal in-house-developed homology-directed repair approach. Integrative multi-omic analysis revealed that HGD deficiency induces widespread metabolic rewiring extending beyond disrupted tyrosine catabolism. HGD-deficient hepatocytes exhibited elevated oxidative stress accompanied by impaired mitochondrial respiration and a pseudohypoxic metabolic adaptation toward increased glycolytic dependency. Despite this glycolytic shift, the cells displayed reduced anabolic and translational activity alongside attenuated proliferation, consistent with a chronic stress-adaptive survival state rather than a proliferative metabolic phenotype. This study provides systems-level insights into the pathophysiology of AKU and establishes a versatile platform for mechanistic and therapeutic investigation.

cell biology↗
bioRxiv2026

P-body sequestration of clock transcripts delays repressor synthesis to set circadian period in Drosophila

Negative-feedback oscillators require a delay between the accumulation of a repressor's mRNA and the action of its protein. In the circadian clock, this delay has been attributed largely to post-translational control of PERIOD (PER) stability and nuclear entry. The RNA-binding proteins shown to regulate per translation, ATAXIN2 and its partners, promote it, leaving open whether any step holds clock transcripts back before they are translated. Here, using time-resolved miniTurbo proximity labeling of endogenous PER across four phases of the circadian cycle in Drosophila clock neurons, we define a 252-protein PER proximitome that partitions into a nuclear arm and a cytoplasmic RNA-metabolism arm. A behavioral RNAi screen identified two P-body components, the DEAD-box helicase Me31B (DDX6) and the 5'-3' exonuclease Pacman (Pcm; XRN1), as strong regulators of circadian rhythms. Using single-molecule RNA-FISH, proximity RNA editing and ribosome profiling, we show that as per and tim transcripts accumulate, they localize to Me31B-labeled P-bodies and are poorly translated, most prominently at ZT12. Me31B knockdown disrupts P-bodies and releases per mRNA from them, causing PER to accumulate earlier and to ~2-fold higher levels, whereas Me31B overexpression delays PER accumulation and lengthens the free-running period by ~2 h. Knockdown of Pcm, in contrast, impairs clearance of per mRNA, sustaining PER and TIM accumulation, prolonging the repression phase and abolishing cycling of ~89% of rhythmic transcripts. Together, these findings identify P-body sequestration as a repressive step that delays repressor synthesis, and Pcm-dependent decay as required to end repression on time. Given the deep conservation of DDX6 and XRN1, RNP compartments may provide a conserved means of generating delay in circadian and other negative-feedback circuits.

cell biology↗
bioRxiv2026

Defining redundancy in the stickers and spacers of the cell-cell junction protein Canoe's intrinsically disordered region

Cell-cell adherens junctions (AJs) and their dynamic cytoskeletal linkage power morphogenesis. AJs are enormous complexes with hundreds of proteins linked by multivalent interactions. Like other biomolecular condensates, intrinsically disordered regions (IDRs) in junctional proteins play important roles in AJ assembly and function, using spacer elements to span distances, and stickers to engage targets. To define molecular mechanisms, we need to define the functional units within IDRs. Drosophila Canoe, homolog of human Afadin, is our model. Canoe mediates morphogenesis and has an extensive IDR, with two conserved F-actin-binding stickers and two poorly conserved spacers. We combined biochemical, genetic and cell biological approaches to define the function of these IDR elements. While no single element is essential, deleting the full IDR essentially eliminates Canoe function. By scrambling the amino acid sequence of the spacers, we find that length and composition are more important than amino acid sequences, though sequences in the C-terminal spacer affect Canoe localization. Finally, we test redundancy of the F-actin-binding stickers. Deleting both reduces but does not eliminate viability, and sensitized assays reveal their redundant roles. These data reveal the robustness of IDRs.

cell biology↗