Blood vessels are not static pipes. During development, and indeed whenever tissues grow or repair themselves, vascular networks must be extensively remodeled: new sprouts extend into avascular territory, redundant branches regress, and existing vessels adapt their caliber and shape to match the demands of blood flow. In the central nervous system, this orchestration is guided in part by Wnt signaling, a family of pathways with two major branches. The canonical Wnt/β-catenin branch is well established as a regulator of endothelial specialization and of the blood–brain barrier, the selective fortress that shields neural tissue from the bloodstream. The non-canonical Wnt/Planar Cell Polarity (PCP) branch, by contrast, is known to govern vascular remodeling and the ability of endothelial cells to sense and adapt to the mechanical forces of flowing blood. What has remained stubbornly unclear is how the PCP pathway—activated at the cell surface—translates its instructions into the internal polarity machinery that tells a cell which way is forward.

The new study, led by Cécile Duplàa and Thierry Couffinhal of Inserm unit UMR1034 at the University of Bordeaux, with contributions from Alexandre Dubrac at the Sainte-Justine Research Center and Université de Montréal, answers that question by zeroing in on MCC, short for Mutated in Colorectal Cancer. MCC is a PDZ-domain protein, a class of scaffold molecules that physically assemble signaling complexes at specific cellular locations. It had previously been implicated in cell migration in epithelial cells and identified as an effector of non-canonical Wnt signaling during convergence and extension movements in zebrafish embryos—developmental processes that depend intimately on planar cell polarity. The Bordeaux team, building on their laboratory’s long-standing interest in vascular morphogenesis, hypothesized that MCC might perform an analogous role inside endothelial cells.

The researchers’ mechanistic work centered on a striking molecular partnership. Using proximity-dependent biotinylation (BioID), a technique that maps proteins sitting close to a protein of interest within living cells, combined with mass spectrometry proteomics, they found that MCC interacts with CEP131, a component of centriolar satellites. Centriolar satellites are electron-dense granules that cluster around the centrosome—the cell’s principal microtubule-organizing center—and help regulate centrosome function, protein turnover and cilia biology. The team’s proteomics data, deposited in the ProteomeXchange Consortium, show that MCC does not merely associate with CEP131; it actively promotes the satellite protein’s degradation, engaging both the proteasome, the cell’s cytosolic protein-shredding machinery, and autophagy, the lysosomal degradation system often used for bulk recycling of cellular components. In other words, MCC functions as a quality-control switch for the structures surrounding the centrosome.

Why would this matter for polarity? The answer lies in the geometry of a migrating endothelial cell. To move directionally, a cell must establish a front–rear axis: the microtubule cytoskeleton and the microtubule-organizing center must be positioned and oriented toward the leading edge, while the Golgi apparatus and nucleus reposition accordingly. Previous work from several groups, including studies showing that excess centrosomes scatter and derail endothelial migration, had established that centrosome-associated organization is a linchpin of directional movement. By keeping centriolar satellite material in check through regulated turnover, MCC appears to preserve the clean, polarized centrosomal architecture that directional migration demands. When the researchers depleted MCC from endothelial cells, this organization fell apart—and with it, the cells’ ability to polarize front-to-back.

One of the most intriguing findings of the study is what did not fall apart. When the team subjected MCC-depleted endothelial cells to flow, mimicking the shear stress that blood exerts on vessel walls in vivo, the cells still elongated and aligned their cytoskeletons with the direction of flow—indeed, this flow-induced elongation was preserved and even enhanced. This dissociation is biologically revealing. It demonstrates that two processes often lumped together as “endothelial alignment” are mechanistically separable: the passive morphological response to fluid shear, in which cells stretch along the flow axis, can proceed without MCC, while the active, directional front–rear polarization required for guided migration depends on it. For vascular biologists, this functional split offers a new framework for dissecting how vessels respond to hemodynamic forces.

The in vivo evidence came from the postnatal mouse retina, a classic and visually tractable model of angiogenesis in which a vascular plexus expands radially across the retinal surface during the first weeks of life, driven by proliferating “tip” cells at the angiogenic front. When the researchers deleted the Mcc gene specifically in endothelial cells of newborn mice, the retinal vasculature failed to remodel properly. Vessel density was abnormal, endothelial proliferation dropped, and—critically—the front–rear polarity of endothelial cells at the angiogenic front was disrupted. Tip cells, which must polarize and migrate persistently to lead the vascular sprout, lost their organizational bearings.

To rule out the possibility that these polarity defects were merely secondary consequences of a grossly malformed vasculature, the team employed an elegant pharmacological intervention. Captopril, an angiotensin-converting enzyme inhibitor long used as a blood pressure drug, is known to normalize vascular density and promote vessel regression in the remodeling retina. When the researchers treated the MCC-deficient mice with captopril, vascular density normalized and pruning proceeded—but endothelial polarity remained broken. This result is pivotal: it indicates that MCC’s role is cell-intrinsic. The protein is not simply required to generate a vascular environment in which polarity is possible; it is required within each endothelial cell to construct the polarity machinery itself.

The study also situates MCC within a broader signaling hierarchy. Prior work by the Bordeaux group and collaborators had identified the E3 ubiquitin ligase PDZRN3 as a Wnt/PCP pathway component required for vascular morphogenesis, and proteomic analyses had placed PDZRN3 downstream of Wnt5a–Ror signaling, a prototypical non-canonical Wnt cascade. The new findings extend this wiring: MCC now emerges as a downstream effector that converts PCP pathway activity into centrosome-associated proteostasis—the controlled degradation of satellite components—thereby closing the gap between a signal received at the membrane and a polarized cytoskeleton inside the cell.

Beyond developmental biology, the work carries implications for human disease. MCC was originally named for its frequent mutation in colorectal tumors, and it has since been characterized as a putative tumor suppressor that represses β-catenin-dependent transcription. Its newly described role in endothelial biology suggests that alterations in MCC could contribute to vascular pathologies as well. Aberrant angiogenesis and defective vascular remodeling underlie a wide range of conditions, from diabetic retinopathy—where neurovascular crosstalk fails and vessels in the retina deteriorate—to ischemic disease, where therapeutic revascularization is limited by the vessels’ inability to remodel productively. Cerebral small vessel disease, another area of active investigation by members of the consortium, may also intersect with pathways controlling endothelial polarity and mechanosensing. If the MCC–CEP131 axis proves druggable, it could offer a handle for promoting or restraining vascular remodeling in clinical contexts.

The technical breadth of the study is itself noteworthy. The team combined live-cell polarity assays and automated image analysis, single-cell RNA sequencing of mouse retina—data publicly available through the Gene Expression Omnibus under accession GSE175895—and quantitative proteomics to characterize the MCC interactome. Such multi-omics integration is increasingly the norm in vascular biology, where the behavior of a single endothelial cell must be understood simultaneously at the level of gene expression, protein interaction networks and subcellular architecture.

For the field, the study fills a genuine conceptual hole. The Wnt/PCP pathway has been implicated in angiogenesis for nearly two decades, with components such as Celsr1, DAAM1 and Kif26b variously shown to regulate endothelial junctions, proliferation and polarity. Yet the route from pathway activation at the plasma membrane to the microtubule-organizing center has remained speculative. By identifying MCC as the bridge—and by showing that the bridge is built from regulated protein degradation at the centrosome—the Bordeaux-led consortium has supplied both the missing connection and a mechanistic explanation for why it matters. As vascular biologists now probe how this axis operates in pathological angiogenesis and in the mature vasculature of the adult brain, MCC may shed its reputation as merely a cancer gene and take on a new identity: a master organizer of the cell’s sense of direction.

Endothelial cells, which line the interior surface of blood vessels, play a critical role in vascular biology, influencing processes such as inflammation, coagulation, and angiogenesis. Quaking is known to modulate various signaling pathways that govern endothelial cell functions. Its significance extends beyond mere structural roles; it actively participates in the regulation of gene expression and cellular responses to environmental stimuli. Researchers have observed that variations in Quaking expression levels correspond with aberrations in endothelial cell behavior, potentially contributing to pathological conditions.

A pivotal area of focus concerning Quaking revolves around its involvement in angiogenesis, the process through which new blood vessels form from pre-existing ones. This is particularly important during embryonic development, wound healing, and in response to ischemic conditions. The latest research sheds light on how Quaking influences endothelial cell proliferation, migration, and survival during angiogenesis. By regulating the expression of downstream genes, Quaking accentuates the balance between pro-angiogenic and anti-angiogenic factors, suggesting that fine-tuned Quaking activity could determine the success or failure of new vessel formation.

Moreover, the dysregulation of Quaking has been linked to various diseases, including cancer. Tumors often hijack the angiogenic process to secure an adequate blood supply, thereby facilitating their growth and dissemination. In this context, understanding how Quaking modulates endothelial responses to tumor-secreted factors could illuminate new therapeutic avenues. For instance, targeting Quaking’s regulatory mechanisms might hinder the vascular architecture of tumors, potentially stifling their growth or improving the efficacy of chemotherapeutics that rely on optimal blood supply.

Studies have also unveiled the interactions between Quaking and other RNA-binding proteins, suggesting a complex network of regulatory mechanisms at play. These interactions may enhance or inhibit Quaking’s functions, allowing cells to respond rapidly to alterations in their microenvironment. This adaptability is crucial, as endothelial cells continually encounter varying blood flow and pressure conditions. Through sophisticated molecular choreography, Quaking and its partners ensure not only the maintenance of stable blood vessel structures but also their functional plasticity.

Furthermore, investigations into the post-translational modifications of Quaking have provided insight into its functional versatility. Phosphorylation, methylation, and other modifications can alter Quaking’s stability and activity, enabling cells to finely tune their responses. These modifications can be particularly relevant in pathological scenarios where altered signaling pathways dictate the fate of endothelial cells. Therefore, understanding the biochemical landscape governing Quaking’s functionality could be paramount in designing targeted interventions that promote healthy angiogenesis.

The research encompassing Quaking also highlights the importance of cross-talk between endothelial cells and surrounding tissues. Extracellular signals, such as those from pericytes and inflammatory cells, can profoundly influence Quaking expression and activity. This intercellular communication is vital not only for normal physiological processes but also for the progression of diseases where the endothelial barrier becomes compromised or dysfunctional. Such complexities underscore the need for a comprehensive approach to study the roles of Quaking within the broader context of tissue microenvironments.

Emerging technologies, such as CRISPR/Cas9 gene editing and single-cell RNA sequencing, are poised to revolutionize the exploration of Quaking’s multiple roles. These advancements allow for precise manipulation of Quaking expression levels and provide insights into the heterogeneity of endothelial cell populations. Understanding the diverse responses within these populations could refine therapeutic strategies aimed at modulating angiogenesis in various diseases, including cardiovascular ailments and cancer.

Moreover, the implications of Quaking research extend beyond the vascular field. Cardiovascular diseases remain a leading cause of mortality worldwide, and strategies to harness the power of angiogenesis could pave the way for innovative treatments. Enhancing Quaking function in endothelial cells might boost reparative angiogenesis after myocardial infarction or stroke, highlighting its potential utility in regenerative medicine.

Collaborative efforts across disciplines are essential to unravel the multifaceted roles of Quaking comprehensively. By bringing together molecular biologists, geneticists, pharmacologists, and clinicians, the scientific community can accelerate discoveries that bridge basic research and clinical applications. Such collaborative endeavors are likely to yield new insights into how Quaking can be manipulated safely to promote vascular health and combat disease.

In summary, the significance of Quaking in endothelial cell biology is becoming increasingly apparent. From regulating angiogenesis to modulating responses to external stimuli, its diverse roles present exciting research opportunities. As studies continue to elucidate the complex networks surrounding Quaking, the potential for transformative therapeutic strategies in treating vascular-related diseases becomes more promising. Researchers are committed to pushing the boundaries of knowledge, paving the way for future innovations that can capitalize on the properties of this remarkable protein.

The future looks bright for Quaking research, as our understanding of this protein expands. It is clear that Quaking is not merely a passive participant in endothelial cell biology; it is a dynamic regulator of crucial processes that maintain vascular integrity and functionality. Continued investigations will refine our grasp of its complex roles, illuminating paths toward novel interventions that could improve outcomes for patients suffering from a myriad of vascular diseases. With its diverse roles meticulously mapped, Quaking could very well hold the key to groundbreaking therapies that harness the body’s innate ability to heal itself.

Subject of Research: Diverse roles of Quaking in endothelial cell biology

Article Title: Diverse roles of quaking in endothelial cell biology

Article References: Edatt, L., Li, D., Dudley, A.C. et al. Diverse roles of quaking in endothelial cell biology. Angiogenesis 29, 4 (2026). https://doi.org/10.1007/s10456-025-10020-w

Image Credits: AI Generated

DOI: https://doi.org/10.1007/s10456-025-10020-w

Keywords: Quaking, endothelial cells, angiogenesis, vascular biology, RNA-binding proteins, disease mechanisms, cell signaling, therapeutic interventions.