The research, led by Kwonho Hong of Konkuk University in Seoul together with an international team spanning institutions in Korea, China, and the United States, focused on a deceptively simple question: how do transcription factors gain access to the DNA they need to control during the critical window of lymphatic development? Transcription factors are the proteins that bind specific DNA sequences and switch genes on or off, but they can only reach their targets when the genome’s packaging material, chromatin, is open and accessible. The study reveals that INO80, a large molecular machine that slides and repositions nucleosomes, is what keeps those access points properly configured in lymphatic endothelial cells.

Using chromatin accessibility profiling in embryonic lymphatic endothelial cells, the team mapped the landscape of open chromatin between embryonic days 10.5 and 12.5, a period when the lymphatic vasculature is being established. They found a striking increase in accessibility at regulatory motifs for ETS family transcription factors, a group of well-known drivers of endothelial identity, and for YY1, a versatile transcriptional regulator that also happens to be a component of the INO80 complex itself. This temporal opening of the genome suggested that the cell was actively preparing its regulatory elements to receive developmental instructions, and that INO80 was positioned at the heart of that preparation.

To test whether INO80 was merely present or genuinely essential, the researchers deleted the Ino80 gene specifically in endothelial cells of mouse embryos. The result was catastrophic for the developing lymphatic system. Animals lacking INO80 in their endothelium displayed lethal lymphatic defects, including dermal edema, a swelling of the skin caused by fluid that the compromised lymphatic vessels could no longer drain. The lymphatic vessels of mutant embryos filled with blood, a hallmark phenotype of defective lymphatic-venous separation, and the lymphatic networks of the heart and mesentery were hypoplastic, meaning they failed to grow to their proper size and complexity.

At the molecular level, the consequences of INO80 loss were equally dramatic. Gene expression analysis revealed widespread dysregulation of genes controlling cell adhesion, cell migration, and vessel formation, the very processes that lymphatic endothelial cells must execute with precision to build a functional vascular network. The finding underscores a principle increasingly recognized in developmental biology: transcription factors alone are not sufficient to run a differentiation program. Without the chromatin remodeling machinery that maintains the correct accessibility landscape, even the right transcription factors cannot execute the right instructions at the right time.

The study went further, asking where INO80 actually sits in the genome of developing lymphatic endothelial cells. Mapping INO80-bound regions revealed a strong enrichment for ETS transcription factor motifs, and these occupied sites were preferentially associated with endothelial developmental genes. This genomic colocalization pointed to a functional partnership: INO80 does not act randomly across the genome but concentrates at regulatory elements where ETS factors operate, effectively shaping the chromatin terrain on which those factors depend.

One of the most intriguing discoveries involved the transcription factor ERG, an ETS family member with established roles in endothelial biology. The researchers observed that INO80 peaks containing ERG motifs were preferentially linked to angiogenic genes, genes that drive blood vessel growth, and that these same genes became dysregulated after INO80 loss. The data suggest a model in which INO80 and ERG collaborate to restrain aberrant angiogenic gene expression in lymphatic endothelial cells. In other words, INO80 is not simply an activator of the lymphatic program; it also appears to act as a gatekeeper, preventing lymphatic vessels from inappropriately adopting blood vessel-like behaviors during development.

This dual role, enabling lymphatic identity while suppressing inappropriate angiogenic programs, offers a fresh perspective on how chromatin remodelers contribute to cell fate decisions. The INO80 complex, first characterized in yeast as a regulator of nucleosome positioning and DNA repair, has emerged in vertebrates as a versatile player in transcriptional control. The new findings place it squarely within the epigenetic toolkit that lymphatic endothelial cells use to navigate their differentiation journey, alongside better-studied regulators such as the master lymphatic transcription factor PROX1 and the vascular ETS factors.

The clinical implications are potentially far-reaching. Lymphedema affects hundreds of millions of people worldwide, and congenital lymphatic malformations often trace back to defects in the same developmental pathways explored in this study. If INO80-mediated chromatin remodeling proves to be a conserved requirement for lymphatic specification in humans, it could open new avenues for understanding inherited lymphatic disorders and for designing regenerative strategies that coax lymphatic endothelial cells into forming functional vessels. Chromatin remodelers are also increasingly pursued as drug targets in oncology, and lymphatic vessels are a known route for cancer metastasis, adding another layer of therapeutic relevance.

For now, the study stands as a compelling demonstration that the three-dimensional accessibility of the genome is not a passive backdrop but an active, dynamically regulated feature of lymphatic development. By showing that INO80 shapes chromatin accessibility at ETS transcription factor-associated regulatory elements, the researchers have connected the epigenetic machinery to the transcriptional programs that build the lymphatic system, and they have revealed what happens when that connection breaks. As the field moves toward a complete mechanistic map of lymphatic vascular development, INO80 now occupies a prominent place on that map, a molecular architect whose work, though invisible to the naked eye, determines whether the body’s drainage network forms at all.

Subject of Research: INO80 chromatin remodeling in ETS transcription factor-mediated gene regulation during lymphatic endothelial cell development

Article Title: INO80 function in ETS transcription factor-mediated transcriptional programs in developing lymphatic endothelial cells

Article References: La, H., Yoo, H., Kwon, O., Thang, N. X., Moon, E.-H., Choi, D. Y., Park, C., Han, D. W., Lee, Y. J., Do, J. T., Lee, M. R., Song, H., Rhee, S., Hong, Y.-K., Jang, Y.-J., Choi, Y., & Hong, K. (2026). INO80 function in ETS transcription factor-mediated transcriptional programs in developing lymphatic endothelial cells. Cellular and Molecular Life Sciences. https://doi.org/10.1007/s00018-026-06460-2

Image Credits: AI Generated

DOI: 10.1007/s00018-026-06460-2

Keywords: INO80, lymphatic endothelial cells, chromatin remodeling, ETS transcription factors, ERG, YY1, lymphatic development, chromatin accessibility, epigenetics, gene regulation, angiogenesis, lymphedema

The research, led by Wagner and colleagues, centers on lymphatic endothelial cells, the specialized cells that line the interior of lymphatic vessels. In the heart, these vessels perform a demanding job. They clear interstitial fluid and macromolecules that accumulate as blood plasma filters out of coronary capillaries, and they provide the principal routes by which antigen-bearing immune cells migrate away from cardiac tissue and toward the draining lymph nodes. When lymphatic drainage falters, fluid and immune mediators build up in the tissue, and the heart’s immune environment shifts from a controlled, surveilled state to a chronically inflamed one.

By comparing lymphatic vessels in young and aged hearts, the investigators found that lymphatic integrity declines markedly with age. Lymphatic endothelial cells in older hearts showed structural and functional impairment, and the lymphatic network itself lost density and organization. This age-associated loss of lymphatic vasculature was consistently accompanied by heightened cardiac inflammation, including accumulation of inflammatory immune cells within heart tissue. The correlation raised a critical mechanistic question: is the lymphatic decline merely a consequence of inflammation, or does it actively promote the inflammatory state of the aging heart?

The study’s central finding points to the lymphatic defect as a cause rather than a consequence. The authors traced the impairment to elevated levels of nuclear interleukin-33, an immune regulatory protein, within the lymphatic endothelial cells themselves. Interleukin-33 is a member of the interleukin-1 cytokine family and is typically regarded as an alarmin, a danger signal released by stressed or damaged cells. Its cellular distribution matters enormously: when resident in the nucleus, it can regulate gene expression programs, while extracellular interleukin-33 acts as a potent immune activator through its receptor ST2. The new work indicates that in aged lymphatic endothelial cells, increased nuclear interleukin-33 expression disrupts the cells’ homeostatic function and undermines the structural integrity of the lymphatic network they support.

This mechanistic identification is what elevates the study from descriptive observation to a testable model of cardiac aging. Interleukin-33 signaling has long been implicated in inflammatory and fibrotic processes across multiple tissues, but its role within cardiac lymphatic endothelial cells had remained poorly defined. By localizing the pathological signal to the nucleus of the cells responsible for lymphatic vessel maintenance, the researchers uncovered a cell-autonomous mechanism by which the heart’s own drainage system degrades with age. The result is a self-reinforcing cycle: compromised lymphatic clearance permits inflammatory mediators to persist in the tissue, and the resulting inflammatory milieu further stresses the lymphatic endothelium, deepening the dysfunction.

Crucially, the researchers did not stop at describing the failure. They tested whether the decline could be reversed. Using cardiac overexpression of vascular endothelial growth factor C, or Vegfc, the master growth factor governing lymphatic vessel development and maintenance, they were able to counteract the age-related lymphatic deterioration. Vegfc signals through its receptor VEGFR-3 on lymphatic endothelial cells, promoting their survival, proliferation, and sprouting, and it is the pivotal driver of lymphangiogenesis, the formation of new lymphatic vessels. When Vegfc was overexpressed in the aging heart, the integrity of the lymphatic network improved, suggesting that the age-associated loss of lymphatic vasculature is not an irreversible consequence of time but a dynamic, modifiable process.

The therapeutic implications are substantial. Current approaches to cardiac aging and inflammation largely target the inflammatory cells themselves or downstream cytokines, strategies that often carry broad immunosuppressive consequences. Restoring the heart’s lymphatic drainage offers a fundamentally different intervention point. Rather than dampening the immune response indiscriminately, lymphatic-targeted therapy would strengthen the structural system that normally regulates immune cell traffic and fluid balance, potentially resolving inflammation by addressing one of its upstream causes. The finding that Vegfc overexpression can rescue aged lymphatic vessels provides a proof of principle that this axis is pharmacologically accessible.

The study also reframes how the field understands interstitial physiology in the aging heart. The myocardial interstitium, the space between heart muscle cells and capillaries, is not an inert filler but a dynamically regulated compartment. Its composition depends on a continuous balance of fluid filtration from the blood, drainage through the lymphatic system, and clearance of extracellular matrix components and metabolic byproducts. Age-related lymphatic impairment tips this balance toward accumulation, creating a microenvironment that favors fibroblast activation, matrix deposition, and chronic immune cell infiltration, all recognized contributors to cardiac fibrosis and declining heart function in the elderly.

Questions remain before these findings can be translated into clinical strategies. The precise transcriptional programs by which nuclear interleukin-33 disrupts lymphatic endothelial cell function have not been fully delineated, and it is not yet clear whether pharmacological modulation of interleukin-33 itself, rather than Vegfc-based promotion of lymphatic growth, could also interrupt the pathological cycle. The long-term safety of stimulating lymphatic growth in the heart, particularly in the context of other cardiovascular diseases such as ischemic heart disease or heart failure, will require dedicated investigation. Dosing, timing, and the reversibility of lymphatic injury at different stages of aging are all open territory. Nonetheless, the identification of a defined molecular driver and a corresponding molecular rescue establishes a clear experimental roadmap.

For a rapidly aging global population, in which heart disease remains the leading cause of death, interventions that address the underlying biology of cardiac aging carry enormous public health weight. The demonstration that a vascular system long treated as peripheral to cardiovascular medicine plays a causative role in age-related cardiac inflammation adds lymphatic vessel maintenance to the growing list of tissues and pathways implicated in healthy aging. If the Vegfc–interleukin-33 axis can be safely harnessed in humans, the heart’s own drainage network may one day become a target for keeping the aging myocardium calm, well-drained, and resilient.

Subject of Research: Age-associated loss of cardiac lymphatic vessels driven by nuclear interleukin-33 in lymphatic endothelial cells and its reversal by Vegfc overexpression

Article Title: Age-associated loss of lymphatic vessels promotes cardiac inflammation

Article References: Wagner, J. U. G., Gulshan, H., Sultan, I., Antila, S., Esteve, L.-C., Rodriguez Morales, D., Ruz Jurado, M., John, D., Solomonidis, E. G., Schmitz, K., Panthel, J., Kujundzic, H., Hille, S., Müller, O. J., Kugler, C., Sami, H., Ogris, M., Glaser, S.-F., Abplanalp, W. T., … Dimmeler, S. (2026). Age-associated loss of lymphatic vessels promotes cardiac inflammation. Nature Cardiovascular Research. https://doi.org/10.1038/s44161-026-00870-y

Image Credits: AI Generated

DOI: 10.1038/s44161-026-00870-y

Keywords: cardiac lymphatic vessels, aging, lymphatic endothelial cells, interleukin-33, VEGFC, cardiac inflammation, lymphangiogenesis, heart aging, VEGFR-3, cardiac fibrosis, immune cell trafficking, Nature Cardiovascular Research

The research, spearheaded by a multidisciplinary team at the University of Colorado Anschutz, integrates expertise from medicine, immunology, microbiology, and molecular genetics. At the heart of their investigation is the question: how do LECs participate in storing antigenic information to fortify immune responses against future infections? What emerged is a detailed map of the gene expression profile that orchestrates antigen uptake, retention, and presentation within the lymphatic niche.

By employing cutting-edge single-cell RNA sequencing, the investigators precisely identified genes being expressed within individual LECs in real time, under the influence of immune stimuli. This level of resolution allowed them to pinpoint a transcriptional program—unique to lymphatic endothelial cells—that governs their capacity to archive immunological ‘memories’. Notably, this program modulates antigen handling in a way that can be predicted and potentially manipulated, shedding light on the cellular mechanisms fundamental to adaptive immunity.

Further refining their approach, the team integrated spatial transcriptomics to understand how these gene expression patterns manifest across lymph node architecture. This technique elucidates the regional specialization and temporal dynamics of LECs’ antigen-storage functions. Their work goes beyond static snapshots, following the trajectory of these cells over multiple time points, revealing a dynamic, evolving interplay between LEC genetic programs and immune environment.

Central to this progress was the application of sophisticated machine learning algorithms, which enabled the researchers to analyze immense datasets and identify patterns predictive of immune memory potential. By quantitatively correlating gene expression with antigen retention capacity, they demonstrated that the genetic “signature” within LECs can serve as a biomarker for robust immune memory across a spectrum of diseases and even across different species, highlighting evolutionary conservation.

The senior author, Dr. Beth Tamburini, emphasizes that this insight overturns previous notions that underestimated LECs’ immunological roles. “We now appreciate that lymphatic endothelial cells are not passive players but active architects of immune memory,” she explains. “Our identification of a dedicated genetic program signifies that these cells can be targeted therapeutically to either amplify or modulate immune responses.”

The first author, Dr. Ryan Sheridan, highlights that the integration of machine learning was critical in isolating this transcriptional program among the cellular complexity found in lymph nodes. “Without advanced computational tools, deciphering the nuanced gene regulatory networks within these cells over time would have been impossible,” he notes. The research thus stands at the intersection of bioinformatics, immunology, and molecular biology.

Importantly, this study’s implications extend to vaccine design. By manipulating the antigen-archiving capabilities of LECs, future vaccines could achieve longer-lasting, more potent immune protection. This could be particularly transformative for pathogens that evade immune memory or for cancers where immune recall responses require reinforcement. The identification of genetic targets within LECs represents a paradigm shift in immunotherapy strategies.

Methodologically, this investigation is distinguished not only by its technological sophistication but also by its experimental design which includes active intervention in cellular pathways to observe causal effects. By experimentally manipulating the antigen archival system within LECs, the researchers could confirm the functional relevance of the transcriptional program they identified. Such a multi-layered approach ensures that findings are robust, mechanistically grounded, and translatable.

This pioneering work also underscores the value of longitudinal studies in immunology. Traditionally, immune cell characterization has relied on isolated time points, limiting understanding of the temporal changes underlying memory formation. Here, monitoring LECs longitudinally exposed how their antigen-processing roles evolve, offering a richer, more accurate picture of their involvement in sustained immune defense.

While focused primarily on mammalian lymph nodes, the team posits that similar genetic programs may exist in other vertebrates, facilitating cross-species insights into immune memory mechanisms. This evolutionary perspective may foster comparative studies that deepen our grasp of immunity’s fundamental principles, potentially revealing universal targets for immune modulation.

Ultimately, this research marks a significant leap forward in immunological science, elevating lymphatic endothelial cells from overlooked lymph node residents to pivotal orchestrators of immune memory. The elucidation of their gene expression program provides a critical tool for designing next-generation immunotherapies and vaccines, aimed at harnessing the body’s natural memory systems to optimize disease protection.

Subject of Research: Immunological role and genetic programming of lymphatic endothelial cells in antigen archiving and immune memory formation.

Article Title: A specific gene expression program underlies antigen archiving by lymphatic endothelial cells in mammalian lymph nodes

News Publication Date: 2025

Web References:

• Nature Communications Article
• DOI Link

Keywords: Immunology, Immune memory, Lymphatic endothelial cells, Antigen archiving, Single-cell RNA sequencing, Spatial transcriptomics, Genetic transcriptional program, Vaccine development, Immune response, Machine learning, Immune therapies, Cellular immunity