The Proposed Bone Post-Arterial Type R Capillaries Resolve into Venous and Fatty Acid-Handling Endothelial Cells

Jain, S.; Joseph, J. D.; Liu, H.; Bhowmick, N. R.; Yang, Y.; Mundapat, S. N.; Machan, R.; Glaviano, A.; Chandra, A.; Dalan, R.; Chen, J.; Verma, N. K.; Cohen-Solal, M.; Risbud, M. V.; Bozec, A.; Kusumbe, A. P.

doi:10.64898/2026.07.27.741009

bioRxiv · 10.64898/2026.07.27.741009

The Proposed Bone Post-Arterial Type R Capillaries Resolve into Venous and Fatty Acid-Handling Endothelial Cells

Jain, S.·Joseph, J. D.·Liu, H.·Bhowmick, N. R.·Yang, Y.·Mundapat, S. N.·Machan, R.·Glaviano, A.·Chandra, A.·Dalan, R.·Chen, J.·Verma, N. K.·Cohen-Solal, M.·Risbud, M. V.·Bozec, A.·Kusumbe, A. P.

View original source ↗Export metadata ↓

Abstract

Endothelial specialization is increasingly recognized as a fundamental regulator of tissue homeostasis, yet the cellular diversity of the skeletal vasculature remains incompletely resolved. Here, we integrate large-scale single-cell transcriptomics, cross-tissue comparisons, and imaging to comprehensively define endothelial heterogeneity across the skeleton. Our analyses demonstrate that the proposed post- arterial "type R" endothelial population is not a distinct endothelial subtype but instead comprises canonical venous endothelial cells and fatty acid-handling endothelial state. RNA velocity supports a venous continuum, while the proposed type R markers FMO2, and AQP7 lack both endothelial and skeletal specificity. The fatty acid-handling endothelial state, characterized by Lpl and Cd36 is conserved across multiple skeletal sites and non-skeletal tissues, indicating a general endothelial metabolic programme. Within bone, this endothelial state expands following high-fat diet and is suppressed during injury. Together, these findings redefine skeletal endothelial heterogeneity and establish the proposed type R population as part of a venous continuum.

Explore related subjects

cell biology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Jain, S., Joseph, J. D., Liu, H., Bhowmick, N. R., Yang, Y., Mundapat, S. N., Machan, R., Glaviano, A., Chandra, A., Dalan, R., Chen, J., Verma, N. K., Cohen-Solal, M., Risbud, M. V., Bozec, A., Kusumbe, A. P.. 2026-07-28. The Proposed Bone Post-Arterial Type R Capillaries Resolve into Venous and Fatty Acid-Handling Endothelial Cells. https://doi.org/10.64898/2026.07.27.741009

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

KEEP EXPLORING

Related preprints

bioRxiv2026

Differential requirement for the Ire1 luminal domain in Candida albicans drug susceptibility and pathogenicity

The opportunistic human pathogen Candida albicans depends on the unfolded protein response (UPR) for cell wall integrity, antifungal tolerance, filamentous growth, and virulence. The UPR is driven by the conserved transmembrane sensor Ire1, which is activated either by misfolded proteins through its luminal domain or by lipid bilayer stress (LBS) through its transmembrane domain. In budding yeast, these two activation modes deploy divergent transcriptional programs. Whether the requirement for these two input domains is separable in C. albicans, where the cell membrane and cell wall are themselves the targets of major antifungal drug classes, remains unknown. Here, we engineered a C. albicans strain expressing Ire1 lacking an intact luminal domain (ire1{Delta}LD), which no longer detects proteotoxic stress. The ire1{Delta}LD strain grew in the presence of the azole antifungals fluconazole and miconazole but was highly sensitive to heat shock, cell wall stress, and the echinocandin caspofungin. It was also unable to sustain filamentous growth and showed reduced virulence in a Caenorhabditis elegans infection model. RNA sequencing revealed only modest changes to the steady-state transcriptome of ire1{Delta}LD cells. Together, these findings define a differential requirement for the input domains of C. albicans Ire1, uncoupling growth under azole-induced membrane stress from the cell wall, thermal, and virulence-associated outputs that depend on proteotoxic sensing, a distinction that could inform antifungal strategies targeting the UPR.

cell biology↗

bioRxiv2026

Nucleosome Core Allostery Governs Chromatin Recognition and Cell Fate

Nucleosomes regulate chromatin folding, accessibility, and factor recruitment. Current models primarily attribute these functions to histone tail modifications, while the core is largely viewed as a structural scaffold. Yet subtle changes within the nucleosome core can produce profound functional consequences, and the mechanisms underlying these effects remain unclear. Here, we describe nucleosome core allostery as a fundamental principle of chromatin regulation that amplifies the impact of minimal nucleosome variations. Leveraging natural differences between H2A.Z variants, we show that the nucleosome core encodes distinct conformational dynamics that propagate allosterically, thereby controlling nucleosome accessibility and recognition by chromatin factors. As a result, a single buried amino acid substitution alone is sufficient to reprogram nucleosome dynamics and bias cell identity. Our findings establish the nucleosome core as an allosteric regulatory module and provide a generalizable framework for how subtle variation within nucleosomes is amplified into diverse biological outcomes in development and disease.

cell biology↗

bioRxiv2026

YAP/TAZ-controlled ERK dynamics coordinate progenitor expansion and differentiation commitment

Progenitor cells must proliferate to expand the cell population, yet terminal differentiation requires this proliferative state to end. How signaling controls the duration of this proliferative window remains poorly understood. Using adipogenesis and live single-cell imaging of differentiation, cell-cycle, and ERK-activity reporters, we show that YAP and TAZ coordinate progenitor expansion with differentiation commitment by regulating ERK dynamics. YAP/TAZ maintain cells in a fluctuating high-ERK state that promotes proliferation while actively keeping the differentiation driver PPARG below the threshold for irreversible commitment. Crucially, this differentiation block is not explained by proliferation alone: inhibiting CDK4/6 or AKT suppressed proliferation without restoring differentiation, whereas MEK-ERK inhibition restored differentiation even when YAP/TAZ activity remained high. As YAP/TAZ activity decreases, dampened ERK fluctuations trigger PPARG activation. These findings support a self-limiting model in which YAP/TAZ-driven progenitor expansion progressively increases cell density and contact-dependent Hippo signaling, reducing YAP/TAZ activity and terminating the proliferative phase. Consequently, transient YAP/TAZ activation expands the progenitor pool while preserving subsequent differentiation, whereas sustained activation suppresses commitment. Together, these findings identify YAP/TAZ-controlled ERK dynamics as the nexus coordinating progenitor expansion with terminal differentiation and suggest that slower density-dependent Hippo feedback may set the duration of this proliferative window to regulate differentiated cell-number output.

cell biology↗