Hauger, P. C. | bioRxiv Science

bioRxiv2026

Marfan Patient iPSC-Derived Endothelial Cells Carrying FBN1 Variants Reveal Endothelial Dysfunction

Marfan syndrome (MFS) is an inherited connective tissue disorder caused by pathogenic variants in FBN1, encoding fibrillin-1, with life-threatening aortic complications arising in part from endothelial cell (EC) dysfunction. To study this in a human model, we generated hiPSC-derived ECs from three MFS patients (iMFS-ECs). We show that iMFS-ECs recapitulate known disease phenotypes, including impaired alignment in the direction of flow. Moreover, we found that iMFS-ECs do not recover from TNF--induced loss of barrier integrity, due to sustained EC contractility. iMFS-ECs exhibited TNF--induced ICAM1 upregulation and NF-{kappa}B activation comparable to healthy donor-derived hiPSC-ECs by bulk RNA-seq, while expression of genes linked to cytoskeletal arrangements, cell signaling and ECM remodeling were dysregulated. In conclusion, we show that hiPSC derived ECs can serve as a model to investigate MFS pathology. These findings establish a human iPSC platform for MFS endothelial research and suggest impaired inflammatory resolution as a novel therapeutic target.

cell biology↗

bioRxiv2025

Pericytes and Wnt signaling induce functional blood-brain barrier phenotype in human iPSC-based model

The blood-brain barrier (BBB), formed by brain microvascular endothelial cells (BMECs), restricts vascular permeability through tight junctions, selective transporters, and low transcytosis. BBB dysfunction contributes to cerebrovascular and neurodegenerative disease, yet current human in vitro models recapitulate only a subset of BMEC features. Here, we describe a strategy generate BMECs (hiBMECs) from human induced pluripotent stem cell-derived endothelial cells by co-culture with isogenic brain pericytes and activation of Wnt/{beta}-catenin signaling. The resulting hiBMECs display barrier properties, active efflux transporters, and appropriate inflammatory responses. Transcriptomic profiling revealed convergence of pericyte-derived cues and Wnt/{beta}-catenin activation on ETS1, SMAD3/4, and PPAR{gamma} transcriptional networks, establishing a gene signature closely matching the adult human BBB. Downstream analysis revealed that hiBPC cues engaged sphingosine-1-phosphate, TGF-{beta}, and angiopoietin/Tie2 pathways, which were further regulated by canonical Wnt activation. These findings uncover a synergistic mechanism by which brain pericytes and Wnt/{beta}-catenin signaling orchestrate BMEC differentiation and function, providing mechanistic insight into human BBB development and an improved hiPSC-derived BBB model for future drug screening and disease modeling. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=36 SRC="FIGDIR/small/678752v1_ufig1.gif" ALT="Figure 1"> View larger version (11K): org.highwire.dtl.DTLVardef@186ba4corg.highwire.dtl.DTLVardef@310cc7org.highwire.dtl.DTLVardef@3e1970org.highwire.dtl.DTLVardef@f80f5e_HPS_FORMAT_FIGEXP M_FIG C_FIG The paper explainedO_ST_ABSPROBLEMC_ST_ABSThe blood-brain barrier (BBB) protects the brain by tightly regulating the passage of molecules and cells. Its dysfunction contributes to disorders such as stroke, dementia, and multiple sclerosis. Yet, existing human in vitro models fail to capture the full complexity of BBB biology, limiting our ability to study disease mechanisms or test brain-targeted drugs. RESULTSWe discovered that two signals are essential for generating functional human BBB endothelial cells from stem cells: cues from brain pericytes and activation of the Wnt/{beta}-catenin pathway. Together, these signals enabled endothelial cells to form tight barriers, operate transporters, and mount appropriate responses to inflammation. Transcriptomic analyses of the resulting cells revealed a gene signature closely matching the adult human BBB and identified how pericyte- and Wnt-activated pathways converge on specific transcriptional programs driving BBB identity. IMPACTThis study provides both a molecular framework for in vitro BBB development and a reliable and reproducible human BBB model. This platform can be applied to explore BBB dysfunction in neurological disease and to accelerate the development of drugs that need to reach the brain or target the brain vasculature.

bioengineering↗

bioRxiv2025

Vessel-on-Chip Model Of The Microcirculation In Abdominal Aortic Aneurysms

Abdominal aortic aneurysms (AAA) are pathological dilations of the abdominal aorta. To date, surgical intervention is the only option for managing large AAAs, with no pharmacological therapies to prevent growth of small aneurysms. A current limitation in investigating further pharmacological avenues is the translatability of results from animal models, or from patient trials that are limited by co-morbidities and disease severity. To bridge this knowledge gap, we created a novel, patient-specific vessel-on-chip (VoC) model of the microcirculation in AAA (AAA-VoC). We found that co-culture of both C (control)-VSMCs and AAA-patient derived VSMCs with healthy, hiPSC-derived ECs generate lumenized and perfusable microvascular networks. We show that AAA-VoCs are characterized by an enlarged average vascular diameter. We furthermore found that AAA-VSMCs show phenotypical deviations from C- VSMCs after 7 days in co-culture such as increased number and surface area, indicative of a preserved pathological phenotype in our in vitro model. Lastly, we demonstrate that AAA-VoCs showed an increased level of pro-inflammatory cytokine expression over C-VoCs and displayed an impaired endothelial barrier function, resulting in vascular leakage. With this study, we show that AAA-VSMCs affect microvascular networks formed by healthy hiPSC-ECs and that a AAA phenotype is preserved in 3D co-culture, making this model valuable for future studies investigating treatments for AAA.

cell biology↗