Biology subjects

Arevalo, O.

Publications and source records attributed to Arevalo, O..

3 recordsLinked to original sources

bioRxiv2026

Blood-brain barrier model architecture shapes peripheral immune cell trafficking in Parkinson's disease

Parkinsons disease (PD) is a neurodegenerative disorder traditionally characterized by dopaminergic neuron loss in the substantial nigra pars compacta, but peripheral immune dysregulation and blood-brain barrier (BBB) dysfunction have been increasingly implicated in disease etiology. However, how circulating immune cells interact with the human BBB and how these interactions are captured across experimental models remains poorly understood. In particular, human BBB models offer multiple platforms to interrogate these biological questions, with organ-on-chip approaches attracting significant interest. In this context, it is essential to determine whether model architecture influences the assessment of immune-endothelial interactions in PD, and if it may lead to fundamentally different interpretations of immune cell trafficking at the human BBB. Here, we compared peripheral blood mononuclear cells (PBMCs) from control donors or individuals with PD in human induced pluripotent stem cell (iPSC)-derived BBB models to determine how static and dynamic BBB systems influence immune cell behavior. To do so, we leveraged our brain chip platform to establish a model based on expression of the PD-associated SNCA triplication mutation. Using a two-dimensional transwell system and a three-dimensional (3D) microfluidic BBB chip, we evaluated PBMC attachment and transmigration under conditions of PBMC disease status, endothelial genotype associated with SNCA triplication, and exposure to -synuclein (-Syn) monomers or preformed fibrils (PFFs). PBMCs from PD donors showed increased baseline reactivity and altered endothelial interactions compared with controls. In transwell models, SNCA triplication increased PBMC attachment and selectively enhanced PD PBMC transmigration, while PFF increased attachment without affecting transmigration. In contrast, in the microfluidic BBB chip, attachment was largely unchanged by endothelial genotype or -Syn exposure, whereas transmigration increased following -Syn monomer pre-treatment. Together, PBMC-BBB interactions in PD appear to be shaped by immune cell status, endothelial genotype, and -Syn exposure, but are strongly influenced by BBB model dimensionality and flow. This study underscores the importance of physiologically relevant multicellular and flow-based BBB systems and provides a human-focused framework for studying peripheral immune cell trafficking across the diseased BBB. These findings also emphasize that biological insights into BBB function are inherently shaped by the experimental model used, underscoring the need for complementary human BBB platforms.

neuroscience↗

bioRxiv2025

Parkinson's disease risk factors are expressed at brain barriers.

Parkinsons disease (PD) is characterized by the selective loss of dopaminergic neurons in the substantia nigra pars compacta, but whether its etiology is cell autonomous remains unclear. Increasing evidence implicates the blood-central nervous system (CNS) barriers in disease development, highlighting the importance of identifying genetic risk factors linked to cells forming the cerebrovasculature to advance this emerging area of research. The objective of this study is to identify PD genetic risk factors associated with blood-brain (BBB) and blood-cerebrospinal fluid (BCSFB) barriers, and to validate protein localization in human tissue and experimental models. To do so, we integrated genome-wide association studies and single nuclei RNA-sequencing datasets from the human postmortem substantia nigra (SN), midbrain, or cortical samples from control and PD donors. An in-depth bioinformatics analysis identified genes enriched in cell types that form the multicellular architecture of brain barriers, including CAVIN2, ANXA1, ANO2, and LRP1B. We further validated whether corresponding proteins were present in cell types associated with the blood-CNS barriers in human and mouse post-mortem tissues, as well as in iPSC-differentiated cells and choroid plexus organoids. Results showed that quantifying the proportion of endothelial cells expressing PD-related genes was under-evaluated at the transcript level compared to immunofluorescence analyses. In addition, we observed that CAVIN2 and ANXA1 proteins were more abundant at the vasculature of the substantia nigra vs. cortex, and CAVIN2 protein levels were reduced in PD vs. control human postmortem tissues. In contrast, the investigation of mouse postmortem samples demonstrated that the CAVIN2 protein is only present in a subset of mouse blood vessels, compared to nearly all vessels in human tissue. Similarly, mouse ANXA1 protein localizes to dopaminergic neurons of the substantia nigra and not at the vasculature, as seen in human tissue. The primary outcome of this study is the identification of PD-relevant risk genes specifically expressed at brain barriers and enriched in PD-relevant brain regions. The secondary outcome is the demonstration of poor transcript-protein correlation in - at least - a subset of PD risk factors, and a low interspecies conservation of protein localization for the selected candidates. In conclusion, the BBB and BCSFB may represent understudied contributors to PD, endothelial-specific proteins appear differentially regulated compared to transcripts, and experimental models require comprehensive validation to ensure relevance to the human condition.

neuroscience↗

bioRxiv2024

Enhanced lentiviral gene delivery to mammalian cells via paired cell surface and viral envelope engineering

Lentiviral vectors that facilitate gene delivery to desired cell types have been widely used in routine laboratory research and therapeutic cell engineering. However, the lack of proper entry receptors on many cell types often results in poor gene delivery. Here, we present a simple paired virus-cell engineering approach that promotes lentiviral gene delivery into mammalian cells. Lentiviruses are dual-pseudotyped with VSV-G and a chimeric envelope protein specifically recognizing a small molecule fluorescein (FITC-Env), and target cells are transiently labelled with FITC to create surrogate receptors for lentivirus attachment. The synthetic interaction between FITC-labeled cells and FITC-binding LVs enables efficient LV docking, viral entry and stable transgene expression in a range of mammalian cell lines and primary T cells. We showed that this approach enabled efficient delivery of a CD19-targeted chimeric antigen receptor (CAR) into naive human T cells that are naturally refractory to conventional VSV-G LVs, which upon activation rapidly eradicated CD19+ leukemic cells. This paired cell surface and virus envelope engineering approach may serve as a universal method for engineering synthetic virus-cell interactions to improve lentiviral gene delivery to mammalian cells.

bioengineering↗