Biology subjects

Arboleda-Velasquez, J. F.

Publications and source records attributed to Arboleda-Velasquez, J. F..

3 recordsLinked to original sources

bioRxiv2026

A lifespan single-cell atlas of the human developing hippocampus benchmarks familial Alzheimer's disease brain organoids.

Familial Alzheimer's disease (fAD) is an early-onset form of AD caused by autosomal-dominant variants in APP, PSEN1, or PSEN2, with PSEN1 accounting for most genetically defined cases [1]. The hippocampus is among the earliest and most severely affected brain regions in AD [2,3]. Human induced pluripotent stem cell (iPSC)-derived brain organoids recapitulate key features of early human brain development and provide a tractable model for studying how fAD mutations perturb neurodevelopmental processes [4]. However, their interpretation is complicated by heterogeneous regional identity, variable maturation state, and cell-type composition across protocols [5,6]. Existing single-cell studies of human hippocampus cover prenatal [7] and postnatal [8-10] stages but do not provide a continuous developmental reference. By elevating the atlas approach in utilizing single-cell RNA-sequencing data, we obtain standardized information on the organoid cell class and type composition and maturation states. Here, we constructed the Human Developing Hippocampus Atlas (HuDeHA), an integrated single-cell reference comprising 658,059 cells spanning post-conceptional week 3 to 15.3 years, and used it to benchmark iPSC-derived brain organoids carrying PSEN1 E280A which is associated with fAD in a large Colombian population. Reference-based mapping revealed altered cellular composition in PSEN1 E280A organoids, including reduced radial glia and increased neural crest-derived neurons. These changes were accompanied by cross-lineage transcriptional alterations, including broad upregulation of the ventral patterning factor MEIS2 and reduced expression of the {beta}-binding protein transthyretin (TTR) in choroid-plexus and ependymal-associated populations. Reconstructed neuronal-lineage trajectories showed a shift toward mature states in PSEN1 E280A organoids. Together, these findings establish HuDeHA as a resource for developmental benchmarking of hippocampus-relevant organoid systems and describe cell-lineage-specific developmental changes in PSEN1 E280A organoids that may inform interpretation of early cellular alterations in fAD.

neuroscience↗

bioRxiv2024

Plasma Proteomics of Genetic Brain Arteriosclerosis and Dementia Syndrome Identifies Signatures of Fibrosis, Angiogenesis, and Metabolic Alterations

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is the most common monogenic form of vascular cognitive impairment and dementia. A genetic arteriolosclerotic disease, the molecular mechanisms driving vascular brain degeneration and decline remain unclear. With the goal of driving discovery of disease-relevant biological perturbations in CADASIL, we used machine learning approaches to extract proteomic disease signatures from large-scale proteomics generated from plasma collected from three distinct cohorts in US and Colombia: CADASIL-Early (N = 53), CADASIL-Late (N = 45), and CADASIL-Colombia (N = 71). We extracted molecular signatures with high predictive value for early and late-stage CADASIL and performed robust cross- and external-validation. We examined the biological and clinical relevance of our findings through pathway enrichment analysis and testing of associations with clinical outcomes. Our study represents a model for unbiased discovery of molecular signatures and disease biomarkers, combining non-invasive plasma proteomics with clinical data. We report on novel disease-associated molecular signatures for CADASIL, derived from the accessible plasma proteome, with relevance to vascular cognitive impairment and dementia.

neuroscience↗

bioRxiv2023

APOE3 Christchurch modulates tau phosphorylation and regulates β-catenin/Wnt/Cadherin signaling in induced pluripotent stem cell-derived cerebral organoids from Alzheimer's cases

Alzheimers disease (AD) is the most common cause of dementia among older adults. APOE3 Christchurch (R136S, APOE3Ch) variant homozygosity was reported in an individual with extreme resistance to autosomal dominant AD due to the PSEN1 E280A mutation. This subject had a delayed clinical age at onset and resistance to tauopathy and neurodegeneration despite extremely high amyloid plaque burden. We established induced pluripotent stem (iPS) cell-derived cerebral organoids from this resistant case and from a non-protected kindred control (with PSEN1 E280A and APOE3/3). We used CRISPR/Cas9 gene editing to successfully remove the APOE3Ch to wild type in iPS cells from the protected case and to introduce the APOE3Ch as homozygote in iPS cells from the non-protected case to examine causality. We found significant reduction of tau phosphorylation (pTau 202/205 and pTau396) in cerebral organoids with the APOE3Ch variant, consistent with the strikingly reduced tau pathology found in the resistant case. We identified Cadherin and Wnt pathways as signaling mechanisms regulated by the APOE3Ch variant through single cell RNA sequencing in cerebral organoids. We also identified elevated {beta}-catenin protein, a regulator of tau phosphorylation, as a candidate mediator of APOE3Ch resistance to tauopathy. Our findings show that APOE3Ch is necessary and sufficient to confer resistance to tauopathy in an experimental ex-vivo model establishing a foundation for the development of novel, protected case-inspired therapeutics for tauopathies, including Alzheimers.

neuroscience↗