Biology subjects

Heras-Garvin, A.

Publications and source records attributed to Heras-Garvin, A..

4 recordsLinked to original sources

bioRxiv2025

Multiparametric MRI and imaging transcriptomics reveal molecular and cellular correlates of neurodegeneration in experimental multiple system atrophy

Multiple system atrophy (MSA) is an atypical Parkinsonian disorder marked by oligodendroglial -synucleinopathy and selective neurodegeneration. Although MRI can capture regional atrophy and microstructural alterations in MSA brain, the molecular substrates underlying these phenotypes remain poorly defined. Imaging transcriptomics provides a computational framework to relate spatial imaging patterns to brain-wide gene expression. While this approach has been applied to human MSA, interpretation is constrained by limited experimental control and lack of disease-matched molecular validation. Here, we apply imaging transcriptomics in a controlled preclinical setting by integrating high-resolution ex vivo multimodal MRI with transcriptomic mapping in the PLP-Syn mouse model of MSA. Structural and diffusion MRI revealed distinct patterns of regional atrophy and microstructural abnormalities. Atlas-based analyses associated imaging phenotypes to gene programs related to oligodendrocyte biology, energy metabolism, and neuroinflammation, with modality-specific signatures. These associations were supported by independent RNA-sequencing and showed convergence with human MSA findings. Our work benchmarks MRI-transcriptomic relationships in MSA and provides a translational framework for interpreting imaging biomarkers in synucleinopathies.

neuroscience↗

bioRxiv2025

Pharmacologic NLRP3 Inhibition Modulates Parkinson's Disease-Associated Microglial Transcriptomic Signatures and Mitigates α-Synuclein-Triggered Neurodegeneration

BackgroundParkinsons disease (PD), the second most common neurodegenerative disorder after Alzheimers disease, and the rare disorder multiple system atrophy (MSA), are both characterized by intracellular accumulation of -synuclein fibrils and early, sustained microglial reactivity in parallel to the neurodegeneration. Activation of the NLRP3 inflammasome in disease-associated reactive microglia is increasingly recognized as a key pathogenic driver and a promising therapeutic target in synucleinopathies. Dapansutrile (OLT1177(R)) is a selective, orally bioavailable NLRP3 inhibitor with a favorable safety profile in clinical trials for non-neurological indications. Here, we evaluated the therapeutic potential of dapansutrile in preclinical models of PD and MSA and explored the predictive and translational value of its effects. MethodsTwo established mouse models of synucleinopathy with nigral neurodegeneration were employed: the -synuclein preformed fibril (PFF) propagation model and the transgenic PLP--syn model expressing human wild-type -synuclein in oligodendrocytes. Pharmacokinetic analyses assessed plasma and brain exposure after oral administration. The efficacy of six-month dapansutrile treatment was examined in both preventive (post-PFF injection) and therapeutic (PLP--syn mice) paradigms, using behavioral, histopathological, and molecular readouts. Transcriptomic profiling of striatal and midbrain microglia identified differentially expressed genes (DEGs) associated with treatment and compared them with post-mortem transcriptomic signatures of disease-associated microglia in PD patients. Plasma IL-18 and neurofilament light chain (NfL) levels were evaluated as translational biomarkers. ResultsChronic oral dapansutrile treatment at clinically relevant doses improved motor performance, reduced -synuclein inclusions, attenuated gliosis, and mitigated nigral neurodegeneration in both models. Microglial transcriptomic analyses revealed that dapansutrile reversed key transcriptional signatures characteristic of PD-associated reactive microglia. Moreover, plasma IL-18 and NfL levels correlated with neuropathological and functional outcomes, supporting their potential as biomarkers of target engagement and treatment efficacy. ConclusionsThese data identify chronic NLRP3 activation as a shared and targetable mechanism in PD and MSA and highlight dapansutrile as a CNS-penetrant, clinically advanced candidate for disease modification in -synucleinopathies. The observed transcriptomic reprogramming of microglia and the parallel changes in blood biomarkers provide a strong translational bridge to clinical development.

neuroscience↗

bioRxiv2024

The PHD3-FOXO3 axis modulates the interferon type I response in microglia aggravating Alzheimer's disease progression

Microglia respond to Alzheimers disease (AD) with a variety of transcriptional responses. However, the regulation of specific transcriptional signatures and the contribution of each individual response to disease progression is only starting to be characterized. We have previously shown that hypoxia via hypoxia inducible factor 1 (HIF1) is a strong regulator of A{beta} plaque-associated microglia (A{beta}AM). Here, we characterize the role of HIF1-mediated transcription of Egln3, encoding for PHD3, in A{beta}AM. We show that oligomeric A{beta} treatment (oA{beta}) in vitro induces the expression of Hif1a and Egln3 in microglia, which correlates with the transcriptional activation of genes involved in the interferon type I signature (IFNS) in a PHD3-dependent manner. Mechanistically, we demonstrate FOXO3 to be an important repressor of IFNS in microglia, whose abundance decreases upon A{beta} presence, and, correspondingly, both in human single-nucleus (sn) and mouse A{beta}AM transcriptomics, FOXO3 DNA binding sites define the IFNS. FOXO3 repression of the IFNS is dependent on PHD3, with our results suggesting a physical interaction between both proteins in vitro. In vivo, loss of PHD3 correlate with abrogation of the IFNS and activation of the disease-associated microglia signature (DAM) in A{beta}AM. Transcriptional changes in microglia associate with increased microglia proximity to A{beta} plaques, augmented phagocytosis of A{beta} by microglia, reduced parenchymal levels of A{beta}, and an increase in small-sized plaques. PHD3 deficiency also reduced the A{beta} plaque-associated neuropathology and rescued behavioural deficits of an AD mouse model. Finally, we also demonstrate that microglial PHD3 overexpression during development in the absence of A{beta} pathology is sufficient to induce the IFNS and to behavioural alterations. Altogether, our data strongly indicate that the PHD3-FOXO3 axis controls the microglial IFNS in a cell autonomous manner, contributing to the progression of AD.

neuroscience↗

bioRxiv2019

A genome-wide genetic pleiotropy approach identified shared loci between multiple system atrophy and inflammatory bowel disease

We aimed to identify shared genetic background between multiple system atrophy (MSA) and autoimmune diseases by using the conjFDR approach. Our study showed significant genetic overlap between MSA and inflammatory bowel disease and identified DENND1B, C7, and RSP04 loci, which are linked to significant changes in methylation or expression levels of adjacent genes. We obtained evidence of enriched heritability involving immune/digestive categories. Finally, an MSA mouse model showed dysregulation of the C7 gene in the degenerating midbrain compared to wildtype mice. The results identify novel molecular mechanisms and implicate immune and gut dysfunction in MSA pathophysiology.

genetics↗