Biology subjects

Rosety, I.

Publications and source records attributed to Rosety, I..

5 recordsLinked to original sources

bioRxiv2025

Autophagy Dysfunction in iPSCs-Derived Neurons and Midbrain Organoids Carrying a SNCA Triplication

Parkinsons disease (PD), characterized by -Synuclein aggregation and dopaminergic neuronal loss, has no current cure. Autophagy is critical for -Synuclein clearance, yet its real-time dynamics remain challenging to assess in human-relevant systems. Here, we used live-cell imaging to assess autophagy within human neuronal cultures and midbrain organoids (hMOs) derived from induced pluripotent stem cells (iPSCs) of PD patients carrying a triplication of the -Synuclein gene (3xSNCA). Using the LC3-Rosella dual-fluorescent reporter, we quantified autolysosomes dynamics in real time. In 3xSNCA neuronal cultures, we detected early autophagy defects. In 3xSNCA hMOs, reduced autolysosome area, increased total and phosphorylated -Synuclein (pS129), and decreased electrophysiological activity were observed at 50 days of differentiation (DoD). By 70 DoD, autophagy impairment became more pronounced, overlapping with dopaminergic neuron loss. These findings support the use of human iPSCs-derived models to study autophagy dysfunction in PD and demonstrate a temporal correlation between impaired autophagy, -Synuclein pathology and neuronal degeneration.

neuroscience↗

bioRxiv2025

Parkinsons disease microglia induce endogenous alpha-Synuclein pathology in patient-specific midbrain organoids.

The accumulation of misfolded -synuclein and the loss of dopaminergic neurons are hallmarks of Parkinsons disease (PD), contributing to the development of synucleinopathies. Although considerable progress has been made in understanding -synucleins role in PD pathology, the precise mechanisms involved remain unclear. Human midbrain organoids (hMOs) have emerged as valuable models for studying PD, yet the lack of microglia limits the ability to investigate neuroimmune interactions. Recent studies show that integrating microglia into hMOs enhances neuronal maturation and functionality. Here, we generated a human midbrain assembloid model by incorporating iPSC-derived microglia into midbrain organoids from healthy control individuals and a PD patient carrying the SNCA triplication (3xSNCA) mutation. Our results show that 3xSNCA microglia alone are sufficient to induce early, endogenous formation of phosphorylated -synuclein (pS129) pathology in the absence of exogenous fibril seeding. This PD-pathology emerged as early as day 50 of culture and was not observed in models lacking microglia. These findings highlight a critical role for patient-derived microglia in driving - synuclein pathology and provide a physiologically relevant platform for studying early neuroimmune mechanisms in PD and testing potential therapeutic strategies.

neuroscience↗

bioRxiv2025

Released mitochondrial DNA and neurofilament light chain as Parkinson's disease phenotypes in patient-specific midbrain assembloids

Parkinsons Disease is the second most common neurodegenerative disorder worldwide, with growing numbers and considerable societal and economic concerns. Human cell culture systems are efficient models for neurodegenerative disorders and allow for personalized, non-invasive analysis of cellular and molecular disease mechanisms. Midbrain organoids and assembloids are advanced 3D culture systems that recapitulate the human midbrain, which is highly affected by Parkinsons disease. Here, we used healthy control and patient-specific midbrain assembloids to assess mitochondrial DNA phenotypes and NfL levels alongside neurodegeneration and alpha-synuclein phosphorylation. Importantly, alterations in mitochondrial DNA homeostasis and NfL levels can be assayed in the supernatant and therefore are particularly suitable as biomarkers and for high throughput screening approaches.

neuroscience↗

bioRxiv2019

Parkinson’s disease phenotypes in patient specific brain organoids are improved by HP-β-CD treatment

The etiology of Parkinsons disease (PD) is only partially understood despite the fact that environmental causes, risk factors, and specific gene mutations are contributors to the disease. Biallelic mutations in the PTEN-induced putative kinase 1 (PINK1) gene involved in mitochondrial homeostasis, vesicle trafficking, and autophagy, are sufficient to cause PD. By comparing PD patient-derived cells, we show differences in their energetic profile, imbalanced proliferation, apoptosis, mitophagy, and a reduced differentiation efficiency to dopaminergic neurons compared to control cells. Using CRISPR/Cas9 gene editing, correction of a patients point mutation ameliorated the metabolic properties and neuronal firing rates but without reversing the differentiation phenotype. However, treatment with 2-Hydroxypropyl-{beta}-Cyclodextrin (HP-{beta}-CD) increased the mitophagy capacity of neurons leading to an improved dopaminergic differentiation of patient specific neurons in midbrain organoids. In conclusion, we show that treatment with a repurposed compound is sufficient for restoring dopaminergic differentiation of PD patient-derived cells.

neuroscience↗

bioRxiv2019

Machine learning-assisted neurotoxicity prediction in human midbrain organoids

A major challenge in the field of neurodegenerative diseases is the poor translation of pre-clinical models to clinical applications. The human brain is an immensely complex structure, which makes it difficult to recapitulate its development, function and disorders. In the recent years, brain organoids derived from human induced pluripotent stem cells have risen as novel tools to study neurodegenerative diseases such as Parkinsons disease (PD). PD is a multifactorial disorder, with aging, genetics and environmental factors as key etiological elements. The majority of the PD cases are idiopathic and proposed to result from a complex interaction between genetic predisposition and environmental exposure. Consequently, the identification of potentially disease causing environmental factors is of critical importance. Organoids, as complex multi-cellular tissue proxies, are an ideal tool to study cellular response to environmental changes. However, with increasing complexity of the system, usage of quantitative tools becomes challenging. This led us to develop an automated high-content image analysis pipeline for image-based cell profiling in the organoid system. Here, we introduce a midbrain organoid system that recapitulates features of neurotoxin-induced PD, representing a platform for machine-learning-assisted prediction of neurotoxicity in high-content imaging data. This model is a valuable tool for advanced in vitro PD modeling and for the screening of putative neurotoxic compounds.

pharmacology and toxicology↗