Biology subjects

Emmi, A.

Publications and source records attributed to Emmi, A..

3 recordsLinked to original sources

bioRxiv2024

Quantitative cytoarchitectural phenotyping of deparaffinized human brain tissues

Advanced 3D imaging techniques and image segmentation and classification methods can profoundly transform biomedical research by offering deep insights into the cytoarchitecture of the human brain in relation to pathological conditions. Here, we propose a comprehensive pipeline for performing 3D imaging and automated quantitative cellular phenotyping on Formalin-Fixed Paraffin-Embedded (FFPE) human brain specimens, a valuable yet underutilized resource. We exploited the versatility of our method by applying it to different human specimens from both adult and pediatric, normal and abnormal brain regions. Quantitative data on neuronal volume, ellipticity, local density, and spatial clustering level were obtained from a machine learning-based analysis of the 3D cytoarchitectural organization of cells identified by different molecular markers in two subjects with malformations of cortical development (MCD). This approach will grant access to a wide range of physiological and pathological paraffin-embedded clinical specimens, allowing for volumetric imaging and quantitative analysis of human brain samples at cellular resolution. Possible genotype-phenotype correlations can be unveiled, providing new insights into the pathogenesis of various brain diseases and enlarging treatment opportunities.

neuroscience↗

bioRxiv2024

Atypical chemokine receptor 3 regulates synaptic removal in disease astrocytes

Astrocytes participate in the clearance of obsolete or unwanted neuronal synapses. However, the molecular machinery involved in recognizing these synapses remains unclear, particularly under pathological conditions. Here, we investigated the phagocytic process of astrocytes through individual gene silencing with a druggable gene library. Our study demonstrates that astrocyte- mediated synapse engulfment is regulated by the Atypical chemokine receptor 3 (Ackr3). Mechanistically, we showed that Ackr3 recognizes phosphatidylethanolamine (PE)-bound C-X-C motif chemokine 12 (CXCL12) at synaptic terminals both in vitro and in vivo, thus serving as a novel marker of synaptic dysfunction. Notably, both the receptor and its ligand are upregulated in post- mortem human Alzheimers disease (AD) brains, and AD mouse models. Downregulation of the Ackr3 in AD mice significantly diminishes astrocyte-mediated synaptic elimination, and rescues pathological phenotypes, including synapse loss and cognitive impairment. Overall, this work unveils a novel, possibly targetable mechanism of astrocyte-mediated synaptic engulfment implicated in neurodegenerative disease.

neuroscience↗

bioRxiv2022

COVID-19 Neuropathology: evidence for SARS-CoV-2 invasion of Human Brainstem Nuclei

Neurological manifestations are common in COVID-19, the disease caused by SARS-CoV-2. Despite reports of SARS-CoV-2 detection in the brain and cerebrospinal fluid of COVID-19 patients, its still unclear whether the virus can infect the central nervous system, and which neuropathological alterations can be ascribed to viral tropism, rather than immune-mediated mechanisms. Here, we assess neuropathological alterations in 24 COVID-19 patients and 18 matched controls who died due to pneumonia / respiratory failure. Aside from a wide spectrum of neuropathological alterations, SARS-CoV-2-immunoreactive neurons were detected in specific brainstem nuclei of 5 COVID-19 subjects. Viral RNA was also detected by real-time RT-PCR. Quantification of reactive microglia revealed an anatomically segregated pattern of inflammation within affected brainstem regions, and was higher when compared to controls. While the results of this study support the neuroinvasive potential of SARS-CoV-2, the role of SARS-CoV-2 neurotropism in COVID-19 and its long-term sequelae require further investigation.

neuroscience↗