Biology subjects

Cuni-Lopez, C.

Publications and source records attributed to Cuni-Lopez, C..

6 recordsLinked to original sources

bioRxiv2025

APOE genotypes differentially remodel the astrocytic lipiddroplet-associated proteome to shape lipid droplet dynamics

The lipids and proteins that comprise lipid droplets regulate several cellular functions including lipid storage, stress responses, and inflammation. Glial lipid droplets have been implicated in the pathogenesis and progression of Alzheimers disease (AD), yet the mechanisms linking genetic risk to lipid droplet biology remain unclear. Here we examined how APOE, the strongest genetic modulator of late-onset AD, impacts lipid droplet composition and dynamics. We defined the lipid droplet-associated proteome and lipidome in human induced pluripotent stem cell-derived astrocytes harboring the three common APOE genotypes: APOE2 (protective), APOE3 (neutral), and APOE4 (risk). Each APOE variant displays distinct lipid droplet-associated proteins and lipids. These molecular changes yield differences in lipophagy; lipid droplets in APOE2 astrocytes undergo autophagic turnover, whereas those in APOE4 astrocytes are resistant to degradation. These findings suggest that impaired lipid droplet clearance, rather than accumulation, distinguishes APOE4-associated AD risk, and may present a new metabolic node for modulating risk.

cell biology↗

bioRxiv2024

Impact of wildfire smoke and diesel exhaust on inflammatory response in aging human microglia

BackgroundAir pollution, particularly from Diesel Exhaust Particles (DEP) and Wildfire Smoke (WFS), is increasingly recognised as a significant driver of neuroinflammation linked to brain diseases. However, the role of microglia in mediating these neuroinflammatory responses remains poorly understood. This study aimed to investigate the effects of air pollution on monocyte-derived microglia-like cells (MDMi) from both young (< 40 years of age), and (older > 60 years of age) healthy individuals, focusing on immune response, cytokine secretion, nitrosative stress, and phagocytic activity. ResultsOur study demonstrated that DEP and WFS extract (WFSE) significantly upregulated expression of the oxidative stress marker, heme-oxygenase-1 (HO-1) in MDMi after 24 hr, with levels normalising by 96 hr, indicating a transient oxidative stress response. Both DEP and WFSE elicited distinct inflammatory cytokine profiles. DEP induced a rapid response, increasing TNF-, IL-6, IL-23, and IL-33 within 2 hr in young MDMi and 24 hr in aged MDMi. In contrast, WFSE triggered a delayed but sustained inflammatory response, with TNF-, IFN-{gamma}, IL-23, and IL-33 levels persisting at 96 hr in aged MDMi, highlighting an age-related vulnerability to air pollutant-induced inflammation. Both pollutants activated p38, ERK, and NF-{kappa}B pathways, with p38 activity resolving by 96 hours and ERK activation persisting, reflecting their distinct roles in cellular stress and inflammation. NF-{kappa}B p65 nuclear translocation, observed at 24 hours, highlighted its critical role in cytokine release and inflammation following exposure to DEP and WFSE. This is the first report of NF-{kappa}B activation in human microglia exposed to air pollutants. ConclusionsThese results highlight the distinct and potentially harmful effects of DEP and WFSE on immune and inflammatory responses in MDMi, particularly in ageing populations, with significant implications for brain health. DEP triggers acute oxidative stress and inflammatory responses, while WFSE induces more prolonged effects, especially in aged microglia. Both pollutants activate the MAPK and NF-{kappa}B pathways and exhibit unique cytokine profiles, underscoring their overlapping yet distinct mechanisms of action. These findings advance our understanding of air pollutant-induced neuroinflammation and its contribution to neurodegeneration, providing a foundation for developing targeted interventions to mitigate the neurotoxic effects of air pollution.

cell biology↗

bioRxiv2023

A novel patient-derived cellular platform for validating microglia-targeted therapeutics for Alzheimer's disease

The scarcity of effective biomarkers and therapeutic strategies for predicting disease onset and progression in Alzheimers disease (AD) is a major challenge to improve much-needed therapeutic outcomes. Conventional drug discovery approaches have been unsuccessful in providing efficient interventions due to their one-size-fits-all nature. As an alternative, personalised drug development holds promise to pre-select responders and identify suitable drug efficacy indicators. In this study, we established a preclinical drug testing strategy by assessing the efficacy of anti-inflammatory drugs in 2D and 3D in vitro models of monocyte-derived microglia-like cells (MDMi) derived from AD and mild cognitive impairment (MCI) patients, and matched healthy individuals. We observed that the cytokine inflammatory profiles of MDMi in response to drugs clustered separately between cohorts, with the 3D model showing a more defined separation between healthy and patient donors than 2D. By ranking donor and cytokine responses to drugs, we identified that drug efficacy was limited in AD patients and involved cohort-specific responsive cytokines. Our findings suggest that MDMi models have the potential to predict disease progression, stratify responders and identify biomarkers for estimating the efficacy of microglia-targeted drugs. Together, our pipeline could serve as a valuable tool to enhance the clinical translational value of preclinical drug screens and ultimately improve drug outcomes for AD.

cell biology↗

bioRxiv2022

An Alzheimer's disease patient-derived olfactory cell model identifies gene expression changes associated with cognition

An early symptom of Alzheimers disease (AD) is an impaired sense of smell, for which the molecular basis remains elusive. Here, we generated human olfactory neurosphere-derived (ONS) cells from people with AD and mild cognitive impairment (MCI), and performed global RNA sequencing to determine gene expression changes. ONS cells expressed markers of neuroglial differentiation, providing a unique cellular model to explore early AD-associated disease pathways. Our transcriptomics data from ONS cells revealed differentially expressed genes (DEGs) associated with cognitive processes in AD cells compared to MCI, or matched healthy controls (HC). A-Kinase Anchoring Protein 6 (AKAP6) was the most significantly altered gene in AD compared to both MCI and HC, and has been linked to cognitive function. The greatest change in gene expression of all DEGs occurred between AD and MCI. Gene pathway analysis revealed defects in multiple cellular processes with aging, intellectual deficiency and alternative splicing being the most significantly dysregulated in AD ONS cells. Our results demonstrate that ONS cells can provide a cellular model for AD that recapitulates disease-associated differences. We have revealed potential novel genes, including AKAP6 that may have a role in AD, particularly MCI to AD transition, and should be further examined.

neuroscience↗

bioRxiv2021

3D models of Alzheimer's disease patient microglia recapitulate disease phenotype and show differential drug responses compared to 2D

Alzheimers disease (AD) is an incurable neurodegenerative disorder with a rapidly increasing prevalence worldwide. Current approaches targeting hallmark pathological features of AD have had no consistent clinical benefit. Neuroinflammation is a major contributor to neurodegeneration and hence, microglia, the brains resident immune cells, are an attractive target for potentially more effective therapeutic strategies. However, there is no current in vitro model system that faithfully recapitulates patient-specific microglial characteristics. To address this shortcoming, we developed novel 3D models of monocyte-derived microglia-like cells (MDMi) from AD patients. MDMi in 3D exhibited mature microglial features, including a highly branched morphology and enhanced bonafide microglial marker expression compared to 2D. Moreover, AD MDMi in 3D co-cultures with neuro-glial cells showed altered cell-to-cell interactions, growth factor and cytokine secretion profiles and responses to amyloid-{beta}. Drug screening assays in 3D AD MDMi revealed different cytokine responses compared to 2D. Our study demonstrates disease- and drug-specific responses in 3D MDMi models that are not apparent in 2D and presents a new 3D platform for more effective and personalised drug testing.

neuroscience↗

bioRxiv2020

ALS monocyte-derived microglia reveal cytoplasmic TDP-43 accumulation, DNA damage, and cell-specific impairment of phagocytosis associated with disease progression.

AimsAmyotrophic lateral sclerosis (ALS) is a multifactorial neurodegenerative disease characterised by the loss of upper and lower motor neurons. Neuroinflammation mediated by microglial activation is evident in post-mortem brain tissues, and in brain imaging of patients with ALS. However, the exact role of microglia in ALS remains to be elucidated partly due to the lack of an accurate microglial model system that is able to recapitulate the clinical pathology of ALS. Moreover, direct sampling of microglia from patients with ALS is not feasible, further limiting the study of microglial function in ALS. To address this shortcoming, we describe an approach that generates monocyte-derived microglia (MDMi) that are capable of expressing molecular markers, and functional characteristics similar to resident human brain microglia. Importantly, MDMi can be routinely and reproducibly generated from ALS patient blood, and reveal patient heterogeneity associated with age, sex and disease subgroup. MethodsMDMi were successfully established from all 30 ALS patients, including 15 patients with slow disease progression, 6 with intermediate progression, and 9 with rapid progression, together with 20 non-affected heathy controls (HC). ResultsOur ALS MDMi model recapitulated canonical pathological features of ALS including non-phosphorylated and phosphorylated-TDP-43-positive pathological inclusions. We further observed significantly impaired phagocytosis, altered cytokine expression and microglial morphology, as well as elevated DNA damage in ALS compared to HC MDMi. Abnormal phagocytosis was observed in all ALS cases, and was correlated to the progression of disease. Moreover, in-depth analysis of individual microglia revealed cell-specific variation in phagocytic function that was significantly altered, and exacerbated in rapid disease progression. ConclusionsOur approach enabled us to generate ALS patient microglia from peripheral blood samples using a rapid, robust, cost-effective, and reproducible protocol. We have shown that ALS monocyte-derived microglia have significantly altered functional behaviour compared to age-matched HCs, with a major deficit in phagocytic activity. This is also the first demonstration of abnormal TDP-43 localisation in microglia grown from ALS patients. Overall, this approach is highly applicable to monitor disease progression and can be applied as a functional readout in clinical trials for anti-neuroinflammatory agents. Additionally, this model system can be used as a basis for personalised therapeutic treatment for ALS, as well as other neurodegenerative diseases.

neuroscience↗