Biology subjects

Gomes, C. M.

Publications and source records attributed to Gomes, C. M..

5 recordsLinked to original sources

bioRxiv2025

Engineering a perfusion bioreactor system for hiPSC-derived progenitor co-culture capturing microglial features in CNS development

Microglia are critical regulators of brain homeostasis and immune responses in the central nervous system (CNS). However, existing human-based models fail to reproduce the early and complex microglia-neural cell interactions. The differentiation of human induced pluripotent stem cells (hiPSCs) into specialized cell types offers promising avenues for understanding human development and disease modeling. Herein, we explore the differentiation of hiPSC-derived erythromyeloid progenitors (iEMPs) and their 3D co-culture with hiPSC-derived neurospheres, utilizing the Ambr(R) 250 Modular system. The aim of this research was to build a complex co-culture model between iEMP and neurospheres in a scalable and controlled environment. Our results demonstrate that the Ambr(R) 250 Modular system effectively supports the co-culture process, with iEMPs integration into the neurospheres, exhibiting cell density, aggregate morphology and concentration similar to the neurosphere monocultures. The co-culture environment induced the upregulation of transcription factors critical for microglial lineage commitment. iEMP-neurospheres displayed a unique secretory profile, releasing proteins involved in extracellular matrix remodeling and neuronal differentiation, essential for microenvironment remodeling. In conclusion, this study underscores the role of iEMPs in CNS development and presents a robust platform for preclinical research.

bioengineering↗

bioRxiv2025

Innate immunocompetent iNSpheroids: A hiPSC-derived 3D model to study the central nervous system captures an early CNS response to rAAV

Gene therapies using adeno-associated viruses (AAVs) for central nervous system (CNS) disorders face challenges due to host immune responses not represented in classical preclinical models. Here, we present a human-induced pluripotent stem cell (hiPSC)-derived innate immunocompetent 3D CNS model that recapitulates neuroinflammatory hallmarks, serving as a platform for preclinical gene therapy development. Utilizing various scales of stirred-tank bioreactor systems, we generated (neurospheroids) iNSpheroids composed of neurons, astrocytes, and oligodendrocytes, alongside microglial cells (iMGL) to mimic the neuro-immune axis. These systems enabled large-scale production of iNSpheroids and subsequent miniaturization for co-culture experiments and screening of inflammatory stimuli, while maintaining a highly controlled environment. The iMGL-iNSpheroids demonstrated active neuron-microglia crosstalk and exhibited distinct inflammatory responses to a series of neuroinflammatory factors. iMGL-iNSpheroids mounted a mild and transient response to rAAV9, mediated by the activation of inflammatory pathways (e.g., TNF-via NF-{kappa}B activation) in glial cell populations. This model offers a valuable tool to dissect neuroinflammatory mechanisms, accelerating gene therapy development. TeaserImmune-competent 3D human CNS model recapitulates glial responses to rAAVs, enabling reliable preclinical gene therapy screening.

bioengineering↗

bioRxiv2025

Neuronal expression of S100B triggered by oligomeric Aβ peptide protects against cytoskeletal damage and synaptic loss

Alzheimers disease (AD) is a complex neurodegenerative disorder characterized by the intracellular deposition of Tau protein and extracellular deposition of amyloid-{beta} peptide (A{beta}). AD is also characterized by neuroinflammation and synapse loss, among others. The S100 family is a group of calcium-binding proteins with intra- and extracellular functions, that are important modulators of inflammatory responses. S100B, which is upregulated in AD patients and the most abundant member of this family, was shown to inhibit in vitro the aggregation and toxicity of A{beta}42, acting as a neuroprotective holdase-type chaperone. Although S100B is primarily produced by astrocytes, it is also expressed by various cells, including neurons. In this work, we investigated if S100B neuronal expression is triggered as a response to A{beta} toxic species, to provide protection during disease progression. We used the AD mouse model A{beta}PPswe/PS1A246E to show that neuronal S100B levels are significantly higher in 10-month-old animals, and cellular assays to demonstrate that A{beta} oligomers significantly increase S100B expression in SH-SY5Y cells, but not monomeric or fibrillar A{beta}. Using primary cultures of rat hippocampal neurons, we showed that S100B partially reverts A{beta}-induced cofilin-actin rods (synapse disruptors), and rescues the decrease in active synapses and post- (PSD-95) synaptic marker, imposed by A{beta} peptide. Altogether, these findings establish the neuroprotective activity of S100B in response to proteotoxic stress in cells, highlighting its chaperone function as a crucial factor in understanding proteostasis regulation in the diseased brain and identifying potential therapeutic targets.

neuroscience↗

bioRxiv2023

3D human retinal organoid model for the study of early diabetic retinopathy

Diabetic retinopathy (DR) is a significant complication of diabetes and a primary cause of visual impairment among working-age individuals. DR is a degenerative condition in which hyperglycaemia results in morphological and functional changes in certain retinal cells. Existing treatments mainly address the advanced stages of the disease, which involve vascular defects such as macular edema or neovascularization. However, it is now known that retinal neurodegeneration and inflammation precede these vascular changes. Therefore, there is a pressing need to identify new therapeutic approaches that target the early stages of DR and prevent its progression. In the last decade, the development of reliable in vitro models resembling the complexity of the retinal tissue has significantly improved. Namely, three-dimensional (3D) retinal organoids derived from human induced-pluripotent stem cells (hiPSCs) recapitulate the cellular organization and complexity of the human retina. Here, we used hiPSCs-derived retinal organoids to generate a model of early DR. In this model, we observe well-established molecular and cellular features of early DR: i) loss of retinal ganglion and amacrine cells; ii) glial reactivity and inflammation, with increased expression of the vascular endothelial-derived growth factor (VEGF) and interleukin-1{beta} (IL-1{beta}), and monocyte chemoattractant protein-1 (MCP-1) secretion; iii) increased levels of reactive oxygen species accompanied by activation of key enzymes involved in antioxidative stress response. The data provided highlight the utility of retinal organoid technology in modelling early-stage DR. This offers new avenues for the development of targeted therapeutic interventions on neurodegeneration and inflammation in the initial phase of DR, potentially slowing the diseases progression.

neuroscience↗

bioRxiv2020

Deglutarylation of GCDH by SIRT5 controls lysine metabolism in mice

ABSTRACTA wide range of protein acyl modifications has been identified on enzymes across various metabolic processes; however, the impact of these modifications remains poorly understood. Protein glutarylation is a recently identified modification that can be non-enzymatically driven by glutaryl-CoA. In mammalian systems, this unique metabolite is only produced in the lysine and tryptophan oxidative pathways. To better understand the biology of protein glutarylation, we studied the relationship between enzymes within the lysine/tryptophan catabolic pathways, protein glutarylation, and regulation by the deglutarylating enzyme Sirtuin 5 (SIRT5). Here, we identify glutarylation on the lysine oxidation pathway enzyme glutaryl-CoA dehydrogenase (GCDH). We show increased GCDH glutarylation when glutaryl-CoA production is stimulated by lysine catabolism. Our data reveal glutarylation of GCDH impacts its function, ultimately decreasing lysine oxidation. We then demonstrate the ability of SIRT5 to deglutarylate GCDH, restoring its enzymatic activity. Finally, metabolomic and bioinformatic analyses indicate an expanded role for SIRT5 in regulating amino acid metabolism. Together, these data support a model whereby a feedback loop exists within the lysine/tryptophan oxidation pathway, in which glutaryl-CoA is produced, in turn inhibiting GCDH function via glutaryl modification of GCDH lysine residues, and can be relieved by SIRT5 deacylation activity.View Full Text

biochemistry↗