Biology subjects

Valero, J.

Publications and source records attributed to Valero, J..

16 recordsLinked to original sources

bioRxiv2026

Bone Marrow-Derived Cells Fuse with Bergmann Glia in Experimental Autoimmune Encephalomyelitis

Bone marrow-derived cells (BMDCs) can infiltrate the brain and adopt new identities through transdifferentiation or fusion, yet their interactions with specific neural cells remain poorly defined. We examined BMDC fusion with Bergmann glia (BG), a key cerebellar support cell, in a mouse model of multiple sclerosis. After bone marrow transplantation, BMDCs fused with BG to form heterokaryons, retaining BG morphology and molecular markers. These heterokaryons contained donor and host nuclei that differed in both morphology and transcriptional activity. Remarkably, the BMDC nucleus localized not only to the soma but also along BG processes. This discovery identifies BMDC-BG fusion as a previously unrecognized form of glial plasticity, opening avenues for therapeutic strategies aimed at potentiating glial-mediated repair.

neuroscience↗

bioRxiv2026

RNA Organelles in DNA-based Artificial Cells Provide Spatial Aptamer Functions and Enhanced Signal Processing

Naturally occurring biomolecular condensates orchestrate key cellular processes by creating spatially distinct reaction environments, yet engineering synthetic condensates that combine structural programmability with spatioselectively encoded function remains challenging. Here we report multiphase DNA-RNA artificial cells (ACs) that embed functional RNA condensates as organelle-like compartments within programmable DNA core-shell ACs. A single thermal assembly protocol yields three-phase ACs comprising a glassy RNA core organelle embedded in a liquid-like DNA compartment, surrounded by a crosslinked DNA shell. The RNA organelles contain aptamer function, enabling selective protein recruitment and small-molecule activation, while the DNA scaffold provides independent addressability, regulates RNA-condensate size and enhances resistance to serum-mediated degradation. We further show that RNA chemistry can be used to adjust environmental responsiveness: unmodified RNA organelles undergo rapid degradation in serum and release captured protein cargo, whereas 2'-fluoro-modified RNA organelles remain stable for at least 24 h. Finally, by coupling transcriptional modules localized in the DNA core to cell-free protein translation in the surrounding medium, we establish sender-receiver communication between AC populations and self-actuating signal processing within individual DNA-RNA ACs. These results establish hybrid nucleic-acid ACs as programmable, spatially organized systems that couple compartment architecture, RNA molecular recognition and biochemical communication. TOC Figure O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=125 SRC="FIGDIR/small/733869v1_ufig1.gif" ALT="Figure 1"> View larger version (43K): org.highwire.dtl.DTLVardef@23ee9org.highwire.dtl.DTLVardef@1706336org.highwire.dtl.DTLVardef@181a241org.highwire.dtl.DTLVardef@1c374d8_HPS_FORMAT_FIGEXP M_FIG C_FIG Multiphase DNA-RNA artificial cells integrate a protective DNA shell, a transcriptionally active DNA core, and a functional RNA organelle. Spatial compartmentalization enables signal generation, external protein expression, and selective recapture via RNA aptamers.

Synthetic Biology↗

bioRxiv2026

Expanding the chemical diversity of RNA by transcriptional incorporation of amino acid- and glycosyl-modified nucleotides

With the increasing interest in RNA-based therapies, there is a pressing need to incorporate new chemistries into more complex RNA molecules. These modifications can protect RNA from degradation, improve its pharmacokinetics, and enhance its targeting properties. Here we describe the enzymatic synthesis of chemically modified RNA derivatives using a mutant T7 RNA polymerase to incorporate 23 different base modifications alongside stabilizing ribose modifications, such as 2'-fluoro and 2'-deoxy groups. To investigate the impact on transcription efficiency and fidelity, we employed a pool of 38 template sequences and analyzed the transcripts by next-generation sequencing of the cDNA. Results demonstrated that all modifications were successfully incorporated into RNA, with transcription efficiency influenced by three main factors: type of modification, base modified, and the sequence context. Misincorporation levels during transcription and reverse transcription into cDNA were generally low (<1%) but included noticeable exceptions for some nucleobase-modification combinations. As a robust proof-of-concept we demonstrated the selection of Histidine-U modified aptamer, relying on multiple rounds of transcription and amplification, binding Influenza hemagglutinin protein with low nanomolar KD. We anticipate that this work will significantly contribute to the design and production of chemically modified RNAs with novel functionalities, advancing applications in biomedicine and synthetic biology. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=76 SRC="FIGDIR/small/720138v2_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@29b6daorg.highwire.dtl.DTLVardef@a3c425org.highwire.dtl.DTLVardef@1a27a4aorg.highwire.dtl.DTLVardef@ab0e9_HPS_FORMAT_FIGEXP M_FIG C_FIG

molecular biology↗

bioRxiv2026

Fluorinated RNA origami enables serum-stable nanodevices for sensing and targeting

Chemically modified RNAs with increased stability and reduced immunogenicity have transformed RNA therapeutics. Rational RNA design methods, including RNA origami, seek to further extend RNA medicine and biotechnology by encoding advanced functions such as signalling, targeting, and controlled release within the RNA polymer. However, current design methods lack the ability to integrate chemical modification or predict how it shapes the structure of large RNA assemblies inhibiting its use in RNA therapeutics. Here we demonstrate that 2-fluoro pyrimidine RNA (FY-RNA) origami structures can be co-transcriptionally folded to generate serum-stable nanodevices. Cryogenic electron microscopy reveals that FY-RNA can alter folding pathways and perturb tertiary motifs, while molecular dynamics simulations show how 2-fluoro modification affects hydrogen bonding, sugar pucker, and helix-helix interactions. Despite these structural perturbations, fluorogenic aptamers embedded within RNA origami retain partial activity and enable logic-based molecular sensing in human serum. Finally, we use an FY-RNA scaffold to determine the structure of an FY-RNA anti-Spike aptamer bound to the Spike protein at 3.4 [A] resolution, uncovering fluorine-specific structural motifs and protein interactions. Together, our results establish design principles for nuclease-resistant RNA architectures and position FY-RNA as a versatile polymer for constructing medical nanodevices and environmental sensors. More broadly, this work provides a framework for systematically exploring the folding landscape of chemically modified RNAs, expanding the chemical and functional diversity accessible to nucleic acid nanotechnology and RNA medicine.

biochemistry↗

bioRxiv2025

Single-Particle Tracking and Positional Phenotyping Reveals Variant-Specific Early Checkpoints in SARS-CoV-2 Cell Entry

SARS-CoV-2 entry is governed by Spike (S) protein-mediated engagement of ACE2 and subsequent activation of either plasma membrane fusion mediated by TMPRSS2 or endocytic uptake. Currently, most insights into these pathways come from bulk assays that obscure the fate of individual virions, thereby concealing intricate mechanistic details that can inform on therapeutic intervention strategies. Here, we applied single-particle fluorescence imaging to directly observe the early checkpoints of SARS-CoV-2 cell entry pathways and separate binding from internalization. Fluorescent virus-like particles (VLPs) pseudotyped with either G614 or Omicron BA.5 S protein variants were imaged on HEK293T-ACE2 (TMPRSS2-negative) and classified at the single-particle level as surface-interacting, crossing, or internal. At baseline, G614 VLPs show higher binding and a larger internalized share than BA.5 VLPs, revealing general divergence in early entry behavior between variants. A trivalent anti-S receptor-binding domain aptamer reduces G614 binding and lowers its internalization. Conversely, the aptamer does not block BA.5 VLP cell binding but increases its internalization efficiency. Pitstop 2, an inhibitor of clathrin-mediated endocytosis, causes no significant change in this observation window, consistent with early clathrin-sensitive events having already progressed. Quantification of trajectories reveals variant-specific mobility: BA.5 displays higher step length than G614, consistent with greater lateral scanning and surface retention. Together, these compact single-particle readouts expose variant-resolved early checkpoints in entry and provide a simple platform to test how ligands and pathway probes shift binding and internalization.

biophysics↗

bioRxiv2025

Epigenetic control of microglial developmental milestones from proliferative progenitors to efficient phagocytes

Early immune perturbations increase the risk of neurodegenerative and neurodevelopmental disorders, yet the mechanisms underlying the maturation of microglia, the resident immune cells of the brain parenchyma, remain poorly defined. Specifically, how proliferation, morphological differentiation, and phagocytosis are coordinated among microglia progenitors as they colonize the embryonic brain remains unclear. Here, we combined mathematical modeling with spatiotemporal analyses of the murine hippocampus and cerebellum from postnatal day 2 (P2) to P60 to reconstruct the trajectory of microglial development. We identified a proliferative-to-quiescent (P/Q) switch around P3/P4 that preceded the acquisition of morphological complexity and efficient phagocytosis and was accompanied by coordinated shifts in cell-cycle dynamics and metabolic state. Strikingly, this P/Q switch was recapitulated in repopulation contexts in mice and in the human fetal brain, where later stages displayed enhanced phagocytic function coupled to reduced proliferation. Perturbing the proliferative phase through pharmacological or genetic disruption of CSF1R signaling impaired subsequent microglial complexity and phagocytosis efficiency, revealing an unexpected reliance of phagocytosis on proliferation-driven colonization. Finally, we show that microglia stepwise maturation during development is associated with chromatin remodeling and driven by the epigenetic regulator Ikaros. Together, these findings uncover the sequential milestones of microglial development, revealing a potential period of early vulnerability and establishing an unexpected linkage between proliferation and phagocytosis essential to understanding how these processes are coordinated in neurodegenerative disorders.

neuroscience↗

bioRxiv2025

Metabolic and transcriptional adaptations to phagocytosis in microglia sustain their functionality and regenerative properties

Phagocytosis of apoptotic cells, or efferocytosis, is a tightly regulated process that ensures tissue homeostasis and prevents mounting inflammatory responses. In the brain parenchyma, it is executed by microglia, which are encumbered by large numbers of apoptotic debris generated during development, in adult neurogenic niches, aging, and brain diseases. Emerging evidence suggest that phagocytosis is not limited to garbage disposal, but triggers adaptations in the phagocytes that may have a functional impact. To test it we developed an in vivo model of superphagocytosis induced by low cranial irradiation (LCI, 2Gy) that specifically induced apoptosis in the neurogenic niche of the adult hippocampus, synchronizing microglia in a phagocytic state within 6h and leading to full clearance by 24h. Single cell RNA sequencing and metabolomics revealed an unexpected oxidative stress in post-phagocytic microglia, accompanied by catabolic shutdown, mitochondrial remodeling, increased expression of galectin 3, and production of polyamines that led to cell death and compensatory proliferation. To test whether these changes impaired subsequent microglial phagocytosis, we used a glioblastoma model treated with sequential irradiation to induce tumor cell apoptosis. The phagocytosis efficiency of tumor-associated microglia/macrophages was comparable in the first and second apoptotic challenge, suggesting that the metabolic remodeling induced by phagocytosis was adaptive and destined to sustain their functionality. Finally, we assessed the functional impact of post-phagocytosis adaptations using galectin 3 deficient mice under LCI. We found that the recovery of the neurogenic niche after LCI strongly depended on galectin 3, demonstrating the regenerative capacity of post-phagocytic microglia. Overall, our data unveils the complexity of post-phagocytosis adaptations in microglia, underscoring their unexplored therapeutic potential in brain disorders.

neuroscience↗

bioRxiv2025

Targeting Langerhans cells using a modular mannosylated nucleic acid-based vaccine platform

The skin is a diverse reservoir of immune cells with strong potential for immunotherapeutic delivery. Langerhans cells (LCs) in the epidermis are antigen-presenting cells, accessible for vaccination using carbohydrate-conjugated therapeutics targeting their endocytic lectin receptor, Langerin. As carbohydrate-lectin binding is highly dependent on valency, scaffolds that enable control over ligand spacing and stoichiometry are instrumental in enhancing receptor binding and selectivity. Here we utilized a self-assembled nucleic acid-based Holliday Junction scaffold, fully modified for nuclease protection and with a well-defined carbohydrate arrangement to optimize drug delivery to LCs. In vitro screening with Langerin-expressing cells revealed that mannosylated Holliday Junctions showed the strongest binding. This was confirmed in human epidermal cell suspensions, demonstrating specificity and valency-driven interactions. Topical administration of mannosylated scaffolds on skin explants enabled effective targeting of epidermal LCs. Finally, in an antigen-presentation assay, in vitro differentiated LCs loaded with mannosylated and peptide-conjugated scaffolds significantly enhanced T cell activation. Overall, our study presents a promising nucleic acid-based platform for precise LC targeting and drug delivery, with broad potential for skin-directed immunotherapies.

molecular biology↗

bioRxiv2025

Lock, Protect, and Bind: In Vitro Selection of LNA-modified Aptamers Using a Mutant T7 RNA Polymerase

RNA therapeutics are powerful tools for gene modulation and targeted therapies, but their clinical application is hindered by nuclease degradation and immunogenicity. Incorporating chemical modifications, like locked nucleic acids (LNAs), can enhance nuclease resistance, targeting properties, and thermal stability. Traditionally, LNA incorporation has relied on solid-phase synthesis of short RNAs. Engineered polymerases capable of incorporating xenonucleic acids (XNAs), including LNA, into longer RNAs have been described. However, their XNA yield is limited by primer and template copy numbers, and the generated DNA-XNA duplexes can be difficult to purify. We present a novel approach for incorporating LNA-ATP and LNA-TTP alongside 2Fluoro (2F)-modified pyrimidines via in vitro transcription using a mutant T7 RNA polymerase. This method enables efficient, primer-independent synthesis and amplification of LNA-modified RNA with low error rates. To demonstrate its utility, we performed in vitro selection (SELEX) of LNA- and 2F-modified aptamers targeting Influenza hemagglutinin (HA) and human CD40 ligand (hCD40L), two therapeutically relevant proteins. Iterative SELEX cycles yielded aptamers with low-nanomolar affinities, high specificity, and high nuclease resistance. Overall, this approach provides a scalable and versatile platform for generating chemically stabilized RNAs, fully compatible with SELEX, and holds potential for developing next-generation RNA-based therapeutics with improved pharmacokinetics.

molecular biology↗

bioRxiv2024

A bottom-up approach identifies the antipsychotic and antineoplastic trifluoperazine and the ribose derivative deoxytubercidin as novel microglial phagocytosis inhibitors.

Phagocytosis is an indispensable function of microglia, the brain professional phagocytes. Microglia are particularly efficient phagocytosing cells that undergo programmed cell death (apoptosis) in physiological conditions. However, mounting evidence suggests microglial phagocytosis dysfunction in multiple brain disorders. These observations prompted us to search for phagocytosis modulators (enhancers or inhibitors) with therapeutic potential. We used a bottom-up strategy that consisted on the identification of phagocytosis modulators using phenotypic high throughput screenings (HTSs) in cell culture and validation in organotypic cultures and in vivo. We performed two complementary HTS campagnes: at Achucarro, we used primary cultures of mouse microglia and compounds of the Prestwick Chemical Library; at Roche, we used human iPSC derived macrophage-like cells and a proprietary chemo-genomic library with 2,200 compounds with known mechanism-of-action. Next, we validated the more robust compounds using hippocampal organotypic cultures and identified two hits: trifluoperazine, a dopaminergic and adrenergic antagonist used as an antipsychotic and antineoplastic; and deoxytubercidin, a ribose derivative. Finally, we tested whether these compounds were able to modulate phagocytosis of apoptotic newborn cells in the adult hippocampal neurogenic niche in vivo by administering them into the mouse hippocampus using osmotic minipumps. We confirmed that both trifluoperazine and deoxytubercidin have anti-phagocytic activity in vivo, and validated our bottom-up strategy to identify novel phagocytosis modulators. These results show that chemical libraries with anotated mechanism of action are an starting point for the pharmacological modulation of microglia in drug discovery projects aiming at the therapeutic manipulation of phagocytosis in brain diseases. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=194 SRC="FIGDIR/small/599284v1_ufig1.gif" ALT="Figure 1"> View larger version (49K): org.highwire.dtl.DTLVardef@13ed994org.highwire.dtl.DTLVardef@13ea710org.highwire.dtl.DTLVardef@4a1c7dorg.highwire.dtl.DTLVardef@1945f00_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2022

A new method and tool for volumetric estimation of brain structures after serial sectioning.

Volume estimations are crucial for many neuroscience studies, allowing the evaluation of changes in the size of brain areas that may have relevant functional consequences. Classical histological methods and modern human brain imaging techniques rely on obtaining physical or digital sections, with a known thickness, of the organ to be analyzed. This "slicing" strategy is associated with an ineludible loss of information about the three-dimensional organization of the analyzed structures, especially affecting the precision of volumetric measurements. To overcome this problem, several methods have been developed. One of the most commonly used approaches for volume estimation is the classical Cavalieris method. Within this book chapter, we provide first an overview of Cavalieris method and propose a new one, named the Truncated Cone Shape (TCS) method, for the estimation of volumes from tissue sections. Second, we compare the accuracy of both methods using computer-generated objects of different shapes and sizes. We conclude that, more frequently, the TCS method provides a better estimate of real volumes than Cavalieris method. And third, we describe a protocol to estimate volumes using a self-developed and freely available tool for ImageJ: VolumestJ (https://github.com/Jorvalgl/VolumestJ). This new tool helps to implement both Cavalieris and TCS methods using digital images of tissue sections. We consider that VolumestJ will facilitate the labor of researchers interested in volume estimations.

neuroscience↗

bioRxiv2021

A rhythmically pulsing leaf-spring nanoengine that drives a passive follower

Molecular engineering seeks to create functional entities for the modular use in the bottom-up design of nanoassemblies that can perform complex tasks. Such systems require fuel-consuming nanomotors that can actively drive downstream passive followers. Most molecular motors are driven by Brownian motion, but the generated forces are scattered and insufficient for efficient transfer to passive second-tier components, which is why nanoscale driver-follower systems have not been realized. Here, we describe bottom-up construction of a DNA-nanomachine that engages in an active, autonomous and rhythmical pulsing motion of two rigid DNA-origami arms, driven by chemical energy. We show the straightforward coupling of the active nanomachine to a passive follower unit, to which it then transmits its own motion, thus constituting a genuine driver-follower pair. Our work introduces a versatile fuel-consuming nanomachine that can be coupled with passive modules in nanoassemblies, the function of which depends on downstream sequences of motion.

biophysics↗

bioRxiv2021

A neuron, microglia, and astrocyte triple coculture model to study Alzheimer disease

Glial cells are essential to understand Alzheimers disease (AD) progression, given their role in neuroinflammation and neurodegeneration. There is a need for reliable and easy to manipulate models that allow studying the mechanisms behind neuron and glia communication. Currently available models such as cocultures require complex methodologies and/or might not be affordable for all laboratories. With this in mind, we aimed to establish a straightforward in vitro setting with neurons and glial cells to study AD. We generated a triple co-culture with neurons, microglia and astrocytes. Immunofluorescence, western blot and ELISA techniques were used to characterize the effects of oligomeric A{beta} (oA{beta}) in this model. We found that, in the triple co-culture, microglia increased the expression of anti-inflammatory markers Arginase I and TGF-{beta}1, and reduced pro-inflammatory iNOS and IL-1{beta}, compared with microglia alone. Astrocytes reduced expression of pro-inflammatory A1 markers AMIGO2 and C3, and displayed a ramified morphology resembling physiological conditions. Lastly, neurons increased post-synaptic markers, and developed more and longer branches than in individual primary cultures. Addition of oA{beta} in the triple coculture reduced synaptic markers and increased microglial activation, which are hallmarks of AD. Consequently, we developed a reliable model, where cells better resemble physiological conditions: microglia are less inflammatory, astrocytes are less reactive and neurons display a more mature morphology than in individual primary cultures. Moreover, we were able to recapitulate A{beta}-induced synaptic loss and inflammation. This model emerges as a powerful tool to study neurodegeneration and inflammation in the context of AD and other neurodegenerative diseases. Table of content image O_FIG_DISPLAY_L [Figure 1] M_FIG_DISPLAY C_FIG_DISPLAY Main pointsO_LIIn our model, microglia and astrocytes are less reactive, and neurons have a more mature morphology than in primary cultures. C_LIO_LIoA{beta} reduced synaptic markers and increased microglial activation. C_LIO_LIThis triple co-culture is a reliable tool to study neurodegeneration and gliosis in vitro. C_LI

neuroscience↗

bioRxiv2021

Microglial phagocytosis dysfunction during stroke is prevented by rapamycin

Microglial phagocytosis is rapidly emerging as a therapeutic target in neurodegenerative and neurological disorders. An efficient removal of cellular debris is necessary to prevent buildup damage of neighbor neurons and the development of an inflammatory response. As the brain professional phagocytes, microglia are equipped with an array of mechanisms that enable them to recognize and degrade several types of cargo, including neurons undergoing apoptotic cell death. While microglia are very competent phagocytes of apoptotic cells under physiological conditions, here we report their dysfunction in mouse and monkey (Macaca fascicularis and Callithrix jacchus) models of stroke by transient occlusion of the medial cerebral artery (tMCAo). The impairment of both engulfment and degradation was related to energy depletion triggered by oxygen and nutrients deprivation (OND), which led to reduced process motility, lysosomal depletion, and the induction of a protective autophagy response in microglia. Basal autophagy, which is in charge of removing and recycling intracellular elements, was critical to maintain microglial physiology, including survival and phagocytosis, as we determined both in vivo and in vitro using knock-out models of autophagy genes and the autophagy inhibitor MRT68921. Notably, the autophagy inducer rapamycin partially prevented the phagocytosis impairment induced by tMCAo in vivo but not by OND in vitro. These results suggest a more complex role of microglia in stroke than previously acknowledged, classically related to the inflammatory response. In contrast, here we demonstrate the impairment of apoptotic cell phagocytosis, a microglial function critical for brain recovery. We propose that phagocytosis is a therapeutic target yet to be explored and provide evidence that it can be modulated in vivo using rapamycin, setting the stage for future therapies for stroke patients.

neuroscience↗

bioRxiv2020

Microglial phagocytosis dysfunction is related to local neuronal activity in a genetic model of epilepsy

Microglial phagocytosis of apoptotic cells is an essential component of the brain regenerative response in neurodegenerative diseases. Phagocytosis is very efficient in physiological conditions, as well as during apoptotic challenge induced by excitotoxicity or inflammation, but is impaired in mouse and human mesial temporal lobe epilepsy (MTLE). Here we extend our studies to a genetic model of progressive myoclonus epilepsy type 1 (EPM1) in mice lacking cystatin B (CSTB), an inhibitor of cysteine proteases involved in lysosomal proteolysis. We first demonstrated that microglial phagocytosis was impaired in the hippocampus in Cstb knock-out (KO) mice when seizures arise and hippocampal atrophy begins, at 1 month of age. To test if this blockage was related to the lack of Cstb in microglia, we used an in vitro model of phagocytosis and siRNAs to acutely reduce Cstb expression but we found no significant effect in the phagocytosis of apoptotic cells. We then tested whether seizures were involved in the phagocytosis impairment, similar to MTLE, and analyzed Cstb KO mice before seizures begin, at postnatal day 14. Here, phagocytosis impairment was restricted to the granule neuron layer but not to the subgranular zone, where there are no active neurons. Furthermore, we observed apoptotic cells (both phagocytosed and not phagocytosed) in Cstb deficient mice at close proximity to active, cFos+ neurons and used mathematical modeling to demonstrate that the physical relationship between apoptotic cells and cFos+ neurons was specific for Cstb KO mice. These results suggest a complex crosstalk between apoptosis, phagocytosis and neuronal activity, hinting that local neuronal activity could be related to phagocytosis dysfunction in Cstb KO mice. Overall, this data suggest that phagocytosis impairment is an early feature of hippocampal damage in epilepsy and opens novel therapeutic approaches for epileptic patients based on targeting microglial phagocytosis.

neuroscience↗

bioRxiv2019

Microglia actively remodels adult hippocampal neurogenesis through the phagocytosis secretome

During adult hippocampal neurogenesis, the majority of newborn cells undergo apoptosis and are rapidly phagocytosed by resident microglia to prevent the spillover of their intracellular contents. Here, we propose that phagocytosis is not merely a passive process of corpse removal but has an active role in maintaining adult hippocampal neurogenesis. First, we found that neurogenesis was disrupted in mice chronically deficient for two microglial phagocytosis pathways (P2Y12 and MerTK/Axl), but was transiently increased in mice in which MerTK expression was conditionally downregulated. Next, we performed a transcriptomic analysis of microglial phagocytosis in vitro and identified genes involved in metabolism, chromatin remodeling, and neurogenesis-related functions. Finally, we discovered that the secretome of phagocytic microglia limits the production of new neurons both in vivo and in vitro. Our data suggest that reprogrammed phagocytic microglia act as a sensor of local cell death, modulating the balance between cell proliferation and cell survival in the neurogenic niche, thereby supporting the long-term maintenance of adult hippocampal neurogenesis.\n\nGRAPHICAL ABSTRACT

cell biology↗