Biology subjects

Beato, M.

Publications and source records attributed to Beato, M..

At least 19 recordsLinked to original sources

bioRxiv2026

Spinal circuits encode a map of the trunk to control skin twitches

Reflexive skin twitches are stereotypical behaviours, triggered in most mammals by mechanosensory stimuli. The neural circuits controlling this behaviour are thought to lie in the spinal cord, with motor neurons positioned in the lower cervical spinal cord innervating the cutaneous maximus muscle responsible for the twitches. The spatial matching of the motor output to the location of the sensory stimulus points to selective innervation of particular cutaneous maximus motor neurons by specific sensory-responsive circuits organised in a spatially-dependent manner. Using mouse genetics and viral tracing, we observed that a subset of dorso-lateral dI3 neurons forms ascending projections to motor neurons mediating skin twitches. Their projections are somatotopically organized to map a two dimensional space onto specific sub-compartments of the cutaneous maximus motor pool. Furthermore, direct optogenetic stimulation of thoraco-lumbar dI3 ascending projections in the cervical spinal cord induces skin twitches. Together, we demonstrate the circuit basis of a spinal sensory-motor representation of the dorsolateral trunk that participates in an ethological behaviour shared by most mammals allowing them to reduce the burdens of irritants such as insects.

neuroscience↗

bioRxiv2026

In vivo motor unit decoding and in vitro cellular characterisation of spinal circuits for urination in adult mice

Urinary dysfunction affects billions of individuals worldwide; however, the fundamental cellular and circuit properties that govern perineal motor control remain largely unknown, serving as a functional "black box". Here, we describe several methods that, when used in concert, characterise cellular, synaptic, and motor unit properties underlying the control of urination in adult mice. High-density electromyography combined with real-time cystometry were used to study external urethral sphincter (EUS) motor units, which follow a hierarchical ("onion skin") recruitment pattern during bladder filling. The transition to the voiding phase is marked by inhibition, followed by synchronised bursts. Furthermore, through concurrent recordings of ischiocavernosus (IC) muscles, the relationship between IC and EUS motor units could be studied to look for shared common inputs that could shed light on circuitry. Whole-cell patch-clamp recordings from retrogradely identified neurons revealed a fundamental biophysical divergence: urinary parasympathetic preganglionic neurons (PPGN) are significantly smaller and more excitable than somatic EUS and IC motoneurons and lack the recurrent excitatory and inhibitory circuits present in both EUS and IC motor pools. Finally, using a novel pressure-clamp preparation, we showed that acute tibial nerve stimulation (a widely used treatment for urinary dysfunction) evokes short-latency inhibition of EUS motor units. Collectively, these methods can be used to delineate patterns of motor unit recruitment, local recurrent microcircuit architecture, and distinct biophysical properties of the perineal motor system, providing mechanistic insights into urinary function.

neuroscience↗

bioRxiv2025

Evidence of spinal cord comparator modules for rapid corrections of movements

Successful movement requires continuous adjustments in response to changes in internal and external environments. To do so, neural circuits continuously compare efference copies of motor commands with sensory feedback to respond to sensory prediction errors. Some responses need to be very fast, indicating that they likely occur within spinal cord circuits. Here, we describe spinal cord circuits involving dI3 neurons, showing that they receive multimodal sensory inputs and direct efferent copies from both Renshaw cells and motor neurons. We further show that they form connections to motor pools. Reducing dI3 neuronal activity diminished stumbling responses, as did disrupting Renshaw cell circuits, providing evidence for a comparator role of dI3 neurons for online corrections. Together, our findings reveal a pivotal role for dI3 neurons functioning as comparators of efference copies and external sensory feedback to mediate rapid corrections of ongoing movements.

neuroscience↗

bioRxiv2025

PARP1 Regulates 3D Structure and Function of Super-Enhancers and Hormone-Control Regions in Breast Cancer Cells

Poly (ADP-ribose) polymerase 1 (PARP1) has been linked to various genomic pathways and in the maintenance of genomic stability. PARP1 has also been postulated to regulate cis-regulatory elements, but the mechanisms remain largely unknown. Here, we employed genomic approaches to show how PARP1 occupies Super-Enhancers (SEs) of luminal A T47D breast cancer cells and how some PARP1 is dynamically relodged by progesterone at hormone-control regions (HCRs). Disruption of PARP1 causes transcriptome reprogramming, altering the expression of both SE-associated and HCRs-regulated genes. This is achieved through a dual coordinated action in the establishment of long-range and intra-TADs chromatin loops, which are lost upon PARP1 ablation, but enforced by its catalytic inhibition. We show that PARP1 also plays a role in regulation of chromatin compartments. Our results reveal PARP1, as a new chromatin looper and compartments organizer controlling SEs and HCRs genes linked to cell identity and hormonal response in breast cancer cells via 3D genome organization. Highlights (Separate document)O_LIPARP1 occupies cell specific super-enhancers and hormone-control regions. C_LIO_LILoss of PARP1 alters the cell identity and progestin-induced gene expression signature. C_LIO_LIGene expression changes upon PARP1 loss relay on altered 3D chromatin looping and compartments. C_LI eTOC blurbWe have discovered that the nuclear repair protein and cancer drug target; PARP1 is preferentially bound at super-enhancers. The binding of PARP1 is essential for the underlying, cell specific gene expression program and the 3D structure of the chromatin surrounding the super-enhancer regions. Graphical abstractSeparate document O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=198 SRC="FIGDIR/small/668155v1_ufig1.gif" ALT="Figure 1"> View larger version (81K): org.highwire.dtl.DTLVardef@1da9027org.highwire.dtl.DTLVardef@2e1966org.highwire.dtl.DTLVardef@8582eaorg.highwire.dtl.DTLVardef@155e77b_HPS_FORMAT_FIGEXP M_FIG C_FIG

genomics↗

bioRxiv2025

Personalized mapping of inhibitory spinal circuits via neural decoding of high-density electromyography and in silico modelling

Studying human motoneuron activity through electromyography (EMG) can yield insights into the operation of fundamental spinal cord microcircuits. Traditional surface and needle electromyography (EMG) methodologies have limited capacity to shed light on the diversity of motor unit (MU) control strategies that may be unique to each individual. Here, we employed high-density surface EMG (HDsEMG) to sample multiple MUs per subject to investigate the dynamics of inhibitory spinal microcircuits in both upper and lower limb control. We characterised the net inhibition as a function of individual MU firing rates, revealing subject-specific relationships. In silico modelling replicated these experimental characteristics and suggested that properties of the inhibitory currents rather than motoneuron size are responsible for net functional inhibition. Our results show that HDsEMG can highlight distinct control strategies across circuits and motor pools, revealing subject-specific properties of inhibitory spinal microcircuits. TEASERHigh-density surface EMG electrodes can reveal the functional properties of inhibitory spinal circuits

neuroscience↗

bioRxiv2024

Spinal microcircuits go through multiphasic homeostatic compensations in a mouse model of motoneuron degeneration

In many neurological conditions, early-stage neural circuit adaption can preserve relatively normal behaviour. In some diseases, spinal motoneurons progressively degenerate yet movement is initially preserved. We therefore investigated whether these neurons and associated microcircuits adapt in a mouse model of progressive motoneuron degeneration. Using a combination of in vitro and in vivo electrophysiology and super-resolution microscopy, we found that, early in the disease, neurotransmission in a key pre-motor circuit, the recurrent inhibition mediated by Renshaw cells, is reduced by half due to impaired quantal size associated with decreased glycine receptor density. This impairment is specific, and not a widespread feature of spinal inhibitory circuits. Furthermore, it recovers at later stages of disease. Additionally, an increased probability of release from proprioceptive afferents leads to increased monosynaptic excitation of motoneurons. We reveal that in motoneuron degenerative conditions, spinal microcircuits undergo specific multiphasic homeostatic compensations that may contribute to preservation of force output.

neuroscience↗

bioRxiv2023

The Hippo kinase LATS1 controls CTCF chromatin occupancy and the hormonal response of three-dimensionally grown breast cancer cells

The cancer epigenome has been studied in cells cultured in 2D monolayers on plastic surfaces, but recent studies highlight the impact of the extracellular matrix (ECM) and the 3D environment on multiple cellular functions. Here, we report the physical, biochemical and genomic differences between T47D breast cancer cells cultured in 2D monolayer and as 3D spheroids in Matrigel. Cells within 3D spheroids exhibit a rounder nucleus with less accessible, more compacted chromatin, and altered expression of over 2,000 genes, the majority of which become repressed. Hi-C analysis reveals that cells grown in 3D exhibit enrichment in regions belonging to the B compartment, decrease on chromatin bound CTCF and increased fusion of Topologically Associating Domains (TADs). Upregulation of the Hippo pathway in 3D spheroids results in the activation of the LATS1 kinase, which promotes phosphorylation and displacement of CTCF from DNA, likely responsible for the observed TAD fusions. Cells grown in 3D exhibit higher progesterone receptor (PR) binding to chromatin, leading to an increase in the number hormone-regulated genes. This effect is in part mediated by the LATS1 activation, which favors cytoplasmic retention of YAP and CTCF removal.

genomics↗

bioRxiv2023

On the origin of F-wave: involvement of central synaptic mechanisms

Neurophysiological methods are used widely to gain information about motoneuron excitability and axon conduction in neurodegenerative diseases. The F-wave is a common biomarker used to test motoneuron properties in the diagnosis of neurological diseases. Although the origin of the F-wave is a subject of debate, the most widely accepted mechanism posits that the F-wave is generated by the backfiring of motoneurons stimulated antidromically from the periphery. In this study, we developed an ex vivo mouse sciatic nerve-attached spinal cord preparation with sensory axons severed in which stimulation of the whole sciatic nerve or its tibial branch evoked responses with the electrophysiological signatures of F-waves. Manipulations of synaptic transmission by either removal of extracellular calcium or block of post-synaptic glutamate receptors abolished these responses. These results suggest that F-waves are mediated by spinal microcircuits activated by recurrent motor axon collaterals via glutamatergic synapses.

neuroscience↗

bioRxiv2023

A progesterone derivative linked to a stable phospholipid activates breast cancer cell response without leaving the cell membrane

In hormone-responsive breast cancer cells, progesterone (P4) has been shown to act via its nuclear receptor (PR), a ligand-activated transcription factor. A small fraction of PR is palmitoylated and anchored to the cell membrane (mbPR) forming a complex with estrogen receptor alpha (ER). Upon hormone exposure, either directly or via interaction with ER mbPR activates the SRC/RAS/ERK kinase pathway leading to phosphorylation of PR by ERK. Kinase activation is essential for P4 gene regulation, as the ERK and MSK1 kinases are recruited by the PR to its genomic binding sites and trigger chromatin remodeling. An interesting open question is whether activation of mbPR can result in gene regulation in the absence of ligand binding to intracellular PR. This matter has been investigated in the past using P4 attached to serum albumin, but the attachment is leaky and albumin can be endocytosed and degraded, liberating P4. Here we propose a more stringent approach to address this issue by ensuring attachment of P4 to the cell membrane via covalent binding to a stable phospholipid. This strategy identifies the actions of P4 independent of hormone binding to intracellular PR. We found that a membrane-attached progestin can activate mbPR, the ERK signalling pathway leading to PR phosphorylation, initial gene regulation and entry into the cell cycle, in the absence of detectable intracellular progestin.

genomics↗

bioRxiv2022

Quantitative analysis of cellular morphology during in vitro decidualization

Decidualization is a differentiation process involving shape reorganization from a fibroblast to an epithelioid-like appearance of endometrial stromal cells. Specificities of these cells impede the use of existing automated tools to follow morphological changes during differentiation; we therefore developed a simple but accurate methodology to quantify the phenotypical changes that occur in an in vitro decidualization system. The approach consists of the analysis of the circularity of the cells directly from light microscopy images. Here, we used this methodology to follow the effects of progesterone or progestin R5020 in combination with estradiol (E2) and cAMP on inducing the decidualization of human endometrial cells. We further implemented a statistical model to detect the differences in the kinetics of decidualization of the two hormonal stimuli before all the cell population acquired the decidual phenotype. We found that 2 days after stimulation are sufficient to detect statistical differences in morphology between decidualization induced and control cells. Here, we detail the model and scripts in order to provide a useful, practical and low cost tool to evaluate morphological aspects of endometrial stromal differentiation. Availability and implementationSee supplementary methods Supplementary informationSupplementary data is available online.

bioinformatics↗

bioRxiv2022

Evolutionary insights reveal a new role of PADI2 in transcriptional elongation

Peptidyl arginine deiminases (PADIs) catalyze protein citrullination, a post-translational conversion of arginine to citrulline. The most widely expressed member of this family, PADI2, regulates cellular processes that impact several diseases. We hypothesized that we could gain new insights into PADI2 function through a systematic evolutionary and structural analysis. Here, we identify 20 positively selected PADI2 residues, 16 of which are structurally exposed and maintain PADI2 interactions with cognate proteins. Many of these selected residues reside in non-catalytic regions of PADI2. We validate the importance of a prominent loop in the middle domain that encompasses PADI2 L162, a residue under positive selection. This site is essential for interaction with the transcription elongation factor (P-TEFb) and mediates active transcription of the oncogenes c-MYC, and CCNB1, as well as impacting cellular proliferation. These insights could be key to understanding and addressing the role of the PADI2 c-MYC axis in cancer progression. Significance StatementHere we use a systematic evolutionary analysis to identify positively selected residues in the non-catalytic domain of PADI2 and link the positive selection of key residues to a role in transcription. Specifically, a structurally exposed loop in the PADI2 middle domain encompasses the positively selected residue L162 which is linked to transcription and cellular proliferation. This loop contributes to PADI2 interaction with the P-TEFb complex and cellular proliferation. Our results showcase the utility of combining evolutionary and experimental approaches to dissect the evolution of essential functional processes.

evolutionary biology↗

bioRxiv2022

Pathophysiology of Dyt1 dystonia is mediated by spinal cord dysfunction

Dystonia, a neurological disorder defined by abnormal postures and disorganised movements, is considered to be a neural circuit disorder with dysfunction arising within and between multiple brain regions. Given that spinal circuits constitute the final pathway for motor control, we sought to determine their contribution to the movement disorder. Focusing on the most common inherited dystonia, DYT1-TOR1A, we confined a conditional knockout of Tor1a to the spinal cord and dorsal root ganglia (DRG) and found that these mice recapitulated the phenotype of the human condition, developing early onset generalised torsional dystonia. Physiologically, these mice bore the hallmark features of dystonia: spontaneous contractions at rest, excessive sustained contractions during voluntary movements including co-contractions of motor antagonists, and altered sensory-motor reflexes. Furthermore, spinal locomotor circuits were impaired. Together, these data challenge current understanding of dystonia, and lead to broader insights into spinal cord function and movement disorder pathophysiology.

neuroscience↗

bioRxiv2022

In vitro longitudinal lumbar spinal cord preparations to study sensory and recurrent motor microcircuits of juvenile mice

In vitro spinal cord preparations have been extensively used to study microcircuits involved in the control of movement. By allowing precise control of experimental conditions coupled with state-of-the-art genetics, imaging and electrophysiological techniques, isolated spinal cords from mice have been an essential tool in detailing the identity, connectivity and function of spinal networks. The majority of the research has arisen from in vitro spinal cords of neonatal mice, which are still undergoing important postnatal maturation. Studies from adults have been attempted in transverse slices, however, these have been quite challenging due to the poor motoneuron accessibility and viability, as well as to the extensive damage to the motoneuron dendritic trees. In this work, we describe two types of coronal spinal cord preparations with either the ventral or the dorsal horn ablated, obtained from mice of different postnatal ages, spanning from pre-weaned to one month old. These semiintact preparations allow recordings of sensory-afferent and motor-efferent responses from lumbar motoneurons using whole cell patch-clamp electrophysiology. We provide details of the slicing procedure and discuss the feasibility of whole-cell recordings. The in vitro dorsal and ventral horn-ablated spinal cord preparations described here are an useful tool to study spinal motor circuits in young mice that have reached the adult stages of locomotor development. New & NoteworthyIn the past 20 years, most of the research into the mammalian spinal circuitry has been limited to in vitro preparations from embryonic and neonatal mice. We describe two in vitro longitudinal lumbar spinal cord preparations from juvenile mice, that allow the study of motoneuron properties and respective afferent or efferent spinal circuits through whole-cell patch-clamp. These preparations will be useful to those interested in the study of microcircuits at mature stages of motor development.

neuroscience↗

bioRxiv2022

Particle flow modulates growth dynamics and nanoscale-arrested growth of transcription factor condensates in living cells

Liquid-liquid phase separation (LLPS) is emerging as key physical principle for biological organization inside living cells, forming condensates that play important roles in the regulation of multiple functions. Inside living nuclei, transcription factor (TF) condensates regulate transcriptional initiation and amplify transcriptional output of expressed genes. Yet, the biophysical parameters controlling TF condensation are still poorly understood. Here we applied a battery of single molecule imaging tools, theory and simulations to investigate the physical properties of TF condensates of the Progesterone Receptor (PR) in vivo. Analysis of individual PR trajectories at different ligand concentrations showed marked signatures of a ligand-tunable and regulated LLPS process. Using a machine learning architecture, we uncovered that diffusion within condensates follows fractional Brownian motion, reflecting viscoelastic interactions between PR and chromatin within condensates. High density single molecule localization maps further revealed that condensate growth dynamics is dominated by Brownian motion coalescence (BMC) at shorter times, but deviate at longer timescales reaching a growth plateau with nanoscale condensate sizes. To understand our observations we developed an extension of the BMC model by including stochastic unbinding of particles within condensates. The model reproduced the BMC behavior together with finite condensate sizes a steady-state, fully recapitulating our experimental data. Our results are thus consistent with droplet growth dynamics being regulated by the escaping probability of TFs molecules from condensates. The interplay between condensation assembly and molecular escaping maintains an optimum physical condensate size. Such phenomena must have implications for the biophysical regulation of other TF condensates and could also operate in multiple biological scenarios.

biophysics↗

bioRxiv2021

Spinal neurons innervating multiple local and distant motor pools

Motor neurons control muscle contractions, and their recruitment by premotor circuits is tuned to produce accurate motor behaviours. To understand how these circuits coordinate movement across and between joints, it is necessary to understand whether spinal neurons pre-synaptic to motor pools, project to more than one motor neuron population. Here, we used modified rabies virus tracing in mice to investigate premotor INs projecting to synergist flexor or extensor motor neurons, as well as those projecting to antagonist pairs of muscles controlling the ankle joint. We show that similar proportions of premotor neurons diverge to agonist and antagonist motor pools. Divergent premotor neurons were seen throughout the spinal cord, with decreasing numbers but increasing proportion with distance from the hindlimb enlargement. In the cervical cord, divergent long descending propriospinal neurons were found in contralateral lamina VIII, had large somata, were excitatory, projected to both lumbar and cervical motoneurons, and were at least in part of the V0 class. We conclude that distributed spinal premotor neurons coordinate activity across multiple motor pools and that there are spinal neurons mediating co-contraction of antagonist muscles.

neuroscience↗

bioRxiv2021

On the distribution of spinal premotor interneurons

Elaborate behaviours are produced by tightly controlled flexor-extensor motor neuron activation patterns. Motor neurons are regulated by a network of interneurons within the spinal cord, but the computational processes involved in motor control are not fully understood. The neuroanatomical arrangement of motor and premotor neurons into topographic patterns related to their controlled muscles is thought to facilitate how information is processed by spinal circuits. Rabies retrograde monosynaptic tracing has been used to label premotor interneurons innervating specific motor neuron pools, with previous studies reporting topographic mediolateral positional biases in flexor and extensor premotor interneurons. To more precisely define how premotor interneurons contacting specific motor pools are organized we used multiple complementary viral-tracing approaches to minimize systematic biases associated with each method. Contrary to expectations, we found that premotor interneurons contacting motor pools controlling flexion and extension of the ankle are highly intermingled rather than segregated into specific domains like motor neurons. Thus, premotor spinal neurons controlling different muscles process motor instructions in the absence of clear spatial patterns among the flexor-extensor circuit components. The paper can be downloaded in executable format as a MATLAB live script from https://github.com/marcobeato/Spinal_premotor_interneurons_controlling_antagonistic_muscles_are_spatially_intermingled, where all the data are available An R version of the executable paper is available at https://mybinder.org/v2/gh/rronzano/Spinal_premotor_interneurons_controlling_antagonistic_muscles_are_spatially_intermingled.git/HEAD?urlpath=rstudio

neuroscience↗

bioRxiv2020

Signalling Network of Breast Cancer Cells in Response to Progesterone

Breast cancer cells enter into the cell cycle following progestin exposure by the activation of signalling cascades involving a plethora of enzymes, transcription factors and co-factors that transmit the external signal from the cell membrane to chromatin, ultimately leading to a change of the gene expression program. Although many of the events within the signalling network have been described in isolation, how they globally team up to generate the final cell response is unclear. In this study we use antibody microarrays and phosphoproteomics to provide a dynamic global signalling map that reveals new key regulated proteins and links between previously known and novel pathways. Detailed analysis of the data revealed intriguing changes in protein complexes involved in nuclear structure, EMT, cell adhesion, as well as transcription factors previously not associated with breast cancer proliferation. As different post-translational modifications can mediate complex crosstalk mechanisms and massive PARylation is also rapidly induced by progestins, we provide details of important chromatin regulatory complexes containing both phosphorylated and PARylated proteins. This study contributes an important resource for the scientific community, as it identifies novel players and connections meaningful for breast cancer cell biology and potentially relevant for cancer management. (197 w)

molecular biology↗

bioRxiv2020

Phase separation of tunable biomolecular condensates predicted by an interacting particle model

Phase separation is emerging as key principle in the spatiotemporal organization of living cells. Given its relevance in the regulation of numerous biological functions, including gene transcription and chromatin architecture, modeling biomolecular condensation is gaining interest. Yet, most models developed so far rely on specific descriptions and/or experimentally inaccessible properties. Here we propose a theoretical model, where phase separation is explained by means of interaction probabilities between particles. With minimum model requirements, particle condensates emerge above a critical interaction probability. We tested the model predictions with single molecule experiments of tunable transcription factor condensates in the nucleus of living cells. Phase separation, condensate sizes, diffusion behavior, and mobility parameters, quantified by data analysis and machine learning, are fully recapitulated by our model. Our combined theoretical and experimental approach provides a general framework to investigate the biophysical parameters controlling phase separation in living cells and in other soft matter-based interacting systems.

biophysics↗