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Li, E.

Publications and source records attributed to Li, E..

At least 55 records · Page 3Linked to original sources
bioRxiv2024

Transcriptomic Profiling of Thyroid Eye Disease Orbital Fat Demonstrates Differences in Adipogenicity and IGF-1R Pathway

Despite recent advances in the treatment of thyroid eye disease (TED), significant gaps remain in our understanding of the underlying molecular mechanisms, particularly concerning the insulin-like growth factor-1 receptor (IGF-1R) pathway. To dissect the pathophysiology of TED, we utilized single nucleus RNA-Seq to analyze orbital fat specimens from both TED patients and matched controls. The analysis demonstrated a marked increase in the proportion of fibroblasts transitioning to adipogenesis in the orbital fat of TED patients compared to controls. This was associated with diverse alterations in immune cell composition. Significant alterations in the IGF-1R signaling pathway were noted between TED specimens and controls, indicating a potential pathological mechanism driven by IGF-1R signaling abnormalities. Additionally, our data show that linsitinib, a small molecule inhibitor of IGF-1R, effectively reduces adipogenesis in TED orbital fibroblasts in vitro, suggesting its potential utility as a therapeutic agent. Our findings reveal that beyond immune dysfunction, abnormal IGF-1R signaling leading to enhanced adipogenesis is a crucial pathogenic mechanism in TED.

cell biology↗
bioRxiv2024

A Novel Magnetic Field Device: Effects of Magnetic Fields on Planktonic Yeasts and Fungal Mats

Microorganisms evolved within the geomagnetic field and can be affected by magnetic field exposure. However, the mechanisms underlying many magnetic phenomena in microbes remain to be elucidated. We develop a 3D-printed magnetic field exposure device to perform experiments on microbes. This device is designed in AutoCAD, modeled in COMSOL, and validated using a Gaussmeter. Using the magnetic field exposure device, we perform static magnetic field experiments on different strains of the budding yeast Saccharomyces cerevisiae. We find that static magnetic field exposure slows the spatially-structured expansion of yeast mats that expands in two dimensions, but not yeast mats that expand in three dimensions, across the surface of semi-solid media. We also find that magnetic fields do not affect the growth of yeast cells in well-mixed liquid media. This study provides a novel device for magnetic field exposure experiments on microorganisms and advances our understanding of the effects of magnetic fields on fungi. Why it mattersMicroorganisms have evolved to function, survive, and reproduce in Earths magnetic field. However, the mechanisms underlying magnetic phenomena in microorganisms are unknown. This is especially true for fungi, which are important microorganisms for microbiological research, industrial application, and infectious disease. To elucidate mechanisms driving magnetic phenomena, we need devices to perform controlled experiments in a variety of conditions. We develop a 3D-printed magnetic field exposure device using computer-aided design, physics modeling software, and a magnetometer. Using this novel magnetic field device, we discover that magnetic fields can slow the growth of yeast on agar plates, but that magnetic fields do not affect the growth of yeast in liquid media.

biophysics↗
bioRxiv2024

Toxin-glycolipid interactions measured by imaging surface plasmon resonance on artificial membranes predicts diffusion behavior and lipid dependence of binding to cells

Membrane-protein interactions mediate cellular invasion by toxins, and are thought to involve organized plasma membrane lipid domains, often containing glycolipids, other sphingolipids, and/or cholesterol. Here, we characterize an isolated glycolipid-interacting domain of the tetanus toxin heavy chain (Hc) as a fluorescently labelled peptide, TeNT46, and describe its membrane dynamics and binding characteristics on artificial bilayers and cellular membranes. We show that this novel ganglioside-interacting probe TeNT46 retains the glycolipid binding preferences of the parent toxin, using imaging-SPR (iSPR) on a micro-patterned hybrid bilayer surface. On live cell membranes, using fluorescence correlation spectroscopic (FCS) diffusion measurements to compare TeNT46 to the well-studied GM1-binding toxin CTxB, we find that both probes display ordered domain-binding characteristics, but distinct cholesterol and sphingolipid dependencies. Strikingly, the contrasting lipid requirements of TeNT46 from those of CTxB in cells are predicted by their iSPR binding preferences on hybrid synthetic membranes. Based on the combined findings from iSPR and FCS, we propose a model for toxin-membrane interaction whereby a unique lipid constellation determines optimum binding for each probe independently of lateral confinement, which is more generally imposed by cholesterol. Our resulting understanding of the specific lipid requirements of these toxin targets and their dynamics in cell membranes could be important for the future design of preventive membrane-based nano-decoys and cell-delivery tools.

cell biology↗
bioRxiv2024

The Ubiquitin Ligase RBX2/SAG Regulates Mitochondrial Ubiquitination and Mitophagy

Clearance of damaged mitochondria via mitophagy is crucial for cellular homeostasis. While the role of ubiquitin (Ub) ligase PARKIN in mitophagy has been extensively studied, increasing evidence suggests the existence of PARKIN-independent mitophagy in highly metabolically active organs such as the heart. Here, we identify a crucial role for Cullin-RING Ub ligase 5 (CRL5) in basal mitochondrial turnover in cardiomyocytes. CRL5 is a multi-subunit Ub ligase comprised by the catalytic RING box protein RBX2 (also known as SAG), scaffold protein Cullin 5 (CUL5), and a substrate-recognizing receptor. Analysis of the mitochondrial outer membrane-interacting proteome uncovered a robust association of CRLs with mitochondria. Subcellular fractionation, immunostaining, and immunogold electron microscopy established that RBX2 and Cul5, two core components of CRL5, localizes to mitochondria. Depletion of RBX2 inhibited mitochondrial ubiquitination and turnover, impaired mitochondrial membrane potential and respiration, and increased cell death in cardiomyocytes. In vivo, deletion of the Rbx2 gene in adult mouse hearts suppressed mitophagic activity, provoked accumulation of damaged mitochondria in the myocardium, and disrupted myocardial metabolism, leading to rapid development of dilated cardiomyopathy and heart failure. Similarly, ablation of RBX2 in the developing heart resulted in dilated cardiomyopathy and heart failure. Notably, the action of RBX2 in mitochondria is not dependent on PARKIN, and PARKIN gene deletion had no impact on the onset and progression of cardiomyopathy in RBX2-deficient hearts. Furthermore, RBX2 controls the stability of PINK1 in mitochondria. Proteomics and biochemical analyses further revealed a global impact of RBX2 deficiency on the mitochondrial proteome and identified several mitochondrial proteins as its putative substrates. These findings identify RBX2-CRL5 as a mitochondrial Ub ligase that controls mitophagy under physiological conditions in a PARKIN-independent, PINK1-dependent manner, thereby regulating cardiac homeostasis.

pathology↗
bioRxiv2024

Cellular heterogeneity in the developing forebrain masks transcriptional outcomes and principles of Evf2 enhancer lncRNA-Dlx5/6UCE-gene guidance

During mouse embryonic brain development, the Evf2 ultraconserved enhancer (UCE) lncRNA guides the Dlx5/6UCE to [~]129 sites across chr6. However, previous work identified only 4 transcriptionally regulated targets associated with Evf2-Dlx5/6UCE enhancer-gene guided sites (EGGs), raising questions about the significance of the majority of Evf2-EGGs. Here, single cell transcriptomics (scRNAseq) shows that Evf2-EGGs on chr6 coincide with subpopulation-specific Evf2 transcriptional targets, revealing far greater alignment between EGGs and transcriptional targets than previously reported. Surprisingly, subpopulation-specific Evf2 regulated gene networks in embryonic progenitors predict adult synaptic and seizure defects. Evf2 regulation of EGGs to gene bodies (GB, Dlx5/6UCE locations within {+/-}5kb of the target gene) divides chr6 into short-range (<10Mb distant), highly activated genes, and long/super-long-range (10-129Mb), moderately repressed genes. Clustering of Evf2 transcriptionally regulated chr6 targets in populations where Evf2 is first activated supports that Evf2-EGG transcriptional effects can occur from EGG shifts as far as 3Mb, uncoupling enhancer shift distance and transcriptional direction from transcriptional outcome. Evf2 RNA binding sites (RBSs) divide chr6 into 4 major regions, consistent with a role for RBS chromosomal spacing in long-and super-long-range EGG selectivity. Surprisingly, 95% of 147 RBSs genome-wide potentially form inter-chromosomal DNA loops. Evf2-regulated combinatorial recruitment of Evf2-ribonucleoproteins at EGGs and RBSs, together with effects on homeodomain transcription factor DNA motif recognition, support a novel model of lncRNA directed multi-modal EGG selectivity during intra- and inter-chromosomal gene regulation.

molecular biology↗
bioRxiv2024

ESPressoscope: a small and powerful platform for in situ microscopy

Microscopy is essential for detecting, identifying, analyzing, and measuring small objects. Access to modern microscopy equipment is crucial for scientific research, especially in the biomedical and analytical sciences. However, the high cost of equipment, limited availability of parts, and challenges associated with transporting equipment often limit the accessibility and operational capabilities of these tools, particularly in field sites and other remote or resource-limited settings. Thus, there is a need for affordable and accessible alternatives to traditional microscopy systems. We address this challenge by investigating the feasibility of using a simple microcontroller board not only as a portable and field-ready digital microscope, but furthermore as a versatile platform which can easily be adapted to a variety of imaging applications. By adding a few external components, we demonstrate that a low-cost ESP32 camera board can be used to build an autonomous in situ platform for digital time-lapse imaging of cells. This platform, which we call the ESPressoscope, can be adapted to applications ranging from monitoring incubator cell cultures in the lab to observing ecological phenomena in the sea, and it can be adapted for other techniques such as microfluidics or spectrophotometry. The ESPressoscope achieves a low power consumption and small size, which makes it ideal for field research in environments and applications where microscopy was previously infeasible. Its Wi-Fi connectivity enables integration with external image processing and storage systems, including on cloud platforms when internet access is available. Finally, we present several web browser-based tools to help users operate and manage the ESPressoscopes software. Our findings demonstrate the potential for low-cost, portable microscopy solutions to enable new and more accessible experiments for biological and analytical applications.

microbiology↗
bioRxiv2023

dact1/2 modifies noncanonical Wnt signaling and calpain 8 expression to regulate convergent extension and craniofacial development

Wnt signaling plays crucial roles in embryonic patterning including the regulation of convergent extension during gastrulation, the establishment of the dorsal axis, and later, craniofacial morphogenesis. Further, Wnt signaling is a crucial regulator of craniofacial morphogenesis. The adapter proteins Dact1 and Dact2 modulate the Wnt signaling pathway through binding to Disheveled. However, the distinct relative functions of Dact1 and Dact2 during embryogenesis remain unclear. We found that dact1 and dact2 genes have dynamic spatiotemporal expression domains that are reciprocal to one another suggesting distinct functions during zebrafish embryogenesis. Both dact1 and dact2 contribute to axis extension, with compound mutants exhibiting a similar convergent extension defect and craniofacial phenotype to the wnt11f2 mutant. Utilizing single-cell RNAseq and an established noncanonical Wnt pathway mutant with a shortened axis (gpc4), we identified dact1/2 specific roles during early development. Comparative whole transcriptome analysis between wildtype and gpc4 and wildtype and dact1/2 compound mutants revealed a novel role for dact1/2 in regulating the mRNA expression of the classical calpain capn8. Over-expression of capn8 phenocopies dact1/2 craniofacial dysmorphology. These results identify a previously unappreciated role of capn8 and calcium-dependent proteolysis during embryogenesis. Taken together, our findings highlight the distinct and overlapping roles of dact1 and dact2 in embryonic craniofacial development, providing new insights into the multifaceted regulation of Wnt signaling.

developmental biology↗
bioRxiv2023

Open resource of bacterial biofilm for the prediction of biofilm-associated proteins

SummaryBacterial biofilms are organized heterogeneous assemblages of microbial cells encased within a self-produced matrix of exopolysaccharides, extracellular DNA and proteins. Over the last decade, more and more biofilm-associated proteins have been discovered and investigated. Furthermore, omics techniques such as transcriptomes, proteomes also play important roles in identifying new biofilm-associated genes or proteins. However, those important data have been uploaded separately to various databases, which creates obstacles for biofilm researchers to have a comprehensive access to these data. In this work, we constructed BBSdb, a state-of-the-art open resource of bacterial biofilm-associated protein. It includes 48 different bacteria species, 105 transcriptome datasets, 21 proteome datasets, 1205 experimental samples, 57,823 differentially expressed genes (DEGs), 13,605 differentially expressed proteins (DEPs), 1,930 Top 5% differentially expressed genes and a predictor for prediction of biofilm-associated protein. In addition, 1,781 biofilm-associated proteins, including annotation and sequences, were extracted from 942 articles and public databases via text-mining analysis. We used E. coli as an example to represent how to explore potential biofilm-associated proteins in bacteria. We believe that this study will be of broad interest to researchers in field of bacteria, especially biofilms, which are involved in bacterial growth, pathogenicity, and drug resistance. Availability and implementationThe BBSdb is freely available at http://124.222.145.44/#!/.

bioinformatics↗
bioRxiv2023

In situ cryoET reveals inhibitor-induced perturbations in Pf80S GTPase interactions

Malaria parasites rely heavily on rapid, high fidelity protein synthesis to infect and replicate in human erythrocytes, making translation an attractive target for new antimalarials. Here, we have determined in situ structures of Pf80S ribosomes in thirteen conformational and compositional states from cryoFIB-milled Plasmodium falciparum-infected human erythrocytes across the stages of asexual intraerythrocytic parasite replication. We observe eight active translation intermediates, enabling us to define the native malarial translation elongation cycle, which surprisingly features a bifurcation at the decoding stage of the cycle that has not previously been described. Examination of perturbations in the distribution of ribosomes among these states in the presence of a malaria-specific translation inhibitor suggests that the inhibitor impedes PfeEF2 and PfeEF1 interactions with the ribosome. We integrated our in situ cryoET data with proteomic and ultrastructural data to arrive at a deeper understanding of malarial translation, which will inform development of new therapies.

biophysics↗
bioRxiv2023

Activity-Induced MeCP2 Phosphorylation Regulates Retinogeniculate Synapse Refinement

Mutations in MECP2 give rise to Rett syndrome (RTT), an X-linked neurodevelopmental disorder that results in broad cognitive impairments in females. While the exact etiology of RTT symptoms remains unknown, one possible explanation for its clinical presentation is that loss of MeCP2 causes miswiring of neural circuits due to defects in the brains capacity to respond to changes in neuronal activity and sensory experience. Here we show that MeCP2 is phosphorylated at four residues in the brain (S86, S274, T308, and S421) in response to neuronal activity, and we generate a quadruple knock-in (QKI) mouse line in which all four activity-dependent sites are mutated to alanines to prevent phosphorylation. QKI mice do not display overt RTT phenotypes or detectable gene expression changes in two brain regions. However, electrophysiological recordings from the retinogeniculate synapse of QKI mice reveal that while synapse elimination is initially normal at P14, it is significantly compromised at P20. Notably, this phenotype is distinct from that previously reported for Mecp2 null mice, where synapses initially refine but then regress after the third postnatal week. We thus propose a model in which activity-induced phosphorylation of MeCP2 is critical for the proper timing of retinogeniculate synapse maturation specifically during the early postnatal period. SIGNIFICANCE STATEMENTRett syndrome (RTT) is an X-linked neurodevelopmental disorder that predominantly affects girls. RTT is caused by loss of function mutations in a single gene MeCP2. Girls with RTT develop normally during their first year of life, but then experience neurological abnormalities including breathing and movement difficulties, loss of speech, and seizures. This study investigates the function of the MeCP2 protein in the brain, and how MeCP2 activity is modulated by sensory experience in early life. Evidence is presented that sensory experience affects MeCP2 function, and that this is required for synaptic pruning in the brain. These findings provide insight into MeCP2 function, and clues as to what goes awry in the brain when the function of MeCP2 is disrupted.

neuroscience↗
bioRxiv2023

Engineering ligand stabilized aquaporin reporters for magnetic resonance imaging

Imaging transgene expression in live tissues requires reporters that are detectable with deeply penetrant modalities, such as magnetic resonance imaging (MRI). Here, we show that LSAqp1, a water channel engineered from aquaporin-1, can be used to create background-free, drug-gated, and multiplex images of gene expression using MRI. LSAqp1 is a fusion protein composed of aquaporin-1 and a degradation tag that is sensitive to a cell-permeable ligand, which allows for dynamic small molecule modulation of MRI signals. LSAqp1 improves specificity for imaging gene expression by allowing reporter signals to be conditionally activated and distinguished from the tissue background by difference imaging. In addition, by engineering destabilized aquaporin-1 variants with different ligand requirements, it is possible to image distinct cell types simultaneously. Finally, we expressed LSAqp1 in a tumor model and showed successful in vivo imaging of gene expression without background activity. LSAqp1 provides a conceptually unique approach to accurately measure gene expression in living organisms by combining the physics of water diffusion and biotechnology tools to control protein stability.

bioengineering↗
bioRxiv2023

Projectome-defined subtypes and modular intra-hypothalamic subnetworks of peptidergic neurons

The hypothalamus plays a vital role in coordinating essential neuroendocrine, autonomic, and somatomotor responses for survival and reproduction. While previous studies have explored population-level projections of hypothalamic neurons, the specific innervation patterns of individual hypothalamic axons remain unclear. To understand the organization of hypothalamic axon projections, we conducted a comprehensive reconstruction of single-cell projectomes from 7,180 mouse hypothalamic neurons expressing specific neuropeptides. Our analysis identified 31 distinct subtypes based on projectome-defined characteristics, with many exhibiting long-range axon collateral projections to multiple brain regions. Notably, these subtypes selectively targeted specific subdomains within downstream areas, either unilaterally or bilaterally. Furthermore, we observed that individual peptidergic neuronal types encompassed multiple projectome-defined subtypes, explaining their diverse functional roles. Additionally, by examining intra-hypothalamic axon projections, we uncovered six modular subnetworks characterized by enriched intramodular connections and distinct preferences for downstream targets. This modular organization of the intra-hypothalamic network likely contributes to the coordinated organization of hypothalamic outputs. In summary, our comprehensive projectome analysis reveals the organizational principles governing hypothalamic axon projections, providing a framework for understanding the neural circuit mechanisms underlying the diverse and coordinated functions of the hypothalamus.

neuroscience↗
bioRxiv2023

De novo distillation of thermodynamic affinity from deep learning regulatory sequence models of in vivo protein-DNA binding

Transcription factors (TF) are proteins that bind DNA in a sequence-specific manner to regulate gene transcription. Despite their unique intrinsic sequence preferences, in vivo genomic occupancy profiles of TFs differ across cellular contexts. Hence, deciphering the sequence determinants of TF binding, both intrinsic and context-specific, is essential to understand gene regulation and the impact of regulatory, non-coding genetic variation. Biophysical models trained on in vitro TF binding assays can estimate intrinsic affinity landscapes and predict occupancy based on TF concentration and affinity. However, these models cannot adequately explain context-specific, in vivo binding profiles. Conversely, deep learning models, trained on in vivo TF binding assays, effectively predict and explain genomic occupancy profiles as a function of complex regulatory sequence syntax, albeit without a clear biophysical interpretation. To reconcile these complementary models of in vitro and in vivo TF binding, we developed Affinity Distillation (AD), a method that extracts thermodynamic affinities de-novo from deep learning models of TF chromatin immunoprecipitation (ChIP) experiments by marginalizing away the influence of genomic sequence context. Applied to neural networks modeling diverse classes of yeast and mammalian TFs, AD predicts energetic impacts of sequence variation within and surrounding motifs on TF binding as measured by diverse in vitro assays with superior dynamic range and accuracy compared to motif-based methods. Furthermore, AD can accurately discern affinities of TF paralogs. Our results highlight thermodynamic affinity as a key determinant of in vivo binding, suggest that deep learning models of in vivo binding implicitly learn high-resolution affinity landscapes, and show that these affinities can be successfully distilled using AD. This new biophysical interpretation of deep learning models enables high-throughput in silico experiments to explore the influence of sequence context and variation on both intrinsic affinity and in vivo occupancy.

genomics↗
bioRxiv2023

CRISPRi-based screens in iAssembloids to elucidate neuron-glia interactions

The sheer complexity of the brain has complicated our ability to understand the cellular and molecular mechanisms underlying its function in health and disease. Genome-wide association studies have uncovered genetic variants associated with specific neurological phenotypes and diseases. In addition, single-cell transcriptomics have provided molecular descriptions of specific brain cell types and the changes they undergo during disease. Although these approaches provide a giant leap forward towards understanding how genetic variation can lead to functional changes in the brain, they do not establish molecular mechanisms. To address this need, we developed a 3D co-culture system termed iAssembloids (induced multi-lineage assembloids) that enables the rapid generation of homogenous neuron-glia spheroids. We characterize these iAssembloids with immunohistochemistry and single-cell transcriptomics and combine them with large-scale CRISPRi-based screens. In our first application, we ask how glial and neuronal cells interact to control neuronal death and survival. Our CRISPRi-based screens identified that GSK3{beta} inhibits the protective NRF2-mediated oxidative stress response in the presence of reactive oxygen species elicited by high neuronal activity, which was not previously found in 2D monoculture neuron screens. We also apply the platform to investigate the role of APOE- 4, a risk variant for Alzheimers Disease, in its effect on neuronal survival. We find that APOE- 4-expressing astrocytes may promote more neuronal activity as compared to APOE- 3- expressing astrocytes. This platform expands the toolbox for the unbiased identification of mechanisms of cell-cell interactions in brain health and disease.

neuroscience↗
bioRxiv2023

Blind Assessment of Monomeric AlphaFold2 Protein Structure Models with Experimental NMR Data

Recent advances in molecular modeling of protein structures are changing the field of structural biology. AlphaFold-2 (AF2), an AI system developed by DeepMind, Inc., utilizes attention-based deep learning to predict models of protein structures with high accuracy relative to structures determined by X-ray crystallography and cryo-electron microscopy (cryoEM). Comparing AF2 models to structures determined using solution NMR data, both high similarities and distinct differences have been observed. Since AF2 was trained on X-ray crystal and cryoEM structures, we assessed how accurately AF2 can model small, monomeric, solution protein NMR structures which (i) were not used in the AF2 training data set, and (ii) did not have homologous structures in the Protein Data Bank at the time of AF2 training. We identified nine open source protein NMR data sets for such "blind" targets, including chemical shift, raw NMR FID data, NOESY peak lists, and (for 1 case) 15N-1H residual dipolar coupling data. For these nine small (70 - 108 residues) monomeric proteins, we generated AF2 prediction models and assessed how well these models fit to these experimental NMR data, using several well-established NMR structure validation tools. In most of these cases, the AF2 models fit the NMR data nearly as well, or sometimes better than, the corresponding NMR structure models previously deposited in the Protein Data Bank. These results provide benchmark NMR data for assessing new NMR data analysis and protein structure prediction methods. They also document the potential for using AF2 as a guiding tool in protein NMR data analysis, and more generally for hypothesis generation in structural biology research. HighlightsO_LIAF2 models assessed against NMR data for 9 monomeric proteins not used in training. C_LIO_LIAF2 models fit NMR data almost as well as the experimentally-determined structures. C_LIO_LIRPF-DP, PSVS, and PDBStat software provide structure quality and RDC assessment. C_LIO_LIRPF-DP analysis using AF2 models suggests multiple conformational states. C_LI O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=63 SRC="FIGDIR/small/525096v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@be0a41org.highwire.dtl.DTLVardef@9336e9org.highwire.dtl.DTLVardef@fa1d24org.highwire.dtl.DTLVardef@8f4efe_HPS_FORMAT_FIGEXP M_FIG C_FIG

bioinformatics↗
bioRxiv2022

Extracellular disintegration of viral proteins as an innovative strategy for developing broad-spectrum antivirals against coronavirus

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has claimed millions of lives worldwide, not to mention innumerable losses in the global economy and disruptions in social relationships. Unfortunately, state-of-the-art treatments still lag behind the fast emergence of new variants of concern. The key to resolve this issue is to develop broad-spectrum antivirals with innovative antiviral mechanisms in which coronaviruses are deactivated regardless of their variant development. Herein, we report a new antiviral strategy involving extracellular disintegration of viral proteins that are indispensable for viral infection with hyperanion-grafted enediyne molecules. The sulfate groups ensure low cellular permeability and rather low cytotoxicity of the molecules, while the core enediyne generates reactive radical species and causes significant damage to the spike (S) protein of coronavirus. The enediyne compounds exhibit antiviral activity at micromolar to nanomolar concentrations, and the selectivity index of up to 20,000 against four kinds of human coronaviruses, including the SARS-CoV-2 omicron variant, suggesting the high potential of this new strategy in combating the COVID-19 pandemic.

biochemistry↗
bioRxiv2022

Control of lipolysis by a population of oxytocinergic sympathetic neurons

Oxytocin (OXT), a nine amino acid peptide produced in the hypothalamus and released by the posterior pituitary, has well-known actions in parturition, lactation, and social behavior1, and has become an intriguing therapeutic target for diseases like autism and schizophrenia2. Exogenous OXT has also been shown to promote weight loss, among other beneficial metabolic effects1,3, suggesting that its therapeutic potential may extend to diabetes and obesity1,4. It is unclear, however, whether endogenous OXT participates in metabolic homeostasis. Here we show that OXT is a critical regulator of adipose tissue lipolysis in both mice and humans. In addition, OXT serves to license the ability of {beta}- adrenergic agonists to fully promote lipolysis. Most surprisingly, the relevant source of OXT in these metabolic actions is a previously unidentified subpopulation of tyrosine hydroxylase (TH)-positive sympathetic neurons. Our data reveal that OXT from the peripheral nervous system is an endogenous regulator of adipose and systemic metabolism.

physiology↗