Biology subjects

Hu, L.

Publications and source records attributed to Hu, L..

At least 73 records · Page 4Linked to original sources

bioRxiv2024

Risk assessment of zoonotic viruses in urban-adapted wildlife

The repeated emergence of pandemic viruses underscores the linkages between land-use change and wildlife disease, and urban-adapted wildlife are of special interest due to their close proximity to humans. However, viral diversity within urban-adapted species and their zoonotic potential remains largely unexplored. We compiled a large dataset on seven priority urban-adapted mammal species and their viruses covering over 115 countries from 1574 to 2023. These urban-adapted species host 286 virus species spanning 24 orders and 38 families, 14 of which are potentially high risk for human infection. Raccoons carried the most high-risk viruses, while raccoon dogs had increased viral positivity in urban habitats compared to raccoons, wild boars, and red foxes. Many viruses in urban-adapted species were phylogenetically related to those found in humans, and we also observed evidence of possible viral spillback. These results highlight zoonotic risks associated with urban-adapted species and suggest enhanced surveillance to mitigate future outbreaks.

ecology↗

bioRxiv2024

A novel and robust method for assessing mitochondrial (dys)function in healthy and diseased frozen cardiac tissue

Cardiovascular diseases are often associated with impairment in mitochondrial function detected by reduced mitochondrial oxygen consumption using high-resolution respirometry. However, existing respirometry protocols are limited by the necessity for fresh tissue samples. This study developed a method with tailored substrate-inhibitor titration (TSIT) of mitochondrial electron transport complexes (ETC) to measure mitochondrial function in frozen cardiac samples using high-resolution respirometry. Briefly, acetyl-CoA was added to fuel the tricarboxylic acid (TCA) cycle for NADH production, enabling complex I (CI)-linked respiratory assessment. NADH was then added to measure maximum CI-linked respiratory capacity, followed by rotenone and succinate to assess complex II (CII)-linked respiratory capacity. TSIT detected mitochondrial functional differences between frozen atrial and ventricular tissue, with comparable results as measured in fresh samples. It also detected cardiac mitochondrial dysfunction across various (patho)physiological mouse models (including aging, ischemia reperfusion, obesity, and CI deficiency) as well as in frozen human donor samples, highlighting its clinical potential. Furthermore, we showed the first evidence for supercomplexes (SCs) formation between ETC-SCs and the TCA cycle metabolon, underpinning TSIT feasibility. In conclusion, we established a novel, robust, sensitive and translational method (TSIT) for assessing mitochondrial (dys)function in frozen cardiac samples from various species, enabling flexible analysis of mitochondrial function in both laboratory and clinical settings.

physiology↗

bioRxiv2024

Unveiling the diversity, transmission, and zoonotic potential of microbes in true insectivores

The Eulipotyphla (true insectivores) is the third largest mammalian order, comprising over 500 species, and could be an important source of human infectious diseases. However, relatively little is known about the diversity of microbes in insectivores and the contribution of insectivores to virus transmission more specifically among wild hosts. In this study, we compiled a comprehensive dataset containing over 400,000 records of insectivores and their associated microbes from 1903 to 2023. Our analyses showed that insectivores host a wide spectrum of 941 microbes, 60% of which are viruses and are predominantly found in the shrew and hedgehog families. Notably, human-associated viruses harbored by shrews and hedgehogs were phylogenetically closely related to those found in humans, suggesting potential bidirectional transmission between insectivores and humans. Moreover, virus-sharing networks revealed that insectivores held the second-most central position for virus sharing, just second to bats, among all mammalian orders. Insectivores had a high proportion of cross-order transmitted viruses, including many human-associated viruses. Dietary diversity, habitat diversity, and distributional traits (e.g. geographical range size, mean latitude, and urban adaptation status) emerged as the key ecological factors contributing to this cross-species virus transmission. Our findings highlight the microbial diversity present in insectivores, indicating this order may act as potential incubators for novel viruses capable of infecting mammals and spreading viruses of public health concern.

ecology↗

bioRxiv2024

BioLLM: A Standardized Framework for Integrating and Benchmarking Single-Cell Foundation Models

The application and evaluation of single cell foundational models (scFMs) present significant challenges stemming from the heterogeneity of architectural frameworks and coding standards. To address these issues, we introduce BioLLM, a framework facilitating the integration and application of scFMs in single-cell RNA sequencing data analysis. BioLLM provides a universal interface, bridging diverse scFMs into a seamless ecosystem. By mitigating architectural disparities and coding conventions, it empowers researchers with streamlined access to scFMs. With standardized APIs and comprehensive documentation, BioLLM streamlines model switching and comparative analyses, while incorporating best practices for consistent model evaluation. Our comprehensive evaluation of scFMs revealed distinct strengths and limitations, highlighting scGPTs robust performance across all tasks, both in zero-shot and fine-tuning scenarios. Geneformer and scFoundation also demonstrated strong capabilities in gene-level tasks, benefiting from effective pretraining strategies. In contrast, scBERT underperformed relative to other models, likely attributable to its considerably smaller parameter count and the limited size of the training dataset. Ultimately, BioLLM aims to empower the scientific community to leverage the full potential of foundational models, advancing our understanding of complex biological systems through enhanced single-cell analysis.

bioinformatics↗

bioRxiv2024

Geographic-specific Diversification of Vaginal Microbiota in China

The vaginal microbiota is pivotal to womens reproductive health, with significant geographic and ethnic heterogeneity suggesting evolutionary adaptations to environmental, climatic, and lifestyle factors. In this multi-centric study, we analyzed vaginal microbiome samples from women across five provinces in China, each characterized by distinct climatic, ethnic, and lifestyle traits. Our results indicate that the vaginal microbiota among Chinese women is characterized by low alpha diversity, with Lactobacillus crispatus being the dominant species in Community State Type (CST) I, especially in the northern regions. While most participants exhibited stable CSTs throughout their menstrual cycles, fluctuations were observed in some individuals. We also detected low-abundance bacterial species such as Fannyhesea vaginae and Sneathia vaginalis. Comparative genomic analysis of high-quality metagenome-assembled genomes of L. crispatus revealed minimal single nucleotide polymorphism (SNP) variations within individuals but substantial diversity between individuals, delineating a distinct separation between vaginal-associated populations (VAP) and gut-associated populations (GAP). These findings highlight the intricate dynamics of the vaginal microbiome, which are markedly influenced by geographic and individual determinants. This study offers an in-depth phylogenetic and genomic analysis of the vaginal microbiota among Chinese women, underscoring the imperative for further research into the impact of regional and individual variations on microbial community composition. Such knowledge could facilitate the development of personalized vaginal health management strategies that accommodate the unique microbiome profiles specific to different geographical regions. ImportanceThis study provides a groundbreaking analysis of the vaginal microbiota among Chinese women, offering insights into the population structure and evolutionary dynamics of this critical component of womens reproductive health. The research reveals that Lactobacillus crispatus, a key species in vaginal health, has a recent evolutionary emergence and exhibits significant geographic variation in prevalence, being more common in northern China. This discovery, along with the identification of distinct vaginal-associated and gut-associated populations, underscores the importance of understanding the vaginal microbiotas complexity. The findings have profound implications for developing personalized strategies to manage vaginal health, tailored to regional microbiome characteristics. This work not only advances our understanding of the vaginal microbiotas role in health and disease but also sets the stage for future research into the factors that shape microbial community structures across diverse populations.

microbiology↗

bioRxiv2024

Longitudinal profiling of B cells primed by mRNA vaccine and recalled by Omicron variants uncovers antibodies broadly neutralizing sarbecoviruses

A key question on ancestral SARS-CoV-2 immune imprinting is to what extent imprinted B cells can develop neutralizing breadth and potency in immune recalls. Here, we longitudinally tracked B cells recognizing wild-type spike in two individuals, who were sequentially infected by Omicron variants after receiving mRNA vaccines. Functional and genetic analysis of 632 monoclonal antibodies (mAbs) from those B cells reveals that mAbs cloned after second infection have dramatically enhanced neutralizing breadth and potency, which is attributed to recall and maturation of pre-existing memory B cells. Among the 11 mAbs that potently neutralize SARS-CoV-2 variants from wild-type to KP.3, 5 mAbs are classified into public clonotypes encoded by IGHV3-53 or IGHV3-66, whereas the rest belong to a rarely reported clonotype encoded by IGHV3-74. Notably, IGHV3-74 mAbs can also broadly neutralize other sarbecoviruses by targeting a novel epitope on receptor-binding domain of spike. These results support that ancestral SARS-CoV-2 immune imprinting can be harnessed in developing pan-SARS-CoV-2 and even pan-sarbecovirus vaccines. SummaryChen et al. demonstrate that B cells imprinted by ancestral SARS-CoV-2 have tremendous potential to develop neutralizing breadth and potency in repeated immune recalls driven by Omicron variants, implicating that ancestral SARS-CoV-2 immune imprinting can be harnessed in developing pan-SARS-CoV-2 and even pan-sarbecovirus vaccines.

immunology↗

bioRxiv2024

HEXIM1 is correlated with Alzheimer's disease pathology and regulates immediate early gene dynamics in neurons

Cognitive processes require de novo gene transcription in neurons. Memory requires the rapid and robust transcription of a class of genes called immediate early genes (IEGs). IEG transcription is facilitated by the formation of a poised basal state, in which RNA polymerase II (RNAP2) initiates transcription, but remains paused downstream of the promoter. Upon neuronal depolarization, the paused RNAP2 is released to complete the synthesis of messenger RNA (mRNA) transcripts, a process stimulated by positive transcription elongation factor b (P-TEFb). In many cell types, P-TEFb is sequestered into a large inactive complex containing Hexamethylene bisacetamide inducible 1 (HEXIM1), but the impact of this interaction on neuronal gene transcription is not yet fully understood. In this study, we found that neuronal expression levels of HEXIM1 mRNA are highly correlated with impaired cognition in Alzheimers disease. It is also induced in the hippocampus during memory formation, and following depolarization in neurons. The role of HEXIM1 in neuronal gene transcription was then explored in murine neuronal cultures where we found that calcium frees P-TEFb from the HEXIM1 inhibitory complex. Modulation of P-TEFb by inhibiting the activity of the cyclin-dependent kinase 9 (CDK9) subunit of this complex significantly impacts IEG induction, particularly during repeated depolarization. Our findings indicate that HEXIM1 in complex with P-TEFb plays an important role in establishing and resetting the poised RNAP2 state, enabling efficient activation of genes necessary for synaptic plasticity.

neuroscience↗

bioRxiv2024

CellClear: Enhancing Single-cell RNA Data Quality via Biologically-Informed Ambient RNA Correction

Ambient RNA, caused by the pool of mRNA molecules released from lysed or dead cells in samples, poses persistent challenges to single-cell RNA sequencing data analysis, and leads to potential problems such as inaccurate classification of cell types and downstream functional analyses. Here we propose CellClear to estimate and remove the ambient RNA expression programs in single-cell RNA sequencing data. CellClear demonstrates significant increase in the accuracy of ambient gene expression correction comparing with state-of-art methods, without distorting native information of individual cell types.

bioinformatics↗

bioRxiv2024

Intraperitoneal programming of tailored CAR macrophages via mRNA-LNP to boost cancer immunotherapy

Therapeutic strategies for peritoneal metastasis in solid tumors are urgently needed in the clinic. Programming chimeric antigen receptor macrophages (CAR-Ms) in situ offers opportunities for an unmet demand. However, potential intracellular domains (ICDs) for CAR design and their antitumor mechanisms for macrophage empowerment remain to be explored systematically. By developing a targeted mRNA-LNP delivery system for macrophages, we have investigated 36 CAR combinations to determine the impact of CAR-Ms on immune regulation in vitro and in vivo. In two solid tumor mouse models, intraperitoneal programming of CAR-Ms was shown to elicit robust adaptive immune activation and significantly synergize with PD-1/L1 therapy. Single-cell RNA sequencing (scRNA-seq) analysis revealed that CAR-Ms could reshape the immunosuppressive tumor microenvironment (TME) and boost the TCF1+PD-1+ progenitor- exhausted CD8+ T cells (Tpex) population. Meanwhile, we found that tailored CAR-M with CD3{zeta}/TLR4 ICDs could favorably maintain proinflammatory phenotype and simultaneously upregulate MHC I and PD-L1 expression by perturbing NF-{kappa}B pathways. Moreover, the synergism between macrophage PD-L1 knockdown and CAR-M therapy highlighted the need to block the PD-1/L1 axis in antigen cross-presentation. In short, we developed an mRNA-LNP delivery system for intraperitoneal programming of tailored CAR-Ms in vivo and broadened understanding of both regulatory and feedback mechanisms for CAR-M therapies against solid tumors.

bioengineering↗

bioRxiv2024

SSRI antidepressant citalopram reverses the Warburg effect to inhibit hepatocellular carcinoma by directly targeting GLUT1

Although there is growing appreciation for effective repurposing of selective serotonin reuptake inhibitors (SSRIs) for cancer therapy, particularly hepatocellular carcinoma (HCC), efforts are hampered by limited knowledge of their molecular targets and mechanism of action. Global inverse gene-expression profiling method, drug affinity responsive target stability assay, and in silico molecular docking analysis was performed to identify the targets of SSRIs. Murine subcutaneous, orthotopic models, and patient-derived xenograft were employed to explore the therapeutic effects and underlying mechanisms of SSRIs in HCC. The clinical relevance of SSRI use was verified with real world data. SSRIs exhibit significant anti-HCC effects independent of their known target serotonin reuptake transporter. The glucose transporter 1 (GLUT1) is identified as a new target of SSRIs. Citalopram binds to and antagonizes GLUT1, resulting in reduced glycolytic flux and ATP generation. Mutant GLUT1 in the binding site E380 of citalopram compromises the inhibitory effects of citalopram on the Warburg effect and tumor growth. In preclinical models, citalopram dampens the growth kinetics of GLUT1high liver tumors and displays a synergistic effect with anti-PD-1 therapy. Retrospective analysis of health records found that SSRIs use is associated with a lower risk of metastasis among HCC patients. Our study reveals an unprecedented role of SSRIs in cancer metabolism, and establishes a rationale for repurposing SSRIs as potential anticancer drugs for HCC.

cancer biology↗

bioRxiv2024

Calorie Restriction Induces Degeneration of Neurons with Mitochondrial DNA Depletion by Altering ER-Mitochondria Calcium Transfer

Mitochondrial DNA (mtDNA) mutations and/or depletion are implicated in epilepsy and many neurodegenerative diseases. However, systematic investigation into how mtDNA alterations relate to epilepsy and neural degeneration is needed. Here, we established a mouse model where in mtDNA depletion induced by Herpes Simplex Virus Type 1 (HSV-1) protein-UL12.5 in the brain led to an epileptic phenotype characterized by abnormal electroencephalography (EEG) patterns and increased neural excitability in hippocampus. We also found that UL12.5 mediated mtDNA depletion in neurons in vitro (rho-) causes epilepsy-like abnormal EEG. Caloric restriction (CR) is a strategy proven to reduce epileptic activity, however CR mimetic 2-deoxy-D-glucose (2-DG), induced degeneration in mtDNA depleted neurons. Mechanistically, mtDNA depletion increased mitochondria-endoplasmic reticulum (ER) contacts, facilitating CR-induced mitochondrial calcium overload. Rho- neurons did not show changes in mitochondrial motility or membrane potential. Our study revealed an unexpected axis of mtDNA depletion, ER-mitochondrial contacts, and calcium overload in the rho- neuron model. This is the first description of animal and neuronal models of mitochondrial epilepsy. Our findings with these models suggest that CR may not be a viable clinical intervention in patients with mtDNA depletion.

cell biology↗

bioRxiv2024

Multi-parametric thrombus profiling microfluidics detects intensified biomechanical thrombogenesis associated with hypertension and aging

Arterial thrombosis, which represents a critical complication of cardiovascular diseases, is a leading cause of death and disability worldwide with no effective bioassay for clinical prediction. As a symbolic feature of arterial thrombosis, severe stenosis in the blood vessel creates a high-shear, high-gradient flow environment that effectively facilitates platelet aggregation towards vessel occlusion even with platelet amplification loops inhibited. However, no approach is currently available to comprehensively characterize the size, composition and platelet activation status of thrombi forming under this biorheological condition. Here, we present a thrombus profiling assay that monitors the multi-dimensional attributes of thrombi forming in conditions mimicking the physiological scenario of arterial thrombosis. Using this platform, we demonstrate that different receptor-ligand interactions contribute distinctively to the composition and activation status of the thrombus. Our investigation into hypertensive and older individuals reveals intensified biomechanical thrombogenesis and multi-dimensional thrombus profile abnormalities, demonstrating a direct contribution of mechanobiology to arterial thrombosis and endorsing the diagnostic potential of the assay. Furthermore, we identify the hyperactivity of GPIb-integrin IIb{beta}3 mechanosensing axis as a molecular mechanism that contributes to hypertension-associated arterial thrombosis. By studying the interactions between anti-thrombotic inhibitors and hypertension, and the inter-individual variability in personal thrombus profiles, our work reveals a critical need for personalized anti-thrombotic drug selection that accommodates each patients pathological profile.

bioengineering↗

bioRxiv2024

A replicable and generalizable neuroimaging-based indicator of pain sensitivity across individuals

Developing neural indicators of pain sensitivity is crucial for revealing the neural basis of individual differences in pain and advancing individualized pain treatment. To identify reliable neural indicators of pain sensitivity, we leveraged six large and diverse functional magnetic resonance imaging (fMRI) datasets (total N=1046). We found replicable and generalizable correlations between nociceptive-evoked fMRI responses and pain sensitivity for laser heat, contact heat, and mechanical pains. These fMRI responses correlated more strongly with pain sensitivity than with tactile, auditory, and visual sensitivity. Moreover, we developed a machine learning model that accurately predicted not only pain sensitivity but also pain reduction from different interventions in healthy individuals. Notably, these findings were influenced considerably by sample sizes, requiring >200 for univariate correlation analysis and >150 for multivariate machine learning modelling. Altogether, we demonstrate the validity of decoding pain sensitivity from fMRI responses, thus facilitating interpretations of subjective pain reports and promoting more mechanistically informed investigation of pain physiology.

neuroscience↗

bioRxiv2024

The Role of ADGRA3 in Adipose Thermogenesis: A Potential Therapeutic Target for Obesity

The induction of adipose thermogenesis plays a critical role in maintaining body temperature and improving metabolic homeostasis to combat obesity. {beta}3-adrenoceptor ({beta}3-AR) is widely recognized as a canonical {beta}-adrenergic G protein-coupled receptor (GPCR) that plays a crucial role in mediating adipose thermogenesis in mice. Nonetheless, the limited expression of {beta}3-AR in human adipocytes restricts its clinical application. The objective of this study was to identify a GPCR that is highly expressed in human adipocytes and to explore its potential involvement in adipose thermogenesis. Our research findings have demonstrated that the adhesion G protein-coupled receptor A3 (ADGRA3), an orphan GPCR, plays a significant role in adipose thermogenesis through its constitutively active effects. ADGRA3 exhibited high expression levels in human adipocytes and mouse brown fat. Furthermore, the knockdown of Adgra3 resulted in an exacerbated obese phenotype and a reduction in the expression of thermogenic markers. Conversely, Adgra3 overexpression activated the adipose thermogenic program and improved metabolic homeostasis without an exogenous ligand supplementation. We found that ADGRA3 facilitates the biogenesis of beige adipocytes through the Gs-PKA-CREB axis. Moreover, hesperetin was identified as a potential agonist of ADGRA3, capable of inducing adipocyte browning and ameliorating insulin resistance. In conclusion, our study demonstrated that the overexpression of constitutively active ADGRA3 or the activation of ADGRA3 by hesperetin can induce adipocyte browning by Gs-PKA-CREB axis. These findings indicate that the utilization of hesperetin and the selectively overexpression of ADGRA3 in adipose tissue could serve as promising therapeutic strategies in the fight against obesity.

cell biology↗

bioRxiv2024

Ancestral SARS-CoV-2 immune imprinting persists on RBD but not NTD after sequential Omicron infections

Whether Omicron exposures could overcome ancestral SARS-CoV-2 immune imprinting remains controversial. Here we analyzed B cell responses evoked by sequential Omicron infections in vaccinated and unvaccinated individuals. Plasma neutralizing antibody titers against ancestral SARS-CoV-2 and variants indicate that immune imprinting is not consistently induced by inactivated or recombinant protein vaccines. However, once induced, immune imprinting is not countered by successive Omicron challenges. We compared binding specificities, neutralizing capacities, developing origins and targeting epitopes of monoclonal antibodies from individuals with or without immune imprinting. Although receptor-binding domain (RBD) and N-terminal domain (NTD) of spike are both primary targets for neutralizing antibodies, immune imprinting only shapes antibody responses to RBD by impeding the production of Omicron-specific neutralizing antibodies while facilitating the development of broadly neutralizing antibodies. We propose that immune imprinting can be either neglected by NTD-based vaccines to induce variant-specific antibodies or leveraged by RBD-based vaccines to induce broadly neutralizing antibodies.

immunology↗

bioRxiv2024

Unraveling the Genetic Comorbidity Landscape of Alzheimer's Disease

Alzheimers disease (AD) has emerged as the most prevalent and complex neurodegenerative disorder among the elderly population. However, the genetic comorbidity etiology for AD remains poorly understood. In this study, we conducted pleiotropic analysis for 41 AD phenotypic comorbidities, identifying ten genetic comorbidities with 16 pleiotropy genes associated with AD. Through biological functional and network analysis, we elucidated the molecular and functional landscape of AD genetic comorbidities. Furthermore, leveraging the pleiotropic genes and reported biomarkers for AD genetic comorbidities, we identified 50 potential biomarkers for AD diagnosis. Our findings deepen the understanding of the occurrence of AD genetic comorbidities and provide new insights for the search for AD diagnostic markers. HighlightsThe present study has focused on the comorbidities associated with Alzheimers disease (AD) by constructing a landscape of these comorbidities at various levels, including diseases, genetics, and pathways. O_LIThe study findings reveal novel and significant pathways that contribute to the etiology of AD and its comorbidities. C_LIO_LIBy exploring pleiotropic genes and reported biomarkers of AD comorbidities, the study has identified several potential diagnostic biomarker candidates for AD. C_LI O_FIG O_LINKSMALLFIG WIDTH=192 HEIGHT=200 SRC="FIGDIR/small/583453v1_figG1.gif" ALT="Figure 1"> View larger version (33K): org.highwire.dtl.DTLVardef@2fc040org.highwire.dtl.DTLVardef@f6d801org.highwire.dtl.DTLVardef@1df65a4org.highwire.dtl.DTLVardef@18a307e_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOGraphic abstract.C_FLOATNO Study pipeline. C_FIG

neuroscience↗

bioRxiv2024

Sub-optimal activity of gut microbiome functional pathways increases the odds of Irritable Bowel Syndrome in a large adult human population

Functional gastrointestinal disorders present diagnostic and therapeutic challenges, and there is a strong need for molecular markers that enable early health insights and intervention. Herein, we present an approach to assess the gut microbiome with stool-based gut metatranscriptome data from a large adult human population (n = 80,570), using irritable bowel syndrome as an example that features both an abnormal gut microbiome and a spectrum of distinct conditions. We develop a suite of eight gut microbial functional pathway scores, each of which represents the activity of a set of interacting microbial functional features (based on KEGG orthology) relevant to known gut biochemical activities. We use a normative approach within a subpopulation (n = 9,350) to define "Good" and "Not Optimal" activities for these transcriptome-based gut pathway scores. We hypothesize that Not Optimal scores are associated with irritable bowel syndrome (IBS) and its subtypes (i.e., IBS-Constipation, IBS-Diarrhea, IBS-Mixed Type). We show that Not Optimal functional pathway scores are associated with higher odds of IBS or its subtypes within an independent cohort (n = 71,220) using both the Rome IV Diagnostic Questionnaire as well as self-reported phenotypes. Rather than waiting to diagnose IBS after symptoms appear, these functional pathway scores can help to provide early health insights into molecular pathways that may contribute to IBS. These molecular endpoints could also assist with measuring the efficacy of practical interventions, developing related algorithms, providing personalized nutritional recommendations, diagnostic support, and treatments for gastrointestinal disorders like IBS. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=68 SRC="FIGDIR/small/580548v4_ufig1.gif" ALT="Figure 1"> View larger version (19K): org.highwire.dtl.DTLVardef@d84aaeorg.highwire.dtl.DTLVardef@f2276org.highwire.dtl.DTLVardef@19fab7aorg.highwire.dtl.DTLVardef@1b2f738_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2024

Cortico-spinal Mechanisms of Periphery Neuromodulation induced Analgesia

BackgroundTranscutaneous Electrical Nerve Stimulation (TENS) is widely used for pain management, yet how different parameters--Conventional (high frequency, low intensity) versus Acupuncture-Like (low frequency, high intensity)--modulate pain remains controversial. These modes produce variable analgesic effects, but their underlying brain-spinal mechanisms are unclear. Clarifying these pathways could refine TENS protocols, optimize clinical outcomes, and reduce opioid reliance, highlighting the need for more precise, non-pharmacological approaches to advanced pain care. MethodsThis single-blind, three-arm randomized trial recruited 95 healthy adults (18-30 years) and assigned them (1:1:1) to Conventional TENS, Acupuncture-Like TENS, or sham. Participants underwent a 30-minute TENS intervention on the left forearm (C5-C6 dermatome) with simultaneous brain-spinal fMRI before and after thermal nociceptive stimuli. The primary outcomes were changes in Numeric Rating Scale (NRS) pain scores and brain-spinal BOLD signals. Secondary outcomes included psycho-physiological interaction (PPI) and mediation analyses of periaqueductal gray (PAG) activity and brain- cord connectivity. FindingsBoth TENS modes significantly reduced pain but engaged distinct cortico-spinal pathways. Conventional TENS yielded local analgesia via dlPAG-driven spinal inhibition plus partial cortical involvement (PAG-vmPFC). By contrast, Acupuncture-Like TENS produced diffuse analgesia through vlPAG-linked top-down modulation reliant on spinal gating. Correlation and mediation analyses confirmed that Conventional TENS integrates spinal and cortical synergies, whereas Acupuncture-Like TENS is dominated by robust descending control. InterpretationDifferent TENS parameters yield distinct analgesic mechanisms. Conventional TENS couples direct spinal inhibition with partial cortical regulation, while Acupuncture-Like TENS relies heavily on top-down pathways passing through the spinal cord. Recognizing these unique descending networks can guide targeted TENS protocols for diverse pain conditions, optimizing clinical outcomes and reducing reliance on pharmacological approaches. FundingsThis work was supported by the National Key R&D Program of China (2022YFC3500603), the National Natural Science Foundation of China (32071061, 82072010, 82030121 and 32100861, 82330057), the Beijing Natural Science Foundation (IS23108, JQ22018).

neuroscience↗