Research square最新文献

{"title":"CD40 agonism enhances immune checkpoint blockade and generates immunologic memory via CD4⁺ T cells in ERα+ mammary tumors.","authors":"Casey Lam, Olivia Lanchoney, Vishnu Maddipatla, Nune Markosyan, Nikhil Joshi, Courtney Ray Fofana, Shan Zeng, Ronald P DeMatteo, Robert H Vonderheide, Jennifer Q Zhang","doi":"10.21203/rs.3.rs-6823527/v1","DOIUrl":"10.21203/rs.3.rs-6823527/v1","url":null,"abstract":"<p><p>There has been marked improvement in the clinical outcome of triple-negative breast cancer (TNBC) with the use of immune checkpoint blockade (ICB) although serious immune-related adverse effects are not uncommon. Unlike TNBC, ERα + breast tumors are largely unresponsive to ICB. Here we demonstrate defective priming by cross-presenting conventional dendritic cells (cDCs) and a blunted response to ICB in ERα + mouse mammary tumors compared to TNBC. Systemic administration of an agonistic CD40 antibody (aCD40) induced T cell proliferation and activation in tumor-draining lymph nodes and attracted effector T cells to the tumor bed from the periphery. This effect was largely due to activation, maturation and migration of type 1 conventional dendritic cells (cDC1s). aCD40 alone slowed tumor growth in ERα + tumors but its combination with ICB cured tumor-bearing mice, accomplishing a \"vaccine effect\" and the immune-mediated rejection of tumor rechallenge. The anti-tumor effect of aCD40 effect was cDC1 and CD8 + T cell-dependent, whereas the rejection of secondary tumor rechallenge in cured mice required CD4 + T cells. Importantly, intra-tumoral administration of aCD40 combined with systemic or intra-tumoral ICB - to mimic neoadjuvant therapeutic approaches-induced complete regressions of both treated and distant tumors. These findings indicate that aCD40 achieves DC activation required for the response to immunotherapy in ERα + tumors and further supports intra-tumoral administration of both aCD40 and ICB as an effective treatment that might limit systemic exposure and lower risk of immune-related toxicity.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204351/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DrugReX: an explainable drug repurposing system powered by large language models and literature-based knowledge graph.","authors":"Liang-Chin Huang, Hunki Paek, Kyeryoung Lee, Ediz Calay, Deepak Pillai, Nneka Ofoegbu, Bin Lin, Hua Xu, Xiaoyan Wang","doi":"10.21203/rs.3.rs-6728958/v1","DOIUrl":"10.21203/rs.3.rs-6728958/v1","url":null,"abstract":"<p><p>Drug repurposing offers a time-efficient and cost-effective approach for therapeutic development by finding new uses for existing drugs. Additionally, achieving explainability in drug repurposing remains a challenge due to the lack of transparency in decision-making processes, hindering researchers' understanding and trust in the generated insights. To address these issues, we present DrugReX, a system integrating a literature-based knowledge graph, embedding, scoring system, and explanation modules using large language models (LLMs). We validated DrugReX on 15 established drug repurposing cases, achieving significantly high scores. As a real-world use case, we applied DrugReX to identify candidate drugs for Alzheimer's disease and related dementias (ADRD) and thoroughly evaluated the pipeline. The system identified 25 promising candidates, with nine clustering with FDA-approved ADRD drugs and 10 linked to ongoing clinical trials. For explainability, an LLM was employed to generate explanations supported by evidence from the literature-based knowledge graph. Domain expert evaluation revealed that DrugReX-produced explanations were superior in quality and clarity than using an LLM alone, enhancing the explainability of repurposing predictions. This study represents the first integration of LLMs to provide explainable insights into drug repurposing, bridging computation precision with explainability, and thus, ultimately enabling more transparent and reliable decision-making in therapeutic development.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532623","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An induced pluripotent stem cell model of Schwann cell differentiation reveals NF2- related gene regulatory networks.","authors":"Olivia Lazaro, Sihong Li, William Carter, Jake Smiley, Oluwamayowa Awosika, Sylvia Robertson, Angela Haskell, Raven Hinkel, Brooke E Hickey, Steven P Angus, Austin House, D Wade Clapp, Abdul Q Syed, Travis S Johnson, Steven D Rhodes","doi":"10.21203/rs.3.rs-6775534/v1","DOIUrl":"10.21203/rs.3.rs-6775534/v1","url":null,"abstract":"<p><p>Schwann cells are vital to development and maintenance of the peripheral nervous system and their dysfunction has been implicated in a range of neurological and neoplastic disorders, including <i>NF2</i>-related schwannomatosis (<i>NF2</i>-SWN). We have developed a novel human induced pluripotent stem cell (hiPSC) model for the study of Schwann cell differentiation in health and disease. We performed transcriptomic, immunofluorescence, and morphological analysis of hiPSC derived Schwann cell precursors (SPCs) and terminally differentiated Schwann cells (SCs) representing distinct stages of development. To further validate our findings, we performed integrated, cross-species analyses across multiple external datasets at bulk and single cell resolution. Our hiPSC model of Schwann cell development shared overlapping gene expression signatures with human amniotic mesenchymal stem cell (hAMSCs) derived SCs and <i>in vivo</i> mouse models, but also revealed unique features that may reflect species-specific aspects of Schwann cell biology. Moreover, we have identified gene co-expression modules that are dynamically regulated during hiPSC to SC differentiation associated with ear and neural development, cell fate determination, the <i>NF2</i> gene, and extracellular matrix (ECM) organization. Through integrated analysis of multiple datasets and genetic disruption of NF2 via CRISPR-Cas9 gene editing in hiPSC derived SCPs, we have identified a series of novel ECM associated genes regulated by Merlin. Our hiPSC model further provides a tractable platform for studying Schwann cell development in the context of rare diseases such as <i>NF2</i>-SWN which lack effective medical therapies.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204348/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiplexed Targeted Spatial Mass Spectrometry Imaging Assays to monitor lipids and NAD⁺ metabolites in CD38 knockout mice exhibiting improved metabolism.","authors":"Birgit Schilling, Charles Schurman, Joanna Bons, Prasanna Kumaar, Jingji Fang, Andrea Roberts, Genesis Hormazabal, Rebeccah Riley, Nannan Tao, Eric Verdin","doi":"10.21203/rs.3.rs-6743284/v1","DOIUrl":"10.21203/rs.3.rs-6743284/v1","url":null,"abstract":"<p><p>Mass spectrometry imaging (MSI) is a rapidly advancing technology that provides mapping of the spatial molecular landscape of tissues for a variety of analytes. Matrix-assisted laser desorption/ionization (MALDI)-MSI is commonly employed, however, confident <i>in situ</i> identification and accurate quantification of analytes remain challenging. We present a novel imaging methodology combining trapped ion mobility spectrometry (TIMS)-based parallel accumulation-serial fragmentation (PASEF) with MALDI ionization for targeted imaging parallel reaction monitoring (iprm-PASEF). We investigated the spatial distribution of lipids and metabolites in liver tissues from wild-type and CD38 knockout mice (CD38^-/-). CD38, an enzyme involved in nicotinamide adenine dinucleotide (NAD+) metabolism, significantly influences liver metabolic function and contributes to age-related NAD+ decline. Although CD38 deletion previously was linked to improved metabolic phenotypes, the underlying spatial metabolic mechanisms are poorly understood. The spatial iprm-PASEF workflow enabled confident identification and differentiation of lipid isomers at the MS2 fragment ion level and revealed increased NAD⁺ and decreased adenosine diphosphate ribose (ADPR), a by-product of NAD⁺ hydrolysis, in CD38^-/- livers. This approach provided confident, specific, and robust MS2-based identification and quantification of fragment ions in spatial MSI experiments. Additionally, the innovative iprm-PASEF opens unprecedented opportunities for spatial metabolomics and lipidomics, offering spatially resolved insights into molecular mechanisms.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204368/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compartment-specific analysis reveals disrupted astrocytic calcium transients in Alzheimer's mice.","authors":"Md Joynal Abedin, Yee Fun Lee, Melinda Zhang, Alyssa N Russ, Dmitry Gerashchenko, Brian J Bacskai, Ksenia V Kastanenka","doi":"10.21203/rs.3.rs-6682029/v1","DOIUrl":"10.21203/rs.3.rs-6682029/v1","url":null,"abstract":"<p><p>Alzheimer's disease (AD) is characterized by presence of extracellular amyloid plaques, intracellular tau tangles, and extensive neuronal cell death. In addition to neurons, astrocytes modulate neuronal network activity through tripartite synapses and are increasingly recognized for their involvement in AD pathology. Astrocytic calcium signaling has been implicated in AD pathological processes, including disrupted synaptic transmission, dysregulated glutamate homeostasis, and impaired vascular function via astrocytic endfeet. However, a systematic analysis of calcium dynamics within specific astrocytic compartments has been lacking. Using in vivo multiphoton imaging of Yellow Cameleon 3.6, a genetically encoded calcium indicator targeted to astrocytes in APP/PS1 mice, we analyzed spontaneous calcium transients in cortical astrocytes at 4-6 months of age. We quantified event rate, activity duration, area under the curve (AUC), and peak amplitude across four compartments: soma, processes, microdomains, and endfeet. In APP/PS1 mice, somas exhibited increased activity duration and peak amplitude, while processes and microdomains showed reduced duration, AUC, and amplitude despite higher event rates. Endfeet showed reductions in all parameters. Correlation analysis revealed enhanced astrocyte synchrony in APP/PS1 mice, with distance-dependent correlation decay observed only in nontransgenic controls. Our findings highlight compartment-specific disruptions of astrocytic calcium activity caused by amyloidosis.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204480/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Qualitative Exploration of Multi-level Factors that Support Effective Community Health Worker-Social Worker Collaboration.","authors":"Nidhi Monga Nakra, Liana J Petruzzi, Alexander B Diller, Julie Smithwick, Lily Lee, Geoff Wilkinson, Joshua Collier, Sarah Chang","doi":"10.21203/rs.3.rs-6733746/v1","DOIUrl":"10.21203/rs.3.rs-6733746/v1","url":null,"abstract":"<p><strong>Background: </strong>Interdisciplinary collaboration is critical for improving healthcare delivery through coordinated care and streamlined healthcare navigation. Community health workers (CHWs) and social workers (SWs) are uniquely positioned to address the needs of individuals with complex social and health challenges. Despite the integration of CHWs and SWs into health and community settings, there is a paucity of literature on what facilitates successful collaboration between these two workforces. This qualitative study, conducted from April 2022 to June 2023, explores multilevel factors related to CHW-SW collaboration in health and community settings.</p><p><strong>Methods: </strong>We conducted eight, 90-minute virtual focus groups with CHWs (n = 20) and SWs (n = 17) collaborating in four healthcare and community health settings across the United States (California, Texas, New Jersey, and South Carolina). Focus groups were conducted between April 2022 and June 2023.</p><p><strong>Results: </strong>Themes were thematically organized according to the socio-ecological model. Individual and relationship-level factors included: roles and scopes of practice, communication, mutual respect, supportive supervision, and power dynamics. Organizational and community-level factors comprised: commitment to equity, leadership buy-in, standardized training, clear workflows, and shared documentation and physical space. Societal-level factors included: power dynamics, supportive policies and sustainable funding.</p><p><strong>Conclusions: </strong>Findings highlighted that CHW-SW collaboration can promote patient-centered care and address social determinants of health when both workforces are well integrated in healthcare systems. Key organizational commitments, community rapport, and relational dynamics should be established to optimize interdisciplinary collaboration and advance health equity.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204489/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"ASET: An end-to-end pipeline for quantification and visualization of allele specific expression.","authors":"Weisheng Wu, Kerby Shedden, Claudius Vincenz, Chris Gates, Beverly Strassmann","doi":"10.21203/rs.3.rs-6844336/v1","DOIUrl":"10.21203/rs.3.rs-6844336/v1","url":null,"abstract":"<p><strong>Motivation: </strong>Allele-specific expression (ASE) analyses from RNA-Seq data provide quantitative insights into imprinting and genetic variants affecting transcription. Robust ASE analysis requires the integration of multiple computational steps, including read alignment, read counting, data visualization, and statistical testing-this complexity creates challenges around reproducibility, scalability, and ease of use.</p><p><strong>Results: </strong>Here, we present ASE Toolkit (ASET), an end-to-end pipeline that streamlines SNP-level ASE data generation, visualization, and testing for parent-of-origin (PofO) effect. ASET includes a modular pipeline built with Nextflow for ASE quantification from short-read transcriptome sequencing reads, an R library for data visualization, and a Julia script for PofO testing. ASET performs comprehensive read quality control, SNP-tolerant alignment to reference genomes, read counting with allele and strand resolution, annotation with genes and exons, and estimation of contamination. In sum, ASET provides a complete and easy-to-use solution for molecular and biomedical scientists to identify and interpret patterns in ASE from RNA-Seq data.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204500/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osteocalcin induces phosphorylation of FOXO1 in human beta-cells and restores insulin expression under hyperglycemic conditions.","authors":"Shubhashish Sarkar, A Osama Gaber, Christine A Beamish, Omaima M Sabek","doi":"10.21203/rs.3.rs-6474216/v1","DOIUrl":"10.21203/rs.3.rs-6474216/v1","url":null,"abstract":"<p><p>Forkhead box O1 (FOXO1) is a key transcription factor that plays an important role in pancreatic β-cell compensation under physiological and pathological conditions and serves as a key regulator of glucose homeostasis. While FOXO1 expression in osteoblasts contributes to glucose maintenance through regulating osteocalcin, interestingly, osteocalcin acts directly on β-cells by regulating PDX1 and insulin expression. Here, we investigate the effect of osteocalcin on the FOXO1 expression in human pancreatic β-cells. In a human β-cell line and pancreatic islets, the fate of FOXO1 binding to the PDX1 promoter was investigated after osteocalcin treatment, with or without AKT inhibition. Furthermore, we investigated the effect of osteocalcin on PDX1 and insulin gene expression as well as the subcellular localization of FOXO1 and PDX1 in human islets. The data show that osteocalcin treatment increased the amount of phosphorylated FOXO1-S256 via AKT in human islet from high BMI donor. Moreover, human islets from donors with and without diabetes treated with osteocalcin showed a reduced nuclear FOXO1 and an increase in nuclear PDX1. In a human β-cell line and pancreatic islets, osteocalcin increases insulin and PDX1 expression following phosphorylation-dependent ubiquitination and degradation of FOXO1 via the protein kinase B pathway.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204463/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532603","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimating a change-point of baseline age in the longitudinal trajectories of biomarkers: application to an imaging study of preclinical Alzheimer disease.","authors":"Chengjie Xiong, Folasade Agboola, Jingqin Luo","doi":"10.21203/rs.3.rs-6681661/v1","DOIUrl":"10.21203/rs.3.rs-6681661/v1","url":null,"abstract":"<p><strong>Background: </strong>Biomarkers are routinely measured from human biospecimens and imaging scans in Alzheimer disease (AD) research. Age is a well-known risk factor for AD. Detecting the age at which the longitudinal change in biomarkers starts to accelerate, i.e., a change-point in age, is important to design preventive interventions.</p><p><strong>Methods: </strong>We analyzed longitudinal biomarker data by a random intercept and random slope model where the slope (longitudinal rate of change) was modeled as a piecewise linear and continuous function of baseline age. We proposed to estimate the intersection of the two linear functions, i.e., the change-point in age by multiple methods: maximum (profile) likelihood, minimum squared pseudo bias, minimum variance, minimum mean square error (MSE), and a two-stage method. We simulated large numbers of data sets to evaluate the performance of these estimators and implemented them to analyze the longitudinal white matter hypointensity from brain magnetic resonance imaging scans in an AD cohort study of 616 participants to estimate the age when the longitudinal rate of change starts to accelerate.</p><p><strong>Results: </strong>Our simulations indicated that performance was universally poor for all point estimators and CI estimates when the true change-point was near the boundary or when sample size was small (N=100). Yet, the proposed change-point estimators became approximately unbiased and showed relatively small MSE when sample size increased (N>200) and the true change-point was away from boundary. The 95% CIs from these methods also provided good nominal coverage with large sample sizes if the change-point was away from boundary. When applied to the AD biomarker study, we found that almost all methods yielded similar estimates to the change-point from 59.19 years to 65.78 years, but the profile likelihood approach led to a much later estimate.</p><p><strong>Conclusions: </strong>Our proposed estimators for the change-point performed reasonably well, especially when it is away from the boundary and the sample sizes are large. Our methods revealed a largely consistent age when the longitudinal change in white matter hypointensity started to accelerate. Further research is needed to tackle more complex challenges, i.e., multiple change-points that may depend on other AD risk factors.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204498/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The gut microbiota metabolite phenylacetylglycine regulates cardiac Ca²⁺ signaling by interacting with adrenergic receptors.","authors":"Elisa Bovo, Aleksey V Zima","doi":"10.21203/rs.3.rs-6701722/v1","DOIUrl":"10.21203/rs.3.rs-6701722/v1","url":null,"abstract":"<p><p>Phenylacetylglutamine (PAGln) and phenylacetylglycine (PAGly) are small molecules derived from the metabolism of phenylalanine by gut microbiota. Elevated levels of PAGln and PAGly in serum have been associated with increased risks for cardiovascular diseases. It has been suggested that PAGln and PAGly reduce cardiac contraction by blunting the adrenergic response during sympathetic stimulation. However, little is known whether the effect of PAGln and PAGly on the heart function is associated with an alteration of intracellular Ca²⁺ homeostasis. Here, we studied the effect of PAGly on Ca²⁺ regulation in mouse ventricular myocytes, as PAGly is the predominant phenylalanine metabolite in rodent's serum. Analysis of cytosolic Ca²⁺ dynamics revealed that PAGly (100 μM) increases action potential-induced Ca²⁺ transients and sarcoplasmic reticulum (SR) Ca²⁺ load. These effects of PAGly were significantly smaller than those produced by the adrenergic receptor agonist isoproterenol (ISO; 0.1 μM). The adrenergic receptor blocker propranolol (10 μM) and the protein kinase A (PKA) inhibitor H89 (10 μM) prevented the PAGly effects on intracellular Ca²⁺ dynamics. Further analysis of Ca²⁺ regulation revealed that pretreatment of cardiomyocytes with PAGly reduced the stimulatory effect of ISO on intracellular Ca²⁺ dynamics. Concurrently, PAGly did not produce any stimulatory effects on intracellular Ca²⁺ in the presence of ISO. In conclusion, PAGly regulates intracellular Ca²⁺ dynamics in ventricular myocytes by activating the adrenergic receptor-mediated signaling, but less efficiently than selective adrenergic agonists. By interacting with adrenergic receptors, PAGly can partially blunt the stimulatory effect of adrenergic receptor agonists.</p>","PeriodicalId":519972,"journal":{"name":"Research square","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12204485/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144532633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}