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Sullivan, R.

Publications and source records attributed to Sullivan, R..

17 recordsLinked to original sources

Dietary fibre responses emerge through host-dietary regime interplay: Apple pectin modulates immune reactivity in adult zebrafish

Dietary fibres are rarely consumed independently. Instead, they form part of an overall diet that includes dietary fibres from different sources, in varying amounts and consumed under different feeding patterns. Here, we tested how dietary regimes containing apple pectin, oat {beta}-glucan, or cellulose shaped the host. We analysed gut microbiome composition by 16S rRNA sequencing, measured brain and intestinal SCFA profiles by targeted metabolomics, and assessed immunomodulation by measuring gene expression systemically in the blood and locally in the spleen, as well as intestinal enzyme activity. The dietary intervention was conducted for 12 weeks on adult female and male zebrafish (Danio rerio). Our results show that the gut microbial composition can be relatively stable across different dietary fibre exposure patterns yet still vary significantly between the sexes. Additionally, the effect of sex on the gut microbiome may become more evident when dietary fibres are administered at high dosages, but intermittently. Dietary fibre regimes can alter intestinal short-chain fatty acid profiles more readily than brain profiles, which show a stronger sexually dimorphic response. Interestingly, apple pectin modulated the zebrafish immune response through interactions dependent on the overall regime, tissue, sex, and host immune status. Notably, tissue il1b gene expression differed depending on how apple pectin was administered and the host's physiological state. Collectively, our study emphasises the highly context-specific effects of dietary fibres, shaped by the dynamic interplay between the overall dietary regime and intertwined host factors.

systems biology↗

Distinct prefrontal-amygdala connectivity drives consolidated fear memories

Elucidating the neuronal circuitry that underpins memory formation is critical to understanding how organisms use past experience to guide adaptive behaviour. While memory formation has long been framed as the reactivation of a static ensemble of neurons established during initial learning, growing evidence suggests that memory traces are highly dynamic and undergo substantial reorganisation during consolidation. During the formation of auditory fear memory, initial acquisition is primarily mediated by the basolateral amygdala (BLA), whereas long-term expression relies on the medial prefrontal cortex (mPFC). However, the circuit motifs that coordinate this systemic redistribution remain poorly understood. Here, using targeted anatomical tracing and electrophysiology, we show that the reciprocal connectivity between the mPFC and BLA is organised as a parallel topography along the rostro-caudal axis. Leveraging this novel anatomical understanding of reciprocal communication between the amygdala and prefrontal cortex, we reveal an underlying circuitry mechanism by which fear memory traces are redistributed into subcortical-cortical networks after learning. Using activity-dependent engram capture and optogenetic manipulation, we demonstrate that post-learning engagement of a distinct sub-circuit linking the rostral BLA and rostral mPFC is a hallmark of the consolidated fear memory. These insights reveal that the consolidated engram requires the targeted engagement of a post-learning engram circuit, rather than a simple reactivation of neurons engaged during initial learning.

neuroscience↗

Going Against the Grain: Investigating the C4 Wheat Hypothesis with Spatial Transcriptomics

The possibility of a C4 photosynthetic pathway present in the developing grain of wheat, a C3 plant, has been the source of scientific debate. Wheat is critical to food security and may benefit greatly from the biological advantages conferred by C4 photosynthesis under heat and drought stress. Therefore, significant research has gone towards engineering wheat to use C4 biochemistry, resulting in the discovery of a unique photosynthetic pathway in the grain that has been suggested to be C4 specific. Here, we employed a spatial transcriptomics analysis of the developing wheat grain to further investigate the spatial expression patterns of C4 specific genes. Our results showed that most of the genes related to C4 photosynthesis were expressed in the grain in the theorised tissue locations, including phosphoenolpyruvate carboxylase (ppc) and pyruvate orthophosphate dikinase (ppdk). The photosynthetic pericarp cells were the site of ppc synthesis while the endosperm was the site of ppc carboxylation activity. Notably, isoforms of aspartate aminotransferase, alanine aminotransferase and malate dehydrogenase exhibited spatially distinct expression patterns, with tissue specificity, possibly linked to the unique functions of individual isoforms. As wheat performance under stress has been associated with the levels of expression of these C4 genes, confirmation of an active C4 pathway in the grain would have significant agronomic implications. Our results provide novel gene expression data for key genes related to photosynthesis, which could contribute to future development of highly productive, climate change resilient wheat varieties.

genetics↗

Spatial transcriptomics of developing wheat seed reveals radial expression patterns in endosperm and subgenome biased expression of key genes

Gene expression of developing seeds drives essential processes such as nutrient storage, stress tolerance and germination. However, the spatial organisation of gene expression within the complex structure of the seed remains largely unexplored. Here we report the use of the STOmics spatial transcriptomics platform to visualise spatial expression patterns in the wheat (Triticum aestivum) seed at the critical period of grain filling in mid seed development. We analysed >4,000,000 spatially resolved transcripts, achieving subcellular resolution of transcript localization across multiple tissue domains, and identified gene expression clusters linked to eight functional cellular groups. Notably, our analysis characterised four distinct clusters within the endosperm, which exhibited radial expression patterns from the inner to outer regions of the grain, and identified novel marker gene candidates for the clusters found. We further investigated known tissue-specific genes and identified subgenome biased expression between paralogs of puroindoline-B, metallothionein protein, and -amylase/subtilisin inhibitor. These findings provide new detail about gene expression across and within different functional cellular groups of the developing seed and demonstrate that spatial transcriptomics could further our understanding of subgenome differences in polyploid plants.

plant biology↗

Hypothalamic Sex-Specific Metabolic Shift by Canagliflozin during Aging

The hypothalamus undergoes significant changes with aging and plays crucial roles in age-related metabolic alterations. Sodium-glucose co-transporter 2 inhibitors (SGLT2i) are anti-diabetic agents that promote glucose excretion, and promote metabolic homeostasis. Recent studies have shown that SGLT2i, Canagliflozin (Cana), can extend the median survival of genetically heterogeneous UM-HET3 male mice and improve central metabolic control via increases in hypothalamic insulin responsiveness in aged males, as well as reduced age-associated hypothalamic inflammation. We studied the long- and short-term effects of Cana on hypothalamic metabolic control in UM-HET3 mice. We show that Cana treatment reduced body weight and fat mass in male mice that was associated with enhanced glucose tolerance and insulin sensitivity observed by 12 months. Indirect calorimetry showed that short-term Cana treatment (5 months) increased energy expenditure in male, but not female mice, at 12 months of age. Long-term Cana treatment (18 months) increased metabolic rates in both sexes, and markedly increasing formation of both orexigenic and anorexigenic projections to the paraventricular nucleus of the hypothalamus (PVH) mostly in females by 25 months. Hypothalamic RNA-sequencing analysis revealed sex-specific genes and signaling pathways related to insulin signaling, glycogen catabolic pathway, neuropeptide signaling, and mitochondrial function upregulated by Cana, with males showing a more pronounced and sustained effect on metabolic pathways at both age groups. Overall, our data provide critical evidence for sex-specific mechanisms that are impacted by Cana during aging suggesting key targets of hypothalamic Cana-induced neuroprotection for metabolic control.

neuroscience↗

Microglial NF-κB Signaling Deficiency Protects Against Metabolic Disruptions Caused by Volatile Organic Compound via Modulating the Hypothalamic Transcriptome

Prolonged exposure to benzene, a prevalent volatile organic compound (VOC), at concentrations found in smoke, triggers hyperglycemia, and inflammation in mice. Corroborating this with existing epidemiological data, we show a strong correlation between environmental benzene exposure and metabolic impairments in humans. To uncover the underlying mechanisms, we employed a controlled exposure system and continuous glucose monitoring (CGM), revealing rapid blood glucose surges and disturbances in energy homeostasis in mice. These effects were attributed to alterations in the hypothalamic transcriptome, specifically impacting insulin and immune response genes, leading to hypothalamic insulin resistance and neuroinflammation. Moreover, benzene exposure activated microglial transcription characterized by heightened expression of IKK{beta}/NF-{kappa}B-related genes. Remarkably, selective removal of IKK{beta} in immune cells or adult microglia in mice alleviated benzene-induced hypothalamic gliosis, and protected against hyperglycemia. In summary, our study uncovers a crucial pathophysiological mechanism, establishing a clear link between airborne toxicant exposure and the onset of metabolic diseases.

neuroscience↗

The mycobacterial glycoside hydrolase LamH enables capsular arabinomannan release and stimulates growth

Mycobacterial glycolipids are important cell envelope structures that drive host-pathogen interactions. Arguably, the most important amongst these are lipoarabinomannan (LAM) and its precursor, lipomannan (LM), which are both trafficked out of the bacterium to the host via unknown mechanisms. An important class of exported LM/LAM is the capsular derivative of these molecules which is devoid of its lipid anchor. Here, we describe the identification of a glycoside hydrolase family 76 enzyme that we term LamH which specifically cleaves -1,6-mannoside linkages within LM and LAM, driving its export to the capsule releasing its phosphatidyl-myo-inositol mannoside lipid anchor. Unexpectedly, we found that the catalytic activity of this enzyme is important for efficient exit from stationary phase cultures where arabinomannan acts as a signal for growth phase transition. Finally, we demonstrate that LamH is important for Mycobacterium tuberculosis survival in macrophages. These data provide a new framework for understanding the biological role of LAM in mycobacteria.

microbiology↗

Antagonistic Neural Circuits Drive Opposing Behaviors towards the Young in Females

In many species, including mice, females show strikingly different pup-directed behaviors based on their reproductive state1,2. Naive wild female mice often kill pups while lactating females are dedicated to pup caring3,4. The neural mechanisms that mediate infanticide and its switch to maternal behaviors during motherhood remain unclear. Here, based on the hypothesis that maternal and infanticidal behaviors are supported by distinct and competing neural circuits5,6, we used the medial preoptic area (MPOA), a key site for maternal behaviors7-11, as a starting point and identified three MPOA-connected brain regions that drive differential negative pup-directed behaviors. Further functional manipulation and in vivo recording revealed that estrogen receptor alpha (Esr1) expressing cells in the principal nucleus of the bed nucleus of stria terminalis (BNSTprEsr1) are necessary, sufficient, and naturally activated during infanticide in female mice. Furthermore, MPOAEsr1 and BNSTprEsr1 neurons form reciprocal inhibition and change their excitability in opposite directions with reproductive state. The shift in balance between BNSTprEsr1 and MPOAEsr1 cell activity is likely a key mechanism for the behavioral switch during motherhood.

neuroscience↗

Molecular epidemiology of carbapenemase-producing Acinetobacter spp. from Israel, 2001-2006: earliest report of blaNDM predating the oldest known blaNDM-positive strains

BackgroundCarbapenem-resistant Acinetobacter baumannii (CRAb) is a WHO priority 1 critical pathogen. Despite early emergence of elevated CRAb rates in Israel, limited molecular data from this location are available. We searched for carbapenemases among 198 clinical Acinetobacter spp. from Israel between 2001 and 2006. MethodsStrains from 3 archives underwent whole-genome sequencing (Illumina NovaSeq on all, MinION on a subset) and computational analyses: assembly (Unicycler), annotation (prokka), identification (Kraken, rpoB similarity), search for carbapenemases (ResFinder, BLDB curation). FindingsA. baumannii (Ab) represented 179 (90{middle dot}4%) Acinetobacter spp. Eighty-four Ab (46{middle dot}9%) carried a carbapenemase: 38 (45{middle dot}2%) blaOXA-72 (blaOXA-24-like); 28 (33{middle dot}3%) blaOXA-23-like (20 blaOXA-23 and 8 blaOXA-225); 18 (21{middle dot}5%) blaOXA-58 (16 from 2001-2). Carbapenemase rates increased yearly from 2002 (32%) to 2006 (67%). Eight species of non-baumannii Acinetobacter (NbA) accounted for 19 isolates (9{middle dot}6%). Two of three A. junii contained blaOXA-58, one of which, Ajun-H1-3, isolated in January 2004, also possessed blaNDM-1. The pNDM-Ajun-H1-3 plasmid matched numerous NDM-positive plasmids reported from 2005 onwards in Acinetobacter spp. as well as Enterobacterales. InterpretationWe assessed carbapenemase diversity among Acinetobacter spp. in Israel from 2001-2006. Findings in Ab predate observations elsewhere: rapidly rising carbapenemase rates, driven by blaOXA-23-like and blaOXA-24-like genes replacing blaOXA-58. Among NbA, an A. junii isolated in 2004 carried blaNDM-1, making it the earliest NDM-positive isolate reported to date, preceding those from 2005 in India. Further research into blaNDMs emergence is warranted, in order to shed light on the evolution and spread of this and other antibiotic-resistance genes. FundingCentre de recherche Charles-Le Moyne; Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Universite de Sherbrooke; Fonds de recherche du Quebec - Sante; New Frontiers in Research Fund Grant NFRFE-2019-00444; CIFAR-Azrieli Global Scholars Program.

microbiology↗

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↗

TraDIS-validate: a method for curating ordered gene-replacement libraries

In recent years the availability of genome sequence information has grown logarithmically resulting in the identification of a plethora of uncharacterised genes. To address this gap in functional annotation, many high-throughput screens have been devised with the goal of uncovering novel gene functions. Gene-replacement libraries are one such tool that can be screened in a high-throughput way to link genotype and phenotype and are key community resources. However, for a phenotype to be attributed to a specific gene, there needs to be confidence in the genotype. Construction of large libraries can be laborious and occasionally errors will arise. Here, we present a rapid and accurate method for the validation of any ordered gene-replacement library. We applied our method (TraDIS-Validate) to the well-known Keio library of Escherichia coli gene-deletion mutants. Our method identified 3,718 constructed mutants out of a total of 3,728 confirmed isolates. TraDIS-validate therefore had a success rate of 99.7% for identifying the correct kanamycin cassette position. This dataset provides a benchmark for the purity of the Keio mutants and a screening method for mapping the position of an antibiotic resistance cassette in any ordered library.

genetics↗

Altered interactions between circulating and tissue-resident CD8 T cells with the colonic mucosa define colitis associated with immune checkpoint inhibitors

Therapeutic blockade of co-inhibitory immune receptors PD-1 and CTLA-4 has revolutionized oncology, but treatments are limited by immune-related adverse events (IRAEs). IRAE Colitis (irColitis) is the most common, severe IRAE affecting up to 25% of patients on dual PD-1 and CTLA-4 inhibition. Here, we present a systems biology approach to define the cell populations and transcriptional programs driving irColitis. We collected paired colon mucosal biopsy and blood specimens from 13 patients with irColitis, 8 healthy individuals, and 8 controls on immune checkpoint inhibitors (ICIs), and analyzed them with single-cell/nuclei RNA sequencing with paired TCR and BCR sequencing, multispectral fluorescence microscopy, and secreted factor analysis (Luminex). We profiled 299,407 cells from tissue and blood and identified 105 cell subsets that revealed significant tissue remodeling in active disease. Colon mucosal immune populations were dominated by tissue-resident memory (TRM) ITGAE-expressing CD8 T cells representing a phenotypic spectrum defined by gene programs associated with T cell activation, cytotoxicity, cycling, and exhaustion. CD8 TRM and effector CD4 T cells upregulated type 17 immune programs (IL17A, IL26) and Tfh-like programs (CXCL13, PDCD1). We also identified for the first time an increased abundance of two KLRG1 and ITGB2-expressing CD8 T cell populations with circulatory cell markers, including a GZMK TRM-like population and a CX3CR1 population that is predicted to be intravascular. These two populations were more abundant in irColitis patients treated with dual PD-1/CTLA-4 inhibition than those receiving anti-PD-1 monotherapy. They also had significant TCR sharing with PBMCs, suggesting a circulatory origin. In irColitis we observed significant epithelial turnover marked by fewer LGR5-expressing stem cells, more transit amplifying cells, and upregulation of apoptotic and DNA-sensing programs such as the cGAS-STING pathway. Mature epithelial cells with top crypt genes upregulated interferon-stimulated pathways, CD274 (PD-L1), anti-microbial genes, and MHC-class II genes, and downregulated aquaporin and solute-carrier gene families, likely contributing to epithelial cell damage and absorptive dysfunction. Mesenchymal remodeling was defined by increased endothelial cells, both in irColitis patients and specifically in patients on dual PD-1/CTLA-4 blockade. Cell-cell communication analysis identified putative receptor-ligand pairs that recruit CD8 T cells from blood to inflamed endothelium and positive feedback loops such as the CXCR3 chemokine system that retain cells in tissue. This study highlights the cellular and molecular drivers underlying irColitis and provides new insights into the role of CTLA-4 and PD-1 signaling in maintaining CD8 TRM homeostasis, regulating CD8 T recruitment from blood, and promoting epithelial-immune crosstalk critical to gastrointestinal immune tolerance and intestinal barrier function.

immunology↗

Regional Differences in the Ghrelin-Growth Hormone Secretagogue Receptor Signalling System in Human Heart Disease

The hormone ghrelin and its receptor, the growth hormone secretagogue receptor (GHSR) are expressed in myocardium. GHSR binding activates signalling pathways coupled to cardiomyocyte survival and contractility. These properties have made the ghrelin-GHSR axis a candidate for a biomarker of cardiac function. The dynamics of ghrelin-GHSR are altered significantly in late stages of heart failure and cardiomyopathy, when left ventricular (LV) function is failing. We examined the relationship of GHSR with ghrelin in cardiac tissue from patients with valvular disease with no detectable changes in LV function. Biopsy samples from the LV and left atrium (LA) were obtained from 25 patients with valvular disease (of whom 13 also had coronary artery disease) and preserved LV ejection fraction, and compared control samples obtained via autopsy. Using quantitative confocal fluorescence microscopy, levels of GHSR were determined using a fluorescent peptide analog of ghrelin, Cy5-ghrelin(1-19); ghrelin, the heart failure marker natriuretic peptide type-b (BNP), and contractility marker sarcoplasmic reticulum ATPase pump (SERCA2a) were measured by immunofluorescence. A positive correlation between GHSR and ghrelin was apparent in only diseased tissue. Ghrelin and BNP significantly correlated in the LV and strongly co-localized to the same intracellular compartment in both diseased and control tissue. GHSR, ghrelin and BNP all strongly and significantly correlated with SERCA2a in the LV of diseased tissue only. Our results suggest that the dynamics of the myocardial ghrelin/GHSR axis is altered in cardiovascular disease in the absence of measurable changes in heart function, and may accompany a regional shift in endocrine programming.

molecular biology↗

Adverse caregiving in infancy blunts neural processing of the mother: Translating across species

The roots of psychopathology frequently take shape during infancy in the context of parent-infant interactions and adversity. Yet, neurobiological mechanisms linking these processes during infancy remain elusive. Here, using responses to attachment figures among infants who experienced adversity as a benchmark, we assessed rat pup cortical Local Field Potentials (LFP) and behaviors exposed to adversity in response to maternal rough and nurturing handling by examining its impact on pup separation-reunion with the mother. We show that during adversity, pup cortical LFP dynamic range decreased during nurturing maternal behaviors, but was minimally impacted by rough handling. During reunion, adversity-experiencing pups showed aberrant interactions with mother and blunted cortical LFP. Blocking pup stress hormone during either adversity or reunion restored typical behavior, LFP power, and cross-frequency coupling. This translational approach suggests adversity-rearing produces a stress-induced aberrant neurobehavioral processing of the mother, which can be used as an early biomarker of later-life pathology.

neuroscience↗

Oxytocin Neurons Enable Social Transmission of Maternal Behavior

Maternal care is profoundly important for mammalian survival, and non-biological parents can express it after experience with infants. One critical molecular signal for maternal behavior is oxytocin, a hormone centrally released by hypothalamic paraventricular nucleus (PVN). Oxytocin enables plasticity within the auditory cortex, a necessary step for responding to infant vocalizations. To determine how this change occurs during natural experience, we continuously monitored homecage behavior of female virgin mice co-housed for days with an experienced mother and litter, synchronized with recordings from virgin PVN cells, including from oxytocin neurons. Mothers engaged virgins in maternal care by ensuring their nest presence, and demonstrated maternal behavior in self-generated pup retrieval episodes. These social interactions activated virgin PVN and gated behaviorally-relevant cortical plasticity for pup vocalizations. Thus rodents can acquire maternal behavior by social transmission, and our results describe a mechanism for adapting brains of adult caregivers to infant needs via endogenous oxytocin. One Sentence SummaryMother mice help co-housed virgins become maternal by enacting specific behaviors that activate virgin oxytocin neurons.

neuroscience↗

Modelling bistable tumour population dynamics to design effective treatment strategies

Despite recent advances in targeted drugs and immunotherapy, cancer remains \"the emperor of all maladies\" due to inevitable emergence of resistance. Drug resistance is thought to be driven by mutations and/or dynamic plasticity that deregulate pathway activities and regulatory programs of a highly heterogeneous tumour. In this study, we propose a modelling framework to simulate population dynamics of heterogeneous tumour cells with reversible drug resistance. Drug sensitivity of a tumour cell is determined by its internal states, which are demarcated by coordinated activities of multiple interconnected oncogenic pathways. Transitions between cellular states depend on the effects of targeted drugs and regulatory relations between the pathways. Under this framework, we build a simple model to capture drug resistance characteristics of BRAF-mutant melanoma, where two cell states are described by two mutually inhibitory - main and alternative - pathways. We assume that cells with an activated main pathway are proliferative yet sensitive to the BRAF inhibitor, and cells with an activated alternative pathway are quiescent but resistant to the drug. We describe a dynamical process of tumour growth under various drug regimens using the explicit solution of mean-field equations. Based on these solutions, we compare efficacy of three treatment strategies: static treatments with continuous and constant dosages, periodic treatments with regular intermittent phases and drug holidays, and treatments derived from optimal control theory (OCT). Based on these analysis, periodic treatments outperform static treatments with a considerable margin, while treatments based on OCT outperform the best periodic treatment. Our results provide insights regarding optimal cancer treatment modalities for heterogeneous tumours, and may guide the development of optimal therapeutic strategies to circumvent drug resistance and due to tumour plasticity.

cancer biology↗

The Growth Hormone Secretagogue Receptor, Ghrelin and Biochemical Signaling Molecules in Human Heart Failure

BackgroundCurrently, the early pre-clinical detection of left ventricular (LV) dysfunction is difficult as biomarkers are not specific for the cardiomyopathic process. The underlying molecular mechanisms leading to heart failure remain elusive, highlighting the need for identification of cardiac-specific markers. The growth hormone secretagogue receptor (GHSR) and its ligand ghrelin are present in cardiac tissue and are known to contribute to myocardial energetics. Here, we examined tissue ghrelin-GHSR levels as specific markers of cardiac dysfunction in patients who underwent cardiac transplantation.\n\nMethods and ResultsSamples of cardiac tissue were obtained from 10 cardiac transplant patients at the time of organ harvesting, and during serial post-transplant biopsies. Quantitative fluorescence microscopy using a novel fluorescent ghrelin analog was used to measure levels of GHSR, and immunofluorescence was used to measure levels of ghrelin, b-type natriuretic peptide (BNP) and tissue markers of cardiomyocyte contractility and growth. GHSR and ghrelin expression levels were highly variable in the explanted heart, less in the grafted heart biopsies. GHSR and ghrelin were strongly positively correlated, and both markers were negatively correlated with LV ejection fraction. Ghrelin had stronger positive correlations than BNP with the signaling markers for contractility and growth.\n\nConclusionsThese data suggest that GHSR-ghrelin have potential use as an integrated marker of cardiac dysfunction. Interestingly, tissue ghrelin appeared to be a more sensitive indicator than BNP to the biochemical processes that are characteristic of heart failure. This work allows for further use of ghrelin-GHSR to interrogate cardiac-specific biochemical mechanisms in pre-clinical stages of HF.\n\nPrecisThis study shows the relationships between GHSR, ghrelin, and signaling molecules with relation to heart function in human heart failure with tissue from diseased heart and healthy heart biopsies.

cell biology↗