Biology subjects

Georgiou, P.

Publications and source records attributed to Georgiou, P..

12 recordsLinked to original sources

bioRxiv2026

Ethanol withdrawal induces temporally distinct alterations in oxytocinergic, opioidergic, glutamatergic and neuroimmune systems associated with recognition memory deficits

Alcohol use disorder is associated with persistent neuroadaptations and cognitive impairments, particularly during withdrawal, yet the temporal dynamics and interactions between these processes remain poorly understood. In the present study, we investigated time-dependent alterations in the oxytocin receptor (OTR), -opioid receptor (MOPr), metabotropic glutamate receptor 5 (mGlu5R), and translocator protein (TSPO) following chronic ethanol exposure and withdrawal, and their relationship to behavioral impairments. Male C57BL/6J mice were exposed to a 10-day escalating-dose ethanol liquid diet paradigm followed by 1, 4, or 7 days of withdrawal. Motor coordination and recognition memory were assessed using rotarod and novel object recognition tests, and receptor binding was quantified using autoradiography across multiple brain regions. Chronic ethanol exposure induced motor deficits that persisted during early withdrawal, whereas recognition memory impairments emerged after 7 days of withdrawal. Ethanol exposure and withdrawal produced region- and time-dependent alterations across all systems examined, with increased OTR binding in septal regions and transient reductions in basomedial amygdala OTR binding during intermediate withdrawal that normalized following prolonged withdrawal, transient increases in MOPr binding in striatal regions at 4 days of withdrawal, increased mGlu5R binding in the nucleus accumbens core, basolateral amygdala, and hippocampus, and early transient increases in TSPO binding indicative of neuroimmune activation. Notably, mGlu5R binding in the caudate-putamen and amygdala was associated with recognition memory deficits in a withdrawal stage-dependent manner. Bioinformatic analysis of human postmortem hippocampal transcriptomic datasets from individuals with alcohol use disorder revealed no consistent changes in GRM5 expression, suggesting that mGlu5R dysregulation may be driven by post-transcriptional mechanisms. These findings demonstrate that ethanol withdrawal is characterized by temporally distinct neuroadaptations across multiple systems and identify mGlu5R as a key correlate of withdrawal-associated memory impairment, highlighting its potential as a translational therapeutic target.

pharmacology and toxicology↗

bioRxiv2025

VirTarget: Virus-Informed Pharmacogenomics Framework Identifies Immunotherapies That Mitigate Epstein-Barr Virus-Driven Dysregulation in Multiple Sclerosis

BackgroundEpstein-Barr virus (EBV) is increasingly recognized as a central driver of multiple sclerosis (MS), yet current immunotherapies are selected without regard to their effects on EBV or EBV-MS genetic interactions. To address this gap, we developed VirTarget, the first virus-informed pharmacogenomics network framework that systematically evaluates approved MS immunotherapies with respect to EBV-driven pathogenesis and host genetic susceptibility risk. MethodsVirTarget integrates three complementary layers: (1) EBV-host interactomics, mapping viral-host protein- protein interactions within MS-relevant pathways; (2) host genetic susceptibility, linking MS-associated variants to EBV-targeted, therapy-modulated networks; and (3) transcriptomics directionality analysis, contrasting drug signatures with the convergent MS-EBV transcriptomic signature to classify therapies as reinforcers or reversers. ResultsNetwork analysis revealed substantial heterogeneity among therapies. Dimethyl fumarate showed the strongest and broadest engagement with the MS-EBV network, followed by natalizumab and interferons, while anti-CD20 antibodies and S1P modulators exerted the weakest effects. Genetic mapping highlighted convergence on key risk genes (HLA-DRB1, IL7R, IL2RA, CD40, TYR) directly targeted by EBV proteins within therapy-modulated pathways. Transcriptomic profiling stratified therapies into reinforcers (e.g., dimethyl fumarate, fingolimod, dexamethasone, interferon-{beta}1b) and reversers (e.g., prednisolone, cladribine, interferon-{beta}1a, rituximab), reflecting opposing influences on the MS{cap}EBV signature. Notably, multiple therapies reversed EBV-driven dysregulation of cytokine and innate immune pathways, suggesting their benefits extend in counteracting viral-mediated modulation of immune processes. ConclusionVirTarget provides the first systems-level, virus-informed comparative map of how MS immunotherapies engage with the MS-EBV network, intersect with MS genetic susceptibility risk, and modulate both MS- and EBV-related transcriptomic signatures. By revealing drug-specific patterns of viral pathway engagement and genetic convergence, this framework establishes a foundation for precision treatment strategies in MS, where therapeutic selection is informed by viral serostatus, host genetics, and system-level transcriptomic responses.

bioinformatics↗

bioRxiv2023

(2R,6R)-hydroxynorketamine facilitates extinction and prevents emotional impairment and stress-induced reinstatement in morphine abstinent mice

Opioid addiction is a pressing public health concern marked by frequent relapse during periods of abstinence, perpetuated by negative affective states and anhedonia-driven behaviors. In addition to the current epidemic that was declared in the U.S.A., opioid-related deaths are increasing in other countries around the world. Classical antidepressants, or the currently prescribed opioid substitution pharmacotherapies have limited efficacy to reverse maladaptive behavioral responses, negative affect or prevent relapse in opioid abstinent individuals. Here, by establishing and using novel mouse models for the study of opioid addiction, we demonstrate, for the first time, the therapeutic potential of ketamines metabolite, (2R,6R)-hydroxynorketamine (HNK). In particular, our studies showcase (2R,6R)-HNKs ability to reverse conditioning to sub-effective doses of morphine in stress-susceptible mice, prevent conditioned-place aversion and mitigate acute somatic withdrawal symptoms in opioid-dependent animals. In addition, we show that this metabolite reverses anhedonia, anxiety-like behaviors, cognitive impairment, and general stress susceptibility associated with protracted opioid withdrawal, thereby presenting a promising therapeutic avenue for opioid relapse prevention. Our results strongly suggest that (2R,6R)-HNK, potentially by augmenting downstream brain-derived neurotrophic factor (BDNF) and GluN2A N-methyl-D-aspartate receptor signaling, effectively reverses maladaptive behavioral responses typical of protracted opioid abstinence. Furthermore, it facilitates the extinction of opioid conditioning and prevents stress-induced reinstatement of opioid-seeking behaviors. Our findings highlight how (2R,6R)-HNK, through an enhancement of synaptic plasticity in mood-regulating brain areas, has the potential to be an effective, next-generation pharmacotherapy for opioid use disorders by addressing emotional disturbances associated with protracted abstinence. SIGNIFICANCE STATEMENTOur studies represent a comprehensive exploration into the critical facets of opioid addiction and abstinence, offering critical insights into the significant potential of (2R,6R)-HNK as a treatment for this disorder. By unraveling the complex dynamics of opioid withdrawal and addressing the profound emotional disturbances underlying relapse vulnerability, our findings illuminate a promising innovative avenue for therapeutic intervention. The demonstrated ability of (2R,6R)-HNK to reverse maladaptive behaviors emerging during protracted opioid abstinence, facilitate extinction of opioid conditioning, prevent stress-induced reinstatement, represents a paradigm shift in addiction research. These revelations not only deepen our comprehension of the neurobehavioral complexities associated with opioid abstinence but also underscore the profound implications of (2R,6R)-HNK as a prospective pharmacotherapy in mitigating the devastating impact of opioid use disorder, potentially transforming addiction treatment strategies.

neuroscience↗

bioRxiv2023

Biocompatibility characterisation of CMOS-based Lab-on-Chip electrochemical sensors for in vitro cancer cell culture applications

Lab-on-Chip electrochemical sensors, such as Ion-Sensitive Field-Effect Transistors (ISFETs), are being developed for use in point-of-care diagnostics, such as pH detection of tumour microenvironments, due to their integration with standard Complementary Metal Oxide Semiconductor technology. With this approach, the passivation of the CMOS process is used as a sensing layer to minimise post-processing, and Silicon Nitride (Si3N4) is the most common material at the microchip surface. ISFETs have the potential to be used for cell-based assays however, there is a poor understanding of the biocompatibility of microchip surfaces. Here, we quantitatively evaluated cell adhesion, morphogenesis, proliferation and mechano-responsiveness of both normal and cancer cells cultured on a Si3N4, sensor surface. We demonstrate that both normal and cancer cell adhesion decreased on Si3N4. Activation of the mechano-responsive transcription regulators, YAP/TAZ, are significantly decreased in cancer cells on Si3N4 in comparison to standard cell culture plastic, whilst proliferation marker, Ki67, expression markedly increased. Non-tumorigenic cells on chip showed less sensitivity to culture on Si3N4 than cancer cells. Treatment with extracellular matrix components increased cell adhesion in normal and cancer cell cultures, surpassing the adhesiveness of plastic alone. Moreover, poly-l-ornithine and laminin treatment restored YAP/TAZ levels in both non-tumorigenic and cancer cells to levels comparable to those observed on plastic. Thus, engineering the electrochemical sensor surface with treatments will provide a more physiologically relevant environment for future cell-based assay development on chip.

cancer biology↗

bioRxiv2022

Detection of YAP1 and AR-V7 mRNA for Prostate Cancer prognosis using an ISFET Lab-On-Chip platform

Prostate cancer (PCa) is the second most common cause of male cancer-related death worldwide. The gold standard of treatment for advanced PCa is androgen deprivation therapy (ADT). However, eventual failure of ADT is common and leads to lethal metastatic castration resistant PCa (mCRPC). As such, the detection of relevant biomarkers in the blood for drug resistance in mCRPC patients could lead to personalized treatment options. mRNA detection is often limited by the low specificity of qPCR assays which are restricted to specialised laboratories. Here, we present a novel reversetranscription loop-mediated isothermal amplification (RT-LAMP) assay and have demonstrated its capability for sensitive detection of AR-V7 and YAP1 RNA (3x101 RNA copies per reaction). This work presents a foundation for the detection of circulating mRNA in PCa on a non-invasive Lab-on-chip (LoC) device for use at point-of-care. This technique was implemented onto a Lab-on-Chip platform integrating an array of chemical sensors (ion-sensitive field-effect transistors - ISFETs) for real-time detection of RNA. Detection of RNA presence was achieved through the translation of chemical signals into electrical readouts. Validation of this technique was conducted with rapid detection (<15 min) of extracted RNA from prostate cancer cell lines 22Rv1s and DU145s.

bioengineering↗

bioRxiv2022

Electricity-free nucleic acid extraction method from dried blood spots on filter paper for point-of-care diagnostics

BackgroundNucleic acid extraction is a crucial step for molecular biology applications, being a determinant for any diagnostic test procedure. Dried blood spots (DBS) have been used for decades for serology, drug monitoring, environmental investigations, and molecular studies. Nevertheless, nucleic acid extraction from DBS remains one of the main challenges to translate them to the point-of-care (POC). MethodWe have developed a fast nucleic acid extraction (NAE) method from DBS which is electricity-free and relies on cellulose filter papers (DBSFP). The performance of NAE was assessed with loop-mediated isothermal amplification (LAMP), targeting the human reference gene beta-actin. The developed method was evaluated against FTA cards and magnetic bead-based purification, using time-to-positive (min) for comparative analysis. We optimised and validated the developed method for elution (eluted disk) and disk directly in the reaction (in-situ disk), RNA and DNA detection, and whole blood stored in anticoagulants (K2EDTA and lithium heparin). Furthermore, the compatibility of DBSFP with colourimetric detection was studied to show the transferability to the POC. ResultsThe proposed DBSFP is based on grade 3 filter paper pre-treated with 8% (v/v) igepal surfactant, 1 min washing step with PBS 1X and elution in TE 1X buffer after 5 min incubation at room temperature, enabling NAE under 7 min. Obtained results were comparable to gold standard methods across tested matrices, targets and experimental conditions, demonstrating the versatility of the methodology. Lastly, eluted disk colourimetric detection was achieved with a sample-to-result turnaround time under 35 min. ConclusionsThe developed method is a fast, electricity-free, and low-cost solution for NAE from DBSFP enabling molecular testing in virtually any POC setting.

molecular biology↗

bioRxiv2022

An adaptive filtering framework for non-specific and inefficient reactions in multiplex digital PCR based on sigmoidal trends

Real-time digital PCR (qdPCR) coupled with artificial intelligence has shown the potential of unlocking scientific breakthroughs, particularly in the field of molecular diagnostics for infectious diseases. One of the most promising applications is the use of machine learning (ML) methods to enable single fluorescent channel PCR multiplex by extracting target-specific kinetic and thermodynamic information contained in amplification curves. However, the robustness of such methods can be affected by the presence of undesired amplification events and nonideal reaction conditions. Therefore, here we proposed a novel framework to filter non-specific and low efficient reactions from qdPCR data using outlier detection algorithms purely based on sigmoidal trends of amplification curves. As a proof-of-concept, this framework is implemented to improve the classification performance of the recently reported ML-based Amplification Curve Analysis (ACA), using available data from a previous publication where the ACA method was used to screen carbapenemase-producing organisms in clinical isolates. Furthermore, we developed a novel strategy, named Adaptive Mapping Filter (AMF), to consider the variability of positive counts in digital PCR. Over 152,000 amplification events were analyzed. For the positive reactions, filtered and unfiltered amplification curves were evaluated by comparing against melting peak distribution, proving that abnormalities (filtered out data) are linked to shifted melting distribution or decreased PCR efficiency. The ACA was applied to compare classification accuracies before and after AMF, showing an improved sensitivity of 1.18% for inliers and 20% for outliers (p-value < 0.0001). This work explores the correlation between kinetics of amplification curves and thermodynamics of melting curves and it demonstrates that filtering out non-specific or low efficient reactions can significantly improve the classification accuracy for cutting edge multiplexing methodologies.

molecular biology↗

bioRxiv2022

Estradiol mediates stress-susceptibility in the male brain

In susceptible populations, stress is a major risk factor for the development of mental disorders, including depression. Estradiol, often considered a female hormone, is distributed in the male brain via aromatization of testosterone. The role of estrogen receptors (ERs) in male stress susceptibility and depression is not well understood. We found that absence of ER{beta} is associated with susceptibility to stress in male mice and that activity of ER{beta}-projecting neurons from the basolateral amygdala to nucleus accumbens is reduced in hypogonadal mice subjected to stress, while activation of this circuit reverses stress-induced maladaptive behaviors. We identified that absence of estradiol, but not testosterone per se, underlies stress susceptibility and that brain-selective delivery of estradiol prevents the development of depression-related behaviors. Our findings provide evidence for an estrogen-based mechanism underlying stress susceptibility and offer an unexpected therapeutic strategy for treating depression in males.

neuroscience↗

bioRxiv2022

Experimenter sex modulates mouse biobehavioural and pharmacological responses

Differential rodent responses to the sex of human experimenters could have far reaching consequences in preclinical studies. Here, we show that the sex of human experimenters affects mouse behaviours and responses to the rapid-acting antidepressant ketamine and its bioactive metabolite (2R,6R)-hydroxynorketamine. We found that mice manifest aversion to human male odours, preference to female odours, and increased susceptibility to stress when handled by male experimenters. This male induced aversion and stress susceptibility is mediated by the activation of brain corticotropin-releasing factor (CRF) neurons projecting from the entorhinal cortrex to hippocampal area CA1. We further establish that exposure to male scent prior to ketamine administration activates CRF neurons projecting from the entorhinal cortex to hippocampus, and that CRF is necessary and sufficient for ketamines in vivo and in vitro actions. Further understanding of the specific and quantitative contributions of the sex of human experimenters to different experimental outcomes in rodents may lead not only to reduced heterogeneity between studies, but also increased capability to uncover novel biological mechanisms.

neuroscience↗

bioRxiv2019

Quantitative and rapid Plasmodium falciparum malaria diagnosis and artemisinin-resistance detection using a CMOS Lab-on-Chip platform

Early and accurate diagnosis of malaria and drug-resistance is essential to effective disease management. Available rapid malaria diagnostic tests present limitations in analytical sensitivity, drug-resistant testing and/or quantification. Conversely, diagnostic methods based on nucleic acid amplification stepped forwards owing to their high sensitivity, specificity and robustness. Nevertheless, these methods commonly rely on optical measurements and complex instrumentation which limit their applicability in resource-poor, point-of-care settings. This paper reports the specific, quantitative and fully-electronic detection of Plas-modium falciparum, the predominant malaria-causing parasite worldwide, using a Lab-on-Chip platform developed in-house. Furthermore, we demonstrate on-chip detection of C580Y, the most prevalent single-nucleotide polymorphism associated to artemisinin-resistant malaria. Real-time non-optical DNA sensing is facilitated using Ion-Sensitive Field-Effect Transistors, fabricated in unmodified complementary metal-oxide-semiconductor technology, coupled with loop-mediated isothermal amplification. This work holds significant potential for the development of a fully portable and quantitative malaria diagnostic that can be used as a rapid point-of-care test.

bioengineering↗

bioRxiv2018

Simultaneous single-channel multiplex and quantification of carbapenem-resistant genes using multidimensional standard curves

Multiplexing and absolute quantification of nucleic acids, both have, in their own right, significant and extensive use in biomedical related fields, especially in point-of-care applications. Currently, the ability to detect several nucleic acid targets in a single-reaction scales linearly with the number of targets; an expensive and time-consuming feat. Here, we propose a new methodology based on multidimensional standard curves that extends the use of real-time PCR data obtained by common qPCR instruments. By applying this novel methodology, we achieve simultaneous single-channel multiplexing and enhanced quantification of multiple targets using only real-time amplification data. This is obtained without the need of fluorescent probes, agarose gels, melting curves or sequencing analysis. Given the importance and demand for tackling challenges in antimicrobial resistance, the proposed method is applied to the four most prominent carbapenem-resistant genes: blaOXA-48, blaNDM, blaVIM and blaKPC, which account for 97% of the UKs reported carbapenemase-producing Enterobacteriaceae.

microbiology↗

bioRxiv2018

A framework for analysis of real-time nucleic acid amplification data using novel multidimensional standard curves

Research into improving methods for absolute quantification of nucleic acids using standard curves has plateaued despite its positive, far-reaching impact on biomedical applications and clinical diagnostics. Currently, the mathematics involved in this mature area is restricted by the simplicity of conventional standard curves such as the gold standard cycle-threshold (Ct) method. Here, we propose a novel framework that expands current methods into multidimensional space and opens the door for more complex mathematical techniques, signal processing and machine learning to be implemented. The heart of this work revolves around two new concepts: the multidimensional standard curve and its home - the feature space. This work has been validated using phage lambda DNA and standard qPCR instruments. We show that the capabilities of standard curves can be extended in order to simultaneously: enhance absolute quantification, detect outliers and provide insights into the intersection between molecular biology and amplification data. This work and its vision aims to maximise the information extracted from amplification data using current instruments without increasing the cost or complexity of existing diagnostic settings.

bioinformatics↗