Biology subjects

Di Domenico, F.

Publications and source records attributed to Di Domenico, F..

8 recordsLinked to original sources

bioRxiv2025

Peri-operative pregabalin does not adversely impact experimentaloutcomes in rat models of chronic pain

IntroductionMultiple mechanisms contribute to the experience of pain where the use of model organisms to dissect mechanistically sensory regulatory circuitry is a vital component of discovering underlying causes of persistent pain in disease states. Such disease states can be modelled in animals using surgical procedures that, ethically, should involve administration of analgesia. However, since basic pain researchers often wish to measure pain-related events, animals may be denied peri-operative analgesia to avoid adversely influencing experimental outcomes. MethodsWe conducted a systematic review of peri-operative analgesia usage in rat spinal nerve ligation (SNL) and cancer-induced bone pain (CIBP) models. Using a combination of behavioural testing and in vivo electrophysiology in the dorsal horn of the spinal cord, we assessed the impact of peri-operative pregabalin on nociceptive behaviours in the acute recovery phase, and behavioural and electrophysiological experimental outcomes in the chronic phase, of rat SNL and CIBP models. ResultsA literature search revealed that, for studies using rat models of SNL or CIBP, only 5.37 % and 12.69 % respectively reported the use of peri-operative analgesia. We then demonstrated that the use of pregabalin as a peri-operative analgesic reduced mechanical hypersensitivity in the acute period following SNL surgery, with no impact on behavioural, electrophysiological or neuropharmacological outcomes in the chronic phase of either model. ConclusionsThis study challenges the basic science researchers reasoning that peri-operative analgesia confounds neurobiological outcomes. The use of peri-operative analgesia should be an important consideration to improve animal welfare in chronic models of pain. SummaryPeri-operative analgesia can improve animal welfare without adversely affecting long term behavioural or pharmacological experimental outcomes in chronic pain models.

neuroscience↗

bioRxiv2024

Pathological mechanisms and candidate therapeutic approaches in the hearing loss of mice carrying human MIR96 mutations

Progressive hearing loss is a common problem in the human population with no effective therapeutics currently available. However, it has a strong genetic contribution, and investigating the genes and regulatory interactions underlying hearing loss offers the possibility of identifying therapeutic candidates. Mutations in regulatory genes are particularly useful for this, and an example is the microRNA miR-96, a transcriptional regulator which controls hair cell maturation. Mice and humans carrying mutations in Mir96 all develop hearing loss, but different mutations result in different physiological, structural and transcriptional phenotypes. Here we present our characterisation of two lines of mice carrying different human mutations knocked-in to Mir96. While mice homozygous for either mutation are profoundly deaf from two weeks old, the heterozygous phenotypes differ markedly, with only one mutation resulting in hearing impairment in heterozygosis. Investigations of the structural phenotype showed that one mutation appears to lead to synaptic defects, while the other has a much more severe effect on the hair cell stereociliary bundles. Transcriptome analyses revealed a wide range of misregulated genes in both mutants which were notably dissimilar. We used the transcriptome analyses to investigate candidate therapeutics, and tested one, finding that it delayed the progression of hearing loss in heterozygous mice. Our work adds further support for the importance of the gain of novel targets in microRNA mutants, and offers a proof of concept for the identification of pharmacological interventions to maintain hearing.

genetics↗

bioRxiv2024

Cognitive and molecular characterization of the Ts66Yah murine model of Down syndrome: deepening on hippocampal changes associated with genotype and aging.

Down syndrome (DS) is the most common condition with intellectual disability and is caused by trisomy of Homo sapiens chromosome 21 (HSA21). The increased dosage of genes on HSA21 is the cause for the initial neurodevelopmental disorder and for further development of cognitive decline, however the molecular mechanisms promoting brain pathology along ageing are still missing. One of the major challenges in the study of DS is the lack of reliable murine model able to accurately replicate genotypic and phenotypic aspects observed in humans along ageing. Preclinical studies in DS were pioneered using the Ts65Dn murine model, which despite its genetic limitations, has been extremely helpful in characterising the progression of brain degeneration. The novel Ts66Yah model represents an evolution of the Ts65Dn, with phenotypes only induced by trisomic HSA21 homologous genes, closer to human DS condition. In this study, we confirmed the behavioural features of Ts66Yah mice with improvement in the detection of spatial memory defects and also a new anxiety-related phenotype. The molecular characterisation of Ts66Yah demonstrated the aberrant regulation of redox balance, proteostasis, stress response, metabolic pathways, programmed cell death and synaptic plasticity. Intriguingly, the genotype-related alterations of those pathways occur early promoting the alteration of brain development and the onset of a condition of premature aging. Overall, data collected in Ts66Yah provide novel and consolidated insights, devoid of genome bias, concerning trisomy-driven processes that contribute to brain pathology in conjunction with aging. This, in turn, aids in bridging the existing gap in comprehending the intricate nature of DS phenotypes.

pathology↗

bioRxiv2022

The origin of diffuse noxious inhibitory controls

Pain alerts us to actual or potential tissue damage. During acute pain, our central nervous system acts endogenously to modulate pain processing, thus reducing or enhancing pain perception. However, during chronic pain, the balance between inhibitory and facilitatory processes are tipped in favour of pro-pain modulation. Diffuse noxious inhibitory controls (DNIC) is a naturally occurring pain inhibitory pathway that projects from the brainstem to the spinal cord to inhibit neuronal activity therein in a manner that is 1) subserved by noradrenaline, and 2) dysfunctional in chronicity. To harness its high therapeutic potential, we aimed to anatomically and functionally define DNIC. Through employing an intersectional opto- and chemogenetic approach to modulate activity in brainstem noradrenergic nuclei, here we show that spinal neuronal firing observed upon DNIC activation during electrophysiological experiments, and animal pain thresholds observed during behavioural experiments, are modulated in a pro-pain manner upon opto-manipulation of A5 spinally projecting noradrenergic neurons, thus evidencing the DNIC origin. Given the plasticity of the functional expression of DNIC in disease, and the success of back and forward translation of paradigms that evoke DNIC in pre-clinical and clinical models, our findings offer an attractive avenue of studies for disease specific analgesic interventions.

neuroscience↗

bioRxiv2021

Distinct brainstem to spinal cord noradrenergic pathways differentially regulate spinal neuronal activity

Brainstem to spinal cord pathways modulate spinal neuronal activity. We implemented locus coeruleus (LC) targeting strategies by microinjecting CAV-PRS-ChR2 virus in the spinal cord (LC:SC module) or LC (LC:LC module). While activation of both modules inhibited evoked spinal neuronal firing via 1-adrenoceptor-mediated actions, LC:SC opto-activation abolished diffuse noxious inhibitory controls. The LC as a pain generator is likely mechanistically underpinned by maladaptive communication with discrete descending modulatory pathways.

neuroscience↗

bioRxiv2021

Collateral damage: Identification and characterisation of spontaneous mutations causing deafness from a targeted knockout programme

Mice carrying targeted mutations are important for investigating gene function and the role of genes in disease, but the process of culturing embryonic stem cells during the making of a targeted allele offers opportunities for spontaneous mutations to arise. Identifying spontaneous mutations relies on the detection of phenotypes segregating independently of targeted alleles, and many phenotypes are easy to miss if not specifically looked for. Here we present data from a large, targeted knockout programme in which mice were analysed through a phenotyping pipeline. Twenty-five lines out of 1311 displayed different deafness phenotypes that did not segregate with the targeted allele. We have identified 8 different mutations causing deafness in 16 of these 25 lines and characterised the resulting phenotypes. Our data show that spontaneous mutations with observable effects on phenotype are a common side effect of intensive breeding programmes, including those underlying targeted mutation programmes.

genetics↗

bioRxiv2020

Novel therapeutic targets to mitigate early neuronal dysfunction and cognitive deficits in tauopathy

Tauopathies are a group of more than twenty known disorders that involve progressive neurodegeneration, cognitive decline, and pathological tau accumulation. Current therapeutic strategies provide only limited, late-stage symptomatic treatment. This is partly due to lack of understanding of the molecular mechanisms linking tau and cellular dysfunction, especially during the early stages of disease progression. In this study, we treated early stage tau transgenic mice with a multi-target kinase inhibitor to identify novel substrates that contribute to cognitive impairment and exhibit therapeutic potential. Drug treatment significantly ameliorated brain atrophy and cognitive function as determined by behavioral testing and a sensitive imaging technique called manganese-enhanced magnetic resonance imaging (MEMRI) with quantitative R1 mapping. Surprisingly, these benefits occurred despite unchanged hyperphosphorylated tau levels. To elucidate the mechanism behind these improved cognitive outcomes, we performed quantitative proteomics to determine the altered protein network during this early stage in tauopathy and compare this model with the human AD proteome. We identified a cluster of preserved pathways shared with human tauopathy with striking potential for broad multi-target kinase intervention. We further report high confidence candidate proteins as novel therapeutically relevant targets for the treatment of tauopathy. One Sentence SummaryMulti-target kinase inhibition rescues cognitive function in early stage tauopathy mice and reverses proteomic shifts common to Alzheimers disease in humans.

neuroscience↗

bioRxiv2019

Hearing impairment due to Mir183/96/182 mutations suggests both loss and gain of function effects

The microRNA miR-96 is important for hearing, as point mutations in humans and mice result in dominant progressive hearing loss. Mir96 is expressed in sensory cells along with Mir182 and Mir183, but the roles of these closely-linked microRNAs are as yet unknown. Here we analyse mice carrying null alleles of Mir182, and of Mir183 and Mir96 together to investigate their roles in hearing. We found that Mir183/96 heterozygous mice had normal hearing and homozygotes were completely deaf with abnormal hair cell stereocilia bundles and reduced numbers of inner hair cell synapses at four weeks old. Mir182 knockout mice developed normal hearing then exhibited progressive hearing loss. Our transcriptional analyses revealed significant changes in a range of other genes, but surprisingly there were fewer genes with altered expression in the organ of Corti of Mir183/96 null mice compared with our previous findings in Mir96Dmdo mutants, which have a point mutation in the miR-96 seed region. This suggests the more severe phenotype of Mir96Dmdo mutants compared with Mir183/96 mutants, including progressive hearing loss in Mir96Dmdo heterozygotes, is likely to be mediated by the gain of novel target genes in addition to the loss of its normal targets. We propose three mechanisms of action of mutant miRNAs; loss of targets that are normally completely repressed, loss of targets whose transcription is normally buffered by the miRNA, and gain of novel targets. Any of these mechanisms could lead to a partial loss of a robust cellular identity and consequent dysfunction.

systems biology↗