Pharmacological Effect of Verapamil on Brain Oxidative Parameters and Mania-Like Behaviour in Paradoxical Sleep Deprived Mice

Although the implication of calcium signalling in the aetiology of anxiety remains elusive, drugs modulating calcium (like calcium channel blockers) have been discovered to be some worth beneficial as treatment option for anxiety related disorders. This study was therefore undertaken to assess probable ameliorative potential of verapamil against manic-like (stereotype behaviour) and anxiety-like symptoms in mice exposed to sleep deprivation. Mice were allotted into five treatment groups (n=5): group 1 and 2 received 10 mL/kg distilled water, groups 3 and 4 verapamil (25 and 50 mg/kg) while group 5 received astaxanthin (50 mg/kg) which served as the reference drug. Treatment was for 7 days and animals were sleep-deprived on the final 72 hours. Various behavioural tests to determine degree of stereotypical behaviour and locomotor activity were carried out. Anxiety test was done via the aid of a light/dark box and plus maze while stereotype behaviour was assess utilizing an open field box. Oxidative stress parameters; malondialdehyde and glutathione were assessed. Histopathological perturbations in the caudate putamen were also recorded. Data were subjected to ANOVA at α0.05. The results obtained suggest that verapamil significantly suppressed stereotyped behaviour and reduced the incidence of manic-like behaviour which was induced by paradoxical sleep deprivation. Verapamil also significantly restored antioxidant levels and protected against loss of caudate neurons. In conclusion, verapamil ameliorates manic-like symptoms and anxiety in mice derived of sleep, while protecting brain neurons against oxidative stress damage induced by sleep deprivation.

Integrated multiple transcriptomes in oviductal tissue across the porcine oestrous cycle reveal functional roles in oocyte maturation and transport

Understanding the changes in the swine female reproductive system is important for solving issues related to reproductive failure and litter size. Elucidating the regulatory mechanisms of the natural oestrous cycle in the oviduct under non-fertilisation conditions can improve our understanding of its role in the reproductive system. Herein, whole transcriptome RNA sequencing of oviduct tissue samples was performed. The differentially expressed genes (DEGs) were identified for each time point relative to Day 0 and classified into three clusters based on their expression patterns. Clusters 1 and 2 included genes involved in the physiological changes through the oestrous cycle. Cluster 1 genes were mainly involved in PI3K-Akt signalling and steroid hormone biosynthesis pathways. Cluster 2 genes were involved in extracellular matrix-receptor interactions and protein digestion pathways. In Cluster 3, the DEGs were downregulated in the luteal phase; they were strongly associated with cell cycle, calcium signalling, and oocyte meiosis. The gene expression in the oviduct during the oestrous cycle influenced oocyte transport and fertilisation. Our findings provide a basis for successfully breeding pigs and elucidating the mechanisms underlying the changes in the pig oviduct during the oestrous cycle.

Plant Viruses Can Alter Aphid-Triggered Calcium Elevations in Infected Leaves

Alighting aphids probe a new host plant by intracellular test punctures for suitability. These induce immediate calcium signals that emanate from the punctured sites and might be the first step in plant recognition of aphid feeding and the subsequent elicitation of plant defence responses. Calcium is also involved in the transmission of non-persistent plant viruses that are acquired by aphids during test punctures. Therefore, we wanted to determine whether viral infection alters calcium signalling. For this, calcium signals triggered by aphids were imaged on transgenic Arabidopsis plants expressing the cytosolic FRET-based calcium reporter YC3.6-NES and infected with the non-persistent viruses cauliflower mosaic (CaMV) and turnip mosaic (TuMV), or the persistent virus, turnip yellows (TuYV). Aphids were placed on infected leaves and calcium elevations were recorded by time-lapse fluorescence microscopy. Calcium signal velocities were significantly slower in plants infected with CaMV or TuMV and signal areas were smaller in CaMV-infected plants. Transmission tests using CaMV-infected Arabidopsis mutants impaired in pathogen perception or in the generation of calcium signals revealed no differences in transmission efficiency. A transcriptomic meta-analysis indicated significant changes in expression of receptor-like kinases in the BAK1 pathway as well as of calcium channels in CaMV- and TuMV-infected plants. Taken together, infection with CaMV and TuMV, but not with TuYV, impacts aphid-induced calcium signalling. This suggests that viruses can modify plant responses to aphids from the very first vector/host contact.

CPVT-associated calmodulin variants N53I and A102V dysregulate calcium signalling via different mechanisms

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited condition that can cause fatal cardiac arrhythmia. Human mutations in the Ca2+ sensor calmodulin (CaM) have been associated with CPVT susceptibility, suggesting that CaM dysfunction is a key driver of the disease. However, the detailed molecular mechanism remains unclear. Focusing on the interaction with the cardiac ryanodine receptor (RyR2), we determined the effect of CPVT-associated variants N53I and A102V on the structural characteristics of CaM and on Ca2+ fluxes in live cells. We provide novel data showing that binding of both Ca2+/CaM-N53I and Ca2+/CaM-A102V to RyR23583-3603 is decreased. Ca2+/CaM:RyR23583-3603 high-resolution crystal structures highlight subtle conformational changes for the N53I variant, with A102V being similar to wild-type. We show that co-expression of CaM-N53I or CaM-A102V with RyR2 in HEK293 cells significantly increased the duration of Ca2+ events, CaM-A102V exhibited a lower frequency of Ca2+ oscillations. In addition, we show that CaMKIIδ phosphorylation activity is increased for A102V, compared to CaM-WT. This paper provides novel insight into the molecular mechanisms of CPVT-associated CaM variants and will facilitate development of strategies for future therapies.

Genomics and transcriptomics landscapes associated to changes in insulin sensitivity in response to endurance exercise training

Despite good adherence to supervised endurance exercise training (EET), some individuals experience no or little improvement in peripheral insulin sensitivity. The genetic and molecular mechanisms underlying this phenomenon are currently not understood. By investigating genome-wide variants associated with baseline and exercise-induced changes (∆) in insulin sensitivity index (Si) in healthy volunteers, we have identified novel candidate genes whose mouse knockouts phenotypes were consistent with a causative effect on Si. An integrative analysis of functional genomic and transcriptomic profiles suggests genetic variants have an aggregate effect on baseline Si and ∆Si, focused around cholinergic signalling, including downstream calcium and chemokine signalling. The identification of calcium regulated MEF2A transcription factor as the most statistically significant candidate driving the transcriptional signature associated to ∆Si further strengthens the relevance of calcium signalling in EET mediated Si response.

Two-Pore Channels in Cancer Hallmarks: An Update Review

Cancer is one of the most disastrous diseases that leads to a serious threat to millions of people’s health worldwide. Cancer is distinguished by multiple common criteria, known as the “cancer hallmarks" which calcium signaling has either direct or indirect correlation with each of them. An emerging body of evidence suggests that two-pore channels/calcium signaling machinery has a crucial role in the promotion of diverse aspects of cancer, particularly in several cancer hallmarks including cell proliferation, angiogenesis, migration, invasion, metastasis, and metabolic reprogramming. Recent findings linked two-pore channels/calcium signaling machinery with autophagy, chemoresistance, and patients' survival in cancer. The present review provides current findings on the roles of two-pore channels in cancer, particularly in several cancer hallmarks, autophagy, and chemoresistance. Furthermore, a specific focus on recent data concerning the two-pore channels antagonists and novel inhibitors is discussed. This review will furnish readers with a more in-depth understanding of the significance of two-pore channel calcium signalling in cancer and its potential as a druggable target for cancer therapy

Novel aspects of regulatory T cell dysfunction as a therapeutic target in giant cell arteritis

ObjectivesGiant cell arteritis (GCA) is the most common primary vasculitis, preferentially affecting the aorta and its large-calibre branches. An imbalance between proinflammatory CD4+ T helper cell subsets and regulatory T cells (Tregs) is thought to be involved in the pathogenesis of GCA and Treg dysfunction has been associated with active disease. Our work aims to explore the aetiology of Treg dysfunction and the way it is affected by remission-inducing immunomodulatory regimens.MethodsA total of 41 GCA patients were classified into active disease (n=14) and disease in remission (n=27). GCA patients’ and healthy blood donors’ (HD) Tregs were sorted and subjected to transcriptome and phenotypic analysis.ResultsTranscriptome analysis revealed 27 genes, which were differentially regulated between GCA-derived and HD-derived Tregs. Among those, we identified transcription factors, glycolytic enzymes and IL-2 signalling mediators. We confirmed the downregulation of forkhead box P3 (FOXP3) and interferon regulatory factor 4 (IRF4) at protein level and identified the ineffective induction of glycoprotein A repetitions predominant (GARP) and CD25 as well as the reduced T cell receptor (TCR)-induced calcium influx as correlates of Treg dysfunction in GCA. Inhibition of glycolysis in HD-derived Tregs recapitulated most identified dysfunctions of GCA Tregs, suggesting the central pathogenic role of the downregulation of the glycolytic enzymes. Separate analysis of the subgroup of tocilizumab-treated patients identified the recovery of the TCR-induced calcium influx and the Treg suppressive function to associate with disease remission.ConclusionsOur findings suggest that low glycolysis and calcium signalling account for Treg dysfunction and inflammation in GCA.

Nitro-Deficient Niclosamide Confers Reduced Genotoxicity and Retains Mitochondrial Uncoupling Activity for Cancer Therapy

Niclosamide is an oral anthelmintic drug, approved for use against tapeworm infections. Recent studies suggest however that niclosamide may have broader clinical applications in cancers, spurring increased interest in the functions and mechanisms of niclosamide. Previously, we reported that niclosamide targets a metabolic vulnerability in p53-deficient tumours, providing a basis for patient stratification and personalised treatment strategies. In the present study, we functionally characterised the contribution of the aniline 4′-NO2 group on niclosamide to its cellular activities. We demonstrated that niclosamide induces genome-wide DNA damage that is mechanistically uncoupled from its antitumour effects mediated through mitochondrial uncoupling. Elimination of the nitro group in ND-Nic analogue significantly reduced γH2AX signals and DNA breaks while preserving its antitumour mechanism mediated through a calcium signalling pathway and arachidonic acid metabolism. Lipidomics profiling further revealed that ND-Nic-treated cells retained a metabolite profile characteristic of niclosamide-treated cells. Notably, quantitative scoring of drug sensitivity suggests that elimination of its nitro group enhanced the target selectivity of niclosamide against p53 deficiency. Importantly, the results also raise concern that niclosamide may impose a pleiotropic genotoxic effect, which limits its clinical efficacy and warrants further investigation into alternative drug analogues that may ameliorate any potential unwanted side effects.

Treatment of schizophrenia and bipolar disorder (ChAD) - a review of the literature

Introduction and aims of the study: The aim of this study is to present recent reports on the treatment and therapy of schizophrenia and bipolar disorder (ChAD). The current treatment of patients affected by these diseases is difficult and unsatisfactory, therefore it is necessary to find new therapeutic options that will improve the effectiveness of treatment For the purpose of this study, scientific papers were reviewed using the Google Scholar search engine covering studies from 2016 to 2021. A dozen papers covering the scope of the publication were selected. Results: In the treatment of schizophrenia, the use of cannabinoids is of greatest interest due to the action of the preparations on the endocannabinoid system. In the treatment of ChaD, promising reports have been published on the therapy with aripiprazole and the need to improve its use in the treatment of both akathisia and agitation. Furthermore, from the fact that abnormalities of calcium signalling are considered a possible pathophysiological process in ChAD, it has been suggested that calcium channel L antagonists may be potential therapeutic agents in bipolar affective disorder. One study also demonstrated the potential use of vortioxetine in the treatment of patients with a depressive episode. Conclusions: The results of recent studies on the treatment of schizophrenia and ChAD cited in this paper offer the prospect of creating treatment regimens that are more effective and targeted in the aforementioned diseases. However, further randomised trials are needed to confirm the effective use of the cited drugs in the treatment of these diseases.

Proteinase-activated receptors in GtoPdb v.2021.3

Proteinase-activated receptors (PARs, nomenclature as agreed by the NC-IUPHAR Subcommittee on Proteinase-activated Receptors [39]) are unique members of the GPCR superfamily activated by proteolytic cleavage of their amino terminal exodomains. Agonist proteinase-induced hydrolysis unmasks a tethered ligand (TL) at the exposed amino terminus, which acts intramolecularly at the binding site in the body of the receptor to effect transmembrane signalling. TL sequences at human PAR1-4 are SFLLRN-NH2, SLIGKV-NH2, TFRGAP-NH2 and GYPGQV-NH2, respectively. With the exception of PAR3, synthetic peptides with these sequences (as carboxyl terminal amides) are able to act as agonists at their respective receptors. Several proteinases, including neutrophil elastase, cathepsin G and chymotrypsin can have inhibitory effects at PAR1 and PAR2 such that they cleave the exodomain of the receptor without inducing activation of Gαq-coupled calcium signalling, thereby preventing activation by activating proteinases but not by agonist peptides. Neutrophil elastase (NE) cleavage of PAR1 and PAR2 can however activate MAP kinase signaling by exposing a TL that is different from the one revealed by trypsin [82]. PAR2 activation by NE regulates inflammation and pain responses [111, 72] and triggers mucin secretion from airway epithelial cells [112].