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Brain : a Journal of Neurology Dec 2022Pathogenic variants in the voltage-gated sodium channel gene family lead to early onset epilepsies, neurodevelopmental disorders, skeletal muscle channelopathies,...
Pathogenic variants in the voltage-gated sodium channel gene family lead to early onset epilepsies, neurodevelopmental disorders, skeletal muscle channelopathies, peripheral neuropathies and cardiac arrhythmias. Disease-associated variants have diverse functional effects ranging from complete loss-of-function to marked gain-of-function. Therapeutic strategy is likely to depend on functional effect. Experimental studies offer important insights into channel function but are resource intensive and only performed in a minority of cases. Given the evolutionarily conserved nature of the sodium channel genes, we investigated whether similarities in biophysical properties between different voltage-gated sodium channels can predict function and inform precision treatment across sodium channelopathies. We performed a systematic literature search identifying functionally assessed variants in any of the nine voltage-gated sodium channel genes until 28 April 2021. We included missense variants that had been electrophysiologically characterized in mammalian cells in whole-cell patch-clamp recordings. We performed an alignment of linear protein sequences of all sodium channel genes and correlated variants by their overall functional effect on biophysical properties. Of 951 identified records, 437 sodium channel-variants met our inclusion criteria and were reviewed for functional properties. Of these, 141 variants were epilepsy-associated (SCN1/2/3/8A), 79 had a neuromuscular phenotype (SCN4/9/10/11A), 149 were associated with a cardiac phenotype (SCN5/10A) and 68 (16%) were considered benign. We detected 38 missense variant pairs with an identical disease-associated variant in a different sodium channel gene. Thirty-five out of 38 of those pairs resulted in similar functional consequences, indicating up to 92% biophysical agreement between corresponding sodium channel variants (odds ratio = 11.3; 95% confidence interval = 2.8 to 66.9; P < 0.001). Pathogenic missense variants were clustered in specific functional domains, whereas population variants were significantly more frequent across non-conserved domains (odds ratio = 18.6; 95% confidence interval = 10.9-34.4; P < 0.001). Pore-loop regions were frequently associated with loss-of-function variants, whereas inactivation sites were associated with gain-of-function (odds ratio = 42.1, 95% confidence interval = 14.5-122.4; P < 0.001), whilst variants occurring in voltage-sensing regions comprised a range of gain- and loss-of-function effects. Our findings suggest that biophysical characterisation of variants in one SCN-gene can predict channel function across different SCN-genes where experimental data are not available. The collected data represent the first gain- versus loss-of-function topological map of SCN proteins indicating shared patterns of biophysical effects aiding variant analysis and guiding precision therapy. We integrated our findings into a free online webtool to facilitate functional sodium channel gene variant interpretation (http://SCN-viewer.broadinstitute.org).
Topics: Animals; Channelopathies; Peripheral Nervous System Diseases; Voltage-Gated Sodium Channels; Epilepsy; Phenotype; Mammals
PubMed: 35037686
DOI: 10.1093/brain/awac006 -
Molecular Pain 2021Trigeminal neuralgia (TN) is a severe facial pain disease of unknown cause and unclear genetic background. To examine the existing knowledge about genetics in TN, we...
Trigeminal neuralgia (TN) is a severe facial pain disease of unknown cause and unclear genetic background. To examine the existing knowledge about genetics in TN, we performed a systematic study asking about the prevalence of familial trigeminal neuralgia, and which genes that have been identified in human TN studies and in animal models of trigeminal pain. MedLine, Embase, Cochrane Library and Web of Science were searched from inception to January 2021. 71 studies were included in the systematic review. Currently, few studies provide information about the prevalence of familial TN; the available evidence indicates that about 1-2% of TN cases have the familial form. The available human studies propose the following genes to be possible contributors to development of TN: CACNA1A, CACNA1H, CACNA1F, KCNK1, TRAK1, SCN9A, SCN8A, SCN3A, SCN10A, SCN5A, NTRK1, GABRG1, MPZ gene, MAOA gene and SLC6A4. Their role in familial TN still needs to be addressed. The experimental animal studies suggest an emerging role of genetics in trigeminal pain, though the animal models may be more relevant for trigeminal neuropathic pain than TN per se. In summary, this systematic review suggests a more important role of genetic factors in TN pathogenesis than previously assumed.
Topics: Animals; Facial Pain; Humans; NAV1.7 Voltage-Gated Sodium Channel; Serotonin Plasma Membrane Transport Proteins; Trigeminal Neuralgia
PubMed: 34000891
DOI: 10.1177/17448069211016139 -
Clinical Pharmacology and Therapeutics Jul 2023The P-glycoprotein efflux pump, encoded by the ABCB1 gene, has been shown to alter concentrations of various antidepressants in the brain. In this study, we conducted a... (Meta-Analysis)
Meta-Analysis Review
The P-glycoprotein efflux pump, encoded by the ABCB1 gene, has been shown to alter concentrations of various antidepressants in the brain. In this study, we conducted a systematic review and meta-analysis to investigate the association between six ABCB1 single-nucleotide polymorphisms (SNPs; rs1045642, rs2032582, rs1128503, rs2032583, rs2235015, and rs2235040) and antidepressant treatment outcomes in individuals with major depressive disorder (MDD), including new data from the Canadian Biomarker and Integration Network for Depression (CAN-BIND-1) cohort. For the CAN-BIND-1 sample, we applied regression models to investigate the association between ABCB1 SNPs and antidepressant treatment response, remission, tolerability, and antidepressant serum levels. For the meta-analysis, we systematically summarized pharmacogenetic evidence of the association between ABCB1 SNPs and antidepressant treatment outcomes. Studies were included in the meta-analysis if they investigated at least one ABCB1 SNP in individuals with MDD treated with at least one antidepressant. We did not find a significant association between ABCB1 SNPs and antidepressant treatment outcomes in the CAN-BIND-1 sample. A total of 39 studies were included in the systematic review. In the meta-analysis, we observed a significant association between rs1128503 and treatment response (T vs. C-allele, odds ratio = 1.30, 95% confidence interval = 1.15-1.48, P value (adjusted) = 0.024, n = 2,526). We did not find associations among the six SNPs and treatment remission nor tolerability. Our findings provide limited evidence for an association between common ABCB1 SNPs and antidepressant outcomes, which do not support the implementation of ABCB1 genotyping to inform antidepressant treatment at this time. Future research, especially on rs1128503, is recommended.
Topics: Humans; Depressive Disorder, Major; Canada; Antidepressive Agents; ATP Binding Cassette Transporter, Subfamily B, Member 1; Biomarkers; Polymorphism, Single Nucleotide; Genotype; ATP Binding Cassette Transporter, Subfamily B
PubMed: 36681895
DOI: 10.1002/cpt.2854 -
Neuroscience and Biobehavioral Reviews Sep 2023Recent lifestyle changes have resulted in tremendous peer pressure and mental stress, and increased the incidences of chronic psychological disorders; like addiction,... (Review)
Review
Recent lifestyle changes have resulted in tremendous peer pressure and mental stress, and increased the incidences of chronic psychological disorders; like addiction, depression and anxiety (ADA). In this context, the stress-tolerance levels vary amongst individuals and genetic factors play prominent roles. Vulnerable individuals may often be drawn towards drug-addiction to combat stress. This systematic review critically appraises the relationship of various genetic factors linked with the incidences of ADA development. For coherence, we focused solely on cocaine as a substance of abuse in this study. Online scholarly databases were used to screen pertinent literature using apt keywords; and the final retrieval included 42 primary-research articles. The major conclusion drawn from this systematic analysis states that there are 51 genes linked with the development of ADA; and 3 (BDNF, PERIOD2 and SLC6A4) of them are common to all the three aspects of ADA. Further, inter-connectivity analyses of the 51 genes further endorsed the central presence of BDNF and SLC6A4 genes in the development of ADA disorders. The conclusions derived from this systematic study pave the way for future studies for the identification of diagnostic biomarkers and drug targets; and for the development of novel and effective therapeutic regimens against ADA.
Topics: Humans; Cocaine-Related Disorders; Depression; Brain-Derived Neurotrophic Factor; Anxiety; Anxiety Disorders; Cocaine; Serotonin Plasma Membrane Transport Proteins
PubMed: 37271299
DOI: 10.1016/j.neubiorev.2023.105270 -
American Journal of Obstetrics and... Jan 2023The contribution of genetic factors to the presence of an overactive bladder is recognized. This study aimed to (1) assemble and synthesize available data from studies... (Review)
Review
OBJECTIVE
The contribution of genetic factors to the presence of an overactive bladder is recognized. This study aimed to (1) assemble and synthesize available data from studies assessing differential gene expression in patients with overactive bladder vs controls without overactive bladder and (2) determine possible correlations and functional pathways between genes.
DATA SOURCES
We searched PubMed, Ovid or Medline, and Wiley Cochrane Central Register of Controlled Trials databases between January 1, 2000, and December 15, 2021.
STUDY ELIGIBILITY CRITERIA
Studies were included if gene expression was detected and quantified using molecular approaches performed on human bladder tissue specimens directly and excluded if the gene expression analysis was carried out from blood and urine specimens alone.
METHODS
A systematic review was completed to identify publications that reported differently expressed gene candidates among patients with overactive bladder vs healthy individuals. Gene networking connections and pathway analysis were performed employing Metascape software, where inputs were identified from our systematic review of differentially expressed genes in overactive bladder.
RESULTS
A total of 9 studies were included in the final analysis and 11 genes were identified as being up-regulated (purinergic receptor P2X 2 [P2RX2], smoothelin [SMTN], growth-associated protein 43 [GAP43], transient receptor potential cation channel subfamily M member 8 [TRPM8], cadherin 11 [CDH1], gap junction protein gamma 1 [GJC1], cholinergic receptor muscarinic 2 [CHRM2], cholinergic receptor muscarinic 3 [CHRM3], and transient receptor potential cation channel subfamily V member 4 [TRPV4]) or down-regulated (purinergic receptor P2X 2 [P2RX3] and purinergic receptor P2X 5 [P2RX5]) in patients with overactive bladder. Gene network analysis showed that genes are involved in chemical synaptic transmission, smooth muscle contraction, blood circulation, and response to temperature stimulus. Network analysis demonstrated a significant genetic interaction between TRPV4, TRPM8, P2RX3, and PR2X2 genes.
CONCLUSION
Outcomes of this systematic review highlighted potential biomarkers for treatment efficacy and have laid the groundwork for developing future gene therapies for overactive bladder in clinical settings.
Topics: Humans; Urinary Bladder, Overactive; TRPV Cation Channels; Genetic Markers; Cholinergic Antagonists; Receptors, Cholinergic; Receptors, Purinergic; Receptor, Muscarinic M3
PubMed: 35932882
DOI: 10.1016/j.ajog.2022.07.044 -
European Archives of... Oct 2023Allergic and non-allergic rhinorrhea in the forms of acute or chronic rhinosinusitis can mean a watery nasal discharge that is disabling. Primary objective was to review... (Review)
Review
PURPOSE
Allergic and non-allergic rhinorrhea in the forms of acute or chronic rhinosinusitis can mean a watery nasal discharge that is disabling. Primary objective was to review the evidence supporting the hypothesis that rhinorrhea is due to increased chloride secretion through the CFTR chloride channel.
METHODS
The structure of the evidence review followed the EQUATOR Reporting Guidelines. Databases searched from inception to February 2022 included Pubmed, EMBASE and the Cochrane library using keywords "Rhinorrhea", "chloride", "chloride channel", "CFTR" and "randomized controlled trial". Quality assessment was according to the Oxford Centre for Evidence-based Medicine.
RESULTS
49 articles were included. They included randomized controlled trials out of which subsets of data with the outcome of rhinorrhea on 6038 participants were analysed and in vitro and animal studies. The review revealed that drugs, which activate CFTR are associated with rhinorrhea. Viruses, which cause rhinorrhea like rhinovirus were found to activate CFTR. The chloride concentration in nasal fluid showed an increase in patients with viral upper respiratory tract infection. Increased hydrostatic tissue pressure, which is an activator of CFTR was observed in allergic upper airway inflammation. In this condition exhaled breath condensate chlorine concentration was found to be significantly increased. Drugs, which can reduce CFTR function including steroids, anti-histamines, sympathomimetic and anticholinergic drugs reduced rhinorrhea in randomized controlled trials.
CONCLUSIONS
A model of CFTR activation-mediated rhinorrhea explains the effectiveness of anticholinergic, sympathomimetic, anti-histamine and steroid drugs in reducing rhinorrhea and opens up avenues for further improvement of treatment by already known specific CFTR inhibitors.
Topics: Animals; Chloride Channels; Cystic Fibrosis Transmembrane Conductance Regulator; Chlorides; Sympathomimetics; Nasal Mucosa; Randomized Controlled Trials as Topic
PubMed: 37338585
DOI: 10.1007/s00405-023-08067-w -
Seizure Jan 2013The gamma-aminobutyric acid A receptor, gamma 2 (GABRG2) gene encodes the GABRγ2 protein, which has been implicated in susceptibility to epilepsy. Several studies have... (Meta-Analysis)
Meta-Analysis Review
PURPOSE
The gamma-aminobutyric acid A receptor, gamma 2 (GABRG2) gene encodes the GABRγ2 protein, which has been implicated in susceptibility to epilepsy. Several studies have examined a possible link between the exonic GABRG2 rs211037 locus and susceptibility to febrile seizure (FS) and idiopathic generalized epilepsy (IGE), however results have been inconclusive. We therefore performed a systematic review and meta-analysis to examine whether this polymorphism is associated with FS or IGE.
METHODS
Eight studies comprising 1871 epilepsy patients and 1387 controls, which evaluated association of the GABRG2 rs211037 polymorphism with susceptibility to epilepsy, were included in this meta-analysis. Meta-analysis was carried out separately for FS and IGE.
RESULTS
Meta-analysis showed a significant association between this polymorphism and susceptibility to FS in a codominant (TT vs. CC, OR 0.47, 95% CI 0.30-0.73, p=0.0008 and TT vs. CT, OR 0.59, 95% CI 0.42-0.83, p=0.003) and dominant (OR 0.54, 95% CI 0.39-0.75, p=0.0002) genetic models, influenced by two studies with small sample size. Neither allele nor genotype association was observed with IGE.
CONCLUSION
This study showed significant association of GABRG2 rs211037 with susceptibility to FS, caused by two studies with small sample sizes, however the possibility of false positive results due to the effect of significant studies for FS cannot be excluded. Future studies with larger sample sizes of these patients are suggested to verify the results.
Topics: Epilepsy; Genetic Association Studies; Genetic Predisposition to Disease; Humans; Polymorphism, Single Nucleotide; Receptors, GABA-A
PubMed: 23140995
DOI: 10.1016/j.seizure.2012.10.007 -
Mitochondrion May 2022Mitochondrial permeability transition pore (mPTP) is a channel that opens at the inner mitochondrial membrane under conditions of stress. Sirtuin 3 (Sirt3) is a... (Review)
Review
Mitochondrial permeability transition pore (mPTP) is a channel that opens at the inner mitochondrial membrane under conditions of stress. Sirtuin 3 (Sirt3) is a mitochondrial deacetylase known to play a major role in stress resistance and a regulatory role in cell death. This systematic review aims to elucidate the role of Sirt3 in mPTP inhibition. Electronic databases, including PubMed, EMBASE, Web of Science and Cochrane Library were searched up to May 2020. Original studies that investigated the relationship between Sirt3 and mPTP were included. Two reviewers independently extracted data on study characteristics, methods and outcomes. A total of 194 articles were found. Twenty-nine articles, which met criteria were included in the systematic review. Twenty-three studies provided evidence of the inhibitory effect of Sirt3 on the mPTP aperture. This review summarizes up-to-date evidence of the protective and inhibitory role of Sirt3 through deacetylating Cyclophilin D (CypD) on the mPTP aperture. Furthermore, we discuss the implications of this effect in disease.
Topics: Peptidyl-Prolyl Isomerase F; Mitochondrial Membrane Transport Proteins; Mitochondrial Permeability Transition Pore; Sirtuin 3
PubMed: 35346868
DOI: 10.1016/j.mito.2022.03.004 -
Drug Design, Development and Therapy 2018The aim of this study was to summarize the characteristics, efficacy, and safety of vesicular monoamine transporter-2 (VMAT-2) inhibitors for treating tardive dyskinesia... (Meta-Analysis)
Meta-Analysis Review
AIM
The aim of this study was to summarize the characteristics, efficacy, and safety of vesicular monoamine transporter-2 (VMAT-2) inhibitors for treating tardive dyskinesia (TD).
MATERIALS AND METHODS
We conducted a literature search in PubMed, Cochrane Database, and ClinicalTrials.gov, screening for systematic reviews, meta-analyses or double-blind, randomized, placebo-controlled trials (DBRPCTs) reporting efficacy or safety data of VMAT-2 inhibitors (tetrabenazine, deutetrabenazine, and valbenazine) in patients with TD. A random effects meta-analysis of efficacy and safety data from DBRPCTs was performed.
RESULTS
Two acute, 12-week DBRPCTs with deutetrabenazine 12-48 mg/day (n=413) and 4 acute, 4-6-week double-blind trials with valbenazine 12.5-100 mg/day (n=488) were meta-analyzable, without meta-analyzable, high-quality data for tetrabenazine. Regarding reduction in total Abnormal Involuntary Movement Scale (AIMS) scores (primary outcome), both deutetrabenazine (k=2, n=413, standardized mean difference [SMD] =-0.40, 95% confidence interval [CI] =-0.19, -0.62, <0.001; weighted mean difference (WMD) =-1.44, 95% CI =-0.67, -2.19, <0.001) and valbenazine (k=4, n=421, SMD =-0.58, 95% CI =-0.26, -0.91, <0.001; WMD =-2.07, 95% CI =-1.08, -3.05, <0.001) significantly outperformed placebo. Results were confirmed regarding responder rates (≥50% AIMS total score reduction; deutetrabenazine: risk ratio [RR] =2.13, 95% CI =1.10, 4.12, =0.024, number-needed-to-treat [NNT] =7, 95% CI =3, 333, =0.046; valbenazine: RR =3.05, 95% CI =1.81, 5.11, <0.001, NNT =4, 95% CI =3, 6, <0.001). Less consistent results emerged from patient-rated global impression-based response (=0.15) and clinical global impression for deutetrabenazine (=0.088), and for clinical global impression change for valbenazine (=0.67). In an open-label extension (OLE) study of deutetrabenazine (≤54 weeks) and a dose-blinded valbenazine study (≤48 weeks), responder rates increased over time. With valbenazine, discontinuation effects were studied, showing TD symptom recurrence towards baseline severity levels within 4 weeks after valbenazine withdrawal. No increased cumulative or specific adverse (AEs) events versus placebo (acute trials) in extension versus acute trial data were observed.
CONCLUSION
The 2 VMAT-2 inhibitors, valbenazine and deutetrabenazine, are effective in treating TD, both acutely and long-term, without concerns about increased risk of depression or suicide in the TD population. No head-to-head comparison among VMAT-2 inhibitors and no high-quality, meta-analyzable data are available for tetrabenazine in patients with TD.
Topics: Antipsychotic Agents; Humans; Randomized Controlled Trials as Topic; Tardive Dyskinesia; Tetrabenazine; Valine; Vesicular Monoamine Transport Proteins
PubMed: 29795977
DOI: 10.2147/DDDT.S133205 -
BMJ Clinical Evidence May 2011Acetylcholinesterase inhibition by organophosphorus pesticides or organophosphate nerve agents can cause acute parasympathetic system dysfunction, muscle weakness,... (Review)
Review
INTRODUCTION
Acetylcholinesterase inhibition by organophosphorus pesticides or organophosphate nerve agents can cause acute parasympathetic system dysfunction, muscle weakness, seizures, coma, and respiratory failure. Prognosis depends on the dose and relative toxicity of the specific compound, as well as pharmacokinetic factors.
METHODS AND OUTCOMES
We conducted a systematic review and aimed to answer the following clinical question: What are the effects of treatments for acute organophosphorus poisoning? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
RESULTS
We found 62 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
CONCLUSIONS
In this systematic review we present information relating to the effectiveness and safety of the following interventions: activated charcoal (single or multiple doses), alpha(2) adrenergic receptor agonists, atropine, benzodiazepines, butyrylcholinesterase replacement therapy, cathartics, extracorporeal clearance, gastric lavage, glycopyrronium bromide (glycopyrrolate), ipecacuanha (ipecac), magnesium sulphate, milk or other home remedy immediately after ingestion, N-methyl-D-aspartate receptor antagonists, organophosphorus hydrolases, oximes, removing contaminated clothes and washing the poisoned person, and sodium bicarbonate.
Topics: Acute Disease; Atropine; Charcoal; Gastric Lavage; Humans; Organophosphate Poisoning; Pesticides; Poisoning; Receptors, N-Methyl-D-Aspartate
PubMed: 21575287
DOI: No ID Found