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Background Inflammatory responses play key roles in the development and progression of many pathological conditions, including neurodegenerative diseases. Accurate quantification of inflammatory factors in saliva would be highly advantageous, given its convenience and non-invasive nature, especially in elderly populations. Methods In this study, we measured levels of 10 cytokines, and the pro-inflammatory factor, YKL-40, in plasma and saliva samples from a cohort of nondemented older adults (n = 71; 62% female; 70.3 ± 6.4 years) using sensitive electrochemiluminescence-based immunoassays. Results We found that the mean levels of all cytokines were higher in saliva compared to plasma and that strong sex differences were observed for both saliva and plasma cytokines in this population. Comparing each cytokine between the two biofluids, we found that levels of interferon-gamma (IFNγ), interleukin (IL)-6 and tumor necrosis factor-alpha (TNFα) in blood were significantly correlated with their respective levels in saliva. We further observed that levels of these cytokines in blood were significantly correlated with additional cytokines in saliva, including IL-1β, IL-10, IL-8, IL12p70 and IL-13. Conclusions These findings show that inflammatory markers in saliva are associated with those found in circulation, suggesting shared inflammatory mechanisms between these two fluids. The higher levels of cytokines measured in saliva suggest that it might represent a better peripheral fluid to gauge inflammatory processes. Finally, our findings of robust sex differences in several salivary cytokines could have important implications for their potential use as disease biomarkers in the elderly and might be related to sex differences in the prevalence of age-related conditions.

IntroductionMeasuring Huntingtin (Htt) protein in peripheral cells represents an essential step in biomarker discovery for Huntington’s Disease (HD), however to date, investigations into the salivary expression of Htt has been lacking.MethodIn the current study, we quantified total Htt (tHtt) and mutant Htt (mHtt) protein in matched blood and saliva samples using single molecule counting (SMC) immunoassays: 2B7-D7F7 (tHtt) and 2B7-MW1 (mHtt). Matched samples, and clinical data, were collected from 95 subjects: n=19 manifest HD, n=34 premanifest HD (PM), and n=42 normal controls (NC). ResultsTotal Htt and mHtt levels were not correlated in blood and saliva. Plasma tHtt was significantly associated with age, and participant sex; whereas salivary mHtt was significantly correlated with age, CAG repeat length and CAP score. Plasma and salivary tHtt did not differ across cohorts. Salivary and plasma mHtt were significantly increased in PM compared to NC; salivary mHtt was also significantly increased in HD compared to NC. Only salivary tHtt and mHtt were significantly correlated with clinical measures.Conclusions Salivary Htt is uniquely associated with clinical measures of HD and offers significant promise as a relevant, non-invasive HD biomarker. Its use could be immediately implemented into both translational and clinical research applications.

ObjectiveTo investigate whether plasma NfL levels correlate with clinical symptom severity in premanifest (PM) and manifest HD (HD) individuals, and whether a NfL cut-point could distinguish PM from HD patients with reasonable accuracy.Method98 participants (33 control, 26 PM, 39 HD), underwent blood sample collection and clinical assessment, using both UHDRS and non-UHDRS measures, at one academic HD Center. Years to onset (YTO), probability of disease onset in 5 years, and predicted years until 60% onset probability were also calculated. NfL levels were measured using a Meso Scale Discovery assay.ResultsCohorts differed by age. NfL levels differed significantly across diagnostic groups and were significantly correlated with age. Age-adjusted NfL levels were not correlated with clinical measures in either HD or PM cohorts, but were correlated when cohorts were combined. In PM subjects, NfL levels correlated with YTO, probability of onset in 5 years, and years until 60% onset probability. Using ROC analysis, a NfL cut-point of

Inflammatory responses play key roles in the development and progression of many pathological conditions, including neurodegenerative conditions. Accurate quantification of inflammatory factors in saliva would be highly advantageous, given its convenience and non-invasive nature, enabling use as biomarkers for disease processes especially in older adults. However, few studies have attempted to validate salivary assays by directly comparing cytokine levels in blood and saliva samples the same individuals. In this study, we measured levels of 10 cytokines, interferon gamma (IFNg), interleukin (IL)-1 beta (IL-1b), IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13 and tumor necrosis factor alpha (TNFa), as well as the inflammatory glycoprotein, YKL-40, in blood and saliva samples from a cohort of nondemented older adults (n = 71; 62% female; mean age 70.3 +/- 6.4 yrs; ) using sensitive electrochemiluminescence-based immunoassays. We found that the mean levels of all cytokines were higher in saliva compared to plasma, and specifically that levels of IL-1b, IL-2, IL-4, IL-12p70 and IL-13 in plasma were below the instrument detection limit for more than 50% of the subjects. We found strong sex differences in both saliva and plasma cytokines, with levels of several salivary cytokines, as well as YKL-40, showing higher concentrations in males compared to females. Comparing each cytokine between the two biofluids, we found that levels of IFNg, IL-6 and TNFa in blood were significantly correlated with their respective levels in saliva. We further observed that levels of these cytokines in blood were significantly correlated with additional cytokines in saliva, including IL-1b, IL-10, IL-8, IL12p70 and IL-13. These findings show that inflammatory markers in saliva are associated with those found in circulation, suggesting that inflammatory mechanisms between these two fluids are, at least to some extent, related. Consistent with prior work, several salivary markers were more likely to surpass the detection threshold than plasma markers, suggesting that salivary assays may, at least in some cases, be more useful for detecting physiological changes. Further our findings of robust sex differences in several salivary cytokines could have important implications for their potential use as health or disease biomarkers.

IntroductionThe inclusion of premanifest Huntington's Disease (Pre-HD) subjects in clinical trials necessitates selecting those who are near transition to manifest Huntington's disease (Man-HD). We previously determined that plasma neurofilament light (NfL) levels are significantly correlated with predicted years to Man-HD onset, using established formulae. Recently, a new normalized prognostic index (PIN) score for predicting Pre-HD disease progression has been validated. Our objective was to determine whether plasma NfL levels are similarly associated with PIN score and PIN score-derived years to Man-HD onset (PIN-YTO).Method112 individuals (46 Pre-HD, 66 Man-HD) underwent blood sample collection and clinical assessment, inclusive of the Symbol Digit Modalities Test and Unified Huntington's Disease Rating Scale Total Motor Score. Plasma NfL levels were measured using a Meso Scale Discovery assay.ResultsPre-HD and Man-HD cohorts differed by age (p10 predicted years from Man-HD onset, compared to those ≤10 predicted years.ConclusionsWe have extensively shown that plasma NfL levels are associated with predicted years to manifest HD onset in Pre-HD participants, and present a plasma NfL cut-point that may help exclude far-from-onset Pre-HD patients from clinical trials.

The narrow therapeutic window of lithium medications necessitates frequent serum monitoring, which can be expensive and inconvenient for the patient. The use of saliva as a biofluid may have advantages over blood, as it is non-invasive, easier to collect, requires less processing, and can be collected without the need for trained personnel. This study investigated the utility of saliva as a longitudinal means of monitoring lithium levels. We measured lithium levels using Inductively-Coupled Plasma Optical Emission Spectrometry (ICP-OES) in n=171 saliva samples collected via the passive drool method, from a multi-center cohort consisting of n=75 patients with bipolar disorder or other psychiatric conditions. We found that saliva and serum levels of lithium were highly correlated (unadjusted Spearman r=0.74, ppp Data availability statement Anonymized summary data will be shared by reasonable formal request from qualified researchers, subject to a data sharing agreement and in compliance with the requirements of the funding bodies and institutions.

The Sports Concussion Assessment Tool-5th Edition (SCAT5) and the child version (Child SCAT5) are the current editions of the SCAT and have updated the memory testing component from previous editions. This study aimed to validate this new memory component against the Rey Auditory Verbal Learning Test (RAVLT) as the validated standard. This prospective, observational study, carried out within The Royal Children's Hospital Emergency Department, Melbourne, Australia, recruited 198 participants: 91 with concussion and 107 upper limb injury or healthy sibling controls. Partial Pearson correlations showed that memory acquisition and recall on delay aspects of the SCAT5 were significantly correlated with the RAVLT equivalents when controlling for age (

Growing evidence suggests that inflammatory responses, in both the brain and peripheral tissues, contribute to disease pathology in Huntington&rsquo, s disease (HD), an inherited, progressive neurodegenerative disorder typically affecting adults in their 30&ndash, 40 s. Hence, studies of inflammation-related markers in peripheral fluids might be useful to better characterize disease features. In this study, we measured levels of C-reactive protein (CRP), Interleukin-6 (IL-6), interleukin 1 beta (IL-1B), and alpha-amylase (AA) in saliva and plasma from n = 125 subjects, including n = 37 manifest HD patients, n = 36 premanifest patients, and n = 52 healthy controls, using immunoassays. We found increases in salivary levels of IL-6, IL-1B and CRP across different disease groups and increased levels of IL-6 in the plasma of HD patients as compared to premanifest patients and controls. The levels of salivary IL-6 were significantly correlated with each of the other salivary markers, as well as with IL-6 levels measured in plasma. Further, salivary IL-6 and IL-1B levels were significantly positively correlated with Total Motor Score (TMS) and chorea scores and negatively correlated with Total Functional Capacity (TFC) in HD patients, whereby in healthy control subjects, IL-6 was significantly negatively correlated with Montreal Cognitive Assessment (MoCA) and the Symbol Digit Modalities test (SDM). Interestingly, the plasma levels of IL-6 did not show similar correlations to any clinical measures in either HD or control subjects. These findings suggest that salivary IL-6 is particularly relevant as a potential non-invasive biomarker for HD symptoms. The advent of an effective, dependable salivary biomarker would meet the urgent need for a less invasive means of identifying and monitoring HD disease progression.

Objective To summarize all current studies focusing on blood biomarkers in paediatric mild traumatic brain injury (mTBI) and to outline the possible use of blood biomarkers for diagnostic, prognostic and monitoring purposes within this setting. Methods A systematic review following the PRISMA guidelines was conducted using the MEDLINE, PubMed and EMBASE databases. Results A total of 21 studies were included in the review, encompassing a total of 14 different biomarkers. Seventeen (81%) of these studies found a significant association between biomarker concentration and mTBI characteristics, however results from studies to date are diverse and at times conflicting. Conclusion GFAP appears to be a promising blood biomarker for the prognosis and monitoring of mTBI, whereas UCH-L1 appears more promising at mTBI diagnosis. Despite this, the overall heterogeneity in assessed biomarkers, study design and measurement tools has made drawing specific conclusions challenging. Future research will require more uniform study design and methodological approaches to allow for the comparison, corroboration and validation of blood biomarkers within the context of paediatric mTBI.

By age 16, 20% of children will suffer a concussion. Many experience persisting post-concussive symptoms (PCS), the cause(s) of which remain unclear. We mapped concussion recovery to 3 months post-injury and explored non-modifiable (e.g., age, sex, pre-injury factors, injury mechanism, acute PCS) and modifiable (post-acute child symptoms) predictors of persisting symptoms in order to identify opportunities for early intervention. We conducted a prospective, longitudinal study in the emergency department of a tertiary, pediatric hospital recruiting children within 48 h of concussion (T0), with follow-up at 2 days (T1), 2 weeks (T2), 1 month (T3), and 3 months (T4). Primary outcome was T2 clinician diagnosis. Clinical history, injury mechanism, acute symptoms, and physical and cognitive function were assessed. Parents rated child behavior and fatigue, and their mental health. We enrolled 256 participants, 72% males: 62 (24.3%) were symptomatic at T2. Recovered and symptomatic groups endorsed similar pre-injury PCS, but group differences were found at T1 across all PCS subscales, except Emotional, where symptoms were not evident until T2. By T2, there was significant PCS reduction, steepest in the "Recovered" group, which also had a lower rate of pre-injury psychiatric diagnoses, acute CT scans and less severe parent-rated PCS at T1 than the symptomatic group. They all demonstrated lower parent-rated PCS and less internalizing behaviors (all, p

Excitatory amino acid transporter (EAAT)1 and EAAT2 mediate glutamatergic neurotransmission and prevent excitotoxicity through binding and transportation of glutamate into glia. These EAATs may be regulated by metabotropic glutamate receptor 5 (mGluR5), which is also expressed by glia. Whilst we have data from an Affymetrix™ Human Exon 1.0 ST Array showing higher levels of EAAT1 mRNA (+36%) in Brodmann's are (BA)9 of subjects with schizophrenia, there is evidence that EAAT1 and EAAT2, as well as mGluR5 levels, are altered in the cortex of subjects with the disorder. Hence, we measured mRNA levels of these genes in other cortical regions in subjects with that disorder. EAAT1, EAAT2 and mGluR5 mRNA were measured, in triplicate, using Quantitative PCR in BA10 and BA46 from subjects with schizophrenia (n = 20) and age and sex matched controls (n = 18). Levels of mRNA were normalised to the geometric mean of two reference genes, transcription factor B1, mitochondrial (TFB1M) and S-phase kinase-associated protein 1A (SKP1A), for which mRNA did not vary between diagnostic groups in either region. Normalised levels of EAAT1 and EAAT2 mRNA were significantly higher in BA10 (EAAT1: U = 58, p = 0.0002; EAAT2 U = 70, p = 0.0009), but not BA46 (EAAT1: U = 122, p = 0.09; EAAT2: U = 136, p = 0.21), from subjects with schizophrenia compared to controls. mGluR5 levels in BA10 (U = 173, p=0.85) and BA46 (U = 178, p = 0.96) did not vary by cohort. Our data suggests that region-specific increases in cortical EAAT1 and EAAT2 mRNA are involved in schizophrenia pathophysiology and that disrupted glutamate uptake in schizophrenia may be of particular significance in BA10.

Having reported associations between catechol-O-methyltransferase (COMT) genotypes at SNPs rs4818 and rs4680 with levels of soluble COMT (S-COMT) in human dorsolateral prefrontal cortex (DLPFC), we postulated that changes in the levels of cortical S-COMT could impact on behavioural abilities associated with COMT genotype through S-COMT-mediated changes in gene expression. To test this hypothesis, we have examined the relationships between COMT genotypes and gene expression measured using the Affymetrix™ Human Exon 1.0 ST Array in the DLPFC from 141 individuals, some of whom had had a psychiatric disorder. There were significant differences in levels of expression of 15 genes between individuals with a homozygous genotype at rs4818 (GG vs CC), compared to differences in levels of expression of 6 genes between homozygotes at rs4680 (GG vs AA); levels of expression of CEP128, EFCAB13, and FAM133A differed between homozygotes at both SNPs. Fourteen of the genes differentially expressed in the DLPFC according to COMT genotypes have oestrogen receptor elements and their expression could, therefore, be regulated by catecholestrogens, which are substrates for COMT that occupy and activate oestrogen receptors. In addition, the changes in gene expression between the homozygotes at rs4818 or rs4680 would be expected to impact on neuronal function, synaptic plasticity, cognition, and attention. These data would support a hypothesis that the mechanism underlying the association between COMT genotype and cognition involves differential changes in cortical gene expression.

IntroductionThe majority of children who sustain a concussion will recover quickly, but a significant minority will experience ongoing postconcussive symptoms, known as postconcussion syndrome (PCS). These symptoms include emotional, behavioural, cognitive and physical symptoms and can lead to considerable disability. The neurobiological underpinnings of PCS are poorly understood, limiting potential clinical interventions. As such, patients and families frequently re-present to clinical services, who are often ill equipped to address the multifactorial nature of PCS. This contributes to the high cost of concussion management and the disability of children experiencing PCS. The aims of the present study are: (1) to plot and contrast recovery pathways for children with concussion from time of injury to 3 months postinjury, (ii) evaluate the contribution of acute biomarkers (ie, blood, MRI) to delayed recovery postconcussion and (3) estimate financial costs of child concussion to patients attending the emergency department (ED) of a tertiary children’s hospital and factors predicting high cost.Methods and analysisTake C.A.Re is a prospective, longitudinal study at a tertiary children’s hospital, recruiting and assessing 525 patients aged 5–Ethics and disseminationEthical approval has been obtained through the Royal Children’s Hospital Melbourne Human Research Ethics Committee (33122). We aim to disseminate the findings through international conferences, international peer-reviewed journals and social media.Trial registration numberACTRN12615000316505; Results.

IntroductionWhile most children recover from a concussion shortly after injury, approximately 30% experience persistent postconcussive symptoms (pPCS) beyond 1-month postinjury. Existing research into the treatment of pPCS have evaluated unimodal approaches, despite evidence suggesting that pPCS likely represent an interaction across various symptom clusters. The primary aim of this study is to evaluate the effectiveness of a multimodal, symptom-tailored intervention to accelerate symptom recovery and increase the proportion of children with resolved symptoms at 3 months postconcussion.Methods and analysisIn this open-label, assessor-blinded, randomised clinical trial, children with concussion aged 8–18 years will be recruited from The Royal Children’s Hospital (The RCH) emergency department, or referred by a clinician, within 17 days of initial injury. Based on parent ratings of their child’s PCS at ~10 days postinjury, symptomatic children (≥2 symptoms at least 1-point above those endorsed preinjury) will undergo a baseline assessment at 3 weeks postinjury and randomised into either Concussion Essentials (CE, n=108), a multimodal, interdisciplinary delivered, symptom-tailored treatment involving physiotherapy, psychology and education, or usual care (UC, n=108) study arms. CE participants will receive 1 hour of intervention each week, for up to 8 weeks or until pPCS resolve. A postprogramme assessment will be conducted at 3 months postinjury for all participants. Effectiveness of the CE intervention will be determined by the proportion of participants for whom pPCS have resolved at the postprogramme assessment (primary outcome) relative to the UC group. Secondary outcome analyses will examine whether children receiving CE are more likely to demonstrate resolution of pPCS, earlier return to normal activity, higher quality of life and a lower rate of utilisation of health services, compared with the UC group.Ethics and disseminationEthics were approved by The RCH Human Research Ethics Committee (HREC: 37100). Parent, and for mature minors, participant consent, will be obtained prior to commencement of the trial. Study results will be disseminated at international conferences and international peer-reviewed journals.Trial registration numberACTRN12617000418370; pre-results.

Levels of a reference protein must be the same as a proportion of total protein in all tissues and, in the study of human diseases, cannot vary with factors such as age, gender or disease pathophysiology. It is increasingly apparent that there may be few, if any, proteins that display the characteristics of a reference protein within the human central nervous system (CNS). To begin to challenge this hypothesis, we used Western blotting to compare variance in levels of the "gold standard" reference protein, β-actin, in Brodmann's area 9 from 194 subjects to variance of total transferred protein measured as intensity of Ponceau S staining. The coefficient of variance of sum intensity measurements for β-actin levels across all donors was 47% compared to 24 and 27% for the sum intensity of Ponceau S staining measured using two different detection techniques. These data strongly suggest that the level of β-actin, proportional to total protein, is not constant in human cortex which raises further doubt about the use of reference proteins to normalise data in human CNS studies. Considering our data, we suggest an alternative approach to presenting data from Western blotting of human CNS.

Catechol-O-methyltransferase (COMT) is an enzyme that catalyses the O-methylation, and thereby the inactivation, of catechol-containing molecules. In humans, it has been suggested that COMT modulates cognitive ability, possibly by regulating degradation of dopamine in the prefrontal cortex. Hence, it is significant that two COMT SNPs, rs4680 (c.472 G > A, p.Val158Met) and rs4818 (c.408 C > G), have been associated with cognitive ability in humans. We have shown these SNPs to be associated with levels of muscarinic M1 receptor mRNA in human cortex, which is significant as that receptor also regulates cognitive ability. We decided to determine if COMT genotype was associated with varying levels of COMT protein, as this could be a mechanism by which COMT genotype could be associated with changes in muscarinic M1 receptor mRNA levels. Hence, we measured COMT levels in prefrontal cortex obtained postmortem from 199 subjects, some of whom had a history of schizophrenia, major depressive disorders or bipolar disorders. Our data show, independent of diagnostic status, that genotype at rs4680 and rs4818, but not at rs737865 and rs165599, is associated with differing levels of soluble COMT (S-COMT), but not membrane-bound COMT (MB-COMT). These findings suggest that the association between COMT polymorphisms and cognitive functioning could be, at least in part, due to their association with varying levels of S-COMT. This is important as, unlike MB-COMT, the substrates targeted by S-COMT are likely to be intra-cellular rather than, like dopamine, located mainly in the synaptic vesicles or the extra-cellular space.

Glutamate is the predominant excitatory neurotransmitter in the human brain and it has been shown that prolonged activation of the glutamatergic system leads to nerve damage and cell death. Following release from the pre-synaptic neuron and synaptic transmission, glutamate is either taken up into the pre-synaptic neuron or neighbouring glia by transmembrane glutamate transporters. Excitatory amino acid transporter (EAAT) 1 and EAAT2 are Na+-dependant glutamate transporters expressed predominantly in glia cells of the central nervous system. As the most abundant glutamate transporters, their primary role is to modulate levels of glutamatergic excitability and prevent spill over of glutamate beyond the synapse. This role is facilitated through the binding and transportation of glutamate into astrocytes and microglia. The function of EAAT1 and EAAT2 is heavily regulated at the levels of gene expression, post-transcriptional splicing, glycosylation states and cell-surface trafficking of the protein. Both glutamatergic dysfunction and glial dysfunction have been proposed to be involved in psychiatric disorder. This review will present an overview of the roles that EAAT1 and EAAT2 play in modulating glutamatergic activity in the human brain, and mount an argument that these two transporters could be involved in the aetiologies of schizophrenia and affective disorders as well as represent potential drug targets for novel therapies for those disorders.

In developing brain neuronal migration, dendrite outgrowth and dendritic spine outgrowth are controlled by Cdc42, a small GTPase of the Rho family, and its activators. Cdc42 function in promoting actin polymerization is crucial for glutamatergic synapse regulation. Here, we focus on GABAergic synapse-specific activator of Cdc42, collybistin (CB) and examine functional differences between its splice isoforms CB1 and CB2. We report that CB1 and CB2 differentially regulate GABAergic synapse formation in vitro along proximal-distal axis and adult-born neuron maturation in vivo. The functional specialization between CB1 and CB2 isoforms arises from their differential protein half-life, in turn regulated by ubiquitin conjugation of the unique CB1 C-terminus. We report that CB1 and CB2 negatively regulate Cdc42; however, Cdc42 activation is dependent on CB interaction with gephyrin. During hippocampal adult neurogenesis CB1 regulates neuronal migration, while CB2 is essential for dendrite outgrowth. Finally, using mice lacking Gabra2 subunit, we show that CB1 function is downstream of GABAARs, and we can rescue adult neurogenesis deficit observed in Gabra2 KO. Overall, our results uncover previously unexpected role for CB isoforms downstream of α2-containing GABAARs during neuron maturation in a Cdc42 dependent mechanism., Author summary GABAergic inhibition regulates distinct stages of brain development; however, cellular mechanisms downstream of GABAA receptors (GABAARs) that influence neuronal migration, maturation and synaptogenesis are less clear. ArfGEF9 encodes for RhoGEF with Cdc42 and TC10 GTPase as its substrates. Interestingly, ArhGEF9 is the only known RhoGEF essential for GABAergic synapse formation and maintenance. We report that during brain development ArfGEF9 mRNA splicing regulation generates different ratios of CB1 and CB2 splice isoforms. CB1 mRNA splicing is enhanced during early brain developmental, while CB2 levels remains constant throughout brain development. We also show that CB1 protein has shorter half-life and ubiquitin proteasome system restricts CB1 abundance within developing neuron to modulate neuron migration and distributing GABAergic synapse along the proximal-distal axis. On the other hand, CB2 isoform although expressed abundantly throughout brain development is essential for neuron dendrite maturation. Together, our data identifies specific post-transcriptional and post-translational mechanisms downstream of GABAARs influencing ArhGEF9 function to regulate distinct aspects of neuronal maturation process.