The role of gut microbiota in the high-risk construct of severe mental disorders: A mini review

Severe mental disorders (SMD) are highly prevalent psychiatric conditions exerting an enormous toll on society. Therefore, prevention of SMD has received enormous attention in the last two decades. Preventative approaches are based on the knowledge and detailed characterization of the developmental stages of SMD and on risk prediction. One relevant biological component, so far neglected in high risk research, is microbiota. The human microbiota consists in the ensemble of microbes, including viruses, bacteria, and eukaryotes, that inhabit several ecological niches of the organism. Due to its demonstrated role in modulating illness and health, as well in influencing behavior, much interest has focused on the characterization of the microbiota inhabiting the gut. Several studies in animal models have shown the early modifications in the gut microbiota might impact on neurodevelopment and the onset of deficits in social behavior corresponding to distinct neurosignaling alterations. However, despite this evidence, only one study investigated the effect of altered microbiome and risk of developing mental disorders in humans, showing that individuals at risk for SMD had significantly different global microbiome composition than healthy controls. We then offer a developmental perspective and provided mechanistic insights on how changes in the microbiota could influence the risk of SMD. We suggest that the analysis of microbiota should be included in the comprehensive assessment generally performed in populations at high risk for SMD as it can inform predictive models and ultimately preventative strategies

Surviving to acute myocardial infarction: The role of psychological factors and alexithymia in delayed time to searching care: A systematic review

The time from symptom onset to reperfusion is a critical determinant of myocardial salvage and clinical outcomes in patients with acute myocardial infarction (AMI). This time period could be delayed if people do not seek help promptly and/or if the health system is not efficient in responding quickly and attending to these individuals. The aim of this study was to identify psychological factors associated with pre-hospital delay (PHD) or patients’ decisional delay (PDD) in people with an ongoing AMI. A search in PubMed/Medline from 1990 to 2021 with the keywords “pre-hospital delay” OR “prehospital delay” OR “patient delay” OR “decisional delay” OR “care seeking behavior” AND “psychological factors” OR “alexithymia” AND “myocardial infarction” was performed. Thirty-six studies were included, involving 10.389 patients. Wrong appraisal, interpretation and causal beliefs about symptoms, denial of the severity of the symptoms and high levels of alexithymia were found related to longer PHD or PDD. Alexithymia may be an overarching construct that explains the disparate findings of the studies exploring the role of psychological factors in PHD or PDD. Further studies are needed in order to analyse the role of alexithymia in patients with risk factors for AMI to prevent delay

Surviving to acute myocardial infarction: The role of psychological factors and alexithymia in delayed time to searching care: A systematic review

The time from symptom onset to reperfusion is a critical determinant of myocardial salvage and clinical outcomes in patients with acute myocardial infarction (AMI). This time period could be delayed if people do not seek help promptly and/or if the health system is not efficient in responding quickly and attending to these individuals. The aim of this study was to identify psychological factors associated with pre-hospital delay (PHD) or patients’ decisional delay (PDD) in people with an ongoing AMI. A search in PubMed/Medline from 1990 to 2021 with the keywords “pre-hospital delay” OR “prehospital delay” OR “patient delay” OR “decisional delay” OR “care seeking behavior” AND “psychological factors” OR “alexithymia” AND “myocardial infarction” was performed. Thirty-six studies were included, involving 10.389 patients. Wrong appraisal, interpretation and causal beliefs about symptoms, denial of the severity of the symptoms and high levels of alexithymia were found related to longer PHD or PDD. Alexithymia may be an overarching construct that explains the disparate findings of the studies exploring the role of psychological factors in PHD or PDD. Further studies are needed in order to analyse the role of alexithymia in patients with risk factors for AMI to prevent delay

Expression of l1 cell adhesion molecule (l1cam) in extracellular vesicles in the human spinal cord during development

OBJECTIVE: L1 cell adhesion molecule (L1CAM) is a glycoprotein characterized by three components: an extracellular region, a transmembrane segment, and a cytoplasmic tail. L1CAM is expressed in multiple human cells, including neurons. The neural cell adhesion molecule L1 has been implicated in a variety of neurologic processes, including neuritogenesis and cerebellar cell migration. The presence of L1CAM on the surface of nerve cells allows the adhesion of neurons among them. Furthermore, when it is bound to itself or to other proteins, L1-CAM induces signals inside the cell. The aim of this work was to study L1CAM expression in the human spinal cord during development, at different gestational ages, through immunohistochemistry. MATERIALS AND METHODS: Immunohistochemical analysis for L1CAM was performed in five human spinal cord samples, including three embryos and two fetuses of different gestational ages, ranging from 8 to 12 weeks. RESULTS: L1CAM expression was detected in all 5 spinal cords examined in this study. The adhesion molecule was found in the vast majority of cells. The highest levels of immunoreactivity for L1CAM were detected at the periphery of the developing organs, in the spinal cord zones occupied by sensory and motor fibers. In the alar and basal columns, immunoreactivity for L1CAM was characterized by a reticular pattern, being mainly expressed in axons. Strong reactivity of L1CAM was also found in extracellular vesicles. This extracellular localization might indicate the ability of L1CAM to mediate the transduction of extracellular signals that support axon outgrowth. CONCLUSIONS: The high reactivity of L1cam in the axons of developing neurons in the fetal spinal cord confirms previous studies on the ability of L1CAM to promote axon sprouting and branching in the developing nervous system. In this work, a new actor is reported to have a role in the complex field of human spinal cord development: L1CAM, whose expression is highly found in the developing neuronal and glial precursors

Identifying Neurobiological Markers in Obsessive–Compulsive Disorder: A Study Protocol for a Cross-Sectional Study in Subgroups of Differing Phenotype

Obsessive–compulsive disorder (OCD) represents a frequent and highly disabling mental disorder. Past attempts to characterize different disease subgroups focused on the time of onset (late vs. early onset), presence of insight (poor insight), and post-infectious forms (pediatric acuteonset neuropsychiatric syndrome, PANS). Each subgroup may be associated with a differing impact on cognition, functioning, sleep quality, and treatment response profile. Certain lines of evidence suggest brain-derived neurotrophic factor (BDNF) levels may differ between individuals living with OCD as compared with controls, but there is a lack of evidence on the variation of BDNF levels in OCD subgroups. Lastly, the potential of assessing inflammatory states, electroencephalogram, and polysomnography to characterize these subtypes has been hardly explored. Estimates of drugresistance rates indicate that 20% and up to 65% of affected adults and up to 35% of the pediatric population may not benefit from pharmacological treatments. At least part of the variability in treatment response could depend on the underlying biological heterogeneity. In the present project, we aim to increase the accuracy in characterizing the phenotypical and biological signature for the different OCD subtypes through clinical, cognitive, and sleep markers, along with other possible markers that may be biologically plausible

Open-label add-on treatment trial of minocycline in fragile X syndrome

<p>Abstract</p> <p>Background</p> <p>Fragile X syndrome (FXS) is a disorder characterized by a variety of disabilities, including cognitive deficits, attention-deficit/hyperactivity disorder, autism, and other socio-emotional problems. It is hypothesized that the absence of the fragile X mental retardation protein (FMRP) leads to higher levels of matrix metallo-proteinase-9 activity (MMP-9) in the brain. Minocycline inhibits MMP-9 activity, and alleviates behavioural and synapse abnormalities in <it>fmr1 </it>knockout mice, an established model for FXS. This open-label add-on pilot trial was conducted to evaluate safety and efficacy of minocycline in treating behavioural abnormalities that occur in humans with FXS.</p> <p>Methods</p> <p>Twenty individuals with FXS, ages 13-32, were randomly assigned to receive 100 mg or 200 mg of minocycline daily. Behavioural evaluations were made prior to treatment (baseline) and again 8 weeks after daily minocycline treatment. The primary outcome measure was the Aberrant Behaviour Checklist-Community Edition (ABC-C) Irritability Subscale, and the secondary outcome measures were the other ABC-C subscales, clinical global improvement scale (CGI), and the visual analog scale for behaviour (VAS). Side effects were assessed using an adverse events checklist, a complete blood count (CBC), hepatic and renal function tests, and antinuclear antibody screen (ANA), done at baseline and at 8 weeks.</p> <p>Results</p> <p>The ABC-C Irritability Subscale scores showed significant improvement (p < 0.001), as did the VAS (p = 0.003) and the CGI (p < 0.001). The only significant treatment-related side effects were minor diarrhea (n = 3) and seroconversion to a positive ANA (n = 2).</p> <p>Conclusions</p> <p>Results from this study demonstrate that minocycline provides significant functional benefits to FXS patients and that it is well-tolerated. These findings are consistent with the <it>fmr1 </it>knockout mouse model results, suggesting that minocycline modifies underlying neural defects that account for behavioural abnormalities. A placebo-controlled trial of minocycline in FXS is warranted.</p> <p>Trial registration</p> <p>ClinicalTrials.gov Open-Label Trial NCT00858689.</p

Targeted treatments for fragile X syndrome

Fragile X syndrome (FXS) is the most common identifiable genetic cause of intellectual disability and autistic spectrum disorders (ASD), with up to 50% of males and some females with FXS meeting criteria for ASD. Autistic features are present in a very high percent of individuals with FXS, even those who do not meet full criteria for ASD. Recent major advances have been made in the understanding of the neurobiology and functions of FMRP, the FMR1 (fragile X mental retardation 1) gene product, which is absent or reduced in FXS, largely based on work in the fmr1 knockout mouse model. FXS has emerged as a disorder of synaptic plasticity associated with abnormalities of long-term depression and long-term potentiation and immature dendritic spine architecture, related to the dysregulation of dendritic translation typically activated by group I mGluR and other receptors. This work has led to efforts to develop treatments for FXS with neuroactive molecules targeted to the dysregulated translational pathway. These agents have been shown to rescue molecular, spine, and behavioral phenotypes in the FXS mouse model at multiple stages of development. Clinical trials are underway to translate findings in animal models of FXS to humans, raising complex issues about trial design and outcome measures to assess cognitive change that might be associated with treatment. Genes known to be causes of ASD interact with the translational pathway defective in FXS, and it has been hypothesized that there will be substantial overlap in molecular pathways and mechanisms of synaptic dysfunction between FXS and ASD. Therefore, targeted treatments developed for FXS may also target subgroups of ASD, and clinical trials in FXS may serve as a model for the development of clinical trial strategies for ASD and other cognitive disorders

FMR1 premutation and full mutation molecular mechanisms related to autism

Fragile X syndrome (FXS) is caused by an expanded CGG repeat (>200 repeats) in the 5′ un-translated portion of the fragile X mental retardation 1 gene (FMR1) leading to a deficiency or absence of the FMR1 protein (FMRP). FMRP is an RNA-binding protein that regulates the translation of a number of other genes that are important for synaptic development and plasticity. Furthermore, many of these genes, when mutated, have been linked to autism in the general population, which may explain the high comorbidity that exists between FXS and autism spectrum disorders (ASD). Additionally, premutation repeat expansions (55 to 200 CGG repeats) may also give rise to ASD through a different molecular mechanism that involves a direct toxic effect of FMR1 mRNA. It is believed that RNA toxicity underlies much of the premutation-related involvement, including developmental concerns like autism, as well as neurodegenerative issues with aging such as the fragile X-associated tremor ataxia syndrome (FXTAS). RNA toxicity can also lead to mitochondrial dysfunction, which is common in older premutation carriers both with and without FXTAS. Many of the problems with cellular dysregulation in both premutation and full mutation neurons also parallel the cellular abnormalities that have been documented in idiopathic autism. Research regarding dysregulation of neurotransmitter systems caused by the lack of FMRP in FXS, including metabotropic glutamate receptor 1/5 (mGluR1/5) pathway and GABA pathways, has led to new targeted treatments for FXS. Preliminary evidence suggests that these new targeted treatments will also be beneficial in non-fragile X forms of autism