Chromosomal abnormalities and schizophrenia.
Bassett A S,Chow E W,Weksberg R
American journal of medical genetics
Schizophrenia is a common and serious psychiatric illness with strong evidence for genetic causation, but no specific loci yet identified. Chromosomal abnormalities associated with schizophrenia may help to understand the genetic complexity of the illness. This paper reviews the evidence for associations between chromosomal abnormalities and schizophrenia and related disorders. The results indicate that 22q11.2 microdeletions detected by fluorescence in-situ hybridization (FISH) are significantly associated with schizophrenia. Sex chromosome abnormalities seem to be increased in schizophrenia but insufficient data are available to indicate whether schizophrenia or related disorders are increased in patients with sex chromosome aneuploidies. Other reports of chromosomal abnormalities associated with schizophrenia have the potential to be important adjuncts to linkage studies in gene localization. Advances in molecular cytogenetic techniques (i.e., FISH) have produced significant increases in rates of identified abnormalities in schizophrenia, particularly in patients with very early age at onset, learning difficulties or mental retardation, or dysmorphic features. The results emphasize the importance of considering behavioral phenotypes, including adult onset psychiatric illnesses, in genetic syndromes and the need for clinicians to actively consider identifying chromosomal abnormalities and genetic syndromes in selected psychiatric patients.
10.1002/(sici)1096-8628(200021)97:1<45::aid-ajmg6>3.0.co;2-9
MiRNAs of peripheral blood as the biomarker of schizophrenia.
Hereditas
The diagnosis of schizophrenia is currently based on the symptoms and bodily signs rather than on the pathological and physiological markers of the patient. In the search for new molecular targeted therapy medicines, and recurrence of early-warning indicators have become the major focus of contemporary research, because they improve diagnostic accuracy. Biomarkers reflect the physiological, physical and biochemical status of the body, and so have extensive applicability and practical significance. The ascertainment of schizophrenia biomarkers will help diagnose, stratify of disease, and treat of schizophrenia patients. The detection of biomarkers from blood has become a promising area of schizophrenia research. Recently, a series of studies revealed that, MiRNAs play an important role in the genesis of schizophrenia, and their abnormal expressions have the potential to be used as biomarkers of schizophrenia. This article presents and summarizes the value of peripheral blood miRNAs with abnormal expression as the biomarker of schizophrenia.
10.1186/s41065-017-0044-2
Detection of circulating miRNA levels in schizophrenia.
Wei Hui,Yuan Yanbo,Liu Sha,Wang Cheng,Yang Fude,Lu Zheng,Wang Chuanyue,Deng Hong,Zhao Jinping,Shen Yan,Zhang Chenyu,Yu Xin,Xu Qi
The American journal of psychiatry
OBJECTIVE:Diagnosis of schizophrenia is currently dependent on symptom-based criteria and lacks objective indicators. In this study, the authors investigated whether circulating miRNA can serve as a diagnostic biomarker for schizophrenia. METHODS:Global plasma miRNAs were profiled in a test cohort of 164 schizophrenia patients and 187 control subjects, using Solexa sequencing, TaqMan Low Density Array, and quantitative reverse transcription polymerase chain reaction (qRT-PCR) assays. The captured miRNAs were then validated by qRT-PCR assays in an independent cohort of 400 schizophrenia patients, 213 control subjects, and 162 patients with nonschizophrenia psychiatric disorders; the 400 schizophrenia patients underwent a 12-month follow up study of regular treatment with an atypical antipsychotic (risperidone and aripiprazole). RESULTS:The global plasma miRNA screening revealed eight miRNAs that were up-regulated in schizophrenia, as revealed by both assay platforms. The qRT-PCR analysis showed the up-regulation of miR-130b and miR-193a-3p in schizophrenia but not in nonschizophrenia disorders. CONCLUSIONS:The up-regulation of miR-130b and miR-193a-3p is a state-independent biomarker for schizophrenia, and these two miRNAs could be used to develop a diagnostic tool for schizophrenia.
10.1176/appi.ajp.2015.14030273
BSA nanoclusters-based sensor for detection of dopamine in schizophrenia from biofluids.
Drug development and industrial pharmacy
OBJECTIVE:To develop nontoxic and stable fluorescent emission B-Cu nanoclusters (NCs) for the specific detection of dopamine at low concentrations in cerebrospinal fluid (CSF). SIGNIFICANCE:Fluorescent gold and copper NCs conjugated with proteins, such as bovine serum albumin (BSA), offer photostability and healthcare potential. This study focused on fabricating B-Cu NCs that exhibited superior characteristics for sensitive dopamine detection. METHODS:The study employed various instrumental techniques including attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), spectrofluorometry, and transmission electron microscopy (TEM) to characterize the formulated B-Cu NCs. The NCs were synthesized, resulting in particle size ∼300 nm. The highest observed fluorescence was recorded at 24542.81 relative fluorescence units (RFU). RESULTS:The introduction of dopamine at concentrations of 0.1, 0.2, 0.3, and 0.4 ng/mL led to decreased fluorescence in both B-Au and B-Cu NCs due to an electron transport system. This reduction in fluorescence allowed dopamine concentration analysis in phosphate buffer and biological fluids such as blood plasma and CSF. B-Cu NCs showed potential as a biosensing system for point-of-care (POC) applications, specifically for diagnosing schizophrenia. CONCLUSION:The study successfully synthesized stable and nontoxic B-Cu NCs with enhanced fluorescent emission properties. These NCs exhibited the capacity to detect dopamine at low concentrations in CSF. The study's findings hold promise for future applications, particularly in the development of a B-Cu NCs-based biosensing system for convenient POC detection of schizophrenia by both patients and clinicians. The potential impact of this technology on healthcare and biomedical fields is substantial.
10.1080/03639045.2024.2328722
Synthetic cannabinoids and their impact on neurodevelopmental processes.
Alexandre João,Carmo Helena,Carvalho Félix,Silva João Pedro
Addiction biology
Cannabinoids comprise a broad group of psychoactive substances that activate endogenous cannabinoid (EC) receptors (ie, CB R and CB R), altering neurotransmitter release in the brain. The importance of their regulatory role in different biological processes has prompted the development of synthetic cannabinoids (SCs), substantially more potent than tetrahydrocannabinol (THC, the main psychoactive substance of cannabis). Although SCs were primarily designed given their therapeutic applications, their recreational use has become a major public health concern due to several reports of severe intoxications and deaths. SCs have favored increased popularity over recent years due to their intensified psychoactive effects, compared with THC, turning regular cannabis users into SCs. Among cannabinoid users (mainly young people), pregnant women and women of child-bearing potential (WoCBP) comprise particular risk groups, due to the potential onset of neurodevelopment disorders in the offspring (eg, schizophrenia and autism spectrum disorders). Understanding the role played by cannabinoids, and the potential action of emerging SCs in the regulation of the neuronal function, especially during neuronal development, thus assumes critical relevance. Here, we review the mechanistic regulation of neuronal processes, namely during neuronal development, by the endocannabinoid system. Most important, we further develop on the potential of SCs to modulate such mechanisms and subsequently disrupt proper neurodevelopment.
10.1111/adb.12824
The gut microbiota promotes the pathogenesis of schizophrenia via multiple pathways.
Yuan Xiuxia,Kang Yulin,Zhuo Chuanjun,Huang Xu-Feng,Song Xueqin
Biochemical and biophysical research communications
Schizophrenia is a severe mental disorder with unknown etiology. Many mechanisms, including dysregulation of neurotransmitters, immune disturbance, and abnormal neurodevelopment, are proposed for the pathogenesis of schizophrenia. The significance of communication between intestinal flora and the central nervous system through the gut-brain axis is increasingly being recognized. The intestinal microbiota plays an important role in regulating neurotransmission, immune homeostasis, and brain development. We hypothesize that an imbalance in intestinal flora causes immune activation and dysfunction in the gut-brain axis, contributing to schizophrenia. In this review, we examine recent studies that explore the intestinal flora and immune-mediated neurodevelopment of schizophrenia. We conclude that an imbalance in intestinal flora may reduce protectants and increase neurotoxin and inflammatory mediators, causing neuronal and synaptic damage, which induces schizophrenia.
10.1016/j.bbrc.2019.02.152
Cytochrome P450 testing for prescribing antipsychotics in adults with schizophrenia: systematic review and meta-analyses.
Fleeman N,Dundar Y,Dickson R,Jorgensen A,Pushpakom S,McLeod C,Pirmohamed M,Walley T
The pharmacogenomics journal
There is wide variability in the response of individuals to standard doses of antipsychotic drugs. It has been suggested that this may be partly explained by differences in the cytochrome P450 (CYP450) enzyme system responsible for metabolizing the drugs. We conducted a systematic review and meta-analyses to consider whether testing for CYP450 single nucleotide polymorphisms in adults starting antipsychotic treatment for schizophrenia predicts and leads to improvements in clinical outcomes. High analytic validity in terms of sensitivity and specificity was seen in studies reporting P450 testing. However, there was limited evidence of the role of CYP2D6 polymorphisms in antipsychotic efficacy, although there was an association between CYP2D6 genotype and extrapyramidal adverse effects. No studies reported on the prospective use of CYP2D6 genotyping tests in clinical practice. In conclusion, evidence of clinical validity and utility of CYP2D6 testing in patients being prescribed antipsychotics is lacking, and thus, routine pharmacogenetic testing prior to antipsychotic prescription cannot be supported at present. Further research is required to improve the evidence base and to generate data on clinical validity and clinical utility.
10.1038/tpj.2010.73
Exploring the Relationship Between Schizophrenia and Cardiovascular Disease: A Genetic Correlation and Multivariable Mendelian Randomization Study.
Veeneman Rada R,Vermeulen Jentien M,Abdellaoui Abdel,Sanderson Eleanor,Wootton Robyn E,Tadros Rafik,Bezzina Connie R,Denys Damiaan,Munafò Marcus R,Verweij Karin J H,Treur Jorien L
Schizophrenia bulletin
Individuals with schizophrenia have a reduced life-expectancy compared to the general population, largely due to an increased risk of cardiovascular disease (CVD). Clinical and epidemiological studies have been unable to unravel the nature of this relationship. We obtained summary-data of genome-wide-association studies of schizophrenia (N = 130 644), heart failure (N = 977 323), coronary artery disease (N = 332 477), systolic and diastolic blood pressure (N = 757 601), heart rate variability (N = 46 952), QT interval (N = 103 331), early repolarization and dilated cardiomyopathy ECG patterns (N = 63 700). We computed genetic correlations and conducted bi-directional Mendelian randomization (MR) to assess causality. With multivariable MR, we investigated whether causal effects were mediated by smoking, body mass index, physical activity, lipid levels, or type 2 diabetes. Genetic correlations between schizophrenia and CVD were close to zero (-0.02-0.04). There was evidence that liability to schizophrenia causally increases heart failure risk. This effect remained consistent with multivariable MR. There was also evidence that liability to schizophrenia increases early repolarization pattern, largely mediated by BMI and lipids. Finally, there was evidence that liability to schizophrenia increases heart rate variability, a direction of effect contrasting clinical studies. There was weak evidence that higher systolic blood pressure increases schizophrenia risk. Our finding that liability to schizophrenia increases heart failure is consistent with the notion that schizophrenia involves a systemic dysregulation of the body with detrimental effects on the heart. To decrease cardiovascular mortality among individuals with schizophrenia, priority should lie with optimal treatment in early stages of psychosis.
10.1093/schbul/sbab132
Cognitive Impairment Associated with Schizophrenia: From Pathophysiology to Treatment.
Annual review of pharmacology and toxicology
Cognitive impairment is a core feature of schizophrenia and a major contributor to poor functional outcomes. Methods for assessment of cognitive dysfunction in schizophrenia are now well established. In addition, there has been increasing appreciation in recent years of the additional role of social cognitive impairment in driving functional outcomes and of the contributions of sensory-level dysfunction to higher-order impairments. At the neurochemical level, acute administration of -methyl-d-aspartate receptor (NMDAR) antagonists reproduces the pattern of neurocognitive dysfunction associated with schizophrenia, encouraging the development of treatments targeted at both NMDAR and its interactome. At the local-circuit level, an auditory neurophysiological measure, mismatch negativity, has emerged both as a veridical index of NMDAR dysfunction and excitatory/inhibitory imbalance in schizophrenia and as a critical biomarker for early-stage translational drug development. Although no compounds have yet been approved for treatment of cognitive impairment associated with schizophrenia, several candidates are showing promise in early-phase testing.
10.1146/annurev-pharmtox-051921-093250