More than 20 years of the discovery of Park2

Critical roles of parkin and PINK1 in coxsackievirus B3-induced viral myocarditis

Viral myocarditis is an inflammatory disease of the myocardium, often leads to cardiac dysfunction and death. PARKIN (PRKN) and PINK1, well known as Parkinson's disease-associated genes, have been reported to be involved in innate immunity and mitochondrial damage control. Therefore, we investigated the role of parkin and PINK1 in coxsackievirus B3 (CVB3)-induced viral myocarditis because the etiology of myocarditis is related to abnormal immune response to viral infection and mitochondrial damage. After viral infection, the survival was significantly lower and myocardial damage was more severe in parkin knockout (KO) and PINK1 KO mice compared to wild-type (WT) mice. Parkin KO and PINK1 KO showed defective immune cell recruitment and impaired production of antiviral cytokines such as interferon-gamma, allowing increased viral replication. In addition, parkin KO and PINK1 KO mice were more susceptible to CVB3-induced mitochondrial damage than WT mice, resulting in susceptibility to viral-induced cardiac damage. Finally, using publicly available RNA-seq data, we found that pathogenic mutants of the PRKN gene are more common in patients with dilated cardiomyopathy and myocarditis than in controls or the general population. This study will help elucidate the molecular mechanism of CVB3-induced viral myocarditis.

Epigenetic Factors Related to Low Back Pain: A Systematic Review of the Current Literature

Low back pain (LBP) is one of the most common causes of pain and disability. At present, treatment and interventions for acute and chronic low back pain often fail to provide sufficient levels of pain relief, and full functional restoration can be challenging. Considering the significant socio-economic burden and risk-to-benefit ratio of medical and surgical intervention in low back pain patients, the identification of reliable biomarkers such as epigenetic factors associated with low back pain could be useful in clinical practice. The aim of this study was to review the available literature regarding the epigenetic factors associated with low back pain. This review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The search was carried out in October 2022. Only peer-reviewed articles were considered for inclusion. Fourteen studies were included and showed promising results in terms of reliable markers. Epigenetic markers for LBP have the potential to significantly modify disease management. Most recent evidence suggests that epigenetics is a more promising field for the identification of factors associated with LBP, offering a rationale for further investigation in this field with the long-term goal of finding epigenetic biomarkers that could constitute biological targets for disease management and treatment.

Post-traumatic stress disorder: clinical and translational neuroscience from cells to circuits

Post-traumatic stress disorder (PTSD) is a maladaptive and debilitating psychiatric disorder, characterized by re-experiencing, avoidance, negative emotions and thoughts, and hyperarousal in the months and years following exposure to severe trauma. PTSD has a prevalence of approximately 6-8% in the general population, although this can increase to 25% among groups who have experienced severe psychological trauma, such as combat veterans, refugees and victims of assault. The risk of developing PTSD in the aftermath of severe trauma is determined by multiple factors, including genetics - at least 30-40% of the risk of PTSD is heritable - and past history, for example, prior adult and childhood trauma. Many of the primary symptoms of PTSD, including hyperarousal and sleep dysregulation, are increasingly understood through translational neuroscience. In addition, a large amount of evidence suggests that PTSD can be viewed, at least in part, as a disorder that involves dysregulation of normal fear processes. The neural circuitry underlying fear and threat-related behaviour and learning in mammals, including the amygdala-hippocampus-medial prefrontal cortex circuit, is among the most well-understood in behavioural neuroscience. Furthermore, the study of threat-responding and its underlying circuitry has led to rapid progress in understanding learning and memory processes. By combining molecular-genetic approaches with a translational, mechanistic knowledge of fear circuitry, transformational advances in the conceptual framework, diagnosis and treatment of PTSD are possible. In this Review, we describe the clinical features and current treatments for PTSD, examine the neurobiology of symptom domains, highlight genomic advances and discuss translational approaches to understanding mechanisms and identifying new treatments and interventions for this devastating syndrome.

Epigenetics of Mitochondria-Associated Genes in Striated Muscle

Striated muscle has especially large energy demands. We identified 97 genes preferentially expressed in skeletal muscle and heart, but not in aorta, and found significant enrichment for mitochondrial associations among them. We compared the epigenomic and transcriptomic profiles of the 27 genes associated with striated muscle and mitochondria. Many showed strong correlations between their tissue-specific transcription levels, and their tissue-specific promoter, enhancer, or open chromatin as well as their DNA hypomethylation. Their striated muscle-specific enhancer chromatin was inside, upstream, or downstream of the gene, throughout much of the gene as a super-enhancer (CKMT2, SLC25A4, and ACO2), or even overlapping a neighboring gene (COX6A2, COX7A1, and COQ10A). Surprisingly, the 3' end of the 1.38 Mb PRKN (PARK2) gene (involved in mitophagy and linked to juvenile Parkinson's disease) displayed skeletal muscle/myoblast-specific enhancer chromatin, a myoblast-specific antisense RNA, as well as brain-specific enhancer chromatin. We also found novel tissue-specific RNAs in brain and embryonic stem cells within PPARGC1A (PGC-1α), which encodes a master transcriptional coregulator for mitochondrial formation and metabolism. The tissue specificity of this gene's four alternative promoters, including a muscle-associated promoter, correlated with nearby enhancer chromatin and open chromatin. Our in-depth epigenetic examination of these genes revealed previously undescribed tissue-specific enhancer chromatin, intragenic promoters, regions of DNA hypomethylation, and intragenic noncoding RNAs that give new insights into transcription control for this medically important set of genes.

Clinical and molecular genetic findings of hereditary Parkinson's patients from Turkey

INTRODUCTION

The majority of Parkinson's disease (PD) ensue late-onset with a complex spectrum of environmental and genetic risk factors. Awareness of genetic causes in patients with PD is essential for genetic counseling and future genotype-oriented therapeutic developments.

METHODS

Large pathogenic changes in eight PD-related genes and small pathogenic sequence variants in 22 PD-related genes were investigated simultaneously in 82 PD patients from 79 families where clinical evaluations were performed. The phenotypic characteristics of the patients with molecular changes were examined for genotype-phenotype relations.

RESULTS

Pathogenic variants in SNCA, PRKN, DJ-1, FBXO7, and GBA genes were determined in 25 patients from 24 families (24/79, 30%). Associated variants were found in PRKN in 14, SNCA in three, FBXO7 in two, and DJ-1 in one patient. A novel homozygous deletion (c.491delT, p.(V164Dfs*13) (SCV001733595)) leading to protein truncation in the PRKN gene was identified in two patients from the same family. Furthermore, heterozygous GBA gene variants were detected in five patients from different families.

CONCLUSION

It has been shown that the most common cause of genetically transmitted PD is the PRKN gene, while LRRK2 does not play an essential role in this selected population. It has been suggested that even if the autosomal recessive inheritance is expected, genes with autosomal dominant effects such as SNCA should not be overlooked and suggested for investigation. Our study is also the first for evaluating the pathogenic GBA variants' frequency in PD patients from Turkey.

Cross-Platform Evaluation of Commercially Targeted and Untargeted Metabolomics Approaches to Optimize the Investigation of Psychiatric Disease

Metabolomics methods often encounter trade-offs between quantification accuracy and coverage, with truly comprehensive coverage only attainable through a multitude of complementary assays. Due to the lack of standardization and the variety of metabolomics assays, it is difficult to integrate datasets across studies or assays. To inform metabolomics platform selection, with a focus on posttraumatic stress disorder (PTSD), we review platform use and sample sizes in psychiatric metabolomics studies and then evaluate five prominent metabolomics platforms for coverage and performance, including intra-/inter-assay precision, accuracy, and linearity. We found performance was variable between metabolite classes, but comparable across targeted and untargeted approaches. Within all platforms, precision and accuracy were highly variable across classes, ranging from 0.9-63.2% (coefficient of variation) and 0.6-99.1% for accuracy to reference plasma. Several classes had high inter-assay variance, potentially impeding dissociation of a biological signal, including glycerophospholipids, organooxygen compounds, and fatty acids. Coverage was platform-specific and ranged from 16-70% of PTSD-associated metabolites. Non-overlapping coverage is challenging; however, benefits of applying multiple metabolomics technologies must be weighed against cost, biospecimen availability, platform-specific normative levels, and challenges in merging datasets. Our findings and open-access cross-platform dataset can inform platform selection and dataset integration based on platform-specific coverage breadth/overlap and metabolite-specific performance.