Aneurysmal subarachnoid haemorrhage: effect of CRHR1 genotype on fatigue and depression

CRHR1 antagonist alleviated depression-like behavior by downregulating p62 in a rat model of post-stroke depression

Post-stroke depression (PSD) is a complication of cerebrovascular disease, which can increase mortality after stroke. CRH is one of the main signaling peptides released after activation of the hypothalamic-pituitary-adrenal (HPA) axis in response to stress. It affects synaptic plasticity by regulating inflammation, oxidative stress and autophagy in the central nervous system. And the loss of spines exacerbates depression-like behavior. Therefore, synaptic deficits induced by CRH may be related to post-stroke depression. However, the underlying mechanism remains unclear. The Keap1-Nrf2 complex is one of the core components of the antioxidant response. As an autophagy associated protein, p62 participates in the Keap1-NrF2 pathway through its Keap1 interaction domain. Oxidative stress is involved in the feedback regulation between Keap1-Nrf2 pathway and p62.However, whether the relationship between CRH and the Keap1-Nrf2-p62 pathway is involved in PSD remains unknown. This study found that serum levels of CRH in 22 patients with PSD were higher than those in healthy subjects. We used MCAO combined with CUMS single-cage SD rats to establish an animal model of PSD. Animal experiments showed that CRHR1 antagonist prevented synaptic loss in the hippocampus of PSD rats and alleviated depression-like behavior. CRH induced p62 accumulation in the prefrontal cortex of PSD rats through CRHR1. CRHR1 antagonist inhibited Keap1-Nrf2-p62 pathway by attenuating oxidative stress. In addition, we found that abnormal accumulation of p62 induces PSD. It alleviates depression-like behavior by inhibiting the expression of p62 and promoting the clearance of p62 in PSD rats. These findings can help explore the pathogenesis of PSD and design targeted treatments for PSD.

Neurobiological and psychological factors to depression

Major Depressive Disorder (MDD) is a common condition with complex psychological and biological background. While its aetiology is still unclear, chronic stress stands amongst major risk factors to MDD pathogenesis. When researching on MDD, it is necessary to be familiar with the neurobiological effects of several prominent contributors to the chronic stress factor experienced across hypothalamic-pituitary-adrenal (HPA) axis, neurotransmission, immune system reflexivity, and genetic alterations. Bi-directional flow of MDD pathogenesis suggests that psychological factors produce biological effects. Here, a summary of how the MDD expresses its mechanisms of action across an overactive HPA axis, the negative impacts of reduced neurotransmitter functions, the inflammatory responses and their gene x environment interactions. This paper builds on these conceptual factors and their input towards the MDD symptomatology with a purpose of synthesising the current findings and create an integrated view of the MDD pathogenesis. Finally, relevant treatment implications will be summarised, along with recommendations to a multimodal clinical practice.

Epigenetic Effects in HPA Axis Genes Associated with Cortical Thickness, ERP Components and SUD Outcome

Association between familial loading for alcohol use disorders (AUD) and event-related potentials (ERPs) suggests a genetic basis for these oscillations though much less is known about epigenetic pathways influenced by environmental variation. Early life adversity (ELA) influences negative outcomes much later in life. The stress-activated neuropeptide corticotropin-releasing hormone (CRH) contributes to the deleterious effects of ELA on brain structure and function in animals. Accordingly, we hypothesized that ELA would be related to cortical thickness and electrophysiological characteristics through an epigenetic effect on CRH receptor type-1 (CRHR1) methylation. A total of 217 adolescent and young adult participants from either multiplex alcohol dependence or control families were scanned using magnetic resonance imaging (MRI) at 3T and cortical thickness was determined. Longitudinal follow-up across childhood, adolescence, and young adulthood provided developmental ERP data and measures of adversity. Blood samples for genetic and epigenetic analyses were obtained in childhood. Cortical thickness and visual ERP components were analyzed for their association and tested for familial risk group differences. Visual P300 amplitude at Pz and cortical thickness of the left lateral orbitofrontal region (LOFC), were significantly related to risk group status. LOFC cortical thickness showed a negative correlation with CRHR1 methylation status and with childhood total stress scores from the Life Stressors and Social Resources Inventory (LISRES). Stress scores were also significantly related to P300 amplitude recorded in childhood. The present results suggest that early life adversity reflected in greater total LISRES stress scores in childhood can impact the methylation of the CRHR1 gene with implications for brain development as seen in cortical thickness and electrophysiological signals emanating from particular brain regions.

Prevalence of fatigue after stroke: A systematic review and meta-analysis

Background and Purpose

Post-stroke fatigue is a debilitating and long-lasting condition. However, there are uncertainties regarding its prevalence and variability between studies. This review aims to estimate the prevalence of fatigue and determine the factors responsible for its variation in the literature.

Methods

A systematic review was conducted for all published studies (search to November 2020) using AMED, CINAHL, EMBASE, MEDLINE, PsycINFO, SCOPUS and Web of Science. Papers were included if they recruited participants with stroke, used a validated scale to measure fatigue and were in English. Two reviewers screened and assessed the relevant studies for eligibility (n = 96). The included papers were appraised using the Joanna Briggs Institute (JBI) tool for prevalence studies, and data were extracted by one reviewer. To understand the variation in PSF prevalence between papers, data were pooled and analysed based on relevant methodological (e.g. time of assessment) or clinical factors (e.g. depression) using Review Manager 5.4 software.

Results

While 48 studies were included and summarised (N = 9004), only 35 were appropriate for the meta-analysis (N = 6851). The most frequently used tool to measure fatigue was the Fatigue Severity Scale (FSS) (n = 31). The prevalence was calculated with a cut-off point of four or more using FSS and resulted in an estimate of 48% (95% CI 42-53%). Time of assessment (<6 vs ≥6 months), stroke type (ischaemic vs haemorrhagic/subarachnoid haemorrhage) and geographical location (East Asia vs Europe) could explain the prevalence variation between studies.

Conclusions

Fatigue is prevalent among stroke survivors. This condition varies in terms of occurrence between studies; however, time of assessment, stroke type and geographical location might explain this variation. As this review estimates the overall burden of fatigue after stroke, it provides a useful indicator to inform policy, planning and healthcare professionals. Further efforts are required to investigate the mechanisms that lead to PSF, particularly in the groups that show high prevalence, in order to prevent or alleviate it.