Differential changes in platelet reactivity induced by acute physical compared to persistent mental stress

Exploring the Role of MMP-9 and MMP-9/TIMP-1 Ratio in Subacute Stroke Recovery: A Prospective Observational Study

Despite the significant changes that unfold during the subacute phase of stroke, few studies have examined recovery abilities during this critical period. As neuroinflammation subsides and tissue degradation diminishes, the processes of neuroplasticity and angiogenesis intensify. An important factor in brain physiology and pathology, particularly neuroplasticity, is matrix metalloproteinase 9 (MMP-9). Its activity is modulated by tissue inhibitors of metalloproteinases (TIMPs), which impede substrate binding and activity by binding to its active sites. Notably, TIMP-1 specifically targets MMP-9 among other matrix metalloproteinases (MMPs). Our present study examines whether MMP-9 may play a beneficial role in psychological functions, particularly in alleviating depressive symptoms and enhancing specific cognitive domains, such as calculation. It appears that improvements in depressive symptoms during rehabilitation were notably linked with baseline MMP-9 plasma levels (r = -0.36, p = 0.025), and particularly so with the ratio of MMP-9 to TIMP-1, indicative of active MMP-9 (r = -0.42, p = 0.008). Furthermore, our findings support previous research demonstrating an inverse relationship between pre-rehabilitation MMP-9 serum levels and post-rehabilitation motor function. Crucially, our study emphasizes a positive correlation between cognition and motor function, highlighting the necessity of integrating both aspects into rehabilitation planning. These findings demonstrate the potential utility of MMP-9 as a prognostic biomarker for delineating recovery trajectories and guiding personalized treatment strategies for stroke patients during the subacute phase.

Depression proteomic profiling in adolescents with transcriptome analyses in independent cohorts

Introduction

Depression is a major global burden with unclear pathophysiology and poor treatment outcomes. Diagnosis of depression continues to rely primarily on behavioral rather than biological methods. Investigating tools that might aid in diagnosing and treating early-onset depression is essential for improving the prognosis of the disease course. While there is increasing evidence of possible biomarkers in adult depression, studies investigating this subject in adolescents are lacking.

Methods

In the current study, we analyzed protein levels in 461 adolescents assessed for depression using the Development and Well-Being Assessment (DAWBA) questionnaire as part of the domestic Psychiatric Health in Adolescent Study conducted in Uppsala, Sweden. We used the Proseek Multiplex Neuro Exploratory panel with Proximity Extension Assay technology provided by Olink Bioscience, followed by transcriptome analyses for the genes corresponding to the significant proteins, using four publicly available cohorts.

Results

We identified a total of seven proteins showing different levels between DAWBA risk groups at nominal significance, including RBKS, CRADD, ASGR1, HMOX2, PPP3R1, CD63, and PMVK. Transcriptomic analyses for these genes showed nominally significant replication of PPP3R1 in two of four cohorts including whole blood and prefrontal cortex, while ASGR1 and CD63 were replicated in only one cohort.

Discussion

Our study on adolescent depression revealed protein-level and transcriptomic differences, particularly in PPP3R1, pointing to the involvement of the calcineurin pathway in depression. Our findings regarding PPP3R1 also support the role of the prefrontal cortex in depression and reinforce the significance of investigating prefrontal cortex-related mechanisms in depression.

Hypothalamic Gene Expression in a Rat Model of Chronic Unpredictable Mild Stress Treated with Electroacupuncture

Depression is characterized by the loss of pleasure and a depressed mood, and it is a common mental disorder in the twenty-first century. Multiple gene imbalances, which are considered pathological factors in depression, were detected in the brain. Electroacupuncture is an effective therapeutic approach for depression that has minimal side effects. As a crucial structure in the hypothalamus-pituitary-adrenal, the hypothalamus plays a key role in depression. Our study focused on the transcriptome level in the hypothalamus of depressive rats. After chronic unpredictable mild stress, the rats exhibited depressive-like behaviors, such as decreased sucrose consumption in the SPT, increased time in the central area of the OFT and increased immobility in the FST. Moreover, electroacupuncture alleviated depressive behaviors. Because of the importance of the hypothalamus in depression, we next detected gene expression in the hypothalamus. A total of 510 genes (125 upregulated genes and 385 downregulated genes) were detected in the hypothalamus of depressive rats. 15 of the 125 upregulated genes and 63 of the 385 downregulated genes could be altered by electroacupuncture, which suggests the antidepressant effect of electroacupuncture. Our study also provided the evidence that regulation of transcriptome in the hypothalamus might be a potential mechanism of electroacupuncture treatment.

The sex-dependent response to psychosocial stress and ischaemic heart disease

Stress is an important risk factor for modern chronic diseases, with distinct influences in males and females. The sex specificity of the mammalian stress response contributes to the sex-dependent development and impacts of coronary artery disease (CAD). Compared to men, women appear to have greater susceptibility to chronic forms of psychosocial stress, extending beyond an increased incidence of mood disorders to include a 2- to 4-fold higher risk of stress-dependent myocardial infarction in women, and up to 10-fold higher risk of Takotsubo syndrome-a stress-dependent coronary-myocardial disorder most prevalent in post-menopausal women. Sex differences arise at all levels of the stress response: from initial perception of stress to behavioural, cognitive, and affective responses and longer-term disease outcomes. These fundamental differences involve interactions between chromosomal and gonadal determinants, (mal)adaptive epigenetic modulation across the lifespan (particularly in early life), and the extrinsic influences of socio-cultural, economic, and environmental factors. Pre-clinical investigations of biological mechanisms support distinct early life programming and a heightened corticolimbic-noradrenaline-neuroinflammatory reactivity in females vs. males, among implicated determinants of the chronic stress response. Unravelling the intrinsic molecular, cellular and systems biological basis of these differences, and their interactions with external lifestyle/socio-cultural determinants, can guide preventative and therapeutic strategies to better target coronary heart disease in a tailored sex-specific manner.

Matrix Metalloproteinase-9 as an Important Contributor to the Pathophysiology of Depression

Matrix metalloproteinases (MMPs) are physiologically expressed in the central nervous system in neurons, astrocytes and microglia, and their aberrant elevation contributes to a number of diseases. Amongst the MMP members, MMP−9 has generated considerable attention because of its possible involvement in inflammatory responses, blood-brain barrier permeability, the regulation of perineuronal nets, demyelination, and synaptic long-term potentiation. Emerging evidence indicate an association between MMP−9 and the syndrome of depression. This review provides an updated and comprehensive summary of the probable roles of MMP−9 in depression with an emphasis on the mechanisms and potential of MMP−9 as a biomarker of depression.

Variables affecting the potential efficacy of PRP in providing chronic pain relief

Although chronic pain affects about 1% of the US population, it remains largely resistant to treatment. Despite great variability in pain outcomes, the application of autologous platelet-rich plasma (PRP) has become increasingly popular in attempts to reduce chronic pain. The variability in PRP efficacy raises the question of whether PRP actually has an analgesic capacity, and if so, can that capacity be made consistent and maximized. The best explanation for the variability in PRP analgesic efficacy is the failure during PRP preparation and application to take into account variables that can increase or eliminate its analgesic capabilities. This suggests that if the variables are reduced and controlled, a PRP preparation and application protocol can be developed leading to PRP inducing reliable, complete, and long-term pain relief. The goal of this study was to examine some of the variables that influence platelets and see how they might be controlled to increase the analgesic potential of PRP. Among the variables examined are the physiological status of the patient, methods used to prepare PRP, and methods of PRP application. The goal of modifying these variables is to minimize platelet serotonin content, maximize platelet content of factors that reduce inflammation and pain, while maintaining their bioactivity, maximize platelet capacity to aggregate at injury sites, induce rapid and simultaneous release of their contents, and optimize PRP application protocols. It is concluded that controlling some or many of these variables will lead to PRP that induces reliable, maximum, and long-term relief of chronic pain.