Comparable assessment of adolescent repeated physical or psychological stress effects on adult cardiac performance in female rats.

Extensive evidence highlights a robust connection between various forms of chronic stress and cardiovascular disease (CVD). In today's fast-paced world, with chronic stressors abound, CVD has emerged as a leading global cause of mortality. The intricate interplay of physical and psychological stressors triggers distinct neural networks within the brain, culminating in diverse health challenges. This study aims to discern the unique impacts of chronic physical and psychological stress on the cardiovascular system, unveiling their varying potencies in precipitating CVD. Twenty-one adolescent female rats were methodically assigned to three groups: (1) control (n = 7), (2) physical stress (n = 7), and (3) psychological stress (n = 7). Employing a two-compartment enclosure, stressors were administered to the experimental rats over five consecutive days, each session lasting 10 min. After a 1.5-month recovery period post-stress exposure, a trio of complementary techniques characterized by high specificity or high sensitivity were employed to meticulously evaluate CVD. Echocardiography and single-photon emission computed tomography (SPECT) were harnessed to scrutinize left ventricular architecture and myocardial viability, respectively. Subsequently, the rats were ethically sacrificed to facilitate heart removal, followed by immunohistochemistry staining targeting glial fibrillary acidic protein (GFAP). Rats subjected to psychological stress showed a wider range of significant cardiac issues compared to control rats. This included left ventricular hypertrophy [IVSd: 0.1968 ± 0.0163 vs. 0.1520 ± 0.0076, P < 0.05; LVPWd: 0.2877 ± 0.0333 vs. 0.1689 ± 0.0057, P < 0.01; LVPWs: 0.3180 ± 0.0382 vs. 0.2226 ± 0.0121, P < 0.05; LV-mass: 1.283 ± 0.0836 vs. 1.000 ± 0.0241, P < 0.01], myocardial ischemia [21.30% vs. 32.97%, P < 0.001], and neuroinflammation. This outcome underscores the imperative of prioritizing psychological well-being during adolescence, presenting a compelling avenue to curtail the prevalence of CVD in adulthood. Furthermore, extending such considerations to individuals grappling with CVD might prospectively enhance their overall quality of life.

A knowledge-based protein-protein interaction inhibition (KPI) pipeline: an insight from drug repositioning for COVID-19 inhibition.

The inhibition of protein-protein interactions (PPIs) by small molecules is an exciting drug discovery strategy. Here, we aimed to develop a pipeline to identify candidate small molecules to inhibit PPIs. Therefore, KPI, a Knowledge-based Protein-Protein Interaction Inhibition pipeline, was introduced to improve the discovery of PPI inhibitors. Then, phytochemicals from a collection of known Middle Eastern antiviral herbs were screened to identify potential inhibitors of key PPIs involved in COVID-19. Here, the following investigations were sequenced: 1) Finding the binding partner and the interface of the proteins in PPIs, 2) Performing the blind ligand-protein inhibition (LPI) simulations, 3) Performing the local LPI simulations, 4) Simulating the interactions of the proteins and their binding partner in the presence and absence of the ligands, and 5) Performing the molecular dynamics simulations. The pharmacophore groups involved in the LPI were also characterized. Aloin, Genistein, Neoglucobrassicin, and Rutin are our new pipeline candidates for inhibiting PPIs involved in COVID-19. We also propose KPI for drug repositioning studies.Communicated by Ramaswamy H. Sarma.

Cannabidiol Inhibits Tau Aggregation In Vitro.

A hallmark of Alzheimer's disease (AD) is the accumulation of tau protein in the brain. Compelling evidence indicates that the presence of tau aggregates causes irreversible neuronal destruction, eventually leading to synaptic loss. So far, the inhibition of tau aggregation has been recognized as one of the most effective therapeutic strategies. Cannabidiol (CBD), a major component found in Cannabis sativa L., has antioxidant activities as well as numerous neuroprotective features. Therefore, we hypothesize that CBD may serve as a potent substance to hamper tau aggregation in AD. In this study, we aim to investigate the CBD effect on the aggregation of recombinant human tau protein 1N/4R isoform using biochemical methods in vitro and in silico. Using Thioflavin T (ThT) assay, circular dichroism (CD), and atomic force microscopy (AFM), we demonstrated that CBD can suppress tau fibrils formation. Moreover, by quenching assay, docking, and job's plot, we further demonstrated that one molecule of CBD interacts with one molecule of tau protein through a spontaneous binding. Experiments performed by quenching assay, docking, and Thioflavin T assay further established that the main forces are hydrogen Van der Waals and some non-negligible hydrophobic forces, affecting the lag phase of tau protein kinetics. Taken together, this study provides new insights about a natural substance, CBD, for tau therapy which may offer new hope for the treatment of AD.

The brain 3ß-HSD up-regulation in response to deteriorating effects of background emotional stress: an animal model of multiple sclerosis.

The brain 3ß-hydroxysteroid dehydrogenase (3ß-HSD), is the enzyme that catalyzes the biosynthesis of a neuroprotective factor, progesterone. The regulation of 3ß-HSD in response to stress exposure in the cuprizone-induced model of Multiple Sclerosis was investigated and the reaction related to the demyelination extremity. 32 female Wistar rats divided into four groups (i.e., control group (Cont), non-stress cuprizone treated (N-CPZ), physical stress- cuprizone treated (P-CPZ) and emotional stress- cuprizone treated (E-CPZ). A witness foot-shock model used to induce background stress for 5 days. An elevated-plus maze applied to validate the stress induction. Followed by 6 weeks of cuprizone treatment, the Y-maze test performed to confirm brain demyelination. 3ß-HSD gene expression as an indicator of progesterone synthesis examined. At the behavioral level, both stressed groups reflected more impaired spatial memory compared to the N-CPZ group (p < 0.01), with more severe results in the E-CPZ group (p < 0.01). The results of mRNA expression of 3ß-HSD illustrated significant elevation in all cuprizone treated groups (p < 0.001) with a higher up-regulation (p < 0.001) in the E-CPZ group. Background stress -particularly emotional type- exacerbates the demyelination caused by cuprizone treatment. The brain up-regulates the 3ß-HSD gene expression as a protective response relative to the myelin degradation extent.

Biofluid Biomarkers in Traumatic Brain Injury: A Systematic Scoping Review.

Emerging evidence suggests that biofluid-based biomarkers have diagnostic and prognostic potential in traumatic brain injuries (TBI). However, owing to the lack of a conceptual framework or comprehensive review, it is difficult to visualize the breadth of materials that might be available. We conducted a systematic scoping review to map and categorize the evidence regarding biofluid-based biochemical markers of TBI. A comprehensive search was undertaken in January 2019. Of 25,354 records identified through the literature search, 1036 original human studies were included. Five hundred forty biofluid biomarkers were extracted from included studies and classified into 19 distinct categories. Three categories of biomarkers including cytokines, coagulation tests, and nerve tissue proteins were investigated more than others and assessed in almost half of the studies (560, 515, and 502 from 1036 studies, respectively). S100 beta as the most common biomarker for TBI was tested in 21.2% of studies (220 articles). Cortisol was the only biomarker measured in blood, cerebrospinal fluid, urine, and saliva. The most common sampling time was at admission and within 24 h of injury. The included studies focused mainly on biomarkers from blood and central nervous system sources, the adult population, and severe and blunt injuries. The most common outcome measures used in studies were changes in biomarker concentration level, Glasgow coma scale, Glasgow outcome scale, brain computed tomography scan, and mortality rate. Biofluid biomarkers could be clinically helpful in the diagnosis and prognosis of TBI. However, there was no single definitive biomarker with accurate characteristics. The present categorization would be a road map to investigate the biomarkers of the brain injury cascade separately and detect the most representative biomarker of each category. Also, this comprehensive categorization could provide a guiding framework to design combined panels of multiple biomarkers.

Astaxanthin Decreases Spatial Memory and Glutamate Transport Impairment Induced by Fluoride.

Excessive exposure to the sources of fluoride in drinking water, oral care products, and food is a widespread problem. Fluoride is associated with impairment in child intelligence development. It causes DNA damage, oxidative stress, and mitochondrial dysfunction, mainly due to the production of reactive oxygen species (ROS). It has been postulated that the use of antioxidants such as astaxanthin, may alleviate fluoride's adverse effects. This study assessed the effects of fluoride on cellular ROS content and rat's learning and memory ability and investigated the protective potency of astaxanthin with emphasis on the role of glutamate using the Morris Water Maze test, glutamate concentration determination, and western blot techniques. The fluoride treatment of cells results in an increment of cellular ROS, whereas astaxanthin inhibits lipid peroxidation. Fluoride significantly decreases the cellular glutamate uptake and glutamate transporter, protein level, possibly due to the disruption of mitochondrial energy metabolism and defect of the transporter recycle, respectively. The in-vivo study indicated that the treatment of rats with fluoride led to a loss of learning, while astaxanthin improved memory dysfunction. Measurement of ROS and glutamate levels of rat brain hippocampus showed that fluoride increased the ROS but decreased the glutamate. On the other hand, the utilization of astaxanthin decreased the brain ROS content and increased the glutamate level. It seems that fluoride disrupts the normal function of neurons via increment of ROS production and decrement of glutamate level, whereas astaxanthin has neuroprotective potency due to the ROS scavenging ability.

The Changes in 1H-MRS Metabolites in Cuprizone-Induced Model of Multiple Sclerosis: Effects of Prior Psychological Stress.

Stress is considered as an important risk factor in the progression and the onset of many disorders such as multiple sclerosis. However, metabolite changes as a result of demyelination under the detrimental effects of stress are not well understood. Thus, 36 female Wistar rats (i.e., groups (1) no-cuprizone (Cont), (2) no-stress + cuprizone-treated (Cup), (3) physical stress + cuprizone-treated (P-Cup), (4) psychological stress + cuprizone-treated (Psy-Cup), (5) physical stress + no-cuprizone-treated (P), (6) psychological stress + no-cuprizone-treated (Psy)) were used in this study. Following induction of repetitive stress, cuprizone treatment was carried out for 6 weeks to instigate demyelination in all groups except the control animal. Relative metabolite concentrations of the brain were investigated by single-voxel proton magnetic resonance spectroscopy (reporting N-acetyl-aspartate (NAA), glycerophosphocholine with phosphocholine (tCho) relative to total creatine (tCr)). According to 1H-MRS, rats in the Cup group indicated a reduction in NAA/ tCr (p < 0.001) as well as tCho/ tCr (p < 0.05) compared with that in the Cont group. In contrast, in both stress + cuprizone-treated groups, NAA/tCr and tCho/tCr ratios remarkably increased versus the Cup group (p < 0.001) and the Cont group (p < 0.001 for the Psy-Cup group and p < 0.05 for the P-Cup group). Both P and Psy groups revealed normal metabolite concentrations similar to the Cont group 6 weeks post stress. Seemingly, in the case of cuprizone alone, decreased level of metabolites is mainly relevant to neuronal cell impairments. Meanwhile, as a result of oxidative stress enhancement due to stress exposure, oligodendrocyte becomes the main victim indicating the increased level of metabolite ratios.

Telemetric Intracranial Pressure Monitoring: A Systematic Review.

Telemetric intracranial pressure (ICP) monitoring is a new method of measuring ICP which eliminates some of the shortcomings of previous methods. However, there are limited data on specific characteristics, including the advantages and disadvantages of this method. The main aim of this study was to demonstrate the indications, benefits, and complications of telemetric ICP monitoring. PubMed, MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for relevant studies without language or date restriction in May 2019. Human studies in which telemetric ICP monitoring was the main subject of the study were included. Our initial search resulted in 1650 articles from which 50 studies were included. There were no randomized controlled trials. The majority of the studies were case reports or case series (68%). The most common aim of studies was testing of the device (52%), and monitoring the disease progression or recovery (46%). The most common indications for telemetric ICP monitoring in these studies were testing cerebrospinal fluid shunt function (46%), ICP control after the procedure (36%), and diagnosing intracranial hypertension (22%) and hydrocephalus (12%). In total, 1423 brain disease patients had been monitored in studies. The possibility of long-term ICP monitoring as the main benefit was reported in 38 (76%) studies. The associated complication rate was 7.1%. Despite the increasing application of telemetric monitoring devices, studies to evaluate specific characteristics of this method have been infrequent and inadequate. Future research using a higher level of scientific methods is needed to evaluate advantage and disadvantages.

Time-dependent microglia and macrophages response after traumatic spinal cord injury in rat: a systematic review.

OBJECTIVE: To acquire evidence-based knowledge in temporal and spatial patterns of microglia/macrophages changes to facilitate finding proper intervention time for functional restoration after traumatic spinal cord injury (TSCI). SETTING: Sina Trauma and Surgery Research Center, Tehran University of Medical Sciences, Tehran, Iran. METHODS: We searched PubMed and EMBASE via Ovid SP with no temporal and linguistic restrictions. Besides, hand-search was performed in the bibliographies of relevant studies. The experimental non-interventional and non-transgenic animal studies confined to the rat species which assess the pathological change of microglia /macrophages at the specified time were included. RESULTS: We found 15,315 non-duplicate studies. Screening through title and abstract narrowed down to 607 relevant articles, 31 of them were selected based on the inclusion criteria. The reactivity of the microglia/macrophages initiates in early hours PI in contusion, compression and transection models. Cells activity reached a maximum within 48 h to 28 days in compression, 7 days in contusion and between 4 and 60 days in transection models. Inflammatory response occurred at the epicenter, in or near the lesion site in both gray and white matter in all three injury models with a maximum extension of one centimeter caudal and rostral to the epicenter in the gray matter in contusion and transection models. CONCLUSION: This study was designed to study spatial-temporal changes in the activation of microglia/macrophages overtime after TSCI. We were able to demonstrate time-dependent cell morphological changes after TSCI. The peak times of cell reactivity and the areas where the cells responded to the injury were determined.

Comparative evaluation of adolescent repeated psychological or physical stress effects on adult cognitive performance, oxidative stress, and heart rate in female rats.

Multiple adult health problems are associated with adolescent stress. As the brain discriminates physical and psychological stressors by activation of different neural networks, we hypothesized that behavioral and physiological performance would be modulated differently based on the nature of the stressors. Thus, we studied the comparative effects of adolescent repeated physical and psychological stresses on adult cognitive performance, pro-oxidant-antioxidant balance (PAB) and heart rate in female rats. The aim was to differentiate disparate potency of chronic psychological and physical stresses leading to long-term behavioral and physiological alterations. Twenty-one female rats were divided randomly into three groups of seven rats each; control, physical, and psychological stress. Experimental rats were exposed to the stressors for five consecutive days (10 min daily) via a two-communication box. After verifying stress induction by serum corticosterone measurement, the rats were returned to their home cage for 6 weeks, until adulthood, elevated plus maze (EPM), forced swimming test (FST), Y-maze, object recognition task (ORT), and passive avoidance test (PAT) were used as five different behavioral tests to evaluate cognitive performance of each group. Serum PAB and heart rate were measured to assess long-term stress-induced physiological disorders. The results showed exposure to adolescent psychological stress resulted in a larger set of significant changes (in behavioral variation, oxidative stress, and elevated heart rate) 6 weeks post-stress compared to adolescent physical stress. Hence, mental health care in adolescence and therapies targeting PAB and heart rate could be prevention and treatment approaches to confront persistent adolescent stress-induced disorders. Lay summaryThe aim of our study on female laboratory rats was to differentiate disparate potency of chronic psychological and physical stresses in adolescence leading to long-term behavioral and physiological alterations. The results suggest that psychological stresses result in a greater extent of changes compared to physical stress. Adolescent chronic psychological stress may reveal itself in the form of certain behavioral and physiological variations in adulthood. Therefore, mental health care in adolescence could be a valuable prevention approach to confront a variety of adult stress-induced disorders.

Psychological stress effects on myelin degradation in the cuprizone-induced model of demyelination.

Multiple sclerosis (MS) is known as the most common demyelinating disease worldwide in which previous studies have shown that stress is a risk factor for the disease's onset and progression. Nevertheless, further studies are needed to investigate the consequences of stress in MS pathology. In this study, after 5 days of exposure to psychological and physical stress as a repetitive distress modality, rats were treated with cuprizone. The demyelination degree was compared in animal groups using Luxol fast blue staining, immunohistochemical staining for myelin basic protein and transmission electron microscopy. Outcomes revealed that animals exposed to stress prior to cuprizone ingestion, elicit more intense demyelination. Continuous psychological distress has more severe effects on myelin sheath destruction in the preclinical stage.

Correlation between adolescent chronic emotional stress and incidence of adult cardiovascular disease in female rats.

OBJECTIVES: Association of adolescent emotional stress (ES) with the incidence of cardiovascular disease (CVD) at older age was investigated. MATERIALS AND METHODS: 21 female rats were divided into three groups of 7 each; ES, foot-shock, and control. Chronic ES was induced by exposing the rats to witness foot-shock of their neighboring counterparts in the stress-box system in 5 successive days. 6 weeks after the last stress exposure, M-Mode echocardiographic assessment, qRT-PCR, and western blotting were performed in adult rats to determine the persistent effect of adolescent ES on cardiac performance and gene/protein expression levels of cardiac natriuretic peptide receptor 3 (NPR3) as a biomarker of CVD. RESULTS: Interventricular septum thicknesses in diastole (IVSd) increased from 0.152±0.007 cm to 0.197±0.016 cm (P<0.05), left ventricular posterior wall thickness in diastole (LVPWd) significantly enlarged from 0.169±0.006 cm to 0.288±0.033 cm (P<0.01), left ventricular posterior wall thickness in systole (LVPWs) enlarged from 0.223±0.012 cm to 0.318±0.038 cm (P<0.05), left ventricular mass increased from 1.000±0.024 g to 1.283±0.084 g (P<0.01), and mean heart rate elevated from 229.42±6.57 bpm to 280.29±10.45 bpm (P<0.01). Moreover, ES significantly upregulated the expression levels of cardiac NPR3 gene (P<0.01) and protein (P<0.01). CONCLUSION: The incidence of adult CVD seemed to be increased under the influence of adolescent ES. Consequently, we suggest that mental healthcare during adolescence would be a critical factor for adult CVD prevention.