Environmental Enrichment in Stroke Research: an Update.

Environmental enrichment (EE) refers to different forms of stimulation, where the environment is designed to improve the levels of sensory, cognitive, and motor stimuli, inducing stroke recovery in animal models. Stroke is a leading cause of mortality and neurological disability among older adults, hence the importance of developing strategies to improve recovery for such patients. This review provides an update on recent findings, compiling information regarding the parameters affected by EE exposure in both preclinical and clinical studies. During stroke recovery, EE exposure has been shown to improve both the cognitive and locomotor aspects, inducing important neuroplastic alterations, increased angiogenesis and neurogenesis, and modified gene expression, among other effects. There is a need for further research in this field, particularly in those aspects where the evidence is inconclusive. Moreover, it is necessary refine and adapt the EE paradigms for application in human patients.

Age-related tolerance to paraquat-induced parkinsonism in Drosophila melanogaster.

Paraquat (PQ) is a widely used herbicide that can cross the dopaminergic neuronal membrane, accumulate in mitochondria and damage complex I of the electron transport chain, leading to neuronal death. In Drosophila melanogaster, PQ exposure leads to the development of parkinsonism and is a classical model for studying Parkinson's Disease (PD). Muscle mitochondrial dysfunction, affecting survival and locomotion, is described in familial PD in D. melanogaster mutants. However, no study has shown the effects of PQ-induced parkinsonism in D. melanogaster regarding muscle ultrastructure and locomotor behavior at different ages. Thus, we evaluated survival, locomotion, and morphological parameters of mitochondria and myofibrils using transmission electron microscopy in 2 and 15-day-old D. melanogaster, treated with different PQ doses: control, 10, 50, 100, 150, and 200 mM. PQ100mM presented 100% lethality in 15-day-old D. melanogaster, while in 2-day-old animals PQ150mM produced 20% lethality. Bradykinesia was only observed in 15-day-old D. melanogaster treated with PQ10 mM and PQ50 mM. However, these results are unlikely to be associated with changes to morphology. Taken together, our data indicate pathophysiological differences between PQ-induced parkinsonism and familial parkinsonism in D. melanogaster (resultant from gene mutations), demonstrating for the first time a differential susceptibility to PQ in two developmental stages.

Contagious depression: Automatic mimicry and the mirror neuron system - A review.

Contagious depression is a theory proposing that depression can be induced or triggered by our social environment. This theory is based on emotional contagion, the idea that affective states can be transferred during social interaction, since humans can use emotional contagion to communicate feelings and emotions in conscious and unconscious ways. This review presents behavioral, physiological, and neuroanatomical aspects of two essential contagious depression mechanisms, automatic mimicry and the mirror neuron system.

Morphological and mechanical changes induced by quercetin in human T24 bladder cancer cells.

Quercetin is a flavonoid found in a great variety of foods such as vegetables and fruits. This compound has been shown to inhibit the proliferation of various types of cancer cells, as well as the growth of tumors in animal models. In the present study, we analyze morphological and mechanical changes produced by quercetin in T24 bladder cancer cells. Decreased cell viability and cell number were observed following quercetin treatment at 40 µM and 60 µM, respectively, as observed by the MTT assay and trypan blue exclusion test, supporting the hypothesis of quercetin anticancer effect. These assays also allowed us to determine the 40, 60, and 80 µM quercetin concentrations for the following analyses, Lactate Dehydrogenase assay (LDH); Nuclear Morphometric Analysis (NMA); and atomic force microscopy (AFM). The LDH assay showed no cytotoxic effect of quercetin on T24 cancer cells. The AFM showed morphological changes following quercetin treatment, namely decreased cell body, cytoplasmic retraction, and membrane condensation. Following quercetin treatment, the NMA evidenced an increased percentage of nuclei characteristic to the apoptotic and senescence processes. Cells also presented biophysical alterations consistent with cell death by apoptosis, as increased roughness and aggregation of membrane proteins, in a dose-dependent manner. Cellular elasticity, obtained through force curves, showed increased stiffness after quercetin treatment. Data presented herein demonstrate, for the first time, in a quantitative and qualitative form, the morphological and mechanical alterations induced by quercetin on bladder cancer cells.

Does Angiotensin II Peak in Response to SARS-CoV-2?

Human infection by the SARS-CoV-2 is causing the current COVID-19 pandemic. With the growing numbers of cases and deaths, there is an urgent need to explore pathophysiological hypotheses in an attempt to better understand the factors determining the course of the disease. Here, we hypothesize that COVID-19 severity and its symptoms could be related to transmembrane and soluble Angiotensin-converting enzyme 2 (tACE2 and sACE2); Angiotensin II (ANG II); Angiotensin 1-7 (ANG 1-7) and angiotensin receptor 1 (AT1R) activation levels. Additionally, we hypothesize that an early peak in ANG II and ADAM-17 might represent a physiological attempt to reduce viral infection via tACE2. This viewpoint presents: (1) a brief introduction regarding the renin-angiotensin-aldosterone system (RAAS), detailing its receptors, molecular synthesis, and degradation routes; (2) a description of the proposed early changes in the RAAS in response to SARS-CoV-2 infection, including biological scenarios for the best and worst prognoses; and (3) the physiological pathways and reasoning for changes in the RAAS following SARS-CoV-2 infection.

Multimodal physical activity increases brain-derived neurotrophic factor levels and improves cognition in institutionalized older women.

Physical activity has been proposed as a promising intervention to improve cognition and decrease the risk of dementia in older adults. Brain-derived neurotrophic factor (BDNF) appears to mediate, at least partially, these effects of exercise. However, intervention studies of the effects of multimodal exercises on cognition and BDNF levels are scarce and composed by small samples. Thus, the generalization of the conclusions of these studies depends on the reproducibility of the results. In order to contribute to the knowledge on the field, the present study evaluated the effects of a physical activity intervention composed by muscle strengthening and aerobic conditioning on BDNF levels and cognition in older women. Independent and non-demented subjects (≥75 years) were assigned to a 3-month physical activity intervention (n = 22, 60 min exercise sessions three times a week) or to a control condition (n = 10, no exercise). Clinical (anxiety and depression symptoms), neuropsychological (Digit Span, Stroop, Trail Making, and Contextual Memory tests), physical (upper and lower limb strength, aerobic conditioning), and physiological (serum BDNF) parameters were evaluated immediately before, 1 month, and 3 months after starting intervention. Results indicated that controls had stable levels for all measured variables, whereas the intervention group improved on physical fitness, depressive symptoms, cognitive performance, and BDNF levels. Moreover, a linear regression identified an association between aerobic conditioning and BDNF levels. In conclusion, combined muscle strengthening and aerobic conditioning was able to improve cognitive performance and increase BDNF levels. Aerobic conditioning seems to be an important mediator of these outcomes.

Evidence for Immune Activation and Resistance to Glucocorticoids Following Childhood Maltreatment in Adolescents Without Psychopathology.

Early-life stress (ELS) increases the risk for psychopathology. Immune and endocrine changes have been reported in adults and are associated with maladaptation of stress-responsive systems. Here we investigated the effects of ELS on endocrine and immune pathways in adolescents without psychopathology. Thirty adolescents with a history of childhood maltreatment and 27 adolescents without ELS history were recruited. Blood and hair samples were obtained from all participants. Lymphocytes were isolated and stimulated in vitro. Flow cytometry was used to evaluate lymphocyte subsets, Th1/Th2/Th17 cytokines, mitogen-activated protein kinase (MAPK), and nuclear factor kappa B (NF-κB) signaling pathways, as well as lymphocyte sensitivity to dexamethasone. Brain-derived neurotrophic factor (BDNF) and hair cortisol were assessed with enzyme-linked immunosorbent assays (ELISAs). Adolescents with a history of ELS had increased percentages of T-cell activation markers (CD3+CD4+CD25+ and CD3+CD69+) and senescent T cells (CD8+CD28- and CD4+CD28-), as well as decreased percentages of NK (CD3-CD56+) and NK T cells (CD3+CD56+). Following stimulation, lymphocytes of ELS+ adolescents produced significantly more IL-2, IL-4, IFN-γ, and IL-17 and engaged more MAPK ERK and NF-κB signaling. ELS was associated with increased hair cortisol levels in parallel with increased lymphocyte resistance to dexamethasone and low plasma BDNF levels. These data provide the first indication of the presence of immune activation and pro-inflammatory profiles in healthy adolescents exposed to ELS, which could contribute to increased vulnerability of trauma-related psychopathology later in life. The underlying mechanisms of this impairment may include the enhanced activation of both MAPK and NF-κB signaling in parallel to partial resistance to glucocorticoids.

Microbiota abnormalities and the therapeutic potential of probiotics in the treatment of mood disorders.

Major depressive disorder (MDD) and bipolar disorder (BD) are among the leading causes of burden and disability worldwide. Despite intensified research efforts to improve the treatment options and remission rates in mood disorders, no disease modifying treatment exists for these disorders. Accumulating evidence implicates the involvement of the gut microbiota in processes relevant to etiopathology of central nervous system-based disorders. The objective of this article was to critically evaluate the evidence supporting the link between gastrointestinal microbiota and mood disorders and to discuss the potential benefits of using probiotics in the treatment of MDD and BD. The concept of psychobiotics, which is bacterial-based interventions with mental health benefit, is emerging in the field. On the other hand, while probiotics might potentially represent a significant advance, specific roles of microbiota in the pathophysiology of mood disorders still need further investigation along with intervention studies.

Autoantibodies against myelin sheath and S100ß are associated with cognitive dysfunction in patients with rheumatoid arthritis.

Rheumatoid arthritis (RA) has been associated with cognitive impairment and peripheral production of autoantibodies. Autoantibodies against central nervous system (CNS) proteins and S100 calcium-binding ß (S100ß) were found increased in diseases characterized by cognitive impairment like Alzheimer disease and Neuropsychiatric Systemic Lupus Erythematosus (NPSLE). The aim of this study was to investigate the plasma levels of autoantibodies against myelin basic protein (anti-MBP), myelin oligodendrocyte glycoprotein (anti-MOG) and S100ß, and their relationships with cognitive performance in RA patients. Twenty patients with active rheumatoid arthritis and 19 age-, sex-, and schooling-matched healthy controls were recruited. Multiple dimensions of cognitive function were evaluated by structured clinical questionnaires. Autoantibodies and S100ß levels were assessed by ELISAs. Patients had significantly higher levels of anti-MBP IgG (17.51 ± 1.36 vs. 5.24 ± 0.53 ng/mL), anti-MOG IgG (5.68 ± 1.34 vs. 0.51 ± 0.49 ng/mL), and S100ß protein (2.24 ± 0.50 vs. 0.47 ± 0.06) than controls (all p < 0.0001). After adjusting for potential confounders, RA group presented worse cognitive performance involving the working memory and executive functions such as inhibition, flexibility, and mental control in parallel to higher autoantibodies and S100ß levels than healthy controls (all p < 0.001). Levels of anti-MBP were negatively associated with delayed verbal recall (DVR; r = -0.42, p = 0.005), Stroop Color-Word (r = -0.48, p = 0.004), and N-Back Total scores (r = -0.59, p < 0.0001) and positively with Trail Making Test B (TMB, r = 0.53, p = 0.001). Negative correlation was found between levels of anti-MOG and DVR (r = -0.64, p < 0.0001), N-Back Total scores (r = -0.35, p = 0.03), Stroop Color-Word (r = -0.51, p = 0.001), and positively with TMB (r = 0.50, p = 0.003). S100ß levels were associated with DVR (r = -0.51, p = 0.002), TMB (r = 0.46, p = 0.008), Stroop Color-Word (r = -0.67, p < 0.0001), and N-Back Total (r = -0.52, p = 0.003). RA is associated with impaired cognitive performance associated with higher levels of CNS-related autoantibodies and S100ß levels. Given the importance of myelin integrity to cognition, our data indicate that these autoantibodies may be harmful to proper cognitive function.

The brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism affects memory performance in older adults

Objective: Memory impairment is an important contributor to the reduction in quality of life experienced by older adults, and genetic risk factors seem to contribute to variance in age-related cognitive decline. Brain-derived neurotrophic factor (BDNF) is an important nerve growth factor linked with development and neural plasticity. The Val66Met polymorphism in the BDNF gene has been associated with impaired episodic memory in adults, but whether this functional variant plays a role in cognitive aging remains unclear. The purpose of this study was to investigate the effects of the BDNF Val66Met polymorphism on memory performance in a sample of elderly adults. Methods: Eighty-seven subjects aged > 55 years were recruited using a community-based convenience sampling strategy in Porto Alegre, Brazil. The logical memory subset of the Wechsler Memory Scale-Revised was used to assess immediate verbal recall (IVR), delayed verbal recall (DVR), and memory retention rate. Results: BDNF Met allele carriers had lower DVR scores (p = 0.004) and a decline in memory retention (p = 0.017) when compared to Val/Val homozygotes. However, we found no significant differences in IVR between the two groups (p = 0.088). Conclusion: These results support the hypothesis of the BDNF Val66Met polymorphism as a risk factor associated with cognitive impairment, corroborating previous findings in young and older adults.

The brain-derived neurotrophic factor (BDNF) gene Val66Met polymorphism affects memory performance in older adults.

OBJECTIVE:: Memory impairment is an important contributor to the reduction in quality of life experienced by older adults, and genetic risk factors seem to contribute to variance in age-related cognitive decline. Brain-derived neurotrophic factor (BDNF) is an important nerve growth factor linked with development and neural plasticity. The Val66Met polymorphism in the BDNF gene has been associated with impaired episodic memory in adults, but whether this functional variant plays a role in cognitive aging remains unclear. The purpose of this study was to investigate the effects of the BDNF Val66Met polymorphism on memory performance in a sample of elderly adults. METHODS:: Eighty-seven subjects aged > 55 years were recruited using a community-based convenience sampling strategy in Porto Alegre, Brazil. The logical memory subset of the Wechsler Memory Scale-Revised was used to assess immediate verbal recall (IVR), delayed verbal recall (DVR), and memory retention rate. RESULTS:: BDNF Met allele carriers had lower DVR scores (p = 0.004) and a decline in memory retention (p = 0.017) when compared to Val/Val homozygotes. However, we found no significant differences in IVR between the two groups (p = 0.088). CONCLUSION:: These results support the hypothesis of the BDNF Val66Met polymorphism as a risk factor associated with cognitive impairment, corroborating previous findings in young and older adults.

Distinct behavioral and immunoendocrine parameters during crack cocaine abstinence in women reporting childhood abuse and neglect.

AIM: To assess plasma levels of cortisol and cytokines between cocaine-dependent women with and without childhood maltreatment (CM) history during cocaine detoxification treatment. METHOD: We assessed immunoendocrine and clinical parameters of 108 crack cocaine female users during 3 weeks of inpatient detoxification treatment, and 24 healthy women to obtain reference values. Women with (CM+, n=53) or without (CM-, n=55) CM history were identified answering the Childhood Trauma Questionnaire (CTQ). Blood samples and clinical assessment were collected before lunch during the first, second and third week post-treatment admission. Flow cytometry was used to assess TNF-α, IFN-γ, IL-2, IL-4, IL-6, IL-10, IL-17A plasma levels and ELISA assay was used to measure plasma cortisol levels. RESULTS: At baseline, lower Th1 and Th17-related cytokines levels and higher Th2 cytokines levels were observed in crack cocaine users compared with reference values. Cytokines levels of cocaine dependents gradually became closer to reference values along detoxification treatment. However, when CM+ and CM- groups were compared, increased levels of IL-6, IL-4 and TNF-α across time were observed in CM+ group only. Additionally, a Th1/Th2 immune imbalance was observed within CM+ group, which was negatively correlated with the severity of the crack withdrawal. Finally, loading trauma exposure severity, immunoendocrine and clinical parameters in factor analysis, we identified three clusters of observed variables during detoxification: (1) systemic immunity and trauma exposure, (2) pro-inflammatory immunity and (3) behavior CONCLUSION: Our results suggest the existence of an immunological phenotype variant associated with CM exposure during crack cocaine detoxification of women.

The impact of childhood maltreatment on redox state: Relationship with oxidative damage and antioxidant defenses in adolescents with no psychiatric disorder.

Early life stress (ELS) has been associated with biological and psychosocial alterations due to developmental reprogramming. Here, we investigated whether childhood maltreatment is associated with an imbalance between the production of oxidative markers and antioxidant defenses. Thirty adolescents with no psychiatric disorder but reporting childhood maltreatment and twenty-seven adolescents with no psychiatric disorder and no history of ELS were recruited for the study. Childhood maltreatment was investigated by the Childhood Trauma Questionnaire (CTQ). Redox state was estimated by plasma levels of protein carbonylation, total thiol content (SH), superoxide dismutase (SOD), glutathione peroxidase (GPx), as well as total reactive antioxidant potential (TRAP). Childhood maltreatment was associated with oxidative stress as shown by increased protein carbonylation. Interestingly, adolescents exposed to maltreatment also displayed higher SOD levels, TRAP kinetics and reduced GPx levels when compared with adolescents who had not undergone childhood maltreatment. No significant differences were observed for SH levels. Taken together, we provide novel evidence indicating that childhood maltreatment is associated with increased oxidative stress markers in otherwise healthy adolescents.

Toll-like receptor expression and function in type I bipolar disorder.

Bipolar disorder (BD) has been associated with immune imbalance and low-grade inflammation. The underlying mechanisms remain largely obscure but may involve changes in cell signaling. Toll-like receptors (TLRs) are widely expressed by immune cells. Specific binding of TLRs to pathogen- or danger-associated signals leads to inflammatory responses. Here, we analyzed the frequencies of TLR-1, TLR-2, TLR-4, TLR-5 and TLR-6 in monocytes, regulatory T cells (Tregs) and activated T cells from type I BD euthymic patients and healthy controls (HCs). Monocytes were stimulated in vitro with specific TLR agonists (flagellin, LPS, LTA, BLP and PGN) and immunophenotyped. Cytokines (IL-8, IL-1beta, IL-6, IL-10, TNF-alpha and IL-12p70) were assessed with cytometric bead arrays. At baseline, increased percentages of TLR-1+ and TLR-2+ monocytes and reduced expression of TLR-5 were observed in BD. Following stimulation, the percentage of TLR-1+, TLR-2+, and TLR-6+ monocytes was higher in BD subjects than in HCs. Increased levels of IL-8, IL-12p70 and TNF were observed following stimulation with TLR-1, TLR-2 and TLR-6 agonists, suggesting increased signaling via these receptors in BD. In contrast to HCs, BD patients exhibited no changes in TLR-5 expression following stimulation. The percentage of TLR-2+ Treg cells as well as activated T cells expressing both TLR-2 and TLR-5 increased in BD patients. Given the importance of TLRs in triggering immune responses, our data indicate a role for these receptors in the low-grade inflammatory profile documented in BD.

Neuroendocrine and viral correlates of premature immunosenescence.

Aging continuously remodels the immune system, a process known as immunosenescence. Here, we review evidence of premature immunosenescence in younger individuals under conditions of chronic psychological stress, chronic inflammation, or exposure to certain persistent viral infections. Chronic stress may accelerate various features of immunosenescence by activating key allostatic systems, notably the hypothalamic-pituitary-adrenal axis and increased cortisol levels. Chronic stress is associated with thymic involution, blunted T cell proliferation, increased serum proinflammatory markers, and shorter telomere lengths. Human cytomegalovirus (CMV) infection has been implicated in accelerating immunosenescence by shrinking the T cell receptor repertoire and causing clonal expansion of senescent CD8(+) CD28(-) T cells with a proinflammatory profile. These factors increase inflammation associated with aging, or "inflammaging," particularly as it relates to etiology of several age-related diseases and increased mortality. Patients with rheumatoid arthritis have been shown to have several signatures of premature immunosenescence, including expansion of senescent T cells associated with cognitive impairment. We end by speculating that bipolar disorder can be considered as a model of accelerated aging because it has been associated with shortened telomeres, higher CMV IgG titers, and expansion of senescent and regulatory T cells.

Acupuncture for sleep quality, BDNF levels and immunosenescence: a randomized controlled study.

Poor sleep in elderly populations is associated with detrimental neuropsychological, and physiological changes including premature immunosenescence and reduced brain derived neurotrophic factor (BDNF). Here, we evaluated the effects of acupuncture on sleep quality, psychological distress and immunosenescence in elderly, as well as effects on BDNF levels. Forty-eight community-dwelling elderly were randomized into true or placebo acupuncture, and intervention consisted of ten sessions. Sleep quality, depression and stress scores were evaluated by the Pittsburgh sleep quality index (PSQI), beck depression inventory (BDI II) and perceived stress scale (PSS), respectively, before and after the intervention. Lymphocyte subsets commonly associated with stress, sleep impairment and immunosenescence were phenotyped by flow cytometry. BDNF plasma levels were assessed by ELISAs. Acupuncture was highly effective for improving sleep quality (-53.23%; p<0.01), depression (-48.41%; p<0.01), and stress (-25.46%; p<0.01). However, neither lymphocyte subpopulations nor BDNF levels changed following the intervention.

Pro-inflammatory cytokines and soluble receptors in response to acute psychosocial stress: differential reactivity in bipolar disorder.

Mounting evidence suggests a chronic pro-inflammatory state in individuals with bipolar disorder (BD). Stress exposure is known to exacerbate several inflammatory conditions as well as psychiatric disorders. Here, we analyzed plasma levels of pro-inflammatory cytokines and their soluble receptors to realistic acute psychosocial stress challenge in BD. Thirteen euthymic type 1 BD patients and 15 matched controls underwent the Trier Social Stress Test protocol (TSST). Blood samples were collected before and after TSST and plasma cytokines interleukin IL-2, IL-6, IL-33, and tumor necrosis factor alpha (TNF-α) were measured. In addition TNF-α soluble receptors TNFR1 and TNFR2, and IL-33 soluble receptor sST2 were assessed. Increased IL-33 and reduced sST2 levels were observed in BD subjects as compared to controls, independently of stress exposure. Following TSST, there were higher levels of IL-2 and reduced levels of sTNFR1 in both groups. However, the magnitude change for both cytokines was found higher in controls than BD subjects. Our data suggest that BD patients have differential stress reactivity as compared to controls, possibly related to an immunologic imbalance and failure of regulatory mechanisms.

Mesenchymal stem cell therapy and acute graft-versus-host disease: a review.

Mesenchymal stem cells (MSCs) are being widely studied as potential cell therapy agents due to their immunomodulatory properties, which have been established by in vitro studies and in several clinical trials. Within this context, mesenchymal stem cell therapy appears to hold substantial promise, particularly in the treatment of conditions involving autoimmune and inflammatory components. Nevertheless, many research findings are still contradictory, mostly due to difficulties in characterization of the effects of MSCs in vivo. The purpose of this review is to report the mechanisms underlying mesenchymal stem cell therapy for acute graft-versus-host disease, particularly with respect to immunomodulation, migration, and homing, as well as report clinical applications described in the literature.

Early life stress and tumor necrosis factor superfamily in crack cocaine withdrawal.

BACKGROUND: Both early life stress (ELS) and substance abuse, especially cocaine, have robust effects on the inflammatory system. Considering the role of the tumor necrosis factor system in inflammatory signaling and its association with ELS, the aim of the study was to compare plasma levels of TNF-alpha, its soluble receptors and ligands during early abstinence of crack cocaine. METHODS: This study included 24 crack cocaine-dependent women with (CRACK-ELS) and 20 without (CRACK) a history of ELS. A healthy control group (HC), containing 25 participants, was included to provide reference values. The Childhood Trauma Questionnaire (CTQ) retrospectively assessed childhood maltreatment history of patients. Plasma levels of TNF-alpha, TNF-related weak inducer of apoptosis (TWEAK), TNF-related apoptosis-inducing ligand (TRAIL), soluble receptors TNFRI (sTNFRI) and TNFRII (sTNFRII) were assessed on the 18th day of treatment. RESULTS: The CRACK-ELS group had higher TNF-alpha and lower TWEAK levels compared to the CRACK and HC groups. sTNFRII was increased, but only in comparison with the crack cocaine group and the controls. TRAIL levels were slightly higher in the CRACK-ELS group, while no differences were found for sTNFRI levels. Also, TNF-alpha plasma level was positively predicted by abstinence severity and childhood maltreatment severity, and TWEAK was negatively predicted by childhood maltreatment severity. CONCLUSIONS: This is the first study to evaluate the newly secreted tumor necrosis factor superfamily ligands, TWEAK and TRAIL, during crack cocaine abstinence, supporting the association between early life stress and peripheral pro-inflammatory levels.