Psychosocial stress contributes to the development of anxiety and depression. Recent clinical studies have reported increased inflammatory leukocytes in circulation of individuals with stress-related psychiatric disorders. Parallel to this, our work in mice shows that social stress causes release of inflammatory monocytes into circulation. In addition, social stress caused the development of prolonged anxiety that was dependent on inflammatory monocytes in the brain. Therefore, we hypothesize that chronic stress drives the production of inflammatory monocytes that are actively recruited to the brain by microglia, and these monocytes augment neuroinflammatory signaling and prolong anxiety. Here we show that repeated social defeat stress in mice activated threat appraisal centers in the brain that spatially coincided with microglial activation and endothelial facilitation of monocyte recruitment. Moreover, microglial depletion with a CSF1R antagonist prior to stress prevented the recruitment of monocytes to the brain and abrogated the development of anxiety. Cell-specific transcriptional profiling revealed that microglia selectively enhanced CCL2 expression, while monocytes expressed the pro-inflammatory cytokine IL-1β. Consistent with these profiles, the recruited inflammatory monocytes with stress adhered to IL-1R1+ neurovascular endothelial cells and this interaction was blocked by microglial depletion. Furthermore, disruption of IL-1β signaling by caspase-1KO specifically within bone marrow-derived cells revealed that monocytes promoted anxiogenesis through stimulation of neurovascular IL-1R1 by IL-1β. Collectively, the development of anxiety during stress was caused by microglial recruitment of IL-1β-producing monocytes that stimulated brain endothelial IL-1R1. Thus, monocyte IL-1β production represents a novel mechanism that underlies behavioral complications associated with stress-related psychiatric disorders.
Psychosocial stress is associated with altered immunity, anxiety and depression. Previously we showed that repeated social defeat (RSD) promoted microglia activation and social avoidance behavior that persisted for 24 days after cessation of RSD. The aim of the present study was to determine if imipramine (a tricyclic antidepressant) would reverse RSD-induced social avoidance and ameliorate neuroinflammatory responses. To test this, C57BL/6 mice were divided into treatment groups. One group from RSD and controls received daily injections of imipramine for 24 days, following 6 cycles of RSD. Two other groups were treated with saline. RSD mice spent significantly less time in the interaction zone when an aggressor was present in the cage. Administration of imipramine reversed social avoidance behavior, significantly increasing the interaction time, so that it was similar to that of control mice. Moreover, 24 days of imipramine treatment in RSD mice significantly decreased stress-induced mRNA levels for IL-6 in brain microglia. Following ex vivo LPS stimulation, microglia from mice exposed to RSD, had higher mRNA expression of IL-6, TNF-α, and IL-1β, and this was reversed by imipramine treatment. In a second experiment, imipramine was added to drinking water confirming the reversal of social avoidant behavior and decrease in mRNA expression of IL-6 in microglia. These data suggest that the antidepressant imipramine may exert its effect, in part, by down-regulating microglial activation.
Objective Psychosocial stress is associated with altered immunity, anxiety, and depression. Repeated social defeat (RSD), a model of social stress, triggers egress of inflammatory myeloid progenitor cells (MPCs; CD11b+ /Ly6Chi) that traffic to the brain, promoting anxiety-like behavior. In parallel, RSD enhances neuroinflammatory signaling and long-lasting social avoidant behavior. Lorazepam and clonazepam are routinely prescribed anxiolytics that act by enhancing GABAergic activity in the brain. Besides binding to the central benzodiazepine binding site (CBBS) in the central nervous system (CNS), lorazepam binds to the translocator protein (TSPO) with high affinity causing immunomodulation. Clonazepam targets the CBBS and has low affinity for the TSPO. Here the aims were to determine if lorazepam and clonazepam would: 1) prevent stress-induced peripheral and central inflammatory responses, and 2) block anxiety and social avoidance behavior in mice subjected to RSD. Methods C57/BL6 mice were divided into experimental groups, and treated with either lorazepam (0.10mg/kg), clonazepam (0.25 mg/kg) or vehicle (0.9%NaCl). Behavioral data and tissues were collected the morning after the last cycle of RSD. Results Lorazepam and clonazepam were effective in attenuating mRNA expression of CRH in the hypothalamus and corticosterone in plasma in mice subjected to RSD. Both drugs blocked stress-induced levels of IL-6 in plasma. Lorazepam and clonazepam had different effects on stress-induced enhancement of myelopoiesis and inhibited trafficking of monocytes and granulocytes in circulation. Furthermore, lorazepam, but not clonazepam, inhibited splenomegaly and the production of pro-inflammatory cytokines in the spleen following RSD. Additionally, lorazepam and clonazepam, blocked stress-induced accumulation of macrophages (CD11b+/CD45high) in the CNS. In a similar manner, both lorazepam and clonazepam prevented neuroinflammatory signaling and reversed anxiety-like and depressive-like behavior in mice exposed to RSD. Conclusion These data support the notion that lorazepam and clonazepam, aside from exerting anxiolytic and antidepressant effects, may have therapeutic potential as neuroimmunomodulators during psychosocial stress. The reversal of RSD-induced behavioral outcomes may be due to the enhancement of GABAergic neurotransmission, or some other off-target effect. The peripheral actions of lorazepam, but not clonazepam, seem to be mediated by TSPO activation.
Psychosocial stress is capable of causing immune dysregulation and increased neuroinflammatory signaling by repeated activation of the neuroendocrine and autonomic systems that may contribute to the development of anxiety and depression. The stress model of repeated social defeat (RSD) recapitulates many of the stress-driven alterations in the neuroimmune system seen in humans experiencing repeated forms of stress and associated affective disorders. For example, RSD-induced neuronal and microglia activation corresponds with sympathetic outflow to the peripheral immune system and increased ability of bone marrow derived myeloid progenitor cells (MPC) to redistribute throughout the body, including to the central nervous system (CNS), reinforcing stress-associated behaviors. An overview of the neuroendocrine, immunological, and behavioral stress-induced responses will be reviewed in this chapter using RSD to illustrate the mechanisms leading to stress-related alterations in inflammation in both the periphery and CNS, and stress-related changes in behavioral responses.
In order to relieve anxiety and depression accompanying stress, physicians resort to tricyclic antidepressants, such as imipramine. We had previously shown that imipramine reversed stress-induced social avoidance behavior, and down-regulated microglial activation 24 days after stress cessation. To further characterize the effects of imipramine on stress induced neuroimmune dysregulation and associated changes in behavior, the aims of this study were to determine if imipramine 1) ameliorated stress-induced inflammation in the periphery and central nervous system, and 2) prevented stress related anxiety- and depressive-like behaviors. C57BL/6 mice were treated with imipramine (15mg/kg) in their drinking water, and exposed to repeated social defeat (RSD). Imipramine attenuated stress-induced corticosterone and IL-6 responses in plasma. Imipramine decreased the percentage of monocytes and granulocytes in the bone marrow and circulation. However, imipramine did not prevent splenomegaly, stress-related increased percentage of granulocytes in this organ, and the production of pro-inflammatory cytokines in the spleen, following RSD. Moreover, imipramine abrogated the accumulation of macrophages in the brain in mice exposed to RSD. Imipramine blocked neuroinflammatory signaling and prevented stress-related anxiety- and depressive-like behaviors. These data support the notion that pharmacomodulation of the monoaminergic system, besides exerting anxiolytic and antidepressant effects, may have therapeutic effects as a neuroimmunomodulator during stress.
In Chile breast cancer (BC) is the first cause of death in women. While the most important risk factor for its development is estrogenic stimulation, environmental factors and lifestyles also contribute to its pathogenesis. Epidemiological studies show a direct relationship between physical activity (PA), incidence and recurrence of BC. Supervised PA practice is recommended in most cancer patients to improve their quality of life, to reduce adverse effects from treatment and eventually to improve the prognosis of the disease. We review the epidemiological evidence linking PA and BC and the biological basis of this relationship. We also review the relevant interventional studies and we explore some practical indications of PA in patients with BC, as a model for other tumors of epidemiological importance.
BackgroundGingivitis is a common oral health problem. Untreated gingivitis may progress to periodontitis, a common cause of tooth loss. The prevalence of gingivitis and calculus among Puerto Rican children is unknown. Understanding this prevalence can support early public health preventative strategies. This study aims to estimate the prevalence of gingivitis and calculus among 12-year-old Puerto Ricans by health region and to explore differences in distribution by school type (proxy for socio-economic status) and gender.MethodsA probability-based sample of 113 schools was selected proportional to enrollment size and stratified by health region, school type, and gender. Two trained examiners evaluated the presence of gingivitis and both supragingival and subgingival dental calculus. Gingivitis was defined as the presence of gingival bleeding upon gentle probing (BOP) in at least one site, and the extent of the problem was classified according to the percentage of teeth whose gingiva presented BOP (limited: 25–49% of the teeth tested; extensive: >50% of teeth tested). Logistic and linear regression models, adjusted for health regions, were used to compare gingivitis and calculus prevalence and extent between genders and school types.ResultsGingivitis was found in 80.41% of the 1586 children evaluated. Urban-public schoolchildren had a slightly higher prevalence (83.24%) compared to private (79.15%, p = 0.16); those in rural-public (77.59%) and private schools had similar prevalence (p = 0.15). Extensive gingivitis was present in 60.81% of all children. The mean percentage of sites presenting BOP (BOP%) was 17.79%. Rural and urban public schoolchildren presented significantly higher BOP% compared to children from private schools (p = 0.0005, p = 0.002, respectively). Dental calculus was detected in 61.59% of the sample, boys presenting significantly higher (p = 0.005) total and supragingival calculus. Rural-public schoolchildren had a significantly higher prevalence of subgingival calculus compared to private schoolchildren (p = 0.02).ConclusionsGingivitis prevalence is higher among 12-year-old Puerto Ricans compared to data reported for U.S. adolescents. Public schoolchildren presented significantly higher BOP% sites compared to private schoolchildren. Boys presented a significantly higher total and supragingival calculus prevalence than girls. Oral health disparities related to gender and school type were identified by this study. Studies exploring the reasons for these disparities are recommended.Electronic supplementary materialThe online version of this article (10.1186/s12903-017-0471-5) contains supplementary material, which is available to authorized users.
Arginine regimen provided the greatest reduction in Tactile and Air-Blast dentine hypersensitivity compared to potassium and negative control regimens; and provides faster dentine hypersensitivity relief than potassium regimen.
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