Candesartan ameliorates impaired fear extinction induced by innate immune activation.

Patients with post-traumatic stress disorder (PTSD) tend to show signs of a relatively increased inflammatory state suggesting that activation of the immune system may contribute to the development of PTSD. In the present study, we tested whether activation of the innate immune system can disrupt acquisition or recall of auditory fear extinction using an animal model of PTSD. Male adolescent rats received auditory fear conditioning in context A. The next day, an intraperitoneal injection of lipopolysaccharide (LPS; 100 µg/kg) prior to auditory fear extinction in context B impaired acquisition and recall of extinction. LPS (100 µg/kg) given after extinction training did not impair extinction recall suggesting that LPS did not affect consolidation of extinction. In contrast to cued fear extinction, contextual fear extinction was not affected by prior injection of LPS (100 µg/kg). Although LPS also reduced locomotion, we could dissociate the effects of LPS on extinction and locomotion by using a lower dose of LPS (50 µg/kg) which impaired locomotion without affecting extinction. In addition, 15 h after an injection of 250 µg/kg LPS in adult rats, extinction learning and recall were impaired without affecting locomotion. A sub-chronic treatment with candesartan, an angiotensin II type 1 receptor blocker, prevented the LPS-induced impairment of extinction in adult rats. Our results demonstrate that activation of the innate immune system can disrupt auditory fear extinction in adolescent and adult animals. These findings also provide direction for clinical studies of novel treatments that modulate the innate immune system for stress-related disorders like PTSD.

Depression, Anxiety, and Social Environmental Adversity as Potential Modulators of the Immune Tumor Microenvironment in Breast Cancer Patients.

Background: Mounting data suggest that exposure to chronic stress is associated with worse breast cancer outcomes. This study aimed to explore the impact of social environmental adversity (SEA, e.g., child abuse, crime, sexual, and physical violence), depressive symptomatology, and anxiety on immune cell infiltration into the breast tumor microenvironment. Methods: Participants (n = 33) completed a series of surveys assessing depression and anxiety symptoms, adverse childhood events (ACE), and trauma history. Tumor-associated macrophages (CD68+), B cells (CD19+), and T cells (CD3+) were identified by immunohistochemical analyses of formalin-fixed paraffin-embedded tumor samples and quantified. Spearman rank tests were used to explore the relationships between the variables studied. Results: Exposure to SEA was high (ACE = 72%, exposure to crime = 47%, and exposure to physical/sexual assault = 73%) among participants. Moreover, 30% reported a comorbid history of depression and ACE; 39% reported one or more traumatic events, and clinically significant depression symptomatology, while 21% reported trauma history and significant anxiety symptomatology. Increased tumor-infiltrating B cells were significantly correlated with exposure to crime, anxiety symptoms, and exposure to an ACE. The ACE plus anxiety group presented the highest infiltration of B cells, T cells, and macrophages. Conclusion: These findings support a role for SEA, anxiety symptoms, and depression as potential modulators of the immune tumor microenvironment in breast cancer.

Zoledronic Acid Abrogates Restraint Stress-Induced Macrophage Infiltration, PDGF-AA Expression, and Ovarian Cancer Growth.

Multiple studies suggest that chronic stress accelerates the growth of existing tumors by activating the sympathetic nervous system. Data suggest that sustained adrenergic signaling can induce tumor growth, secretion of pro-inflammatory cytokines, and macrophage infiltration. Our goal was to study the role of adrenergic-stimulated macrophages in ovarian cancer biology. Cytokine arrays were used to assess the effect of adrenergic stimulation in pro-tumoral cytokine networks. An orthotopic model of ovarian cancer was used to assess the in vivo effect of daily restraint stress on tumor growth and adrenergic-induced macrophages. Cytokine analyses showed that adrenergic stimulation modulated pro-inflammatory cytokine secretion in a SKOV3ip1 ovarian cancer cell/U937 macrophage co-culture system. Among these, platelet-derived growth factor AA (PDGF-AA), epithelial cell-derived neutrophil-activating peptide (ENA-78), Angiogenin, vascular endothelial growth factor (VEGF), granulocyte-macrophage colony-stimulating factor (GM-CSF), interleukin-5 (IL-5), Lipocalin-2, macrophage migration inhibitory factor (MIF), and transferrin receptor (TfR) were upregulated. Enriched biological processes included cytokine-mediated signaling pathways and positive regulation of cell proliferation. In addition, daily restraint stress increased ovarian cancer growth, infiltration of CD68+ macrophages, and expression of PDGF-AA in orthotopic models of ovarian cancer (SKOV3ip1 and HeyT30), while zoledronic acid, a macrophage-depleting agent, abrogated this effect. Furthermore, in ovarian cancer patients, high PDGFA expression correlated with worse outcomes. Here, it is shown that the adrenergic regulation of macrophages and PDGFA might play a role in ovarian cancer progression.

Impact of a natural disaster on access to care and biopsychosocial outcomes among Hispanic/Latino cancer survivors.

Cancer is the leading cause of death in Puerto Rico (PR). Hurricane Maria (HM) and its aftermath lead to widespread devastation on the island, including the collapse of the healthcare system. Medically fragile populations, such as cancer survivors, were significantly affected. The goal of this study was to assess the impact of HM on barriers to care, emotional distress, and inflammatory biomarkers among cancer survivors in PR. This exploratory longitudinal study was conducted in health care facilities and community support groups from PR. Cancer survivors (n = 50) and non-cancer participants (n = 50) completed psychosocial questionnaires and provided blood samples that were used to assess inflammatory cytokines levels. Among this cohort, we identified 41 matched cancer survivors/non-cancer participants pairs. Data were analyzed through descriptive, frequencies, correlational, and regression analyses. Cancer survivors that were affected by HM reported increased barriers in accessing medical care, which were directly associated with anxiety, perceived stress, and post-traumatic symptomatology. Moreover, being a cancer survivor, predicted more barriers to receiving health care, especially in the first six weeks after the event, after which the effect was attenuated. Several inflammatory cytokines, such as CD31, BDNF, TFF3, Serpin E-1, VCAM-1, Vitamin D BP, and PDGF-AA, were significantly upregulated in cancer survivors while MMP9 and Osteopontin both had significant positive correlations with barriers to care. HM significantly impacted Puerto Ricans psychosocial well-being. Cancer survivors had significant barriers to care and showed increased serum inflammatory cytokines but did not show differences in anxiety, stress, and post-traumatic symptoms compared to non-cancer participants.

Plasticity of NMDA Receptors at Ventral Hippocampal Synapses in the Infralimbic Cortex Regulates Cued Fear.

The medial prefrontal cortex (mPFC) processes contextual information from the hippocampus to generate appropriate fear responses. In rodents, one path for sending contextual information to the mPFC is via the direct projections from the ventral hippocampus (vHC) to the infralimbic cortex (IL). Plasticity in the synaptic communication from the vHC to the IL could contribute to the behavioral changes produced by the acquisition and extinction of conditioned fear. To examine this possibility, we used optogenetic stimulation of vHC synapses in brain slices from trained rats. We found that fear acquisition reduced NMDA receptor (NMDAR) currents at vHC synapses onto IL pyramidal neurons. The depression of NMDAR currents reversed more efficiently after extinction in the conditioning context than extinction in a novel context. Moreover, a cohort of animals that exhibited poor extinction retrieval failed to reverse the plasticity induced by fear conditioning. In addition, ex vivo application of brain-derived neurotrophic factor (BDNF), which is known to simulate extinction in IL, reversed this conditioning-induced plasticity mimicking extinction. Therefore, we have identified a novel mechanism that modulates conditioned fear via changes in NMDAR current at vHC synapses onto IL pyramidal neurons. Disruption of this mechanism could contribute to the abnormal contextual modulation of fear seen in posttraumatic stress disorder (PTSD).