Effects of alprazolam on cellular immune response to surgical stress in mice

Lorazepam Stimulates IL6 Production and Is Associated with Poor Survival Outcomes in Pancreatic Cancer

PURPOSE

This research investigates the association between benzodiazepines (BZD) and cancer patient survival outcomes, the pancreatic cancer tumor microenvironment, and cancer-associated fibroblast (CAF) signaling.

EXPERIMENTAL DESIGN

Multivariate Cox regression modeling was used to retrospectively measure associations between Roswell Park cancer patient survival outcomes and BZD prescription records. IHC, H&E, Masson's trichrome, RNAscope, and RNA sequencing were used to evaluate the impact of lorazepam (LOR) on the murine PDAC tumor microenvironment. ELISA and qPCR were used to determine the impact of BZDs on IL6 expression or secretion by human-immortalized pancreatic CAFs. PRESTO-Tango assays, reanalysis of PDAC single-cell sequencing/TCGA data sets, and GPR68 CRISPRi knockdown CAFs were used to determine the impact of BZDs on GPR68 signaling.

RESULTS

LOR is associated with worse progression-free survival (PFS), whereas alprazolam (ALP) is associated with improved PFS, in pancreatic cancer patients receiving chemotherapy. LOR promotes desmoplasia (fibrosis and extracellular matrix protein deposition), inflammatory signaling, and ischemic necrosis. GPR68 is preferentially expressed on human PDAC CAFs, and n-unsubstituted BZDs, such as LOR, significantly increase IL6 expression and secretion in CAFs in a pH and GPR68-dependent manner. Conversely, ALP and other GPR68 n-substituted BZDs decrease IL6 in human CAFs in a pH and GPR68-independent manner. Across many cancer types, LOR is associated with worse survival outcomes relative to ALP and patients not receiving BZDs.

CONCLUSIONS

We demonstrate that LOR stimulates fibrosis and inflammatory signaling, promotes desmoplasia and ischemic necrosis, and is associated with decreased pancreatic cancer patient survival.

Changes in blood CD4+T and CD8+T lymphocytes in stressed rats pretreated chronically with desipramine are more pronounced after chronic open field stress challenge

The present study examines the influence of a chronic (14 consecutive days) desipramine (10mg/kg i.p.) pretreatment by itself vs. after chronic (7 consecutive day) open-field (OF) on immune system alterations in response to acute (30 min) OF in Wistar rats (n=60). Opposing to the effect of desipramine injected alone, the combined pretreatment after chronic OF challenge exerts suppressive effects on peripheral blood T/B, CD4(+)T-helper/inducer and CD8(+)T-cytotoxic/suppressor but not NK cell number, decreased interferon-γ/interleukin-10 ratio and thymus weight in the stressed rats. It suggests that chronic stress exposure is important for the immunomodulatory effects of pretreatment with antidepressants.

Urinary biopyrrins: potential biomarker for monitoring of the response to treatment with anxiolytics

During periods of psychological stress, excess amounts of free radicals are produced. Bilirubin oxidative metabolites (biopyrrins; BOM) are generated from bilirubin as a result of its scavenging action against free radicals. We investigated whether the urinary excretion of biopyrrins is altered by anxiolytics. In the present study, mice were immobilized for a period of 6 hr. Alprazolam (0.1-1 mg/kg of body-weight) was administered 30 min. before subjecting the animals to acute stress. The BOM concentrations in urine and the corticosterone levels in serum were measured by ELISA with an anti-bilirubin antibody and EIA, respectively. We observed an increase in urinary biopyrrins in stressed mice in comparison with non-stressed mice and a decrease after the treatment of stressed animals with alprazolam. A correlation between urinary BOM and serum corticosterone levels was found. Urinary levels of biopyrrins might be used to assess the response to anxiolytics prescribed during acute stress periods.

The antioxidant potential of alprazolam on the redox status of peripheral blood leukocytes in restraint-stressed mice

AIMS

Stress can cause adverse reactions in the body that induce a wide range of biochemical and behavioral changes. Oxidative damage is an established outcome of stress that has been implicated in the pathogenesis of mood and anxiety disorders. Anxiolytic drugs are widely prescribed to treat these conditions; however, no animal study has investigated the effect of benzodiazepines on the levels of intracellular reactive oxygen species (ROS) in the peripheral blood leukocytes of stressed mice.

MAIN METHODS

Mice were immobilized for a period of 6h. Alprazolam (0.1-0.8 mg/kg of body weight) was administered 30 min before subjecting the animals to acute stress. The level of intracellular ROS in lymphocytes, granulocytes, and monocytes in the peripheral blood of stressed mice was investigated by using a 2',7'-dichlorofluorescein diacetate (DCFH-DA) probe.

KEY FINDINGS

Our results show that restraint stress significantly increases the generation of ROS in peripheral defense cells. Treatment with alprazolam partially reverses the adverse effects of stress.

SIGNIFICANCE

Our findings suggest that the therapeutic efficacy of alprazolam may be mediated, at least partially, by the reversal of oxidative damage as demonstrated by the protective enhancement of antioxidant status following a stress-induced decline. Because alprazolam is used for the treatment of anxiety in patients with cancer, neurodegenerative disease, inflammatory bowel diseases, and other diseases, these results may have important clinical implications.

Strain-specific outcomes of repeated social defeat and chronic fluoxetine treatment in the mouse

Social stress is a risk factor for affective disorders in vulnerable individuals. Although the biological nature of stress susceptibility/resilience remains to be elucidated, genetic variation is considered amongst the principal contributors to brain disorders. Furthermore, genetic predisposition may be determinant for the therapeutic outcome, as proposed for antidepressant treatments. In the present studies we compared the inherently diverse genetic backgrounds of 2 mouse strains by assessing the efficacy of a chronic antidepressant treatment in a repeated social stress procedure. C57BL/6J and BalbC mice underwent 10-day social defeats followed by 28-day fluoxetine treatment (10 mg/kg/mL, p.o.). In C57BL/6J, most of the social defeat-induced changes were of metabolic nature including persistently altered feed efficiency and decreased abdominal fat stores that were ameliorated by fluoxetine. BalbC mouse behavior was persistently affected by social defeat both in the social avoidance and the forced swim tests, and in either procedure it was restored by chronic fluoxetine, whereas their endocrine parameters were mostly unaffected. The highlighted strain-specific responsivity to the metabolic and behavioral consequences of social defeat and to the chronic antidepressant treatment offers a promising research tool to further explore the underlying neural mechanisms and genetic basis of stress susceptibility and treatment response.

Psychological stress increases expression of IL-10 and its homolog IL-19 via beta-adrenoceptor activation: reversal by the anxiolytic chlordiazepoxide

Recent studies from our laboratory indicate that psychological stress is a potent inducer of the anti-inflammatory cytokine interleukin (IL)-10, raising the possibility that the IL-10 family of cytokines may be key mediators of stress-induced immunosuppression. In this study we examined the impact of psychological stress (restraint stress) on expression of IL-10, and the novel IL-10 family members IL-19, IL-20 and IL-24 in mouse spleen following an in vivo challenge with lipopolysaccharide (LPS). We found that stressor exposure significantly augmented LPS-induced IL-10 expression. Similarly, IL-19 expression was induced by LPS, and this was significantly enhanced by restraint stress. In contrast, expression of IL-24 was not significantly altered by LPS or stress, and expression of IL-20 was largely not detectable in vivo in either saline or LPS-treated animals. Consistent with a role for sympathetic nervous system (SNS) activation in stress-induced immune regulation, the sympathetic neurotransmitter noradrenaline increased LPS-induced IL-10 and IL-19 expression in splenocytes and dendritic cells, and the ability of noradrenaline to induce expression of these cytokines was blocked by pre-treatment with the beta-adrenoceptor antagonist propranolol. Similarly, pre-treatment of mice with the peripherally acting beta-adrenoceptor antagonist nadolol completely blocked the stress-induced increase in IL-10 and IL-19 mRNA expression. Finally, pre-treatment with the benzodiazepine anxiolytic chlordiazepoxide prevented the stress-induced increase in IL-10 and IL-19 expression. Taken together, these data demonstrate that psychological stress induces expression of the IL-10 and its homolog IL-19 via activation of beta-adrenoceptors, and the ability of stress to induce these cytokines is prevented by treatment with the anxiolytic chlordiazepoxide. The findings suggest that stress enhances the production of immunosuppressive cytokines, which may impact on stress-related disease processes.

Effects of fluoxetine on cellular immune response in stressed mice

We studied the effects of fluoxetine, a non-tricyclic antidepressant drug that selectively inhibits re-uptake of serotonin by presinaptic neurons in the brain, on cellular immune responses in mice exposed to a chronic auditory stressor. The natural killer (NK) cell activity was reduced after 4, 8, 12, 16 and 20 days of stress exposure with a partial recovery on days 16 and 20. Daily treatment with fluoxetine partially reversed these adverse effects of stress in a dose-dependent manner. Significant differences appeared when fluoxetine was administered at 2 mg/kg and maximum effect was reached at doses of 5 mg/kg. The capacity of T cells to generate cytotoxic T-lymphocytes (CTL) in mixed lymphocyte cultures and in vivo was reduced after 4 days of stress application and this effect was partially reduced when mice were injected with 5 mg/kg of fluoxetine. Nevertheless, in our experiments, fluoxetine did not significantly affect the cellular immunity in unstressed mice. In conclusion, fluoxetine seems to partially recover the adverse effects of chronic stress on cellular immune response.

Effects of nefazodone on the development of experimentally induced tumors in stressed rodents

RATIONALE

Anxiety and depression are commonly encountered in patients with cancer and constitute risk and prognostic factors for the disease. Although previous findings do not support an overall association between the use of antidepressants and higher prevalence of cancer, results for serotonin uptake inhibitors are not entirely reassuring.

OBJECTIVES

We evaluated the effects of nefazodone, a serotonin and norepinephrine (NE) reuptake inhibitor and 5-HT(2A) receptor antagonist antidepressant, on the appearance of breast cancer induced by mammary tumor virus (MTV) in mice, and on the development of lung metastases in rats injected intravenously with Walker 256 (W-256) carcinosarcoma cells.

METHODS

Female C3H/He mice carrying the MTV were monitored for mammary tumor incidence and latent periods while being treated with a daily intraperitoneal injection with placebo or nefazodone. Rats were administered 10(4) W-256 cells, exposed to a chronic auditory stressor for 8 days, and then killed to evaluate metastatic nodules in the lungs.

RESULTS

Although all of the mice were potential candidates for MTV-induced breast cancer, those treated with nefazodone were partially protected against adverse effects of stress induced by the daily administration of placebo on both parameters. Relative to placebo, nefazodone reduced the stress-induced increase in the number and percentage area of metastases in the frontal section through pulmonary hilus and increased the survival periods of rats given W-256 cells and exposed to a chronic auditory stressor.

CONCLUSIONS

Our results provide evidence of the beneficial effects of nefazodone against the adverse effects of stress on tumor development and metastaticity in rodents, but did not show significant effects in unstressed rodents.

Potential prophylactic measures against postoperative immunosuppression: could they reduce recurrence rates in oncological patients?

BACKGROUND

Removing the primary tumor is indispensable for eliminating the major pool of metastasizing cells, but the surgical procedure itself is suspected of promoting metastases. This adverse effect is attributed to several mechanisms acting in synergy, including mechanical release of tumor cells, enhanced angiogenesis, secretion of growth factors, and immunosuppression. Here we provide new insights into mechanisms of postoperative immunosuppression and assess the assumptions underlying the hypothesis that, by suppressing cell-mediated immunity (CMI), surgery may render the patient vulnerable to metastases that otherwise could have been controlled.

METHODS

An extensive review of relevant articles in English identified by using the MEDLINE database and cross-referencing.

RESULTS

Current literature suggests that (1) CMI can control minimal residual disease, especially if surgery is performed early; (2) major surgery transiently but markedly suppresses CMI through multiple mechanisms now better understood; (3) surgical stress promotes experimental metastasis through immunosuppression, but the clinical evidence remains indirect because of ethical limitations.

CONCLUSIONS

Minimizing postoperative immunosuppression seems feasible, may limit recurrence, and should be introduced into the broader array of considerations when planning oncological surgeries. In the short run, physicians could try to avoid immunosuppressive anesthetic approaches, inadvertent hypothermia, excessive blood transfusions, and untended postoperative pain. When feasible, minimally invasive surgery should be considered. In the long run, clinical trials should evaluate prophylactic measures, including perioperative immunostimulation and several antagonists to cytokines and hormones specified herein.

Effects of psychological stress and alprazolam on development of oral candidiasis in rats

Psychological stress has been found to suppress cell-mediated immune responses that are important in limiting the proliferation of Candida albicans. Since anxiolytic drugs can restore cellular immunity in rodents exposed to stress conditions, we designed experiments conducted to evaluate the effects of alprazolam (1 mg/kg of body weight/day), a central benzodiazepine anxiolytic agonist, on the development of oral candidiasis in Sprague-Dawley rats exposed to a chronic auditory stressor. Animals were submitted to surgical hyposalivation in order to facilitate the establishment and persistence of C. albicans infection. Application of stress and treatment with drugs (placebo or alprazolam) were initiated 7 days before C. albicans inoculation and lasted until the end of the experiments (day 15 postinoculation). Establishment of C. albicans infection was evaluated by swabbing the inoculated oral cavity with a sterile cotton applicator on days 2 and 15 after inoculation, followed by plating on YEPD (yeast extract-peptone-dextrose) agar. Tissue injury was determined by the quantification of the number and type (normal or abnormal) of papillae on the dorsal tongue per microscopic field. A semiquantitative scale was devised to assess the degree of colonization of the epithelium by fungal hyphae. Our results show that stress exacerbates C. albicans infection of the tongues of rats. Significant increases in Candida counts, the percentage of the tongue's surface covered with clinical lesions, the percentage of abnormal papillae, and the colonization of the epithelium by fungal hyphae were found in stressed rats compared to those found in the unstressed rats. Treatment with alprazolam significantly reversed these adverse effects of stress, showing that, besides the psychopharmacological properties of this anxiolytic drug against stress, it has consequences for Candida infection.

Effects of nefazodone on the immune system of mice

Mice exposed to a chronic auditory stressor and treated with nefazodone (10 mg/kg/day s.c.), showed a reduction in stress-induced suppression of thymus and spleen cellularity, and in peripheral T-Iymphocyte population. The in vitro blastogenic response of spleen lymphoid cells to mitogen concanavalin A, the in vitro and in vivo activity of phagocytosis, both measured using the zymosan and carbon clearance tests, respectively, were also assessed and nefazodone was found to partially reverse the inhibitory effect of stress on those parameters. Nefazodone did not significantly affect those parameters in unstressed mice. In conclusion, this report provides evidence on the immunoprotective effects of this novel antidepressant drug against the adverse effects of stress in mice.

Acute effects of glucocorticoids: behavioral and pharmacological perspectives

There has been evidence since the early eighties that glucocorticoids, apart from their well known chronic effects, may have acute, short-term effects. However, a lack of understanding of the molecular mechanisms of action has hampered appreciation of these observations. Mounting evidence over the years has continued to confirm the early observations on a fast corticosterone control of acute behavioral responses. We summarize experimental data obtained mainly in rats but also in other species which show: (1) that glucocorticoid production is sufficiently quick to affect ongoing behavior; (2) that there exist molecular mechanisms that could conceivably explain the fast neuronal effects of glucocorticoids (although these are still insufficiently understood); (3) that glucocorticoids are able to stimulate a wide variety of behaviors within minutes; and (4) that acute glucocorticoid production (at least in the case of aggressive behavior) is linked to the achievement of the behavioral goal (winning). The achievement of the behavioral goal reduces glucocorticoid production. It is argued that glucocorticoids are regulatory factors having a well-defined behavioral role. Both the acute (stimulatory) effects and the chronic (inhibitory) effects are adaptive in nature. The acute control of behavior by corticosterone is a rather unknown process that deserves further investigation. The pharmacologic importance of the acute glucocorticoid response is that it may readily affect the action of pharmacologic agents. An interaction between acute glucocorticoid increases and noradrenergic treatments has been shown in the case of offensive and defensive agonistic behavior. Non-behavioral data demonstrate that acute increases in glucocorticoids may interfere with other neurotransmitter systems (e.g., with the 5HT system) as well. These observations show the importance of taking into account endocrine background and endocrine responsiveness in behavior pharmacological experiments.

Severity, time, and beta-adrenergic receptor involvement in surgery-induced immune alterations

Although investigations of surgical stress in animals have reported immune alterations, surprisingly little is known about the variables or mechanisms contributing to the effect. Thus, we completed a series of experiments investigating the immune-altering effects of surgery severity, time of maximal immune alterations, and recovery, as well as the involvement of beta-adrenergic receptors in surgery-induced immune alterations in Lewis rats. Immune alterations included natural killer (NK) cell cytotoxicity as well as B- and T-cell proliferation. Results showed increased immune suppression with larger incisions (6 cm > 3 cm > anesthesia > saline). In addition, maximal immune alterations induced by surgery occurred after 24 h; anesthesia effects predominated at the earlier time points. Recovery of immune status varied depending on the immunological measure of interest. Although NK cell cytotoxicity returned to control values within 2 days, B-cell proliferation remained suppressed for at least 8 days, and T-cell proliferation did not begin to recover until 4-8 days following the surgical procedure. To assess the mechanisms involved in surgery-induced immune alterations, follow-up assessments evaluated the effect of nadolol, a beta-adrenergic receptor antagonist, on surgery-induced immune alterations. Results show that nadolol blocks the surgery-induced reduction in B- and T-cell proliferation but has no effect on the suppression of NK cell cytotoxicity. These results indicate the need to consider surgical severity and postoperative time of immune assessment when investigating the immune-altering effects of surgery. Importantly, activation of beta-adrenergic receptors appears to play a modulatory role in surgery-induced immune alterations.

Benzodiazepines, anxiety and immunity

Experimental and clinical studies suggest that the central and peripheral benzodiazepine (BDZ) receptors together with their ligands form the molecular basis of a novel regulatory network that contributes to the effects of anxiety on immune status. The peripheral-type receptors located on phagocytes and glial cells appear to play a key role in mediating the effects of endogenous and exogenous BDZs both on the defence mechanisms that protect the host against pathogens and on inflammatory reactions that take place within the periphery and the brain in response to injury. In addition, the central-type receptor, which forms part of the gamma-aminobutyric acidA receptor complex, may contribute to the regulation of T-cell function by modulating the activity of the hypothalamo-pituitary-adrenocortical axis or the sympathoadrenal system or both, which, in turn, exert a significant effect on immune function. Thus, anxiogenic BDZs in general suppress the immune response, whereas anxiolytic BDZs may protect the individual from stress-induced immunosuppression.

Effects of fluoxetine on the immunosuppressive response to stress in mice

Mice exposed to a chronic auditory stressor and treated with fluoxetine (5 mg/kg) showed a reduction in stress-induced suppression of thymus and spleen cellularity, and in peripheral T lymphocyte population. The blastogenic response of spleen lymphoid cells and the delayed type hypersensitivity response (DTH) to sheep red blood cells (SRBC) were also assessed and fluoxetine was found to partially reverse the inhibitory effect of stress on both parameters.