Anti-inflammatory effects of ß-FNA are sex-dependent in a pre-clinical model of LPS-induced inflammation.

BACKGROUND: Inflammation is present in neurological and peripheral disorders. Thus, targeting inflammation has emerged as a viable option for treating these disorders. Previous work indicated pretreatment with beta-funaltrexamine (ß-FNA), a selective mu-opioid receptor (MOR) antagonist, inhibited inflammatory signaling in vitro in human astroglial cells, as well as lipopolysaccharide (LPS)-induced neuroinflammation and sickness-like-behavior in mice. This study explores the protective effects of ß-FNA when treatment occurs 10 h after LPS administration and is the first-ever investigation of the sex-dependent effects of ß-FNA on LPS-induced inflammation in the brain and peripheral tissues, including the intestines. RESULTS: Male and female C57BL/6J mice were administered LPS followed by treatment with ß-FNA-immediately or 10 h post-LPS. Sickness- and anxiety-like behavior were assessed using an open-field test and an elevated-plus-maze test, followed by the collection of whole brain, hippocampus, prefrontal cortex, cerebellum/brain stem, plasma, spleen, liver, large intestine (colon), proximal small intestine, and distal small intestine. Levels of inflammatory chemokines/cytokines (interferon γ-induced-protein, IP-10 (CXCL10); monocyte-chemotactic-protein 1, MCP-1 (CCL2); interleukin-6, IL-6; interleukin-1ß, IL-1ß; and tumor necrosis factor-alpha, TNF-α) in tissues were measured using an enzyme-linked immunosorbent assay. Western blot analysis was used to assess nuclear factor-kappa B (NF-κB) expression. There were sex-dependent differences in LPS-induced inflammation across brain regions and peripheral tissues. Overall, LPS-induced CXCL10, CCL2, TNF-α, and NF-κB were most effectively downregulated by ß-FNA; and ß-FNA effects differed across brain regions, peripheral tissues, timing of the dose, and in some instances, in a sex-dependent manner. ß-FNA reduced LPS-induced anxiety-like behavior most effectively in female mice. CONCLUSION: These findings provide novel insights into the sex-dependent anti-inflammatory effects of ß-FNA and advance this agent as a potential therapeutic option for reducing both neuroinflammation an intestinal inflammation.

Anti-inflammatory actions of ß-funaltrexamine in a mouse model of lipopolysaccharide-induced inflammation.

Neuroinflammation is involved in a wide range of brain disorders, thus there is great interest in identifying novel anti-inflammatory agents to include in therapeutic strategies. Our previous in vitro studies revealed that beta-funaltrexamine (ß-FNA), a well-characterized selective mu-opioid receptor (MOR) antagonist, inhibits inflammatory signaling in human astroglial cells, albeit through an apparent MOR-independent mechanism. We also previously determined that lipopolysaccharide (LPS)-induced sickness behavior and neuroinflammation in mice are prevented by pretreatment with ß-FNA. Herein we investigated the temporal importance of ß-FNA treatment in this pre-clinical model of LPS-induced neuroinflammation. Adult, male C57BL/6J mice were administered an i.p. injection of LPS followed by treatment (i.p. injection) with ß-FNA immediately or 4 h post-LPS. Sickness behavior was assessed using an open-field test, followed by assessment of inflammatory signaling in the brain, spleen, and plasma. Levels of inflammatory chemokines/cytokines (interferon γ-induced protein, CXCL10; monocyte chemotactic protein 1, CCL2; and interleukin-6, IL-6) in tissues were measured using an enzyme-linked immunosorbent assay and nuclear factor-kappa B (NFκB), p38 mitogen activated kinase (p38 MAPK), and glial fibrillary acidic protein (GFAP) expression were measured by western blot. LPS-induced sickness behavior and chemokine expression were inhibited more effectively when ß-FNA treatment occurred immediately after LPS administration, as opposed to 4 h post-LPS; and ß-FNA-mediated effects were time-dependent as evidenced by inhibition at 24 h, but not at 8 h. The inhibitory effects of ß-FNA on chemokine expression were more evident in the brain versus the spleen or plasma. LPS-induced NFκB-p65 and p38 MAPK expression in the brain and spleen were inhibited at 8 and 24 h post-LPS. These findings extend our understanding of the anti-inflammatory effects of ß-FNA and warrant further investigation into its therapeutic potential.

Relationship Between Circulating Metabolic Hormones and Their Central Receptors During Ovariectomy-Induced Weight Gain in Rats.

Although increasing research focuses on the phenomenon of body weight gain in women after menopause, the complexity of body weight regulation and the array of models used to investigate it has proven to be challenging. Here, we used ovariectomized (OVX) rats, which rapidly gain weight, to determine if receptors for ghrelin, insulin, or leptin in the dorsal vagal complex (DVC), arcuate nucleus (ARC), or paraventricular nucleus (PVN) change during post-ovariectomy weight gain. Female Sprague-Dawley rats with ad libitum access to standard laboratory chow were bilaterally OVX or sham OVX. Subgroups were weighed and then terminated on day 5, 33, or 54 post-operatively; blood and brains were collected. ELISA kits were used to measure receptors for ghrelin, insulin, and leptin in the DVC, ARC, and PVN, as well as plasma ghrelin, insulin, and leptin. As expected, body weight increased rapidly after ovariectomy. However, ghrelin receptors did not change in any of the areas for either group, nor did circulating ghrelin. Thus, the receptor:hormone ratio indicated comparable ghrelin signaling in these CNS areas for both groups. Insulin receptors in the DVC and PVN decreased in the OVX group over time, increased in the PVN of the Sham group, and were unchanged in the ARC. These changes were accompanied by elevated circulating insulin in the OVX group. Thus, the receptor:hormone ratio indicated reduced insulin signaling in the DVC and PVN of OVX rats. Leptin receptors were unchanged in the DVC and ARC, but increased over time in the PVN of the Sham group. These changes were accompanied by elevated circulating leptin in both groups that was more pronounced in the OVX group. Thus, the receptor:hormone ratio indicated reduced leptin signaling in the DVC and PVN of both groups, but only in the OVX group for the ARC. Together, these data suggest that weight gain that occurs after removal of ovarian hormones by ovariectomy is associated with selective changes in metabolic hormone signaling in the CNS. While these changes may reflect behavioral or physiological alterations, it remains to be determined whether they cause post-ovariectomy weight gain or result from it.

Case report: systolic murmur associated with pulmonary embolism.

BACKGROUND: This case study's novelty lies in the potential to link a new sign in pulmonary embolism diagnosis which does not increase cost but could lead to more rapid treatment. Early intervention in these cases is vital to decrease morbidity and mortality. CASE PRESENTATION: An otherwise healthy 20-year-old female patient presents to the emergency department for evaluation of a syncopal episode which occurred just prior to arriving to the emergency department. Patient also complains of ongoing shortness of breath while performing activities of daily living for 3 weeks. In this patient with no known valvular disease, physical exam revealed a systolic murmur heard only posteriorly. Subsequent emergency department workup revealed bilateral massive pulmonary emboli. IMPLICATIONS: A new flow murmur heard in atypical locations could be an early sign to aid in the detection and diagnosis of pulmonary embolism. This is especially important in rural community hospitals with limited access to advanced imaging modalities.

Temporal and Site-Specific Changes in Central Neuroimmune Factors During Rapid Weight Gain After Ovariectomy in Rats.

Systemic inflammation is present in obesity and emerging evidence, primarily from studies using male rodents fed high-fat diets, suggests neuroimmune signaling also is involved. We investigated early changes in neuroimmune signaling during the weight gain that follows ovariectomy in rats. Ovariectomized (OVX) rats were given standard rat chow and terminated 5 days (baseline), 4 or 8 weeks after ovariectomy. Levels of interleukin-6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) in plasma and periuterine adipose were not affected by ovariectomy. In contrast, compared to baseline levels, IL-6 expression in the arcuate nucleus (ARC) and dorsal vagal complex (DVC) decreased by 4 weeks after OVX, but was not affected in the paraventricular nucleus (PVN). MCP-1 expression decreased by 4 weeks in the ARC and by 8 weeks in the PVN, but was not affected in the DVC. Increased glial fibrillary acidic protein (GFAP) expression in the PVN indicated astrocyte activation; decreased toll-like receptor 4 (TLR4) expression in the ARC, but not other regions, suggested early effects on innate immune factors. Importantly, in reproductively intact rats, IL-6 and MCP-1 levels in plasma, periuterine adipose, and brain regions were not affected after 8 weeks. Unlike OVX rats, GFAP expression in the DVC of intact rats was decreased at 8 weeks, and TLR4 expression in the ARC was increased at 8 weeks. Taken together, these dynamic and selective changes in neuroimmune factors co-incident with post-ovariectomy weight gain provide insight into the role of neuroimmune signaling in obesity, particularly in females.

Female-Paced Mating does not Affect Pair-Bond Expression by Male Prairie Voles (Microtus ochrogaster).

Prairie vole males typically display robust preferences for affiliation with their respective mates that indicate the expression of a pair-bond. However, it recently has been shown that the strength of a male vole's pair-bond can differ depending on the reproductive status of his mate. In the present study, we examined the possibility that female-controlled pacing of the mating sequence could alter males' affiliative behaviors in a partner-preference test by affecting reproductive success. We expected an earlier onset of mating and thus earlier onset of pregnancy would occur if females controlled the pace of mating, in turn, reinforcing males' preference for their familiar mates vs for a stranger. We found that female-pacing did not affect latency to mating, mating duration, or any of our other measures of social or mating behaviors. Further, female paced-mating did not alter reproductive success as indicated by litter size. We conclude that female-paced mating in prairie voles does not impact the formation, consolidation and/or expression of a pair-bond, either directly or indirectly, by their male partners.