Prenatal stress or glucocorticoid administration has persisting "programming" effects on offspring in rodents and other model species. Multiple doses of glucocorticoids are in widespread use in obstetric practice. To examine the clinical relevance of glucocorticoid programming, we gave 50, 120, or 200 μg/kg/d of dexamethasone (dex50, dex120, or dex200) orally from mid-term to a singleton-bearing nonhuman primate, Chlorocebus aethiops (African vervet). Dexamethasone dose-dependently reduced maternal cortisol levels without effecting maternal blood pressure, glucose, electrolytes, or weight gain. Birth weight was unaffected by any dexamethasone dose, although postnatal growth was attenuated after dex120 and dex200. At 8 months of age, dex120 and dex200 offspring showed impaired glucose tolerance and hyperinsulinemia, with reduced (approximately 25%) pancreatic β cell number at 12 months. Dex120 and dex200 offspring had increased systolic and diastolic blood pressures at 12 months. Mild stress produced an exaggerated cortisol response in dex200 offspring, implying hypothalamic-pituitary-adrenal axis programming. The data are compatible with the extrapolation of the glucocorticoid programming hypothesis to primates and indicate that repeated glucocorticoid therapy and perhaps chronic stress in humans may have long-term effects.
Peripheral immune activation can have profound physiological and behavioral effects including induction of fever and sickness behavior. One mechanism through which immune activation or immunomodulation may affect physiology and behavior is via actions on brainstem neuromodulatory systems, such as serotonergic systems. We have found that peripheral immune activation with antigens derived from the nonpathogenic, saprophytic bacterium, Mycobacterium vaccae, activated a specific subset of serotonergic neurons in the interfascicular part of the dorsal raphe nucleus (DRI) of mice, as measured by quantification of c-Fos expression following intratracheal (12 h) or s.c. (6 h) administration of heat-killed, ultrasonically disrupted M. vaccae, or heat-killed, intact M. vaccae, respectively. These effects were apparent after immune activation by M. vaccae or its components but not by ovalbumin, which induces a qualitatively different immune response. The effects of immune activation were associated with increases in serotonin metabolism within the ventromedial prefrontal cortex, consistent with an effect of immune activation on mesolimbocortical serotonergic systems. The effects of M. vaccae administration on serotonergic systems were temporally associated with reductions in immobility in the forced swim test, consistent with the hypothesis that the stimulation of mesolimbocortical serotonergic systems by peripheral immune activation alters stress-related emotional behavior. These findings suggest that the immune-responsive subpopulation of serotonergic neurons in the DRI is likely to play an important role in the neural mechanisms underlying regulation of the physiological and pathophysiological responses to both acute and chronic immune activation, including regulation of mood during health and disease states. Together with previous studies, these findings also raise the possibility that immune stimulation activates a functionally and anatomically distinct subset of serotonergic neurons, different from the subset of serotonergic neurons activated by anxiogenic stimuli or uncontrollable stressors. Consequently, selective activation of specific subsets of serotonergic neurons may have distinct behavioral outcomes.
Because asthmatic patients show increased nerve growth factor (NGF) serum levels, we examined the effect of NGF on airway function. Intravenously administered NGF potentiates the histamine- induced bronchoconstriction with a maximum of over 200% in anesthetized spontaneously breathing guinea pigs. Doses of 8 ng and 80 ng NGF/kg body weight induce a significant hyperresponsiveness to histamine. NGF itself does not affect airway reactivity. Airway hyperresponsiveness is observed 30 min and 3 h after NGF administration, and has disappeared after 24 h. The neurokinin-1 receptor antagonist SR 140333 completely blocks the NGF-induced hyperresponsiveness, pointing to a role for tachykinins. This is the first report showing a direct relation between peripherally administered NGF and airway hyperresponsiveness. Taking into consideration that plasma NGF levels have been shown to be elevated in asthmatic patients, our result points to an important role for NGF in the pathogenesis of asthma.
ObjectiveExaggerated central nervous system (CNS) inflammatory responses to peripheral stressors may be implicated in delirium. This study hypothesised that the IL-1β family is involved in delirium, predicting increased levels of interleukin-1β (IL-1β) and decreased IL-1 receptor antagonist (IL-1ra) in the cerebrospinal fluid (CSF) of elderly patients with acute hip fracture. We also hypothesised that Glial Fibrillary Acidic Protein (GFAP) and interferon-γ (IFN-γ) would be increased, and insulin-like growth factor 1 (IGF-1) would be decreased.MethodsParticipants with acute hip fracture aged > 60 (N = 43) were assessed for delirium before and 3–4 days after surgery. CSF samples were taken at induction of spinal anaesthesia. Enzyme-linked immunosorbent assays (ELISA) were used for protein concentrations.ResultsPrevalent delirium was diagnosed in eight patients and incident delirium in 17 patients. CSF IL-1β was higher in patients with incident delirium compared to never delirium (incident delirium 1.74 pg/ml (1.02–1.74) vs. prevalent 0.84 pg/ml (0.49–1.57) vs. never 0.66 pg/ml (0–1.02), Kruskal–Wallis p = 0.03). CSF:serum IL-1β ratios were higher in delirious than non-delirious patients. CSF IL-1ra was higher in prevalent delirium compared to incident delirium (prevalent delirium 70.75 pg/ml (65.63–73.01) vs. incident 31.06 pg/ml (28.12–35.15) vs. never 33.98 pg/ml (28.71–43.28), Kruskal–Wallis p = 0.04). GFAP was not increased in delirium. IFN-γ and IGF-1 were below the detection limit in CSF.ConclusionThis study provides novel evidence of CNS inflammation involving the IL-1β family in delirium and suggests a rise in CSF IL-1β early in delirium pathogenesis. Future larger CSF studies should examine the role of CNS inflammation in delirium and its sequelae.
Allergic airway inflammation (AAI) is characterized by airway hyperreactivity, eosinophilia, goblet cell hyperplasia, and elevated serum IgE, however, it is unclear what mediates natural resolution after cessation of allergen exposure. This is important because the outcome of subsequent allergen challenge may depend on the concurrent inflammatory milieu of the lung. Using a murine AAI model, we demonstrate that after exposure to a defined natural protein allergen, Der p1, the response in lungs and draining mediastinal lymph nodes (dMLN) peaks between 4 and 6 days then declines until resolution by 21 days. Der p1-specific serum IgE follows the same pattern while IgG1 continues to increase. Resolution of AAI is mediated by CD4+CD25+Foxp3+ regulatory T cells (Tregs), which appear in lungs and dMLN following airway challenge. Treg depletion exacerbated lung eosinophilia, increased dMLN IL-5 and IL-13 but not IL-10 secretion, and increased allergic Ab responses. Most convincingly, transfer of CD4+CD25+Foxp3+ T cells from Ag naive mice (natural Tregs) abolished AAI, decreased dMLN IL-5 and IL-13 secretion, increased dMLN IL-10 secretion, abolished IgE, and decreased IgG1 Abs. Blocking IL-10 receptor function in vivo did not block the anti-inflammatory function of transferred natural Tregs but did restore dMLN IL-5 and IL-13 secretion. Thus natural Tregs can control AAI in an IL-10 independent manner.
Background and Aims: Golimumab has been approved recently to treat refractory moderate-tosevere ulcerative colitis [UC]. To date it is not clear why a considerable fraction of patients do not respond, or lose initial response, to golimumab therapy. Our aim was to investigate whether a low golimumab serum concentration and/or a positive anti-golimumab antibody status reduces the efficacy of this drug in patients with UC. Methods: Serum samples of 21 patients with moderate-to-severe UC were collected during the first 14 weeks of golimumab therapy. For measurement of golimumab serum concentrations, both a tumour necrosis factor [TNF]-coated enzyme-linked immunosorbent assay [ELISA] and a sandwich-type ELISA were developed. Anti-golimumab antibodies were measured using a bridging ELISA and a newly-developed drug-tolerant immunoassay. Clinical response and mucosal healing were assessed 14 weeks after start of treatment. Results Out of 21 patients, 10 [48%] reached partial clinical response at Week 14. Median [interquartile range] serum golimumab concentration was significantly higher in partial clinical responders than in non
See editorial on page 925. BACKGROUND & AIMS:We evaluated the ability of vedolizumab to induce endoscopic and histologic remission in patients with Crohn's disease (CD). METHODS: We performed a prospective study of 110 patients with active CD, based on CD activity index (CDAI) scores >220 and mucosal ulcerations, who received open-label vedolizumab (300 mg) infusions at weeks 0, 2, and 6, and every 8 weeks thereafter through week 52 at tertiary centers in Europe. Patients received an additional infusion at week 10 if their CDAI score had not decreased by 70 points. Patients underwent ileocolonoscopy with collection of biopsies at baseline and weeks 26 and 52; a local and central reader determined simple endoscopic index for CD (SES-CD) scores. Histologic features were assessed by a blinded pathologist at week 26. Serum concentrations of vedolizumab were measured at serial time points. The primary outcome was endoscopic and histologic remission in patients with active CD treated with vedolizumab for 52 weeks. RESULTS: At weeks 26 and 52, 36 patients (29%) and 34 patients (31%), respectively, were in corticosteroid-free clinical remission (CDAI score <150), respectively. Based on intent-to-treat analysis, endoscopic remission (SES-CD score <4) was achieved by 36 patients (33%) and 40 patients (36%) at weeks 26 and 52. Endoscopic responses (decrease in SES-CD score 50%) occurred in 44 patients (40%) at week 26 and 5 patients (45%) at week 52. Serum concentrations of vedolizumab were higher at weeks 2, 10, and 22 in patients with lower SES-CD scores. Histologic remission at week 26 was observed in 43 (64%) of 67 patients based on Geboes Score and 37 (66%) of 56 patients based on Robarts Histopathology Index scores in analyses of paired biopsies with inflammation at baseline. Serum concentrations of vedolizumab above 10 mg/L at week 22 were associated with endoscopic remission at week 26. CONCLUSIONS: In a prospective trial, we found that approximately one-third of patients with CD achieve endoscopic remission after 52 weeks of treatment with vedolizumab and two-thirds achieve histologic remission at week 26. Higher serum concentrations of vedolizumab were associated with better outcomes. EUDRACT no: 2014-005376-29.
Metabotropic glutamate receptor (mGluR) agonists induce extensive phosphoinositide (P1) hydrolysis in astrocytes grown in a chemically defined medium with select growth factors. These astrocytes express mGluR5 transcripts, but none of the splice variants of mGluRl, thus permitting the characterization of mGluR5 in a native CNS cell without interference from mGluRl activity. mGluR5 activation (1) was not associated with stimulation of cyclic AMP formation, (2) showed high sensitivity to the removal of extracellular versus intracellular Ca 2~, (3) displayed high coupling efficiency relative to receptor density, and (4) induced P1 hydrolysis that was suppressed by phorbol esters with low potency. The rank order of agonist potency was similar to that observed in mGluRl and mGluR5 transfected cells. The phenylglycine antagonists tested were effective in blocking responses to 1 -aminocyclopentane-1 S ,3R-dicarboxylic acid, but not to glutamate. Prolonged exposure to agonists induced a two-phase desensitization of mGluR5 function, an initial phase (completed by 1 h and plateaus for another 3 h) and a late phase (progressive decrease tõ -~3O% of control levels by 24 h). Only the latter phase was associated with receptor down-regulation. Desensitization of mGluR5 function did not involve receptor internalization or phosphorylation mediated by protein kinase o or A; it was purely homologous, and reversible. Resensitization after short agonist treatment did not require prior receptor sequestration. Recovery after prolonged agonist exposure required new protein synthesis, but the restoration of function was more rapid than normalization of receptor protein levels, indicating that regulation also involves other components of the transduction system. The protracted desensitization of mGluR5 in astrocytes suggests that the functions mediated by this receptor are maintained under a variety of conditions ranging from repetitive stimulation to injury responses. Key Words: Metabotropic glutamate receptor 5 (mGluR5) -Astrocytes-Phosphoinositide hydrolysis-Receptor desensitization-Receptor resensitization -Calcium. J. Neurochem. 69, 151-163 (1997).Glutamate (Glu) is believed to be the major excitatory transmitter in the CNS. Its effect is mediated through the activation of ionotropic and metabotropic glutamate receptors (mGluRs), which are widely expressed not only in neurons but also in glia. mGluRs are large monomeric proteins, coupled through G proteins either directly to ion channels or to effectors, such as phospholipase C (PLC) or adenyl cyclase (AC), generating second messengers (Tanabe et al., 1992;Schoepp, 1994; Pin and Duvoisin, 1995). mGluRs comprise three subgroups on the basis of the gene structure, the coupled transduction systems, and pharmacological properties. In particular, two mGluRs (1 and 5) are primarily coupled to PLC (group I), whereas groups II and III are primarily associated with AC and ion channels. Because native neural cells express an unknown number of receptor subgroups, most of the information on the ...
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