Gender comparison in a murine model of allergen-driven airway inflammation and the response to budesonide treatment

BACKGROUND: Evidence suggests that gender differences exist in the severity of many immunological diseases and their response to glucocorticosteroid treatment. In this report, we have used a murine model of ovalbumin-induced lung inflammation to address whether gender could affect the systemic response, airway inflammation and hyperreactivity and their responses to budesonide. RESULTS: Following an acute ovalbumin challenge, actively sensitised BALB/c mice developed a time-dependent increase in interleukin-4 and interleukin-5 production and inflammatory cell influx into bronchoalveolar lavage fluid. Apart from an increased number of lymphocytes in female mice at day 3 post-challenge, none of the above parameters were affected by gender. Blood leukocyte numbers were also unaffected, whereas a two-fold increase in total serum immunoglobulin E was observed in female mice. Budesonide, given intranasally, did not affect the blood parameters, but dose-dependently inhibited the pulmonary inflammation and airway hyperreactivity in both male and female mice. Female mice were slightly less sensitive to budesonide's inhibitory action on interleukin-5 production and the development of airway hyperreactivity. CONCLUSIONS: Our results suggest that, apart from a 2-fold increase in serum immunoglobulin E levels observed in female mice, gender is not a major factor in the present murine model of ovalbumin-induced lung inflammation. In contrast, gender might slightly influence the potency of test compounds such as steroids

In vivo models of lung neutrophil activation. Comparison of mice and hamsters

BACKGROUND: Evidence suggests that both the migration and activation of neutrophils into the airway is of importance in pathological conditions such as pulmonary emphysema. In the present study, we describe in vivo models of lung neutrophil infiltration and activation in mice and hamsters. RESULTS: BALB/c and C57BL/6 mice were intranasally treated with lipopolysaccharide (0.3 mg/kg). Twenty-four hours after, animals were treated intranasally with N-Formyl-Met-Leu-Phe (0 to 5 mg/kg). Golden Syrian hamsters were treated intratracheally with 0.5 mg/kg of lipopolysaccharide. Twenty-four hours after, animals were treated intratracheally with 0.25 mg/kg of N-Formyl-Met-Leu-Phe. Both mice and hamster were sacrificed two hours after the N-Formyl-Met-Leu-Phe application. In both BALB/c and C57BL/6 mice, a neutrophil infiltration was observed after the sequential application of lipopolysaccharide and N-Formyl-Met-Leu-Phe. However, 5 times less neutrophil was found in C57BL/6 mice when compared to BALB/c mice. This was reflected in the neutrophil activation parameters measured (myeloperoxidase and elastase activities). Despite the presence of neutrophil and their activation status, no lung haemorrhage could be detected in both strains of mice. When compared with mice, the lung inflammation induced by the sequential application of lipopolysaccharide and N-Formyl-Met-Leu-Phe was much greater in the hamster. In parallel with this lung inflammation, a significant lung haemorrhage was also observed. CONCLUSIONS: Both mouse and hamster can be used for pharmacological studies of new drugs or other therapeutics agents that aimed to interfere with neutrophil activation. However, only the hamster model seems to be suitable for studying the haemorrhagic lung injury proces

A molecular circuit composed of CPEB-1 and c-Jun controls growth hormone-mediated synaptic plasticity in the mouse hippocampus

Cytoplasmic polyadenylation element binding protein 1 (CPEB-1) resides at postsynaptic sites in hippocampal neurons in which it controls polyadenylation-induced translation. CPEB-1 knock-out (KO) mice display defects in some forms of synaptic plasticity and hippocampal-dependent memories. To identify CPEB-1-regulated mRNAs, we used proteomics to compare polypeptides in wild-type (WT) and CPEB-1 KO hippocampus. Growth hormone (GH) was reduced in the KO hippocampus, as were the GH signaling molecules phospho-JAK2 and phospho-STAT3. GH mRNA and pre-mRNA were reduced in the KO hippocampus, suggesting that CPEB-1 controls GH transcription. The transcription factor c-Jun, which binds the GH promoter, was also reduced in the KO hippocampus, as was its ability to coimmunoprecipitate chromatin containing the GH promoter. CPEB-1 binds c-Jun 3\u27 untranslated region CPEs in vitro and coimmunoprecipitates c-Jun RNA in vivo. GH induces long-term potentiation (LTP) when applied to hippocampal slices from WT and CPEB-1 KO mice, but the magnitude of LTP induced by GH in KO mice is reduced. Pretreatment with GH did not reverse the LTP deficit observed in KO mice after theta-burst stimulation (TBS). Cordycepin, an inhibitor of polyadenylation, disrupted LTP induced by either GH application or TBS. Finally, GH application to hippocampal slices induced JAK2 phosphorylation in WT but not KO animals. These results indicate that CPEB-1 control of c-Jun mRNA translation regulates GH gene expression and resulting downstream signaling events (e.g., synaptic plasticity) in the mouse hippocampus

The ion channel transient receptor potential melastatin-2 does not play a role in inflammatory mouse models of chronic obstructive pulmonary diseases

<p>Abstract</p> <p>Background</p> <p>There is strong evidence that oxidative stress is associated with the pathogenesis of chronic obstructive pulmonary disease (COPD). The transient receptor potential melastatin-2 (TRPM2) is an oxidative stress sensing channel that is expressed in a number of inflammatory cells and therefore it has been suggested that inhibition of TRPM2 could lead to a beneficial effect in COPD patients. In this study, we have investigated the role of TRPM2 in a variety of mouse models of oxidative stress and COPD using TRPM2-deficent mice.</p> <p>Methods</p> <p>Mice were exposed to ozone (3 ppm for 4 h) or lipopolysaccharide (LPS, 0.3 mg/kg, intranasaly). In another model, mice were exposed to tobacco smoke (750 μg/l total wet particulate matter) for 30 min twice a day on three consecutive days. For the exacerbation model, the smoke exposure on the morning of day 3 animals was replaced with intranasal administration of LPS (0.3 mg/kg). Animals were killed 3 and 24 h after the challenge (ozone and LPS model) or 18 h after the last tobacco smoke exposure. In vitro neutrophil chemotaxis and monocyte activation were also studied using cells isolated from wild type and TRPM2-deficient animals. Statistical significance for the in vivo data (<it>P </it>< 0.05) was determined using analysis of variance with Kruskal-Wallis and Dunns multiple comparison test.</p> <p>Results</p> <p>In all models studied, no difference in the bronchoalveolar lavage inflammation could be evidenced when comparing wild type and TRPM2-deficient mice. In addition, no difference could be seen in the lung inflammation as assessed by the measurement of various cytokines/chemokines. Similarly in various in vitro cellular activation assays using isolated neutrophils and monocytes no significant differences could be observed when comparing wild type and TRPM2-deficient mice.</p> <p>Discussion</p> <p>We have shown, in all the models tested, no difference in the development of airway inflammation or cell activation between TRPM2-deficient mice and their wild type counterparts. These results would suggest that inhibiting TRPM2 activity in COPD would have no anti-inflammatory effect.</p

Predicting the effects of potentially therapeutic modified peptides on polyclonal T cell populations in a mouse model of multiple sclerosis

Altered peptide ligands (APLs) have routinely been studied in clonal populations of Th cells that express a single T cell receptor (TCR), but results generated in this manner poorly predict the effects of APLs on polyclonal Th cells in vivo, contributing to the failure of phase II clinical trials of APLs in autoimmune diseases such as multiple sclerosis (MS). We have used a panel of APLs derived from an encephalitogenic epitope of myelin proteolipid protein to investigate the relationship between antigen cross-reactivity in a polyclonal environment, encephalitogenicity, and the capacity of an APL to provide protection against experimental autoimmune encephalomyelitis (EAE) in SJL mice. In general, polyclonal Th cell lines specific for encephalitogenic APLs cross-reacted with other encephalitogenic APLs, but not with non-encephalitogenic APLs, and vice versa. This, alongside analysis of TCR V beta usage, suggested that encephalitogenic and non-encephalitogenic subgroups of APIs expand largely non-cross-reactive Th cell populations. As an exception to the rule, one non-encephalitogenic APL, L188, induced proliferation in polyclonal CD4(+) T cells specific for the native encephalitogen, with minimal induction of cytokine production. Co-immunization of L188 alongside the native encephalitogen slightly enhanced disease development. In contrast, another APL, A188, which induced 1L-10 production without proliferation in CD4+ T cells specific for the native encephalitogen, was able to protect against development of EAE in a dose-dependent fashion when co-immunized alongside the native encephalitogen. These results suggest that testing against polyclonal Th cell lines in vitro may be an effective strategy for distinguishing between potentially therapeutic and non-therapeutic APLs. (C) 2017 Elsevier B.V. All rights reserved

Thiopalmitoylation of altered peptide ligands enhances their protective effects in an animal model of multiple sclerosis

Previously, we have shown that conjugation of a palmitic chain via a thioester bond to a cysteine residue in weakly or nonencephalitogenic or neuritogenic peptides markedly enhances their ability to induce autoimmune disease in an MHC class II–restricted manner. From those studies, however, it was not clear whether thiopalmitoylation of the peptides was merely enhancing their disease-inducing potential or whether the lipid was itself playing a pathogenic role. To investigate this further, we have now tested the effects of thiopalmitoylation on MHC class II–restricted altered peptide ligands (APLs), which are normally protective in experimental autoimmune encephalomyelitis, the animal model of multiple sclerosis. We hypothesized that if thiopalmitoylation of a peptide merely enhances its innate potential, then thiopalmitoylated APLs (S-palmAPLs) should show enhanced protective effects. Alternatively, if thiopalmitoylation itself can make a peptide pathogenic, then S-palmAPLs should have decreased therapeutic potential. We synthesized APLs and corresponding S-palmAPLs and showed that the S-palmAPLs were much more effective than the nonconjugated APL at inhibiting the development of experimental autoimmune encephalomyelitis. This was due to several features of the S-palmAPL:S-palmAPL–primed cells show an enhanced ability to proliferate and produce the anti-inflammatory cytokine, IL-10, in vitro. Furthermore, the bioavailability of S-palmAPL was greatly enhanced, compared with the nonpalmitoylated APL, and S-palm APL was taken up more rapidly into dendritic cells and channeled into the MHC class II processing pathway. These results show that thiopalmitoylation of MHC class II–restricted peptides is a simple way to enhance their effects in vivo and could have wide therapeutic application

with Anti-Inflammatory Activities

ABSTRACT We investigated the pharmacology of a new class of phosphodiesterase 4 (PDE4) inhibitor, 6,8-disubstituted 1,7-naphthyridines, by using 4-(8-benzo[1,2,5]oxadiazol-5-yl- [1,7]naphthyridin-6-yl)-benzoic acid (NVP-ABE171) as a representative compound and compared its potency with the most advanced PDE4 inhibitor, undergoing clinical trials, Ariflo [cis-4-cyano-4-(3-cyclopentyloxy-4-methoxyphenyl-r-1-cyclohexanecarboxylic acid)]. NVP-ABE171 inhibited the activity of phosphodiesterase 4A, 4B, 4C, and 4D with respective IC 50 values of 602, 34, 1230, and 1.5 nM. Ariflo was about 40 times less potent. In human cells, NVP-ABE171 inhibited the eosinophil and neutrophil oxidative burst, the release of cytokines by T cells, and the tumor necrosis factor-␣ release from monocytes, in the nanomolar range. Ariflo presented a similar inhibition profile but was 7 to 50 times less potent. In BALB/c mice challenged with lipopolysaccharide, NVP-ABE171 inhibited the airway neutrophil influx and activation with an ED 50 in the range of 3 mg/kg. Ariflo was inactive up to a dose of 10 mg/kg. In ovalbumin sensitized Brown Norway rats, NVP-ABE171 inhibited the lipopolysaccharide-induced airway neutrophil influx and activation (ED 50 of 0.2 mg/kg) and the ovalbumin-induced airway eosinophil influx and activation (ED 50 of

Modulation and functions of dopamine receptor heteromers in drugs of abuse-induced adaptations

Drug addiction is a chronic and relapsing disorder that leads to compulsive drug intake despite deleterious consequences. By increasing dopamine (DA) in the mesolimbic system, drugs of abuse hijack the brain reward circuitry, which is critical for the development of enduring behavioral alterations. DA mainly acts onto DA D1 (D1R) and D2 (D2R) receptor subtypes, which are positively and negatively coupled to adenylyl cyclase, respectively. Extensive research has aimed at targeting these receptors for the treatment of addiction, however this often results in unwanted side-effects due to the implication of DA receptors in numerous physiological functions. A growing body of evidence indicates that the physical interaction of DA receptors with other receptors can finely tune their function, making DA receptor heteromers promising targets for more specific treatment strategies. An increasing number of articles highlighted the ability of both D1R and D2R to form heteromers, however, most studies carried out to date stem from observations in heterologous systems and the biological significance of DA receptor heteromers in vivo is only emerging. We focused this review on studies that were able to provide insights into functions on D1R and D2R heteromers in drug-evoked adaptations and discuss the limitations of current approaches to study receptor heteromers in vivo. This article is part of the Special Issue entitled 'Receptor heteromers and their allosteric receptor-receptor interactions'.Rôle des heteromères formés par les récepteurs dopamine-glutamate et de signalisation dépendante du calcium nucléaire associée dans l'addictionImpact de la composition lipidique membranaire sur la transmission dopaminergique dépendante du récepteur D2 et la motivationProgram Initiative d’Excellenc

Striatal dopaminergic reward response relates to age of first drunkenness and feedback response in atâ risk youth

Dopamine receptor concentrations, primarily in the striatum, are hypothesized to contribute to a developmental imbalance between subcortical and prefrontal control systems in emerging adulthood potentially biasing motivation and increasing risky behaviors. Positron emission tomography studies have found significant reductions in striatal dopamine D2 receptors, and blunted amphetamineâ induced dopamine release, in substance users compared with healthy controls. Extant literature is limited and inconsistent concerning vulnerability associated with having a family history of substance abuse (FH+). Some studies have reported familial liability associated with higher dopamine receptor levels, reduced dopamine response to stimulant challenges and decreased response to oral alcohol. However, other reports have failed to find group differences based on family history. We explored the interaction of familial liability and behavioral risk with multiâ modal molecular and neural imaging of the dopaminergic system. Fortyâ four young adult male subjects performed monetary incentive delay tasks during both [11C]raclopride positron emission tomography and functional magnetic resonance imaging scans. FH+ subjects were identified as low (nâ =â 24) or high risk (nâ =â 9) based on early initiation of drunkenness. FH+ highâ risk subjects exhibited heightened striatal dopamine response to monetary reward but did not differ in neural activations compared with FH+ low risk subjects and controls with no familial loading (nâ =â 11). Across all subjects, a negative relationship was found between dopamine release and age of first drunkenness and a positive relationship with neural response to reward receipt. These results suggest that in atâ risk individuals, higher dopamine transmission associated with monetary reward may represent a particularly useful neurobiological phenotype.The mesolimbic dopamine system is hypothesized to play a role in vulnerability to substance use disorders. Using multiâ modal methods (functional magnetic resonance imaging and positron emission tomography), we tested whether young adult male subjects at high risk for substance use disorders based on family history and early drunkenness had differences in response to monetary rewards compared with controls. We found heightened striatal dopamine response in highâ risk male subjects during positron emission tomography. This was further associated with age of first drunkenness, suggesting it may represent a neurobiological risk phenotype.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136239/1/adb12341.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136239/2/adb12341_am.pd

Chemogenetic activation or inhibition of histaminergic neurons bidirectionally modulates recognition memory formation and retrieval in male and female mice

Abstract Several lines of evidence demonstrate that the brain histaminergic system is fundamental for cognitive processes and the expression of memories. Here, we investigated the effect of acute silencing or activation of histaminergic neurons in the hypothalamic tuberomamillary nucleus (TMNHA neurons) in vivo in both sexes in an attempt to provide direct and causal evidence of the necessary role of these neurons in recognition memory formation and retrieval. To this end, we compared the performance of mice in two non-aversive and non-rewarded memory tests, the social and object recognition memory tasks, which are known to recruit different brain circuitries. To directly establish the impact of inactivation or activation of TMNHA neurons, we examined the effect of specific chemogenetic manipulations during the formation (acquisition/consolidation) or retrieval of recognition memories. We consistently found that acute chemogenetic silencing of TMNHA neurons disrupts the formation or retrieval of both social and object recognition memory in males and females. Conversely, acute chemogenetic activation of TMNHA neurons during training or retrieval extended social memory in both sexes and object memory in a sex-specific fashion. These results suggest that the formation or retrieval of recognition memory requires the tonic activity of histaminergic neurons and strengthen the concept that boosting the brain histaminergic system can promote the retrieval of apparently lost memories