Library

Notes: Dipeptidyl peptidase-IV (DPP-IV, CD26), a serine protease with broad distribution in mammalian tissues and known activity in serum, participates in T-cell activation and promotes a Th1-like cytokine response. Previous data on murine abortion indicate that DPP-IV may play a critical role in pregnancy failure by inducing a Th1 local response. Here, we investigated the possible participation of DPP-IV in the onset of human spontaneous abortion (SA).The systemic (peripheral blood) and local (decidua) percentages of CD4+, CD8+, CD26+ and CD56+ cells as well as the number of Th1 lymphocytes (CCR5+ cells) were assessed in samples from women after SAs (n = 20) and from women with normally progressing pregnancies (NPs) (n = 27) using flow cytometry and immunohistochemistry. We further measured the DPP-IV activity and concentrations of Th1 (interferon-γ and tumour necrosis factor-α), Th2 [interleukin-4 (IL-4), IL-10] and Th3 (transforming growth factor-β2) cytokines in serum samples.We could not find any difference in the number of CD4+, CD8+, CD26+, CD26+/CD4+ or CD8+/CD26+ blood cells between NP and SA patients. No differences in the Th1, Th2 or Th3 cytokine levels could be observed between both groups. However, the percentages of decidual CD26+ lymphocytes as well as the number of decidual Th1 cells were significantly higher in SA samples compared to samples from patients with NP.Our data support the hypothesis that CD26+ decidual lymphocytes with DPP-IV activity may play a critical role in SAs, as previously suggested in an abortion mice model. This abortive effect may be mediated by enhancing the levels of Th1 abortogenic cytokines only locally.

Notes: Heme oxygenases (HOs) are responsible for heme degradation. Besides their enzymatic activities, HOs are involved in tissue protection. Failing upregulation of HOs has been linked to increased necrosis in inflammatory tissues. Interestingly, previously published data indicated that mice exposed to sonic stress during early gestation show an augmented production of decidual inflammatory T-helper 1 (Th1) cytokines, thus resulting in increased abortion rate. No data linked the Th1-inducer interleukin (IL)-12 with the event of abortion. As little is known about the role of HO in pregnancy maintenance, we evaluated the expression of decidual and placental HO-1 and HO-2 in the abortion-prone murine mating combination CBA/J × DBA/2 J with (1) CBA/J female control mice, (2) CBA/J mice exposed to stress during early gestation and (3) CBA/J females injected with recombinant IL-12. Decidual and placental HOs protein expression was analysed by immunohistochemistry and mRNA levels by real time polymerase chain reaction (PCR).As expected, an increased abortion rate was present in mice exposed to stress compared with the control. IL-12 injections also boosted the abortion rate compared with control mice, mimicking the effect of stress. HOs' proteins could be detected in placenta and decidua. Real time PCR revealed lower levels of HO-1 and HO-2 mRNA in stress-triggered and IL-12-injected mice. We conclude that increased Th1-cytokine levels during murine pregnancy may result in low expression of HO-1 and HO-2, thus leading to placental necrosis and foetal rejection.

Notes: In the CBA × DBA/2 mouse model, stress-triggered abortions are mediated by a Th1-like cytokine response of decidual lymphocytes. The factors that determine the cytokine pattern leading to abortion are currently unknown. Dipeptidyl Peptidase IV (DP IV) enhances Th1-cytokine responses and impairs the evolvement of a Th2 cytokine profile. The T-cell-activation antigen, CD26, possesses DP IV activity. The aim of the present study was to investigate the role of DP IV activity and CD26-positive decidual lymphocytes in murine stress-triggered abortions by inhibition of DP IV activity. DBA/2-mated CBA mice were stressed on day 5.5 of pregnancy and received daily injections of an inhibitor of DP IV activity, Ile-thiazolidide (20 µmol/kg). On day 13 of gestation, the animals were sacrificed and the percentage of implants and abortions documented. CD26-positive lymphocytes in spleen and uterine decidua and the intracellular cytokines interferon (IFN)-γ and interleukin (IL)-10 were determined by flow cytometry. Stressed and nonstressed animals receiving an inactive stereoisomeric form were used as controls. In mice receiving the DP IV inhibitor, stress failed to boost the abortion rate (37.2% versus 13.6%, P 〈 0.01). IFN-γ producing cells were increased in stressed animals, but returned to the baseline upon the inhibition of DP IV. The number of IL-10 producing cells was reduced in stressed animals, independent from DP IV inhibition.

Notes: Background Histamine receptors play an important role in the pathogenesis of nasal allergy. Activation of histamine receptor 1 (H1R) and 2 (H2R) can cause allergic symptoms which can be blocked effectively by antihistamines. H1R and H2R transcript levels have been found to be up-regulated in perennial – but not in seasonal – allergic rhinitis (AR). The present study aimed to explore H1R and H2R expression in complex tissues of the nasal mucosa of perennial allergic rhinitis (PAR).Methods Ten patients with PAR and 13 non-AR subjects were recruited for the study by medical history, physical examination and laboratory screening tests. In this study, we have analysed single cells dissected from the nasal mucosa biopsies by laser-assisted microdissection. H1R mRNA expression was analysed in different cell types such as epithelial, endothelial, mucus and inflammatory cells isolated from the nasal mucosa of PAR in comparison with non-AR subjects.Results H1R mRNA gene expression level was significantly increased in the nasal mucosa of PAR in comparison with non-AR (P〈0.0001). H1R mRNA was significantly elevated in epithelial (P〈0.001) and mucus cells (P〈0.05) of PAR in comparison with non-AR whereas H1R gene expression levels in endothelial cells between both groups were not changed (P=0.23). Interestingly, inflammatory cells in the nasal mucosa of PAR patients were also strongly expressed H1R mRNA (P〈0.001).Conclusion The present study indicates that PAR alters the expression of H1R mRNA in epithelial, mucus and inflammatory cells of the nasal mucosa and but not in endothelial cells. Therefore, epithelial, mucus and inflammatory cells may play an important role in histamine-mediated allergic airway inflammation in PAR.

Notes: Background Allergic airway inflammation has been shown to induce pro-inflammatory neuropeptides such as tachykinin peptides substance P (SP) and neurokinin A (NKA) together with related peptide like calcitonin gene-related peptide (CGRP) in nodose sensory neurons innervating guinea-pig airways.Objective The present study was designed to examine the effects of allergen sensitization and challenge on the SP/NKA expression in the jugular–nodose ganglion neurons innervating the murine airways.Methods Using retrograde neuronal tracing technique in combination with double-labelling immunohistochemistry, the expression of SP/NKA was investigated in a murine model of allergic airway inflammation.Results Allergic airway inflammation was found to induce the expression of SP/NKA (13.2±1.43% vs. 5.8±0.37%, P〈0.01) in large-diameter (〉20 μm) vagal sensory neurons retrograde labelled with Fast blue dye from the main stem bronchi.Conclusion Based on the induction of tachykinins in airway-specific large-sized jugular–nodose ganglia neurons by allergic airway inflammation, the present study suggests that allergen sensitization and challenge may lead to de novo induction of tachykinins in neurons. This may partly contribute to the pathogenesis of airways diseases such as allergic airway inflammation.

Notes: Background Nerve growth factor (NGF) is elevated in allergic diseases such as bronchial asthma and can lead to an induction of substance P (SP) and related neuropeptides in guinea-pigs large-diameter, neurofilament-positive airway neurons.Objective In the present study, the effect of NGF on tyrosine kinase receptor trkA and the capsaicin receptor TRPV1 expression in airway-specific vagal sensory neurons located in the jugular–nodose ganglia complex (JNC) of mice was investigated.Methods Using retrograde neuronal tracing in combination with double-labelling immunohistochemistry, SP, trkA- and TRPV1-receptor expression was examined in airway-specific sensory neurons of BALB/c mice before and after NGF treatment.Results NGF injected into the lower airway was able to induce SP (13.0±2.03% vs. 5.9±0.33%) and trkA expression (78±2.66% vs. 60±2.11%) in larger diameter (〉25 μm), capsaicin-insensitive and trkA-positive vagal sensory neurons that were retrograde-labelled with Fast Blue dye from the main stem bronchi.Conclusion Based on the extent of SP and trkA co-expression in airway-specific neurons by NGF treatment, the present study suggests that, following a peripheral activation of trkA receptor on SP afferent by NGF which is elevated in allergic inflammation, there may be trkA-mediated SP induction to mediate neurogenic airway inflammation.

Notes: Background The traditional neurotransmitter catecholamine and the neuropeptide tyrosine in sympathetic airway nerves have been proposed to be involved in the pathogenesis of airway diseases.Objective The aim of the present study was to investigate the effect of allergic airway inflammation on the expression of catecholamine enzyme tyrosine hydroxylase (TH), neuropeptide tyrosine (NPY) and tachykinins in mouse sympathetic airway ganglia.Methods Using neuronal tracing in combination with immunohistochemistry, the present study was designed to characterize TH, NPY and tachykinin profiles of superior cervical (SCG) and stellate ganglia after allergen challenge.Results The vast majority of fast blue-labelled SCG neurons (allergen: 97.5±1.22% (mean±SEM) vs. controls: 94.5±1.48%, P=0.18) and stellate neurons (allergen: 95.3±1.01% vs. controls: 93.6±1.33%, P=0.34) were immunoreactive for TH. Of the TH immunoreactive and fast blue-labelled SCG neurons, 52.0±1.01% allergen vs. 51.2±3.58% controls (P=0.83) and stellate neurons, 57.3%±0.97 allergen vs. 56.4±1.65% controls (P=0.64) were positive for TH only but not NPY, whereas 45.3±1.05% allergen vs. 43.3±1.18% controls (P=0.47) of fast blue-labelled SCG neurons and 37.9±0.86% allergen vs. 37.1±1.24% controls (P=0.62) of fast blue-labelled stellate neurons were immunoreactive for both TH and NPY immunoreactivities. There was a trend of an increase, but not significant one, in the percentage of TH-/NPY-immunoreactive and fast blue-labelled neurons in allergen-treated animals in comparison with the controls. Tachykinins, however, were not expressed by sympathetic neurons and were also not induced in sympathetic neurons after allergen challenge.Conclusion The present study indicates that allergic airway inflammation does not alter the expression of noradrenalin and NPY in sympathetic ganglia and also shows that sympathetic neurons do not respond to allergic airway inflammation with tachykinins induction. However, a participation of catecholamine and NPY in the pathogenesis of allergic airway inflammation cannot be excluded in the present study as a higher neurotransmitter output per neuron following allergen challenge could be possible.

Notes: Stress is said to induce itchiness of the skin and exacerbate inflammatory skin diseases such as atopic dermatitis. In this context, stress mediators such as the neuropeptide substance P play a role as immunmodulators and in a wider sense growth factors. For example, we were recently able to show that stress or treatment of mice with substance P is associated with mast cell degranulation, increased cutaneous inflammation and increased apoptosis in the hair follicle. However, local interactions between the nervous and immune systems, especially under perceived stress, have rarely been reported. Here, we show for the first time, that 24 and 48 h after sonic stress exposure, the number of SP-immunoreactive nerve fibres in the back skin of C57BL/6 mice with all there hair follicles in the resting phase of the hair cycle (telogen, low numbers of cutaneous nerve fibres) increased significantly over non-stressed mice with the strongest increase after 24 h. Such substance P immunoreactive nerve fibres contacted mast cells more frequently, which became significant after 48 h. At the same time, the percentage of degranulated mast cells increased significantly after 24 and 48 h with the strongest increase after 48 h when apoptotic cells also became significantly upregulated. The same stressor increased dermal infiltration, e.g. by eosinophils in C57BL/6 mice with experimentally induced allergic dermatitis over mice that were either stressed or had allergic dermatitis as well as over untreated controls. Increased infiltration was associated with increased epidermal thickness in stressed mice with allergic dermatitis and with an increased number of VCAM-immunoreactive blood vessels. At the same time, the percentage of degranulated mast cells increased significantly, and the number of substance P-immunoreactive peptidergic sensory nerve fibres decreased in the acute allergic dermatitis lesions. By semiquantitative RT-PCR, allergic dermatitis increased cutaneous IL-4 and to a lesser degree IFN-γ production, but this was not affected by stress. Ultrastructural investigation showed unmyelinated peptidergic nerve fibres in a state of deterioration close to degranulating mast cells and eosinophils in the skin of stressed mice with allergic dermatitis, suggesting a decreased number of substance P-immunoreactive nerve fibres due to active release of SP. This may lead to an upregulation of endothelial adhesion molecules and increased infiltration by immunocytes to the skin but at mRNA level does not alter the production of classical atopy-related cytokines in skin. These data provide first evidence for stress-induced exacerbation of cutaneous allergic diseases such as atopic dermatitis by local interaction of the peripheral nervous system with substance P.