Volatile components of selected species of the liverwort genera Frullania and Schusterella (Frullaniaceae) from New Zealand,Australia and South America: a chemosystematic approach

The volatile components of 25 taxa of the liverwort family Frullaniaceae from New Zealand, Australia and South America have been analyzed by GC-MS. The present Frullania species are chemically divided into five major types: (1) sesquiterpene lactones, (2) sesquiterpene lactones-bibenzyls, (3) bibenzyls, (4) 2-alkanone and (5) triterpene types; the latter two chemo-types are newly proposed for the genus. Schusterella chevalierii, belonging to the Frullaniaceae, is closely related chemically to the sesquiterpene lactone type of the Frullania species since it elaborates two eudesmanolides, beta-cyclocostunolide and dihydro-beta-cyclocostunolide as major components.     

Mast cell chymase regulates dermal mast cell number in mice

Chymase inhibitor reduced the increase in the number of dermal mast cells in 2,4-dinitrofluorobenzene-induced dermatitis in a dose-dependent manner. Intradermal injection of human chymase to mouse ear significantly increased histamine content, the marker for mast cell number in the skin. These results suggest that chymase released by mast cells may participate in local mast cell accumulation in a positive feedback fashion. Immunohistochemical analysis revealed that the intradermal injection of chymase reduces expression of stem cell factor (SCF) on surface of the skin keratinocytes. In addition, incubation of human keratinocytes with chymase in vitro resulted in release of SCF into the culture medium. Since soluble SCF is thought to regulate mast cell number, the chymase-induced mast cell accumulation may occur via the ability of chymase to process membrane-bound SCF on the epidermal keratinocytes.     

丹参凝胶治疗对特应性皮炎小鼠模型皮肤屏障功能、表皮增生以及免疫功能的影响

摘要 目的：研究丹参凝胶治疗对特应性皮炎小鼠模型皮肤屏障功能、表皮增生以及免疫功能的影响。方法：30只C57BL/6小鼠被随机分为Control组、AD组和SG组,每组10只。AD组和SG组背部涂抹对二硝基氟苯建立特应性皮炎小鼠模型,SG小鼠在模型建立成功后涂抹丹参凝胶治疗3周,Control组和AD组涂抹凡士林作为对照。3周后,测量所有小鼠经皮水分丢失量( TEWL) 、皮肤厚度、脾脏指数、胸腺指数,血清IgE、IFN-γ和IL-4,脾脏树突状细胞、Th1和Th2细胞比例。结果：丹参凝胶治疗3周后,AD组和SG组小鼠TEWL、皮肤厚度、脾脏指数、胸腺指数,血清IgE、IFN-γ和IL-4含量,以及脾脏Th2细胞比例均显著高于对照组正常小鼠（P<0.05）,而脾脏树突状细胞、Th1细胞和Th1/Th2细胞比例均显著低于对照组正常小鼠（P<0.05）;与AD组小鼠相比,SG组小鼠TEWL、皮肤厚度、脾脏指数、胸腺指数,血清IgE、IFN-γ和IL-4含量,以及脾脏Th2细胞比例均显著降低（P<0.05）,而脾脏树突状细胞、Th1细胞和Th1/Th2细胞比例均显著升高（P<0.05）。结论：丹参凝胶具有保护特应性皮炎样小鼠皮肤屏障功能和抑制表皮增生的功能,并且可以影响特应性皮炎样小鼠脾脏树突状细胞和辅助性T细胞比例。     

The Skin Commensal Yeast Malassezia Triggers a Type 17 Response that Coordinates Anti-fungal Immunity and Exacerbates Skin Inflammation

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Suitability of Nicotinic Acetylcholine Receptor α7 and Muscarinic Acetylcholine Receptor 3 Antibodies for Immune Detection: Evaluation in Murine Skin

Recent evidence reveals a crucial role for acetylcholine and its receptors in the regulation of inflammation, particularly of nicotinic acetylcholine receptor α7 (Chrna7) and muscarinic acetylcholine receptor 3 (Chrm3). Immunohistochemistry is a key tool for their cellular localization in functional tissues. We evaluated nine different commercially available antibodies on back skin tissue from wild-type (Wt) and gene-deficient (KO) mice. In the immunohistochemical analysis, we focused on key AChR-ligand sensitive skin cells (mast cells, nerve fibers and keratinocytes). All five antibodies tested for Chrm3 and the first three Chrna7 antibodies stained positive in both Wt and respective KO skin. With the 4th antibody (ab23832) nerve fibers were unlabeled in the KO mice. By western blot analysis, this antibody detected bands in both Wt and Chrna7 KO skin and brain. qRT-PCR revealed mRNA amplification with a primer set for the undeleted region in both Wt and KO mice, but none with a primer set for the deleted region in KO mice. By 2D electrophoresis, we found β-actin and β-enolase cross reactivity, which was confirmed by double immunolabeling. In view of the present results, the tested antibodies are not suitable for immunolocalization in skin and suggest thorough control of antibody specificity is required if histomorphometry is intended.     

Prevalence of positive atopy patch test in an unselected pediatric population

Background

In the latest decades, epidemiological studies on allergic disorders in children, including atopic dermatitis, rhinitis and asthma, demonstrated a continuous increase in prevalence. However, such studies are usually performed by questionnaires and, sometimes, by skin prick test or in vitro IgE tests, while the portion of allergy sustained by the cell-mediated mechanism is neglected, because the essential test, i.e. the atopy patch test is not performed.

Methods

This cross-sectional survey studied by a specific questionnaire, skin prick test and atopy patch test, an unselected population, represented by the entire scholastic population attending a Primary school and a Junior Secondary school in the rural town of San Marco in Lamis, 12.000 inhabitants (Puglia, Italy).

Results

Among the 456 subjects included, 78 (17.1 %) had a positive skin prick test and 57 (12.5 %) had a positive atopy patch test. In particular, 13.4 % of subjects were positive only to skin prick test and 8.8 % were positive only to atopy patch test. The allergen most frequently positive was the house dust mite, with 41 positive results to skin prick test and 55 to atopy patch test, while for pollen positive results concerned almost exclusively the skin prick test.

Conclusions

This survey on an unselected population of children detected a prevalence of positive results to atopy patch test not so distant from the positive results to skin prick test, and in 8.8 % of subjects the atopy patch test was the only positive test. This would suggest to add the atopy patch test in future epidemiological studies on allergy, in order to avoid to overlook the not negligible portion of patients with T-cell-mediated allergy.     

Haptenization of ovalbumin with the skin sensitizer methyl octanesulfonate: characterization of the methylated OVA323-339 T-cell epitope at His331.

Our interest is focused on the induction of allergic contact dermatitis (ACD) by the strong skin sensitizer, methyl octanesulfonate, which is a potent methyl transfer agent, especially to histidine and methionine residues. We are particularly interested to study the effect of methylation on the presentation and recognition of the ovalbumin (OVA) T-cell epitope, OVA323-339, by the T-cell receptor (TCR). Here we report the synthesis of the modified monomer N-alpha-Fmoc-N-tau-methyl-L-histidine and its incorporation by solid phase synthesis into the three possible methylated analogues of OVA323-339, that were needed as references for the subsequent studies. Native OVA was haptenized by methyl octanesulfonate. Using classical protein chemistry techniques (trypsin digestion, gel permeation, HPLC, MS and Edman sequencing) we were able to show that OVA323-339 was selectively methylated at His331. Circular dichroism (CD) studies showed that the methylation has no influence on the secondary structure of the peptide.     

Inhibitory effect of Pterocarpus indicus Willd water extract on IgE/Ag-induced mast cell and atopic dermatitis-like mouse models

Pterocarpus indicus Willd has been widely used as a traditional medicine to treat edema, cancer, and hyperlipidemia, but its antiallergic properties and underlying mechanisms have not yet been studied. The purpose of this study was to evaluate the antiallergic activity of Pterocarpus indicus Willd water extract (PIW) using activated mast cells and an atopic dermatitis (AD)-like mouse model. PIW decreased IgE/Ag-induced mast cell degranulation and the phosphorylation of Syk and downstream signaling molecules such as PLC-γ, Akt, Erk 1/2, JNK compared to stimulated mast cells. In DNCB-induced AD-like mice, PIW reduced IgE level in serum, as well as AD-associated scratching behavior and skin severity score. These results indicate that PIW inhibits the allergic response by reducing mast cell activation and may have clinical potential as an antiallergic agent for disorders such as AD.