The oligosaccharidic component of the glycoconjugates in lichen planus, granuloma annulare, seborrheic keratosis and palmoplantar keratoderma: lectin histochemical study

It is well known that cell surface glycoconjugates play an important role in cell proliferation, adhesion and differentiation. The aim of this investigation was to define the changes of the glycoconjugate saccharidic moieties in the epidermis and derma of patients affected by several skin pathologies such as seborrheic keratosis, lichen planus, granuloma annulare and palmoplantaris keratoderma.Bioptical specimens from skin lesions as well as from normal skin were fixed in Carnoy's fluid and routinely processed. The sections were treated with HRP-lectins (PNA, DBA, SBA, WGA, ConA, LTA and UEAI). Cytochemical controls were performed for specificity of lectin-sugar reaction. Some sections were pre-treated with neuraminidase prior to staining with I-IRP lectins. In comparison with normal human skin, epidermal lectin binding pattern in the considered diseases showed considerable qualitative and quantitative variations. In general, in all the considered pathologies, a lack andtor a decrease in lectin binding at the epidermal layers was observed; among the various diseases, differences in cellular localisation of the sugar residues were also noted. In such respect, an exception was represented by seborrheic keratosis, where the cells of the basal layer showed PNA reactivity, which was absent in the basal layer of the normal skin. Although seborrheic keratosis and lichen planus have been studied by others authors, our findings are not in total accordance concerning lectin binding; this is probably due to the different fixatives employed. Our findings seem to reveal significant changes in keratinocyte glycoconjugate oligosaccharides in the previously mentioned diseases, providing clues to their pathogenesis

The oligosaccharidic component of the glycoconjugates in lichen planus, granuloma annulare, seborrheic keratosis and palmoplantar keratoderma: lectin histochemical study

It is well known that cell surface glycoconjugates play an important role in cell proliferation, adhesion and differentiation. The aim of this investigation was to define the changes of the glycoconjugate saccharidic moieties in the epidermis and derma of patients affected by several skin pathologies such as seborrheic keratosis, lichen planus, granuloma annulare and palmoplantaris keratoderma. Bioptical specimens from skin lesions as well as from normal skin were fixed in Carnoy's fluid and routinely processed. The sections were treated with HRP-lectins (PNA, DBA, SBA, WGA, ConA, LTA and UEAI). Cytochemical controls were performed for specificity of lectin-sugar reaction. Some sections were pre-treated with neuraminidase prior to staining with I-IRP lectins. In comparison with normal human skin, epidermal lectin binding pattern in the considered diseases showed considerable qualitative and quantitative variations. In general, in all the considered pathologies, a lack andtor a decrease in lectin binding at the epidermal layers was observed; among the various diseases, differences in cellular localisation of the sugar residues were also noted. In such respect, an exception was represented by seborrheic keratosis, where the cells of the basal layer showed PNA reactivity, which was absent in the basal layer of the normal skin. Although seborrheic keratosis and lichen planus have been studied by others authors, our findings are not in total accordance concerning lectin binding; this is probably due to the different fixatives employed. Our findings seem to reveal significant changes in keratinocyte glycoconjugate oligosaccharides in the previously mentioned diseases, providing clues to their pathogenesis

Cerato-platanin and cerato-populin induce differential gene expression in Platanus acerifolia

Cerato-platanin (CP) and cerato-populin (Pop1) are small non-catalytic proteins produced by the ascomycetes Ceratocystis platani and C. populicola. C. platani is responsible for the canker stain disease of plane trees, and C. populicola for the black canker of poplar trees. CP and Pop1 are PAMPs (pathogen-associated molecular patterns) inducing typical defense responses in various host and non-host plants. CP and Pop1 have an identity of about 63 and the conservative substitution of approximately 12 of amino acids, and both belong to the “cerato-platanin family” (Pfam PF07249). The aim of the present research was to analyse the gene expression induced in Platanus acerifolia leaves after treatments with CP and Pop1 using cDNA microarrays containing sequences isolated from suppressive subtractive libraries (SSH) from P. acerifolia after treatment with CP, and from Populus after cold or ozone treatment. There are many reports on cross-tolerance induction by abiotic stresses against other biotic stresses and vice versa and on the existence of a network of regulatory signalling occurring in plants during the interaction with biotic and abiotic stresses. PCR amplified sequences of the clones isolated from the cDNA libraries were spotted on microarray glass slides by CRIBI (Padoa, Italy). For the cDNA microarray analysis, mRNA was reverse transcribed in the presence of Cy3-dUTP or Cy5-dUTP. RNAs were extracted from leaves treated with sterile distilled water droplets containing CP or Pop1, or sterile distilled water as a control. Out of the 318 genes, 131 and 50 genes resulted to be modulated in CP- and Pop1-treated leaves, respectively. Moreover, several transcripts were differentially regulated. In both treatments the up-regulated genes were more than the down-regulated ones. Inducible expression of some candidate genes selected from the microarray results was confirmed by using semi-quantitative RT-PCRs. These results show that several differentially regulated genes induced by the PAMPs CP and Pop1 in P. acerifolia are in common with those induced in response to ozone and cold stresses in Populus, underlying the existence of a conserved network of genes activated by different stresses during plant defence responses

Cerato-platanin and cerato-populin induce differential resistance responses in plane leaves

Cerato-platanin (CP) and cerato-populin (Pop1) are small proteins produced by the phytopathogenic fungi Ceratocystis platani and C. populicola, respectively. CP and Pop1 behaved as PAMPs, since they elicited typical defense responses in various host and non-host plants. CP and Pop1 are well-structured α/β proteins with a identity of about 63% and the conservative substitution of approximately 12% of amino acids. Also the analysis by circular dichroism showed differences in the secondary structure between the two proteins. The present work aimed to understand whether these structural differences are reflected in differences in their eliciting activity. For this purpose we have used the plane leaves because this is the model on which we work long and know really. In addition to assess the inhibition of fungal growth on plane leaves, we studied the following parameters at 3, 6, 9, 12, 24, 48 hours post treatment: (1) determination and visualization of hydrogen peroxide and nitric oxide by using the specific probe 2’-7’-dichlorodihydrofluorescein diacetate and the fluorescent dye 4,5 diaminofluorescein diacetate, respectively; (2) the viability of cells determined by staining with propidium iodide and the in situ detection of DNA fragmentation (TUNEL assay); (3) the expression of the genes PR5 (thaumatin), LTP (Lipid transfer protein) e APX (Ascorbato perossidasi). All results show marked differences in the eliciting capacity of the two proteins; in particular the plane resistance responses are activated earlier by CP than by Pop1. These results are the basis for identifying the protein region(s) involved in the PAMP activity