Vasculopathies, cutaneous necrosis and emergency in dermatology.

Most emergencies in dermatology comprise a variety of entities with a usually benign course. However, vasculopathies and vasculitis are not common, but they could represent respectively 1.9% and 4.4% of these entities according to some studies of Emergency Dermatology Department. They become an important disease which has to be identified early to establish appropriate management and treatment. Some of them are well known, such as the leukocitoclastic vasculitis, Schölein-Henoch, panarteritis nodosa, antineutrophil cytoplasmic antibody associated vasculitis, giant cell arteritis, cryoglobulinemic vasculitis and antiphospholipid syndrome. More frequent vasculopathies are livedoid vasculopathy, pigmented purpuric dermatosis and calciphylaxis. Less common ones are caused by interferon and cholesterol crystal embolization. Others are very infrequent as Degos disease and Sneddon Syndrome. Among the more recently described ones there are deficiency of adenosine deaminase type 2 and crystalglobulinemia. The other group is composed of vasculopathies associated to microorganism as infective endocarditis, septic vasculopathy, aspergillosis, fusariosis, strongiloidosis, ecthyma gangrenosum, lucio phenomenon of leprosy and necrotic arachnidism. Finally, among these entities we can also find diseases associated with proinflammatory stages as disseminated intravascular coagulation, myeloproliferative disorders, intravascular lymphoma, metastasis intravascular. When we face cutaneous lesions characterized by reticulated violaceous lesions, palpable purpura or cutaneous necrosis, a careful clinico-pathological correlation as well as some laboratory or radiological tests are mandatory to further delineate a diagnosis and a proper first line empirical treatment.

Characterization of a glucosyltransferase enzyme involved in the formation of kaempferol and quercetin sophorosides in Crocus sativus.

UGT707B1 is a new glucosyltransferase isolated from saffron (Crocus sativus) that localizes to the cytoplasm and the nucleus of stigma and tepal cells. UGT707B1 transcripts were detected in the stigma tissue of all the Crocus species analyzed, but expression analysis of UGT707B1 in tepals revealed its absence in certain species. The analysis of the glucosylated flavonoids present in Crocus tepals reveals the presence of two major flavonoid compounds in saffron: kaempferol-3-O-ß-D-glucopyranosyl-(1-2)-ß-D-glucopyranoside and quercetin-3-O-ß-D-glucopyranosyl-(1-2)-ß-D-glucopyranoside, both of which were absent from the tepals of those Crocus species that did not express UGT707B1. Transgenic Arabidopsis (Arabidopsis thaliana) plants constitutively expressing UGT707B1 under the control of the cauliflower mosaic virus 35S promoter have been constructed and their phenotype analyzed. The transgenic lines displayed a number of changes that resembled those described previously in lines where flavonoid levels had been altered. The plants showed hyponastic leaves, a reduced number of trichomes, thicker stems, and flowering delay. Levels of flavonoids measured in extracts of the transgenic plants showed changes in the composition of flavonols when compared with wild-type plants. The major differences were observed in the extracts from stems and flowers, with an increase in 3-sophoroside flavonol glucosides. Furthermore, a new compound not detected in ecotype Columbia wild-type plants was detected in all the tissues and identified as kaempferol-3-O-sophoroside-7-O-rhamnoside. These data reveal the involvement of UGT707B1 in the biosynthesis of flavonol-3-O-sophorosides and how significant changes in flavonoid homeostasis can be caused by the overproduction of a flavonoid-conjugating enzyme.

Developmental and stress regulation of gene expression for a 9-cis-epoxycarotenoid dioxygenase, CstNCED, isolated from Crocus sativus stigmas.

Oxidative cleavage of cis-epoxycarotenoids by 9-cis-epoxycarotenoid dioxygenase (NCED) is the critical step in the regulation of abscisic acid (ABA) synthesis in higher plants. ABA has been associated with dormancy and flower senescence, while also regulating plant adaptive responses to various environmental stresses. An NCED gene, CstNCED, was cloned from Crocus sativus stigmas. The deduced amino acid sequence of the CstNCED protein shared high identity with other monocot NCEDs, and was closely related to the liliopsida enzymes. At the N-terminus of CstNCED a chloroplast transit peptide sequence is located. However, its expression in chloroplast-free tissues suggested localization in other plastid types. The relationship between expression of CstNCED and the endogenous ABA level was investigated in the stigma and corms, where it was developmentally regulated. The senescence of the unpollinated stigma is preceded by an increase in ABA levels and CstNCED expression. In corms, a correlation was observed between CstNCED expression and dormancy. Furthermore, CstNCED expression was correlated with the presence of zeaxanthin in the dormant corms. When detached C. sativus leaves and stigmas were water and salt stressed, increases in CstNCED mRNA were observed. The results provided evidence of the involvement of CstNCED in the regulation of ABA-associated processes such as flower senescence and corm dormancy in monocotyledonous saffron.

Genomic analysis and gene structure of the plant carotenoid dioxygenase 4 family: a deeper study in Crocus sativus and its allies.

The plastoglobule-targeted enzyme carotenoid cleavage dioxygenase (CCD4) mediates the formation of volatile C13 ketones, such as ß-ionone, by cleaving the C9-C10 and C9'-C10' double bonds of cyclic carotenoids. Here, we report the isolation and analysis of CCD4 genomic DNA regions in Crocus sativus. Different CCD4 alleles have been identified: CsCCD4a which is found with and without an intron and CsCCD4b that showed the presence of a unique intron. The presence of different CCD4 alleles was also observed in other Crocus species. Furthermore, comparison of the locations of CCD4 introns within the coding region with CCD4 genes from other plant species suggests that independent gain/losses have occurred. The comparison of the promoter region of CsCCD4a and CsCCD4b with available CCD4 gene promoters from other plant species highlighted the conservation of cis-elements involved in light response, heat stress, as well as the absence and unique presence of cis-elements involved in circadian regulation and low temperature responses, respectively. Functional characterization of the Crocus sativus CCD4a promoter using Arabidopsis plants stably transformed with a DNA fragment of 1400 base pairs (P-CsCCD4a) fused to the ß-glucuronidase (GUS) reporter gene showed that this sequence was sufficient to drive GUS expression in the flower, in particular high levels were detected in pollen.

Crocins transport in Crocus sativus: the long road from a senescent stigma to a newborn corm.

Saffron, the desiccated stigmas of Crocus sativus, is highly appreciated by its peculiar colour, flavour and aroma. The main compounds that accumulated throughout stigma development in C. sativus are crocetin, its glucoside derivatives, crocins, and picrocrocin, all of which increased as stigmas reached a fully developed stage. After anthesis, and in the absence of fertilization, the flower enters in a senescence programme, which represents the ultimate stage of floral development and results in wilting of whole flower. The programmed senescence of flowers allows the removal of a metabolically active tissue. We studied the composition of saffron apocarotenoids during the senescence of C. sativus flowers, and observed that changes in crocins were due to their transport from the senescent stigma to the ovaries and the developing corm. Afterwards, deglucosylation of crocins in these tissues results in crocetin accumulation. This mobilization mimics the export to storage cells (resorbed) of different compounds during leaf senescence avoiding loss of nutrients in leaves that would otherwise be cycled back into the soil system through leaf litter decomposition. In C. sativus, the resorbed apocarotenoids are stored within the developing corm, where they are not further detected in the advanced stages of development, suggesting that they are metabolized during the early and active phases of corm development, where the glucose molecules from crocins might contribute to cell initiation and elongation.