Botulinum toxin injections as an effective treatment for patients with intertriginous Hailey-Hailey or Darier disease: an open-label 6-month pilot interventional study.

BACKGROUND: Patients with Hailey-Hailey and Darier diseases present with disabling inflammatory lesions located in large skin folds, which are often exacerbated or induced by sweating. Quality of life is highly impaired because of pain and recurrent skin infections. An improvement in skin lesions after botulinum toxin A injections has previously been reported in some patients but no prospective interventional studies are available. The aim of this open-label, 6-month, interventional pilot study (NCT02782702) was to evaluate the effectiveness and safety of botulinum toxin A for patients with moderate to very severe skin lesions located in folds. RESULTS: Thirty patients (26 Hailey-Hailey/4 Darier) were included. Botulinum toxin A proved effective within the first month in two-thirds of patients, taking all study parameters (itchiness, cutaneous pain, sweating and odour, infections, psychosocial impairment and quality of life) into account and persisted during the 6-month follow-up period. No patient was classed as a BtxA non-responder, but 11 (37%) Hailey-Hailey patients (the most severe ones), experienced a relapse during the study. No serious side effects were reported. Mild transient clear fluid discharge at the site of the injections was reported for 27% of patients. CONCLUSIONS: Botulinic toxin seems to be an effective and safe treatment for Hailey-Hailey and Darier diseases. Nevertheless, it may prove insufficient for the severest of Hailey-Hailey cases and could be considered as supplementary to other conventional treatments. Further studies are required to confirm our results on larger Darier cohorts.

Probing the Functions of Carbohydrate Binding Modules in the CBEL Protein from the Oomycete Phytophthora parasitica.

Oomycetes are microorganisms that are distantly related to true fungi and many members of this phylum are major plant pathogens. Oomycetes express proteins that are able to interact with plant cell wall polysaccharides, such as cellulose. This interaction is thought to be mediated by carbohydrate-binding modules that are classified into CBM family 1 in the CAZy database. In this study, the two CBMs (1-1 and 1-2) that form part of the cell wall glycoprotein, CBEL, from Phytophthora parasitica have been submitted to detailed characterization, first to better quantify their interaction with cellulose and second to determine whether these CBMs can be useful for biotechnological applications, such as biomass hydrolysis. A variety of biophysical techniques were used to study the interaction of the CBMs with various substrates and the data obtained indicate that CBEL's CBM1-1 exhibits much greater cellulose binding ability than CBM1-2. Engineering of the family 11 xylanase from Talaromyces versatilis (TvXynB), an enzyme that naturally bears a fungal family 1 CBM, has produced two variants. The first one lacks its native CBM, whereas the second contains the CBEL CBM1-1. The study of these enzymes has revealed that wild type TvXynB binds to cellulose, via its CBM1, and that the substitution of its CBM by oomycetal CBM1-1 does not affect its activity on wheat straw. However, intriguingly the addition of CBEL during the hydrolysis of wheat straw actually potentiates the action of TvXynB variant lacking a CBM1. This suggests that the potentiating effect of CBM1-1 might not require the formation of a covalent linkage to TvXynB.

Redefining XynA from Penicillium funiculosum IMI 378536 as a GH7 cellobiohydrolase.

The secretome of Penicillium funiculosum contains two family GH7 enzymes, one of which (designated XynA) has been described as a xylanase. This is unusual because it is the only xylanase in family GH7, which is mainly composed of cellobiohydrolases and endoglucanases, and also because XynA is highly similar to the cellobiohydrolase I from Talaromyces emersonii and Trichoderma reesei (72 and 65 % identity, respectively). To probe this enigma, we investigated the biochemical properties of XynA, notably its activity on xylans and ß-D-glucans. A highly pure sample of XynA was obtained and used to perform hydrolysis tests on polysaccharides. These revealed that XynA is 100-fold more active on ß-1,4-glucan than on xylan. Likewise, XynA was active on both 4-nitrophenyl-ß-D-lactopyranoside (pNP-ß-D-Lac) and 4-nitrophenyl-ß-D-cellobioside (pNP-cellobiose), which shows that XynA is principally an exo-acting type 1 cellobiohydrolase enzyme that displays 5.2-fold higher performance on pNP-cellobiose than on pNP-ß-D-Lac. Finally, analyses performed using cellodextrins as substrate revealed that XynA mainly produced cellobiose (C2) from substrates containing three or more glucosyl subunits, and that C2 inhibits XynA at high concentrations (IC(50) (C2) = 17.7 µM). Overall, this study revealed that XynA displays typical cellobiohydrolase 1 activity and confirms that the description of this enzyme in public databases should be definitively amended. Moreover, the data provided here complete the information provided by a previous proteomics investigation and reveal that P. funiculosum secretes a complete set of cellulose-degrading enzymes.