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Objectives: Intestinal alkaline sphingomyelinase, by exerting a major role in dietary sphingomyelin digestion, is responsible for the generation of messengers able to trigger the rapid turnover and apoptosis in intestinal epithelial cells. Markedly reduced mucosal alkaline sphingomyelinase activity has been associated with human colorectal neoplasms. The aim of this study was to analyze the alkaline sphingomyelinase activity in feces from healthy subjects and colorectal adenocarcinoma patients and to correlate it with the enzyme activity in intestinal tissues. Materials and Methods: The enzyme activity was measured both in the intestinal samples from 12 healthy controls and 51 patients with colorectal adenocarcinoma (tumoral and paratumoral tissue) and in the fecal samples of 34 healthy subjects and 29 patients with adenocarcinoma. The relation between sphingomyelinase activity and Dukes' stage, cell differentiation degree, age, and gender was also analyzed.Results: Alkaline sphingomyelinase was significantly decreased (P < 0.001; mean reduction >90%) in tumoral intestinal mucosa of patients compared with controls independently of Dukes' stage and tumor differentiation grade. Interestingly, the enzyme activity in histologically normal paratumoral tissues was statistically lower than control samples (P < 0.001). As occurs in neoplastic tissues, a relevant mean reduction (P < 0.0001; almost 90%) of alkaline sphingomyelinase was revealed in stool samples from tumor patients when compared with controls. Conclusion: These findings may have implications for cancer biology and perhaps also for the design of clinical test, thus suggesting that the fecal sphingomyelinase activity could really reflect the human intestinal mucosa enzyme level and could represent a new marker for human colorectal adenocarcinoma, mainly taking into account its early appearance in intestinal neoplasms. (Cancer Epidemiol Biomarkers Prev 2005;14(4):856 -62)

Current management of atopic dermatitis is mainly directed to the reduction of cutaneous inflammation. Since patients with atopic dermatitis show abnormalities in immunoregulation, a therapy aimed to adjust their immune function could represent an alternative approach, particularly in the severe form of the disease. Indeed, T-lymphocytes constitute a large population of cellular infiltrate in atopic/allergic inflammation and a dysregulated T-cell induced keratinocyte apoptosis appears to be an important pathogenetic factor of the eczematous disease. In recent years, attention has been focused on the interaction between host and probiotics which may have anti-inflammatory properties and immunomodulatory activities. The aim of the present work is to investigate the effect of a selected probiotic extract, the Bifidobacterium infantis extract, on a human keratinocyte cell line (HaCaT) abnormal apoptosis induced by activated-T-lymphocyte. An in vitro model of atopic dermatitis was used to assess the ability of the probiotic extract to protect HaCaT from apoptosis induced by soluble factors (IFN-γ and CD95 ligand) released by human T-lymphocytes in vitro activated with anti-CD3/CD28 mAbs or Phytohemoagglutinin. Evidence is given that the bacterial extract treatment was able to totally prevent T lymphocyte-induced HaCaT cell apoptosis in vitro. The mechanism underlying this inhibitory effect has been suggested to depend on the ability of the bacterial extract to significantly reduce anti-CD3/CD28 mAbs and mitogen-induced T-cell proliferation, IFN-γ generation and CD95 ligand release. These preliminary results may represent an experimental basis for a potential therapeutic approach mainly targeting the skin disorders-associated immune abnormalities.

An artificial wound in a confluent monolayer of human keratinocyte HaCaT cells or mouse embryo fibroblast Swiss NIH 3T3 cells was used to analyze the effects of the nitric oxide (NO) chemical donor, S-nitroso-N-acetylpenicillamine (SNAP). SNAP exposure promoted an enhanced rate of wound closure and accelerated motility of both keratinocytes and fibroblasts compared to control cells. The wounded monolayer cultures of HaCaT and NIH 3T3 cells, treated with or without SNAP, were monitored under a phase contrast microscope. Structural and ultrastructural modifications were analyzed by scanning electron microscopy (SEM). The images were captured by a digital camera at different time points (0-28 h) and the wound area was analyzed through software included in Matlab®. As early as 15 min, SNAP induced significant cytoskeletal remodeling, as shown by immunostaining (phalloidin-labelling), which in turn was associated with increased filopodium number and length rise. NO donor treatment also induced overexpression of Ki-67 protein, a typical marker of cell proliferation, as shown by immunostaining. Both SNAP-induced migration and proliferation were antagonized by the NO-sensitive GC inhibitor 1H-[1,2,4]oxadiazolo[-4,3-a]quinoxalin-1-one (ODQ), which suggests activation of the NO/cGMP signalling cascade in the observed SNAP-induced effects in the early stages of the healing process. Moreover, we provide evidence that PPAR-β antagonist (GSK0660) may interfere with NO-mediated wound healing process. J. Cell. Physiol. 231: 2185-2195, 2016. © 2016 Wiley Periodicals, Inc.