Psoriasis in Tigray, Ethiopia: Focusing on available treatments.

Psoriasis has been reported to be rare in people with skin of color. However, the actual prevalence is probably underestimated by the lack of wide epidemiological studies. The aim of the study is to present our experience in Tigray, Ethiopia, focusing on the issues related to diagnosis, clinical features and therapies. A total of 1288 people affected by psoriasis were visited and 954 were included in a retrospective analysis through the review of medical records of patients attending at three Dermatologic Centers in Ethiopia from 2005 to 2016. The most common clinical form is plaque psoriasis (62.9%), followed by guttate (13.9%), pustular (9.5%), inverse (7.5%), and erythrodermic (6.1%) ones. The prevalence of psoriatic arthritis is 17%. It is often diagnosed late resulting in particularly deforming and debilitating disease. Patients with severe psoriasis often require hospitalization due to the reduced availability of effective treatments and appropriate skin care, resulting in a prolonged recurrence rate or decreased disease-free interval. In poorer rural areas, patients use some traditional African plants such as Kigelia africana which have been shown to have partial benefits in the treatment of psoriasis. Unfortunately, the only available conventional therapies are topical steroids, salicylic acid, methotrexate, and the sun. More studies concerning the appropriate management of people with psoriasis in low income countries, including standardization of indigenous therapies and a reduction of costs of conventional drugs, could help the care of people with psoriasis.

Anti-Inflammatory and Pro-Differentiating Properties of the Aryl Hydrocarbon Receptor Ligands NPD-0614-13 and NPD-0614-24: Potential Therapeutic Benefits in Psoriasis.

The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor expressed in all skin cell types, plays a key role in physiological and pathological processes. Several studies have shown that this receptor is involved in the prevention of inflammatory skin diseases, e.g., psoriasis, atopic dermatitis, representing a potential therapeutic target. We tested the safety profile and the biological activity of NPD-0614-13 and NPD-0614-24, two new synthetic AhR ligands structurally related to the natural agonist FICZ, known to be effective in psoriasis. NPD-0614-13 and NPD-0614-24 did not alter per se the physiological functions of the different skin cell populations involved in the pathogenesis of inflammatory skin diseases. In human primary keratinocytes stimulated with tumor necrosis factor-α or lipopolysaccharide the compounds were able to counteract the altered proliferation and to dampen inflammatory signaling by reducing the activation of p38MAPK, c-Jun, NF-kBp65, and the release of cytokines. Furthermore, the molecules were tested for their beneficial effects in human epidermal and full-thickness reconstituted skin models of psoriasis. NPD-0614-13 and NPD-0614-24 recovered the psoriasis skin phenotype exerting pro-differentiating activity and reducing the expression of pro-inflammatory cytokines and antimicrobial peptides. These data provide a rationale for considering NPD-0614-13 and NPD-0614-24 in the management of psoriasis.

Functional and pharmacodynamic evaluation of metronomic cyclophosphamide and docetaxel regimen in castration-resistant prostate cancer.

AIM: The aim of our study was to investigate the association of docetaxel and metronomic cyclophosphamide (CYC) in castration-resistant prostate cancer (CRPC). MATERIALS & METHODS: CRPC xenografts were established with PC3 cells. Mice were treated with a combination of CYC (50 mg/kg/day) and docetaxel (10-30 mg/kg/week) or with docetaxel alone. Docetaxel plasma levels were analyzed in patients receiving the drug alone or combined with CYC. RESULTS: Metronomic CYC is an effective adjuvant in blocking tumor growth in vivo, with comparable efficacy and less toxic effects compared with docetaxel treatment. CYC acts by downregulating cell proliferation and inducing apoptosis thorough upregulation of p21 and inhibition of angiogenesis. Finally, CYC increases docetaxel plasma levels in patients. CONCLUSION: Metronomic CYC exerts anti-tumoral effects in an in vivo model of prostate cancer and in patients with CRPC, and also increases the bioavailability of docetaxel. These results explain the favorable toxicity and activity profiles observed in patients treated with this regimen.

In vitro research on vitiligo: strategies, principles, methodological options and common pitfalls.

Understanding the cellular and molecular mechanisms leading to melanocyte loss in vitiligo is a mandatory step in improving the overall management of vitiligo patients. Until now, the study of vitiligo was characterised by a fragmented approach, and it is very hard to share and compare the data obtained by the different teams. The scenario mirrors the pathogenic puzzle, but it delays a true productive focus on the disease. The in vitro research is based on different models, ranging from monolayer cell culture of epidermal and dermal cells or 3D reconstructed skin to histological data, gene expression, computer simulation profile. For each model, several different (biochemical, phenotypic, immunological) aspects have been considered, increasing the mass of data difficult to be merged. Our purpose was to provide a practical synopsis of consolidated and advanced possibilities in the study of vitiligo, showing how data have been poorly shared until now. Following a short overview of the background of the disease, the approaches, ranging from basic cell biology to molecular and 'omics' studies, are summarised. New fluorescent probes and techniques open new possibilities for functional studies. Next, intracellular and superficial markers of the melanocytes, the main involved cells, are listed. Moving the focus from the epidermal level to the systemic and subcellular ones, this review aims to propose innovative multidisciplinary options for the vitiligo understanding. This paper focuses on the major practical and theoretical questions to be solved. It may be the basis for a more coordinated and productive approach to the biological question.

Membrane lipid defects are responsible for the generation of reactive oxygen species in peripheral blood mononuclear cells from vitiligo patients.

The pathogenesis of vitiligo, an acquired depigmenting disease of the skin, involves oxidative stress. Based on that, the generation of reactive oxygen species (ROS) by the mitochondria may be relevant in the pathogenesis of vitiligo. Here, we evaluate the biochemical and functional alterations involved in the defective activity that has been previously described both in melanocytes and peripheral blood mononuclear cells (PBMC) from vitiligo patients. Moreover, we used a freeze-thaw test as a mild stress stimulus to disclose any latent defects in the assembly of membrane lipids that may compromise the functionality of the membrane itself. We show that the lipid constitution of the membrane is altered in vitiligo. Specifically, the cardiolipin (CL) level in the mitochondrial inner membrane is reduced and the level of cholesterol is increased. Furthermore, an increase in the expression level of 3-hydroxy-3methyl-glutaryl-CoenzymeA-reductase (HMG-CoA reductase), the rate-limiting enzyme for cholesterol biosynthesis, was also seen. Associated with that, the expression of electron transport chain (ETC) lipid-dependent subunits was also modified, and their expression was further affected by the freeze-thaw stress. The expression of CL-independent mitochondrial proteins, such as porin and Bcl2, were unaffected in vitiligo PBMC. These data confirm that ETC protein expression mainly correlates with lipid arrangement and that loss of their expression is not due to generalized or random oxidative-mediated damage. We suggest that the modification of membrane lipid components in vitiligo cells may be the biochemical basis for the mitochondrial impairment and the subsequent production of intracellular ROS following the exposure to a mild stress.

Vitiligo Skin: Exploring the Dermal Compartment.

There is an increasing interest in the apparently normal skin in vitiligo. Altered expression of the adhesion molecule E-cadherin and persistent deregulated intracellular redox status that promotes the acquisition of a stress-induced senescent phenotype in melanocytes of normally pigmented skin from patients with vitiligo have been described. Growing evidence has shown that such cellular and functional alterations are not necessarily restricted to melanocytes but may be extended to other cutaneous cell populations in both lesional and nonlesional areas. However, whether dermal fibroblasts exhibit related alterations that may contribute to the defects associated with melanocytes in vitiligo is not known. Here we reveal within the dermal compartment cells a myofibroblast phenotype and a predisposition to premature senescence, indicating the existence of altered cross-talk between dermal and epidermal components that may affect melanocyte functionality even in the apparently normal skin of patients with vitiligo.

Energetic mitochondrial failing in vitiligo and possible rescue by cardiolipin.

Vitiligo is characterized by death or functional defects of epidermal melanocytes through still controversial pathogenic process. Previously, we showed that mitochondria-driven pre-senescent phenotype diminishes the capability of vitiligo melanocytes to cope with stressful stimuli. In the current study, we investigated markers of mitochondrial energy metabolism including the PGC1a axis, and then we determined the index of mitochondrial impairment using a cytomic approach. We found in cultured epidermal vitiligo melanocytes, compared to healthy ones, low ATP, increased proton leakage, and altered expression of several glycolytic enzymes (hexokinase II, pyruvic dehydrogenase kinase 1 and pyruvic kinase M2), We suggest that the low ATP production may be sufficient in steady-state conditions but it is unable to cover further needs. We also found in vitiligo melanocyrtes hyper-activation of the PGC1α axis, finalized to counteract the energy defect. Cytomic analysis, supported by MitoTracker Red pattern and ex-vivo immunohistochemistry, suggested an increased mitochondrial mass, possibly useful to ensure the essential ATP level. Finally, pharmacological cardiolipin stabilization reverted the energetic impairment, confirming the initial mitochondrial role. In conclusion, we report new insight in the pathogenetic mechanism of viitligo and indicate that the mitochondrial failure rescue by cardiolipin manipulation may be a new intriguing target in treatment development.

The laminA/NF-Y protein complex reveals an unknown transcriptional mechanism on cell proliferation.

Lamin A is a component of the nuclear matrix that also controls proliferation by largely unknown mechanisms. NF-Y is a ubiquitous protein involved in cell proliferation composed of three subunits (-YA -YB -YC) all required for the DNA binding and transactivation activity. To get clues on new NF-Y partner(s) we performed a mass spectrometry screening of proteins that co-precipitate with the regulatory subunit of the complex, NF-YA. By this screening we identified lamin A as a novel putative NF-Y interactor. Co-immunoprecipitation experiments and confocal analysis confirmed the interaction between the two endogenous proteins. Interestingly, this association occurs on euchromatin regions, too. ChIP experiments demonstrate lamin A enrichment in several promoter regions of cell cycle related genes in a NF-Y dependent manner. Gain and loss of function experiments reveal that lamin A counteracts NF-Y transcriptional activity. Taking advantage of a recently generated transgenic reporter mouse, called MITO-Luc, in which an NF-Y-dependent promoter controls luciferase expression, we demonstrate that lamin A counteracts NF-Y transcriptional activity not only in culture cells but also in living animals. Altogether, our data demonstrate the occurrence of lamin A/NF-Y interaction and suggest a possible role of this protein complex in regulation of NF-Y function in cell proliferation.

Ferritin contributes to melanoma progression by modulating cell growth and sensitivity to oxidative stress.

PURPOSE: Employing an in vitro model system of human melanoma progression, we previously reported ferritin light chain (L-ferritin) gene overexpression in the metastatic phenotype. Here, we attempted to characterize the role of ferritin in the biology of human melanoma and in the progression of this disease. EXPERIMENTAL DESIGN: Starting from the LM human metastatic melanoma cell line, we engineered cell clones in which L-ferritin gene expression was down-regulated by the stable expression of a specific antisense construct. These cells were then assayed for their growth capabilities, chemoinvasive properties, and sensitivity to oxidative stress. Additionally, ferritin protein content in primary and metastatic human melanomas was determined by immunohistochemistry. RESULTS: Artificial L-ferritin down-regulation in the LM cells strongly inhibited proliferation and chemoinvasion in vitro and cell growth in vivo. In addition, L-ferritin down-regulated cells displayed enhanced sensitivity to oxidative stress and to apoptosis. Concurrently, immunohistochemical analysis of a human melanoma tissue array revealed that ferritin expression level in metastatic lesions was significantly higher (P < 0.0001) than in primary melanomas. Furthermore, ferritin expression was constantly up-regulated in autologous lymph node melanoma metastases when compared with the respective primary tumors in a cohort of 11 patients. CONCLUSIONS: These data suggest that high ferritin expression can enhance cell growth and improve resistance to oxidative stress in metastatic melanoma cells by interfering with their cellular antioxidant system. The potential significance of these findings deserves to be validated in a clinical setting.

In vitro effects of nickel-sulphate on immune functions of normal and nickel-allergic subjects: a regulatory role for zinc.

Nickel hypersensitivity represents a very common human disease state, mainly occurring in females, defined as allergic contact dermatitis. Ni is a transition metal whose activity may be modulated by congeners. Zinc, an essential component for living organisms, has been shown to counteract Ni effects in patients with Ni hypersensitivity. We analysed immune responses to both Ni and Zn in healthy subjects and patients with allergic contact dermatitis to Ni. Our in vitro results show that Ni modulates surface receptors expression, reduces phytohemagglutinin (PHA)-driven lymphoproliferation, and upregulates some proinflammatory cytokines production, including interferon (IFN)-gamma. Zn also induced CD4+ lymphocyte proliferation, but it abolished or reduced most Ni-mediated effects. Our data are consistent with the hypothesis that Zn and Ni, as part of the heavy transition metals, may exchange roles in immune-mediated phenomena leading to expression of allergic contact dermatitis.

Vitiligo: a possible model of degenerative diseases.

Vitiligo is characterized by the progressive disappearance of pigment cells from skin and hair follicle. Several in vitro and in vivo studies show evidence of an altered redox status, suggesting that loss of cellular redox equilibrium might be the pathogenic mechanism in vitiligo. However, despite the numerous data supporting a pathogenic role of oxidative stress, there is still no consensus explanation underlying the oxidative stress-driven disappear of melanocytes from the epidermis. In this study, in vitro characterization of melanocytes cultures from non-lesional vitiligo skin revealed at the cellular level aberrant function of signal transduction pathways common with neurodegenerative diseases including modification of lipid metabolism, hyperactivation of mitogen-activated protein kinase (MAPK) and cAMP response element-binding protein (CREB), constitutive p53-dependent stress signal transduction cascades, and enhanced sensibility to pro-apoptotic stimuli. Notably, these long-term effects of subcytotoxic oxidative stress are also biomarkers of pre-senescent cellular phenotype. Consistent with this, vitiligo cells showed a significant increase in p16 that did not correlate with the chronological age of the donor. Moreover, vitiligo melanocytes produced many biologically active proteins among the senescence-associated secretory phenotype (SAPS), such as interleukin-6 (IL-6), matrix metallo proteinase-3 (MMP3), cyclooxygenase-2 (Cox-2), insulin-like growth factor-binding protein-3 and 7 (IGFBP3, IGFBP7). Together, these data argue for a complicated pathophysiologic puzzle underlying melanocytes degeneration resembling, from the biological point of view, neurodegenerative diseases. Our results suggest new possible targets for intervention that in combination with current therapies could correct melanocytes intrinsic defects.

On the pathophysiology of vitiligo: possible treatment options.

Vitiligo is an acquired depigmenting disorder usually classified as non-segmental and segmental types with a higher incidence of the non-segmental ones. The cause of non-segmental vitiligo is still unknown. Currently, it is a dogma that there are several genes affecting the immune system and the pigment system that predisposes someone to develop vitiligo. A precipitating factor must then ellicit an interaction between the immune system and the melanocyte, resulting in destruction of the melanocyte population in discrete areas of the skin. Starting from the overlapping but distinct pathomechanisms, treatment should be finalized to the cellular targets and possibly related to the disease phase.

The eumelanin intermediate 5,6-dihydroxyindole-2-carboxylic acid is a messenger in the cross-talk among epidermal cells.

Interest in colorless intermediates of melanocyte metabolism has traditionally been related to their role as melanin precursors, though several lines of evidence scattered in the literature suggested that these compounds may exert an antioxidant and protective function per se unrelated to pigment synthesis. Herein, we disclose the remarkable protective and differentiating effects of 5,6-dihydroxyindole-2-carboxylic acid (DHICA), a diffusible dopachrome tautomerase (DCT)-dependent eumelanin intermediate, on primary cultures of human keratinocytes. At micromolar concentrations, DHICA induced: (a) time- and dose-dependent reduction of cell proliferation without concomitant toxicity; (b) enhanced expression of early (spinous keratins K1 and K10 and envelope protein involucrin) and late (loricrin and filaggrin) differentiation markers; (c) increased activities and expression of antioxidant enzymes; and (d) decreased cell damage and apoptosis following UVA exposure. The hitherto unrecognized role of DHICA as an antiproliferative, protective, and antiapoptotic endogenous cell messenger points to a reappraisal of the biological functions of melanocytes and DCT in skin homeostasis and photoprotection beyond the mere provision of melanin pigments, and provides, to our knowledge, a previously unreported possible explanation to the higher resistance of the dark-skinned eumelanic phenotypes to sunburn and skin cancer.

Membrane lipid alterations as a possible basis for melanocyte degeneration in vitiligo.

The occurrence of oxidative stress has been proposed as a pathogenetic mechanism for melanocyte degeneration in vitiligo. In order to evaluate this possible correlation we focused on the lipid component of cell membranes. We observed in vitiligo melanocytes, through FACS methods, an increased median fluorescence intensity of rhodamine 123 and C11-BODIPY581/591 indicating a spontaneous higher production of reactive oxygen species (ROS) and membrane lipoperoxidation, associated with an altered pattern of cardiolipin (CL) distribution, defined on the basis of the fluorescence pattern after staining with 10-nonyl acridine orange. We confirmed membrane peroxidation by confocal and contrast-phase microscopes and demonstrated impaired activity of the mitochondrial electron transport chain (ETC) complex I. Finally, we observed increased apoptotic events following exposure to the pro-oxidant cumene hydroperoxide by Annexin V/propidium iodide fluorescence. We hypothesize that in vitiligo melanocytes lipid instability, with a defect in the synthesis or recycling of CL, induces ETC impairment and ROS production. In basal conditions melanocytes maintain the redox balance whereas following chemical or physical stress ROS-mediated membrane peroxidation is increased with a possible further CL oxidation, leading to cell death or detachment.

A review and a new hypothesis for non-immunological pathogenetic mechanisms in vitiligo.

Vitiligo is an acquired depigmenting disorder characterized by the loss of functioning epidermal melanocytes because of multifactorial and overlapping pathogenetic mechanisms. Besides the immunological approach, the study of the metabolic deregulations leading to toxic damage of the melanocytes appears to be more and more relevant. It was only last year that the first in vitro evidence supporting the link and the temporal sequence between the immune response and the cellular oxidative stress was provided, suggesting that the intrinsic damage of the melanocytes is primitive. What can be the guide line of the multiple altered metabolisms? A compromised membrane could render the cell sensitive to the external and internal agents differently, usually ineffective on the cell activity and survival. The primitive altered arrangement of the lipids may affect the transmembrane housing of proteins with enzymatic or receptorial activities, also conferring on them antigenic properties.

Differential in vitro cellular response induced by exposure to synthetic vitreous fibers (SVFs) and asbestos crocidolite fibers.

In this study, we analyzed the effects of synthetic vitreous fibers (SVFs) on a mesothelial (MeT5A) and a fibroblast cell line (NIH3T3), compared to those exerted by crocidolite asbestos fibers. SVFs (glass wool, rock wools) do not induce significant changes in cell mortality, whereas crocidolite asbestos fibers caused a dose-dependent cytotoxicity. We investigated the correlation between the fiber-induced cytotoxicity and the extent and type of interaction of the fibers with the cell surface, and we observed that SVFs, unlike crocidolite asbestos fibers, establish few and weak interactions. Moreover, after internalization, crocidolite asbestos fibers are often found free in the cytoplasm, whereas glass wool fibers are mainly localized inside cytoplasmic vacuoles. After treatments, we also detected signs of oxidative stress, revealed by an increased reactive oxygen species (ROS) production and by an induction of superoxide dismutase (SOD) activity. The lipoperoxidative damage was characterized by a decrease in polyunsaturated fatty acids (PUFA), an increase in the content of thiobarbituric reactive species (TBARS) and a consumption of vitamin E, as a lipophilic antioxidant. Furthermore, we investigated the effect of fiber exposure on cell proliferation. and it was found that, unlike crocidolite asbestos fibers, SVFs did not induce a significant increase in DNA synthesis.

Alterations of mitochondria in peripheral blood mononuclear cells of vitiligo patients.

The possible role for a defective mitochondrial functionality in the pathogenesis of vitiligo was investigated by measuring intracellular levels of reactive oxygen species and of antioxidants, the activity of Krebs cycle enzymes, as well as the effects of inhibitors of the electron transport chain, in peripheral blood mononuclear cells from patients with active or stable disease vs. normal subjects. Plasma glyoxal levels were also determined in the same groups of subjects as an index of systemic oxidative stress. In patients with vitiligo in active phase, we observed an increased intracellular production of reactive oxygen species with a consequent imbalance of the prooxidant/antioxidant equilibrium, whereas plasma did not show apparent alterations in glyoxal levels, ruling out a systemic oxidative stress. In patients with stable disease, the balance between pro-oxidants and anti-oxidants seems to be maintained. Moreover, a marked increase in the expression of mitochondrial malate dehydrogenase activity and a specific sensitivity to electron transport chain complex I inhibitor were observed. Overall, these data provide further evidence for an altered mitochondrial functionality in vitiligo patients.