Iron Chelator Deferasirox Reduces Candida albicans Invasion of Oral Epithelial Cells and Infection Levels in Murine Oropharyngeal Candidiasis.

Candida albicans, the causative agent of mucosal infections, including oropharyngeal candidiasis (OPC), as well as bloodstream infections, is becoming increasingly resistant to existing treatment options. In the absence of novel drug candidates, drug repurposing aimed at using existing drugs to treat off-label diseases is a promising strategy. C. albicans requires environmental iron for survival and virulence, while host nutritional immunity deploys iron-binding proteins to sequester iron and reduce fungal growth. Here we evaluated the role of iron limitation using deferasirox (an FDA-approved iron chelator for the treatment of patients with iron overload) during murine OPC and assessed deferasirox-treated C. albicans for its interaction with human oral epithelial (OE) cells, neutrophils, and antimicrobial peptides. Therapeutic deferasirox treatment significantly reduced salivary iron levels, while a nonsignificant reduction in the fungal burden was observed. Preventive treatment that allowed for two additional days of drug administration in our murine model resulted in a significant reduction in the number of C. albicans CFU per gram of tongue tissue, a significant reduction in salivary iron levels, and significantly reduced neutrophil-mediated inflammation. C. albicans cells harvested from the tongues of animals undergoing preventive treatment had the differential expression of 106 genes, including those involved in iron metabolism, adhesion, and the response to host innate immunity. Moreover, deferasirox-treated C. albicans cells had a 2-fold reduction in survival in neutrophil phagosomes (with greater susceptibility to oxidative stress) and reduced adhesion to and invasion of OE cells in vitro Thus, deferasirox treatment has the potential to alleviate OPC by affecting C. albicans gene expression and reducing virulence.

Elastosis en la queilitis actínica. Revisión de literatura / Elastosis in Actinic Cheilitis. Literature Review

Resumen La matriz extracelular (MEC) juega un papel importante en la regulación de los eventos biológicos, tales como, el desarrollo de la migración celular, proliferación y diferenciación. La exposición crónica a la luz ultravioleta (UV) provoca elastosis (en distintos grados), que corresponde a una degeneración basófila de la MEC. La queilitis actínica (QA) es una lesión potencialmente maligna del labio inducida por la exposición regular y prolongada a la luz UV, que afecta principalmente al bermellón del labio inferior. Las lesiones de QA tienen un estroma complejo, se observa siempre la presencia de elastosis, infiltrado inflamatorio crónico de distinta intensidad y la aparición de vasos sanguíneos telangiectásicos. Dentro de este infiltrado inflamatorio se ha descrito un aumento significativo de mastocitos (MCs), localizados especialmente alrededor de las zonas de elastosis y en la zona subepitelial. Se ha propuesto que la elastosis actínica se produce tanto por procesos degenerativos como de síntesis anormal de fibras elásticas por parte de fibroblastos con daño solar, lo que va acompañado de cambios morfológicos del colágeno. A pesar de que el fibroblasto tendría un rol preponderante en la formación de la elastosis actínica, diversos estudios sugieren que otros tipos celulares como el MC también contribuirían en forma significativa al daño actínico de la MEC. El propósito de esta revisión es analizar las características de la elastosis en la QA.

Abstract The extracellular matrix (ECM) plays an important role in the regulation of biological events, such as cell migration, proliferation and differentiation. Chronic exposure to ultraviolet (UV) light causes elastosis (to varying degrees), which corresponds to a basophilic degeneration of the ECM. Actinic cheilitis (AC) is a potentially malignant lip lesion induced by regular and prolonged exposure to UV light, which mainly affects the vermilion. AC lesions have a complex stroma characterized by the presence of elastosis, chronic inflammatory infiltrate of different intensity and the appearance of telangiectatic blood vessels. Within this inflammatory infiltrate a significant increase of mast cells (MCs) has been described, located especially around areas of elastosis and at the subepithelial zone. It has been proposed that actinic elastosis is produced both, by degenerative processes and by abnormal synthesis of elastic fibers by photodamaged fibroblasts, which is accompanied by morphological changes in collagen. Although the fibroblast would play a major role in actinic elastosis formation, several studies suggest that other cell types such as MCs also contribute significantly to actinic ECM damage. The purpose of this review is to discuss the characteristics of elastosis in AC.

CD8+ and FoxP3+ T-cell infiltration in actinic cheilitis.

BACKGROUND: Differences in immune profile between actinic cheilitis (AC), a precursor of lip squamous cell carcinoma, and normal lip vermillion (NL) have not been elucidated. OBJECTIVES: To compare density, distribution, and ratios of CD8+ and FoxP3+ cells between AC and NL and assess their associations with clinicopathologic variables. METHODS: Samples of AC and NL obtained between 2001 and 2013 at the College of Dentistry of the University of Concepcion, Chile, were retrospectively analyzed for immunohistochemical detection of CD8+ and FoxP3+ cells. Differences between groups were tested by Mann-Whitney U and Fisher's exact tests. Independent effects of cell densities and CD8/FoxP3 ratio with AC were assessed by multiple logistic regression analysis after adjustment for potential confounding. RESULTS: A total of 62 AC and 24 NL biopsies were included. Densities of CD8+ and FoxP3+ cells in AC were significantly higher than in NL. Conversely, the CD8+/FoxP3+ ratio was significantly lower in AC as compared to NL. After adjustment for sun exposure, age, gender, and smoking status, a stromal FoxP3+ cell density higher than 0.35 cells/field was significantly associated with increased odds of AC (odds ratio [OR] = 5.01, 95% confidence interval [CI]: 1.18-21.31), while a stromal CD8+/FoxP3+ ratio higher than 5.91 was associated with decreased odds of AC (OR = 0.29, 95% CI: 0.08-1.08). CONCLUSIONS: AC is characterized by increased FoxP3+ cell infiltration and a reduced CD8/FoxP3 ratio as compared to NL. Therefore, increased infiltration of FoxP3+ cells relative to CD8+ cells may contribute to the transition from normal to preneoplastic stages in lip carcinogenesis.

Candida glabrata Binding to Candida albicans Hyphae Enables Its Development in Oropharyngeal Candidiasis.

Pathogenic mechanisms of Candida glabrata in oral candidiasis, especially because of its inability to form hyphae, are understudied. Since both Candida albicans and C. glabrata are frequently co-isolated in oropharyngeal candidiasis (OPC), we examined their co-adhesion in vitro and observed adhesion of C. glabrata only to C. albicans hyphae microscopically. Mice were infected sublingually with C. albicans or C. glabrata individually, or with both species concurrently, to study their ability to cause OPC. Infection with C. glabrata alone resulted in negligible infection of tongues; however, colonization by C. glabrata was increased by co-infection or a pre-established infection with C. albicans. Furthermore, C. glabrata required C. albicans for colonization of tongues, since decreasing C. albicans burden with fluconazole also reduced C. glabrata. C. albicans hyphal wall adhesins Als1 and Als3 were important for in vitro adhesion of C. glabrata and to establish OPC. C. glabrata cell wall protein coding genes EPA8, EPA19, AWP2, AWP7, and CAGL0F00181 were implicated in mediating adhesion to C. albicans hyphae and remarkably, their expression was induced by incubation with germinated C. albicans. Thus, we found a near essential requirement for the presence of C. albicans for both initial colonization and establishment of OPC infection by C. glabrata.

MMP-8 overexpression and persistence of neutrophils relate to stress-impaired healing and poor collagen architecture in mice.

Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) are critical for tissue remodeling during wound repair. Psychological stress has been found to impair wound healing in humans and animals. The objective of this study was to assess MMP and TIMP gene expression during stress-impaired healing. Female SKH-1 mice (n=299) were divided into control and stress groups (13h restraint/day for 3days prior to and 5days post-wounding). Two 3.5mm cutaneous full-thickness wounds were placed on the dorsum of each mouse and wound measurements were performed daily. RT-PCR for gene expression of MMP-2, MMP-8, MMP-9, TIMP-1 and TIMP-2 was performed at days 1, 3 and 5. Immunohistochemical analyses of the healed wounds were performed at days 15 and 28. As expected, wounds healed more slowly in restraint-stressed mice compared to controls. Stressed mice exhibited MMP-8 overexpression and lower TIMP-1 levels during healing, and poorer collagen organization once healed. MMP-8 overexpression may have stemmed from a higher level of neutrophils, observed in wound tissue on days 3 and 5. These findings implicate higher neutrophil numbers, MMP-8 overexpression, and TIMP-1 under-expression, as mechanisms that may compromise wound outcomes such as scarring under conditions of stress.

Restraint stress alters neutrophil and macrophage phenotypes during wound healing.

Previous studies reported that stress delays wound healing, impairs bacterial clearance, and elevates the risk for opportunistic infection. Neutrophils and macrophages are responsible for the removal of bacteria present at the wound site. The appropriate recruitment and functions of these cells are necessary for efficient bacterial clearance. In our current study we found that restraint stress induced an excessive recruitment of neutrophils extending the inflammatory phase of healing, and the gene expression of neutrophil attracting chemokines MIP-2 and KC. However, restraint stress did not affect macrophage infiltration. Stress decreased the phagocytic abilities of phagocytic cells ex vivo, yet it did not affect superoxide production. The cell surface expression of adhesion molecules CD11b and TLR4 were decreased in peripheral blood monocytes in stressed mice. The phenotype of macrophages present at the wound site was also altered. Gene expression of markers of pro-inflammatory classically activated macrophages, CXCL10 and CCL5, were down-regulated; as were markers associated with wound healing macrophages, CCL22, IGF-1, RELMα; and the regulatory macrophage marker, chemokine CCL1. Restraint stress also induced up-regulation of IL10 gene expression. In summary, our study has shown that restraint stress suppresses the phenotype shift of the macrophage population, as compared to the changes observed during normal wound healing, while the number of macrophages remains constant. We also observed a general suppression of chemokine gene expression. Modulation of the macrophage phenotype could provide a new therapeutic approach in the treatment of wounds under stress conditions in the clinical setting.

Increased fibroblast density in actinic cheilitis: association with tryptase-positive mast cells, actinic elastosis and epithelial p53 and COX-2 expression.

BACKGROUND: Actinic cheilitis (AC) is characterized by epithelial and connective tissue alterations caused by ultraviolet sunlight overexposure known as photodamage. Fibroblasts have been linked to photodamage and tumor progression during skin carcinogenesis; however, their role in early lip carcinogenesis remains unknown. The aim of this study was to assess the density of fibroblasts in AC and normal lip (NL) samples and determine their association with markers of lip photodamage. METHODS: Fibroblasts, mast cells, p53, COX-2, and elastin were detected in NL (n = 20) and AC (n = 28) biopsies using immunohistochemistry/histochemistry. Mast cell and fibroblast density and epithelial p53 and COX-2 expression scores were then obtained. Elastosis was scored 1-4 according to elastin fiber density and tortuosity. RESULTS: Fibroblasts, mast cells, p53, COX-2, and elastosis were increased in AC as compared to NL (P < 0.001). Multivariate analysis showed an association between fibroblast and mast cell density at the papillary and reticular areas of AC and NL (P < 0.05). Papillary fibroblast density was also associated with epithelial p53 and COX-2 expression (P < 0.05). Increased fibroblast density, both papillary and reticular, was found in the high elastosis group (scores 3-4) as compared to the low elastosis group (scores 1-2) (P < 0.01). Increased reticular mast cell density was detected only in the high elastosis group (P < 0.01). CONCLUSIONS: Fibroblasts are increased in AC, and they are associated with mast cell density, epithelial p53 and COX-2 expression, and actinic elastosis. Therefore, fibroblasts may contribute to lip photodamage and could be considered useful markers of early lip carcinogenesis.

Effect of white cell counts on the presence of human herpes simplex virus type-1 in saliva of pediatric oncology patients.

OBJECTIVE: The objective of this study was to assess if there is increased herpes simplex virus type 1 (HSV-1) salivary shedding in oncology pediatric patients with severe cytopenia (SC). STUDY DESIGN: HSV-1 was detected by real time PCR in saliva samples from oncology pediatric patients (n = 30) during SC and relative cytopenia (RC), and from healthy children (n = 27). RESULTS: The frequency of HSV-1 positive saliva samples was higher in patients with SC as compared to controls (P < .05), and this frequency presented a significant reduction during RC periods (P < .02). The SC group positive for HSV-1 presented both a twofold increase in the neutrophil-to-lymphocyte ratio as compared with SC patients negative for HSV-1 (P < .05), and a positive correlation between neutrophil and lymphocyte counts (P < .05, R = 0.82, R(2) = 0.67). This correlation was not found in oncology patients negative for HSV-1 during SC and RC. CONCLUSION: Severe cytopenia in oncology pediatric patients could be an important susceptibility factor for increased HSV-1 salivary shedding.