Contact allergens and sodium lauryl sulphate upregulate vascular endothelial growth factor in normal keratinocytes

Telangiectasia diameter in response to thermal stimulus: experimental data and possible clinical applications

BACKGROUND

Telangiectasias are dilated blood vessels on the skin that develop progressively because of several diseases, including chronic venous disease. The skin blood flow has differences compared to the rest of the circulatory system. These vessels have a permanent vasoconstrictor tone that can respond to vasoconstriction/vasodilation stimulative substances and higher or lower temperatures. The aim of this study was to investigate any possible telangiectasias vasoconstriction or vasodilation in response to temperature changes.

METHODS

This study is a clinical trial with 26 outpatients of vascular surgery with telangiectasias in the lower limbs. We used direct skin digital microscopy to obtain telangiectasias images at room temperature and after the thermal stimulus with cold pads. These photographs were processed using AmScopeAmLite (United Scope LLC Euromex Optics Group b.v., Los Angeles, CA, USA) and the capillary diameter and area were measured in Adobe Illustrator (Adobe Inc., Mountain View, CA, USA). The data collected was analyzed in SPSS Statistics (SPSS Inc., Chicago, IL, USA) with a paired t-test for the telangiectasias area and a Wilcoxon matched-pairs signed-rank test for the telangiectasias diameter.

RESULTS

In comparison to telangiectasias measures at room temperature, we found a statistically significant decrease in the diameter (median of -0.04 mm; interquartile range: -0.10 mm to -0.01 mm; P<0.001) and area (mean of -26.54 mm²; 95% Confidence interval (-36.31, -16.76) mm²; P<0.001 in response to the cold stimulus.

CONCLUSIONS

Telangiectasias respond to cold patch application with a significantly statistical microscale quantifiable vasoconstriction. This intervention has the potential to improve the current state of telangiectasias sclerotherapy due to its mechanism helping to stabilize the applied foam. We speculate that topic cold used as a neoadjuvant treatment could improve the efficiency, stability, and other outcomes of sclerotherapy. Also, complementary use of topical cold stimulus application may be of interest in the therapeutic management of telangiectasias.

Microfluidics-based skin irritation test using in vitro 3D angiogenesis platform

A global ban on animal experiments has been proposed. Hence, it is imperative to develop alternative models. Artificial skin models should reflect the responses of subcutaneous blood vessels and the immune system to elucidate disease and identify cosmetics' base materials. Notably, in vivo skin-irritation cascades involve disruption of the epidermal barrier and the release of proinflammatory mediators in response to chemical stimuli. Such proinflammatory factors promote angiogenesis and blood vessel permeability, as observed in irritant contact dermatitis. As an alternative to animal models, we propose a novel skin-irritation model based on a three-dimensional in vitro angiogenesis platform, in which irritated keratinocytes biochemically stimulate vascular endothelial growth factors. Our microfluidic platform hosts interactions between keratinocytes and dermal fibroblasts, which promote angiogenic sprouting. We use sodium lauryl sulfate (SLS) and steartrimonium chloride (SC) as chemical irritants. The irritative effects of SLS and SC are of particular interest due to the ubiquity of both SLS and SC in cosmetics. SLS was observed to significantly affect angiogenic performance, with increasing sprout length. Further promotion of vessel sprouting and lumen formation was observed with 10, 20, and 60 μM of SC, despite its classification as nonirritating and use in supposedly safe formulations. This platform provides an alternative to animal testing as a basis for testing cosmetics and pharmaceutical substances, in addition to serving as a disease model for irritant contact dermatitis.

Synthetic nickel-containing superoxide dismutase attenuates para-phenylenediamine-induced bladder dysfunction in rats

Para (p)-phenylenediamine and its toxic metabolites induce excess reactive oxygen species formation that results in bladder voiding dysfunction. We determined the effects of synthetic Ni-containing superoxide dismutase mimics and the role of oxidative stress in p-phenylenediamine-induced urinary bladder dysfunction. P-phenylenediamine (60 μg/kg/day) was intraperitoneally administered for 4 weeks to induce bladder injury in female Wistar rats. Synthetic Ni-containing superoxide dismutase mimics, WCT003 (1.5 mg/kg) and WCT006 (1.5 mg/kg), were then intraperitoneally administered for 2 weeks. Transcystometrograms were performed in urethane-anesthetized rats. The in vitro and in vivo reactive oxygen species levels and pathological changes in formalin-fixed bladder sections were evaluated. Western blotting and immunohistochemistry elucidated the pathophysiological mechanisms of oxidative stress-induced apoptosis, autophagy, and pyroptosis. P-phenylenediamine increased voiding frequency, blood and urinary bladder levels of reactive oxygen species, and neutrophil and mast cell infiltration. It also upregulated biomarkers of autophagy (LC3 II), apoptosis (poly (ADP-ribose) polymerase), and pyroptosis (Caspase 1). WCT003 and WCT006 ameliorated reactive oxygen species production, inflammation, apoptosis, autophagy, pyroptosis, and bladder hyperactivity. P-phenylenediamine increased oxidative stress, inflammatory leukocytosis, autophagy, apoptosis, and pyroptosis formation within the urinary bladder. Novel synthetic nickel-containing superoxide dismutase mimics relieved p-phenylenediamine-induced bladder inflammation and voiding dysfunction.

Keratinocytic vascular endothelial growth factor as a novel biomarker for pathological skin condition

Skin is an emerging target tissue in pharmaceutical and cosmetic science. Safety assessment for dermal toxicity is a critical step for development of topically applicable pharmaceutical agents and ingredients in cosmetics. Urgent needs exist to set up toxicity testing methods for dermal safety, and identification of novel biomarkers for pathological cutaneous alteration is highly required. Here we will discuss if vascular endothelial growth factor (VEGF) has a potential as a biomarker for dermal impairment. Experimental and clinical evidences for induction of keratinocytic VEGF under pathological conditions will be reviewed.

Impaired Contact Hypersensitivity Reaction and Reduced Production of Vascular Endothelial Growth Factor in Tumor Necrosis Factor-α Gene-Deficient Mice

Tumor necrosis factor (TNF)-alpha is an important proinflammatory cytokine in contact hypersensitivity (CHS) reactions. Previous efforts to assay CHS in TNF-alpha gene-deficient (-/-) mice have demonstrated a significant reduction in ear skin weight at 24 h following challenge by oxazolone, although the mechanisms of this suppression have not been examined. To further characterize the impaired CHS during evolution of the elicitation phase in TNF-alpha -/- mice and to clarify its mechanisms, focusing on the roles of TNF-alpha and vascular endothelial growth factor (VEGF), we used an established method of CHS assay-sensitization and challenge by trinitrochlorobenzene (TNCB)- in TNF-alpha -/- and wild-type mice. We compared the histopathology of the sequential evolution of CHS between the two groups of mice and assessed both the extent of inflammatory cell infiltration and the degree of dilatation in dermal vessels labeled with CD31. We quantified the production of VEGF in the epidermis at specific time points by using a murine VEGF ELISA kit. The CHS reaction was markedly suppressed in TNF-alpha -/- mice at all time points of the elicitation phase. Histologically, in TNF-alpha -/- mice we observed diminished vascular permeability, reduced numbers of infiltrating inflammatory cells, neutrophils at 12 h, mononuclear cells and eosinophils at 24 h, and a decreased area of dilatation of vessels labeled with CD31. The level of epidermal VEGF in wild type mice increased rapidly after challenge and peaked at 24 h, paralleling the peak of ear swelling. In contrast, the peak level of epidermal VEGF in TNF-alpha -/- mice was significantly reduced. These results suggest that TNF-alpha plays an enhancing role in the elicitation phase of the CHS reaction. Diminished degrees of vascular permeability, dilatation of CD31+ vessels, and inflammatory cell infiltration in TNF-alpha -/- mice are likely to be the result of a lack of TNF-alpha and reduced production of epidermal VEGF.

Pilot Study of Intraperitoneal Administration of Triamcinolone Acetonide for Cancerous Ascites in Patients With End-Stage Gynecological Cancer

Objective

Patients with end-stage cancer have poorly controlled ascites retention resulting due to cancerous peritonitis. We intraperitoneally administered triamcinolone acetonide (TA) to patients with end-stage gynecological cancer as a pilot study, and our treatment results are reported herein.

Patients and Methods

We enrolled 26 patients with end-stage gynecological cancer requiring frequent abdominal paracentesis for ascites drainage between April 2010 and September 2012. The volume of ascites drainage was 2000 to 3000 mL per drainage session, and TA at 10 mg/kg was intraperitoneally administered after drainage. We compared abdominal paracentesis intervals, performance status (PS), total protein level, albumin level, white blood cell count, changes in C-reactive protein (CRP) level, and adverse events before and after TA use.

Results

Triamcinolone acetonide was administered to 26 patients for a total of 59 times. The abdominal paracentesis intervals, PS, and mean (SD) of C-reactive protein before and after TA use were 13.2 (12.6) days and 21.9 (23.6) days (P = 0.0117), 2.4 (0.7) and 1.6 (1.1) (P < 0.0001), and 7.5 (5.2) mg/dL and 5.5 (5.0) mg/dL (P = 0.007), respectively. With regard to adverse events, abdominal pain of grade 2 was observed once (1.7%), but there were no other acute adverse events. Four subjects (15.4%) had intestinal perforation.

Conclusions

Intraperitoneal administration of TA after drainage was considered to be a useful treatment, as it seems to extend paracentesis intervals and improve PS while maintaining quality of life for end-stage gynecological cancer patients with massive ascites.

Cytokines and chemokines in irritant contact dermatitis

Irritant contact dermatitis is a result of activated innate immune response to various external stimuli and consists of complex interplay which involves skin barrier disruption, cellular changes, and release of proinflammatory mediators. In this review, we will focus on key cytokines and chemokines involved in the pathogenesis of irritant contact dermatitis and also contrast the differences between allergic contact dermatitis and irritant contact dermatitis.

Differential cytokine expression in skin after single and repeated irritation by sodium lauryl sulphate

In vivo levels of cytokines and presence of neutrophils and eosinophils in skin irritation are not well known. Our objective was to get more insight in inflammatory mediators and markers involved in single and repeated skin irritation. We sampled epidermis-derived fluid using a novel technology that includes application of a negative pressure on the skin after creation of micropores in the stratum corneum by a laser. In nine volunteers, transdermal fluid was sampled after a single 4-h 10% sodium lauryl sulphate exposure and a repeated 3-week exposure (0.1% sodium lauryl sulphate). Twenty-seven cytokines were assessed by multiplex assay, and IL-1alpha, eosinophil cationic protein and myeloperoxidase by enzyme-linked immunosorbent assay. Levels of eosinophil cationic protein were increased after irritation and correlated with levels of myeloperoxidase. The levels of inflammatory mediators showed large interindividual differences in unexposed and exposed skin. Despite this variation, several mediators clearly showed increased levels: CC chemokine ligand (CCL)11, CXCL10 and vascular endothelial growth factor after both single and repeated exposure, IL-1alpha and basic fibroblast growth factor after single exposure and interleukin-1 receptor antagonist (IL-1RA) after repeated exposure. After repeated exposure, CCL5 and the ratio IL-1RA/IL-1alpha both increased compared with single exposure. We conclude that single and repeated irritation induces differential and concerted expression of various inflammatory mediators and markers.

Upregulation of TNF-alpha production by IFN-gamma and LPS in cultured canine keratinocytes: application to monosaccharides effects

Activated keratinocytes play a key role in the cutaneous immune system by their interactions with other cell types through the production of cytokines with both autocrine and paracrine activity. But there is little knowledge about epidermal cytokines in the dog. In this study, cultured canine keratinocytes were stimulated by human recombinant interferon gamma (IFN-gamma) and lipopolysaccharide (LPS) and cell supernatants were tested for tumour necrosis factor alpha (TNF-alpha) concentration using a cell viability assay on a murine cell line. We show that IFN-gamma in combination with LPS significantly increases TNF-alpha secretion by canine keratinocytes. The best stimulations were obtained using confluent cultures and the association of IFN-gamma (400 ng/ml) and LPS (40 microg/ml). The experimental protocol we describe represents a new method for studying keratinocyte activation and its modulation in the dog. We provide an example of application of our method: the study of the effects of different monosaccharides on canine keratinocyte activation.

Analysis of the signal transduction pathway of nickel-induced matrix metalloproteinase-2 expression in the human keratinocytes in vitro: preliminary findings

BACKGROUND

Nickel can induce cellular and nuclear damages responsible for chronic diseases, like allergic contact dermatitis (ACD). We previously showed that matrix metalloproteinase-2 (MMP-2) gene expression was induced by nickel in nontumorigenic human keratinocytes cell line (HaCat).

OBJECTIVE

To investigate the signal transduction pathways involved in gelatinolytic activity induced in HaCat under nickel stimulation.

METHODS

We analyzed the involvement of protein kinase A (PKA), protein kinase C (PKC), tyrosine kinase (PTK), nuclear factor-kB (NF-kB) and activator protein-1 (AP-1) using specific inhibitors (H89, calphostin C, genistein, carpain and curcumin) by electrophoretic mobility shift assay, reverse transcription-polymerase chain reaction and gelatin zymography.

RESULTS

Our results indicate that nickel-induced MMP-2 production was inhibited with PTK, PKC and AP-1 specific inhibitors. Moreover, both PKA and NF-kB were not involved in nickel pathway.

CONCLUSIONS

Using HaCat, we showed that curcumin and genistein can revert nickel-induced MMP-2 upregulation. Whether the use of PTK and AP-1 inhibitors has therapeutic ramifications in the management of ACD remains to be investigated.

Surfactant Sodium Lauryl Sulfate Enhances Skin Vaccination

The skin is a highly accessible organ and thus provides an attractive immune environment for cost-effective, simple, and needle-free delivery of vaccines and immunomodulators. In this study, we pretreated mouse skin with an anionic surfactant, sodium lauryl sulfate (SLS), for a short period of time (10 min) followed by epicutaneous vaccination with hen egg lysozyme antigen. We demonstrated for the first time that pretreatment of skin with surfactant SLS significantly enhances the production of antibody to hen egg lysozyme. Short term pretreatment with SLS disorganized the stratum corneum, extracted partial lamellar lipids, induced the maturation of Langerhans cells, and did not result in epidermis thickening. To reveal the mechanism underlying these changes, particularly at the molecular level, we used a novel proteomic technique using ultrafiltration capillaries and mass spectrometry to identify in vivo proteins/peptides secreted in the SLS-pretreated skin. Two secretory proteins, named as calcium-binding protein S100A9 and thymosin beta4, were identified by this novel technique. These two proteins thus may provide new insight into the enhancing effect of surfactants on skin vaccination.

Decreased mRNA stability as a mechanism of glucocorticoid-mediated inhibition of vascular endothelial growth factor gene expression by cultured keratinocytes

Epidermal keratinocyte-derived overexpression of vascular endothelial growth factor has been functionally linked to increased density of tortuous and hyperpermeable dermal microvessels, representing a characteristic component of cutaneous inflammation. We hypothesized that potent anti-inflammatory properties of synthetic glucocorticoids are attributed in part to their interference with the regulated vascular endothelial growth factor expression by keratinocytes. As vascular endothelial growth factor is markedly upregulated by autocrine transforming growth factor alpha and paracrine hepatocyte growth factor/scatter factor expression, the effect of glucocorticoids on growth-factor-induced vascular endothelial growth factor production by primary and immortalized keratinocytes was examined. Glucocorticoids were shown to suppress vascular endothelial growth factor protein and mRNA expression in a concentration- and time-dependent fashion. In transcriptional activation studies, however, common 5'-regulatory regions of the vascular endothelial growth factor gene failed to confer inhibitory glucocorticoid effects. Instead, glucocorticoids were shown to increase vascular endothelial growth factor mRNA turnover, indicating that post-transcriptional modes of glucocorticoid action are employed to negatively regulate induced vascular endothelial growth factor expression. Together, these studies identify vascular endothelial growth factor upregulation by epidermal keratinocytes as a putative target of glucocorticoid action in cutaneous inflammation. Our data provide strong evidence that mRNA destabilization may represent a mechanism by which glucocorticoids inhibit growth-factor-regulated vascular endothelial growth factor gene expression by keratinocytes.

Epidermal proliferative response induced by sodium dodecyl sulphate varies with environmental humidity

BACKGROUND

Previous studies have suggested that susceptibility of skin to external agents increases in the dry winter season.

OBJECTIVES

To test the hypothesis that environmental humidity affects skin sensitivity to irritants.

METHODS

The epidermal hyperplasia induced by sodium dodecyl sulphate (SDS) under various humidity conditions was evaluated on the skin of hairless mice.

RESULTS

Mice kept under low humidity for 2 days showed more obvious epidermal proliferation 24 h after topical application of SDS than those kept under high or normal humidity for 2 days. In contrast, mice kept under high humidity for 2 weeks showed more obvious epidermal proliferation 24 h after topical application of SDS than those kept under low or normal humidity. The transepidermal water loss was altered significantly in the animals kept under high humidity for 2 weeks, although it was not altered during the first 7 days under either low or high humidity.

CONCLUSIONS

These results suggest that environmental humidity influences the sensitivity of skin to topical application of SDS and that increased sensitivity is not always associated with alteration of the water impermeability of the stratum corneum.

Topically applied lactic acid increases spontaneous secretion of vascular endothelial growth factor by human reconstructed epidermis

BACKGROUND

Alpha-hydroxy acids (AHAs) are widely used for the treatment of hyperkeratotic skin disorders and photodamaged skin.

OBJECTIVES

To investigate the effect of lactic acid (LA) on the secretion of cytokines by keratinocytes (KCs) of human reconstructed epidermis.

METHODS

Creams containing 1.5%, 3% or 5% LA or vehicle controls were topically applied on to human epidermal equivalents (EEs). After 24 h, EEs were analysed for morphology and for the presence of apoptotic cells. Secretion of vascular endothelial growth factor (VEGF), angiogenin (ANG) and interleukin (IL)-8 was measured in the supernatants by enzyme-linked immunosorbent assay.

RESULTS

LA led to a concentration-dependent increase in apoptotic cells as determined by cell morphology and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling. VEGF secretion was increased 2.5- and 2.8-fold (P < 0.05) over vehicle control after treatment with 1.5% and 3% LA, respectively. No significant increase in VEGF secretion was detected with 5% LA. In contrast to VEGF, secretion of ANG was decreased by LA in a concentration-dependent manner (0.5-fold for 5% LA; P < 0.01). No significant changes in IL-8 secretion were found with any of the concentrations tested.

CONCLUSIONS

Our data demonstrate that the topical application of AHAs modulates the secretion of cytokines by KCs. Regulation of KC-derived growth factors and cytokines by AHAs might represent a mechanism contributing to their therapeutic effects in disorders such as photoageing.

A phase II trial of triamcinolone hexacetanide for symptomatic recurrent malignant ascites

Ascites is a common complication of advanced cancer and frequently requires paracentesis to reduce symptoms of pain, anorexia, and dyspnea. For many patients repeat paracenteses are required at short intervals. We prospectively studied 15 patients with recurrent ascites of malignancy to determine if intraperitoneal triamcinolone hexacetonide, a slowly metabolized corticosteroid, produced objective and symptomatic responses. After biochemical, radiological, and symptom assessment and the establishment of the interval between paracenteses, patients underwent large-volume paracentesis followed by intraperitoneal triamcinolone hexacetonide 10 mg/kg. Patients were followed after treatment for assessment of symptoms and physical signs of ascites. Repeat paracentesis was performed when symptomatic ascites recurred. Symptomatic ascites recurred in 13 of 15 patients, but the interval between paracenteses was extended from 9.5 +/- 1.6 days to 17.5 days (P = 0.0086). Symptom questionnaire scores assessing well-being, nausea, abdominal pain, dyspnea, appetite, appearance, and change in abdominal size on a scale from 0 to 6 averaged 3.2 +/- 0.3 at entry and 2.5 +/- 0.2 at the 2-week assessment (P = 0.026). Self-assessed symptoms, feeling of well-being, abdominal distention, and physical appearance improved significantly. The mean serum cortisol decreased from baseline, suggesting that some systemic corticosteroid absorption occurred. Thirteen of 15 patients have died, with a median survival of 42 days. Potential adverse effects included 1 episode each of transient abdominal pain, bacterial peritonitis, and localized herpes zoster infection. In patients with ascites of malignancy, intraperitoneal triamcinolone hexacetonide appears to postpone the requirement for repeat paracentesis and improve symptoms of malignant ascites.

Retinoids downregulate vascular endothelial growth factor/vascular permeability factor production by normal human keratinocytes

Normal human keratinocytes (KC) are a prominent source of vascular endothelial growth factor (VEGF)/vascular permeability factor (VPF), both in vivo and in tissue culture. In this report we have investigated the influence of retinoids, which are used to treat several skin diseases, on VEGF/VPF production by KC. All-trans retinoic acid (RA), 13-cis RA, and all-trans retinol reduced VEGF/VPF secretion by KC in primary cultures by a mean +/- SD of 58 +/- 25%, 46 +/- 21%, and 54 +/- 20%, respectively, compared with control values. Reductions were observed at concentrations as low as 10(-10)M for all-trans RA, a level that is easily reached in vivo during retinoid treatment. The reduction in VEGF/VPF protein by 10(-6)M all-trans RA was paralleled by a strong downregulation of VEGF/VPF mRNA levels. In contrast to normal KC, all-trans RA had no effect on the HaCaT keratinocyte cell line, and it stimulated VEGF/VPF release by the epidermoid carcinoma cell line A431 2-fold. Our data demonstrate that retinoids are potent inhibitors of VEGF/VPF production by normal human KC. Downregulation of VEGF/VPF production in these cells by retinoids may contribute to the therapeutic effects or retinoids in diseases that are accompanied by angioproliferation, such as psoriasis.