The influence of sun exposure on the DNA methylation status of <Emphasis Type="Italic">MMP9</Emphasis>, <Emphasis Type="Italic">miR-137</Emphasis>, <Emphasis Type="Italic">KRT14</Emphasis> and <Emphasis Type="Italic">KRT19</Emphasis> genes in human skin

Background

Studies have shown that a variety of environmental factors and habits are associated with epigenetic changes. In addition, various genes are also found to respond to UV radiation.

Objectives

The aim of this study was to investigate the sun exposure influence on the DNA methylation profile on the matrix metalloprotease-9 (MMP9), microRNA 137 (miR-137), cytokeratin 14 (KRT14) and 19 (KRT19) genes of skin cells of subjects with no history of skin diseases.

Methods

Skin biopsies (5mm) were obtained using a punch technique on sun-exposed (outer forearm) and sun-protected areas (inner arm) from 30 corpses from the Brazilian Service of Death Investigation. Skin types were ranked according to Fitzpatrick’s criteria. Genomic DNA was extracted and a DNA methylation analysis was performed using Methylation Specific PCR (MSP) or Methylation-Sensitive Restriction Enzymes (MSRE) of sun-exposed and sun-protected skin areas.

Results

No differences were found among the areas (p>0.05; McNemar), with the partially methylated condition found to be a common event in skin for both MMP9 and miR-137 genes and the methylated condition for both KRT14 and KRT19 genes. Additional analysis showed no differences in the methylation status when age, gender and skin type were considered, however, the methylation status of miR-137 gene seems to be genderrelated.

Conclusions

We conclude that sun exposure does not induce changes in the DNA methylation status in MMP9, miR-137, KRT14 and KRT19 genes.

     

Inflammatory peeling skin syndrome caused a novel mutation in <Emphasis Type="Italic">CDSN</Emphasis>

Generalized peeling skin syndrome (PSS) is a rare autosomal recessive dermatosis manifesting with continuous exfoliation of the stratum corneum. The inflammatory (type B) subtype of PSS was recently found to be caused by deleterious mutations in the CDSN gene encoding corneodesmosin, a major component of desmosomal junctions in the uppermost layers of the epidermis. In the present study, we assessed a 10-month-old baby, who presented with generalized superficial peeling of the skin. Using PCR amplification and direct sequencing, we identified the third PSS-associated mutation in CDSN, a homozygous 4 bp duplication in the second exon of the gene (c.164_167dup GCCT; p.Thr57ProfsX6). These data further support the notion that corneodesmosin deficiency impairs cell–cell adhesion in the upper epidermis, paving the way for an abnormal inflammatory response due to epidermal barrier disruption.     

Expression of<Emphasis Type="Italic"> p53</Emphasis>,<Emphasis Type="Italic"> bcl-2</Emphasis> and growth hormone receptor in actinic keratosis,hypertrophic type

According to novel investigations, actinic keratosis (AK) is not a premalignant lesion but is a malignant lesion in the evolution to invasive squamous cell carcinoma (SCC). Thus, we analyzed p53, bcl-2 and growth hormone receptor (GHR) expression in hypertrophic-type AK (HAK) to determine the relative importance of these protooncogenes in the biological behavior of HAK. Expression of p53, bcl-2 and GHR was determined by immunohistochemistry in 33 HAK specimens and surrounding perilesional normal skin (PNS). The relative proportions of immunoreactive cells were determined. Of the 33 HAK specimens, 30 (91%) showed immunopositive staining for p53, 33 (100%) for bcl-2, and 12 (36%) for GHR. Highly positive p53 expression in HAK lesions could indicate that p53 mutation is an early and crucial event in lesion development. The detected pattern of the p53/ bcl-2 ratio in HAK suggests an important role for another gene: the proapoptotic gene bax. Our findings indicate that GHR expression could be a biological marker of progression of HAK to SCC.     

Cosmetic formulations containing <Emphasis Type="Italic">Lithospermum erythrorhizon</Emphasis> root extract show moisturizing effects on human skin

Retention of water in the stratum corneum of skin epidermis plays an important role in regulation of skin function. Loss of water may decline skin appearance gradually and lead to irregular skin disorders. The root extract of Lithospermum erythrorhizon (LES) is known for its various pharmacological activities. However, the potential skin care effect of LES is not clear. The aim of this study was to evaluate the moisturizing efficacy and skin barrier repairing activity of LES. For this study, 30 healthy Asian females (age 20-30) with healthy skin had applied the test emulsions twice daily over a period of 28 days. The skin properties were measured by skin bioengineering techniques. Our preliminary results indicated that LES show moisturizing effect on skin hydration in a time- and dose-dependent pattern, and the maximum increase in skin humidity was 11.77 +/- 1.18% for emulsion LES5.00. Particularly, LES-containing emulsions significantly improve skin barrier function by decreasing the value of transepidermal water loss (TEWL) in a time- and dose-dependent pattern, and the maximum decrease in TEWL value was 7.68 +/- 0.79% for emulsion LES5.00. Taken together, our data demonstrate that LES is more effective in increasing skin humidity and decreasing the TEWL values, indicating the potential skin care effects of LES.     

Searching for experimental models of <Emphasis Type="Italic">Pemphigus vulgaris</Emphasis>

The current knowledge on Pemphigus vulgaris (PV) pathophysiology suggests that blister formation relies on both PV IgG and non-IgG serum factors activity. PV autoimmunity seems to develop against both desmoglein 1/3 and acetylcholine receptors leading to transduction of signals to the cell mediated by phosphorilation events. Serum factors other than IgG also participate to PV acantholysis through apoptotic or cytokine-mediated mechanisms. Apart from the role played by each actor within the acantholysis, however, the current scenario arises important methodological issues. For example, the use of PV IgG or monoclonal anti-Dsg3 antibodies to experimentally reproduce the disease appears inadequate, as it does not take into account the role of non-IgG factors. On the basis of the above observations and those from our laboratories, here we propose that using whole sera from PV patients with active disease represents the most faithful manner to mimic the disease.     

Recurrent mutations in functionally-related <Emphasis Type="Italic">EDA</Emphasis> and <Emphasis Type="Italic">EDAR</Emphasis> genes underlie X-linked isolated hypodontia and autosomal recessive hypohidrotic ectodermal dysplasia

Mutations in three functionally related genes EDA, EDAR and EDARDD have been reported to cause hypohidrotic ectodermal dysplasia (HED), which is characterized by sparse hair, reduced ability to sweat, and hypodontia. In few cases mutations in the EDA gene have been found to result in X-linked recessive isolated hypodontia. In the study, presented here, we have ascertained two large Pakistani families (A and B) with autosomal recessive form of hypohidrotic ectodermal dysplasia and X-linked recessive isolated hypodontia. Genetic mapping showed linkage of family A to EDAR gene on chromosome 2q11-q13 and family B to EDA gene on chromosome Xq12-q13.1. Subsequently, DNA sequencing of the coding regions of EDAR and EDA genes revealed previously described mutations. Sequence analysis identified a four base-pair splice-junction deletion mutation (c.718_721delAAAG) in EDAR gene in family A and a missense mutation (c.T1091C; p.M364T) in EDA gene in family B. Recurrence of mutations in EDAR and EDA genes in unrelated families is evocative of the dispersion of ancestral chromosome in different locality groups through common ancestors.     

Antimelanogenic and antioxidative properties of <Emphasis Type="Italic">Bifidobacterium bifidum</Emphasis>

Various skin hyperpigmentation disorders consist in accumulation and overproduction of melanin. In this report, we investigated the melanogenesis inhibitory and antioxidant effects of Bifidobacterium bifidum culture filtrate. The results revealed that B. bifidum culture filtrate effectively suppresses murine tyrosinase activity and decreases the amount of intracellular melanin in a dose-dependent manner. Additionally, the bacterial culture filtrate-scavenged DPPH and ABTS radicals, and shows potent-reducing power in a dose-dependent pattern. Our results expand the application of B. bifidum culture filtrate in the development and research of skin-whitening ingredients.     

Solvent effects in permeation assessed <Emphasis Type="Italic">in vivo</Emphasis> by skin surface biopsy

Background  

Transdermal drug delivery has become an important means of drug administration. It presents numerous advantages but it is still limited by the small number of drugs with a suitable profile. The use of solvents that affect the skin barrier function is one of the classic strategies of penetration enhancement. Some of these solvents have well characterised actions on the stratum corneum, but the majority are still selected using empirical criteria. The objective of this work was to conduct a systematic study on the ability to affect skin permeation of solvents commonly used in transdermal formulations. An innovative methodology in this area was employed, consisting of the combination of skin surface biopsy with colorimetry.     

<Emphasis Type="Italic">FOXI2</Emphasis>: a possible gene contributing to ectodermal dysplasia

Background

Cardio-facio-cutaneous syndrome (CFC), Noonan syndrome (NS), and Costello syndrome are a group of diseases that belong to the RASopathies. The syndromes share clinical features making diagnosis a challenge.

Objectives

To investigate the phenotype and genotype of a 10-year-old Iraqi girl with overlapping features of CFC, NS, and Costello syndromes, with additional features of ectodermal dysplasia.

Materials & methods

DNA was examined by exome sequencing and protein expression by immunohistochemistry.

Results

Exome sequencing identified a mutation in the SOS1 gene and a de novo deletion in the FOXI2 gene whichwas neither present in the international databases, nor in 400 chromosomes from the same population. Based on immunohistochemical staining, FOXI2was identified in the basal cell layer of the skin and overlapped with the expression of P63, a major player in ectodermal dysplasia.

Conclusion

We therefore suggest screening for FOXI2 mutation in the setting of ectodermal features that are not associated with genes known to contribute to ectodermal dysplasia.

     

Incidental detection of <Emphasis Type="Italic">S. pyogenes</Emphasis>-DNA in psoriatic skin by PCR

Psoriasis vulgaris is a T cell-mediated autoimmune skin disease. First disease onset and disease worsening are often triggered by tonsillar infection with Streptococcus pyogenes. Here we demonstrate the incidental detection of S. pyogenes DNA in samples of different biological origin from patients with chronic plaque-type psoriasis by PCR. These findings may support the model of molecular mimicry in psoriasis pathogenesis.     

Antifungal susceptibility testing of <Emphasis Type="Italic">Trichophyton rubrum</Emphasis> by E-test

Trichophyton rubrum isolates were used in susceptibility testing for azoles by E-test. Voriconazole was the most and fluconazole was the less-active drug. Our results are in agreement with susceptibility data observed by researchers that used others’ methodologies. E-test seems to be a reliable methodology to susceptibility-testing for T. rubrum.     

Exogenous <Emphasis Type="Italic">N</Emphasis>-acetylglucosamine increases hyaluronan production in cultured human dermal fibroblasts

Application of hyaluronan (HA) containing cosmetic products to the skin is reported to moisturize and restore elasticity thereby achieving an antiwrinkle effect. In the skin, HA can be synthesized by dermal fibroblasts and N-acetylglucosamine (NAG) is a precursor for HA biosynthesis in the body. To study the effects of exogenous NAG on HA production in human dermal fibroblasts, HA production and HA-synthesizing enzymes 1, 2 and 3 mRNA expression in cultured human dermal fibroblasts were measured by ELISA and RT-PCR, respectively. The results showed that NAG promoted HA production while had no effect on the expression of HA-synthesizing enzymes 1, 2 and 3 mRNA in human dermal fibroblasts.     

<Emphasis Type="Italic">N</Emphasis>-Linked neutral oligosaccharides in the stratum corneum of normal and ichthyotic skin

N-Glycan oligosaccharides are thought to play multiple, important roles in a variety of biological events. However, N-glycan profiles in the stratum corneum of human skin have not yet been studied in detail. To clarify the N-glycan profiles in the stratum corneum of normal and ichthyotic epidermis, N-glycan profiles were studied by high-performance liquid chromatography using normal human epidermal samples and scales from hyperkeratotic skin of ichthyosis patients. Chromatograms of patient scale samples showed unique alterations in three peaks eluted at 15.8, 18.8 and 26.9 min. The N-glycan profiles were significantly altered in ichthyotic hyperkeratotic skin compared with normal non-hyperkeratotic controls. These findings indicate the reduction of N-acetylglucosaminyltransferase II and fucosyltransferase 8 activities. Alteration of N-glycan structures in hyperkeratotic skin suggests the biological role of N-glycans in keratinization.