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.

     

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.     

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.     

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.     

A stimulatory effect of <Emphasis Type="Italic">Cassia occidentalis</Emphasis> on melanoblast differentiation and migration

In vitiligo, the active melanocytes in the epidermis are totally missing, whereas melanoblast cells in the outer root sheath of hair follicles are not affected. In an attempt to find potent repigmenting agents for vitiligo therapy, pod extracts of Cassia occidentalis was found to be effective in inducing differentiation and migration of mouse melanoblast cell line. Methanolic extract redissolved in DMSO at 12.5 μg/ml was found to cause 3.5- to 3.8-fold melanin induction in melb-a melanoblast cells after 4 days in treatment medium. In addition it induced the tyrosinase activity and altered melb-a cell morphology. Transwell migration assay showed the potential of this herbal candidate to induce direct migration of treated cells. To the best of our knowledge, this is the first report investigating the effect of Cassia occidentalis on the differentiation and migration of melanoblast cells. The findings of present study are significant in designing preclinical and clinical studies on the efficacy of C. occidentalis as a stimulant for skin repigmentation in vitiligo.     

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.     

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.     

<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.

     

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.     

<Emphasis Type="Italic">Cucumis sativus</Emphasis> fruit-potential antioxidant,anti-hyaluronidase,and anti-elastase agent

The aim of this study was to screen the antioxidant, anti-hyaluronidase, and anti-elastase activity of the lyophilized juice of Cucumis sativus fruit (CSLJ). The CSLJ was subjected to DPPH and superoxide radical scavenging assay in reference to butylated hydroxytoluene. The hyaluronidase and elastase inhibitory assay was performed in reference to oleanolic acid. Furthermore, the activities have been rationalized with HPLC analysis of the CSLJ with standard reference compound of ascorbic acid. The CSLJ exhibited DPPH-free radical and superoxide radical scavenging activity, IC₅₀ at a concentration of 14.73 ± 1.42 and 35.29 ± 1.30 μg/mL, respectively. The CSLJ also showed strong anti-hyaluronidase (^c P < 0.001) and anti-elastase (^c P < 0.001) activity, IC₅₀ at a concentration of 20.98 ± 1.78 and 6.14 ± 1.74 μg/mL, respectively. The HPLC ‘chromatogram’ of standard and CSLJ showed specific peak at retention time 2.905 and 3.066 min, respectively. Content of ascorbic acid was calculated with respect to the standard compound and it was found to be 3.5 ± 0.23% w/w. CSLJ is the rich source of ascorbic acid and this study thereby rationalizes the use of C. sativus as potential anti-wrinkle agent in cosmetic products.     

A novel mutation in <Emphasis Type="Italic">RASA1</Emphasis> causes capillary malformation and limb enlargement

Capillary malformations are common vascular malformations. Several syndromes have been described in which CMs are present in association with limb enlargement, among these are Klippel-Trenaunay syndrome (KTS) and Parkes Weber syndrome (PWS). Mutations in the RASA1 gene have been shown to underlie the capillary malformation-arterio-venous malformation (CM-AVM) syndrome, sometimes presenting with PWS. We identified a family comprising a patient with CMs and limb enlargement and a number of family members with CM/CM-AVM. A novel mutation in RASA1 was found to underlie the disease in this case. The present results illustrate the extensive degree of phenotypic heterogeneity associated with deleterious mutations in RASA1.