Effects of glyceryl glucoside on AQP3 expression, barrier function and hydration of human skin.

BACKGROUND/AIM: Aquaporins (AQPs) present in the epidermis are essential hydration-regulating elements controlling cellular water and glycerol transport. In this study, the potential of glyceryl glucoside [GG; alpha-D-glucopyranosyl-alpha-(1->2)-glycerol], an enhanced glycerol derivative, to increase the expression of AQP3 in vitro and ex vivo was evaluated. METHODS: In vitro studies with real-time RT-PCR and FACS measurements were performed to test the induction by GG (3% w/v) of AQP3 mRNA and protein in cultured human keratinocytes. GG-containing formulations were applied topically to volunteer subjects and suction blister biopsies were analyzed to assess whether GG (5%) could penetrate the epidermis of intact skin, and subsequently upregulate AQP3 mRNA expression and improve barrier function. RESULTS: AQP3 mRNA and protein levels were significantly increased in cultured human keratinocytes. In the studies on volunteer subjects, GG significantly increased AQP3 mRNA levels in the skin and reduced transepidermal water loss compared with vehicle-controlled areas. CONCLUSION: GG promotes AQP3 mRNA and protein upregulation and improves skin barrier function, and may thus offer an effective treatment option for dehydrated skin.

Keratinocyte-specific onset of serine protease BSSP expression in experimental carcinogenesis.

Malignant transformation of mouse skin by chemical carcinogens and tumor promoters, such as the phorbol ester 12-O-tetradecanoylphorbol-13-acetate, is a multistage process leading to the formation of squamous cell carcinomas. In an effort to identify target genes whose expression is associated with skin tumorigenesis we combined elements of suppression subtractive hybridization with differential screening to isolate genes that are differentially upregulated in mouse skin after short-term treatment with 12-O-tetradecanoylphorbol-13-acetate and that exhibit a high constitutive expression in squamous cell carcinomas. Here, we report the detailed analysis of one of these cDNAs encoding the serine protease BSSP in mouse skin. Phorbol ester application increases BSSP expression in keratinocytes of the epidermis and the hair follicle several-fold starting 4 h post- treatment. Transcriptional activation of BSSP by 12-O-tetradecanoylphorbol-13-acetate was found to be independent of c-Fos expression and resistant to downregulation by glucocorticoids. By monitoring BSSP expression throughout experimental skin carcinogenesis we found strong constitutive expression in hyperplastic epidermis as well as in proliferatively active keratinocytes of benign and malignant skin tumors. These results establish a novel link between expression of an as yet ill-defined serine protease and skin carcinogenesis.

Toxin profile in samples collected in fresh and brackish water in Germany.

The simultaneous detection of cyanotoxins is an important issue in order to prevent intoxications. In the present paper an Ultra Performance liquid Chromatography tandem mass spectrometry UPLC-MS/MS method was developed in order to simultaneously identify and quantify cylindrospermopsin (CYN), several microcystins (MC-LR, MC-RR, MC-YR) and some anatoxin-a (ATX-a) analogues. By using this new method all these toxins can be quickly separate. In addition the amino acid phenylalanine (Phe) can also be separate and therefore misidentifications with ATX-a can be avoided. By using this new method the presence of these toxins was studied in samples collected in several German localizations within the sampling program of the European Project µAqua (Universal microarrays for the evaluation of fresh-water quality based on detection of pathogens and their toxins). In these conditions, several ATX-a analogues, Phe, MC-LR and MC-RR were reported in samples collected.

In situ hybridization and reverse transcription--polymerase chain reaction studies on the expression of the GABA(C) receptor rho1- and rho2-subunit genes in avian and rat brain.

The pharmacological properties of homo-oligomeric channels formed by the GABA type A receptor-like rho1 and rho2 polypeptides are very reminiscent of those of the GABA type C receptors that have been extensively characterized in the retina. Similar receptors have been reported to occur in certain brain regions of a variety of vertebrate species. We have used in situ hybridization to investigate the expression patterns of the rho1- and rho2-polypeptide genes in the brain of the 1-day-old chick (Gallus domesticus) and the adult rat (Rattus norvegicus). Our results show that in the chick both the rho1- and rho2-subunit transcripts are present in the cerebellum, the optic tectum, the epithalamus and the nucleus pretectalis. However, the two messenger RNAs are often found in different populations of cells. Thus, only the rho1-subunit gene is expressed in the deep cerebellar nuclei, the dorsal thalamus, the ectostriatum and the tractus vestibulomesencephalicus, while only the rho2-subunit gene is transcribed in the nucleus habenularis lateralis and the nucleus isthmo-opticus. In contrast, neither of the rho-polypeptide messenger RNAs can be detected by in situ hybridization in the rat central nervous system. Reverse transcription-polymerase chain reaction amplification has been used to confirm the expression of the two rho-subunit genes in the chicken brain. Surprisingly, this highly sensitive technique also revealed transcription of these genes in the rat brain. We conclude that the rho1- and rho2-subunit genes are expressed at a much higher level in the avian brain than in the rat brain and that, at least in birds, subtypes of the GABA(C) receptor exist.