Differential effects of graphene materials on the metabolism and function of human skin cells

Most of our knowledge about the process of penetration of skin, by cercariae of Schistosoma mansoni, has been gained from studies carried out in vivo with laboratory animals. Human skin is significantly different from that of other animals but there are obvious practical difficulties in directly studying attachment and penetration with human skin. Techniques have been developed which enable a 3-dimensional ‘skin equivalent’ to be grown in tissue culture, made from different types of human skin cells. The aim of the present study was to investigate cercarial interactions with confluent cultures of the individual skin cell types that make up normal human skin and which will be used to construct a multi-component model. Cercariae behaved differently towards the various cell types tested. They responded least to monolayers of endothelial cells and most to primary keratinocytes, derived from human foreskin and differentiated at an air/liquid interface. This study demonstrates, therefore, that cercariae are capable of distinguishing between different types of skin cells and they preferentially attach to differentiated cells which form the epidermis.

Download Full-text

Differential expression of selenoproteins by human skin cells and protection by selenium from UVB-radiation-induced cell death

Biochemical Journal ◽

10.1042/bj3320231 ◽

1998 ◽

Vol 332 (1) ◽

pp. 231-236 ◽

Cited By ~ 70

Author(s):

Teresa S. RAFFERTY ◽

Roderick C. McKENZIE ◽

John A. A. HUNTER ◽

A. Forbes HOWIE ◽

John R. ARTHUR ◽

...

Keyword(s):

Cell Death ◽

Human Skin ◽

Sodium Selenite ◽

Human Fibroblasts ◽

Human Keratinocytes ◽

Uvb Radiation ◽

Skin Damage ◽

Skin Cells ◽

Radiation Induced ◽

Human Skin Cells

The generation of reactive oxygen species has been implicated as part of the mechanism responsible for UVB-radiation-induced skin damage. In mice, evidence suggests that increased dietary selenium intake may protect skin from many of the harmful effects of UVB radiation. We sought to determine the selenoprotein profile of cultured human skin cells and whether selenium supplementation could protect keratinocytes and melanocytes from the lethal effects of UVB radiation. Labelling experiments using [75Se]selenite showed qualitative and quantitative differences in selenoprotein expression by human fibroblasts, keratinocytes and melanocytes. This was most noticeable for thioredoxin reductase (60 kDa) and phospholipid glutathione peroxidase (21 kDa); these proteins were identified by Western blotting. Despite these differences, we found that a 24 h preincubation with sodium selenite or selenomethionine protected both cultured human keratinocytes and melanocytes from UVB-induced cell death. With primary keratinocytes, the greatest reduction in cell death was found with 10 nM sodium selenite (79% cell death reduced to 21.7%; P< 0.01) and with 50 nM selenomethionine (79% cell death reduced to 13.2%; P< 0.01). Protection could be obtained with concentrations as low as 1 nM with sodium selenite and 10 nM with selenomethionine. When selenium was added after UVB radiation, little protection could be achieved, with cell death only being reduced from 88.5% to about 50% with both compounds. In all of the experiments sodium selenite was more potent than selenomethionine at providing protection from UVB radiation.

Download Full-text