IMPACT OF BLUE LIGHT EXPOSURE ON PREMATURE SKIN AGEING
587
Presented by: Olivier Doucet
The damaging effect of skin exposed to UV radiation has been extensively studied and since recent years in vitro and in vivo studies have also demonstrated that blue light induced biological effects. Blue light, thank to its relatively high energy and long wavelength, can penetrate the skin, and reach the dermis. Studies have especially shown that blue light induces reactive oxygen species, reduce the intracellular antioxidative defence and impairs the proliferative capacity of cells.
In the present study, we assessed, in vitro, the effect of blue light exposure (415nm) on normal human fibroblasts. Reactive oxygen species (ROS) were quantified with dichlorofluorescin diacetate (DCFH-DA) assay. Expression of genes involved in antioxidant enzymes, extracellular matrix (ECM) and dermal epidermal junction (DEJ) synthesis were studied through RT-PCR. Cell migration was assessed on monolayer fibroblasts, with the use of silicone inserts with a defined cell-free gap.
The results showed that blue light exposure induced the production of intracellular ROS, and down regulated the expression of antioxidant enzymes as catalase and superoxide dismutase. Gene expression of several keys components of extracellular matrix were regulated, as a clear down regulation of several collagens, elastin, fibrillin and a decrease of various TIMP. On the opposite, the expression of MMP1, MMP3, MMP12 were highly up regulated. The dermal epidermal junction was also impacted with the down regulation of collagen IV, collagen VII, nidogen. Blue light exposure also induced a clear slowdown of fibroblasts migration compared to non-exposed cells.
Based on these results, we can conclude that blue light generated ROS which can cause cellular dysfunction, and down regulated the intracellular antioxidant defense of cells. The function of fibroblasts is highly impacted since the synthesis of keys components of the ECM and the DEJ is modified. Their migration is also slowed down, disturbing the normal wound healing process. Blue light exposure impairs the homeostasis of the dermis, which contribute to skin premature ageing.
In the present study, we assessed, in vitro, the effect of blue light exposure (415nm) on normal human fibroblasts. Reactive oxygen species (ROS) were quantified with dichlorofluorescin diacetate (DCFH-DA) assay. Expression of genes involved in antioxidant enzymes, extracellular matrix (ECM) and dermal epidermal junction (DEJ) synthesis were studied through RT-PCR. Cell migration was assessed on monolayer fibroblasts, with the use of silicone inserts with a defined cell-free gap.
The results showed that blue light exposure induced the production of intracellular ROS, and down regulated the expression of antioxidant enzymes as catalase and superoxide dismutase. Gene expression of several keys components of extracellular matrix were regulated, as a clear down regulation of several collagens, elastin, fibrillin and a decrease of various TIMP. On the opposite, the expression of MMP1, MMP3, MMP12 were highly up regulated. The dermal epidermal junction was also impacted with the down regulation of collagen IV, collagen VII, nidogen. Blue light exposure also induced a clear slowdown of fibroblasts migration compared to non-exposed cells.
Based on these results, we can conclude that blue light generated ROS which can cause cellular dysfunction, and down regulated the intracellular antioxidant defense of cells. The function of fibroblasts is highly impacted since the synthesis of keys components of the ECM and the DEJ is modified. Their migration is also slowed down, disturbing the normal wound healing process. Blue light exposure impairs the homeostasis of the dermis, which contribute to skin premature ageing.