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Y Wu,
M S Matsui,
J Z S Chen,
X Jin,
C-M Shu,
G-Y Jin,
G-H Dong, Y-K Wang,
X-H Gao,
H-D Chen,
Y-H Li
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ABSTRACT: Exposure of human skin to ultraviolet radiation (UVR) results in erythema, pigment darkening, skin cancer and photoageing. In addition to conventional organochemical and the physical-mineral type sunscreens (SS), other non-SS protective strategies have been investigated, including antioxidants (AOx) and topical DNA repair enzymes.
To investigate whether AOx could improve the protection provided by a broad-spectrum sunscreen (SS) preparation.
Volunteers were exposed to repetitive solar-simulated (ss)UVR at 1.5 times minimal erythema dose for four consecutive days. Thirty minutes before each exposure and 6, 24 and 48 h after the last exposure, the test materials [vehicle, SS (sun protection factor 25) alone, AOx alone and SS plus AOx] were applied to four different sites. Another two sites received ssUVR only, or SS plus AOx only, and a third site was left untreated (neither ssUVR or product). Erythema and pigmentation were measured using a Mexameter. Biopsy specimens were taken 72 h after the last irradiation. The thickness of the stratum corneum and epidermis were measured by microscopy. Expression of cytokeratins (CKs), matrix metalloproteinases (MMPs) and CD1a-positive Langerhans cells (LCs) analysed by immunohistochemical staining, and relative expression levels were compared between all seven sites.
AOx alone did not reduce erythema. There was a significant reduction in pigmentation, and the product almost completely protected against LC depletion. AOx plus SS gave better protection against pigment formation and CK5/6 induction than SS alone. AOx alone protected against ssUVR-induced hyperproliferation, as shown by epidermal thickness and CK16 biomarkers, and was better than SS alone. Interestingly, although protection against induction of MMP-9, a marker of photoageing, did not reach significance when either SS or AOx were applied separately, there was complete protection against MMP-9 induction when these were combined.
Non-SS materials such as AOx can contribute significantly to sun protection when added to a broad-spectrum SS and applied topically to human skin in vivo.
Clinical and Experimental Dermatology 03/2011; 36(2):178-87. · 1.20 Impact Factor
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ABSTRACT: We report a 62-year-old Chinese woman with a 2-year history of lichen planus presenting with extensive violaceous maculopapules and plaques 1 week after taking an oral preparation of Chinese herbs. The patient developed vesiculobullous skin lesions 7 weeks later. Histopathological examination showed subepidermal blisters and adjacent bandlike lymphocytic infiltration. Direct immunofluorescence revealed linear deposits of IgG and C3 along the basement membrane zone. Indirect immunofluorescence showed IgG antibody deposition along the epidermal side of salt-split human skin. Circulating anti-bullous pemphigoid 180 antibodies were detected by ELISA. Lichen planus pemphigoides (LPP) was diagnosed. To our knowledge, this is the first report of LPP associated with oral Chinese herbs.
Clinical and Experimental Dermatology 09/2008; 34(3):329-32. · 1.20 Impact Factor
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ABSTRACT: Epidermal Langerhans cells (LCs) play an important role in cutaneous immunological reactions. Freshly obtained or intraepidermal LCs are incapable of activating autologous naive T cells. However, when they are cultured for 2-3 days, LCs are able to activate autologous T cells. It has been proposed that haptoglobin (Hp) is the inhibitor that prevents LC functional transformation in the skin. Abundant Hp has been found in the cytoplasm of epidermal LCs. However, the source of Hp in LCs has not been addressed.
To determine the expression of Hp in epidermal cells, and to provide evidence that there is a functional relationship between LCs and keratinocytes (KCs) through Hp.
Normal human epidermal cells and HaCaT cells were used for detection of Hp mRNA by in situ hybridization and reverse transcription-polymerase chain reaction, and Hp protein by immunohistochemical staining, immunofluorescence counterstaining and Western blotting.
Hp mRNA was expressed in normal human KCs and HaCaT cells, but not in normal human epidermal LCs. Hp protein was detected by immunohistochemical staining and immunofluorescence counterstaining in CD1a+ epidermal dendritic cells (LCs), but not in KCs. Hp protein was weakly expressed by HaCaT cells.
Hp mRNA is present in normal human KCs and HaCaT cells, suggesting that they have the potential to synthesize Hp protein. Normal human epidermal LCs are unable to synthesize Hp protein by themselves, although they have abundant Hp protein in their cytoplasm. It is likely that LCs acquire Hp through an exogenous pathway.
British Journal of Dermatology 12/2005; 153(5):894-9. · 3.67 Impact Factor
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ABSTRACT: Evidence is presented that some endogenous Langerhans cells (LCs) may persist indefinitely in skin grafts. This evidence is based on the observation that although 2 weeks after grafting F1 hybrid mice and rats with genetically compatible skin, most of the LCs in the grafts were replaced with those of the host, some LCs of graft origin persisted for as long as the grafts were followed (154 days in mice and 249 days in rats). It has also been demonstrated that the spleen may be as good a source of LCs as the marrow. Thus, 6 weeks after lethally irradiated mice were restored with F1 hybrid spleen cells, most of the LCs in the epidermis of their pinnae were of donor origin. LCs of donor origin also were found in the epidermis of the pinnae of animals that had been inoculated at birth with spleen and lymph node cells (mice) or bone marrow cells (rats). Hence the occurrence of these cells provides another means of confirming that tolerance (chimerism) has been induced.
Journal of Investigative Dermatology 07/1986; 86(6):630-3. · 6.31 Impact Factor
