Modulation of Ku70/80, clusterin/ApoJ isoforms and Bax expression in indocyanine-green-mediated photo-oxidative cell damage

PURPOSE: In order to characterize the biological effects and molecular mechanism underlying indocyanine-green (ICG)-mediated photo-oxidative cell damage, human cultured retinal pigmented epithelium (RPE) cells preloaded with ICG were exposed to 810-nm laser irradiation. Cell viability and death induction were examined, as well as the modulation of proteins involved in cell death and DNA repair. METHODS: ARPE-19 cells preloaded with 100 microM ICG were irradiated using continuous and micropulsed 810-nm laser for the dye photoactivation, and cell viability and apoptosis were evaluated. The expression and subcellular localization of Bax, Ku70, Ku80 and clusterin/ApoJ were analyzed by immunocytochemistry and Western blot. RESULTS: ICG photoactivation induced apoptosis in RPE cells. The micropulsed laser irradiation induced a higher percentage of cell killing as compared to continuous wave. Cell killing was inhibited by sodium azide, suggesting the involvement of reactive oxygen species in the laser-induced cell damage. Bax was strongly induced after 4 and up to 24 h of treatment. The nuclear proapoptotic isoform of clusterin/ApoJ was selectively upregulated after 24 h of treatment. The DNA repair machinery was upregulated after 4 and up to 24 h. CONCLUSION: These data elucidate some molecular mechanisms involved in cell death induced by ICG photosensitization. The increase and relocalization of Bax into the mitochondria and the upregulation and translocation of the proapoptotic isoform of clusterin/ApoJ in the nucleus demonstrated the involvement of these proteins in the photo-oxidative cell death pathway. These data point out new molecular targets and suggest potential applications in the therapy of the retinal diseases that could benefit by selective RPE treatment.     

Human melanocytes grown in epidermal equivalents transfer their melanin to follicular outer root sheath keratinocytes

Abstract Because outer root sheath (ORS) cells are valuable substitutes for interfollicular epidermal keratinocytes, we wanted to determine whether epidermal equivalents generated from ORS cells and containing cultured melanocytes can serve as an in vitro model for skin pigmentation. In such epidermal equivalents prepared with ORS cells and melanocytes from donors of phototypes II, III and VI, a stratified epithelium resembling normal epidermis developed within 14 days, as documented by histological, ultrastructural (e.g. basement membrane-like structure, keratohyalin granules, keratinosomes) and immunohistochemical (e.g. keratins, integrins, gp80, involucrin, filaggrin) criteria. The melanocytes were localized in the basal layer and accounted for 10% of the total cell number. Heavily pigmented melanocytes from black donors contained regular melanosomes in all stages of maturation, whereas melanocytes derived from white donors contained predominantly melanosomes of stages I and II. Melanosome-laden dendrites were readily detected extending from the heavily pigmented melanocytes, while they were less conspicuous in melanocytes from white donors. The extent of melanosome transfer was independent of the racial origin of the ORS cells. Melanosomes could also be transferred “through racial barriers”. Melanosomes, mainly of stages III and IV, were detected in the ORS cells, being distributed either as single or compound melanosomes, again irrespective of the racial origin of the ORS cells. In conclusion, pigmented epidermal equivalents generated from ORS cells offer practical advantages over other in vitro pigmentation models: (1) the ORS cells are easily and repeatedly available from any donor regardless of age; (2) primary cultures of ORS cells are free of contaminating melanocytes, a bias if using interfollicular epidermal keratinocytes; (3) a high degree of epidermal differentiation is maintained for 3 weeks in fully defined medium, enabling labelling and stimulation experiments to be performed and compounds interfering with melanin pigmentation to be tested. Received: 3 April 1998 / Received after revision: 7 December 1998 / Accepted: 11 December 1998     

Peroral nickel provocation in nondyshidrosiform and dyshidrosiform nickel eczema

The flare-up of pompholyx-type nickel eczema induced by oral nickel challenge has been dealt with in several publications. To compare the reactivity of non-pompholyx and pompholyx-type nickel eczema, we challenged three groups of female volunteers (7 with non-pompholyx-type and 12 with pompholyx-type nickel eczema plus 10 control subjects without nickel allergy) with an oral dose of 2.5 mg nickel. By patch testing we additionally determined the degree of cutaneous nickel sensitivity using a series of nickel sulfate dilutions (5.0-0.00001%) and an possible cobalt allergy using 1% cobalt chloride. In 8 of the 19 patients with nickel allergy, the oral nickel challenge was positive (rash, flare-up at sites of healed eczema and former nickel patch tests, and worsening of preexisting eczema; acute pompholyx lesions only in patients with pompholyx-type eczema). The positive results showed the same frequency in non-pompholyx eczema (43%) as in the pompholyx type (42%). Moreover, no substantial difference was found in the degree of cutaneous nickel sensitivity between the two groups of eczema, and there was no correlation between these results and the outcome of the oral nickel challenge. An additional cobalt allergy was recorded significantly more often in pompholyx-type eczema (P = 0.048), yet there was no influence on the oral nickel challenge. The laboratory parameters examined (differential white cell count and total IgE) did not differ in either of the two eczema groups and did not change substantially during nickel challenge reactions.     

High sensitization rate to emulsifiers in patients with chronic leg ulcers

Emulsifiers are common constituents of most topical preparations. To study the sensitization rate in a population with frequent use of these agents, we selected 47 patients with chronic or recurrent (> 1 year) inflammatory skin disease (leg ulcers, contact dermatitis, atopic dermatitis, psoriasis) for patch testing with the following emulsifiers: Tween 40 (polyoxyethylene sorbitan monopalmitate), Tween 80 (polyoxyethylene sorbitan monooleate), Span 60 (sorbitan monostearate), Span 80 (sorbitan monooelate), Ariacel 83 (sorbitan sesquioleate), Atlas G 2162 (polyoxyethylene oxypropylene stearate), Atlas G 1441 (polyoxyethylene sorbitol lanolin derivative), triethanolamine, Lanette O (cetylstearyl alcohol), Lanette N. 12 patients had at least 1 positive reaction (25.5%) at 3 or 4 days. Among them, 10 had leg ulcers (43.4% of the leg ulcer group), and 2 had contact dermatitis (13.3% of the contact dermatitis group). No positive reaction was observed in the other patients. When the patients were tested with their own topical preparations or wound dressings, 6 of them, all with leg ulcers, had positive reactions. These results show a surprisingly high prevalence of sensitization to emulsifiers in patients with chronic leg ulcers, in contrast to patients with other inflammatory skin diseases.     

Female genital schistosomiasis as an evidence of a neglected cause for reproductive ill-health: a retrospective histopathological study from Tanzania

Background  

Schistosomiasis affects the reproductive health of women. Described sequelae are ectopic pregnancy, infertility, abortion, and cervical lesions and symptoms mimicking cervical cancer and STIs. There are indications that cervical schistosomiasis lesions could become co-factors for viral infection such as HIV and HPV.