The α-melanocyte stimulating hormone-related tripeptide K(D)PT stimulates human hair follicle pigmentation in situ under proinflammatory conditions

Background  α-Melanocyte stimulating hormone (α-MSH) is a well-tolerated immunomodulator with cytoprotective and anti-inflammatory effects that is known to stimulate melanogenesis and proliferation of follicular melanocytes. As human hair follicles (HFs) locally synthesize α-MSH, pharmacologically more easily handled α-MSH-related tripeptides, such as K(D)PT, may imitate this endogenous regulation, and may show a favourable side-effect profile on clinical use.
Objectives  To investigate the effect of the synthetic, α-MSH-related peptide K(D)PT [which is identical to interleukin (IL)-1β_193–195] on melanogenesis in human anagen HFs, under normal and proinflammatory growth conditions.
Methods  Normal human anagen VI scalp HFs were microdissected and organ cultured with different concentrations of K(D)PT with or without coadministration of a proinflammatory, catagen-inducing stimulus, interferon (INF)-γ. Masson–Fontana histochemistry and NKI/beteb immunohistochemistry were employed to assess changes in the degree of human HF pigmentation and melanocyte dendricity.
Results  As confirmed by quantitative (immuno-)histomorphometry, compared with controls, K(D)PT alone did not affect human HF pigmentation in organ culture. However, in the presence of a strong, prototypic proinflammatory stimulus (IFN-γ), K(D)PT significantly stimulated HF melanin content and melanocyte dendrite formation in situ .
Conclusions  The IL-1β- and α-MSH-related tripeptide, K(D)PT, displays interesting hair pigmentation-stimulatory activities under proinflammatory conditions. These might become exploitable for innovative antigreying strategies, notably in postinflammatory poliosis (regrowth of white hair, e.g. during recovery from alopecia areata), where no effective clinical therapy is yet available.     

Polymorphisms in the interleukin-1 gene influence the stratum corneum interleukin-1 alpha concentration in uninvolved skin of patients with chronic irritant contact dermatitis

Background:  Interleukin (IL)-1α and its receptor antagonist IL-1ra play a role in skin inflammation. Several polymorphisms in the IL1 gene cluster, coding for IL-1α, IL-1ra, and IL-1β, influence their protein expression. Within this cluster, strong linkage disequilibrium has been shown.
Objective:  We studied the association between the polymorphisms IL1A -889 (C→T) and IL1B -31 (T→C) and the concentration of IL-1α and IL-1ra in the stratum corneum (SC).
Method:  In 124 patients with chronic irritant contact dermatitis, we genotyped the IL1A -889 and IL1B -31 polymorphisms and determined the amount of IL-1α and IL-1ra on tape strips obtained from uninvolved skin of the volar forearm.
Results:  The SC IL-1α concentration was 23% and 47% lower in subjects with IL1A -889 C/T genotype and T/T genotype, respectively, compared with wild-type genotype. In subjects with IL1B -31 C/C genotype, the IL-1α concentration was 51% lower compared with C/T and T/T genotypes. The ratio IL-1ra/IL-1α increased twofold in IL1A -889 C/T genotype and threefold in T/T genotype compared with wild type.
Conclusions:  We have shown a clear effect of IL1 genotype on protein expression in the SC. This altered expression may be responsible for the interindividual differences in the inflammatory response of the skin.     

Clinical relevance of serum levels of matrix metallopeptidase-2, and tissue inhibitor of metalloproteinase-1 and -2 in patients with malignant melanoma

The interaction and/or balance between matrix metallopeptidase (MMP)-2 and tissue inhibitor of metalloproteinase (TIMP)-2 in vivo may play important roles in the process of tumor growth, invasion and metastasis of malignant melanoma. In this study, we investigated the serum levels and immunohistochemical expression of MMP-2, TIMP-1 and TIMP-2 in patients with melanoma and analyzed the correlation with clinicopathological parameters. The level of serum MMP-2 in patients was significantly higher than that of the control. Moreover, the level of MMP-2 was significantly higher than that of the control in patients who were: (i) female; (ii) pT1 and pT4; (iii) with and without lymph node (LN) metastasis; (iv) in stage I and stage IV; (v) with and without recurrence; and (v) alive and dead. The level of serum TIMP-1 in patients with melanoma was significantly higher than that of the control. Among melanoma patients, the level of TIMP-1 with pT4 was significantly higher for patients who were: (i) pT1 and pT3; (ii) with LN metastasis (vs those without); (iii) in stage IV (vs those in stages I, II and III); and (iv) dead (vs those alive). The level of serum TIMP-2 in patients with melanoma was not different from the control. However, the level of TIMP-2 in patients with pT4 was significantly higher than for patients who were: (i) pT1, pT3 and control; (ii) with LN metastasis (vs those without metastasis and control); (iii) with stage IV (vs those in stages I and II and control); (iv) in recurrence (vs control); and (v) dead (vs those alive and control). These results suggest that increased serum levels of TIMP-1 and TIMP-2 reflected the extent of metastatic melanoma lesions, and that serum levels of TIMP-1 may be a new useful marker for melanoma progression.     

Sensitizing capacity of some trimers in p-tert-butylphenol-formaldehyde resin

Contact allergy to p-tert-butylphenol formaldehyde resin (PTBP-F-R) is not rare. This resin consists of a large number of substances, most of which are still unknown. For diagnostic and preventive reasons the chemical identity of the sensitizers should be known, as well as their sensitizing capacities, cross-reaction patterns and presence in the environment. The aims of this study were to investigate the sensitizing capacities and potential cross-reacting patterns for 4-tert-butyl- 2,6-bis-(5-tert-butyl-2-hydroxy-3-hydroxymethyl-benzyloxymethyl)-phenol (XIII), 4-tert-butyl-2- (5 - tert - butyl - 2 - hydroxy-benzyloxymethyl) - 6 - (5 - tert - butyl - 2 - hydroxy - 3 - hydroxymethyl-benzyloxy methyl)-phenol (XIVa) and 7,15,23-tri-tert-butyl-25,26,27-trihydroxy-2,3,10,11,18,19-hexahomo-3,11,19-trioxacalix(3)arene (XVIII) by the guinea pig maximization test. 4-tert-Butyl-2,6-bis-hydroxymethyl-phenol, 4-tert-butylbenzene-1,2-diol, 4-tert-butyl-2-hydroxymethyl-phenol, 4-tert-butyl-phenol, 4-tert-butyl-2-(5-tert-butyl-2-hydroxy-3-hydroxymethyl-benzyloxymethyl)-6-hydroxymethyl-phenol, 4-tert-butyl-2-[5-tert-butyl-3-(5-tert-butyl-2-hydroxy-3-hydroxymethyl-benzyloxymethyl) - 2 -hydroxy-benzyloxymethyl] - 6 - (5 - tert-butyl- 2 -hydroxy- 3 -hydroxymethyl-benzyloxymethyl)- phenol and were used as potential cross-reacting substances. In this study it is strongly indicated that the linear trimer XIII has a sensitizing capacity in the guinea pig which was significant when compared to the controls (p = 0.024). No cross-reactions were detected in animals induced with the linear trimer XIII. The linear trimer XIVa and the cyclic trimer XVIII failed to induce sensitization.     

Topical D-vitamins: multiparametric comparison of the irritant potential of calcipotriol, tacalcitol and calcitriol in a hairless guinea pig model

The irritant potential of calcipotriol. 1α.24-diliydroxy vitamin D₃, (tacalcitol) and 1α, 25-dihyd rosy-vitamin- D₃ (calcitriol) was compared in a hairless guinea pig model. Randomized, occlusive patch testing for 2 days was used. Each group of X animals was tested simultaneously with the 3 substances and a placebo vehicle. 3 dose levels i.e. 500 μg/ml, 50 μg/ml and 5 μg/ml were used, Test sites were evaluated at day 2 (2 h after removal of the patches) and again at day 3. Evaluation was blinded and based on a multiple parameter assessment of skin irritancy. comparing clinical scoring. skin perfusion using high resolution laser Doppler image scanning, skin colour (a*, Minolta ChromaMeter) and skin thickening (20 MHz ultrasound) indicating oedema. Skin biopsies were taken for histological preparation and assessment of epidermal hyperplasia. No difference was observed between the irritant potential of calcipotriol, tacalcitol and calcitriol bused on clinical scoring as well as objective non-invasive measuring techniques. All 3 substances showed a dose-dependent and equal increase in clinical irritation score. cutaneous blood flow, skin colour and epidermal hyperplasia. The cutaneous inflammatory reaction was dominated by vasodilation and increased cutaneous perfusion. Oedema formation was only seen ill the highest dosages tested. Skin barrier damage was not induced as TEWL remained unaffected. The hairless guinea pig appears a valid model to test irritancy of topical D-vitamins since the same profile of irritancy was previously established in humans for 2 of the compounds tested. calcitriol and calcipotriol.     

Molecular determination of laminin-5 degradation: a biomarker for mustard gas exposure diagnosis and its mechanism of action

Abstract:  Laminin-5, a heterotrimer of laminin α3, β3 and γ2 subunits, is a component of epithelial cell basement membranes. Laminin-5 functions as a ligand of the α3β1 and α6β4 integrins to regulate cell adhesion, migration and morphogenesis. In the skin, laminin-5 facilitates the assembly of basement membranes; thus it is essential for a stable attachment of the epidermis to the dermis and recovery of damaged skin. Sulphur mustard (SM), also known as mustard gas, is a vesicant that has been employed as a chemical weapon in various conflicts during the twentieth century. Skin exposure to SM results in fluid-filled blisters; proposed mechanisms are inflammation, protease stimulation, basal cell death and separation of the epidermis from the dermis apparently because of the degradation of attachment proteins like laminin-5. Therefore, we investigated the effects of SM exposure on the degradation of laminin-5 and its three subunits, α3, β3 and γ2 by exposing normal human epidermal keratinocytes (NHEK) to SM (0–300 μ m , 1–24 h). We found that SM degraded laminin-5 and its two subunits β3 and γ2, but not α3. Preincubation of cells with a serine protease inhibitor (PMSF), or a metalloprotease inhibitor (1,10-phenanthroline) prior to SM exposure partially prevented SM-induced degradation of laminin-5 subunits, β3 and γ2. Specificity studies showed that the degradation of laminin-5 γ2 was due to a bifunctional mustard compound such as SM, but not due to the other alkylating agents tested. Our results support that laminin-5 degradation is an important mechanism of SM injury as well as a useful biomarker of SM exposure. The knowledge of the mechanisms of laminin-5 degradation in SM-exposed NHEK has potential application in developing cutaneous therapeutics against SM.     

High viral load of human wart-associated papillomaviruses (PV) but not β-PV in cutaneous warts independent of immunosuppression

Background  A broad spectrum of human papillomaviruses (HPV) has been detected in warts from immunocompetent patients and a much more diverse range from immunosuppressed organ transplant recipients (OTR).
Objectives  To determine the HPV types in warts from OTR, we assessed present infections of mucosal (α-PV), wart-associated (α-, μ- and ν-PV) and cutaneous HPV types (β-/γ-PV) in immunocompetent patients and OTR.
Patients/methods  Forty-one warts from 29 immunocompetent patients (non-OTR) and 53 warts from 33 OTR were analysed for DNA of human α-, β-, γ-, μ- and ν-PV. For frequent types viral load was determined by quantitative real-time PCR.
Results  Compared with non-OTR prevalence of cutaneous HPV (79% vs. 49%, P  <   0·01) and the number of multiple infections (62% vs. 17%, P  <   0·0001) were significantly increased. The mean viral load of the wart-associated HPV was more than 10⁵-fold higher compared with human β-PV in both cohorts.
Conclusions  The high load of wart-associated HPV suggests an active role of these viruses rather than cutaneous types in warts independent of immunosuppression; however, the substantial fraction of warts with low HPV genome copies remains to be explained.     

Transient re-emergence of oil of turpentine allergy in the pottery industry

Allergy to oil Of turpentine has diminished largely due to the use of cheaper substitutes in many occupations. However, 2 particular areas still reliant on real oil of turpentine are those of the perfume industry and ceramic decoration. We report 24 cases of hand dermal it is in pottery workers involved in ceramic decoration, paintresses, liners, gilders, enamellers and a line china painter. seen in a 6-month period following a change from Portuguese to Indonesian turpentine, of whom 14 were sensitive to Indonesian turpentine. 8 to α-pinene. 4 to Δ-3-carene and 2 positive to turpentine peroxides, Previous reports suggest that, Δ-3-carene is the main allergen and reports of sensitivity to α-pinene in the absence of sensitivity to Turpentine peroxide, in particular to the hydro-peroxide of. Δ-3-carcne. are few. Turpentine allergy continues Lo be a problem in The pottery industry and is more common than allergy to the heavy metals of the colours used in ceramic decoration. α-pinene, an unusual allergen, appears to he the most common in our area. Reversion to Portuguese turpentine seems to have alleviated the problem.     

Rationale for use and clinical responsiveness of hexafluoro-1,25-dihydroxyvitamin D3 for the treatment of plaque psoriasis: a pilot study

BACKGROUND: Vitamin D analogues are useful in topical therapy of psoriasis. OBJECTIVES: To evaluate the effect of hexafluoro-1,25-dihydroxyvitamin D3 (F6-1,25(OH)2D3) in treatment of psoriasis. METHODS: Fifteen patients with plaque-type psoriasis were enrolled in a single centre double-blind, right/left comparison, placebo-controlled study, and received 0.1 g of petrolatum containing 5 microg of F6-1,25(OH)2D3 or 0.1 g of petrolatum (placebo) for 3 months. After completion of this double-blind study, a subset of these patients (n = 12) applied F6-1,25(OH)2D3 ointment (50 microg g-1 of petrolatum) to all their lesions (total area, 100-5000 cm2, mean area: 3300 m2) for 2 months as a single application at night. RESULTS: The mean severity score in the right/left-sided controlled topical F6-1,25(OH)2D3 (50 microg g-1) therapy group showed a decrease of 85%. In contrast, the mean severity score for the placebo-treated areas showed a decrease of 45% (P < 0.001). In the 12 patients who subsequently applied F6-1,25(OH)2D3 (50 microg g-1) ointment to all of their lesions, 91.6% showed moderate to excellent improvement. The mean Psoriasis Area and Severity Index score decreased by 44.9% (from 33.6 +/- 15 to 18.5 +/- 13). No effect on calcium homeostasis was noted. Adverse events included mild irritation in two patients that resolved during therapy. CONCLUSIONS: Topical F6-1,25(OH)2D3 is a safe and effective once a day treatment for psoriasis.     

Effect of Cuscuta reflexa Roxb on androgen-induced alopecia

Background  Alopecia is a psychologically distressing condition. Androgenetic alopecia, which affects millions of men and women, is an androgen-driven disorder. Here, Cuscuta reflexa Roxb is evaluated for hair growth activity in androgen-induced alopecia.
Methods  Petroleum ether extract of C. reflexa was studied for its hair growth–promoting activity. Alopecia was induced in albino mice by testosterone administration for 20 days. Its inhibition by simultaneous administration of extract was evaluated using follicular density, anagen/telogen ratio, and microscopic observation of skin sections. To investigate the mechanism of observed activity, in vitro experiments were performed to study the effect of extract and its major component on activity of 5α-reductase enzyme.
Results  Petroleum ether extract of C. reflexa exhibited promising hair growth–promoting activity as reflected from follicular density, anagen/telogen ratio, and skin sections. Inhibition of 5α-reductase activity by extract and isolate suggest that the extract reversed androgen-induced alopecia by inhibiting conversion of testosterone to dihydrotestosterone.
Conclusions  The petroleum ether extract of C. reflexa and its isolate is useful in treatment of androgen-induced alopecia by inhibiting the enzyme 5α-reductase.     

Expression of integrin receptors and ICAM-1 on keratinocytes in vivo and in an in vitro reconstructed epidermis: Effect of sodium dodecyl sulphate

Several integrin heterodimers such as 21, 64 and _v5 are expressed on basal keratinocytes of the epidermis. Because overexpression of these integrins as well as induction of the intercellular adhesion molecule-1 (ICAM-1) have been found in inflammatory dermatoses, we sought to determine whether these modulations could be used as markers of skin irritation. In normal epidermis, topical application of 1% sodium dodecyl sulphate (SDS) for 24 h caused an upregulation of 3, 1, 6, 4, _v, 5 and to a lesser extent 2 integrin chains as well as an induction of ICAM-1. To investigate whether these parameters could also be used for evaluation of skin irritancy in vitro, SDS was applied for 24 h to reconstructed epidermis on de-epidermized dermis (RE-DED). In RE-DED, integrin overexpression and aberrant 5 expression was seen under normal in vitro culture conditions and topical application of SDS caused only marginal additional upregulation. We could not detect any ICAM-1 reactivity on either normal or irritated RE-DED. Our results demonstrate that the modulation of integrin and ICAM-1 expression can be used as markers of irritation of the epidermis in vivo, but not in vitro.This work was supported in part by the Bundesministerium für Forschung und Technik, Bonn, Germany (BMFT: 421-4001-01HK9195).Part of this work was presented at The Second Tricontinental Meeting of the JSID, SID and ESDR, Kyoto, Japan, 28–31 October 1993     

Psoriasis and streptococci: the natural selection of psoriasis revisited

We have previously postulated that surviving invasive streptococcal infections may have been a factor in psoriasis becoming a common skin disease in some parts of the world. Many of the candidate genes linked to psoriasis are associated with the acquired or innate immune system, which are also important in host defence to invasive streptococcal infections. High rates of positive streptococcal throat swabs among patients with chronic plaque psoriasis suggest that they are efficient at internalizing/carrying β-haemolytic streptococci. Internalization of streptococci in the throat is dependent upon the transforming growth factor (TGF)-β/fibronectin/α5β1 integrin pathway. The immune cell Th17 and its related cytokine network are important in mucosal defence, being very effective against extracellular microbes but having little effect on intracellular organisms. The TGF-β/fibronectin/α5β1 integrin pathway and the Th17 cell network also appear to be operative in psoriasis, animal models of both TGF-β and α5β1 cutaneous overexpression being associated with characteristic psoriasis lesions. We postulate that some of the genotypic/phenotypic changes in different immunological pathways in psoriasis, including the acquired T-cell response, the innate immune response, the TGF-β/fibronectin/α5β1 integrin pathway and the Th17 cell system, confer protection against mortality during epidemics of invasive streptococcal infections, heightened efficiency in internalizing and allowing carriage of streptococci as well as predisposition to the development of psoriasis.     

Quantitative analysis of α1(I) and α1(III) procollagen mRNA expression in systemic sclerosis skin tissue – an in situ hybridization study

Abstract Human α1(I) and α1(III) procollagen mRNA expression in skin tissue from 15 systemic sclerosis (SSc) patients and from 7 normal control subjects was quantitatively analyzed using in situ hybridization. The grains accumulating in each area, representing procollagen mRNA expression per cell, were counted. To normalize the results from each subject, the number of cells and the number of grains per cell were divided by the area of the skin specimen (in square millimeters). The number of cells per square millimeter expressing α<1(I) and α1(III) procollagen mRNA in SSc skin was significantly elevated compared with normal control skin (both P < 0.01). The number of grains per cell per square millimeter expressing α1(III) procollagen mRNA in SSc skin was also significantly elevated compared with normal control skin (P < 0.01). The relationship between procollagen mRNA expression and the histological findings in SSc was also studied. The numbers of cells and grains per cell per square millimeter expressing α1(I) procollagen mRNA in fibrotic zone SSc skin were significantly elevated compared with normal control skin (both P < 0.01). The numbers of cells and grains per cell per square millimeter expressing α1(III) procollagen mRNA in SSc skin were significantly elevated compared with normal control skin (both P < 0.01) and with border zone SSc skin (number of cells P < 0.01, number of grains P < 0.05). These results indicate an increase in the number of cells showing elevated expression of α1(I) and α1(III) procollagen mRNA, and a close relationship between α1(I) and α1(III) procollagen mRNA expression and the histological findings in SSc. Received: 24 February 1999 / Received after revision: 20 May 1999 / Accepted: 16 August 1999     

An increased ratio of interleukin-1 receptor antagonist to interleukin-1α in inflammatory skin diseases

Abstract: IL-1 receptor antagonist (IL-1ra) is a cytokine that competitively binds the IL-1 receptor to antagonize IL-1 activity without any agonist function. Previous experiments indicated that the ratio of IL-1ra to IL-1α in the normal stratum corneum (SC) was much higher in the sunexposed face than in the sun-protected area, upper arms. It was also reported by another laboratory that IL-1ra is increased in the lesional skin of psoriatic patients. This study was designed to measure the contents of IL-1α and IL-1ra in non-lesional and pathological SC obtained from inflammatory skin diseases including psoriasis and non-psoriatic dermatoses such as atopic dermatitis. The SC materials were obtained with a noninvasive tape-stripping method. Their soluble fractions were prepared and assayed for IL-1α and IL-1ra by enzyme-linked immunosorbent assays. As a result we confirmed the previous findings that the ratio of IL-1ra to IL-1α in the normal SC was much higher in the face than in the sun-protected sites, the trunk as well as extremities. Next, we found that IL-1α contents were significantly reduced in the SC samples obtained from inflammatory skin regardless of whether their IL-1ra contents increased or unchanged. Moreover, we noted that an increased ratio of IL-1ra to IL-1α in the SC was not specific to psoriasis, but was also found in other inflammatory skin diseases including atopic dermatitis. This ratio was found to become lower after successful treatment of these skin lesions with topical glucocorticoids. We conclude from these observations that the increased ratio of IL-1ra to IL-1α in the SC is a non-specific phenomenon that can occur in any inflammatory skin diseases regardless of the inflammatory pattern, probably reflecting a skin regulation process against various kinds of inflammation.     

UVB induces a biphasic response of HIF-1alpha in cultured human keratinocytes

Abstract:  Hypoxia in the skin is important in chronic degenerative dermo-epidermal changes, inflammation, photoageing and carcinogenesis. In these processes, vascular endothelial growth factor (VEGF) plays a crucial role and is known to be affected by ultraviolet radiation (UVR). Hypoxia-inducible factor-1 (HIF-1) closely regulates the expression of VEGF in several experimental settings. We set out to study the impact of acute UVB irradiation on the level of HIF-1 as a major regulator of hypoxia-induced genes. Effects of UVB exposure on HIF-1α expression were investigated in HaCaT cells after a single irradiation by Western blots. Downstream target gene expression was measured by quantitative real-time polymerace chair reaction (PCR). UVB treatment resulted in an initial decrease of the HIF-1α protein level followed by a subsequent prolonged increase. If cells were exposed to additional UVB irradiation, another decrease in HIF-1α was provoked, similar to the original effect. The observed changes followed a strict timeline and were dose-dependent. The role of the PI3K/AKT pathway was examined. No change in the total level of AKT after UVB treatment was seen; however, its phosphorylation level was found to be markedly higher. In accordance with these observations, wortmannin, an inhibitor of PI3-kinase effectively blocked the UVB-induced increase in HIF-1α. In agreement with previous findings, UVB irradiation increased VEGF and haem oxygenase-1 mRNA levels determined by quantitative real-time PCR. It is concluded that changes in HIF-1α expression underlie the alterations in expression of VEGF upon UVB irradiation. Our findings indicate the involvement of PI3K in UVB-mediated HIF-1α upregulation.     

Expression of 25-hydroxyvitamin D3-1alpha-hydroxylase in subcutaneous fat necrosis

Background  The most serious complication of subcutaneous fat necrosis (SCFN), a rare condition of the newborn characterized by indurated purple nodules, is hypercalcaemia. However, the mechanism for this hypercalcaemia remains unclear.
Objectives  To determine whether the hypercalcaemia associated with SCFN involves expression of the vitamin D-activating enzyme 25-hydroxyvitamin D₃-1α-hydroxylase (1α-hydroxylase) in affected tissue.
Methods  Skin biopsies from two male patients with SCFN and hypercalcaemia were taken. The histological specimens were assessed using a polyclonal antibody against 1α-hydroxylase.
Results  Histology in both cases showed strong expression of 1α-hydroxylase protein (brown staining) within the inflammatory infiltrate associated with SCFN. This was consistent with similar experiments in other granulomatous conditions.
Conclusions  Hypercalcaemia in SCFN appears to be due to abundant levels of 1α-hydroxylase in immune infiltrates associated with tissue lesions. This is consistent with previous observations of extrarenal 1α-hydroxylase in skin from other granulomatous conditions such as sarcoidosis and slack skin disease.     

Suprabasal expression of epidermal α2β1 and α3β1 integrins in skin treated with topical retinoic acid

In normal adult human skin, expression of epidermal integrins is confined to keratinocytes in the basal layer. However, suprabasal expression of α2, α3 and β1 integrin subunits is noted in hyperproliferative epidermis in wound repair and psoriasis. In this study, we examined the effect of topical all- trans -retinoic acid (RA), known to induce epidermal hyperplasia, on expression of integrins in human epidermis. Immunostaining of vehicle-treated skin revealed expression of α2, α3 and β1, as well as α6 and β4 integrin subunits entirely on basal keratinocytes. Topical application of RA (0.1%) for 2 weeks resulted in marked suprabasal expression of α2, α3 and β1 integrin subunits, whereas α6 and β4 staining remained on basal keratinocytes. Staining for putative ligands of α2β1 and α3β1 integrins, i.e. type IV collagen, laminin-5 and fibronectin, was not detected in the epidermal layer in RA- or vehicle-treated skin. Treatment of HaCaT keratinocytes in culture with RA (1 μmol/L) enhanced α2 and β1 mRNA abundance. Furthermore, RA slightly up-regulated the expression of α2, α3 and β1 integrin subunits on primary epidermal keratinocytes and HaCaT cells in culture with no effect on cell proliferation. These results provide evidence that RA-elicited epidermal hyperplasia is associated with aberrant suprabasal expression of α2β1 and α3β1 integrins, and that this also involves direct stimulation of keratinocyte integrin expression by RA.     

Effects of 1α,25-dihydroxy-vitamin D3 and calcipotriol on organotypic cultures of outer root sheath cells: a potential model to evaluate antipsoriatic drugs

In the human hair follicle, outer root sheath (ORS) cells constitutively express the hyperproliferation-associated keratins 6, 16 and 17 instead of keratins 1 and 10 found in interfollicular epidermis. In organotypic cultures, ORS cells form a stratified epithelium which in many respects resembles psoriatic skin: it has a hyperplastic tissue architecture and a poorly developed granular layer, and expresses hyperproliferation-associated keratins. Therefore, we studied the effects of the antipsoriatic compounds 1,25-dihydroxy-vitamin D₃ (1,25-(OH)₂-D₃) and its synthetic derivative calcipotriol on cultured ORS cells. In monolayer cultures, 10^–6 M 1,25-(OH)₂-D₃ or calcipotriol completely blocked ORS cell proliferation. This inhibitory effect was substantially reduced at 10^–8 M. Incubation of organotypic ORS cultures with both vitamin D analogues resulted in a marked thinning of the living cell compartment concomitant with a thickening of the horny layer. A reduced expression of differentiation markers such as keratins 10,16 and 17, involucrin and filaggrin paralleled the thinning of the stratum Malpighi. As determined by quantification of BrdU-positive cells, ORS cell proliferation was apparently not affected by the vitamin D analogues, indicating that these compounds mainly operate by accelerating the differentiation pathway within the suprabasal living cell compartment. No alteration in the expression of the 6- and 1-integrin chains was found.     

蓝酱汤治疗尖锐湿疣的疗效研究

目的：评估蓝酱汤治疗尖锐湿疣(CA)及其免疫调节作用。方法：将68例CA患分为常规治疗A组,中西结合疗法B组(加服蓝酱汤);中西结合疗法C组(再加蓝酱汤外洗)。三组病例治疗前及治疗后4周采用双抗体夹心ELISA法检测血清IL—2、IL—12,并跟踪观察半年。结果：常规A组与B组创面愈合时间基本相同,C组愈合时间较短,治疗后B、C二组血清IL—2、IL—12水平升高较明显,复发率较低。结论：蓝酱汤具有抗病毒及免疫调节作用,能降低CA的复发率,且外敷及侵泡外用能有效的促进创面愈合。