Toshio Ohtani

Effects of alpha-hydroxy acids on the human skin of Japanese subjects: The rationale for chemical peeling

Alpha‐hydroxy acid (AHA) agents, such as glycolic acid and lactic acid, have been used as therapeutic agents for more than a quarter of a century. Recently, they have been used as agents to rejuvenate photo‐aged skin. It is believed that these AHA agents induce the epidermis to remodel and accelerate desquamation, thus exerting their therapeutic effects. In this study, we investigated the histological differences in skin treated with glycolic, lactic, citric and acetic acids once daily for 6 weeks. The melanin pigments in the basal layer were less prominent in the glycolic and lactic acid‐treated skin than in the citric and acetic acid‐treated skin. The melanin deposits in the horny layers were equal for all AHA. However, the melanin deposits in the squamous layers were less prominent in the glycolic and lactic acid‐treated skins than in the citric and acetic acid‐treated skins; this was analogous to observations of the basal layers. Collagen I and procollagen I were increased after treatment with glycolic, lactic and citric acid in the upper dermis, but were not increased with acetic acid treatment. However, the staining of the epidermis and dermis for matrix metalloproteinase‐1 (MMP‐1) after treatment was not significantly different among the agents. Our data suggest that longer treatment intervals with glycolic and lactic acid can cause improvements in both the epidermal and dermal components and support the usefulness of AHA for rejuvenating photo‐damaged skin.

Susceptibility of T cell receptor-α chain knock-out mice to ultraviolet B light and fluorouracil: a novel model for drug-induced cutaneous lupus erythematosus

The anticancer agent 5‐fluorouracil (FU) frequently induces cutaneous lupus erythematosus (LE) lesions on sun exposed sites. Based on this observation, we have tried to establish a cutaneous LE model of C57BL/6 J (B6) mice, B6 T cell receptor (TCR)‐α–/– mice and B6 TCR‐δ–/– mice treated with FU and/or ultraviolet B light (UVBL) in order to clarify the role of T cells and the cytokine profile of cutaneous lupus lesions. Cutaneous LE‐like skin lesions could be induced in TCR‐α–/– mice with low FU (0·2 mg) plus UVBL, and in B6 mice treated with a high dose of FU (2·0 mg) plus UVBL. In contrast, low FU plus UVBL induced such skin lesions in TCR‐δ–/– mice at a very low incidence. Specifically, the skin lesions of TCR‐α–/– mice with low FU plus UVBL appeared more rapidly and were more severe than lesions in B6 mice. The former had the common characteristic features of human chronic cutaneous LE such as typical histology, positive IgG at the dermoepidermal junction, low antinuclear antibody and low mortality. Furthermore, a Th1 response was induced in the development of drug‐induced cutaneous LE. FU and UVBL‐induced cutaneous LE‐like eruption is an excellent model for better understanding the pathomechanisms of skin lesion development in LE.

Slow acetylator genotypes as a possible risk factor for infectious mononucleosis-like syndrome induced by salazosulfapyridine.

Summary We report two patients with infectious mononucleosis‐like syndrome induced by salazosulfapyridine (SASP). In both cases, high fever, skin rash, liver dysfunction and atypical lymphocytosis developed 3 weeks after initiating treatment with SASP. SASP is known to be mainly metabolized by N‐acetyltransferase 2 (NAT2), and acetylation phenotypes (rapid, intermediate and slow acetylator) correlate with NAT2* genotypes. In our two patients, we investigated NAT2* genotypes by the polymerase chain reaction–restriction fragment length polymorphism method. We identified NAT2*6/*7 in one patient, and NAT2*6/*5 in the other, suggesting that both were slow acetylator phenotypes. In 20 healthy volunteers we found no slow acetylator genotypes. Genotyping prior to medication may be useful in evaluating patients with a high risk of severe systemic reaction to SASP.

Unique therapeutic effects of the Japanese -Chinese herbal medicine, Sairei-to, on Th1/Th2 cytokines balance of the autoimmunity of MRL/lpr mice

Sairei-to, one of the Japanese-Chinese herbal medicines has been used for the treatment of various diseases, especially collagen disease and edema in nephrotic syndrome. However, the mechanism of the therapeutic effects remains uncertain. Therefore, we investigated the immunological changes of skin, kidney, spleen cells and serum in autoimmune-prone MRL/lpr, MRL/n and C57BL/6J mice treated with Sairei-to. In MRL/lpr mice treated with Sairei-to, the improvement of proteinuria, reduction in the number of hematoxylin bodies in kidney, and reduced serum levels of blood urea nitrogen were observed. These results indicate that Sairei-to can improve or inhibit the progression of lupus nephritis. The proportion of CD19 and the serum levels of IgG1, which is one of the pathogenesis of lupus dermatoses and lupus nephritis, were significantly reduced in Sairei-to-treated MRL/lpr mice. Therefore, it is suspected that the B cell function was suppressed by Sairei-to. In addition, CD4/8 ratio in spleen cells and the degree of lymphoproliferation in MRL/lpr mice also decreased. Interestingly, IL-4 producing spleen cells were increased significantly by ELISPOT assay, and IFN-gamma mRNA expressions were reduced in Sairei-to-treated MRL/lpr mice. Regarding the Th balance, an imbalance towards Th1 predominance may play a significant role in MRL/lpr mice, and the Th1 axis was suppressed and the Th2 axis became predominant in Sairei-to-treated MRL/lpr mice. On the other hand, Th2 cell type immunoglobulins (IgG1) were suppressed. These results suggested that Sairei-to is potential for impairing shifted Th1/Th2 balance and hypergammaglobulinemia resulting in therapeutic effects.

Cyclophosphamide enhances TNF-α-induced apoptotic cell death in murine vascular endothelial cell

Cyclophosphamide (CPA) is one of the therapeutic agents for systemic inflammatory disorders. In murine dermal endothelial cells (F‐2), 4‐hydroxycyclophosphamide (4‐HC), which is active metabolite of CPA, enhanced TNF‐α‐induced DNA fragmentation. In addition, 4‐HC was shown to elevate TNF‐α‐induced caspase‐3 activation. Caspase‐8 activation was identified by the treatment of TNF‐α, whereas 4‐HC was no effect. In contrast, only when treated with 4‐HC, caspase‐9 activation and the increase in the intracellular expression of Bax were detected. These results suggest that CPA may sensitize endothelial cells to TNF‐α‐induced apoptosis through a mitochondria‐dependent pathway and clinically may contribute to the limitation of inflammatory process.

Clinical effects of undershirts coated with borage oil on children with atopic dermatitis: A double-blind, placebo-controlled clinical trial

It has been reported that γ‐linolenic acid contained in borage oil is effective against atopic dermatitis. The clinical effects of undershirts coated with borage oil rich in γ‐linolenic acid on atopic dermatitis were evaluated. Thirty‐two children, aged 1–10 years, were involved in the clinical control study. Sixteen had worn undershirts coated with borage oil everyday for 2 weeks, and 16 had worn non‐coated undershirts as a placebo. Their symptoms were assessed on a 4‐point scale. Those children who had worn undershirts coated with borage oil for 2 weeks showed improvements in their erythema and itch, which were statistically significant. Transepidermal water loss from the back was decreased. In the placebo group, there were no statistically significant differences. The undershirts coated with borage oil were found to be statistically effective, and had no side‐effects on children with mild atopic dermatitis.

Comparison of anti 60 and 52 kDa SS-A/Ro antibodies in the pathogenesis of cutaneous lupus erythematosus

Anti SS-A/Ro antibodies are involved in the pathogenesis of cutaneous lupus erythematosus (CLE) in a part through antibody dependent cellular cytotoxicity (ADCC). However, it is still obscure which and how anti 60 and anti 52 kDa Ro antibodies are involved. To address the issue, we examined both types of anti Ro antibodies of sera from patients with systemic LE (SLE) or discoid LE (LE). The titer of anti 60 kDa antibody in SLE was significantly much higher than that of DLE or control. The positive ratio of DLE showed more higher tendency than control, but it was not statistically significant. The similar tendency was observed in the titer of anti 52 kDa antibody. An association between the anti 60 kDa antibody and the anti 52 kDa antibody was statistically significant in SLE patients. Although the relative index (RI) was statistically significant in DLE, they included many negative sera, which biased the statistics. Both anti 60 kDa antibody and anti 52 kDa antibody could induce significant ADCC of ultraviolet B (UVB) light-irradiated keratinocytes from neonatal foreskins and/or normal adults, in which anti 60 kDa antibody showed higher cytotoxicity than anti 52 kDa antibody. The autologous combination studies (keratinocytes and monospecific anti 60 or anti 52 kDa antibody from patients) suggested anti 60 kDa antibody was more potent to induce ADCC activity than anti 52 kDa antibody. Taken together, it is likely that anti 60 kDa antibody dependent keratinocyte damage plays more significant role in the pathogenesis of SLE skin lesions than anti 52 kDa dependent damage. However, both type antibodies seemed to have little contribution to the pathogenesis of DLE skin lesion.

The effects of vitamin A derivative etretinate on the skin of MRL mice.

MRL/Mp-lpr/lpr (MRL/lpr) mice are characterized by the disorder of apoptosis due to defects in Fas antigens and autoimmune symptoms including spontaneous lupus erythematosus (LE)-like skin lesions. MRL/Mp- +/+ (MRL/n) mice do not carry the defect of lpr mutation nor do they exhibit skin disorders during the first six months of life. Retinoids are known to inhibit the proliferation of skin fibroblasts, collagen synthesis, modulate immune responses, and apoptosis by Fas ligand upregulation in skin fibroblasts. We examined changes in dermal thickness and appearance of skin disorders in five months old MRL/lpr mice by oral treatment with etretinate, a retinoic acid derivative. Etretinate treated MRL/lpr mice did not have skin lesions or dermatopathological characteristics including an increase in cells infiltrating the dermis. The mean dermal thickness of MRL/lpr and MRL/n mice treated with etretinate decreased significantly and apoptotic cells density in the dermis of MRL/lpr mice with etretinate was significantly higher compared with the control group (P, 0.05) although MRL/lpr mice have a defect within the Fas antigen. We assumed that etretinate reduced dermal thickness, and suppressed the appearance of skin lesions by inducting apoptosis and perhaps regulation of cytokine expression.

P-cadherin expression in skin peeled with phenol or trichloroacetic acid (TCA).

P‐cadherin expression patterns were studied in trichloroacetic acid (TCA) or phenol treated skin. The expression was absent or very weak on the basal cell surfaces by day 2. Seven days after peeling, P‐cadherin was clearly distributed in a continuous granular pattern over the cell surface of the entire epidermis of the 40% TCA treated skin, in a weak granular pattern on a few suprabasal cells and basal cells of the phenol treated skin, and very weakly expressed on the lateral surfaces and in the cytoplasm of basal cells of the 60% TCA treated skin. Based on the present results and previous reports, it is likely that there are distinct patterns of P cadherin expression. Furthermore, a specific type of P cadherin expression might be involved in wound healing in general, which could provide new insights into tissue repair mechanisms after chemical peeling.

Recessive dystrophic epidermolysis bullosa : Case of non-Hallopeau-Siemens variant with premature termination codons in both alleles

Dystrophic epidermolysis bullosa (DEB) is caused by mutations in the COL7A1 gene encoding collagen, the major component of anchoring fibrils. Premature termination codon (PTC) mutations in both alleles usually lead to the Hallopeau–Siemens variant that shows the most severe phenotype. We experienced a case of the non‐Hallopeau–Siemens variant (nHS‐RDEB), which had a mild clinical severity although it has PTC mutations in both alleles. Our patient was a compound heterozygote for a nonsense mutation (R669X) in exon 15 and a nonsense mutation (E2857X) in exon 116. But we confirmed the existence of some anchoring fibrils on electron micrograph. This suggested that a PTC close to the 3′ end of COL7A1 does not completely abolish the collagen VII mRNA. We hypothesized that the truncated procollagen VII from the mutant allele with a nonsense mutation (E2857X) in exon 116 included two out of eight cysteines needed for disulfide bond formation, and hence a few functional anchoring fibrils could be formed.