Hideo Kanauchi

Susceptibility to UVB light in cultured keratinocytes of cutaneous lupus erythematosus.

In this study, we investigated UVB-light-induced cytotoxicity and the binding of antibodies to extractable nuclear antigens on cultured keratinocytes from patients with cutaneous lupus erythematosus (LE). Keratinocytes from cutaneous LE patients showed a higher susceptibility to single-dose UVB light irradiation compared to keratinocytes from normal controls. The binding of antibodies to U1RNP and Ro/SS-A antigens on cultured keratinocytes was induced by UVB light and more up-regulated when cultured keratinocytes were reacted with autologous sera. Antibody-dependent cellular cytotoxicity (ADCC) was induced when cultured keratinocytes irradiated with UVB light were combined with autologous sera, using peripheral mononuclear cells of normal controls. Immunohistochemical studies of skin biopsy specimens from patients with systemic LE revealed an increased number of epidermal Langerhans cells at the peripheral sites of skin lesions and a relative dominance of infiltrative CD8-positive lymphocytes in the central area of skin lesions. Based on these findings we suggested that ADCC mechanisms were involved in the development of skin lesions, and the distribution of Langerhans cells and infiltrated CD8 cells were responsible for the expansion and persistence of lesions.

Evaluation of the Japanese-Chinese Herbal Medicine, Kampo, for the Treatment of Lupus Dermatoses in Autoimmune Prone MRL/Mp-lpr/lpr Mice

Kampo, a Japanese‐Chinese traditional herbal medicine, has been used for the treatment of various diseases for about 3,000 years in China. Among herbal medicines, Sairei‐to is well known for improving the symptoms of rheumatoid arthritis (RA) and other collagen diseases. However, its immunosuppressive effects on autoimmune cutaneous phenomena are not completely understood. We investigated the effects of Sairei‐to on the development of lupus dermatoses in autoimmune‐prone MRL/Mp‐lpr/lpr (MRL/lpr) mice, an animal model which spontaneously develops skin lesions similar to those seen in human lupus erythematosus. Virgin female MRL/lpr mice at 1 month of age, which were treated orally with Sairei‐to, had reduced amounts of IgG deposition at the dermoepidermal junction, titers of anti‐DNA antibodies and rheumatoid factor, and lymphoproliferation. These results support the use of traditional herbal medicines in patients with human RA and systemic lupus erythematosus.

Coexistence of Pemphigus and Bullous Pemphigoid

Widespread tense blisters developed on a 60‐year‐old Japanese man who had been diagnosed with pemphigus 11 years earlier, because of a history of pruritic erythema and erosions on his face, chest, and back, mild supra‐basal layer blister formation found in a biopsy specimen, and a positive direct immunofluorescence test showing IgG deposition in the intercellular space. The histological findings showed subepidermal blister, and the immunoblot study detected 180kD bullous pemphigoid antigen. Direct immunofluorescence test revealed intercellular staining for IgG, and indirect immunofluorescence tests repeatedly demonstrated the presence of circulating antibodies to the intercellular space. From these observations, this case suggests the coexistence of pemphigus and bullous pemphigoid.

Pathogenesis of Lupus Dermatoses in Autoimmune Mice

The skin of New Zealand, MRL and BXSB mice was immunohistopathologically examined in order to study the appearance of skin immunologublin (Ig) deposition and its correlation with the occurrence of anti-single-stranded (ss) DNA antibodies in sera. Our studies revealed Ig deposition at the dermoepidermal junction (DEJ) in non-lesional skin and a significant age-related correlation between skin Ig deposition and serum anti-ssDNA antibodies. However, immunofluorescent study of autoimmune mice using anti-ultraviolet-irradiated DNA antiserum failed to demonstrate DNA antigens at the DEJ.

Effect of ultraviolet irradiation on the activity of rat skin prostaglandin D synthetase.

The effect of ultraviolet light-B (UVB) irradiation on the activity of prostaglandin (PG) D synthetase was investigated in adult rat skin. Rats were irradiated with 500 mJ/cm2 of UVB, and PGD synthetase activity was determined in 100,000 g supernatant of the homogenate of rat skin in the presence of glutathione (GSH) before and 3, 6, 12, and 24 h after irradiation. The PGD synthetase activity was decreased time dependently, and within 24 h after UVB irradiation it had dropped to 50% of the control level before irradiation. In contrast, the synthesizing activities of PGE2 and PGF2 alpha were unaffected by UVB irradiation. The reduction of PGD synthetase activity after UVB irradiation was much more prominent in the epidermis than in the dermis, which was separated by heat treatment (55 degrees C, 30 sec). Immunohistochemical studies, using anti-(rat spleen PGD synthetase) antibody, revealed that the number of immunopositive cells, which were identified as Langerhans cells, decreased in the basal layer of the epidermis 24 h after UVB irradiation. These results, together with the reduction of ATPase positive cells in the epidermis after UVB irradiation, suggest that the decrease of PGD synthetase activity in rat skin by UVB irradiation is, at least in part, due to the reduced Langerhans cell population in the basal layer of the epidermis.

Histological detection of c-myb and c-myc proto-oncogene expression in infiltrating cells in cutaneous lupus erythematosus-like lesions of MRL/l mice by in situ hybridization☆

A relationship between lymphocytic activation and the overexpression of proto-oncogenes such as c-myb or c-myc has been demonstrated in human autoimmune disease. In autoimmune-prone MRL/l mice, which spontaneously develop lupus erythematosus (LE)-like lesions on the back, increased expression of myb RNA has been found in the lymphoid organs. We detected the overexpression of c-myb and c-myc proto-oncogenes in infiltrating cells in the cutaneous lesions of MRL/l mice by using in situ hybridization. No specific hybridization signals of either of the probes used were seen in the nonlesional skin of MRL/l mice or in the apparently normal skin of aged MRL/n and young MRL/l mice. These results suggest that the increased expression of myb and myc proto-oncogenes in the cutaneous LE-like lesions of MRL/l mice is related to a state of activation in the infiltrating cells and is involved in the development of these lesions.

Trichilemmal neoplasm developing in seborrheic keratosis--report of two cases.

Granulation‐like, flesh colored tumors developed in the verrucous plaques of a 70‐year‐old man and a 86‐year‐old man. The verrucous plaques, which had appeared more than 15 or 20 years earlier, were found to be a common type of seborrheic keratosis. The newly appearing tumors histologically consisted of large, glycogen‐rich, clear epidermal cells and surrounding basaloid cells, resulting in multilobular architecture. Dyskeratotic cells and parakeratotic plugs showing trichilemmal keratinization were present in both cases. Bowenoid changes were seen in a part of the plaque from one case, and many mitotic cells and an invading figure in the tumorous cells of the other. These cases demonstrate the rare possibility of trichilemmal neoplasms developing in a common type of seborrheic keratosis.

Giant Metastatic Malignant Melanoma with an Unknown Primary Site

We report a case of malignant melanoma of unknown primary origin which presented with a giant metastatic tumor in his right inguinal region. A 94‐year‐old man noticed a small subcutaneous tumor in the right inguinal region 3 years earlier, which eventually became as large as 9 cm in diameter without treatment. Although a histological examination of the lesion showed malignant melanoma, extensive examination did not reveal its primary lesion or any metastasis other than that to the right inguinal area. Our case took an interesting course in that this well‐growing metastatic tumor was localized in only one region and supported a previous report indicating that malignant melanoma with unknown primary origin has a low tendency to metastasize and a relatively good prognosis.

Distribution of Langerhans cells in skin lesions of MRL/l mice

The role of Langerhans cells (LCs) in various skin diseases has been studied by several investigators [7, 10, 16, 24] because LCs play an important role in immunological phenomena as antigen-presenting cells [14, 18, 21, 22]. Cutaneous lesions in patients with lupus erythematosus (LE) have a lower density of LCs than found in normal skin sites [20]. However, the detailed distribution of LCs in LE patients remains obscure. To clarify the pathogenesis of lupus skin lesions, autoimmune mice have been used for dermatopathological analysis [2, 3, 8]. The MRL/Mp-lpr/lpr (MRL/ 1) mouse is a new autoimmune model characterized by the spontaneous development of skin lesions after 3 months of age; these lesions are similar to those in human SLE [8, 9, 11, 12]. In this study, we examined the distribution pattern of LCs in skin lesions of MRL/ 1 mice. MRL/1, the control M R L / M p + / + (MRL/n), and BALB/c mice were purchased from Jackson Laboratory (Bar Harbor, Maine, USA) and maintained under specific pathogen-free conditions in the Experimental Animal Center (Faculty of Medicine, Kyoto University), in which mice are protected from bacterial infection. Skin biopsy specimens of tested mice showed no bacterial growth [9]. Such conditions are essential for the development of spontaneous LE-like skin lesions because common bacterial infection easily induces ulcerative skin lesions which resemble LE-like

The Uterus Lupus Band Test and Its Correlation with the Skin Lupus Band Test in Autoimmune Mice

(DEJ) of the skin lesion in patients with SLE. The term lupus band (LB) was used to this skin lesion (20), and the LB test (LBT) is now regarded to be of diagnostic and prognostic value in SLE. However, the immunological mechanisms of Ig deposition at the DEJ are still obscure. Several strains of SLE-prone mice have been developed for studies on the pathogenesis of SLE (13, 16, 19, 21). Recently we found that positivity of the LBT in nonlesional skin is a common feature in New Zealand, MRL/Mp-lpr/lpr (MRL/l) and BXSB mice (7, 8, 11). Furthermore, this LBT positivity in New Zealand mice is regulated by genetic factors (9). Recently we observed Ig deposition along the subepithelial junction of the uterine cervix (tentatively designated uterus LB) in female MRL/1 and BXSB mice. In this study, we report the age related incidence of a positive uterus-LBT and its correlation with a positive skin-LBT and the effects of ultraviolet (UV) irradiation on the skin-LBT and uterus-LBT. MRL/1, MRL/Mp+/ + (MRL/n), and BXSB mice were purchased from Jackson Laboratories, Bar Harbor, ME, U.S.A. BALB/c mice were obtained from our colony. These mice were maintained under specific-pathogen-free conditions. All mice used in this study were virgin females. Specimens of the uterus were obtained from the caudal portion of the uterus which was considered to be equivalent to the human uterine cervix, and those of the skin from the backs of MRL mice and the tails of BXSB and BALB/c mice. All specimens were frozen immediately in a bath of acetone and dry ice, and stored at -80 C until use. The following antisera were used: FITC-labeled anti-mouse Ig, FITC-labeled anti-mouse IgG, goat anti-mouse IgM (Cappel Laboratories, Cochranville, PA, U.S.A.), FITC-labeled anti-goat Ig (prepared in our laboratory), FITC-labeled anti-mouse C3 (Cappel), and anti-Rauscher gp 70, which was kindly donated by