Categorization of cutaneous epithelioid angiomatous nodule as epithelioid hemangioma or angiolymphoid hyperplasia with eosinophilia: Clinicopathologic, immunohistochemical, and molecular analyses of seven lesions.

BACKGROUND: The status of cutaneous epithelioid angiomatous nodule (CEAN) as a distinct entity remains controversial. This study investigated the relationship between CEAN and epithelioid hemangioma/angiolymphoid hyperplasia with eosinophilia (ALHE). METHODS: Data of seven lesions with CEAN features from four cases (Cases 1-4: 61-year-old, 76-year-old, 53-year-old, and 21-year-old men, respectively) were investigated. RESULTS: Cases 1 and 2 showed multiple lesions in the head and neck region, but Cases 3 and 4 showed solitary lesions on the back and scalp, respectively. Moreover, the histopathologic findings of the lesions of Cases 1 and 2 were consistent with those of conventional epithelioid hemangioma or classic cutaneous ALHE. Diffuse immunoexpression of FOSB was observed in Cases 1 and 2, but FOSB split signals were absent in break-apart fluorescence in situ hybridization (FISH). In contrast, the histopathologic findings of the lesions of Cases 3 and 4 were consistent with those of cellular-type epithelioid hemangiomas. Diffuse immunoreactivity for c-FOS was observed in Cases 3 and 4, and split signals of FOS were present in break-apart FISH in Case 3. CONCLUSIONS: This study showed that the seven tumors with CEAN features could be reclassified under the epithelioid hemangioma/ALHE group, although the small sample size is a limitation.

Adipose-derived stem cells express higher levels of type VII collagen under specific culture conditions.

Type VII collagen (Col7) is a major component of the anchoring fibrils at the dermoepidermal junction. Adipose-derived stem cells (ADSCs) are a cell population highly useful in regenerative medicine because of their ease of isolation and their potential for multilineage differentiation. Based on the observations that K14 was expressed in undifferentiated ADSCs and the expression was downregulated after differentiation into adipocytes, we speculated that ADSCs are keratinocyte stem/progenitor cells. ADSCs were co-cultured with fibroblasts on type IV collagen in a medium containing all-trans retinoic acid and bone morphogenetic protein 4. At day 14 of culture in keratinocyte serum-free medium, the cells were harvested and subjected to immunofluorescence, flow cytometry, real-time PCR, and western blotting. Approximately, 45% of ADSCs were immunostained positively for anti-human cytokeratin 10, and approximately 80% were stained positively for Col7. Flow cytometry, real-time PCR, and western blotting also confirmed that differentiated ADSCs expressed higher levels of Col7. These findings support the therapeutic potential of ADSCs, not only for wound healing, but also for the correction of Col7 deficiencies.

Keratinocyte progenitor cells reside in human subcutaneous adipose tissue.

The differentiation of adipose-derived stem cells (ASCs) towards epithelial lineages has yet to be demonstrated using a standardized method. This study investigated whether keratinocyte progenitor cells are present in the ASC population. ASCs isolated from subcutaneous adipose tissue were cultured and examined for the expression of the keratinocyte progenitor markers p63 and desmoglein 3 (DSG3) by immunofluorescence microscopy and flow cytometry. In addition, p63 and DSG3 expression levels were assessed before and after differentiation of ASCs into adipocytes by real-time PCR and western blot analysis, as well as in subcutaneous adipose tissue by real-time reverse transcriptase polymerase chain reaction. Both markers were expressed in ASCs, but were downregulated after the differentiation of ASCs into adipocytes; p63-positive cells were also detected in subcutaneous adipose tissue. ASCs co-cultured with human fibroblasts and incubated with all-trans retinoic acid and bone morphologic protein 4 showed an upregulation in DSG3 level, which was also increased in the presence of type IV collagen. They also showed an upregulation in cytokeratin-5 level only in the presence of type IV collagen. These results provide the demonstration that keratinocyte progenitor cells reside in subcutaneous adipose tissue.

A retrospective study of 231 Japanese vitiligo patients with special reference to phototherapy.

Although the outcomes of various treatment modalities for vitiligo have been studied extensively, the influence of the participant's characteristics on treatment response has not been thoroughly investigated. Therefore, we retrospectively investigated treatment effects and their association with clinical characteristics in Japanese patients with vitiligo. The charts of patients with vitiligo treated in our institution were reviewed. Clinical response was evaluated as a marked response rate, defined as repigmentation in >75% of the initial lesional area. 162 patients were treated with phototherapy, while 69 were treated with topical mono-therapy. The patients treated with phototherapy and those treated with both phototherapy and topical treatment demonstrated significantly higher clinical response rates compared to patients treated solely with topical mono-therapy (marked response rate: 19.1% vs. 5.8%, P<0.05; and 23.5% vs. 5.8%, P<0.01, respectively). Among the phototherapy-treated patients, younger subjects (≤15 years old) were more responsive to phototherapy compared to older patients (37.0% vs. 15.6%; P=0.015). The disease subtypes did not affect treatment response. In conclusion, phototherapy appears to have a therapeutic effect superior to topical mono-therapy on both focal and generalized vitiligo, especially in younger patients. Thus, any type of psychosocially devastating lesions in a pediatric patient may be a good target for phototherapy.

A case of phaeohyphomycosis caused by Exophiala oligosperma successfully treated with local hyperthermia.

A 58-year-old Japanese woman who was engaged in dairy farming presented with multiple subcutaneous nodules and abscesses on the dorsum of her left hand from 5 months ago. These had been unsuccessfully treated with oral itraconazole. The patient had a history of Sjögren syndrome and diabetes mellitus, for which she had been taking oral prednisolone for 10 years. Direct microscopy of a pus sample treated with potassium hydroxide (KOH) showed brownish-red branching hyphae. In fungal culture, black colonies covered with gray-white villi were formed. Slide culture showed conidiogenesis from an annellide. The fungal strain was identified as Exophialia oligosperma by molecular biological techniques. Histopathological examination revealed abscesses and surrounding granulomatous infiltration in the dermis and subcutis, and hyphae in the granulomatous infiltration in the outer area. However, no eumycotic granules were observed. The diagnosis was phaeohyphomycosis caused by E. oligosperma. Since the previous treatment with itraconazole had not been effective, we performed daily hyperthermia using a disposable body warmer and drainage of the pus, which ceased after 3 weeks. After approximately 4 months, the skin eruptions became scarred. To the best of our knowledge, this is the second case of phaeohyphomycosis caused by E. oligosperma reported in Japan which was successfully treated with hyperthermia.

Role of PU.1 in MHC class II expression through transcriptional regulation of class II transactivator pI in dendritic cells.

BACKGROUND: PU.1 is a hematopoietic cell-specific transcription factor belonging to the Ets family. We hypothesized that PU.1 is involved in MHC class II expression in dendritic cells (DCs). OBJECTIVE: The role of PU.1 in MHC class II expression in DCs was analyzed. METHODS: Transcriptional regulation of the DC-specific pI promoter of the class II transactivator (CIITA) gene and subsequent MHC class II expression was investigated by using PU.1 small interfering RNA (siRNA) and reporter, chromatin immunoprecipitation, and electrophoretic mobility shift assays. RESULTS: PU.1 siRNA introduction suppressed MHC class II expression, allogeneic and syngeneic T-cell activation activities of bone marrow-derived DCs (BMDCs) with reduction of CIITA mRNA driven by the DC-specific promoter pI, and MHC class II mRNA. The chromatin immunoprecipitation assay showed constitutive binding of PU.1 to the pI region in BMDCs, whereas acetylation of histone H3 on pI was suppressed by LPS stimulation in parallel with shutdown of CIITA transcription. PU.1 transactivated the pI promoter through cis-elements at -47/-44 and -30/-27 in a reporter assay and to which PU.1 directly bound in an electrophoretic mobility shift assay. Acetylation of histones H3 and H4 on pI was reduced in PU.1 siRNA-introduced BMDCs. Knockdown of interferon regulatory factor 4 or 8, which is a heterodimer partner of PU.1, by siRNA did not affect pI-driven CIITA transcription or MHC class II expression. CONCLUSION: PU.1 basally transactivates the CIITA pI promoter in DCs by functioning as a monomeric transcription factor and by affecting histone modification, resulting in the subsequent expression and function of MHC class II.

Suppressive effects of transcription factor GATA-1 on cell type-specific gene expression in dendritic cells.

To evaluate the effects of the transcription factor GATA-1 on determining cell fate between dendritic cell (DC) and mast cell (MC) lineages, GATA-1 was exogenously expressed in bone marrow-derived (BM) DCs. Exogenous expression of GATA-1 by a retrovirus in BMDCs inhibited expression of CD11c, CD80, CD86, and major histocompatibility complex class II with suppression of antigen-presenting ability and morphological changes toward granulocyte-like cells. Transcription of MC proteases and c-kit was markedly upregulated by GATA-1. Expression of IRF-4 and -8 was markedly suppressed, whereas PU.1 mRNA level was not affected by GATA-1. Chromatin immunoprecipitation assay showed that recruitment of PU.1 on the IRF-8 promoter was reduced in GATA-1-expressing DCs. These results indicate that GATA-1 suppresses PU.1 function but not PU.1 transcription. Thus, GATA-1 appears to determine cell fate by regulating several cell-specific transcription factors.

FcepsilonRIalpha gene -18483A>C polymorphism affects transcriptional activity through YY1 binding.

Three frequent genetic polymorphisms in the human high-affinity IgE receptor alpha-subunit (FcepsilonRIalpha) were shown to be associated with allergic disorders and/or total serum IgE levels in allergic patients. Two of these were previously demonstrated to affect FcepsilonRIalpha expression while the third -18483A>C (rs2494262) has not yet been subjected to functional studies. We hypothesized that the -18483A>C variant affects transcriptional activity of the FcepsilonRIalpha distal promoter in monocytes in which FcepsilonRIalpha transcription is driven through that regulatory region. Indeed, we confirmed preferential binding of the YY1 transcription factor to the -18483C allele, resulting in lower transcriptional activity when compared with the -18483A allele.

Involvement of PU.1 in the transcriptional regulation of TNF-alpha.

PU.1 is a myeloid- and lymphoid-specific transcription factor that serves many important roles in the development and specific gene regulation of hematopoietic lineages. Mast cells (MC) and dendritic cells (DC) express PU.1 at low and high levels, respectively. Previously, we found that enforced expression of PU.1 in MC resulted in acquisition of DC-like characteristics, including repression of several IgE-mediated responses due to reduced expression of IgE-signaling related molecules. In contrast, PU.1 overexpression in MC up-regulated TNF-alpha production in response to IgE- and LPS-stimulation suggesting that PU.1 positively regulates TNF-alpha expression. However, the role of PU.1 in the expression of TNF-alpha is largely unknown. In the present study, the effects of PU.1 on the TNF-alpha promoter in mouse bone marrow-derived (BM) MC and DC were studied. Real-time PCR, ELISA, and chromatin immunoprecipitation assays indicated that the kinetics and magnitude of TNF-alpha expression levels following LPS- or IgE-stimulation are related to the amount of PU.1 binding to the promoter. In brief, higher and delayed up-regulation of TNF-alpha promoter function was observed in DC, whereas there were lower and rapid responses in MC. When PU.1-overexpressing retrovirus vector was introduced into MC, the amount of PU.1 recruited to the TNF-alpha promoter markedly increased. The knockdown of PU.1 in BMDC by siRNA resulted in a reduction of TNF-alpha protein produced from LPS-stimulated BMDC. These observations indicate that PU.1 transactivates the TNF-alpha promoter and that the amount of PU.1 binding on the promoter is associated with promoter activity.

Two different transcription factors discriminate the -315C>T polymorphism of the Fc epsilon RI alpha gene: binding of Sp1 to -315C and of a high mobility group-related molecule to -315T.

The alpha-chain is a specific component of FcepsilonRI, which is essential for the cell surface expression of FcepsilonRI and the binding of IgE. Recently, two single nucleotide polymorphisms (SNPs) in the alpha-chain promoter, -315C>T and -66T>C, have been shown by statistic studies to associate with allergic diseases. The effect of -66 SNP on GATA-1-mediated promoter activity has been already indicated. In the present study, to investigate roles of the -315 SNP on the alpha-chain promoter functions, the transcription activity was evaluated by reporter assay. The alpha-chain promoter carrying -315T (minor allele) possessed significantly higher transcriptional activity than that of -315C (major allele). EMSA indicated that the transcription factor Sp1, but not Myc-associated zinc finger protein (MAZ), was bound to the -315C allele probe and that a transcription factor belonging to a high mobility group-family bound to the -315T allele probe. The chromatin immunoprecipitation assay suggested that high mobility group 1, 2, and Sp1 bound around -315 of FcepsilonRIalpha genomic DNA in vivo in the human basophil cell line KU812 with -315C/T and in human peripheral blood basophils with -315C/C, respectively. When cell surface expression level of FcepsilonRI on basophils was analyzed by flow cytometry, basophils from individuals carrying -315T allele expressed significantly higher amount of FcepsilonRI compared with those of -315C/C. The findings demonstrate that a -315 SNP significantly affects human FcepsilonRI alpha-chain promoter activity and expression level of FcepsilonRI on basophils by binding different transcription factors to the SNP site.