Eosinophil-derived galectin-10 upregulates matrix metalloproteinase expression in bullous pemphigoid blisters.

BACKGROUND: Bullous pemphigoid (BP) is an autoimmune bullous disease in which abundant eosinophils accumulate in the blisters. Galectin-10 abounds in the cytoplasm of eosinophils and is released as a result of eosinophil extracellular trap cell death (EETosis). OBJECTIVE: To identify EETosis and the pathological roles of galectin-10 in BP. METHODS: EETosis and galectin-10 in BP blisters were confirmed by immunofluorescence and transmission electron microscopy. The concentrations of galectin-10 in serum and blister fluid from BP patients were studied by ELISA. The matrix metalloproteinase (MMP) expression in BP blisters was immunohistochemically compared to that in healthy controls. As an in vitro assay, normal human epidermal keratinocytes (NHEKs) and normal human dermal fibroblasts (NHDFs) were stimulated with galectin-10, followed by MMP expression measurement by real-time PCR and ELISA. The signaling pathways activated by galectin-10 were studied using Western blotting and confirmed by inhibition assays. RESULTS: Galectin-10-containing eosinophil infiltration and the extracellular deposition of major basic protein were observed in BP blisters. The ultrastructural characteristics of tissue eosinophils indicated piecemeal degranulation and EETosis. In the BP patients, the concentration of galectin-10 was higher in the blister fluid than in the serum. Several types of MMPs were upregulated in BP blisters. Galectin-10 upregulated the production of MMPs through the pathways of p38 MAPK, ERK and JNK in NHEKs and NHDFs. CONCLUSION: In the BP blisters, the eosinophils underwent EETosis and released galectin-10. Galectin-10 might contribute to BP blister formation through the production of MMPs by keratinocytes and fibroblasts.

Atypical protein kinase C isoforms differentially regulate directional keratinocyte migration during wound healing.

BACKGROUND: The epidermis possesses regenerative properties that become apparent only after wounding. Atypical protein kinase C (aPKC) isoforms aPKCζ and aPKCλ form a ternary complex with Par3 and Par6, and play crucial roles in establishing and maintaining epithelial cell polarity. The epidermal loss of aPKCλ results in progressive depletion of hair follicle stem cells. However, it is unclear whether aPKCs have equivalent activities in epidermal regeneration. OBJECTIVES: To clarify functional differences between aPKCζ and aPKCλ in cutaneous wound healing. METHODS: We compared cutaneous wound healing processes in vivo using mutant mice with genetic deletion of each aPKC isoform. We also analyzed functional differences between aPKCζ and aPKCλ in cell proliferation, directional cell migration, and formation of microtubules in vitro using primary keratinocytes established from each mutant mouse. RESULTS: Wound healing was significantly retarded in epidermis-specific aPKCλ knockout mice. In aPKCλ-deleted keratinocytes, the correct orientation of cell protrusions toward the wound was disrupted through the destabilization of Par6ß. The elongation of stabilized ß-tubulin was also deteriorated in aPKCλ-deleted keratinocytes, leading to defects in cell spreading. Conversely, wound healing and directional cell migration in aPKCζ-deleted mice were comparable to those in their control littermates. CONCLUSIONS: aPKCs are not functionally equivalent; aPKCλ, but not aPKCζ, plays a primary role in cutaneous wound healing.

Sox13 is a novel early marker for hair follicle development.

Sox13, a group D member of the Sry-related high-mobility group box (Sox) transcription factor family, is expressed in various tissues including the hair follicle. However, its spatiotemporal expression patterns in the hair follicle and its role in hair development remain to be elucidated. To address these questions, we generated Sox13-LacZ-knock-in mice (Sox13LacZ/+), in which the LacZ reporter gene was inserted in-frame into exon 2, which contains the translation initiation codon. X-gal staining in Sox13LacZ/+ embryos revealed that Sox13 is initially expressed in the epithelial portion of the placode, and subsequently in the hair germ and the hair peg during early hair follicle development. In postnatal catagen and anagen, Sox13 was detected in the epithelial sheath, whereas in telogen, Sox13 was localized in the bulge region, where hair follicle stem cells reside. Immunohistochemistry with an anti-ß-galactosidase antibody and anti-hair keratin antibodies that specifically mark the different layers of the hair follicle revealed that Sox13 was predominantly expressed in the outer root sheath in anagen. However, the integumentary structures of Sox13LacZ/LacZ mice were grossly and histologically indistinguishable from those of wild type mice. These results suggest that although Sox13 is dispensable for epidermal and adnexal development, Sox13 is a useful marker for early hair follicle development.

Incidence rate of cutaneous squamous cell carcinoma is rapidly increasing in Akita Prefecture: Urgent alert for super-aged society.

Incidence rates of cutaneous squamous cell carcinoma (SCC) are increasing in many countries. To estimate detailed trends of SCC incidence rates in the population of Akita Prefecture as the forerunner of super-aged societies, we conducted a retrospective analysis of patients diagnosed with SCC between 2007 and 2016 in Akita University Hospital. The crude SCC incidence rate increased rapidly between 2007 and 2016 from 2.5 to 10.0/100 000 people. Remarkably, the age-specific incidence rate of people aged 80 years or over increased between 2007 and 2016 from 14.7 to 51.6/100 000 people, suggesting that SCC incidence rates increase possibly due to not only the increased number of aged people but also because of unidentified cancer-prone environments. When the findings of the present study are generalized to other regions entering the era of super-aging, it is clear that we need to prepare for the economic disease burden together with careful monitoring to confirm future trends for SCC.

Topical 3-bromopyruvate is a novel targeted therapy for melanoma in a preclinical model.

BACKGROUND: Targeting cancer metabolism is a promising strategy in improving cancer treatment. OBJECTIVE: To introduce a targeted therapy with topical 3-bromopyruvate (3BP), aglycolytic inhibitor, into the clinic in the near future. METHOD: We investigated the anti-tumor efficacy of 3BP on melanoma cells in vitro and in a preclinical model. RESULTS: Our cell-based study demonstrated that 3BP showed cytotoxicity for melanoma cells under anchorage-dependent or independent cell growth via a reactive oxygen species-mediated and caspase-independent cell death pathway. Moreover, 3BP inhibited both self-renewal potential and growth of slow-cycling phenotype in melanoma cells. Remarkably, the preclinical mouse xenograft model shed light on topical application of 3BP, showing significant anti-tumor effects with no apparent toxicity in surrounding normal tissues. CONCLUSION: We have now proposed that a targeted therapy with topical 3BP is an innovative strategy for adjuvant chemotherapy of technically or medically unresectable melanoma and possibly other skin cancers.