Norihiro Fujimoto

Collagen-derived dipeptide, proline-hydroxyproline, stimulates cell proliferation and hyaluronic acid synthesis in cultured human dermal fibroblasts.

Orally ingested collagen undergoes degradation to small di‐ or tripeptides, which are detected in circulating blood 2 h after ingestion. The influence of collagen‐derived peptides on dermal extracellular matrix components and cell proliferation was studied using cultured human dermal fibroblasts. Of the various collagenous peptides tested here, the dipeptide proline‐hydroxyproline (Pro‐Hyp) enhanced cell proliferation (1.5‐fold) and hyaluronic acid synthesis (3.8‐fold) at a dose of 200 nmol/mL. This was concomitant with a 2.3‐fold elevation of hyaluronan synthase 2 (HAS2) mRNA levels. Small interfering RNA (siRNA)‐mediated knockdown of the HAS2 gene in human dermal fibroblasts inhibited Pro‐Hyp‐induced HAS2 mRNA transcription and cell mitotic activity. Addition of genistein or H7, a protein kinase inhibitor, abolished the Pro‐Hyp‐induced HAS2 mRNA stimulation. Pro‐Hyp elevated phosphorylation of signal transducer and activator of transcription 3 (STAT3) within a short time period (60 min). These results suggest that Pro‐Hyp stimulates both cell mitotic activity and hyaluronic acid synthesis, which is mediated by activation of HAS2 transcription.

The presence of D-β-aspartic acid-containing peptides in elastic fibers of sun-damaged skin : A potent marker for ultraviolet-induced skin aging

Biologically uncommon d-aspartyl residues have been reported in proteins of various elderly tissues. We prepared a polyclonal antibody against d-beta-Asp-containing peptide and examined its immunoreactivity in the skin. The antibody recognized integrated or disintegrated elastic fibers in the sun-exposed skin but not in the sun-protected skin of the elderly donors. Western blot analysis of the proteins isolated from sun-damaged skin demonstrated that the 50 kDa protein was immunoreactive with both antibodies for d-beta-Asp-containing peptide and elastin. Ultraviolet (UV) irradiation on normal skin caused the appearance of d-beta-Asp-containing peptide-immunoreactive fibers in the dermis. These results suggest that UV irradiation is closely related to the formation of d-beta-Asp in the elastic fibers of skin. We propose that the antibody could be a useful indicator for sun damage of the skin.

Facial lichen striatus: successful treatment with tacrolimus ointment.

Summary We report a 22‐year‐old Japanese woman with facial lichen striatus (LS). The distribution of the lesions corresponded to that of Blaschkos lines. Histology of the lesional skin showed an inflammatory cell infiltrate around hair follicles and eccrine glands. Treatment of the linear lesions with tacrolimus ointment once or twice daily resulted in a dramatical improvement in a short time. LS is a T‐cell‐mediated inflammatory disease and tacrolimus ointment may be an effective alternative treatment for this disease especially when the lesions are located on the face.

Leukocytapheresis treatment for pyoderma gangrenosum.

A 42‐year‐old man presented with painful erythema with pustules and multiple small ulcers on the shins. He had suffered from ulcerative colitis (UC) and received oral glucocorticosteroid and salicylazosulfapyridine therapies for 7 years. Biopsy of the lesion demonstrated mixed cellular infiltrates with dominant neutrophils. The patient was diagnosed with pyoderma gangrenosum (PG) and underwent leukocytapheresis (LCAP), an extracorporeal leucocyte removal therapy, once a week for 5 weeks without changing the doses of the oral medications. The skin lesions as well as clinical signs of UC rapidly improved after LCAP, and no recurrence was seen during a follow‐up period. There were no major complications during LCAP. LCAP will provide an effective and safe tool for the treatment of PG.

A Pediatric Case of Atypical Mycobacterium avium Infection of the Skin

We report a case of cutaneous atypical mycobacteriosis in a 12‐year‐old healthy girl due to Mycobacterium avium. The cutaneous symptoms were three well‐defined subcutaneous nodules on both buttocks and on the posterior surface of the left thigh. One had a fistulous opening on the skin surface. Histopathological examination revealed epithelioid cell granulomas surrounded by dense lymphocytic infiltration and acid‐fast bacteria were seen with modified periodic acid‐carbol fuchsin staining. Using Ogawas medium at 37°C, acid‐fast bacteria were isolated from the biopsied specimen and identified by the DNA‐DNA hybridization method as Mycobacterium avium. In drug susceptibility test, these were resistant to all antituberculous drugs. Oral administration of minocycline 100 mg/day for two months had little effect on the two remaining lesions, which were therefore excised. Based upon reported cases of Mycobacterium avium complex, we considered that our pediatric patient with multiple intradermal or subcutaneous nodules on the buttocks and the thigh exhibited the characteristic symptoms of M. avium infection.

Immunohistochemical study of chronological and photo-induced aging skins using the antibody raised against D-aspartyl residue-containing peptide.

Background:  Biologically uncommon d‐aspartyl residues have been reported in the elderly tissues such as tooth, eye lens, aorta, and brain. We have previously prepared the antibody against d‐aspartyl residue‐containing peptide and found that it reacted with elastotic material of actinic elastosis.

Bullous pyoderma gangrenosum: a case report and review of the published work.

Pyoderma gangrenosum (PG) is an ulcerative skin disorder characterized by neutrophilic infiltrations. PG is generally classified into four types: (i) ulcerative; (ii) pustular; (iii) bullous; and (iv) vegetative. Among them, bullous PG is known as a rare type. Herein, we report a case of bullous PG together with a summary of the 12 PG cases treated in our department over the previous 15 years, and we review 38 well‐documented bullous PG cases (65.8% female; aged 18–80 years [mean ± standard deviation, 51.6 ± 16.8]) in the published work, including the present case, from 1972–2011. Although the disease most frequently associated with PG is inflammatory bowel disease, bullous PG is most commonly associated with hematological disorders (25/38, 65.8%), which indicates the characteristic pathophysiology specific to bullous PG.

Expression of 67-kDa elastin receptor in annular elastolytic giant cell granuloma: elastin peptides induce monocyte-derived dendritic cells or macrophages to form granuloma in vitro

Abstract: Annular elastolytic giant cell granuloma (AEGCG) is characterized by non‐palisading granuloma and elastophagocytic giant cells. Granulomas consist of structured masses of macrophages, dendritic cells, and T lymphocytes which play an essential role in granuloma formation. Two lineage systems of dendritic cells and macrophages originated from peripheral blood monocytes have been established in vitro. To know how elastin fragments are involved in the granuloma formation in AEGCG, we tested in vitro whether elastin fragments potentially induce monocyte‐derived macrophages or dendritic cells to form granuloma and multinucleated giant cells. Immunohistochemical studies of the lesional skins of AEGCG (n = 5) revealed that the 67‐kDa elastin receptor was specifically expressed in the epithelioid or multinucleated giant cells. Proliferation of factor XIIIa+ cells and CD68+ cells was also seen in the lesional skins of AEGCG. Factor XIIIa+ dendritic cells or CD68+ macrophages were established by the treatment of granulocyte/macrophage‐colony stimulating factor (GM‐CSF)/interleukin‐4 or M‐CSF, respectively. Further treatments of these dendritic cells or macrophages with elastin peptide resulted in the formation of granuloma or multinucleated giant cells which were immunoreactive with anti‐67‐kDa elastin receptor antibody. These findings suggest that elastic tissue induces factor XIIIa+ cells and CD68+ macrophages to form granuloma or multinucleated giant cells and plays an essential role in the formation of granuloma in AEGCG.

Eruptive vellus hair cyst in patients with chronic renal failure.

Two cases of eruptive vellus hair cysts associated with chronic renal failure are reported. Histologically the lesions of both cases showed cystic structures in the dermis lined by squamous epithelium which contained varying amounts of vellus hair shafts. Immunohistochemical studies using monoclonal anti-AGE (advanced glycation end product) antibody demonstrated that keratinous materials within the cystic structures were immunoreactive to the antibody, whereas those of cystic lesions (epidermal cyst, eruptive vellus hair cyst, steatocystoma multiplex, trichofolliculoma and trichilemmal cyst) seen in otherwise healthy individuals were negative. Because it has been reported that plasma and skin levels of AGE are elevated in renal failure patients, AGE-modified keratinous materials may be associated with the formation of cystic structures by stimulating the occlusion of the epithelium.

Expression of 36-kDa microfibril-associated glycoprotein (MAGP-36) in human keratinocytes and its localization in skin

Microfibril-associated glycoprotein-36 (MAGP-36) is a recently isolated elastin-binding protein and considered to be a member of microfibril-associated glycoproteins (MAGPs). We studied the expression of MAGP-36 in cultured normal human keratinocytes and its localization in the skin. MAGP-36 was found to be expressed in cultured human keratinocytes by Western blot and RT-PCR assays. The levels of MAGP-36 (polypeptide and mRNA) and the number of MAGP-36-producing keratinocytes were greatly increased during Ca(2+)-induced differentiation of keratinocytes. Immunohistochemical studies demonstrated that MAGP-36 colocalized with elastic fibers and formed candelabra like-fibers in the superficial dermis of normal skin. In the elderly skin of sun-exposed region, immunoreactivity of MAGP-36 in the superficial dermis disappeared. In the lesional skin of pseudoxanthoma elasticum which is an elastin-related disorder, immunoreactivity of MAGP-36 was found in the accumulation of disintegrated elastic fibers. The results show that MAGP-36 is a component of elastic fibers in the dermis and co-operates with elastin in normal and diseased conditions.