Effect of IGF-1 on the Proliferation of Cultured Normal Human Melanocytes / 대한피부과학회지

BACKGROUND: Human growth hormone(hGH) plays a central role in linear bone growth and body metabolism. Its mitogenic effect in human tissues is mediated via direct and indirect actions. As proposed by the "somatomedin hypothesis", many circulating GH-mediated effects are exerted indirectly and systemically via stimulation of hepatic synthesis of insulin-like growth factor 1(IGF-1). Given additional evidences for the expression of growth hormone receptor(GH-R) and IGF-1 receptor(IGF-1R) on many target tissues including keratinocytes, melanocytes, and fibroblasts, it is now evident that the GH can act via systemic IGF-1 secreted by the liver and locally produced IGF-1, as well as directly through the GH receptor. OBJECTIVE: The purpose of this study was to investigate not only the effect of IGF-1 on the morphologic changes, proliferation, and melanization of cultured human melanocytes but also on its signal transduction pathway through the IGF-1R. METHODS: Melanocytes were exposed to IGF-1 at 10, 25, 50, 75, 100ng/ml and we examined the changes of cell morphology, number of cells, [3H]-thymidine incorporation, MTS assay, and melanization according to the concentrations and exposure times of IGF-1. Also, the activity of p44/42 MAPK/ERK according to the various exposure times of IGF-1(25ng/ml) was examined using the Western blotting method to find out about the signal transdution pathway of IGF-1. RESULTS: The results were as follows: 1. There were no significant morphological changes of cells between the control and experimental groups according to the concentrations and exposure times of IGF-1. 2. The effects on melanocytes according to the concentrations of IGF-1 5 days after adding IGF-1 : 1) The number of cells, [3H]-thymidine incorporation, and MTS assay were significantly higher than those of control group in all experimental groups(p<0.05). 2) The melanin content showed an insignificant decrease in all experimental groups. 3) The melanocytes responded independent of the IGF-1 concentration in the assay of cell number, [3H]-thymidine incorporation and MTS. 3. The effects on melanocytes according to the exposure times(3 days, 5 days, 7 days) of IGF-1(25 ng/ml) : 1) The number of cells, [3H]-thymidine incorporation, and MTS assay increased as time went by, and was significantly higher than those of control group at all exposure times(p<0.05). 2) The melanin content decreased after exposure of IGF-1, especially that of 3 days exposure group showed a significant decrease(p<0.05). 4. The activities of p44/42 MAPK/ERK increased suddenly at 5 minutes with a peak at 60 minutes and then abruptly decreased at 120 minutes after adding IGF-1 CONCLUSION: In summary, this study demonstrates that IGF-1 has no effect on the morphology, but it does increase the proliferation and slightly decrease the melanization of cultured human melanocytes. In addition, it is suggested that IGF-1 plays a role in regulation of proliferation of melanocytes via the receptor PTK pathway with activation of p44/42 MAPK/ERK.

Effects of Alopecia Areata Serum on Proliferation of Cultured Dermal Papilla Cells / 대한피부과학회지

BACKGROUND: Dermal papilla cells, which are mesenchymal components of the hair bulb are considered to play an important role in the regulation of hair growth by production of diffusible factors that stimulate follicular epithelial cells. Degenerative changes in the dermal papilla cells in the involved scalp of alopecia areata cases indicate that these cells are one of the important targets in this disease. OBJECTIVE: We investigated the effects of serum from alopecia areata patients on the proliferation of dermal papilla cells. METHOD: Dermal papilla cells and fibroblasts from normal human scalp were cultured in DMEM media with 10% or 20% of normal and alopecia areata serum for 48hrs and 96hrs. Cell proliferation was measured by cell counts and [3H]-thymidine incorpoartion. RESULTS: Both 10% and 20% alopecia areata serum had no significant effects on the proliferation of dermal papilla cells and fibroblasts after 48hrs and 96hrs. CONCLUSION: These results suggest that there are no serum factors that inhibit the proliferation of dermal papilla cells.

Microscopic Findings of Cultured Human Melanocytes from a Vitiligo Subject / 대한피부과학회지

Vitiligo is an acquired systemic disease of the skin characterized by circumscribed patches of complete pigment loss due to destruction of melanocytes. A 28-year old male patient presented with generalized depigmented patchs. We performed microscopic studies of cultured melanocytes from this patient and compared them with those of normal neonatal foreskin. Phase contrast microscopic findings revealed no difference between the two groups of melanocytes, but transmission electron microscopic findings showed dilated circular rough endoplasmic reticulum in cultured melanocytes from our vitiligo patient. We could observe the innate cellular structural aberration of melanocytes from the vitiligo subject.

Follicular Mycosis Fungoides

We report a case of mycosis fungoides with small follicular papules and plaques on the trunk. Histopathological findings showed lymphocytic infiltration within and around the follicular epithelium and Pautrier's microabscess in the epidermis. Immunohistochemical studies showed atypical T lymphocytes infiltrating the follicles and electron microscopic examination revealed the presence of lymphocytes with large convoluted nuclei around the follicles. These findings suggest that the follicular lesions were specific for a special variant of mycosis fungoides.

Viability of Cultured Human Keratinocyte and Melanocyte after UVB Exposure / 대한피부과학회지

BACKGROUND: Each kind of human cell has its own characteristic morphological and functional property. In the skin, epidermal cells, including keratinocyte and melanocyte, also have their own functional characteristics. Thus, it is expected that there are some different responses to external stimuli, such as ionizing radiatio,, free radicals, and cytokines between these cells. OBJECTIVE AND METHODS: To im estigate whether there are different effects of UV light on the viability of cultured human ker tinocytes and rnelanocytes. Cultured human keratinocytes and melanocytes are irradiated by UVB at 5, 25, 50, and 100mJ/cm, and examined by Methylthiazole tetrazollium assay at 0, 1, 3, 6, 24, 48, and 72 hours after UVB exposure. RESULTS: 1. The effects on viability according to the doses of UVB are as follows: 1) In the keratinocytes, the viability was increased in most of the UVB exposure groups within 24 hours after UVB exposure, and was significantly increased at 25, 50, and 100mJ/cm of UVB at 3 hours after UVB exposur.(p<0.05). However, the viability was significantly decreased at relatively high doses of UVB (50, 100mJ/cm) from 48 hours after UVB exposure (p<0.05). 2) In the melanocytes, the viability was decreased in all of the UVB exposure groups within 3 hours, and was significantly decreased in all of the UVB exposure groups at, 1 hour after UVB exposure (p<0.05). The viability was increased from 6 to 24 hours, which was significantly decreased at 100mJ/cm of UVB from 48 hours after UVB exposure (p<0.05). 2. The effects on viability according to the time after UVB exposure at the same dose of UUB In both cells, the viability was increased as time went by. The slopes of the viability curve gradually decreased according to the increment of UVB doses. CONCLUSION: The viability of keratinocyte was decreased at 50mJ/cm of UVB which melanocyte did not show decrease. Melanocyte was more easily damaged than keratinocyte in relatively earlier time period after UVB exposure. These results suggest that the change of viability in cultured keratinocyte and melanocyte after UVB exposure at the dose of less than 100mJ/cm is related to the time course after UVB exposure as well as to the UVB dose.

A Case of Lymphocutaneous Sporotrichosis with Unusual Clinical Features / 대한피부과학회지

We report a case of lymphocutaneous sporotrichosis with unusual clinical features in a 62-year-old male patient, who presented with a painless, well-defined psoriasiform plaque and central ulceration on the dorsam of the right hand which progressively spread into the lymphatics draining area. The fully matared lesions produced a chain of firm. mild prickling subcutaneous nodules on both upper extremities probably due to autoinoculation. The biopsy specimen of the lesion showed hyperkeratosis with chronic granulomatous inflammation and PAS-positive fungal spores in the dermis. Sporothrix schenckii was identified using a fungal culture of tissue specimen. The lesions improved with treatment of a topical antifungal agent and KI solution at the dose of 2 g/day for 1 month, but returned to initial cutaneous manifestation due to the patient failing to the treatment.

A Case of Pityriasis Rubra Pilaris Associated with Incidental Acantholysis

Pityriasis Rubra Pilaris is a rare, chronic, mildly inflammatory disease characterized by fine acuminate follicular papules with orange-red to salmon-colored scaling of the skin and erythroderma that surround islands of normal, uninvolved skin, particular in the trunk. Most patients also develop palmoplantar hyperkeratosis in the early course of the disease. Focal acantholysis occurring in pityriasis rubra pilaris is an unusual and incidental histologic finding within the spectrum of histologic change of the disease. No case featuring this concomitant histologic finding has been reported in the Korean literatures up to date. We report a case of focal acantholysis occurring in a patient with the clinical features of pityriasis rubra pilaris which may be considered as an incidental finding.

A Case of Addison' s Disease / 대한피부과학회지

Addison's disease is a rare disorder resulted from a chronic deficiency of the adreanl cortical hormone. The clinical manifestations are general weakness, weight loss, hyperpigmentation, hypovolemia with hyponatremia and hyperkalemia. We report a case of Addison's disease in a 60-year-old woman who has experienced slowly progressive weakness, weight loss and generalized cutaneous pigmentation, especially sun exposed area, extensor surface and nail bed for the last, 2 years. On a hormonal assay of the adrenal glands, basal plasma cortisol level was decreased and basal plasma ACTH level was markedly elevated. A chest X-ray showed streaky tuberculous infiltration in left, upper lobe field and adrenal CT scan showed calcific densities of both adrenal glands with nodular enlargement of right adrenal gland. There was a clinical improvement with steroid replacement therapy and anti-tuber- culosis chemotherapy. A nearly normal appearance was obtained after 5 months' treatment.