The pattern and morphology of cellular infiltration of iris melanocytes implanted into the corneal stroma were studied with a rabbit corneal model. Iris melanocytes are transformed into fibroblast-like cells with a loss of pigment granules, which may reflect the in vivo characteristics of iris melanocytes under pathologic conditions. The metaplastic chararter of iris melanocytes appears to be related to the formation of retrocorneal pigmentation and fibrous membrane.
Animals ; Cell Division ; Cornea/*cytology/pathology/surgery ; Iris/*cytology ; Melanocytes/*cytology/physiology/transplantation ; Metaplasia/pathology ; Rabbits

OBJECTIVETo construct an in vitro equivalent of the pigmented skin using tissue engineering methods.

METHODSSurgically removed foreskins was used as the source of keratinocytes and melanocytes harvested by routine tissue digestion. The fibroblasts were enriched by tissue block culture and seeded into the scaffold constructed using mouse tail collagens to construct the pigmented skin equivalent model. The general structure and the melanocyte distribution and growth status in this model were observed with HE staining and Fontana Masson staining. The ultrastructure of the constructed pigmented skin equivalent was observed by transmission electron microscope.

RESULTS AND CONCLUSIONThe pigmented skin equivalent model was structurally intact, and allowed optimal cell growth. Fontana Masson staining identified in the basal layer numerous melanocytes in normal growth, and the constructed model was structurally similar to normal skin tissue, suggesting successful construction of the pigmented skin equivalent model.

Animals ; Foreskin ; cytology ; Humans ; Keratinocytes ; cytology ; Male ; Melanocytes ; cytology ; Mice ; Skin Pigmentation ; Skin, Artificial ; Tissue Engineering ; methods

Melanoblasts, the precursors to melanocytes, originate in the neural crest. Some melanoblasts can travel to the hair follicle and further differentiate into pigment melanin-producing melanocytes. Hair follicles contain a pool of undifferentiated melanocyte stem cells (MSCs), which are sources of differentiated melanocytes, and functional melanocytes exhist in the hair bulb. The volume, life, and activity of melanocytes in a hair follicle is closely related with the growth cycle of follicle. Appearance of gray hair gray results from incomplete MSCs maintenance.
Aging ; physiology ; Cell Differentiation ; Hair Follicle ; cytology ; physiology ; Humans ; Melanocytes ; physiology ; Stem Cells ; physiology

Ota's nevus is mongolian spot-like macular blue-black or gray-brown patchy pigmentation that most commonly ocurrs in areas innervated by the first and second division of the trigeminal nerve. Acquired, bilateral nevus of Ota-like macules (ABNOM) is located bilaterally on the face, appears later in life, is blue-brown or slate-gray in color. It is not accompanied by macules on the ocular and mucosal membranes. There is also debate as to whether ABNOM is part of the Ota's nevus spectrum. We report an interesting case of ABNOM associated with Ota's nevus. A 36-yr-old Korean women visited our clinic with dark bluish patch on the right cheek and right conjunctiva since birth. She also had mottled brownish macules on both forehead and both lower eyelids that have developed 3 yr ago. Skin biopsy specimens taken from the right cheek and left forehead all showed scattered, bipolar or irregular melanocytes in the dermis. We diagnosed lesion on the right cheek area as Ota's nevus and those on both forehead and both lower eyelids as ABNOM by clinical and histologic findings. This case may support the view that ABNOM is a separate entity from bilateral Ota's nevus.
Adult ; Biopsy ; Face/pathology ; Female ; Humans ; Melanocytes/cytology ; Nevus of Ota/diagnosis/*pathology ; Nevus, Pigmented/diagnosis/*pathology

The development of human melanocyte culture in vitro from normal adult skin and uninvolved skin of vitiligo patients is essential to investigate the mechanism of depigmentation in vitiligo and other pigmentary dermatoses. By using selective growth and long-term maintenance conditions, we selectively cultured melanocytes derived from normal foreskins and arm skins, and uninvolved foreskins and arm skins of vitiligo patients. The melanocytes of the arm skins were successfully cultured from the roofs of suction blisters. Melanocyte Growth Media (MGM) consisting of MCDB-153 formulation with basic fibroblast growth factor (bFGF), bovine pituitary extract (BPE), insulin, hydrocortisone, phorbol 12-myristate 13-acetate (PMA) and 10% human AB serum was sufficient to grow the melanocytes from normal and vitiligo donors. Melanocytes from uninvolved skin of vitiligo donors showed no different morphologic features, initial seeding capacity and population doubling time compared with those from normal skin. Melanocytes from both cell types grew without any lag period for more than 6 months (6-11 passages). Melanocytes obtained from foreskins had higher initial seeding capacity and shorter population doubling time than those obtained from arm skins using suction-blistered roofs. Our results suggest that the culture method using suction blisters may be a simple and easy way to obtain melanocytes. In addition, vitiligo melanocytes can be successfully cultured with appropriate growth conditions and may show no defective growth patterns. This culture system will be applied to investigate the basic pathophysiology of vitiligo and other various pigmentary dermatoses.
Cells, Cultured ; *Cytological Techniques ; Human ; Melanocytes/*cytology/*pathology ; Reference Values ; Support, Non-U.S. Gov't ; Vitiligo/*pathology

OBJECTIVETo investigate the interference effect of nicotinamide on UVA-induced cell proliferation in human skin melanocyte.

METHODSTo apply the optimum UVA dose expected to cause cell proliferation: 0.2 cm2, nicotinamide was added after the 0.2 cm2 UVA exposure immediately or 48 h later, then the rate of cell proliferation, calcium concentration and the activities of Na+-K+, Ca2+-ATP enzymes of melanocytes were measured respectively.

RESULTSAfter treatment with 1.000 mg/ml nicotinamide following UVA exposure, the rate of cell proliferation was decreased significantly 24 hours later. Treatment with 0.125 mg/ml nicotinamide 48 hours after UVA exposure also significantly inhibited the cell proliferation; 1.25 mg/ml nicotinamide increased calcium concentration in cells; 0.250 mg/ml nicotinamide increased the activities of Na+-K+, Ca2+-ATP enzymes in melanocytes (P < 0.05).

CONCLUSIONNicotinamide has more obvious effect on inhibiting melanocyte's proliferation if added immediately following UVA exposure. Our discovery indicated that nicotinamide may affect the melanocyte through modulating the calcium concentration. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

Cell Proliferation ; drug effects ; radiation effects ; Cells, Cultured ; Humans ; Melanocytes ; cytology ; Niacinamide ; pharmacology ; Skin ; cytology ; Ultraviolet Rays

OBJECTIVETo explore the method of constructing tissue-engineered skin using melanocytes and bone marrow mesenchymal stem cells (BMSCs) in vivo.

METHODSMelanocytes were isolated from human foreskin. BMSCs were isolated from human bone marrow. Both of them were co-cultured at a ratio of 1:10, and then were implanted into the collagen membrane to construct the tissue-engineered skin, which was applied for wound repair in nude mice. The effectiveness of wound repair and the distribution of melanocytes were evaluated by morphological observation, in vivo 4,6-diamidino-2-phenylindole, dihydrochloride (DAPI) fluorescent staining tracing, HE staining, S-100 immunohistochemistry, and transmission electron microscopy.

RESULTSThe wounds were satisfactorily repaired among the nude mice. The melanocytes were distributed in the skin with normal structure, as confirmed by DAPI fluorescent staining tracing, HE staining, S-100 immunohistochemistry, and transmission electron microscopy.

CONCLUSIONMelanocytes and BMSCs, after proper in vitro culture at an appropriate ratio, can construct the tissue-engineered skin with I type collagen membrane.

Animals ; Bone Marrow Cells ; cytology ; Cells, Cultured ; Coculture Techniques ; Collagen Type I ; Humans ; Melanocytes ; cytology ; Mesenchymal Stromal Cells ; cytology ; Mice ; Mice, Nude ; Skin ; injuries ; Skin, Artificial ; Tissue Engineering

OBJECTIVETo investigate the effects of 8-methoxypsoralen on human melanocytes [Ca(2+)]i and cytoskeleton actin organization in vitro.

METHODSHuman melanocytes were obtained from normal foreskins. Laser confocal microscope was employed to measure [Ca(2+)]i and rhodamine-conjugated phalloidin was used to visualize the cytoskeleton actin.

RESULTS8-methoxypsoralen increased [Ca(2+)]i and induced organization of actin stress fiber cytoskeleton.

CONCLUSION8-methoxypsoralen might influence the migration of melanocytes by increasing the intracellular free Ca(2+) concentration and cytoskeleton actin reorganization.

Actins ; biosynthesis ; genetics ; Calcium ; metabolism ; Cell Movement ; drug effects ; Cells, Cultured ; Cytoskeletal Proteins ; biosynthesis ; genetics ; Humans ; Melanocytes ; cytology ; drug effects ; metabolism ; Methoxsalen ; pharmacology ; Skin ; cytology

Calcitonin ; Carcinoma, Papillary ; drug therapy ; pathology ; surgery ; Female ; Humans ; Melanins ; Melanocytes ; cytology ; pathology ; Middle Aged ; Prognosis ; S100 Proteins ; Thyroid Neoplasms ; drug therapy ; pathology

OBJECTIVETo investigate the effects of Liuweidihuang Decoction on the proliferation and melanin synthesis of cultured human melanocytes in vitro.

METHODSMTT assay was used to assess the proliferation of cultured human melanocytes after treatment with Liuweidihuang Decoction, and NaOH assay was employed to determine melanin synthesis.

RESULTSLiuweidihuang Decoction at the concentration of 5%-15% did not affect the proliferation of the melanocytes (P>0.05), and the decoction at 20%-30% significantly inhibited the cell proliferation, especially at the optimal concentration of 30% (P<0.01). The decoction promoted melanin synthesis in the melanocytes at the concentration of 10%-15% with the optimal concentration of 15% (P<0.01) but failed to produce such an effect at 20%-30%.

CONCLUSIONLiuweidihuang Decoction exert a two-way regulation on the proliferation and melanin synthesis of cultured human melanocytes in vitro.

Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Drugs, Chinese Herbal ; pharmacology ; Humans ; Melanins ; biosynthesis ; Melanocytes ; cytology ; drug effects ; metabolism