Immunohistochemical Expression of Stem Cell Markers during the Wound Healing Process of Cutaneous Burn

PURPOSE: A cutaneous wound healing requires a well-orchestrated integration of the complex biological and molecular events of cell migration and proliferation, extracellular matrix deposition, angiogenesis and remodeling. Finally, skin regeneration is the main goal. Stem cells are self-renewing multipotent progenitors with the broadest developmental potential in a given tissue at a given time. The aim of this study was to examine the role of stem cells during the wound healing process of cutaneous burn in hairless mice by using immunohistochemical stainings (nestin, cytokeratin 15 and CD31). METHODS: Each mouse received 2 burns at the dorsal area by applying a metal stick heated in boiling water. Burn wound sites were dressed with duoderm. The mice were sacrificed at 0, 2, 7, 14 and 21 days after burn. Histological findings and immunohistochemical expression for stem cell markers were observed. RESULTS: Nestin was expressed in the stromal cells beneath the epidermis, hair follices, dermal cysts and endothelial cells. Cytokeratin 15 was expressed in the epidermis except in basal cells. On 7 and 14 days after burn, the regenerated epidermis didn't express cytokeratin 15. CD31 was expressed in the endothelial cells on 7 and 14 days after burn. The amount of nestin expression was the highest. CONCLUSION: Our results showed that nestin may have various effects on burn wound healing. Cytokeratin 15 was expressed before burn and after burn. It is likely that other cytokeratin may stimulate epithelial regeneration. CD31 may act in vascular regeneration during burn healing.

The Effect of 1320 nm Nd: YAG Laser and Long-pulsed 1064 nm Nd: YAG Laser Irradiation on Hairless Mouse Skin / 대한피부과학회지

BACKGROUND: The treatment of facial rhytides has traditionally centered around methods that involve removal of the epidermis and superficial dermis, encouraging the production of a new epidermis with collagenesis and remodelling. But all of the resurfacing techniques lead to postoperative complications such as oozing, bleeding, infections, "downtime" as the skin begins to reepithelialize, and the occasional incidence of posttreatment, postinflammatory pigmentary changes. 1320nm and 1064nm wavelengths are nonspecifically absorbed in the human dermis and are unique for its significant horizontal scattering. These wavelengths, when used for localized facial areas, have been shown to produce new collagen formation and improvement in the quality of treated skin. OBJECTIVE: The purpose of this study was to examine the effect of 1320nm Nd: YAG laser and long-pulsed 1064nm Nd: YAG laser irradiation on hairless mouse skin and rat skin. METHODS: In this study, the effect of 1320nm Nd: YAG laser and long-pulsed 1064nm Nd: YAG laser irradiation were examined by Hematoxylin and eosin (H&E) stain, Masson's trichrome stain, immunohistochemical stain for type I collagen and dot-blot hybridization for alpha1(I) procollagen mRNA. RESULTS: In the H&E stain, Masson's trichrome stain, and immunohistochemical stain of the hairless mouse skin, the number of collagen fibers with a greater density of fibers increased, compared to the non-irradiated controls on both the 1320nm Nd: YAG laser and the long-pulsed 1064nm Nd: YAG laser. In the dot-blot hybridization in the hairless mouse, levels of alpha1(I) procollagen mRNA were increased 3.0-fold, 4.8-fold and 5.2-fold at each 1 week, 4 weeks and 12 weeks after irradiation in 1320nm Nd: YAG laser and 1.8-fold and 2.1-fold at each 4 weeks and 12 weeks after irradiation in long-pulsed 1064nm Nd: YAG laser, compared to the non-irradiated controls. But in the 1320nm Nd: YAG laser irradiation on the rat, there is no significant change in the number and density of collagen fibers, compared to the non- irradiated controls. CONCLUSION: These results indicate that the 1320nm Nd: YAG laser and the long-pulsed 1064nm Nd: YAG laser may be a powerful up-regulator of collagen synthesis through significant dermal damage and the 1320nm Nd: YAG laser is better than the long-pulsed 1064nm Nd: YAG laser for collagen synthesis. Therefore, the 1320nm Nd: YAG laser can be more effective clinically than the long-pulsed 1064nm Nd: YAG laser for the treatment of photodamaged skin.

Therapeutic effect of phenol-croton oil on photoaging skin of hairless mice / 中华医学美学美容杂志

Objective To promote the use of chemical peeling in facial rejuvenation with the phenol and croton oil peeling agents to the UVA/B-irradiated skin of hairless mice, and to provide the experimental evidence for the clinical application of the treatment of irradiated skin.Methods Sixty BALB/C hairless mice were photo-aged by use of chronic ultraviolet A and ultraviolet B irradiation for 20 weeks. After irradiation the animals were randomly divided into two groups:untreated (10 mice) and treated (50 mice). The phenol and croton oil chemical peeling agents were applied to the dorsal skin of treated animal group while it was full anesthetized. Punch biopsies were taken at 7, 14, 30, 60, and 90 days after peel for histological analysis. At 60 days after irradiation, the skin wrinkling of animals were analyzed by macroscopy, cleavage line amplification, and computer imaging analysis system. Results The treated areas of irradiated skin recovered rejuvenation and exhibited a unique connective tissue layer composed of fine collagen fibers beneath the epidermis. Conclusion The mixture of phenol-croton oil may reverses the visible stigmata of photoaging skin. Our results will be of great help to promote the use of chemical peeling in facial rejuvenation.

Photoprotective Effect of Various Sunscreens Against Ultraviolet B - induced Chronic Skin Damage / 대한피부과학회지

BACKGROUND: Chronic exposure to ultraviolet radiation(UVE) nduces photoaging characterized by dry, deeply wrinkled, inelastic, leathery, and irregulaity pigmented skin. UVR also induces solar keratosis and carcinoma, and is a contributing factor in melanoma. Sunscreens are used to prevent solar damage to skin and, if used on a daily lass should significantly reduce the incidence of the chronie photodamaging events. OBJECTIVE: We tried to evaulate the photoaging effects of UVR in the skin and the photoprotective effect of sunscreens. METHOD: We examined the gross and microscopic changes skin of albino hairless Skh : HR-1 mice exposed chronically to ultraviolet B(UVB) and suncreen-treated mice. RESULTS: The skin of the UVB-irradiated mouse shows chear, cteristic signs of photoaging, such as deep wrinkles across the back, and thickened and a hery skin. Histologically, the photoaged skin shows increased epidermal thickness, numeross fibroblasts and inflammatory cell infiltration in the upper dermis, and many enlarged keratering cysts in the lower dermis. By the 20th week, seven of the total of 9 mice(78%) in UVB irradiated mice developed at least one tumor. Histologically, the tumor is a papilloma, but the he are many dyskeratotic cells and loss of polarity in epidermis. Octyl methoxycinnamate or TiO ZnO Talc-treated mic show a significantly decreased wrinkling score, mimmal epidermal hyperplasia, slightly increased dermal cellularity, and lack of proliferation of cysts. The octyl dimethyl PABA-treatd mice shows significantly increased wrinkling score and marked inflammatory infiltration dermis. By the 20th week, only one mouse had developed a tumor in the octyl methoxy irmamate-treated group and no evidence of tumor was seen in the TiO ZnO Talc-treated group. In the octyl dimethyl PABA-treated group, five of 7 mice(71%) developed at least one tumor. CONCLUSION: The skin which is chronically exposed to UVB is subject to photoaging and photocarcinogenesis and regular use of an adequate sunscreen would prevent these photodamaging effects of UVB.

Morphological and biochemical alteration by ultraviolet B irradiation in hairless mouse / 대한피부과학회지

BACKGROUND: It is well known that ultraviolet light(UVL) may cause skin cancer, decrease immune function and promote skin ageing. It is also known that an increase of chlorofluorocabons as air pollution, which csuses the depletion of ozone of the earth in ihe atmosphere, enables harmful ultraviolet-B(UVB) to reaeh the surface of the earth more easily: The purpose of this study is to determine the harmful effect of UVB on the skin by observing coicurrently the morphologieal snd biochemical changes in the UVB irradiated skin. OBJECTIVE: The animal used was the hairless mouse(Hr+/Kud) which are considered to be the most suitable for a UVB irradiation experiment. The Fluorescent sunlamp(Toshiba FL, 20SE, Toshiba electrie Co., Tokyo, Japan) was used as a source of UVB. METHOD: The skin of the back and ear was irradiated by an increasing doses of UVB. In morphological changes, the slteration in keratinocytes and Langerhans cells in cell number and morphology were observed. In biochemical changes, activities of tte superoxide dismutase and eatalsse, which scsvanges reactive oxygen species(O and H) producec in the skin by UVB irradistion were assayed. RESULT: Sunburn cells appeared st 60mJ/cm of UVB and increased in number in proportion to the UVB irradiation with dose dependent pattern. The Langerhans cell decreased in number in proportion to UVB irrsdiation in dose dependent manner(half maximum dose was 60mJ/cm), and was not found at 1J/cm. The morphological changes of the Langerhans cells, such as a loss of dendrites and granulation, were noticed at 60mJ/cm of UVB irradiation. The enzyme activity of catalase decreased in proportion to UVB irradiation. The enzyme activity of SOD was not changed by UVB irradiation, however, it significantly increased at 1000mJ/cm UVB irradiation. CONCLUSION: This study suggest that UVB irradiation to the skin causes a reduction in the immune funetion and alters the normal biochemical function of the skin.