The Expression of Human Beta Defensins by Thermal Injury

PURPOSE: Defensins are important components of innate immune system. These peptides have antimicrobial activity against a wise variety of pathogens that associated with burn wound infection. In particular, human beta-defensins are expressed in normal epidermal region and showed differential expression of some skin disease. We investigated that expression of human beta-defensin by in vitro and ex-vivo by thermal condition. METHODS: To investigate the expression of human beta-defensins in acute burn condition, we cultured keratinocytes and used to rat's skin at this experiment. After thermal condition, we showed the expression of beta-defensins-2 (hBD-2), -3 (hBD-3), keratins, keratinocyte differentiation and junction protein levels by RT-PCR and immunohistochemistry (IHC). RESULTS: HBD-2 & involucrin were down-regulated from 1 hr to 8 hrs in mRNA level. But others were not changed in mRNA level. In protein level, hBD-3 was decreased but pan-cytokeratin and beta-catenin were not changed. CONCLUSION: HBD-2 was down-regulated in thermal injury. Because thermal injury could induce the influence of keratinocyte differentiation and the decrease of skin protection ability. Our results suggested that human beta-defensins plays an important role in protection by several injury.

The Therapeutic Effect of Porcine Placenta Extract for Improvement Sequelae of Burn

PURPOSE: Burn injury cause pruritis, pain, psychological and functional sequelae. The one of burn injury sequelae is the hypertrophic scar. It is difficult to control devastating fibrotic condition for hypertrophic scar. The objective of this study was to investigated the therapeutic effect on burn hypertrophic scar and wound healing for sequelae of burn injury by Porcine placenta extract (PPE). METHODS: To investigate the effect of PPE, we performed in vitro cell cytotoxity test (MTT assay), antioxidant activity assay (SOD like activity), melanin content assay, cell migration asssay and RT-PCR. RESULTS: As a result of cell cytotoxity test (MTT assay), PPE showed above 80% cell viability. From Antioxidant activity assay (SOD like activity), this effect was similar to vitamin C. In the melanin content assay, melanin synthesis was inhibited 23% on PPE treatment than control. PPE enhanced cell migration on human fibroblast and decreased the expression of hypertropic scar related gene (a-SMA and P311). CONCLUSION: Our data showed anti-oxidant effect, diminution of melanin and decrease of the expression of hypertropic scar related gene on the treatment of PPE. These results may provide the insight into the potential use of porcine placenta extract as support to control skin fibrosis related to burn hypertrophic scar and alternative medicine for burn sequelae.