Biochemical mechanisms of skin radiation burns inhibition and healing by the volumetric autotransplantation of fibroblasts and of keratinocytes with fibroblasts composition

Abstract

Mechanisms of influence of volumetric autotransplantation of fibroblasts and of the mixture of fibroblasts and keratinocytes on the development of the local 3rd degree X-ray burn and the radiation skin ulcer in guinea pigs were investigated. We used d eep administration into the irradiation zone on its perimeter of 6 doses, which contained (150 – 160)×10 3 fibroblasts and (130 – 140)×10 3 keratinocytes in 100 µl. It is shown that this autotransplantation carried out 1 hour after the irradiation, and then every 24 hours, reduces the area of burn on the 35th day , compared to the control by 63%. Radiation ulcer appears on the 10th day after irradiation and is completely healed on the 25th day. With the same regimen of administration of only fibroblasts containing (200 – 210)×10 3 cells in 100 µl, these parameters of treatment were equal to 31% on 4th and 35th day, respectively. It is shown that as a result of radiation in the area of burn the level of gene expression of collagen types I and III, elastin, fibronectin, vinculin, decorin, hyaluronan synthases 1, 2, 3 , matrix metalloproteinases 1, 2, 3, 7, 9 and hyaluronidase is reduce d . Besides, i n the burn area the level of gene expression of transforming growth factor α, fibroblast growth factors 1, 2, 8 and anti - inflammatory cytokines – interleukin 10 and transforming growth factor-β1 – is reduced, while the level of gene expression of proinflammatory cytokine ( interleykin 1β ) increase s . Both types of autotransplantation cause the growth of the expression level of all the structural genes and regulatory proteins of biopolymers and decrease in the expression level of interleukin 1β, which leads to activation of tissue regeneration and healing of the burn wound. Reasons for the higher efficiency of autotransplantation using the mixture of fibroblasts and keratinocytes compared to autotransplantation by fibroblasts only are both the larger total number of liv e cells regularly replacing dead cells in the burn area , and mutual stimulation of auto - fibroblasts and auto - keratinocytes to proliferate and to synthesize biologically active substances , i.e. cytokines and growth factors.