Effects Of IL-1β On Proliferation And Collagen Expression Of Hypertrophic Scar Fibroblasts

Hypertrophic scar is a series of hyperplasia of dermis after deep dermalwounds. Fibroblasts play a crucial role in the process of wound repair. Tounderstand and control the biological behaviour of fibroblasts is the foundationand key of promoting wound healing and preventing the formation of scar. Inrecent years, as the rapid development and research of modern cell biology andmolecular biology in the field of scar, we have a further understanding of theinteractions between fibroblasts, extracellular matrix and cytokine. We acquirethat fibroblasts can secrete of extracellular matrix. However, the proliferation offibroblast, synthesis and degradation of collagen in extracellular matrix, thegreat production of sectional cytokines and the close relationship between thethree constitutes make up the biological basis of hypertrophic scar formation.The study found that epidermal cells and dermal cells secreted IL-1at thebeginning of the wound, and IL-1had promoted the proliferation of fibroblasts,vascular endothelial cell and extracellular matrix deposition. In this paper, westudied the proliferation of human skin fibroblasts(HFB), hypertrophic scarfibroblasts(HSF) and the changes of collagen metabolism in the extracellular matrix of the above two kinds of fibroblasts after different concentrations ofexogenous IL-1stimulation in vitro on a cellular level, and combined withbiological method and means which assisted us to further understand the biologymechanism of scar formation as well as the treatment and evaluation ofhypertrophic scar. The main work and conclusions are as follows:(1) HSF were extractd and cultivated using tissue explants adherentmethod, HFB were extractd and cultivated using collagenase digestion method.HSF had no obvious differences with HFB in morphology, and they were longfusiform. This experiment used the third to fifth generations which were in goodgrowth status and in logarithmic growth phase, and1.5×104fibroblasts wereseeded in a hole of6well plate and103fibroblasts were seeded in a hole of96well plate. After24hours, the fibroblasts were cultured with differentconcentration of IL-1at2.5,5,10and20ng/mL respectively for24hours. Thefibroblasts cultured without IL-1were considered as control group. Thefibroblasts proliferation and the collagen metabolism in the extracellular matrixwere detected.(2) MTT test was used to detect the proliferation of fibroblasts, and flowcytometry was used to determine cell cycle and to analyze the S-stage of cellcycle. The above two detection methods showed that IL-1promted theproliferation of HFB, and restrained the proliferation of HSF to inhibit theformation of scar. With the increasing of IL-1doses, IL-1promoted HFBproliferation more effectively, and also inhibited HSF proliferation more effectively.(3) The method of ELISA was used to determine the concentrations of typeI and type Rcollagens in the liquid supernatant of different groups. The methodindicated that IL-1accelerated HFB synthesised and secreted type I and typeRcollagens, and restrained HSF synthesised and secreted type I and type Rcollagens to inhibit the formation of scar. With the increasing of IL-1doses,IL-1promoted the collagen metabolism of HFB more effectively, and inhibitedthe collagen metabolism of HSF more effectively as well. The concentration ofIL-1has a crucial role in influencing fibroblasts to synthesis and secrete type Iand type Rcollagens.The study has being to provide theoretical basis for drugdosage control of related diseases.