Expression And Significance Of SDF-1, CXCR4 And ERK1/2 In Pathologic Scar Tissue

BACKGROUND AND OBJECTIVEPathologic scars, including keloid and hypertrophic scars are the dys-repairing product of skin, Characterized by the abnormal proliferation of fibroblast and the massive deposition of extracellular matrix (ECM).Usually accompanied by pain and tickle, it disfigures patient's appearance and influence the corresponding function. Pathologic scars are a puzzle confronted the surgeon, for its mechanism is still unknown. Recently, a lot of studies prove that the over-increase and the suppressive apoptosis of fibroblast, the imbalance of composing and degradation of extracellular matrix and the produce of cytokine are the primary causes of pathologic scars. Stromal cell-derived factor-1(SDF-1) is one kind of CXC chemokines, it is produced by the bone marrow stromal cells (BMSCS),named CXC chemokine ligand-12(CXCL).CXC Chemokine Receptor-4(CXCR4) is the solely receptor of SDF-1.They form SDF-1/CXCR4 biological axis. When they join together, they will play an important role in cell migration, information transferring, wound healing and other physiology and pathology process.SDF-1 and CXCR4 widely convey in various cell and organized system, including immunological cell, brain, heart, kidney, liver, lungs and spleen, they play a very important part in the development of immune, circulation and central nervous system. Extracellular-signal regulated protein kinase 1/2(ERK1/2) is one of mitogen activated protein kinases signal transduction pathways.ERK1/2 participates in the process that extracellular signal transmit to nucleus.It correlates with cell multiplication, cell differentiation, and the formation of tumor. This experiment is to test the distributions and expressions of SDF-1,CXCR4 and ERK1/2 in pathologic scars by immunohistochemistry method, to offer a new train of thought for the mechanisms of pathologic scar.MATERIALS AND METHODSAll samples of experimental tissue were obtained from patients of Plastic Surgery department,the First Affiliated Hospital, Zhengzhou University,during 2008 and 2009.There are 66 cases of Pathologic scars,37 males and 29 females,4～52 (35.5±16.0) years old; 25 cases of non-pathological scar,14 males and 11 females,2～50 (26.0±12.0) years old; 27 cases of normal skins,15 males and 12 females,3-65 (23.4±11.4) years old. All the experimental tissues were taken from face, neck, chest, shoulders or the four limbs. All the tissues were fixed in 10% neutral formalin and desiccated and embedded in paraffin, then cut as slices.The SABC immunohistochemical technique was used to detect the expression of SDF-1,CXCR4 and ERK1/2 in 66 cases of Pathologic scars tissue,25 cases of non-pathological scar tissue and 27 cases of normal skin tissue.The data was processed by SPSS13.0,using fourfold table chi-square test to compare two sample rates.Use Fisher precise statistical method when the data is inconformity with the condition of chi-square test. Use chi-square test of ranks data to compare many sample rates.Use Spearman correlation analysis method to analyse the correlation. The significance level isα=0.05.RESULTSThe expressions of SDF-1,CXCR4 and ERK1/2 in pathological scar tissues were 73.3%,80.3%和74.3%,exceeded the expressions in non-pathological scar tissues and normal skin tissues(p<0.05).In pathological scars, the expressions of SDF-1 and ERK1/2 had evident positive relevance (r=0.293,p<0.05),the expressions of CXCR4 and ERK1/2 also have evident positive relevance(r=0.284,p< 0.05).CONCLUSIONThe positivity of SDF-1 and CXCR4 in pathological scars prompted that SDF-1 partake the form of pathological scars by its receptor CXCR4.The positivity of ERK1/2 in pathological scars prompted that the SDF-1/CXCR4 biological axis probably through adjusting the ERK1/2 ways,and play an important role in pathological scarring.