Metalloproteinases-eight And Tissue Inhibitor Of Matrix Metallo-proteinases-one In Fascia Transversalis Of Adult Primary Inguinal Hernias

Background and ObjectiveInguinal hernia is one of the most common disease in general surgery,but the exact reason for the development of inguinal hernia,especially for adult inguinal hernia,has not been completely determined.At academic circles,many persons consider the main etiological factor of inguinal hernia is that:①the lower intension of abdominal wall(the patency of processus vaginalis,weak transverse fascia);②the higher intraabdominal pressure.Among the total,the weak transverse fascia play a very capital role in the development of inguinal hernia..At present,there are more and more scholars alive to the relationships between the dysbolism of connective tissue and the generation and development of inguinal hernia.Findings confirm that matrix metalloproteinases and tissue inhibitor of matrix metallo- proteinases participate in the course of the generation and development of inguinal hernia one after another.MMPs and its inhibiting factor TIMPs are the most important enzymes which participate in the metabolism of collagen and the metabolic balance of Extracellular Matrix.MMPs is a group of endopeptidase depended on Zn²⁺ synthetized and secreted by fibroblasts.More than 20 MMP had been discovered up to now,which constitutes MMPs family for highly homology.Generally,MMP-1,MMP-8, MMP-13 take part in the metabolism of typeⅠ,Ⅲcollagen fiber,majorly the cross linkage and maturation of new synthetic collagen fiber,and the occurrence of henia. TIMPs is the natural inhibitor of MMPs discovered for the past few years,which bring about depressant effect through irreversible binding with MMPs,preventing degradation of extracellular matrix,and playing important role in the course of reconstruction of normal ECM and various kinds of pathologic processes.Under many circumstances,TIMPscombind with MMPs according to the ratio 1:1,thus prohibiting the binding between MMPs and substrate,resulting in the deactivation of MMPs.It is known that the balance between MMPs and TIMPs has play a significant important role in maintaining collagen stabilize,and play a certain part in the generation and recurrence of inguinal hernia.At present,there were very few studies of MMP s and TIMPs in inguinal hernia,and those finding must be certified further.In this study,expression of MMP-8 and TIMP-1 in the fascia transversalis derived from patients with inguinal hernias and from patients without inguinal hernias were detected by immunohistochemistry.The aim of this study was to investigate whether an alteration in amounts of MMP-8 and TIMP-1 were associated with the development of adult primary inguinal hernia.We expect the experimental result will provide some favourable rationale based on molecular mechanism of inguinal hernia,and scientific and effective treatment for inguinal hernia.Materials and MethodsBetween July 2007 and July 2008,45 patients who underwent primary hernia repair in the Department of General Surgery at the First Affiliated Hospital of Zhengzhou University participated in the study.The materials is transverse fascia from posterior wall of inguinal canal,controlgroup was constructed by 10 patients who underwent operation of lower abdomen,but without inguinal hernia,the materials is transverse fascia from low abdominal wall.All the tissue samples obtained of fascia transversalis were fixed with 10%formalin immediately after surgery and then transferred to the laboratory where the tissue samples were embedded in paraffin.We determined the expression of MMP-8 and its tissue inhibitors(TIMP-1) by immunohistochemistry.According to semiquantitative mark method depended on coloring density and coloring intensity,to give a mark for result of immunohistochemisty dyeing,and regard the score≥1 as positive result.The software package SPSS13.0 was used to data processing.The analysis of all data was performed with x² test or Fihser's exact probability test,and spearman rank correlation with P≤0.05 as statistical difference.Results1.The positive expression of MMP-8 and TIMP-1 protein could be detected in transversalis fascias from each of the study groups.Positive staining presented with brown and mainly localized in cytoplasm of fibroblasts.2.There is statistics difference(P＜0.05) between the expression of MMP-8 and TIMP-1 in experimental group and control group.The expression rate of MMP-8 in experimental group(P=62.2%)is higher than that of control group(P=20.0%),but the expression rate of TIMP-1 in experimental group(P=42.2%) is lower than that of control group(P=90.0%).3.The expression of MMP-8 in transversalis fascias of inguinal hernia is related with the patients' age,type of henia and long-term smoking,but not related with the patients'classification of hernia and single or bilateral henia.4.The expression of TIMP-1 in transversalis fascias of inguinal hernia is related with the patients' age,type of henia,but not related with the patients'classification of hernia,single or bilateral henia and long-term smoking.5.The expression between MMP-8 and TIMP-1 in transversalis fascias of inguinal hernia is negatively correlated.(r=-0.355,p=0.017).Conclusion1.The expression of MMP-8 in experimental group is higher than control group,and there is statistical significance.We find out that MMP-8 is positively correlated with age and type of hernia,the older the age is,the higher the expression of MMP-8 is;Prompts the MMP-8 expression and the organization gets older related.And the expression rate of MMP-8 in transverse fascia of typeⅢinguinal hernia is higher than that of typeⅠ～Ⅱinguinal hernia.The expression rate of MMP-8 of long-term smoking group is higher than non-long-term smoking group.The prompt possibly smokes to promote the MMP-8 expression.2.The expression of TIMP-1 in experimental group is lowerer than control group,and there is statistical significance.We find out that TIMP-1 is negatively correlated with age and type of hernia,the older the age is,the lower the expression of TIMP-1 is;Prompts TIMP-1 the expression also to concern with organization's aging.And the expression rate of TIMP-1 in transverse fascia of typeⅢinguinal hernia is lower than that of typeⅠ～Ⅱinguinal hernia.The expression rate of TIMP-1 is not related with the patients' classification of hernia,single or bilateral henia and long-term smoking or not.Prompted TIMP-1 to participate in the collagen metabolism adjustment.3.The expression between MMP-8 and TIMP-1 in transversalis fascias of inguinal hernia is negatively correlated.The up-regulation expression of MMP-8 and the down regulation expression of TIMP-1 lead to the faster degradation of ECM.