| Objective：Osteoarthritis(OA) is a degenerative joint disease with aprogressive articular cartilage damage as the main feature，the predilectioncrowd of which is the middle-aged and elderly，the predilection site of which isthe knee．With the acceleration of the process of ageing population，theincidence of OA in the elderly increased every year．As a result，OA hasbecome one of the most important causes of disability in the elderly andbrought great pain to the patient，thus seriously affecting their quality oflife． Till now， the etiology and pathogenesis of OA has not yet beendiscovered，so it is still the hot field of orthopedic research．Some studies showthat integrin is a member of the family of cell adhesion molecules and is atransmembrane proteinlocated in the cell surface．which plays an important rolein cell adhesion and signal transduction involving in the regulation of cellshape，polarity，adhesion，motility，growth，proliferation, differentiation，apoptosis and other physiological functions．Chondrocytes can express a varietyof integrins and the adult chondrocytes mainly express integrinα5β1．Integrinα5β1plays a vital role in chondrocytes mechanical signaltransduction，differentiation and proliferation，et al．Some research find thatintegrinα5β1is closely related to a variety of cartilage lesions，such as theinjury and repair of chondrocytes and the changes of cell phenotypic and soon．We hypothesize that the differential expression of integrinα5β1in cartilage may be associated with the degeneration of cartilage．At present，the differentialexpression of integrinα5β1in different levels of degeneration of cartilage andits relationship with the degeneration of cartilage is lack of relevant studies．Inthis study，we investigated the expression of integrinα5β1in different levels ofdegeneration of KOA articular cartilage and its relationship with thedegeneration of cartilage by detecting the expression of integrinα5β1indifferent levels of degeneration articular cartilage on the weight-bearing surfaceof distal femur of patients with knee osteoarthritis (KOA)．Methods：Collecting20cases of distal femoral osteotomy tissue in total knee arthroplasty of KOApatients, by general observation, according to the Outerbridge classificationcriteria selected degenerative cartilage specimens40cases（Each case of thespecimens is divided into three pieces by sagittal plane，one with10%neutralformalin-fixed， and the other two with-80℃frozen preservatio）． Thespecimens fixed with10%neutral formalin are made into paraffin tissues afterdecalcified， sliced for3μm， stained for HE and observed bymicroscope．According to Bobinac stage，the specimens were divided into threegroups：mild degeneration group (0-6points)，moderate degeneration group(7-9points), severe degeneration group (10-14points)．Take the methods ofImmunohistochemistry， Real-time PCR and Western blot to detect theexpression of integrinα5β1in the three groups with different levels ofdegeneration cartilage by mRNA and protein levels．Using mean±standarddeviation for the experimental data，using SPSS17.0software for statistical analysis, using One-way analysis of variance for the comparison between thethree groups, the differences is statistically significant for p<0.05．Results：Inthis study，the work of osteotomy in the distal of femoral for the20cases KOApatients was going well．The cartilage on the weight-bearing surface of distalfemur of patients was preserved well without damage and pollution．We selectthe cartilage specimens for40cases，which stained for HE was dyeing uniform,red and blue distinct, organizational structure clear, cytoplasmic nucleus legible,endoscopic observation and judgment well．According to Bobinac stage，thespecimens were divided into three groups：13cases of mild degenerationgroup，15cases of moderate degeneration group and12cases ofseveredegeneration group．Immunohistochemical staining showedthat Integrinα5β1was expressed in all levels of degeneration of cartilage．In mild degenerationgroup, it mainly expressed in the chondrocyte of shallow surface layer andtransition layer．In moderate degeneration group，it mainly expressed in thechondrocyte excepted which come from the calcified layer and the vascularendothelial cells invaded cartilage tide line．In severe degenerative group, itexpressed in all the chondrocyte and vascular endothelial cells invadedcartilage．The expression of integrinα5β1is low in mild degeneration group，while it increased in the moderate degeneration group, which was significantlyenhanced in the severe degenerative group．Among the three groups, thedifference was statistically significant (P <0.05)．Real-time PCR detectionshowed：The mRNA of integrinα5β1was expressed in all of the different levels of degeneration of cartilage．The expression of integrinα5β1is low in milddegeneration group，while it increased in the moderate degeneration group,which was significantly enhanced in the severe degenerative group．Among thethree groups, the difference was statistically significant (P <0.05)．Western blotanalysis showed that the protein of integrinα5β1was expressed in all of thedifferent levels of degeneration of cartilage．The expression of integrinα5β1islow in mild degeneration group，while it increased in the moderate degenerationgroup, which was significantly enhanced in the severe degenerativegroup．Among the three groups, the difference was statistically significant (P<0.05)． Conclusions： Integrinα5β1was expressed in all levels ofdegeneration of cartilage． Among the three groups, the expression ofintegrinα5β1is significant difference． As the degeneration of KOA escalated，the expression sites of integrinα5β1range from shallow surface to full layersand the expression level also increased. Hence, we conclude that the expressionof integrin α5β1in different levels of degeneration of KOA articular cartilagewas differential witch was associated with the degeneration of cartilage．... |
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