The Detection And Clinical Significance Of Molecular Architecture Of Adherens Junctions In Patients With Detrusor Instability

Objective: To identify the protein composition of adherens junction (AJ),which couple smooth muscle cells mechanically,by immuno histochemistry and electron microscopy.And to reveal the possible correlation betweem detrusor instability(DI) and AJ through confirming their diversity in bladder dysfunctions due to DI produced by bladder outlet obstruction (BOO).Methods: Detrusor biopsies were obtained from video urodynamically valuated 35 patients (mean age 69.1 years, range 62-87) with detrusor instability(DI) caused by benign prostatic hyperplasia(BPH), and also from 9 patients(mean age66.3 years,range57-80)with primitive singular Ta bladder cancer,no significant urinary symptoms, serving as controls.Detrusor biopsies were taken during scheduled open operations, with the written informed consent of all patients. Open biopsy from the lateral bladder wall was excised by scalpel to obviate tissue destruction and artefacts of electro cautery.Each biopsy was placed immediately in fixative(10% formaldehyde or 2% glutaraldehyde).Tissue samples from human breast cancer,appendix caecalis and endometrial cancer were used as positive controls for pan-cadherin,α-,β-,andγ-catenin.The urothelium served as an additional internal positive contro. Immunohistochemistry technique was employed to detect the expression of adherens junctions and its protein in DI.Sections were evaluated using a semiquantitative scale.The results were correlated with the patient groups.Standardized specimen processing included slitting,transsection,paraffin imbedding,sectioned,then stained with polyclonal pan-cadherin antibody, monoclonalα-,β-,γ-catenin antibodies. All antibodies wereknown to react with proteins of adherens junctions.Observe the ultramicrostructure of AJ from the experiment group and control group. Determine the expression of pan-cadherin,α-,β-,γ-catenin ,at least 10 visual fields per detrusor biopsy were evaluated on the sections.Computerized morphmiric analysis of the stained sections were performed with an image analysis system,and an average content of every sample was evaluated, and then compared respectively. The results were correlated with the patient groups.Results:1,Stained sections were observed by light microscope ,and then semi- determinalion was performed via computerized morphmiric analysis with an image analysis system(1)Immunohistochemical staining of pan-cadherin,α-,β- andγ-catenin were detected in detrusor smooth muscle within each group; and AJs were deteched between the bladder smooth muscles.(2)Tincture of pan-cadherin,α-,β-,γ-catenin in the sections from experiment group ( DI ) was comparatively light,uneven, and pecilo- distributed ,AJs were few and comparatively light,some tangle fibers were arounded.Colouration of pan-cadherin,α-,β-,γ-catenin in the sections from control group( DI) was comparatively heavy and well-distributed.The proteins of AJ in experiment group were obviously lower than in control group(P<0.01);(3)The quantity of AJ between smooth muscles cells in two groups were were obviously lower than that in their myoepithelium(P<0.01).2.Observed under transmission electron microscopy( TEM). The myofilaments in DI group were derangement , and a lot of electron-dense materies were cumulated around the tunica muscularis;AJ was the main conjunction between the smooth muscle cells in the control group.Conclusions:1,There are pan-cadherin,α-,β- andγ-catenin of cell-cell adherens junctions in bladder smooth muscle.2,The decrease of adherens junctions intercellular within the human detrusor is negative correlated with DI.3,Further studies are needed to identify the complete protein composition of adherens junctions within smooth muscle cells.