| Stress urinary incontinence(SUI)is a common forms of pelvic floor dysfunction,and there are over 200 million people worldwide with incontinence.SUI is essentially due to weakness of pelvic floortissue and urinary tract,the physiological changes occurring during pregnancy and the processes of childbirth have a detrimental effect on the structure and function of the muscles,nerves and fascial tissues.The main reasons of stress urinary incontinence are concluded two major categories: over moving of the urinary tract and intrinsic sphincter deficiency(ISD).At present,most researchers believe that most of the patients with stress urinary incontinence have not only urethral hyper mobility but also intrinsic sphincter deficiency,intrinsic sphincter deficiency play an important role in the pathogenesis of SUI[1-3].A 80-year of the femalemay have to bear 11.1% of the risk of pelvic surgery in lifetime,29 per cent experienced at least one operation.15 years later,There is similar results which about 12.2% of the risk of pelvic surgery,of which 19% had reoperation risk,in which 6.2% underwent surgery again[4].In addition,based on the US data claims,the estimated lifetime risk of surgery for either SUI or POP in women is 20.0% by the age of 80 years[5].The urethral sling surgery and periurethral injection of bulking agents for the initial urinary incontinence(UI)has been recognized.However,Midurethral slings were 30% to experienced reoperation,meanwhile periurethral injectables were 9 times the former.The despite havingsurgery success rate to achieve 85% to 90%,which means that 10% to 15% of patientswill have persisting incontinence.However,use of these methods has leading to sling erosion,obstruction of the lower urinary tract and infection.The methods of treatment of urinary incontinence have only solve the bladder neck dysfunction and improve urethral support local pressure at present,but it is difficult to solve the problem of ISD,so long-term effect is not ideal,moreover more complications.The self-renewal and multipotent differentiation of stem cells,leading to sphincter regeneration is new ideas for the treatment of SUI.With the development of stem cell biology,cell transplantation for the treatment of SUI has very important significance.Umbilical cord blood stem cell(UCBSC)consists mainly of hematopoietic stem cells and mesenchymal stem cells,and is a kind of differentiation potential of primitive cells,which has self-renewal and proliferation,and weak immunogenicity,and be able to influence or induce a variety of types cells or tissue differentiation,but are also a very promising stem cell resources.With the establishment and standardized management of Cord Blood Bank,cord bloodis expected to become the most reliable and stable source of cells for the treatment of SUI in future.Human cord blood mononuclear cells(HCMNCs)from cord blood contains stem cells,which is multiple heterogeneous cell populations,can secrete a variety of cytokines,and therefore may be an ideal source for cell transplantation.In this study,the purpose of the experiment is to studythe distribution of the cells within the tissue of the urethra and urodynamic curve after the cord blood mononuclear cells transplanted into proximal urethra of SUI rat,we conducted this experiments to investigate whether HCMNCs could repair and reconstruction of sphincter function,thus providing a theoretical foundation for clinical stem cell therapies.In this study,to establish female rats SUI model and to investigate the effects of prolonged vaginal distension by simulating the birth canal injury.Thismodel will be useful for mechanistic investigation of therapeutic intervention by taking advantage of cells transplantation.HCMNCswere separated by density gradient centrifugation,which were cultured and labeled.The labeled cells transplanted into proximal urethra of SUI rat,and the distribution of transplanted cells within the tissue and morphological changes of urethral tissue,as well as change of urodynamic curve were researched.The main experimental methods and results are as follows.1.Grouping of animals,SUI rat model was established and the histology alteration of urethraForty virgin female SD rats were randomly divided into 2 groups,the sham VD group included 10 rats and experimental group 30 rats.Experimental group included 15 rats with transplantation and 15 wild-type rats as control group.Experimental group rats were anesthetized,After disinfection perineum,vaginal accommodation of urethral dilators was achieved by sequentially inserting and removing increasing sizes of urethral dilators lubricated.Then,a modified 8-Fr Foley catheter was lubricated and inserted into the vagina and was secured to the vaginal introitus with a 4/0 silk suture.To distend the vagina,3 ml of saline water was injected into the balloon.After 2 h,the balloon was deflated and removed.The vagina is expanded again after 7 days.The SD rats of the sham VD groupwere onlyinserted with catheterwithout expansion.The results: Then the models was validated through the sneeze testing,extending from the pudendal cleft,measurement of the retrograde urethral perfusion pressure(RUPP)?maximum bladder capacity of experimental animals(MBC)and the histologic sections.2.Human umbilical cord blood mononuclear cells were isolated,cultured and markedWe establish the method for isolation and culture of Human umbilical cord blood mononuclear cells from human umbilical cord blood(UB).The 50 ml to 100 ml UB was separated under aseptic conditionwithin 6 hours,and human cord blood mononuclear cells was isolated by density gradient centrifugation.The results: After the umbilical cord blood mononuclear cells were cultured,the cells into spindle cells and cell clusters,and HCMNCs were labeled by 4,6-diamidine-2-pheny-lindole dihydrochloride(DAPI)and 5-bromo-2-deoxyuridine(BrdU)in L-DMEM.3.To improve SUI rats urinary capacity,and promote the repair of urethral sphincter3.1The labeled cells transplanted into proximal urethra of SUI rat and the proximal urethral tissues were obtained,we observed the shape and fluorescent distribution of cells by laser scanning confocal microscope,suggesting that HCMNCs can remain alive and distribute in the damaged urethral sphincter.3.2 We observed the morphological changes in sections of the proximal urethral tissues through the mid-urethra with hematoxylin and eosin(H&E)staining and with Masson special staining.Recovery of continence function following vaginal distension is associated with repair of the external urethral sphincter.The transplantation group(T)showed better repair compared to the control group(C)in damaged urethral sphincter,the continence function of urethral sphincter in SUI rat models was significantly improved[6].DiscussionThis study successfully isolated and cultured and labeled HCMNCs,Vaginal distension have been used for creation of SUI in rats by simulated the birth canal injury.HCMNCs can be successfully transplanted into urethral sphincter to improve SUI rats urinary capacity,and promote the repair of urethral sphincter,suggesting human cord blood mononuclear cell transplantation may be an effective method to treat female stress urinary incontinence.We can supplies the theory foundation for therapies. |
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