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Dive into the research topics where Sara Bouhout is active.

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Featured researches published by Sara Bouhout.


The Journal of Sexual Medicine | 2011

Surgical option for the correction of Peyronie's disease: an autologous tissue-engineered endothelialized graft.

Annie Imbeault; Geneviève Bernard; Gabrielle Ouellet; Sara Bouhout; Serge Carrier; Stéphane Bolduc

INTRODUCTION Surgical treatment is indicated in severe cases of Peyronies disease. Incision of the plaque with subsequent graft material implantation is the option of choice. Ideal graft tissue is not yet available. AIM To evaluate the use of an autologous tissue-engineered endothelialized graft by the self-assembly method, for tunica albuginea (TA) reconstruction in Peyronies disease. METHODS Two TA models were created. Human fibroblasts were isolated from a skin biopsy and cultured in vitro until formation of fibroblast sheets. After 4 weeks of maturation, human umbilical vein endothelial cells (HUVEC) were seeded on fibroblasts sheets and wrapped around a tubular support to form a cylinder of about 10 layers. After 21 days of tube maturation, HUVEC were seeded into the lumen of the fibroblast tubes for the endothelialized tunica albuginea (ETA). No HUVEC were seeded into the lumen for the TA model. Both constructs were placed under perfusion in a bioreactor for 1 week. MAIN OUTCOME MEASURES Histology, immunohistochemistry, and burst pressure were performed to characterize mature tubular graft. Animal manipulations were also performed to demonstrate the impact of endothelial cells in vivo. RESULTS Histology showed uniform multilayered fibroblasts. Extracellular matrix, produced entirely by fibroblasts, presented a good staining for collagen 1. Some elastin fibers were also present. For the TA model, anti-human von Willebrand antibody revealed the endothelial cells forming capillary-like structures. TA model reached a burst pressure of 584 mm Hg and ETA model obtained a burst pressure of 719 mm Hg. CONCLUSIONS This tissue-engineered endothelialized tubular graft is structurally similar to normal TA and presents an adequate mechanical resistance. The self-assembly method used and the autologous property of this model could represent an advantage comparatively to other available grafts. Further evaluation including functional testing will be necessary to characterize in vivo implantation and behavior of the graft.


International Journal of Biological Macromolecules | 2015

Anticancer properties of chitosan on human melanoma are cell line dependent.

Laure Gibot; Stéphane Chabaud; Sara Bouhout; Stéphane Bolduc; François A. Auger; Véronique Moulin

PURPOSE Chitosan, a natural macromolecule, is widely used in medical and pharmaceutical fields because of its distinctive properties such as bactericide, fungicide and above all its antitumor effects. Although its antitumor activity against different types of cancer had been previously described, its mechanism of action was not fully understood. MATERIALS AND METHODS Coating of chitosan has been used in cell cultures with A375, SKMEL28, and RPMI7951 cell lines. Adherence, proliferation and apoptosis were investigated. RESULTS Our results revealed that whereas chitosan decreased adhesion of primary melanoma A375 cell line and decreased proliferation of primary melanoma SKMEL28 cell line, it had potent pro-apoptotic effects against RPMI7951, a metastatic melanoma cell line. In these latter cells, inhibition of specific caspases confirmed that apoptosis was effected through the mitochondrial pathway and Western blot analyses showed that chitosan induced an up regulation of pro-apoptotic molecules such as Bax and a down regulation of anti-apoptotic proteins like Bcl-2 and Bcl-XL. More interestingly, chitosan exposure induced an exposition of a greater number of CD95 receptor at RPMI7951 surface, making them more susceptible to FasL-induced apoptosis. CONCLUSION Our results indicate that chitosan could be a promising agent for further evaluations in antitumor treatments targeting melanoma.


The Scientific World Journal | 2013

Tissue Engineering of Urinary Bladder and Urethra: Advances from Bench to Patients

Hazem Orabi; Sara Bouhout; Amélie Morissette; Alexandre Rousseau; Stéphane Chabaud; Stéphane Bolduc

Urinary tract is subjected to many varieties of pathologies since birth including congenital anomalies, trauma, inflammatory lesions, and malignancy. These diseases necessitate the replacement of involved organs and tissues. Shortage of organ donation, problems of immunosuppression, and complications associated with the use of nonnative tissues have urged clinicians and scientists to investigate new therapies, namely, tissue engineering. Tissue engineering follows principles of cell transplantation, materials science, and engineering. Epithelial and muscle cells can be harvested and used for reconstruction of the engineered grafts. These cells must be delivered in a well-organized and differentiated condition because water-seal epithelium and well-oriented muscle layer are needed for proper function of the substitute tissues. Synthetic or natural scaffolds have been used for engineering lower urinary tract. Harnessing autologous cells to produce their own matrix and form scaffolds is a new strategy for engineering bladder and urethra. This self-assembly technique avoids the biosafety and immunological reactions related to the use of biodegradable scaffolds. Autologous equivalents have already been produced for pigs (bladder) and human (urethra and bladder). The purpose of this paper is to present a review for the existing methods of engineering bladder and urethra and to point toward perspectives for their replacement.


European Urology | 2011

Mechanical Stimuli-induced Urothelial Differentiation in a Human Tissue-engineered Tubular Genitourinary Graft

Valérie Cattan; Geneviève Bernard; Alexandre Rousseau; Sara Bouhout; Stéphane Chabaud; François A. Auger; Stéphane Bolduc

BACKGROUND A challenge in urologic tissue engineering is to obtain well-differentiated urothelium to overcome the complications related to other sources of tissues used in ureteral and urethral substitution. OBJECTIVE We investigated the effects of in vitro mechanical stimuli on functional and morphologic properties of a human tissue-engineered tubular genitourinary graft (TTGG). DESIGN, SETTING, AND PARTICIPANTS Using the self-assembly technique, we developed a TTGG composed of human dermal fibroblasts and human urothelial cells without exogenous scaffolding. Eight substitutes were subjected to dynamic flow and hydrostatic pressure for up to 2 wk compared to static conditions (n=8). MEASUREMENTS Stratification and cell differentiation were assessed by histology, electron microscopy, immunostaining, and uroplakin gene expression. Barrier function was determined by permeation studies with carbon 14-urea. RESULTS AND LIMITATIONS Dynamic conditions showed well-established stratified urothelium and basement membrane formation, whereas no stratification was observed in static culture. The first signs of cell differentiation were perceived after 7 d of perfusion and were fully expressed at day 14. Superficial cells under perfusion displayed discoidal and fusiform vesicles and positive staining for uroplakin 2, cytokeratine 20, and tight junction protein ZO-1, similar to native urothelium. Mechanical stimuli induced expression of the major uroplakin transcripts, whereas expression was low or undetectable in static culture. Permeation studies showed that mechanical constraints significantly improved the barrier function compared to static conditions (p<0.01 at 14 d, p<0.05 at 7 d) and were comparable to native urothelium. CONCLUSIONS Mechanical stimuli induced in vitro terminal urothelium differentiation in a human genitourinary substitute displaying morphologic and functional properties equivalent to a native urologic conduit.


Journal of Pediatric Urology | 2011

Bladder substitute reconstructed in a physiological pressure environment.

Sara Bouhout; Robert Gauvin; Laure Gibot; David Aubé; Stéphane Bolduc

PURPOSE Bladder reconstruction performed by enterocystoplasty or with bioengineered substitutes is still associated with complications, which led us to develop an autologous vesical equivalent (VE). This model has already proven its structural conformity. The challenge is to reconstruct our model in a more physiological environment, with the use of a bioreactor that mimics the dynamic of bladder filling and emptying, to acquire physiological properties. MATERIALS AND METHODS Fibroblasts and urothelial cells evolved in a three-dimensional culture to obtain a reconstructed VE. This was then cultured in our bioreactor which delivers a cyclic pressure increase up to 15 cm H(2)O, followed by a rapid decrease, to achieve a dynamically cultured VE (dcVE). To compare with the statically cultured VE, the dcVE was characterized using histology and immunofluorescence. The mechanical resistance was evaluated by uniaxial tensile tests, and the permeability level was measured with 14C-urea. RESULTS Compared to our static model, the dynamic culture led to a urothelium profile like that of native bladder. Permeability analysis displayed a profile comparable to native bladder, coinciding with basal cell organization in the dcVE, while an appropriate resistance for suturing and handling was shown. CONCLUSIONS This new alternative method offers a promising avenue for regenerative medicine. It is distinguished by its autologous character and its efficiency as a barrier to urea. These properties could significantly reduce inflammation, necrosis, and therefore, possible rejection.


Journal of Tissue Engineering and Regenerative Medicine | 2015

Lysophosphatidic acid enhances collagen deposition and matrix thickening in engineered tissue

Stéphane Chabaud; Thomas‐Louis Marcoux; Marie‐Pier Deschênes‐Rompré; Alexandre Rousseau; Amélie Morissette; Sara Bouhout; Geneviève Bernard; Stéphane Bolduc

The time needed to produce engineered tissue is critical. A self‐assembly approach provided excellent results regarding biological functions and cell differentiation because it closely respected the microenvironment of cells. Nevertheless, the technique was time consuming for producing tissue equivalents with enough extracellular matrix to allow manipulations. Unlike L‐arginine supplementation that only increased accumulation of collagen in cell culture supernatant in our model, addition of lysophosphatidic acid, a natural bioactive lipid, did not modify the amount of accumulated collagen in the cell culture supernatant; however, it enhanced the matrix deposition rate without inducing fibroblast hyperproliferation and tissue fibrosis. Copyright


Archive | 2013

Potential of Different Tissue Engineering Strategies in the Bladder Reconstruction

Sara Bouhout; Alexandre Rousseau; Stéphane Chabaud; AmélieMorissette; Stéphane Bolduc

Organism‘s functions are provided by different biological apparatus and one of them is essential for maintaining the integrity of this system. Indeed activities of each organs lead to the cellular production of metabolites. These metabolic products are discharged into the blood system to be supported by the urinary apparatus. The purification of the blood is essential to preserve the homeostasis of the organism and the blood pressure. The upper urinary tract is composed of kidneys which filter the blood to evacuate the excessive water, ions and toxic metabolic products. Then, this mixture called terminal urine is transported in the lower urinary tract by the ureters. The lower urinary tract consists of the bladder which stocks the urine until its evacuation by the urethra. The terminal urine is cytotoxic because of its composition of nitrogenous and potential carcinogenic elements, also its pH which varies between 4.5 and 8.3 [1, 2]. Therefore, the storage of urine need to be safe, this is why the bladder possesses two specific characteristics.


World Journal of Urology | 2016

Organ‑specific matrix self‑assembled by mesenchymal cells improves the normal urothelial differentiation in vitro

Sara Bouhout; Stéphane Chabaud; Stéphane Bolduc

PurposeEnterocystoplasty is the gold standard to perform bladder reconstruction. Since this technique has a high morbidity rate, several matrix scaffolds have been proposed to support the urothelial maturation. Unfortunately, epithelial cells failed to fully integrate the cell–matrix interactions and therefore appropriate signalling pathways of normal differentiation. Based on these observations, we proposed to culture bladder urothelial cells (BUC) onto a matrix self-assembled by bladder mesenchymal cells (BMC), to form a vesical model (VM).MethodsDifferent serum proportions were assessed to obtain a manipulable matrix deposited by BMC. The BUC were then seeded onto the BMC’s matrix to evolve in a three-dimensional culture. Haematoxylin–eosin staining, immunolabeling, scanning electron microscopy, western blot and matrix metalloproteinases analysis were performed for the VM characterization.ResultsWe were able to obtain an original matrix made of collagen-I and presenting specific organization. Matrix remodelling was observed and led to a cellular compartmentalization. The reconstructed urothelium developed in a pseudostratified arrangement, displaying an adequate cellular polarity and apical membrane remodelling of superficial cells. Like native bladder, cytokeratin 14 immunolabeling was not observed in our VM, which indicate the conformity of the development sequence taken by BUC under the influence of the BMC’s matrix.ConclusionThus, it was possible to elaborate a VM without the use of exogenous matrices. The particular characteristics of the BMC’s matrix permitted the development of an urothelium that shared the phenotype of native tissue. The autologous character of our VM, and its appropriate urothelial maturation, could potentially promote a better integration after grafting.


The Journal of Urology | 2015

A Novel and Faster Method to Obtain a Differentiated 3-Dimensional Tissue Engineered Bladder

Sara Bouhout; Francine Goulet; Stéphane Bolduc

PURPOSE We report what is to our knowledge a novel approach that led to the rapid development of a 3-dimensional bladder model, including a differentiated urothelium reconstructed without a period of exposure to the air-liquid interface. MATERIALS AND METHODS Bilayered bladder constructs were produced using anchored mesenchymal cell seeded collagen gels to create the mesenchymal layer. Gels were coated with urine for 20 minutes before urothelial cell seeding. The 3-dimensional bladder models were cultured under submerged conditions for 15 days. RESULTS Pure urine coating of the collagen matrix surface combined with its intermittent presence during urothelial development was found to be best to maintain urothelial cell properties. Immunohistological and ultrastructural analyses showed the formation of a pseudostratified urothelium devoid of abnormal K14 expression, allowing for uroplakin trafficking and forming an asymmetrical unit membrane at the apical surface. CONCLUSIONS Such tissues could be adapted for clinical applications, including bladder repair. In the context of basic science this model could serve as a good alternative to animal use for fundamental and pharmacological studies of normal or pathological bladder tissues.


Journal of Tissue Engineering and Regenerative Medicine | 2017

Urothelial cell expansion and differentiation are improved by exposure to hypoxia

Stéphane Chabaud; Ingrid Saba; Clément Baratange; Brice Boiroux; Maude Leclerc; Alexandre Rousseau; Sara Bouhout; Stéphane Bolduc

Cells obtained from a patients biopsy have to be expanded after extraction to produce autologous tissues, but standard cell culture conditions often limit their growth or lifespan and could induce early and inadequate cell differentiation. Moreover, it has previously been reported that the air–liquid interface, that induces maturation of the urothelium, stimulated inadequate differentiation associated with aberrant keratin‐14 expression. The aim of this study was to test the benefits of hypoxia during expansion of urothelial cells and maturation of the bladder epithelium in the context of tissue engineering. Bladder mucosa substitutes were reconstructed using the self‐assembly method with urothelial cells (UCs) expanded in normoxia or hypoxia. Hypoxia improved UCs expansion until passage P7, whereas normoxic conditions limited the use of UCs to passage P4. Maturation of the urothelium was also compared in normoxic vs. hypoxic conditions. Using laminin V, p63, Ki‐67, keratin‐5 and ‐14, Claudin‐4 and zonula occludens protein‐1, we show a better organization of the basal UC layer in hypoxia despite a thinner intermediate layer. Finally, barrier function was assessed by permeation tests. Cell culture in hypoxia allowed the generation of bioengineered urological tissue closer to native bladder characteristics, which represents a promising avenue to circumvent the lack of adequate tissues for reconstructive surgery. Copyright

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