Personne : Larouche, Danielle
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Département d'épidémiologie, Faculté de Médecine, Université Laval
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- PublicationRestreintStem cells of the skin and cornea : their clinical applications in regenerative medicine(Rapid Science Publishers, 2011-02-01) Germain, Lucie; Larouche, Danielle; Gauvin, Robert; Proulx, Stéphanie; Fradette, JuliePurpose of review: The use of stem cells is of great interest for the treatment of various pathologies and ultimately for the restoration of organ function. Progress pointing towards future treatments of skin and corneal epithelial stem cell defects are reviewed, including the transplantation of living tissue-engineered substitutes. Recent findings: This article focuses on substitutes optimized for permanent replacement of skin and cornea. New skin substitutes for burn care are currently under development. More complex tissue-engineered skin substitutes in which stroma, adipose tissue, capillaries, and neurons are combined with the epithelium are being developed. Some dermal/epidermal substitutes have been applied to the treatment of patients. Cultured corneal epithelial cells have been characterized and more complete corneal substitutes are being designed. Long-term clinical results on the transplantation of cultured corneal stem cells for the treatment of limbal stem cell deficiency have been reported. Summary: Advances in tissue engineering for the development of substitutes that will benefit patients suffering from skin or corneal stem cell deficiencies are reviewed. These products are often a combination of cells, scaffolds and other factors. Key considerations in the development of corneal and skin substitutes for clinical applications are discussed.
- PublicationRestreintLa médecine régénératrice : les cellules souches, les interactions cellulaires et matricielles dans la reconstruction cutanée et cornéenne par génie tissulaire(Elsevier Masson, 2008-06-02) Germain, Lucie; Larouche, Danielle; Paquet, Claudie; Auger, François A.; Proulx, Stéphanie; Carrier, Patrick; Lavoie, Amélie; Beauparlant, Annie.Le génie tissulaire vise à produire des tissus ou organes in vitro pour le remplacement permanent des tissus endommagés. À cette fin, la production de tissus autologues possède l’avantage d’éviter tout risque de rejet suite à leur transplantation sur un patient. La maîtrise des conditions de culture des cellules souches humaines postnatales est essentielle à la réalisation de tels tissus. Il est aussi souhaitable que leur organisation histologique et leur fonctionnalité se rapprochent de celles des tissus natifs. De plus, les cellules souches jouent un rôle essentiel au niveau du remplacement des cellules épithéliales différenciées dans les tissus qui doivent constamment se renouveler, tels que la peau et la cornée. Nous avons décrit une méthode qui permet de produire des organes vivants in vitro à partir de cellules humaines postnatales sans ajouter de biomatériaux. Cette méthode d’auto-assemblage repose sur la capacité qu’ont les cellules mésenchymateuses de s’organiser en tissu en présence des conditions de culture adéquates. Grâce à différentes techniques, ces tissus peuvent ensuite être assemblés en organes plus complexes tels que les vaisseaux sanguins, les valves cardiaques, la peau ou encore la cornée. Ces divers tissus pourront éventuellement être utilisés pour le remplacement d’organes malades ou endommagés et fourniront de nouvelles alternatives pour la médecine régénératrice de demain. Cet article de revue sera concentré sur la peau et la cornée. L’importance d’utiliser des conditions d’isolement et de culture qui permettent de conserver les cellules souches et de contrôler l’organisation des tissus afin d’assurer la qualité et la fonctionnalité des organes reconstitués par génie tissulaire sera discutée.
- PublicationRestreintProspective study on the treatment of lower-extremity chronic venous and mixed ulcers using tissue-engineered skin substitute made by the self-assembly approach(Lippincott Williams & Wilkins, 2013-09-01) Beaudoin-Cloutier, Chanel; Germain, Lucie; Larouche, Danielle; Labbé, Raymond; Rochon, Marie-Hélène; Roy, Michel A.; Genest, Hervé; Soucy, Jacques; Dubé, Nathalie; Auger, François A.; Ospina, Carlos E.; Arsenault, Frédéric; Rodrigue, Bertrand; Boa, Olivier; Moulin, VéroniqueBACKGROUND: Despite present optimal standard treatment of lower-extremity ulceration, a high incidence of recurrence and treatment failure is observed. The objective of this project was to evaluate the effect of a self-assembled skin substitute (SASS) made by tissue engineering as a temporary cutaneous dressing in the treatment of hard-to-heal chronic ulcers. PATIENTS AND METHODS: The prospective uncontrolled case study includes patients suffering from venous or mixed ulcers lasting more than 6 months and unresponsive to compression therapy, with an Ankle Brachial Index greater than 0.5. Compression therapy was combined with the weekly application of SASS, produced from the patient’s own skin cells, until healing. A weekly follow-up recorded wound size, skin aspect, pain, drainage, and percentage of wound healing. Photographs were also taken to assess ulcer evolution. RESULTS: Fourteen ulcers present on 5 patients were treated. A mean of 6.7 SASS depositions by ulcer was required for healing. Two ulcers developed a minor wound infection, which was treated with oral antibiotics; another 2 ulcers recurred, and 1 healed with a second course of treatment, whereas 1 ulcer had a small recurrence treated with local wound care. CONCLUSION: The authors’ study suggests that the SASS used as a biological dressing is a promising treatment for hard-to-heal chronic venous and mixed ulcers that are unresponsive to compression therapy.
- PublicationRestreintDynamic mechanical stimulations induce anisotropy and improve the tensile properties of engineered tissues produced without exogenous scaffolding(Elsevier, 2011-09-01) Germain, Lucie; Parenteau-Bareil, Rémi; Larouche, Danielle; Bisson, Francis; Marcoux, Hugo; Bolduc, Stéphane; Auger, François A.; Gauvin, Robert; Bonnet, AdrienMechanical strength and the production of extracellular matrix (ECM) are essential characteristics for engineered tissues designed to repair and replace connective tissues that are subject to stress and strain. In this study, dynamic mechanical stimulation (DMS) was investigated as a method to improve the mechanical properties of engineered tissues produced without the use of an exogenous scaffold, referred to as the self-assembly approach. This method, based exclusively on the use of human cells without any exogenous scaffolding, allows for the production of a tissue sheet comprised of cells and ECM components synthesized by dermal fibroblasts in vitro. A bioreactor chamber was designed to apply cyclic strain to engineered tissues in order to determine if dynamic culture had an impact on their mechanical properties and ECM organization. Fibroblasts were cultured in the presence of ascorbic acid for 35 days to promote ECM production and allow the formation of a tissue sheet. This sheet was grown on a custom-built anchoring system allowing for easy manipulation and fixation of the tissue in the bioreactor. Following the 35 day period, tissues were maintained for 3 days in static culture (SC), or subjected either to a static mechanical stimulation of 10% strain, or a dynamic DMS with a duty cycle of 10% uniaxial cyclic strain at 1 Hz. ECM was characterized by histology, immunofluorescence labeling and Western blotting. Both static and dynamic mechanical stimulation induced the alignment of assessed cytoskeletal proteins and ECM components parallel to the axis of applied strain and increased the ECM content of the tissues compared to SC. Measurement of the tensile mechanical properties revealed that mechanical stimulation significantly increases both the ultimate tensile strength and tensile modulus of the engineered tissues when compared to the non-stimulated control. Moreover, we demonstrated that cyclic strain significantly increases these parameters when compared to a static-loading stimulation and that mechanical stimulation contributes to the establishment of anisotropy in the structural and mechanical properties of self-assembled tissue sheets.
- PublicationRestreintConsiderations in the choice of a skin donor site for harvesting keratinocytes containing a high proportion of stem cells for culture in vitro(Butterworth-Heinemann, 2010-12-03) Germain, Lucie; Larouche, Danielle; Paquet, Claudie; Fugère, Claudia.; Genest, Hervé; Auger, François A.; Gauvin, Robert; Têtu, Félix-Andre; Bouchard, Maurice; Roy, Aphonse; Fradette, Julie; Lavoie, Amélie; Beauparlant, Annie.The treatment of severely burned patients has benefited from the grafting of skin substitutes obtained by expansion of epithelial cells in culture. The aim of this study was to evaluate whether the anatomic site chosen for harvesting skin had an impact on the quality of the derived cell cultures. Considering that hair follicles contain epithelial stem cells, we compared hairy skin sites featuring different densities and sizes of hair follicles for their capacity to generate high quality keratinocyte cultures. Three anatomic sites from adult subjects were compared: scalp, chest skin and p-auricular (comprising pre-auricular and post-auricular) skin. Keratin (K) 19 was used as a marker to evaluate the proportion of stem cells. Keratinocytes were isolated using the two-step thermolysin and trypsin cell extraction method, and cultured in vitro. The proportion of K19-positive cells harvested from p-auricular skin was about twice that of the scalp. This K19-positive cell content also remained higher during the first subcultures. In contrast to these in vitro results, the number of K19-positive cells estimated in situ on skin sections was about double in scalp as in p-auricular skin. Chest skin had the lowest number of K19-positive cells. These results indicate that in addition to the choice of an adult anatomic site featuring a high number of stem cells in situ, the quality of the cultures greatly depends on the ability to extract stem cells from the skin biopsy
- PublicationRestreintTissue engineering of skin and cornea : Development of new models for in vitro studies(Academy of Sciences, 2010-06-02) Guérin, Sylvain; Germain, Lucie; Larouche, Danielle; Bisson, Francis; Paquet, Claudie; Robitaille, Hubert; Auger, François A.; Gaudreault, Manon.; Martel, Israël; Duranceau, Louise; Proulx, Stéphanie; Carrier, Patrick; Simard-Bisson, Carolyne; Fradette, JulieHuman beings are greatly preoccupied with the unavoidable nature of aging. While the biological processes of senescence and aging are the subjects of intense investigations, the molecular mechanisms linking aging with disease and death are yet to be elucidated. Tissue engineering offers new models to study the various processes associated with aging. Using keratin 19 as a stem cell marker, our studies have revealed that stem cells are preserved in human skin reconstructed by tissue engineering and that the number of epithelial stem cells varies according to the donor's age. As with skin, human corneas can also be engineered in vitro. Among the epithelial cells used for reconstructing skin and corneas, significant age-dependent variations in the expression of the transcription factor Sp1 were observed. Culturing skin epithelial cells with a feeder layer extended their life span in culture, likely by preventing Sp1 degradation in epithelial cells, therefore demonstrating the pivotal role played by this transcription factor in cell proliferation. Finally, using the human tissue-engineered skin as a model, we linked Hsp27 activation with skin differentiation.
- PublicationRestreintVibrissa hair bulge houses two populations of skin epithelial stem cells distinct by their keratin profile(Federation of American Societies for Experimental Biology, 2007-12-27) Germain, Lucie; Tong, Xuemei; Larouche, Danielle; Fradette, Julie; Coulombe, Pierre A.Defining the properties of postnatal stem cells is of interest given their relevance for tissue homeostasis and therapeutic applications, such as skin tissue engineering for burn patients. In hair follicles, the bulge region of the outer root sheath houses stem cells. We show that explants from the prominent bulge area, but not the bulb, in rodent vibrissa follicles can produce epidermis in a skin model of tissue engineering. Using morphological criteria and keratin expression, we typified epithelial stem cells of vibrissa bulge. Two types of slow-cycling cells (Bb, Bs1) featuring a high colony-forming capacity occur in the bulge. Bb cells are located in the outermost basal layer, express K5, K15, K17, and K19, and feature a loosely organized keratin network. Bs1 cells localize to the suprabasal layers proximal to Bb cells and express K5/K17, corre lating with a network of densely bundled filaments. These prominent bundles are missing in K17-null mice, which lack vibrissa. Atypically, both the Bb and Bs1 keratinocytes lack K14 expression. These findings show heterogeneity within the hair follicle stem cell reposi tory, establish that a subset of slow-cycling cells are suprabasal in location, and point to a special role for K5/K17 filaments in a newly defined subset of stem cells. Our results are discussed in the context of long-term survival of engineered tissues after grafting that requires the presence of stem cells.
- PublicationRestreintRegeneration of skin and cornea by tissue engineering(Springer, 2018-02-01T16:37:44Z) Germain, Lucie; Larouche, Danielle; Paquet, Claudie; Auger, François A.; Carrier, Patrick; Fradette, Julie; Audet, Julie; Stanford, William L.Progress in tissue engineering has led to the development of technologies allowing the reconstruction of autologous tissues from the patient’s own cells. Thus, tissue-engineered epithelial substitutes produced from cultured skin epithelial cells undergo long-term regeneration after grafting, indicating that functional stem cells were preserved during culture and following grafting. However, these cultured epithelial sheets reconstruct only the upper layer of the skin and lack the mechanical properties associated to the connective tissue of the dermis. We have designed a reconstructed skin entirely made from human cutaneous cells comprising both the dermis and the epidermis, as well as a well-organized basement membrane by a method named the self-assembly approach. In this chapter, protocols to generate reconstructed skin and corneal epithelium suitable for grafting are described in details. The methods include extraction and culture of human skin keratinocytes, human skin fibroblasts as well as rabbit and human corneal epithelial cells, and a complete description of the skin reconstructed by the self-assembly approach and of corneal epithelium reconstructed over a fibrin gel
- PublicationRestreintHuman fibroblast-derived ECM as a scaffold for vascular tissue engineering(IPC Science and Technology Press, 2012-12-01) Germain, Lucie; Larouche, Danielle; Labbé, Raymond; Bourget, Jean-Michel; Auger, François A.; Gauvin, Robert; Lavoie, AmélieThe self-assembly approach is based on the capability of mesenchymal cells to secrete and organize their own extracellular matrix (ECM). This tissue engineering method allows for the fabrication of autologous living tissues, such as tissue-engineered blood vessels (TEBV) and skin. However, the secretion of ECM by smooth muscle cells (SMCs), required to produce the vascular media, may represent a long process in vitro. The aim of this work was to reduce the time required to produce a tissue-engineered vascular media (TEVM) and extend the production of TEVM with SMCs from all patients without compromising its mechanical and functional properties. Therefore, we developed a decellularized matrix scaffold (dMS) produced from dermal fibroblasts (DF) or saphenous vein fibroblasts (SVF), in which SMCs were seeded to produce a TEVM. Mechanical and contractile properties of these TEVM (referred to as nTEVM) were compared to standard self-assembled TEVM (sTEVM). This approach reduced the production time from 6 to 4 weeks. Moreover, nTEVM were more resistant to tensile load than sTEVM and their vascular reactivity was also improved. This new fabrication technique allows for the production of a vascular media using SMCs isolated from any patient, regardless of their capacity to synthesize ECM. Moreover, these scaffolds can be stored to be available when needed, in order to accelerate the production of the vascular substitute using autologous vascular cells.