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1.
Adv Skin Wound Care ; 36(7): 1-4, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-37338952

RESUMO

ABSTRACT: Eccrine angiomatous hamartoma (EAH) is a rare hamartoma characterized by a benign proliferation of eccrine glands and vascular structures in the dermis. These tumors rarely regress spontaneously, so surgical excision of the involved tissue is required when pain or enlargement occurs. Here, the authors report the clinical case of a patient affected by an extremely painful EAH with the atypical localization at the last phalanx of the thumb of the right hand with involvement of nail matrix and nail bed. This report aims to emphasize the application of Mohs micrographic surgery for the treatment of painful EAH in a very difficult area at potential risk of amputation while preserving the maximum anatomical integrity and function of the damaged area. These results can pave the way for the use of Mohs micrographic surgery for very carefully selected benign neoplasms when their surgical removal is required.


Assuntos
Hamartoma , Doenças das Glândulas Sudoríparas , Humanos , Cirurgia de Mohs , Doenças das Glândulas Sudoríparas/diagnóstico , Doenças das Glândulas Sudoríparas/cirurgia , Doenças das Glândulas Sudoríparas/patologia , Glândulas Écrinas/patologia , Glândulas Écrinas/cirurgia , Hamartoma/complicações , Hamartoma/cirurgia , Hamartoma/patologia , Mãos , Dor
2.
Antioxidants (Basel) ; 11(7)2022 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-35883741

RESUMO

The biological properties of the human amniotic membrane (HAM) and its characteristic ability to be a reservoir of growth factors promoting wound healing make it an ideal biological dressing for the treatment of different clinical conditions, such as burns and non-healing wounds. However, the application of a preservation method on the HAM is required during banking to maintain biological tissue properties and to ensure the release overtime of protein content for its final clinical effectiveness after application on the wound bed. Although cryopreservation and freezing are methods widely used to maintain tissue properties, reactive oxygen species (ROS) are produced within tissue cellular components during their switching from frozen to thawed state. Consequently, these methods can lead to oxidative stress-induced cell injury, affecting tissue regenerative properties and its final clinical effectiveness. Taking advantage of the antioxidant activity of the natural compound quercetin, we used it to improve the antioxidant and regenerative properties of frozen or cryopreserved HAM tissues. In particular, we evaluated the oxidative damage (lipid peroxidation, malondialdehyde) as well as the regenerative/biological properties (bFGF growth factor release, wound healing closure, structure, and viability) of HAM tissue after its application. We identified the effectiveness of quercetin on both preservation methods to reduce oxidative damage, as well as its ability to enhance regenerative properties, while maintaining the unaltered structure and viability of HAM tissue. The use of quercetin described in this study appears able to counteract the side effects of cryopreservation and freezing methods related to oxidative stress, enhancing the regenerative properties of HAM. However, further investigations will need to be performed, starting from these promising results, to identify its beneficial effect when applied on burns or non-healing wounds.

3.
Adv Skin Wound Care ; 33(10): 1-4, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32889820

RESUMO

Darier disease is an autosomal dominant skin disorder characterized by keratotic papules. After their appearance, these lesions tend to grow over time, producing large and exudative plaques that compromise the general condition of the affected patient's skin. The authors report the clinical case of a patient affected by Darier disease with superinfected de-epithelialized areas over 30% of his body. In addition to antibiotic and antifungal therapy, providers used allograft skin to cover the injured areas and stimulate their progressive re-epithelialization with complete healing after 2 months. To the authors' knowledge, this is the first clinical case of treating Darier disease with allograft skin on an extensively damaged area. The effectiveness of this treatment may lead clinicians to consider allograft skin tissue a new, alternative dressing to treat Darier disease when this pathologic condition manifests with extensive eroded skin.


Assuntos
Aloenxertos/transplante , Doença de Darier/patologia , Doença de Darier/terapia , Transplante de Pele , Idoso , Antibacterianos/uso terapêutico , Seguimentos , Humanos , Masculino , Transplante Autólogo
5.
J Burn Care Res ; 41(5): 1084-1091, 2020 09 23.
Artigo em Inglês | MEDLINE | ID: mdl-32227080

RESUMO

The rapid eschar removal by surgical debridement is currently considered the standard of care for the treatment of burned patients. However, the excision of viable dermal residues can frequently occur when this procedure is applied affecting, in turn, the possible spontaneous re-epithelialization of the lesion area and increasing the amount of autologous skin grafts required for its treatment. To overcome these problems, the use of enzymatic debridement by proteolytic enzymes enriched in Bromelain has aroused great interest in the clinical field as a valid alternative to surgical procedure for the treatment of burns when they appear of indeterminate depth. With the aim to evaluate the effectiveness of this new approach in comparison with a surgical procedure for the treatment of these types of burns we performed a retrospective data analysis taking into account patients hospitalized in our Burn Center from 2014 to 2017. The results obtained show a significant reduction in the time frame to perform debridement when an enzymatic approach is chosen, with the maintenance of viable dermal tissue on the superficial areas of the wounds, their spontaneous re-epithelialization, and a reduction of the bleeding time in the treated patients. A reduced amount of autologous skin grafts is also used when enzymatic treatment is applied. The length of stay of the patients treated with enzymatic debridement did not show significant differences compared to that treated with surgery, with excellent aesthetic results after 1 to 3 years.


Assuntos
Bromelaínas/uso terapêutico , Queimaduras/terapia , Desbridamento , Adulto , Idoso , Queimaduras/patologia , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Transplante de Pele , Fatores de Tempo , Resultado do Tratamento , Cicatrização
6.
Int J Low Extrem Wounds ; 19(1): 78-85, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31679415

RESUMO

The closure of wounds associated with soft tissue defects is surgically challenging, frequently requiring extensive plastic surgery and free flaps. The combination of ADM and STSG is an innovative method used to cover such wounds. The human-derived ADMs (H-ADMs) are the most described in the literature but according to European legislations, Companies H-ADMs outside the EC are not allowed to commercialize them in Europe, H-ADMs being "human products" and not "medical devices", so being ruled by European legislations on transplants. The Skin Bank of the Bufalini Hospital (Cesena, Italy) obtained in 2009 the approval for the production and distribution of the first human cadaver-donor derived ADM from the Italian National Transplant Center and National Health Institute, we called with the Italian acronym M.O.D.A. (Matrice Omologa Dermica Acellulata). We present here the first use of a new H-ADM for treatment of distal lower extremity wounds with exposed tendons managed in one-stage pocedure with STSG. The excellent performance suggests that in cases where autologous tissue is unavailable or undesirable, the use of M.O.D.A. in one-stage procedure represents a promising alternative for covering wounds associated with tendons exposition.


Assuntos
Derme Acelular , Traumatismos do Tornozelo/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Transplante de Pele/métodos , Lesões dos Tecidos Moles/cirurgia , Transplante Heterólogo/métodos , Técnicas de Fechamento de Ferimentos , Adulto , Feminino , Humanos , Itália , Avaliação de Processos e Resultados em Cuidados de Saúde , Recuperação de Função Fisiológica , Tendões , Cicatrização
7.
Cell Tissue Bank ; 20(2): 183-192, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30767153

RESUMO

Full-thickness skin wounds occur in many different clinical cases and the use of biological acellular dermal matrices (ADMs) to reconstruct the damaged area is increasing in the field of plastic and reconstructive surgery. In particular, the ability of ADMs to maintain the structural properties of extracellular matrix as well as to provide a suitable environment for cell growth makes their use suitable for the improvement of wound healing and the reduction of side effects deriving from contracture and scar tissue formation. In this study, we describe the clinical use of a recently developed human dermal matrix (HDM) in combination with graft skin as an alternative reconstructive solution for the treatment of full-thickness skin wounds. The HDM was applied in combination with autologous graft skin on three different clinical cases in which full-thickness skin wounds occurred. The clinical outcomes were evaluated in the patients during their follow-up. Histological as well as ultra-structural analysis were also performed on skin biopsy of the clinical case 3 one year after the treatment with HDM. The use of HDM stimulates the wound healing process in all clinical cases of full-thickness skin wounds here described with a functional and aesthetic rescue of the damaged area. Histological and ultra-structural analysis show a regenerative healing of the wound area with well-organized/oriented connective tissue in which cellular infiltration as well as blood vessels are evident. Our results support the clinical use of HDM as a permanent dermal replacement for the treatment of full-thickness skin wounds.


Assuntos
Derme Acelular , Matriz Extracelular/fisiologia , Transplante de Pele/métodos , Pele/lesões , Humanos , Pele Artificial , Cicatrização/fisiologia
8.
Joints ; 7(4): 228-232, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34235391

RESUMO

Fractures, especially if articular and periarticular, are frequently associated to functional and clinical disabling outcomes and chronic pain. In particular, the injuries with loss of bone, ligament, and/or tendon tissue in which the full recovery of the wound area is not obtained are the worst anatomical/pathological conditions to heal. In this study, three different biological materials were used as regenerative approaches to rebuild the medial malleolus fracture of the ankle in which loss of bone, ligament, and tendon tissue occur. In particular, the morselized human bone tissue was combined with the human dermis decellularized, both augmented with homologous platelet-rich plasma. The magnetic resonance imaging study with contrast at the follow-up showed a signal compatible with vascularization of the tissue without sign of degeneration. Our new regenerative approach in which different biological materials were combined together showed a good choice of treatment for the reconstruction of not repairable outcome of a fracture.

9.
Aesthetic Plast Surg ; 42(2): 434-441, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29302735

RESUMO

INTRODUCTION: The introduction of acellular dermal matrices (ADMs) contributed to the growing diffusion of direct-to-implant breast reconstruction (DTI-BR) following mastectomy for breast cancer. According to specific legislations, European specialists could not benefit from the use of human-derived ADMs, even though most evidence in the literature are available for this kind of device, showed optimal outcomes in breast reconstruction. The Skin Bank of the Bufalini Hospital (Cesena, Italy) obtained in 2009 the approval for the production and distribution of a new human cadaver-donor-derived ADM (named with the Italian acronym, MODA, for matrice omologa dermica acellulata) from the Italian National Transplant Center and National Health Institute. We report preliminary results of MODA application in direct-to-implant breast reconstruction following nipple-areola complex (NAC)-sparing mastectomy for breast cancer treatment. MATERIALS AND METHODS: We prospectively enrolled all women undergoing NAC-sparing mastectomy for breast cancer and DTI-BR in our breast surgical unit from June 2015 to January 2017. We enrolled a selected population without previous chest wall irradiation, not being heavy tobacco smokers or diabetic, with a BMI < 30 kg/m2 and requiring less than 550 cc silicone implants. We assessed short-term outcomes, defined as postoperative complications presenting in the first 30 postoperative days and long-term outcomes at 6 and 12 months. RESULTS: From June 2015 to January 2017, we treated 56 breasts. At a mean follow-up of 14 months, we observed only two minor complications described as limited wound dehiscences, conservatively managed with complete resolution without implant exposure or re-intervention. CONCLUSIONS: Our preliminary results show very good performance of MODA in direct-to-implant breast reconstruction following NAC-sparing mastectomy for breast cancer treatment. This is particularly relevant for the European market, where no other human-derived devices are available for breast reconstruction due to regulatory restrictions. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .


Assuntos
Implantes de Mama , Neoplasias da Mama/cirurgia , Mamoplastia/métodos , Mastectomia Subcutânea/métodos , Cicatrização/fisiologia , Derme Acelular , Adulto , Idoso , Neoplasias da Mama/patologia , Estudos de Coortes , Estética , Feminino , Seguimentos , Humanos , Itália , Pessoa de Meia-Idade , Cuidados Pós-Operatórios/métodos , Estudos Retrospectivos , Resultado do Tratamento
10.
J Tissue Eng ; 9: 2041731418812613, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30622692

RESUMO

The circumcision of males is emphatically linked to numerous sexual dysfunctions. Many of the purported benefits do not hold up to the scrutiny of extensive literature surveys. Involuntary circumcision, particularly when not medically warranted, is also associated with many psychological and emotional traumas. Current methods to reconstruct the ablated tissue have significant drawbacks and produce a simple substitute that merely imitates the natural foreskin. Extracellular matrix-based scaffolds have been shown to be highly effective in the repair and regeneration of soft tissues; however, due to the unique nature of the foreskin tissue, commercially available biomaterial scaffolds would yield poor results. Therefore, this study discusses the development and evaluation of a tissue engineering scaffold derived from decellularized human foreskin extracellular matrix for foreskin reconstruction. A chemicophysical decellularization method was applied to human foreskin samples, sourced from consenting adult donors. The resulting foreskin dermal matrices were analyzed for their suitability for tissue engineering purposes, by biological, histological, and mechanical assessment; fresh frozen foreskin was used as a negative control. Sterility of samples at all stages was ensured by microbiological analysis. MTT assay was used to evaluate the absence of viable cells, and histological analysis was used to confirm the maintenance of the extracellular matrix structure and presence/integrity of collagen fibers. Bioactivity was determined by submitting tissue extracts to enzyme-linked immunosorbent assay and quantifying basic fibroblast growth factor content. Mechanical properties of the samples were determined using tensile stress tests. Results found foreskin dermal matrices were devoid of viable cells (p < 0.0001) and the matrix of foreskin dermal matrices was maintained. Basic fibroblast growth factor content doubled within after decellularization (p < 0.0001). Tensile stress tests found no statistically significant differences in the mechanical properties (p < 0.05). These results indicate that the derived foreskin dermal matrix may be suitable in a regenerative approach in the reconstruction of the human foreskin.

11.
Ultrastruct Pathol ; 42(1): 32-38, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29192810

RESUMO

Recently, interest has been increasing for human decellularized matrices, due to their ability to reduce numerous side effects related to hernia repair. To date, only animal studies investigated the biological interaction post-implant of human decellularized matrices for soft tissue repair. Therefore, the aim of this study was to evaluate the morphological response one year post implant of human decellularized matrix, through morphological analysis of human biopsies. The histological and ultrastructural results revealed a perfect cellular repopulation and neoangiogenesis, with minimal inflammatory response and a well-organized collagen matrix. The results have indicated that this scaffold can be an effective treatment for hernia.


Assuntos
Derme Acelular , Herniorrafia/métodos , Matriz Extracelular/ultraestrutura , Feminino , Humanos , Masculino , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade
12.
Ann Ital Chir ; 5: 443-448, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28874630

RESUMO

BACKGROUND: Interest is increasing for human decellularized scaffolds for their ability to favor healing and cell infiltration after transplantation, in the treatment of abdominal wall defects. The purpose of the present study is to show the clinical results obtained after the application of human decellularized dermal matrix (HDM) produced by RER Skin Bank, on patients suffering from different abdominal wall defects. METHODS: Between 2012 and 2014, 64 patients, average age 64 years, received HDM, to replace and cover the damage area during abdominal wall surgery. After surgical procedures, all patients were followed weekly for the first month and then monthly up to 6 months postoperative and any major problem or complication were recorded. Six months follow up included abdominal exams, serological tests and MRI analysis in order to evaluate integration of HDM with the patient's surroundings tissues and eventual long-term complications. RESULTS: Incisional hernia was the most frequent clinical condition in which HDM was applied, requiring also the highest amount of human decellularized dermal matrix. One month after the surgical operation, 61 patients revealed a well tolerability of HDM and a normal wound healing was also identified in all the damage areas. Only 3 patients experienced postoperative infections. Moreover the follow up after 6 months reported no signs of dermis rejection and that none of the patients was positive to serological tests. CONCLUSIONS: Human decellularized dermal matrix can be considered a safe and useful bioproduct to treat large abdominal defects, characterized by minor complications and simplicity to be implanted. KEY WORDS: Abdominal wall defects, Human decellularized dermal matrix, Skin Bank, Tissue regeneration.


Assuntos
Parede Abdominal/cirurgia , Técnicas de Fechamento de Ferimentos Abdominais , Derme Acelular , Traumatismos Abdominais/cirurgia , Neoplasias Abdominais/cirurgia , Idoso , Feminino , Hérnia Umbilical/cirurgia , Humanos , Hérnia Incisional/cirurgia , Masculino , Pessoa de Meia-Idade , Bancos de Tecidos
13.
Front Cell Dev Biol ; 4: 136, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27921032

RESUMO

The graft of autologous fat for the augmentation of soft tissue is a common practice frequently used in the field of plastic and reconstructive surgery. In addition, the presence of adipose derived stem cells (ASCs) in adipose tissue stimulates the regeneration of tissue in which it is applied after the autologous fat grafting improving the final clinical results. Due to these characteristics, there is an increasing interest in the use of ASCs for the treatment of several clinical conditions. As a consequence, the use of clean room environment is required for the production of cell-based therapies. The present study is aimed to describe the biological properties of adipose tissue and cells derived from it cultured in vitro in clean room environment according to current regulation. The collection of adipose tissue was performed using the water-jet assisted liposuction in order to preserve an high cell viability increasing their chances of future use for different clinical application in the field of plastic and reconstructive surgery.

14.
J Vis Exp ; (109): e53579, 2016 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-26967938

RESUMO

Several new methods have been developed in the field of biotechnology to obtain autologous cellular suspensions during surgery, in order to provide one step treatments for acute and chronic skin lesions. Moreover, the management of chronic but also acute wounds resulting from trauma, diabetes, infections and other causes, remains challenging. In this study we describe a new method to create autologous micro-grafts from cutaneous tissue of a single patient and their clinical application. Moreover, in vitro biological characterization of cutaneous tissue derived from skin, de-epidermized dermis (Ded) and dermis of multi-organ and/or multi-tissue donors was also performed. All tissues were disaggregated by this new protocol, allowing us to obtain viable micro-grafts. In particular, we reported that this innovative protocol is able to create bio-complexes composed by autologous micro-grafts and collagen sponges ready to be applied on skin lesions. The clinical application of autologous bio-complexes on a leg lesion was also reported, showing an improvement of both re-epitalization process and softness of the lesion. Additionally, our in vitro model showed that cell viability after mechanical disaggregation with this system is maintained over time for up to seven (7) days of culture. We also observed, by flow cytometry analysis, that the pool of cells obtained from disaggregation is composed of several cell types, including mesenchymal stem cells, that exert a key role in the processes of tissue regeneration and repair, for their high regenerative potential. Finally, we demonstrated in vitro that this procedure maintains the sterility of micro-grafts when cultured in Agar dishes. In summary, we conclude that this new regenerative approach can be a promising tool for clinicians to obtain in one step viable, sterile and ready to use micro-grafts that can be applied alone or in combination with most common biological scaffolds.


Assuntos
Técnicas de Cultura de Células , Transplante de Pele/métodos , Engenharia Tecidual/métodos , Células Cultivadas , Humanos , Células-Tronco Mesenquimais/citologia , Regeneração , Cicatrização
16.
Autophagy ; 10(5): 803-21, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24577098

RESUMO

Autophagy is a degradative pathway through which cells overcome stressful conditions and rapidly change their phenotype during differentiation. Despite its protective role, when exacerbated, autophagy may lead to cell death. Several growth factors involved in cell survival and in preventing differentiation are able to inhibit autophagy. Here we investigated the autophagic role of FGF7/KGF, an important player in epithelial cell protection and differentiation. Biochemical and quantitative fluorescence approaches showed that FGF7 and its signaling induce autophagy in human keratinocytes and the use of specific inhibitors indicated that this effect is independent of the PI3K-AKT-MTOR pathway. The selective block of autophagosome-to-lysosome fusion clarified that FGF7 induces autophagy stimulating autophagosome formation. However, quantitative fluorescence approaches also indicated that, upon a prolonged autophagic stimulus, FGF7 is able to accelerate autophagosome turnover. Moreover, in differentiating keratinocytes, the use of the autophagic inhibitor 3-MA as well as the depletion of BECN1 and ATG5, 2 essential regulators of the process, counteracted the FGF7-induced increase of the differentiation marker KRT1/K1, suggesting that autophagy is required for the FGF7-mediated early differentiation. These results provide the first evidence of a role of FGF7 in the regulation of sequential steps of the autophagic process and strengthen the hypothesis of a direct interplay between autophagy and differentiation. On the other hand, the ability of FGF7 to accelerate autophagosome turnover, preventing their dangerous accumulation, is consistent with the well-established protective role played by the growth factor in epithelial cells.


Assuntos
Autofagia/genética , Fator 7 de Crescimento de Fibroblastos/fisiologia , Queratinócitos/fisiologia , Fagossomos/genética , Fagossomos/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Humanos , Lisossomos/fisiologia , Fusão de Membrana/genética
17.
Oncotarget ; 4(2): 192-205, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23545251

RESUMO

The E5 oncogenic protein of the human papillomavirus type 16 (HPV16 E5) cooperates in epithelial transformation perturbing the behaviour of differentiating suprabasal cells. Among the receptor tyrosine kinases deregulated by 16E5 expression, the key paracrine mediator of epithelial homeostasis keratinocyte growth factor receptor (KGFR/FGFR2b) is altered in its signaling and endocytic traffic in undifferentiated keratinocytes expressing 16E5 and it would represent a major target of the viral protein in differentiated cells. With the aim to specifically address the possible interplay of 16E5 with KGFR/FGFR2b in cells already committed to differentiation, we took advantage of an in vitro model for forced overexpression or depletion of KGFR in E5 expressing human keratinocytes under synchronous waves of differentiation. Quantitative RT-PCR, biochemical and immunofluorescence analysis showed that KGFR down-modulation is responsible for a E5-mediated decrease of the early differentiation marker K1 and that the receptor re-expression as well as triggering of its kinase activity and signaling are able to efficiently counteract the impairment of differentiation, providing a further demonstration of the tumor-suppressive role of KGFR in the new unexplored context of HPV16 E5-mediated carcinogenesis. In addition, KGFR induced a ligand-dependent decrease of p63 through a miR-203 independent mechanism and this effect was blocked by inhibition of the PI3K/Akt signaling, which is the main pathway involved in KGFR-dependent keratinocyte differentiation, suggesting that alterations of the KGFR/p63 crosstalk are responsible for the impairment of keratinocyte differentiation induced by 16E5 and that the opposite tumor-suppressive action of KGFR and oncogenic role of E5 might both involve p63.


Assuntos
Papillomavirus Humano 16/metabolismo , Queratinócitos/citologia , Queratinócitos/virologia , Proteínas Oncogênicas Virais/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Diferenciação Celular/fisiologia , Linhagem Celular , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Humanos , Queratinócitos/metabolismo , Proteínas Oncogênicas Virais/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Transfecção
18.
PLoS One ; 6(9): e24194, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21957444

RESUMO

The FGFRs trigger divergent responses, such as proliferation and differentiation, and the cell type as well as the context-dependent signaling are crucial for the functional outcome. The FGFR2b/KGFR is expressed exclusively on epithelial cells and plays a key role in skin homeostasis. Here we analyzed in vitro the role of KGFR in the early differentiation of keratinocytes modulating its expression by KGFR cDNA transient transfection or KGFR siRNA microinjection and inducing a synchronous wave of differentiation in pre-confluent cells. Immunofluorescence, biochemical and molecular approaches demonstrated that KGFR overexpression increased the early differentiation marker keratin 1 at both transcriptional and translational levels, while receptor depletion reduced it. Ligand-dependent receptor activation and signaling were required for this differentiative effect. Overexpression of kinase negative KGFR mutant or Tyr769 KGFR signaling mutant, which is not able to recruit and activate PLC-γ, showed that the receptor kinase activity, but not its PLCγ-mediated signaling, is required for differentiation. Reduction of K1 expression, obtained by AKT inhibition, demonstrated that the PI3K/Akt signaling pathway is involved in the control of KGFR-mediated keratinocyte differentiation. This in vitro experimental model indicates that FGFR2b/KGFR expression represents a key event regulating keratinocyte early differentiation during the switch from undifferentiated to differentiating cells.


Assuntos
Diferenciação Celular , Queratinócitos/citologia , Queratinócitos/enzimologia , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Humanos , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Mutagênese , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo
19.
FASEB J ; 25(1): 170-81, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20844240

RESUMO

Membrane and actin cytoskeleton dynamics during phagocytosis can be triggered and amplified by the signal transduction of receptor tyrosine kinases. The epidermal keratinocytes appear to use the phagocytic mechanism of uptake to ingest melanosomes released by the melanocytes and play a pivotal role in the transfer process. We have previously demonstrated that the keratinocyte growth factor KGF/FGF7 promotes the melanosome uptake through activation of its receptor tyrosine kinase FGFR2b/KGFR. The aim of the present study was to investigate the contribution of KGFR expression, activation, and signaling in regulating the phagocytic process and the melanosome transfer. Phagocytosis was analyzed in vitro using fluorescent latex beads on human keratinocytes induced to differentiate. Melanosome transfer was investigated in keratinocyte-melanocyte cocultures. KGFR depletion by small interfering RNA microinjection and overexpression by transfection of wild type or defective mutant KGFR were performed to demonstrate the direct effect of the receptor on phagocytosis and melanosome transfer. Colocalization of the phagocytosed beads with the internalized receptors in phagolysosomes was analyzed by optical sectioning and 3-dimensional reconstruction. KGFR ligands triggered phagocytosis and melanosome transfer in differentiated keratinocytes, and receptor kinase activity and signaling were required for these effects, suggesting that FGFR2b/KGFR expression/activity and PLCγ signaling pathway play crucial roles in phagocytosis.


Assuntos
Queratinócitos/metabolismo , Melanossomas/metabolismo , Fagocitose/fisiologia , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais/fisiologia , Western Blotting , Linhagem Celular , Linhagem Celular Tumoral , Técnicas de Cocultura , Fator 10 de Crescimento de Fibroblastos/metabolismo , Fator 10 de Crescimento de Fibroblastos/farmacologia , Fator 7 de Crescimento de Fibroblastos/metabolismo , Fator 7 de Crescimento de Fibroblastos/farmacologia , Imunofluorescência , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Microesferas , Mutação , Fagocitose/efeitos dos fármacos , Fosfolipase C gama/metabolismo , Ligação Proteica , Interferência de RNA , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética
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