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1.
Int J Mol Sci ; 25(8)2024 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-38673856

RESUMO

Immune response to biomaterials, which is intimately related to their surface properties, can produce chronic inflammation and fibrosis, leading to implant failure. This study investigated the development of magnetic nanoparticles coated with silica and incorporating the anti-inflammatory drug naproxen, aimed at multifunctional biomedical applications. The synthesized nanoparticles were characterized using various techniques that confirmed the presence of magnetite and the formation of a silica-rich bioactive glass (BG) layer. In vitro studies demonstrated that the nanoparticles exhibited bioactive properties, forming an apatite surface layer when immersed in simulated body fluid, and biocompatibility with bone cells, with good viability and alkaline phosphatase activity. Naproxen, either free or encapsulated, reduced nitric oxide production, an inflammatory marker, while the BG coating alone did not show anti-inflammatory effects in this study. Overall, the magnetic nanoparticles coated with BG and naproxen showed promise for biomedical applications, especially anti-inflammatory activity in macrophages and in the bone field, due to their biocompatibility, bioactivity, and osteogenic potential.


Assuntos
Materiais Revestidos Biocompatíveis , Vidro , Nanopartículas de Magnetita , Naproxeno , Naproxeno/farmacologia , Naproxeno/química , Vidro/química , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Nanopartículas de Magnetita/química , Animais , Camundongos , Humanos , Óxido Nítrico/metabolismo , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Dióxido de Silício/química , Sobrevivência Celular/efeitos dos fármacos , Células RAW 264.7 , Osteogênese/efeitos dos fármacos
2.
J Cell Biochem ; 125(4): e30540, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38372191

RESUMO

Breast cancer is the most common cancer in women. Although chemotherapy is still broadly used in its treatment, adverse effects remain a challenge. In this scenario, aptamers emerge as a promising alternative for theranostic applications. Studies using breast cancer cell lines provide useful information in laboratory and preclinical investigations, most of which use cell lines established from metastatic sites. However, these cell lines correspond to cell populations of the late stage of tumor progression. On the other hand, studies using breast cancer cells established from primary sites make it possible to search for new theranostic approaches in the early stages of the disease. Therefore, this work aimed to select RNA aptamers internalized by MGSO-3 cells, a human breast cancer cell line, derived from a primary site previously established in our laboratory. Using the Cell-Internalization SELEX method, we have selected two candidate aptamers (ApBC1 and ApBC2). We evaluated their internalization efficiencies, specificities, cellular localization by Reverse Transcription-qPCR (RT-qPCR) and confocal microscopy assays. The results suggest that both aptamers were efficiently internalized by human breast cancer cells, MACL-1, MDA-MB-231, and especially by MGSO-3 cells. Furthermore, both aptamers could effectively distinguish human breast cancer cells derived from normal human mammary cell (MCF 10A) and prostate cancer cell (PC3) lines. Therefore, ApBC1 and ApBC2 could be promising candidate molecules for theranostic applications, even in the early stages of tumor progression.


Assuntos
Aptâmeros de Nucleotídeos , Neoplasias da Mama , Humanos , Feminino , Aptâmeros de Nucleotídeos/genética , Neoplasias da Mama/genética , Neoplasias da Mama/tratamento farmacológico , Células MCF-7 , Linhagem Celular Tumoral , Técnica de Seleção de Aptâmeros
3.
Stem Cell Rev Rep ; 18(7): 2522-2534, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35247143

RESUMO

Up to 40% of donor corneas are deemed unsuitable for transplantation, aggravating the shortage of graft tissue. In most cases, the corneal extracellular matrix is intact. Therefore, their decellularization followed by repopulation with autologous cells may constitute an efficient alternative to reduce the amount of discarded tissue and the risk of immune rejection after transplantation. Although induced pluripotent (hiPSCs) and orbital fat-derived stem cells (OFSCs) hold great promise for corneal epithelial (CE) reconstruction, no study to date has evaluated the capacity of decellularized corneas (DCs) to support the attachment and differentiation of these cells into CE-like cells. Here, we recellularize DCs with hiPSCs and OFSCs and evaluate their differentiation potential into CE-like cells using animal serum-free culture conditions. Cell viability and adhesion on DCs were assessed by calcein-AM staining and scanning electron microscopy. Cell differentiation was evaluated by RT-qPCR and immunofluorescence analyses. DCs successfully supported the adhesion and survival of hiPSCs and OFSCs. The OFSCs cultured under differentiation conditions could not express the CE markers, TP63, KRT3, PAX6, and KRT12, while the hiPSCs gave rise to cells expressing high levels of these markers. RT-qPCR data suggested that the DCs provided an inductive environment for CE differentiation of hiPSCs, supporting the expression of PAX6 and KRT12 without the need for any soluble induction factors. Our results open the avenue for future studies regarding the in vivo effects of DCs as carriers for autologous cell transplantation for ocular surface reconstruction.


Assuntos
Tecido Adiposo , Células-Tronco Pluripotentes Induzidas , Animais , Diferenciação Celular , Córnea , Matriz Extracelular , Humanos
5.
Appl Biochem Biotechnol ; 193(11): 3704-3718, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34363139

RESUMO

In recent years, stem cell therapy has shown promise in regenerative medicine. The lack of standardized protocols for cell isolation and differentiation generates conflicting results in this field. Mesenchymal stem cells derived from adipose tissue (ASC) and fibroblasts (FIB) share very similar cell membrane markers. In this context, the distinction of mesenchymal stem cells from fibroblasts has been crucial for safe clinical application of these cells. In the present study, we developed aptamers capable of specifically recognize ASC using the Cell-SELEX technique. We tested the affinity of ASC aptamers compared to dermal FIB. Quantitative PCR was advantageous for the in vitro validation of four candidate aptamers. The binding capabilities of Apta 2 and Apta 42 could not distinguish both cell types. At the same time, Apta 21 and Apta 99 showed a better binding capacity to ASC with dissociation constants (Kd) of 50.46 ± 2.28 nM and 72.71 ± 10.3 nM, respectively. However, Apta 21 showed a Kd of 86.78 ± 9.14 nM when incubated with FIB. Therefore, only Apta 99 showed specificity to detect ASC by total internal reflection microscopy (TIRF). This aptamer is a promising tool for the in vitro identification of ASC. These results will help understand the differences between these two cell types for more specific and precise cell therapies.


Assuntos
Tecido Adiposo/metabolismo , Aptâmeros de Nucleotídeos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Fibroblastos/metabolismo , Células-Tronco Mesenquimais/metabolismo , Tecido Adiposo/citologia , Aptâmeros de Nucleotídeos/química , Células Cultivadas , Fibroblastos/citologia , Humanos , Células-Tronco Mesenquimais/citologia
6.
Sci Rep ; 11(1): 17077, 2021 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-34426608

RESUMO

The capacity of tumor cells to shift dynamically between different states could be responsible for chemoresistance and has been commonly linked to the acquisition of stem cell properties. Here, we have evaluated the phenotype switching associated with drug resistance in breast cancer cell lines and cell lineage obtained from Brazilian patients. We have highlighted the role of the cancer stem cell marker CD24 in the dynamics of cell plasticity and the acquirement of drug resistance. We showed that the translocation of CD24 from cytosol to cell membrane is a triggering event for the phenotype change of breast tumor cells exposed to drug stress. Here, we provide evidence that the phenotype switching is due to the presence of a cytosolic pool of CD24. Importantly, the cellular localization of CD24 was correlated with the changes in the dynamics of p38 MAPK activation. A strong and continuous phosphorylation of the p38 MAPK led to the overexpression of Bcl-2 after treatment in persistent cells presenting high density of CD24 on cell membrane. This phenotype enabled the cells to enter in slow-down of cell cycle, after which several weeks later, the dormant cells proliferated again. Importantly, the use of a p38 activity inhibitor sensitized cells to drug treatment and avoided chemoresistance.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/metabolismo , Antígeno CD24/metabolismo , Resistencia a Medicamentos Antineoplásicos , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Citosol/metabolismo , Feminino , Humanos , Transporte Proteico , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
7.
Cell Biochem Funct ; 39(3): 442-454, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33389760

RESUMO

Human adipose-derived stromal/stem cells (ASC) have immunomodulatory properties and the potential to differentiate into several cell lines, important for application in regenerative medicine. However, the contamination with dermal fibroblasts (FIB) can impair the beneficial effects of ASC in cell therapy. It is then essential to develop new strategies that contribute to the distinction between these two cell types. In this study, we performed functional assays, high-throughput RNA sequencing (RNA-Seq) and quantitative PCR (qPCR) to find new markers that can distinguish ASC and FIB. We showed that ASC have adipogenic and osteogenic differentiation capacity and alkaline phosphatase activity, not observed in FIB. Gene expression variation analysis identified more than 2000 differentially expressed genes (DEG) between these two cell types. We validated 16 genes present in the list of DEG, including the alkaline phosphatase gene (ALPL). In conclusion, we showed that ASC and FIB have distinct biological properties as demonstrated by alkaline phosphatase activity and differentiation capacity, besides having different gene expression profiles. SIGNIFICANCE OF THE STUDY: Although many differences between stromal stem cells derived from human adipose tissue (ASC) and human dermal fibroblasts (FIB) are described, it is still difficult to find specific markers to differentiate them. This problem can interfere with the therapeutic use of ASC. This work aimed to find new markers to differentiate these two cell populations. Our findings suggest that these cells can be distinguished by biological and molecular characteristics, such as adipogenic and osteogenic differentiation, alkaline phosphatase activity and differential gene expression profiles. The DEG were related to the regulation of the cell cycle, development process, structural organization of the cell and synthesis of the extracellular matrix. This study helps to find new cellular markers to distinguish the two populations and to better understand the properties of these cells, which can improve cell therapy.


Assuntos
Tecido Adiposo/metabolismo , Derme/metabolismo , Fibroblastos/metabolismo , RNA-Seq , Células-Tronco/metabolismo , Tecido Adiposo/citologia , Derme/citologia , Fibroblastos/citologia , Humanos , Especificidade de Órgãos , Células-Tronco/citologia , Células Estromais/citologia , Células Estromais/metabolismo
8.
J Biomed Mater Res A ; 109(7): 1051-1064, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32876363

RESUMO

Bioactive glasses (BGs) have shown great potential for tissue regeneration and their composition flexibility allows the incorporation of different ions with physiological activities and therapeutic properties in the glass network. Among the many ions that could be incorporated, cobalt (Co) is a significant one, as it mimics hypoxia, triggering the formation of new blood vessels by the vascular endothelial growth factor A (VEGFA), due to the stabilizing effect on the hypoxia inducible factor 1 subunit alpha (HIF1A), an activator of angiogenesis-related genes, and is therefore of great interest for tissue engineering applications. However, despite its promising properties, the effects of glasses incorporated with Co on angiogenesis, through human umbilical cord vein endothelial cells (HUVECs) studies, need to be further investigated. Therefore, this work aimed to evaluate the biocompatibility and angiogenic potential of a new sol-gel BG, derived from the SiO2 -CaO-P2 O5 -CoO system. The structural evaluation showed the predominance of an amorphous glass structure, and the homogeneous presence of cobalt in the samples was confirmed. in vitro experiments showed that Co-containing glasses did not affect the viability of HUVECs, stimulated the formation of tubes and the gene expression of HIF1A and VEGFA. in vivo experiments showed that Co-containing glasses stimulated VEGFA and HIF1A expression in blood vessels and cell nuclei, respectively, in the deep dermis layer of the dorsal region of rats, featuring considerable local stimulation of the angiogenesis process due to Co-release. Co-containing glasses showed therapeutic effect, and Co incorporation is a promising strategy for obtaining materials with superior angiogenesis properties for tissue engineering applications.


Assuntos
Materiais Biomiméticos/química , Cobalto/química , Vidro/química , Fator 1 Induzível por Hipóxia/análise , Neovascularização Fisiológica , Fator A de Crescimento do Endotélio Vascular/análise , Animais , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Materiais Biomiméticos/farmacologia , Cobalto/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Neovascularização Fisiológica/efeitos dos fármacos , Ratos Wistar
9.
PLoS Negl Trop Dis ; 14(8): e0008635, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32853206

RESUMO

BACKGROUND: In view of the potential immunosuppressive and regenerative properties of mesenchymal stem cells (MSC), we investigated whether transplantation of adipose tissue-derived stem cells (ASC) could be used to control the granulomatous reaction in the liver of mice infected with Schistosoma mansoni after Praziquantel (PZQ) treatment. METHODOLOGY/PRINICPAL FINDINGS: C57BL/6 mice infected with S. mansoni were treated with PZQ and transplanted intravenously with ASC from uninfected mice. Liver morpho-physiological and immunological analyses were performed. The combined PZQ/ASC therapy significantly reduced the volume of hepatic granulomas, as well as liver damage as measured by ALT levels. We also observed that ASC accelerated the progression of the granulomatous inflammation to the advanced/curative phase. The faster healing interfered with the expression of CD28 and CTLA-4 molecules in CD4+ T lymphocytes, and the levels of IL-10 and IL-17 cytokines, mainly in the livers of PZQ/ASC-treated mice. CONCLUSIONS: Our results show that ASC therapy after PZQ treatment results in smaller granulomas with little tissue damage, suggesting the potential of ASC for the development of novel therapeutic approaches to minimize hepatic lesions as well as a granulomatous reaction following S. mansoni infection. Further studies using the chronic model of schistosomiasis are required to corroborate the therapeutic use of ASC for schistosomiasis.


Assuntos
Tecido Adiposo/fisiologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Hepatopatias/terapia , Fígado/parasitologia , Praziquantel/uso terapêutico , Esquistossomose/tratamento farmacológico , Animais , Citocinas/metabolismo , Modelos Animais de Doenças , Granuloma , Fígado/metabolismo , Fígado/patologia , Hepatopatias/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Schistosoma mansoni , Esquistossomose/patologia , Esquistossomose mansoni
10.
Burns ; 46(4): 928-936, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-31722838

RESUMO

INTRODUCTION: Chemical ocular burns are among the most frequently eye-related injuries, which require immediate and intensive evaluation and care since they may lead to potential complications such as superinfection, corneal perforation, and blindness.Vasconcellea cundinamarcensis, a species from Caricaceae family, contains highly active proteolytic enzymes in its latex that show healing activity in animal models bearing lesions of different etiologies. METHODS: We evaluate the ocular toxicity of the proteolytic fraction from V. cundinamarcensis (P1G10) by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and Hen's Egg Test-Chorioallantoic Membrane test. The corneal healing property of P1G10 was studied by the ethanol-chemical burn in the rabbit's eyes. RESULTS: P1G10 is safe for ocular administration, except when administrated at 10µg/mL. P1G10 at 1µg/mL accelerates the corneal re-epithelization achieving complete wound closure after 72h of chemical burn. Also, P1G10 modulated the inflammatory response and controlled the arrangement of collagen fibers in the stroma, demonstrating its potential corneal healing properties. CONCLUSIONS: Our work was the first one to evaluate the ophthalmic application of P1G10. Here we demonstrated that P1G10 is suitable for ocular administration and it has a promising corneal healing activity which may emerge as a new pharmacological tool to the development of a new drug for ocular surface chemical injuries in the future.


Assuntos
Queimaduras Químicas/patologia , Caricaceae/enzimologia , Córnea/efeitos dos fármacos , Lesões da Córnea/patologia , Queimaduras Oculares/patologia , Fibroblastos/efeitos dos fármacos , Peptídeo Hidrolases/farmacologia , Reepitelização/efeitos dos fármacos , Administração Oftálmica , Animais , Queimaduras Químicas/metabolismo , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Colágeno/efeitos dos fármacos , Córnea/citologia , Córnea/metabolismo , Córnea/patologia , Lesões da Córnea/metabolismo , Relação Dose-Resposta a Droga , Etanol/toxicidade , Queimaduras Oculares/metabolismo , Humanos , Técnicas In Vitro , Inflamação , Látex/química , Coelhos , Solventes/toxicidade , Cicatrização/efeitos dos fármacos
11.
Stem Cells Int ; 2017: 9841035, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29358958

RESUMO

Mesenchymal stem/stromal cells (MSCs) are promising tools in cell therapy. They secrete extracellular vesicles (EVs) that carry different classes of molecules that can promote skin repair, but the mechanisms are poorly understood. Skin wound healing is a complex process that requires the activity of several signaling pathways and cell types, including keratinocytes and fibroblasts. In this study, we explored whether adipose tissue MSC-derived EVs could accelerate migration and proliferation of keratinocytes and fibroblasts, activate the AKT pathway, and promote wound healing in vivo. Furthermore, we evaluated if EV effects are miR-205 dependent. We found that MSC EVs had an average diameter of 135 nm. Keratinocytes and fibroblasts exposed to EVs exhibited higher levels of proliferation, migration, and AKT activation. Topical administration of EVs accelerated skin wound closure. Knockdown of miR-205 decreased AKT phosphorylation in fibroblasts and keratinocytes, whereas migration was decreased only in keratinocytes. Moreover, knockdown of miR-205 failed to inhibit AKT phosphorylation in fibroblasts and keratinocytes exposed to EVs. About the mechanism of EV effects, we found that incubation with EVs prevented inhibition of AKT activation by miR-205 knockdown, suggesting that EVs activate AKT independently of miR-205. In conclusion, we demonstrated that EVs are a promising tool for wound healing.

12.
Microbes Infect ; 18(2): 137-47, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26597327

RESUMO

Paracoccidioidomycosis is caused by fungi of the Paracoccidioides genus and constitutes the most prevalent deep mycosis in Latin America. Toll-like receptors promote immune response against infectious agents. Recently, it was reported that TLR9 is crucial for mice survival during the first 48 h of P. brasiliensis infection. In this study, we used CPG oligodeoxynucleotide motif as an adjuvant with and without rPb27 to immunize mice against Paracoccidioidomycosis. CPG adjuvant induced differential recruitment of lymphocytes in the inflammatory process and a lower recruitment of neutrophils. In addition, CPG induced the production of pro-inflammatory cytokines such as IL-1ß, TNF-α, IL-6 and IL-12; increased phagocytic ability and microbicidal activity by macrophages; and induced differential production of lgG2a and lgG2b, subtypes of Ig. Knockout mice for TLR9 and IL-12 showed higher fungal loads and rates of mortality compared to control mice after 30 days of infection. The association between CPG and rPb27 induced a high level of protection against Paracoccidioidomycosis after the first 30 days of infection but not at 60 days. Our findings demonstrate that TLR 9 plays a role in the protection induced by immunization with rPb27 and confirms the importance of TLR9 in the initial protection against Paracoccidioidomycosis.


Assuntos
Vacinas Bacterianas/imunologia , Proteínas Fúngicas/imunologia , Paracoccidioides/imunologia , Paracoccidioidomicose/prevenção & controle , Receptor Toll-Like 9/metabolismo , Adjuvantes Imunológicos/administração & dosagem , Animais , Vacinas Bacterianas/administração & dosagem , Vacinas Bacterianas/genética , Contagem de Colônia Microbiana , Proteínas Fúngicas/genética , América Latina , Camundongos Endogâmicos BALB C , Camundongos Knockout , Oligodesoxirribonucleotídeos/administração & dosagem , Paracoccidioidomicose/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Análise de Sobrevida , Vacinas Sintéticas/administração & dosagem , Vacinas Sintéticas/genética , Vacinas Sintéticas/imunologia
13.
J Cancer Sci Ther ; 5(2): 58-65, 2013 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24738023

RESUMO

Cancer is comprised of a multitude of epigenetic abnormalities, including the global loss and regional gain of DNA methylation as well as alterations in histone methylation. Here, we characterize a new methyltransferase, SET domain-containing protein 4 (SETD4), which is involved in breast carcinogenesis. Quantitative real-time PCR (qPCR) showed elevated expression levels of SETD4 in several breast cancer cell lines. SETD4 overexpression was confirmed by western blot analysis suggesting a correlation between high expression of SETD4 and a lack of the estrogen receptor (ER) in breast cancer. In addition, cell fractionation studies and confocal immunofluorescence revealed the nuclear and non-nuclear localization of this new protein. SETD4 knockdown in breast cancer cell lines significantly suppressed their proliferation and delayed the G1/S cell cycle transition without affecting apoptosis. Furthermore, western blot analysis showed that knockdown of SETD4 decreased cyclin D1 expression, revealing the involvement of SETD4 in cell cycle regulation. These data imply that SETD4 plays a crucial role in breast carcinogenesis and could be a novel molecular target for the development of new strategies for the diagnosis and treatment of breast cancer.

14.
Int J Nanomedicine ; 7: 6011-20, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23251090

RESUMO

This work aims to develop solid lipid nanoparticles (SLNs) loaded with retinoic acid (RA) to evaluate the influence of two lipophilic amines, stearylamine (SA) and benethamine (BA), and one hydrophilic, triethylamine (TA), on drug-encapsulation efficiency (EE) and cytotoxicity in cancer cell lines. The SLNs were characterized for EE, size, and zeta potential. The mean particle size decreased from 155 ± 1 nm (SLNs without amine) to 104 ± 4, 95 ± 1, and 96 ± 1 nm for SLNs prepared with SA, BA, and TA, respectively. SA-RA-loaded SLNs resulted in positively charged particles, whereas those with TA and BA were negatively charged. The EEs were significantly improved with the addition of the amines, and they increased from 36% ± 6% (without amine) to 97% ± 2%, 90% ± 2%, and 100% ± 1% for SA, TA, and BA, respectively. However, stability studies showed higher EE for BA-RA-loaded SLNs than TA-RA-loaded SLNs after 30 days. The formulations containing SA loaded or unloaded (blank SLNs) with RA were cytotoxic in normal and cancer cell lines. In contrast, the blank SLNs containing TA or BA did not show cytotoxicity in human breast adenocarcinoma cells (MCF-7), while RA-loaded SLNs with the respective amines were significantly more cytotoxic than free RA. Furthermore, the cytotoxicity of BA-RA-loaded SLNs was significantly higher than TA-RA-loaded SLNs. These findings are in agreement with the data obtained in the evaluation of subdiploid DNA content and cell-cycle analysis, which showed better anticancer activity for BA-RA-loaded SLNs than TA-RA-loaded SLNs and free RA. Taken together, these findings suggest that the BA-RA-loaded SLN formulation is a promising alternative for the intravenous administration of RA in the treatment of cancer.


Assuntos
Lipídeos/química , Nanocápsulas/química , Nanocápsulas/ultraestrutura , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/patologia , Tretinoína/administração & dosagem , Tretinoína/química , Antineoplásicos/administração & dosagem , Linhagem Celular Tumoral , Cristalização/métodos , Difusão , Sinergismo Farmacológico , Humanos , Íons , Resultado do Tratamento
15.
Artigo em Inglês | MEDLINE | ID: mdl-22232182

RESUMO

Pseudomonas putida G7 is one of the most studied naphthalene-degrading species. The nah operon in P. putida, which is present on the 83 kb metabolic plasmid NAH7, codes for enzymes involved in the conversion of naphthalene to salicylate. The enzyme NahF (salicylaldehyde dehydrogenase) catalyzes the last reaction in this pathway. The nahF gene was subcloned into the pET28a(TEV) vector and the recombinant protein was overexpressed in Escherichia coli Arctic Express at 285 K. The soluble protein was purified by affinity chromatography followed by gel filtration. Crystals of recombinant NahF (6×His-NahF) were obtained at 291 K and diffracted to 2.42 Å resolution. They belonged to the hexagonal space group P6(4)22, with unit-cell parameters a = b = 169.47, c = 157.94 Å. The asymmetric unit contained a monomer and a crystallographic twofold axis generated the dimeric biological unit.


Assuntos
Aldeído Oxirredutases/química , Pseudomonas putida/enzimologia , Aldeído Oxirredutases/genética , Aldeído Oxirredutases/isolamento & purificação , Aldeído Oxirredutases/metabolismo , Cristalografia por Raios X , Expressão Gênica , Naftalenos/metabolismo
16.
Biochem Biophys Res Commun ; 412(2): 341-6, 2011 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-21821003

RESUMO

The epidermal growth factor (EGF) transduces its actions via the EGF receptor (EGFR), which can traffic from the plasma membrane to either the cytoplasm or the nucleus. However, the mechanism by which EGFR reaches the nucleus is unclear. To investigate these questions, liver cells were analyzed by immunoblot of cell fractions, confocal immunofluorescence and real time confocal imaging. Cell fractionation studies showed that EGFR was detectable in the nucleus after EGF stimulation with a peak in nuclear receptor after 10 min. Movement of EGFR to the nucleus was confirmed by confocal immunofluorescence and labeled EGF moved with the receptor to the nucleus. Small interference RNA (siRNA) was used to knockdown clathrin in order to assess the first endocytic steps of EGFR nuclear translocation in liver cells. A mutant dynamin (dynamin K44A) was also used to determine the pathways for this traffic. Movement of labeled EGF or EGFR to the nucleus depended upon dynamin and clathrin. This identifies the pathway that mediates the first steps for EGFR nuclear translocation in liver cells.


Assuntos
Núcleo Celular/enzimologia , Clatrina/metabolismo , Dinaminas/metabolismo , Receptores ErbB/metabolismo , Fígado/enzimologia , Transporte Ativo do Núcleo Celular , Animais , Linhagem Celular Tumoral , Células Cultivadas , Clatrina/genética , Dinaminas/genética , Fator de Crescimento Epidérmico/metabolismo , Hepatócitos/enzimologia , Humanos , Mutação , Interferência de RNA , RNA Interferente Pequeno/genética , Ratos
17.
Mem Inst Oswaldo Cruz ; 104(1): 33-6, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19274373

RESUMO

Symptomatic prostatic paracoccidioidomycosis (PCM) is a very rare condition; however, it may express as a typical benign prostatic hyperplasia or a simulating prostatic adenocarcinoma. This case report presents PCM mimicking prostatic adenocarcinoma. The purpose of this paper is to call the general physician's attention to this important differential diagnosis.


Assuntos
Paracoccidioidomicose/diagnóstico , Hiperplasia Prostática/parasitologia , Neoplasias da Próstata/diagnóstico , Antiprotozoários/uso terapêutico , Diagnóstico Diferencial , Humanos , Itraconazol/uso terapêutico , Masculino , Pessoa de Meia-Idade , Paracoccidioides/isolamento & purificação , Paracoccidioidomicose/tratamento farmacológico , Antígeno Prostático Específico/sangue , Hiperplasia Prostática/tratamento farmacológico , Sulfametoxazol/uso terapêutico , Trimetoprima/uso terapêutico
18.
Arq Bras Oftalmol ; 70(2): 371-5, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17589717

RESUMO

Stem cells have been studied in several fields of Medicine, and their applications are not too far from the clinical practice. Retinal impairment by neuronal death has been considered incurable due to the limited regenerative capacity of the central nervous system. The capacity of stem cells to regenerate tissues, as well as their plasticity makes them a potential source for retinal repair. The stem cells are a great promise for the therapy of inherited retinal disorders and retinal-neuronal degenerative diseases, such as retinitis pigmentosa and allied retinal dystrophies, which can result in blindness. Because of the accessibility, expansibility, and multipotentiality mesenchymal stem cells are expected to be useful for clinical applications, especially in regenerative medicine and tissue engineering. Mesenchymal stem cells are clonogenic, nonhematopoietic stem cells present in the bone marrow. Given the appropriate microenvironment, they could differentiate into cardiomyocytes or even into cells of nonmesodermal derivation including hepatocytes and neurons. So far, the results of a few studies are consistent with the belief that cell-based therapies using mesenchymal stem cells may be effective when it comes to retinal damaged tissue repair.


Assuntos
Regeneração , Retina , Células-Tronco , Animais , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Multipotentes/fisiologia , Retina/citologia , Retina/fisiologia , Células-Tronco/citologia , Células-Tronco/fisiologia
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