Análise da influência de proteínas da matriz extracelular e fibrinogênio na formação de biofilme por cepas de Enterococcus faecalis isoladas de infecção endodôntica primária / Analysis of influence of extracellular matrix proteins and fibrinogen in biofilm formation by Enterococcus faecalis strains isolated from primary endodontic infection

Enterococcus faecalis é um patógeno oportunista com peculiar potencial para a manutenção da infecção perirradicular endodôntica após o preparo químico-mecânico do sistema de canais radiculares. Adicionalmente, possui aptidão para desenvolver-se em biofilme e apresenta em sua parede celular adesinas compatíveis com substratos colagênicos, como a composição da matriz extracelular da dentina e dos túbulos dentinários. Esse estudo propôs-se a caracterizar geneticamente 23 amostras de E faecalis isoladas de infecções endodônticas primárias através da técnica da reação em cadeia da polimerase (PCR, do inglês Polymerase Chain Reaction) e investigar a influência de COL I (colágeno tipo I), FN (fibronectina) e fibrinogênio (FBG) na formação de biofilme em superfície abiótica. Assim, após a sensibilização de ¾ dos poços de placas de poliestireno estéreis com 50 µl da solução de proteína de matriz (COL I, FN e FBG) na concentração de 1mg/ml, transferiu-se 50µl de suspensão bacteriana (1,5 x 108 bact/mL) correspondente a cada amostra, de modo a preencher tanto os poços sensibilizados como os não sensibilizados. A quantificação da formação de biofilme foi realizada por meio de leitura por densidade óptica, cujos resultados revelaram que houve formação de biofilme por todas as em superfície abiótica, porém com diferentes graus de intensidade. Todas as cepas foram identificadas geneticamente como Enterococcus faecalis e a presença do gene gelE foi dominante. Contudo, nenhuma apresentou amplificação para os genes esp e agg, e, apesar de 73,9% das amostras amplificarem para o gene ace, apenas 2 cepas (P7 e P75) isoladas de infecções endodônticas primárias tiveram aumento de formação de biofilme na presença de COL I (P<0,05). Embora a presença de FBG não forneça subsídio estatisticamente significante para a formação de biofilme, COL I e FN influenciaram na redução da formação do biofilme para a maior parte das amostras. É possível que a capacidade de formação de biofilme inerente ao E. faecalis e a afinidade para FN e COL I através da expressão gênica de ace contribuam substancialmente para a manutenção desse micro-organismo no ambiente radicular mesmo após o tratamento endodôntico minucioso.

Enterococcus faecalis is an opportunistic pathogen with peculiar potential to maintain the periradicular endodontic infection even after chemical-mechanical preparation of the root canal system. In addition, it has the ability to develop into biofilms and presents in your cell wall adhesins compatible with collagenous substrates, as the composition of the extracellular matrix of the dentine and dentinal tubules. This study aims to characterize genetically 23 samples of E. faecalis isolated from primary endodontic infections by Polymerase Chain Reaction (PCR) technique and investigate the influence of collagen type I (COL I), fibronectin (FN) and fibrinogen (FBG) in biofilm formation on abiotic surface. Thus, after the sensitization of ¾ the wells of sterile microtiter plates with 50 ul of matrix protein solution (COL I and FN FBG) at a concentration of 1mg / ml, was transferred 50mL of bacterial suspension (1.5 x 108 bact / ml) corresponding to each sample in order to fill both wells sensitized and non-sensitized. Quantification of biofilm formation was performed by optical density, so the results showed that there were biofilm formation by all strains on abiotic surface, but with different degrees of intensity. All strains were genetically identified as Enterococcus faecalis and the presence of gelE gene was prevalent. However, none showed amplification for the esp and agg gene, and, while 73.9% of the samples for amplifying ace gene, only 2 strains (P7 and P75) isolated from primary endodontic infections they had increased biofilm formation in the presence of COL I (P <0.05). Although the presence of FBG no provides significant support for the biofilm formation, COL I and FN were relevant influence in the reduction of biofilm formation for most of the samples. It is possible that the biofilm-forming ability inherent in E. faecalis and affinity for FN and COL I through ace gene expression contribute substantially to maintain of this microorganism in the root environment even after thorough endodontic treatment.

The expression of connective tissue growth factor and matrix metalloproteinase 9 in the ovary of rat models of polycystic ovarian syndrome / 中国组织工程研究

BACKGROUND:Several studies have demonstrated that the physiological process of the ovary, including folicle development, maturity, ovulation, corpus luteum formation and regression, is related to the formation of extracelular matrix. However, matrix metaloproteinase 9 and connective tissue growth factors had a close relationship with the formation of extracelular matrix. OBJECTIVE:To investigate the relationship between the expression of connective tissue growth factor and matrix metaloproteinase 9 and polycystic ovary syndrome. METHODS:The female SD rats with regular estrous cycle were randomly divided into control and model groups. The rats in the model group were intragastricaly with letrozole to establish the model of polycystic ovary syndrome, while the rats in the control group were intragastricaly with the same amount of carboxymethyl celulose. When the natural law of estrous cycle of rats in the model group did not exist and consecutive interval appeared, rat serum and ovarian tissues were colected. Rats in the control group were detected by colecting specimen in the interval. RESULTS AND CONCLUSION:Radioimmunoassay and immunohistochemical staining results showed that compared with the control group, the expression of serum luteinizing hormone, serum prolactin levels, connective tissue growth factor in preantral folicles theca cytoplasm, connective tissue growth factors in folicular basement membrane cytoplasm, connective tissue growth factors in albuginea and matrix metaloproteinase 9 in corpus luteum significantly increased (P < 0.05). The contents of folicle stimulating hormone and serum estradiol, and expression of matrix metaloproteinase 9 in folicular basement membrane significantly decreased (P < 0.05). The results indicate that connective tissue growth factors may be related to the excessive growth of smal folicles and ovulation disorders in polycystic ovary syndrome, while matrix metaloproteinase 9 may be related to ovulation disorders in polycystic ovary syndrome.

Isolamento, expressão, e caracterização de três variantes de splicing do gene supressor de tumor RECK em modelo de astrocitoma humano / Isolation, expression, and characterization of three alternatively spliced variants of the RECK tumor suppressor gene in the human astrocytoma model

Glioblastoma multiforme (G BM), ou astrocitoma grau IV, é o tumor mais comum e letal do sistema nervoso central. Uma de suas características mais marcantes é seu alto potencial invasivo do tecido normal adjacente. Neste processo, o remodelamento da matriz extracelular, modulado por enzimas que degradam seus componentes e por inibidores destas enzimas, é crucial. Foi descrito que a expressão de MMP-2 e MMP-9, membros da família das metaloproteinases de matriz, aumentam conforme a progressão de astrocitomas. A variante canônica de RECK suprime a invasão tumoral e metástase através da inibição da atividade de, pelo menos, três MMPs: MMP-2, MMP-9 e MMP-14. Uma correlação positiva tem sido observada entre a abundância da expressão de RECK em amostras tumorais e um prognóstico mais favorável para pacientes com diversos tipos de tumores. Neste estudo, variantes de splicing do gene supressor de tumor RECK foram identificadas através da análise de Expressed sequenced Tags (ESTs), isoladas por RT-PCR, sequenciadas e clonadas. Três novas variantes de splicing do gene RECK foram identificadas e caracterizadas. O perfil de expressão dos transcritos de RECK foi determinado através de ensaios de RT-PCR quantitativo em um painel de tecidos normais e, também, durante a progressão de astrocitomas. Foram utilizadas, para esta análise, amostras macro dissecadas de tumores de pacientes com astrocitomas grau I (n=15), II (n=15), III (n=15) e GBMs (n=30). Os resultados mostram que maior expressão de RECK canônico, acompanhada de maior razão de expressão da variante canônica em relação às variantes de splicing alternativo, correlaciona positivamente com maior sobrevida global de pacientes com GBM, sugerindo seu papel como potenciais biomarcadores para o prognóstico destes pacientes. Análise funcional das isoform as de RECK em células U87 MG revelou que as células superexpressando as isoformas não apresentam inibição do processo de invasão celular, como observado para superexpressão da proteína canônica. Dentre as isoformas analisadas, destaca-se RECK-B, isoforma potencialmente ancorada à membrana plasmática por GPI, como a proteína canônica RECK, sugerindo uma possível colocalização destas variantes. Observa-se que células superexpressando RECK-B apresentam maior capacidade tumorigênica. Os resultados indicam que as variantes de RECK e o balanço entre a expressão destas variantes, apresentam um papel importante no comportamento e na agressividade de GBMs, tendo potencial valor na clínica. Além disso, para abrir perspectivas para o estudo das variantes de RECK, o balanço de expressão dos transcritos canônico e alternativos deste gene foi explorado durante os processos de diferenciação osteogênica e adipogênica. Os resultados indicam que a expressão da variante canônica é mais abundante em relação à expressão de suas isoformas em estágios tardios da adipogênese, sendo que o perfil inverso é observado em relação à isoforma B durante a osteogênese, sugerindo que o balanço entre os níveis de expressão das isformas de RECK possui um potencial papel biológico que deve ser explorado durante esses processos. Em conjunto, os resultados demonstram a existência de, pelo menos, três variantes de splicing do gene supressor de tumor RECK com envolvimento na tumorigênese e na diferenciação celular, abrindo novas perspectivas para o estudo e a aplicação do gene RECK na clínica

Glioblastoma multiforme (GBM) or grade IV astrocytoma is the most common and lethal tumor of the central nervous system. One of the most striking features of GBMs is their invasive potential of the normal surrounding brain tissue. It has been described that MMP-2 and MMP-9 expression levels increase during astrocytoma progression. Canonical RECK suppresses tumor invasion and metastasis by negatively regulating at least three matrix metalloproteinases, namely: MMP-9, MMP-2 and MT1-MMP. A positive correlation has been observed between the abundance of RECK express ion in tumor samples and a more favorable prognosis for patients with several types of tumors. In this study, splice variants of the RECK tumor suppressor gene were identified by Expressed Sequence Tag (EST) analysis, isolated by RT-PCR, sequenced and cloned. Three novel alternatively spliced variants of the RECK tumor suppressor gene were identified and characterized. The RECK transcripts expression profiles were investigated using quantitative RT-PCR assays in a normal tissue RNA panel and, also, during astrocytoma progression in macrodissected tumor samples of patients with astrocytoma grades I (n=15), II (n=15), III (n=15) and IV/GBM (n=30). The results show that higher canonical RECK expression, accompanied by a higher ratio of canonical to alternative transcript expression, positively correlated with higher overall survival rate after chemotherapeutic treatment of GBM patients. Our findings suggest that these RECK transcript variants may potentially be used as biomarkers for prognosis of GBM patients. U87 MG cells overexpressing each RECK alternative variant were generated and found to lack the supressive role of cellular invasion processes found upon overexpressing the canonical protein. Among the characterized isoforms, RECK-B stands out, since this isoform is potentially anchored to the cell membrane by a GPI anchor, exactly as the canonical RECK and, also, since cells overexpressing RECK-B display greater tumorigenic capacity. The results indicate that RECK variants and the balance between the expressions of these variants, play an important role in the behavior and aggressiviness of GBMs, therefore have a potential translational application. In addition, in order to investigate new perspectives for the analysis of these isoforms, the expression balance of RECK transcripts was assessed during osteogenesis and adipogenesis, by qRT - PCR. The results show that the expression of the canonical RECK variant is more abundant that that of its alternative isoforms in later stages of adipogenic differentiation. The opposite profile is found regarding RECK-B during osteogenesis, suggesting that the balance between the expressions of these transcripts may have a potential role during these processes. Taken together, the results show the existence of, at least, three alternatively spliced variants of the RECK tumor suppressor gene, which are involved in tumogigenesis and cellular differentiation, o pening new perspectives for studies and clinical application of the RECK gene

Cartilage construction in nude mice with microencapsulated stem cells derived from human umbilical cord Wharton’s jelly / 中国组织工程研究

BACKGROUND:Cartilage extracelular matrix with a large number of signaling molecule proteins and factors is likely to be an ideal material for tissue engineering cartilage. OBJECTIVE: To investigate the possibility of calcium alginate and cartilage extracelular matrix combined with microencapsulated stem cels derived from human umbilical cord Wharton’s jely to construct ectopic tissue-engineered cartilage in nude mice. METHODS: Microfilament suspension of the cartilage extracelular matrix was prepared. Human stem cels derived from Wharton’s jely of the umbilical cord were inoculated in to calcium alginate and cartilage extracelular matrix gel microspheres as experimental group. Stem cels derived from human umbilical cord Wharton’s jely were incubated in simple alginate gel microspheres as control group. After in vitro culture, the microspheres wereimplanted into the dorsal subcutaneous tissue of nude mice. Samples were taken after 4 weeks, respectively, for gross and histological observation. RESULTS AND CONCLUSION:The stem cels exhibited paralel-chondrocyte morphology in microspheres, which grew and proliferated quite wel during in vitro culture. A new paralel-cartilaginous tissue was found in the subcutaneous tissue 4 weeks after surgery in the experimental group, and the tissue was positive for hematoxylin-eosin, safranine O, toluidine blue and colagen II. A large number of paralel-chondrocytes and cartilage lacuna-like structures were observed under a microscope with no obvious inflammatory reaction around the microspheres. The control group showed the partial degradation of microspheres, surrounded by only a smal number of inflammatory cels and lymphocytes. Calcium alginate and cartilage extracelular matrix microspheres have a rather good histocompatibility which can be used to construct paralel-cartilaginous tissues by implanting stem cel-microspheric compound into the subcutaneous tissue of nude mice.

Cultura de fibroblastos dérmicos humanos na presença de ácido hialurônico e polietilenoglicol: efeitos na proliferação celular, produção de colágeno e enzimas relacionadas à remodelação da matriz extracelular / Culture of human dermal fibroblasts in the presence of hyaluronic acid and polyethylene glycol: effects on cell proliferation, collagen production, and related enzymes linked to the remodeling of the extracellular matrix

Introdução: Os preenchimentos cutâneos representam procedimentos comuns na dermatologia atual, sendo a maioria realizada com ácido hialurônico isolado ou associado a outras substâncias. Objetivo: Estudar os efeitos da adição de ácido hialurônico e polietilenoglicol a culturas de fibroblastos dérmicos humanos. Métodos: Foram avaliados: proliferação celular e produção de colágeno tipo 1 (COL1A1), na presença ou não de anticorpos antiCD44 (receptor de membrana de ácido hialurônico); síntese de metaloproteinase1 (MMP-1), fator tecidual inibidor de metaloproteinase1 (TIMP-1) e fator transformador de crescimento ß (TGF-ß), pela análise da expressão gênica via PCR (polymerase chain reaction); proliferação celular através da detecção da incorporação de um análogo da timidina no DNA celular. Resultados: Observou-se aumento na proliferação dos fibroblastos, bem como da síntese de colágeno nas culturas expostas ao ácido hialurônico, inibido parcialmente pela presença dos anticorpos antiCD44 nas culturas. A exposição das culturas ao ácido hialurônico aumenta a produção de TIMP-1 e TGF-ß e reduz a expressão de MMP-1. Esses efeitos não foram notados nas culturas expostas ao polietilenoglicol. Conclusão: In vitro, a adição de ácido hialurônico a culturas de fibroblastos dérmicos humanos aumenta a proliferação e síntese de COL1A1,TIMP-1 e TGF-ß, diminuindo a de MMP-1.A adição de antiCD44 às culturas reduz a proliferação celular e síntese de colágeno, podendo indicar o papel desse receptor na mediação desses eventos.

Introduction: Cutaneous fillings are a common procedure in today's dermatology, with the majority being carried out with hyaluronic acid isolated or combined with other substances. Objective: To study the effects of adding hyaluronic acid and polyethylene glycol to cultures of human dermal fibroblasts. Methods: The study evaluated: cell proliferation and production of type 1 collagen (COL1A1) in the presence or absence of anti-CD44 antibodies (membrane receptor for hyaluronic acid); the synthesis of metalloproteinase-1 (mmp-1), of tissue factor inhibitor of metalloproteinase-1 (TIMP - 1) and of transforming growth factor-α (TGF-α) through the analysis of gene expression via PCR (polymerase chain reaction); cell proliferation through the detection of the incorporation of a thymidine analogue in the cellular DNA. Results: Increased proliferation of fibroblasts and collagen synthesis were observed in the cultures exposed to hyaluronic acid, partially inhibited by the presence of anti-CD44 antibodies in the cultures. The exposure of cultures to hyaluronic acid enhances the production of TIMP-1 and TGF - α, and reduces the expression of MMP-1. These effects were not noticed in the cultures exposed to polyethyene glycol. Conclusion: In an in vitro setting, the addition of hyaluronic acid to cultures of human dermal fibroblasts increases proliferation and synthesis of COL1A1, TIMP-1 and TGF-α, decreasing that of MMP-1. The addition of anti-CD44 to the cultures reduces cell proliferation and collagen synthesis, which may indicate the role of that receptor in mediating those events.