Imunoexpressão de clic4, α-sma, e-caderina e vimentina em lesões odontogênicas epitelias benígnas / Immunoexpression of clic4, α-sma, e-cadherin and vimentin in benign epithelial odontogenic lesions

As lesões odontogênicas epiteliais benignas constituem um grupo heterogêneo de lesões. A proteína CLIC4 atua na regulação dos processos de parada de crescimento e apoptose, participando também do processo de transdiferenciação dos fibroblastos em miofibroblastos que passam a expressar α-SMA. Além disso, a expressão de CLIC4 pode interferir no processo de transição epitélio-mesenquima (TEM) em neoplasias. Este trabalho avaliou a imunoexpressão de CLIC4, α-SMA, E-caderina e Vimentina em ameloblastomas (AM) (n = 16), ceratocistos odontogênicos (n = 20) e tumores odontogênicos adenomatóides (TOA) (n = 8). A análise da expressão imunoistoquímica das proteínas CLIC4, E-caderina e vimentina no componente epitelial das lesões e de CLIC4 e α-SMA no tecido conjuntivo foi realizada de forma semi-quantitativa por um avaliador previamente calibrado. A expressão no componente epitelial de CLIC4 foi analisada separadamente no núcleo e no citoplasma, bem como a marcação de E-caderina que foi avaliada na membrana e no citoplasma. As comparações dos percentuais de imunorreatividade em relação aos grupos estudados foram realizadas por meio dos testes não paramétricos de Kruskal-Wallis e Mann-Whitney. Possíveis correlações entre a expressão de CLIC4, α-SMA, E-caderina e Vimentina foram avaliadas por meio do teste de correlação de Spearman. O nível de significância foi estabelecido em 5% (p < 0,05). Foram observados diferentes padrões de marcação entre os grupos analisados, observando-se que a imunoexpressão exclusivamente citoplasmática da CLIC4 no componente epitelial dos AM (p < 0,001) e TOA (p < 0,001) foi significativamente superior a dos CO, não demonstrarando significância estatística entre os AM e TOA. A imunoexpressão (nuclear e citoplasmática) da CLIC4 no revestimento epitelial CO foi significativamente superior à encontrada no componente epitelial dos AM (p < 0,001) e dos TOA (p < 0,001). A imunoexpressão estromal de CLIC4 foi significativamente superior nos AM (p = 0,009) e CO (p = 0,004) quando comparados aos TOA. A imunoexpressao de α-SMA significativamente maior em AM (p = 0,016) e CO (p = 0,034) quando comparados aos TOA. Para a imunoexpressão membranar da E-caderina em CO foi significativamente superior em comparação à encontrada nos AM (p = 0,009) e nos TOA (p = 0,024). Foi observada maior imunoexpressão de E-caderina (membranar e citoplasmática) nos COs, quando comparados aos AM (p < 0,001) e aos TOAs (p < 0,001). A expressão de Ecaderina citoplasmática foi significativamente maior nos AM e TOA (p < 0,001) quando comparados aos CO. Observou-se diferença estatisticamente significativa na imunoexpressão de vimentina entre os casos de AM e os casos de TOA (p = 0,038) e CO (p < 0,001), bem como entre o TOA e CO (p < 0,001). As correlações testadas entre os escores das proteínas estudadas evidenciou que no grupo dos AM foi possível evidenciar moderada correlação positiva e estatisticamente significativa (r = 0,527; p = 0,036) entre a expressão citoplasmática da CLIC4 e a expressão citoplasmática da E-caderina. Também foi verificada fraca correlação negativa e estatisticamente significativa (r = -0,499; p = 0,049) entre a expressão núcleo-citoplasmática da CLIC4 e a expressão citoplasmática da E-caderina nos AM. Além disso, uma moderada correlação positiva e estatisticamente significativa entre a expressão estromal da CLIC4 e a expressão da α-SMA nos AM (r = 0,648; p = 0,007) e nos CO (r = 0,541; p = 0,014). Foi observada forte correlação negativa e estatisticamente significativa (r = -0,813; p < 0,001) entre a expressão da E-caderina e a expressão da vimentina nos AM. Os resultados deste estudo sugerem um potencial envolvimento de CLIC4 no processo de transdiferenciação de miofibroblastos, e que a presença destas células é mais frequentemente associada a lesões de comportamento biológico mais agressivo como os AM e CO, além de uma possível atuação desta proteína na regulação do ciclo celular e na TEM nas lesões estudadas (AU).

Benign epithelial odontogenic lesions constitute a heterogeneous group of lesions. the CLIC4 protein acts in the regulation of growth arrest and apoptosis processes, also participating in the process of transdifferentiation of fibroblasts Into myofibroblasts that begin to express α-SMA. Furthermore, CLIC4 expression can interfere with the epithelialmesenchymal transition (EMT) process in neoplasms. This work evaluated the immunoexpression of CLIC4, α-SMA, e-cadherin and vimentin in ameloblastomas (AM) (n = 16), odontogenic keratocysts (OK) (n = 20) and adenomatoid odontogenic tumors (AOT) (n = 8). The analysis of the immunohistochemical expression of the proteins CLIC4, ecadherin and vimentin in the epithelial component of the lesions and of CLIC4 and α-SMA in the connective tissue was carried out in a semi-quantitative way by a previously calibrated evaluator. Expression in the epithelial component of CLIC4 was analyzed separately in the nucleus and cytoplasm, as well as e-cadherin labeling, which was evaluated in the membrane and cytoplasm. Comparisons of the percentages of immunoreactivity in relation to the studied groups were carried out using the nonparametric kruskal-wallis and mann-whitney tests. Possible correlations between the expression of CLIC4, α-SMA, e-cadherin and vimentin were evaluated using the spearman correlation test. The significance level was set at 5% (p < 0.05). Different staining patterns were observed between the groups analyzed, observing that the exclusively cytoplasmic immunoexpression of CLIC4 in the epithelial component of AM (p < 0.001) and AOT (p < 0.001) was significantly higher than that of OK, not demonstrating statistical significance between the AM and AOT. The immunoexpression (nuclear and cytoplasmic) of CLIC4 in the co epithelial lining was significantly higher than that found in the epithelial component of AM (p < 0.001) and AOT (p < 0.001). Stromal CLIC4 immunoexpression was significantly higher in AM (p = 0.009) and OK (p = 0.004) when compared to AOT. The immunoexpression of α-SMA is significantly higher in AM (p = 0.016) and OK (p = 0.034) when compared to AOT. For e-cadherin membrane immunoexpression in co was significantly higher compared to that found in AM (p = 0.009) and AOT (p = 0.024). Greater immunoexpression of e-cadherin (membrane and cytoplasmic) was observed in OK, when compared to AM (p < 0.001) and AOT (p < 0.001). Cytoplasmic ecadherin expression was significantly higher in AM and AOT (p < 0.001) when compared to OK. A statistically significant difference in vimentin immunoexpression was observed between cases of AM and cases of AOT (p = 0.038) and OK (p < 0.001), as well as between AOT and OK (p < 0.001). The correlations tested between the scores of the proteins studied showed that in the am group it was possible to demonstrate a moderate positive and statistically significant correlation (r = 0.527; p = 0.036) between the cytoplasmic expression of clic4 and the cytoplasmic expression of e-cadherin. A weak and statistically significant negative correlation (r = -0.499; p = 0.049) was also found between the nucleus-cytoplasmic expression of clic4 and the cytoplasmic expression of e- cadherin in AM. Furthermore, a moderate positive and statistically significant correlation between the stromal expression of CLIC4 and the expression of α-SMA in AM (r = 0.648; p = 0.007) and OK (r = 0.541; p = 0.014). Additionally, a strong negative and statistically significant correlation (r = -0.813; p < 0.001) was observed between the expression of ecadherin and the expression of vimentin in AM. The results of this study suggest a potential involvement of CLIC4 in the myofibroblast transdifferentiation process, and that the presence of these cells is more frequently associated with lesions with more aggressive biological behavior such as AM and OK, in addition to a possible role of this protein in the regulation of cell cycle and EMT in the lesions studied (AU).

Tumor miofibroblástico inflamatorio de laringe: a propósito de un caso / Inflammatory myofibroblastic tumor of the larynx: a case report

Resumen El tumor miofibroblástico inflamatorio (TMI) es una patología muy poco frecuente. Los TMI localizados en laringe pueden ocasionar disfonía o sensación de cuerpo extraño. El diagnóstico se realiza a través de pruebas de imagen y visualización directa con obtención de muestras para estudio histopatológico. Presentamos el caso de una mujer de 43 años, con antecedentes personales de carcinoma indiferenciado de nasofaringe, tratado con radioterapia y quimioterapia, que acude a revisiones periódicas en consulta de otorrinolaringología. Se objetiva por nasofibroscopia una lesión rugosa en cuerda vocal izquierda. Se realiza biopsia con fibroscopio de canal, compatible con tumoración fusocelular atípica, con áreas celulares y mixoides, sospechosa de malignidad, con necesidad de completar estudio inmunohistoquímico. En comité de tumores de cabeza y cuello se decide cirugía programada (laringectomía supracricoidea con cricohioidoepiglotopexia) y posterior tratamiento adyuvante con quimioterapia y/o radioterapia, según resultados del estudio histopatológico. Como conclusión, el TMI es una patología que se encuentra predominantemente en el pulmón, siendo rara la afectación laríngea. Su pronóstico es favorable y el diagnóstico histopatológico es de vital importancia. El diagnóstico correcto va seguido de una escisión local amplia para prevenir la recurrencia, sin embargo, el tratamiento debe adaptarse a la ubicación del tumor y al estado del paciente.

Abstract Inflammatory myofibroblastic tumor (IMT) is a very rare pathology. IMTs located in the larynx can cause dysphonia or foreign body sensation. The diagnosis is made through imaging tests and direct visualization and confirmation with samples for histopathological study. We present the case of a 43-year-old woman with a personal history of undifferentiated carcinoma of the nasopharynx treated with radiotherapy and chemotherapy, who attended periodic check-ups in an otolaryngology clinic. A rough granulomatous lesion was observed by nasofibrolaryngoscopy in the left vocal cord. A canal fibroscope biopsy is performed, compatible with an atypical spindle cell tumor, with cellular and myxoid areas, suspicious of malignancy, requiring an immunohistochemical study to be completed. The head and neck tumor committee decides on scheduled surgery (supracricoid laryngectomy with cricohyoidoepiglottopexy) and subsequent adjuvant treatment with chemotherapy and/or radiotherapy, according to the results of the histopathological study. As a conclusion finally, the IMT is a pathology found predominantly in the lung, laryngeal involvement being rare. Its prognosis is favorable and the histopathological diagnosis is of vital importance to be able to be differentiated from other malignant neoplasms. The correct diagnosis is followed by a wide local excision to prevent recurrence, however, treatment must be tailored to the location of the tumor and the condition of the patient.

Tumor miofibroblástico inflamatorio de vías biliares en un paciente pediátrico / Inflammatory miofibroblastic tumor of the biliary tract in a pediatric patient

RESUMEN El tumor miofibroblástico inflamatorio es una neoplasia mesenquimal infrecuente, realizar el diagnóstico clínico así como el patológico por biopsias es un desafío. Presentamos un caso de un paciente pediátrico con tumor miofibroblástico inflamatorio localizado a nivel de las vías biliares. Se realizaron estudios de laboratorio así como imagenológicos en los cuales se planteó un diagnóstico inexacto, del mismo modo cuando se envió la muestra de la lesión para el análisis intraoperatorio a través de técnicas de congelación, el reporte microscópico también fue incorrecto. Sin embargo cuando se realizó la revisión de las láminas tras la inclusión de la lesión y complementando con estudios de inmunohistoquimica, se concluyó que la lesión correspondió a un tumor miofibroblástico inflamatorio.

ABSTRACT The inflammatory myofibroblastic tumor is an infrequent mesenchymal neoplasm, making the clinical as well as the pathological diagnosis by biopsies is a challenge. We present a case of a pediatric patient with an inflammatory myofibroblastic tumor located at the level of the bile ducts. We sent the lesion sample for intraoperative analysis through freezing techniques, the microscopic report was also incorrect. However, when the plates were reviewed after the inclusion of the lesion and supplemented by immunohistochemical studies, it was concluded that the lesion corresponded to an inflammatory myofibroblastic tumor.

Tumor miofibroblástico inflamatorio: presentación variable de una misma patología / Inflammatory myofibroblastic tumor: variable presentation of the same pathology

INTRODUCCIÓN: El tumor miofibroblástico inflamatorio (TMI) es una neoplasia benigna infrecuente, de comportamiento clínico impredecible. OBJETIVOS: describir 3 casos de TMI diagnosticados entre marzo 2014 y enero 2018 en Hospital Clinico San Borja Arriaran, y realizar una revisión actualizada de la literatura. CASO 1: Adolescente de género masculino de 14 años de edad, hospitalizado por dolor abdominal, diagnosticado de invaginación yeyunoyeyunal secundaria a un tumor de pared intestinal. La histología fue compatible con un tumor miofibroblástico inflamatorio. CASO 2: Adolescente de género femenino, edad 12 años, hospitalizada por neumonía y dolor lumbar en estudio asociado a pérdida de peso. Se diagnosticó una masa retroperitoneal que comprometía el músculo psoas derecho, músculos paravertebrales, vértebras, riñón derecho y diafragma ipsilateral. Se efectuó biopsia por punción cuyo resultado fue compatible con un tumor miofibroblástico inflamatorio. CASO 3: Preadolescente de género femenino de 11 años de edad, hospitalizada para estudio de infección del tracto urinario a repetición. Se identificó un tumor vesical y la biopsia mostró ser compatible con tumor miofibroblástico inflamatorio. CONCLUSIÓN: Debido al comportamiento variable del tumor miofibroblástico inflamatorio, el manejo de este dependerá de la localización, la expresión del anaplasic like lymphoma (ALK), el comportamiento del tumor y la posibilidad de resección.

INTRODUCTION: The inflammatory myofibroblastic tumor is an infrequent benign neoplasm with unpredictable cli nical behavior. OBJECTIVES: to describe three clinical cases at the San Borja Arriarán Clinical Hospital between March 2014 and January 2018 and to carry out an updated review of the literature. CASE 1: 14-year-old male adolescent, hospitalized due to abdominal pain, diagnosed with jejunojejunal intus susception secondary to an intestinal wall tumor. The histology was compatible with an inflamma tory myofibroblastic tumor. CASE 2: 12-year-old female adolescent, hospitalized due to pneumonia and low-back pain under study associated with weight loss. A retroperitoneal mass was diagnosed involving the right psoas muscle, paravertebral muscles, vertebrae, right kidney, and ipsilateral dia phragm. A puncture biopsy was performed and the result was compatible with an inflammatory myofibroblastic tumor. CASE 3: 11-year-old female pre-adolescent, hospitalized to study recurrent urinary tract infection. A bladder tumor was identified, and the biopsy showed compatibility with inflammatory myofibroblastic tumor. CONCLUSION: Due to the variable behavior of the inflammatory myofibroblastic tumor, its management will depend on the location, expression of the anaplastic lymphoma kinase (ALK), tumor behavior, and the resection possibility.

Immunohistochemical profile of stromal constituents and lymphoid cells over the course of wound healing in murine model

PURPOSE: To assess the evolution profile of the immunohistochemical expression of stromal constituents over the time-course of wound healing in a murine model. METHODS: Surgical wounds were performed in the back of 24 Wistar rats. After three, seven, 14 and 21 days, six rats were euthanized and the wounded histologically processed to assess the immunohistochemical expression of CD3, CD20, CD31, α-SMA and type-I collagen. Non-injured skin samples (NSS) were used as control. Data were subjected to statistical analysis using ANOVA and Tukey test. RESULTS: The mean of CD3 and CD20 positive cells in the wounds was significantly higher than in NSS at seven and 14 days (p<0.001). The blood vessels content was significantly lower than in NSS (p<0.05) at three days, but increased at seven and 14 days (p<0.01). The mean of α-SMA positive cells at seven, 14 and 21 days was higher than in NSS (p<0.05). The relative content of type I collagen increased from three to 21 days, but remained lower than in NSS (p<0.05). CONCLUSIONS: Lymphoid cells, myofibroblasts and microvessels contents varied over the time-course of wound healing, with peak at seven days and progressive reduction until 21 days. The type I collagen content increased over time. .

Miofibroblastos e sua relação com o carcinoma de células escamosas oral / Myofibroblasts and their relationship with oral squamous cell carcinoma

Os miofibroblastos são células especializadas que exibem um fenótipo híbrido, com características de fibroblastos e células musculares lisas. Devido sua habilidade contrátil e capacidade de síntese de componentes da matriz extracelular, citocinas, proteases e fatores pró-angiogênicos, os miofibroblastos têm sido implicados na patogênese de doenças fibrocontráteis e na progressão de diversos tumores, incluindo o carcinoma de células escamosas (CCE) oral. OBJETIVO: Fazer uma revisão da literatura sobre a origem dos miofibroblastos, seus principais aspectos morfofisiológicos e imuno-histoquímicos, assim como discutir sua relação com o CCE oral. MÉTODO: Realizou-se uma busca eletrônica na base de dados PubMed, selecionando os principais artigos da literatura em língua inglesa relacionados ao tema, publicados entre janeiro de 1991 e dezembro de 2011. CONCLUSÃO: Os miofibroblastos representam um componente importante do estroma de CCE orais, embora não estejam presentes em todos os casos desta neoplasia. A presença abundante destas células pode estar associada com a recorrência local da doença e diminuição da sobrevida dos pacientes. No entanto, em virtude do número relativamente limitado de estudos sobre o assunto, pesquisas ainda são necessárias para esclarecer os mecanismos moleculares pelos quais os miofibroblastos são capazes de influenciar no comportamento biológico do CCE oral.

Myofibroblasts are hybrid-phenotype differentiated cells in between fibroblasts and smooth muscle cells. Due to their contractile features and ability to synthesize extracellular matrix components, cytokines, proteases, and proangiogenic factors, myofibroblasts have been implicated in the pathogenesis of fibrocontractive diseases and in the progression of many tumors, including oral squamous cell carcinoma (SCC). OBJECTIVE: To perform a literature review on the origin of myofibroblasts, their main morpho-physiological and immunohistochemical aspects, and to discuss the correlations with oral SCC. METHOD: A search was made on the PubMed database to select the main papers in the literature in English related to the subject, published between January 1991 and December 2011. CONCLUSION: Myofibroblasts are an important component of the stroma of oral SCCs, although they are not present in all tumors. Abundant presence of myofibroblasts may be associated with local disease recurrence and decreased patient survival. However, given the relatively limited number of studies on the subject, further research is needed to clarify the molecular mechanisms by which myofibroblasts influence the biological behavior of oral SCC.

Stromal myofibroblasts in focal reactive overgrowths of the gingiva

Focal reactive overgrowths are among the most common oral mucosal lesions. The gingiva is a significant site affected by these lesions, when triggered by chronic inflammation in response to microorganisms in dental plaque. Myofibroblasts are differentiated fibroblasts that actively participate in diseases characterized by tissue fibrosis. The objective of this study was to evaluate the presence of stromal myofibroblasts in the main focal reactive overgrowths of the gingiva: focal fibrous hyperplasia (FFH), peripheral ossifying fibroma (POF), pyogenic granuloma (PG), and peripheral giant cell granuloma (PGCG). A total of 10 FFHs, 10 POFs, 10 PGs, and 10 PGCGs from archival specimens were evaluated. Samples of gingival mucosa were used as negative controls for stromal myofibroblasts. Oral squamous cell carcinoma samples, in which stromal myofibroblasts have been previously detected, were used as positive controls. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin (α-sma). Myofibroblast immunostaining was qualitatively classified as negative, scanty, or dense. Differences in the presence of myofibroblasts among FFH, POF, PG, and PGCG were analyzed using the Kruskal-Wallis test. Stromal myofibroblasts were not detected in FFH, POF, PG, or PGCG. Consequently, no differences were observed in the presence of myofibroblasts among FFH, POF, PG, or PGCG (p > 0.05). In conclusion, stromal myofibroblasts were not detected in the focal reactive overgrowths of the gingiva that were evaluated, suggesting that these cells do not play a significant role in their pathogenesis.

Evaluation of myofibroblasts and its association with TGF-β and IFN-γ in lesions of patients with american tegumentary leishmaniasis / Avaliação de miofibroblastos e sua associação com TGF-β e IFN-γ em lesões de pacientes com leishmaniose tegumentar americana

BACKGROUND: Leishmaniasis is caused by protozoa of Leishmania spp. genus. It is transmitted by the bite of the sand fly insect. It is believed that 12 million people are infected with this disease and that its annual incidence is 2 million; this number is increasing. OBJECTIVES: The present study aimed to evaluate the expression of myofibroblasts through alpha smooth muscle actin labeling, and to analyze their relationship with the expression of the cytokines Interferon gama (IFN-γ) and Transforming growth factor beta (TGF-β1) in lesions of American tegumentary leishmaniasis (ATL). METHODS: For this retrospective study, we gathered 28 patients diagnosed with ATL between 2002 and 2006. We verified α-SMA positivity and performed IFN-γ and TGF-β1 immunolabeling to identify the profile of these cytokines in both positive and negative cases for myofibroblasts, via immunohistochemistry, in order to assess the presence of myofibroblasts,. RESULTS: We observed that out of the 28 cases, 17 (60.71%) were positive for alpha smooth muscle actin, while 11 (39.29%) were negative, and IFN-γ was more expressed than TGF-β1 (p=0.007). The mean percentages of expression of IFN-γ and TGF-β1 in the group negative for alpha smooth muscle actin were different, with an increased expression of IFN-γ (p=0.047). However, in the group positive for alpha smooth muscle actin, there was no difference in cytokine labeling (p>0.05). CONCLUSION: We verified the presence of positive α-SMA stromal cells in the majority of the cases of ATL, indicating the presence of myofibroblasts. In cases negative for alpha smooth muscle actin, an increased expression of IFN-γ compared to TGF-β1 was observed, revealing an inflammatory phase progressing to a healing process.

FUNDAMENTOS: A leishmaniose é causada pelo protozoário do gênero Leishmania spp., sendo transmitida via picada do inseto flebotomíneo. Estima-se que 12 milhões de indivíduos estejam infectados com a doença, sendo a incidência anual de 2 milhões, número este que tende a aumentar. OBJETIVOS: Avaliar a expressão de miofibroblastos através da imunomarcação de actina de músculo liso alfa, e analisar sua relação com a expressão de citocinas IFN-γ e TGF-β1 nas lesões de pacientes com leishmaniose tegumentar americana. MÉTODOS: Trata-se de um estudo retrospectivo, em que foram avaliados 28 pacientes diagnosticados com leishmaniose tegumentar americana durante o período de 2002 a 2006. Na técnica de imuno-histoquímica avaliou-se a presença de miofibroblastos, através do marcador actina de músculo liso alfa, além da imunomarcação do IFN-γ e TGF-β1 para identificar o perfil dessas citocinas nos casos positivos e negativos para miofibroblastos. RESULTADOS: Observou-se que dos 28 casos, 17 (60,71%) foram positivos para actina de músculo liso alfa, enquanto 11 (39,29%) foram negativos. IFN-γ teve uma maior expressão do que TGF-β1 (p=0,007). A porcentagem média de expressão de IFN-γ e TGF-β1 no grupo negativo para actina de músculo liso alfa foi diferente, apresentando uma maior expressão de IFN-γ (p=0.047). Entretanto, o grupo positivo para actina de músculo liso alfa não apresentou uma diferença estatisticamente significativa (p>0,05). CONCLUSÃO: Verificou-se uma expressão de actina de músculo liso alfa nos casos de leishmaniose tegumentar americana, indicando a presença de miofibroblastos. Nos casos negativos para actina de músculo liso alfa, observou-se uma maior expressão de IFN-γ comparando com TGF-β1, revelando que a fase inflamatória está envolvida no processo de cicatrização da lesão.

Estudo imuno-histoquímico da presença de miofibroblastos e da expressão do fator transformador de crescimento-beta1, interferon gama, mataloproteinase de matriz 13 e indutor de metaloproteinases de matriz em lesões odontogênicas epiteliais / Immunohistochemical study of the presence of myofibroblasts and the expression of transforming growth factor-beta1, interferon gamma, mataloproteinase matrix 13 and matrix metalloproteinase inducer in odontogenic epithelial lesions

Os miofibroblastos são células que apresentam um fenótipo híbrido exibindo características morfológicas de fibroblastos e de células musculares lisas, sendo a aquisição de tal fenótipo denominada diferenciação, passando então a expressar a a-SMA, a qual é importante na identificação dessas células. Estudos têm sugerido que os miofibrobíastos apresentam relação com a agressividade de diversas lesões e que o seu processo de diferenciação estaria relacionado à expressão do TGF-pl e do IFN-y atuando, respectivamente, no estímulo e na inibição dessa diferenciação. O objetivo deste trabalho foi investigar o papel dos miofibroblastos em lesões odontogênicas epiteliais, relacionando-os à agressividade das lesões e analisar por meio da imuno-histoquímica. a expressão do TGF-pl e IFN-y no processo de diferenciação, além da análise da MMP-13 que é ativada por miofibroblastos e do indutor de metaloproteinases de matriz (EMMPRIN) como precursor desta MMP. A amostra foi constituída por 20 ameloblastomas sólidos, 10 ameloblastomas unicfsticos, 20 ceratocistos odontogênicos e 20 tumores odontogênícos adenomatóides. Para a avaliação dos miofibroblastos, foram quantificadas as células imunorreativas ao anticorpo a-SMA presentes no tecido conjuntivo, próximo ao tecido epitelial. As expressões de TGF-pl, IFN-y, MMP-13 e EMMPRIN, foram avaliadas no componente epitelial e no conjuntivo, estabelecendo-se o percentual de imunorreatividade e atribuindo-se escores de 0 a 4. A análise dos miofibroblastos evidenciou maior concentração nos ameloblastomas sólidos (média de 30,55), seguido pelos ceratocistos odontogênicos (22,50), ameloblastomas unicísticos (20,80) e tumores odontogênicos adenomatóides (19,15) com valor de p= 0,001. Não foi encontrada correlação significativa entre TGF-pl e IFN-y no processo de diferenciação dos miofibroblastos, bem como na relação entre a quantidade de miofibroblastos e a expressão da MMP-13. Constatou-se, correlação estatística entre MMP-13 e TGF-pi (r= 0,087; p= 0,011) além de significante correlação entre MMP-13 e IFN-y (r=0,348; p=0,003). Entre EMMPRÍN e MMP-13 verificou-se significância (r= 0,474; p<0,001) assim como entre EMMPRIN e IFN-y (r=0,393; p=0,001). A maior quantidade de miofibroblastos evidenciada nos ameloblastomas sólidos, ceratocistos odontogênicos e ameloblastomas unicísticos sugere que estas células podem ser um dos fatores responsáveis para um comportamento biológico mais agressivo destas lesões, embora a população de miofibroblastos não tenha apresentado correlação com TGF- -pi, IFN-y ,MMP-13 e EMMPRIN. Quanto a correlação evidenciada entre MMP-13 e TGF-pl, isto pode sugerir um papel indutor do TGF-pl para a expressão da MMP-13, assim como os resultados deste estudo reforçam a relação bem estabelecida do EMMPRIN como indutor da MMP-13. Constatou-se também relação entre EMMPRIN e IFN-y assim como entre MMP-13 e IFN-y sugerindo, dessa forma, um sinergismo na ação anti-fibrótica desses marcadores.

Myofibroblasts are cells that exhibit a hybrid phenotype, sharing the morphoíogical characteristics of fibroblasts and smooth muscle cells, which is acquired during a process called differentiation. These cells then start to express a-SMA, a marker that can be used for their identification. Studies suggest that myofibroblasts are related to the aggressiveness of different tumors and that TGF-pl and IFN-y play a role in myofibroblast differentiation, stimulating or inhibiting this differentiation, respectively. The objective of this study was to investigate the role of myofibroblasts in epithelial odontogenic tumors, correlating the presence of these cells with the aggressiveness of the tumor. Immunohistochemistry was used to evaluate the expression of TGF-pl and IFN-y in myofibroblast differentiation, as well as the expression of MMP-13, which is activated by myofibroblasts, and of EMMPRIN (extracellular matrix metalloproteinase inducer) as a precursor of this MMP. The sample consisted of 20 solid ameloblastomas, 10 unicystic ameloblastomas, 20 odontogenic keratocysts, and 20 adenomatoid odontogenic tumors. For evaluation of myofibroblasts, anti-a-SMA-immunoreactive cells were quantified in connective tissue close to the epithelium. Immunoexpression of TGF-pl, IFN-y, MMP-13 and EMMPRIN was evaluaíed in the epithelial and connective tissue components, attributing scores of 0 to 4. The results showed a higher concentration of myofibroblasts in solid ameloblastomas (mean of 30.55), followed by odontogenic keratocysts (22.50), unicystic ameloblastomas (20.80), and adenomatoid odontogenic tumors (19.15) (p=0.00). No significant correlation between TGF-pl and IFN-y was observed during the process of myofibroblast differentiation. There was also no correlation between the quantity of myofibroblasts and MMP-13 expression. Significant correlations were found between MMP-13 and TGF-pi (r=0.087; p=0.01 1), between MMP-13 and ÍFN-y (r=0.348; p=0.003), as well as between EMMPRIN and MMP-13 (r=0.474; /xO.001) and between EMMPRIN and IFN-y (r=0.393; p=0.00). The higher quantity of myofibroblasts observed in solid ameloblastomas, odontogenic keratocysts and unicystic ameloblastomas suggests that these cells are one of the factors responsible for the more aggressive biological behavior of these tumors, although the myofibroblast population was not correlated with TGF-01, IFN-y, MMP-13 or EMMPRIN. The correlation between MMP-13 and TGF-pl suggests that the latter induces the expression of this metalloproteinase. The present results also support the well-established role of EMMPRIN as an inducer of MMP-13. Furthermore, the relationship between EMMPRIN and IFN-y and between MMP-13 and IFN-y suggests synergism in the antifibrotic effect of these markers.

Dermatomiofibroma: relato de caso de doença rara / Dermatomyofibroma: a case report of a rare disease

O Dermatomiofibroma está incluído no grupo de lesões neoplásicas mesenquimais benignas de linhagem fibroblástica e miofibroblástica da pele. É uma doença rara, havendo aproximadamente 100 casos descritos na literatura mundial até o momento. Este artigo relata o caso de uma mulher jovem com apresentação clínica típica e diagnóstico histopatológico de dermatomiofibroma. Foram realizadas colorações especiais que mostraram preservação das fibras colágenas e a imunohistoquímica revelou positividade para vimentina e negatividade para actina e S100. Por se tratar de doença rara, os achados histopatológicos são de grande importância, mas a supeição clínica é possível em casos típicos como este.

Dermato myofibroma is included in the group of benign cutaneous mesenchymal neoplastic lesions of fibroblastic and myofibroblastic lineage. It's a rare disease and there are approximately only one hundred cases described worldwide in the medical literature up to now. The present study reports the case of a young woman with typical clinical cutaneous lesion and histopathological diagnosis of dermato myofibroma. Special stains were carried out which showed preserved collagen fibers and immunohistochemistry was positive for vimentin and negative for actin and S100. As it is a rare disease, the histopathological findings are of great importance but clinical suspicion is possible in typical cases such as this one.

An endodontic sealer induces a pathological condition when associated with persistent tissue toxicity and presence of myofibroblasts

The aims of this study were to evaluate the ratio between inflammatory reactions induced by four endodontic sealers and the occurrence of fibrosis and the number of myofibroblasts with positivity to α-smooth-actin muscle (α-SMA). Polyethylene tubes were filled with a root canal sealer (Endofill, AH Plus, Acroseal and Epiphany) and inserted into 4 site at the dorsal region of 24 Wistar rats; 2 empty tubes (control) were grafted in 6 rats. After 7, 21, and 45 days, 8 animals were euthanized, providing 6 specimens per test group and 2 specimens from the control group. The fragments were subjected to histological processing and immunohistochemical analysis for anti α-SMA protein. All specimens, except those from the control group, presented severe inflammatory reaction on the 7th postoperative day, which also coincided with a large number of myofibroblasts. On the 21st and 45th days post-surgery, the inflammatory reaction induced by Endofill, AH Plus and Acroseal decreased significantly, which coincided with reduced presence of myofibroblasts and usual collagen deposition. In contrast, in the group filled with Epiphany, significant inflammatory cell infiltrate was present in all analyzed periods. The persistence of an inflammatory reaction induced by endodontic sealer may also induce the development of fibrosis in combination with presence of myofibroblasts.

O objetivo deste estudo foi avaliar a relação entre reação inflamatória induzida por quatro cimentos endodônticos e a presença de fibrose e quantidade de miofibroblastos que apresentam positividade para α-SMA. Tubos de polietileno foram preenchidos com o cimento (I: Endofill; II: AH Plus; III: Acroseal; IV: Epiphany) e inseridos em 4 regiões do dorso de 24 ratos Wistar, enquanto 2 tubos vazios (V - controle) foram inseridos em 6 ratos. Após 7, 21 e 45 dias, oito animais foram sacrificados obtendo 6 indivíduos por grupo e 2 para o grupo controle. Os fragmentos foram submetidos ao processamento histológico e à análise imuno-histoquímica para a proteína anti-α-SMA. Todos os grupos, exceto o controle, demonstraram notável reação inflamatória no 7º dia pós-operatório, que também coincidiu com uma grande quantidade de miofibroblastos. No 21º e 45º dia pós-operatório, a reação inflamatória induzida pelo Endofill, AH Plus e Acroseal diminuiu significativamente, o que coincidiu com reduzida presença de miofibroblastos e deposição de colágeno normal. Em contraste, no grupo Epiphany, infiltrado inflamatório significativo esteve presente em todos os períodos analisados. A persistência do infiltrado inflamatório induzido por cimento endodôntico pode também provocar uma fibrose associada com a presença de miofibroblastos.

Methylation of eukaryotic elongation factor 2 induced by basic fibroblast growth factor via mitogen-activated protein kinase

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)-p21(Cip/WAF1) activation, and suppressed by the mitogen-activated protein kinase (MAPK) inhibitor PD98059 and p21(Cip/WAF1) short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway.

Methylation of eukaryotic elongation factor 2 induced by basic fibroblast growth factor via mitogen-activated protein kinase

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)-p21(Cip/WAF1) activation, and suppressed by the mitogen-activated protein kinase (MAPK) inhibitor PD98059 and p21(Cip/WAF1) short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway.