Knockdown of transglutaminase-2 prevents early age-induced vascular changes in mice

Purpose:To determine whether the absence of transglutaminase 2 enzyme (TG2) in TG2 knockout mice (TG2-/-) protect them against early age-related functional and histological arterial changes.Methods:Pulse wave velocity (PWV) was measured using non-invasive Doppler and mean arterial pressure (MAP) was measured in awake mice using tail-cuff system. Thoracic aortas were excised for evaluation of endothelial dependent vasodilation (EDV) by wire myography, as well as histological analyses.Results:PWV and MAP were similar in TG2-/-mice to age-matched wild type (WT) control mice. Old WT mice exhibited a markedly attenuated EDV as compared to young WT animals. The TG2-/-young and old mice had enhanced EDV responses (p<0.01) as compared to WT mice. There was a significant increase in TG2 crosslinks by IHC in WT old group compared to Young, with no stain in the TG2-/-animals. Optical microscopy examination of Old WT mice aorta showed thinning and fragmentation of elastic laminae. Young WT mice, old and young TG2-/-mice presented regularly arranged and parallel elastic laminae of the tunica media.Conclusion:The genetic suppression of TG2 delays the age-induced endothelial dysfunction and histological modifications.(AU)

Morpho-pathological and ultrastructural analysis of the murinemelanoma B16F10 and B16F0 cell lines and derived tumors / Anáalise morfo-patolóogica e ultraestrutural de linhagens celulares B16F10 E B16F0 e melanoma decamundongo e tumores derivados

Murine B16 cell lines of tumorigenic melanocytes have been widely used as cellular model for biochemicaland molecular studies in melanoma research. Despite such importance there is still a lack of information onthe microanatomy and cytopathology of these B16 models. The aim of this study was to shed light on themorpho-pathological specificities of the murine melanoma cell lines B16F10 and B16F0, and derived tumors,and correlate the findings with distinct metastatic potential. Cyto- and histopathological analysis carried outby optical and transmission electron microscopy (TEM) revealed that both tumor cell lines exhibit typicalfeatures of carcinogenic cells such as atypical mitoses, multiple nucleoli and enlarged nucleus. In agreementwith their highest metastatic potential, B16F10 cells and tumors exhibited more aberrant morphology thanthat observed in B16F0 samples. Also the histopathological analysis revealed that only the B16F10 tumor cellscould invade adjacent muscle tissues. Under TEM, B16F0 cell line presented mitochondrial hyperplasia andhypertrophia and a large number of melanosomes, while B16F10 showed a larger number of mitochondria ina wider range of shapes and sizes, numerous polyribosomes, cellular peripheral fibrillar material, and abnormalclusters of mitochondria. These morphological features related to the differential metastatic potentials ofB16F10 and B16F0, provide new insights on the cellular changes involved in melanoma metastatic progressionand also would be instrumental to expand the application of these cell lines as models in melanoma research.AU

Linhas de células B16 de melanócitos tumorais de camundongos têm sido amplamente utilizadascomo modelo celular para estudos bioquímicos e moleculares na pesquisa de melanoma. Apesardessa importância, ainda há uma falta de informação sobre a micro anatomia e citopatologia destesmodelos B16. O objetivo deste estudo foi pesquisar sobre as especificidades morfo-patológicas das linhasde células de melanoma de camundongos B16F10 e B16F0 e tumores derivados, e correlacionaros achados com potencial metastático distinto. Cito e análise histopatológica realizada por microscopiaóptica e eletrônica de transmissão (TEM) revelou que ambas as linhagens celulares tumoraisexibem características típicas de células cancerígenas, como mitoses atípicas, múltiplos nucléolos enúcleo aumentado. De acordo com seu potencial mais elevado, as células B16F10 e tumores metastáticosexibiram morfologia mais aberrante do que a observada em amostras de B16F0. A análisehistopatológica também revelou que apenas as células tumorais B16F10 poderiam invadir os tecidosmusculares adjacentes. De acordo com TEM, a linhagem de células B16F0 apresentou hiperplasiae hipertrofia mitocondrial e um grande número de melanossomas, enquanto B16F10 demonstrouum maior número de mitocôndrias em uma ampla gama de formas e tamanhos, numerosos polirribossomas,material fibrilar celular periférico e aglomerados de mitocôndrias anormais. Estascaracterísticas morfológicas relacionadas aos diferenciais pote nciais metastáticos de B16F10 e B16F0forneceram novas compreensões sobre as mudanças celulares envolvidas na progressão metastáticade melanoma e também seria fundamental para ampliar a aplicação dessas linhagens celulares comomodelo na pesquisa melanoma.(AU)

Morpho-pathological and ultrastructural analysis of the murinemelanoma B16F10 and B16F0 cell lines and derived tumors / Anáalise morfo-patolóogica e ultraestrutural de linhagens celulares B16F10 E B16F0 e melanoma decamundongo e tumores derivados

Murine B16 cell lines of tumorigenic melanocytes have been widely used as cellular model for biochemicaland molecular studies in melanoma research. Despite such importance there is still a lack of information onthe microanatomy and cytopathology of these B16 models. The aim of this study was to shed light on themorpho-pathological specificities of the murine melanoma cell lines B16F10 and B16F0, and derived tumors,and correlate the findings with distinct metastatic potential. Cyto- and histopathological analysis carried outby optical and transmission electron microscopy (TEM) revealed that both tumor cell lines exhibit typicalfeatures of carcinogenic cells such as atypical mitoses, multiple nucleoli and enlarged nucleus. In agreementwith their highest metastatic potential, B16F10 cells and tumors exhibited more aberrant morphology thanthat observed in B16F0 samples. Also the histopathological analysis revealed that only the B16F10 tumor cellscould invade adjacent muscle tissues. Under TEM, B16F0 cell line presented mitochondrial hyperplasia andhypertrophia and a large number of melanosomes, while B16F10 showed a larger number of mitochondria ina wider range of shapes and sizes, numerous polyribosomes, cellular peripheral fibrillar material, and abnormalclusters of mitochondria. These morphological features related to the differential metastatic potentials ofB16F10 and B16F0, provide new insights on the cellular changes involved in melanoma metastatic progressionand also would be instrumental to expand the application of these cell lines as models in melanoma research.

Linhas de células B16 de melanócitos tumorais de camundongos têm sido amplamente utilizadascomo modelo celular para estudos bioquímicos e moleculares na pesquisa de melanoma. Apesardessa importância, ainda há uma falta de informação sobre a micro anatomia e citopatologia destesmodelos B16. O objetivo deste estudo foi pesquisar sobre as especificidades morfo-patológicas das linhasde células de melanoma de camundongos B16F10 e B16F0 e tumores derivados, e correlacionaros achados com potencial metastático distinto. Cito e análise histopatológica realizada por microscopiaóptica e eletrônica de transmissão (TEM) revelou que ambas as linhagens celulares tumoraisexibem características típicas de células cancerígenas, como mitoses atípicas, múltiplos nucléolos enúcleo aumentado. De acordo com seu potencial mais elevado, as células B16F10 e tumores metastáticosexibiram morfologia mais aberrante do que a observada em amostras de B16F0. A análisehistopatológica também revelou que apenas as células tumorais B16F10 poderiam invadir os tecidosmusculares adjacentes. De acordo com TEM, a linhagem de células B16F0 apresentou hiperplasiae hipertrofia mitocondrial e um grande número de melanossomas, enquanto B16F10 demonstrouum maior número de mitocôndrias em uma ampla gama de formas e tamanhos, numerosos polirribossomas,material fibrilar celular periférico e aglomerados de mitocôndrias anormais. Estascaracterísticas morfológicas relacionadas aos diferenciais pote nciais metastáticos de B16F10 e B16F0forneceram novas compreensões sobre as mudanças celulares envolvidas na progressão metastáticade melanoma e também seria fundamental para ampliar a aplicação dessas linhagens celulares comomodelo na pesquisa melanoma.