Photosynthetic metabolism and antioxidant in Ormosia arborea are modulated by abscisic acid under water deficit? / Metabolismo fotossintético e antioxidante em mudas de Ormosia arborea são modulados pelo ácido abscísico sob deficit hídrico?

The aim of this research was to evaluate the effect of abscisic acid (ABA) on gas exchange and the activity of antioxidant enzymes of Ormosia arborea (Vell.) Harms seedlings under water deficit and its influence on the recovery potential of the seedlings. The experiment was conducted using four treatments, being daily irrigation or water restriction without and with 10 μM ABA. Seedlings under water deficit + ABA showed greater adjustment to drought, and when re-irrigated, they restored photosynthetic metabolism and water potential. ABA minimizes the reduction in the photosynthetic metabolism and water potential of the leaf, however, it does not increase the antioxidant activity of the O. arborea seedlings under water deficit. These results suggest that this species exhibits plasticity, which enables it to survive also in environments subjected to temporary water deficit regardless of the supplementation of ABA. We suggest that other doses of ABA be researched to expand the beneficial effect of ABA on this species.

O objetivo deste trabalho foi avaliar o efeito do ácido abscísico (ABA) nas trocas gasosas e na atividade de enzimas antioxidantes de mudas de Ormosia arborea (Vell.) Harms sob deficiência hídrica e sua influência no potencial de recuperação das mudas. O experimento foi conduzido com quatro tratamentos, sendo eles irrigação diária ou restrição hídrica sem e com 10 μM ABA. As mudas sob déficit hídrico + ABA apresentaram maior ajuste à seca e ao serem re-irrigadas restabeleceram o metabolismo fotossintético e o potencial hídrico. O ABA minimizou a redução do metabolismo fotossintético e do potencial da água na folha, porém, não aumentou a atividade antioxidante de mudas de O. arborea sob déficit hídrico. Esses resultados sugerem que esta espécie apresenta plasticidade fisiológica, o que lhe permite sobreviver em ambientes sujeitos a déficit hídrico temporário, independente da suplementação de ABA. Sugerimos que outras doses de ABA sejam avaliadas para ampliar os efeitos benéficos do ABA sobre esta espécie.

Photosynthetic metabolism and antioxidant in Ormosia arborea are modulated by abscisic acid under water deficit?

Abstract The aim of this research was to evaluate the effect of abscisic acid (ABA) on gas exchange and the activity of antioxidant enzymes of Ormosia arborea (Vell.) Harms seedlings under water deficit and its influence on the recovery potential of the seedlings. The experiment was conducted using four treatments, being daily irrigation or water restriction without and with 10 M ABA. Seedlings under water deficit + ABA showed greater adjustment to drought, and when re-irrigated, they restored photosynthetic metabolism and water potential. ABA minimizes the reduction in the photosynthetic metabolism and water potential of the leaf, however, it does not increase the antioxidant activity of the O. arborea seedlings under water deficit. These results suggest that this species exhibits plasticity, which enables it to survive also in environments subjected to temporary water deficit regardless of the supplementation of ABA. We suggest that other doses of ABA be researched to expand the beneficial effect of ABA on this species.

Resumo O objetivo deste trabalho foi avaliar o efeito do ácido abscísico (ABA) nas trocas gasosas e na atividade de enzimas antioxidantes de mudas de Ormosia arborea (Vell.) Harms sob deficiência hídrica e sua influência no potencial de recuperação das mudas. O experimento foi conduzido com quatro tratamentos, sendo eles irrigação diária ou restrição hídrica sem e com 10 M ABA. As mudas sob déficit hídrico + ABA apresentaram maior ajuste à seca e ao serem re-irrigadas restabeleceram o metabolismo fotossintético e o potencial hídrico. O ABA minimizou a redução do metabolismo fotossintético e do potencial da água na folha, porém, não aumentou a atividade antioxidante de mudas de O. arborea sob déficit hídrico. Esses resultados sugerem que esta espécie apresenta plasticidade fisiológica, o que lhe permite sobreviver em ambientes sujeitos a déficit hídrico temporário, independente da suplementação de ABA. Sugerimos que outras doses de ABA sejam avaliadas para ampliar os efeitos benéficos do ABA sobre esta espécie.

Photosynthetic metabolism and antioxidant in Ormosia arborea are modulated by abscisic acid under water deficit? / Metabolismo fotossintético e antioxidante em mudas de Ormosia arborea são modulados pelo ácido abscísico sob deficit hídrico?

The aim of this research was to evaluate the effect of abscisic acid (ABA) on gas exchange and the activity of antioxidant enzymes of Ormosia arborea (Vell.) Harms seedlings under water deficit and its influence on the recovery potential of the seedlings. The experiment was conducted using four treatments, being daily irrigation or water restriction without and with 10 µM ABA. Seedlings under water deficit + ABA showed greater adjustment to drought, and when re-irrigated, they restored photosynthetic metabolism and water potential. ABA minimizes the reduction in the photosynthetic metabolism and water potential of the leaf, however, it does not increase the antioxidant activity of the O. arborea seedlings under water deficit. These results suggest that this species exhibits plasticity, which enables it to survive also in environments subjected to temporary water deficit regardless of the supplementation of ABA. We suggest that other doses of ABA be researched to expand the beneficial effect of ABA on this species.

O objetivo deste trabalho foi avaliar o efeito do ácido abscísico (ABA) nas trocas gasosas e na atividade de enzimas antioxidantes de mudas de Ormosia arborea (Vell.) Harms sob deficiência hídrica e sua influência no potencial de recuperação das mudas. O experimento foi conduzido com quatro tratamentos, sendo eles irrigação diária ou restrição hídrica sem e com 10 µM ABA. As mudas sob déficit hídrico + ABA apresentaram maior ajuste à seca e ao serem re-irrigadas restabeleceram o metabolismo fotossintético e o potencial hídrico. O ABA minimizou a redução do metabolismo fotossintético e do potencial da água na folha, porém, não aumentou a atividade antioxidante de mudas de O. arborea sob déficit hídrico. Esses resultados sugerem que esta espécie apresenta plasticidade fisiológica, o que lhe permite sobreviver em ambientes sujeitos a déficit hídrico temporário, independente da suplementação de ABA. Sugerimos que outras doses de ABA sejam avaliadas para ampliar os efeitos benéficos do ABA sobre esta espécie.

Photosynthetic metabolism and antioxidant in Ormosia arborea are modulated by abscisic acid under water deficit?

The aim of this research was to evaluate the effect of abscisic acid (ABA) on gas exchange and the activity of antioxidant enzymes of Ormosia arborea (Vell.) Harms seedlings under water deficit and its influence on the recovery potential of the seedlings. The experiment was conducted using four treatments, being daily irrigation or water restriction without and with 10 µM ABA. Seedlings under water deficit + ABA showed greater adjustment to drought, and when re-irrigated, they restored photosynthetic metabolism and water potential. ABA minimizes the reduction in the photosynthetic metabolism and water potential of the leaf, however, it does not increase the antioxidant activity of the O. arborea seedlings under water deficit. These results suggest that this species exhibits plasticity, which enables it to survive also in environments subjected to temporary water deficit regardless of the supplementation of ABA. We suggest that other doses of ABA be researched to expand the beneficial effect of ABA on this species.

Prognostic Value of ADAMTS Proteases and Their Substrates in Epithelial Ovarian Cancer

Background: ADAMTS are metalloproteases with disintegrin and thrombospondin motifs. They are secreted proteases playing a role in biological processes such as inflammation, angiogenesis, and urogenital development. ADAMTS have specific substrates, such as the proteoglycans (PG) versican, aggrecan, and brevican. Despite data indicating a role of ADAMTS in tumor invasion and metastases, effects played by these molecules in cancer progression are still controversial. In ovarian cancer, the importance of ADAMTS gene mutations was recently described and related to chemotherapy outcome. Objective: To analyze protein levels of ADAMTS-1, -4, and -5, and TIMP-3 in human ovarian cancer classified as benign, borderline, or malignant. We also assessed the expression of the ADAMTS substrates aggrecan, brevican, and versican in these neoplasms. Correlations between overall survival and protein expression were performed. Methods: Tumors were classified according to the WHO Classification of Tumors of Female Reproductive Organs. Protein and PG expression was studied by immunohistochemistry. Differences in labeling were analyzed by percent measurements of stained areas. Results: ADAMTS-1, ADAMTS-5, and its tissue inhibitor TIMP-3 are increased in borderline and malignant tumors compared to benign neoplasms. Aggrecan and versican levels were increased in malignant subtypes compared to benign ovarian cancer. Higher ADAMTS-1, TIMP-3, and versican expression was associated with a shorter overall survival. Conclusions: Comparison of protease, TIMP-3, and substrate expression showed that in malignant tumors all ADAMTS and TIMP-3 expression levels were significantly raised compared to the substrates studied.

Retinoic acid and cAMP inhibit rat hepatocellular carcinoma cell proliferation and enhance cell differentiation

Hepatocellular carcinoma (HCC) is the third highest cause of cancer death worldwide. In general, the disease is diagnosed at an advanced stage when potentially curative therapies are no longer feasible. For this reason, it is very important to develop new therapeutic approaches. Retinoic acid (RA) is a natural derivative of vitamin A that regulates important biological processes including cell proliferation and differentiation. In vitro studies have shown that RA is effective in inhibiting growth of HCC cells; however, responsiveness to treatment varies among different HCC cell lines. The objective of the present study was to determine if the combined use of RA (0.1 µM) and cAMP (1 mM), an important second messenger, improves the responsiveness of HCC cells to RA treatment. We evaluated the proliferative behavior of an HCC cell line (HTC) and the expression profile of genes related to cancer signaling pathway (ERK and GSK-3β) and liver differentiation (E-cadherin, connexin 26 (Cx26), and Cx32). RA and cAMP were effective in inhibiting the proliferation of HTC cells independently of combined use. However, when a mixture of RA and cAMP was used, the signals concerning the degree of cell differentiation were increased. As demonstrated by Western blot, the treatment increased E-cadherin, Cx26, Cx32 and Ser9-GSK-3β (inactive form) expression while the expression of Cx43, Tyr216-GSK-3β (active form) and phosphorylated ERK decreased. Furthermore, telomerase activity was inhibited along treatment. Taken together, the results showed that the combined use of RA and cAMP is more effective in inducing differentiation of HTC cells.

Retinoic acid and cAMP inhibit rat hepatocellular carcinoma cell proliferation and enhance cell differentiation.

Hepatocellular carcinoma (HCC) is the third highest cause of cancer death worldwide. In general, the disease is diagnosed at an advanced stage when potentially curative therapies are no longer feasible. For this reason, it is very important to develop new therapeutic approaches. Retinoic acid (RA) is a natural derivative of vitamin A that regulates important biological processes including cell proliferation and differentiation. In vitro studies have shown that RA is effective in inhibiting growth of HCC cells; however, responsiveness to treatment varies among different HCC cell lines. The objective of the present study was to determine if the combined use of RA (0.1 µM) and cAMP (1 mM), an important second messenger, improves the responsiveness of HCC cells to RA treatment. We evaluated the proliferative behavior of an HCC cell line (HTC) and the expression profile of genes related to cancer signaling pathway (ERK and GSK-3ß) and liver differentiation (E-cadherin, connexin 26 (Cx26), and Cx32). RA and cAMP were effective in inhibiting the proliferation of HTC cells independently of combined use. However, when a mixture of RA and cAMP was used, the signals concerning the degree of cell differentiation were increased. As demonstrated by Western blot, the treatment increased E-cadherin, Cx26, Cx32 and Ser9-GSK-3ß (inactive form) expression while the expression of Cx43, Tyr216-GSK-3ß (active form) and phosphorylated ERK decreased. Furthermore, telomerase activity was inhibited along treatment. Taken together, the results showed that the combined use of RA and cAMP is more effective in inducing differentiation of HTC cells.

Intracellular nitric oxide assessment in whole blood leukocytes by flow cytometry: optimization and applicability to monitor patients with chronic graft nephropathy.

Flow cytometry has been proposed as an alternative method for direct determination of intracellular NO by using the 4,5-diaminofluorescein-diacetate (DAF-2DA) as a fluorescent probe. In the present study, the protocol for intracellular NO determination in peripheral blood monocytes and neutrophils of by flow cytometry was optimized and applied to monitor chronic graft nephropathy patients. The optimize method consists to incubate plasma-free whole blood samples with DAF-2DA at 2.0 microM for 180 min at 37 degrees C to determine the percentage of DAF-2T+ monocytes and neutrophils. Distinct intracellular NO profiles in monocytes and neutrophils from chronic graft nephropathy patients as compared to the healthy individuals. Although the pre-incubation with LPS was able to trigger higher percentages of DAF-2T+ monocytes and neutrophils in both groups, our data demonstrated that LPS had a greater impact on monocytes as compared to neutrophils, selectively in the group of healthy individuals. Moreover, our findings demonstrated that LPS had lower impact on monocytes from chronic graft nephropathy as compared to healthy individuals. Supplementary analysis revealed that the LPS impact tends to be resorted in those patients with longer post-transplant time, as demonstrated by a significant positive correlation index. Furthermore, our results demonstrated that AG had lower inhibitory impact on neutrophils as compared to monocytes, selectively in the group of chronic graft nephropathy patients. Taken together, this study showed a new approach to monitor the immunological status of patients with chronic graft nephropathy opening new perspectives of research regarding the monocyte and neutrophil functions in patient undergoing immunosuppressive therapy.

Local invasiveness of ameloblastoma. Role played by matrix metalloproteinases and proliferative activity.

AIMS: Ameloblastoma is an odontogenic neoplasm characterized by local invasiveness and recurrence. In this study we analysed the role played by matrix metalloproteinases (MMPs) in the local invasiveness of ameloblastoma. We also attempted to establish a relationship between the presence of MMPs and the proliferative activity of ameloblastoma cells. METHODS AND RESULTS: Immunohistochemistry was carried out to detect different MMPs in formalin-fixed paraffin-embedded samples of human ameloblastoma. Immunohistochemistry, however, does not establish whether a given MMP is latent or active. To address this point, we carried out biochemical methods, namely zymography and Western blotting. Our results showed expression of latent and active forms of MMPs 1, 2 and 9 in ameloblastoma. These enzymes may digest bone matrix and release mitogenic factors, which would increase tumour proliferation. This possibility prompted us to study the proliferation of ameloblastoma cells located in close proximity to bone. Silver-stained nucleolar organizer region morphometry revealed that ameloblastoma cells in the vicinity of bone show increased proliferation, when compared with controls. CONCLUSIONS: Our results suggest an interdependent mechanism involving MMPs and proliferation of ameloblastoma cells, which may contribute to the local invasiveness of this tumour.

Laminin-1 and SIKVAV a laminin-1-derived peptide, regulate the morphology and protease activity of a human salivary gland adenoid cystic carcinoma cell line.

In a previous paper, we demonstrated that laminin-1 and its derived peptide SIKVAV modulates the morphology of an adenoid cystic carcinoma cell line (CAC2 cells). Light microscopy of CAC2 cells grown in three-dimensional preparations of SIKVAV-enriched laminin-1 showed the presence of pseudocystic spaces. Pseudocysts are hallmarks of adenoid cystic carcinoma in vivo. We hypothesized that these pseudocystic spaces could be due to the protease-inducing/activating role of SIKVAV. Thus, we studied the presence of matrix metalloproteinases (MMPs) in CAC2 cells treated either by laminin-1 or by SIKVAV-enriched laminin-1. Immunohistochemistry and zymography suggested that SIKVAV enhanced the secretion of MMP-2 and MMP-9 in CAC2 cells. We propose that SIKVAV induces pseudocystic formation probably through the secretion of MMPs 2 and 9.

Effect of N-CAM on in vitro invasion of human adenoid cystic carcinoma cells.

Adenoid cystic carcinoma of salivary glands is characterised by aggressive behaviour, high rate of local recurrences, neurotropism and late metastasis. In a previous work we demonstrated that adenoid cystic carcinoma cultured cells (CAC2 cells) expressed N-CAM. It was suggested that this expression, modulated by extracellular matrix, would be correlated to cell movement. The aim of our study was to verify whether CAC2 cells presented invasion capacity. Moreover, we tested whether the neural adhesion molecule (N-CAM) would participate in this process. CAC2 cells were either previously treated, or not (control), with a monoclonal antibody against N-CAM. Invasion assays were carried out using a modified Boyden chamber (Transwell chamber). CAC2 cells (10(5)) were dispensed into Transwell upper chamber on the top of Matrigel coated filter. The cells that invaded the filters in the first 8 h were counted under light microscopy, yielding data for the invasion rates (%). Control CAC2 cells presented an invasion rate of 5.28+/-0.04%. The invasion rate raised to 6.53+/-0.2% when N-CAM was blocked with monoclonal antibody. N-CAM impaired the adenoid cystic carcinoma cell invasion in vitro. Therefore, we suggest an anti-invasive role for N-CAM in adenoid cystic carcinoma.