A link between FXYD3 (Mat-8)-mediated Na,K-ATPase regulation and differentiation of Caco-2 intestinal epithelial cells.

FXYD3 (Mat-8) proteins are regulators of Na,K-ATPase. In normal tissue, FXYD3 is mainly expressed in stomach and colon, but it is also overexpressed in cancer cells, suggesting a role in tumorogenesis. We show that FXYD3 silencing has no effect on cell proliferation but promotes cell apoptosis and prevents cell differentiation of human colon adenocarcinoma cells (Caco-2), which is reflected by a reduction in alkaline phosphatase and villin expression, a change in several other differentiation markers, and a decrease in transepithelial resistance. Inhibition of cell differentiation in FXYD3-deficient cells is accompanied by an increase in the apparent Na+ and K+ affinities of Na,K-ATPase, reflecting the absence of Na,K-pump regulation by FXYD3. In addition, we observe a decrease in the maximal Na,K-ATPase activity due to a decrease in its turnover number, which correlates with a change in Na,K-ATPase isozyme expression that is characteristic of cancer cells. Overall, our results suggest an important role of FXYD3 in cell differentiation of Caco-2 cells. One possibility is that FXYD3 silencing prevents proper regulation of Na,K-ATPase, which leads to perturbation of cellular Na+ and K+ homeostasis and changes in the expression of Na,K-ATPase isozymes, whose functional properties are incompatible with Caco-2 cell differentiation.

Respostas do cacaueiro �� aplica����o de N, P e K em dois solos da Amaz��nia Brasileira

A cacauicultura da Amaz��nia est�� implantada em solos eutr��ficos, com predomin��ncia da Terra Roxa Estruturada, e em Latossolos ou Podz��licos distr��ficos, sendo desconhecidas as limita����es nutricionais desses solos na fase produtiva do cacaueiro. As respostas do cacaueiro �� aplica����o de N, P e K foram determinadas em dois experimentos instalados nos munic��pios de Medicil��ndia, ao longo da Rodovia Transamaz��nica, e Benevides, Par��, em solos das unidades Terra Roxa Estrutura eutr��fica (TR) e Latossolo Amarelo (LA), respectivamente. As lavouras de cacau do h��brido Sca 6 x Be 10 foram implantadas ap��s o corte e queima da mata prim��ria, utilizando-se, como esquema experimental, um fatorial NPK 2�� com tratamentos adicionais de P. Os resultados obtidos demonstraram que o P foi o principal nutriente que limitou a produ����o, provocando incrementos de produtividade (P < 0,01) da ordem de 13,7% (110 kg ha-1) e 44,3% (214 kg ha-1) nos solos TR e LA, respectivamente, na m��dia do per��odo 1987 a 1993. O K tamb��m aumentou (P < 0,01) o rendimento de am��ndoas secas de cacau no solo LA, verificando-se, ainda, intera����es significativas (P < 0,05) entre N x K e P x K neste solo. A resposta linear do cacaueiro ao P e o aumento ou diminui����o da taxa de infec����o de vassoura-de-bruxa ao N, P e K evidenciam a necessidade de novas pesquisas para definir a dosagem econ��mica de P, de K e o efeito da intera����o dos nutrientes com a enfermidade.

[Archives de la Parole]. , Parable of the prodigal son : in Kodaku, from Surguja / [Sir George Grierson], ��d. ; Linguistic survey of India ; [J��than Ko�����k��], voix

[Traditions. Asie. Inde. Madhya Pradesh. Chhattisgarh]

[Archives de la Parole]. , Parable of the prodigal son : in Korwa, from Surguja (C.P.) [i.e. Central Provinces] / [Sir George Grierson], ��d. ; Linguistic survey of India ; [Nathu K��rw��], voix

[Traditions. Asie. Inde. Madhya Pradesh. Chhattisgarh]