RESUMO
The expression of DDX5 protein (RNA-helicase p68) correlates with processes of proliferation and differentiation. However there is no direct evidence of involvement of the protein in these processes. In present work, we studied the influence of DDX5 protein inactivation by si-RNA on the proliferation of Jurkat cells and dynamic of DDX5 expression during differentiation of U-937 cells induced by phorbol 12-myristate-13-acetate (PMA). We showed that the content of DDX5 in Jurkat cells is less in phases G0/G1 as compare to phases G2/M. The treatment of cells with the antisense LV-shDDX5 was followed by the increase of G0/G1 cells. It was also shown that the increase of expression of the DDX5 protein occurred during the initial stages of differentiation, and the peak of expression was registered during the first 2-3 hours after the induction of the cells, later the DDX5 content decreases. The increase of the number of macrophage surface marker CR3 on the membrane of cells occurred only in 24 hours after induction of the cells by PMA. Thus, these data confirm that: (1) the DDX5 protein is essential for normal cell proliferation; (2) the transition from G1 to S/G2 phase is accompanied by an increase of DDX5 protein concentration in the cells; (3) the concentration of the DDX5 protein increases on early stages of U-937 cells differentiation and after decreases.
Assuntos
Diferenciação Celular/genética , Proliferação de Células/genética , RNA Helicases DEAD-box/metabolismo , RNA Helicases DEAD-box/antagonistas & inibidores , RNA Helicases DEAD-box/genética , Fase G1/genética , Fase G2/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Células Jurkat , Ésteres de Forbol/farmacologia , Fosforilação/efeitos dos fármacosRESUMO
One of the hypotheses suggests that test cells play a part in a larval tunic formation like morula cells in adult ascidians. It was shown that the antibodies against morula cell proteins of 26 and 48 kDa of the ascidian Styela rustica react on the paraffin sections with both the granules of morula cells and test cells of ascidians S. rustica and Boltenia echinata. Among the test cell proteins of S. rustica SDS-electrophoresis revealed at least 5 major proteins but no one with the molecular mass of 26 and 48 kDa and none of them react with the antibodies. At the same time AB26 bind the proteins with similar molecular masses in blood cells and in the probe containing test cells--27 and 28 kDa, correspondingly,--of ascidian Molgula citrina. Comparative histochemical analysis of morula and test cells of these three ascidian species was carried out. There are a lot of acid polysaccharides combined with proteins in test cells whereas morula cells contain mainly positively charged proteins. Thus it could be supposed that degree of manifestation of antigens might be different in the conditions of immunoblot and immunohistochemical analysis. The hypothesis of the similarity in morula and test cells functions and their interrelationship is discussed.
