Effect of bradykinin in focal contact (FC) organization of immature rat renal papillary cells

GAGLIANO L; MARQUEZ MG; STERIN-SPEZIALE N

Iguazu, Misiones

Congreso; XL REUNIÓN DE LA SOCIEDAD ARGENTINA DE INVESTIGACIONES BIOQUÍMICAS Y BIOLOGÍA MOLECULAR; 2004

SOCIEDAD ARGENTINA DE INVESTIGACIONES BIOQUÍMICAS Y BIOLOGÍA MOLECULAR (SAIB)

Focal Contacts (FC) are structures of cell attachment to extracelular matrix. Bradykinin (BK) modulates the assembly of FC in adult rats. The BK receptor is highly expressed in newborn rats. Vinculin (V) and Talin (T) are markers of FC, and have high affinity to phosphatidylinositol 4,5 biphosphate (PIP2). Inmunofluorescence technique was used to analyze BK effects of BK at differents times in 10 days rat collecting duct cells culture. Control cells showed two different kind of FC, which are parallel distributed between themselves. One type is an elongated FC at the periphery of the cell. The other type is centrally-located wide short stick FC. V staining is concentrated in both FC, colocalized with PIP2. T staining is specially visualized in the stick-like FC. When cells are treated with BK, colocalization of V-PIP2 it is lost. After 1 minute of BK, V and PIP2 dissipated from FC. T staining is increased in both FC. After 5 minutes of BK, V staining reappears in both FC, PIP2 staining is similar to control cells, and T staining dissipated. Within 10 minutes of BK, PIP2 showed the same pattern as control cell as well as T staining. V staining is increased on both FC, and has a net distribution, which is form by long wide axis from nucleus to the edge with transversal parallel lines interlacing them. These results establish the existence of different molecular forms of FC with distinct shapes which are restructured by BK in ten days-rat papillary cells; suggesting a migratory stimulation associated with the growth action of this hormone.