Kidney proximal tubule cells: epithelial cells without EGTA-extractable annexins?

The expression and the subcellular localizations of annexins I, II, IV, VI, and XIII in renal epithelial cells were investigated, using immunological techniques with specific monoclonal antibodies. Upon performing Western blotting experiments, no annexins VI and XIII were detected in kidney, whereas annexins I, II, and IV were. Immunofluorescence labelling procedure performed on thin frozen renal sections showed the presence of these three annexins along the plasma membrane of the collecting duct cells with a restricted expression of annexin I at principal cells.

Polarized localizations of annexins I, II, VI and XIII in epithelial cells of intestinal, hepatic and pancreatic tissues.

The cellular and subcellular localizations of annexins I, II, VI and XIII in the rabbit intestine, liver and pancreas were studied by performing immunofluorescence labeling on thin frozen tissue sections using specific monoclonal antibodies. The expression of annexins was found to be finely regulated. Annexins XIII and I were expressed exclusively in the small intestine and the colon, respectively, whereas annexin II was present in all the tissues tested and annexin VI specifically in the liver and pancreas.

Cellular and subcellular localization along the digestive and pulmonary tracts of a rabbit intestinal mucin differing from MUC2 and containing a 150 kDa light chain.

Two immunologically different rabbit intestinal mucins were separated by performing fractionated ammonium sulfate precipitation, dialysis against pH 5.5 buffer and filtration through a Sepharose CL 2B column. They each contain a light chain with apparent molecular masses of 150 and 140 kDa, respectively.

Cellular and subcellular localizations of annexins I, IV, and VI in lung epithelia.

The cellular and subcellular localizations of annexins I, IV, and VI in the rabbit tracheal and alveolar epithelia were studied by performing immunofluorescence labeling on thin frozen sections of these tissues, using specific monoclonal antibodies. Annexin I was highly expressed by ciliated cells, where it was concentrated in the cilia but was also present along the basolateral domain of the plasma membrane and in the nuclei. It was also abundant in the cytoplasm of type II pneumocytes and alveolar macrophages.

Changes in expression and subcellular localization of annexin IV in rabbit kidney proximal tubule cells during primary culture.

In the present study, we investigated the polarized expression of annexin IV at various stages in the growth of rabbit kidney proximal tubule cells (PTC) in primary cultures. The results of immunoblotting analysis and indirect immunofluorescence studies using a specific anti-annexin IV monoclonal antibody, indicated that annexin IV is expressed in proximal tubule cultured cells, although it was not detected in the proximal tubules present in frozen sections of kidney cortex and freshly isolated proximal tubule cells. In either non-confluent or confluent cells which remained attached to the collagen-coated support, annexin IV was mainly concentrated around the nucleus, whereas in PTC forming the monolayer of domes, it was restricted to the basolateral membrane domain.