Podocyte

The podocytes (from Greek pous, podos =, foot ' and Greek Cytos = cell ') are cells of the renal corpuscles. To form the inner leaf of the Bowman's capsule, and are therefore, together with the basement membrane, for the filtering function of the kidney is particularly important. Due to their external form - often interlocked with each other appendages - they are also referred to as so-called filtration slits, as they are only permeable to molecules up to a molecular mass of about 70 kDa. They are thus part of the blood - urine barrier.

Another object of the podocytes refers to the cleaning of the glomerular filter. Presumably, they are also responsible for the delivery of new Basalmaterials together with the endothelial cells.

For the function of podocytes important proteins include Podoplanin, nephrin and podocin, whose recent discovery of knowledge has significantly expanded by the podocyte.

B7 -1 expression by podocytes

Under certain circumstances, podocytes can also express B7 -1 surface protein ( CD80 ), especially in proteinuric kidney disease. These B7-1 -positive podocytes have a reduced binding to the surrounding extracellular matrix via β1 integrin. A clinical study of five patients with primary or recurrent focal segmental glomerulosclerosis, which have B7- 1- positive podocytes, showed in all patients a partial or complete remission of proteinuria during treatment with abatacept, a fusion protein of the peptide CTLA and immunoglobulin. Abatacept is an inhibitor of the costimulatory B7 -1 molecule on the T cell, which is already successfully used in the treatment of rheumatoid arthritis.