Podocyte

Podocytes enclose a section of the glomerolus . Numerous filtration slits are visible between the podocyte processes.

The podocytes (from Greek pous, podos = 'foot' and Greek cytos = 'cell') are cells of the kidney corpuscles . They form the inner leaf of the Bowman capsule and are therefore, together with the basement membrane , of particular importance for the filter function of the kidneys . Due to their external shape - often interlocking projections - they are also referred to as so-called filtration slots, since they are only permeable for molecules up to a molar mass of about 70 kDa .

You are part of the blood-urinary barrier .

Another task of the podocytes is related to cleaning the glomerular filter. Together with the endothelial cells , they are probably also responsible for the delivery of new basal material.

Proteins that are important for the function of podocytes include: a. Podoplanin , Nephrin, and Podocin , the recent discovery of which has greatly expanded our knowledge of podocyte function.

B7-1 expression by podocytes

Under certain circumstances, podocytes can also express B7-1 as a surface protein ( CD 80), especially in proteinuric kidney disease. These B7-1-positive podocytes have reduced binding to the surrounding extracellular matrix via β1 integrin . A clinical study with five patients with primary or relapsed focal segmental glomerulosclerosis who had B7-1-positive podocytes showed a partial or complete remission of proteinuria in all patients under treatment with abatacept , a fusion protein made from the peptide CTLA and immunoglobulin . Abatacept is an inhibitor of the costimulatory B7-1 molecule on the T cell , which is already used successfully in the treatment of rheumatoid arthritis .

Individual evidence

1. ↑ T. Heinzeller, CM Büsing: Histology, histopathology and cytology for an introduction. Georg Thieme Verlag, 2001, ISBN 3-131-26831-X , p. 209. Restricted preview in the Google book search
2. ↑ Chih-Chuan Yu, Alessia Fornoni, Astrid Weins, Samy Hakroush, Dony Maiguel, Junichiro Sageshima, Linda Chen, Gaetano Ciancio, Mohd. Hafeez Faridi, Daniel Behr, Kirk N. Campbell, Jer-Ming Chang, Hung-Chun Chen, Jun Oh, Christian Faul, M. Amin Arnaout, Paolo Fiorina, Vineet Gupta, Anna Greka, George W. Burke, III, Peter Mundel : Abatacept in B7-1-Positive Proteinuric Kidney Disease New England Journal of Medicine 2013, Volume 369, Issue 25, December 19, 2013, pages 2416-2423; DOI: 10.1056 / NEJMoa1304572