podocitarias

Podocitarias is a term used in nephrology to denote podocytes, the specialized visceral epithelial cells that cover the glomerular capillaries in the kidney. They form the visceral layer of Bowman's capsule and contribute to the integrity of the glomerular filtration barrier.

Podocitaria structure and location: Podocitarias have a cell body with several primary processes that extend into foot processes (pedicels) that interdigitate with those of neighboring podocitarias. The slit diaphragms between foot processes, built from proteins such as nephrin, NEPH1, and podocin, are essential for filtration. They rest on the glomerular basement membrane and receive regulatory signals from endothelial and mesangial cells.

Development and maintenance: Podocitarias arise from the metanephric mesenchyme and differentiate under genetic control (for example, WT1). Their architecture is sustained by the actin cytoskeleton and signaling pathways involving VEGF-A, nephrin, and podocin. Injury or genetic mutations can cause foot process effacement and barrier dysfunction.

Function: The main role is to restrict the passage of large molecules while contributing to charge-based selectivity of the filtration barrier. Podocitarias also participate in intercellular signaling with glomerular endothelial cells and influence the peri-glomerular extracellular milieu.

Clinical relevance: Podocytopathies describe diseases where podocitaria injury drives proteinuria and progressive kidney disease. Examples include minimal change disease, focal segmental glomerulosclerosis, membranous nephropathy, and diabetic nephropathy. Genetic mutations in NPHS1 or NPHS2 can cause congenital disease. Diagnosis combines clinical findings with urine studies; electron microscopy may show foot process effacement. Treatments aim to reduce injury and preserve podocitarias.