What are podocyte cells?
What are podocyte cells?
Podocytes are specialized epithelial cells that cover the outer surfaces of glomerular capillaries. Unique cell junctions, known as slit diaphragms, which feature nephrin and Neph family proteins in addition to components of adherens, tight, and gap junctions, connect adjacent podocyte foot processes.
What cells make the glomerular basement membrane?
The GBM lies between, and is initially synthesized by, the glomerular endothelial cells that line the glomerular capillaries and the podocytes (also called visceral epithelial cells) that sit on the opposite side of the GBM within the urinary space (Fig. 1).
What is a podocyte and what is its function?
Podocytes are cells in Bowman’s capsule in the kidneys that wrap around capillaries of the glomerulus. Podocytes make up the epithelial lining of Bowman’s capsule, the third layer through which filtration of blood takes place.
How does the basement membrane of the glomerular tuft acts as a filter?
Numerous glycoproteins, such as acidic proteoglycans and laminin, together with the collagen fibers form the complete structure of the membrane. The glomerular filtration barrier selectively filters molecules based on size (70 kDa), electrical charge (the more cationic, the more permeable), and capillary pressure.
What is podocyte effacement?
Injured podocytes undergo effacement whereby they lose their structure and spread out, leading to a reduction in filtration barrier function. Effacement is typically associated with the presence of proteinuria in focal segmental glomerulosclerosis, minimal change disease, and diabetes.
What happens when podocytes are damaged?
Podocyte injury causes proteinuria and detachment from the glomerular basement membrane. In addition to “sick” podocytes and their detachment, our understanding of glomerular responses following podocyte loss needs to address the pathways from podocyte injury to sclerosis.
What layer of the glomerular membrane consists of podocytes?
Podocytes are specialised epithelial cells of Bowman’s capsule which form the visceral layer of the capsule.
What is basement membrane made up of?
Basement membranes are composed of several specific molecules such as type IV collagen, laminin, proteoglycans and entactin/nidogen and are produced mainly by the endothelial cell layer.
Which part of the nephron contains podocytes quizlet?
Which part of the nephron contains podocytes? *The podocytes cling to the capillary walls of the glomerulus within the glomerular capsule.
What is podocyte foot process effacement?
In glomerular diseases, podocytes lose the usual interdigitating pattern of foot processes between neighboring podocytes, and this alteration, known as “foot process effacement,” is regarded as a pathologic indicator of podocyte injury.
Why are proteins not filtered at the glomerulus?
Blood cells and plasma proteins are not filtered through the glomerular capillaries because they are relatively larger in physical size. However water and salts are forced out of the glomerular capillaries and pass into the Bowman’s Capsule and are called the glomerular filtrate.
Where are podocytes cells?
Podocytes are highly specialized cells of the kidney glomerulus that wrap around capillaries and that neighbor cells of the Bowman’s capsule.
What is the role of podocytes in glomerular filtration?
When it comes to glomerular filtration, podocytes play an active role in preventing plasma proteins from entering the urinary ultrafiltrate by providing a barrier comprising filtration slits between foot processes, which in aggregate represent a dynamic network of cellular extensions.
What is the function of the podocytes?
Podocytes are specialized epithelial cells that cover the outer surfaces of glomerular capillaries. Unique cell junctions, known as slit diaphragms, which feature nephrin and Neph family proteins in addition to components of adherens, tight, and gap junctions, connect adjacent podocyte foot processes.
Is there a zipper-like structure in the podocyte plasma membrane?
From early ultrastructural studies, a zipper-like substructure was described where protein bridges emanating from the podocyte plasma membrane link to a central filament in a lattice arrangement with rectangular pores ( 136 ).
How many receptors are there in the podocyte?
• Other podocyte cell surface receptors include syndecans and dystroglycan, but the importance of these receptors in the podocyte has yet to be fully determined. • Adhesion complexes contain over 232 components, which are dependent on cell type and context.