[HTML][HTML] Integrin β1-mediated matrix assembly and signaling are critical for the normal development and function of the kidney glomerulus

K Kanasaki, Y Kanda, K Palmsten, H Tanjore… - Developmental …, 2008 - Elsevier
K Kanasaki, Y Kanda, K Palmsten, H Tanjore, SB Lee, VS Lebleu, VH Gattone Jr, R Kalluri
Developmental biology, 2008Elsevier
The human kidneys filter 180 l of blood every day via about 2.5 million glomeruli. The three
layers of the glomerular filtration apparatus consist of fenestrated endothelium, specialized
extracellular matrix known as the glomerular basement membrane (GBM) and the podocyte
foot processes with their modified adherens junctions known as the slit diaphragm (SD). In
this study we explored the contribution of podocyte β1 integrin signaling for normal
glomerular function. Mice with podocyte specific deletion of integrin β1 (podocin-Cre β1-fl/fl …
The human kidneys filter 180 l of blood every day via about 2.5 million glomeruli. The three layers of the glomerular filtration apparatus consist of fenestrated endothelium, specialized extracellular matrix known as the glomerular basement membrane (GBM) and the podocyte foot processes with their modified adherens junctions known as the slit diaphragm (SD). In this study we explored the contribution of podocyte β1 integrin signaling for normal glomerular function. Mice with podocyte specific deletion of integrin β1 (podocin-Cre β1-fl/fl mice) are born normal but cannot complete postnatal renal development. They exhibit detectable proteinuria on day 1 and die within a week. The kidneys of podocin-Cre β1-fl/fl mice exhibit normal glomerular endothelium but show severe GBM defects with multilaminations and splitting including podocyte foot process effacement. The integrin linked kinase (ILK) is a downstream mediator of integrin β1 activity in epithelial cells. To further explore whether integrin β1-mediated signaling facilitates proper glomerular filtration, we generated mice deficient of ILK in the podocytes (podocin-Cre ILK-fl/fl mice). These mice develop normally but exhibit postnatal proteinuria at birth and die within 15 weeks of age due to renal failure. Collectively, our studies demonstrate that podocyte β1 integrin and ILK signaling is critical for postnatal development and function of the glomerular filtration apparatus.
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