TY - JOUR
T1 - Podocyte glutamatergic signaling contributes to the function of the glomerular filtration barrier
AU - Giardino, Laura
AU - Armelloni, Silvia
AU - Corbelli, Alessandro
AU - Mattinzoli, Deborah
AU - Zennaro, Cristina
AU - Guerrot, Dominique
AU - Tourrel, Fabien
AU - Ikehata, Masami
AU - Li, Min
AU - Berra, Silvia
AU - Carraro, Michele
AU - Messa, Piergiorgio
AU - Rastaldi, Maria P.
PY - 2009/9
Y1 - 2009/9
N2 - Podocytes possess the complete machinery for glutamatergic signaling, raising the possibility that neuron-like signaling contributes to glomerular function. To test this, we studied mice and cells lacking Rab3A, a small GTPase that regulates glutamate exocytosis. In addition, we blocked the glutamate ionotropic N-methyl-D-aspartate receptor (NMDAR) with specific antagonists. In mice, the absence of Rab3A and blockade of NMDAR both associated with an increased urinary albumin/creatinine ratio. In humans, NMDAR blockade, obtained by addition of ketamine to general anesthesia, also had an albuminuric effect. In vitro, Rab3A-null podocytes displayed a dysregulated release of glutamate with higher rates of spontaneous exocytosis, explained by a reduction in Rab3A effectors resulting in freedom of vesicles from the actin cytoskeleton. In addition, NMDAR antagonism led to profound cytoskeletal remodeling and redistribution of nephrin in cultured podocytes; the addition of the agonist NMDA reversed these changes. In summary, these results suggest that glutamatergic signaling driven by podocytes contributes to the integrity of the glomerular filtration barrier and that derangements in this signaling may lead to proteinuric renal diseases.
AB - Podocytes possess the complete machinery for glutamatergic signaling, raising the possibility that neuron-like signaling contributes to glomerular function. To test this, we studied mice and cells lacking Rab3A, a small GTPase that regulates glutamate exocytosis. In addition, we blocked the glutamate ionotropic N-methyl-D-aspartate receptor (NMDAR) with specific antagonists. In mice, the absence of Rab3A and blockade of NMDAR both associated with an increased urinary albumin/creatinine ratio. In humans, NMDAR blockade, obtained by addition of ketamine to general anesthesia, also had an albuminuric effect. In vitro, Rab3A-null podocytes displayed a dysregulated release of glutamate with higher rates of spontaneous exocytosis, explained by a reduction in Rab3A effectors resulting in freedom of vesicles from the actin cytoskeleton. In addition, NMDAR antagonism led to profound cytoskeletal remodeling and redistribution of nephrin in cultured podocytes; the addition of the agonist NMDA reversed these changes. In summary, these results suggest that glutamatergic signaling driven by podocytes contributes to the integrity of the glomerular filtration barrier and that derangements in this signaling may lead to proteinuric renal diseases.
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U2 - 10.1681/ASN.2008121286
DO - 10.1681/ASN.2008121286
M3 - Article
C2 - 19578006
AN - SCOPUS:69849093919
VL - 20
SP - 1929
EP - 1940
JO - Journal of the American Society of Nephrology : JASN
JF - Journal of the American Society of Nephrology : JASN
SN - 1046-6673
IS - 9
ER -