Podocyte Protein, Nephrin, Is a Substrate of Protein Tyrosine Phosphatase 1B
Figure 7
PTP1B and PTP-PEST are upregulated in glomeruli of rats with PAN. PAN was induced and glomeruli were isolated by differential sieving as in Section 2. (a) mRNA expression of PTP1B and PTP-PEST was quantified by qPCR. * versus control, rats for PTP1B and rats for PTP-PEST. (b) Glomerular lysates were analyzed in duplicate by immunoblotting. Both PTP1B and PTP-PEST were upregulated in a similar time course to the respective mRNAs. Values for proteinuria are mean ± SEM of 4 rats. Lower panel: densitometric analysis for PTP1B ( rats) and PTP-PEST ( rats) proteins. *, ** versus control (c) Immunohistochemistry of control and PAN-treated rat kidneys. In normal rat glomeruli, weak PTP1B and PTP-PEST expression was detected with some staining in the extracapillary location compatible with podocytes (arrows). In the kidney from PAN rats, expression of the two PTP was upregulated, in particular in podocytes (arrowheads, day 7 for PTP1B and day 14 for PTP-PEST). There was no staining when the primary antibodies were replaced with control IgG (not shown).
