Receptor‐mediated induction of aminopeptidase A (APA) of human glomerular epithelial cells (HGEC) by glucocorticoids

FEBS Letters

Vlahovic, P.¹  Stefanovic, V.¹  Ardaillou, R.¹  Ardaillou, N.¹ 

[1] INSERM 64, Hôpital Tenon, Paris, France

关键词: Aminopeptidase A;    Glomerular epithelial cells;    Glucocorticoids;    Angiotensin II;   

DOI  :  10.1016/0014-5793(91)80661-L

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Membrane-bound peptidases are critical regulators of peptide hormones. We therefore characterized aminopeptidase A (APA) activity in human glomerular epithelial cells (HGEC) and studied the control of its expression. APA, which splits off the N-terminal Asp from angiotensin II (AII), was present at the surface of HGECs (55% of the total enzyme). APA activity was calcium-dependent and was inhibited by amastatin. Treatment of HGECs by dexamethasone (DEX) increased ecto-APA activity in a dose- and time-dependent manner. Maximal increase of APA activity (× 2) occurred after treatment with 0.5 μM DEX for 5 days. Higher concentrations (1·10 μM) of aldosterone (ALD) stimulated APA activity to a lesser extent (× 1.25). Actinomycin D and cycloheximide prevented and RU 38486, a glucocorticoid receptor antagonist, suppressed the DEX-induced increase in APA activity. These results indicate that AII availability at glomerular receptor sites may be reduced by DEX and suggest a role for glucocorticoids in AII-dependent changes of glomerular filtration rate.

【 授权许可】

Unknown