Angiotensin II stimulation of the stress-activated protein kinases in renal mesangial cells is mediated by the angiotensin AT1 receptor subtype

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Abstract

Treatment of renal mesangial cells with the vasoconstrictor angiotensin II stimulates a concentration-dependent increase in stress-activated protein kinase (SAPK) activity as measured by phosphorylation of the substrate c-Jun. Time course studies reveal a transient SAPK activation by angiotensin II which is maximal after 5–10 min of stimulation and rapidly declines thereafter to basal levels within 30 min. Using the highly selective angiotensin II AT1 receptor antagonist valsartan, a concentration-dependent inhibition of angiotensin II-induced SAPK activity is observed, clearly implying the AT1-receptor in this angiotensin II-mediated response. To further elucidate the mechanism involved in angiotensin II-induced SAPK activation, cells were treated with different inhibitors. Genistein, a tyrosine kinase inhibitor, greatly blocks (by 90%) the angiotensin II response, whereas pertussis toxin only partially inhibits angiotensin II-activated SAPK activity (by 76%). A highly potent protein kinase C inhibitor {3-[1-[3-(amidinothio)propyl-1H-indoyl-3-yl]-3-(1-methyl-1H-indoyl-3-yl) maleimide methane sulfonate}, Ro 31-8220, as well as protein kinase C depletion from the cells by prolonged phorbol ester pretreatment, fail to inhibit the angiotensin II-induced SAPK activation. In summary these results suggest that angiotensin II AT1-receptor is able to activate the SAPK cascade in mesangial cells by a pathway independent of protein kinase C, but requiring both pertussis-toxin-sensitive and -insensitive G-proteins and tyrosine kinase activation.

Introduction

Mesangial cells are a major determinant in the regulation of the glomerular filtration rate. Morphologically, mesangial cells resemble vascular smooth muscle cells and are able to contract upon stimulation by vasoactive hormones like angiotensin II or arginine vasopressin (Menè et al., 1989; Pfeilschifter, 1989).

Angiotensin II is involved in a variety of physiological functions and regulates vascular tone, glomerular haemodynamics, tubular transport and also chemoattraction of cells, mesangial cell processing of macromolecules, immunomodulation, angiogenesis and growth regulation (Bottari et al., 1993; De Gasparo and Levens, 1994).

Mechanistically, angiotensin II binds to specific surface receptors on mesangial cells (Pfeilschifter, 1990a) and activates via a G-protein, a phospholipase C which hydrolyses phosphatidylinositol 4,5-bisphosphate to inositol 1,4,5-trisphosphate and 1,2-diacylglycerol. Inositol 1,4,5-trisphosphate mobilizes Ca2+ from the endoplasmatic reticulum, while diacylglycerol activates protein kinase C (Menè et al., 1989; Pfeilschifter, 1989). By the development of specific peptidic and non-peptidic angiotensin II receptor antagonists two subtypes of angiotensin II receptors were identified (Chiu et al., 1989; Whitebread et al., 1989; Smith and Timmermans, 1994), the AT1 type and the AT2 type. The former one has recently been shown to mediate angiotensin II-stimulated phosphoinositide turnover (Pfeilschifter, 1990a) and angiotensin II-stimulated phospholipase D activation in mesangial cells (Pfeilschifter et al., 1992). In contrast, the signalling pathways triggered by the angiotensin II AT2 receptor are still poorly defined, but do not include the aforementioned classical messenger pathway. Reportedly, angiotensin II AT2 receptors do not interact with guanine nucleotide-binding proteins, thus excluding all the signalling cascades involving G-proteins. (Bottari et al., 1991; Pucell et al., 1991).

In mammals, three structural families of mitogen-activated protein (MAP) kinase have been identified that have distinct substrate specificities (Cano and Mahadevan, 1995; Woodgett et al., 1996). The members of one family, the extracellular signal-regulated kinase (ERK)-1 and ERK-2, also named p44 and p42 mitogen-activated protein kinases (mapk), are activated primarily by mitogenic agonists. The c-Jun N-terminal kinase (JNK) family, also known as stress-activated protein kinases (SAPK) and the p38mapk/reactivating kinase (RK), which is the closest structural homolog of the yeast HOG1, are activated either in common or parallel pathways by cellular stresses such as interleukin-1 and tumour necrosis factor-α, heat shock, UV-light, osmotic shock and metabolic poisons and to a lesser extent by growth factors.

In this study we show that mesangial cells respond to angiotensin II stimulation with increased SAPK activity and that this angiotensin II effect is mediated by the AT1-receptor subtype in a protein kinase C-independent, but tyrosine kinase-dependent manner.

Section snippets

Chemicals

Angiotensin II, 12-O-tetradecanoyl-phorbol 13-acetate (TPA) and genistein were purchased from Calbiochem, Lucerne, Switzerland; [32P]ATP and Hyperfilm MP were from Amersham International, Amersham, Bucks., UK; glutathione-sepharose was from Pharmacia Fine Chemicals, Uppsala, Sweden; CGP 42 112A (angiotensin II-(4–8)-peptide), valsartan and glutathione S-transferase-coupled c-Jun were synthesized and prepared by Ciba-Geigy, Basel, Switzerland; pertussis toxin was from Sigma; N-acetyl-cysteine

Results

Previously it was reported that ERK and SAPK families phosphorylate Ser-63 and Ser-73 of the N-terminal transactivation domain of c-Jun in vitro (Alvaresz et al., 1991). In contrast to ERKs which do not bind c-Jun with high affinity (Hibi et al., 1993; Gupta and Davis, 1994), the SAPKs bind to c-Jun and may be responsible for phosphorylation of c-Jun in vivo (Kallukini et al., 1994). We used a solid-phase kinase assay with c-Jun (5–89) coupled to glutathione S-transferase as a substrate that

Discussion

Our results demonstrate that angiotensin II evokes a very rapid and transient activation of the SAPK cascade in mesangial cells. The potent inhibitory action of valsartan on A II-induced SAPK activity clearly demonstrates that this effect is mediated by the angiotensin II AT1-receptor. The angiotensin II AT1 receptor has been cloned and Northern blot analysis has revealed that the mRNA for this receptor subtype is expressed in bovine adrenal medulla and cortex, kidney and vascular smooth muscle

Acknowledgements

This work was supported by Swiss National Foundation Grant 31-43090.95 by a grant from the Commission of the European Union (Biomed 2, PL 950 979) and by a grant from the Wilhelm-Sander-Stiftung to J.P.A.H. was supported by a research fellowship of the Swiss National Science Foundation. G.v.R. was an exchange student from the University of Utrecht supported by the Erasmus exchange programme.

References (43)

  • J.A Garcia-Sainz et al.

    Angiotensin II stimulates phosphoinositide turnover and phosphorylase through AII-1 receptors in isolated rat hepatocytes

    Biochem. Biophys. Res. Commun.

    (1990)
  • S Gupta et al.

    MAP kinase binds to the NH2-terminal activation domain of c-Myc

    FEBS Lett.

    (1994)
  • A Huwiler et al.

    Immunocharacterization of δ and ζ-isoenzymes of protein kinase C in rat renal mesangial cells

    FEBS Lett.

    (1992)
  • E Nishio et al.

    α1-Adrenergic receptor stimulation causes arachidonic acid release through pertussis toxin-sensitive GTP-binding protein and JNK activation in rabbit aortic smooth muscle cells

    Biochem. Biophys. Res. Commun.

    (1996)
  • J Pfeilschifter

    Angiotensin II B-type receptor mediates phosphoinositide hydrolysis in mesangial cells

    Eur. J. Pharmacol.

    (1990)
  • J Pfeilschifter et al.

    Angiotensin II stimulation of phospholipase D in rat renal mesangial cells is mediated by the AT1 receptor subtype

    Eur. J. Pharmacol. Mol. Pharmacol.

    (1992)
  • M Ui

    Islet-activating protein, pertussis toxin: A probe for functions of the inhibitory guanine nucleotide regulatory component of adenylate cyclase

    Trends Pharmacol. Sci.

    (1984)
  • S Whitebread et al.

    Preliminary biochemical characterization of two angiotensin II receptor subtypes

    Biochem. Biophys. Res. Commun.

    (1989)
  • E Alvaresz et al.

    Pro–Leu–Ser/Thr–Pro is a consensus primary sequence for substrate protein phosphorylation

    J. Biol. Chem.

    (1991)
  • P.H Bauer et al.

    DuP 753 can antagonize the effects of angiotensin II in rat liver

    Mol. Pharmacol.

    (1991)
  • K Cadwallader et al.

    Differential regulation of extracellular signal-regulated protein kinase 1 and Jun N-terminal kinase 1 by Ca2+ and protein kinase C in endothelin-stimulated Rat-1 cells

    Biochem. J.

    (1997)
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