Enalapril stimulates collagen biosynthesis through prolidase-dependent mechanism in cultured fibroblasts

Lukasz Szoka,Ewa Karna,Renata Pawlak Morka,Jerzy A Palka

doi:10.1007/s00210-015-1114-5

Lukasz Szoka, Ewa Karna + Show 2 more

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https://doi.org/10.1007/s00210-015-1114-5

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Abstract

The mechanism of a lower incidence of dermatological manifestations in patients treated with enalapril compared to patients treated with other ACE-inhibitors, e.g., captopril, is not known. The finding that prolidase plays an important role in collagen biosynthesis and that some angiotensin-converting enzyme inhibitors affect prolidase activity led us to evaluate its effect on collagen biosynthesis in cultured human skin fibroblasts. Since insulin-like growth factor (IGF-I) and transforming growth factor beta 1 (TGF-β1) are the most potent stimulators of both collagen biosynthesis and prolidase activity, and prolidase is regulated by β1 integrin signaling, the effect of enalapril and enalaprilat on IGF-IR, TGF-β1, and β1 integrin receptor expressions was evaluated. Cells were treated with milimolar concentrations (0.3 and 0.5 mM) of enalapril and enalaprilat for 24 h. The activity of prolidase was determined by colorimetic assay. Collagen biosynthesis was evaluated by radiometric assay. Expression of signaling proteins was evaluated using Western blot. It was found that enalapril- and enalaprilat-dependent increase in prolidase activity and expression was accompanied by parallel increase in collagen biosynthesis. The exposure of the cells to 0.5 mM enalapril and enalaprilat contributed to increase in IGF-IR and α2β1 integrin receptor as well as TGF-β1 and NF-κB p65 expressions. Enalapril- and enalaprilat-dependent increase of collagen biosynthesis in fibroblasts results from increase of prolidase activity and expression, which may undergo through activation of α2β1 integrin and IGF-IR signaling as well as upregulation of TGF-β1 and NF-κB p65, the inhibitor of collagen gene expression.

Highlights

Enalapril, (S)-1-[N-(1-etoxycarbonyl)-3-phenylpropyl]-Lproline, a prodrug, is converted by deesterification to angiotensin-converting enzyme inhibitor (ACE-I), enalaprilat, (S)-1-[N-(1-carboxy-3-phenylpropyl)-L-alanyl]-L-proline dihydrate, commonly used to control hypertension (Ovchinnikov et al 2009)
Enalaprilat had no inhibitory effect on porcine kidney prolidase (PKP) (King et al 1989)
Collagen biosynthesis and prolidase activity were measured in confluent human dermal fibroblasts, which have been treated

Summary

Introduction

Enalapril, (S)-1-[N-(1-etoxycarbonyl)-3-phenylpropyl]-Lproline, a prodrug, is converted by deesterification to angiotensin-converting enzyme inhibitor (ACE-I), enalaprilat, (S)-1-[N-(1-carboxy-3-phenylpropyl)-L-alanyl]-L-proline dihydrate, commonly used to control hypertension (Ovchinnikov et al 2009). Enalaprilat had no inhibitory effect on porcine kidney prolidase (PKP) (King et al 1989) This dipeptidase is present in all tissues and plays an important role in the recycling of proline from imidodipeptides (derived from degradation products of collagen) for collagen re-synthesis (Yaron and Naider 1993) and cell growth (Emmerson and Phang 1993). Prolidase activity is stimulated through a signal mediated by collagen–β1 integrin receptor interaction (Palka and Phang 1997, 1998) This pathway is known to be involved in phosphorylation of several intracellular proteins, including prolidase (Surazynski et al 2001). Another important point of collagen biosynthesis regulation is at the level of insulin-like growth factor-I receptor (IGF-IR). Considering the above mentioned factors, we studied the cellular mechanisms for the effect of enalapril-prodrug and enalaprilat-active form of the drug on collagen biosynthesis in cultured human dermal fibroblasts

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