Collagen production in cardiac fibroblasts during inhibition of angiotensin-converting enzyme and aminopeptidases.
OBJECTIVE
To determine whether lisinopril, an angiotensin-converting enzyme (ACE) inhibitor, and bestatin, an aminopeptidase inhibitor with broad specificity, could affect collagen production in control and transforming growth factor (TGF)-beta1-treated cardiac fibroblasts.


METHODS
Cardiac fibroblasts from passage 2 from normal male adult rats were cultured to confluency, incubated with or without 600 pmol/l TGF-beta1 for 2 days in serum-free Dulbecco's modified Eagle's medium and then incubated with the test products (lisinopril or bestatin) for 1 day in this medium with added ascorbic acid, beta-aminoproprionitrile and tritiated proline. Soluble collagen was measured in the conditioned medium and non-soluble collagen in the cell layer. ACE activity was measured fluorimetrically with hippuryl-histidyl-leucine as substrate, and DNA with the bisbenzimide dye, Hoechst 33,258. Aminopeptidase activity was estimated by spectrophotometric determination of the liberation of p-nitroaniline from alanine-p-nitroanilide.


RESULTS
Lisinopril dose-dependently reduced ACE activity in control and TGF-beta1-treated cardiac fibroblasts. Bestatin inhibited the basal and TGF-beta1-stimulated aminopeptidase activity in a concentration-dependent manner. Lisinopril (10 micromol/l) decreased (P < 0.05) the production of soluble and non-soluble collagen in control cardiac fibroblasts. TGF-beta1 (600 pmol/l) increased (P < 0.05) the production of soluble and non-soluble collagen, and this effect was decreased (P < 0.05) by lisinopril. Bestatin (100 micromol/l) reduced (P < 0.01) the production of soluble collagen in control and TGF-beta1-treated cardiac fibroblasts, but did not affect the production of non-soluble collagen in these cells.


CONCLUSIONS
Our data suggest that ACE and aminopeptidases are involved in the basal and TGF-beta1-stimulated production of collagen in adult rat cardiac fibroblasts in culture.
Lijnen
Paul J
PJ
Hypertension and Cardiovascular Rehabilitation Unit, Department of Molecular and Cardiovascular Research, Catholic University of Leuven (K.U. Leuven), Belgium. paul.lijnen@med.kuleuven.ac.be
Petrov
Victor V
VV
Fagard
Robert H
RH
D000626:Aminopeptidases / Q000008:administration & dosage* / Q000037:antagonists & inhibitors* / Q000378:metabolism; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage*; D000814:Aniline Compounds / Q000378:metabolism; D000818:Animals; D002478:Cells, Cultured; D003094:Collagen / Q000187:drug effects* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism*; D007930:Leucine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D017706:Lisinopril / Q000008:administration & dosage; D008297:Male; D023421:Models, Animal; D008955:Models, Cardiovascular; D009206:Myocardium / Q000166:cytology* / Q000378:metabolism; D009842:Oligopeptides / Q000187:drug effects / Q000378:metabolism; D007703:Peptidyl-Dipeptidase A / Q000187:drug effects / Q000378:metabolism; D011480:Protease Inhibitors / Q000008:administration & dosage; D051381:Rats; D017208:Rats, Wistar; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D053773:Transforming Growth Factor beta1
D000806:Angiotensin-Converting Enzyme Inhibitors; D000814:Aniline Compounds; D009842:Oligopeptides; D011480:Protease Inhibitors; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C004813:alanine-4-nitroanilide; C010980:hippuryl-histidyl-leucine; D003094:Collagen; D017706:Lisinopril; D000626:Aminopeptidases; D007703:Peptidyl-Dipeptidase A; D007930:Leucine; C012211:ubenimex