This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Khamaisi, M. Articles by Raz, I. Search for Related Content PubMed PubMed Citation Articles by Khamaisi, M. Articles by Raz, I.

Role of Protein Kinase C in the Expression of Endothelin Converting Enzyme-1

Diabetes Research Unit (M.K., R.D., I.R.), and Department of Medicine (M.K., I.R., S.N.H.), Hadassah Hospital, Ein Kerem, Mt. Scopus, and the Hebrew University Medical School, Jerusalem 91240, Israel; and Departments of Cardiology (S.H.) and Physiology (Z.A.), Rappaport Faculty of Medicine, Technion, Haifa 31048, Israel

Address all correspondence and requests for reprints to: Mogher Khamaisi, M.D., Ph.D., Department of Medicine, Hadassah Hospital, Ein Kerem and the Hebrew University Medical School, P.O. Box 12000, Jerusalem 91240, Israel. E-mail: m_khamaisi{at}rambam.health.gov.il Khamaisi{at}gmail.com.

Increased expression of endothelin converting enzyme-1 (ECE-1) is associated with diabetic nephropathy. The molecular mechanisms underlying this association, as yet unknown, possibly involve protein kinase C (PKC) pathways. In the present study, we examined the effects of high glucose and PKC activation on ECE-1 expression in primary human umbilical vein endothelial cells (HUVECs) and in HUVEC line (EA.hy926). Increasing glucose concentration, but not mannitol, from 5.5–22.2 mmol/liter for 3 d, enhanced prepro endothelin-1 (ET-1) mRNA expression, ET-1 levels, ECE-1 protein, and mRNA expressions by 7, 4, 20, and 2.6-fold, respectively. High glucose increased ECE-1 protein expression dose and time dependently. By Western blot analysis, PKC-β1, -β2, and - isoform levels were significantly increased relative to other isoforms when glucose level was increased. Treatment with Rottlerin, a PKC- isoform inhibitor, reduced significantly the glucose-induced ET-1 secretion, and ECE-1 protein expression, but (S)-13-[(dimethylamino)methyl]-10,11,14,15-tetrahydro-4,9:16,21-dimetheno 1H,1³H-dibenzo[e,k]pyrrolo[3,4-h] (1, 4, 3) oxadiaza-cyclohexadecene-1,3(2H)-dione or Gö6976, specific PKC-β and - inhibitors, respectively, did not. Overexpression of PKC- but not PKC- or -β1 isoforms by adenovirus vector containing the respective cDNA in HUVECs incubated with 5.5 mmol/liter glucose, increased in parallel PKC proteins, and glucose-induced endothein-1 and ECE-1 protein expression by 4- to 6-fold. These results show that enhanced ECE-1 expression induced by hyperglycemia is partly due to activation of the PKC- isoform. Thus, inhibition of this PKC isoform may prevent diabetes-related increase in ET-1.