Immunohistochemical study of angiotensin-converting enzyme in human tissues using monoclonal antibodies

Danilov, Sergei M.; Faerman, Alexander; OYu, Printseva; Martynov, A.; Sakharov, Ivan Yu.; Trakht, Ilya

doi:10.1007/bf00496822

Cited by 70 publications

(39 citation statements)

References 22 publications

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“…Both enzymes have been localized by immunohistochemistry to polarized cell types in the kidney; the epithelia of proximal tubules and the endothelia of intrarenal vessels (3,30,49,50). The apical and basolateral distribution of ACE in MDCKII cells is in agreement with studies in humans (51,52).…”

Section: Discussionsupporting

confidence: 70%

Angiotensin-converting Enzyme 2 (ACE2), But Not ACE, Is Preferentially Localized to the Apical Surface of Polarized Kidney Cells

Warner

Lew

Smith

et al. 2005

Journal of Biological Chemistry

177

157

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Angiotensin-converting enzyme-2 (ACE2) is a homologue of angiotensin-I converting enzyme (ACE), the central enzyme of the renin-angiotensin system (RAS). ACE2 is abundant in human kidney and heart and has been implicated in renal and cardiac function through its ability to hydrolyze Angiotensin II. Although ACE2 and ACE are both type I integral membrane proteins and share 61% protein sequence similarity, they display distinct modes of enzyme action and tissue distribution. This study characterized ACE2 at the plasma membrane of non-polarized Chinese hamster ovary (CHO) cells and polarized Madin-Darby canine kidney (MDCKII) epithelial cells and compared its cellular localization to its related enzyme, ACE, using indirect immunofluorescence, cell-surface biotinylation, Western analysis, and enzyme activity assays. This study shows ACE2 and ACE are both cell-surface proteins distributed evenly to detergent-soluble regions of the plasma membrane in CHO cells. However, in polarized MDCKII cells under steady-state conditions the two enzymes are differentially expressed. ACE2 is localized predominantly to the apical surface (ϳ92%) where it is proteolytically cleaved within its ectodomain to release a soluble form. Comparatively, ACE is present on both the apical (ϳ55%) and basolateral membranes (ϳ45%) where it is also secreted but differentially; the ectodomain cleavage of ACE is 2.5-fold greater from the apical surface than the basolateral surface. These studies suggest that both ACE2 and ACE are ectoenzymes that have distinct localization and secretion patterns that determine their role on the cell surface in kidney epithelium and in urine. Angiotensin-I converting enzyme (ACE)3 is a zinc metallopeptidase, which functions as a fundamental regulator of the renin-angiotensin system (RAS) by converting angiotensin I (Ang I) to the potent vasoconstrictor, angiotensin II (Ang II). ACE is an important target for the control of blood pressure and ACE inhibitors, being the primary treatment for hypertension, have been shown to have the broadest impact of any drug in cardiovascular medicine (1).In 2000, a human homologue of ACE, angiotensin-converting enzyme-2 (ACE2), was independently identified by our group (2) and by others (3). ACE2 is an 805-amino acid protein that shares ϳ42% sequence identity to the N-and C-domains of somatic ACE (2). The predicted topology of ACE2 is that of a type I integral membrane protein consisting of a short C-terminal cytoplasmic domain (22 amino acids), a transmembrane domain anchoring ACE2 to the plasma membrane, and a large N-terminal ectodomain of 740 amino acids in which the catalytic zinc binding motif, HEXXH, is located. ACE2 functions exclusively as a carboxypeptidase (4, 5) and, therefore, differs in specificity from ACE, which can behave either as a peptidyl dipeptidase or an endopeptidase (6). ACE2 most efficiently cleaves apelin-13, dynorphin A (1-13), and des-Arg 9 bradykinin (4, 5). However, it is the ability of ACE2 to cleave the vasoconstrictor peptide Ang II to a putative cardi...

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Section: Discussionsupporting

confidence: 70%

Angiotensin-converting Enzyme 2 (ACE2), But Not ACE, Is Preferentially Localized to the Apical Surface of Polarized Kidney Cells

Warner

Lew

Smith

et al. 2005

Journal of Biological Chemistry

177

157

View full text Add to dashboard Cite

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“…It has been proposed, therefore, that this enhanced angiotensin conversion may contribute to the vulnerability of diastolic function of hypertrophied hearts during hypoperfusion (12), probably due to angiotensin-II effects on intracellular free Ca 2+ in the ischemic myocytes (19). Conversely, intracoronary infusion of an ACE inhibitor avoiding systemic effect of the drug resulted in a decrease in coronary vascular (56). In the rat, ACE has been detected by radioactive labeling in several regions of the heart, yet to a variable extent.…”

Section: Resultsmentioning

confidence: 99%

Increased angiotensin-I converting enzyme gene expression in the failing human heart. Quantification by competitive RNA polymerase chain reaction.

Studer¹,

Reinecke²,

Müller³

et al. 1994

J. Clin. Invest.

187

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Local activation of the components of the renin angiotensin system in the heart is regarded as an important modulator of cardiac phenotype and function; however, little is known about their presence, regulation, and potential activation in the human heart. To investigate the gene expression of major angiotensin-II-forming enzymes in left ventricles of normal (n = 9) and failing human hearts (n = 20), we established a competitive RNA-polymerase chain reaction (PCR) for mRNA quantification of angiotensin-I converting enzyme (ACE) and human heart chymase. For each gene, competitor RNA targets with small internal deletions were used as internal standards to quantify the original number of transcripts and to control reverse transcription and PCR. In PCR, each target and the corresponding competitor were amplified by competing for the same primer oligonucleotides. The variability of ACE RNA-PCR was 11% indicating a high reproducibility of this method. In addition, ACE mRNA levels obtained by competitive RNA-PCR correlated favorably with traditional slot blot hybridization (r = 0.69, n = 10; P < 0.05). Compared with nonfailing hearts, the number of ACE transcripts referred to 100 ng of total RNA was increased threefold in patients with chronic heart failure (4.2±2.5 vs. 12.8±6 x 105; P < 0.0005). In contrast, no significant difference was found in chymase gene expression between normal and failing hearts. Thus, the expression of the cardiac ACE but not of human heart chymase is upregulated in failing human heart indicating an activation of the cardiac renin-angiotensin system in patients with advanced heart failure. (J. Clin. Invest. 1994. 94:301-310.)

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“…A monoclonal antibody to ACE (9B9) was used (29,30) to investigate the distribution of ACE antigen in the pulmonary circulation before and during the development of hypoxic pulmonary hypertension. Cryostat sections of frozen tissue were cut (4 ,um thick) and fixed in 1% formaldehyde for 1 min followed by acetone for 5 min at room temperature.…”

Section: Methodsmentioning

confidence: 99%

Angiotensin converting enzyme expression is increased in small pulmonary arteries of rats with hypoxia-induced pulmonary hypertension.

Morrell

Atochina²,

Danilov³

et al. 1995

J. Clin. Invest.

190

130

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Previous studies suggest that while lung angiotensin converting enzyme (ACE) activity is reduced during chronic hypoxia, inhibitors of ACE attenuate hypoxic pulmonary hypertension. In an attempt to explain this paradox we investigated the possibility that whole lung ACE activity may not reflect local pulmonary vascular ACE expression. The experimental approach combined in vivo hemodynamic studies in control and chronically hypoxic rats, measurement of whole lung ACE activity, and evaluation of local pulmonary vascular ACE expression by in situ hybridization and immunohistochemistry. Total lung ACE activity was reduced to 50% of control activity by 5 d of hypoxia and remained low for the duration of the study. Immunohistochemistry showed a marked reduction of ACE staining in alveolar capillary endothelium. However, an increase in ACE staining was observed in the walls of small newly muscularized pulmonary arteries at the level of alveolar ducts and walls. In situ hybridization studies showed increased signal for ACE mRNA in the same vessels. Inhibition of ACE by captopril during chronic hypoxia attenuated pulmonary hypertension and markedly reduced distal muscularization of small pulmonary arteries. In addition, we demonstrated marked longitudinal variation in ACE expression along the normal pulmonary vasculature with the highest levels found in small muscular arteries associated with terminal and respiratory bronchioles. We conclude that local ACE expression is increased in the walls of small pulmonary arteries during the development of hypoxic pulmonary hypertension, despite a generalized reduction in alveolar capillary ACE expression, and we speculate that local arteriolar ACE may play a role in the vascular remodeling associated with pulmonary hypertension. (J. Clin. Invest. 1995.

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Immunohistochemical study of angiotensin-converting enzyme in human tissues using monoclonal antibodies

Cited by 70 publications

References 22 publications

Angiotensin-converting Enzyme 2 (ACE2), But Not ACE, Is Preferentially Localized to the Apical Surface of Polarized Kidney Cells

Angiotensin-converting Enzyme 2 (ACE2), But Not ACE, Is Preferentially Localized to the Apical Surface of Polarized Kidney Cells

Increased angiotensin-I converting enzyme gene expression in the failing human heart. Quantification by competitive RNA polymerase chain reaction.

Angiotensin converting enzyme expression is increased in small pulmonary arteries of rats with hypoxia-induced pulmonary hypertension.

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