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Molecular imaging using mass spectrometry to localize renal angiotensin converting enzyme 2 (ACE2) activity
Author(s) -
Grobe Nadja,
Cool David R.,
Grunwald William C.,
Elased Khalid M.,
Morris Mariana
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.664.3
In light of recent evidence suggesting renoprotective effects of ACE2, we developed a sensitive and highly specific method using MALDI imaging to measure the regional distribution of renal ACE2 activity in mice. Kidney sections (12 μm) were incubated with 1 mM Ang II and peptides verified using MALDI‐TOF/TOF. The figure illustrates the conversion of Ang II ( m/z 1046, Fig. A) to Ang‐(1–7) ( m/z 899, Fig. B) by ACE2 localized in the renal cortex. Presence of ACE2 was confirmed by immunostaining. Product formation was dose and time dependent. ACE2 activity peaked at 15 min of incubation as calculated by the ratio of Ang II/Ang‐(1–7) and was absent in tissue sections exposed to autoclave temperatures. The ACE2 inhibitor, MLN‐4760, reduced ACE2 activity in a dose‐dependent manner to 71% ± 6 and 44% ± 9 with 8 μM and 84 μM MLN‐4760, respectively. Results show the utility of MALDI imaging to study regional patterns of enzyme activity in renal tissue. This novel and powerful approach will further aid our understanding of the role of ACE2 in various metabolic and cardiovascular pathologies. Supported by NIH R01 HL093567.