Premium
A2E Nitration Study in Human Bruch's Membrane
Author(s) -
Suh KyungShin,
Gaillard Elizabeth
Publication year - 2007
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.21.5.a235-d
Subject(s) - bruch's membrane , chemistry , retinal , lipofuscin , retinal pigment epithelium , fragmentation (computing) , pigment , adduct , nitric oxide , nitration , biochemistry , chromatography , biophysics , biology , organic chemistry , ecology
The accumulation of lipid‐like material in Bruch's membrane (BM) is characteristic of age‐related maculopathy and may be related to lipofuscin, an autofluorescent pigment in the retinal pigment epithelium (RPE) whose major component is A2E. It has been hypothesized that abnormal lipid accumulation in BM blocks nutrient and waste circulation between the RPE and choriocapillaris. In this work, we hypothesize that nitrogen oxide may be generated by induced nitrogen oxide synthase (iNOS) due to this blockage of circulation by these deposits and that the detection of A2E nitration may be evidence of inflammation. A2E and its nitro adduct have been synthesized and analyzed by ESI‐LC/MS (ThermoElectron Advantage ion trap MS/Surveyor LC). In addition, the organic soluble extract of old human Bruch's membrane (ca. 70–80 years) was analyzed with the same methods For both samples, an m/z 637.5 ion, corresponding to the nitro‐A2E adduct, was detected and this fraction has a constant retention time and absorption in the visible region between 400–450nm. The m/z 637.5 ion was selected for MS/MS fragmentation and the parent A2E m/z 592.5 was observed. Importantly, there are no visible wavelength absorbing species detected in the organic extract from young Bruch's membrane (18 and 34 year old). These data are the first molecular evidence by a retina specific biomarker that inflammation may contribute to age related tissue damage.