Abstract
We have investigated species-specific isotope dilution mass spectrometry (IDMS) for the quantification of ferritin-bound iron in murine serum and brain. Therefore, fresh samples were analyzed using size exclusion chromatography inductively coupled plasma mass spectrometry (SEC-ICP-MS). Isotopically labeled (57Fe)ferritin was used as calibrant for the quantification of ferritin-bound iron in murine samples. Assessment of the iron load of serum ferritin was impaired by concomitant iron-containing proteins of similar size and shape, which could not be separated by SEC nor centrifugal ultra-filtration. In contrast, ferritin was the main iron-containing protein in cytosolic extracts of murine brain, which showed a total ferritin-bound iron content of (1.05 ± 0.12) µg g−1 (n= 10; U, k= 2). The relative expanded uncertainty achieved for a mass fraction of ca. 1 µg g−1 ferritin-bound iron was 11% (Urel, k = 2). The relative expanded uncertainty of the iron mass fraction of the (57Fe)ferritin spike was 5.7% and represented the major contributing factor to the overall uncertainty. Statistical tests suggested no significant difference in ferritin-bound iron content between mouse brain hemispheres. The presented analytical tool provides low limits of quantification (2.2 ng g−1) and uncertainties (11%, Urel, k = 2), thus enables the quantification of ferritin-bound iron in murine brain extracts with high sensitivity and accuracy. Furthermore, this analytical workflow assures comparability of measurement results across research laboratories. This provides the basis for investigation of the iron loading of ferritin in brain tissue of healthy and Alzheimer’s disease mouse models, which may help answering the question if iron regulation is impaired in Alzheimer’s disease.
Highlights
The Alzheimer’s disease (AD) is a neurodegenerative disease, which affects millions of people worldwide [1]
We have investigated species-specific isotope dilution mass spectrometry (IDMS) for the quantification of ferritin-bound iron in murine serum and brain
The presented analytical tool provides low limits of quantification (2.2 ng g−1) and uncertainties (11%, Urel, k = 2), enables the quantification of ferritin-bound iron in murine brain extracts with high sensitivity and accuracy. This analytical workflow assures comparability of measurement results across research laboratories. This provides the basis for investigation of the iron loading of ferritin in brain tissue of healthy and Alzheimer’s disease mouse models, which may help answering the question if iron regulation is impaired in Alzheimer’s disease
Summary
The Alzheimer’s disease (AD) is a neurodegenerative disease, which affects millions of people worldwide [1]. One hypothesis suggests that AD is a result of dysregulation of iron homeostasis in brain [2, 3]. It is believed that ferritin (FER), the major iron storage protein in cells [4], cannot fulfill its regulatory function. This leads to an excess of free iron (Fe2+), a chemical form which can cause oxidative stress and cell damage [5]. To investigate this hypothesis, solid knowledge on FER-bound iron levels in healthy and AD brain are required. It is suggested that damaged cells release FER to serum [6]. When the iron contents of brain and serum FER correlate, the latter might represent a highly promising new biomarker for AD
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
