Fe and Zn concentrations in the heart of 13 FA^a patients and 8 normal controls (bulk digests).

<p>^aAbbreviations: FA, Friedreich ataxia; Fe, iron; LVW, left ventricular wall; RVW, right ventricular wall; VS, ventricular septum; Zn, zinc</p><p>^bResults of Fe and Zn are expressed as mean μg metal/g wet tissue ± standard deviation. Number of FA patients and normal controls are given in parentheses. In one FA patient, only LVW tissue was available.</p><p>^cp-values are based on statistical comparison by two-tailed t-test at α = 0.05, assuming unequal variances</p><p>Fe and Zn concentrations in the heart of 13 FA<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#t003fn001" target="_blank">^a</a> patients and 8 normal controls (bulk digests).</p

Cytosolic and mitochondrial ferritin in FA cardiomyopathy.

<p>(a) and (b), positive contrast immunohistochemistry of adjacent sections (LVW, FA patient FA10, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.t001" target="_blank">Table 1</a>); (c-h), laser scanning confocal immunofluorescence (LVW, FA patient FA7, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.t001" target="_blank">Table 1</a>). (a), cytosolic ferritin; (b) mitochondrial ferritin; (c) and (f), cytosolic ferritin visualized by Cy3 (red); (d) and (g), mitochondrial ferritin visualized by Alexa 488 (green); (e) and (h) are merged images of (c) and (d), and (f) and (g), respectively. Cytosolic (a) and mitochondrial ferritin (b) show extensive co-localization of their immunohistochemical reaction products. In the series (c-e), three heart fibers display co-localization of cytosolic and mitochondrial ferritin. In the series (f-h), a single fiber is strongly fluorescent for cytosolic ferritin but does not express mitochondrial ferritin. Bars: (a-b), 100 μm; (c-h), 20 μm.</p

Fiber hypertrophy in FA cardiomyopathy.

<p>A Tukey box-and-whisker plot together with the raw data points to the left of each box, shows fiber size distribution in the LVW of 15 patients with FA (FA1-FA15, corresponding to <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.t001" target="_blank">Table 1</a>) and 10 normal controls (N1-N10). FA cases are shown in red, normal controls in blue. In the box plot, the central rectangle spans the first quartile to the third quartile (the interquartile range), and the horizontal line within the rectangle marks the median. The diamond symbol indicates the mean. The "whiskers" above and below the box are drawn to the furthest point within 1.5 x IQR from the box (the non-outlier range). The range of fiber sizes in FA is much larger than in normal controls. All medians and means in FA are higher than in normal controls. See text for statistical analysis of the data.</p

Hepcidin and cytosolic ferritin in FA myocarditis.

<p>LVW of patient FA7 (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.t001" target="_blank">Table 1</a>). Double-label laser scanning confocal immunofluorescence of hepcidin (Alexa 488 green, a and d), α-actinin (Cy3 red, b), and cytosolic ferritin (Cy3 red, e); (c) and (f) are merged images of (a-b) and (d-e), respectively. (a-c) Invasion of a cardiomyocyte by hepcidin-reactive cells. The circles in (a-c) indicate hepcidin-reactive processes among remaining α-actinin-reactive Z-discs. (d-f) Inflammatory cells in the endomysium. Most inflammatory cells contain both hepcidin and cytosolic ferritin (d-f). The interrupted lines indicate hepcidin-reactive cells that display no ferritin fluorescence. Bars: 10 μm.</p

XRF mapping and quantitative <i>in situ</i> measurements of Fe.

<p>(a) LVW in FA (patient FA5, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.t001" target="_blank">Table 1</a>), (b) LVW in a normal control. Pseudocolors represent the intensity of Fe XRF. White indicates maximal emission. Red, orange, green, light blue, and dark blue represent progressively lower fluorescence, respectively. The distribution of Fe in FA and normal heart is heterogeneous. Circles with an area of 1 mm² were placed over regions of strongest Fe XRF, and 25 point measurements were made inside the outlined area. Fe concentrations in μg/ml tissue volume were calculated by reference to PEG-encapsulated Fe-III- and Zn-II-mesoporphyrin as previously described [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.ref006" target="_blank">6</a>,<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.ref008" target="_blank">8</a>]. In FA (a), the Fe-rich regions appear larger and show a more extended gradient into the surrounding tissue than the control (b). In FA (a), 25 repeated measurements in the circular area of 1 mm² yields an average Fe concentration of 131.8 μg/ml tissue volume; in the illustrated normal control (b), the averaged Fe level is 33.7 μg/ml tissue volume. Quantitative Zn levels in the same outlined regions were obtained after switching to the Zn XRF "map". Levels are 24.3 μg/ml in FA (a) and 20.7 μg/ml in the control sample (b). Bars, 5 mm.</p

The inflammatory infiltrate in FA cardiomyopathy.

<p>Immunohistochemistry of CD68 (a-c) and hepcidin (d-f). All sections derive from LVW of FA patients in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.t001" target="_blank">Table 1</a>: FA5 (a-b), FA8 (c), FA7 (d-e), FA13 (f). The microphotographs in (c) and (f) were taken under differential interference optics to improve contrast, visualize cross-striations of cardiac muscle, and highlight fiber invasion by pseudopods of monocytes (arrows). The cellular infiltrate may be restricted to the endomysium (a) but is most intense following fiber invasion (b and e). Fiber invasion seems to begin with close attachment and breaching of the plasma membrane by delicate CD68- or hepcidin-positive processes, respectively (c and f, arrows). Bars: (a) and (d), 50 μm; (b) and (e), 20 μm; (c) and (f), 10 μm (oil immersion).</p

Fiber counts and cross-sectional areas in FA cardiomyopathy.

<p>(a) FA (patient FA2, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#pone.0116396.t001" target="_blank">Table 1</a>), (b) normal control. Transverse Brazilin-stained sections of VS were photographed at a magnification of 200X, and analyzed for fiber density and cross-sectional area within a field of 0.15 mm². (a) FA: The section shows paucity of fibers, hypertrophy, irregular contours, size variability, and endomysial thickening. The total number of fibers/0.15 mm² is 73, corresponding to 487/mm². The mean cross-sectional area is 804 μm² (range, 37–3953). (b) Normal control: Fibers are much smaller. The total number of fibers/0.15 mm² is 337, corresponding to 2247/mm². The mean cross-sectional area is 249 μm² (range, 24–664). Bars, 50 μm.</p

<i>In situ</i> quantification of Fe and Zn in the hearts of 15 patients with FA^a and 10 normal controls (XRF).

<p>^aAbbreviations: FA, Friedreich ataxia; Fe, iron; LVW, left ventricular wall; RVW, right ventricular wall; VS, ventricular septum; Zn, zinc</p><p>^bResults of Fe and Zn are expressed as mean μg metal/ml tissue volume ± standard deviation. Number of FA patients and normal controls are given in parentheses.</p><p>^cp-values based on statistical comparison by two-tailed t-test at α = 0.05, assuming unequal variances</p><p><i>In situ</i> quantification of Fe and Zn in the hearts of 15 patients with FA<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0116396#t002fn001" target="_blank">^a</a> and 10 normal controls (XRF).</p