Proteomics dataset for Membrane and Cytosolic proteins expression level from sheep with or without AFib

Proteomics raw data from sheep with or without AFib</p

Resistance to Atrial Fibrillation Domestication and Mitochondrial Dysfunction in Sheep

In this study, we conducted a comprehensive proteomic analysis on sheep heart samples, focusing on the variations associated with to atrial fibrillation (AF). The samples were categorized into three distinct groups: sham-operated (control), AF-sensitive, and AF-resistant. The sham group provided baseline data, representing normal cardiac tissue without exposure to AF. The AF-sensitive samples were derived from sheep that exhibited a high susceptibility to AF, characterized by a rapid onset of arrhythmia upon induction. In contrast, the AF-resistant group comprised samples from sheep that showed resilience to AF, maintaining regular heart rhythm despite induction attempts. This proteomic comparison aimed to unravel the molecular underpinnings that differentiate the cardiac response in AF-sensitive and AF-resistant sheep, potentially revealing critical protein expressions or pathways that could be targeted for novel AF therapies or preventive strategies.</p

Infarct size and hemodynamic recovery of hearts in all experiments.

<p>Infarct size and hemodynamic recovery of hearts in all experiments.</p

Measurement of mitochondrial H₂O₂ following ischemia / reperfusion in the perfused heart using MitoPY1 and aconitase activity.

<p><b>A</b>, MitoPY1 fluorescence (535 nm) in control (black) and IP (grey) in Langendorff-perfused hearts subjected to 30 min ischemia + 30 min reperfusion. Fluorescence was normalized to the 1 min pre-iscaemic value. MitoPY1 was successfully loaded into the hearts as shown by the increase in fluorescence upon addition of H₂O₂ to the perfusion medium. <b>B,</b> Mean 535 nm fluorescence (± SEM as error bars) was normalized to the average value between 20.5 and 21.5 min obtained on reperfusion after 30 min global ischemia in control (black, n = 10) and IP hearts (grey, n = 8). <b>C</b>, Corresponding autofluorescence data for hearts subject to a mock loading protocol (n = 6 in both control and IP hearts). Corresponding infarct sizes are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167300#pone.0167300.t001" target="_blank">Table 1</a>. <b>D</b>, Aconitase activity in mitochondria isolated from normoxic control hearts (Cont) and both control (CP Rep) and ischemic preconditioned (IP Rep) hearts subjected to 30 min ischemia and 90 s reperfusion as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167300#pone.0167300.s001" target="_blank">S1 Fig</a> The grey bars confirm the reduction in aconitase activity following treatment of the mitochondrial extract with 200 μmol/L H₂O₂. Data are given as means ± SEM (error bars) of 4 hearts in each group.</p

Validation of the bespoke surface fluorescence apparatus.

<p><b>A,</b> Time course of NAD(P)H (top) and flavoprotein (bottom) surface fluorescence and the reflectance signals at the corresponding excitation and emission wavelengths together with data for the left ventricular pressure (LVP). <b>B,</b> Example of Indo-1 fluorescence transients recorded at 405 nm (in blue) and at 485 nm (in red), and Indo-1 ratio calculated after subtracting background autofluorescence. The top trace shows corresponding LVP data.</p

Proteomics dataset for proteins expression level from sheep / Sham vs AF sensitive vs AF Resistant

Proteomics dataset for proteins expression level from sheep / Sham vs AF sensitive vs AF Resistant</p

Specific effects of OP2113 on ROS/H₂O₂ production at different sites in isolated rat heart mitochondria.

The rates of ROS/H2O2 production were measured under conditions specifically designed by MD brand's group for the identification of the different mitochondrial ROS production sites [21, 22, 24, 38](see Methods section for details). The effects of increasing concentrations of OP2113 (from 2.5 to 80 μM) were tested for each condition of ROS/H2O2 production. Data are based on 3 to 5 independent experiments, each performed in duplicate or triplicate. *P versus control group.</p

Main sites of oxygen radical production by isolated mitochondria.

This scheme gives background information regarding the potential sites for ROS production, using different mitochondrial-targeted drugs in a protocol specifically designed for a study of the effect of a compound on mitochondrial ROS/H2O2 production. When mitochondria are energized by a combination of complex I (malate-glutamate) and complex II (succinate) substrates and in the absence of specific inhibitors of the complexes, ROS production is considered as mainly derived from reverse electron transport (RET) at site IQ (A). Of note, ROS produced by complex I, either at site IQ (quinone site) or at site If (flavin site), are delivered to the inner- (matrix-) side of the inner mitochondrial membrane. In the presence of rotenone, a specific inhibitor of complex I which blocks RET, ROS production is thought to occur predominantly at site IIIQO, possibly with residual production at site If (B) [24]. If complex III is inhibited as it is the case in the presence of antimycin a, the reduced to oxidized quinone ratio increases due to complex II activity and triggers an increase in ROS production, essentially at site IIIQO (C). Finally, myxothiazol (inhibitor of complex III site IIIQO) is supposed to block complex III ROS production, and the remaining production is usually ascribed to the flavin site of complex I for which there is no known inhibitor (D)[25]. However, due to matrix antioxidant machinery, the possibility that some ROS/H2O2 produced in the matrix may escape to the measurement has been suggested from experiments carried out with submitochondrial particles [37]. A typical recording of ROS production kinetics by mitochondria during the designed inhibitor sequence is presented in E.</p

Perfusion protocols used for fluorescence measurements.

<p><b>A,</b> A 30 min dye loading protocol was used for loading the heart with 5 μmol/L 5-cH₂DCFDA, diAM, 0.4 μmol/L calcein-AM or 3 μmol/L MitoPY1. <b>B,</b> A 45 min dye loading protocol with recirculation was used to load the heart with 3 μmol/L Indo-1. <b>C,</b> Hearts were perfused with 5 μmol/L PO1 for 30 min before index ischemia and 30 min on reperfusion. Further details are given in Supporting Information.</p

H₂O₂ production measured using PO1 fluorescence in control and IP hearts during ischemia / reperfusion.

<p><b>A</b>, Averaged fluorescence data for control (black) or IP (grey) hearts perfused with 5 μmol/L PO1. PO1 was present in the perfusion solution from 30 min (Control) or 40 min (IP) before starting global ischemia. PO1 was excluded from the perfusion solution after 30 min of reperfusion. The fluorescence was normalized using the value obtained at -11 min for control and -21 min for IP hearts and then averaged for each group. <b>B</b>, Mean data (± SEM as error bars; n = 11 for control and n = 9 for IP hearts) for PO1 fluorescence during the reperfusion period. <b>C,</b> Mean data (± SEM as error bars; n = 17 for control and n = 16 for CsA-treated hearts) for PO1 fluorescence during reperfusion of control hearts (black) and CsA-treated hearts (grey). Data were normalized to the fluorescence value at -16 min. Where present, CsA (0.2 mmol/L) was added to the PO1 perfusion solution 15 min before ischemia and during 30 min of reperfusion. Statistically significant effects of IP and CsA are shown by the horizontal lines (* p ≤ 0.05; ** p ≤ 0.01). Corresponding infarct sizes are presented in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0167300#pone.0167300.t001" target="_blank">Table 1</a>.</p