Mitochondrial damage and dysfunction occur during ischemia and modulate cardiac function and cell survival significantly during reperfusion. We hypothesized that transplantation of autologously derived mitochondria immediately prior to reperfusion would ameliorate these effects. New Zealand White rabbits were used for regional ischemia (RI), which was achieved by temporarily snaring the left anterior descending artery for 30 min. Following 29 min of RI, autologously derived mitochondria (RI-mitochondria; 9.7 ± 1.7 × 10(6)/ml) or vehicle alone (RI-vehicle) were injected directly into the RI zone, and the hearts were allowed to recover for 4 wk. Mitochondrial transplantation decreased (P < 0.05) creatine kinase MB, cardiac troponin-I, and apoptosis significantly in the RI zone. Infarct size following 4 wk of recovery was decreased significantly in RI-mitochondria (7.9 ± 2.9%) compared with RI-vehicle (34.2 ± 3.3%, P < 0.05). Serial echocardiograms showed that RI-mitochondria hearts returned to normal contraction within 10 min after reperfusion was started; however, RI-vehicle hearts showed persistent hypokinesia in the RI zone at 4 wk of recovery. Electrocardiogram and optical mapping studies showed that no arrhythmia was associated with autologously derived mitochondrial transplantation. In vivo and in vitro studies show that the transplanted mitochondria are evident in the interstitial spaces and are internalized by cardiomyocytes 2-8 h after transplantation. The transplanted mitochondria enhanced oxygen consumption, high-energy phosphate synthesis, and the induction of cytokine mediators and proteomic pathways that are important in preserving myocardial energetics, cell viability, and enhanced post-infarct cardiac function. Transplantation of autologously derived mitochondria provides a novel technique to protect the heart from ischemia-reperfusion injury.

Recently we have shown that the cardioprotection afforded by cardioplegia is modulated by age and gender and is significantly decreased in the aged female. In this report we use microarray and proteomic analyses to identify transcriptomic and proteomic alterations affecting cardioprotection using cold blood cardioplegia in the mature and aged male and female heart. Mature and aged male and female New Zealand White rabbits were used for in situ blood perfused cardiopulmonary bypass. Control hearts received 30 min sham ischemia and 120 min sham reperfusion. Global ischemia (GI) hearts received 30 min of GI achieved by cross-clamping of the aorta. Cardioplegia (CP) hearts received cold blood cardioplegia prior to GI. Following 30 min of GI the hearts were reperfused for 120 min and then used for RNA and protein isolation. Microarray and proteomic analyses were performed. Functional enrichment analysis showed that mitochondrial dysfunction, oxidative phosphorylation and calcium signaling pathways were significantly enriched in all experimental groups. Glycolysis/gluconeogenesis and the pentose phosphate pathway were significantly changed in the aged male only (P < 0.05), while glyoxylate/dicarboxylate metabolism was significant in the aged female only (P < 0.05). Our data show that specific pathways associated with the mitochondrion modulate cardioprotection with CP in the aged and specifically in the aged female. The alteration of these pathways significantly contributes to decreased myocardial functional recovery and myonecrosis following ischemia and may be modulated to allow for enhanced cardioprotection in the aged and specifically in the aged female.

and left ventricular (LV) myocardium differ in their pathophysiological response to pressure-overload hypertrophy. In this report we use microarray and proteomic analyses to identify pathways modulated by LV-aortic banding (AOB) and RV-pulmonary artery banding (PAB) in the immature heart. Newborn New Zealand White rabbits underwent banding of the descending thoracic aorta [LV-AOB; n ϭ 6]. RV-PAB was achieved by banding the pulmonary artery (n ϭ 6). Controls (n ϭ 6 each) were sham-manipulated. After 4 (LV-AOB) and 6 (RV-PAB) wk recovery, the hearts were removed and matched RNA and proteins samples were isolated for microarray and proteomic analysis. Microarray and proteomic data demonstrate that in LV-AOB there is increased transcript expression levels for oxidative phosphorylation, mitochondria energy pathways, actin, ILK, hypoxia, calcium, and protein kinase-A signaling and increased protein expression levels of proteins for cellular macromolecular complex assembly and oxidative phosphorylation. In RV-PAB there is also an increased transcript expression levels for cardiac oxidative phosphorylation but increased protein expression levels for structural constituents of muscle, cardiac muscle tissue development, and calcium handling. These results identify divergent transcript and protein expression profiles in LV-AOB and RV-PAB and provide new insight into the biological basis of ventricular specific hypertrophy. The identification of these pathways should allow for the development of specific therapeutic interventions for targeted treatment and amelioration of LV-AOB and RV-PAB to ameliorate morbidity and mortality.heart; hypertrophy; microarray; proteomics VENTRICULAR OUTFLOW TRACT obstruction in congenital heart defects such as interrupted aortic arch, coarctation of the aorta on the left side, and pulmonary artery stenosis on the right side, causes progressive cardiac hypertrophy and, if unrelieved, leads to ventricular dilatation with contractile dysfunction and ultimately irreversible heart failure. Initially, the myocardium compensates to elevated pressure-loading by increasing wall thickness to normalize wall stress. These changes allow for maintenance of contractile function in left ventricular pressureoverload hypertrophy [LV-aortic banding (AOB)], whereas in right ventricular pressure-overload hypertrophy [RV-pulmonary artery banding (PAB)] these changes are less effective and progression to failure occurs more rapidly (2, 4, 15).Our previous studies using the rabbit model of LV-AOB and RV-PAB have demonstrated that disease progression involves both cellular and extracellular components of the myocardium. We have demonstrated that changes in cardiomyocyte viability, lack of adaptive capillary growth, fibrosis, and response to metabolic stress are differentially regulated in LV-AOB and RV-PAB (11,13,16,20). However, the mechanisms involved in the compensated phase of LV-AOB and RV-PAB have yet to be clearly elucidated. In this report we present microarray and proteomic analyses of the LV and RV during t...