Myocardial ischemia-reperfusion (IR) injury contributes to adverse cardiac outcomes after myocardial ischemia, cardiac surgery, or circulatory arrest. In this study, we evaluated the ability of combined SS31-mitochondria (Mito) therapy to protect heart cells from myocardial IR injury. Adult male SD rats (n = 8/each group) were randomized: group 1 (sham-operated control), group 2 (IR, 30-min ischemia/72 h reperfusion), group 3 (IR-SS31 (2 mg intra-peritoneal injection at 30 min/24 h/48 h after IR)), group 4 (IR-mitochondria (2 mg/derived from donor liver/intra-venous administration/30 min after IR procedure)), and group 5 (IR-SS31-mitochondria). In H9C2 cells, SS31 suppressed menadione-induced oxidative-stress markers (NOX-1, NOX-2, oxidized protein) while it increased SIRT1/SIRT3 expression and ATP levels. In adult male rats 72 h after IR, left ventricular ejection fraction (LVEF) was highest in sham-operated control animals and lowest in the IR group. LVEF was also higher in IR rats treated with SS31-Mito than untreated IR rats or those treated with Mito or SS31 alone. Areas of fibrosis/collagen-deposition showed the opposite pattern. Likewise, levels of oxidative-stress markers (NOX-1, NOX-2, oxidized protein), inflammatory markers (MMP-9, CD11, IL-1β, TNF-α), apoptotic markers (mitochondrial-Bax, cleaved-caspase-3, PARP), fibrosis markers (p-Smad3, TGF-β), DNA-damage (γ-H2AX), sarcomere-length, and pressure/volume overload markers (BNP, β-MHC) all showed a pattern opposite that of LVEF. Conversely, anti-apoptotic (BMP-2, Smad1/5) and energy integrity (PGC-1α/mitochondrial cytochrome-C) markers exhibited a pattern identical to that of LVEF. This study demonstrates that the combined SS31-Mito therapy is superior to either therapy alone for protecting myocardium from IR injury and indicates that the responsible mechanisms involved increased SIRT1/SIRT3 expression, which suppresses inflammation and oxidative stress and protects mitochondrial integrity.

Background: This study investigated the association between innate immune reaction and myocardial damage after acute myocardial infarction (AMI) and anti-inflammatory role of tacrolimus in reducing infarct size. Male mini-pigs (n=18) were equally categorized into sham control (SC), untreated AMI (by ligation of left anterior descending coronary artery), and AMI-Tacrolimus (AMI-Tac) (0.5 mg intra-coronary injection 30 minutes post-AMI). Cardiac magnetic resonance imaging (MRI) was performed at post-AMI days 2, 5 and 21 before sacrificing the animals. Results: By post-AMI day 21, left ventricular ejection fraction (LVEF) was lowest in untreated AMI animals, significantly higher in SC than in AMI-Tac group (all p<0.003). Infarct areas at basal, middle, and apical levels, numbers of CD14+ and iNOS+ cells in infarct area (IA) and peri-IA, and protein expression of CD14, CD68, and Ly6g from circulating inflammatory cells showed an opposite pattern compared with that of LVEF in all groups (all p<0.005). Protein expressions of MCP-1, MIP-1, TNF-α, NF-κB, iNOS, and IL-12 in IA and peri-IA exhibited an identical pattern compared to that of CD14, CD68, and Ly6g from circulating inflammatory cells (all p<0.01). Expressions of myocardial damage biomarkers in IA and peri-IA [γ-H2AX, β-myosin heavy chain (MHC), Smad3, TGF-β] were highest in AMI and higher in AMI-Tac than in SC, whereas expressions of myocardial integrity biomarkers (connexin43, mitochondrial cytochrome-C, α-MHC, BMP-2, Smad1/5) were opposite to those of damage biomarkers (all p<0.001). Conclusion: Innate immune responses were markedly augmented and LVEF was significantly reduced after AMI but were remarkably improved after tacrolimus treatment.

Https://doi.org/10.18632/oncotarget.21433 Hon-Kan Yip, Mel S. Lee, Cheuk-Kwan Sun, Kuan-Hung Chen, Han-Tan Chai, Pei-Hsun Sung, Kun-Chen Lin, Sheung-Fat Ko, Chun-Man Yuen, Chu-Feng Liu, Pei-Lin Shao,...

Increased circulating level of uraemic solute p‐cresyl sulphate (PCS) in patients with chronic kidney disease (CKD) is known to increase myocardial burden relevant to mitochondrial abnormalities. This study aimed at investigating mitochondrial response to PCS in H9C2 cardiomyoblasts. H9C2 cardiomyoblasts were treated with four different concentrations of PCS (3.125, 6.25, 12.5 and 25.0 µg/mL) to study the changes in cell proliferation, cell size and mitochondrial parameters including morphology, respiration, biogenesis and membrane potential. The lowest effective dose of PCS (6.25 µg/mL) induced mitochondrial hyperfusion with enhanced mitochondrial connectivity, mitochondrial oxygen consumption rates, mitochondrial mass, mitochondrial DNA copy number and increased volume of cardiomyoblasts. After PCS treatment, phosphorylation of energy‐sensing adenosine monophosphate‐activated protein kinase (AMPK) was increased without induction of apoptosis. In contrast, mitochondrial mass was recovered after AMPK silencing. Additionally, mitochondrial hyperfusion and cell volume were reversed after cessation of PCS treatment. The results of the present study showed that low‐level PCS not only caused AMPK‐dependent mitochondrial hyperfusion but also induced cell enlargement in H9C2 cardiomyoblasts in vitro.

This study tested the hypothesis that extracorporeal shock wave‐ (ECSW‐) assisted adipose‐derived stromal vascular fraction (SVF) therapy could preserve left ventricular ejection fraction (LVEF) and inhibit LV remodeling in a rat after acute myocardial infarction (AMI). Adult male SD rats were categorized into group 1 (sham control), group 2 (AMI induced by left coronary artery ligation), group 3 [AMI + ECSW (280 impulses at 0.1 mJ/mm², applied to the chest wall at 3 h, days 3 and 7 after AMI), group 4 [AMI + SVF (1.2 × 10⁶) implanted into the infarct area at 3 h after AMI], and group 5 (AMI + ECSW‐SVF). In vitro, SVF protected H9C2 cells against menadione‐induced mitochondrial damage and increased fluorescent intensity of mitochondria in nuclei (p < 0.01). By day 42 after AMI, LVEF was highest in group 1, lowest in group 2, significantly higher in group 5 than in groups 3 and 4, and similar between the latter two groups (all p < 0.0001). LV remodeling and infarcted, fibrotic, and collagen deposition areas as well as apoptotic nuclei exhibited an opposite pattern to LVEF among the groups (all p < 0.0001). Protein expressions of CD31/vWF/eNOS/PGC‐1α/α‐MHC/mitochondrial cytochrome C exhibited an identical pattern, whilst protein expressions of MMP‐9/TNF‐α/IL‐1β/NF‐κB/caspase‐3/PARP/Samd3/TGF‐β/NOX‐1/NOX‐2/oxidized protein/β‐MHC/BNP exhibited an opposite pattern to LVEF among five groups (all p < 0.0001). Cellular expressions of CXCR4/SDF‐1α/Sca‐1/c‐Kit significantly and progressively increased from groups 1 to 5 (all p < 0.0001). Cellular expression of γ‐H2AX/CD68 displayed an opposite pattern to LVEF among the five groups (all p < 0.0001). In conclusion, ECSW‐SVF therapy effectively preserved LVEF and inhibited LV remodeling in rat AMI.

This phase II randomized controlled trial tested whether intracoronary autologous CD34+ cell therapy could further improve left ventricular (LV) systolic function in patients with diffuse coronary artery disease (CAD) with relatively preserved LV ejection fraction (defined as LVEF >40%) unsuitable for coronary intervention. Between December 2013 and November 2017, 60 consecutive patients were randomly allocated into group 1 (CD34+ cells, 3.0 × 10⁷/vessel/n = 30) and group 2 (optimal medical therapy; n = 30). All patients were followed for one year, and preclinical and clinical parameters were compared between two groups. Three-dimensional echocardiography demonstrated no significant difference in LVEF between groups 1 and 2 (54.9% vs. 51.0%, respectively, p = 0.295) at 12 months. However, compared with baseline, 12-month LVEF was significantly increased in group 1 (p < 0.001) but not in group 2 (p = 0.297). From baseline, there were gradual increases in LVEF in group 1 compared to those in group 2 at 1-month, 3-months, 6-months and 12 months (+1.6%, +2.2%, +2.9% and +4.6% in the group 1 vs. −1.6%, −1.5%, −1.4% and −0.9% in the group 2; all p < 0.05). Additionally, one-year angiogenesis (2.8 ± 0.9 vs. 1.3 ± 1.1), angina (0.4 ± 0.8 vs. 1.8 ± 0.9) and HF (0.7 ± 0.8 vs. 1.8 ± 0.6) scores were significantly improved in group 1 compared to those in group 2 (all p < 0.001). In conclusion, autologous CD34+ cell therapy gradually and effectively improved LV systolic function in patients with diffuse CAD and preserved LVEF who were non-candidates for coronary intervention (Trial registration: ISRCTN26002902 on the website of ISRCTN registry).