Abstract 090: Long-term Therapy with a Bendavia (MTP-131), a Novel Mitochondria-Targeting Peptide, Normalizes Cardiolipin Biosynthesis and Remodeling in Left Ventricular Myocardium of Dogs with Advanced Heart Failure

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Hani N Sabbah ◽  
Quan He ◽  
Ramesh C Gupta ◽  
Sharad Rastogi ◽  
Mengjun Wang ◽  
...  
Keyword(s):  
Heart Failure ◽  
Atp Synthesis ◽  
Left Ventricular ◽  
Advanced Heart Failure ◽  
Term Therapy ◽  
Complex Iv ◽  
Targeting Peptide ◽  
Long Term Therapy ◽  
Mitochondria Targeting

Background: Cardiolipin (CL) is a signature phospholipid of the mitochondrial inner membrane and responsible for modulation of activities of various enzymes essential for oxidative phosphorylation. Cardiac CL is biosynthesized in a series of steps from phosphatidic acid and remodeled into a form which contains four 18:2 fatty acid chains, tetralinoleol CL [(18:2) 4 CL]. Long-term therapy with Bendavia (MTP-131), a novel mitochondria-targeting peptide, was previously shown to improve left ventricular (LV) function, increase ATP synthesis, and increase the activity and protein levels of mitochondria cytochrome c oxidase (complex IV) in LV myocardium of dogs with advanced heart failure (HF). This study examined the effects of Bendavia on total CL and (18:2) 4 CL in LV myocardium of dogs with HF. Methods: LV tissue was obtained from 12 dogs with microembolization-induced HF randomized to 3 months therapy with subcutaneous injections of Bendavia (0.5 mg/kg once daily, n=7) or saline (Control, n=7). LV tissue from 7 normal dogs was used for comparison. Total CL and (18:2) 4 CL were measured using electrospray ionization mass spectroscopy and quantified in nmol/mg of non-collagen protein (NCP). Results: Total CL was significantly decreased in LV myocardium of Control dogs compared to normal dogs (19.1±1.1 vs. 26.7±1.4 nmol/mg, p<0.05) as was (18:2) 4 CL (14.2±0.9 vs. 20.5±1.2 nmol/mg, p<0.05). Long-term therapy with Bendavia significantly increased both total CL (23.6±1.1 nmol/mg) and (18:2) 4 CL (17.8±1.0 nmol/mg) to near normal levels in LV myocardium of treated HF dogs compared to untreated HF Controls (p<0.05). Conclusions: Total CL and (18:2) 4 CL are decreased in LV myocardium of dogs with HF. Treatment with Bendavia normalizes total CL and (18:2) 4 CL. These findings are consistent with observed normalization of mitochondrial complex IV activity, normalization of rate of ATP synthesis and improvement of global LV performance in dogs with HF after long-term therapy with Bendavia.

Abstract 85: Long-term Monotherapy with Bendavia (MTP-131), A Novel Mitochondria-Targeting Peptide, Restores H11 Kinase Protein Levels in Mitochondrial Fractions of Left Ventricular Myocardium of Dogs with Advanced Heart Failure

2014 ◽  
Vol 115 (suppl_1) ◽  
Author(s):  
Ramesh C Gupta ◽  
Kristina Szekely ◽  
Mengjun Wang ◽  
Sharad Rastogi ◽  
Kefei Zhang ◽  
...  
Keyword(s):  
Mitochondrial Respiration ◽  
Atp Synthesis ◽  
Term Therapy ◽  
Protein Levels ◽  
Chronic Therapy ◽  
Mitochondrial Fractions ◽  
Targeting Peptide ◽  
Long Term Therapy ◽  
Mitochondria Targeting

Background: The heat shock protein H11 kinase (H11K) is expressed in the heart of dogs, rodents and humans and rapidly increases in response to increased contractile workload. Deletion of H11K in pressure overload transgenic mice accelerates LV dysfunction and remodeling by deactivating STAT3, a stress-inducible transcription factor. Deactivation of STAT3 has been shown to adversely impact mitochondrial respiration and consequently oxidative phosphorylation. We previously showed that chronic therapy (3 months) with Bendavia (BEN, MTP-131), a novel mitochondria-targeting peptide, improves LV systolic function in dogs with heart failure (HF) and normalizes mitochondrial respiration and rate of ATP synthesis in LV myocardium of dogs with HF. This study tested the hypothesis that H11K is reduced in mitochondria of the failing heart and that long-term therapy with BEN normalizes levels of this key heat shock protein. Methods: LV tissue was obtained from 12 dogs with microembolization-induced HF (LV ejection fraction ~30%) randomized to 3 months therapy with subcutaneous injections of BEN (0.5 mg/kg once daily, n=6) or saline (Control, n=6). LV tissue from 6 normal dogs was used for comparison. Tissue samples were used to extract mitochondrial fractions (MF). Protein levels of H11K and Porin, a mitochondrial protein not altered in HF, were determined in MF by Western blotting and protein band were quantified in densitometric units (du). Results: Protein level of Porin in MF was similar among NL, Control and BEN-treated dogs (0.24±0.0 vs. 0.22±0.01 vs. 0.23±0.01 du, respectively). Level of H11K was 0.45±0.03 du in NL, decreased to 0.17±0.02 in Controls (p<0.05vs. NL) and was normalized by BEN (0.37±0.05, p<0.05 vs. Control). H11K normalized to Porin was 1.93±0.23 du in MF of NL dogs, decreased to 0.78±0.0.09 du in Controls (p<0.05 vs. NL) and was restored to near normal levels after treatment with BEN (1.61±0.20 du, p<0.05 vs. Control). Conclusions: H11K protein levels are reduced in MF from LV myocardium of dogs with HF and normalized after chronic therapy with BEN. Restoring H11K with BEN likely contributed to the observed improvement in mitochondrial respiration and rate of ATP synthesis previously reported after long-term therapy with BEN.

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