Changes in myocardial protein expression in pacing-induced canine heart failure

Abstract

Canine rapid ventricular pacing produces a low output cardiomyopathic state which is similar to dilated cardiomyopathy. In this study dogs were paced at 245 beats per minute (bpm) for 3—4 weeks until signs of heart failure were apparent. Unpaced dogs were used as controls. A previous study identified myocardial protein changes in the pH region 4—7 following ventricular pacing by using two‐dimensional electrophoresis (2‐DE) (Heinke et al., Electrophoresis 1998 19, 2021—2030). Many of these proteins were associated with mitochondria, energy metabolism within the cardiomyocyte, the cytoskeleton and calcium cycling. The present study aimed to examine the proteins migrating in the more basic region of the 2‐DE pattern using immobilised pH gradient 3—10 strips to separate myocardial proteins. The expression of 31 proteins was altered in the paced myocardium: 21 were decreased and 10 increased. Following the identification of 23 of these spots by either amino acid compositional analysis or peptide mass fingerprinting or a combination of both, we confirm that many of the proteins whose expression is altered following ventricular pacing are associated with the mitochondria and energy production within the cardiomyocyte, including creatine kinase M, triosephosphate isomerase, phosphoglycerate mutase, cytochrome c oxidase, cytochrome b5, hydroxymethyl glutaryl CoA synthase, myoglobin, and 3,2‐trans‐enoyl‐CoA transferase. Additionally, the cytoskeletal protein actin was increased in the paced hearts. These results strongly support the notion that energy production is impaired and mitochondrial dysfunction is involved in the development of heart failure in the paced dog.

NGFI-B targets mitochondria and induces cardiomyocyte apoptosis in restraint-stressed rats by mediating energy metabolism disorder

“…A disorder in the lipid metabolism might be an important characteristic of stress-induced dysfunction of mitochondria. The present data are consistent with the observations of Heinke et al (1999) and Weekes et al (1999) in experimental models of pacing-induced canine heart failure and bovine dilated cardiomyopathy. Glucose-regulated protein is a member of the HSP70 superfamily.…”

“…Three protein bands were found to contain NGFI-B, all of which were successfully identified. Most of the interesting proteins were mitochondrial proteins related to energy production (Kotyza et al 2009;Lee et al 2009;Heinke et al 1999;Weekes et al 1999). In this work, we detected mitochondrial respiratory function, ATP synthase activity, and ATP content in cardiomyocytes by biochemical methods.…”

A better understanding of molecular mechanisms underlying human disease

“…They studied the pacing-induced dilated-type heart failure in dogs by 2-DE, finding alterations in the same classes of proteins as those in human DCM (cytoskeletal and myofibrilar proteins, proteins associated with stress responses and proteins associated with mitochondria and energy production) [239,240]. Bovine heredity DCM, a good potential model of human DCM, was analysed by the same group using 2-DE as well [241].…”

Cardiovascular Proteomics

“…81 In addition, a number of putative PTMs have been documented in dilated cardiomyopathy. 65,66,68,78,79,[82][83][84] For example, detailed 2-DE analysis of dilated cardiomyopathy-diseased human myocardial tissue revealed more than fifty HSP27 protein species by immunoblotting. 66,82 Although only nine were finally confirmed to belong to HSP27 and none were analyzed for the presence of PTMs, this illustrates the potentially large number of PTMs possible for a single protein.…”

“…In this case, greater sequence coverage is also beneficial because it increases the likelihood of matching a highly conserved region of the protein. 92 Database searches based on newly developed DCM indicates models of dilated cardiomyopathy including human myocardium from an explanted/transplanted or donor heart 65,83 ; fast pacing-induced failure dog model 78,79 ; and genetic bovine model 84 ; rat phen. hypertrophy, phenylephrine-stimulated hypertrophy of cultured neonatal rat myocytes were compared with control untreated cells 80 ; heat-shock cells, cultured endothelial cells that underwent heat shock were compared with control untreated cells.…”