BACKGROUND: There is a scarcity of cardiac tissue available for research. OBJECTIVE: (1) To investigate the feasibility of obtaining myocardial tissue from extracted pacemaker and defibrillator leads for gene expression analysis and (2) to examine the nitric oxide 1 adaptor protein (NOS1AP) RNA expression as a function of patient genotype. METHODS: Seventeen patients (age = 56 ± 20 years; 12 men; 5 pacemakers; 12 defibrillators) undergoing lead extractions for standard indications (5 device erosion; 1 vascular occlusion; 11 lead malfunction or recall) were genotyped for 2 NOS1AP single nucleotide polymorphisms-rs10494366 (T to G) and rs10918594 (C to G)-and had RNA levels measured by real-time polymerase chain reaction for collagen I, troponin I, Ca(v)1.2, Kv4.3, HERG, KvLQT1, connexin 43, NOS1AP, and sodium-calcium exchanger. Ventricular tissue obtained from 3 failing hearts at transplantation served as reference. RESULTS: A high ratio of cardiac troponin I/collagen I RNA identified 9 of the 17 patient samples (muscle rich), in which the gene expression profile was similar to that of the reference ventricular samples and significantly different (P < .003) from the expression profile of samples with a low troponin I/collagen ratio (muscle poor). TT and CC polymorphisms were associated with significantly lower NOS1AP RNA levels (P < .01 compared with the GG genotype). CONCLUSIONS: Performing gene expression analyses on right ventricular tissue samples extracted with pacemaker and defibrillator leads is feasible. A significant number of samples contain cardiomyocytes that express troponin I and ion channels at levels comparable to those seen in explanted hearts. Decreased NOS1AP expression in rs10494366 TT and rs10918594 CC homozygotes may underlie shorter repolarization times. Copyright Â
BACKGROUND: There is a scarcity of cardiac tissue available for research. OBJECTIVE: (1) To investigate the feasibility of obtaining myocardial tissue from extracted pacemaker and defibrillator leads for gene expression analysis and (2) to examine the nitric oxide 1 adaptor protein (NOS1AP) RNA expression as a function of patient genotype. METHODS: Seventeen patients (age = 56 ± 20 years; 12 men; 5 pacemakers; 12 defibrillators) undergoing lead extractions for standard indications (5 device erosion; 1 vascular occlusion; 11 lead malfunction or recall) were genotyped for 2 NOS1AP single nucleotide polymorphisms-rs10494366 (T to G) and rs10918594 (C to G)-and had RNA levels measured by real-time polymerase chain reaction for collagen I, troponin I, Ca(v)1.2, Kv4.3, HERG, KvLQT1, connexin 43, NOS1AP, and sodium-calcium exchanger. Ventricular tissue obtained from 3 failing hearts at transplantation served as reference. RESULTS: A high ratio of cardiac troponin I/collagen I RNA identified 9 of the 17 patient samples (muscle rich), in which the gene expression profile was similar to that of the reference ventricular samples and significantly different (P < .003) from the expression profile of samples with a low troponin I/collagen ratio (muscle poor). TT and CC polymorphisms were associated with significantly lower NOS1AP RNA levels (P < .01 compared with the GG genotype). CONCLUSIONS: Performing gene expression analyses on right ventricular tissue samples extracted with pacemaker and defibrillator leads is feasible. A significant number of samples contain cardiomyocytes that express troponin I and ion channels at levels comparable to those seen in explanted hearts. Decreased NOS1AP expression in rs10494366 TT and rs10918594 CC homozygotes may underlie shorter repolarization times. Copyright Â
Authors: Lei Huang; Yangeng Yu; Yili Chen; David J Tester; Shuangbo Tang; Michael J Ackerman; Zichuang Yuan; Jianding Cheng Journal: Int J Legal Med Date: 2014-02-07 Impact factor: 2.686