Cardiovascular Research Advance Access first published online on October 9, 2009
This version [Corrected Proof] published online on November 6, 2009
Cardiovascular Research, doi:10.1093/cvr/cvp336
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Influence of heart failure on nucleocytoplasmic transport in human cardiomyocytes
1 Cardiocirculatory Unit, Research Center, Hospital Universitario La Fe, Valencia, Spain
2 Cardiology Unit, Hospital Universitario La Fe, Valencia, Spain
3 Experimental Neurology, Research Center, Hospital Universitario La Fe, Valencia, Spain
4 Cell Biology and Pathology Unit, Research Center, Hospital Universitario La Fe, Avd. Campanar, 21, Valencia 46009, Spain
* Corresponding author. Tel: +34 96 386 27 00, Fax: +34 96 197 30 18, Email: portoles_man{at}gva.es
Aims: The role of the cell nucleus in the development of heart failure (HF) is unknown, so the objectives of this study were to analyse the effect of HF on nucleocytoplasmic transport and density of the nuclear pore complex (NPC).
Methods and results: A total of 51 human heart samples from ischaemic (ICM, n = 30) and dilated (DCM, n = 16) patients undergoing heart transplantation and control donors (CNT, n = 5) were analysed by western blotting. Subcellular distribution of proteins and NPC were analysed by fluorescence and electron microscopy, respectively. When we compared nucleocytoplasmic machinery protein levels according to aetiology of HF, ICM showed higher levels of importins [(IMP-β3) (150%, P < 0.0001), IMP-
2 (69%, P = 0.001)] and exportins [EXP-1 (178%, P < 0.0001), EXP-4 (81%, P = 0.006)] than those of the CNT group. Furthermore, DCM also showed significant differences for IMP-β3 (192%, P < 0.0001), IMP-2 (52%, P = 0.025), and EXP-1 (228%, P < 0.0001). RanGTPase-activating proteins (RanGAP1 and RaGAP1u) were increased in ICM (76%, P = 0.005; 51%, P = 0.012) and DCM (41%, P = 0.042; 50%, P = 0.029). Furthermore, subcellular distribution of nucleocytoplasmic machinery was not altered in pathological hearts. Finally, nucleoporin (Nup) p62 was increased in ICM (80%) and DCM (109%) (P < 0.001 and P = 0.024). Nuclear pore density was comparable in pathological and CNT hearts, and ICM showed a low diameter (P = 0.005) and different structural configuration of NPC.
Conclusion: This study shows the effect of HF on nucleocytoplasmic trafficking machinery, evidenced by higher levels of importins, exportins, Ran regulators and Nup p62 in ischaemic and dilated human hearts than those in the controls, with NPCs acquiring a different configuration and morphology in ICM.
KEYWORDS Heart failure; Ischaemia; Human cardiomyocytes; Nucleocytoplasmic transport
Time for primary review: 23 days
The first two authors contributed equally to the study.