Mitochondrial ultrastructure and markers of dynamics in hepatocytes from aged, calorie restricted mice fed with different dietary fats

PMCID: PMC4104696
In this paper we analyzed changes in hepatocyte mitochondrial mass and ultrastructure as well as in mitochondrial markers of fission/fusion and biogenesis in mice subjected to 40% calorie restriction (CR) for 18. months versus ad libitum-fed controls. Animals subjected to CR were separated into three groups with different dietary fats: soybean oil (also in controls), fish oil and lard. Therefore, the effect of the dietary fat under CR was studied as well. Our results show that CR induced changes in hepatocyte and mitochondrial size, in the volume fraction occupied by mitochondria, and in the number of mitochondria per hepatocyte. Also, mean number of mitochondrial cristae and lengths were significantly higher in all CR groups compared with controls. Finally, CR had no remarkable effects on the expression levels of fission and fusion protein markers. However, considerable differences in many of these parameters were found when comparing the CR groups, supporting the idea that dietary fat plays a relevant role in the modulation of CR effects in aged mice.
Supported by NIH grant 1R01AG028125-01A1 (to JJR, PN and JMV), Ministerio de Economía y Competitividad and European FEDERBFU2011-23578 (to JMV), Junta de Andalucía Proyectos de Excelencia grant P09-CVI-4887 (to JMV), Junta de Andalucía Proyectos Internacionales (to JMV), and BIO-276 (Junta de Andalucía and the University of Córdoba, to JMV and EGC). JALD and LFdR were funded by predoctoral fellowships of the Spanish Ministerio de Educación and by BIO-276. HK was funded by a predoctoral fellowship of the Agencia Española de Cooperación Internacional al Desarrollo and by BIO-276.