Mitochondrial stress and the pathogenesis of diabetic neuropathy

Abstract

Diabetic neuropathy is a major complication of diabetes that affects the sensory and autonomic nervous systems and leads to significant morbidity and impact on the quality of life of patients. Mitochondrial stress has been proposed as a major mediator of neurodegeneration in diabetes. This review briefly summarizes the nature of sensory and autonomic nerve dysfunction and presents these findings in the context of diabetes-induced nerve degeneration mediated by alterations in mitochondrial ultrastructure, physiology and trafficking. Diabetes-induced dysfunction in calcium homeostasis is discussed at length and causative associations with suboptimal mitochondrial physiology are discussed. It is clear that across a range of complications of diabetes mitochondrial physiology is impaired, in general a reduction in electron transport chain capability is apparent. This abnormal activity may predispose mitochondria to generate elevated reactive oxygen species, although experimental proof is still lacking, but more importantly will deleteriously alter the bioenergetic status of neurons. It is proposed that the next 5 years of research should focus on identifying changes in mitochondrial phenotype and associated cellular impact, identifying sources of reactive oxygen species in neurons and analyzing mitochondrial trafficking under diabetic conditions.

Keywords::

• calcium
• dorsal root ganglia
• electron transport chain
• mitochondrial trafficking
• reactive oxygen species
• respiration
• sensory polyneuropathy
• sympathetic neuropathy

Financial & competing interests disclosure

Subir Roy Chowdhury was supported by grants to Paul Fernyhough from CIHR (MOP-84214), to Paul Fernyhough and Robert Schmidt from Juvenile Diabetes Research Foundation (1-2008-193) and to Robert Schmidt from the NIH (DK19645). This work was also funded by the St Boniface General Hospital and Research Foundation and the Manitoba Medical Services Foundation. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.