In the news

To investigate effects of two of the three forms of the human apoE protein (apoE3 and apoE4) on the form and function of a healthy and degenerating peripheral nervous system (PNS) using mouse models.  

The researchers expressed human apoE3 and apoE4 in mice lacking other apoE proteins. Proteomic screens were used to examine protein networks involved in cellular growth and regeneration and the blood-nerve barrier in mice expressing apoE3 and apoE4, with healthy and injured peripheral nervous systems.

Healthy nerves were not affected by the expression of either apoE3 or apoE4. In mice expressing human apoE4, a significant delay in nerve regeneration was observed on injured peripheral nerves. However, there was no effect of apoE4 on neurodegeneration, a process known to be modulated by apoE4 in the central nervous system (CNS). 

The most significant observation of this study was the negative effect of apoE4 on nerve regeneration and neuromuscular reinnervation in the injured PNS. There results are consistent with the previously reported association between the APOE4 human genotype and the risk of progressive diseases of the PNS, including diabetic and HIV-associated neuropathies. 

The APOE4 gene variant is known to be associated with degeneration in the CNS, and is a risk factor for Alzheimer’s disease (see previous news); this new study provides insight into the role of the ApoE4 protein in diseases of the peripheral nervous system and aids the search for new treatments. Genetic testing for APOE4 (see previous news) could potentially become an element of personalised medicine, informing doctors about individual patient’s prospects for recovery from nerve injuries and diseases