Bridging the genetical environmental gap in Parkinson's disease through epigenetics

Abstract

Parkinson's Disease (PD) is a progressive neurodegenerative disorder affecting 2% of the population over 60 years old, yet the exact molecular mechanism underlying its pathogenesis remains elusive. PD is a multifactorial disease with genetic and environmental factors intricately associated. Recently, epigenetic mechanisms have been recognized as potential mediators of environmental factors participating in the pathogenesis of PD. Epigenetics refer to the heritable changes in gene expression that do not involve changes to the underlying DNA sequence. Altered epigenetic mechanisms have been attributed to PD, Alzheimer’s and Huntington’s disease. Several studies have shown that DNA methylation, histone modifications and non-coding RNAs mechanisms contribute to the pathogenesis of PD. Accumulation of toxic metals such as manganese and iron, due to abnormal environmental exposure or increased dietary intake, can impact varied components of the epigenetic machinery through free radical formation. Current pharmacological agents only provide symptomatic relief, of which levodopa still remains the gold standard. However, drugs that halt or delay progression of PD are still lacking. In recent years, there has been considerable progress in the development of epigenetic drugs as a novel therapeutic modality in the management of PD. Cell replacement therapy is a promising avenue for the treatment of PD with scientific research making great progress in the development of Induced Pluripotent Stem Cells (iPSCs) to produce midbrain dopamine phenotypes. With direct access to the neurons that are affected in PD, the pace of discovery should speed up and the cure for PD should become an attainable goal.