Hyposmia, identified as reduced sensitivity to odor, is a common non-motor symptom of Parkinson’s disease (PD) that antedates the typical motor symptoms by several years. It occurs in ~90% of early-stage cases of PD. In addition to the high prevalence, the occurrence of hyposmia may also predict a higher risk of PD. Investigations into hyposmia and its relationship with PD may help elucidate the underlying pathogenic mechanisms. This review provides an update of olfactory dysfunction in PD and its potential as a biomarker for this devastating disease.
Alzheimer’s disease(AD)is the most common neurodegenerative disorder affecting the elderly people.AD is characterized by progressive and gradual decline in cognitive function and memory loss.While familial early-onset AD is usually associated with gene mutations,the etiology of sporadic late-onset form of AD is largely unknown.It has been reported that environmental factors and epigenetic alterations significantly contribute to the process of AD.Our previous studies have documented that chronic hypoxia is one of the environmental factors that may trigger the AD development and aggravate the disease progression.In this review,we will summarize the pathological effects of chronic hypoxia on the onset and development of AD and put forward the possible molecule mechanisms underlying the chronic hypoxia mediated AD pathogenesis.Finally,we propose that epigenetic regulations may represent new opportunity for the therapeutic intervention of this disease.
