Decreased Expression of Cerebral Dopamine Neurotrophic Factor in Platelets of Probable Alzheimer Patients

BACKGROUND: Alzheimer disease (AD) patients experience progressive neurological and cognitive decline attributed to neurodegeneration. Cerebral dopamine neurotrophic factor (CDNF) has been identified to protect and rescue neurons in various preclinical neurodegeneration models. The expression of this protein occurs in both the central nervous system and peripheral blood. Blood platelets exhibit several biochemical impairments similar to the brain tissues of patients with neurological disorders. This study examines CDNF mRNA expression in human blood platelets in healthy subjects and Alzheimer-probable patients. METHODS: Platelets were extracted from whole blood from patients. mRNA was extracted to synthesize cDNA and quantify CDNF gene expression from 21 Alzheimer-probable patients and 73 healthy age-matched control subjects using real-time qPCR. Grouping analysis of the data with regard to sex was conducted. RESULTS: CDNF mRNA expression was significantly decreased in Alzheimer-probable patients relative to the control subjects (P<0.05). Further analysis demonstrated reduced CDNF expression in male Alzheimer-probable patients compared with their age and sex-matched controls (P<0.05). However, no change in female subjects was observed. Interestingly, there is a lower level of CDNF expression in the female control group relative to the control male group (P<0.05). CONCLUSION: Alzheimer-probable male patients demonstrated significant reductions in CDNF expression, suggesting that CDNF plays a significant role in the pathogenesis of AD. In addition, it may assist in diagnosing male Alzheimer patients.