Final answer:
The western blot data supports option D: Nicotine-induced upregulation of miRNA-214 enhances SYN expression.
Step-by-step explanation:
The western blot data supports option D: Nicotine-induced upregulation of miRNA-214 enhances SYN expression. In Parkinson's disease, alpha-SYN is upregulated forming Lewy bodies, leading to apoptosis in neurons. Nicotine, when introduced into neurons, upregulates miRNA-214.
The western blot exhibits SYN levels in the presence of varying concentrations of miRNA-214. The data shows that as miRNA-214 increases, SYN levels also increase, indicating that nicotine-induced upregulation of miRNA-214 enhances SYN expression.