Figure 1
Morphological changes in microglia and an increase in microglial TLR4 in the SN of PD brains.
(a) Patients with PD showed a decrease in neuromelanin-positive neurons (DA neurons) in the SN compared with age-matched controls. The pictures show a representative SN section from each group. Scale bar, 30 μm. (b) In SN sections from patients with PD, many microglia stained with anti-Iba1 showed an activated morphology, characterized by enlarged cell bodies with short processes. Insets show representative resting and activated microglia in the SN of an age-matched control and a patient with PD, respectively. Scale bar, 20 μm. (c) Western blot analysis showed that TH expression was significantly decreased in the SN samples from patients with PD compared with age-matched controls (CON), but there was not a significant difference in the levels of either Iba1 or OX-42. *p = 0.001 vs. CON (n = 4, each group). In addition, western blot analysis of TLR4 showed that patients with PD exhibited a significant increase in its expression in the SN compared with CON. &p = 0.005 vs. CON (n = 4, each group). (d) Immunofluorescence double staining for Iba1 (microglia, red) and TLR4 (green) in the SN of patients with PD and age-matched controls. Brown arrowheads and yellow arrows indicate the location of DA neurons and TLR4-positive cells merged with microglia, respectively, in SN sections of human brain. Increases in TLR4 expression and activated microglia were observed in the SN of patients with PD compared with age-matched controls and increased TLR4 expression was mainly localized within microglia. Scale bar, 30 μm.
