Confocal images showing the distribution of APC (A, D, G, J, green), tumor necrosis factor receptor 1 (TNF-R₁) (B, E, red) and interleukin-1 receptor 1 (IL-1R₁) (H, K, red) in oligodendrocytes (arrows) in the PWM at 7 days after the hypoxic exposure and the corresponding control.

<p>The co-localized expression of APC with TNF-R₁ and IL-1R₁ is depicted in C and F, I and L, respectively. Note the expression of TNF-R₁ and IL-1R₁ is upregulated after the hypoxic exposure. Scale bars: A–L, 50 µm.</p

Confocal images of cultured control astrocytes showing the expression of GFAP (A, G, green), TNF-α (B red), IL-1β (H red) and co-localized expression of GFAP and TNF-α (C), GFAP and IL-1β (I).

<p>D–F show the expression of GFAP (D, green), TNF-α (E, red) and colocalized expression of GFAP and TNF-α (F) after treatment with 3% oxygen for 3 h. Note the elevated expression of TNF-α following treatment with 3% oxygen for 3 h (E) as compared with the control cells (B). J–L show the expression of GFAP (J, green), IL-1β (K, red) and colocalized expression of GFAP and IL-1β (L) after treatment with 3% oxygen for 3 h. The expression of IL-1β is greatly increased in the astrocytes after hypoxic exposure for 3 h. Scale bars: A–L, 50 µm.</p

Confocal images showing APC immunolabeled oligodendrocytes (arrows)(A, D, red) and caspase-3 positive apoptotic cells (B, E; green) (arrows) as detected by double immunofluorescence in the PWM of a control and a hypoxic rat at 7d after the hypoxic exposure.

<p>The colocalized expression of APC and caspase-3 labeling can be seen in C and F. Note the increase in frequency of apoptotic nuclei in the PWM after the hypoxic exposure. Bar graphs in G and H show the significant increase in percentage of caspase-3 positive apoptotic cells (H) and decrease in the number of APC positive oligodendrocytes/view (G) in the PWM after the hypoxic exposure (* <i>P</i><0.01). Scale bars: A-F, 50 µm.</p

Upregulation of TNF-R₁ and IL-1R₁ expression in primary cultured oligodendrocytes following hypoxia.

<p>Confocal images showing TNF-R₁ and IL-1R₁ expression (B, E, H, K, red) in primary cultured oligodendrocytes labeled with APC (A, D, G, J, green) in both control and hypoxia for 3 h. Note TNF-R₁ and IL-1R₁ immunofluroscence intensity is markedly enhanced after hypoxic exposure (E, K) in comparison with the control (B, H). Scale bars: A–L, 50 µm.</p

Confocal images showing the distribution of GFAP-labeled (A, D, G, J green), and TNF-α (B, E red), IL-1β (H, K red) immunoreactive astrocytes (arrows) in the PWM at 7 days after the hypoxic exposure and the corresponding control rats.

<p>The co-localized expression of GFAP and TNF-α, IL-1β in astrocytes can be seen in panels C, F, I and L. Note TNF-α and IL-1β expression in astrocytes (arrows) is markedly enhanced at 7 days after the hypoxic exposure. Scale bars: A-L, 20 µm. GFAP = glial fibrillary acidic protein; PWM = periventricular white matter.</p

Hypoxia induces hypomyelination in the PWM in the hypoxic P28d rats.

<p>A–D show PLP protein expression in the PWM at 28 days after the hypoxic exposure and the corresponding control rats. Confocal images showing the expression of PLP in the PWM at 28 days of the hypoxic exposure (B) and the corresponding control rats (A). Note the PLP protein expression is saliently reduced following the hypoxic exposure (B) as compared with the control (A). C shows PLP (30 KDa) and β-actin (42 KDa) immunoreactive bands, respectively. Bar graph in D shows significant decrease in the optical density of PLP following hypoxic exposure when compared with the corresponding controls (*<i>P</i><0.01). E-I Electron micrographs show hypomyelination and aberrant ensheathment of axons in the PWM at 28d after the hypoxic exposure. Electron microscopic images of PWM in cross sections are shown at 2 different magnifications. The number of myelinated axons is markedly decreased in the PWM at 28d after the hypoxic exposure (F) when compared with corresponding control (E). Higher magnification EM images showing thinner myelin in the PWM of hypoxic rats (G, H). I is bar graph showing increased g-ratio of myelinated axons in the PWM at 28d after the hypoxic exposure. Scale bars: A–B, 100 µm. Scale bars: E–H, 500 nm.</p