Anat Cell Biol.  2017 Jun;50(2):135-142. 10.5115/acb.2017.50.2.135.

Age-related change of Iba-1 immunoreactivity in the adult and aged gerbil spinal cord

• Lee KY
• Kang JY
• Yun JI
• Chung JY
• Hwang IK
• Won MH
• Choi JH

• KMID: 2451239
• DOI: http://doi.org/10.5115/acb.2017.50.2.135

Abstract

In the present study, we examined change of ionized calcium-binding adapter molecule 1 (Iba-1) in the adult and aged gerbil spinal cords. Significant change of morphological feature and neuronal cell loss were not observed in both adult and aged spinal cords of gerbil after NeuN immunohistochemistry and Fluoro-Jade B histofluoresce staining. Iba-1-immunoreactive microglia broadly distributed in the spinal cord. Most of Iba-1-immunoreactive microglia showed ramified forms in the adult gerbil cervical and lumbar spinal cords. However, morphological changes of Iba-1-immunoreactive microglia were observed in the cervical and lumbar regions of the aged gerbil spinal cord. These microglia were showed a hypertrophied body with shortened swollen processes which was characteristic of activated microglia. In addition, Iba-1 protein level significantly higher in aged cervical and lumbar spinal cords than those in the adult gerbil. The present study showed an increase of activated forms of Iba-1-immunoreactive microglia and its protein level without marked changes in morphological features and neuronal loss in the aged spinal cord compared to those in the adult gerbil spinal cord. This result suggests that the increase of Iba-1 expression in the aged spinal cord may be closely associated with age-related changes in aged gerbil spinal cord.

Keyword

Iba-1; Spinal cord; Microglia; Gerbil

MeSH Terms

Adult*
Gerbillinae*
Humans
Immunohistochemistry
Lumbosacral Region
Microglia
Neurons
Spinal Cord*

Figure

• 

  Fig. 1 Immunohistochemical staining for NeuN in the cervical and lumbar spinal cords of the adult (A, B) and aged (C, D) gerbils. Fluoro-Jade B (F-J B) histofluorescence staining for neurodegenerative neurons in the spinal cords of the adult (E, F, I, J) and aged (G, H, K, L) gerbils. Scale bar=200 µm (A–D), 80 µm (E–L). (M) The number of NeuN-immunoreactive neurons in the cervical and lumbar spinal cords per section. The bars indicate the means±SEM.

• 

  Fig. 2 Immunohistochemical staining for ionized calcium-binding adapter molecule 1 (Iba-1) in the cervical region of the adult (A–C) and aged (D, E) gerbils. High magnification photos of white boxes in panels (A) and (D) show in panels (B) to (C) and panels (E) to (F) with same character, respectively. (G, H) High magnification photos of white boxes in panels (C) and (F) show ramified and activated forms of Iba-1–immunoreactive microglia respectively. Scale bar=200 µm (A, D), 80 µm (B, C, E, F), 20 µm (G, H).

• 

  Fig. 3 Immunohistochemical staining for ionized calcium-binding adapter molecule 1 (Iba-1) in the lumbar region of the adult (A–C) and aged (D, E) spinal cords. High magnification photos of white boxes in panel (A) and (D) show in panels (B) to (C) and panels (E) to (F) with same character respectively. (G–I) High magnification photos of white boxes in panels (C) and (F) show ramified, activated and amoeboid forms of Iba-1–immunoreactive microglia respectively. Scale bar=200 µm (A, D), 80 µm (B, C, E, F), 20 µm (G, H).

• 

  Fig. 4 Western blot analysis of ionized calcium-binding adapter molecule 1 (Iba-1) in the adult and aged spinal cords. Relative optical density of immunoblot band values are normalized to corresponding adult spinal region represents as percent (n=5 per group; *P<0.05, significantly different from the corresponding adult spinal region). The bars indicate the mean±SE.

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