Expression of Iba1 protein in microglial cells of zitter mutant rat
Taro Kadowaki1, Kazuhiko Nakadate, Shin-ichi Sakakibara
1Department of Neurology, Dokkyo University School of Medicine, Mibu, Tochigi 321-0293, Japan.
Abstract:
Microglial activation has been associated with the pathogenesis of neurodegenerative disease. To characterize microglial responses in the zitter mutant rat, which shows progressive spongy degeneration, the development of microglial cells was investigated using ionized calcium-binding adaptor molecule (Iba1) antibody as a specific marker of microglial cells. Neurochemical analysis showed transiently increased Iba1 protein levels in the brains of developing Sprague-Dawley (SD) rats. However, high Iba1 protein readings continued in aged zitter rats. Immunohistochemical analysis revealed time-course differences in the transformation of microglia between SD and zitter rats and prolonged activation of microglial cells in the zitter rat. In the zitter rat, activated microglial cells characterized by swollen cell bodies and shorter, thicker processes were distributed throughout the brain from 2-weeks- to 2-months-old. After 2-months-old, numbers of activated microglial cells gradually decreased. However, these cells were not observed in SD rats. Iba1-immunoreactive cell-clusters organized by at least five activated microglial cells were also prominent in the zitter brain. These differences reflect the neuropathology of this mutant rat triggered by deletion of the attractin gene. The present data may thus suggest that microglial cells directly or indirectly contribute to progressive spongy degeneration in zitter mutant rats.
Insights
Microglial activation, marked by ionized calcium-binding adaptor molecule 1 (Iba1), is prolonged in zitter mutant rats, suggesting a role in spongy degeneration. This contrasts with normal Sprague-Dawley rats, highlighting a key difference in neuroinflammation.
Area of Science:
- Neuroscience
- Immunology
- Genetics
Background:
- Microglial activation is implicated in neurodegenerative diseases.
- The zitter mutant rat exhibits progressive spongy degeneration, offering a model to study microglial responses.
Purpose of the Study:
- To investigate microglial cell development and activation in zitter mutant rats.
- To characterize the role of ionized calcium-binding adaptor molecule 1 (Iba1) as a marker for microglial activation in this model.
Main Methods:
- Utilized ionized calcium-binding adaptor molecule 1 (Iba1) antibody for immunohistochemical analysis.
- Performed neurochemical analysis to quantify Iba1 protein levels.
- Compared microglial responses in zitter mutant rats with Sprague-Dawley (SD) rats over time.
Main Results:
- Zitter rats showed persistently high Iba1 protein levels compared to transient increases in SD rats.
- Immunohistochemistry revealed prolonged microglial activation in zitter rats, with distinct morphological changes and cell clustering.
- Activated microglia were widespread in zitter rats from 2 weeks to 2 months old, but not observed in SD rats.
Conclusions:
- Microglial cells exhibit prolonged activation and unique characteristics in zitter mutant rats, correlating with spongy degeneration.
- These findings suggest that microglial cells contribute directly or indirectly to the neuropathology of zitter rats.
- The observed differences in microglial response are linked to the attractin gene deletion in zitter mutant rats.
