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Updated: Sep 23, 2026
Use of Primary Cultured Hippocampal Neurons to Study the Assembly of Axon Initial Segments
Published on: February 12, 2021
Progressive ankylosis (Ank) protein is expressed by neurons and Ank immunohistochemical reactivity is increased by
Manuel Yepes1, Elizabeth Moore, Sharron A N Brown
1Departments of Vascular Biology, Jerome H. Holland Laboratory for the Biomedical Sciences, American Red Cross, Rockville, Maryland 20855, USA.
Abstract:
Ank is a 492-amino acid multipass transmembrane protein involved in the regulation of extracellular inorganic pyrophosphate levels and the control of tissue calcification. Previous Northern blot hybridization experiments revealed that Ank mRNA was expressed in the brain, but there have been no reports describing the anatomical sites or specific cell types in the brain that express Ank protein. In this study, we demonstrate that Ank is expressed primarily in human brain neurons, with the highest levels of expression observed in the thalamus, the III and V cortical layers, the Purkinje cells of the cerebellum, clusters of cells in the dorsal portion of the pons and midbrain, and neurons of the anterior horn of the spinal cord. In primary mouse neuronal cell cultures, Ank is detected on both the cell body and on cell extensions, mainly dendrites. In the rat brain, Ank mRNA is expressed at relatively high levels in the thalamus, midbrain, and spinal cord, and the Ank protein expression pattern is similar to that observed in the human brain. Finally, we observed a significant increase in Ank immunoreactivity in the rat amygdala, the CA-2 and CA-3 layers of the hippocampus, and the cerebral cortex after the induction of seizure activity. Ank regulation of ATP and/or inorganic pyrophosphate release from neurons may function to modulate the membrane excitability and cell death associated with seizure activity.
Insights
Ank protein is found in human brain neurons, particularly in areas like the thalamus and cerebellum. Its expression increases in specific brain regions following seizure activity, suggesting a role in neuronal excitability.
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- Ank is a transmembrane protein regulating extracellular inorganic pyrophosphate and tissue calcification.
- Previous studies indicated Ank mRNA expression in the brain, but protein localization was unknown.
Purpose of the Study:
- To determine the anatomical distribution and cell-type specificity of Ank protein expression in the brain.
- To investigate the role of Ank in neuronal function and its response to seizure activity.
Main Methods:
- Immunohistochemistry on human, mouse, and rat brain tissues.
- Primary mouse neuronal cell cultures.
- Analysis of Ank expression in response to induced seizure activity in rats.
Main Results:
- Ank protein is predominantly expressed in human brain neurons, with high levels in the thalamus, cortical layers III/V, Purkinje cells, pons, midbrain, and spinal cord.
- In mouse neuronal cultures, Ank is localized to cell bodies and dendrites.
- Rat brain Ank expression patterns mirror human findings.
- Seizure induction significantly increased Ank immunoreactivity in the amygdala, hippocampus (CA-2/CA-3), and cerebral cortex.
Conclusions:
- Ank protein is widely expressed in the central nervous system, primarily in neurons.
- Ank's role in regulating ATP/inorganic pyrophosphate release may influence neuronal excitability and cell death during seizures.
