Tenascin-R

Tenascin-R is a protein that in humans is encoded by the TNR gene. It is a member of the tenascin family, a group of extracellular matrix proteins that are involved in the development, function, and remodeling of the nervous system. Tenascin-R is predominantly expressed in the central nervous system (CNS), where it plays a crucial role in regulating the structure and function of neural networks.

Structure

Tenascin-R is a large, multimodular glycoprotein characterized by an assembly of distinct domains, including an amino-terminal assembly domain, a series of epidermal growth factor-like (EGF-like) repeats, fibronectin type III domains, and a fibrinogen-like globe. This structure allows Tenascin-R to interact with various components of the extracellular matrix and cell surface receptors, mediating a range of cellular functions.

Function

The primary role of Tenascin-R within the CNS is to modulate the interaction between neurons and glia, influencing neural migration, synaptogenesis, and synaptic stability. It is involved in the formation of perineuronal nets (PNNs), specialized extracellular matrix structures that enwrap certain neurons and are critical for synaptic stabilization and plasticity. Through its interactions, Tenascin-R influences the balance between neural plasticity and stability, playing a vital role in learning, memory, and neural repair mechanisms.

Clinical Significance

Alterations in Tenascin-R expression have been associated with various neurological disorders, including multiple sclerosis, Alzheimer's disease, and epilepsy. In these conditions, dysregulation of Tenascin-R expression may contribute to the pathological remodeling of neural networks, affecting disease progression and severity. Research into Tenascin-R and its functions may offer insights into novel therapeutic strategies for these and other neurological diseases.

Research Directions

Current research on Tenascin-R is focused on elucidating its precise roles in the CNS, including its interactions with other extracellular matrix components and its impact on neural plasticity and regeneration. Studies are also exploring the potential of targeting Tenascin-R pathways to develop new treatments for neurological disorders characterized by altered neural connectivity and plasticity.

See Also

• Extracellular matrix
• Neural plasticity
• Perineuronal nets
• Synaptogenesis