Structure, interaction and nervous connectivity of beta cell primary cilia

Area of Science:

• Cell biology
• Endocrinology
• Neuroscience

Background:

• Primary cilia are sensory organelles involved in cell signaling.
• In pancreatic beta cells, cilia dysfunction is linked to diabetes, but their structure and function are poorly understood.
• Understanding beta cell cilia is crucial for insights into islet function and metabolic diseases.

Purpose of the Study:

• To elucidate the three-dimensional structure of primary cilia in pancreatic beta cells.
• To investigate the interactions and synaptic connections of beta cell cilia within the pancreatic islet.
• To explore the role of beta cell cilia in integrating intra-islet and extrinsic neural signals.

Main Methods:

• Three-dimensional reconstructions using electron microscopy.
• Expansion microscopy for high-resolution imaging of cilia structure.
• Analysis of cilia-cilia and cilia-cell interactions, including synaptic formations.

Main Results:

• Beta cell primary cilia are confined within ciliary pockets or intercellular spaces and lack motility structures.
• An unstructured axoneme organization was observed in these cilia.
• Numerous cilia-cilia and cilia-cell interactions were identified, including novel axo-ciliary synapses with cholinergic innervation.

Conclusions:

• Beta cell primary cilia possess unique structural features adapted to their confined environment.
• These cilia play a significant role in islet connectivity by mediating intra-islet and extrinsic neural signaling.
• The findings provide a structural basis for understanding beta cell cilia function in health and diabetes.