The intestinal tuft cell nanostructure in 3D

Area of Science:

• Cell Biology
• Gastroenterology
• Microscopy

Background:

• Tuft cells, a type of intestinal epithelial cell, have historically been considered enigmatic due to their peculiar morphology.
• Understanding their ultrastructure is crucial for elucidating their function.

Purpose of the Study:

• To provide a detailed volumetric ultrastructure of intestinal tuft cells at nanometer resolution.
• To identify novel cellular components and their potential roles.

Main Methods:

• Serial Block-Face (SBF) Scanning Electron Microscopy (SEM)
• Automated Tape-collecting Ultra-Microtome (ATUM) SEM
• Volume rendering of serial sections

Main Results:

• Identified a short basal cytoplasmic process lacking secretory vesicles.
• Discovered thin cytospinules extending from tuft cells into neighboring epithelial cell nuclei.
• Revealed an interconnected tubular network within tuft cells, linking microvilli to the rough endoplasmic reticulum.

Conclusions:

• The unique ultrastructure, including cytospinules and the tubular network, suggests a role for tuft cells in molecular exchange.
• These structures may facilitate communication with neighboring cell nuclei and the gut lumen.