Three-dimensional (3-D) structures formed by immortalized human fibroblast cells in simulated microgravity

Area of Science:

• Cell biology
• Gravitational biology
• Biophysics

Background:

• Cell morphology is influenced by the cellular environment.
• Understanding cellular responses to different culture conditions is crucial for biological research.
• Fibroblast cells are widely used models in cell biology studies.

Purpose of the Study:

• To investigate the morphological changes in immortalized human fibroblasts (CH cells) cultured in a 3-D rotating system.
• To compare the filopodial structures of CH cells in 3-D rotating cultures versus traditional 2-D monolayer cultures.
• To assess the potential of CH cells as a model for studying the effects of mechanical environments, such as gravity, on cell structure.

Main Methods:

• Cultivation of CH immortalized human fibroblasts using rotary suspension on glass microcarrier beads to create 3-D structures.
• Scanning electron microscopy (SEM) was employed to examine the detailed morphology of the cells.
• Comparative analysis of cell structures between 3-D rotating cultures and 2-D stationary monolayer cultures.

Main Results:

• Significant structural alterations were observed in the fibrillar filopodia of CH cells in 3-D cultures compared to 2-D cultures.
• Observed changes included reduced filopodial length, uneven caliber, increased curvature, and disrupted branching patterns.
• Unique filopodial formations such as protuberances, "mammoth's tusk"-like offshoots, distal foamy spreadings, and spiral windings were identified.

Conclusions:

• The mechanical environment significantly influences the morphology of CH immortalized human fibroblasts.
• The observed structural modifications in filopodia highlight the sensitivity of cell structure to physical forces.
• CH cells in 3-D rotating cultures represent a promising model for gravitational biology research due to their responsive morphology.