Controlled mechanical loading affects the osteocyte transcriptome in porcine trabecular bone in situ

Area of Science:

• Bone biology
• Mechanobiology
• Transcriptomics

Background:

• Osteocytes, embedded in bone, regulate adaptation to mechanical stress via cell communication.
• Understanding osteocyte gene expression under mechanical load can reveal targets for osteoporosis and cancer treatments.

Purpose of the Study:

• To investigate the transcriptional response of osteocytes to mechanical loading in situ.
• To compare gene expression changes after one and three days of controlled mechanical loading.

Main Methods:

• Porcine trabecular bone explants were cultured and subjected to mechanical loading.
• RNA sequencing and bioinformatic analyses (Tuxedo suite, IPA) were used to identify differentially expressed genes and pathways.

Main Results:

• Approximately 4000 genes were differentially expressed after in situ culture.
• Loading induced 106 differentially expressed genes after 1 day and 913 after 3 days, with only 45 overlapping.
• Analysis revealed distinct transcriptional profiles between loaded and non-loaded groups after 3 days.

Conclusions:

• Sustained mechanical loading significantly increases osteocyte gene expression, indicating sequential pathway activation.
• Differentially expressed genes are linked to osteoarthritis, osteocyte, and chondrocyte signaling.
• Early loading affects NFkB and TNF signaling, potentially influencing mechanobiological responses and catabolic processes.