SIRT3 protein slows spinal disc aging in mice

Intervertebral discs sit between vertebrae and keep the spine flexible. Over time they lose water and structural integrity. According to the researchers, this process is closely tied to two hallmarks of aging: mitochondrial dysfunction and cellular senescence. Senescent cells are cells that stop dividing but do not die; instead they release inflammatory signals that damage surrounding tissue.

SIRT3 as a key regulator

The protein SIRT3 governs how mitochondria produce energy. In human disc tissue, lower SIRT3 levels correlated with greater disc degeneration. In mice, knocking out the Sirt3 gene caused clear disc deterioration along with elevated inflammatory markers and signs of senescence. Mitochondrial function declined, and both calcium signaling and ATP production were disrupted. ATP is the cell’s primary energy currency.

The team identified two hub genes, Ckm and Atp2a1, linking SIRT3 deficiency to these disruptions. They then tested a SIRT3-activating compound called 2-APQC in aged mice. Treated animals showed restored mitochondrial function, reduced inflammation, and fewer signs of senescence in disc tissue.

What this means beyond mice

This is animal research, and whether the same mechanism applies in humans has not yet been demonstrated. The correlation between low SIRT3 and disc degeneration was also observed in human tissue samples, which adds some relevance. From a longevity perspective, the finding that mitochondrial dysfunction and senescence are linked here is notable: improving one appears to benefit the other.

Chronic back pain is a leading cause of disability globally. A treatment that addresses the underlying disc biology rather than simply managing pain could represent a meaningful advance. That remains a prospect for now, but the mechanism is now mapped in considerably more detail.

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