Large scale analysis of osteocyte lacunae in klotho hypomorphic mice using high-resolution micro-computed tomography

Area of Science:

• Bone biology and biomechanics
• Osteocyte morphology and function
• Skeletal tissue engineering

Background:

• Osteocytes, the most abundant bone cells, influence bone mass and fragility.
• Conventional CT resolution limits detailed analysis of osteocyte lacunae.
• Understanding lacunar morphology is crucial for bone health assessment.

Purpose of the Study:

• To compare osteocyte lacuna parameters in wild-type (WT) and αKlotho-hypomorphic (kl/kl) mice using high-resolution micro-CT.
• To investigate large-scale lacunar morphology differences in a mouse model of osteopenia.
• To correlate lacunar geometry with potential alterations in bone metabolism.

Main Methods:

• Utilized high-resolution (700 nm) micro-CT for detailed bone morphometry.
• Analyzed approximately 45,700 osteocyte lacunae per mouse in tibial metaphyseal cortical bone.
• Compared lacunar parameters between WT and kl/kl mice, a model exhibiting osteopenia.

Main Results:

• kl/kl mice showed significantly lower lacunar surface per volume and larger lacuna diameters compared to WT mice.
• Lacunar sphericity was higher in kl/kl mice.
• Significant differences in major and minor axis diameters were observed, particularly in the proximal region.

Conclusions:

• Osteocyte lacunae shape significantly differs between WT and kl/kl mice.
• Observed geometric changes may affect mechanical strain transmission and osteocyte responses.
• Site-specific anomalies in mechanosensitive effects in kl/kl mice could impact bone metabolism and function.