Práh intenzity přetvoření pro přímou aktivaci funkce osteoblastů v zatěžovaných horních čelistech myší

A threshold of mechanical strain intensity for the direct activation of osteoblast function exists in a murine maxilla loading model

journal article in Web of Science

en

The response to the mechanical loading of bone tissue has been extensively investigated; however, precisely how much strain intensity is necessary to promote bone formation remains unclear. Combination studies utilizing histomorphometric and numerical analyses were performed using the established murine maxilla loading model to clarify the threshold of mechanical strain needed to accelerate bone formation activity. For 7 days, 191 kPa loading stimulation for 30 min/day was applied to C57BL/6J mice. Two regions of interest, the AWAY region (away from the loading site) and the NEAR region (near the loading site), were determined. The inflammatory score increased in the NEAR region, but not in the AWAY region. A strain intensity map obtained from microCT images was superimposed onto the images of the bone formation inhibitor, sclerostin-positive cell localization. The number of sclerostin-positive cells significantly decreased after mechanical loading of more than 150 micro strain in the AWAY region, but not in the NEAR region. The mineral apposition rate, which shows the bone formation ability of osteoblasts, was accelerated at the site of surface strain intensity, namely around 170 micro strain, but not at the site of lower surface strain intensity, which was around 80 micro strain in the AWAY region, thus suggesting the existence of a strain intensity threshold for promoting bone formation. Taken together, our data suggest that a threshold of mechanical strain intensity for the direct activation of osteoblast function and the reduction of sclerostin exists in a murine maxilla loading model in the non-inflammatory region.

V práci byla rozsáhle zkoumána reakce kostní tkáně na mechanické zatížení. Kombinovaná studie využívající histomorfometrické a numerické analýzy byla provedeny u modelů horních čelistí myší za účelem objasnit práh mechanického namáhání potřebného k urychlení tvorby kostní aktivity.

The response to the mechanical loading of bone tissue has been extensively investigated; however, precisely how much strain intensity is necessary to promote bone formation remains unclear. Combination studies utilizing histomorphometric and numerical analyses were performed using the established murine maxilla loading model to clarify the threshold of mechanical strain needed to accelerate bone formation activity. For 7 days, 191 kPa loading stimulation for 30 min/day was applied to C57BL/6J mice. Two regions of interest, the AWAY region (away from the loading site) and the NEAR region (near the loading site), were determined. The inflammatory score increased in the NEAR region, but not in the AWAY region. A strain intensity map obtained from microCT images was superimposed onto the images of the bone formation inhibitor, sclerostin-positive cell localization. The number of sclerostin-positive cells significantly decreased after mechanical loading of more than 150 micro strain in the AWAY region, but not in the NEAR region. The mineral apposition rate, which shows the bone formation ability of osteoblasts, was accelerated at the site of surface strain intensity, namely around 170 micro strain, but not at the site of lower surface strain intensity, which was around 80 micro strain in the AWAY region, thus suggesting the existence of a strain intensity threshold for promoting bone formation. Taken together, our data suggest that a threshold of mechanical strain intensity for the direct activation of osteoblast function and the reduction of sclerostin exists in a murine maxilla loading model in the non-inflammatory region.

Intenzita přetvoření, horní čelist myší, tvorba kostí, zánět, sclerostin, numerická analýza

Mechanical strain intensity, Murine maxilla, Bone formation, Inflammation, Sclerostin, Numerical analysis

01.10.2016

Springer

Germany

1617-7959

15

5

1091–1100

10