Optimization of the Time Window of Interest in Ovariectomized Imprinting Control Region Mice for Antiosteoporosis Research

Abstract

This study was performed to determine the optimal window of time during which the properties of osteoporosis are obvious and to explore the best region of interest for microstructural evaluation in antiosteoporosis research in an ovariectomized mouse model by examining changes in micro-computed tomography parameters and serum indices. Ovariectomized mice and sham-operated mice were randomly divided into five groups. At the end of the 4th, 8th, 12th, 16th, and 20th weeks after ovariectomy, the microstructure of the proximal tibia and distal femur was scanned by micro-computed tomography and blood samples were collected to detect serum biochemical indicators including alkaline phosphatase, osteocalcin, N-terminal propeptide of type I procollagen (P1NP), and C-terminal telopeptide fragment of type I collagen (CTX1). The trabecular number and connectivity density decreased while the trabecular thickness and trabecular separation increased, indicating substantial changes in the trabecular microstructure of both the tibia and femur and significant changes in bone turnover after ovariectomy, as indicated by lower levels of serum alkaline phosphatase, osteocalcin, and P1NP and higher level of CTX1 in the ovariectomy than sham group. The proximal tibia from weeks 8 to 16 after ovariectomy was optimal for osteoporosis research in this model.

Lithium chloride promotes osteogenesis and suppresses apoptosis during orthodontic tooth movement in osteoporotic model via regulating autophagy

“…At 8 weeks after surgery, when osteoporosis model was established [ 24 ], the body weights of all mice were measured again. Orthodontic appliances were mounted according to our previous studies [ 22 , 25 ].…”

Long-term bisphosphonate treatment coupled with ovariectomy in mice provokes deleterious effects on femoral neck fracture pattern and modifies tibial shape

“…We also examined proximal tibia metaphysis trabecular bone; a focus region for many studies. Song et al 35 found most marked effects after eight to 16 weeks of OVX in this region (in eight-week-old mice), which were much less marked later, suggesting that prolongation does not expand the bone losses. Advanced age and the 44-week timescale post-OVX 16 , 35 in our study may not, therefore, be ideal and may underpin the lack of any overt OVX-induced difference.…”

“…Song et al 35 found most marked effects after eight to 16 weeks of OVX in this region (in eight-week-old mice), which were much less marked later, suggesting that prolongation does not expand the bone losses. Advanced age and the 44-week timescale post-OVX 16 , 35 in our study may not, therefore, be ideal and may underpin the lack of any overt OVX-induced difference. It is key, however, that we evaluated long-term bisphosphonate effects as our aim was to discern whether this aligned with clinical observations of modified strength and fracture susceptibility.…”

Anti-osteoporotic and Anti-adipogenic Effects of Rhus chinensis Nutgalls in Ovariectomized Mice Fed with a High-fat Diet

“…In our µ-CT analysis, the Tb.Th value was not altered by OVX. Previous reports have also shown that OVX did not significantly decrease the Tb.Th values of the femur and tibia in OVX mice and rats [16,17]. This phenomenon might be due to a rapid change of trabecular structure from a plate-like to a rod-like structure [17].…”