ABSTRACT: To investigate the expression of receptor activator of nuclear factor-κB (RANK), its ligand RANKL, and osteoprotegrin, and observe the effects of αD3 on their expressions in male rats at different ages.
Wistar rats at 6 weeks, 6 months, and 24 months (n=15) were examined for mRNA expressions of RANK/RANKL and osteoprotegrin in the left proximal femur using RT-PCR and for their protein expressions in the right femur using immunohistochemistry. RANK/RANKL and osteoprotegrin expressions were also detected in another 15 rats aged 24 months following intragastric administration of 0.05 µg/kg αD3 (3 times a week for 10 weeks).
Compared with 6-week-old rats, 6-month- and 24-month-old rats showed a 6.2-fold and 7.3-fold increase of RANKL mRNA expression, respectively (P<0.05), and osteoprotegrin mRNA levels increased slightly with age. αD3 treatment resulted in significantly increased expression of RANK in 24-month-old rats with a lowered RANKL/osteoprotegrin ratio. RANKL and osteoprotegrin were co-localized in the osteoblasts and chondrocytes. αD3 treatment also caused an increased expression of osteoprotegrin mRNA in 24-month-old rats.
The age-related increase of the ratio of RANKL/osteoprotegrin mRNA promotes osteoclast activity and bone turnover. αD3 has favorable effect on osteogenesis and suppress bone absorption in the femur possibly by reducing RANK expression and lowering RANKL/osteoprotegrin ratio.
Nan fang yi ke da xue xue bao = Journal of Southern Medical University 09/2011; 31(9):1539-42.
ABSTRACT: The relationship between bone turnover markers (BTMs) and BMD decreasing rate (BDR) in Chinese women is unclear. Wu investigated the relationship between (BTMs) and BDR at various skeletal sites in Chinese middle-aged women.
A cross-section study of 555 healthy Chinese women over 35-60years of age. BMD at posteroanterior spine, the left hip, and the left forearm were measured with a DXA. Levels of serum osteocalcin (OC), bone-specific alkaline phosphatase (BAP), cross-linked N-terminal telopeptides of type I collagen (sNTX) and total urinary deoxypyridinoline (uDPD) were determined.
BDR at various skeletal sites had significant negative correlation with serum OC(r=-0.395 to -0.530), BAP(r=-0.297 to -0.486), and sNTX(r=-0.207 to -0.272). After adjustment of age and weight, serum OC, BAP, and sNTX rather than total uDPD still exhibited significant correlations with BDR. Stepwise regression analyses showed that, serum OC and BAP were the significantly negative determinants of BDR. Between 4.7-27.7% and 1.2-16.1% of the changes in BDR were determined by serum OC and BAP, respectively. However, sNTX and total uDPD had no significant effect on BDR at various skeletal sites.
This study indicated the correlation between BTMs and early-stage BDR in Chinese middle-aged women and suggested that serum OC and BAP, rather than sNTX and total uDPD, are the key determining factors of early BMD decreases.
Clinica chimica acta; international journal of clinical chemistry 08/2011; 412(17-18):1648-57. · 2.54 Impact Factor
ABSTRACT: To investigate the relationship between male osteoporosis and the expression of receptor activator of NF-κB ligand(RANKL) and osteoprotegerin(OPG)-mRNA in male mandible at different ages.
Between May 2008 and January 2009, bone tissues of the mandible were collected as the experimental material from 46 patients suffering from jaw facial deformity and extraction. The patients with periodontist, systemic disorder and smoking as well as drinking were excluded.They were divided into three groups: young group, whose age was 10-29 years old ;middle age group, whose age was 30-59 years old; aged group, whose age was 60-89 years old. The expression of RANKL mRNA and OPG mRNA was examined by real-time PCR. The data was analyzed using ANOVA followed by least significant difference (LSD) test with SPSS16.0 software package.
(1)Compared with the young group, RANKL mRNA level in mandible was 2.1-fold and 5.3-fold higher in the middle age and aged groups, respectively, whereas OPG mRNA level was 3.3-fold and 4.8-fold higher in middle age and aged groups, respectively. RANKL and OPG were positively correlated with age.(2)The ratio of RANKL/OPG in middle age group was lower than that of young group and old group,respectively.
(1)The expression of RANKL and OPG increases with age remarkably.(2)Bone formation of the mandible is activated in middle aged group. The formation is over absorption.(3)Bone formation of the mandible in aged group is at low level. Bone absorption exceeds bone formation.
Shanghai kou qiang yi xue = Shanghai journal of stomatology 06/2011; 20(3):278-81.
ABSTRACT: To investigate the effects of monofluorphosphate and alphaD3 on the bone mineral density of mandibular of ovariectomy rats.
39 female Sprague-Dawley rats about 90 days of age were randomly divided into the following treatment groups and treated for 12 weeks: SHAM group, OVX group, MFP group, MFP+alphaD3 group. Rats of MFP group received monofluorphosphate by gastric feeding. Rats of MFP+alphaD3 group received monofluorphosphate and alphatD3 by gastric feeding. The femur and the mandibles were collected for histomorphometry and bone mineral density measurement.
The bone area, bone thick, and bone mineral density of femur in the OVX group were significantly lower than those of other groups, while the trabecular separation of the OVX group was significantly higher than that of other groups. The bone mineral density of mandible was increased in OVX group and MFP+alphaD3 group compared with SHAM group.
Monofluorphosphate and alphaD3 can obviously increase the mass of mandible. The bone mineral density of femur decreased after ovariectomy while it increased in mandibular.
Hua xi kou qiang yi xue za zhi = Huaxi kouqiang yixue zazhi = West China journal of stomatology 03/2007; 25(1):33-6.