促红细胞生成素对破骨细胞调控机理的研究

目的研究小鼠单核巨噬细胞在体外向破骨细胞分化的过程中,促红细胞生成素（erythropoietin,EPO）与破骨细胞表面受体Epor结合发挥作用的机理。方法 EPO作用于Epor受体沉默的经诱导的小鼠单核巨噬细胞,观察TRAP阳性多核细胞数目变化。Real-time PCR检测RAW264.7向破骨细胞分化过程中相关基因Epor、Nfatc1、Mmp9、EphrinB2基因的表达。结果与对照组比较,4天后,Epor沉默组的Nfatc1、EphrinB2 mRNA的表达明显升高（P〈0.01）,Ctsk Mmp9 mRNA的表达明显降低（P〈0.01）。结论 EPO通过与破骨细胞表面受体Epor结合,引发破骨细胞内相关基因表达改变,进而影响破骨细胞的分化和活化。     

Menatetrenone (Vitamin K<Subscript>2</Subscript>) Acts Directly on Circulating Human Osteoclast Precursors

It is still not certain what the direct effect of menatetrenone is on osteoclast precursors. In the present study, we investigated whether menatetrenone has a direct effect on circulating osteoclast precursors to influence osteoclast differentiation. Monocytes isolated from human peripheral blood were cultured with receptor-activated NF-B ligand (RANKL) and macrophage colony-stimulating factor (M-CSF). Menatetrenone or vitamin K₁ was then added to the cultures. Geranylgeraniol or phytol (the respective side chain) was also added to the cultures instead of menatetrenone or vitamin K₁, respectively. After 7 and 14 days incubation, cultures were evaluated for cytochemical and functional evidence of osteoclast formation. The number of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs) and the percentage area of lacunar resorption induced by RANKL and M-CSF were decreased when menatetrenone or geranylgeraniol was added to the cultures. Dose-dependent inhibition of osteoclast formation and lacunar resorption was seen when the cultures were treated with menatetrenone or geranylgeraniol. In contrast, vitamin K₁ or phytol did not affect the number of TRAP-positive MNCs nor the percentage area of lacunar resorption. These results indicate that menatetrenone not only influences osteoclast formation via bone stromal cells but also acts directly on circulating osteoclast precursors to influence osteoclast differentiation. These findings also suggest that geranylgeraniol, the side chain of menatetrenone, plays an important role in this inhibitory effect.     

Flurbiprofen-induced stimulation of periosteal bone formation and inhibition of bone resorption in older rats

The skeletal effects of flurbiprofen (Fb), a nonsteroidal antiinflammatory drug, was studied by histomorphometry in 9-month-old retired female breeder, Sprague-Dawley rats. Flurbiprofen was given subcutaneously at 0, 0.2, 0.1, 0.5, 2.5, or 5 mg/kg/d for 21 days. Flurbiprofen had no effect on longitudinal growth, but stimulated radial growth (+200%) over controls. In the tibial shaft, Fb stimulated the mineral apposition rate (+25%), mineral bone formation rate (+100%), and periosteal labeling length (+64%) at the 2.5 and 5.0 mg Fb/kg dose levels, and had no effect on marrow cavity size compared to controls. However, these changes were insufficient to increase cortical bone mass. In the proximal tibial metaphysis, Fb suppressed osteoclasts/mm² of metaphyseal tissue (-47%), osteoclasts/mm of bone surface (-46%), and the osteoclast/osteoblast ratio (-50%), increased the calcified cartilage core population (+100%), and had no effect on osteoblast numbers at all dose levels. There was an insignificant increase in metaphyseal cancellous bone mass. The current study leads to the conclusion that flurbiprofen-stimulated periosteal bone growth was due to direct stimulation of osteoblast recruitment and activity independent of longitudinal bone growth. Further, it confirms early findings in young rats that flurbiprofen induced depressed bone resorption without lowering bone formation. However, because of insufficient treatment time, the older rat did not accumulate bone as the young rats did.     

ODF诱导骨髓细胞向破骨细胞分化

目的:研究小鼠骨髓细胞在破骨细胞分化因子(ODF)和单核巨噬细胞集落刺激因子(M-CSF)的诱导刺激下向破骨细胞诱导分化的新方法。方法:分离小鼠骨髓细胞,ODF、M-CSF诱导培养,在倒置显微镜下观察细胞形态变化,酒石酸酸性磷酸酶(T-ACP)阳性表达。结果:小鼠骨髓细胞在ODF和M-CSF作用下,表现为长梭形和圆形细胞增多,增大。体外培养6d,有多核T-ACP阳性细胞产生。结论:小鼠骨髓细胞在ODF和M-CSF共同诱导作用下分化成破骨细胞,为体外研究破骨细胞的分化发育和功能调节提供新方法。     

Effects of the Drug （BSZGC）-containing Serum on Proliferation of Rat＇s Osteoclasts and TRACP Activity in vitro

Objective： To observe effects of the drug-containing serum ofBu Shen Zhuang Gu Capsule （BSZGC 补肾壮骨胶囊 Capsule for Tonifying the Kidney to Strengthen the Bones） on proliferation of the rat＇s osteoclasts and tartrate-resistant acid phosphatase （TRACP） activity in vitro so as to delve into the mechanisms of its preventive and therapeutic actions on osteoporosis. Methods： Forty female Sprague-Dawley rats aged three months were randomly divided into high dosage BSZGC group, medium dosage BSZGC group, low dosage BSZGC group, and the control group. BSZGC was orally administered into the rats of high, medium, and low dosage groups at different dosages for 12 days, and isometric normal saline was orally administered to the rats of the control group. The drug-containing serum and control serum were prepared. Osteoclasts isolated mechanically from the femur and tibia of Sprague-Dawley rats aged one week were cultured with medium added with different drug-containing sera and control serum. The growth of osteoclasts was observed under an inverted phase-contrast microscope, and optic density （OD） value of osteoclasts was determined by MTT colorimetric assay. TRACP activity was measured by the diazol method. Results： OD value of osteoclasts in the high dosage drug-containing serum group, medium dosage drug-containing serum group, and low dosage drug-containing serum group was significantly lower than that in the control serum group （P〈0.05） with a dose-effect correlation. TRACP activity in high dosage drug-containing serum group, medium dosage drug-containing serum group, low dosage drug-containing serum group was significantly lower than that of the control serum group （P〈0.01）, and no significant differences in TRACP activity were not found among the different dosages drug-containing serum groups. Conclusions： BSZGC can inhibit the proliferation of the osteoclasts and reduce TRACP activity, which may be one of the mechanisms of its preventive and theraoeutic actions on osteooorosis     

氟对骨的影响研究进展

综述了氟对骨的作用特性、致病特点以及氟对成骨细胞、破骨细胞的作用,以期为氟骨病的基础和临床研究提供文献依据。     

Failure of cells of the mononuclear phagocyte series to resorb bone

Summary Monocytes, peritoneal macrophages, inflammatory polykaryons, and myeloid cell lines were incubated on slices of human cortical bone and assessed for their capacity to resorb bone by scanning electron microscopy. None of these cell types, mononuclear or multinucleate, induced any detectable change in the bone surface, even after prolonged incubation, and even in the presence of macrophage activators. These findings emphasise the inadequacies of mononuclear phagocytes as surrogate osteoclasts, and expose a discrepancy between⁴⁵Ca release and bone resorption.     

Biphasic anti-osteoclastic action of intravenous alendronate therapy in multiple myeloma bone disease

Multiple myeloma is a malignancy of plasma cells with osteolytic bone destruction. Bisphosphonates inhibit osteoclast activity and are widely used for the treatment of myeloma bone disease. We analyzed the changes in urinary cross-linked N-telopeptides of collagen (u-NTx) and urinary calcium (u-Ca) after bisphosphonate alendronate therapy in ten patients with myeloma bone disease. In all patients, the levels of u-Ca and u-NTx decreased within a week. After the maximum decrease of u-NTx, u-NTx started increasing in half of the patients. However, this further increase in u-NTx decreased again without any additional therapy. Disease severity and pretreatment u-NTx concentrations did not differ between patients with and without the rebound. Patients who did not have rebound had decreased bone marrow monocytes and decreased serum concentrations of interleukin 18, which is produced by monocytes. Our results suggest that impaired activity of monocytes, which are possible osteoclast precursors, is related to reduced bone destruction in multiple myeloma.     

Osteocyte Apoptosis and Osteoclast Presence in Chicken Radii 0–4 Days Following Osteotomy

Osteocyte apoptosis caused by load-induced microdamage is followed by osteoclastic bone remodeling, and a causal link between apoptosis and repair has been suggested. The objectives of the present study were to use a chick model to examine the incidence of osteocyte apoptosis and the presence of osteoclasts during the first 96 hours following an osteotomy, prior to extensive callus mineralization. Osteotomies were performed on the right radii of 24 chicks at 23–24 days of age. The left radii served as controls. Radii were collected and processed at six time points following surgery (0, 12, 24, 48, 72, and 96 hours). Decalcified bone tissue sections were stained either for apoptosis using a modified TUNEL procedure or for tartrate-resistant acid phosphatase to identify osteoclasts in the intracortical and periosteal envelopes. The percentage of apoptotic osteocytes, as well as osteoclast counts (n/mm or n/mm²) were quantified in four regions (0–1, 1–2, 2–4, and 4–8 mm from the site of the osteotomy; regions 1–4, respectively) in the osteotomized radii and in the same measured areas in the control radii. Data for osteocyte apoptosis and osteoclasts in the control limb were subtracted from the osteotomized limb data to identify differences due to surgical influence. The incidence of osteocyte apoptosis was significantly higher at 12, 24, 48, and 72 hours versus 0 hours following osteotomy, and the response was highest in region 1; however, there was no interaction between time and region. Intracortical osteoclast counts (n/mm²) were elevated after 48 hours, and the response was similar in all regions. The data demonstrate that osteocyte apoptosis occurs within 24 hours in response to an osteotomy and temporally precedes an increase in osteoclast presence. Hence, osteocyte apoptosis may play a role in signaling during the bone healing process.