Docetaxel inhibits bone resorption through suppression of osteoclast formation and function in different manners

Osteoclasts are formed from the monocyte-macrophage lineage in response to receptor activator of nuclear factor κB ligand (RANKL) expressed by osteoblasts. Bone is the most common site of breast cancer metastasis, and osteoclasts play roles in the metastasis. The taxane-derived compounds paclitaxel and docetaxel are used for the treatment of malignant diseases, including breast cancer. Here we explored the effects of docetaxel on osteoclastic bone resorption in mouse culture systems. Osteoclasts were formed within 6 days in cocultures of osteoblasts and bone marrow cells treated with 1,25-dihydroxyvitamin D₃ plus prostaglandin E₂. Docetaxel at 10⁻⁸ M inhibited osteoclast formation in the coculture when added for the entire culture period or for the first 3 days. Docetaxel, even at 10⁻⁶ M added for the final 3 days, failed to inhibit osteoclast formation. Osteoprotegerin, a decoy receptor of RANKL, completely inhibited osteoclast formation when added for the final 3 days. Docetaxel at 10⁻⁸ M inhibited the proliferation of osteoblasts and bone marrow cells. RANKL mRNA expression induced by 1,25-dihydroxyvitamin D₃ plus prostaglandin E₂ in osteoblasts was not affected by docetaxel even at 10⁻⁶ M. Docetaxel at 10⁻⁶ M, but not at 10⁻⁸ M, inhibited pit-forming activity of osteoclasts cultured on dentine. Actin ring formation and l-glutamate secretion by osteoclasts were also inhibited by docetaxel at 10⁻⁶ M. Thus, docetaxel inhibits bone resorption in two different manners: inhibition of osteoclast formation at 10⁻⁸ M and of osteoclast function at 10⁻⁶ M. These results suggest that taxanes have beneficial effects in the treatment of bone metastatic cancers. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Increased Bone Resorption Is Associated With Increased Risk of Cardiovascular Events in Men: The MINOS Study

Better assessment of the association between cardiovascular disease and osteoporosis in older men may help identify shared etiologies for bone and heart health in this population. We assessed the association of BMD and bone turnover markers (BTMs) with risk of cardiovascular events (myocardial infarction or stroke) in 744 men ≥50 yr of age. During the 7.5‐yr prospective follow‐up, 43 strokes and 40 myocardial infarctions occurred in 79 men. After adjustment for confounders (age, weight, height, smoking, education, physical activity, self‐reported history of diabetes, hypertension, and prevalent ischemic heart disease), men in the lowest quartile of BMD at the spine, whole body, and forearm had a 2‐fold increased risk of cardiovascular events. Men in the highest quartile of bone resorption markers (deoxypyridinoline [DPD], C‐telopeptide of type I collagen) had a 2‐fold increased risk of cardiovascular events (e.g., multivariable‐adjusted hazard ratio [including additional adjustment for BMD] was 2.11 [95% CI: 1.26–3.56], for the highest quartile of free DPD relative to the lowest three quartiles). The results were similar for men without prevalent ischemic heart disease and for myocardial infarction and stroke analyzed separately. Our data suggest that men with low BMD or high bone resorption may be at increased risk of myocardial infarction and stroke in addition to fracture. Thus, men with osteoporosis may benefit from screening for cardiovascular disease. Further study to elucidate the biological mechanism shared by bone and vascular disease may help efforts to identify men at risk or develop treatment.     

Developmental plasticity and human disease: research directions

The conceptual basis of the 'developmental origins' paradigm has converged on the role of developmental plasticity responding to signals from the early environment, with heightened risk of disease if the induced phenotype does not match the later environment. Nevertheless, numerous questions remain, including the current burden of disease that can be attributed to early environmental factors; the pathways, mechanisms and windows of plasticity; the identification of early markers of environmentally induced change; and the feasibility, costs and benefits of intervention. A focused agenda of research is needed to convince policy makers of the importance of developmental factors in human disease.     

CD39/NTPDase-1 activity and expression in normal leukocytes

INTRODUCTION: CD39/NTPDase-1 is a cell surface enzyme expressed on leukocytes and endothelial cells that metabolizes ATP to ADP and AMP. CD39 is expressed on numerous different types of normal leukocytes, but details of its expression have not been determined previously. METHODS: We examined CD39 expression and activity in leukocytes isolated from healthy volunteers. Expression of CD39 on leukocytes was measured by FACS and activity of CD39 in lymphocytes and neutrophils was determined by an enzymatic radio-TLC assay. RESULTS: We established that CD39 is expressed on neutrophils, lymphocytes, and monocytes. The enzyme is found on >90% of monocytes, neutrophils, and B-lymphocytes, and 6% of T-lymphocytes and natural killer cells. Per cell density of expression varied, with the highest expression on monocytes and B-lymphocytes. ATPase and ADPase activities were highest on B-lymphocytes, lower on neutrophils, lowest on T-lymphocytes. The ratio of ADPase:ATPase activity was 1.8 for neutrophils and B-lymphocytes and 1.4 for T-lymphocytes. Hypertensive volunteers had lower levels of CD39 on their T-lymphocytes and NK cells. No correlation between age, gender, ethnic background, or cholesterol level and CD39 expression was observed. CONCLUSIONS: We conclude that CD39 activity and expression are present to varying degrees on all leukocytes types examined. Differences between leukocyte types should be considered when examining CD39 in disease states.     

胚胎脊髓移植兼用神经生长因子促进成年大鼠损伤脊髓功能恢复的研究

目的研究胚胎脊髓（FSC）移植兼用神经生长因子（NGF）对损伤脊髓的修复作用。方法用改良Allen打击法制作脊髓损伤动物模型。将实验动物分为4组：A组：单纯脊髓损伤组;B组：脊髓损伤＋NGF组;C组：脊髓损伤＋移植FSC组;D组：脊髓损伤＋移植FSC＋NGF组。手术后应用行为学、组织形态学观察损伤脊髓功能恢复情况;应用Nissl染色方法观察脊髓神经元的大小;采用计算机图像分析技术进行定量分析。结果脊髓胚胎移植可以在宿主脊髓中存活、发育、生长、分化并形成神经连接,促进损伤脊髓功能恢复。神经生长因子可以防止成年大鼠脊髓轴突损伤引起的神经元萎缩。CBS评分、图像分析显示对脊髓损伤功能恢复的作用,B、C、D组好于A组,B、C组间无显著差异,D组效果最好。FSC移植与运用外源性NGF对于促进成鼠损伤脊髓功能恢复具有协同效应。结论胚胎脊髓移植兼用神经生长因子能维持神经元的细胞形态,对成年大鼠损伤脊髓功能恢复有促进作用。     

Significance and therapeutic potential of endothelial progenitor cell transplantation in a cirrhotic liver rat model

BACKGROUND & AIMS: We investigated whether endothelial progenitor cell (EPC) transplantation could reduce established liver fibrosis and promote hepatic regeneration by isolating rat EPCs from bone marrow cells. METHODS: Recipient rats were injected intraperitoneally with carbon tetrachloride (CCl(4)) twice weekly for 6 weeks before initial administration of EPCs. CCl(4) was then readministered twice weekly for 4 more weeks, and EPC transplantation was carried out for these same 4 weeks. RESULTS: At 7 days in culture, the cells expressed Thy-1, CD31, CD133, Flt-1, Flk-1, and Tie-2, suggesting an immature endothelial lineage. Immunohistochemical analyses showed fluorescent-labeled, transplantation EPCs were incorporated into the portal tracts and fibrous septa. Single and multiple EPC transplantation rats had reduced liver fibrosis, with decreased alpha2-(I)-procollagen, fibronectin, transforming growth factor-beta, and alpha-smooth muscle actin-positive cells. Film in situ zymographic analysis revealed strong gelatinolytic activity in the periportal area, in accordance with EPC location. Real-time polymerase chain reaction analysis of multiple EPC-transplantation livers showed significantly increased messenger RNA levels of matrix metalloproteinase (MMP)-2, -9 and -13, whereas tissue inhibitor of metalloproteinase-1 expression was significantly reduced. Expression of hepatocyte growth factor, transforming growth factor-alpha, epidermal growth factor, and vascular endothelial growth factor was increased in multiple EPC-transplantation livers, while hepatocyte proliferation increased. Transaminase, total bilirubin, total protein, and albumin levels were maintained in EPC-transplantation rats, significantly improving survival rates. CONCLUSIONS: We conclude that single or repeated EPC transplantation halts established liver fibrosis in rats by suppressing activated hepatic stellate cells, increasing matrix metalloproteinase activity, and regulating hepatocyte proliferation.     

Epidemiology, genes and the environment: lessons learned from the Helsinki Birth Cohort Study

Nonoptimal growth during fetal life and infancy is associated with an increased risk of coronary heart disease and type 2 diabetes later in life. This early pattern of growth is associated with an increased disease risk especially when followed by a relative gain in body size later in childhood. Genetic factors are closely involved in growth and disease pathogenesis and gene-early life environmental interactions will be described affecting adult health outcomes. This overview will primarily focus upon findings from the Helsinki Birth Cohort Study consisting of 15846 subjects born 1924-1944 on whom growth data and information on adult health are available.     

Programming of the stress response: a fundamental mechanism underlying the long‐term effects of the fetal environment?

There is a large body of evidence which suggests that an adverse fetal environment results in a heightened biobehavioral response to stress, with increased activity of the classical mediators of the stress response, including the hypothalamic-pituitary adrenal axis and autonomic nervous system. Although this has been amply demonstrated in animal experiments, several recent studies suggest that the same processes operate in human populations and may have important consequences for health. The evidence suggests that an adverse early environment or markers of an adverse environment such as low birth weight are linked with long-term alterations in these neuroendocrine systems. However, these studies also demonstrate that there is a considerable degree of heterogeneity in the responses observed which appear to depend on a variety of factors such as the nature or timing of the adverse exposure as well as the gender of the offspring. The mediators of these classical neuroendocrine responses such as cortisol and catecholamines are biologically potent and may directly influence disease susceptibility by means of their effects on metabolism and the vasculature. However, lifelong changes in the set point of these neuroendocrine systems in response to the early environment may also direct the course of development during fetal life, infancy and childhood towards the generation of a phenotype adapted for the adult environment predicted by the clues available during fetal life. This has biological advantages if the actual adult environment turns out to be appropriate for the phenotype. However, ill health may occur if the phenotype is not well matched to the actual environment encountered in adult life.     

Bone structure and metabolism in a rodent model of male senile osteoporosis

Osteoporosis is a common and severe condition in elderly men, which is poorly characterized. In order to identify the hallmarks of age-related bone loss in the male mammalian skeleton, we studied several aspects of bone structure and metabolism in 23-month-old male Sprague-Dawley rats and compared them to 5-month-old animals. Cancellous bone mineral density, bone volume and trabecular number were markedly reduced in the proximal tibia of aged rats when compared to the young rats. An increase in bone matrix material density indicating a reduced deposition of new bone matrix was seen. Also, serum levels of osteocalcin, a marker of bone formation, were reduced in old males. The decreased bone formation could in part be linked to the decreased serum insulin-like growth factor 1 (IGF-1) levels which were observed in these animals. Serum levels of RatLaps (c-terminal telopeptide of type I collagen) were increased. Interestingly, an ex vivo osteoclast generation assay revealed that bone marrow from aged rats formed fewer osteoclasts than that from young rats. Consistent with this observation, serum levels of soluble RANKL, a critical osteoblast derived factor for osteoclastogenesis, were decreased in aged rats and RANKL mRNA expression was slightly reduced in bone marrow cells. Elevated leptin and adiponectin levels present in these animals could have contributed further to impaired osteoclastogenesis. We conclude that aged male rodents are characterized by a severely diminished cancellous bone network and a bone turnover situation in which bone formation is decreased to such an extent that it is outweighed by bone resorption, despite a blunted osteoclast generation potential of the bone marrow.     

人胎儿血红蛋白的纯化及免疫活性鉴定

目的研究胎儿血红蛋白纯化的最佳方法,并对其进行免疫活性鉴定。方法采用生理盐水洗涤、四氯化碳萃取得到粗提胎儿血红蛋白,再经sephadexG50凝胶层析柱纯化。纯化后的胎儿血红蛋白利用SDS—PAGE电泳、蛋白质印迹鉴定其性质。结果获得了具有生物活性的胎儿血红蛋白．经SDS-PAGE电泳鉴定纯化蛋白杂带消失,蛋白单体相对分子质量为16000Mr,纯度为95％,蛋白质印迹结果显示纯化后的蛋白具有良好的抗原性。结论该方法成功获得了纯度较高的胎儿血红蛋白,且操作简便,纯化效果好。