Pattern of Uptake of Americium-241 by the Rat Skeleton and its Subsequent Redistribution and Retention: Implications for Human Dosimetry and Toxicology

1983 ◽  
Vol 2 (1) ◽  
pp. 101-120 ◽  
Author(s):  
N.D. Priest ◽  
G. Howells ◽  
D. Green ◽  
J.W. Haines
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Cortical Bone ◽  
Female Rat ◽  
Half Time ◽  
Bone Surface ◽  
Similar Model ◽  
Phagocytic Cells ◽  
Biological Half Time

The distribution and retention of intravenously injected 241Am in the skeleton of the female rat has been investigated using autoradiographic and radiochemical techniques. The studies were designed to assess the dosimetric and toxicologic implications of an 241Am intake by man. They showed that in the rat approximately one third of the intravenously injected 241Am was deposited in the skeleton where it appeared to be retained with a long biological half-time. The studies also showed: 1241Am is initially deposited onto all types of bone surface including endosteal surfaces, periosteal surfaces and those of the vascular canals within cortical bone, but seems to be preferentially deposited onto those that are resorbing, 2 Bone accretion results in the burial of surface deposits of 241Am, 3 Bone resorption causes the removal of 241 Am from surfaces, 4 Resorbed 241Am is retained by phagocytic cells (probably macrophages) in the bone marrow, 5 The transfer of 241Am from the phagocytic cells in the marrow to adjacent bone surfaces seems to occur, (local recycling). 6 The possibility that some of the 241Am removed from the bone surfaces enters the blood and is redeposited in bone, (systemic recycling) cannot be dismissed These results show that 241Am deposition and redistribution in bone shares many characteristics with other 'bone surface-seeking radionuclides' typified by 239Pu. Consequently, it is suggested that a similar model to that used to calculate annual limits of intake for 239Pu in man would be suitable for the calculation of corresponding values for the 241Am isotopes.

Uranium in Bone: Metabolic and Autoradiographic Studies in the Rat

1982 ◽  
Vol 1 (2) ◽  
pp. 97-114 ◽  
Author(s):  
N.D. Priest ◽  
G.R. Howells ◽  
D. Green ◽  
J.W. Haines
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Alkaline Earth ◽  
Female Rat ◽  
Half Time ◽  
Bone Surface ◽  
Uranium Contamination ◽  
Hexavalent Uranium ◽  
Alkaline Earth Elements ◽  
Biological Half Time

The distribution and retention of intravenously injected hexavalent uranium-233 in the skeleton of the female rat has been investigated using a variety of autoradiographic and radiochemical techniques. These showed that approximately one third of the injected uranium is deposited in the skeleton where it is retained with an initial biological half-time of ∼40 days. The studies also showed that: 1 Uranium is initially deposited onto all types of bone surface, but preferentially onto those that are accreting. 2 Uranium is deposited in the calcifying zones of skeletal cartilage. 3 Bone accretion results in the burial of surface deposits of uranium. 4 Bone resorption causes the removal of uranium from surfaces. 5 Resorbed uranium is not retained by osteoclasts and macrophages in the bone marrow. 6 Uranium removed from bone surfaces enters the bloodstream where most is either redeposited in bone or excreted via the kidneys. 7 The recycling of resorbed uranium within the skeleton tends to produce a uniform level of uranium contamination throughout mineralized bone. These results are taken to indicate that uranium deposition in bone shares characteristics in common with both the 'volume-seeking radionuclides' typified by the alkaline earth elements and with the 'bone surface-seeking radionuclides' typified by plutonium.

scholarly journals Cytokine-Activated Endothelium Recruits Osteoclast Precursors

Endocrinology ◽  
2001 ◽  
Vol 142 (4) ◽  
pp. 1678-1681 ◽  
Author(s):  
Neil W. A. McGowan ◽  
Emily J. Walker ◽  
Heather Macpherson ◽  
Stuart H. Ralston ◽  
Miep H. Helfrich
Keyword(s):  
Bone Marrow ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Bone Resorption ◽  
Vitamin D3 ◽  
Peripheral Blood ◽  
Human Peripheral Blood ◽  
Osteoclast Formation ◽  
Bone Surface ◽  
Osteoclast Precursors

Abstract Osteoclast precursors reach sites of osteoclast formation and remodelling via the vasculature and are therefore destined to encounter endothelium before migrating to the bone surface. Here we investigated the hypothesis that endothelium may be involved in the regulation of osteoclast precursor recruitment to sites of bone resorption. Osteoclast precursors in human peripheral blood were identified by their ability to form mature osteoclasts in 21-day cultures supplemented with RANKLigand, M-CSF, 1,25(OH)2-vitamin D3, dexamethasone and prostaglandin E2. Under control conditions few osteoclast precursors adhered to endothelial cells (the human bone marrow-derived endothelial cell line BMEC-1). However, BMEC-1 cells treated with the resorption stimulating cytokines IL-1β and TNFα depleted the PBMC population of all osteoclast precursors. These results provide the first evidence that osteoclast precursors can adhere to endothelium and suggest that endothelium could play an important role in the recruitment of osteoclast precursors to sites of bone resorption.

scholarly journals Diagnosis and Treatment of Bone Disease in Multiple Myeloma: Spotlight on Spinal Involvement

Scientifica ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Patrizia Tosi
Keyword(s):  
Spinal Cord ◽  
Multiple Myeloma ◽  
Bone Marrow ◽  
Bone Resorption ◽  
Spinal Cord Compression ◽  
Bone Disease ◽  
Cord Compression ◽  
Diagnosis And Treatment ◽  
Conventional Chemotherapy ◽  
Spinal Involvement

Bone disease is observed in almost 80% of newly diagnosed symptomatic multiple myeloma patients, and spine is the bone site that is more frequently affected by myeloma-induced osteoporosis, osteolyses, or compression fractures. In almost 20% of the cases, spinal cord compression may occur; diagnosis and treatment must be carried out rapidly in order to avoid a permanent sensitive or motor defect. Although whole body skeletal X-ray is considered mandatory for multiple myeloma staging, magnetic resonance imaging is presently considered the most appropriate diagnostic technique for the evaluation of vertebral alterations, as it allows to detect not only the exact morphology of the lesions, but also the pattern of bone marrow infiltration by the disease. Multiple treatment modalities can be used to manage multiple myeloma-related vertebral lesions. Surgery or radiotherapy is mainly employed in case of spinal cord compression, impending fractures, or intractable pain. Percutaneous vertebroplasty or balloon kyphoplasty can reduce local pain in a significant fraction of treated patients, without interfering with subsequent therapeutic programs. Systemic antimyeloma therapy with conventional chemotherapy or, more appropriately, with combinations of conventional chemotherapy and compounds acting on both neoplastic plasma cells and bone marrow microenvironment must be soon initiated in order to reduce bone resorption and, possibly, promote bone formation. Bisphosphonates should also be used in combination with antimyeloma therapy as they reduce bone resorption and prolong patients survival. A multidisciplinary approach is thus needed in order to properly manage spinal involvement in multiple myeloma.

scholarly journals GPR109A mediates the effects of hippuric acid on regulating osteoclastogenesis and bone resorption in mice

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Jin-Ran Chen ◽  
Haijun Zhao ◽  
Umesh D. Wankhade ◽  
Sree V. Chintapalli ◽  
Can Li ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Bone Mass ◽  
Hippuric Acid ◽  
Ex Vivo ◽  
Marrow Cell ◽  
Osteoclast Differentiation ◽  
Bone Homeostasis ◽  
Wild Type ◽  
Osteoclast Precursors

AbstractThe G protein-coupled receptor 109 A (GPR109A) is robustly expressed in osteoclastic precursor macrophages. Previous studies suggested that GPR109A mediates effects of diet-derived phenolic acids such as hippuric acid (HA) and 3-(3-hydroxyphenyl) propionic acid (3-3-PPA) on promoting bone formation. However, the role of GPR109A in metabolic bone homeostasis and osteoclast differentiation has not been investigated. Using densitometric, bone histologic and molecular signaling analytic methods, we uncovered that bone mass and strength were significantly higher in tibia and spine of standard rodent diet weaned 4-week-old and 6-month-old GPR109A gene deletion (GPR109A−/−) mice, compared to their wild type controls. Osteoclast numbers in bone and in ex vivo bone marrow cell cultures were significantly decreased in GPR109A−/− mice compared to wild type controls. In accordance with these data, CTX-1 in bone marrow plasma and gene expression of bone resorption markers (TNFα, TRAP, Cathepsin K) were significantly decreased in GPR109A−/− mice, while on the other hand, P1NP was increased in serum from both male and female GPR109A−/− mice compared to their respective controls. GPR109A deletion led to suppressed Wnt/β-catenin signaling in osteoclast precursors to inhibit osteoclast differentiation and activity. Indeed, HA and 3-3-PPA substantially inhibited RANKL-induced GPR109A expression and Wnt/β-catenin signaling in osteoclast precursors and osteoclast differentiation. Resultantly, HA significantly inhibited bone resorption and increased bone mass in wild type mice, but had no additional effects on bone in GPR109A−/− mice compared with their respective untreated control mice. These results suggest an important role for GPR109A during osteoclast differentiation and bone resorption mediating effects of HA and 3-3-PPA on inhibiting bone resorption during skeletal development.

scholarly journals CCAAT/enhancer binding protein β-deficiency enhances type 1 diabetic bone phenotype by increasing marrow adiposity and bone resorption

2011 ◽  
Vol 300 (5) ◽  
pp. R1250-R1260 ◽  
Author(s):  
Katherine J. Motyl ◽  
Michelle Raetz ◽  
Srinivasan Arjun Tekalur ◽  
Richard C. Schwartz ◽  
Laura R. McCabe
Keyword(s):  
Bone Marrow ◽  
Type 1 Diabetes ◽  
Bone Resorption ◽  
Bone Loss ◽  
Wild Type ◽  
Bone Stiffness ◽  
Bone Phenotype ◽  
Enhancer Binding Protein ◽  
Marrow Adiposity

Bone loss in type 1 diabetes is accompanied by increased marrow fat, which could directly reduce osteoblast activity or result from altered bone marrow mesenchymal cell lineage selection (adipocyte vs. osteoblast). CCAAT/enhancer binding protein beta (C/EBPβ) is an important regulator of both adipocyte and osteoblast differentiation. C/EBPβ-null mice have delayed bone formation and defective lipid accumulation in brown adipose tissue. To examine the balance of C/EBPβ functions in the diabetic context, we induced type 1 diabetes in C/EBPβ-null (knockout, KO) mice. We found that C/EBPβ deficiency actually enhanced the diabetic bone phenotype. While KO mice had reduced peripheral fat mass compared with wild-type mice, they had 5-fold more marrow adipocytes than diabetic wild-type mice. The enhanced marrow adiposity may be attributed to compensation by C/EBPδ, peroxisome proliferator-activated receptor-γ2, and C/EBPα. Concurrently, we observed reduced bone density. Relative to genotype controls, trabecular bone volume fraction loss was escalated in diabetic KO mice (−48%) compared with changes in diabetic wild-type mice (−22%). Despite greater bone loss, osteoblast markers were not further suppressed in diabetic KO mice. Instead, osteoclast markers were increased in the KO diabetic mice. Thus, C/EBPβ deficiency increases diabetes-induced bone marrow (not peripheral) adipose depot mass, and promotes additional bone loss through stimulating bone resorption. C/EBPβ-deficiency also reduced bone stiffness and diabetes exacerbated this (two-way ANOVA P < 0.02). We conclude that C/EBPβ alone is not responsible for the bone vs. fat phenotype switch observed in T1 diabetes and that suppression of CEBPβ levels may further bone loss and decrease bone stiffness by increasing bone resorption.

scholarly journals Pivotal Role of OCL-Derived IGF1 in Drug Resistance and Bone Destruction in MM

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 4336-4336
Author(s):  
Jumpei Teramachi ◽  
Kazuaki Miyagawa ◽  
Delgado-Calle Jesus ◽  
Jolene Windle ◽  
Noriyoshi Kurihara ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Drug Resistance ◽  
Bone Resorption ◽  
Bone Marrow Cells ◽  
Critical Role ◽  
Bone Destruction ◽  
Bone Marrow Microenvironment ◽  
Rank Ligand ◽  
Marrow Cells

Multiple myeloma (MM) is largely incurable, and is characterized by devastating bone destruction caused by increased osteoclast (OCL) differentiation and bone resorption in more than 85% of MM patients. OCLs in MM not only promote bone resorption but also increase MM cell growth and drug resistance. Despite recent advances in anti-myeloma treatment, development of anti-MM drug resistance is a major limitation of MM therapy. Therefore, new treatment modalities are urgently needed to overcome drug resistance and decrease bone resorption. IGF1 is a crucial factor for tumor cell growth and survival of malignant cells, especially in MM. IGFI also contributes to development of drug resistance of MM cells to anti-MM agents, including proteasome inhibitors and immunomodulatory agents, but how OCLs contribute to drug resistance is still not clearly delineated. We found that IGF1 was highly expressed in OCLs attached to bone and bone marrow myeloid cells in vivo, and the expression levels of IGF1 in OCLs from MM bearing mice is higher than in normal OCLs. Intriguingly, OCLs produced more IGF1 (0.8 ng/ml/protein) than MM cells (not detected) and bone marrow stromal cells (BMSCs) (0.4 ng/ml/protein) in vitro. In addition, IGF1 protein expression in OCLs was upregulated (1.8 fold) by treatment with conditioned media (CM) from 5TGM1 murine MM cells, TNF-α or IL-6, major paracrine factors that are increased in the bone marrow microenvironment in MM. These results suggest that OCLs are a major source of local IGF1 in the MM bone marrow microenvironment. To further characterize the role of OCL-derived IGF1, we generated a novel mouse with targeted deletion of Igf1 in OCLs (IGF1-/--OCL), and assessed the role of OCL-derived IGF1 in drug resistance of MM cells and bone destruction. Treatment of 5TGM1 cells with bortezomib (BTZ) (3 nM, 48 hours) decreased the viability of 5TGM1 cells by 50%. Importantly, the cytotoxic effects of BTZ on MM cells were decreased (by 5%) when MM cells were cocultured with OCLs from wild type (WT) mice. In contrast, coculture of MM cells with IGF1-/--OCLs or WT-OCLs treated with IGF1 neutralizing antibody (IGF1-ab) did not block BTZ's effects on MM cell death. Consistent with these results, coculture of MM cells with IGF1-/--OCLs or WT-OCLs treated with IGF1-ab resulted in BTZ-induced caspase-dependent apoptosis in MM cells. We next examined the effects of OCLs on the signaling pathways responsible for MM cell survival. WT-OCL-CM promptly induced the phosphorylation of Akt and activation of p38, ERK and NF-κB in MM cells. However, these pathways were not activated by MM cells treated with IGF1-/--OCL-CM or IGF1-ab-treated WT-OCL-CM. Since adhesion of MM cells to BMSCs via interaction of VLA-4 and VCAM-1 plays a critical role in cell adhesion-mediated drug resistance (CAMDR) in MM, we tested if treatment of human BMSCs with human OCL-CM upregulated VCAM-1 expression. We found that OCL-CM upregulated VCAM-1 expression on BMSCs (x fold). In contrast, treatment of BMSCs with OCLs treated with IGF1-ab blocked VCAM-1 induction. These data suggest that OCL-derived IGF1 can contribute to MM cell drug resistance in the bone marrow microenvironment. We then examined the role of IGF1 inhibition on osteoclastogenesis and the bone resorption capacity of OCLs. RANK ligand induced the expression of cathepsin K and NFATc1 in CD11b+ bone marrow cells from WT mice, differentiation markers of OCLs, and the formation of TRAP-positive multinucleated OCLs. However, OCLs formed by RANK ligand treatment of CD11b+ bone marrow cells from IGF1-/- mice had markedly decreased cathepsin K and NFATc1 expression and OCL formation. Next, we tested the bone resorption capacity of OCLs formed by CD11b+ bone marrow cells from IGF1-/- mice vs. WT mice. Similar numbers of OCLs were cultured with RANK ligand on bone slices for 72 hours. The bone resorption activity of Igf1-/--OCLs was significantly decreased (70%) compared with WT-OCLs. These results suggest that OCL-derived IGF1 plays a critical role in MM drug resistance and bone destruction, and that inhibition of the effect of IGF1 in OCLs should decrease MM drug resistance and bone destruction. Disclosures Roodman: Amgen trial of Denosumab versus Zoledronate: Membership on an entity's Board of Directors or advisory committees; Amgen: Membership on an entity's Board of Directors or advisory committees.

Inhibition of intravacuolar acidification by antisense RNA decreases osteoclast differentiation and bone resorption in vitro

1999 ◽  
Vol 112 (21) ◽  
pp. 3657-3666 ◽  
Author(s):  
T. Laitala-Leinonen ◽  
C. Lowik ◽  
S. Papapoulos ◽  
H.K. Vaananen
Keyword(s):  
Bone Marrow ◽  
Bone Resorption ◽  
Antisense Rna ◽  
Osteoclast Differentiation ◽  
Osteoclast Formation ◽  
Gm Csf ◽  
Monocytes And Macrophages ◽  
Marrow Cultures ◽  
Rat Bone

The role of proton transport and production in osteoclast differentiation was studied in vitro by inhibiting the transcription/translation of carbonic anhydrase II (CA II) and vacuolar H(+)-ATPase (V-ATPase) by antisense RNA molecules. Antisense RNAs targeted against CA II, or the 16 kDa or 60 kDa subunit of V-ATPase were used to block the expression of the specific proteins. A significant decrease in bone resorption rate and TRAP-positive osteoclast number was seen in rat bone marrow cultures and fetal mouse metacarpal cultures after antisense treatment. Intravacuolar acidification in rat bone marrow cells was also significantly decreased after antisense treatment. The CA II antisense RNA increased the number of TRAP-positive mononuclear cells, suggesting inhibition of osteoclast precursor fusion. Antisense molecules decreased the number of monocytes and macrophages, but increased the number of granulocytes in marrow cultures. GM-CSF, IL-3 and IL-6 were used to stimulate haematopoietic stem cell differentiation. The 16 kDa V-ATPase antisense RNA abolished the stimulatory effect of GM-CSF, IL-3 and IL-6 on TRAP-positive osteoclast formation, but did not affect the formation of monocytes and macrophages after IL-3 treatment, or the formation of granulocytes after IL-6 treatment. These results suggest that CA II and V-ATPase are needed, not only for the actual resorption, but also for osteoclast formation in vitro.

Abstract 17423: Unique Features of Cortical Bone Stem Cells Associated With Enhanced Cardiac Repair

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Sadia Mohsin ◽  
Thomas E Sharp ◽  
Shavonn Smith ◽  
Hajime Kubo ◽  
Remus M Berretta ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Stem Cells ◽  
Bone Marrow ◽  
Cell Surface ◽  
Cortical Bone ◽  
Surface Marker ◽  
Lineage Commitment ◽  
Population Doubling ◽  
Rt Pcr ◽  
Cardiac Lineage

Rationale: Adoptive transfer of bone marrow and cardiac derived stem cells (CDCs) into failing human hearts has been shown to be safe, yet these cells have induced modest improvements in myocardial function. Recently we have shown in a mouse model that cortical bone derived stem cells (CBSCs) induced a greater enhancement of cardiac function after myocardial infarction than CDCs, possibly through enhanced paracrine signaling and transdifferentiation of the transplanted cells. However, the relative reparative potential of CBSCs relative to other known stem cell types including bone marrow derived mesenchymal stem cells (MSCs) and cardiac derived stem cells (CDCs) is not known. Objective: To characterize surface marker expression, proliferation, survival and differentiation capacity of swine CBSCs relative to MSCs and CDCs. Methods and Results: CBSCs, MSCs and CDCs were isolated from cortical bone, bone marrow and heart (left ventricle) of Gottingen miniswine. CBSCs were morphologically distinct from MSCs and CDCs, with differences in length to width ratio and overall cell surface area. Cell surface marker profiling using RT-PCR analysis revealed that CBSCs express some of the classical MSC markers such as CD106, CD271, CD105, CD90, CD44 and CD29 and are negative for CD45 and CD11-b. CBSCs had an enhanced proliferation capacity versus CPCs and MSCs, measured by CyQuant assay. Concurrently CBSCs had significantly a decreased population doubling time (3.57 and 1.26 fold decrease) as compared to MSC and CDCs respectively. CBSCs were also more hydrogen peroxide stress tolerant than CSCs and MSCs as measured by Annexin-V and propidium iodide (PI) labeling using flow cytometery. A significantly greater % of CBSCs expressed markers of cardiac lineage commitment when exposed to dexamethasone than did CSCs or MSCs. Markers of cardiac lineages including GATA-4, α SMA, Troponin T, Nkx2.5, sm22 were measured with RT-PCR and immunocytochemistry. Conclusion: CBSCs have enhanced proliferative capacity, survival in oxidative stress conditions and cardiac lineage commitment versus CSCs and MSCs. These features make them a promising cell source for cardiac regeneration after myocardial infarction.

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