Wnt signaling and bone cell activity

2020 ◽  
pp. 177-204
Author(s):  
Bart O. Williams ◽  
Mark L. Johnson
Keyword(s):  
Wnt Signaling ◽  
Cell Activity ◽  
Bone Cell

scholarly journals The Development of Molecular Biology of Osteoporosis

2021 ◽  
Vol 22 (15) ◽  
pp. 8182
Author(s):  
Yongguang Gao ◽  
Suryaji Patil ◽  
Jingxian Jia
Keyword(s):  
Bone Resorption ◽  
Molecular Biology ◽  
Bone Formation ◽  
Bone Mass ◽  
Bone Remodeling ◽  
Bone Cells ◽  
Cell Activity ◽  
Bone Cell ◽  
Bone Disorders ◽  
Molecular Aspects

Osteoporosis is one of the major bone disorders that affects both women and men, and causes bone deterioration and bone strength. Bone remodeling maintains bone mass and mineral homeostasis through the balanced action of osteoblasts and osteoclasts, which are responsible for bone formation and bone resorption, respectively. The imbalance in bone remodeling is known to be the main cause of osteoporosis. The imbalance can be the result of the action of various molecules produced by one bone cell that acts on other bone cells and influence cell activity. The understanding of the effect of these molecules on bone can help identify new targets and therapeutics to prevent and treat bone disorders. In this article, we have focused on molecules that are produced by osteoblasts, osteocytes, and osteoclasts and their mechanism of action on these cells. We have also summarized the different pharmacological osteoporosis treatments that target different molecular aspects of these bone cells to minimize osteoporosis.

Morphological studies of bone and tendon

1992 ◽  
Vol 73 (2) ◽  
pp. S10-S13 ◽  
Author(s):  
S. B. Doty ◽  
E. R. Morey-Holton ◽  
G. N. Durnova ◽  
A. S. Kaplansky
Keyword(s):  
Electron Microscopy ◽  
Bone Cells ◽  
Weight Bearing ◽  
Light And Electron Microscopy ◽  
Cell Activity ◽  
Bone Cell ◽  
Electron Microscopic ◽  
Adult Rats ◽  
Morphological Studies ◽  
Metatarsal Bones

The Soviet biosatellite COSMOS 2044 carried adult rats on a spaceflight that lasted 13.8 days and was intended to repeat animal studies carried out on COSMOS 1887. Skeletal tissue and tendon from animals flown on COSMOS 2044 were studied by light and electron microscopy, histochemistry, and morphometric techniques. Studies were confined to the bone cells and vasculature from the weight-bearing tibias. Results indicated that vascular changes at the periosteal and subperiosteal region of the tibia were not apparent by light microscopy or histochemistry. However, electron microscopy indicated that vascular inclusions were present in bone samples from the flight animals. A unique combination of microscopy and histochemical techniques indicated that the endosteal osteoblasts from this same mid-diaphyseal region demonstrated a slight (but not statistically significant) reduction in bone cell activity. Electron-microscopic studies of the tendons from metatarsal bones showed a collagen fibril disorganization as a result of spaceflight. Thus changes described for COSMOS 1887 were present in COSMOS 2044, but the changes ascribed to spaceflight were not as evident.

Circadian variation in biochemical markers of bone cell activity and insulin-like growth factor-I in two-year-old horses1

2003 ◽  
Vol 81 (11) ◽  
pp. 2804-2810 ◽  
Author(s):  
B. F. Jackson ◽  
A. Blumsohn ◽  
A. E. Goodship ◽  
A. M. Wilson ◽  
J. S. Price
Keyword(s):  
Growth Factor ◽  
Biochemical Markers ◽  
Circadian Variation ◽  
Cell Activity ◽  
Bone Cell ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Growth Factor I

scholarly journals Unsaturated fatty acyl recognition by Frizzled receptors mediates dimerization upon Wnt ligand binding

2017 ◽  
Vol 114 (16) ◽  
pp. 4147-4152 ◽  
Author(s):  
Aaron H. Nile ◽  
Susmith Mukund ◽  
Karen Stanger ◽  
Weiru Wang ◽  
Rami N. Hannoush
Keyword(s):  
Crystal Structure ◽  
Fatty Acid ◽  
Wnt Signaling ◽  
Bone Growth ◽  
Cell Activity ◽  
Fatty Acyl ◽  
Lipid Binding ◽  
Receptor Expression ◽  
Rich Domain ◽  
Binding Groove

Frizzled (FZD) receptors mediate Wnt signaling in diverse processes ranging from bone growth to stem cell activity. Moreover, high FZD receptor expression at the cell surface contributes to overactive Wnt signaling in subsets of pancreatic, ovarian, gastric, and colorectal tumors. Despite the progress in biochemical understanding of Wnt–FZD receptor interactions, the molecular basis for recognition of Wnt cis-unsaturated fatty acyl groups by the cysteine-rich domain (CRD) of FZD receptors remains elusive. Here, we determined a crystal structure of human FZD7 CRD unexpectedly bound to a 24-carbon fatty acid. We also report a crystal structure of human FZD5 CRD bound to C16:1 cis-Δ9 unsaturated fatty acid. Both structures reveal a dimeric arrangement of the CRD. The lipid-binding groove exhibits flexibility and spans both monomers, adopting a U-shaped geometry that accommodates the fatty acid. Re-evaluation of the published mouse FZD8 CRD structure reveals that it also shares the same architecture as FZD5 and FZD7 CRDs. Our results define a common molecular mechanism for recognition of the cis-unsaturated fatty acyl group, a necessary posttranslational modification of Wnts, by multiple FZD receptors. The fatty acid bridges two CRD monomers, implying that Wnt binding mediates FZD receptor dimerization. Our data uncover possibilities for the arrangement of Wnt–FZD CRD complexes and shed structural insights that could aide in the identification of pharmacological strategies to modulate FZD receptor function.

Decreased potassium stimulates bone resorption

1997 ◽  
Vol 272 (6) ◽  
pp. F774-F780 ◽  
Author(s):  
D. A. Bushinsky ◽  
D. R. Riordon ◽  
J. S. Chan ◽  
N. S. Krieger
Keyword(s):  
Bone Resorption ◽  
Collagen Synthesis ◽  
Cell Activity ◽  
Bone Cell ◽  
Osteoblastic Cell ◽  
Enzyme Release ◽  
Osteoblastic Cell Line ◽  
Glucuronidase Activity ◽  
K Concentration ◽  
Low K

Metabolic acidosis induces net calcium efflux (JCa+) from cultured bone, in part, through an increase in osteoclastic resorption and a decrease in osteoblastic formation. In humans provision of base as potassium (K+) citrate, but not sodium (Na+) citrate, reduces urine Ca (UCa), and oral KHCO3 decreases bone resorption and UCa in postmenopausal women. Potassium deprivation alone leads to an increase in UCa. To determine whether decreased extracellular K+ concentration ([K+]) at a constant pH, PCO2, and [HCO-3] alters JCa+ and bone cell activity, we measured JCa+, osteoblastic collagen synthesis, and osteoclastic beta-glucuronidase release from neonatal mouse calvariae cultured for 48 h in medium of varying [K+]. Calvariae were cultured in control medium (approximately 4 mM [K+]) or medium with mildly low K+ (MLK, approximately 3 mM [K+]), very low K+ (VLK, approximately 2 mM [K+]), or extremely low K+ (ELK, approximately 1 mM [K+]) (n > or = 9 in each group). Compared with control, ELK, but not MLK or VLK, resulted in a marked increase in JCa+ and an increase in beta-glucuronidase release and a decrease in collagen synthesis. JCa+ was correlated directly with medium beta-glucuronidase activity and inversely with collagen synthesis. To determine whether the reduction in medium [K+] was associated with a decrease in intracellular pH (pHi), we measured pHi in MC3T3-E1 cells, a mouse osteoblastic cell line. Incubation in 1 mM [K+] led to a significant decrease in pHi compared with 3 mM [K+]. Thus incubation in a reduced [K+] medium stimulates JCa+ and osteoclastic enzyme release and inhibits osteoblastic collagen synthesis, which may be mediated by a reduction in bone cell pH.

scholarly journals Bone Cell Activity in Clinical Prostate Cancer Bone Metastasis and Its Inverse Relation to Tumor Cell Androgen Receptor Activity

2018 ◽  
Vol 19 (4) ◽  
pp. 1223 ◽  
Author(s):  
Annika Nordstrand ◽  
Erik Bovinder Ylitalo ◽  
Elin Thysell ◽  
Emma Jernberg ◽  
Sead Crnalic ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Androgen Receptor ◽  
Bone Metastasis ◽  
Tumor Cell ◽  
Cell Activity ◽  
Bone Cell ◽  
Receptor Activity ◽  
Inverse Relation ◽  
Androgen Receptor Activity

Genes associate with abnormal bone cell activity in bone metastasis

2012 ◽  
Vol 31 (3-4) ◽  
pp. 569-578 ◽  
Author(s):  
G. David Roodman
Keyword(s):  
Bone Metastasis ◽  
Cell Activity ◽  
Bone Cell

Evolution of some biochemical markers of growth in relation to osteoarticular status in young horses: results of a longitudinal study in three breeds

2007 ◽  
Vol 4 (1) ◽  
pp. 23-29 ◽  
Author(s):  
J P Valette ◽  
C Robert ◽  
M P Toquet ◽  
J M Denoix ◽  
G Fortier
Keyword(s):  
Biochemical Markers ◽  
Cell Activity ◽  
Bone Cell ◽  
Rapid Decrease ◽  
Radiographic Examination ◽  
Alkaline Phosphatases ◽  
Radiographic Findings ◽  
Bone Fraction ◽  
Young Horses ◽  
Kinetics Of

AbstractOsteocalcin (OC), bone fraction of alkaline phosphatases (BAP) and hydroxyproline (HOP) are markers of bone cell activity. The kinetics of these markers and the analysis of their variations could be related to the osteoarticular status (OAS) of young horses. The growth of Thoroughbreds, French Trotters and Selle Français horses was followed up to 18 months. Blood samples were taken regularly to measure OC, HOP and BAP by standardized techniques. The OAS was evaluated by radiographic examination of the limbs. Based on radiographic findings, two groups of horses were investigated, with no lesions or severely affected. Analysis of variance was used to detect the effects of age and breed, and OAS on parameters. The logarithmic model was used to determine the kinetics of the markers. A rapid decrease in marker concentrations with age and differences between breed was observed. At birth, BAP, OC and HOP concentrations were significantly higher in normal horses (1910 UI l− 1, 192 ng ml− 1 and 35 mg l− 1, respectively) than in horses with severe lesions (1620 UI l− 1, 149 ng ml− 1 and 24 mg l− 1, respectively). During the first 6 months, OC, HOP and BAP remained lower in severely affected horses.

scholarly journals Bone cell activity influences bone fragility and fracture risk

2010 ◽  
Vol 69 (Suppl 2) ◽  
pp. A20-A21
Author(s):  
J Caetano-Lopes ◽  
I Aleixo ◽  
A Rodrigues ◽  
I P Perpetuo ◽  
D Fernandes ◽  
...  
Keyword(s):  
Fracture Risk ◽  
Cell Activity ◽  
Bone Fragility ◽  
Bone Cell
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