scholarly journals Wnt Pathway Extracellular Components and Their Essential Roles in Bone Homeostasis

Genes ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 138
Author(s):  
Núria Martínez-Gil ◽  
Nerea Ugartondo ◽  
Daniel Grinberg ◽  
Susanna Balcells

The Wnt pathway is involved in several processes essential for bone development and homeostasis. For proper functioning, the Wnt pathway is tightly regulated by numerous extracellular elements that act by both activating and inhibiting the pathway at different moments. This review aims to describe, summarize and update the findings regarding the extracellular modulators of the Wnt pathway, including co-receptors, ligands and inhibitors, in relation to bone homeostasis, with an emphasis on the animal models generated, the diseases associated with each gene and the bone processes in which each member is involved. The precise knowledge of all these elements will help us to identify possible targets that can be used as a therapeutic target for the treatment of bone diseases such as osteoporosis.

2020 ◽  
Vol 27 (6) ◽  
pp. 838-853 ◽  
Author(s):  
Madalina Icriverzi ◽  
Valentina Dinca ◽  
Magdalena Moisei ◽  
Robert W. Evans ◽  
Mihaela Trif ◽  
...  

: Among the multiple properties exhibited by lactoferrin (Lf), its involvement in bone regeneration processes is of great interest at the present time. A series of in vitro and in vivo studies have revealed the ability of Lf to promote survival, proliferation and differentiation of osteoblast cells and to inhibit bone resorption mediated by osteoclasts. Although the mechanism underlying the action of Lf in bone cells is still not fully elucidated, it has been shown that its mode of action leading to the survival of osteoblasts is complemented by its mitogenic effect. Activation of several signalling pathways and gene expression, in an LRPdependent or independent manner, has been identified. Unlike the effects on osteoblasts, the action on osteoclasts is different, with Lf leading to a total arrest of osteoclastogenesis. : Due to the positive effect of Lf on osteoblasts, the potential use of Lf alone or in combination with different biologically active compounds in bone tissue regeneration and the treatment of bone diseases is of great interest. Since the bioavailability of Lf in vivo is poor, a nanotechnology- based strategy to improve the biological properties of Lf was developed. The investigated formulations include incorporation of Lf into collagen membranes, gelatin hydrogel, liposomes, loading onto nanofibers, porous microspheres, or coating onto silica/titan based implants. Lf has also been coupled with other biologically active compounds such as biomimetic hydroxyapatite, in order to improve the efficacy of biomaterials used in the regulation of bone homeostasis. : This review aims to provide an up-to-date review of research on the involvement of Lf in bone growth and healing and on its use as a potential therapeutic factor in bone tissue regeneration.


2019 ◽  
Vol 17 (6) ◽  
pp. 610-617 ◽  
Author(s):  
Giovanna Muscogiuri ◽  
Luigi Barrea ◽  
Barbara Altieri ◽  
Carolina Di Somma ◽  
Harjit pal Bhattoa ◽  
...  

Vitamin D and calcium are considered crucial for the treatment of bone diseases. Both vitamin D and calcium contribute to bone homeostasis but also preserve muscle health by reducing the risk of falls and fractures. Low vitamin D concentrations result in secondary hyperparathyroidism and contribute to bone loss, although the development of secondary hyperparathyroidism varies, even in patients with severe vitamin D deficiency. Findings from observational studies have shown controversial results regarding the association between bone mineral density and vitamin D/calcium status, thus sparking a debate regarding optimum concentrations of 25-hydroxyvitamin D and calcium for the best possible skeletal health. Although most of the intervention studies reported a positive effect of supplementation with calcium and vitamin D on bone in patients with osteoporosis, this therapeutic approach has been a matter of debate regarding potential side effects on the cardiovascular (CV) system. Thus, the aim of this review is to consider the current evidence on the physiological role of vitamin D and calcium on bone and muscle health. Moreover, we provide an overview on observational and interventional studies that investigate the effect of vitamin D and calcium supplementation on bone health, also taking into account the possible CV side-effects. We also provide molecular insights on the effect of calcium plus vitamin D on the CV system.


2021 ◽  
Vol 9 (3) ◽  
pp. 24
Author(s):  
Brian Heubel ◽  
Anja Nohe

The osteogenic effects of Bone Morphogenetic Proteins (BMPs) were delineated in 1965 when Urist et al. showed that BMPs could induce ectopic bone formation. In subsequent decades, the effects of BMPs on bone formation and maintenance were established. BMPs induce proliferation in osteoprogenitor cells and increase mineralization activity in osteoblasts. The role of BMPs in bone homeostasis and repair led to the approval of BMP2 by the Federal Drug Administration (FDA) for anterior lumbar interbody fusion (ALIF) to increase the bone formation in the treated area. However, the use of BMP2 for treatment of degenerative bone diseases such as osteoporosis is still uncertain as patients treated with BMP2 results in the stimulation of not only osteoblast mineralization, but also osteoclast absorption, leading to early bone graft subsidence. The increase in absorption activity is the result of direct stimulation of osteoclasts by BMP2 working synergistically with the RANK signaling pathway. The dual effect of BMPs on bone resorption and mineralization highlights the essential role of BMP-signaling in bone homeostasis, making it a putative therapeutic target for diseases like osteoporosis. Before the BMP pathway can be utilized in the treatment of osteoporosis a better understanding of how BMP-signaling regulates osteoclasts must be established.


2021 ◽  
Vol 98 ◽  
pp. 107803
Author(s):  
Peiyao Wu ◽  
Jieyu Zhou ◽  
Yafei Wu ◽  
Lei Zhao

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1779
Author(s):  
Ga-Ram Kim ◽  
Eun-Nam Kim ◽  
Kyoung Jin Park ◽  
Ki Hyun Kim ◽  
Gil-Saeng Jeong

Osteoblasts and osteoclasts play a pivotal role in maintaining bone homeostasis, of which excessive bone resorption by osteoclasts can cause osteoporosis and various bone diseases. However, current osteoporosis treatments have many side effects, and research on new treatments that can replace these treatments is ongoing. Therefore, in this study, the roles of ligustroside (LGS) and oleoside dimethylester (ODE), a natural product-derived compound isolated from Syringa oblata subsp. dilatata as a novel, natural product-derived osteoporosis treatments were investigated. In the results of this study, LGS and ODE inhibited the differentiation of receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced RAW264.7 cells into osteoclasts without cytotoxicity, and down-regulated the activity of TRAP, a specific biomarker of osteoclasts. In addition, it inhibited bone resorption and actin ring formation, which are important functions and features of osteoclasts. Also, the effects of LGS and ODE on the mitogen-activated protein kinase (MAPK) and nuclear factor kappa-light-chain-enhancer of activated B (NF-κB) and phosphoinositide 3-kinases (PI3K)/ protein kinase B (Akt)/mechanistic target of rapamycin (mTOR) signaling pathways that play important roles in osteoclast differentiation were evaluated. In the results, LGS and ODE downregulated the phosphorylation of RANKL-induced MAPK and PI3K/Akt/mTOR proteins in a concentration-dependent manner, translocation of NF-κB into the nucleus was inhibited. As a result, the compounds LGS and ODE isolated from S. oblate subsp. dilatata effectively regulated the differentiation of RANKL-induced osteoclasts and inhibited the phosphorylation of signaling pathways that play a pivotal role in osteoclast differentiation. Therefore, these results suggest the possibility of LGS and ODE as new natural product treatments for bone diseases caused by excessive osteoclasts.


2020 ◽  
Vol 22 (1) ◽  
pp. 222
Author(s):  
Eun-Nam Kim ◽  
Ga-Ram Kim ◽  
Jae Sik Yu ◽  
Ki Hyun Kim ◽  
Gil-Saeng Jeong

In bone homeostasis, bone loss due to excessive osteoclasts and inflammation or osteolysis in the bone formation process cause bone diseases such as osteoporosis. Suppressing the accompanying oxidative stress such as ROS in this process is an important treatment strategy for bone disease. Therefore, in this study, the effect of (2R)-4-(4-hydroxyphenyl)-2-butanol 2-O-β-d-apiofuranosyl-(1→6)-β-d-glucopyranoside (BAG), an arylbutanoid glycoside isolated from Betula platyphylla var. japonica was investigated in RANKL-induced RAW264.7 cells and LPS-stimulated MC3E3-T1 cells. BAG inhibited the activity of TRAP, an important marker of osteoclast differentiation and F-actin ring formation, which has osteospecific structure. In addition, the protein and gene levels were suppressed of integrin β3 and CCL4, which play an important role in the osteoclast-induced bone resorption and migration of osteoclasts, and inhibited the production of ROS and restored the expression of antioxidant enzymes such as SOD and CAT lost by RANKL. The inhibitory effect of BAG on osteoclast differentiation and ROS production appears to be due to the inhibition of MAPKs phosphorylation and NF-κβ translocation, which play a major role in osteoclast differentiation. In addition, BAG inhibited ROS generated by LPS and effectively restores the mineralization of lost osteoblasts, thereby showing the effect of bone formation in the inflammatory situation accompanying bone loss by excessive osteoclasts, suggesting its potential as a new natural product-derived bone disease treatment.


2017 ◽  
Vol 118 (4) ◽  
Author(s):  
Sanja Sever ◽  
Changkyo Gu

Podocyte injury is a hallmark of the glomerular disease, which is a direct cause of chronic kidney diseases. Importantly, podocyte injury is a consequence of the dysregulation of the actin cytoskeleton. In diverse animal models of proteinuric glomerular disease, recovering the integrity of the actin structure in podocytes resulted in beneficial effects. In this review, we focus on the premise of targeting the actin cytoskeleton as a feasible therapeutics for treating chronic kidney diseases


2020 ◽  
Vol 21 (20) ◽  
pp. 7655
Author(s):  
Michèle Roy ◽  
Sophie Roux

Small guanosine triphosphate hydrolases (GTPases) of the Rab family are involved in plasma membrane delivery, fusion events, and lysosomal and autophagic degradation pathways, thereby regulating signaling pathways and cell differentiation and function. Osteoclasts are bone-resorbing cells that maintain bone homeostasis. Polarized vesicular trafficking pathways result in the formation of the ruffled border, the osteoclast’s resorptive organelle, which also assists in transcytosis. Here, we reviewed the different roles of Rab GTPases in the endomembrane machinery of osteoclasts and in bone diseases caused by the dysfunction of these proteins, with a particular focus on autophagy and bone resorption. Understanding the molecular mechanisms underlying osteoclast-related bone disease development is critical for developing and improving therapies.


2017 ◽  
Vol 14 (127) ◽  
pp. 20160958 ◽  
Author(s):  
Michal Shemesh ◽  
Lia Addadi ◽  
Benjamin Geiger

Bone homeostasis is continuously regulated by the coordinated action of bone-resorbing osteoclasts and bone-forming osteoblasts. Imbalance between these two cell populations leads to pathological bone diseases such as osteoporosis and osteopetrosis. Osteoclast functionality relies on the formation of sealing zone (SZ) rings that define the resorption lacuna. It is commonly assumed that the structure and dynamic properties of the SZ depend on the physical and chemical properties of the substrate. Considering the unique complex structure of native bone, elucidation of the relevant parameters affecting SZ formation and stability is challenging. In this study, we examined in detail the dynamic response of the SZ to the microtopography of devitalized bone surfaces, taken from the same area in cattle femur. We show that there is a significant enrichment in large and stable SZs (diameter larger than 14 µm; lifespan of hours) in cells cultured on rough bone surfaces, compared with small and fast turning over SZ rings (diameter below 7 µm; lifespan approx. 7 min) formed on smooth bone surfaces. Based on these results, we propose that the surface roughness of the physiologically relevant substrate of osteoclasts, namely bone, affects primarily the local stability of growing SZs.


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