scholarly journals CHMP5 controls bone turnover rates by dampening NF-κB activity in osteoclasts

2015 ◽  
Vol 212 (8) ◽  
pp. 1283-1301 ◽  
Author(s):  
Matthew B. Greenblatt ◽  
Kwang Hwan Park ◽  
Hwanhee Oh ◽  
Jung-Min Kim ◽  
Dong Yeon Shin ◽  
...  

Physiological bone remodeling requires that bone formation by osteoblasts be tightly coupled to bone resorption by osteoclasts. However, relatively little is understood about how this coupling is regulated. Here, we demonstrate that modulation of NF-κB signaling in osteoclasts via a novel activity of charged multivesicular body protein 5 (CHMP5) is a key determinant of systemic rates of bone turnover. A conditional deletion of CHMP5 in osteoclasts leads to increased bone resorption by osteoclasts coupled with exuberant bone formation by osteoblasts, resembling an early onset, polyostotic form of human Paget’s disease of bone (PDB). These phenotypes are reversed by haploinsufficiency for Rank, as well as by antiresorptive treatments, including alendronate, zolendronate, and OPG-Fc. Accordingly, CHMP5-deficient osteoclasts display increased RANKL-induced NF-κB activation and osteoclast differentiation. Biochemical analysis demonstrated that CHMP5 cooperates with the PDB genetic risk factor valosin-containing protein (VCP/p97) to stabilize the inhibitor of NF-κBα (IκBα), down-regulating ubiquitination of IκBα via the deubiquitinating enzyme USP15. Thus, CHMP5 tunes NF-κB signaling downstream of RANK in osteoclasts to dampen osteoclast differentiation, osteoblast coupling and bone turnover rates, and disruption of CHMP5 activity results in a PDB-like skeletal disorder.

Lupus ◽  
2021 ◽  
Vol 30 (6) ◽  
pp. 965-971
Author(s):  
Wang Tianle ◽  
Zhang Yingying ◽  
Hong Baojian ◽  
Gu Juanfang ◽  
Wang Hongzhi ◽  
...  

Objectives SLE is a chronic autoimmune disease, which can affect the level of bone metabolism and increase the risk of osteoporosis and fracture. The purpose of this research is to study the effect of SLE on bone turnover markers without the influence of glucocorticoids. Methods A total of 865 female subjects were recruited from Zhejiang Provincial People’s Hospital and the First Hospital of Jiaxing, including 391 SLE patients without the influence of glucocorticoids and 474 non-SLE people. We detected Bone turnover markers including amino-terminal propeptide of type 1 procollagen (P1NP), C-terminal turnover of β - I collagen (β-CTX), N-terminal midfragment of osteocalcin (NMID) and 25(OH)D, and analyzed the difference in Bone turnover markers between the SLE group and the control group, as well as the influence of age and season on bone metabolism in female SLE patients. Results In the SLE group, the average age was 43.93±13.95 years old. In the control group, the average age was 44.84±11.42 years old. There was no difference between the two groups (t = 1.03, P = 0.30). P1NP, NMID and 25(OH)D in the SLE group were significantly lower than those in the control group (Z = 8.44, p < 0.001; Z = 14.41, p < 0.001; Z = 2.19, p = 0.029), and β-CTX in the SLE group was significantly higher than that in the control group (Z = 2.61, p = 0.009). In addition, the levers of β-CTX, NMID, P1NP and 25(OH)D in older SLE female patients were statistically significantly higher than those in younger (ρ = 0.104, p = 0.041; ρ = 0.223, p < 0.001; ρ = 0.105, p = 0.038; ρ = 0.289, p < 0.001). Moreover, β-CTX reached a high value in summer and PINP reached a low value in winter. Conclusion The bone formation markers of female SLE patients without glucocorticoid were lower than those of normal people and the bone resorption marker was higher than that of normal people. The 25 (OH) D of female SLE patients without glucocorticoid was lower than that of normal people. The risk of osteoporosis and fracture may be higher in elderly women with SLE. The bone resorption level of female SLE patients is high in summer and the bone formation level is low in winter.


2021 ◽  
Vol 22 (9) ◽  
pp. 4717
Author(s):  
Jin-Young Lee ◽  
Da-Ae Kim ◽  
Eun-Young Kim ◽  
Eun-Ju Chang ◽  
So-Jeong Park ◽  
...  

Lumican, a ubiquitously expressed small leucine-rich proteoglycan, has been utilized in diverse biological functions. Recent experiments demonstrated that lumican stimulates preosteoblast viability and differentiation, leading to bone formation. To further understand the role of lumican in bone metabolism, we investigated its effects on osteoclast biology. Lumican inhibited both osteoclast differentiation and in vitro bone resorption in a dose-dependent manner. Consistent with this, lumican markedly decreased the expression of osteoclastogenesis markers. Moreover, the migration and fusion of preosteoclasts and the resorptive activity per osteoclast were significantly reduced in the presence of lumican, indicating that this protein affects most stages of osteoclastogenesis. Among RANKL-dependent pathways, lumican inhibited Akt but not MAP kinases such as JNK, p38, and ERK. Importantly, co-treatment with an Akt activator almost completely reversed the effect of lumican on osteoclast differentiation. Taken together, our findings revealed that lumican inhibits osteoclastogenesis by suppressing Akt activity. Thus, lumican plays an osteoprotective role by simultaneously increasing bone formation and decreasing bone resorption, suggesting that it represents a dual-action therapeutic target for osteoporosis.


1996 ◽  
Vol 6 (S1) ◽  
pp. 250-250
Author(s):  
HW Woitge ◽  
M Müller ◽  
P Bärtsch ◽  
B Friedmann ◽  
MJ Seibel ◽  
...  

2021 ◽  
Vol 12 ◽  
Author(s):  
Wang Gong ◽  
Xingren Chen ◽  
Tianshu Shi ◽  
Xiaoyan Shao ◽  
Xueying An ◽  
...  

As the society is aging, the increasing prevalence of osteoporosis has generated huge social and economic impact, while the drug therapy for osteoporosis is limited due to multiple targets involved in this disease. Zhuangguguanjie formulation (ZG) is extensively used in the clinical treatment of bone and joint diseases, but the underlying mechanism has not been fully described. This study aimed to examine the therapeutic effect and potential mechanism of ZG on postmenopausal osteoporosis. The ovariectomized (OVX) mice were treated with normal saline or ZG for 4 weeks after ovariectomy following a series of analyses. The bone mass density (BMD) and trabecular parameters were examined by micro-CT. Bone remodeling was evaluated by the bone histomorphometry analysis and ELISA assay of bone turnover biomarkers in serum. The possible drug–disease common targets were analyzed by network pharmacology. To predict the potential biological processes and related pathways, GO/KEGG enrichment analysis was performed. The effects of ZG on the differentiation phenotype of osteoclasts and osteoblasts and the predicted pathway were verified in vitro. The results showed that ZG significantly improved the bone mass and micro-trabecular architecture in OVX mice compared with untreated OVX mice. ZG could promote bone formation and inhibit bone resorption to ameliorate ovariectomy-induced osteoporosis as evidenced by increased number of osteoblast (N.Ob/Tb.Pm) and decreased number of osteoclast (N.Oc/Tb.Pm) in treated group compared with untreated OVX mice. After identifying potential drug–disease common targets by network pharmacology, GO enrichment analysis predicted that ZG might affect various biological processes including osteoblastic differentiation and osteoclast differentiation. The KEGG enrichment analysis suggested that PI3K/Akt and mTOR signaling pathways could be the possible pathways. Furthermore, the experiments in vitro validated our findings. ZG significantly down-regulated the expression of osteoclast differentiation markers, reduced osteoclastic resorption, and inhibited the phosphorylation of PI3K/Akt, while ZG obviously up-regulated the expression of osteogenic biomarkers, promoted the formation of calcium nodules, and hampered the phosphorylation of 70S6K1/mTOR, which can be reversed by the corresponding pathway activator. Thus, our study suggested that ZG could inhibit the PI3K/Akt signaling pathway to reduce osteoclastic bone resorption as well as hamper the mTORC1/S6K1 signaling pathway to promote osteoblastic bone formation.


2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A218-A218
Author(s):  
Melissa Kaori S Litao ◽  
Deepa Badrinath Murthy ◽  
Jason Klein

Abstract Background: Cherubism, caused by autosomal dominant mutations in the SH3BP2 gene, is characterized by increased bone resorption with development of bilateral fibro-osseous lesions limited to the maxilla and mandible. The SH3BP2 gene is thought to be involved in osteoclastogenesis. Affected children, while usually asymptomatic at birth, typically present at 2–5 years of age with cheek and jaw swelling with upward tilting of eyes due to expansion of fibrous tissues. Bone resorption and proliferation of lesions continues until puberty after which spontaneous regression occurs. RANKL is a cytokine expressed on the surface of osteoclast precursors and is responsible for inducing osteoclast differentiation. Denosumab is an anti-RANKL monoclonal antibody which prevents osteoclast maturation. However, it has a short half-life, and effects on bone turnover have been found to be rapidly reversible after drug discontinuation. The rebound increased bone turnover can lead to severe hypercalcemia. Clinical Case: A 4 year old boy with cherubism (c.1253C&gt;G pathogenic variant in SH3BP2), after failing a 10-month trial of tacrolimus, was placed on monthly denosumab (2 mg/kg) for a total of 10 doses. During denosumab therapy, he received calcium and vitamin D to prevent hypocalcemia; these were stopped once denosumab was discontinued. He presented to the hospital 4 months after the final denosumab dose with polyuria, polydipsia, fatigue, nausea and abdominal pain. Work-up revealed serum Ca 15.3 mg/dL (N: 8.4–10.2), PTH &lt;3 pg/mL (N: 24–86), 25-OH vitamin D 32 ng/mL (N: &gt;19 ng/mL), 1,25-dihydroxyvitamin D 6.7 pg/mL (N: 19.9–79.3), and urine Ca/Cr 0.48. Renal ultrasound showed normal kidneys with a small amount of layering debris in the bladder. During hospitalization, he received IV fluids, 1 dose of furosemide, 3 doses of calcitonin, 24 hours of hydrocortisone, and a single 0.5 mg/kg dose of pamidronate. He was discharged 48 hours after the bisphosphonate with serum Ca 9.5 mg/dL. He returned with serum Ca 13.5 mg/dL 9 days after the pamidronate and was readmitted. He again received 4 doses of calcitonin and 1 dose of pamidronate (0.5 mg/kg). Calcium levels improved to 9.5 mg/dL at discharge but rose to 11.6 mg/dL a week later. He received a 0.05 mg/kg dose of zoledronate outpatient, with improvement in serum Ca to 10.1 mg/dL. A week later, he twisted his ankle, resulting in transverse impacted buckle fractures of his left distal tibia and fibula; no lytic or sclerotic lesions were noted on x-ray. His leg was immobilized by Orthopedics. Calcium levels remained within range (9.9 mg/dL) 7 months after the zoledronate. Conclusion: Rebound hypercalcemia can occur months after denosumab withdrawal, indicating the need for close monitoring of calcium levels in patients who receive this drug. The hypercalcemia appears to respond best to bisphosphonates, with a more sustained response to zoledrenate compared to pamidronate.


2020 ◽  
Vol 4 (Supplement_2) ◽  
pp. 71-71
Author(s):  
Joseph Roberts ◽  
Moriah Bellissimo ◽  
Kaitlin Taibl ◽  
Karan Uppal ◽  
Dean Jones ◽  
...  

Abstract Objectives Optimal bone health is maintained through a remodeling cycle consisting of resorption followed by formation. Procollagen type I N-terminal propeptide (P1NP) and C-terminal telopeptides of type I collagen (CTX) are biomarkers of bone metabolism that capture changes in bone formation and bone resorption, respectively. This study aimed to identify unique metabolic pathways related to bone turnover markers (BTMs) in healthy young adults. Methods This cross-sectional study included 34 healthy, young adults (19 females, average age 27.8 years). Bone mineral density (BMD) was assessed by dual-energy x-ray absorptiometry. Fasting plasma was analyzed using dual column liquid chromatography and ultra-high-resolution mass spectrometry for metabolomics. Serum levels of P1NP and CTX were measured with ELISA. Linear regression and pathway enrichment analyses were used to identify metabolic pathways related to the BTMs. Results All participants had a normal whole-body BMD T-score. Metabolites significantly associated with P1NP (at P &lt; 0.05) were significantly enriched in pathways linked to the TCA cycle, pyruvate metabolism, and metabolism of B-vitamins important for energy production (e.g., niacin, thiamin). Other nutrition-related metabolic pathways associated with P1NP were amino acid (proline, arginine, glutamate) and vitamin C metabolism, which are important for collagen formation. Metabolites were associated with CTX levels (at P &lt; 0.05), which were enriched within lipid and fatty acid beta-oxidation metabolic pathways, as well as fat soluble micronutrients pathways including, vitamin D metabolism, vitamin E metabolism, and bile acid biosynthesis. Conclusions High-resolution metabolomics identified several distinct plasma metabolic pathways, including energy-yielding metabolic pathways and pathways related to fatty acid, amino acid, and micronutrient metabolism that were associated with markers of bone formation and bone resorption. Characterizing these metabolism-related pathways associated with BTMs in healthy adults is an important step towards understanding the metabolic perturbations that lead to low bone mass in older and clinical populations. Funding Sources National Institutes of Health and Emory University.


1977 ◽  
Vol 232 (6) ◽  
pp. E535
Author(s):  
B Haldimann ◽  
J P Bonjour ◽  
H Fleisch

The effect of calcium deprivation on the various calcium fluxes was studied in growing rats either sham-operated (SHAM), thyroparathyroidectomized (TPTX), or thyroparathyroidectomized and supplemented with parathyroid hormone (PTH) (TPTX + PTH). In SHAM rats a decrease in the net absorption of calcium (Vna) has no influence on calcemia or on bone formation (Vo+), but leads to an increase in bone resorption (Vo-). In TPTX rats a decrease in Vna induces a decrease in calcemia and in Vo+ but still causes an increase in Vo-. The same is true in TPTX + PTH rats although all the variables measured are increased. In TPTX rats, both without and with PTH, a linear correlation exists between calcemia and Vo+ suggesting that calcemia influences bone formation. Furthermore, it appears that PTH is important in regulating bone turnover, but that the adaptation of Vo- to a change in Vna can occur in the absence or in the presence of a constant amount of this hormone. The mechanism of regulating this adaptation of bone resorption is still unknown.


2011 ◽  
Vol 26 (S2) ◽  
pp. 1257-1257 ◽  
Author(s):  
S. Masand ◽  
R. Sherwood ◽  
K.J. Aitchison

IntroductionSchizophrenia is a mental health disorder associated with high rates of osteoporosis. Studies have suggested antipsychotics as a major cause of accelerated decrease in bone mineral density.Oestrogen deficiency contributes to osteoporosis and causes increased osteoclast numbers/osteoclastic activity. Prolactin suppresses hypothalamo-pituitary-ovarian axis activity, leading to decreased oestrogen concentrations.Aripiprazole, an ‘atypical’ antipsychotic, is a partial agonist at dopamine D2-receptors, while other atypical antipsychotics are antagonists at these receptors. Dopamine inhibits prolactin release via these receptors at the anterior pituitary. Aripiprazole has been found to decrease prolactin concentrations in chronic schizophrenics and may be protective against osteoporosis.Quantitation of specific markers of osteoclastic (cross-linked N-telopeptide (NTX)) and osteoblastic activity (bone alkaline phosphatase (BAP)) can be correlated with bone resorption and bone formation, respectively.ObjectivesExploring whether aripiprazole is effective in stabilising bone turnover.AimsInvestigate changes in urinary markers of bone turnover.MethodsWe performed 52 week, open-label, intention-to-treat study, offering either a switch to aripiprazole or aripiprazole as add-on to initial antipsychotic medication.Serial measurements of prolactin, testosterone, 17-β-oestradiol, serum BAP, albumin, urinary creatinine, and urinary NTX concentrations were taken between 0 and 52 weeks.ResultsAt the end-point of study, versus the baseline, there were significant decreases in concentrations of urinary markers of bone resorption (P = 0.002 for NTX) and bone formation (P = .026 for BAP). Additionally, a significant decrease in prolactin (P = 0.004) and significant increase in 17-β-oestradiol concentrations (P = 0.015) were found.ConclusionsOur results show decreased overall bone turnover; and increased long-term bone stability in patients who changed medication.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Avinash M. Yadav ◽  
Manali M. Bagade ◽  
Soni Ghumnani ◽  
Sujatha Raman ◽  
Bhaskar Saha ◽  
...  

Abstract Bone metabolism is essential for maintaining bone mineral density and bone strength through a balance between bone formation and bone resorption. Bone formation is associated with osteoblast activity whereas bone resorption is linked to osteoclast differentiation. Osteoblast progenitors give rise to the formation of mature osteoblasts whereas monocytes are the precursors for multi-nucleated osteoclasts. Chronic inflammation, auto-inflammation, hormonal changes or adiposity have the potential to disturb the balance between bone formation and bone loss. Several plant-derived components are described to modulate bone metabolism and alleviate osteoporosis by enhancing bone formation and inhibiting bone resorption. The plant-derived naphthoquinone plumbagin is a bioactive compound that can be isolated from the roots of the Plumbago genus. It has been used as traditional medicine for treating infectious diseases, rheumatoid arthritis and dermatological diseases. Reportedly, plumbagin exerts its biological activities primarily through induction of reactive oxygen species and triggers osteoblast-mediated bone formation. It is plausible that plumbagin’s reciprocal actions – inhibiting or inducing death in osteoclasts but promoting survival or growth of osteoblasts – are a function of the synergy with bone-metabolizing hormones calcitonin, Parathormone and vitamin D. Herein, we develop a framework for plausible molecular modus operandi of plumbagin in bone metabolism.


2019 ◽  
Vol 10 (9) ◽  
Author(s):  
Wenxiang Chen ◽  
Ziang Xie ◽  
Pan Tang ◽  
Yongli Wang ◽  
Zhiwei Jie ◽  
...  

Abstract Osteoporosis is caused by an imbalance between bone formation and bone resorption. Receptor activator of nuclear factor-κB ligand (RANKL) promotes the activity and differentiation of osteoclasts via activating the nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways. IMD 0354 is a selective molecular inhibitor of inhibitor of NF-κB kinase subunit beta (IKKβ) and effective for treatment of acute and subacute inflammatory diseases through the suppression of NF-κB activation. However, the effect of IMD 0354 on bone homeostasis is unknown. In this study, we demonstrated that IMD 0354 significantly attenuated ovariectomy-induced bone loss and inhibited osteoclastogenesis in mice, whereas bone formation was not affected. Additionally, IMD 0354 dramatically inhibited osteoclast differentiation and function induced by RANKL and macrophage colony-stimulating factor in bone marrow monocytes as verified by tartrate-resistant acid phosphatase (TRAP) staining as well as bone resorption assay in vitro. Subsequently, we found that activation of NF-κB signaling and the ERK/c-Fos axis were blunted during osteoclast formation induced by RANKL. Transcription factors nuclear factor of activated T cells c1 (NFATc1) and c-Fos were suppressed with the decreased expression of osteoclast-related genes by IMD 0354. Our findings suggest that IMD 0354 could be a potential preventive and therapeutic drug for osteoporosis.


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