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International Journal of Molecular... Aug 2024The ubiquitin (Ub)‑proteasome system (UPS) plays a pivotal role in maintaining protein homeostasis and function to modulate various cellular processes including... (Review)
Review
The ubiquitin (Ub)‑proteasome system (UPS) plays a pivotal role in maintaining protein homeostasis and function to modulate various cellular processes including skeletal cell differentiation and bone homeostasis. The Ub ligase E3 promotes the transfer of Ub to the target protein, especially transcription factors, to regulate the proliferation, differentiation and survival of bone cells, as well as bone formation. In turn, the deubiquitinating enzyme removes Ub from modified substrate proteins to orchestrate bone remodeling. As a result of abnormal regulation of ubiquitination, bone cell differentiation exhibits disorder and then bone homeostasis is affected, consequently leading to osteoporosis. The present review discussed the role and mechanism of UPS in bone remodeling. However, the specific mechanism of UPS in the process of bone remodeling is still not fully understood and further research is required. The study of the mechanism of action of UPS can provide new ideas and methods for the prevention and treatment of osteoporosis. In addition, the most commonly used osteoporosis drugs that target ubiquitination processes in the clinic are discussed in the current review.
Topics: Humans; Osteoporosis; Ubiquitination; Animals; Ubiquitin; Proteasome Endopeptidase Complex; Bone Remodeling; Ubiquitin-Protein Ligases
PubMed: 38940355
DOI: 10.3892/ijmm.2024.5392 -
Frontiers in Pharmacology 2024Although caffeine generally offers benefits to human health, its impact on bone metabolism remains unclear. This study aimed to systematically evaluate the long-term...
Although caffeine generally offers benefits to human health, its impact on bone metabolism remains unclear. This study aimed to systematically evaluate the long-term effects of caffeine administration on osteoclasts, osteoblasts, and ovariectomy-induced postmenopausal osteoporosis (OP). Our findings revealed that 3.125 and 12.5 μg/mL caffeine inhibited RANKL-mediated osteoclastogenesis in RAW 264.7 cells through the MAPK and NF-κB pathways, accompanied by the inactivation of nuclear translocation of nuclear factor NFATc1. Similarly, 3.125 and 12.5 μg/mL of caffeine modulated MC3T3-E1 osteogenesis via the AKT, MAPK, and NF-κB pathways. However, 50 μg/mL of caffeine promoted the phosphorylation of IκBα, P65, JNK, P38, and AKT, followed by the activation of NFATc1 and the inactivation of Runx2 and Osterix, ultimately disrupting the balance between osteoblastogenesis and osteoclastogenesis. studies showed that gavage with 55.44 mg/kg caffeine inhibited osteoclastogenesis, promoted osteogenesis, and ameliorated bone loss in ovariectomized mice. Conversely, long-term intake of high-dose caffeine (110.88 mg/kg) disrupted osteogenesis activity and promoted osteoclastogenesis, thereby disturbing bone homeostasis. Collectively, these findings suggest that a moderate caffeine intake (approximately 400 mg in humans) can regulate bone homeostasis by influencing both osteoclasts and osteoblasts. However, long-term high-dose caffeine consumption (approximately 800 mg in humans) could have detrimental effects on the skeletal system.
PubMed: 38939843
DOI: 10.3389/fphar.2024.1405173 -
JBMR Plus Jul 2024Raloxifene increases lumbar spine bone mineral density (BMD) and lowers vertebral fracture risk in patients with osteoporosis. However, few prospective clinical trials... (Clinical Trial)
Clinical Trial
A randomized controlled trial of the effect of raloxifene plus cholecalciferol versus cholecalciferol alone on bone mineral density in postmenopausal women with osteopenia.
Raloxifene increases lumbar spine bone mineral density (BMD) and lowers vertebral fracture risk in patients with osteoporosis. However, few prospective clinical trials have studied its efficacy in postmenopausal women with osteopenia. This study investigated the efficacy of raloxifene in postmenopausal women with osteopenia. An investigator-initiated, randomized, open-label, prospective, single-center trial was conducted in 112 postmenopausal women with osteopenia. Osteopenia was defined based on the lowest BMD T-score in the lumbar spine, femoral neck, or total hip (-2.5 < lowest T-score < -1.0). Participants were randomly assigned to receive raloxifene 60 mg/day plus cholecalciferol 800 IU/day (RalD) or cholecalciferol 800 IU/day (VitD) for 48 wk. At baseline, mean age (63.1 ± 6.8 yr) did not differ between the two groups. However, in the RalD group, mean body mass index (BMI) and baseline T-score were lower, while 25-hydroxyvitamin D level was higher. At 48 wk, the RalD group showed a greater increase in lumbar spine BMD (RalD vs. VitD; 2.6% vs. -0.6%, =.005) and attenuated the total hip BMD loss (-0.3% vs. -2.9%, = .003). The effect of raloxifene on the lumbar spine remained significant after adjustment for age, BMI, baseline BMD T-score, and other covariates (adjusted β: +3.05 vs. VitD, =.015). In subgroup analysis, the difference in lumbar spine BMD between the RalD and VitD groups was robust in those with severe osteopenia group (lowest T-score ≤ -2.0). Raloxifene plus cholecalciferol significantly improved lumbar spine BMD and attenuated total hip BMD loss compared with cholecalciferol alone, with a more robust effect in severe osteopenia. : The trial was registered with ClinicalTrials.gov (NCT05386784).
PubMed: 38939828
DOI: 10.1093/jbmrpl/ziae073 -
JBMR Plus Jul 2024Previous studies have demonstrated that the administration of zoledronic acid (ZOL) once yearly for 3 years or once over 3 years, yields similar antifracture efficacy....
Previous studies have demonstrated that the administration of zoledronic acid (ZOL) once yearly for 3 years or once over 3 years, yields similar antifracture efficacy. Bone turnover markers can predict the antifracture efficacy of antiresorptive agents, with procollagen type 1 N-terminal propeptide (P1NP) being the most useful marker. In this retrospective cohort study, we explored the effects of intravenous dosing of ZOL guided by serum (S)-P1NP assessment on bone mineral density (BMD) and fractures. Consenting patients ( = 202, mean age 68.2 years) with osteoporosis were treated with ZOL for an average of 4.4 (range 2-8) years. S-P1NP and BMD were measured at baseline and every 1-2 years. We assessed the number of subsequent vertebral and nonvertebral fractures in the 2-year time periods. The number of patients assessed was 202, 147, 69, and 29 at years 1-2, 3-4, 5-6, and 7-8, respectively. A new ZOL infusion was given if S-P1NP exhibited values above 35 μg/L. BMD increased by 6.2% (SD 4.0) over the first 2 years and stabilized in years 2-8 ( <.05). Median S-P1NP exhibited an initial reduction from 58.0 to 31.3 μg/L at year 2 and then increased to 39.0 μg/L at years 7-8. Compared with fractures observed in the last 2 years before baseline, fracture rates exhibited consistent reductions, for vertebral fractures odds ratio (OR) [95% confidence interval] = 0.61 [0.47, 0.80], <.001 and for nonvertebral fractures OR = 0.23 [0.18, 0.31], <.001. In conclusion, intermittent dosing of intravenous ZOL based on the assessment of S-P1NP with cut-off at 35 μg/L resulted in an initial increase followed by a stable BMD, suppression of S-P1NP, and stable reduction of fractures for 8 years. Only 39% of patients needed more than one infusion. This approach reduces healthcare costs and might also reduce the risk of rare side effects such as osteonecrosis of the jaw and atypical femoral fracture.
PubMed: 38939827
DOI: 10.1093/jbmrpl/ziae072 -
JACC. Advances Jan 2024In patients with chronic kidney disease (CKD), fibroblast growth factor (FGF)-23 is suspected to cause death or cardiovascular disease by inducing left ventricular...
BACKGROUND
In patients with chronic kidney disease (CKD), fibroblast growth factor (FGF)-23 is suspected to cause death or cardiovascular disease by inducing left ventricular hypertrophy (LVH).
OBJECTIVES
This study aims to quantify the mediational effect of LVH in the hypothetical causal pathway from FGF-23 to long-term adverse outcomes.
METHODS
From 3,939 adults with CKD stages 2 to 4 enrolled in the CRIC (Chronic Renal Insufficiency Cohort) study, 2,368 participants with available data of FGF-23, left ventricular mass index at 1 year, and covariates were included. We employed linear and Cox proportional hazards regression models to investigate the association between FGF-23 and LVH, all-cause mortality, atrial fibrillation (AF), or congestive heart failure (CHF). Mediation analysis was used within a counterfactual framework to decompose the effect of FGF-23 into natural direct and indirect effects.
RESULTS
Among 2,368 participants (mean age: 57.7 years, 1,252 males, median FGF-23 level: 138.8 RU/mL), left ventricular mass index was positively correlated with FGF-23. During a median of 12.0, 11.1, and 11.1 years, FGF-23 was associated with all-cause mortality (HR: 1.62, 95% CI: 1.24-2.12), AF (HR: 1.58, 95% CI: 1.12-2.24), and CHF (HR: 1.32, 95% CI: 0.95-1.84) when the highest quartile was compared to the lowest quartile. LVH mediated 7.4%, 11.2%, and 21.9% of the effect of FGF-23 on all-cause mortality, AF, and CHF, respectively.
CONCLUSIONS
In CKD patients, FGF-23 had a minor effect on the development of long-term adverse outcomes through LVH. Other potential mediators and the validity of negative effect of FGF-23 should be explored.
PubMed: 38939808
DOI: 10.1016/j.jacadv.2023.100747 -
Bone Reports Jun 2024This study aimed to analyze the current medication treatment status for women with osteoporosis (OP) based on real-world prescription data from 2016 to 2021 in Chinese...
PURPOSE
This study aimed to analyze the current medication treatment status for women with osteoporosis (OP) based on real-world prescription data from 2016 to 2021 in Chinese nine cities' tertiary Grade A hospital and systematically describe the medication treatment patterns in women with OP.
METHODS
Prescription information for female OP patients in nine cities (Beijing, Shanghai, Guangzhou, Hangzhou, Tianjin, Zhengzhou, Chengdu, Shenyang, Harbin) was extracted from the Hospital Prescription Analysis Collaboration Project Database of the Hospital Pharmacy Professional Committee of the Chinese Pharmaceutical Association. Statistical analysis was conducted to evaluate demographic characteristics and medication treatment patterns.
RESULTS
A total of 669,505 prescriptions for medication treatment of female OP patients were included in this study. The majority of patients were aged 60 to 99 years (69.79 %) followed by 50 to 59 years (18.81 %) and 40 to 49 years (6.69 %). Geographically, the highest concentration of patients was in North China (Beijing, Tianjin) (43.05 %) followed by East China (Shanghai, Hangzhou) (31.43 %). The top three prescribed medications were active vitamin D and its analogs (40.78 %), calcium supplements (32.51 %), and bisphosphonates (18.75 %). The prescription frequency of menopausal hormone therapy (MHT) was 0.31 %. The proportion of female OP patients receiving monotherapy and two drug combinations therapy is equivalent (about 37 %).
CONCLUSION
The diagnosis and treatment of female OP patients in China showed regional variations. The most commonly prescribed medications for this population were calcitriol, calcium carbonate with vitamin D3, and alendronate sodium with vitamin D3. The use of MHT was relatively limited.
PubMed: 38939472
DOI: 10.1016/j.bonr.2024.101778 -
Frontiers in Endocrinology 2024Retrospective radiological analysis.
STUDY DESIGN
Retrospective radiological analysis.
OBJECTIVE
The aim of this study is to evaluate the distribution of bone mineral density (BMD) in lumbar vertebrae using the Hounsfield unit (HU) measurement method and investigate the clinical implications of HU values for assessing lumbar vertebrae BMD.
METHOD
Two hundred and ninety-six patients were retrospectively reviewed and divided into six groups according to age: Group 1(20-29 years old), Group 2 (30-39 years old), Group 3 (40-49 years old), Group 4 (50-59 years old), Group 5 (60-69 years old), Group 6 (70-79 years old). Six different locations from each vertebra of L1-L5 were selected as regions of interest: the anterior, middle and posterior parts of the upper and lower slices of the vertebrae. HU values were measured for the six regions of interest, followed by statistical analysis.
RESULTS
The HU values of vertebrae showed a decreasing trend from young patients to elderly patients in Group 1 to Group 5. There was no significant difference in HU values among different vertebrae in the same age group. In all age groups, the HU values of the anterior and posterior part of the vertebral body were significantly different from L1 to L3, with the anterior part of the vertebral body having lower HU values than the posterior part. The HU values of the anterior and posterior part of the vertebral body of L4 and L5 were statistically significant only in Group 5 and Group 6, and the HU values of the anterior part of the vertebral body were lower than those of the posterior part. The HU values of posterior part of L4 and L5 in Group6 were higher than those in Group5.
CONCLUSION
Bone mineral density in the lumbar vertebrae is not uniformly distributed, potentially attributed to varying stress stimuli. The assessment of local HU values in the lumbar spine is of significant importance for surgical treatment.
Topics: Humans; Lumbar Vertebrae; Bone Density; Middle Aged; Female; Male; Retrospective Studies; Adult; Aged; Young Adult; Tomography, X-Ray Computed; Osteoporosis; Absorptiometry, Photon
PubMed: 38938515
DOI: 10.3389/fendo.2024.1398367 -
Revue Medicale Suisse Jun 2024The aim of this article is to draw attention to sex- and gender-related differences in the management of elderly patients. This issue is illustrated with two diseases...
The aim of this article is to draw attention to sex- and gender-related differences in the management of elderly patients. This issue is illustrated with two diseases linked to gender and sex: osteoporosis and high blood pressure. On one hand, patients of the sex less affected by the disease may feel less concerned; on the other hand, these patients are at greater risk of being under-diagnosed by medical and nursing staff. In addition, studies tend to overlook patients of the less-affected sex, resulting in guidelines that do not take account of sex or gender specific characteristics. There is even less literature on gender-related disparities in care in the elderly population than in the young, but it can be assumed that this risk of disparities exists even more in relation to specificities in diagnosis and care of elderly patients.
Topics: Humans; Aged; Female; Sexism; Male; Osteoporosis; Hypertension; Age Factors; Healthcare Disparities; Sex Factors
PubMed: 38938133
DOI: 10.53738/REVMED.2024.20.880.1243 -
European Journal of Endocrinology Jun 2024Osteoanabolic agents are used as a first line treatment in patients at high fracture risk. The PTH receptor 1 (PTH1R) agonists teriparatide (TPTD) and abaloparatide...
Osteoanabolic agents are used as a first line treatment in patients at high fracture risk. The PTH receptor 1 (PTH1R) agonists teriparatide (TPTD) and abaloparatide (ABL) increase bone formation, bone mineral density (BMD), and bone strength by activating PTH receptors on osteoblasts. Romosozumab (ROMO), a humanized monoclonal antibody against sclerostin, dramatically but transiently stimulates bone formation and persistently reduces bone resorption. Osteoanabolic agents increase BMD and bone strength while being more effective than antiresorptives in reducing fracture risk in postmenopausal women. However, direct comparisons of the antifracture benefits of osteoanabolic therapies are limited. In a direct comparison of TPTD and ABL, the latter resulted in greater BMD increases at the hip. While no differences in vertebral or non-vertebral fracture risk were observed between the two drugs, ABL led to a greater reduction of major osteoporotic fractures. Adverse event profiles were similar between the two agents except for hypercalcemia, which occurred more often with TPTD. No direct comparisons of fracture risk reduction between ROMO and the PTH1R agonists exist. Individual studies have shown greater increases in BMD and bone strength with ROMO compared to TPTD in treatment-naïve women and in women previously treated with bisphosphonates. Some safety aspects, such as a history of tumor precluding the use of PTH1R agonists, and a history of major cardiovascular events precluding the use of ROMO, should also be considered when choosing between these agents. Lastly, convenience of administration, reimbursement by national health systems and length of clinical experience may influence patient choice.
PubMed: 38938063
DOI: 10.1093/ejendo/lvae076 -
Cell Biology International Jun 2024Type 2 diabetic osteoporosis (T2DOP) is a skeletal metabolic syndrome characterized by impaired bone remodeling due to type 2 diabetes mellitus, and there are drawbacks...
Type 2 diabetic osteoporosis (T2DOP) is a skeletal metabolic syndrome characterized by impaired bone remodeling due to type 2 diabetes mellitus, and there are drawbacks in the present treatment. Osteoking (OK) is widely used for treating fractures and femoral head necrosis. However, OK is seldom reported in the field of T2DOP, and its role and mechanism of action need to be elucidated. Consequently, this study investigated whether OK improves bone remodeling and the mechanisms of diabetes-induced injury. We used db/db mice as a T2DOP model and stimulated MC3T3-E1 cells (osteoblast cell line) with high glucose (HG, 50 mM) and advanced glycation end products (AGEs, 100 µg/mL), respectively. The effect of OK on T2DOP was assessed using a combined 3-point mechanical bending test, hematoxylin and eosin staining, and enzyme-linked immunosorbent assay. The effect of OK on enhancing MC3T3-E1 cell differentiation and mineralization under HG and AGEs conditions was assessed by an alkaline phosphatase activity assay and alizarin red S staining. The AGEs/insulin-like growth factor-1(IGF-1)/β-catenin/osteoprotegerin (OPG) pathway-associated protein levels were assayed by western blot analysis and immunohistochemical staining. We found that OK reduced hyperglycemia, attenuated bone damage, repaired bone remodeling, increased tibial and femoral IGF-1, β-catenin, and OPG expression, and decreased receptor activator of nuclear kappa B ligand and receptor activator of nuclear kappa B expression in db/db mice. Moreover, OK promoted the differentiation and mineralization of MC3T3-E1 cells under HG and AGEs conditions, respectively, and regulated the levels of AGEs/IGF-1/β-catenin/OPG pathway-associated proteins. In conclusion, our results suggest that OK may lower blood glucose, alleviate bone damage, and attenuate T2DOP, in part through activation of the AGEs/IGF-1/β-catenin/OPG pathway.
PubMed: 38937979
DOI: 10.1002/cbin.12215