Prevent Bone Loss Research Articles

OR13-05 Longitudinal Changes In Bone Turnover Following Withdrawal Of RANKL Inhibition

Abstract Disclosure: A.S. Kim: None. A. Castro-Martinez: None. V. Taylor: None. J. Center: None. C.M. Girgis: None. P.I. Croucher: None. M.M. Mcdonald: None. Denosumab is an effective osteoporosis treatment, preventing bone loss by inhibiting RANKL. However, stopping denosumab leads to rebound bone mineral density(BMD) loss. This is due to accelerated bone resorption by osteoclasts. Serum bone turnover markers such as P1NP and CTX have been utilised in clinical practice to guide sequential therapy following denosumab discontinuation. However, an optimal strategy has not been established. Understanding the temporal changes in osteoclast activity will guide safe, effective sequential therapy following denosumab discontinuation. We hypothesised that serum TRAP5b, a marker of enzymatic activity of osteoclasts, would be a more useful marker in this context to guide sequential treatment following denosumab discontinuation. Seven-week-old female C57BL/6 mice were treated with 2-weeks of thrice-weekly OPG:Fc(10mg/kg) to inhibit RANKL then withdrawn from therapy (OPG-W) or saline(vehicle). Longitudinal BMD and serum TRAP5b were measured throughout the study. Mice were harvested at weeks 2, 8, 11 and 13 to allow a large volume of serum to be collected to concurrently measure serum TRAP5b and the products of collagen formation and breakdown, serum P1NP and CTX respectively . Following OPG:Fc withdrawal, BMD peaked at week 8 in OPG-W mice (92.94 vs75.09mg/cm2, p<0.0001), started to decline at week 10 and normalised to vehicle levels by week 13. Longitudinally, serum TRAP was suppressed by week 2 (0.05 vs 11.90U/L, p<0.0001) and remained suppressed until week 8, following which serum TRAP levels rose progressively to 64% above vehicle levels at week 12 (17.86 vs 10.92U/L, p<0.0001). The rise in TRAP between weeks 8 to 10 preceded the decline in BMD.Serum TRAP was significantly elevated in OPG-W mice at week 11 (15.45 vs 11.46U/L, p=0.01) whereas serum P1NP and CTX remained equivalent to vehicle levels. Serum TRAP, P1NP and CTX were significantly higher in OPG-W mice at week 13 by which time BMD had reached vehicle levels. Our findings show that rebound decline in BMD has already occurred by the time bone turnover markers used in clinical practice (P1NP and CTX) rise above vehicle levels. A significant overshoot in serum TRAP occurs earlier and prior to bone loss and may better inform sequential therapy following denosumab discontinuation. Presentation: Friday, June 16, 2023

SAT668 Can We Treat Osteoporosis, Obesity And Neurodegeneration With A Single FSH-blocking Drug?

Abstract Disclosure: A.R. Pallapati: None. J. Gimenez-Roig: None. S. Rojekar: None. F. Korkmaz: None. D. Sant: None. O. Barak: None. F. Sultana: None. O. Moldavski: None. A. Gumerova: None. H.S. Kannangara: None. U. Cheliadinova: None. C.J. Rosen: None. J.N. Caminis: None. M. Meseck: None. V.E. Demambro: None. S.L. Sims: None. S. Gera: None. R. Witztum: None. S. Miyashita: None. V. Ryu: None. M. Saxena: None. T. Frolinger: None. A. Macdonald: None. S. Kim: None. G. Pevnev: None. D. Lizneva: None. T. Yuen: None. M. Zaidi: None. Pharmacological and genetic studies suggest that FSH is an actionable target for diseases affecting millions, notably osteoporosis, obesity and Alzheimer’s disease (AD). Blocking FSH action prevents bone loss (1, 2), fat accrual (3) and AD-like features in mice (4). We recently developed a first-in-class, humanized, epitope-specific FSH blocking antibody that binds to a 13-amino-acid-long sequence of FSHβ—MS-Hu6—with a KD of 7.52 nM (5). We showed that MS-Hu6 binds specifically to FSHβ, without binding to LH and TSH. For efficacy studies, we have blocked FSH action using either MS-Hu6 or the parent murine antibody, Hf2, targeted to the same epitope. Using our Good Laboratory Practice platform (Code of Federal Regulations, Title 21, Part 58), we report that FSH blockade prevents obesity, osteoporosis and AD in mice. We injected 20-week-old C57BL/6 male mice on a high-fat diet with a range of doses of Hf2 or vehicle s.c. five-days-a-week for 8 weeks. Hf2 (100 µg/mouse/day) reduced the increase in fat mass by 33% starting week 3, with a 7% reduction in in body weight. In separate studies, MS-Hu6 not only caused beiging of white adipose tissue in UCP1-reporter ThermoMice (IVIS imaging), but also improved bone density and microstructure (micro-CT) by elevating bone formation (dynamic histomorphometry). The increase in bone mass and improved microstructure were replicated in Cliff Rosen’s lab using C57BL6 mice 24 weeks post-ovariectomy. Novel Object Recognition testing of AD-prone, ovariectomized 3xTg mice showed a deficit in recognition memory, which was reversed after 8 weeks of Hf2 (100 µg/mouse/day for 5-days-a-week) exposure. Biodistribution studies using 89Zr-labelled, biotinylated or unconjugated MS-Hu6 in mice and monkeys showed localization to bone, bone marrow, fat depots and brain tissue. MS-Hu6 displayed a β phase t½ of 7.5 days in humanized Tg32 mice. In monkeys, an acute single injection of MS-Hu6 did not affect vitals, and biochemical parameters remained within the normative range. We tested 215 variations of excipients using a range of physicochemical techniques, including protein thermal shift, size exclusion chromatography, dynamic light scattering, Fourier-transform infrared spectroscopy, circular dichroism spectroscopy, and differential scanning calorimetry, to yield a formulation with thermal, colloidal, monomeric and structural stability at an ultra-high concentration (100 mg/mL) with acceptable viscosity, clarity and turbidity parameters. MS-Hu6 showed the same “humanness” as human IgG1 in silico and was non-immunogenic in ELISPOT assays for IL-2 and IFNγ in human PBMC cultures. In conclusion, MS-Hu6 is efficacious, durable and manufacturable, and is therefore poised for human testing as a multipurpose therapeutic for obesity, osteoporosis, and perhaps for AD. 1Cell, 2006; 2PNAS, 2018,; 3Nature, 2017; 4Nature, 2022; 5. PNAS, 2020, eLife, 2022. Presentation: Saturday, June 17, 2023

FRI681 OsteoboostTm Is Effective In Preserving Bone Strength And Density Of The Spine In Women With Low Bone Mass

Abstract Disclosure: L.D. Bilek: Grant Recipient; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. L.E. Flores: Employee; Self; Bone Health Technologies. N. Waltman: None. L.R. Mack: None. K. Smith: None. D. Hillstrom: Employee; Self; Bone Health Technologies. M. Griffin: Consulting Fee; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. L. Yecies: Employee; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. M. Jaasma: Consulting Fee; Self; Bone Health Technologies. Stock Owner; Self; Bone Health Technologies. Introduction: Fragility fractures result in significant morbidity and mortality, which is of particular concern in postmenopausal women who are at high risk of fractures due to loss of estrogen. Pharmaceutical interventions are effective but have low uptake and adherence and are generally not indicated for patients with osteopenia. Vibration has the potential to prevent bone loss and holds promise as an effective, yet minimal risk, treatment. The Osteoboost, a novel wearable device delivering targeted vibration to the lumbar spine and hips, is designed to improve bone strength and bone density. Thus, this study aims to evaluate the efficacy of a 12-month intervention with the OsteoboostTM on preserving strength of the first lumbar vertebrae in postmenopausal women with low bone mass. Methods: This double-blinded, randomized controlled trial enrolled postmenopausal women with low bone mass who were not taking bone-active medications. Women had a bone density DXA and assessment of thyroid function to screen for eligibility Those who qualified were randomized to receive Osteoboost treatment 5x/week for 12 months with the belt in either the active or sham setting. The sham device created a sound but did not deliver vibration. Compressive strength (N) and volumetric density of the 1st lumbar vertebra (L1) was analyzed using Finite Element Analysis (FEA) of computed tomography (CT) scans of lumbar spine by ON Diagnostics. Results: 126 women (64 Active, 62 Sham) with low bone mass participated in the study, with an average age of 62.1 years (SD ± 5.8) and 60.6 years (± 5.3) in the Active and Sham groups, respectively. Most participants were of White race (98%) and non-Hispanic (96%). There were no significant differences in baseline demographics between the sham and active groups. Intent to treat analysis revealed no significant difference in percent change in vertebral bone strength between the Active and Sham groups over time (baseline to 12 months). When stratified by age category, significant differences in percent change in vertebral bone strength were present in the 50-60 year old category; the Sham group lost 3.4% of their vertebral bone strength compared to a 0.5% loss in the Active group (p=0.018). While bone was preserved in the active group relative to the sham in the women over 60, it was not significant (p=0.20). With analysis of those who met the compliance criterion of 3x/week, the Sham group lost 2.84% compared to 0.48% in the Active group (p=0.014); representing a 5 times greater loss in the Sham group. Additionally, the Osteoboost treatment preserved volumetric bone density of L1, with the Active treatment group losing 0.29% BMD relative to a 1.97% loss in the Sham group; representing a 6.8 times greater loss in the Sham group (p=0.008). Conclusion: The Osteoboost holds promise as a therapeutic intervention for women with low bone mass to prevent decline to osteoporosis and reduce fracture risk. Presentation: Friday, June 16, 2023

SAT422 Gender Affirming Hormone Therapy in a Non-Binary Individual with Swyer Syndrome

Abstract Disclosure: J.M. Yohannan: None. T. Reisman: None. Background: Swyer syndrome is a rare genetic disorder of sexual development. Patients with Swyer syndrome require physiologic hormone replacement congruent with their gender identity in order to prevent bone loss. It is also important to screen for complications of this condition including osteopenia and dysgerminomas. Clinical Case: A 25 year old individual with a history of Swyer syndrome (46 XY gonadal dysgenesis) presents to clinic to discuss initiation of gender affirming hormone therapy. The patient identifies as non-binary and is interested in starting testosterone for masculinization. The patient was initially diagnosed with Swyer syndrome at age 23 during an evaluation for primary amenorrhea. At that time the patient had a laparoscopic gonadectomy and was found to have a dysgerminoma. Upon diagnosis the patient was started on hormone replacement therapy with norethindrone acetate-ethinyl estradiol 1 - 0.01 mg for bone loss prevention. They had a bone mineral density scan two years prior to presentation that was reportedly normal. To avoid the deleterious effects of hypogonadism they were started on estradiol-norethindrone 0.05 - 0.25 mg patch to provide bone protection. They were also provided testosterone gel for masculinization as part of their gender affirming care. Swyer syndrome is a disorder of sex development in which individuals with XY chromosomes develop phenotypically female Mullerian structures (uterus, fallopian tubes, and vaginal canal). Individuals with Swyer syndrome typically have non-functional “streak gonads” and are diagnosed during evaluation for primary amenorrhea. While some cases may be from a novel mutation, there are case reports showing that the condition can have an autosomal dominant, autosomal recessive, or even X-linked pattern of inheritance depending on the mutated gene. Patients with Swyer syndrome require physiologic doses of hormone replacement for maturation of secondary sex characteristics and bone health. For this patient in particular it is also important to provide appropriate hormone replacement congruent with their gender identity. Additionally, approximately 30% of patients with this condition may develop a gonadal tumor, including dysgerminomas. Because of this, patients frequently have their gonads removed upon diagnosis. Conclusion: Patient’s with Swyer syndrome should be on appropriate hormone replacement as they do not make endogenous sex steroids. Additional consideration of masculinizing hormone replacement should be made for patients that have a gender identity other than cisgender female. It is also important to screen patients for gonadal tumors as there is an increased incidence in this population.

Occlusal Force Maintains Alveolar Bone Homeostasis via Type H Angiogenesis.

Physiologically, teeth and periodontal tissues are exposed to occlusal forces throughout their lifetime. Following occlusal unloading, unbalanced bone remodeling manifests as a net alveolar bone (AB) loss. This phenomenon is termed alveolar bone disuse osteoporosis (ABDO), the underlying mechanism of which remains unclear. Type H vessels, a novel capillary subtype tightly coupled with osteogenesis, reportedly have a role in skeletal remodeling; however, their role in ABDO is not well studied. In the present study, we aimed to explore the pathogenesis of and therapies for ABDO. The study revealed that type H endothelium highly positive for CD31 and endomucin was identified in the periodontal ligament (PDL) but rarely in the AB of the mice. In hypofunctional PDL, the density of type H vasculature and coupled osterix+ (OSX+) osteoprogenitors declined significantly. In addition, the angiogenic factor Slit guidance ligand 3 (SLIT3) was downregulated in the disused PDL, and periodontal injection of the recombinant SLIT3 protein partially ameliorated type H vessel dysfunction and AB loss in ABDO mice. With regard to the molecular mechanism, a mechanosensory signaling circuit, PIEZO1/Ca2+/HIF-1α/SLIT3, was validated by applying cyclic compression to 3-dimensional-cultured PDL cells using the Flexcell FX-5000 compression system. In summary, PDL plays a pivotal role in mechanotransduction by translating physical forces into the intracellular signaling axis PIEZO1/Ca2+/HIF-1α/SLIT3, which promotes type H angiogenesis and OSX+ cell-related osteogenensis, thereby contributing to AB homeostasis. Our findings advance the understanding of PDL in AB disorders. Further therapies targeting SLIT3 may provide new insights into preventing bone loss in ABDO.

Effects of Lactobacillus acidophilus and L. reuteri on bone mass and gut microbiota in ovariectomized mice.

Lactobacillus acidophilusis widely used as a food additive or medication in our daily lives. The objective of this study was to investigate the effects of L. acidophilusand L. reuterion bone mass in OVX mice and their associated mechanisms. Fifty 6-week-old female C57BL/6J mice were subjected to five different treatments: sham surgery, OVX surgery, OVXandL. reuterifed, OVXandL. acidophilusfed, OVXandboth L. reuteriandL. acidophilusco-fed, respectively. Serum samples were collected, and IL-1β,IL-6,TNF-α, and OCN levels were determined. The bone volume fraction and trabecular number, trabecular thickness, trabecular separation, and cortical thickness of the mice were analyzed by micro-CT in both femurs. Mice feces were taken for Illumina high-throughput sequencing to analyze the microbial composition and characteristics. After probiotic feeding, the bone volume fraction, the trabecular number, and the trabecular thickness increased, and the trabecular separation decreased in OVX mice. IL-1β, IL-6, and TNF-α in the blood significantly decreased. The observed Chao1 and ACE indexes increased significantly. Changes in intestinal microorganisms occurred in all groups of mice. The change of index in the gut microbes, may indicate that the bone mass of OVX mice is changing.L. acidophilusshares the same role as L. reuteriin preventing bone loss in OVX mice. The mechanism of action may be through inhibition of the activation of inflammatory factors in the osteoclast activation pathway in bone metabolism, modulation of gut microbial diversity, and alteration of the richness of specific microorganisms that lead to attenuation of bone loss.

Bone Mineral Density and Its Determinants: A Systematic Review of Risk Factors and Prevention Strategies

Bone mineral density (BMD) is a measurement of the amount of minerals, primarily calcium and phosphorus, in bone tissue. Factors that can affect BMD include age, gender, genetics, lifestyle factors, and medical conditions. As people age, the density of their bones starts to decline gradually. Due to hormonal changes during menopause, the chance of developing osteoporosis among women is very high. Genetics also play a role in BMD, with some individuals having a higher genetic predisposition to osteoporosis and lower BMD. Physical activity, alcohol consumption, and smoking are some factors associated with BMD. Regular exercise is a protective factor, whereas other two smoking and excessive alcohol are risk factors. It is important to monitor BMD throughout life to identify any potential health concerns and take steps to prevent bone loss. A healthy lifestyle is an important factor that will help maintain sufficient calcium and vitamin D intake and take medication or supplements as directed by a healthcare professional. Regular physical activity such as walking and running can help promote bone health and maintain BMD.

Anti-Siglec-15 Antibody Prevents Marked Bone Loss after Acute Spinal Cord Injury-Induced Immobilization in Rats.

Rapid and extensive sublesional bone loss after spinal cord injury (SCI) is a difficult medical problem that has been refractory to available interventions except the antiresorptive agent denosumab (DMAB). While DMAB has shown some efficacy in inhibiting bone loss, its concurrent inhibition of bone formation limits its use. Sialic acid-binding immunoglobulin-like lectin (Siglec)-15 is expressed on the cell surface of mature osteoclasts. Anti-Siglec-15 antibody (Ab) has been shown to inhibit osteoclast maturation and bone resorption while maintaining osteoblast activity, which is distinct from current antiresorptive agents that inhibit the activity of both osteoclasts and osteoblasts. The goal of the present study is to test a Siglec-15 Ab (NP159) as a new treatment option to prevent bone loss in an acute SCI model. To this end, 4-month-old male Wistar rats underwent complete spinal cord transection and were treated with either vehicle or NP159 at 20 mg/kg once every 2 weeks for 8 weeks. SCI results in significant decreases in bone mineral density (BMD, -18.7%), trabecular bone volume (-43.1%), trabecular connectivity (-59.7%), and bone stiffness (-76.3%) at the distal femur. Treatment with NP159 almost completely prevents the aforementioned deterioration of bone after SCI. Blood and histomorphometric analyses revealed that NP159 is able to greatly inhibit bone resorption while maintaining bone formation after acute SCI. In ex vivo cultures of bone marrow cells, NP159 reduces osteoclastogenesis while increasing osteoblastogenesis. In summary, treatment with NP159 almost fully prevents sublesional loss of BMD and metaphysis trabecular bone volume and preserves bone strength in a rat model of acute SCI. Because of its unique ability to reduce osteoclastogenesis and bone resorption while promoting osteoblastogenesis to maintain bone formation, Siglec-15 Ab may hold greater promise as a therapeutic agent, compared with the exclusively antiresorptive or anabolic agents that are currently used, in mitigating the striking bone loss that occurs after SCI or other conditions associated with severe immobilization. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Effect of Baduanjin exercise on primary osteoporosis: study protocol for randomized controlled trial

BackgroundLack of exercise is often a major cause of chronic disease. Osteoporosis (OP) is a chronic disease with multifactorial co-morbidity. Baduanjin (BDJ) exercise may be a powerful tool for modifying risk factors. The aim is to provide more evidence about the effectiveness of BDJ exercise in improving pain and balance ability in patients with OP.MethodsIn the prospective randomized controlled trial, 160 participants will be recruited and randomized to the treatment group (BDJ exercise combined with Calcium carbonate and D3) or the control group (Calcium carbonate and D3) at 1:1 ratio. Participants in the treatment group will receive 24-week BDJ exercise for 30–60 min, 3 times a week, along with Calcium carbonate and D3 at each day, while participants in the control group will receive Calcium carbonate and D3 only. All outcome indicators will be measured at baseline, after the 6th month of treatment and 6th month after the end of treatment. The primary outcomes include pain and balance ability, as measured by the visual analogue scale (VAS) and Berg balance scale (BBS). The secondary outcomes will primarily include bone mineral density (BMD), laboratory tests (including P1NP, β-CTX, MSTN, FDF-23, NPY), the timed “up and go” (TUG) test, the morse fall scale (MFS), the five-times sit-to-stand test (FTSST).DiscussionThe study will hopefully confirm that BDJ exercise, as a non-drug intervention, should be recommended for patients with OP to prevent bone loss, falls and fractures.Trial registrationInternational standard randomized controlled trial number (ISRCTN) registry: ISRCTN76945140 registered on 07/06/2022.

Targeting sulfation-dependent mechanoreciprocity between matrix and osteoblasts to mitigate bone loss.

Sulfation is a widespread modification of biomolecules that has been incompletely explored to date. Through cross-phenotype meta-analysis of bone mineral density in up to 426,824 genotyped human participants along with phenotypic characterization of multiple mutant mouse lines, we identified a causative role for sulfate transporter solute carrier family 26 member A2 (SLC26A2) deficiency in osteoporosis. Ablation of SLC26A2 in osteoblasts caused severe bone loss and accumulation of immature bone cells and elicited peculiar pericellular matrix (PCM) production characterized by undersulfation coupled with decreased stiffness. These altered chemophysical properties of the PCM disrupted the formation of focal adhesions in osteoblasts. Bulk RNA sequencing and functional assays revealed that the mechanoreciprocal inhibition of focal adhesion kinase (FAK) and Yes1-associated transcriptional regulator (YAP)/WW domain containing transcription regulator 1 (TAZ) signaling impinged osteoblast maturation upon SLC26A2 deficiency. Moreover, pharmacological abrogation of the Hippo kinases and forced wheel-running ameliorated SLC26A2-deficient osteoporosis by promoting YAP/TAZ activity. Analysis of mouse single-cell RNA sequencing data suggested coordination among sulfate metabolism, focal adhesion, and YAP/TAZ activity during osteoblast-to-osteocyte transition. In addition to the SLC26A2-deficient setting, altered FAK and YAP/TAZ signaling was also observed in bone cells of ovariectomized mice and patients with osteoporosis, and pharmacological enforcing of YAP/TAZ activity ameliorated bone loss in ovariectomized mice. Collectively, these data unveil a role for sulfation in the developmental mechanoreciprocity between matrix and osteoblasts, which could be leveraged to prevent bone loss.

Women's perspectives regarding osteoporosis, fracture risk, and pharmacologic treatment: a cross-sectional study.

Bisphosphonate medications can prevent the substantial bone loss that occurs during early menopause, but little is known about whether women would accept bisphosphonate treatment at this time in their life, when imminent fracture risk is low. We assessed women's perspectives regarding bone loss, fracture risk, and preventative pharmacotherapy in early menopause. In this cross-sectional study, Canadian women aged ≥ 45years were recruited via Facebook advertisement to complete an electronic survey. Primary outcome was the proportion of early menopausal respondents (≤ 5years since final menstrual period) who were worried about bone loss and fractures. Secondary outcomes were the proportionof early menopausal women willing to accept pharmacologic intervention aimed at preventingeither bone loss or future fractures. We compared responses between early menopausal women and older women (> 5years since final menstrual period). 2033 women responded to the Facebook advertisement, 1195 eligible women (aged: 45 to 89years) started the survey, and 966 completed it. Among early menopausal respondents (N = 98), 38 (42%) were worried about future fractures and 9 of 25 (36%) who had a prior bone mineral density scan were worried about their results. A total of 42 (47%) were willing to start medication to prevent fractures, and 48 (54%) would start medication to prevent bone loss. Responses were comparable between early menopausal women and older women. Menopausal women are concerned about bone loss and fractures. Many women would consider early menopausal pharmacotherapy, with the goals of preserving bone health and lowering their risk of fractures.

Anti-osteoporosis mechanism of resistance exercise in ovariectomized rats based on transcriptome analysis: a pilot study.

Postmenopausal osteoporosis is the main cause of fractures in women.Resistance exercise has a positive effect on bone mineral density in postmenopausal osteoporosis patients, but its mechanism is unclear.The purpose of this study was to explore the mechanism of resistance exercise in improving ovariectomized osteoporotic rats based on the transcriptome sequencing technique. Eighteen female Sprague-Dawley rats were randomly divided into the sham-operated group, the non-exercise group, and the resistance exercise group.The rat model of postmenopausal osteoporosis was established by bilateral ovariectomy.Ten weeks after the operation, the resistance exercise group received 2 weeks of adaptive training, and 12 weeks of resistance exercise began in the 13th week.The rats were trained 5 days per week, in 4 sets of 3 repetitions per day.After the intervention, all rats were sacrificed, and the body weight, bone mineral density, trabecular bone microarchitecture, and bone biomechanics were examined.At the same time, RNA-seq and enrichment analysis of gene ontology and Kyoto Encyclopedia of Genes and Genomes were performed on the left tibias, followed by Elisa and RT-qPCR verification. It had been found that resistance exercise can effectively counteract the weight gain of ovariectomized osteoporotic rats, and has a good effect on bone mineral density and trabecular bone microarchitecture. Enrichment analysis showed that regulation of gene expression and osteoclast differentiation is the most closely related biological process and signaling pathway shared by RE/Ovx and NE/Ovx groups. Our results revealed that resistance exercise can play a role in inhibiting osteoclast activation and preventing the enhancement of osteoclast bone resorption function in ovariectomized osteoporotic rats by inhibiting Fos/Fosb-regulated TRAP activation and relieving Calcr inhibition, which has important application value in preventing bone loss caused by estrogen deficiency.

Ataluren prevented bone loss induced by ovariectomy and aging in mice through the BMP-SMAD signaling pathway

Both estrogen deficiency and aging may lead to osteoporosis. Developing novel drugs for treating osteoporosis is a popular research direction. We screened several potential therapeutic agents through a new deep learning-based efficacy prediction system (DLEPS) using transcriptional profiles for osteoporosis. DLEPS screening led to a potential novel drug examinee, ataluren, for treating osteoporosis. Ataluren significantly reversed bone loss in ovariectomized mice. Next, ataluren significantly increased human bone marrow-derived mesenchymal stem cell (hBMMSC) osteogenic differentiation without cytotoxicity, indicated by the high expression index of osteogenic differentiation genes (OCN , BGLAP, ALP, COL1A, BMP2, RUNX2). Mechanistically, ataluren exerted its function through the BMP-SMAD pathway. Furthermore, it activated SMAD phosphorylation but osteogenic differentiation was attenuated by BMP2-SMAD inhibitors or small interfering RNA of BMP2. Finally, ataluren significantly reversed bone loss in aged mice. In summary, our findings suggest that the DLEPS-screened ataluren may be a therapeutic agent against osteoporosis by aiding hBMMSC osteogenic differentiation.

Association of 25-hydroxyvitamin D levels with lipid profiles in osteoporosis patients: a retrospective cross-sectional study

BackgroundIn the literature, scarce data investigate the link between 25-hydroxyvitamin D (25[OH]D) and blood lipids in the osteoporosis (OP) population. 25(OH)D, as a calcium-regulating hormone, can inhibit the rise of parathyroid hormone, increase bone mineralization to prevent bone loss, enhance muscle strength, improve balance, and prevent falls in the elderly. This retrospective cross-sectional study aimed to investigate the association between serum 25(OH)D levels and lipid profiles in patients with osteoporosis, with the objective of providing insight for appropriate vitamin D supplementation in clinical settings to potentially reduce the incidence of cardiovascular disease, which is known to be a major health concern for individuals with osteoporosis.MethodsThis is a retrospective cross-sectional study from the Affiliated Kunshan Hospital of Jiangsu University, including 2063 OP patients who received biochemical blood analysis of lipids during hospitalization from January 2015 to March 2022. The associations between serum lipids and 25(OH)D levels were examined by multiple linear regression. The dependent variables in the analysis were the concentrations of serum lipoprotein, total cholesterol (TC), triglycerides (TGs), apolipoprotein-A, lipoprotein A, high-density lipoprotein cholesterol and low-density lipoprotein cholesterol (LDL-C). The independent variable was the concentration of blood serum 25(OH)D. At the same time, age, body mass index, sex, time and year of serum analysis, primary diagnosis, hypertension, diabetes, statins usage, beta-C-terminal telopeptide of type I collagen, procollagen type I N-terminal propeptide were covariates. Blood samples were collected in the early morning after the overnight fasting and were analyzed using an automated electrochemiluminescence immunoassay on the LABOSPECT 008AS platform (Hitachi Hi-Tech Co., Ltd., Tokyo, Japan). The generalized additive model was further applied for nonlinear associations. The inception result for smoothing the curve was evaluated by two-piecewise linear regression exemplary.ResultsOur results proved that in the OP patients, the serum 25(OH)D levels were inversely connected with blood TGs concentration, whereas they were positively associated with the HDL, apolipoprotein-A, and lipoprotein A levels. In the meantime, this research also found a nonlinear relationship and threshold effect between serum 25(OH)D and TC, LDL-C. Furthermore, there were positive correlations between the blood serum 25(OH)D levels and the levels of TC and LDL-C when 25(OH)D concentrations ranged from 0 to 10.04 ng/mL. However, this relationship was not present when 25(OH)D levels were higher than 10.04 ng/mL.ConclusionsOur results demonstrated an independent relationship between blood lipids and vitamin D levels in osteoporosis patients. While we cannot establish a causal relationship between the two, our findings suggest that vitamin D may have beneficial effects on both bone health and blood lipid levels, providing a reference for improved protection against cardiovascular disease in this population. Further research, particularly interventional studies, is needed to confirm these associations and investigate their underlying mechanisms.

Lactobacillus Reuteri 6475 Prevents Bone Loss in a Clinically Relevant Oral Model of Glucocorticoid-Induced Osteoporosis in Male CD-1 Mice.

Glucocorticoids (GCs) are commonly used anti-inflammatory medications with significant side effects, including glucocorticoid-induced osteoporosis (GIO). We have previously demonstrated that chronic subcutaneous GC treatment in mice leads to gut barrier dysfunction and trabecular bone loss. We further showed that treating with probiotics or barrier enhancers improves gut barrier function and prevents GIO. The overall goal of this study was to test if probiotics could prevent GC-induced gut barrier dysfunction and bone loss in a clinically relevant oral-GC model of GIO. Eight-week-old male CD-1 mice were treated with vehicle or corticosterone in the drinking water for 4 weeks and administered probiotics Lactobacillus reuteri ATCC 6475 (LR 6475) or VSL#3 thrice weekly via oral gavage. As expected, GC treatment led to significant gut barrier dysfunction (assessed by measuring serum endotoxin levels) and bone loss after 4 weeks. Serum endotoxin levels significantly and negatively correlated with bone volume. Importantly, LR 6475 treatment effectively prevented both GC-induced increase in serum endotoxin and trabecular bone loss. VSL#3 had intermediate results, not differing from either control or GC-treated animals. GC-induced reductions in femur length, cortical thickness, and cortical area were not affected by probiotic treatment. Taken together, these results are the first to demonstrate that LR 6475 effectively prevents the detrimental effects of GC treatment on gut barrier, which correlates with enhanced trabecular bone health in an oral mouse model of GIO. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Hydrogen Sulfide Attenuates Mesenchymal Stem Cell Aging Progress via the Calcineurin-NFAT Signaling Pathway.

Aging is a gradual process that is coupled with a decline in the regenerative capacity of stem cells and a subsequent reduction in tissue function and repair. Hydrogen sulfide (H2S) plays an important role in maintaining the function of stem cells. The present study aimed to investigate the role of H2S in mesenchymal stem cell aging and the underlying mechanism and to provide novel insights into stem cell therapies in elderly people. Bone marrow mesenchymal stem cells (BMMSCs) were isolated from young mice (2 months) and from old mice (12 months). Senescence-associated β-galactosidase (SA-β-Gal) activity, reactive oxygen species (ROS) production, ROS scavenging enzymes, and the expression of cell-cycle-related genes were compared between those young and old BMMSCs. The expression of H2S-producing enzymes and the production of H2S in BMMSCs were examined. In vitro osteogenic differentiation and cell senescence were analyzed in young and old BMMSCs before and after H2S treatment. The underlying mechanism was investigated using calcineurin and NFAT1 inhibitors or a Foxp3 siRNA. Bone volume/tissue volume (BV/TV) of femurs in mice was examined using micro-CT with or without systemic injection of an H2S donor. Here, we found that H2S levels in BMMSCs declined with age. When the generation of H2S was blocked with the CBS inhibitor hydroxylamine and the CSE inhibitor dl-propargylglycine, BMMSCs underwent senescence. The elevation of H2S levels rescued BMMSC function in vitro and prevented bone loss in vivo. Mechanistically, H2S represses cell aging via the calcineurin-NFAT1 signaling pathway.

Interleukin-6 receptor blockade improves bone healing following ischemic osteonecrosis in adolescent mice

ObjectiveJuvenile ischemic osteonecrosis (JIO) of the femoral head is one of the most serious hip disorders causing a permanent deformity of the femoral head in childhood. We recently reported that interleukin 6 (IL-6) is significantly increased in the hip synovial fluid of patients with JIO and that articular chondrocytes are primary source of IL-6. Adolescent JIO is particularly challenging to treat and has poor outcome. This study determined if IL-6 receptor blockade prevents bone loss and improves the bone healing in adolescent JIO. MethodAdolescent mice (12-week-old) surgically induced with JIO were treated with either saline or MR16-1, an IL-6 receptor blocker. ResultsMicro-CT assessment showed significantly increased bone volume (p ​< ​0.001, Cohen's d ​= ​2.0) and trabecular bone thickness (p ​< ​0.001, d ​= ​2.3) after the MR16-1 treatment. Histomorphometric assessment showed significantly increased osteoblast number (p ​< ​0.01, d ​= ​2.3), bone formation rate (p ​< ​0.01, d ​= ​4.3), and mineral apposition rate (p ​< ​0.01, d ​= ​4.1) after the MR16-1 treatment. The number of osteoclasts was unchanged. Histologic assessment showed significantly increased revascularization (p ​< ​0.01) and restoration of the necrotic marrow with new hematopoietic bone marrow (p ​< ​0.01). Vascular endothelial growth factor (VEGF) expression was increased in the revascularized area and the articular cartilage, and in the cultured chondrocytes treated with IL-6 receptor inhibitor. ConclusionIL-6 blockade in adolescent mice with JIO enhanced bone formation and revascularization. The findings suggest IL-6 receptor blocker as a potential medical therapy for adolescent JIO.

A cross-sectional study on Chinese oncology nurses’ knowledge of bone health among cancer patients

ObjectiveTo understand the knowledge status, obstacle factors, and management confidence of oncology nurses on the bone health of cancer patients, and in addition to provide reference for establishing bone health knowledge training system for oncology nurses and guiding them to manage bone health of cancer patients.MethodsA total of 602 nurses engaged in oncology nursing in 6 hospitals in Hebei Province were selected by cluster sampling, and an online anonymous survey was conducted by sending questionnaires to oncology nurses from the Hebei Cancer Prevention and Control Association. The questionnaire was developed by the study team. There are 4 parts, namely general information, nurses’ role and job responsibilities, knowledge of skeletal-related events (SREs) and cancer treatment–induced bone loss (CTIBL), and understanding and confidence in bone health management, for a total of 33 questions.ResultsThirty-seven percent of oncology nurses received training on bone health and other related contents; 40.48% of oncology nurses used domestic and foreign guidelines when managing patients with bone metastases or CTIBL. Only approximately one-third of oncology nurses had confidence in managing the side effects of bone metastases and bone modification drugs and identifying patients at risk of CTIBL and fracture; only 33.04% of oncology nurses believed that weight-bearing exercise can prevent bone loss; less than 50% of oncology nurses believed that aromatase inhibitor therapy, ovarian suppression therapy, androgen deprivation therapy, and low body weight were risk factors for pathological fractures. The reasons that hindered oncology nurses from optimizing the management of patients with bone metastases and understanding the preventive measures and risk factors for bone loss mainly included lack of relevant knowledge training, lack of understanding of effective intervention measures, and lack of training and professionalism of specialized nurses, including insufficient development time and guidelines for clinical nursing practice.ConclusionManagers must continuously improve the training system of oncology nurses, enrich the content of training pertaining to bone health for cancer patients, formulate clinical nursing practice guidelines, and give oncology nurses more time for professional development.

Delayed versus immediate use of zoledronic acid for postmenopausal patients with ER/PR positive early breast cancer who are using adjuvant letrozole.

8 Background: Aromatase inhibitors are the standard adjuvant therapy for postmenopausal women with hormone receptor (HR) positive early breast cancer (EBC). In such patients, a significant reduction in bone density was observed. To stop bone loss, bisphosphonates have a powerful effect on reducing bone resorption and improving the survival of patients with EBC. This study compared potential bone-protection of immediate versus delayed administration of zoledronic acid (ZOL) in patients with EBC receiving adjuvant letrozole. Methods: In a prospective two-arm comparative study, 65 postmenopausal patients with HR+ EBC in whom adjuvant letrozole treatment was initiated (2.5 mg/day for 5 years), we included either (45) immediate ZOL treatment or (20) delayed ZOL treatment (both at 4 mg every 6 months). Patients in the delayed ZOL group received ZOL only for fracture or increased bone pain or developed bone mineral density (BMD)T score = or &lt; -2.0. We aimed to assess the change in lumber spine BMD every 3 months for 24 months for both immediate and delayed arm patients, in addition to evaluating bone pain deterioration and the disease-free survival (DFS). Results: Analysis of data showed significant differences between immediate and delayed arms in the first three BMD measurements with mean values were -1.55± 0.4 vs. -1.9± 0.2, -1.56± 0.3 vs. -2.5± 0.3, and -1.4±0.3 vs. -3.5± 0.3 with p&lt;0.002, 0.001, 0.0001 respectively. Despite ZOL administration in delayed arm patients was initiated 6 months later than immediate arm patients, improvement of BMD was detected in delayed arm later on. The median DFS for immediate and delayed arms were 39± 0.6 months and 21± 0.4 months respectively with p&lt;0.001 in both. Although, in pre-ZOL bone pain scoring, most patients of delayed arm (75%) were found to have a score of 3 compared to 51.1% of immediate arm, significant improvement in bone pain scores in both arms separately after ZOL administration was noted with p-values 0.031, and 0.025 respectively. Conclusions: Immediate ZOL administration prevented bone loss, improved bone pain, and ameliorate DFS in postmenopausal women with HR+ EBC receiving adjuvant letrozole. Clinical trial information: PACTR202112813934276.

Eicosapentaenoic acid supplementation modulates the osteoblast/osteoclast balance in inflammatory environments and protects against estrogen deficiency-induced bone loss in mice

An imbalance of osteoblasts (OBs) and osteoclasts (OCs) in a chronic inflammatory microenvironment is an important pathological factor leading to osteoporosis. Eicosapentaenoic acid (EPA) has been shown to suppress inflammation in macrophages and adipocytes. However, the effect of EPA on OBs and OCs has yet to be fully elucidated. We explored the roles of EPA in the differentiation of OBs and OCs, as well as the coupling between OBs and OCs in an inflammatory microenvironment. The effects of EPA on estrogen deficiency-induced osteoporosis were also evaluated. Mouse bone marrow mesenchymal stem cells (mBMSCs) and mouse bone marrow-derived macrophages (mBMMs) were used for invitro OBs and OCs differentiation. TNF-α was used to create an inflammatory microenvironment. We examined the effects of EPA on osteoblastogenesis in the absence or presence of TNF-α and collect OBs' culture medium as the conditioned medium (CM). Then we examined the effects of EPA and CM on RANKL-induced osteoclastogenesis. The invivo effects of EPA were determined using an ovariectomized (OVX) mouse model treated with EPA or vehicle. High-dose EPA was shown to promote osteoblastogenesis in an inflammatory environment invitro, as well as upregulate expression of OBs-specific proteins and genes. ARS and ALP staining also showed that high-dose EPA-treated groups restored mBMSCs' impaired osteogenic capacity caused by TNFa. Mechanistically, EPA suppressed the NF-κB pathway activated by TNF-α in mBMSCs and rescued TNF-α-mediated inhibition of osteoblastogenesis. EPA was also shown to inhibit expression of RANKL and decrease the RANKL/OPG ratio in OBs in an inflammatory environment. CM from TNF-α-stimulated OBs promoted osteoclastogenesis of mBMMs; EPA-treated CM prevented this. In the OVX mouse model, EPA supplementation prevented bone loss in an estrogen deficiency-induced inflammatory environment. EPA was demonstrated for the first time to restore mBMSCs' impaired osteogenic capacity caused by TNFa-induced inflammation and rescue the OBs/OCs balance via regulation of RANKL and OPG expression in OBs. EPA showed a remarkable ability to prevent bone loss in OVX mice, suggesting a potential application of EPA in postmenopausal osteoporosis.