Levels Of Bone Resorption Markers Research Articles

GCTRP3 inhibits oophorectomy‑induced osteoporosis by activating the AMPK/SIRT1/Nrf2 signaling pathway in mice.

C1q/tumor necrosis factor‑related protein 3 (CTRP3) expression is markedly reduced in the serum of patients with osteoporosis. The present study aimed to investigate whether CTRP3 reduces bone loss in oophorectomy (OVX)‑induced mice via the AMP‑activated protein kinase (AMPK)/sirtuin 1 (SIRT1)/nuclear factor E2‑related factor 2 (Nrf2) signaling pathway. Female C57BL/6J mice and MC3T3‑E1 cells were used to construct in vivo and in vitro models of osteoporosis, respectively. The left femurs of mice were examined using micro‑computed tomography scans and bone‑related quantitative morphological evaluation was performed. Pathological changes and the number of osteoclasts in the left femurs of mice were detected using hematoxylin and eosin, and tartrate‑resistant acid phosphatase (TRAP) staining. Runt‑related transcription factor‑2 (RUNX2) expression in the left femurs was detected using immunofluorescence analysis, and the serum levels of bone resorption markers (C‑telopeptide of type I collagen and TRAP) and bone formation markers [osteocalcin (OCN) and procollagen type 1 N‑terminal propeptide] were detected. In addition, osteoblast differentiation and calcium deposits were examined in MC3T3‑E1 cells using alkaline phosphatase (ALP) and Alizarin red staining, respectively. Moreover, RUNX2, ALP and OCN expression levels were detected using reverse transcription‑quantitative PCR, and the expression levels of proteins associated with the AMPK/SIRT1/Nrf2 signaling pathway were detected using western blot analysis. The results revealed that globular CTRP3 (gCTRP3) alleviated bone loss and promoted bone formation in OVX‑induced mice. gCTRP3 also facilitated the osteogenic differentiation of MC3T3‑E1 cells through the AMPK/SIRT1/Nrf2 signaling pathway. The addition of an AMPK inhibitor (Compound C), SIRT1 inhibitor (EX527) or Nrf2 inhibitor (ML385) reduced the osteogenic differentiation of MC3T3‑E1 cells via inhibition of gCTRP3. In conclusion, gCTRP3 inhibits OVX‑induced osteoporosis by activating the AMPK/SIRT1/Nrf2 signaling pathway.

Contrasting bone profiles in PCOS are related to BMI: a systematic review and meta-analysis.

Controversial results have emerged regarding whether PCOS is protective or increases the risk of bone frailty. This study investigated whether the PCOS condition affects bone parameters of premenopausal women. This is an update for a previous meta-analysis published in 2019. We searched MEDLINE and Embase. Studies were considered eligible for the update if published in English between the 1st of October 2018 and the 31st of December 2023. The diagnosis of PCOS should be based on NIH criteria, the Rotterdam Consensus, AE-PCOS society criteria, or ICD codes in women over 18 years old. Only records with the Newcastle-Ottawa Scale > 6 were selected for data extraction. Data were extracted by two independent reviewers. We identified 31 studies that met the inclusion criteria for qualitative analysis from 3322 studies in the whole period (1990-2023). Overall, cross-sectional studies included 1822 individuals with PCOS and 1374 controls, while cohort studies incorporated 30305 women with PCOS and 101907 controls. Contrasting profiles emerged after stratification using a BMI cutoff of 27 kg/m2. Individuals with PCOS and a BMI <27 kg/m2 exhibited lower vertebral and non-vertebral bone density, reduced bone turnover marker (osteocalcin), and increased bone resorption marker (CTX) levels. Conversely, individuals with PCOS and a BMI >27 kg/m2 exhibited increased vertebral and non-vertebral BMD, with no significant changes in bone formation and resorption markers (except osteocalcin). The findings of this study alert for a low bone mass, low bone formation, and increased bone resorption PCOS with a BMI <27 kg/m2.

Neferine alleviates ovariectomy-induced osteoporosis by enhancing osteogenic differentiation of bone marrow mesenchymal stem cells via regulation of the p38MAPK pathway

ABSTRACT Objective Osteoporosis, a skeletal ailment marked by bone metabolism imbalance and disruption of bone microarchitecture, Neferine, a bisbenzylisoquinoline alkaloid with diverse pharmacological activities, has received limited attention in the context of osteoporosis treatment. Methods We employed a bilateral ovariectomy (OVX) rat model to induce osteoporosis and subsequently administered Neferine treatment for four weeks following successful model establishment. Throughout the modeling and treatment phases, we closely monitored rat body weights. We assessed alterations in bone tissue microstructure through micro-CT, HE staining, and safranin O-fast green staining. Levels of bone formation and resorption markers in serum were evaluated using ELISA assay. Western blot analysis was employed to determine the expression levels of p38MAPK, p-p38MAPK, and bone formation-related genes in bone tissue. We isolated and cultured OVX rat BMSCs (OVX-BMSCs) and induced osteogenic differentiation while simultaneously introducing Neferine and the p38MAPK inhibitor SB203580 for intervention. Results Neferine treatment effectively curbed the rapid weight gain in OVX rats, ameliorated bone loss, and decreased serum levels of TRAP, CTX-I, PINP, and BALP. Most notably, Neferine promoted the expression of bone formation-related factors in bone tissue of OVX rats, while concurrently activating the p38MAPK signaling pathway. In in vitro experiments, Neferine facilitated the expression of bone formation-related factors in OVX-BMSCs, increased the osteogenic differentiation potential of OVX-BMSCs, and activated the p38MAPK signaling pathway. Nevertheless, SB203580 partially reversed Neferine’s promotive effect. Conclusion Neferine can boost the osteoblastic differentiation of BMSCs and alleviate OVX-induced osteoporosis in rats by activating the p38MAPK signaling pathway.

Increased Bone Turnover and Decreased BCMA Levels in Patients with Response to Anti-BCMA CAR T Cell Therapy in Relapsed/Refractory Multiple Myeloma

Introduction For most patients (pts), multiple myeloma (MM) remains an incurable disease. Osteolytic lesions (OL) are present in 80% of pts at diagnosis and skeletal-related events are the most common cause for symptomatic relapse. Hence, myeloma bone disease (MBD) is a major cause of morbidity and mortality especially among pts with relapsed/refractory MM (RRMM). B cell maturation antigen (BCMA) targeted chimeric antigen receptor (CAR) T cells have revolutionized treatment of patients with RRMM. While remission rates are high and pts experience long-standing treatment free intervals after CAR T cell treatment, little is known about its effects on MBD and bone turnover. The latter can be determined in plasma by measuring markers of bone formation and resorption. We aimed to analyze the longitudinal development of bone turnover during and after anti-BCMA CAR T cell treatment in RRMM pts. Methods We analyzed 28 consecutive pts with RRMM who underwent treatment with either Idecabtagene-Vicleucel (n=27) or Ciltacabtagen-Autoleucel (n=1) at our center between December 2021 and February 2023. Median age at infusion was 63 (range 39-75) years. 57% of pts were male. All pts were triple-class exposed, 21% had penta-class refractory disease. Status prior to CAR T cell infusion was complete remission (CR, 11%), partial remission (PR, 21%), very good PR (14%), stable disease (4%), or progressive disease (PD, 50%). The impact of CAR T cell treatment on bone turnover was assessed by collecting plasma samples on the day of T cell apheresis, as well as days (d) 30 and 100 after CAR T cell infusion. Samples were analyzed by ELISA to evaluate plasma levels of bone formation marker Osteocalcin (OCN), bone resorption markers Tartrate-resistant acid phosphatase 5b (TRAcP5b) and fibroblast growth factor 23 (FGF23) as well as BCMA as a marker for the targeted myeloma cells. Median levels were compared between subgroups by Wilcoxon tests. Remission status after CAR T cell therapy was first evaluated at d 30 according to International Myeloma Working Group consensus criteria. Median follow-up was 6 months. Results Of the 28 pts treated with anti-BCMA CAR T cells, 64% achieved at least a PR (responders), while 36% had PD shortly (30 d) after. Within 14 d after infusion, 82% developed a cytokine release syndrome (CRS, °I or II), in 30% of which Tocilizumab was applied. Only 1 pt developed immune effector cell-associated neurotoxicity syndrome. In responders, BCMA levels in plasma decreased significantly between apheresis and d 30 ( P&amp;lt;.01) and between apheresis and d 100 ( P&amp;lt;.01), while pts with PD showed no significant change in BCMA levels at the same timepoints ( P=.6 and P=.8). Furthermore, BCMA levels were significantly higher in pts with PD at d 30 ( P&amp;lt;.01) and d 100 ( P=.02), compared to responders (Figure 1). Regarding bone resorption markers, TRAcP5b levels were significantly increased in responders ( P=.01) but not pts with PD ( P=.56) on d 30 after apheresis. Furthermore, we determined a significant increase of intact FGF23 between apheresis and d 30 ( P&amp;lt;.01) and a subsequent significant decrease of intact FGF23 ( P=.02) between d 30 and d 100 in responders. Since FGF23 and interleukin-6 (IL-6) are physiologically dependent, the observed FGF23 dynamics are likely to be an effect of increasing IL-6 in the context of CRS. Aptly, pts who received Tocilizumab because of full-blown CRS had higher intact FGF23 levels at d 30 ( P=.02) compared to pts without Tocilizumab treatment. The bone formation marker OCN showed a significant increase in responders between apheresis and d 100 ( P=.01), as well as between d30 and d100 ( P=.02), while there were no significant changes in OCN levels over the time in pts with PD (Figure 2). Conclusion Pts responding to treatment with anti-BCMA CAR T cells, showed an increased bone turnover shortly after infusion. The increase of bone resorption marker levels appeared to be a short-term trend and could possibly be related to inflammation and high interleukin levels during the first days after infusion. However, we also saw a steady increase of bone formation marker OCN, which remained significant till d 100 in responders. Our data implies, that response to anti-BCMA CAR T cells is accompanied by increasing bone formation. Further analyses are needed to evaluate, whether this treatment can have positive long-term effects on MBD.

MiR-196b-5p Regulates Osteoblast and Osteoclast Differentiation and Bone Homeostasis by Targeting SEMA3A.

miR-196b-5p plays a role in various malignancies. We have recently reported its function in regulating adipogenesis. However, it remains to be clarified whether and how miR-196b-5p affects bone cells and bone homeostasis. In this study, in vitro functional experiments showed an inhibitory effect of miR-196b-5p on osteoblast differentiation. Mechanistic explorations revealed that miR-196b-5p directly targeted semaphorin 3a (Sema3a) and inhibited Wnt/β-catenin signaling. SEMA3A attenuated the impaired osteogenesis induced by miR-196b-5p. Osteoblast-specific miR-196b transgenic mice showed significant reduction of bone mass. Trabecular osteoblasts were reduced and bone formation was suppressed, whereas osteoclasts, marrow adipocytes, and serum levels of bone resorption markers were increased in the transgenic mice. The osteoblastic progenitor cells from the transgenic mice had decreased SEMA3A levels and exhibited retarded osteogenic differentiation, whereas those marrow osteoclastic progenitors exhibited enhanced osteoclastogenic differentiation. miR-196b-5p and SEMA3A oppositely regulated the expression of receptor activator of nuclear factor-κB ligand and osteoprotegerin. The calvarial osteoblastic cells expressing the transgene promoted osteoclastogenesis, whereas the osteoblasts overexpressing Sema3a inhibited it. Finally, in vivo transfection of miR-196b-5p inhibitor to the marrow reduced ovariectomy-induced bone loss in mice. Our study has identified that miR-196b-5p plays a key role in osteoblast and osteoclast differentiation and regulates bone homeostasis. Inhibition of miR-196b-5p may be beneficial for amelioration of osteoporosis. © 2023 American Society for Bone and Mineral Research (ASBMR).

Increased BMP-Smad signaling does not affect net bone mass in long bones.

Bone morphogenetic proteins (BMPs) have been used for orthopedic and dental application due to their osteoinductive properties; however, substantial numbers of adverse reactions such as heterotopic bone formation, increased bone resorption and greater cancer risk have been reported. Since bone morphogenetic proteins signaling exerts pleiotropic effects on various tissues, it is crucial to understand tissue-specific and context-dependent functions of bone morphogenetic proteins. We previously reported that loss-of-function of bone morphogenetic proteins receptor type IA (BMPR1A) in osteoblasts leads to more bone mass in mice partly due to inhibition of bone resorption, indicating that bone morphogenetic protein signaling in osteoblasts promotes osteoclast function. On the other hand, hemizygous constitutively active (ca) mutations for BMPR1A (caBmpr1a wt/+ ) in osteoblasts result in higher bone morphogenetic protein signaling activity and no overt skeletal changes in adult mice. Here, we further bred mice for heterozygous null for Bmpr1a (Bmpr1a +/- ) and homozygous mutations of caBmpr1a (caBmpr1a +/+ ) crossed with Osterix-Cre transgenic mice to understand how differences in the levels of bone morphogenetic protein signaling activity specifically in osteoblasts contribute to bone phenotype. We found that Bmpr1a +/- , caBmpr1a wt/+ and caBmpr1a +/+ mice at 3months of age showed no overt bone phenotypes in tibiae compared to controls by micro-CT and histological analysis although BMP-Smad signaling is increased in both caBmpr1a wt/+ and caBmpr1a +/+ tibiae and decreased in the Bmpr1a +/- mice compared to controls. Gene expression analysis demonstrated that slightly higher levels of bone formation markers and resorption markers along with levels of bone morphogenetic protein-Smad signaling, however, there was no significant changes in TRAP positive cells in tibiae. These findings suggest that changes in bone morphogenetic protein signaling activity within differentiating osteoblasts does not affect net bone mass in the adult stage, providing insights into the concerns in the clinical setting such as high-dose and unexpected side effects of bone morphogenetic protein application.

Osoblyvosti stanu mineralnoi shchilnosty kistkovoi tkanyny u cholovikiv, khvorykh na ankilozyvnyi spondylit: chastota y kharakter porushen; vmist metabolichnykh pokaznykiv syntezu ta rezorbtsii kistkovoi tkanyny, vitaminu D v syrovattsi krovy; dostovirni chynnyky porushen

Introduction. Decreased bone mineral density (BMD) and the development of osteoporosis are common and poorly understood complications of ankylosing spondylitis (AS). Increased bone turnover and high inflammatory activity are important in the pathophysiology of AS-associated osteoporosis, and markers of bone remodeling are valuable markers for detecting bone loss The aim of the study. To find out the features of the BMD state in men with AS, based on establishing the frequency and nature of BMD violations, determining the content of metabolic indicators of bone tissue synthesis and resorption, vitamin D in blood serum, as well as identifying reliable factors involved in its violations. Materials and methods. The research group consisted of 83 men with AS, with an average age of 40.7 ± 0.8 years and a disease duration of 8.7 ± 0.5 years. Disease activity was determined by the BASDAI, ASDAS-CRB index. Laboratory examination included determination of C-reactive protein (CRP) and markers of bone tissue metabolism and vitamin D. BMD was measured using dual-energy X-ray absorptiometry Results. In men with AS, osteoporosis is found in 33.7 % of people, osteopenic syndrome in 28.9 % of patients, and normal indicators of BMD in 37.4 % of patients. We showed that low bone mass was closely related to the total indicators of the activity of the inflammatory process according to ASDAS, BASDAI and CRP content. In particular, in the group of patients with a very high degree of activity, the share of people with osteoporosis was equal to 78.6 %, and was 1.8 times higher than in the group of patients with moderate activity of AS. Similar patterns were observed for the BASDAI activity index and the pro-inflammatory marker CRP. In men with AS, the processes of bone resorption prevail over the processes of biosynthesis of bone tissue, as indicated by the preserved concentration of synthesis markers (OC, PINP) and the increase of the bone resorption marker (NTx) in blood serum. In addition, in the group of patients with osteoporosis, a high content of NTx was found in every second patient, and the average concentration was 39.0 % higher than in the group with preserved BMD. Loss of bone mass is closely related to a deficiency of vitamin D. Thus, in the group of patients with osteoporosis, in addition to probably low levels of vitamin D, a high proportion of people (57.2 %) with a severe deficiency was found, the insufficient level was in 43% and the optimal level equal to only 29.0 % of people. Conclusions. Patients with AS have a high frequency (62.6 %) of a decrease in BMD, while OP occurs in every third patient. Loss of bone mass depends on the activity of the inflammatory process, high levels of bone resorption markers and vitamin D deficiency.

Comparison of Bisphosphonates Versus Teriparatide in Therapy of the Glucocorticoid-Induced Osteoporosis (GIOP): A Meta-Analysis of Randomized Controlled Trials.

Osteoporosis (OP) is characterized as decreased bone mineral density (BMD) and increased risk of bone fracture. Secondary OP resulting from excess endogenous or exogenous glucocorticoid is defined as glucocorticoid-induced osteoporosis (GIOP). Current therapeutic strategies for GIOP are similar to menopausal osteoporosis, including calcium and vitamin D supplementation, bisphosphonates, and parathyroid hormone (PTH) analogues (teriparatide). Previously, several published meta-analyses compared anti-osteoporotic agents for the menopausal or aging-dependent OP. However, the physiopathologic bone metabolism of GIOP is different. In this study, we investigated the efficacy of BMD enhancement, bone fracture rate and safety of bisphosphonates versus teriparatide in the therapy of GIOP. We searched databases including PubMed, Embase, and the Cochrane Library until Jan 2023, and selected ten random clinical trials (RCT)s that compared the efficacy and/or safety of bisphosphonate versus teriparatide for GIOP patients. Teriparatide therapy increased lumber spinal BMD by 3.96% (95% CI 3.01-4.9%, p<0.00001), 1.23% (95% CI 0.36-2.1%, p=0.006) at total hip, and 1.45% (95% CI 0.31-2.58%, p=0.01) at femoral neck, respectively, compared to bisphosphonates at 18-month therapy for GIOP. Teriparatide also reduced bone fracture especially in vertebral bone (p=0.0001, RR 6.27, 95% CI 2.44-16.07), and increased bone formation and resorption marker levels. There was no difference in the incidence of adverse effects in bisphosphonate and teriparatide groups. Teriparatide showed better performance over bisphosphonate in BMD enhancement, bone fracture reduction, and bone remodeling improvement, without increasing the incidence of adverse effects.

Utility of bone turnover markers in metabolic bone diseases

Bone turnover markers (BTMs) are biochemical indicators that provide information about the rate of bone remodeling, which involves the continuous process of bone formation and bone resorption. BTMs are measured in blood or urine samples and are used in the diagnosis, monitoring, and management of various metabolic bone diseases. They aid in the diagnosis of metabolic bone diseases by providing information about the bone turnover status. Abnormal levels of BTMs can indicate increased bone resorption or decreased bone formation, which are characteristic of certain conditions such as osteoporosis, osteomalacia, or Paget's disease. BTMs can provide insights into the severity of metabolic bone diseases. For example, in osteoporosis, elevated levels of bone resorption markers such as C-terminal telopeptide of type I collagen (CTX) or tartrate-resistant acid phosphatase 5b (TRACP-5b) indicate increased bone breakdown and higher fracture risk. Similarly, low levels of bone formation markers like procollagen type I N-terminal propeptide (PINP) or osteocalcin can indicate reduced bone formation and decreased bone strength. BTMs are valuable tools for assessing the response to treatment in metabolic bone diseases. Changes in BTM levels over time can indicate the effectiveness of interventions such as pharmacotherapy, lifestyle modifications, or surgical interventions. Decreased levels of bone resorption markers or increased levels of bone formation markers suggest a positive response to treatment, whereas persistent abnormal BTM levels may indicate the need for treatment adjustment.It's important to note that BTMs should be interpreted in conjunction with other clinical factors and imaging studies. They provide valuable information about bone turnover dynamics but should not be relied upon as standalone diagnostic or prognostic tools.

Sex Differences in Phosphate Homeostasis: Females Excrete More Phosphate and Calcium After an Oral Phosphate Challenge.

Dietary consumption of phosphate is increasing, and elevated serum phosphate is associated with increased cardiovascular disease (CVD) risk. Sex differences in phosphate homeostasis and response to changes in dietary phosphate intake, which are not captured by clinically measured analytes, may contribute to differences in CVD presentation and bone disease. To assess sex differences in acute phosphate homeostasis in response to a single oral phosphate challenge. Cross-sectional. General community. 78 participants (40-76 years) with measured glomerular filtration rate >60 mL/min/1.73 m2 and no clinically diagnosed CVD and 14 young healthy adults. To elucidate subtle alterations in phosphate homeostasis, we employ an acute challenge whereby the hormonal response, circulating mineral levels, and urinary excretion are assessed following an oral challenge of phosphate. Although both males and females had similar changes in circulating phosphate, calcium, and parathyroid hormone in response to the challenge, females excreted ∼1.9x more phosphate and ∼2.7x more calcium than males, despite not consuming calcium. These sex differences were recapitulated in healthy young adults. This excretion response did not correlate to age, serum phosphate, or estradiol levels. The females with greater excretion of phosphate had higher levels of bone resorption markers compared to formation markers. Taken together, these data identify sex differences in acute phosphate homeostasis, specifically that females may mobilize and excrete endogenous sources of calcium and phosphate in response to oral phosphate compared to males. While high levels of dietary phosphate negatively impact bone, our results suggest that females may incur more risk from these diets.

Preparation of chitosan/sodium lignosulfonate/Ag NPs: A potent and green bio-nanocomposite for the treatment of glucocorticoid induced osteoporosis in rats

• CS/NaLS/Ag NPs have antioxidant potentials. • CS/NaLS/Ag NPs have non-cytotoxicity effects. • The results of the CS/NaLS/Ag NPs have revealed that the recent nanocomposite has been formulated as the best. • The treatment of osteoporosis by CS/NaLS/Ag NPs was proven in the recent study. In this study we report the green synthesis of nontoxic, stable, and small size silver nanoparticle by using chitosan/sodium lignosulfonate hydrogel with capping/reducing ability for the synthesis of CS/NaLS/Ag NPs. The prepared bio-nanocomposite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. It has been established that CS/NaLS/Ag NPs have a spherical shape with a mean diameter from 20 to 30 nm. Administration of CS/NaLS/Ag NPs (5 µg/kg/day, po, for 30 days) and risedronate (20 µg/kg, sc, five times a week for 30 days) following methyl prednisolone sodium succinate (10 mg/kg, sc, thrice a week for 4 weeks) induced osteoporosis in Wistar rats showed an increase in the serum levels of bone mineral content markers and a decrease in serum and urinary levels of bone resorption markers. An incline in strength of femur and tibia was seen particularly with 5 µg/kg of CS/NaLS/Ag NPs. Maintenance of calcium homeostasis, formation of collagen and scavenging of free radicals can plausibly be the mode of action of CS/NaLS/Ag NPs thereby combating osteoporosis induced by glucocorticoids.

Bone regeneration after marginal bone resection in two-stage treatment of chronic long bone infection - a combined histopathological and clinical pilot study

IntroductionIn chronic bone infection, marginal bone resection avoids large and difficult to reconstruct bone defects. However, there is still a lack of knowledge on bone regeneration during chronic bone infection and bone healing capability after marginal bone resection. Therefore, the purpose of this study was to investigate the clinical and histopathological outcomes after marginal bone resection in chronic long bone infection. We hypothesized that there is a regenerative bone healing potential after marginal bone resection that results in an acceptable clinical outcome and improved pathohistological bone healing parameters during treatment. Materials and methodsNine patients were treated for chronic bone infections in a two-stage manner with marginal bone resection of the infected area and the placement of an antibiotic-loaded polymethyl methacrylate (PMMA) spacer at stage one followed by bone reconstruction at stage two combined with systemic antibiotic therapy. Comparable bone samples were harvested at the border region between vital and necrotic bone area during stage one and the identical location during stage two. Control bone samples were harvested from five healthy patients without bone infection. Clinical outcome in terms of infection eradication and bone consolidation were assessed. The phenotypic changes of osteocyte and morphological changes of lacunar-canalicular network were investigated by histological and immunohistochemical staining between the two observation periods. Furthermore, expression levels of major bone formation and resorption markers were investigated by immunohistochemical and tartrate-resistant acid phosphatase (TRAP) staining. ResultsThe clinical results with a follow-up of 12.9 months showed that eight of nine patients (88.9%) achieved bone consolidation after a planned two-stage procedure of marginal resection of necrotic bone and consecutive reconstruction. In four of the nine patients (44.4%), additional marginal debridements after stage two had to be performed. After marginal resection at stage one, the improved bone formation ability at stage two was demonstrated by significantly lower percentage of empty lacunae, significantly more mature osteocytes and higher BMP-2 positive cell density, whereas decreased resorption was indicated by significantly lower osteoclast density and RANKL/OPG ratio. In patients requiring additional debridement compared to patients without additional debridements, a significantly higher percentage of empty lacunae was found at stage one. ConclusionMarginal bone resection combined with local and systemic antibiotic therapy is a feasible treatment option to avoid large bone defects as bone from the marginal resection area seems to have good regenerative potential. Despite a high revision rate of 44.4%, this technique avoids large bone resection and revisions can be done by further marginal debridements.

Effects of prior osteoporosis treatment on the treatment response of romosozumab followed by denosumab in patients with postmenopausal osteoporosis.

To investigate the effects of prior osteoporosis treatment on the response to treatment with romosozumab (ROMO) followed by denosumab (DMAb) in patients with postmenopausal osteoporosis. In this prospective, observational, multicenter study, treatment-naïve patients (Naïve; n = 55) or patients previously treated with bisphosphonates (BP; n = 37), DMAb (DMAb; n = 45) or teriparatide (TPTD; n = 17) (mean age, 74.6years; T-scores of the lumbar spine [LS] - 3.2 and total hip [TH] - 2.6) were switched to ROMO for 12months, followed by DMAb for 12months. Bone mineral density (BMD) and serum bone turnover markers were evaluated for 24months. A BMD increase was observed at 12 and 24months in the following patients: Naïve (18.2% and 22.0%), BP (10.2% and 12.1%), DMAb (6.6% and 9.7%), and TPTD (10.8% and 15.0%) (P < 0.001 between the groups at both 12 and 24months) in LS and Naïve (5.5% and 8.3%), BP (2.9% and 4.1%), DMAb (0.6% and 2.2%), and TPTD (4.3% and 5.4%) (P < 0.01 between the groups at 12months and P < 0.001 at 24months) in TH, respectively. The BMD increase in LS from 12 to 24months was negatively associated with the levels of bone resorption marker at 24months. Incidences of major fragility fractures for the respective groups were as follows: Naïve (5.5%), BP (16.2%), DMAb (11.1%), and TPTD (5.9%). Previous treatment affected the BMD increase of following treatment with ROMO, although it did not affect that of following treatment with DMAb after ROMO.

Design and synthesis of chitosan/agar/Ag NPs: A potent and green bio-nanocomposite for the treatment of glucocorticoid induced osteoporosis in rats

In this work we have demonstrated the green synthesis of stable and mono-dispersed Ag NPs using chitosan/Agar hydrogel having reducing/stabilizing ability avoiding any toxic reagents. Agarose was used as a green reductant for the synthesis of Ag NPs which gets stabilized by chitosan. The in situ prepared Ag NPs@CS/Agar nano bio-composite were characterized by advanced physicochemical techniques like Fourier Transformed Infrared spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-ray spectroscopy (EDX) and X-ray Diffraction (XRD) study. The Ag NPs encapsulated by CS/Agar bio-composite have a spherical shape with a mean diameter from 10 to 15 nm. Towards its bioapplication, the Ag NPs@CS/Agar nano bio-composite was administered by 5 µg/kg/day for 30 days in comparison to methyl prednisolone sodium succinate by 10 mg/kg, sc, thrice a week for 4 weeks over Wistar rats having glucocortcoid induced osteoporosis. This showed a significant increase in the serum levels of bone mineral content markers and a decrease in serum and urinary levels of bone resorption markers. An inclination in strength of femur and tibia was seen particularly with 5 µg/kg of Ag NPs@CS/Agar nano bio-composite. Maintenance of calcium homeostasis, formation of collagen and scavenging of free radicals can be the plausible mode of action of this bio-nanocomposite thereby combating osteoporosis induced by glucocorticoids.

Low bone mass in Noonan syndrome children correlates with decreased muscle mass and low IGF-1 levels.

Although musculoskeletal abnormalities have long been described in patients with Noonan syndrome (NS), only a few studies have investigated the bone status of these patients. The aim of this retrospective observational study was to describe the bone health of children with NS. Thirty-five patients with a genetically confirmed diagnosis of NS were enrolled. We analyzed the axial skeleton (lumbar spine) using dual energy X-ray absorptiometry and the appendicular skeleton (hand) with the BoneXpert system. Bone metabolism markers, including mineral homeostasis parameters, serum 25-hydroxy vitamin D (25-OHD) levels and markers of bone formation and resorption were also reported. Compared to the general population, axial and appendicular bone mass was significantly decreased in children with NS (p<0.0001). Serum 25-OHD levels were low in about half of the patients and were negatively correlated with age (r=-0.52; p<0.0001). Patients with NS exhibited reduced bone formation marker levels and increased bone resorption marker levels (p<0.0001). No gender difference or genotype-phenotype correlations were found for the different bone parameters. Muscle mass and, to a lesser extent, serum insulin-like growth factor 1 (IGF-1) levels were independent predictors of whole-body bone mineral content (p<0.0001 for both parameters; adjusted R2=0.97). In conclusion, bone mass is reduced in children with NS and correlates with decreased muscle mass and low serum IGF-1 levels. These data justify addressing all potential threats to bone health including sufficient calcium and vitamin D intake, regular physical exercise, and hormone replacement therapy.

Mesenchymal Stem Cell-Derived Extracellular Vesicles Inhibit Osteoporosis via MicroRNA-27a-Induced Inhibition of DKK2-Mediated Wnt/β-Catenin Pathway.

Osteoporosis (OP) is a systemic skeletal disease that promotes bone fragility and the risk of fractures. Recent studies have shown the relevance of microRNAs (miRNAs) in the development of OP. This study aimed to evaluate the possible mechanisms of action underlying miR-27a loaded by mesenchymal stem cell (MSC)-derived extracellular vesicles (MSC-EVs) in OP. Serum samples from OP patients and normal controls were collected for miRNA microarray analysis. The expression of filtered miRNA was upregulated in osteoblasts (OB) and osteoclasts (OCs) for biological activity assessment. After developing OP mice using ovariectomy (OVX) and confirming OP, the miR-27a expression level was upregulated in mice by MSC-EV application. Dual-luciferase assays were conducted to validate the relationship between miR-27a and DKK2 expression. The poor expression of miR-27a was observed in patients with OP. miR-27a increased the expression of OB markers, the number of ALP-positive cells, and the number of calcium nodules in OCs. In OVX mice, miR-27a increased bone density, improved bone structure damage recovery, decreased the levels of bone resorption markers, and decreased OC number. miR-27a transmitted by MSC-EVs interacted with DKK2. MSC-EVs exerted the same protective effects as miR-27a on OP, whereas miR-27a inhibitor abolished the attenuating effects of MSC-EVs. In contrast, DKK2 depletion reversed the stimulatory effects of the miR-27a inhibitor on OP. The Wnt/β-catenin pathway was activated upon MSC-EV application and DKK2 silencing and was impaired upon the downregulation of the expression of miR-27a. MSC-EVs are effective in preventing mouse OP. This mechanism is mediated by the miR-27a/DKK2/Wnt/β-catenin signaling pathway.

Beneficial effect of dietary geranylgeraniol on glucose homeostasis and bone microstructure in obese mice is associated with suppression of proinflammation and modification of gut microbiome

Geranylgeraniol (GGOH) is found in edible oils such as olive, linseed, and sunflower oils, which have favorable metabolic effects. However, it is unknown whether these physiological benefits are mediated through the gut microbiome. Thus, the purpose of this study was to test the hypothesis that GGOH supplementation would improve glucose homeostasis and benefit the bone microstructure in obese mice through suppression of inflammation and modification of gut microbiota composition. Thirty-six male C57BL/6J mice were divided into 3 groups: a low-fat diet, a high-fat diet (HFD), and an HFD supplemented with 800 mg GGOH/kg diet (GG) for 14 weeks. Glucose and insulin tolerance tests were measured at baseline and end of study. The concentrations of adipokine cytokines (resistin, leptin, monocyte chemoattractant protein-1, interleukin-6) were measured via ELISA. Bone microarchitecture and quality were measured by micro-CT. Microbiome analysis was performed using 16S rRNA amplicon sequencing on cecal content. Relative to the HFD group, the GG group: (1) improved glucose tolerance and insulin sensitivity; (2) reduced production of pro-inflammatory adipokines, (3) increased serum procollagen I intact N-terminal propeptide (bone formation marker) concentrations, while decreasing serum collagen type 1 cross-linked C-telopeptide (bone resorption marker) levels, and (4) increased stiffness at both femur and LV-4 and cortical thickness at femoral midshaft. Compared to the HFD group, the GG group had an increased abundance of Butyricicoccus pullicaecorum and decreased Dorea longicatena in the cecal microbiome. Collectively, GGOH improves glucose homeostasis and bone microstructure in obese mice, probably via suppression of pro-inflammation and modification of microbiome composition.

MO807CORRELATIONS BETWEEN THE INFLAMMATORY AND THE BIOCHEMICAL BONE PROFILE OF PATIENTS ON HEMODIALYSIS

Abstract Background and Aims End stage kidney disease (ESKD) is associated with a malnutrition-inflammation complex that results in several endocrine, musculoskeletal, and metabolic abnormalities. Despite the known resultant derangements from this process, few studies have evaluated the associations between inflammation and skeletal status in ESKD patients. Our goal is to evaluate correlations between inflammatory and biochemical bone profile within and between dialysis patients and a healthy cohort. Method This analysis is a cross-sectional evaluation of a cohort of 40 dialysis patients and 20 healthy controls. Results Significant differences were found between the dialysis and healthy cohort in biochemical bone profile, inflammatory markers and adipokine levels. Dialysis patients with low vs. high PTH (cutoff 50 pg/mL) had differences in bone turnover markers but no differences in inflammatory or adipokine levels (Table 1). More specifically, bone-specific alkaline phosphatase (BSAP), osteocalcin (OCN) and osteoprotegerin (OPG) were positively correlated with insulin-like growth factors but this correlation was not present after adjustment for parathyroid hormone (PTH) levels. C-terminal cross-linking telopeptide (CTX) positively correlated with IGF1 (p-value 0.02, 95% CI (0.14-1.69)) and with IGFBP3 (p-value 0.007 and 95% CI (0.31- 1.84)) after multivariate adjustment for PTH, albumin and sex. Adiponectin positively correlated with IGFBP3 and this remained significant after adjustment for PTH, albumin and sex (p=0.02). IL6, IL8 and TNF did not correlate with bone turnover markers or with adipokine levels after multivariate adjustments. Conclusion In this cross-sectional study, significant differences were found between the dialysis and healthy cohort in biochemical bone profile, inflammatory markers and adipokine levels. In the dialysis cohort, inflammatory markers did not correlate with bone turnover markers or with adipokine levels in dialysis patients. Dialysis patients with high vs. low PTH (cutoff 50 pg/mL) had higher levels of bone formation and bone resorption markers. Inflammatory and adipokine levels did not differ between those with high vs. low PTH.

Adherence to Nutritional Supplementation Determines Postoperative Vitamin D Status, but Not Levels of Bone Resorption Marker, in Sleeve-Gastrectomy Patients.

Taking advantage of isomeric form of vitamin E in the supplement, adherence to supplement could be evaluated by changes in circulating α- and γ-tocopherol concentrations. Accordingly, effects of supplementation on postoperative nutrition and bone metabolism were studied in terms of adherence. Thirty-eight SG patients were all prescribed a postoperative nutritional supplement containing a low dose of vitamin D (600 IU) and calcium (200 mg). Blood samples were collected prior to (M0) and 6 months after (M6) surgery and concentrations of nutrients and C-terminal telopeptide of type I collage (CTX), a marker of bone resorption, were measured. Adherence and non-adherence were stratified according to change (△, M6-M0) in serum α-tocopherol concentrations (> 0 vs. ≤ 0, respectively). When M0 and M6 were compared, there were significant increases in serum concentrations of 25(OH)D, α-tocopherol and selenium, whereas there were reductions in parathyroid hormone, ferritin, and γ-tocopherol. At M6, the prevalence of vitamin D insufficiency (25(OH)D < 30 ng/mL) and high CTX were 72 and 26%, respectively. When comparison was made between adherence and non-adherence, only △25(OH)D concentrations, but no other nutrients nor postoperative CTX differed. Multiple linear regression demonstrated that postoperative vitamin D status was independently associated with its preoperative concentrations (β = 0.85, p < 0.001) and adherence (β = 0.52, p < 0.05). SG patients' adherence to supplementation, even with a low dose of vitamin D and calcium, determined vitamin D status but not bone resorption marker concentrations, at least within 6 months after surgery.

Lower bone mineral density and higher bone resorption marker levels in premenopausal women with type1 diabetes in Japan.

Aims/IntroductionType 1 diabetes is associated with poorer bone quality. Quantitative ultrasound provides an estimate of bone mineral density (BMD) and can also be used to evaluate bone quality, which is associated with an increased fracture risk in people with type 1 diabetes. The aim of this study was to evaluate the association between menopausal status and a bone turnover marker with heel BMD using quantitative ultrasound in women with type 1 diabetes and age‐ and body mass index‐matched controls.Materials and MethodsA total of 124 individuals recruited in Kyoto and Osaka, Japan – 62 women with type 1 diabetes (mean age 47.2 ± 17.3 years) and 62 age‐, menopausal status‐, sex‐ and body mass index‐matched non‐diabetic control individuals (mean age 47.3 ± 16.3 years) – were enrolled in this study. Heel BMD in the calcaneus was evaluated using ultrasonography (AOS‐100NW, Hitachi‐Aloka Medical, Ltd., Tokyo, Japan). A bone turnover marker was also measured.ResultsThe heel BMD Z‐score was significantly lower in premenopausal women with type 1 diabetes than in the premenopausal control group, but not in postmenopausal women with type 1 diabetes. Levels of tartrate‐resistant acid phosphatase‐5b, a bone resorption marker, were significantly higher in premenopausal women with type 1 diabetes than in the premenopausal control group, but not in postmenopausal women with type 1 diabetes. The whole parathyroid hormone level was significantly lower in both pre‐ and postmenopausal women with type 1 diabetes.ConclusionsLower heel BMD, higher tartrate‐resistant acid phosphatase‐5b level and lower parathyroid hormone were observed in premenopausal women with type 1 diabetes. Premenopausal women with type 1 diabetes require osteoporosis precautions for postmenopause.