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Aujourd'hui, le seul score d'activité développé spécifiquement pour la pseudopolyarthrite rhizomélique est le DAS-PPR. Il s'agit d'un score composite calculé grâce à une somme de cinq différents éléments d'intérêt dans la PPR (raideur matinale, élévation des membres supérieurs, évaluation globale du médecin, évaluation de la douleur du patient et la CRP). Cependant, il présente certaines limites car le taux de CRP n'est pas toujours obtenu lors du suivi, et des traitements tels que les antagonistes de l'IL-6 peuvent normaliser la CRP. Des scores dérivés ont été décrits pour éviter ces biais : VS DAS-PPR, Clin DAS-PPR et DAS-PPR imputé mais la concordance et la corrélation entre ces scores sont inconnues. L'objectif de l'étude est de mesurer la corrélation et la concordance du DAS-PPR et du DAS PPR ESR, du Clin DAS-PPR et du DAS-PPR imputé. L'étude SEMAPHORE (Safety and Efficacy of tocilizumab versus Placebo in Polymyalgia rHeumatica With glucocORticoid dEpendence, SEMAPHORE), un essai de supériorité randomisé en double aveugle, parallèle, contre placebo chez des patients atteints de PPR, a cherché à savoir si le tocilizumab permettait d'obtenir un taux de faible activité de la maladie plus bas, combiné à un effet significatif d'épargne des glucocorticoïdes par rapport à un placebo, après 24 semaines. Le critère d'évaluation primaire était le DAS-PPR et les critères secondaires évaluaient les différents DAS PPR. En utilisant les coefficients de corrélation, les diagrammes de dispersion et les graphiques de Bland Altman, nous avons évalué la concordance et la corrélation entre chaque DAS-PPR sur l'ensemble de la population pour différents seuils (1,5 ; 7 ; 10 ; 17) à chaque visite. Au total, 100 patients ont reçu au moins une dose de tocilizumab (49 patients) ou de placebo (51 patients) et ont été inclus dans les analyses de l'inclusion à la semaine 24. Nous avons trouvé une excellente corrélation entre le DAS-PPR et les autres scores, tout au long de l'étude. Les graphiques de Bland Altman utilisant la DAS-PPR comme référence ont montré que les différences sont faibles quelle que soit sa valeur. Les coefficient de corrélation intraclasse étaient tous supérieurs à 0,9 (Tableau 1). Le coefficient ce correlation κ pour les différents seuils était également élevé entre chaque DAS-PPR. La corrélation entre les différents scores DAS-PPR avec ou sans CRP est excellente, reflétant le faible poids de la CRP dans l'indice composite de référence. Dans les essais cliniques utilisant des médicaments qui ont un impact élevé sur le taux de CRP, le DAS-PPR ou d'autres peuvent être utilisés. [ABSTRACT FROM AUTHOR]

Objective: The C reactive protein polymyalgia rheumatica activity score (CRP-PMR-AS) is a composite index that includes CRP levels and was developed specifically for PMR. As treatments such as interleukin-6 antagonists can normalise CRP levels, the erythrocyte sedimentation rate (ESR) of PMR-AS, the clinical (clin)-PMR-AS and the imputed-CRP (imp-CRP)-PMR-AS have been developed to avoid such bias. Our primary objective was to measure the correlation of these activity scores. Our secondary objective was to evaluate the concordance between different cutoffs of the PMR-ASs., Method: Data from the Safety and Efficacy of tocilizumab versus Placebo in Polymyalgia rHeumatica With glucocORticoid dEpendence (SEMAPHORE) trial, a superiority randomised double-blind placebo-controlled trial, were subjected to post hoc analysis to compare the efficacy of tocilizumab versus placebo in patients with active PMR. The CRP-PMR-AS, ESR-PMR-AS, clin-PMR-AS and imp-CRP-PMR-AS were measured at every visit. The concordance and correlation between these scores were evaluated using kappa correlation coefficients, Bland-Altman correlations, intraclass correlation coefficients (ICCs) and scatter plots., Results: A total of 101 patients were included in the SEMAPHORE trial, and 100 were analysed in this study. The correlation between the PMR-ASs was excellent, as the ICC and kappa were >0.85 from week 4 until week 24 (CRP-PMR-AS ≤10 or >10). Bland-Altman plots revealed that the differences between the CRP-PMR-AS and the other threescores were low. The cut-off values for the clin-PMR-AS were similar to those for the CRP-PMR-AS 86% of the time., Conclusion: The correlation between all the PMR-ASs was excellent, reflecting the low weight of CRP. In clinical trials using drugs that have an impact on CRP, the derived activity scores can be used., Trial Registration Number: NTC02908217., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Teriparatide (PTH (1-34)), PTHrP (1-36), and abaloparatide (ABL) have been used for the treatment of osteoporosis, but their efficacy long term is significantly limited. The 3 peptides exert time- and dose-dependent differential responses in osteoblasts, leading us to hypothesize they may also differentially modulate the osteoblast transcriptome. Treatment of mouse calvarial osteoblasts with 1 nM of the peptides for 4 hours results in RNA sequencing data with PTH (1-34) regulating 367 genes, including 194 unique genes; PTHrP (1-36) regulating 117 genes, including 15 unique genes; and ABL regulating 179 genes, including 20 unique genes. There were 83 genes shared among all 3 peptides. Gene ontology analyses showed similarities in Wnt signaling, cAMP-mediated signaling, ossification, but differences in morphogenesis of a branching structure in biological processes; receptor ligand activity, transcription factor activity, and cytokine receptor/binding activity in molecular functions. The peptides increased Vdr , Cited1 , and Pde10a messenger RNAs (mRNAs) in a pattern similar to Rankl , that is, PTH (1-34) greater than ABL greater than PTHrP (1-36). mRNA abundance of other genes, including Wnt4 , Wnt7 , Wnt11 , Sfrp4 , Dkk1 , Kcnk10 , Hdac4 , Epn3 , Tcf7 , Crem , Fzd5 , Ppp2r2a , and Dvl3 , showed that some genes were regulated similarly by all 3 peptides; others were not. Finally, small interfering RNA knockdowns of SIK1/2/3 and CRTC1/2/3 in PTH (1-34)-treated cells revealed that Vdr and Wnt4 genes are regulated by salt-inducible kinases (SIKs) and CREB-regulated transcriptional coactivators (CRTCs), while others are not. Although many studies have examined PTH signaling in the osteoblast/osteocyte, ours is the first to compare the global effects of these peptides on the osteoblast transcriptome or to analyze the roles of the SIKs and CRTCs., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Endocrine Society.)

Background: Medium-dose glucocorticoids can improve symptoms in nearly all patients with polymyalgia rheumatica. According to its good safety profile, abatacept could be used instead of glucocorticoids in early polymyalgia rheumatica. We aimed to determine whether the efficacy of abatacept is sufficient to justify larger studies in early polymyalgia rheumatica., Methods: To evaluate whether abatacept allows low disease activity without glucocorticoids in early polymyalgia rheumatica, we conducted a proof-of-concept, randomised, double-blind, placebo-controlled, parallel-group trial. Participants were recruited from five centres in France (in Brest, Le Mans, Morlaix, Dinan and Saint Malo, and Strasbourg) and were included if they had recent-onset (<6 months) polymyalgia rheumatica with a C-reactive protein (CRP) polymyalgia rheumatica activity score (PMR-AS) of more than 17 without any signs or symptoms of giant cell arteritis (clinical and [ 18 F]fluorodeoxyglucose PET-CT evaluation). Participants were randomly assigned (1:1) to receive weekly subcutaneous abatacept (125 mg) or matching placebo, with glucocorticoid rescue therapy allowed in cases of high disease activity, for 12 weeks, and then glucocorticoid treatment based on disease activity, until week 36. Investigators, patients, outcome assessors, and sponsor personnel were masked to group assignments. The primary endpoint was low disease activity (CRP PMR-AS ≤10) at week 12 without glucocorticoids and without rescue treatment. The study was powered to demonstrate a 60% difference in response rates between groups. Open-ended adverse events were collected at each visit by clinicians and were categorised following system organ class classification after study completion. The ALORS trial is registered with ClinicalTrials.gov, NCT03632187., Findings: 34 patients (22 women and 12 men) were randomly assigned between Dec 13, 2018, and Oct 21, 2021. All patients who had been randomly assigned were included in the analysis. The primary endpoint was reached by eight (50%) of 16 patients in the abatacept group and four (22%) of 18 patients in the placebo group (relative risk 2·2 [0·9-5·5]); crude p=0·15; adjusted p=0·070). Eight (50%) patients in the abatacept and 15 (83%) in the placebo group had adverse events. Four patients (one [6%] in the abatacept group and three [17%] in the placebo group) had serious adverse events. There were no deaths or new safety concerns., Interpretation: This study suggests that the effect of abatacept alone is not strong enough to justify larger studies in early polymyalgia rheumatica. This is only a first step in deciding whether a larger study should be conducted in early polymyalgia rheumatica and does not exclude a potential effect of abatacept in glucocorticoid-dependent polymyalgia rheumatica., Funding: BMS Pharma France., Competing Interests: Declaration of interests ASa reports work from speakers bureaus for speakers bureau for AbbVie, Bristol Myers Squibb (BMS), Galapagos, Lilly, Novartis, Nordic, Pfizer, Roche-Chugai, Sanofi, and Union Chimique Belge (UCB); and grants or research support from AbbVie, BMS, Lilly, and Novartis. GC-A reports work from speakers bureaus for AbbVie, BMS, Chugai, Lilly, and Novartis. AT reports work from speakers bureaus for Galapagos and BMS. RF reports work from speakers bureaus for Amgen, BMS, Galapagos, GSK, Janssen-Cilag, Medac, MSD, Nordic, Novartis, Pfizer, Sanofi, and UCB. SJ-J reports work from speakers bureaus for AbbVie, Amgen, AstraZeneca, BMS, Galapagos, Janssen, Pfizer, UCB, Novartis, MSD, GSK, and Sanofi. TM reports funding from AbbVie, Amgen, Chugaï, Lilly, Mylan, Novartis, and Pfizer. VD-P reports grants and research support from BMS. All other authors declare no competing interests., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

BACKGROUND: Admission to the hospital is a major risk factor for the development of venous thromboembolism (VTE). Whether thromboprophylaxis with low-molecular-weight heparin prevents symptomatic VTE in medically ill, hospitalized older adults remains debated. METHODS: In a prospective, randomized, placebo-controlled, double-blind, multicenter trial, older adults (>70 years of age) hospitalized for acute medical conditions were randomly assigned to receive 40 mg a day of low-molecular-weight heparin (enoxaparin) or placebo for 6 to 14 days. The primary efficacy outcome was the cumulative incidence of symptomatic VTE (distal or proximal deep vein thrombosis, fatal or nonfatal pulmonary embolism) at 30 days. The primary safety outcome was major bleeding. Secondary outcomes included efficacy and safety outcomes at 90 days. RESULTS: The trial was prematurely discontinued in September 2020, 5 years after enrollment began, because of drug supply issues. By the time of trial discontinuation, 2559 patients had been randomly assigned at 47 centers. Median age was 82 years and 60% of patients were female. In the intention-to-treat population, the primary efficacy outcome occurred in 22 out of 1278 (cumulative incidence, 1.8%) patients in the enoxaparin group and in 27 out of 1263 (cumulative incidence, 2.2%) patients in the placebo group (cumulative incidence difference, −0.4 percentage points; 95% confidence interval, −1.5 to 0.7), with no significant difference in time to VTE (P=0.46). The incidence of major bleeding was 0.9% in the enoxaparin group and 1.0% in the placebo group. At 90 days there were 14 symptomatic pulmonary emboli in the enoxaparin group and 25 in the placebo group; all 39 pulmonary embolism events resulted in hospital readmission and/or death, with 5 deaths from pulmonary embolism in the enoxaparin group and 11 deaths in the placebo group. CONCLUSIONS: This trial of thromboprophylaxis in medically ill, hospitalized older adults did not demonstrate that enoxaparin reduced the risk of symptomatic VTE after 1 month. Because the trial was prematurely discontinued, larger trials are needed to definitively address this question. (Funded by the French Ministry of Health Programme Hospitalier de Recherche Clinique, grant number PHRC-N-13-0283; ClinicalTrials.gov number, NCT02379806.)

Introduction: Parathyroid hormone (PTH) plays an important role in maintaining mineral homeostasis by regulating calcium and phosphate levels. Clinical trials have shown that peptides of PTH (1-34), PTH-related protein (PTHrP 1-36), and the new peptide modeled on PTHrP, abaloparatide, can have different anabolic effects on osteoporotic subjects, but the underlying mechanisms are still unclear. The prevalence of moderate and major gingival recession has been shown to be higher in postmenopausal women with osteoporosis. In addition, there is a significant association between osteoporosis and tooth loss., Methods: We investigated the actions of these peptides on the cementoblasts and teeth of mice. The murine cementoblast line, OCCM-30, known to express collagen I (Col1a1), was treated with intermittent PTH (1-34), PTHrP (1-36), or abaloparatide for 6 h/d for 3 days. Microcomputed tomography was performed on the teeth of mice receiving daily injections of phosphate-buffered saline, PTH (1-34), or abaloparatide. Statistical differences were analyzed by a 2-way or 1-way analysis of variance followed by a Tukey's post-hoc test. Results are expressed as mean ± standard deviation, and P <0.05 was considered significant., Results: Gene expression showed regulation of Bsp, Col1a1, Opg, Rankl, and Mmp13 by the 3 peptides in these cells. Western blots revealed that after intermittent treatment for 3 days, PTH (1-34) caused an increase in COL1A1 protein immediately after treatment. In contrast, abaloparatide showed a latent effect in increasing COL1A1 protein 18 hours after treatment. PTHrP had no effect on COL1A1 expression. Immunofluorescence confirmed the same result as the Western blots. Microcomputed tomography of teeth showed PTH (1-34) injections increased molar root mineral density in mice, whereas abaloparatide increased density in roots of incisors and molars., Conclusions: This study reveals the differential anabolic effects of intermittent PTH (1-34), PTHrP (1-36), and abaloparatide on cementoblasts, as revealed by COL1A1 expression and root mineral density. Abaloparatide may be a potential therapeutic approach for achieving improved cementogenesis., (Copyright © 2022 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Abaloparatide is a peptide analog of parathyroid hormone-related protein (PTHrP 1-34) and was approved in 2017 as the second osteoanabolic peptide for treating osteoporosis. We previously showed that intermittent abaloparatide is equally as effective as PTH (1-34). This study was designed to compare the catabolic effects of PTH (1-34) and abaloparatide on bone in young female wild-type mice. Two-month-old C57Bl/6J female mice were continuously infused with human PTH (1-34) or abaloparatide at 80 μg/kg BW/day or vehicle for 2 weeks. At euthanasia, DEXA-PIXImus was performed to assess bone mineral density (BMD) in the whole body, femurs, tibiae, and vertebrae. Bone turnover marker levels were measured in sera, femurs were harvested for micro-computer tomography (μCT) analyses and histomorphometry, and tibiae were separated into cortical and trabecular fractions for gene expression analyses. Our results demonstrated that the infusion of abaloparatide resulted in a similar decrease in BMD as infused PTH (1-34) at all sites. μCT and histomorphometry analyses showed similar decreases in cortical bone thickness and BMD associated with an increase in bone turnover from the increased bone formation rate found by in vivo double labeling and serum P1NP and increased bone resorption as shown by osteoclast numbers and serum cross-linked C-telopeptide. Trabecular bone did not show major changes with either treatment. Osteoblastic gene expression analyses of trabecular and cortical bone revealed that infusion of PTH (1-34) or abaloparatide led to similar and different actions in genes of osteoblast differentiation and activity. As with intermittent and in vitro treatment, both infused PTH (1-34) and abaloparatide similarly regulated downstream genes of the PTHR1/SIK/HDAC4 pathway such as Sost and Mmp13 but differed for those of the PTHR1/SIK/CRTC pathway. Taken together, at the same dose, infused abaloparatide causes the same high bone turnover as infused PTH (1-34) with a net resorption in female wild-type mice. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research., (© 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.)

Importance: Few treatments are available for patients with glucocorticoid-dependent polymyalgia rheumatica. IL-6 antagonists may reduce disease activity in patients with active glucocorticoid-dependent polymyalgia rheumatica., Objective: To compare the efficacy of tocilizumab vs placebo in patients with glucocorticoid-dependent polymyalgia rheumatica., Design, Setting, and Participants: This double-blind, parallel-group, placebo-controlled randomized clinical trial enrolled 101 patients with polymyalgia rheumatica at 17 hospitals in France from February 2017 to October 2019. Final follow-up occurred in November 2020. Inclusion criteria were persistent disease activity (polymyalgia rheumatica activity score computed using the C-reactive protein level [CRP PMR-AS] >10) and prednisone dose greater than or equal to 10 mg per day., Interventions: Patients were randomly assigned to receive intravenous tocilizumab (8 mg/kg; n = 51) or placebo (n = 50) every 4 weeks for 24 weeks, combined with predefined standardized tapering of oral prednisone., Main Outcomes and Measures: The primary efficacy end point was CRP PMR-AS less than 10 (range, 0-100; higher values indicate greater activity; no minimal clinically important difference defined) combined with either prednisone dose less than or equal to 5 mg per day or a decrease in prednisone dose greater than or equal to 10 mg from baseline at week 24. There were 11 secondary outcomes assessed at week 24 included in this report, including disease activity (measured by CRP PMR-AS) and the proportion of patients no longer taking prednisone., Results: Of the 101 randomized patients (mean age, 67.2 years; 68 [67.3%] women), 100 (99%) received at least 1 infusion and 100 completed the trial. The primary end point was achieved in 67.3% of patients in the tocilizumab group and 31.4% of patients in the placebo group (adjusted difference, 36.0% [95% CI, 19.4%-52.6%]; adjusted relative risk, 2.3 [95% CI, 1.5-3.6]; P < .001). Of 11 reported secondary end points at 24 weeks, 7 showed significant differences favoring tocilizumab, including mean CRP PMR-AS score (7.5 [95% CI, 5.4-9.6] vs 14.9 [95% CI, 11.4-18.4]; adjusted difference, -7.5 [95% CI, -11.2 to -3.8]; P < .001) and the percentage of patients no longer receiving prednisone (49.0% vs 19.6%; adjusted difference, 29.3% [95% CI, 18.9%-39.7%]; adjusted relative risk, 2.5 [95% CI, 1.8-3.5]; P < .001). The most frequent adverse events were infections, experienced by 23 patients (46.9%) in the tocilizumab group and 20 (39.2%) in the placebo group., Conclusions and Relevance: Among patients with active polymyalgia rheumatica despite prednisone therapy, tocilizumab, compared with placebo, resulted in a significantly greater percentage of patients with a CRP PMR-AS less than 10 with reduced prednisone requirements at week 24. Further research is needed to confirm efficacy and to determine the balance of potential benefits and harms., Trial Registration: ClinicalTrials.gov Identifier: NCT02908217.

Renal anemia is a common complication in chronic kidney disease (CKD), associated with decreased production of erythropoietin (EPO) due to loss of kidney function, and subsequent decreased red blood cell (RBC) production. However, many other factors play a critical role in the development of renal anemia, such as iron deficiency, inflammation, and elevated fibroblast growth factor 23 (FGF23) levels. We previously reported that inhibition of FGF23 signaling rescues anemia in mice with CKD. In the present study we sought to investigate whether α-Klotho deficiency present in CKD also contributes to the development of renal anemia. To address this, we administered α-Klotho to mice with CKD induced by an adenine-rich diet. Mice were sacrificed 24 h after α-Klotho injection, and blood and organs were collected immediately post-mortem. Our data show that α-Klotho administration had no beneficial effect in mice with CKD-associated anemia as it did not increase RBC numbers and hemoglobin levels, and it did not stimulate EPO secretion. Moreover, α-Klotho did not improve iron deficiency and inflammation in CKD as it had no effect on iron levels or inflammatory markers. Interestingly, Klotho supplementation significantly reduced the number of erythroid progenitors in the bone marrow and downregulated renal Epo and Hif2 α mRNA in mice fed control diet resulting in reduced circulating EPO levels in these mice. In addition, Klotho significantly decreased intestinal absorption of iron in control mice leading to reduced serum iron and transferrin saturation levels. Our findings demonstrate that α-Klotho does not have a direct role in renal anemia and that FGF23 suppresses erythropoiesis in CKD via a Klotho-independent mechanism. However, in physiological conditions α-Klotho appears to have an inhibitory effect on erythropoiesis and iron regulation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Park, Le Henaff and Sitara.)

Hypoferremia results as an acute phase response to infection and inflammation aiming to reduce iron availability to pathogens. Activation of toll-like receptors (TLRs), the key sensors of the innate immune system, induces hypoferremia mainly through the rise of the iron hormone hepcidin. Conversely, stimulation of erythropoiesis suppresses hepcidin expression via induction of the erythropoietin-responsive hormone erythroferrone. Iron deficiency stimulates transcription of the osteocyte-secreted protein FGF23. Here we hypothesized that induction of FGF23 in response to TLR4 activation is a potent contributor to hypoferremia and, thus, impairment of its activity may alleviate hypoferremia induced by lipopolysaccharide (LPS), a TLR 4 agonist. We used the C-terminal tail of FGF23 to impair endogenous full-length FGF23 signaling in wild-type mice, and investigated its impact on hypoferremia. Our data show that FGF23 is induced as early as pro-inflammatory cytokines in response to LPS, followed by upregulation of hepcidin and downregulation of erythropoietin (Epo) expression in addition to decreased serum iron and transferrin saturation. Further, LPS-induced hepatic and circulating hepcidin were significantly reduced by FGF23 signaling disruption. Accordingly, iron sequestration in liver and spleen caused by TLR4 activation was completely abrogated by FGF23 signaling inhibition, resulting in alleviation of serum iron and transferrin saturation deficit. Taken together, our studies highlight for the first time that inhibition of FGF23 signaling alleviates LPS-induced acute hypoferremia.

Parathyroid hormone (PTH) is necessary for the regulation of calcium homeostasis and PTH (1-34) was the first approved osteoanabolic therapy for osteoporosis. It is well established that intermittent PTH increases bone formation and that bone remodeling and several cytokines and chemokines play an essential role in this process. Earlier, we had established that the chemokine, monocyte chemoattractant protein-1 (MCP-1/CCL2), was the most highly stimulated gene in rat bone after intermittent PTH injections. Nevertheless, MCP-1 function in bone appears to be complicated. To identify the primary cells expressing MCP-1 in response to PTH, we performed in situ hybridization of rat bone sections after hPTH (1-34) injections and showed that bone-lining osteoblasts are the primary cells that express MCP-1 after PTH treatment. We previously demonstrated MCP-1's importance by showing that PTH's anabolic effects are abolished in MCP-1 null mice, further implicating a role for the chemokine in this process. To establish whether rhMCP-1 peptide treatment could rescue the anabolic effect of PTH in MCP-1 null mice, we treated 4-month-old wild-type (WT) mice with hPTH (1-34) and MCP-1 -/- mice with rhMCP-1 and/or hPTH (1-34) for 6 weeks. Micro-computed tomography (μCT) analysis of trabecular and cortical bone showed that MCP-1 injections for 6 weeks rescued the PTH anabolic effect in MCP-1 -/- mice. In fact, the combination of rhMCP-1 and hPTH (1-34) has a synergistic anabolic effect compared with monotherapies. Mechanistically, PTH-enhanced transforming growth factor-β (TGF-β) signaling is abolished in the absence of MCP-1, while MCP-1 peptide treatment restores TGF-β signaling in the bone marrow. Here, we have shown that PTH regulates the transcription of the chemokine MCP-1 in osteoblasts and determined how MCP-1 affects bone cell function in PTH's anabolic actions. Taken together, our current work indicates that intermittent PTH stimulates osteoblastic secretion of MCP-1, which leads to increased TGF-β signaling, implicating it in PTH's anabolic actions., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Abaloparatide, a novel analog of parathyroid hormone-related protein (PTHrP 1-34), became in 2017 the second osteoanabolic therapy for the treatment of osteoporosis. This study aims to compare the effects of PTH (1-34), PTHrP (1-36), and abaloparatide on bone remodeling in male mice. Intermittent daily subcutaneous injections of 80 μg/kg/d were administered to 4-month-old C57Bl/6J male mice for 6 weeks. During treatment, mice were followed by DXA-Piximus to assess changes in bone mineral density (BMD) in the whole body, femur, and tibia. At either 4 or 18 hours after the final injection, femurs were harvested for μCT analyses and histomorphometry, sera were assayed for bone turnover marker levels, and tibias were separated into cortical, trabecular, and bone marrow fractions for gene expression analyses. Our results showed that, compared with PTH (1-34), abaloparatide resulted in a similar increase in BMD at all sites, whereas no changes were found with PTHrP (1-36). With both PTH (1-34) and abaloparatide, μCT and histomorphometry analyses revealed similar increases in bone volume associated with an increased trabecular thickness, in bone formation rate as shown by P1NP serum level and in vivo double labeling, and in bone resorption as shown by CTX levels and osteoclast number. Gene expression analyses of trabecular and cortical bone showed that PTH (1-34) and abaloparatide led to different actions in osteoblast differentiation and activity, with increased Runx2, Col1A1, Alpl, Bsp, Ocn, Sost, Rankl/Opg, and c-fos at different time points. Abaloparatide seems to generate a faster response on osteoblastic gene expression than PTH (1-34). Taken together, abaloparatide at the same dose is as effective as PTH (1-34) as an osteoanabolic, with an increase in bone formation but also an increase in bone resorption in male mice. © 2019 American Society for Bone and Mineral Research., (© 2019 American Society for Bone and Mineral Research.)

Osteoporosis can result from the loss of sex hormones and/or aging. Abaloparatide (ABL), an analog of parathyroid hormone-related protein (PTHrP(1-36)), is the second osteoanabolic therapy approved by the United States Food and Drug Administration after teriparatide (PTH(1-34)). All three peptides bind PTH/PTHrP receptor type 1 (PTHR1), but the effects of PTHrP(1-36) or ABL in the osteoblast remain unclear. We show that, in primary calvarial osteoblasts, PTH(1-34) promotes a more robust cAMP response than PTHrP(1-36) and ABL and causes a greater activation of protein kinase A (PKA) and cAMP response element-binding protein (CREB). All three peptides similarly inhibited sclerostin ( Sost ). Interestingly, the three peptides differentially modulated two other PKA target genes, c -Fos and receptor activator of NF-κB ligand ( Rankl ), and the latter both in vitro and in vivo Knockdown of salt-inducible kinases (SIKs) 2 and 3 and CREB-regulated transcription coactivator 3 (CRTC3), indicated that all three are part of the pathway that regulates osteoblastic Rankl expression. We also show that the peptides differentially regulate the nuclear localization of CRTC2 and CRTC3, and that this correlates with PKA activation. Moreover, inhibition of protein phosphatases 1 and 2A (PP1/PP2A) activity revealed that they play a major role in both PTH-induced Rankl expression and the effects of PTH(1-34) on CRTC3 localization. In summary, in the osteoblast, the effects of PTH(1-34), PTHrP(1-36), and ABL on Rankl are mediated by differential stimulation of cAMP/PKA signaling and by their downstream effects on SIK2 and -3, PP1/PP2A, and CRTC3., (© 2018 Ricarte et al.)

The bone catabolic actions of parathyroid hormone (PTH) are seen in patients with hyperparathyroidism, or with infusion of PTH in rodents. We have previously shown that the chemokine, monocyte chemoattractant protein-1 (MCP-1), is a mediator of PTH's anabolic effects on bone. To determine its role in PTH's catabolic effects, we continuously infused female wild-type (WT) and MCP-1 -/- mice with hPTH or vehicle. Microcomputed tomography (µCT) analysis of cortical bone showed that hPTH-infusion induced significant bone loss in WT mice. Further, μCT analysis of trabecular bone revealed that, compared with the vehicle-treated group, the PTH-treated WT mice had reduced trabecular thickness and trabecular number. Notably, MCP-1 -/- mice were protected against PTH-induced cortical and trabecular bone loss as well as from increases in serum CTX (C-terminal crosslinking telopeptide of type I collagen) and TRACP-5b (tartrate-resistant acid phosphatase 5b). In vitro, bone marrow macrophages (BMMs) from MCP-1 -/- and WT mice were cultured with M-CSF, RANKL and/or MCP-1. BMMs from MCP-1 -/- mice showed decreased multinucleated osteoclast formation compared with WT mice. Taken together, our work demonstrates that MCP-1 has a role in PTH's catabolic effects on bone including monocyte and macrophage recruitment, osteoclast formation, bone resorption, and cortical and trabecular bone loss.

Stimulating bone formation is an important challenge for bone anabolism in osteoporotic patients or to repair bone defects. The osteogenic properties of matrix glycosaminoglycans (GAGs) have been explored; however, the functions of GAGs at the surface of bone-forming cells are less documented. Syndecan-2 is a membrane heparan sulfate proteoglycan that is associated with osteoblastic differentiation. We used a transgenic mouse model with high syndecan-2 expression in osteoblasts to enrich the bone surface with cellular GAGs. Bone mass was increased in these transgenic mice. Syndecan-2 overexpression reduced the expression of receptor activator of NF-kB ligand (RANKL) in bone marrow cells and strongly inhibited bone resorption. Osteoblast activity was not modified in the transgenic mice, but bone formation was decreased in 4-month-old transgenic mice because of reduced osteoblast number. Increased proteoglycan expression at the bone surface resulted in decreased osteoblastic and osteoclastic precursors in bone marrow. Indeed, syndecan-2 overexpression increased apoptosis of mesenchymal precursors within the bone marrow. However, syndecan-2 specifically promoted the vasculature characterized by high expression of CD31 and Endomucin in 6-week-old transgenic mice, but this was reduced in 12-week-old transgenic mice. Finally, syndecan-2 functions as an inhibitor of Wnt-β-catenin-T-cell factor signaling pathway, activating glycogen synthase kinase 3 and then decreasing the Wnt-dependent production of Wnt ligands and R-spondin. In conclusion, our results show that GAG supply may improve osteogenesis, but also interfere with the crosstalk between the bone surface and marrow cells, altering the supporting function of osteoblasts.

Patients with cystic fibrosis (CF) display low bone mass and alterations in bone formation. Mice carrying the F508del genetic mutation in the cystic fibrosis conductance regulator (Cftr) gene display reduced bone formation and decreased bone mass. However, the underlying molecular mechanisms leading to these skeletal defects are unknown, which precludes the development of an efficient anti-osteoporotic therapeutic strategy. Here we report a key role for the intermediate filament protein keratin 8 (Krt8), in the osteoblast dysfunctions in F508del-Cftr mice. We found that murine and human osteoblasts express Cftr and Krt8 at low levels. Genetic studies showed that Krt8 deletion (Krt8(-/-)) in F508del-Cftr mice increased the levels of circulating markers of bone formation, corrected the expression of osteoblast phenotypic genes, promoted trabecular bone formation and improved bone mass and microarchitecture. Mechanistically, Krt8 deletion in F508del-Cftr mice corrected overactive NF-κB signaling and decreased Wnt-β-catenin signaling induced by the F508del-Cftr mutation in osteoblasts. In vitro, treatment with compound 407, which specifically disrupts the Krt8-F508del-Cftr interaction in epithelial cells, corrected the abnormal NF-κB and Wnt-β-catenin signaling and the altered phenotypic gene expression in F508del-Cftr osteoblasts. In vivo, short-term treatment with 407 corrected the altered Wnt-β-catenin signaling and bone formation in F508del-Cftr mice. Collectively, the results show that genetic or pharmacologic targeting of Krt8 leads to correction of osteoblast dysfunctions, altered bone formation and osteopenia in F508del-Cftr mice, providing a therapeutic strategy targeting the Krt8-F508del-CFTR interaction to correct the abnormal bone formation and bone loss in cystic fibrosis., (© The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

The prevalent human ΔF508 mutation in the cystic fibrosis transmembrane conductance regulator (CFTR) is associated with reduced bone formation and bone loss in mice. The molecular mechanisms by which the ΔF508-CFTR mutation causes alterations in bone formation are poorly known. In this study, we analyzed the osteoblast phenotype in ΔF508-CFTR mice and characterized the signaling mechanisms underlying this phenotype. Ex vivo studies showed that the ΔF508-CFTR mutation negatively impacted the differentiation of bone marrow stromal cells into osteoblasts and the activity of osteoblasts, demonstrating that the ΔF508-CFTR mutation alters both osteoblast differentiation and function. Treatment with a CFTR corrector rescued the abnormal collagen gene expression in ΔF508-CFTR osteoblasts. Mechanistic analysis revealed that NF-κB signaling and transcriptional activity were increased in mutant osteoblasts. Functional studies showed that the activation of NF-κB transcriptional activity in mutant osteoblasts resulted in increased β-catenin phosphorylation, reduced osteoblast β-catenin expression, and altered expression of Wnt/β-catenin target genes. Pharmacological inhibition of NF-κB activity or activation of canonical Wnt signaling rescued Wnt target gene expression and corrected osteoblast differentiation and function in bone marrow stromal cells and osteoblasts from ΔF508-CFTR mice. Overall, the results show that the ΔF508-CFTR mutation impairs osteoblast differentiation and function as a result of overactive NF-κB and reduced Wnt/β-catenin signaling. Moreover, the data indicate that pharmacological inhibition of NF-κB or activation of Wnt/β-catenin signaling can rescue the abnormal osteoblast differentiation and function induced by the prevalent ΔF508-CFTR mutation, suggesting novel therapeutic strategies to correct the osteoblast dysfunctions in cystic fibrosis., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)

The α5β1 integrin is a key fibronectin (FN) receptor that binds to RGD-containing peptides to mediate cell adhesion. We previously reported that α5β1 integrin promotes osteogenic differentiation in mesenchymal skeletal cells (MSCs), but the underlying mechanisms are not fully understood. In this study, we determined the signaling mechanisms induced by α5β1 integrin interaction with its high-affinity ligand CRRETAWAC in murine and human MSCs and in vivo. We show that cyclized CRRETAWAC fully displaced MSC adhesion to FN, whereas related peptides lacking the full RRET sequence produced a partial displacement, indicating that RRET acts as an RGD-like sequence that is required to antagonize FN-mediated cell adhesion. However, all peptides increased focal adhesion kinase phosphorylation, OSE2 transcriptional activity, osteoblast gene expression, and matrix mineralization in MSCs, indicating that peptide-induced α5β1 integrin priming can promote osteogenic differentiation independently of the RRET sequence. Biochemical analyses showed that peptide-induced α5β1 integrin priming transiently increased PI3K/Akt phosphorylation and promoted Wnt/β-catenin transcriptional activity independently of RRET. Consistently, pharmacological inhibition of PI3K activity reduced osteoblast differentiation and abolished Wnt regulatory gene expression induced by α5β1 integrin priming. In vivo, systemic delivery of cyclized GACRETAWACGA linked to (DSS)6 to allow delivery to bone-forming sites for 6 weeks increased serum osteocalcin levels and improved long bone mass and microarchitecture in SAMP-6 senescent osteopenic mice. The results support a mechanism whereby α5β1 integrin priming by high-affinity ligands integrates Wnt/β-catenin signaling to promote osteoblast differentiation independently of cell adhesion, which could be used to improve bone mass and microarchitecture in the aging skeleton., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)

Intermittent administration of parathyroid hormone (PTH) 1-34 at a standard dose has been shown to induce anabolic effects in bone. However, whether low-dose PTH promotes bone formation during senescence is unknown. To address this issue, we determined the effects of low-dose PTH and analysed the underlying mechanisms in prematurely senescent mice that display osteopenia. Treatment of 9-week-old Samp6 mice for 6 weeks with PTH at a standard dose (100 μg/kg per day) increased vertebral and femoral bone mass and improved bone microarchitecture as a result of increased bone-forming surfaces and mineral apposition rate (MAR). At a tenfold lower dose (10 μg/kg per day), PTH increased axial bone volume and trabecular thickness, as detected by bone histomorphometry but not by micro-computed tomography analysis. This anabolic effect resulted from increased osteoblast activity, as reflected by increased serum N-terminal propeptide of type 1 procollagen (P1NP) levels and MAR, with unchanged bone-forming surface or osteoblast surface. Mechanistically, low-dose PTH increased the expression of osteoblast markers in bone marrow stromal cells and mature osteoblasts, which was associated with increased expression of the Wnt effector Wisp1. Moreover, low-dose PTH decreased the expression of the Mef2c transcription factor, resulting in decreased Sost expression in osteoblasts/osteocytes. These results indicate that PTH at a low dose is effective at promoting bone formation and increased bone volume in senescent osteopenic mice through increased osteoblast activity and modulation of specific Wnt effectors, which raises the potential therapeutic use of intermittent PTH at low dose to increase bone forming activity and bone mass in skeletal senescence., (© 2014 Society for Endocrinology.)

In patients with cystic fibrosis (CF), rib and thoracic vertebral fractures can have adverse effects on lung health because the resulting pain and debilitation can impair airway clearance. The F508del mutation in the CF transmembrane conductance regulator (Cftr) gene induces an osteopenic phenotype in humans and mice. N-butyldeoxynojyrimicin (miglustat), an approved drug for treating type 1 Gaucher disease, was found to normalize CFTR-dependent chloride transport in human F508del CFTR lung cells and in nasal mucosa of F508del CF mice. Herein, we investigated whether targeting F508del-CFTR may rescue the skeletal osteopenic phenotype in murine CF. We found that oral administration of low-dose miglustat (120 mg/kg once a day for 28 days) improved bone mass and microarchitecture in the lumbar spine and femur in F508del mice. The increased bone density was associated with an increased bone formation rate and reduced bone resorption. This effect was associated with increased 17β-estradiol but not with insulin-like growth factor 1 serum levels in miglustat-treated F508del mice. Exposure of primary F508del osteoblasts to miglustat partially restored the deficient CFTR-dependent chloride transport in these bone-forming cells. This study provides evidence that reversal of CFTR-dependent chloride transport in osteoblasts normalizes bone mass and microarchitecture in murine CF. These findings may provide a potential therapeutic strategy to prevent or correct the bone disease in patients with CF., (Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

We studied the relationships between hepatic and mesenteric mean blood-flow velocities (mBFVs) measured by ultrasound imaging and (1) downstream tumor angiogenesis during liver metastasis induced by spleen injection of LS174 human colon cells overexpressing the antiangiogenic Netrin4 (LS174-NT4) or not (LS174-WT) and (2) downstream normal angiogenesis during hepatic regeneration after 50% hepatectomy. Liver volume and mBFVs were measured before and after surgery, at day 30 in the first model and at days 2, 7 and 16 in the second model. LS174-NT-4 vs. LS174-WT mice presented fewer metastases (25% vs. 90%, p < 0.001) and decreased hepatic mBFVs (16.5 ± 0.8 vs. 21.8 ± 1.4 cm s(-1), p < 0.01), without difference in mesenteric mBFVs. After partial hepatectomy, hepatic and mesenteric mBFVs increased at day 7, from 12.4 ± 1.7 and 11.8 ± 2.6 to 19.1 ± 1.8 and 17.5 ± 2.4 cm s(-1), respectively, (p < 0.01) then returned to baseline as liver volume. Duplex Doppler ultrasonography reliably assesses normal or tumor angiogenesis and may provide follow-up functional evaluation., (Copyright © 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

The F508del mutation in the cystic fibrosis transmembrane conductance regulator (Cftr) gene is believed to be an independent risk factor for cystic fibrosis-related bone disease. In this study, we evaluated the bone mineral density as well as the histomorphometric parameters of bone formation and bone mass in both F508del-Cftr homozygous mice (F508del Cftr(tm1Eur)) and Cftr(+/+) littermate controls at 6 (prepubertal), 10 (pubertal), and 14 (young adult) weeks of age in both sexes. The bone architecture of F508del Cftr(tm1Eur) and wild-type (WT) littermate mice was evaluated by bone densitometry, microcomputed tomography, and analysis of the dynamic parameters of bone formation. Serum levels of both insulin-like growth factor 1 and osteocalcin also were determined. Reduced bone mineral density, lower femoral bone mass, and altered trabecular bone architecture were observed in F508del Cftr(tm1Eur) mice compared with controls at 6, 10, and 14 weeks of age. A decrease in the bone formation rate in F508del Cftr(tm1Eur) mice was shown compared with control mice, independently of age and sex. In addition, we found lower insulin-like growth factor 1 levels in F508del Cftr(tm1Eur) mice compared with age-matched controls, whereas osteocalcin levels were normal. Severe osteopenia and altered bone architecture were found in young and mature adult F508del Cftr(tm1Eur) mice. Our findings show that the F508del mutation in CFTR impacts trabecular bone mass by reducing bone formation., (Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.)

Our findings that PlGF is a cancer target and anti-PlGF is useful for anticancer treatment have been challenged by Bais et al. Here we take advantage of carcinogen-induced and transgenic tumor models as well as ocular neovascularization to report further evidence in support of our original findings of PlGF as a promising target for anticancer therapies. We present evidence for the efficacy of additional anti-PlGF antibodies and their ability to phenocopy genetic deficiency or silencing of PlGF in cancer and ocular disease but also show that not all anti-PlGF antibodies are effective. We also provide additional evidence for the specificity of our anti-PlGF antibody and experiments to suggest that anti-PlGF treatment will not be effective for all tumors and why. Further, we show that PlGF blockage inhibits vessel abnormalization rather than density in certain tumors while enhancing VEGF-targeted inhibition in ocular disease. Our findings warrant further testing of anti-PlGF therapies., (Copyright 2010 Elsevier Inc. All rights reserved.)

Background and Aims. An arterial blood supply and phenotypic changes of the sinusoids characterise the liver vasculature in human hepatocellular carcinoma (HCC). We investigated the effects of rosuvastatin on liver vessel anomalies, tumour growth and survival in HCC. Methods. We treated transgenic mice developing HCC, characterized by vessel anomalies similar to those of human HCC, with rosuvastatin. Results. In the rosuvastatin group, the survival time was longer (P < .001), and liver weight (P < .01) and nodule surface (P < .01) were reduced. Rosuvastatin decreased the number of smooth muscle actin-positive arteries (P < .05) and prevented the sinusoid anomalies, with decreased laminin expression (P < .001), activated hepatic stellate cells (P < .001), and active Notch4 expression. Furthermore, rosuvastatin inhibited endothelial cell but not tumour hepatocyte functions. Conclusions. Rosuvastatin reduced the vessel anomalies and tumour growth and prolonged survival in HCC. These results represent new mechanisms of the effects of statin on tumour angiogenesis and a potential target therapy in HCC.

Objective: To compare the diagnostic values of antiperinuclear factor (APF), antikeratin antibody (AKA), and anti-cyclic citrullinated peptides (anti-CCP) to discriminate between patients with and without rheumatoid arthritis (RA) and to determine the diagnostic value of anti-CCP used alone or with other tests., Methods: Two hundred and seventy patients with early arthritis underwent standardized investigations in 1995-1997. The clinical utility of APF, AKA, and anti-CCP in first-visit sera was evaluated using receiver-operating characteristic curves. Combinations of anti-CCP with other laboratory tests were assessed by multiple logistic regression., Results: Anti-CCP, APF, and AKA were not perfectly correlated with one another. Anti-CCP with 53 UI as the cutoff was 47% sensitive and 93% specific, versus 52% and 79%, and 47% and 94%, for APF and AKA, respectively. Multiple logistic regression selected anti-CCP, AKA, IgM-rheumatoid factor (RF) ELISA, and the latex test., Conclusion: Rheumatologists can routinely use 2 or 3 tests for diagnosing RA (latex and/or IgM RF ELISA, and either AKA or anti-CCP ELISA) and can add a third or fourth test when the diagnosis remains in doubt.

Objective: To study the confidence of office-based rheumatologists (OBR) and a college of 5 experts in their diagnosis of spondylarthropathy (SpA) for early arthritis after more than 2 years of follow-up; to determine whether at that time the degree of confidence was improved by the fulfilment of the ESSG criteria., Methods: 270 patients with early-onset (< 1 year) arthritis were prospectively followed-up for 29+/-11 months. At the final examination, OBR and the college of 5 experts rated their confidence in the diagnosis of SpA on a 0-10 analogue scale and on a 1-4 Likert scale, respectively., Results: After 29+/-11 months OBR had classified 56 patients (21%) as SpA, while a collegial diagnosis of probable (N = 32) or certain SpA (N = 14) was made for 46 patients (17%). At the final examination OBR confidence in their diagnosis (gold standard) was only 6.7+/-2.4 for all 56 cases of SpA. The cumulative fulfilment of ESSG criteria for SpA after 29+/-11 months correlated with the confidence of OBR and the experts in SpA, but improved only slightly the final confidence of OBR (7.1+/-2.3 versus 6.7+/-2.4 for all 56 SpA). Similarly, OBR confidence for the 18/56 SpA patients positive for HLA-B27 was only 7.1+/-2.0. Only 21 of these 56 patients were considered as SpA at baseline, although 37/56 (66%) had fulfilled ESSG criteria since thefirst examination., Conclusion: This study indicates a probable lack of consensus on the nosology of early SpA and the limited help provided by the ESSG criteria to differentiate early SpA from otherforms of arthritis at baseline.