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Background Data from large cardiac surgery registries have been depicting a downward trend of mortality and morbidities in the last 20 years. However, despite decades of medical evolution, cardiac surgery and cardiopulmonary bypass still provoke a systemic inflammatory response, which occasionally leads to worsened outcome. This article seeks to outline the mechanism of the phenomenon. Methods A thorough review of the literature has been performed. Criteria for considering studies for this non-systematic review were as follows: observational and interventional studies investigating the systemic inflammatory response to cardiac surgery, experimental studies describing relevant molecular mechanisms, and essential review studies pertinent to the topic. Results The intrinsic variability of the inflammatory response to cardiac surgery, together with its heterogenous perception among clinicians, as well as the arduousness to early discriminate high-responder patients from those who will not develop a clinically relevant reaction, concurred to hitherto unconclusive randomized controlled trials. Furthermore, peremptory knowledge about the pathophysiology of maladaptive inflammation following heart surgery is still lacking. Conclusions Systemic inflammation following cardiac surgery is a frequent entity that occasionally becomes clinically relevant. Specific genomic differences, age, and other preoperative factors influence the magnitude of the response, which elements display extreme redundancy and pleiotropism that the target of a single pathway cannot represent a silver bullet.

Background Data from large cardiac surgery registries have been depicting a downward trend of mortality and morbidities in the last 20 years. However, despite decades of medical evolution, cardiac surgery and cardiopulmonary bypass still provoke a systemic inflammatory response, which occasionally leads to worsened outcome. This article seeks to outline the mechanism of the phenomenon. Methods A thorough review of the literature has been performed. Criteria for considering studies for this non-systematic review were as follows: observational and interventional studies investigating the systemic inflammatory response to cardiac surgery, experimental studies describing relevant molecular mechanisms, and essential review studies pertinent to the topic. Results The intrinsic variability of the inflammatory response to cardiac surgery, together with its heterogenous perception among clinicians, as well as the arduousness to early discriminate high-responder patients from those who will not develop a clinically relevant reaction, concurred to hitherto unconclusive randomized controlled trials. Furthermore, peremptory knowledge about the pathophysiology of maladaptive inflammation following heart surgery is still lacking. Conclusions Systemic inflammation following cardiac surgery is a frequent entity that occasionally becomes clinically relevant. Specific genomic differences, age, and other preoperative factors influence the magnitude of the response, which elements display extreme redundancy and pleiotropism that the target of a single pathway cannot represent a silver bullet.

High risk of cardiovascular events is among leading problems in chronic kidney disease (CKD). Serum Klotho is supposed to be cardio- and nephroprotective; modification of its levels may be important in CKD.To evaluate the impact of vitamin D receptor activators (VDRA) on Klotho serum levels in CKD 3b4 stages patients.Study included 90 CKD 3b4 stages patients who had elevated serum levels of parathyroid hormone (PTH). From them, 47 patients (group 1) started to treat with the selective VDRA (zemplar 1 mcg/day), and 43 patients (group 2) started to treat with non-selective VDRA (alfacalcidol 0.25 mcg/day). At baseline and after 12 months we conducted routine examination, serum Klotho measurement, and broad cardiovascular examination.The patients who managed to maintain a target serum PTH level, had higher Klotho serum level (p=0.037) at the end of the study. Patients who used selective VDRA significantly more often reached the target PTH level (p=0.032), had higher serum Klotho levels (p=0.037), and glomerular filtration rate (eGFR) level (p=0.048) than patients who used non-selective VDRA. In addition, patients treated with alfacalcidol more than 6 months, more often had hypercalcemia (p=0.047) and hyperphosphatemia (p=0.035). Group 2 showed higher: pulse wave velocity (p=0.051), left ventricular myocardial mass index (p=0.033), and more advanced heart valve calcification (p=0.038).Successful parathyroid hormone level control with vitamin D receptor activators was associated with higher serum Klotho, selective agents having shown greater effect. Long-term treatment with selective vitamin D receptor activators may contribute to cardiovascular calcification prevention by modifying Klotho levels.Обоснование. Высокий риск сердечно-сосудистых событий остается одной из ведущих причин смертности у пациентов с хронической болезнью почек (ХБП). В то же время установлено, что циркулирующая форма белка Клото обладает выраженными кардио- и нефропротективными свойствами. Цель. Оценить влияние активаторов рецепторов витамина D (АРВД) на сывороточный уровень Клото у пациентов с ХБП стадии 3b4. Материалы и методы. В исследование включены 90 пациентов с ХБП стадии 3b4, имеющих на момент скрининга повышенный уровень паратиреоидного гормона (ПТГ). Из них 47 пациентов (1-я группа) начали лечение селективным АРВД (Земплар 1 мкг/сут), а 43 пациента (2-я группа) неселективным АРВД (альфакальцидол 0,25 мкг/сут). Исходно и через 12 мес, в дополнение к обычному обследованию при ХБП, изучали уровни Клото в сыворотке крови и провели расширенное сердечно-сосудистое обследование. Результаты. Пациенты, которым удалось достичь и поддерживать целевой уровень ПТГ, имели более высокие уровни Клото в сыворотке крови (p=0,037). Пациенты группы 1 значительно чаще достигали целевого уровня ПТГ (p=0,032), имели более высокие уровни Клото (p=0,037) и расчетной скорости клубочковой фильтрации (p=0,048), чем пациенты группы 2. Кроме того, у пациентов, получавших альфакальцидол более 6 мес, чаще наблюдались гиперкальциемия (p=0,047) и гиперфосфатемия (p=0,035), а также кальцификация клапанов сердца (p=0,048), увеличение скорости пульсовой волны (p=0,024), индекса массы миокарда левого желудочка (p=0,033) и частоты развития гипертрофии левого желудочка (p=0,048). Заключение. У пациентов с ХБП, которым удалось достичь и поддерживать целевой уровень ПТГ в крови, наблюдались более высокие уровни Клото. Использование селективных АРВД связано как с более высокой частотой достижения целевых уровней ПТГ в сыворотке, так и с более высокими уровнями Клото, чем использование неселективных АРВД.

Introduction: We verified the association between selected bacterial profiles and levels of cytokines, chemokines, and the expression of signs and symptoms of primary endodontic infection with apical periodontitis. Methods: Samples were collected from 21 root canals, and macrophages were stimulated for 24 hours. Tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-10, IL-12p70, interferon gamma, and chemokine (C-C motif) ligand 2 (CCL2) were measured using cytometric bead array. We investigated the overlapping networks between cytokines and chemokines with regression analysis. Checkerboard DNA-DNA hybridization was used to assess 40 target bacteria species. Using factor analysis, bacterial species aggregated in 2 factors. The association of bacteria species–based factors on cytokine and chemokine levels and clinical features was estimated with regression analysis. Results: A negative relationship between IL-10 (anti-inflammatory cytokine) and CCL2, TNF-α, and IFN-γ (proinflammatory cytokines) (all P

ObjectiveTo evaluate changes in bone turnover and bone mineral density (BMD) in patients with rheumatoid arthritis (RA) receiving glucocorticoids, after discontinuation of denosumab for 12 months.MethodsWe conducted a randomized, double-blind, placebo-controlled, phase II study of RA patients. Patients received placebo, denosumab 60 mg, or denosumab 180 mg every 6 months for 12 months and were followed up for an additional 12 months after discontinuation, during which no bone loss prevention therapy was instituted. Changes from baseline in serum C-terminal telopeptide of type I collagen (CTX), serum procollagen type I N-terminal propeptide (PINP), and lumbar spine and total hip BMD were evaluated.ResultsIn this post hoc analysis of patients treated with glucocorticoids at study baseline (n=82), levels of CTX and PINP decreased significantly from baseline in both denosumab groups. Following denosumab discontinuation, CTX returned to baseline and was not significantly different from the placebo group 6 and 12 months after discontinuation. Median percentage changes from baseline PINP in those treated with denosumab 60 mg were -0.16% and 15.3% at 6 and 12 months, respectively, after discontinuation (P=0.062 and P=0.017, versus placebo); corresponding changes with denosumab 180 mg were 9.0% and 75.8%, respectively (P=0.018 and P=0.002 versus placebo). Compared to placebo, lumbar spine and total hip BMD increased in patients receiving denosumab and returned to baseline 12 months after discontinuation. No osteoporotic fractures were reported during treatment or in the off-treatment period.ConclusionIn this analysis of short-term denosumab use in RA patients receiving glucocorticoids, denosumab discontinuation resulted in a gradual increase in bone turnover, which was associated with a return to baseline lumbar spine and total hip BMD.

Background Alterations in ambient temperature have been associated with multiple detrimental effects on broilers such as intestinal barrier disruption and dysbiosis resulting in systemic inflammation. Inflammation and 25-hydroxycholecalciferol (25-OH-D3) have shown to play a negative and positive role, respectively, in the regulation of bone mass. Hence the potential of 25-OH-D3 in alleviating heat induced bone alterations and its mechanisms was studied. Results Heat stress (HS) directly induced a decrease in tibia material properties and bone mass, as demonstrated by lower mineral content, and HS caused a notable increase in intestinal permeability. Treatment with dietary 25-OH-D3 reversed the HS-induced bone loss and barrier leak. Broilers suffering from HS exhibited dysbiosis and increased expression of inflammatory cytokines in the ileum and bone marrow, as well as increased osteoclast number and activity. The changes were prevented by dietary 25-OH-D3 administration. Specifically, dietary 25-OH-D3 addition decreased abundance of B- and T-cells in blood, and the expression of inflammatory cytokines, especially TNF-α, in both the ileum and bone marrow, but did not alter the diversity and population or composition of major bacterial phyla. With regard to bone remodeling, dietary 25-OH-D3 supplementation was linked to a decrease in serum C-terminal cross-linked telopeptide of type I collagen reflecting bone resorption and a concomitant decrement in osteoclast-specific marker genes expression (e.g. cathepsin K), whereas it did not apparently change serum bone formation markers during HS. Conclusions These data underscore the damage of HS to intestinal integrity and bone health, as well as that dietary 25-OH-D3 supplementation was identified as a potential therapy for preventing these adverse effects.

Orthodontic tooth movement to therapeutically align malpositioned teeth is supposed to impact blood flow in the surrounding tissues. Here, we evaluated actual vascularization in the tension area of the periodontal ligament during experimental tooth movement in rats (N = 8) with magnetic resonance imaging (MRI). We inserted an elastic band between the left upper first and the second rat molar, the right side was not treated and served as control. After four days of tooth movement, we recorded T1-weighted morphologic and dynamic-contrast-enhanced MRI sequences with an animal-specific 7 Tesla MRI to assess of local vascularization. Furthermore, we quantified osteoclasts and monocytes in the periodontal ligament, which are crucial for orthodontic tooth movement, root resorptions as undesirable side effects, as well as the extent of tooth movement using paraffine histology and micro-CT analysis. Data were tested for normal distribution with Shapiro&ndash, Wilk tests followed by either a two-tailed paired t-test or a Wilcoxon matched-pairs signed rank test. Significant orthodontic tooth movement was induced within the four days of treatment, as evidenced by increased osteoclast and monocyte activity in the periodontal ligament as well as by &micro, CT analysis. Contrast enhancement was increased at the orthodontically-treated side distally of the moved upper first left molar, indicating increased vascularization at the tension side of the periodontal ligament. Accordingly, we detected reduced time-to-peak and washout rates. Our study using MRI to directly assess local vascularization thus seems to confirm the hypothesis that perfusion is enhanced in tension zones of the periodontal ligament during orthodontic tooth movement.

Biomarkers represent promising aids in periodontitis, host-mediate diseases of the tooth-supporting tissues. We assessed the diagnostic potential of matrix metalloproteinase-8 (MMP-8), tartrate-resistant acid phosphatase-5 (TRAP-5), and osteoprotegerin (OPG) to discriminate between healthy patients&rsquo, mild and severe periodontitis sites. Thirty-one otherwise healthy volunteers with and without periodontal disease were enrolled at the Faculty of Dentistry, University of Chile. Periodontal parameters were examined and gingival crevicular fluid was sampled from mild periodontitis sites (M, n = 42), severe periodontitis sites (S, n = 59), and healthy volunteer sites (H, n = 30). TRAP-5 and OPG were determined by commercial multiplex assay and MMP-8 by the immunofluorometric (IFMA) method. STATA software was used. All biomarkers showed a good discrimination performance. MMP-8 had the overall best performance in regression models and Receiver Operating Characteristic (ROC) curves, with high discrimination of healthy from periodontitis sites (area under the curve (AUC) = 0.901). OPG showed a very high diagnostic precision (AUC &ge, 0.95) to identify severe periodontitis sites (S versus H + M), while TRAP-5 identified both healthy and severe sites. As conclusions, MMP-8, TRAP-5, and OPG present a high precision potential in the identification of periodontal disease destruction, with MMP-8 as the most accurate diagnostic biomarker.

Periodontal diseases are chronic, infectious, inflammatory diseases that have a multifactorial character in terms of aetiology and pathogenesis. Periodontal diseases are divided into two major categories as gingivitis and periodontitis both of which are chronic infectious and inflammatory diseases. Microorganisms and/or their virulence factors trigger the host response and the activated immune cells cause periodontal tissue destruction. There are periods of active periodontal tissue destruction and quiescent periods in between them. This chapter provides an outline of the nature of periodontal diseases. Understanding the nature of periodontal diseases is mandatory in order to develop more precise diagnostic and also therapeutic methods.

Due to their potent immunomodulatory anti-inflammatory properties, synthetic glucocorticoids (GCs) are widely utilized in the treatment of chronic inflammatory disease. In this review, we examine our current understanding of how chronic inflammation and commonly used therapeutic GCs interact to regulate bone and muscle metabolism. Whilst both inflammation and therapeutic GCs directly promote systemic osteoporosis and muscle wasting, the mechanisms whereby they achieve this are distinct. Importantly, their interactions in vivo are greatly complicated secondary to the directly opposing actions of GCs on a wide array of pro-inflammatory signalling pathways that underpin catabolic and anti-anabolic metabolism. Several clinical studies have attempted to address the net effects of therapeutic glucocorticoids on inflammatory bone loss and muscle wasting using a range of approaches. These have yielded a wide array of results further complicated by the nature of inflammatory disease, underlying the disease management and regimen of GC therapy. Here, we report the latest findings related to these pathway interactions and explore the latest insights from murine models of disease aimed at modelling these processes and delineating the contribution of pre-receptor steroid metabolism. Understanding these processes remains paramount in the effective management of patients with chronic inflammatory disease.

Due to their potent immunomodulatory anti-inflammatory properties, synthetic glucocorticoids (GCs) are widely utilized in the treatment of chronic inflammatory disease. In this review, we examine our current understanding of how chronic inflammation and commonly used therapeutic GCs interact to regulate bone and muscle metabolism. Whilst both inflammation and therapeutic GCs directly promote systemic osteoporosis and muscle wasting, the mechanisms whereby they achieve this are distinct. Importantly, their interactions in vivo are greatly complicated secondary to the directly opposing actions of GCs on a wide array of pro-inflammatory signalling pathways that underpin catabolic and anti-anabolic metabolism. Several clinical studies have attempted to address the net effects of therapeutic glucocorticoids on inflammatory bone loss and muscle wasting using a range of approaches. These have yielded a wide array of results further complicated by the nature of inflammatory disease, underlying the disease management and regimen of GC therapy. Here, we report the latest findings related to these pathway interactions and explore the latest insights from murine models of disease aimed at modelling these processes and delineating the contribution of pre-receptor steroid metabolism. Understanding these processes remains paramount in the effective management of patients with chronic inflammatory disease.

Co-culture studies investigating the role of periprosthetic fibroblasts (PPFs) in inflammatory osteoclastogenesis reveal contrary results, partly showing an osteoprotective function of fibroblasts and high OPG expression in monolayer. These data disagree with molecular analyses of original periosteolytic tissues. In order to find a more reliable model, PPFs were co-cultivated with peripheral blood mononuclear cells (PBMCs) in a transwell system and compared to conventional monolayer cultures. The gene expression of key regulators of osteoclastogenesis (macrophage colony-stimulating factor (MCSF), receptor activator of NF-&kappa, B ligand (RANK-L), osteoprotegerin (OPG), and tumor necrosis factor alpha (TNF&alpha, )) as well as the ability of bone resorption were analyzed. In monolayer co-cultures, PPFs executed an osteoprotective function with high OPG-expression, low RANK-L/OPG ratios, and a resulting inhibition of osteolysis even in the presence of MCSF and RANK-L. For transwell co-cultures, profound changes in gene expression, with a more than hundredfold decrease of OPG and a significant upregulation of TNF&alpha, were observed. In conclusion, we were able to show that a change of culture conditions towards a transwell system resulted in a considerably more osteoclastogenic gene expression profile, being closer to findings in original periosteolytic tissues. This study therefore presents an interesting approach for a more reliable in vitro model to examine the role of fibroblasts in periprosthetic osteoclastogenesis in the future.

Background/purpose: Caffeic acid phenethyl ester (CAPE) is an antioxidant which is decreases the bone resorption and enhances the bone healing. The aim of this study was to investigate the effects of administering systemic CAPE on alveolar bone loss in rats with experimental periodontitis. Materials and methods: Thirty male Sprague Dawley rats were divided into three groups: control, endotoxin-induced periodontitis (EP), and EP treated with CAPE (EP-CAPE). Endotoxin was injected into the gingiva of test rats on days 1, 3, and 5, whereas saline was injected into the control rats. The EP-CAPE group received 10 mmol/kg/day CAPE intraperitoneally for 28 consecutive days. Saline was given in the control and EP groups in the same manner. At the end of the study, intracardiac blood samples were obtained, and the rats were sacrificed. Alveolar bone loss was analyzed with histometric measurements. The oxidative stress index (OSI) was used to evaluate the oxidative stress. The receptor activator of the nuclear factor kappa B ligand (RANKL) level was analyzed stereologically. Results: CAPE administration significantly decreased the serum OSI and interleukin-1 beta levels. Alveolar bone loss was statistically higher in the EP group compared with the EP-CAPE group (P < 0.05). Immunohistochemical analyses of the RANKL were significantly lower in the EP-CAPE group than in the EP group (P < 0.05). Conclusion: This experimental study revealed that CAPE administration significantly prevented alveolar bone loss and stimulated periodontal tissue healing. (C) 2019 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. C1 [Kizildag, Alper] Pamukkale Univ, Fac Dent, Dept Periodontol, TR-20070 Denizli, Turkey. [Arabaci, Taner] Ataturk Univ, Fac Dent, Dept Periodontol, Erzurum, Turkey. [Albayrak, Mevlut] Ataturk Univ, Hlth Serv Vocat Training Sch, Med Lab Dept, Erzurum, Turkey. [Tasdemir, Ufuk; Senel, Erman] Pamukkale Univ, Fac Dent, Dept Maxillofacial Surg, Denizli, Turkey. [Dalyanoglu, Mukaddes] Pamukkale Univ, Med Sch, Dept Physiol, Denizli, Turkey. [Demirci, Elif] Ataturk Univ, Med Sch, Med Biol Dept, Erzurum, Turkey.

Osteoprotegerin (OPG) serum levels are associated with liver fibrogenesis and have been proposed as a biomarker for diagnosis. However, the source and role of OPG in liver fibrosis are unknown, as is the question of whether OPG expression responds to treatment. Therefore, we aimed to elucidate the fibrotic regulation of OPG production and its possible function in human and mouse livers. OPG levels were significantly higher in lysates of human and mouse fibrotic livers compared to healthy livers. Hepatic OPG expression localized in cirrhotic collagenous bands in and around myofibroblasts. Single cell sequencing of murine liver cells showed hepatic stellate cells (HSC) to be the main producers of OPG in healthy livers. Using mouse precision-cut liver slices, we found OPG production induced by transforming growth factor β1 (TGFβ1) stimulation. Moreover, OPG itself stimulated expression of genes associated with fibrogenesis in liver slices through TGFβ1, suggesting profibrotic activity of OPG. Resolution of fibrosis in mice was associated with decreased production of OPG compared to ongoing fibrosis. OPG may stimulate fibrogenesis through TGFβ1 and is associated with the degree of fibrogenesis. It should therefore be investigated further as a possible drug target for liver fibrosis or biomarker for treatment success of novel antifibrotics.

Objective: Besides its hematopoietic function, erythropoietin (EPO) may protect tissues from degenerative disorders. As such, EPO and its receptors were revealed in nonhematopoietic cells, including stromal and endometrial epithelial cells. However, the role of EPO in endometrial disorders is still unknown. Here, we aimed to examine the role of EPO and its receptor activation in the development of endometriosis in rats. Material and Methods: Animals were treated with EPO, darbepoietin (the synthetic form of EPO) or EPO’s receptor activator, methoxy polyethylene glycol-epoetin beta (MIRCERA), after development of endometriosis. Endometriosis was induced by estrogen-administration following surgical attachment of endometrial surface on the inner abdominal wall. Treatments were started 3 weeks after induction of endometriosis and continued for the following 3 weeks. For the analysis of recurrence of endometriosis, additional analyses were conducted 3 weeks after cessation of treatments. Results: As compared with vehicle-treated animals, lesion size was reduced significantly and recurrence of endometriosis was not observed in all treatment groups. Histopathologic examination revealed that EPO and darbepoietin were more effective than MIRCERA- and vehicle-treated animals. Conclusion: Here we provide evidence that EPO is a promising candidate for the treatment of endometriosis. Our histopathologic results in particular indicate that EPO is more effective than its receptor activator MIRCERA in the development endometriosis. © 2019 by the Turkish-German Gynecological Education and Research Foundation. Türkiye Bilimler Akademisi Acknowledgements: This work was funded by Turkish Academy of Sciences (TUBA). We would like to thank to Laboratory Technician Nurhayat Dönek from Bezmialem University for help throughout this research.

Oxidative stress is involved in the pathogenesis of a variety of inflammatory disorders. Apical periodontitis (AP) usually results in the formation of an osteolytic apical lesion (AL) caused by the immune response to endodontic infection. Reactive oxygen species (ROS) produced by phagocytic cells in response to bacterial challenge represent an important host defense mechanism, but disturbed redox balance results in tissue injury. This mini review focuses on the role of oxidative stress in the local and associated systemic events in chronic apical periodontitis. During endodontic infection, ligation of Toll-like receptors (TLRs) on phagocytes' surface triggers activation, phagocytosis, synthesis of ROS, activation of humoral and cellular responses, and production of inflammatory mediators, such as, cytokines and matrix metalloproteinases (MMPs). The increment in ROS perturbs the normal redox balance and shifts cells into a state of oxidative stress. ROS induce molecular damage and disturbed redox signaling, that result in the loss of bone homeostasis, increased pro-inflammatory mediators, and MMP overexpression and activation, leading to apical tissue breakdown. On the other hand, oxidative stress has been strongly involved in the pathogenesis of atherosclerosis, where a chronic inflammatory process develops in the arterial wall. Chronic AP is associated with an increased risk of cardiovascular diseases (CVD) and especially atherogenesis. The potential mechanisms linking these diseases are also discussed.

Accepted manuscript version. Published version available in Cancer Prevention Research, September 1 2017 (10) (9) 525-534 Receptor activator of nuclear factor-kappa B (RANK)-RANK ligand (RANKL) signaling promotes mammary tumor development in experimental models. Circulating concentrations of soluble RANKL (sRANKL) may influence breast cancer risk via activation of RANK signaling; this may be modulated by osteoprotegerin (OPG), the decoy receptor for RANKL. sRANKL and breast cancer risk by hormone receptor subtype has not previously been investigated. A case–control study was nested in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. This study included 1,976 incident invasive breast cancer cases [estrogen receptor positive (ER+), n = 1,598], matched 1:1 to controls. Women were pre- or postmenopausal at blood collection. Serum sRANKL was quantified using an ELISA, serum OPG using an electrochemiluminescent assay. Risk ratios (RR) and 95% confidence intervals (95% CI) were calculated using conditional logistic regression. Associations between sRANKL and breast cancer risk differed by tumor hormone receptor status (Phet = 0.05). Higher concentrations of sRANKL were positively associated with risk of ER+ breast cancer [5th vs. 1st quintile RR 1.28 (95% CI, 1.01–1.63); Ptrend = 0.20], but not ER− disease. For both ER+ and estrogen and progesterone receptor positive (ER+PR+) breast cancer, results considering the sRANKL/OPG ratio were similar to those for sRANKL; we observed a suggestive inverse association between the ratio and ER−PR− disease [5th vs. 1st quintile RR = 0.60 (0.31–1.14); Ptrend = 0.03]. This study provides the first large-scale prospective data on circulating sRANKL and breast cancer. We observed limited evidence for an association between sRANKL and breast cancer risk.

Glycosphingolipids (GSLs) are essential constituents of cell membranes and lipid rafts and can modulate signal transduction events. The contribution of GSLs in osteoclast (OC) activation and osteolytic bone diseases in malignancies such as the plasma cell dyscrasia multiple myeloma (MM) is not known. Here, we tested the hypothesis that pathological activation of OCs in MM requires de novo GSL synthesis and is further enhanced by myeloma cell-derived GSLs. Glucosylceramide synthase (GCS) inhibitors, including the clinically approved agent N-butyl-deoxynojirimycin (NB-DNJ), prevented OC development and activation by disrupting RANKL-induced localization of TRAF6 and c-SRC into lipid rafts and preventing nuclear accumulation of transcriptional activator NFATc1. GM3 was the prevailing GSL produced by patient-derived myeloma cells and MM cell lines, and exogenous addition of GM3 synergistically enhanced the ability of the pro-osteoclastogenic factors RANKL and insulin-like growth factor 1 (IGF-1) to induce osteoclastogenesis in precursors. In WT mice, administration of GM3 increased OC numbers and activity, an effect that was reversed by treatment with NB-DNJ. In a murine MM model, treatment with NB-DNJ markedly improved osteolytic bone disease symptoms. Together, these data demonstrate that both tumor-derived and de novo synthesized GSLs influence osteoclastogenesis and suggest that NB-DNJ may reduce pathological OC activation and bone destruction associated with MM.

Introduction Erythropoiesis-stimulating agents and iron are commonly used in patients with chronic kidney disease with the aim of correcting anemia and maintaining stable hemoglobin levels. We analyzed pooled data from 13 studies with similar designs included in the Umbrella Continuous Erythropoietin Receptor Activator (C.E.R.A.) program to investigate the effects of continuous erythropoiesis receptor activator in clinically relevant subgroups of patients with chronic kidney disease and to determine whether the efficacy and safety outcomes demonstrated in the overall chronic kidney disease population are maintained in specific subgroups. Methods Data from 13 Phase III trials set up with similar design were retrospectively pooled for this analysis. Patients with chronic kidney disease who had previously been receiving epoetin or darbepoetin were switched to continuous erythropoiesis receptor activator once-monthly after a 4- to 8-week screening period. Patients entered a 16-week continuous erythropoiesis receptor activator dose-titration period followed by an 8-week evaluation period. In total, 2060 patients were included in the analysis. Subgroups were defined based on: hemoglobin target range [lower (10.0–12.0 g/dL)/upper (10.5–13.0 g/dL)], gender (female/male), age (

Made available in DSpace on 2019-09-12T16:53:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2011 NIH, National Institute of Dental and Craniofacial Research Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Fluoxetine, one of the selective serotonin reuptake inhibitors (SSRIs), has been found to possess immune modulation effects, in addition to its antidepressant effects. However, it remains unclear whether SSRIs can suppress the antigen-presenting function of dendritic cells (DCs). Therefore, Fluoxetine was applied to a co-culture of Aggregatibacter actinomycetemcomitans (Aa)-reactive T cells (x Aa-T) isolated from Aa-immunized mice and DCs. This resulted in the suppressed proliferation of x Aa-T stimulated with Aa-antigen presentation by DCs. Specifically, Fluoxetine increased the extracellular 5-hydroxytryptamine (5-HT) in the x Aa-T/DC co-culture, whereas exogenously applied 5-HT promoted T-cell proliferation in the x Aa-T/DC co-culture, indicating that Fluoxetine-mediated suppression of x Aa-T/DC responses cannot be attributed to extracellular 5-HT. Instead, Fluoxetine remarkably suppressed the expression of costimulatory molecule ICOS-L on DCs. Fluoxetine also promoted a greater proportion of CD86(Low) immature DCs than CD86(High) mature DCs, while maintaining the expression levels of CD80, MHC-class-II and PD-L1. These results suggested that Fluoxetine suppressed the ability of DCs to present bacterial antigens to T cells, and the resulting T-cell proliferation, in a SERT/5-HT-independent manner and that diminished expression of ICOS-L on DCs and increase of CD86(Low) immature DCs caused by Fluoxetine might be partially associated with Fluoxetine-mediated suppression of DC/T-cell responses. [Branco-de-Almeida, Luciana S.; Kajiya, Mikihito; Cardoso, Cristina R.; Silva, Marcelo J. B.; Ohta, Kouji; Han, Xiaozhe; Taubman, Martin A.; Kawai, Toshihisa] Forsyth Inst, Dept Immunol, Boston, MA USA [Branco-de-Almeida, Luciana S.; Rosalen, Pedro L.] Univ Estadual Campinas, Piracicaba Dent Sch, Dept Physiol Sci, Campinas, SP, Brazil [Kajiya, Mikihito; Ohta, Kouji; Kawai, Toshihisa] Harvard Univ, Sch Dent Med, Dept Oral Med Infect & Immun, Boston, MA 02115 USA [Cardoso, Cristina R.] Univ Fed Triangulo Mineiro, Dept Biol Sci, Uberaba, MG, Brazil [Franco, Gilson C. N.] Universidade de Taubaté (Unitau), Dept Oral Biol

Familial expansile osteolysis and related disorders are caused by heterozygous tandem duplication mutations in the signal peptide region of the gene encoding receptor activator of NF-kappa B (RANK), a receptor critical for osteoclast formation and function. Previous studies have shown that overexpression of these mutant proteins causes constitutive activation of NF-kappa B signaling in vitro, and it has been assumed that this accounts for the focal osteolytic lesions that are seen in vivo. We show here that constitutive activation of NF-kappa B occurred in HEK293 cells overexpressing wild-type or mutant RANK but not in stably transfected cell lines expressing low levels of each RANK gene. Importantly, only cells expressing wild-type RANK demonstrated ligand-dependent activation of NF-kappa B. When over-expressed, mutant RANK did not localize to the plasma membrane but localized to extensive areas of organized smooth endoplasmic reticulum, whereas, as expected, wild-type RANK was detected at the plasma membrane and in the Golgi apparatus. This intracellular accumulation of the mutant proteins is probably the result of lack of signal peptide cleavage because, using two in vitro translation systems, we demonstrate that the mutations in RANK prevent cleavage of the signal peptide. In conclusion, signal peptide mutations lead to accumulation of RANK in the endoplasmic reticulum and prevent direct activation by RANK ligand. These results strongly suggest that the increased osteoclast formation/activity caused by these mutations cannot be explained by studying the homozygous phenotype alone but requires further detailed investigation of the heterozygous expression of the mutant RANK proteins. (C) 2011 American Society for Bone and Mineral Research.

Stimulation of erythropoiesis by the third-generation erythropoietin drug, continuous erythropoietin receptor activator (CERA), a pegylated derivative of epoetin-β, has provided valuable therapeutic benefits to patients suffering from renal anemia, but has also rapidly found application as an illicit performance-enhancing strategy in endurance sports. We present here a novel method for selective determination of CERA in serum, based on polyethylene glycol precipitation, followed by a commercial homogeneous immunoassay. The developed method was highly discriminating between serum samples from CERA-treated patients and control subjects, as the covalently linked polyethylene glycol chain in CERA strongly enhanced the solubility of the protein in a polyethylene glycol-containing medium. Intravenous administration of CERA could be detected for several weeks in the majority of subjects tested. This assay outperforms the currently available CERA detection methods in terms of simplicity, convenience, cost, and throughput, making it ideal as a screening tool for doping control.

Postmenopausal osteoporosis (PO) is a major public health issue which affects a large fraction of elderly women. Emergingin vitroevidence suggests a central role of oxidative stress (OxS) in postmenopausal osteoporosis (PO) development. Contrariwise, the human studies on this topic are still scarce and inconclusive. In the attempt to address this issue, we sought to determine if OxS, as assessed by 8-hydroxy-2-deoxyguanosine (8-OHdG), may influence the level of receptor activator of nuclear factor-κb ligand (RANKL)/osteoprotegerin (OPG) ratio (a central regulator of bone metabolism) in a samplen=124, including postmenopausal women with osteoporosis, osteopenia and normal bone mass density (BMD). The most striking result that emerged in our study was the independent and positive (beta = 0.449,p=0.004, andR2=0.185) association between the OxS marker and RANKL/OPG ratio which was found in osteopenic but not in the other 2 sample groups. If confirmed by longitudinal studies, our findings would suggest that OxS is implicated in the derangement of bone homeostasis which precedes PO development. In line with these considerations, antioxidant treatment of postmenopausal women with moderately low BMD might contribute to preventing PO and related complications.

We hypothesised that tumour necrosis factor-α(TNF-α) may enhance receptor activator of nuclear factor-κβligand- (RANKL-) mediated osteoclastogenesis in acute Charcot osteoarthropathy. Peripheral blood monocytes were isolated from 10 acute Charcot patients, 8 diabetic patients, and 9 healthy control subjects and culturedin vitroon plastic and bone discs. Osteoclast formation and resorption were assessed after treatment with (1) macrophage-colony stimulating factor (M-CSF) and RANKL and (2) M-CSF, RANKL, and neutralising antibody to TNF-α(anti-TNF-α). Resorption was measured on the surface of bone discs by image analysis and under the surface using surface profilometry. Although osteoclast formation was similar in M-CSF + RANKL-treated cultures between the groups (p>0.05), there was a significant increase in the area of resorption on the surface (p<0.01) and under the surface (p<0.01) in Charcot patients compared with diabetic patients and control subjects. The addition of anti-TNF-αresulted in a significant reduction in the area of resorption on the surface (p<0.05) and under the surface (p<0.05) only in Charcot patients as well as a normalisation of the aberrant erosion profile. We conclude that TNF-αmodulates RANKL-mediated osteoclastic resorptionin vitroin patients with acute Charcot osteoarthropathy.

"This research was originally published in Journal of Biological Chemistry. Lilian I. Plotkin, Arancha R. Gortazar, Hannah M. Davis, Keith W. Condon, Hugo Gabilondo, Marta Maycas, Matthew R. Allen, and Teresita Bellido. Inhibition of Osteocyte Apoptosis Prevents the Increase in Osteocytic Receptor Activator of Nuclear Factor κB Ligand (RANKL) but Does Not Stop Bone Resorption or the Loss of Bone Induced by Unloading*. Journal of Biological Chemistry. 2015; 290:18934-18942. © the American Society for Biochemistry and Molecular Biology.", Apoptosis of osteocytes and osteoblasts precedes bone resorption and bone loss with reduced mechanical stimulation, and receptor activator of NF-κB ligand (RANKL) expression is increased with unloading in mice. Because osteocytes are major RANKL producers, we hypothesized that apoptotic osteocytes signal to neighboring osteocytes to increase RANKL expression, which, in turn, increases osteoclastogenesis and bone resorption. The traditional bisphosphonate (BP) alendronate (Aln) or IG9402, a BP analog that does not inhibit resorption, prevented the increase in osteocyte apoptosis and osteocytic RANKL expression. The BPs also inhibited osteoblast apoptosis but did not prevent the increase in osteoblastic RANKL. Unloaded mice exhibited high serum levels of the bone resorption marker C-telopeptide fragments of type I collagen (CTX), elevated osteoclastogenesis, and increased osteoclasts in bone. Aln, but not IG9402, prevented all of these effects. In addition, Aln prevented the reduction in spinal and femoral bone mineral density, spinal bone volume/tissue volume, trabecular thickness, mechanical strength, and material strength induced by unloading. Although IG9402 did not prevent the loss of bone mass, it partially prevented the loss of strength, suggesting a contribution of osteocyte viability to strength independent of bone mass. These results demonstrate that osteocyte apoptosis leads to increased osteocytic RANKL. However, blockade of these events is not sufficient to restrain osteoclast formation, inhibit resorption, or stop bone loss induced by skeletal unloading, This work was supported, in whole or in part, by National Institutes of Health Grants R01DK076007 and ARRA supplement S10-RR023710 (to T. B.) and R01AR053643 (to L. I. P.). This work was also supported by Veterans Affairs Merit Award I01BX002104 (to T. B.) and an IUSM Biomedical Research grant (to L. I. P.) and by scholarships from the Conchita Rábago Foundation (to A. R. G. and M. M.), the European Molecular Biology Organization (to M. M.), and Universidad Autónoma de Madrid (to H. G)

Copyright: © 2015 Perpétuo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited, Introduction: Ankylosing Spondylitis (AS) is characterized by excessive local bone formation and concomitant systemic bone loss. Tumor necrosis factor (TNF) plays a central role in the inflammation of axial skeleton and enthesis of AS patients. Despite reduction of inflammation and systemic bone loss, AS patients treated with TNF inhibitors (TNFi) have ongoing local bone formation. The aim of this study was to assess the effect of TNFi in the differentiation and activity of osteoclasts (OC) in AS patients. Methods: 13 AS patients treated with TNFi were analyzed at baseline and after a minimum follow-up period of 6 months. 25 healthy donors were recruited as controls. Blood samples were collected to assess receptor activator of nuclear factor kappa-B ligand (RANKL) surface expression on circulating leukocytes and frequency and phenotype of monocyte subpopulations. Quantification of serum levels of bone turnover markers and cytokines, in vitro OC differentiation assay and qRT-PCR for OC specific genes were performed. Results: RANKL+ circulating lymphocytes (B and T cells) and IL-17A, IL-23 and TGF-β levels were decreased after TNFi treatment. We found no differences in the frequency of the different monocyte subpopulations, however, we found decreased expression of CCR2 and increased expression of CD62L after TNFi treatment. OC number was reduced in patients at baseline when compared to controls. OC specific gene expression was reduced in circulating OC precursors after TNFi treatment. However, when cultured in OC differentiating conditions, OC precursors from AS TNFi-treated patients showed increased activity as compared to baseline. Conclusion: In AS patients, TNFi treatment reduces systemic pro osteoclastogenic stimuli. However, OC precursors from AS patients exposed to TNFi therapy have increased in vitro activity in response to osteoclastogenic stimuli., This work was supported by Fundação para a Ciência e Tecnologia (http://www.fct.pt/index.phtml.en) PhD grant (SFRH/BD/70533/2010) and in part by a research grant from Investigator-Initiated Studies Program of Merck Sharp & Dohme Corp (http://www.merck.com/index.html - Merck_P08574). The opinions expressed in this paper are those of the authors and do not necessarily represent those of Merck Sharp & Dohme Corp.

Pendahuluan. Artritis Reumatoid (AR) merupakan penyakit autoimun dengan etiologi yang belum jelas, gejala utama dari AR adalah keradangan pada sendi yang ditandai dengan sinovitis simetris dan erosi tulang, walaupun perjalanan penyakit AR sulit diduga dengan sifat kronik-remisi-eksaserbasi namun secara umum hasil akhir dari AR adalah deformitas sendi. Penelitian terakhir pada AR menunjukkan adanya overekspresi dari sejumlah enzim matrix metallopeoteinases (MMPs) yang mempunyai kemampuan degradasi komponen kolagen dam matriks ekstraseluler tulang rawan Beberapa penelitian menemukan keterlibatan MMP-2,MMP-9, MMP-1 ,MMP-8 dan MMP-3 pada penyakit AR. Penelitian di Taiwan oleh Chang Yh menunjukkan peningkatan kadar dan aktifitas MMP-9 pada pasien AR di Taiwan dibandingkan pada populasi normal.Giannelli melaporkan peningkatan kadar MMP-2, MMP- 9, Tissue Inhibitor Matrix proteinase 1 dan Tissue Inhibitor Matrix proteinase 2 pada pasien dengan AR dan artritis psoriasis, Gruber juga melaporkan adanya peningkatan yang bermakna dari kadar MMP-9 atau gelatinase B pada serum pasien AR. Penelitian ini bertujuan untuk meningkatkan pemahaman mengenai peran MMP-9 pada patofisiologi kerusakan sendi AR, serta mencari korelasi antara kadar MMP-9 , laju endap darah (LED), faktor reumatoid dan lama sakit dengan gambaran radiologis pada pasien AR. Metode. Penelitian ini menggunakan studi potong lintang analitik dengan metode sampling konsekutif yang dilakukan di poliklinik Reumatologi/Ilmu Penyakit Dalam RSUPN Cipto Mangunkusumo. Sebagai variabel bebas adalah : kadar matriks metalloproteinase 9, laju endap darah (LED) , faktor reumatoid dan lama sakit sementara variabel tergantung adalah skor radiologis Sharp. Hasil. Dari 46 subjek penelitian didapatkan peningkatan kadar rerata MMP-9 yaitu sebesar 104,82 ng/ml, rerata LED 58,5 mm/jam, rerata kadar faktor reumatoid 57,13 IU/ml dan rerata lama sakit adalah 4,83 tahun. Korelasi antara kadar MMP-9 dengan skor erosi tulang secara radiologis adalah r=0,3 dengan p=0,02 (bermakna), sementara korelasi antara lama sakit dengan gambaran radiologis (skor Sharp) r=0,36 dengan p=0,014 (bermakna). Korelasi antara LED, dan faktor reumatoid dengan gambaran radiologis adalah r=0,10,p=0,24;dan r=0,19,p=0,09. Simpulan . Didapatkan peningkatan kadar MMP-9 pada pasien AR, kadar MMP-9 berkorelasi dengan gambaran erosi tulang secara radiologis, lama sakit berkorelasi dengan gambaran radiologis (skor Sharp), Faktor reumatoid dan LED tidak berkorelasi dengan gambaran radiologis (skor Sharp).

Introduction: Progression of joint destruction in rheumatoid arthritis (RA) is partly heritably; 45 to 58% of the variance in joint destruction is estimated to be explained by genetic factors. The binding of RANKL (Receptor Activator for Nuclear Factor kappa B Ligand) to RANK results in the activation of TRAF6 (tumor necrosis factor (TNF) receptor associated factor-6), and osteoclast formation ultimately leading to enhanced bone resorption. This bone resorption is inhibited by osteoprotegerin (OPG) which prevents RANKL-RANK interactions. The OPG/RANK/RANKL/TRAF6 pathway plays an important role in bone remodeling. Therefore, we investigated whether genetic variants in OPG, RANK, RANKL and TRAF6 are associated with the rate of joint destruction in RA. Methods: 1,418 patients with 4,885 X-rays of hands and feet derived from four independent data-sets were studied. In each data-set the relative increase of the progression rate per year in the presence of a genotype was assessed. First, explorative analyses were performed on 600 RA-patients from Leiden. 109 SNPs, tagging OPG, RANK, RANKL and TRAF6, were tested. Single nucleotide polymorphisms (SNPs) significantly associated in phase-1 were genotyped in data-sets from Groningen (Netherlands), Sheffield (United Kingdom) and Lund (Switzerland). Data were summarized in an inverse weighted variance meta-analysis. Bonferonni correction for multiple testing was applied. Results: We found that 33 SNPs were significantly associated with the rate of joint destruction in phase-1. In phase-2, six SNPs in OPG and four SNPs in RANK were associated with progression of joint destruction with P-value

Background Low bone mineral density (BMD) has been reported in both paediatric and adult patients with non-alcoholic fatty liver disease (NAFLD). The mechanisms behind the reduced BMD in NAFLD are still not completely understood. Aim To provide a critical overview of the pathophysiological pathways linking NAFLD, reduced BMD and osteoporosis, with a special focus on the alterations of soluble mediators which could link fat accumulation in the liver with bone health. The MEDLINE database was searched by a combination of keywords: non-alcoholic fatty liver disease OR hepatic steatosis OR metabolic syndrome OR insulin resistance AND bone mineral density OR osteoporosis OR bone AND biomarkers OR serum marker. Results Several factors that may influence bone mineralisation and the increased risk of osteoporosis in NAFLD can be discussed. These include the release of cytokines from the inflamed liver which may influence the bone microenvironment, vitamin D deficiency, and limited physical activity. Circulating markers of bone metabolism, including osteopontin, osteoprotegerin, osteocalcin and fetuin-A, have been found to be altered in patients with NAFLD. Conclusion A better understanding of the mechanisms that link bone metabolism and the liver may open a new frontier to fight two highly prevalent conditions like NAFLD and osteoporosis.

Background Adalimumab blocks the action of tumor necrosis factor-alpha and reduces disease progression in rheumatoid arthritis and psoriatic arthritis. The effects of adalimumab in controlling progression of structural damage in erosive hand osteoarthritis (HOA) were assessed. Methods Sixty patients with erosive HOA on radiology received 40 mg adalimumab or placebo subcutaneously every two weeks during a 12-month randomized double-blind trial. Response was defined as the reduction in progression of structural damage according to the categorical anatomic phase scoring system. Furthermore, subchondral bone, bone plate erosion, and joint-space narrowing were scored according to the continuous Ghent University Score System (GUSS (TM)). Results The disease appeared to be active since 40.0% and 26,7% of patients out of the placebo and adalimumab group, respectively, showed at least one new interphalangeal (IP) joint that became erosive during the 12 months follow-up. These differences were not significant and the overall results showed no effect of adalimumab. Risk factors for progression were then identified and the presence of palpable soft tissue swelling at baseline was recognized as the strongest predictor for erosive progression. In this subpopulation at risk, statistically significant less erosive evolution on the radiological image (3.7%) was seen in the adalimumab treated group compared to the placebo group (14.5%) (P = 0.009). GUSSTM scoring confirmed a less rapid rate of mean increase in the erosion scores during the first 6 months of treatment in patients in adalimumab-treated patients. Conclusion Palpable soft tissue swelling in IP joints in patients with erosive HOA is a strong predictor for erosive progression. In these joints adalimumab significantly halted the progression of joint damage compared to placebo.

The discovery of the receptor activator of nuclear factor-kB (RANK)/RANK Ligand (RANKL)/osteoprotegerin (OPG) pathway contributed to the understanding of how bone formation and resorption were processed and regulated. RANKL and OPG are members of the tumor necrosis factor (TNF) and TNF receptor (TNFr) superfamilies, respectively, and binding to receptor activator of NF-kB (RANK) not only regulate osteoclast formation, activation and survival in normal bone modeling and remodeling, but also in several other pathologic conditions characterized by increased bone turnover. There is accumulating evidence of the potential role of OPG and RANKL in other tissues. Looking beyond the RANK/RANKL/OPG axis, Wingless (Wnt) pathway emerged as the osteoblast differentiation way, and also as a bone mass regulator. Researchers have been discovering new molecules and cytokines interactions. Altogether, data suggest that RANK/RANKL/OPG system could be targeted as a new treatment strategy in bone conditions. FREEDOM is the more recently published clinical trial about a RANKL-specific recombinant fully human monoclonal antibody (denosumab). OPG is also a potential innovative therapeutic option to be investigated. publishersversion published

International audience; Bone sialoprotein (BSP) and osteopontin (OPN) belong to the small integrin-binding ligand N-linked glycoprotein (SIBLING) family, whose members interact with bone cells and bone mineral Previously, we showed that BSP knockout (BSP(-/-)) mice have a higher bone mass than wild type (BSP(+/+)) littermates, with very low bone-formation activity and reduced osteoclast surfaces and numbers Here we report that approximately twofold fewer tartrate-resistant acid phosphatase (TRACP)-positive cells and approximately fourfold fewer osteoclasts form in BSP(-/-) compared with BSP(+/+) spleen cell cultures BSP(-/-) preosteoclast cultures display impaired proliferation and enhanced apoptosis Addition of RGD-containing proteins restores osteoclast number in BSP(-/-) cultures to BSP(+/+) levels The expression of osteoclast-associated genes is markedly altered in BSP(-/-) osteoclasts, with reduced expression of cell adhesion and migration genes (alpha V integrin chain and OPN) and increased expression of resorptive enzymes (TRACP and cathepsin K) The migration of preosteoclasts and mature osteoclasts is impaired in the absence of BSP, but resorption pit assays on dentine slices show no significant difference in pit numbers between BSP(+/+) and BSP(-/-) osteoclasts However, resorption of mineral-coated slides by BSP(-/-) osteoclasts is markedly impaired but is fully restored by coating the mineral substrate with hrBSP and partly restored by hrOPN coating In conclusion, lack of BSP affects both osteoclast formation and activity, which is in accordance with in vivo findings Our results also suggest at least some functional redundancy between BSP and OPN that remains to be clarified (C) 2010 American Society for Bone and Mineral Research

Background The molecular mechanisms leading to a fully differentiated thyrocite are still object of intense study even if it is well known that thyroglobulin, thyroperoxidase, NIS and TSHr are the marker genes of thyroid differentiation. It is also well known that Pax8, TTF-1, Foxe1 and Hhex are the thyroid-enriched transcription factors responsible for the expression of the above genes, thus are responsible for the differentiated thyroid phenotype. In particular, the role of Pax8 in the fully developed thyroid gland was studied in depth and it was established that it plays a key role in thyroid development and differentiation. However, to date the bases for the thyroid-enriched expression of this transcription factor have not been unraveled yet. Here, we report the identification and characterization of a functional thyroid-specific enhancer element located far upstream of the Pax8 gene. Results We hypothesized that regulatory cis-acting elements are conserved among mammalian genes. Comparison of a genomic region extending for about 100 kb at the 5'-flanking region of the mouse and human Pax8 gene revealed several conserved regions that were tested for enhancer activity in thyroid and non-thyroid cells. Using this approach we identified one putative thyroid-specific regulatory element located 84.6 kb upstream of the Pax8 transcription start site. The in silico data were verified by promoter-reporter assays in thyroid and non-thyroid cells. Interestingly, the identified far upstream element manifested a very high transcriptional activity in the thyroid cell line PC Cl3, but showed no activity in HeLa cells. In addition, the data here reported indicate that the thyroid-enriched transcription factor TTF-1 is able to bind in vitro and in vivo the Pax8 far upstream element, and is capable to activate transcription from it. Conclusions Results of this study reveal the presence of a thyroid-specific regulatory element in the 5' upstream region of the Pax8 gene. The identification of this regulatory element represents the first step in the investigation of upstream regulatory mechanisms that control Pax8 transcription during thyroid differentiation and are relevant to further studies on Pax8 as a candidate gene for thyroid dysgenesis.

This article has an erratum: http://dx.doi.org/10.1007/s10549-011-1654-4 Since bone metastatic breast cancer is an incurable disease, causing significant morbidity and mortality, an understanding of the underlying molecular mechanisms would be highly valuable. Here, we describe in vitro and in vivo evidences for the importance of serine biosynthesis in the metastasis of breast cancer to bone. We first characterized the bone metastatic propensity of the MDA-MB-231(SA) cell line variant as compared to the parental MDA-MB-231 cells by radiographic and histological observations in the inoculated mice. Genome-wide gene expression profiling of this isogenic cell line pair revealed that all the three genes involved in the L-serine biosynthesis pathway, phosphoglycerate dehydrogenase (PHGDH), phosphoserine aminotransferase 1 (PSAT1), and phosphoserine phosphatase (PSPH) were upregulated in the highly metastatic variant. This pathway is the primary endogenous source for L-serine in mammalian tissues. Consistently, we observed that the proliferation of MDAMB- 231(SA) cells in serine-free conditions was dependent on PSAT1 expression. In addition, we observed that L-serine is essential for the formation of bone resorbing human osteoclasts and may thus contribute to the vicious cycle of osteolytic bone metastasis. High expression of PHGDH and PSAT1 in primary breast cancer was significantly associated with decreased relapse-free and overall survival of patients and malignant phenotypic features of breast cancer. In conclusion, high expression of serine biosynthesis genes in metastatic breast cancer cells and the stimulating effect of L-serine on osteoclastogenesis and cancer cell proliferation indicate a functionally critical role for serine biosynthesis in bone metastatic breast cancer and thereby an opportunity for targeted therapeutic interventions.

The process of osteoclast differentiation and resorption is fine-tuned by signal pathways, which need to be further elucidated. The aim of this study was to explore the possible connections between NF-kappa B and Notch in RANKL-induced osteoclast activity. To this end, RANKL was used to stimulate mouse osteoclast precursor cell line RAW264.7. The number of multinucleated TRAP(+) osteoclasts was counted and the resorption area was measured. NF-kappa B transcriptional factor activity was determined by EMSA. Quantitative RT-PCR and Western blotting analysis were used to determine Hes1 (one of Notch signaling primary targets) mRNA and protein expressions respectively. Mature osteoclasts and bone resorption areas were detected in the present study. NF-kappa B activity was increased in RANKL-induced osteoclast differentiation and resorption. mRNA and protein expressions of Hes1 in RAW264.7 cells were up-regulated after RANKL stimulation. In conclusion, NF-kappa B signaling mediated RANKL-induced osteoclast differentiation and resorption, during which, Notch signaling was activated. Therefore, Notch could be a novel therapeutic target for bone resorption related diseases.

9 páginas, 3 figuras, 4 tablas -- PAGS nros. 1772-1780, Background: Chronic periodontitis is an infectious disease characterized by alveolar bone destruction and teeth loss. Receptor activator of nuclear factor-kappa B ligand (RANKL) is an osteoclastogenic cytokine, a central regulatory factor in the osteoclast’s lifespan, and a participant in physiological and pathological bone resorption. Gingival T cells synthesize RANKL, contributing to molecular local imbalance that entails the alveolar bone resorption seen in periodontitis. Our study was aimed at associating the levels of RANKL with the CD4+ T-cell activity present in gingival tissues of chronic periodontitis patients. Methods: Gingival biopsies were obtained from 33 chronic periodontitis patients and 20 healthy controls. Specimens were either formalin fixed and paraffin embedded for real-time reverse transcription-polymerase chain reaction (RT-PCR) and histologic analysis or tissue digestion processed for cell culture and flow-cytometry analysis. RANKLmRNA and protein levels were determined by quantitative RT-PCR and enzyme-linked immunosorbent assay (ELISA) in gingival-cell culture supernatants. Gingival leukocytes were quantified by flow cytometry. RANKL and CD4 immunoreactivity were analyzed by flow cytometry and confocal microscopy. Results: RANKL mRNA levels were higher in patients with periodontitis than in healthy subjects, and spontaneous and lipopolysaccharide (LPS)- and phytohemagglutinin (PHA)-stimulated RANKL synthesis were higher also in patients than controls. CD4+ T lymphocytes were the predominant infiltrate cell subset present in gingival tissues of periodontitis patients. Furthermore, an association between RANKL and CD4+ T cells was determined by double-staining flow cytometry and confocal microscopy. Conclusion: Taken together, these data demonstrate that gingival CD4+ T cells are the main cells responsible for higher levels of RANKL observed in human chronic periodontitis patients. J Periodontol 2006;77:1772-1780, This research was supported by grant 1050518 of Funding of Scientific and Technological Investigations (FONDECYT), Chile, and grant 01/0073-01 of Funding of Healthy Investigations (FIS), Spain