Static magnetic fields accelerate osteogenesis by regulating FLRT/BMP pathway.

OBJECTIVES: Static magnetic fields (SMF) have been proved to enhance osteogenic differentiation in mesenchymal stem cells (MSCs). However, the effect of SMF on mandibular condylar chondrocytes (MCCs) are less investigated, which contributes to the vertical formation of mandible. The purpose of the present study was to identify whether SMF accelerate the osteogenesis on mature condylar cartilage and explore the potential regulatory mechanism. METHODS: In this study, we presented a 280 mT SMF stimulation set-up to investigate the genomic effects of SMF exposure on MCCs differentiation and osteoblast-related factor secretion in vitro. Induced by Oricell™ for osteogenesis, MCCs from primary SD Rat were stimulated with or without SMF for cell culture. Cell proliferation was determined by CCK-8. The enhanced osteogenetic capacity of the SMF stimulated MCCs was identified by Alizarin red staining (ARS). Additionally, the effects of SMF on the expression of transmembrane protein marker (FLRT3), terminal differentiation markers (BMP2), and transcription factors (Smad1/5/8) were quantified by Western blot and immunofluorescence analysis. RESULTS: Compared with the control group, SMF decreased the proliferation of MCCs (p < 0.05) after 14 days osteogenesis-specific induction. The mineral synthesis of MCCs was upregulated by SMF (p < 0.0001). The expression of BMP2, Smad1/5/8 showed decrease trends while the protein level of FLRT3 acted in contrary manner (p < 0.05). CONCLUSIONS: Our findings emphasized the ability of osteogenesis positively respond to SMF stimulation by exhibiting enhanced differentiation via FLRT/BMP signaling.

Targeting Unique Epitopes on Highly Similar Proteins GDF-11 and GDF-8 with Modified DNA Aptamers.

The mature forms of the TGF-ß family members GDF-11 and GDF-8 are highly similar 25 kDa homodimers with 90% amino acid sequence identity and 99% similarity. Cross-reactivity of GDF-11 and GDF-8 binding reagents is common, making it difficult to attribute distinct roles of these two proteins in biology. We report the selection of GDF-11 and GDF-8 specific SOMAmer (Slow Off-rate Modified Aptamer) reagents aided by a combination of positive selection for one protein coupled with counter-selection against the other. We identified GDF-11 specific SOMAmer reagents from four modified DNA libraries that showed a high affinity (Kd range 0.05-1.2 nM) for GDF-11 but did not bind to GDF-8 (Kd > 1 µM). Conversely, we identified one SOMAmer reagent for GDF-8 from one of the modified libraries that demonstrated excellent affinity (Kd = 0.23 nM) and specificity. In contrast, standard protocols that utilized only positive selection produced binding reagents with similar affinity for both proteins. High affinity and specificity were efficiently encoded in minimal sequences of 21 nucleotides for GDF-11 and 24 nucleotides for GDF-8. Further characterization in pull-down, competition, sandwich-binding, and kinetic studies revealed robust binding under a wide range of buffer and assay conditions. For highly similar proteins like GDF-11 and GDF-8, our method of selection coupled with counter-selection was essential for identification of high-affinity, specific reagents that have the potential to elucidate the fundamental distinction of these growth factors in biology.

Isolation and characterization of a human cementocyte-like cell line, HCY-23.

Cementum is the mineralized tissue covering the tooth root that functions in tooth attachment and post-eruptive adjustment of tooth position. It has been reported to be highly similar to bone in several respects but remains poorly understood in terms of development and regeneration. Here, we investigate whether cementocytes, the residing cells in cellular cementum, have the potential to be protagonist in cementum homeostasis, responding to endocrine signals and directing local cementum metabolism. Cells from healthy erupted human teeth were isolated using sequential collagenase/EDTA digestions, and maintained in standard cell culture conditions. A cementocyte-like cell line was cloned (HCY-23, for human cementocyte clone 23), which presented a cementocyte compatible gene expression signature, including the expression of dentin matrix protein 1 ( DMP1 ), sclerostin ( SOST ), and E11/gp38/podoplanin ( E11 ). In contrast, these cells did not express the odontoblast/dentin marker dentin sialoprotein ( DSPP ). HCY-23 cells produced mineral-like nodules in vitro under differentiation conditions, and were highly responsive to inorganic phosphate (Pi). Within the limits of the present study, it can be concluded that cementocytes are phosphate-responsive cells, and have the potential do play a key role in periodontal homeostasis and regeneration.

Isolation and characterization of a human cementocyte-like cell line, HCY-23

Abstract Cementum is the mineralized tissue covering the tooth root that functions in tooth attachment and post-eruptive adjustment of tooth position. It has been reported to be highly similar to bone in several respects but remains poorly understood in terms of development and regeneration. Here, we investigate whether cementocytes, the residing cells in cellular cementum, have the potential to be protagonist in cementum homeostasis, responding to endocrine signals and directing local cementum metabolism. Cells from healthy erupted human teeth were isolated using sequential collagenase/EDTA digestions, and maintained in standard cell culture conditions. A cementocyte-like cell line was cloned (HCY-23, for human cementocyte clone 23), which presented a cementocyte compatible gene expression signature, including the expression of dentin matrix protein 1 ( DMP1 ), sclerostin ( SOST ), and E11/gp38/podoplanin ( E11 ). In contrast, these cells did not express the odontoblast/dentin marker dentin sialoprotein ( DSPP ). HCY-23 cells produced mineral-like nodules in vitro under differentiation conditions, and were highly responsive to inorganic phosphate (Pi). Within the limits of the present study, it can be concluded that cementocytes are phosphate-responsive cells, and have the potential do play a key role in periodontal homeostasis and regeneration.

Morphologic and molecular alteration during tibia fracture healing in rat.

OBJECTIVE: To monitor morphological feature and related osteogenic and bone metabolic change during healing of tibia fracture in a rat model. MATERIALS AND METHODS: Tibia density and trabecular thickness were evaluated. Histopathology was examined by HE staining. Serous inflammatory factors IL-4, IL-6, TNF-α and metabolic biomarkers ALP, ß-CTX, P1NP, were determined by ELISA. The expression of RUNX2, TGF-ß1, VEGF-α, BMP-2, BMP-4, and BMP-7 in callus tissue were qualified by RT-PCR. RESULTS: Bone density decreased until week 4 and then increased post-operation. Trabeculae in callus were thickened over time with active osteogenesis. ELISA indicated the most severe inflammation at week 2, with the highest level of TNF-α, IL-6, and the lowest level of IL-4. After 4 weeks, the inflammation was alleviated accompanying with the decline of TNF-α and IL-6, while there was the elevation of IL-4. Bone metabolism showed active osteogenesis and resorption at week 6 with high P1NP and ß-CTX. The expression of RUNX2, TGF-ß1, VEGF-α, BMP-2, BMP-4, and BMP-7 increased progressively from week 1 to 6. The major lesions at week 2 in sham were tissue necrosis, periosteal reactive hyperplasia, inflammatory cell infiltration, capillary hyperplasia and slight fibro-blast cytopoiesis. At week 4, proliferation was greatly activated, fibrous callus shaped and chondrogenesis and some osteogenesis occurred at week 8. CONCLUSIONS: In rat model, bone density started to increase at week 6 after fracture, accompanied with trabeculae thickening, serous inflammatory factors decline, and peaked bone morphogenetic protein/growth factors, which indicated active osteogenesis was conforming to the classical phase of secondary fracture healing.

Validation of a novel, rapid, high precision sclerostin assay not confounded by sclerostin fragments.

Sclerostin is a 190 amino acid protein secreted primarily by osteocytes. It was initially identified due to mutations in the SOST gene associated with high bone mass phenotypes. Much recent work has sought to determine the importance of sclerostin across an array of conditions which affect the human skeleton. However, accurate measurement of sclerostin from serum and plasma sources remains a significant impediment, with currently available commercial assays showing marked differences in measured sclerostin values. Accordingly, sclerostin assay standardization remains an important but unmet need before sclerostin measurements can be used for the clinical management of bone disease. Here we characterize a novel automated chemiluminescent sclerostin assay (LIAISON®, DiaSorin) which overcomes many of these limitations. Important assay characteristics include: a wide dynamic range (50-6500pg/mL); high intra- (<2.5%) and inter- (<5%) assay precision; matched serum and plasma equivalence (<10% difference); specificity for the intact sclerostin molecule; and rapid assay results. Serum sclerostin levels measured with the LIAISON® assay in a population-based sample of adult men (n=278) and women (n=348) demonstrated that sclerostin levels were significantly higher in men as compared to women and were positively associated with age in both sexes, consistent with previously published work. In postmenopausal women, serum sclerostin levels measured with the LIAISON® assay were reduced in response to treatment with either estrogen or teriparatide, again consistent with previous findings. Collectively, the above data demonstrate that the LIAISON® sclerostin assay provides a reliable tool for more confident assessment of emergent mechanisms wherein sclerostin may impact a number of bone related pathologies.

ADMP controls the size of Spemann's organizer through a network of self-regulating expansion-restriction signals.

BACKGROUND: The bone morphogenetic protein (BMP) signaling gradient is central for dorsoventral patterning in amphibian embryos. This gradient is established through the interaction of several BMPs and BMP antagonists and modulators, some secreted by Spemann's organizer, a cluster of cells coordinating embryonic development. Anti-dorsalizing morphogenetic protein (ADMP), a BMP-like transforming growth factor beta ligand, negatively affects the formation of the organizer, although it is robustly expressed within the organizer itself. Previously, we proposed that this apparent discrepancy may be important for the ability of ADMP to scale the BMP gradient with embryo size, but how this is achieved is unclear. RESULTS: Here we report that ADMP acts in the establishment of the organizer via temporally and mechanistically distinct signals. At the onset of gastrulation, ADMP is required to establish normal organizer-specific gene expression domains, thus displaying a dorsal, organizer-promoting function. The organizer-restricting, BMP-like function of ADMP becomes apparent slightly later, from mid-gastrula. The organizer-promoting signal of ADMP is mediated by the activin A type I receptor, ACVR1 (also known as activin receptor-like kinase-2, ALK2). ALK2 is expressed in the organizer and is required for organizer establishment. The anti-organizer function of ADMP is mediated by ACVRL1 (ALK1), a putative ADMP receptor expressed in the lateral regions flanking the organizer that blocks expansion of the organizer. Truncated ALK1 prevents the organizer-restricting effects of ADMP overexpression, suggesting a ligand-receptor interaction. We also present a mathematical model of the regulatory network controlling the size of the organizer. CONCLUSIONS: We show that the opposed, organizer-promoting and organizer-restricting roles of ADMP are mediated by different receptors. A self-regulating network is proposed in which ADMP functions early through ALK2 to expand its own expression domain, the organizer, and later functions through ALK1 to restrict this domain. These effects are dependent on ADMP concentration, timing, and the spatial localization of the two receptors. This self-regulating temporal switch may control the size of the organizer and the genes expressed within in response to genetic and external stimuli during gastrulation.

Immature CML cells implement a BMP autocrine loop to escape TKI treatment.

The BCR-ABL specific tyrosine kinase inhibitors (TKI) changed the outcome of chronic myeloid leukemia (CML), turning a life-threatening disease into a chronic illness. However, TKI are not yet curative, because most patients retain leukemic stem cells (LSC) and their progenitors in bone marrow and relapse following treatment cessation. At diagnosis, deregulation of the bone morphogenetic protein (BMP) pathway is involved in LSC and progenitor expansion. Here, we report that BMP pathway alterations persist in TKI-resistant patients. In comparison with patients in complete cytogenetic remission, TKI-resistant LSC and progenitors display high levels of BMPR1b expression and alterations of its cellular localization. In vitro treatment of immature chronic phase CML cells with TKI alone, or in combination with interferon-α, results in the preferential survival of BMPR1b+ cells. We demonstrated persistent and increasing BMP4 production by patients' mesenchymal cells with resistance. Patient follow-up revealed an increase of BMPR1b expression and in BMP4 expression in LSC from TKI-resistant patients in comparison with diagnosis, while remaining unchanged in sensitive patients. Both leukemic and nonleukemic cells exhibit higher BMP4 levels in the bone marrow of TKI-resistant patients. Exposure to BMP2/BMP4 does not alter BCR-ABL transcript expression but is accompanied by the overexpression of TWIST-1, a transcription factor highly expressed in resistant LSC. By modulating BMP4 or BMPR1b expression, we show that these elements are involved in TKI resistance. In summary, we reveal that persistence of BMP alterations and existence of an autocrine loop promote CML-primitive cells' TKI resistance.

Association of α2-HS Glycoprotein with Neurogenic Heterotopic Ossification in Patients with Spinal Cord Injury.

BACKGROUND The aim of this study was to explore the relationship between the α2-HS glycoprotein concentrations in serum and the occurrence of neurogenic heterotopic ossification (NHO) in patients with spinal cord injury (SCI). MATERIAL AND METHODS During the period between January 2011 and January 2012, 75 patients (67 male) with paraplegia caused by spinal cord injury were enrolled. The patients were divided into 2 groups in accordance with the occurrence of heterotopic ossification based on the results high-frequency ultrasound on the bilateral hip joint. The levels of α2-HS glycoprotein, C-reactive protein (CRP), D-dimer, and bone morphogenetic protein (BMP) were detected by ELISA. RESULTS We found a significant decrease of α2-HS glycoprotein in SCI patients with NHO compared to SCI patients without NHO. In contrast, a significant elevation of serum calcium, D-dimer, BMP, and CRP was observed in SCI patients with NHO. The degree of maturity of NHO did not influence the level of α2-HS glycoprotein. Multivariate liner regression analysis showed that the level of serum α2-HS glycoprotein was correlated with CRP and spasticity. CONCLUSIONS The decreased level of α2-HS glycoprotein may be related to the formation of neurogenic heterotopic ossification in patients with spinal cord injury. Our results suggest that α2-HS glycoprotein might be a risk factor for NHO in patients with SCI.

Association between serum dickkopf-1 levels and disease duration in axial spondyloarthritis / Asociación entre niveles séricos de Dickkopf-1 y duración de la enfermedad en espondiloartritis axial

Background. Axial spondyloarthritis (axSpA) is characterized by new bone formation. The complex systems underlying this process involve Wnt-signaling pathway. It has been observed that serum levels of dickkopf-1 (DKK-1), an important inhibitor of Wnt-signaling, are decreased in patients with axSpA. However, these data are from studies including only patients with long-standing disease. The aim of this study is to investigate if symptom duration influences on serum DKK-1 levels in patients with axSpA. Material and methods. A cross-sectional study including consecutive patients with axSpA (ASAS criteria) naïve for anti-TNF therapy. Collected data included demographic and disease characteristics, time since first symptom onset, assessment of disease activity and function, and determination of DKK-1 serum levels. Patients were classified as early axSpA (symptom duration ≤5 years) and established axSpA (>5 years). Linear regression models were employed to investigate the variables related to DKK-1 serum levels. Results. In total, 90 patients were included. Sixty-eight patients had early axSpA and 22 had established disease. Serum levels of DKK-1 were significantly higher in patients with early axSpA compared with established axSpA (22.1±12.6 vs 16.4±10.7pM; p=0.04). Among all tested variables, only symptom duration was significantly and inversely correlated with DKK-1 serum levels (beta: −0.041; p=0.01). Conclusion. Serum DKK-1 levels in axSpA depend on disease duration. As disease duration increases, DKK-1 serum levels decrease. Based on this, an intensive treatment at early stages of the disease could have a better outcome on inhibiting/slowing radiographic progression in patients with axSpA (AU)

Objetivo. Espondiloartritis axial (EsPax) se caracteriza por nueva formación ósea. El complejo sistema que subyace este proceso incluye la vía de señal Wnt. Se ha demostrado que niveles séricos de dickkopf-1 (DKK-1), un importante inhibidor de la vía de señal Wnt, está disminuidos en pacientes con EsPax. Sin embargo, estos datos proceden exclusivamente de pacientes con EsPax de larga duración. El objetivo de este estudio es investigar si la duración de la enfermedad influye en niveles séricos de DKK-1 en pacientes con EsPax. Material y métodos. Estudio transversal en pacientes con EsPax sin terapia anti-TNF. Se recogieron datos demográficos y de la enfermedad, y se determinaron niveles de DKK-1 séricos en la misma visita. Los pacientes fueron clasificados en base a la duración de síntomas en EsPax precoz (≤5 años) y establecida (>5 años). Se emplearon modelos de regresión lineal para investigar las variables asociadas con los niveles de DKK-1. Resultados. Se incluyeron 90 pacientes, 68 con EsPax precoz y 22 con EsPax establecida. Los niveles de DKK-1 fueron superiores en EsPax precoz comparado con EsPax establecida (22.1±12.6 vs 16.4±10.7pM; p=0.04). De todas las variables, sólo la duración de síntomas se asoció significativamente con DKK-1 (beta: −0.041; p=0.01). Conclusiones. Los niveles séricos de DKK-1 en EsPax, dependen de la duración de la enfermedad. A medida que la duración de la enfermedad aumenta, niveles séricos de DKK-1 disminuye. Por lo tanto, el tratamiento intensivo en estadios tempranos de la enfermedad podría tener un mejor resultado en inhibir/disminuir la progresión radiológica en pacientes con EsPax (AU)

Changing concept in treatment of asymptomatic severe aortic stenosis and normal ejection fraction: time for biomarkers reappraisal.

The uncertainty of whether/how to treat asymptomatic patients with isolated severe aortic stenosis and normal left ventricular ejection fraction is one of the most topical in cardiovascular medicine. Recently, the AVATAR trial: first ever randomized trial in the setting of aortic stenosis has been started in an attempt to adequately address this 'burning issue'. In light of this fact it is important to identify biomarkers which might help in risk stratification of these patients, not only in the referring physician's office during a routine exam, but also for preoperative patients scheduled for surgical replacement/transcatheter aortic valve implantation. This report is focusing on novel laboratory parameters which might be helpful in this risk stratification.

Novel bone metabolism-associated hormones: the importance of the pre-analytical phase for understanding their physiological roles.

The endocrine function of bone is now a recognized feature of this tissue. Bone-derived hormones that modulate whole-body homeostasis, are being discovered as for the effects on bone of novel and classic hormones produced by other tissues become known. Often, however, the data regarding these last generation bone-derived or bone-targeting hormones do not give about a clear picture of their physiological roles or concentration ranges. A certain degree of uncertainty could stem from differences in the pre-analytical management of biological samples. The pre-analytical phase comprises a series of decisions and actions (i.e., choice of sample matrix, methods of collection, transportation, treatment and storage) preceding analysis. Errors arising in this phase will inevitably be carried over to the analytical phase where they can reduce the measurement accuracy, ultimately, leading discrepant results. While the pre-analytical phase is all important, in routine laboratory medicine, it is often not given due consideration in research and clinical trials. This is particularly true for novel molecules, such as the hormones regulating the endocrine function of bone. In this review we discuss the importance of the pre-analytical variables affecting the measurement of last generation bone-associated hormones and describe their, often debated and rarely clear physiological roles.

Whole-Exome Sequencing to Identify Novel Biological Pathways Associated With Infertility After Pelvic Inflammatory Disease.

BACKGROUND: Ideal management of sexually transmitted infections (STI) may require risk markers for pathology or vaccine development. Previously, we identified common genetic variants associated with chlamydial pelvic inflammatory disease (PID) and reduced fecundity. As this explains only a proportion of the long-term morbidity risk, we used whole-exome sequencing to identify biological pathways that may be associated with STI-related infertility. METHODS: We obtained stored DNA from 43 non-Hispanic black women with PID from the PID Evaluation and Clinical Health Study. Infertility was assessed at a mean of 84 months. Principal component analysis revealed no population stratification. Potential covariates did not significantly differ between groups. Sequencing kernel association test was used to examine associations between aggregates of variants on a single gene and infertility. The results from the sequencing kernel association test were used to choose "focus genes" (P < 0.01; n = 150) for subsequent Ingenuity Pathway Analysis to identify "gene sets" that are enriched in biologically relevant pathways. RESULTS: Pathway analysis revealed that focus genes were enriched in canonical pathways including, IL-1 signaling, P2Y purinergic receptor signaling, and bone morphogenic protein signaling. CONCLUSIONS: Focus genes were enriched in pathways that impact innate and adaptive immunity, protein kinase A activity, cellular growth, and DNA repair. These may alter host resistance or immunopathology after infection. Targeted sequencing of biological pathways identified in this study may provide insight into STI-related infertility.

Development of an ultra-sensitive Simoa assay to enable GDF11 detection: a comparison across bioanalytical platforms.

BACKGROUND: Four bioanalytical platforms were evaluated to optimize sensitivity and enable detection of recombinant human GDF11 in biological matrices; ELISA, Meso Scale Discovery, Gyrolab xP Workstation and Simoa HD-1. Results & methodology: After completion of custom assay development, the single-molecule ELISA (Simoa) achieved the greatest sensitivity with a lower limit of quantitation of 0.1 ng/ml, an improvement of 100-fold over the next sensitive platform (MSD). DISCUSSION & CONCLUSION: This improvement was essential to enable detection of GDF11 in biological samples, and without the technology the sensitivity achieved on the other platforms would not have been sufficient. Other factors such as ease of use, cost, assay time and automation capability can also be considered when developing custom immunoassays, based on the requirements of the bioanalyst.

Sclerostin expression in bone tumours and tumour-like lesions.

AIMS: To assess the immunophenotypic and mRNA expression of sclerostin in human skeletal tissues and in a wide range of benign and malignant bone tumours and tumour-like lesions. METHODS AND RESULTS: Sclerostin expression was evaluated by immunohistochemistry and quantitative polymerase chain reaction (PCR). In lamellar and woven bone, there was strong sclerostin expression by osteocytes. Osteoblasts and other cell types in bone were negative. Hypertrophic chondrocytes in the growth plate and mineralized cartilage cells in zone 4 of hyaline articular cartilage strongly expressed sclerostin, but most chondrocytes in hyaline cartilage were negative. In primary bone-forming tumours, including osteosarcomas, there was patchy expression of sclerostin in mineralized osteoid and bone. Sclerostin staining was seen in woven bone in fibrous dysplasia, in osteofibrous dysplasia, and in reactive bone formed in fracture callus, in myositis ossificans, and in the wall of solitary bone cysts and aneurysmal bone cysts. Sclerostin was expressed by hypertrophic chondrocytes in osteochondroma and chondroblasts in chondroblastoma, but not by tumour cells in other bone tumours, including myeloma and metastatic carcinoma. mRNA expression of sclerostin was identified by quantitative PCR in osteosarcoma specimens and cell lines. CONCLUSIONS: Sclerostin is an osteocyte marker that is strongly expressed in human woven and lamellar bone and mineralizing chondrocytes. This makes it a useful marker with which to identify benign and malignant osteogenic tumours and mineralizing cartilage tumours, such as chondroblastomas and other lesions in which there is bone formation.

Effects of combined ovariectomy with dexamethasone on rat lumbar vertebrae.

OBJECTIVE: This study investigated the effects of combined ovariectomy with dexamethasone treatment on rat lumbar vertebrae in comparison with osteoporosis induced via ovariectomy or dexamethasone alone, and analysis of the associated molecular mechanism. METHODS: Sixty-two female Sprague-Dawley rats (3 months' old) were randomly divided into five treatment groups: an untreated baseline (BL) group; those receiving a sham operation (SHAM); those receiving a dexamethasone injection alone (DEXA); those undergoing bilateral ovariectomy (OVX); and those subjected to both ovariectomy and dexamethasone injection (OVX-DEXA). Animals in the BL group were euthanized at the beginning of the experiment, whereas animals in the remaining groups were euthanized at the end of the first month (M1), second month (M2), or third month (M3). Bone mineral density, bone microarchitecture, biomechanical properties of vertebrae, and serum levels of estrogen, amino-terminal propeptide of type I collagen (PINP), and ß-C-telopeptide of type I collagen (ß-CTX) were measured. In addition, we examined biglycan, runt-related transcription factor 2 (RUNX2), osteoprotegerin (OPG), lipoprotein receptor-related protein-5 (LRP-5), cathepsin K (CTSK), and sclerostin mRNA expression. RESULTS: Bone mineral content and bone mineral density were markedly lower in the OVX-DEXA group compared with the OVX group at all time points examined. The relative bone surface (BS/TV, mm(-1), relative bone volume (BV/TV,%), and trabecular number (Tb.N, 1/mm) were markedly lower in the OVX-DEXA group compared with the remaining groups, whereas trabecular separation (Tb.Sp, mm) was markedly higher in the OVX-DEXA group compared with the remaining groups at M2 or M3. The OVX-DEXA group showed lower compressive strength and lower stiffness compared with the other groups at M2 and M3. Compressive displacement and energy absorption capacity were also markedly lower in the OVX-DEXA group compared with the OVX group at M3. Estradiol levels were markedly lower in the OVX-DEXA group compared with the other groups. Biglycan, runt-related transcription factor 2, osteoprotegerin, and lipoprotein receptor-related protein-5 were down-regulated in the DEXA, OVX, and OVX-DEXA groups compared with the BL and SHAM groups, whereas cathepsin K and sclerostin were up-regulated in the OVX-DEXA group compared with the DEXA and OVX groups. CONCLUSIONS: Ovariectomy combined with dexamethasone induced more serious osteoporosis in the rat lumbar spine than either ovariectomy or dexamethasone alone. The combined effect may be due to a combination of suppressed bone formation and increased bone resorption related to an estradiol deficit.

[New biomarkers of CKD-MBD]. / I nuovi biomarcatori della CKD-MBD.

Chronic kidney failure involves abnormalities of mineral metabolism, skeletal and of cardiovascular system (so called CKD - MBD) that have a major impact on the survival of renal patient. Increasingly complex pathophysiological mechanisms have been discovered in recent years with evidence of new molecules involved in the development of CKD - MBD. Besides the classical PTH / Vitamin D axis, the most recent discovery of a new FGF23 / Klotho axis has expanded knowledge on the mechanisms of mineral homeostasis but also on the more complex mechanisms of cellular aging, vascular calcification and cardiac remodeling. The importance of bone as an endocrine organ has become even more evident following the discovery of molecules such as Sclerostin (involved in the regulation of osteoblastic proliferation and differentiation) and Sibling (a family of proteins that regulate both local and systemic mineral metabolism). The ability to characterize as biomarkers of CKD - MBD for these new molecules depends on their eventual ability to express a specific pathophysiological processes, identify patients at risk, highlight the response to a therapeutic treatment and to be easily identifiable and quantifiable on biological fluids. As of today, it seems that we can recognize FGF23 as a biomarker of CKD-MBD, while the remaining molecules as still waiting for a more definite settlement.

BMP10 inhibited the growth and migration of gastric cancer cells.

Bone morphogenetic protein 10 (BMP10), a novel member of BMP family, has been identified as an important regulator for angiogenesis. Dysregulation of BMP has been observed in several cancer types. However, its roles in gastric cancer (GC) remain unknown. In this study, the expression of BMP10 was found to be down-regulated in GC samples. Forced expression of BMP10 in GC cells inhibited its growth and migration, while knocking down the expression of BMP10 in GC cells promoted cell growth, migration, and metastasis. BMP10 was shown to negatively regulated beta-catenin/TCF signaling by up-regulating Axin protein level. Taken together, the present study revealed the suppressive function of BMP10 in gastric cancer.

Altered Osteocyte-Specific Protein Expression in Bone after Childhood Solid Organ Transplantation.

BACKGROUND: Bone fragility is common post solid organ transplantation but little is known about bone pathology on a tissue level. Abnormal osteocytic protein expression has been linked to compromised bone health in chronic kidney disease (CKD) and immunosuppressant medications may impact osteocyte function. METHODS: Transiliac bone biopsies were obtained from 22 pediatric solid organ allograft recipients (average age 15.6 years) an average of 6.3 ± 1.2 years after transplantation and from 12 pediatric pre-dialysis CKD patients (average age 13.2 years). Histomorphometry and immunohistochemistry for FGF23, DMP1, sclerostin, and osteopontin were performed on all biopsies. RESULTS: FGF23 and sclerostin were increased in transplant recipients relative to non-transplant CKD, regardless of the type of allograft received and despite, in the case of liver and heart recipients, a higher GFR. Bone DMP1 expression was higher in liver or heart than in kidney recipients, concomitant with higher serum phosphate values. Osteopontin expression was higher in CKD than in transplant recipients (p<0.01). Bone FGF23 and sclerostin correlated directly (r = 0.38, p<0.05); bone FGF23 expression and osteoid thickness correlated inversely (r = - 0.46, p<0.01). CONCLUSIONS: Solid-organ transplantation is associated with increased FGF23 and sclerostin expression. The contribution of these findings to compromised bone health post transplantation warrants further evaluation.