High Sclerostin and Dickkopf-1 (DKK-1) serum levels in children and adolescents with type 1 diabetes mellitus

CONTEXT: Childhood type 1 diabetes (T1DM) is associated with decreased bone mass. Sclerostin and dickkopf-1 (DKK-1) are Wnt inhibitors which regulate bone formation. OBJECTIVE: To evaluate sclerostin and DKK-1 levels in TD1M children and to analyze the influence of the glycaemic control on bone health. DESIGN AND SETTING: Cross-sectional study conducted at a clinical research center. Partecipants: One hundred and six T1DM subjects (12.2 ± 4 years), 66 on multiple daily injections (MDI) and 40 on continuous subcutaneous infusion of insulin (CSII), and 80 controls. RESULTS: The average of bone transmission time (BTT) and amplitude-dependent speed of sound (Ad-Sos) Z-scores was lower in diabetics than controls. Significant increased DKK-1 (3593 ± 1172 vs 2652 ± 689 pg/ml, p<0.006) and sclerostin (29.45 ± 12.32 vs 22.53 ± 8.29, p<0.001) levels were found in diabetics respect to controls, particularly in patients on MDI than ones on CSII. Glycaemic control was improved in CSII patients compared to MDI ones (p<0.001) and was also associated to a significant higher BMI-SDS (p<0.002) and BTT-Z-score (p<0.02). With adjustment for age multiple linear regression analysis for DKK-1 and sclerostin as dependent variables showed that levels of HbA1c%, glucose, 25(OH)-Vitamin D, osteocalcin, PTH, years of diabetes, BMI-SDS and AD-SoS-Z-score are the most important predictors (p<0.0001). CONCLUSIONS: Our study highlighted: 1. the high serum levels of DKK-1 and sclerostin in T1DM children, and their relationship with the altered glycaemic control; 2. the effect of CSII on the improvement of glycaemic control and bone health in T1DM children

Impaired bone remodeling in children with osteogenesis imperfecta treated and untreated with bisphosphonates: the role of DKK1, RANKL, and TNF-α

In this study, we investigated the bone cell activity in patients with osteogenesis imperfecta (OI) treated and untreated with neridronate. We demonstrated the key role of Dickkopf-1 (DKK1), receptor activator of nuclear factor-κB ligand (RANKL), and tumor necrosis factor alpha (TNF-α) in regulating bone cell of untreated and treated OI subjects. These cytokines could represent new pharmacological targets for OI. Introduction: Bisphosphonates are widely used in the treatment of children with osteogenesis imperfecta (OI) with the objective of reducing the risk of fractures. Although bisphosphonates increase bone mineral density in OI subjects, the effects on fracture incidence are conflicting. The aim of this study was to investigate the mechanisms underlying bone cell activity in subjects with mild untreated forms of OI and in a group of subjects with severe OI treated with cycles of intravenous neridronate. Methods: Sclerostin, DKK1, TNF-α, RANKL, osteoprotegerin (OPG), and bone turnover markers were quantified in serum of 18 OI patients (12 females, mean age 8.86 ± 3.90), 8 of which were receiving cyclic intravenous neridronate, and 21 sex- and age-matched controls. The effects on osteoblastogenesis and OPG expression of media conditioned by the serum of OI patients and anti-DKK1 neutralizing antibody were evaluated. Osteoclastogenesis was assessed in cultures from patients and controls. Results: DKK1 and RANKL levels were significantly increased both in untreated and in treated OI subjects with respect to controls. The serum from patients with high DKK1 levels inhibited both osteoblast differentiation and OPG expression in vitro. High RANKL and low OPG messenger RNA (mRNA) levels were found in lymphomonocytes from patients. High amounts of TNF-α were expressed by monocytes, and an elevated percentage of circulating CD11b-CD51/CD61+ osteoclast precursors was observed in patients. Conclusions: Our study demonstrated the key role of DKK1, RANKL, and TNF-α in regulating bone cell activity of subjects with OI untreated and treated with bisphosphonates. These cytokines could represent new pharmacological targets for OI patients

A zinc, copper and citric acid biocomplex shows promise for control of Xylella fastidiosa subsp. pauca in olive trees in Apulia region (southern Italy)

The bacterium Xylella fastidiosa subsp. pauca is associated with the “olive quick decline syndrome” in the Apulia region of southern Italy. To investigate control of this phytopathogen, a compound containing zinc and copper complexed with citric-acid hydracids (Dentamet®) was evaluated for in vitro and in planta bactericidal activity. Confocal laser scanning microscopy, fluorescent quantification and atomic emission spectroscopy were then used to determine if the compound reached the xylem networks of leaves, twigs and branches of olive, to release zinc and copper within the xylem. A 3-year field trial in an olive orchard containing mature Cellina di Nardò and Ogliarola salentina olive trees, and officially declared infected by X. fastidiosa subsp. pauca,was also carried out o to determine if the compound affected severity of the disease. Each year, from early April to October (excluding July and August), six spray treatments of 0.5% (v:v) Dentamet® were applied on the olive tree crowns. The compound reduced severity of symptoms in both cultivars. Most untreated trees died by the end of the trial, whereas all treated trees survived with good vegetative status as assessed by a normalized difference vegetation index. Quantitative real-time PCR was performed from June 2016 to September 2017, following the official procedures established by the European and Mediterranean Plant Protection Organization. The analysis revealed a statistically significant reduction of X. fastidiosa cell densities within the leaves of treated trees. These promising results suggest that integrated management to reduce severity of X. fastidiosa that includes regular pruning and soil harrowing with spring and summer spray treatments with Dentamet®, is likely to effectively control the disease.

Effects of Sweet Cherry Polyphenols on Enhanced Osteoclastogenesis Associated With Childhood Obesity

Childhood obesity is associated with the development of severe comorbidities, such as diabetes, cardiovascular diseases, and increased risk of osteopenia/osteoporosis and fractures. The status of low-grade inflammation associated to obesity can be reversed through an enhanced physical activity and by consumption of food enrich of anti-inflammatory compounds, such as omega-3 fatty acids and polyphenols. The aim of this study was to deepen the mechanisms of bone impairment in obese children and adolescents through the evaluation of the osteoclastogenic potential of peripheral blood mononuclear cells (PBMCs), and the assessment of the serum levels of RANKL and osteoprotegerin (OPG). Furthermore, we aimed to evaluate the in vitro effects of polyphenol cherry extracts on osteoclastogenesis, as possible dietary treatment to improve bone health in obese subjects. High RANKL levels were measured in obese with respect to controls (115.48 ± 35.20 pg/ml vs. 87.18 ± 17.82 pg/ml; p < 0.01), while OPG levels were significantly reduced in obese than controls (378.02 ± 61.15 pg/ml vs. 436.75 ± 95.53 pg/ml, respectively, p < 0.01). Lower Ad-SoS- and BTT Z-scores were measured in obese compared to controls (p < 0.05). A significant elevated number of multinucleated TRAP+ osteoclasts (OCs) were observed in the un-stimulated cultures of obese subjects compared to the controls. Interestingly, obese subjects displayed a higher percentage of CD14+/CD16+ than controls. Furthermore, in the mRNA extracts of obese subjects we detected a 2.5- and 2-fold increase of TNFα and RANKL transcripts compared to controls, respectively. Each extract of sweet cherries determined a dose-dependent reduction in the formation of multinucleated TRAP+ OCs. Consistently, 24 h treatment of obese PBMCs with sweet cherry extracts from the three cultivars resulted in a significant reduction of the expression of TNFα. In conclusion, the bone impairment in obese children and adolescents is sustained by a spontaneous osteoclastogenesis that can be inhibited in vitro by the polyphenol content of sweet cherries. Thus, our study opens future perspectives for the use of sweet cherry extracts, appropriately formulated as nutraceutical food, as preventive in healthy children and therapeutic in obese ones

Clinical significance of serum cytokine levels and thrombopoietic markers in childhood idiopathic thrombocytopenic purpura

Background. Biological markers useful for defining children with newly diagnosed immune thrombocytopenic purpura (ITP) who are likely to develop the chronic form of the disease are partially lacking. The purpose of this study was to assess the clinical role of both immunological and thrombopoietic markers in children with ITP and correlate their levels with different disease stages. Materials and methods. We enrolled 28 children with ITP at the onset of their disease, who were followed-up for a whole year and divided according to whether their disease resolved within the 12 months (n=13) or became chronic (n=15), 11 subjects with chronic ITP off therapy for at least 1 month at the time of enrolment, and 30 healthy matched controls. Serum levels of T helper type 1 and 2 and T regulatory-associated cytokines, such as interferon γ, tumour necrosis factor α, interleukin (IL) 2, IL6, IL10, and thrombopoietin were measured in all children using quantitative immunoenzymatic assays, while reticulated platelets were evaluated by flow cytometric analysis. Results. Serum IL10 levels were significantly higher in patients with an acute evolution of ITP than in either healthy controls (p<0.001) or patients with chronic progression of ITP (p<0.05). Reticulated platelet count and thrombopoietin levels were significantly higher in ITP patients at the onset of their disease, whether with acute resolution or chronic progression, than in healthy subjects (p<0.01; p<0.001), but did not differ between the groups of patients. Conclusion. IL-10 seems to predict the clinical course of ITP, as it is significantly higher at the onset of disease in patients who obtain disease remission in less than 1 year

Bone Remodeling in a Mps-1h Girl after Hematopoietic Stem Cell Transplantation along with Enzymatic Replacement Therapy

Background Mucopolysaccharidosis-1H (Hurler syndrome, MPS-1H) is the most severe form of a lysosomal storage disorder (LSD) caused by variants in IDUA, encoding alpha-L-iduronidase (IDUA). MPS-1H is also associated with various degree of skeletal defects due to the accumulation of partially degraded glycosaminoglycans (GAGs) in the lysosomes of connective tissue cells. The efficacy of hematopoietic stem cell transplantation (HSCT) and enzymatic replacement therapy (ERT) on MPS-1H skeletal manifestations are still considered not satisfactory. Case presentation We report the case of a young girl, who manifested significant changes in bone remodeling markers and osteoclastogenesis potential after HSCT combined with ERT. She received ERT and underwent two HSCT. The skeletal alterations at the time of diagnosis, showed a trend toward improvement of both mobility and radiological features after HSCT. We observed the highest levels of Receptor activator of nuclear factor kappa-Β ligand (RANKL) and RANK/osteoprotegerin (OPG) ratio at diagnosis and during ERT, consistently with a spontaneous osteoclastogenesis. Conversely, after the successful HSCT with ongoing ERT, the highest levels of osteocalcin were observed and all markers of bone formation and resorption improved. Conclusion The combination therapy of ERT and HSCT was effective in reduction of osteoclast activity and increasing osteoblast activity, and these changes were in keeping with the child's bone phenotype, IDUA activity and glycosaminoglycan (GAG) trends. These results represent one of the few human evidences in this context

Paracrine ADP Ribosyl Cyclase-Mediated Regulation of Biological Processes

ADP-ribosyl cyclases (ADPRCs) catalyze the synthesis of the Ca2+-active second messengers Cyclic ADP-ribose (cADPR) and ADP-ribose (ADPR) from NAD+ as well as nicotinic acid adenine dinucleotide phosphate (NAADP+) from NADP+. The best characterized ADPRC in mammals is CD38, a single-pass transmembrane protein with two opposite membrane orientations. The first identified form, type II CD38, is a glycosylated ectoenzyme, while type III CD38 has its active site in the cytosol. The ectoenzymatic nature of type II CD38 raised long ago the question of a topological paradox concerning the access of the intracellular NAD+ substrate to the extracellular active site and of extracellular cADPR product to its intracellular receptors, ryanodine (RyR) channels. Two different transporters, equilibrative connexin 43 (Cx43) hemichannels for NAD+ and concentrative nucleoside transporters (CNTs) for cADPR, proved to mediate cell-autonomous trafficking of both nucleotides. Here, we discussed how type II CD38, Cx43 and CNTs also play a role in mediating several paracrine processes where an ADPRC+ cell supplies a neighboring CNT-and RyR-expressing cell with cADPR. Recently, type II CD38 was shown to start an ectoenzymatic sequence of reactions from NAD+/ADPR to the strong immunosuppressant adenosine; this paracrine effect represents a major mechanism of acquired resistance of several tumors to immune checkpoint therapy

High Dickkopf-1 levels are associated with chronic inflammation in children with sickle cell disease

Objectives: Sickle bone disease (SBD) is a chronic complication of sickle cell disease (SCD) whose pathogenesis is not completely understood. Chronic inflammation associated with SCD could alter bone remodeling. Our aim was to analyze the serum levels of bone remodeling markers in a group of SCD children to evaluate their involvement in the SBD. Methods: We enrolled 26 SCD subjects and 26 age-matched controls, who lived in the same geographic area. DKK-1, sclerostin, RANKL, and OPG serum levels were evaluated. Neutrophil-lymphocyte ratio (NLR) was also evaluated as a marker of inflammation. Results: The analysis of bone remodeling markers did not show any significant difference between the two groups except for DKK-1 levels that were significantly higher in the patients than controls (p &lt; .05). A significant direct correlation between NLR and DKK-1 (p = .004) was found. An inverse correlation between NLR and osteocalcin (p = .01) has also been observed. Conclusions: The chronic inflammation, which represents a peculiar characteristic in SCD patients, would represent the primary causal agent of the activation of osteoblastogenesis inhibitors responsible of bone impairment in these subjects. Further studies will be needed to better explain the role of these inhibitors in SCD, to prevent or treat bone damage in this population

Shedding “LIGHT” on the Link between Bone and Fat in Obese Children and Adolescents

Obesity may aect bone health, but literature reports are contradictory about the correlation of body mass index (BMI) and bone markers. LIGHT, one of the immunostimulatory cytokines regulating the homeostasis of bone and adipose tissue, could be involved in obesity. The study involved 111 obese subjects (12.21 3.71 years) and 45 controls. Patients underwent the evaluation of bone status by quantitative ultrasonography (QUS). LIGHT amounts were evaluated in sera by ELISA, whereas its expression on peripheral blood cells was evaluated by flow cytometry. Osteoclastogenesis was performed by culturing peripheral blood mononuclear cells (PBMCs) with or without anti-LIGHT antibodies. Obese patients showed significant high BMI-standard deviation score (SDS), weight-SDS, and Homeostatic model assessment for insulin resistance (HOMA-IR) that negatively correlated with the reduced Amplitude Dependent Speed of Sound (AD-SoS)-Z-score and Bone Transmission Time (BTT-Z)-score. They displayed significantly higher serum levels of LIGHT compared with controls (497.30 363.45 pg/mL vs. 186.06 101.41 pg/mL, p &lt; 0.001). LIGHT expression on monocytes, CD3+-T-cells, and neutrophils was also higher in obese patients than in the controls. Finally, in PBMC cultures, the addition of anti-LIGHT antibodies induced a significant osteoclastogenesis inhibition. Our study highlighted the high serum levels of LIGHT in obese childre