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Exposure to cigarette smoke represents the largest source of preventable death and disease in the United States. This may be in part due to the nature of the delayed harmful effects as well as the lack of awareness of the scope of harm presented by these products. The presence of "light" versions further clouds the harmful effects of tobacco products. While active smoking in expectant mothers may be reduced by educational and outreach campaigns, exposure to secondhand smoke is often involuntary yet may harm the developing embryo. In this study, we show that the main component of secondhand smoke, sidestream cigarette smoke, from several brands, including harm-reduction versions, triggered unsuccessful hatching at 3 dpf and reduced overall survival at 6 dpf in developing zebrafish. At non-lethal concentrations, craniofacial defects with different severity based on the cigarette smoke extract were noted by 6 dpf. All tested products, including harm-reduction products, significantly impacted cartilage formation and/or bone mineralization in zebrafish embryos, independent of whether the bones/cartilage formed from the mesoderm or neural crest. Together, these results in a model system often used to detect embryonic malformations imply that exposure of a woman to secondhand smoke while pregnant may lead to mineralization issues in the skeleton of her newborn, ultimately adding a direct in utero association to the increased fracture risk observed in children of mothers exposed to cigarette smoke. [ABSTRACT FROM AUTHOR]

Background: Pancreatic cancer (PC) was regarded as the 4th principal cause of cancer-related fatalities in the United States and patients usually suffered from severe nutrition deficiency, muscle wasting, as well as bone loss. In our previous research, we have found that PC-derived exosomes potentially initiate insulin resistance in skeletal muscle cells. However, the role of exosomes in the PC-related bone loss remains unknown. Methods: The effect of PC-derived exosomes on the osteoclast differentiation and femoral bone structure in the orthotopic xenograft mouse model were investigated. MiRNA expression profiles were detected and a dual luciferase experiment was conducted to identify the direct target of miRNA. Results: Our data showed that PC-derived exosomes significantly induced osteoclast differentiation and increased expression of NFAT2, TRAP, CTSK and MMP-9. The bone volume fraction and trabecular thickness of femur significantly reduced in osteoporotic model. Microarray analyses and luciferase reporter assay showed that the process was, at least partially, mediated by the miR-125a-5p/TNFRSF1B signaling pathways. Conclusion: According to the results, novel insights have been claimed the effect of exosomes derived from PC on bone deterioration and explained correlation between PC and cancer-related bone loss. [ABSTRACT FROM AUTHOR]

This study aims to improve the bioactivity response of osteoblasts attachment and proliferation on commercial pure titanium surface by the mixture of nanocomposite coating material of 70% TiO2 (rutile 10-30 nm, Sky Spring Nanomaterials, USA) and 30% ZrO2 (20-30 nm, Sky Spring Nanomaterials, USA). This may increase the likelihood of developing the modified implant surface by electrophoretic deposition and the dipping methods of nanocomposite mixture to enhance the surface bioactivity and promote bone formation. Three groups of commercially pure titanium: one uncoated group and two coated groups with nanocomposite mixture of different coating techniques; one group for electro photic deposition technique (EPD); and one group for dip technique. The bioactivity evaluation of cell cultures, isolation of osteoblast cells from calvaria and long limbs of 3-4 days neonatal rats to evaluate the attachment and the proliferation assay in 4 and 8 days of incubation periods for each group. However, osteoblast cells attachment and proliferation showed the least attached and proliferated cells in uncoated samples, while the EPD coated sample showed the highest. [ABSTRACT FROM AUTHOR]

Abstract: Magnetic resonance imaging (MRI) studies of tissue engineered constructs prior to implantation clearly demonstrate the utility of the MRI technique for studying the bone formation process. To test the utility of our MRI protocols for explant studies, we present a novel test platform in which osteoblast-seeded scaffolds were implanted on the chorioallantoic membrane of a chick embryo. Scaffolds from the following experimental groups were examined by high-resolution MRI: (a) cell-seeded implanted scaffolds (CIM), (b) unseeded implanted scaffolds (UCIM), (c) cell-seeded scaffolds in static culture (CIV) and (d) unseeded scaffolds in static culture (UCIV). The reduction in water proton transverse relaxation times and the concomitant increase in water proton magnetization transfer ratios for CIM and CIV scaffolds, compared to UCIV scaffolds, were consistent with the formation of a bone-like tissue within the polymer scaffold, which was confirmed by immunohistochemistry and fluorescence microscopy. However, the presence of angiogenic vessels and fibrotic adhesions around UCIM scaffolds can confound MRI findings of bone deposition. Consequently, to improve the specificity of the MRI technique for detecting mineralized deposits within explanted tissue engineered bone constructs, we introduce a novel contrast agent that uses alendronate to target a Food and Drug Administration-approved MRI contrast agent (Gd-DOTA) to bone mineral. Our contrast agent termed GdALN was used to uniquely identify mineralized deposits in representative samples from our four experimental groups. After GdALN treatment, both CIM and CIV scaffolds, containing mineralized deposits, showed marked signal enhancement on longitudinal relaxation time-weighted (T1W) images compared to UCIV scaffolds. Relative to UCIV scaffolds, some enhancement was observed in T1W images of GdALN-treated UCIM scaffolds, subjacent to the dark adhesions at the scaffold surface, possibly from dystrophic mineral formed in the fibrotic adhesions. Notably, residual dark areas on T1W images of CIM and UCIM scaffolds were attributable to blood inside infiltrating vessels. In summary, we present the efficacy of GdALN for sensitizing the MRI technique to the deposition of mineralized deposits in explanted polymeric scaffolds. [Copyright &y& Elsevier]

Abstract: Parathyroid hormone (PTH) is currently the only approved anabolic agent for osteoporosis pharmacotherapy in the USA. However, the molecular and cellular mechanisms underlying which intermittent PTH stimulates bone formation are not fully established. Activating transcription factor 4 (ATF4) was recently identified to be a downstream target of PTH signaling in osteoblasts and FGF2 is able to rapidly increase ATF4 mRNA and protein expression in osteoblasts. Furthermore, ATF4 expression is markedly reduced in Fgf2−/− osteoblasts. In addition, FGF2 is required for the anabolic action of PTH on bone formation. Therefore, we hypothesize that the impaired anabolic effect of PTH in Fgf2−/− mice is partially due to reduced ATF4 expression. To test this hypothesis, we examined the ability of PTH to increase ATF4 expression in vitro and in vivo. In vitro data showed that PTH induced a significant increase in ATF4 mRNA expression as early as 15min in Fgf2+/+ primary bone marrow stromal cells (BMSCs) but not in Fgf2−/− BMSCs. In vivo data showed that treatment with PTH (1–34) (40μg/kg/d) treatment for 2weeks in 21–23months female mice increased lumbar vertebrae bone mineral density in Fgf2+/+ (13.8% increase). In contrast there was a 2.1% decrease in Fgf2−/− mice. Interestingly, basal ATF4 mRNA expression in tibiae was significantly lower in Fgf2−/− mice (46% decrease) compared to Fgf2+/+ mice. PTH treatment increased ATF4 mRNA by 97% (p <0.05) in Fgf2+/+ compared to 8% (p =0.57) in Fgf2−/− mice. Immunohistochemistry of vertebrae showed less ATF4 staining in Fgf2−/− tissue, and treatment with PTH increased ATF4 staining in Fgf2+/+ but the increase was attenuated in Fgf2−/− tissue. In summary, reduced ATF4 expression may result in decreased osteoblast differentiation, and possibly contribute to the impaired stimulation of PTH on bone formation in Fgf2−/− mice. [Copyright &y& Elsevier]

Simple Summary: Cytokine release syndrome is a potentially life-threatening complication of therapy with T-cell engaging bispecific antibodies. Here we evaluated the risk, characteristics and biomarkers of treatment-emergent cytokine release syndrome in patients with relapsed/refractory acute myeloid leukemia or myelodysplastic syndrome who received weekly intravenous infusions of the CD3xCD123 bispecific antibody APVO436. Cytokine release syndrome was encountered in 10 of 46 patients (21.7%) treated with APVO436 with a cumulative Grade 3/4 cytokine release syndrome incidence of 8.7%. Cytokine profiling in patients who developed cytokine release syndrome after APVO436 infusion indicated that the predominant cytokine in this inflammatory cytokine response was IL-6. The findings from this research provide new insights regarding the biology and effective management of cytokine release syndrome in leukemia patients treated with T-cell redirecting bispecific antibodies. We evaluate the risk, characteristics and biomarkers of treatment-emergent cytokine release syndrome (CRS) in patients with relapsed/refractory acute myeloid leukemia (AML) or myelodysplastic syndrome (MDS) who received APVO436 during the dose-escalation phase of a Phase 1B study (ClinicalTrials.gov, identifier: NCT03647800). Of four patients who developed Grade ≥ 3 CRS, two received steroid prophylaxis. The dose level, gender, race, obesity, or baseline hematologic parameters in peripheral blood did not predict the risk of CRS. Patients with a higher leukemia burden as determined by a higher total WBC, higher percentage of blasts in bone marrow, or higher percentage of blasts in peripheral blood (by hematopathology or immunophenotyping) did not have a higher incidence of CRS. There was an age difference between patients who did versus patients who did not develop CRS (72.9 ± 1.6 years (Median 73.5 years) vs. 63.3 ± 2.3 years (Median: 65.0 years), which was borderline significant (p = 0.04). Premedication with steroids did not eliminate the risk of CRS. Cytokine profiling in patients who developed CRS after APVO436 infusion indicates that the predominant cytokine in this inflammatory cytokine response was IL-6. APVO436-associated CRS was generally manageable with tocilizumab with or without dexamethasone. Notably, the development of CRS after APVO436 therapy did not appear to be associated with a response. The prolonged stabilization of disease, partial remissions and complete remissions were achieved in both patients who experienced CRS, as well as patients who did not experience CRS after APVO436 infusions. [ABSTRACT FROM AUTHOR]

Purpose of Review: Bone mineral density and systemic factors are used to assess skeletal health in astronauts. Yet, even in a general population, these measures fail to accurately predict when any individual will fracture. This review considers how long-duration human spaceflight requires evaluation of additional bone structural and material quality measures that contribute to microgravity-induced skeletal fragility., Recent Findings: In both humans and small animal models following spaceflight, bone mass is compromised via reduced bone formation and elevated resorption levels. Concurrently, bone structural quality (e.g., trabecular microarchitecture) is diminished and the quality of bone material is reduced via impaired tissue mineralization, maturation, and maintenance (e.g., mediated by osteocytes). Bone structural and material quality are both affected by microgravity and may, together, jeopardize astronaut operational readiness and lead to increased fracture risk upon return to gravitational loading. Future studies need to directly evaluate how bone quality combines with diminished bone mass to influence bone strength and toughness (e.g., resistance to fracture). Bone quality assessment promises to identify novel biomarkers and therapeutic targets.