DOX-Vit D, a Novel Doxorubicin Delivery Approach, Inhibits Human Osteosarcoma Cell Proliferation by Inducing Apoptosis While Inhibiting Akt and mTOR Signaling Pathways

This work is licensed under a Creative Commons Attribution 4.0 International License.Doxorubicin (DOX) is a very potent and effective anticancer agent. However, the effectiveness of DOX in osteosarcoma is usually limited by the acquired drug resistance. Recently, Vitamin D (Vit-D) was shown to suppress the growth of many human cancer cells. Taken together, we synthesized DOX-Vit D by conjugating Vit-D to DOX in order to increase the delivery of DOX into cancer cells and mitigate the chemoresistance associated with DOX. For this purpose, MG63 cells were treated with 10 µM DOX or DOX-Vit D for 24 h. Thereafter, MTT, real-time PCR and western blot analysis were used to determine cell proliferation, genes and proteins expression, respectively. Our results showed that DOX-Vit D, but not DOX, significantly elicited an apoptotic signal in MG63 cells as evidenced by induction of death receptor, Caspase-3 and BCLxs genes. Mechanistically, the DOX-Vit D-induced apoptogens were credited to the activation of p-JNK and p-p38 signaling pathway and the inhibition of proliferative proteins, p-Akt and p-mTOR. Our findings propose that DOX-Vit D suppressed the growth of MG63 cells by inducing apoptosis while inhibiting cell survival and proliferative signaling pathways. DOX-Vit D may serve as a novel drug delivery approach to potentiate the delivery of DOX into cancer cells.Canadian Institutes of Health Research [Grant 106665]U.S. National Cancer Institute [Grant R01CA173292

Using Micro-CT Derived Bone Microarchitecture to Analyze Bone Stiffness – A Case Study on Osteoporosis Rat Bone

Micro-computed tomography images can be used to quantitatively represent bone geometry through a range of computed attenuation-based parameters. Nonetheless, those parameters remain indirect indices of bone micro-architectural strength and require further computational tools to interpret bone structural stiffness and potential for mechanical failure. Finite element analysis (FEA) can be applied to measure trabecular bone stiffness and potentially predict the location of structural failure in preclinical animal models of osteoporosis, although that procedure from image segmentation of micro-CT derived bone geometry to FEA is often challenging and computationally expensive, resulting in failure of the model to build. Notably, the selection of resolution and threshold for bone segmentation are key steps that greatly affect computational complexity and validity. In the following study, we evaluated an approach whereby Micro-CT derived greyscale attenuation and segmentation data guided the selection of trabecular bone for analysis by FEA. We further correlated those FEA results to both two and three dimensional bone microarchitecture from sham and ovariectomized (OVX) rats (n=10/group). A virtual cylinder of vertebral trabecular bone 40% in length from the caudal side was selected for FEA because micro-CT based image analysis indicated the largest differences in microarchitecture between the two groups resided there. Bone stiffness was calculated using FEA and statistically correlated with the three dimensional values of bone volume/tissue volume, bone mineral density, fractal dimension, trabecular separation and trabecular bone pattern factor. Our method simplified the process for the assessment of trabecular bone stiffness by FEA from Micro-CT images and highlighted the importance of bone microarchitecture in conferring significantly increased bone quality capable of resisting failure due to increased mechanical loading

Reacquisition of the lower temporal bar in sexually dimorphic fossil lizards provides a rare case of convergent evolution

34 p.Introducción. Cuando se piensa en centros de atención de usuarios se hace efímero el cuidado de la calidad de los servicios, porque de ello, la población blanco permanece fiel al servicio que se brinda; por esto se hace necesario contar con modelos que permitan conocer la calidad de los mismos, ejemplo de eso es el modelo Service Quality (SERVQUAL), que para efectos de este artículo se pretende enfatizar en el valor que tiene su utilización. Objetivo. Visibilizar la importancia de la utilización del modelo SERVQUAL a partir de una revisión sistemática de la literatura de tipo cualitativa en el periodo 2010-2016. Métodos. Se realiza una revisión sistemática de literatura cualitativa por el tipo de objetivo de la misma, cuya búsqueda finaliza a los veintiocho (28) días del mes de octubre de 2017. Se toma como bases de datos Pubmed, ScienceDirect, SciELO, LILACS, Tripdata base, Cochrane, Google, Google Scholar y Grey Lit. Para evaluar la calidad de los artículos se utiliza dos parrillas, la CASPe y THE JOANNA BRIGGS INSTITUTE, teniendo en cuenta las palabras claves que aparecen a continuación. Resultados. Se realiza un análisis a cuatrocientos treinta y siete (437) artículos de los cuales se obtiene una total de veintinueve (29) artículos, donde se visibiliza que el Modelo SERVQUAL es una buena herramienta en evaluar calidad en comparación con otros modelos Conclusión. El modelo SERVQUAL, dentro de sus bases teóricas se puede destacar, calidad de servicio, calidad de servicios en salud, a partir de ello, se plantean sus dimensiones que sirven como indicadores: tangibles; confiabilidad; sensibilidad; aseguramiento y empatía, de las cuales se destaca esta última, seguida de la tangibilidad, según los reportado en la literatura en estudios que aplicaron el modelo.Introduction. Introduction. When it thinks about user like a service centers, care for the quality of services becomes ephemeral, because of this, the white population remains faithful to the service provided; For this reason, it is necessary to have models that allow to know the quality of the same, example of that is the Service Quality model (SERVQUAL), which for the purposes of this article is intended to emphasize the value of its use. Objective. To make visible the importance of the use of the SERVQUAL model based on a systematic review of the qualitative literature in the period 2010-2016. Methods. A systematic review of qualitative literature is performed by the type of objective of the same, whose search ends on twenty-eight (28) days of the month of October 2017. It is taken as databases Pubmed, ScienceDirect, SciELO, LILACS, Tripdata base, Cochrane, Google, Google Scholar and Gray Lit. To assess the quality of the articles, we use two grills, the CASPe and THE JOANNA BRIGGS INSTITUTE, taking into account the key words that appear below. Results. An analysis is made to four hundred and thirty-seven (437) articles of which a total of twenty-nine (29) articles are obtained, where it is visible that the SERVQUAL Model is a good tool in evaluating quality in comparison with other models. Conclusion. The SERVQUAL model, within its theoretical bases can be highlighted, quality of service, quality of health services, based on this, its dimensions are considered as indicators: tangible; reliability; sensitivity; assurance and empathy, of which the latter stands out, followed by tangibility, as reported in the literature in studies that applied the model

DOX-Vit D, a Novel Doxorubicin Delivery Approach, Inhibits Human Osteosarcoma Cell Proliferation by Inducing Apoptosis While Inhibiting Akt and mTOR Signaling Pathways

Doxorubicin (DOX) is a very potent and effective anticancer agent. However, the effectiveness of DOX in osteosarcoma is usually limited by the acquired drug resistance. Recently, Vitamin D (Vit-D) was shown to suppress the growth of many human cancer cells. Taken together, we synthesized DOX-Vit D by conjugating Vit-D to DOX in order to increase the delivery of DOX into cancer cells and mitigate the chemoresistance associated with DOX. For this purpose, MG63 cells were treated with 10 µM DOX or DOX-Vit D for 24 h. Thereafter, MTT, real-time PCR and western blot analysis were used to determine cell proliferation, genes and proteins expression, respectively. Our results showed that DOX-Vit D, but not DOX, significantly elicited an apoptotic signal in MG63 cells as evidenced by induction of death receptor, Caspase-3 and BCLxs genes. Mechanistically, the DOX-Vit D-induced apoptogens were credited to the activation of p-JNK and p-p38 signaling pathway and the inhibition of proliferative proteins, p-Akt and p-mTOR. Our findings propose that DOX-Vit D suppressed the growth of MG63 cells by inducing apoptosis while inhibiting cell survival and proliferative signaling pathways. DOX-Vit D may serve as a novel drug delivery approach to potentiate the delivery of DOX into cancer cells

Choline kinase beta is required for normal endochondral bone formation.

BACKGROUND: Choline kinase has three isoforms encoded by the genes Chka and Chkb. Inactivation of Chka in mice results in embryonic lethality, whereas Chkb(-/-) mice display neonatal forelimb bone deformations. METHODS: To understand the mechanisms underlying the bone deformations, we compared the biology and biochemistry of bone formation from embryonic to young adult wild-type (WT) and Chkb(-/-) mice. RESULTS: The deformations are specific to the radius and ulna during the late embryonic stage. The radius and ulna of Chkb(-/-) mice display expanded hypertrophic zones, unorganized proliferative columns in their growth plates, and delayed formation of primary ossification centers. The differentiation of chondrocytes of Chkb(-/-) mice was impaired, as was chondrocyte proliferation and expression of matrix metalloproteinases 9 and 13. In chondrocytes from Chkb(-/-) mice, phosphatidylcholine was slightly lower than in WT mice whereas the amount of phosphocholine was decreased by approximately 75%. In addition, the radius and ulna from Chkb(-/-) mice contained fewer osteoclasts along the cartilage/bone interface. CONCLUSIONS: Chkb has a critical role in the normal embryogenic formation of the radius and ulna in mice. GENERAL SIGNIFICANCE: Our data indicate that choline kinase beta plays an important role in endochondral bone formation by modulating growth plate physiology. Biochim Biophys Acta 2014 Mar 14; 1840(7):2112-2122

A novel experimental model for studying transverse orthodontic tooth movement in the rat mandible

OBJECTIVES: To establish a rat model of a one-piece mandible using the principles of gingivoperiosteoplasty and guided bone regeneration to fuse the midline symphyseal area. MATERIALS & METHODS: Twenty-four Sprague-Dawley female rats were divided into two groups: 12 experimental and 12 control. Both groups were imaged using in vivo micro-computed tomography at baseline and at end point (5 months). The experimental group received regenerative surgery at the symphysis area; the control group received no treatment. Outcomes were evaluated by radiographic examination of gross and volumetric bony changes in the symphyseal region of interest marked between the mental foramina bilaterally and the two central incisors near the most coronal margin of the alveolar crests. These landmarks were chosen as they can be reproduced on the computed tomography images at baseline and end point. Histologic examination was performed on all samples at a level 5 mm apical to the alveolar bone crest. RESULTS: Radiologic and histologic examinations of the experimental group revealed complete bony fusion of the symphyseal area in three subjects, partial fusion in five subjects, and thickening of the alveolar bony socket in three subjects; one rat died of anesthesia-related complications. No evidence of fusion or alveolar bone thickening was found in any of the controls. CONCLUSIONS: This surgical animal model demonstrates that a rat mandible can be surgically manipulated to mimic the one-piece human mandible. This novel model may prove useful in studying mandibular bone remodeling and orthodontic mandibular tooth movement

The epithelial sodium/proton exchanger, NHE3, is necessary for renal and intestinal calcium (re)absorption.

Item does not contain fulltextPassive paracellular proximal tubular (PT) and intestinal calcium (Ca(2+)) fluxes have been linked to active sodium (re)absorption. Although the epithelial sodium/proton exchanger, NHE3, mediates apical sodium entry at both these sites, its role in Ca(2+) homeostasis remains unclear. We, therefore, set out to determine whether NHE3 is necessary for Ca(2+) (re)absorption from these epithelia by comparing Ca(2+) handling between wild-type and NHE3(-/-) mice. Serum Ca(2+) and plasma parathyroid hormone levels were not different between groups. However, NHE3(-/-) mice had increased serum 1,25-dihydroxyvitamin D(3). The fractional excretion of Ca(2+) was also elevated in NHE3(-/-) mice. Paracellular Ca(2+) flux across confluent monolayers of a PT cell culture model was increased by an osmotic gradient equivalent to that generated by NHE3 across the PT in vivo and by overexpression of NHE3.( 45)Ca(2+) uptake after oral gavage and flux studies in Ussing chambers across duodenum of wild-type and NHE3(-/-) mice confirmed decreased Ca(2+) absorption in NHE3(-/-) mice compared with wild-type mice. Consistent with this, intestinal calbindin-D(9K), claudin-2, and claudin-15 mRNA expression was decreased. Microcomputed tomography analysis revealed a perturbation in bone mineralization. NHE3(-/-) mice had both decreased cortical bone mineral density and trabecular bone mass. Our results demonstrate significant alterations of Ca(2+) homeostasis in NHE3(-/-) mice and provide a molecular link between Na(+) and Ca(2+) (re)absorption.1 april 201

Synthesis, Characterization and Biodistribution Studies of 125I-Radioiodinated di-PEGylated Bone Targeting Salmon Calcitonin Analogue in Healthy Rats

Purpose: The objective of this study was to prepare a bisphosphonate (BP) mediated bone targeting di-PEGylated salmon calcitonin analogue sCT-2(PEG-BP) as a novel bone targeting pharmaceutical. Methods: HPLC was used for isolation of sCT-2(PEG-BP) from the reaction mixture, followed by determination of possible PEGylation sites by trypsin digestion. Stability of the compound over time, bone mineral affinity using hydroxyapatite, and biodistribution in normal rats after radiolabeling of sCT-2(PEG-BP) or control sCT with 125I was evaluated. Results: PEGylated sCT analogues were synthesized, and sCT-2(PEG-BP) was isolated by HPLC and confirmed by MALDI-TOF and ICP-MS. MALDI-TOF analysis of trypsinized fragments suggested Cys1 (or Lys11) and Lys18 to be the two PEGylation sites. Bone mineral affinity test showed sCT-2(PEG-BP) or 125I-sCT-2(PEG-BP) exhibited significantly increased bone mineral affinity over sCT or 125I-sCT, respectively. sCT-2(PEG-BP) remained stable for at least 1 month. In vivo biodistribution study showed significantly increased bone retention and prolonged plasma circulation time for sCT-2(PEG-BP) compared to the control sCT. Conclusion: Those results support sCT-2(PEG-BP) as a promising new drug candidate for the treatment of resorptive and/or maladaptive bone conditions, such as Osteoporosis, Osteoarthritis, Rheumatoid Arthritis, Paget’s disease and bone cancers