Development of Natural-Based Bone Cement for a Controlled Doxorubicin-Drug Release

Osteosarcoma (OS) accounts for 60% of all global bone cancer diagnoses. Intravenous administration of Doxorubicin Hydrochloride (DOXO) is the current form of OS treatment, however, systemic delivery has been linked to the onset of DOXO induced cardiomyopathy. Biomaterials including calcium phosphate cements (CPCs) and nanoparticles (NPs) have been tested as localized drug delivery scaffolds for OS cells. However, the tumor microenvironment is critical in cancer progression, with mesenchymal stem cells (MSCs) thought to promote OS metastasis and drug resistance. The extent of MSC assisted survival of OS cells in response to DOXO delivered by CPCs is unknown. In this study, we aimed at investigating the effect of DOXO release from a new formulation of calcium phosphate-based bone cement on the viability of OS cells cocultured with hMSC in vitro. NPs made of PLGA were loaded with DOXO and incorporated in the formulated bone cement to achieve local drug release. The inclusion of PLGA-DOXO NPs into CPCs was also proven to increase the levels of cytotoxicity of U2OS cells in mono- and coculture after 24 and 72 h. Our results demonstrate that a more effective localized DOXO delivery can be achieved via the use of CPCs loaded with PLGA-DOXO NPs compared to CPCs loaded with DOXO, by an observed reduction in metabolic activity of U2OS cells in indirect coculture with hMSCs. The presence of hMSCs offer a degree of DOXO resistance in U2OS cells cultured on PLGA-DOXO NP bone cements. The consideration of the tumor microenvironment via the indirect inclusion of hMSCs in this study can act as a starting point for future direct coculture and in vivo investigations

Glycosylation of a CNS-specific extracellular matrix glycoprotein, tenascin-R, is dominated by O-linked sialylated glycans and "brain-type” neutral N-glycans

As a member of the tenascin family of extracellular matrix glycoproteins, tenascin-R is located exclusively in the CNS. It is believed to play a role in myelination and axonal stabilization and, through repulsive properties, may contribute to the lack of regeneration of CNS axons following damage. The contrary functions of the tenascins have been localized to the different structural domains of the protein. However, little is known concerning the influence of the carbohydrate conjugated to the many potential sites for N- and O-glycosylation (10-120% by weight). As a first analytical requirement, we show that >80% of the N-glycans in tenascin-R are neutral and dominated by complex biantennary structures. These display the "brain-type” characteristics of outer-arm- and core-fucosylation, a bisecting N-acetylglucosamine and, significantly, an abundance of antennae truncation. In some structures, truncation resulted in only a single mannose residue remaining on the 3-arm, a particularly unusual consequence of the N-glycan processing pathway. In contrast to brain tissue, hybrid and oligomannosidic N-glycans were either absent or in low abundance. A high relative abundance of O-linked sialylated glycans was found. This was associated with a significant potential for O-linked glycosylation sites and multivalent display of the sialic acid residues. These O-glycans were dominated by the disialylated structure, NeuAcα2-3Galβ1-3(NeuAcα2-6)GalNAc. The possibility that these O-glycans enable tenascin-R to interact in the CNS either with the myelin associated glycoprotein or with sialoadhesin on activated microglia is discusse

Dipping-Induced Azimuthal Helix Orientation in Langmuir-Blodgett Monolayers of α-Helical Amphiphilic Diblock Copolypeptides

The azimuthal helix orientation of the rigid-rod amphiphilic diblock copolypeptides (PLGA-b-PMLGSLGs) of poly(α-L-glutamic acid) (PLGA) and poly(γ-methyl-L-glutamate-ran-γ-stearyl-L-glutamate) with 30 mol % of stearyl substituents (PMLGSLG) in Langmuir-Blodgett (LB) monolayers was investigated using polarized transmission Fourier transform infrared spectroscopy. The relative position of dipping with respect to the previous transfer position can be used to manipulate the azimuthal orientation of the helices parallel to or tilted by an angle of 45° with respect to the dipping direction in the transferred films. The study of the azimuthal order for the LB monolayers of PLGA-b-PMLGSLGs of various block lengths revealed that the observed effect arises mainly from the deformation of the PMLGSLG top brush layer, induced by the flow orientation around the transfer region. In those cases where the PMLGSLG block is tilted by a sufficiently large angle with respect to the surface normal, high azimuthal order parameters of 0.5-0.75 were obtained.

Galectin-8 in IgA Nephritis: Decreased Binding of IgA by Galectin-8 Affinity Chromatography and Associated Increased Binding in Non-IgA Serum Glycoproteins

Background Immunoglobulin A nephritis (IgAN) is the most common primary glomerulonephritis worldwide. It is caused by accumulation of IgA1-containing immune complexes in the kidney resulting in renal failure, which is thought to be due to altered glycosylation of IgA with a decrease of 2-3-sialylated galactosides (NeuAc alpha 2-3Gal). less thanbrgreater than less thanbrgreater thanPurpose The purpose of this study was to analyze whether altered glycosylation of IgA would lead to an altered binding to galectin-8, an endogenous lectin with strong affinity for 2-3-sialylated galactosides. Galectins are a family of beta-galactoside-binding proteins; by binding various glycoproteins, they play important roles in the regulation of cellular functions in inflammation and immunity. Hence, an altered binding of IgA to galectin-8 could lead to pathologic immune functions, such as glomerulonephritis. less thanbrgreater than less thanbrgreater thanMethods Affinity chromatography of serum glycoproteins on the human sialogalactoside-binding lectin galectin-8N permitted quantitation of bound and unbound fractions, including IgA. less thanbrgreater than less thanbrgreater thanResults Analysis of similar to 100 IgA nephritis sera showed that the galectin-8N unbound fraction of IgA increased compared to similar to 100 controls, consistent with the known loss of galactosylation. A subgroup of similar to 15% of the IgAN patients had a ratio of galectin-8 bound/unbound IgA andlt;0.09, not found for any of the controls. Unexpectedly, the galectin-8N-binding fraction of serum glycoproteins other than IgA increased in the sera of IgAN patients but not in controls, suggesting a previously unrecognized change in this disease. less thanbrgreater than less thanbrgreater thanConclusion This is the first study that relates a galectin, an endogenous lectin family, to IgA nephritis and thus should stimulate new avenues of research into the pathophysiology of the disease.Funding Agencies|Swedish Research Council (Vetenskapsradet)|2008-3356|Swedish Foundation for Swedish Research|FFL4|Swedish Healthcare System (ALF)||Region Skane||</p

RAS gene polymorphisms, classical risk factors and the advent of coronary artery disease in the Portuguese population

<p>Abstract</p> <p>Background</p> <p>Several polymorphisms within the renin-angiotensin system cluster of genes have been associated with the advent of coronary artery disease (CAD) or related pathologies. We investigated the distribution of 5 of these polymorphisms in order to find any association with CAD development and distinguish if any of the biochemical and behavioural factors interact with genetic polymorphisms in the advent of the disease.</p> <p>Methods</p> <p><it>ACE </it>I/D (rs4340), <it>ACE </it>A11860G (rs4343), <it>AT1R </it>A1166C (rs5186), <it>AGT </it>T174M (rs4762) and <it>AGT </it>M235T (rs699) gene polymorphisms were PCR-RFLP analysed in 298 CAD patients and 510 controls from Portugal. Several biochemical and behavioural markers were obtained.</p> <p>Results</p> <p><it>ACE </it>I/D DD and <it>ACE</it>11860 GG genotypes are risk factors for CAD in this population. The simultaneous presence of <it>ACE </it>I/D I and <it>ACE</it>11860 A alleles corresponds to a significant trend towards a decrease in CAD incidence. We found several synergistic effects between the studied polymorphisms and classical risk factors such as hypertension, obesity, diabetes and dyslipidaemia: the presence of the DD genotype of <it>ACE </it>I/D (and also <it>ACE</it>11860 GG) increases the odds of developing CAD when associated to each one of these classical risk factors, particularly when considering the male and early onset CAD subgroup analysis; <it>AGT</it>235 TT also increases the CAD risk in the presence of hypertension and dyslipidaemia, and <it>AT1R</it>1166 interacts positively with hypertension, smoking and obesity.</p> <p>Conclusion</p> <p><it>ACE </it>polymorphisms were shown to play a major role in individual susceptibility to develop CAD. There is also a clear interaction between RAS predisposing genes and some biochemical/environmental risk factors in CAD onset, demonstrating a significant enhancement of classical markers particularly by <it>ACE </it>I/D and <it>ACE</it>11860.</p

High fat diet modifies the association of lipoprotein lipase gene polymorphism with high density lipoprotein cholesterol in an Asian Indian population

Background Single nucleotide polymorphisms (SNPs) in lipoprotein lipase gene (LPL) have been shown to influence metabolism related to lipid phenotypes. Dietary factors have been shown to modify the association between LPL SNPs and lipids; however, to date, there are no studies in South Asians. Hence, we tested for the association of four common LPL SNPs with plasma lipids and examined the interactions between the SNPs and dietary factors on lipids in 1,845 Asian Indians. Methods The analysis was performed in 788 Type 2 diabetes cases and 1,057 controls randomly chosen from the cross-sectional Chennai Urban Rural Epidemiological Study. Serum triacylglycerol (TAG), serum total cholesterol, and high-density lipoprotein cholesterol (HDL-C) were measured using a Hitachi-912 autoanalyzer (Roche Diagnostics GmbH, Mannheim, Germany). Dietary intake was assessed using a semi-quantitative food frequency questionnaire. The SNPs (rs1121923, rs328, rs4922115 and rs285) were genotyped by polymerase chain reaction followed by restriction enzyme digestion and 20% of samples were sequenced to validate the genotypes obtained. Statistical Package for Social Sciences for Windows version 22.0 (SPSS, Chicago, IL) was used for statistical analysis. Results After correction for multiple testing and adjusting for potential confounders, SNPs rs328 and rs285 showed association with HDL-C (P = 0.0004) and serum TAG (P = 1×10−5), respectively. The interaction between SNP rs1121923 and fat intake (energy %) on HDL-C (P = 0.003) was also significant, where, among those who consumed a high fat diet (28.4 ± 2.5%), the T allele carriers (TT + XT) had significantly higher HDL-C concentrations (P = 0.0002) and 30% reduced risk of low HDL-C levels compared to the CC homozygotes. None of the interactions on other lipid traits were statistically significant. Conclusion Our findings suggest that individuals carrying T allele of the SNP rs1121923 have increased HDL-C levels when consuming a high fat diet compared to CC homozygotes. Our finding warrants confirmation in prospective studies and randomized controlled trials

Identification of a new European rabbit IgA with a serine-rich hinge region

<div><p>In mammals, the most striking IgA system belongs to Lagomorpha. Indeed, 14 IgA subclasses have been identified in European rabbits, 11 of which are expressed. In contrast, most other mammals have only one IgA, or in the case of hominoids, two IgA subclasses. Characteristic features of the mammalian IgA subclasses are the length and amino acid sequence of their hinge regions, which are often rich in Pro, Ser and Thr residues and may also carry Cys residues. Here, we describe a new IgA that was expressed in New Zealand White domestic rabbits of <i>IGHV</i>a1 allotype. This IgA has an extended hinge region containing an intriguing stretch of nine consecutive Ser residues and no Pro or Thr residues, a motif exclusive to this new rabbit IgA. Considering the amino acid properties, this hinge motif may present some advantage over the common IgA hinge by affording novel functional capabilities. We also sequenced for the first time the IgA14 CH2 and CH3 domains and showed that IgA14 and IgA3 are expressed.</p></div

Uptake of Aortic 18F-FDG Is Correlated with Low-Density Lipoprotein Cholesterol and Leptin in a General Population

Objective: This study investigated the relationship between aortic 18F-fluoro-2-deoxy-D-glucose (18F-FDG) uptake and clinical and laboratory findings related to atherosclerosis in a general population. Copyright:Methods: 18F-FDG uptake in the ascending aorta was measured on the positron emission tomography/computed tomography (PET/CT) scans of 211 Japanese adults. The maximum target-to-background ratio (TBR) was compared with clinical and laboratory atherosclerosis findings.Results: By multivariate regression analysis adjusted for age and sex, TBR-ascending aorta (TBR-A) was significantly correlated with various clinical and laboratory parameters, such as body mass index, log visceral fat area, low-density lipoprotein cholesterol (LDL-C), log fasting immunoreactive insulin, log homeostasis model assessment of insulin resistance, log total adiponectin and log-leptin, in all subjects. Furthermore, by multivariate linear regression analysis adjusted for confounding factors, TBR-A was significantly correlated with LDL-C (β=0.001, p=0.03) and log-leptin (β =0.336, p<0.01) in all subjects.Conclusion: TBR-A was significantly correlated with LDL-C and log-leptin independent from confounding factors. Our results suggest that aortic 18F-FDG uptake is a good marker of atherosclerosis, even in a general population