172 research outputs found
G-quadruplex formation of FXYD1 pre-mRNA indicates the possiblity of regulating expression of its protein product
G-quadruplexes are higher-order nucleic acid structures formed of square-planar arrangements of four guanine bases held together by Hoogsteen-type hydrogen bonds. Stacks of guanine tetrads are stabilised by intercalating potassium ions. FXYD1 encodes for phospholemman, a regulatory subunit of the cardiac Na+/K+-ATPase. Computational sequence analysis of FXYD1 pre-mRNA predicted the formation of stable intramolecular G-quadruplexes in human and orthologue sequences. Multiple sequence alignment indicated that G-rich sequences are conserved in evolution suggesting a potential role of G-quadruplexes in FXYD1 gene expression. The existence of a non-functional alternative splicing product indicated that the G-quadruplex formation may control alternative splicing. Quadruplex formation of human and bovine oligonucleotides was confirmed in vitro by native polyacrylamide gel electrophoresis and intrinsic fluorescence emission spectroscopy. Taking together the evolutionary conservation of G-quadruplex forming sequences with the confirmation of G-quadruplex formation in vitro by two FXYD1 homologues the results point to a potential role of these structures in regulating the expression of FXYD1 and thus regulate indirectly the activity of the cardiac Na+/K+ -ATPase.Peer reviewe
Cannabinoid signalling in TNF-alpha induced IL-8 release
Original article can be found at: http://www.sciencedirect.com/science/journal/00142999 Copyright Elsevier B.V. DOI : 10.1016/j.ejphar.2006.04.015Peer reviewe
Modulation of Macrophage Function by Lactobacillus-Conditioned Medium
open access articleProbiotics are used as microbial food supplements for health and well-being. They are thought to have immunomodulatory effects although their exact physiological mechanism of action is not clear. This study investigated the influence of probiotic Lactobacillus rhamnosus GG conditioned media (LGG-CM) on macrophage phagocytosis of non-pathogenic Escherichia coli HfrC. The gentamicin protection assay was used to study the bacterial killing phases of phagocytosis. Macrophages co-incubated with E. coli for an hour allowed them to ingest bacteria and then the rate of E. coli killing was monitored for up to 300 min to determine the killing or digestion of the bacteria by recovering them from the macrophage lysate. We found that the LGG-CM significantly increased the bacterial killing by approximately 6-fold when compared with that of controls. By contrast, this killing process was found to be associated with enhanced free radical production via the activation of NADPH oxidase, stimulated by the LGG conditioned medium. We also found that the conditioned medium had small effect on nitric oxide (NO) generation, albeit to a lesser extent. This work suggests that LGG-CM may play an important role in suppressing the total microbial load within the macrophages and hence, the extent to which pro-inflammatory molecules such as free radicals and NO are generated. The modulation of inflammation-promoting signals by LGG-CM may be beneficial as it modulates bacterial killing, and thereby prevents any collateral damage to host
7-O-methylpunctatin, a novel homoisoflavonoid, inhibits phenotypic switch of human arteriolar smooth muscle cells
Remodeling of arterioles is a pivotal event in the manifestation of many inflammation-based cardio-vasculopathologies, such as hypertension. During these remodeling events, vascular smooth muscle cells (VSMCs) switch from a contractile to a synthetic phenotype. The latter is characterized by increased proliferation, migration, and invasion. Compounds with anti-inflammatory actions have been successful in attenuating this phenotypic switch. While the vast majority of studies investigating phenotypic modulation were undertaken in VSMCs isolated from large vessels, little is known about the effect of such compounds on phenotypic switch in VSMCs of microvessels (microVSMCs). We have recently characterized a novel homoisoflavonoid that we called 7-O-methylpunctatin (MP). In this study, we show that MP decreased FBS-induced cell proliferation, migration, invasion, and adhesion. MP also attenuated adhesion of THP-1 monocytes to microVSMCs, abolished FBS-induced expression of MMP-2, MMP-9, and NF-?B, as well as reduced activation of ERK1/2 and FAK. Furthermore, MP-treated VSMCs showed an increase in early (myocardin, SM-22?, SM-?) and mid-term (calponin and caldesmon) differentiation markers and a decrease in osteopontin, a protein highly expressed in synthetic VSMCs. MP also reduced transcription of cyclin D1, CDK4 but increased protein levels of p21 and p27. Taken together, these results corroborate an anti-inflammatory action of MP on human microVSMCs. Therefore, by inhibiting the synthetic phenotype of microVSMCs, MP may be a promising modulator for inflammation-induced arteriolar pathophysiology. - 2019 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This work was supported by the American University of Beirut (Grant # MPP 320133 to A.E.), University of Petra (Grant #: 5/4/2019) to A.B., E.B., and A.E., and the National Council for Scientific Research (CNRS) to M.F.Scopu
Asymmetry and structural system analysis of the proximal femur meta-epiphysis: osteoarticular anatomical pathology
<p>Abstract</p> <p>Background</p> <p>The human femur is commonly considered as a subsystem of the locomotor apparatus with four conspicuous levels of organization. This phenomenon is the result of the evolution of the locomotor apparatus, which encompasses both constitutional and individual variability. The work therein reported, therefore, underlies the significance of observing anatomical system analysis of the proximal femur meta-epiphysis in normal conditions, according to the anatomic positioning with respect to the right or left side of the body, and the presence of system asymmetry in the meta-epiphysis structure, thus indicating structural and functional asymmetry.</p> <p>Methods</p> <p>A total of 160 femur bones of both sexes were compiled and a morphological study of 15 linear and angulated parameters of proximal femur epiphysis was produced, thus defining the linear/angulated size of tubular bones. The parameters were divided into linear and angulated groups, while maintaining the motion of the hip joint and transmission of stress to the unwanted parts of the limb. Furthermore, the straight and vertical diameters of the femoral head and the length of the femoral neck were also studied. The angle between the neck and diaphysis, the neck antiversion and angle of rotation of the femoral neck were subsequently measured. Finally, the condylo-diaphyseal angle with respect to the axis of extremity was determined. To visualize the force of intersystem ties, we have used the method of correlation galaxy construction.</p> <p>Results</p> <p>The absolute numeral values of each linear parameter were transformed to relative values. The values of superfluity coefficient for each parameter in the right and left femoral bone groups were estimated and Pearson's correlation coefficient has been calculated (> 0.60). Retrospectively, the observed results have confirmed the presence of functional asymmetry in the proximal femur meta-epiphysis. On the basis of compliance or insignificant difference in the confidence interval of the linear parameters, we have revealed, therefore, a discrepancy in values between the neck and the diaphysis angle and the angle of femoral neck rotation (range displacement of confident interval to a greater degree to the right).</p> <p>Conclusion</p> <p>This study assessed the observations of a systemic anatomical study encompassing the proximal femur meta-epiphysis behavior in normal condition. This work has significance in medical practice as the theoretical basis is also required in knowing the decreased frequency and degree of severity of osteoarthritic pathologies in the dominant lower extremity.</p
Characterizing the Genetic Basis of Inherited Cardiomyopathies in Families From the United Arab Emirates
Ethnic Minority Microparticles have Distinct Pro-Thrombotic and Pro-Oxidative Phenotypes and Interact Differentially with Endothelial Cells in vitro: Implications for Risk to Cardiovascular Disease.
open access articleEthnic minority individuals are disproportionately susceptible to endothelial dysfunction and cardiovascular disease (CVD). Microparticles (MP) are biologically active membrane-bound nanovesicles released from cells that act as biomolecular shuttles. Plasma MP was isolated from healthy White, Black African, and South Asian individuals and analysed using flow cytometry. Their effects and interactions were assessed using fluorescence, confocal, and scanning electron microscopy. Total MP and a sub-population of smaller MP associated with dysfunction and disease progression were significantly increased in Black African individuals. Pro-thrombotic and pro-oxidant MP were substantially more numerous in Black African individuals. The tissue factor activity of ethnic minority MP was significantly greater than White MP. Ethnic minority MP induced significantly greater functional changes and morphology to an endothelial cell line in vitro and integrated into endothelial cells noticeably more than White MP. These data imply distinct differences in ethnic minority MP, suggesting a role in CVD susceptibility
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On the barrier properties of the cornea: a microscopy study of the penetration of fluorescently labeled nanoparticles, polymers, and sodium fluorescein
Overcoming the natural defensive barrier functions of the eye remains one of the greatest challenges of ocular drug delivery. Cornea is a chemical and mechanical barrier preventing the passage of any foreign bodies including drugs into the eye, but the factors limiting penetration of permeants and nanoparticulate drug delivery systems through the cornea are still not fully understood. In this study, we investigate these barrier properties of the cornea using thiolated and PEGylated (750 and 5000 Da) nanoparticles, sodium fluorescein, and two linear polymers (dextran and polyethylene glycol). Experiments used intact bovine cornea in addition to bovine cornea de-epithelialized or tissues pretreated with cyclodextrin. It was shown that corneal epithelium is the major barrier for permeation; pretreatment of the cornea with β-cyclodextrin provides higher permeation of low molecular weight compounds, such as sodium fluorescein, but does not enhance penetration of nanoparticles and larger molecules. Studying penetration of thiolated and PEGylated (750 and 5000 Da) nanoparticles into the de-epithelialized ocular tissue revealed that interactions between corneal surface and thiol groups of nanoparticles were more significant determinants of penetration than particle size (for the sizes used here). PEGylation with polyethylene glycol of a higher molecular weight (5000 Da) allows penetration of nanoparticles into the stroma, which proceeds gradually, after an initial 1 h lag phase
Mutation of epigenetic regulators TET2 and MLL3 in patients with HTLV-I-induced acute adult T-cell leukemia
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