Biochemical and biophysical research communications
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Biochem. Biophys. Res. Commun. · Jan 2010
Laminin-1 induces neurite outgrowth in human mesenchymal stem cells in serum/differentiation factors-free conditions through activation of FAK-MEK/ERK signaling pathways.
Mesenchymal stem cells (MSCs) can be differentiated into cell types derived from all three germ layers by manipulating culture conditions in vitro. A multitude of growth and differentiation factors have been employed for driving MSCs towards a neuronal phenotype. In the present study, we investigated the potential of extracellular matrix (ECM) proteins-fibronectin, collagen-1, collagen-IV, laminin-1, and laminin-10/11, to induce a neuronal phenotype in bone marrow derived human MSCs in the absence of growth factors/differentiating agents. ⋯ Abrogation of FAK phosphorylation by herbimycin-A inhibited neurite formation and also decreased activities of MEK and ERK. Pharmacological inhibitors of MEK (U0126) and ERK (PD98059) also blocked neurite outgrowth in cells plated on laminin-1. Our study demonstrates the involvement of integrin alpha6beta1 and FAK-MEK/ERK signaling pathways in laminin-1-induced neurite outgrowth in MSCs in the absence of serum and differentiation factors.
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Biochem. Biophys. Res. Commun. · Jan 2010
Leptin G-2548A and leptin receptor Q223R gene polymorphisms are not associated with obesity in Romanian subjects.
We aimed to investigate whether polymorphisms LEP G-2548A and LEPR Q223R in the human leptin (LEP), and leptin receptor (LEPR) genes are associated with obesity and metabolic traits in a sample of Romanian population. Two hundred and two subjects divided in obese (body mass index, BMI30 kg/m(2)), and non-obese were included in this study. The polymorphisms were genotyped using polymerase chain reaction (PCR) followed by restriction fragment length polymorphism (RFLP) analysis. ⋯ The association analysis with metabolic syndrome quantitative traits showed that homozygous for LEP -2548G allele had significantly higher leptin levels (17.2+/-6.6 ng/ml vs. 13.2+/-4.9 ng/ml, p=0.011), and carriers of R allele had higher levels of triglycerides (p=0.017) and glucose (p=0.040), and enhanced systolic (p=0.015) and diastolic blood pressure (p=0.026), after adjustment for age, gender, and BMI. These results indicate that LEP G-2548A and LEPR Q223R SNPs may not be considered as genetic risk factors for obesity in a sample of Romanian population. However, LEP -2548GG genotype appear to be important in regulating leptin levels, whereas the LEPR 223R allele might predispose healthy subjects to develop metabolic disturbances.
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Biochem. Biophys. Res. Commun. · Jan 2010
IL-17 primes airway epithelial cells lacking functional Cystic Fibrosis Transmembrane conductance Regulator (CFTR) to increase NOD1 responses.
In Cystic Fibrosis (CF), the absence of functional Cystic Fibrosis Transmembrane conductance Regulator (CFTR) translates into chronic bacterial infection, excessive inflammation, tissue damage, impaired lung function and eventual death. Understanding the mechanisms underlying this vicious circle of inflammation is key to better therapies for CF. In this manuscript, we have found that the presence of IL-17 in the airways of CF patients not only exacerbates inflammation through the recruitment of neutrophils via secretion of CXCL8, but also by priming airway epithelial cells lacking functional CFTR to increase response to the bacterial sensor NOD1. ⋯ Moreover, prior stimulation of AECs expressing the CFTRDeltaF508 mutant with IL-17 showed much greater CXCL8 secretion in response to a NOD1 agonist and Pseudomonas aeruginosa diffusible material. Taken together our results show that IL-17 primes AECs expressing CFTRDeltaF508 to increase host defence response to bacteria through the up-regulation of PRRs, and in particular of NOD1, and identifies another mechanism of action through which the CFTRDeltaF508 mutation leads to increase inflammation in response to bacterial ligands. Therefore preventing IL-17 function in CF may prove an important strategy in decreasing lung inflammation due to both direct and indirect effects.
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Biochem. Biophys. Res. Commun. · Dec 2009
ReviewTRESK channel as a potential target to treat T-cell mediated immune dysfunction.
In this review, we propose that TRESK background K(+) channel could serve as a potential therapeutic target for T-cell mediated immune dysfunction. TRESK has many immune function-related properties. TRESK is abundantly expressed in the thymus, the spleen, and human leukemic T-lymphocytes. ⋯ Calcineurin has been found to interact with TRESK via specific NFAT-like docking site. When the T-cell is activated, calcineurin can bind to the NFAT-docking site of TRESK. The activation of both TRESK and NFAT via Ca(2+)-calcineurin-NFAT/TRESK pathway could modulate the transcription of new genes in addition to regulating several aspects of T-cell function.
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The neuraminidase inhibitor oseltamivir has been identified to have significant anti-influenza activity in clinical practice. However, its efficacy has not been verified in enough subtypes of influenza A virus, particularly, the current pandemic virus, H1N1. ⋯ Conversely, a boosting effect on viral infection was observed, particularly with the 2009 H1N1 pp at oseltamivir concentrations above 0.025muM. Further testing on two wild 2009 H1N1 virus strains, A/California/07/09 and A/Sichuan/1/09, as well as a seasonal flu virus, A/Baoan/51/2008, confirmed these findings.