Acceptor specificity of the Pasteurella hyaluronan and chondroitin synthases and production of chimeric glycosaminoglycans

The hyaluronan (HA) synthase, PmHAS, and the chondroitin synthase, PmCS, from the Gram-negative bacterium Pasteurella multocida polymerize the glycosaminoglycan (GAG) sugar chains HA or chondroitin, respectively. The recombinant Escherichia coli-derived enzymes were shown previously to elongate exogenously supplied oligosaccharides of their cognate GAG (e.g. HA elongated by PmHAS). Here we show that oligosaccharides and polysaccharides of certain noncognate GAGs (including sulfated and iduronic acid-containing forms) are elongated by PmHAS (e.g. chondroitin elongated by PmHAS) or PmCS. Various acceptors were tested in assays where the synthase extended the molecule with either a single monosaccharide or a long chain (approximately 10(2-4) sugars). Certain GAGs were very poor acceptors in comparison to the cognate molecules, but elongated products were detected nonetheless. Overall, these findings suggest that for the interaction between the acceptor and the enzyme (a) the orientation of the hydroxyl at the C-4 position of the hexosamine is not critical, (b) the conformation of C-5 of the hexuronic acid (glucuronic versus iduronic) is not crucial, and (c) additional negative sulfate groups are well tolerated in certain cases, such as on C-6 of the hexosamine, but others, including C-4 sulfates, were not or were poorly tolerated. In vivo, the bacterial enzymes only process unsulfated polymers; thus it is not expected that the PmCS and PmHAS catalysts would exhibit such relative relaxed sugar specificity by acting on a variety of animal-derived sulfated or epimerized GAGs. However, this feature allows the chemoenzymatic synthesis of a variety of chimeric GAG polymers, including mimics of proteoglycan complexes.     

Integrative analysis of mRNA and microRNA expression profiles in laryngeal squamous cell carcinoma

Larynx cancer is a therapeutically challenging disease. Rapidly evolving experimentally validated data have significantly improved our understanding of the complex role of numerous RNA, DNA, and proteins that play a role in the development and progression of cancer. Based on the insights from approximately two decades of research, it seems clear that microRNAs (miRNAs) have revolutionized our concepts related to the main role of noncoding RNAs in different cancers’ progression, development, and metastasis. Mechanistically, miRNAs have been reported to regulate different RNAs and finally protein-coding genes. The expression profiling of miRNAs and messenger RNA (mRNAs) was conducted for a deeper analysis of the miRNAs and mRNAs which play an essential role in larynx cancer. Downregulation or upregulation over twofolds in the miRNAs was considered to be significant, and that of sixfolds or below was considered to be significant for the mRNAs. In accordance with this approach, the expression levels of 43 miRNAs were increased in this study, whereas the expression levels of 129 were decreased. Accordingly, all the genomic expression studies provided evidence of upregulation of 97 genes, whereas 128 genes were found to be downregulated. Among these miRNAs, hsa-miR-20a-3p and hsa-miR-1972 were noted to be important in the etiology of larynx cancer.     

Effect of Iloprost on endothelin-1-induced free radical activation in rabbit brain stem

Iloprost, a stable analogue of prostacyclin, was used to reverse the early period of vasoconstriction provoked by Endothelin-1 by administering into the rabbit basilar artery. We observed if this produced an effect on the central nervous system parenchyma mediated by free radical system. The red neurons were counted in brain stem sections stained with haematoxylin and eosin, while superoxide dismutase and malondialdehyde levels were measured in brain stem tissue samples as a marker of reactive oxygen metabolites; both 30 and 90 min after administration of either Endothelin-1 (0.25 ng) alone or Endothelin-1 followed by Iloprost (0.5 microg/kg) into the basilar artery. Endothelin-1 significantly increased the number of red neurons, while Iloprost significantly reduced them after 30 and 90 min. However, regarding the reactive oxygen metabolites; a similar reversing effect of Iloprost was not observed although superoxide dismutase levels were significantly decreased after Endothelin-1 infusion.     

Elevated levels of matrix metalloprotein-3 in patients with coronary aneurysm: A case control study

BACKGROUND: Matrix metalloproteinases (MMPs) have been implicated in the pathogenesis of arterial aneurysms through increased proteolysis of extracellular matrix proteins. Increased proteolysis due to elevated matrix degrading enzyme activity in the arterial wall may act as a susceptibility factor for the development of coronary aneurysms. The aim of this study was to investigate the association between MMPs and presence of coronary aneurysms. METHODS: Thirty patients with aneurysmal coronary artery disease and stable angina were enrolled into study (Group 1). Fourteen coronary artery disease patients with stable angina were selected as control group (Group 2). MMP-1, MMP-3 and C-reactive protein (CRP) were measured in peripheral venous blood and matched between the groups. RESULTS: Serum MMP-3 level was higher in patients with aneurismal coronary artery disease compared to the control group (20.23 +/- 14.68 vs 11.45 +/- 6.55 ng/ml, p = 0.039). Serum MMP-1 (13.63 +/- 7.73 vs 12.15 +/- 6.27 ng/ml, p = 0.52) and CRP levels (4.78 +/- 1.47 vs 4.05 +/- 1.53 mg/l, p = 0.13) were not significantly different between the groups. CONCLUSION: MMPs can cause arterial wall destruction. MMP-3 may play role in the pathogenesis of coronary aneurysm development through increased proteolysis of extracellular matrix proteins.     

Collective chain dynamics in lipid bilayers by inelastic x-ray scattering

We investigated the application of inelastic x-ray scattering (IXS) to lipid bilayers. This technique directly measures the dynamic structure factor S(q,omega) which is the space-time Fourier transform of the electron density correlation function of the measured system. For a multiatomic system, the analysis of S(q,omega) is usually complicated. But for multiple bilayers of lipid, S(q,omega) is dominated by chain-chain correlations within individual bilayers. Thus IXS provides a unique probe for the collective dynamics of lipid chains in a bilayer that cannot be obtained by any other method. IXS of dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylcholine + cholesterol at two different concentrations were measured. S(q,omega) was analyzed by three-mode hydrodynamic equations, including a thermal diffusive mode and two propagating acoustic modes. We obtained the dispersion curves for the phonons that represent the collective in-plane excitations of lipid chains. The effect of cholesterol on chain dynamics was detected. Our analysis shows the importance of having a high instrument resolution as well as the requirement of sufficient signal-to-noise ratio to obtain meaningful results from such an IXS experiment. The requirement on signal-to-noise also applies to molecular dynamics simulations.     

Effects of zinc supplementation to ration on some hematological parameters in broiler chicks

The aim of the study was to examine the effects of zinc supplementation on some hematological parameters. Sixty newborn male broiler chicks were utilized in the study. Zinc (Zn) was added into drinking water at levels of 0, 125, 500, and 1000 mg/kg. In the study, there was no significant difference between control and Zn-supplemented groups in erythrocyte count, hemoglobin amount, hematocrit levels, total leukocyte count, and differential leukocyte % levels, but the α-naphthyl acetate esterase ANAE(+) lymphocyte rate significantly (p<0.05) increased in the 125-ppm Zn-supplemented group compared with the control group. In conclusion, the data obtained may be beneficial in demonstrating the effects of zinc on, at least, these parameters.     

Evaluation of the immune response to hepatitis B vaccination in children aged 1-3 years in Malatya, Turkey

By the end of 1998, Turkey had launched the routine vaccination of infants against hepatitis B. The purpose of the study is to evaluate the immune response in a sample of vaccinated children aged 1-3 years in the city of Malatya. A total of 210 vaccinated children 12 to 48 months old were selected for the study with 30 cluster sampling in the city of Malatya, Turkey. The children were visited at their homes during January-April 2002. The information on demographic characteristics, family's and child's medical history was gathered, childrens' weight and height were measured and blood samples were taken. Anti-HBs, HbsAg and anti-HBc titers were assayed by micro-ELIZA from the sera. The mean age of the children was 26.3 months, 100 (47.6%) were male and 110 (52.4%) were female. Overall, 203 (96.7%) children had protective anti-HBs levels (> or = 10 IU/l), 0.5% showed evidence of natural infection (with positive anti-HBc and anti-HBs titers), 0.5% had acute or chronic infection (with positive HbsAg and anti-HBc titers) and 2.3% were seronegative. Geometric mean titer of anti-HBs among vaccinated children except those who had positive anti-HBc titers was 138.7 mIU/ml (95% CI:124.7-154.2) and seroconversion rates did not differ by age, sex, anthropometric measurements, time after third dose and place of vaccine administered (P > 0.05). The high seroprotection rate over 95% showed that routine infant vaccination program for hepatitis B was successfully carried out in the city Malatya.     

Anti-inflammatory effects of leptin and cholecystokinin on acetic acid-induced colitis in rats: role of capsaicin-sensitive vagal afferent fibers

Leptin and cholecystokinin (CCK) have a synergistic interaction in the suppression of food intake, and afford similar gastroprotective activity. The present study was designed to investigate the putative protective effects of CCK and leptin on acute colonic inflammation. Leptin or CCK-8s was injected to rats intraperitoneally immediately before and 6 h after the induction of colitis with acetic acid. CCK-A receptor antagonist (L-364,718) or CCK-B receptor antagonist (L-365,260) was injected intraperitoneally 15 min before leptin or CCK treatments. In a group of rats, vagal afferent fibers were denervated by topical application of capsaicin on the cervical vagi. Rats were decapitated at 24 h, and the distal 8 cm of the colon were removed for macroscopic scoring, determination of tissue wet weight index (WWI), histologic assessment and tissue myeloperoxidase (MPO) activity. All inflammation parameters were increased by acetic acid-induced colitis compared to control group. Leptin or CCK-8s treatment reduced these parameters in a similar manner, while co-administration of leptin and CCK was found to be more effective in reducing the macroscopic score and WWI. CCK-8s-induced reduction in the score and WWI was prevented by CCK-A, but not by CCK-B receptor antagonist, whereas neither antagonist altered the inhibitory effect of leptin on colitis-induced injury. On the other hand, perivagal capsaicin prevented the protective effects of both CCK-8s and leptin on colitis. Our results indicate that leptin and CCK have anti-inflammatory effects on acetic acid-induced colitis in rats, which appear to be mediated by capsaicin-sensitive vagal afferent fibers involving the reduction in colonic neutrophil infiltration.