Anti-apoptotic effects of Z alpha-1 antitrypsin in human bronchial epithelial cells.

α1-antitrypsin (α1-AT) deficiency is a genetic disease which manifests as early-onset emphysema or liver disease. Although the majority of α1-AT is produced by the liver, it is also produced by bronchial epithelial cells, amongst others, in the lung. Herein, we investigate the effects of mutant Z α1-AT (ZAAT) expression on apoptosis in a human bronchial epithelial cell line (16HBE14o-) and delineate the mechanisms involved.

Control, M variant α1-AT (MAAT)- or ZAAT-expressing cells were assessed for apoptosis, caspase-3 activity, cell viability, phosphorylation of Bad, nuclear factor (NF)-κB activation and induced expression of a selection of pro- and anti-apoptotic genes.

Expression of ZAAT in 16HBE14o- cells, like MAAT, inhibited basal and agonist-induced apoptosis. ZAAT expression also inhibited caspase-3 activity by 57% compared with control cells (p = 0.05) and was a more potent inhibitor than MAAT. Whilst ZAAT had no effect on the activity of Bad, its expression activated NF-κB-dependent gene expression above control or MAAT-expressing cells. In 16HBE14o- cells but not HEK293 cells, ZAAT upregulated expression of cIAP-1, an upstream regulator of NF-κB. cIAP1 expression was increased in ZAAT versus MAAT bronchial biopsies.

The data suggest a novel mechanism by which ZAAT may promote human bronchial epithelial cell survival.

The redox-Bohr group associated with iron-sulfur cluster N2 of complex I

Proton pumping respiratory complex I (NADH: ubiquinone oxidoreductase) is a major component of the oxidative phosphorylation system in mitochondria and many bacteria. In mammalian cells it provides 40% of the proton motive force needed to make ATP. Defects in this giant and most complicated membrane-bound enzyme cause numerous human disorders. Yet the mechanism of complex I is still elusive. A group exhibiting redox-linked protonation that is associated with iron-sulfur cluster N2 of complex I has been proposed to act as a central component of the proton pumping machinery. Here we show that a histidine in the 49-kDa subunit that resides near iron-sulfur cluster N2 confers this redox-Bohr effect. Mutating this residue to methionine in complex I from Yarrowia lipolytica resulted in a marked shift of the redox midpoint potential of iron-sulfur cluster N2 to the negative and abolished the redox-Bohr effect. However, the mutation did not significantly affect the catalytic activity of complex I and protons were pumped with an unchanged stoichiometry of 4 H+/2e(-). This finding has significant implications on the discussion about possible proton pumping mechanism for complex I.

Cluster randomised controlled trial of an infection control education and training intervention programme focusing on meticillin-resistant Staphylococcus aureus in nursing homes for older people

The aim of this cluster randomised controlled trial was to test the impact of an infection control education and training programme on meticillin-resistant Staphylococcus aureus (MRSA) prevalence in nursing homes. Nursing homes were randomised to intervention (infection control education and training programme; N¼16) or control (usual practice continued; N¼16). Staff in intervention homes were educated and trained (0, 3 and 6 months) in the principles and implementation of good infection control practice with infection control audits conducted in all sites (0, 3, 6 and 12 months) to assess compliance with good practice. Audit scores were fed back to nursing home managers in intervention homes, together with a written report indicating where practice could be improved. Nasal swabs were taken from all consenting residents and staff at 0, 3, 6 and 12 months. The primary outcome was MRSA prevalence in residents and staff, and the secondary outcome was a change in infection control audit scores. In all, 793 residents and 338 staff were recruited at baseline. MRSA prevalence did not change during the study in residents or staff. The relative risk of a resident being colonised with MRSA in an intervention home compared with a control home at 12 months was 0.99 (95% con?dence interval: 0.69, 1.42) after adjustment for clustering. Mean infection control audit scores were signi?cantly higher in the intervention homes (82%) compared with the control homes (64%) at 12 months (P<0.0001). Consideration should be given to other approaches which may help to reduce MRSA in this setting.

Differential modulation of a radiation-induced bystander effect in glioblastoma cells by pifithrin-alpha and wortmannin

The implication of radiation-induced bystander effect (RIBE) for both radiation protection and radiotherapy has attracted significant attention, but a key question is how to modulate the RIBE. The present study found that, when a fraction of glioblastoma cells in T98G population were individually targeted with precise helium particles through their nucleus, micronucleus (MN) were induced and its yield increased non-linearly with radiation dose. After co-culturing with irradiated cells, additional MN could be induced in the non-irradiated bystander cells and its yield was independent of irradiation dose, giving direct evidence of a RIBE. Further results showed that the RIBE could be eliminated by pifithrin-alpha (p53 inhibitor) but enhanced by wortmannin (PI3K inhibitor). Moreover, it was found that nitric oxide (NO) contributed to this RIBE, and the levels of NO of both irradiated cells and bystander cells could be extensively diminished by pifithrin-alpha but insignificantly reduced by wortmannin. Our results indicate that RIBE can be modulated by p53 and PI3K through a NO-dependent and NO-independent pathway, respectively. (C) 2009 Elsevier B.V. All rights reserved.

Non-thiazolidinedione antihyperglycaemic agents. Part 3: The effects of stereochemistry on the potency of alpha-methoxy-beta-phenylpropanoic acids.

Rhizopus delemar lipase catalyzed ester hydrolysis of the alpha-methoxy-beta-phenylpropanoate (I) affords the (R)-(+) and (S)-(-) isomers in > 84% enantiomeric excess. Abs. stereochem. was detd. by a single crystal X-ray anal. of a related synthetic analog. The activity of these two enantiomers on glucose transport in vitro and as anti-diabetic agents in vivo is reported and their unexpected equivalence attributed to an enzyme-mediated stereospecific isomerization of the (R)-(+) isomer. Binding studies using recombinant human PPAR-gamma (peroxisomal proliferator activated receptor gamma), now established as a mol. target for this compd. class, indicate a 20-fold higher binding affinity for the (S) antipode relative to the (R) antipode.

Non-thiazolidinedione antihyperglycemic agents. 2: alpha-Carbon substituted-beta-phenylpropanoic acids.

Buckle, D. R.; Cantello, B. C. C.; Cawthorne, M. A.; Coyle, P. J.; Dean, D. K.; Faller, A.; Haigh, D.; Hindley, R. M.; Lefcott, L. J.; et al. Dep. Medicinal Chem., Smithkline Beecham Pharmaceuticals, Surrey, UK. Bioorganic & Medicinal Chemistry Letters (1996), 6(17), 2127-2130. Publisher: Elsevier, CODEN: BMCLE8 ISSN: 0960-894X. Journal written in English. CAN 125:238227 AN 1996:573179 CAPLUS (Copyright (C) 2009 ACS on SciFinder (R)) Abstract The thiazolidine-2,4-dione ring of insulin-sensitizing antidiabetic agents can be replaced by ?-acyl-, ?-alkyl- and ?-(aralkyl)-carboxylic acids. The inclusion of an addnl. lipophilic moiety affords compds., equipotent to BRL 48482.

Non-thiazolidinedione antihyperglycemic agents. 1: Alpha-Heteroatom substituted-beta-phenylpropanoic acids.

A review with 22 refs. The 5-benzylthiazolidine-2,4-dione moiety of insulin sensitizing antidiabetic agents can be replaced by a range of ?-heteroatom functionalized ?-phenylpropanoic acids. ?-Oxy-carboxylic acids show potent antidiabetic activity and one compd., the ?-ethoxyacid (SB 213068), is one of the most potent antihyperglycemic agents yet reported.

Genetic Variation in the alpha 7 Nicotinic Acetylcholine Receptor is Associated with Delusional Symptoms in Alzheimer's Disease

Psychotic symptoms are common in Alzheimer's disease (AD) and have a negative impact oil quality of life. It is suggested that psychotic symptoms may be attributed to genetic risk factors which are revealed during neurodegeneration. CHRNA7, the gene for the alpha 7 nicotinic acetylcholine receptor, has been associated with schizophrenia in linkage and association Studies. Hence we investigated single SNPs and haplotypes in CHRNA7 in relation to AD with psychosis in a large, well-characterised and previously described cohort within the Northern Ireland population. A significant association between delusions and the T allele of rs6494223 (P = 0.014, OR = 1.63, Cl 1.22-2.17) was found. This suggests that the alpha 7 receptor may be a suitable target for the treatment of AD with psychosis.

Increased expression of fibroblast activation protein-alpha in keloid fibroblasts: implications for development of a novel treatment option.

Keloid scars are common benign fibroproliferative reticular dermal lesions with unknown etiology and ill-defined management with high rate of recurrence post surgery. The progression of keloids is characterized by increased deposition of extracellular matrix proteins, invasion into the surrounding healthy skin and inflammation. Fibroblasts are considered to be the key cellular mediators of fibrogenesis in keloid scars. Fibroblast activation protein alpha (FAP-a) and dipeptidyl peptidase IV (DPPIV) are proteases located at the plasma membrane promoting cell invasiveness and tumor growth and have been previously associated with keloid scars. Therefore, in this study we analyzed in further detail the expression of FAP-a in keloid fibroblasts compared to control skin fibroblasts. Dermal fibroblasts were obtained from punch-biopsies from the active margin of four keloids and four control skin samples. Flow cytometry was used to analyze FAP-a expression and the CytoSelect(®) 24-Well Collagen I Cell Invasion Assay was applied to study fibroblast invasion. Secretion of extracellular matrix (ECM) proteins was investigated by multiplexed particle-based flow cytometric assay and enzyme-linked immunosorbent assay. We found an increased expression of FAP-a in keloid fibroblasts compared to control skin fibroblasts (p