Association of surfactant protein B gene with chronic obstructive pulmonary disease susceptibility.

SETTING: Genetic predisposition, in addition to smoking, is known to play a key role in susceptibility to chronic obstructive pulmonary disease (COPD). Several candidate genes have been proposed for COPD, including surfactant protein B (SFTPB). However, large studies in populations with different ethnic backgrounds and environments are required to clarify the role of SFTPB in COPD. OBJECTIVE: We investigated the association of SFTPB polymorphisms with COPD susceptibility and lung function in a Chinese Han population. DESIGN: Four single nucleotide polymorphisms (SNPs) in the SFTPB gene were genotyped in 680 COPD patients and 687 controls. Allele frequencies and genotype distributions were compared between cases and controls and the potential relationships between these SNPs and lung function were investigated. Associations between haplotypes and COPD susceptibility were also assessed. RESULTS: The SFTPB exon polymorphism rs1130866 significantly protected subjects from COPD (adjusted P = 0.004) and was associated with an increase in forced expiratory volume in 1 s (FEV(1)) (adjusted P = 0.014). CONCLUSIONS: SFTPB variants are associated with COPD susceptibility and lung function in the Chinese Han population.

Cigarette smoke enhances {beta}-defensin 2 expression in rat airways via nuclear factor-{kappa}B activation.

ß-defensin 2 (BD-2), an antimicrobial peptide, participates in airway defence. Cigarette smoke (CS) is a major risk factor for the development of chronic obstructive pulmonary disease. This study mainly aims to investigate the effect of CS on rat BD-2 (rBD-2) expression in rat airways. Rats were exposed to CS and treated with caffeic acid phenethyl ester (CAPE), a nuclear factor (NF)-κB inhibitor, or astragaloside IV (AS-IV), an active ingredient of Astragalus mongholicus. Besides the analysis of bronchoalveolar lavage fluid (BALF) and histological changes after CS exposure, rBD-2 expression was investigated with immunohistochemistry, reverse transcription PCR and ELISA. Total glutathione and nitric oxide (NO) levels in rat lungs were also detected. CS exposure markedly increased rBD-2 immunoreactivity, as well as rBD-2 mRNA and protein levels in rat airways, which were inhibited by CAPE treatment. Moreover, associated airway inflammation induced by CS was demonstrated by histological changes, increased cell counts and pro-inflammatory cytokines in BALF, and NF-κB activation and high levels of total glutathione and NO, which were all reversed by AS-IV in a dose-dependent fashion. In conclusion, CS exposure induces rBD-2 expression in rat airways via a NF-κB-dependent pathway, and AS-IV attenuates CS-induced airway inflammation due to its anti-inflammatory and antioxidant properties, at least partly through NF-κB inactivation.

Effect of sildenafil on acrolein-induced airway inflammation and mucus production in rats.

Airway inflammation with mucus overproduction is a distinguishing pathophysiological feature of many chronic respiratory diseases. Phosphodiesterase (PDE) inhibitors have shown anti-inflammatory properties. In the present study, the effect of sildenafil, a potent inhibitor of PDE5 that selectively degrades cyclic guanosine 3',5'-monophosphate (cGMP), on acrolein-induced inflammation and mucus production in rat airways was examined. Rats were exposed to acrolein for 14 and 28 days. Sildenafil or distilled saline was administered intragastrically prior to acrolein exposure. Bronchoalveolar lavage fluid (BALF) was acquired for cell count and the detection of pro-inflammatory cytokine levels. Lung tissue was examined for cGMP content, nitric oxide (NO)-metabolite levels, histopathological lesion scores, goblet cell metaplasia and mucin production. The results suggested that sildenafil pretreatment reversed the significant decline of cGMP content in rat lungs induced by acrolein exposure, and suppressed the increase of lung NO metabolites, the BALF leukocyte influx and pro-inflammatory cytokine release. Moreover, sildenafil pretreatment reduced acrolein-induced Muc5ac mucin synthesis at both mRNA and protein levels, and attenuated airway inflammation, as well as epithelial hyperplasia and metaplasia. In conclusion, sildenafil could attenuate airway inflammation and mucus production in the rat model, possibly through the nitric oxide/cyclic guanosine 3',5'-monophosphate pathway, and, thus, might have a therapeutic potential for chronic airway diseases.

The effects of antidepressant drug on ethanol-induced cell death.

Alcoholism is a serious health problem. Alcohol-dependent subjects have many health-related problems, such as severe cognitive impairments, alcoholic liver disease and coronary heart disease, resulting from ethanol-induced cell injury or cell death. Understanding the mechanisms underlying the cell death may provide clues for novel treatment strategies to prevent alcohol-induced cell damage. Prolonged ethanol consumption causes apoptotic activity in a host of cell types - more obviously affecting the liver, heart and surprisingly affecting the brain. This study uses four cell lines: neuronal cell line (SH-SY5Y), glia cell line (U-118 MG), liver cell line (E47) and heart cell line (the rat H9c2), and addresses that alcohol does, in fact, cause cell death in these four cell types, whether ethanol induced cell death is through apoptotic pathway, and whether an monoamine oxidase (MAO) inhibitor (e.g. deprenyl) protects cells from the effects of alcohol. We have found that ethanol exposure lowers cell proliferation in all cell types, but affects brain cell lines (neuron and glioma) the most, while ethanol and deprenyl exposure in unison increases cell viability largely in brain cells, and then in liver cells. Our results suggest that MAO mediated apoptosis may contribute to ethanolinduced cell death. Individuals suffering from alcoholism or alcohol abuse may be treated with deprenyl to alleviate the apoptotic activity resulting from alcohol consumption and protect the body's cells from alcohol-induced death. In summary, this study demonstrates the effects of deprenyl as an anti-apoptotic agent against the detrimental effects of alcohol.

Heterodimerization of mineralocorticoid and glucocorticoid receptors at a novel negative response element of the 5-HT1A receptor gene.

Negative regulation of neuronal serotonin (5-HT1A) receptor levels by glucocorticoids in vivo may contribute to depression. Both types I (mineralocorticoid) and II (glucocorticoid) receptors (MR and GR, respectively) participate in corticosteroid-induced transcriptional repression of the 5-HT1A gene; however, the precise mechanism is unclear. A direct repeat 6-base pair glucocorticoid response element (GRE) half-site 5'-TGTCCT separated by 6 nucleotides was conserved in human, mouse, and rat 5-HT1A receptor promoters. In SN-48 neuronal cells that express MR, GR, and 5-HT1A receptors, deletion or inactivation of the nGRE (negative GRE) eliminated negative regulation of the rat 5-HT1A or heterologous promoters by corticosteroids, whereas its inclusion conferred corticosteroid-induced inhibition to a heterologous promoter. Bacterially expressed recombinant MR and GR preferentially bound to the nGRE as a heterodimer, as identified in nuclear extracts of MR/GR-transfected COS-7 cells, and with higher affinity than MR or GR homodimers. In SN48 and COS-7 cells, concentration-dependent coactivation of MR and GR was required for maximal inhibitory action by corticosteroids and was abrogated in the L501P-GR mutant lacking DNA binding activity. Corticosteroid-mediated transcriptional inhibition was greater for MR/GR in combination than for MR or GR alone. These data represent the first identification of an nMRE/GRE and indicate that heterodimerization of MR and GR mediates direct corticosteroid-induced transrepression of the 5-HT1A receptor promoter.

Novel dual repressor elements for neuronal cell-specific transcription of the rat 5-HT1A receptor gene.

The level of expression of the 5-HT1A receptor in the raphe and limbic systems is implicated in the etiology and treatment of major depression and anxiety disorders. The rat 5-HT1A receptor gene is regulated by a proximal TATA-driven promoter and by upstream repressors that inhibit gene expression. Deletion of a 71-base pair (bp) segment between -1590/-1519 bp of the 5-HT1A receptor gene induced over 10-fold enhancement of transcriptional activity in both 5-HT1A receptor-expressing (RN46A raphe and SN48 septal) cells and receptor-negative (L6 myoblast and C6 glioma) cells. A 31-bp segment of the repressor was protected from DNase I digestion by RN46A or L6 nuclear extracts. Within the 31-bp segment, a single protein complex was present in receptor-expressing cells that bound a novel 14-bp DNA element; in receptor-negative cells, an additional complex bound an adjacent 12-bp sequence. In receptor-positive but not receptor-negative cells, mutation of the 14-bp element to eliminate protein binding abrogated repression to nearly the same extent as deletion of the -1590/-1519 bp segment. Additional mutation of both 14-bp and 12-bp elements abolished protein binding and repressor activity in receptor-negative cells. Thus a single protein-DNA complex at the 14-bp element represses the 5-HT1A receptor gene in 5-HT1A receptor-positive neuronal cells, whereas adjacent DNA elements provide a dual repression mechanism in 5-HT1A receptor-negative cells.

The storage of noradrenaline, neuropeptide Y and chromogranins in and stoichiometric release from large dense cored vesicles of the undifferentiated human neuroblastoma cell line SH-SY5Y.

Sucrose gradient centrifugation combined with electron microscopy revealed that undifferentiated SH-SY5Y cells contain predominantly one population of noradrenaline containing vesicles, i.e. large dense cored vesicles. These vesicles have been purified approximately twenty times using sucrose/D2O gradients. Electron microscopy of sucrose/D2O fractions confirms that large dense cored vesicles are enriched in the fractions containing predominantly dopamine- -hydroxylase, chromogranin A, noradrenaline and neuropeptide Y. The membranes of these vesicles contain the typical large dense cored vesicle markers dopamine- -hydroxylase, synaptotagmin, cytochrome b561 and rab 3. Stimulation of SH-SY5Y cells with carbachol and KCl shows that noradrenaline and neuropeptide Y are released in the same proportion as stored in the large dense cored vesicles. The immuno-blot pattern and intensity of chromogranin A and chromogranin B present in large dense cored vesicles and in the released material were definitely the same. This suggests that noradrenaline and the proteins/peptides are released in the same molar stoichiometry as they are stored in large dense cored vesicles. These data provide for the first time experimental evidence that the neuroblastoma cell line SH-SY5Y contains functionally active large dense cored vesicles similar to those of sympathetic neurons and indicate that this cell line is a suitable experimental cell model to study the exocytotic pathway of large dense cored vesicles.