Spi2 gene polymorphism is not associated with recurrent airway obstruction and inflammatory airway disease in thoroughbred horses

The aim was to detect the presence of polymorphisms at exons 1, 2, 3 and 4 of the Spi2 gene, and evaluate a possible association between them and recurrent airway obstruction (RAO) or inflammatory airway disease (IAD) in thoroughbred horses, through single-strand conformational-polymorphism (SSCP) screening. Although polymorphism was not detected in exons 1, 2 and 3, three alleles and six genotypes were identified in exon 4. The frequencies of allele A (0.6388) and genotype AA (0.3888) were higher in horses affected by RAO, although no association was found between polymorphism and horses with either RAO or IAD.     

Elevated amount of Toll-like receptor 4 mRNA in bronchial epithelial cells is associated with airway inflammation in horses with recurrent airway obstruction

Recurrent airway obstruction (RAO) is characterized by neutrophilic airway inflammation and obstruction, and stabling of susceptible horses triggers acute disease exacerbations. Stable dust is rich in endotoxin, which is recognized by Toll-like receptor (TLR) 4. In human bronchial epithelium, TLR4 stimulation leads to elevation of interleukin (IL)-8 mRNA expression. The zinc finger protein A20 negatively regulates this pathway. We hypothesized that TLR4 and IL-8 mRNA and neutrophil numbers are elevated and that A20 mRNA is not increased in RAOs during stabling compared with controls and with RAOs on pasture. We measured the maximal change in pleural pressure (DeltaPpl(max)), determined inflammatory cell counts in bronchoalveolar lavage fluid (BAL), and quantified TLR4, IL-8, and A20 mRNA in bronchial epithelium by quantitative RT-PCR. We studied six horse pairs, each pair consisting of one RAO and one control horse. Each pair was studied when the RAO-affected horse had airway obstruction induced by stabling and after 7, 14, and 28 days on pasture. Stabling increased BAL neutrophils, DeltaPpl(max), and TLR4 (4.14-fold change) significantly in RAOs compared with controls and with RAOs on pasture. TLR4 correlated with IL-8 (R2 = 0.75). Whereas stabling increased IL-8 in all horses, A20 was unaffected. IL-8 was positively correlated with BAL neutrophils (R2 = 0.43) and negatively with A20 (R2 = 0.44) only in RAO-affected horses. Elevated TLR4 expression and lack of A20 upregulation in bronchial epithelial cells from RAO-affected horses may contribute to elevated IL-8 production, leading to exaggerated neutrophilic airway inflammation in response to inhalation of stable dust.     

Vitamin D receptor gene polymorphism is associated with chronic periodontitis

Chronic periodontitis (CP) is caused by enhanced resorption of the alveolar bone supporting the teeth and is associated with intraoral inflammation after infection with certain bacteria. The VDR gene polymorphism was reported recently to be deeply related to the occurrence of tuberculosis and infection of chronic hepatitis B virus. This may be interpreted to indicate a close relationship between VDR gene polymorphism and the immunological action, because vitamin D activates monocytes, stimulates cell-mediated immunity, and suppresses lymphocyte proliferation. The purpose of the present study was to clarify whether polymorphisms in VDR gene exons are associated with the incidence of CP. A case-controlled study was performed on a group of 168 unrelated Japanese subjects whose ages ranged from 35 to 65 years. The Taq I polymorphism in the VDR gene was found to be associated significantly with CP (X2=4.48, P=0.034). We performed multiple logistic regression analyses on the TT genotype, which was found to be associated with CP, and on well-recognized risk factors, smoking and diabetes. The odds ratio (OR) for the genotype (TT/Tt) was 2.73 (95% CI 1.11-6.68, P=0.028), being larger than the unadjusted value. This indicates that the VDR gene polymorphism (TT genotype) is a risk factor for CP, independently of smoking and diabetes.     

Delay of airway epithelial wound repair in COPD is associated with airflow obstruction severity

Background

Airway epithelium integrity is essential to maintain its role of mechanical and functional barrier. Recurrent epithelial injuries require a complex mechanism of repair to restore its integrity. In chronic obstructive pulmonary disease (COPD), an abnormal airway epithelial repair may participate in airway remodeling. The objective was to determine if airway epithelial wound repair of airway epithelium is abnormal in COPD.

Methods

Patients scheduled for lung resection were prospectively recruited. Demographic, clinical data and pulmonary function tests results were recorded. Emphysema was visually scored and histological remodeling features were noted. Primary bronchial epithelial cells (BEC) were extracted and cultured for wound closure assay. We determined the mean speed of wound closure (MSWC) and cell proliferation index, matrix metalloprotease (MMP)-2, MMP-9 and cytokines levels in supernatants of BEC 18 hours after cell wounding. In a subset of patients, bronchiolar epithelial cells were also cultured for wound closure assay for MSWC analyze.

Results

13 COPD and 7 non COPD patients were included. The severity of airflow obstruction and the severity of emphysema were associated with a lower MSWC in BEC (p = 0.01, 95% CI [0.15-0.80]; p = 0.04, 95% CI [−0.77;-0.03] respectively). Cell proliferation index was decreased in COPD patients (19 ± 6% in COPD vs 27 ± 3% in non COPD, p = 0.04). The severity of COPD was associated with a lower level of MMP-2 (7.8 ± 2 10⁵ AU in COPD GOLD D vs 12.8 ± 0.13 10⁵ AU in COPD GOLD A, p = 0.04) and a lower level of IL-4 (p = 0.03, 95% CI [0.09;0.87]). Moreover, higher levels of IL-4 and IL-2 were associated with a higher MSWC (p = 0.01, 95% CI [0.17;0.89] and p = 0.02, 95% CI [0.09;0.87] respectively). Clinical characteristics and smoking history were not associated with MSWC, cell proliferation index or MMP and cytokines levels. Finally, we showed an association of the MSWC of bronchial and corresponding bronchiolar epithelial cells obtained from the same patients (p = 0.02, 95% CI [0.12;0.89]).

Conclusion

Our results showed an abnormal bronchial epithelial wound closure process in severe COPD. Further studies are needed to elucidate the contribution and the regulation of this mechanism in the complex pathophysiology of COPD.

Electronic supplementary material

The online version of this article (doi:10.1186/s12931-014-0151-9) contains supplementary material, which is available to authorized users.     

Dopamine D1 receptor gene polymorphism is associated with myocardial infarction

Dopamine D1 receptor (DRD1) gene is associated with the pathogenesis of myocardial infarction (MI) in aspects of plaque rupture, platelet aggregation, and neutrophil-mediated injury of cardiac myocytes. Thus, the study was designed to explore whether the A-48G polymorphism of the DRD1 gene was associated with MI. The genotype of the DRD1A-48G polymorphism was determined by polymerase chain reaction in the 602 Han Chinese participants, 255 MI patients and 347 controls without MI. A significant association was found between the A-48G polymorphism of DRD1 and MI (genotype model: χ(2)=13.2, unadjusted p=0.001; χ(2)=13.9, adjusted p=0.0002; dominant model: adjusted OR 2.05, 95%CI 1.40-3.00, p=0.0002; recessive model: adjusted OR 2.34, 95%CI 1.01-5.39, p=0.047). The G allele was a risk-increased allele for MI (unadjusted OR 1.83, 95%CI 1.34-2.50, p=0.0001; adjusted OR 1.94, 95%CI 1.40-2.68, p=0.00007). Thus, the study demonstrated the significant association between A-48G polymorphism of the DRD1 gene and MI.     

Bone mineral density is associated with estrogen receptor gene polymorphism in men

In order to identify genetic effects of allelic variation on bone mineral density (BMD), association studies have been performed recently. Examining the relation between PvuII and XbaI restriction fragment length polymorphism (RFLPs) at the estrogen receptor (ER alpha) gene and BMD, in women or men, have yielded conflicting results. We analyzed the association between this polymorphism and BMD Z score values of cancellous bone at the 3rd finger in 344 members of nuclear families of European population, Chuvasha, living in Russia. The population sample included 183 males, aged 18-84, and 161 females, aged 23-79. The analysis has been performed separately for both sexes and for both generations (parents and offspring). We used a novel direct haplotyping method, which determines simultaneously each of the PvuII and XbaI RFLPs and their relation to each other. The haplotypes were represented as the combination of both polymorphic sites on the same chromosome, by using P/p and X/x for PvuII and XbaI restriction sites, respectively. The subjects were classified into 3 groups of genotypes: A = PXPX (homozygote for the PX haplotype); B = PXPx, PXpx (the heterozygotes for the PX haplotype); C = PxPx, Pxpx, pxpx (genotypes that are lacking the PX haplotype). The PXPX genotype (A) was associated with higher BMD Z score values in comparison to the genotypes that are lacking the PX haplotype (C), in total males [0.618 vs. -0.133 (p = 0.004)] and for the "sons" generation [0.724 vs. -0.198 (p = 0.02)]. Similar tendency was observed for the "fathers" generation (0.539 vs. -0.085), though the difference did not approach statistical significance (p = 0.087). These findings were not found in the female samples, nor in the "mothers" or "daughters" generations. The question if there are differences in the mode of action of estrogen through its receptor on bone mass, between the genders or between the males' generations, have to be further investigated.     

A polymorphism in the beta1 adrenergic receptor is associated with resting heart rate

Resting heart rate is significantly associated with cardiovascular morbidity and mortality. However, the extent to which resting heart rate is genetically determined is poorly understood, and no genes have been found that contribute to variation in resting heart rate. Because signaling through the beta1 adrenergic receptor is a key determinant of cardiac function, we tested whether polymorphisms in this receptor are associated with resting heart rate. A cohort of >1,000 individuals of Chinese and Japanese descent, from nuclear families, was genotyped for two polymorphisms, resulting in a serine/glycine substitution at amino acid 49 (Ser49Gly) and an arginine/glycine substitution at residue 389 (Arg389Gly), in the beta1 adrenergic receptor. For comparison, polymorphisms in the beta2 and beta3 adrenergic receptors were also evaluated. The Ser49Gly polymorphism was significantly associated (P=.0004) with resting heart rate, independent of other variables, such as body-mass index, age, sex, ethnicity, exercise, smoking, alcohol intake, hypertension status, and treatment with beta blockers. The data support an additive model in which individuals heterozygous for the Ser49Gly polymorphism had mean heart rates intermediate to those of either type of homozygote, with Ser homozygotes having the highest mean heart rate and with Gly homozygotes having the lowest. Neither the Arg389Gly polymorphism in the beta1 adrenergic receptor nor polymorphisms in the beta2 and beta3 adrenergic receptors were associated with resting heart rate. The heritability of heart rate was 39.7% +/- 7.1% (P<10-7).     

Neurotensin receptor 1 gene (NTSR1) polymorphism is associated with working memory

Background

Recent molecular genetics studies showed significant associations between dopamine-related genes (including genes for dopamine receptors, transporters, and degradation) and working memory, but little is known about the role of genes for dopamine modulation, such as those related to neurotensin (NT), in working memory. A recent animal study has suggested that NT antagonist administration impaired working memory in a learning task. The current study examined associations between NT genes and working memory among humans.

Methods

Four hundred and sixty healthy undergraduate students were assessed with a 2-back working memory paradigm. 5 SNPs in the NTSR1 gene were genotyped. 5 ANOVA tests were conducted to examine whether and how working memory differed by NTSR1 genotype, with each SNP variant as the independent variable and the average accuracy on the working memory task as the dependent variable.

Results

ANOVA results suggested that two SNPs in the NTSR1 gene (rs4334545 and rs6090453) were significantly associated with working memory. These results survived corrections for multiple comparisons.

Conclusions

Our results demonstrated that NTSR1 SNP polymorphisms were significantly associated with variance in working memory performance among healthy adults. This result extended previous rodent studies showing that the NT deficiency impairs the working memory function. Future research should replicate our findings and extend to an examination of other dopamine modulators.     

ET-1-induced bronchoconstriction is mediated via ETB receptor in mice

Nagase, Takahide, Tomoko Aoki, Teruaki Oka, YoshinosukeFukuchi, and Yasuyoshi Ouchi. ET-1-induced bronchoconstriction ismediated via ET_B receptor in mice.J. Appl. Physiol. 83(1): 46-51, 1997.Endothelin (ET)-1 is one of the most potent agonists of airwaysmooth muscle and can act via two different ET receptor subtypes, i.e.,ET_A andET_B. To determine the effects ofET-1 on in vivo pulmonary function and which ET receptors are involved in murine lungs, we investigated 1)the effects of ET and sarafotoxin S6c (S6c), a selectiveET_B agonist, on pulmonary functionand 2) the effects of BQ-123 andBQ-788, specific ET_A- andET_B-receptor antagonists, onET-1-induced bronchoconstriction. ICR mice were anesthetized and mechanically ventilated (frequency = 2.5 Hz, tidalvolume = 8 ml/kg, positive end-expiratory pressure = 3 cmH₂O). Intravenous ET-1, ET-2,and ET-3 increased lung resistance similarly and equipotently, whereasS6c elicited a greater degree of bronchoconstriction. Mice were thenpretreated with saline (Sal), BQ-123 (0.2, 1, and 5 mg/kg), or BQ-788(0.2, 1, and 5 mg/kg) before administration of ET-1(10⁷ mol/kg iv). No dose ofBQ-123 blocked ET-1-induced constriction, whereas pretreatment witheach dose of BQ-788 significantly inhibited ET-1-induced responses.There were significant differences in morphometrically assessed airwayconstriction between Sal and BQ-788 and between BQ-123 and BQ-788,whereas no significant difference was observed between Sal and BQ-123.There were no significant morphometric differences in the airway wallarea among the three groups. These observations suggest that theET_B- but notET_A-receptor subtype may mediatethe changes in murine pulmonary function in response to ET-1. Inaddition, the ET_B-receptorantagonist reduces ET-1-induced airway narrowing by affecting airwaysmooth muscle contraction in mice.

     

IL4 receptor polymorphism is associated with increased risk of sudden deafness in Korean population

The interleukin 4 receptor (IL4R) polymorphism Q576R (rs 180275) has been well known to be associated with atopy and other inflammatory diseases. A single nucleotide polymorphism (SNP) A > G transition potentiates the binding specificity of the adjacent tyrosine residue. In this study we investigated the possible relationship between sudden deafness (SD) and IL4R polymorphism Q576R in 97 Korean SD patients and 613 controls using pyrosequencing method. The odds ratio (OR) for SD associated with the G vs. A allele was 2.58 [P < 0.0001, 95% confidence interval (CI) = 1.84-3.60]. We then sub-grouped SD into Tinnitus positive (+) and Tinnitus negative (-). G allele in Tinnitus (+) is significantly associated with the development of Tinnitus (+) [X(2) = 32.02, P < 0.0001, OR (95% CI) = 2.74 (1.91-3.93)] but not with Tinnitus (-). Taken together these results suggest that G allele could be a risk factor for SD.     

Impaired receptor binding and activation associated with a human prostacyclin receptor polymorphism

The human prostacyclin receptor (hIP) is a seven transmembrane-spanning G-protein-coupled receptor that plays an important role in vascular homeostasis. Recent genetic analyses (SNP database, NCBI) have revealed the first two polymorphisms within the coding sequence, V25M and R212H. Here we present structure-function characterizations of these polymorphisms at physiological pH (7.4) and at an acidic pH (6.8) that would be encountered during stress such as renal, respiratory, or heart failure. Through a series of competition binding and G-protein activation assays (measured by cAMP production), we determined that the V25M polymorph exhibited agonist binding and G-protein activation similar to wild-type receptor at normal pH (7.4). However, the R212H variant demonstrated a significant decrease in binding affinity at lower pH (R212H at pH 7.4, K(i) = 2.2 +/- 1.2 nm; pH 6.8 K(i) = 45.6 +/- 12.0 nm). The R212H polymorph also exhibited abnormal activation at both pH 7.4 and pH 6.8 (pH 7.4, R212H EC(50) = 2.8 +/- 0.5 nm versus wild-type hIP EC(50) = 0.5 +/- 0.1 nm; pH 6.8, R212H EC(50) = 3.2 +/- 1.6 nm versus wild-type hIP EC(50) = 0.5 +/- 0.2 nm). Polymorphisms of the human prostacyclin receptor potentially may be important predictors of disease progress during biological stressors such as acidosis in which urgent correction of bodily pH may be required to restore normal hemostasis and vasodilation. This study provides the mechanistic basis for further research into genetic risk factors and pharmacogenetics of cardiovascular disease associated with hIP.     

The BsmI vitamin D receptor gene polymorphism is associated with ulcerative colitis in Jewish Ashkenazi patients

Susceptibility to inflammatory bowel disease (IBD) has a strong genetic component. The vitamin D receptor (VDR) gene maps to a region on chromosome 12 shown to be associated with IBD in some studies. In this case-control study we determined the association between the BsmI VDR gene polymorphism and IBD in patients with Crohn's disease (CD) and ulcerative colits (UC). Three hundred seventy-nine Jewish Israeli patients with IBD, 228 with CD (129 Ashkenazi and 99 non-Ashkenazi), and 151 patients with UC (72 Ashkenazi, 79 non-Ashkenazi) were studied. The control group included 495 healthy blood donors (352 non-Ashkenazi and 143 Ashkenazi). All subjects were genotyped for the BsmI VDR gene polymorphism. The frequency of the BB genotype was higher in Ashkenazi patients with UC compared to Ashkenazi controls (0.21 vs. 0.11, p = 0.042, odds ratio 2.27, 95% confidence interval [CI] 1.06-4.9). There were no differences in the prevalence of the BB genotype or the B allele between ethnically matched patients with CD and UC. Nor were there differences in the BB genotype or B allele frequencies between CD patients and ethnically matched controls. The BsmI VDR gene polymorphism is associated with increased susceptibility to UC in Israeli Ashkenazi patients with UC.     

Staphylococcus aureus nasal carriage is not associated with known polymorphism in the Vitamin D receptor gene

The vitamin D endocrine system has been shown to influence the immune response and polymorphisms in the vitamin D receptor (VDR) gene have been associated with susceptibility to infectious diseases. We determined if the Cdx2, FokI and BsmI-ApaI-TaqI polymorphisms in the VDR gene were associated with nasal carriage of Staphylococcal aureus. We defined the S. aureus nasal carriage status (persistent, intermittent or non-carriage) for a group of more that 2000 elderly volunteers. The prevalence of persistent S. aureus nasal carriage was 18%, which was, however, not associated with any of the variant VDR genotypes. Our study into genetic determinants of S. aureus carriage patterns is the largest in the field, but still we found no association between VDR gene variation and S. aureus nasal carriage.     

Mu-opioid receptor is associated with phosphatase activity

A preparation of purified mu opioid receptor from bovine brain hydrolyzes p-nitrophenylphosphate. This phosphatase activity has a pH optimum of 9.0, a Km of 9.0 microM, and is stimulated by Mn++ and Mg++ ions. Evidence that the observed activity is not due to a contaminant in the opioid receptor preparation includes 1) the activity is associated primarily with 60,000 molecular weight material which is much smaller than bovine brain alkaline phosphatase; and 2) the activity could not be absorbed by antibodies specific for bovine alkaline phosphatase. Thus this appears to be the first demonstration of enzymatic activity associated with an opioid receptor.     

Cutting edge: a Toll-like receptor 2 polymorphism that is associated with lepromatous leprosy is unable to mediate mycobacterial signaling

Toll-like receptors (TLRs) are key mediators of the innate immune response to microbial pathogens. We investigated the role of TLRs in the recognition of Mycobacterium leprae and the significance of TLR2Arg(677)Trp, a recently discovered human polymorphism that is associated with lepromatous leprosy. In mice, TNF-alpha production in response to M. leprae was essentially absent in TLR2-deficient macrophages. Similarly, human TLR2 mediated M. leprae-dependent activation of NF-kappaB in transfected Chinese hamster ovary and human embryonic kidney 293 cells, with enhancement of this signaling in the presence of CD14. In contrast, activation of NF-kappaB by human TLR2Arg(677)Trp was abolished in response to M. leprae and Mycobacterium tuberculosis. The impaired function of this TLR2 variant provides a molecular mechanism for the poor cellular immune response associated with lepromatous leprosy and may have important implications for understanding the pathogenesis of other mycobacterial infections.