Evidence of gene–environment interaction for the IRF6 gene and maternal multivitamin supplementation in controlling the risk of cleft lip with/without cleft palate

Although multiple genes have been identified as genetic risk factors for isolated, non-syndromic cleft lip with/without cleft palate (CL/P), a complex and heterogeneous birth defect, interferon regulatory factor 6 gene (IRF6) is one of the best documented genetic risk factors. In this study, we tested for association between markers in IRF6 and CL/P in 326 Chinese case–parent trios, considering gene–environment interaction for two common maternal exposures, and parent-of-origin effects. CL/P case–parent trios from three sites in mainland China and Taiwan were genotyped for 22 single nucleotide polymorphisms (SNPs) in IRF6. The transmission disequilibrium test was used to test for marginal effects of individual SNPs. We used PBAT to screen the SNPs and haplotypes for gene–environment (G × E) interaction and conditional logistic regression models to quantify effect sizes for SNP–environment interaction. After Bonferroni correction, 14 SNPs showed statistically significant association with CL/P. Evidence of G × E interaction was found for both maternal exposures, multivitamin supplementation and environmental tobacco smoke (ETS). Two SNPs showed evidence of interaction with multivitamin supplementation in conditional logistic regression models (rs2076153 nominal P = 0.019, rs17015218 nominal P = 0.012). In addition, rs1044516 yielded evidence for interaction with maternal ETS (nominal P = 0.041). Haplotype analysis using PBAT also suggested interaction between SNPs in IRF6 and both multivitamin supplementation and ETS. However, no evidence for maternal genotypic effects or significant parent-of-origin effects was seen in these data. These results suggest IRF6 gene may influence risk of CL/P through interaction with multivitamin supplementation and ETS in the Chinese population.     

Enzymatic synthesis of tea theaflavin derivatives and their anti-inflammatory and cytotoxic activities

Derivatives based on a benzotropolone skeleton (9-26) have been prepared by the enzymatic coupling (horseradish peroxidase/H2O2) of selected pairs of compounds (1-8), one with a vic-trihydroxyphenyl moiety, and the other with an ortho-dihydroxyphenyl structure. Some of these compounds have been found to inhibit TPA-induced mice ear edema, nitric oxide (NO) synthesis, and arachidonic acid release by LPS-stimulated RAW 264.7 cells. Their cytotoxic activities against KYSE 150 and 510 human esophageal squamous cell carcinoma and HT 29 human colon cancer cells were also evaluated.     

Human neutrophil-derived elastase induces airway smooth muscle cell proliferation

Neutrophils and their derived elastase are abundant in chronic inflammatory responses of asthma. This study aimed to investigate the mitogenic effect of elastase on airway smooth muscle (ASM) cells and the implicated signal transduction pathway. Near confluent cultured human ASM cells were treated with human neutrophil elastase (HNE, 0.01 to 0.5 microg/ml) or vehicle for 24 hours with or without extracellular signal-regulated kinase (ERK) inhibitor (PD98059, 30 microM), p38 kinase inhibitor (SB203580, 10 microM) or elastase inhibitor II (100 microg/ml). The ASM cell numbers were counted by a hemocytometer and DNA synthesis was assessed by flowcytometry. Western blots analysis for the expression of ERK, p38 and cyclin D1 was determined. HNE dose-dependently increased ASM cell numbers and the percentage of cells entering S-phase of cell cycle. This response was abolished by neutrophil elastase inhibitors and attenuated by PD98059, but not SB203580. HNE increased ERK phosphorylation and cyclin D1 expression. Pretreatment with PD98059 significantly inhibited elastase-induced cyclin D1 activity. The increased ASM cellular gap and cell shape change by proteolytic activity of HNE may be contributory to ERK activation and therefore cell proliferation. Our results demonstrate that HNE is mitogenic for ASM cells by increasing cyclin D1 activity through ERK signaling pathway.     

Integration of clinical and gene expression endpoints to explore furan-mediated hepatotoxicity

Molecular techniques, such as cDNA microarrays, are being used to aid in the elucidation of the mechanisms of toxicity of a variety of compounds. In this study, we evaluate the molecular effects of furan in the rat liver. Sprague-Dawley rats were exposed to 4 or 40 mg/kg furan for up to 14 days. Furan induced an initial degenerative and necrotic phenotype that was followed by inflammation and fibrosis, consistent with previous observations for this compound. RNA was harvested from each lobe of the liver at several time points to observe whether lobe-specific gene expression effects occurred. Similar gene expression changes were observed in all lobes, however the magnitude of gene expression change was more pronounced in the right lobe. Finally, to help determine the correlation between gene expression changes and liver pathology, we applied traditional microarray visualization tools to the assessment of clinical chemistry and pathology parameters.     

Supraspinal anti-allodynic and rewarding effects of endomorphins in rats

Two potent endogenous opioid peptides, endomorphin-1 (EM-1) and -2 (EM-2), which are selective micro-opioid agonists, have been identified from bovine and human brain. These endomorphins were demonstrated to produce a potent anti-allodynic effect at spinal level. In the present study, we further investigated their supraspinal anti-allodynic effects and rewarding effects. In a neuropathic pain model (sciatic nerve crush in rats), EM-1 and -2 (15 microg, i.c.v.) both showed significant suppressive effects in the cold-water allodynia test, but EM-1 showed a longer duration than EM-2. Naltrexone (NTX; 15 microg) and naloxonazine (NLZ; 15 microg) were both able to completely block the anti-allodynic effects of EM-1 and -2. In the tests of conditioned place preference (CPP), only EM-2 at the dose of 30 microg showed significant positive rewarding effect, whereas both endomorphins did not induce any reward at the dose of 15 microg. Due to the low solubility and the undesired effect (barrel rotation of the body trunk), EM-1 was not tested for the dose of 30 microg in the CPP tests. It was also found that acute EM-2 (30 microg) administration increased dopamine turnover in the shell of nucleus accumbens in the microdialysis experiments. From these results, it may suggest that EM-1 and -2 could be better supraspinal anti-allodynic agents compared with the other opioid drugs, although they may also induce rewarding.