Sphingosine-1-phosphate lyase expression in embryonic and adult murine tissues

Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid involved in immunity, inflammation, angiogenesis, and cancer. S1P lyase (SPL) is the essential enzyme responsible for S1P degradation. SPL augments apoptosis and is down-regulated in cancer. SPL generates a S1P chemical gradient that promotes lymphocyte trafficking and as such is being targeted to treat autoimmune diseases. Despite growing interest in SPL as a disease marker, antioncogene, and pharmacological target, no comprehensive characterization of SPL expression in mammalian tissues has been reported. We investigated SPL expression in developing and adult mouse tissues by generating and characterizing a β-galactosidase-SPL reporter mouse combined with immunohistochemistry, immunoblotting, and enzyme assays. SPL was expressed in thymic and splenic stromal cells, splenocytes, Peyer's Patches, colonic lymphoid aggregates, circulating T and B lymphocytes, granulocytes, and monocytes, with lowest expression in thymocytes. SPL was highly expressed within the CNS, including arachnoid lining cells, spinal cord, choroid plexus, trigeminal nerve ganglion, and specific neurons of the olfactory bulb, cerebral cortex, midbrain, hindbrain, and cerebellum. Expression was detected in brown adipose tissue, female gonads, adrenal cortex, bladder epithelium, Harderian and preputial glands, and hair follicles. This unique expression pattern suggests SPL has many undiscovered physiological functions apart from its role in immunity.     

Widdrol activates DNA damage checkpoint through the signaling Chk2–p53–Cdc25A–p21–MCM4 pathway in HT29 cells

Widdrol is an odorant compound isolated from Juniperus chinensis. We previously reported that widdrol induces Gap 1 (G1) phase cell cycle arrest and leads to apoptosis in human colon adenocarcinoma HT29 cells. It was also reported that this cell cycle arrest is associated with the induction of checkpoint kinase 2 (Chk2), p53 phosphorylation and cyclin dependent kinase (Cdk) inhibitor p21 expression. In this paper, we investigated the molecular mechanisms of widdrol on the activation of G1 DNA damage checkpoint at early phase when DNA damages occurred in HT29 cells. First of all, we examined that widdrol breaks DNA directly or not. As the results of DNA electrophoresis and formation of phosphorylated histone H2AX (γH2AX) foci in HT29 cells, widdrol generates DNA double-strand breaks directly within 0.5?h both in vitro and in vivo. Based on this result, the change of proteins related in checkpoint pathway was examined over a time course of 0.5-24?h. Treatment of HT29 cells with widdrol elicits the following: (1) phosphorylation of Chk2 and p53, (2) reduction of cell division cycle 25A (Cdc25A) expression, (3) increase of Cdk inhibitor p21 expression, and (4) decrease of the levels of Cdk2 and cyclin E expression in a time-dependent manner. Moreover, only the expression level of mini-chromosome maintenance 4 (MCM4) protein, a subunit of the eukaryotic DNA replicative helicase, is rapidly down-regulated in HT29 cells treated with widdrol over the same time course, but those of the other MCM proteins are unchanged. Overall, our results indicated that widdrol breaks DNA directly in HT29 cells, and this DNA damage results in checkpoint activation via Chk2-p53-Cdc25A-p21-MCM4 pathway and finally cells go to G1-phase cell cycle arrest and apoptosis.     

Design, synthesis and biological evaluation of 2-(substituted phenyl)thiazolidine-4-carboxylic acid derivatives as novel tyrosinase inhibitors

Herein we describe the design, synthesis and biological activities of 2-(substituted phenyl)thiazolidine-4-carboxylic acid derivatives as novel tyrosinase inhibitors. The target compounds 2a–2j were designed and synthesized from the structural characteristics of N-phenylthiourea, tyrosinase inhibitor and tyrosine, and l-DOPA, the natural substrates of tyrosinase. Among them, (2R/S,4R)-2-(2,4-dimethoxyphenyl)thiazolidine-4-carboxylic acid (2g) caused the greatest inhibition 66.47% at 20 μM of l-DOPA oxidase activity of mushroom tyrosinase. Kinetic analysis of tyrosinase inhibition revealed that 2g is a competitive inhibitor. We predicted the tertiary structure of tyrosinase, and simulated the docking of mushroom tyrosinase with 2g. These results suggest that the binding affinity of 2g with tyrosinase is high. Also, 2g effectively inhibited tyrosinase activity and reduced melanin levels in B16 cells treated with α-MSH. These data strongly suggest that 2g can suppress the production of melanin via the inhibition of tyrosinase activity.     

The association between the mannose-binding lectin codon 54 polymorphism and systemic lupus erythematosus: a meta-analysis update

The aim of this study was to determine whether the functional mannose-binding lectin (MBL2) exon 1 codon 54 polymorphism (rs1800450) confers susceptibility to systemic lupus erythematosus (SLE) in ethnically different populations. A meta-analysis was conducted on the MBL2 codon 54 polymorphism across 21 comparative studies. Meta-analysis showed an association between the MBL2 codon 54 B allele and SLE in all study subjects [odds ratio (OR) = 1.298, 95% confidence interval (CI) = 1.154–1.459, P = 1.4 × 10⁻⁵]. Analysis after stratification by ethnicity indicated that the MBL2 codon 54 B allele is significantly associated with SLE in Europeans, Asian, and Africans (OR = 1.246, 95% CI = 1.062–1.462, P = 0.007; OR = 1.268, 95% CI = 1.049–1.532, P = 0.014; OR = 1.939, 95% CI = 1.269–2.962, P = 0.002, respectively). However, African Americans had a much lower prevalence of the T allele (5.8%) than any other populations studied, whereas Asians had the highest prevalence (16.2%). This meta-analysis confirms that the MBL2 codon 54 polymorphism is associated with SLE susceptibility in different ethnic groups, and that its prevalence is ethnicity dependent.     

Associations between interleukin-23 receptor polymorphisms and susceptibility to rheumatoid arthritis: a meta-analysis

The aim of this study was to determine whether interleukin-23 receptor (IL-23R) polymorphisms confer susceptibility to rheumatoid arthritis (RA). A meta-analysis was conducted on the associations between the IL-23R rs1343151, rs10489629, rs7517847, rs11209026, rs1004819, and rs2201841 polymorphisms and RA using (1) allele contrast, (2) the recessive model, (3) the dominant model, and (4) the additive model. A total of 13 studies from eight articles involving 10,016 RA patients and 11,967 controls were considered in the meta-analysis. Meta-analysis identified a significant association between RA and the A allele of the rs1343151 polymorphism in the overall population (OR?=?1.110, 95?% CI?=?1.056–1.168, p?=?4.7?×?10^?6). Stratification by ethnicity identified a significant association between this polymorphism and RA in Europeans (OR?=?1.105, 95?% CI?=?1.049–1.163, p?=?1.4?×?10^?5). An association was also found between RA and the A allele carrier of the rs1343151 polymorphism in Europeans (OR?=?1.135, 95?% CI?=?1.058–1.217, p?=?4.0?×?10^?5). Meta-analysis revealed a significant association between RA and the A allele of the rs10489629 polymorphism in the overall population (OR?=?1.079, 95?% CI?=?1.029–1.131, p?=?0.002) and in Europeans (OR?=?1.092, 95?% CI?=?1.038–1.149, p?=?0.001). Meta-analyses of recessive, dominant, and additive models showed the same pattern as the meta-analysis of the A allele of the rs10489629 polymorphism, that is, a significant association with RA in Europeans. However, no association was found between the IL-23R rs7517847, rs11209026, rs1004819, and rs2201841 polymorphisms and RA susceptibility. This meta-analysis shows that the IL-23R rs1343151 and rs10489629 polymorphisms are associated with the development of RA in Europeans. These findings suggest that the IL-23R genes confer susceptibility to RA in the European population, but further study of this association is required in other ethnic groups.     

Indel-II region deletion sizes in the white spot syndrome virus genome correlate with shrimp disease outbreaks in southern Vietnam

Sequence comparisons of the genomes of white spot syndrome virus (WSSV) strains have identified regions containing variable-length insertions/deletions (i.e. indels). Indel-I and Indel-II, positioned between open reading frames (ORFs) 14/15 and 23/24, respectively, are the largest and the most variable. Here we examined the nature of these 2 indel regions in 313 WSSV-infected Penaeus monodon shrimp collected between 2006 and 2009 from 76 aquaculture ponds in the Mekong Delta region of Vietnam. In the Indel-I region, 2 WSSV genotypes with deletions of either 5950 or 6031 bp in length compared with that of a reference strain from Thailand (WSSV-TH-96-II) were detected. In the Indel-II region, 4 WSSV genotypes with deletions of 8539, 10970, 11049 or 11866 bp in length compared with that of a reference strain from Taiwan (WSSV-TW) were detected, and the 8539 and 10970 bp genotypes predominated. Indel-II variants with longer deletions were found to correlate statistically with WSSV-diseased shrimp originating from more intensive farming systems. Like Indel-I lengths, Indel-II lengths also varied based on the Mekong Delta province from which farmed shrimp were collected.