Identification of glyoxalase 1 polymorphisms associated with enzyme activity

The glyoxalase system and its main enzyme, glyoxalase 1 (GLO1), protect cells from advanced glycation end products (AGEs), such as methylglyoxal (MG) and other reactive dicarbonyls, the formation of which is increased in diabetes patients as a result of excessive glycolysis. MG is partly responsible for harmful protein alterations in living cells, notably in neurons, leading to their dysfunction, and recent studies have shown a negative correlation between GLO1 expression and tissue damage. Neuronal dysfunction is a common diabetes complication due to elevated blood sugar levels, leading to high levels of AGEs. The aim of our study was to determine whether single nucleotide polymorphisms (SNPs) in the GLO1 gene influence activity of the enzyme. In total, 125 healthy controls, 101 type 1 diabetes, and 100 type 2 diabetes patients were genotyped for three common SNPs, rs2736654 (A111E), rs1130534 (G124G), and rs1049346 (5′-UTR), in GLO1. GLO1 activity was determined in whole blood lysates for all participants of the study.     

Origin of the prolactin-releasing hormone (PRLH) receptors: evidence of coevolution between PRLH and a redundant neuropeptide Y receptor during vertebrate evolution

We present seven new vertebrate homologs of the prolactin-releasing hormone receptor (PRLHR) and show that these are found as two separate subtypes, PRLHR1 and PRLHR2. Analysis of a number of vertebrate sequences using phylogeny, pharmacology, and paralogon analysis indicates that the PRLHRs are likely to share a common ancestry with the neuropeptide Y (NPY) receptors. Moreover, a micromolar level of NPY was able to bind and inhibit completely the PRLH-evoked response in PRLHR1-expressing cells. We suggest that an ancestral PRLH peptide started coevolving with a redundant NPY binding receptor, which then became PRLHR, approximately 500 million years ago. The PRLHR1 subtype was shown to have a relatively high evolutionary rate compared to receptors with fixed peptide preference, which could indicate a drastic change in binding preference, thus supporting this hypothesis. This report suggests how gene duplication events can lead to novel peptide ligand/receptor interactions and hence spur the evolution of new physiological functions.     

BCL3 gene role in facial morphology

BACKGROUND: Cleft lip (CL) with or without palate (CLP) and isolated cleft palate (CP) are etiologically complex diseases with interactions among various environmental and genetic factors. The aim of the current study was to identify association with genetic markers and phenotypic craniofacial data in patients with CL/CLP/CP parents. METHODS: Posteroanterior and lateral digital radiographs of the cranium were obtained from 74 parents of patients with CL/CLP/CP. One hundred seventy‐three patients with CL/CLP/CP and 190 controls were enrolled in the study for the association test. Five genetic markers of the IRF6 gene and 14 markers of the 19q13 locus were genotyped. Linear regression analysis was performed for the relationship of cephalometric measurements with genotype data adjusted for age, gender, and cleft type. Chi‐square and transmission disequilibrium tests were performed to evaluate differences in alleles of the BCL3 gene. Positive findings were replicated in an independent sample (n = 95) of patients with CL/CLP/CP parents. RESULTS: Genetic markers of the BCL3 gene at 19q13, rs7257231, and rs1979377 in the familial association test and rs10401176 in the case‐control association test, were associated with craniofacial phenotype. Carriers of BCL3 allele rs7257231T had longer posterior cranial bases than noncarriers (p_adjusted = 0.0028), and in the familial‐based association test showed the statistically strongest relationship (p_adjusted = 0.05) to phenotype. Relation of rs7257231 to facial formation was confirmed in the replication group (p = 0.0024). CONCLUSIONS: The results indicate that BCL3, which has functions related to cell adhesion and whose downregulation can cause disruption of ectodermal development, is likely to be important in facial formation. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.     

Genome-wide analysis reveals DNA methylation markers that vary with both age and obesity

The combination of the obesity epidemic and an aging population presents growing challenges for the healthcare system. Obesity and aging are major risk factors for a diverse number of diseases and it is of importance to understand their interaction and the underlying molecular mechanisms. Herein the authors examined the methylation levels of 27578 CpG sites in 46 samples from adult peripheral blood. The effect of obesity and aging was ascertained with general linear models. More than one hundred probes were correlated to aging, nine of which belonged to the KEGG group map04080. Additionally, 10 CpG sites had diverse methylation profiles in obese and lean individuals, one of which was the telomerase catalytic subunit (TERT). In eight of ten cases the methylation change was reverted between obese and lean individuals. One region proved to be differentially methylated with obesity (LINC00304) independent of age. This study provides evidence that obesity influences age driven epigenetic changes, which provides a molecular link between aging and obesity. This link and the identified markers may prove to be valuable biomarkers for the understanding of the molecular basis of aging, obesity and associated diseases.     

Template Activity of Oligoribonucleotides Synthesized by the Phosphoramidite Method Using 2′-O-Tetrahydrofuranyl and 2′-O-Tetrahydropyranyl Protecting Groups

Abstract

Solid-phase synthesis and functional activity of oligoribonucleotides containing native and modified translation initiation region (TIR) of phage MS2 and fr RNA replicase gene have been investigated.     

Functional characterization of two melanocortin (MC) receptors in lamprey showing orthology to the MC1 and MC4 receptor subtypes

Background  

The melanocortin (MC) receptors have a key role in regulating body weight and pigmentation. They belong to the rhodopsin family of G protein-coupled receptors (GPCRs). The purpose of this study was to identify ancestral MC receptors in agnathan, river lamprey.     

The melanocortin system in Fugu: determination of POMC/AGRP/MCR gene repertoire and synteny, as well as pharmacology and anatomical distribution of the MCRs

The G-protein-coupled melanocortin receptors (MCRs) play an important role in a variety of essential functions such as the regulation of pigmentation, energy homeostasis, and steroid production. We performed a comprehensive characterization of the MC system in Fugu (Takifugu rubripes). We show that Fugu has an AGRP gene with high degree of conservation in the C-terminal region in addition to a POMC gene lacking gamma-MSH. The Fugu genome contains single copies of four MCRs, whereas the MC3R is missing. The MC2R and MC5R are found in tandem and remarkably contain one and two introns, respectively. We suggest that these introns were inserted through a reverse splicing mechanism into the DRY motif that is widely conserved through GPCRs. We were able to assemble large blocks around the MCRs in Fugu, showing remarkable synteny with human chromosomes 16 and 18. Detailed pharmacological characterization showed that ACTH had surprisingly high affinity for the Fugu MC1R and MC4R, whereas alpha-MSH had lower affinity. We also showed that the MC2R gene in Fugu codes for an ACTH receptor, which did not respond to alpha-MSH. All the Fugu receptors were able to couple functionally to cAMP production in line with the mammalian orthologs. The anatomical characterization shows that the MC2R is expressed in the brain in addition to the head-kidney, whereas the MC4R and MC5R are found in both brain regions and peripheral tissues. This is the first comprehensive genomic and functional characterization of a GPCR family within the Fugu genome. The study shows that some parts of the MC system are highly conserved through vertebrate evolution, such as regions in POMC coding for ACTH, alpha-MSH, and beta-MSH, the C-terminal region of AGRP, key binding units within the MC1R, MC2R, MC4R, and MC5R, synteny blocks around the MCRs, pharmacological properties of the MC2R, whereas other parts in the system are either missing, such as the MC3R and gamma-MSH, or different as compared to mammals, such as the affinity of ACTH and MSH peptides to MC1R and MC4R and the anatomical expression pattern of the MCRs.     

A nonsynonymous variant I248L of the adenosine A3 receptor is associated with coronary heart disease in a Latvian population

Adenosine plays an important part in the cardiac response to ischemia and reperfusion. The human adenosine receptor A3 (A3R), along with other adenosine receptors, is involved in mediation of those effects. The aim of the study was to ascertain whether the nonsynonymous single-nucleotide polymorphism (SNP) I248L (reference SNP ID: rs35511654) located in the A3R gene is associated with coronary heart disease (CHD). DNA samples from 683 individuals with CHD and from 826 control subjects selected from the Latvian Genome Database were successfully screened for rs35511654 using the TaqMan SNP Genotyping Assay. We observed a significantly decreased frequency of the rs35511654 C allele in a group of CHD patients compared with that in controls (p = 0.009). The association remained significant after adjustment for age, sex, and other nongenetic factors (p = 0.02). These results suggest that A allele of rs35511654 may predispose to CHD.     

Formation of new genes explains lower intron density in mammalian Rhodopsin G protein-coupled receptors

Mammalian G protein-coupled receptor (GPCR) genes are characterised by a large proportion of intronless genes or a lower density of introns when compared with GPCRs of invertebrates. It is unclear which mechanisms have influenced intron density in this protein family, which is one of the largest in the mammalian genomes. We used a combination of Hidden Markov Models (HMM) and BLAST searches to establish the comprehensive repertoire of Rhodopsin GPCRs from seven species and performed overall alignments and phylogenetic analysis using the maximum parsimony method for over 1400 receptors in 12 subgroups. We identified 14 different Ancestral Receptor Groups (ARGs) that have members in both vertebrate and invertebrate species. We found that there exists a remarkable difference in the intron density among ancestral and new Rhodopsin GPCRs. The intron density among ARGs members was more than 3.5-fold higher than that within non-ARG members and more than 2-fold higher when considering only the 7TM region. This suggests that the new GPCR genes have been predominantly formed intronless while the ancestral receptors likely accumulated introns during their evolution. Many of the intron positions found in mammalian ARG receptor sequences were found to be present in orthologue invertebrate receptors suggesting that these intron positions are ancient. This analysis also revealed that one intron position is much more frequent than any other position and it is common for a number of phylogenetically different Rhodopsin GPCR groups. This intron position lies within a functionally important, conserved, DRY motif which may form a proto-splice site that could contribute to positional intron insertion. Moreover, we have found that other receptor motifs, similar to DRY, also contain introns between the second and third nucleotide of the arginine codon which also forms a proto-splice site. Our analysis presents compelling evidence that there was not a major loss of introns in mammalian GPCRs and formation of new GPCRs among mammals explains why these have fewer introns compared to invertebrate GPCRs. We also discuss and speculate about the possible role of different RNA- and DNA-based mechanisms of intron insertion and loss.