Association of aminoacyl-tRNA synthetases gene polymorphisms with the risk of congenital heart disease in the Chinese Han population

Glutamyl-Prolyl-tRNA Synthetase Regulates Proline-Rich Pro-Fibrotic Protein Synthesis During Cardiac Fibrosis

RATIONALE

Increased protein synthesis of profibrotic genes is a common feature in cardiac fibrosis and heart failure. Despite this observation, critical factors and molecular mechanisms for translational control of profibrotic genes during cardiac fibrosis remain unclear.

OBJECTIVE

To investigate the role of a bifunctional ARS (aminoacyl-tRNA synthetase), EPRS (glutamyl-prolyl-tRNA synthetase) in translational control of cardiac fibrosis.

METHODS AND RESULTS

Results from reanalyses of multiple publicly available data sets of human and mouse heart failure, demonstrated that EPRS acted as an integrated node among the ARSs in various cardiac pathogenic processes. We confirmed that EPRS was induced at mRNA and protein levels (≈1.5-2.5-fold increase) in failing hearts compared with nonfailing hearts using our cohort of human and mouse heart samples. Genetic knockout of one allele of Eprs globally (Eprs+/-) using CRISPR-Cas9 technology or in a Postn-Cre-dependent manner (Eprsflox/+; PostnMCM/+) strongly reduces cardiac fibrosis (≈50% reduction) in isoproterenol-, transverse aortic constriction-, and myocardial infarction (MI)-induced heart failure mouse models. Inhibition of EPRS using a PRS (prolyl-tRNA synthetase)-specific inhibitor, halofuginone, significantly decreases translation efficiency (TE) of proline-rich collagens in cardiac fibroblasts as well as TGF-β (transforming growth factor-β)-activated myofibroblasts. Overexpression of EPRS increases collagen protein expression in primary cardiac fibroblasts under TGF-β stimulation. Using transcriptome-wide RNA-Seq and polysome profiling-Seq in halofuginone-treated fibroblasts, we identified multiple novel Pro-rich genes in addition to collagens, such as Ltbp2 (latent TGF-β-binding protein 2) and Sulf1 (sulfatase 1), which are translationally regulated by EPRS. SULF1 is highly enriched in human and mouse myofibroblasts. In the primary cardiac fibroblast culture system, siRNA-mediated knockdown of SULF1 attenuates cardiac myofibroblast activation and collagen deposition. Overexpression of SULF1 promotes TGF-β-induced myofibroblast activation and partially antagonizes anti-fibrotic effects of halofuginone treatment.

CONCLUSIONS

Our results indicate that EPRS preferentially controls translational activation of proline codon rich profibrotic genes in cardiac fibroblasts and augments pathological cardiac remodeling. Graphical Abstract: A graphical abstract is available for this article.

Genome-wide identification of m6A-associated SNPs as potential functional variants for bone mineral density

This study investigated the effect of the N⁶-methyladenosine (m⁶A)-associated SNPs on bone mineral density (BMD) and found plenty of m⁶A-SNPs that were associated with BMD. This study increases our understanding on the regulation patterns of SNP and may provide new clues for further detection of functional mechanism underlying the associations between SNPs and osteoporosis.

INTRODUCTION

m⁶A plays critical roles in many fundamental biological processes and a variety of diseases. The m⁶A-associated SNPs may be potential functional variants for BMD. The aim of this study was to investigate the effect of the genome-wide m⁶A-SNPs on BMD.

METHODS

We examined the association of m⁶A-SNPs with femoral neck (FN) and lumbar spine (LS) BMD in 32,961 individuals and quantitative heel ultrasounds (eBMD) in 142,487 individuals. Furthermore, we performed expression quantitative trait locus (eQTL) analyses for the m⁶A-SNPs using whole genome data of about 10.5 million SNPs and 21,323 mRNAs from 43 Chinese individuals, as well as public available data. Differential expression analyses were also performed to support the identified genes.

RESULTS

We found 138, 125, and 993 m⁶A-SNPs which were associated with FN-BMD, LS-BMD, and eBMD (P < 0.05), respectively. The associations of rs11614913 (P = 8.92 × 10^-10) in MIR196A2 and rs1110720 (P = 2.05 × 10^-10) in ESPL1 with LS-BMD reached the genome-wide significance level. In addition, a total of 24 m⁶A-SNPs were significantly associated with eBMD (P < 5.0 × 10^-8). Further eQTL analyses showed that 47 of these BMD-associated m⁶A-SNPs were associated with expressions of the 46 corresponding local genes. Moreover, the expressions of 26 of these genes were associated with BMD.

CONCLUSION

The present study represents the first effort of investigating the associations and the mechanisms underlying the link between m⁶A-SNPs and BMD. The results suggested that m⁶A-SNP may play important roles in the pathology of osteoporosis.

Association of DARS gene polymorphisms with the risk of isolated ventricular septal defects in the Chinese Han population

BACKGROUND

Ventricular septal defects (VSD) are the most common subtype of congenital heart defects (CHD) and are estimated to account for 20 to 30% of all cases of CHD. The etiology of isolated VSD remains poorly understood. Eight core aminoacyl-tRNA synthetases (ARSs) (EPRS, MARS, QARS, RARS, IARS, LARS, KARS, and DARS) combine with three nonenzymatic components to form a complex known as the multisynthetase complex (MSC). Four single nucleotide polymorphisms (SNPs) in EPRS have been reported to be associated with risks of CHD in Chinese populations.

METHODS

In this study, we hypothesize that SNPs of the DARS gene might influence susceptibility to sporadic isolated VSD. Therefore, we conducted a case-control study of 841 patients with isolated VSD and 2953 non-CHD controls from the Chinese Han population to evaluate how 4 potentially functional SNPs within the DARS gene were associated with the risk of VSD.

RESULTS

We observed that the risk of VSD was significantly associated with rs2164331 [G/A; odds ratio (OR) = 0.78, 95% confidence interval (CI) = 0.69-0.91; P = 3.17 × 10-3], rs6738266 [G/A; OR = 1.17, 95% CI = 1.05-1.29, P = 1.83 × 10-3], and rs309143 [G/A; OR = 1.09, 95% CI = 1.01-1.17; P = 3.12 × 10-2]. Additionally, compared with individuals with 0-2 risk alleles, individuals carrying 3, 4, and 5 or more risk alleles had 1.01-, 1.22- and 1.46-fold greater risks of VSD, respectively. These findings revealed a significant dose-response effect for VSD risk among individuals carrying different numbers of risk alleles (Ptrend = 6.37 × 10-4).

CONCLUSIONS

These findings indicate that genetic variants of the DARS gene may influence individual susceptibility to isolated VSD in the Chinese Han population.

Metabolomics Reveals Dynamic Metabolic Changes Associated with Age in Early Childhood

Objectives

A detailed understanding of the metabolic processes governing rapid growth in early life is still lacking. The aim of this study was to investigate the age-related metabolic changes in healthy children throughout early childhood.

Methods

Healthy children from a birth cohort were enrolled in this study from birth through 4 years of age. Urinary metabolites were assessed at 6 months, and 1, 2, 3, and 4 yr of age by using ¹H-nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate statistical analysis including principal components analysis (PCA) and partial least-squares discriminant analysis (PLS-DA). Metabolic pathway analysis was performed using the MetPA web tool.

Results

A total of 105 urine samples from 30 healthy children were collected and analyzed. Metabolites contributing to the discrimination between age groups were identified by using supervised PLS-DA (Q² = 0.60; R² = 0.66). A significantly higher urinary trimethylamine N-oxide (TMAO) and betaine level was found in children aged 6 months. Urinary glycine and glutamine levels declined significantly after 6 months of age and there was a concomitant compensatory increase in urinary creatine and creatinine. Metabolic pathway analysis using MetPA revealed similar nitrogen metabolism associated energy production across all ages assessed. Pathways associated with amino acid metabolism were significantly different between infants aged 6 months and 1 year, whereas pathways associated with carbohydrate metabolism were significantly different between children at ages 2 and 3 years.

Conclusions

Urine metabolomics ideally represents dynamic metabolic changes across age. Urinary metabolic profiles change significantly within the first year of life, which can potentially provide crucial information about infant nutrition and growth.

Correlation between rs198388 and rs198389 polymorphismsin brainnatriuretic peptide (NPPB) gene and susceptibility to congenital heart diseases in a Chinese population

OBJECTIVE

We discussed the correlation between SNP loci (rs198389 and rs198388) in brain natriuretic peptide gene (NPPB) and susceptibility to congenital heart diseases (CHD).

METHOD

Multiplex SNaPshot technique was adopted for profiling of SNP genotypes at loci rs198389 and rs198388 in NPPB gene among 150 cases of CHDand 150 normal controls.

RESULTS

The distribution frequency of 3 genotypes (AA, AG and GG) at locus rs198389 was 40.7%, 36.0% and 23.3% in CHD group, respectively, showing significant differences compared with the normal controls (P<0.001). Gallele was associated with higher risk of CHD (OR=2.48, 95% CI=1.77-3.48). The distribution frequency of CC, CTand TT genotypes at locus rs198388 was 60.7%, 17.3% and 22.0% in CHD group, respectively, also showing significant differences compared with the normal controls (P<0.001). C allele could increase the risk of CHD (OR=1.92, 95% CI=1.48-2.48).

CONCLUSION

SNP loci rs198389 and rs198388 in NPPB gene were correlated with genetic susceptibility to CHD.