A haplotype of the GOSR2 gene is associated with essential hypertension in Japanese men

Getting Sugar Coating Right! The Role of the Golgi Trafficking Machinery in Glycosylation

The Golgi is the central organelle of the secretory pathway and it houses the majority of the glycosylation machinery, which includes glycosylation enzymes and sugar transporters. Correct compartmentalization of the glycosylation machinery is achieved by retrograde vesicular trafficking as the secretory cargo moves forward by cisternal maturation. The vesicular trafficking machinery which includes vesicular coats, small GTPases, tethers and SNAREs, play a major role in coordinating the Golgi trafficking thereby achieving Golgi homeostasis. Glycosylation is a template-independent process, so its fidelity heavily relies on appropriate localization of the glycosylation machinery and Golgi homeostasis. Mutations in the glycosylation enzymes, sugar transporters, Golgi ion channels and several vesicle tethering factors cause congenital disorders of glycosylation (CDG) which encompass a group of multisystem disorders with varying severities. Here, we focus on the Golgi vesicle tethering and fusion machinery, namely, multisubunit tethering complexes and SNAREs and their role in Golgi trafficking and glycosylation. This review is a comprehensive summary of all the identified CDG causing mutations of the Golgi trafficking machinery in humans.

SNAREs and developmental disorders

Members of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) family mediate membrane fusion processes associated with vesicular trafficking and autophagy. SNAREs mediate core membrane fusion processes essential for all cells, but some SNAREs serve cell/tissue type-specific exocytic/endocytic functions, and are therefore critical for various aspects of embryonic development. Mutations or variants of their encoding genes could give rise to developmental disorders, such as those affecting the nervous system and immune system in humans. Mutations to components in the canonical synaptic vesicle fusion SNARE complex (VAMP2, STX1A/B, and SNAP25) and a key regulator of SNARE complex formation MUNC18-1, produce variant phenotypes of autism, intellectual disability, movement disorders, and epilepsy. STX11 and MUNC18-2 mutations underlie 2 subtypes of familial hemophagocytic lymphohistiocytosis. STX3 mutations contribute to variant microvillus inclusion disease. Chromosomal microdeletions involving STX16 play a role in pseudohypoparathyroidism type IB associated with abnormal imprinting of the GNAS complex locus. In this short review, I discuss these and other SNARE gene mutations and variants that are known to be associated with a variety developmental disorders, with a focus on their underlying cellular and molecular pathological basis deciphered through disease modeling. Possible pathogenic potentials of other SNAREs whose variants could be disease predisposing are also speculated upon.

A novel haplotype of low-frequency variants in the aldosterone synthase gene among northern Han Chinese with essential hypertension

Low-frequency variants showed that there is more power to detect risk variants than to detect protective variants in complex diseases. Aldosterone plays an important role in the renin-angiotensin-aldosterone system, and aldosterone synthase catalyzes the speed-controlled steps of aldosterone biosynthesis. Polymorphisms of the aldosterone synthase gene (CYP11B2) have been reported to be associated with essential hypertension (EH). CYP11B2 polymorphisms such as -344T/C, have been extensively reported, but others are less well known. This study aimed to assess the association between human CYP11B2 and EH using a haplotype-based case-control study. A total of 1024 EH patients and 956 normotensive controls, which consist of north Han population peasants, were enrolled. Seven single nucleotide polymorphisms (SNPs) (rs28659182, rs10087214, rs73715282, rs542092383, rs4543, rs28491316, and rs7463212) covering the entire human CYP11B2 gene were genotyped as markers using the MassARRAY system. The major allele G frequency of rs542092383 was found to be risk against hypertension [odds ratio (OR) 3.478, 95% confidence interval (95% CI) 1.407-8.597, P = .004]. The AG genotype frequency of SNP rs542092383 was significantly associated with an increased risk of hypertension (OR 4.513, 95% CI 1.426-14.287, P = .010). In the haplotype-based case-control analysis, the frequency of the T-G-T haplotype was higher for EH patients than for controls (OR 5.729, 95% CI 1.889-17.371, P = .000495). All |D'| values of the seven SNPs were >0.9, and r values for rs28659182- rs10087214-rs28491316-rs7463212 SNPs were >0.8 and showed strong linkage intensity. Haplotype T-G-T may therefore be a useful genetic marker for EH.

G-T haplotype established by rs3785889-rs16941382 in GOSR2 gene is associated with coronary artery disease in Chinese Han population

Objectives

The aim of the present study is to assess the association between the human GOSR2 gene and coronary artery disease using a haplotype-based case-control study in Chinese Han population.

Methods

A total of 283 coronary artery disease patients and 280 controls were genotyped for the human GOSR2 gene (rs197932, rs3785889, rs197922, rs17608766, and rs16941382). Data were analyzed for three separate groups: the total subjects, men, and women.

Results

For the total subjects, the frequency of the G-T haplotype established by rs3785889-rs16941382 was significantly higher in the coronary artery disease patients as compared to the control subjects (P=0.009). Multiple logistic regression analysis also confirmed that the subjects with G-T haplotype established by rs3785889-rs16941382 (homozygote) were found having significantly higher chance suffering from coronary artery disease than the ones without this haplotype (OR=1.887, P=0.007).

Conclusions

The G-T haplotype established by rs3785889-rs16941382 may be a risk genetic marker for coronary artery disease patients in Chinese Han population.

The association of cholesterol absorption gene Numb polymorphism with Coronary Artery Disease among Han Chinese and Uighur Chinese in Xinjiang, China

BACKGROUND

Hypercholesterolemia is a major risk factor for coronary artery disease (CAD). As Numb is an important regulating factor for intestinal cholesterol absorption and plasma cholesterol level, the aim of the present study is to assess the association between human Numb gene polymorphism and CAD among Han and Uighur Chinese.

METHODS

We have conducted two independent case-control studies in Han Chinese (384 CAD patients and 433 controls) and Uighur Chinese (506 CAD patients and 351 controls) subjects. All subjects were genotyped for four kinds of SNPs (rs12435797, rs2108552, rs1019075 and rs17781919) and SNP is used as a genetic marker for human Numb gene. Genotyping was undertaken using TaqMan SNP genotyping assay, and the subjects' ethnicity and gender were considered in the analysis.

RESULTS

We found that rs2108552 was associated with CAD in the dominant model (CC vs CG + GG) for the total Han Chinese population (n = 200) and Han Chinese males (n = 115) (P = 0.004 and P = 0.001, respectively). The difference remained statistically significant after multivariate adjustment (total: OR = 1.687, P = 0.004; male: OR = 1.498, P = 0.006). Further, for the total (n = 817) and male (n = 490) Han Chinese, the frequency of the haplotype (T-C-T-C) was significantly higher in the CAD patients than in the controls (P = 0.004 and P = 0.002), and the frequency of the haplotype (G-G-T-C) was significantly lower in the CAD patients than in the control subjects (P = 0.013, P = 0.007). In addition, for the total (n = 857) and male (n = 582) Uighur Chinese, we observed that rs12435797 was associated with CAD in an additive and recessive model (P = 0.021 and P = 0.009; P = 0.048 and P = 0.034). However, the difference did not remain statistically significant after multivariate adjustment. The overall distribution of rs2108552, rs1019075 and rs17781919 genotypes, alleles and the frequency of the haplotype established by four SNPs showed no significant difference between CAD patients and control subjects in the total, male and female Uighur Chinese.

CONCLUSIONS

The results of this study indicate that CC genotype of rs2108552 and T-C-T-C haplotypes in Numb gene is a possible risk genetic marker and G allele and G-G-T-C haplotypes is a possible protective genetic marker for CAD in male Han Chinese.

Elevated blood pressure: Our family's fault? The genetics of essential hypertension

AIM

To provide an updated review on current genetic aspects possibly affecting essential hypertension (EH), and to further elucidate their role in EH.

METHODS

We searched for genetic and epigenetic factors in major studies associated with EH between Jan 2008-Oct 2013 using PubMed. We limited our search to reviews that discussed mostly human studies, and were accessible through the university online resource. We found 11 genome wide association studies (GWAS), as well as five methylation and three miRNA studies that fit our search criteria. A distinction was not made between genes with protective effects or negative effects, as this article is only meant to be a summary of genes associated with any aspect of EH.

RESULTS

We found 130 genes from the studies that met our inclusion/exclusion criteria. Of note, genes with multiple study references include: STK39, CYP17A1, MTHFR-NPPA, MTHFR-NPPB, ATP2B1, CSK, ZNF652, UMOD, CACNB2, PLEKHA7, SH2B3, TBX3-TBX5, ULK4, CSK-ULK3, CYP1A2, NT5C2, CYP171A, PLCD3, SH2B3, ATXN2, CACNB2, PLEKHA7, SH2B3, TBX3-TBX5, ULK4, and HFE. The following genes overlapped between the genetic studies and epigenetic studies: WNK4 and BDKRB2. Several of the identified genes were found to have functions associated with EH. Many epigenetic factors were also correlated with EH. Of the epigenetic factors, there were no articles discussing siRNA and its effects on EH that met the search criteria, thus the topic was not included in this review. Among the miRNA targets found to be associated with EH, many of the genes involved were also identified in the GWAS studies.

CONCLUSION

Genetic hypertension risk algorithms could be developed in the future but may be of limited benefit due to the multi-factorial nature of EH. With emerging technologies, like next-generation sequencing, more direct causal relationships between genetic and epigenetic factors affecting EH will likely be discovered creating a tremendous potential for personalized medicine using pharmacogenomics.

Association of Egr3 genetic polymorphisms and coronary artery disease in the Uygur and Han of China

Background

Endothelial cell activation and dysfunction are the foundation of atherosclerosis, including coronary artery disease (CAD). Endothelial cell activation is mediated by the level of gene transcription. Early growth response 3 (Egr3) is a critical determinant of vascular endothelial growth factor (VEGF) signalling in activated endothelial cells. If endothelial cells are excessively activated, it may lead to vasculopathic diseases, such as pathologic angiogenesis, inflammation, and atherosclerosis. The aim of the present study was to assess the association between the Egr3 gene polymorphisms and CAD.

Methods

Two independent case–control studies that involved the Han group (409 CAD patients and 351 control subjects) and the Uygur group (299 CAD patients and 303 control subjects) analysed the relationship between Egr3 SNPs (rs1996147 and rs1008949) and CAD. Genotyping was undertaken using the TaqMan SNP genotyping assay.

Results

The entire Uygur group and the males in the Uygur group showed a higher frequency of the A allele (rs1996147) in CAD patients than in the control subjects (P = 0.003 and P = 0.005, respectively). Additionally, the distribution of the recessive model of rs1996147 (AA vs GG + AG) for the total sample and the males was significantly different between CAD patients and control participants (P = 0.002 and P = 0.003, respectively), and the difference remained statistically significant following multivariate adjustment (Total: OR = 1.705; 95% CI: 1.166-2.494, P = 0.006; males: OR = 1.908, 95% CI: 1.189-3.062, P = 0.007). However, for Uygur females, we did not observe a difference in the allele frequency or genotypic distribution of rs1996147 between CAD patients and control participants. Similarly, the distribution of the rs1996147 allele frequency or genotypes showed no significant difference between patients with CAD and control participants in the Han group. The distribution of rs1008949 genotypes, dominant model, recessive model, and allele frequency did not show a significant difference between patients with CAD and the control subjects in the Han and Uygur groups.

Conclusion

rs1996147 may be a novel polymorphism of the Egr3 gene associated with CAD in males of the Chinese Uygur population.