Association of ALOX15 gene polymorphisms with obesity-related phenotypes in Chinese nuclear families with male offspring

Role and mechanism of specialized pro-resolving mediators in obesity-associated insulin resistance

With the changing times, obesity has become a characteristic epidemic in the context of the current era. Insulin resistance (IR) is most commonly caused by obesity, and IR is a common basis of the pathogenesis of many diseases such as cardiovascular disease, nonalcoholic fatty liver disease, and type 2 diabetes, which seriously threaten human life, as well as health. A major pathogenetic mechanism of obesity-associated IR has been found to be chronic low-grade inflammation in adipose tissue. Specialized pro-resolving mediators (SPMs) are novel lipid mediators that both function as "stop signals" for inflammatory reaction and promote inflammation to subside. In this article, we summarize the pathogenesis of obesity-associated IR and its treatments and outline the classification and biosynthesis of SPMs and their mechanisms and roles in the treatment of obesity-associated IR in order to explore the potential of SPMs for treating metabolic diseases linked with obesity-associated IR.

Association of Rs7217186 Polymorphism of Arachidonic Acid 15-Lipoxygenase (ALOX15) Gene with Susceptibility to Allergic Rhinitis

Background

Allergic rhinitis (AR) is an inflammatory disorder of the nasal mucosa, caused by exposure to environmental allergens. It is known that 15-lipoxygenase (15-LOX) is involved in the biosynthetic pathways of anti-inflammatory lipid mediators, including resolvins and protectins.

Methods

In this study, which was performed on 130 AR patients and 130 healthy controls, we aimed to investigate the association of susceptibility to AR with two selected single-nucleotide polymorphisms (SNPs), that is, rs2619112:A>G and rs7217186:C>T, in the intron regions of arachidonic acid 15-LOX (ALOX15) gene, using SNPinfo and Regulome DB tools.

Results

The results showed that the CT genotype of rs7217186: C>T was significantly associated with the increased risk of AR compared to the CC genotype (P= 0.037, OR=1.943, CI: 1.038-0.638). However, there was no strong evidence of the association of rs2619112: A>G with susceptibility to AR (P> 0.05).

Conclusions

The present results indicated that rs7217186 polymorphism of ALOX15 gene might be a potential biomarker for susceptibility to AR.

LGR4 Gene Polymorphisms Are Associated With Bone and Obesity Phenotypes in Chinese Female Nuclear Families

OBJECTIVE

The current study was conducted to determine whether peak bone mineral density (BMD) and obesity phenotypes are associated with certain LGR4 gene polymorphisms found in Chinese nuclear families with female children.

METHODS

A total of 22 single nucleotide polymorphisms (SNPs) located in and around the LGR4 gene were identified in 1,300 subjects who were members of 390 Chinese nuclear families with female children. Then, BMD readings of the femoral neck, total hip, and lumbar spine as well as measurements of the total lean mass (TLM), total fat mass (TFM), and trunk fat mass were obtained via dual-energy X-ray absorptiometry. The quantitative transmission disequilibrium test was used to analyze the associations between specific SNPs and LGR4 haplotypes and peak BMD as well as between LGR4 haplotypes and TLM, percent lean mass, TFM, percent fat mass, trunk fat mass, and body mass index (BMI).

RESULTS

Here, rs7936621 was significantly associated with the BMD values for the total hip and lumbar spine, while rs10835171 and rs6484295 were associated with the trunk fat mass and BMI, respectively. Regarding the haplotypes, we found significant associations between GAA in block 2 and trunk fat mass and BMI, between AGCGT in block 3 and total hip BMD, between TGCTCC in block 5 and femoral neck BMD, and between TACTTC in block 5 and both lumbar spine and femoral neck BMD (all P-values < 0.05).

CONCLUSION

Genetic variations of the LGR4 gene are related to peak BMD, BMI, and trunk fat mass.

Polymorphisms in Wnt signaling pathway genes are associated with peak bone mineral density, lean mass, and fat mass in Chinese male nuclear families

Our objective was to investigate the associations between polymorphisms in Wnt pathway genes and peak bone mineral density (BMD) and body composition in young Chinese men. Our study identified that WNT5B and CTNNBL1 for both BMD and body composition, and WNT4 and CTNNB1 gene polymorphisms contribute to the variation in BMD and body composition in young Chinese men, respectively.

INTRODUCTION

Our objective was to investigate the associations between polymorphisms in WNT4, WNT5B, WNT10B, WNT16, CTNNB1, and CTNNBL1 genes and peak bone mineral density (BMD), lean mass (LM), and fat mass (FM) in young Chinese men.

METHODS

Using SNPscan(TM) kits, 51 single-nucleotide polymorphisms (SNPs) located in the 6 genes were genotyped in a total of 1214 subjects from 399 Chinese nuclear families. BMD, total lean mass (TLM), and total fat mass (TFM) were measured using dual energy X-ray absorptiometry (DXA). The associations between the 51 SNPs and peak BMD and body composition [including the TLM, percentage lean mass (PLM), TFM, percentage fat mass (PFM), and the body mass index (BMI)] were analyzed through quantitative transmission disequilibrium tests (QTDTs).

RESULTS

For peak BMD, we found significant within-family associations of rs2240506, rs7308793, and rs4765830 in the WNT5B gene and rs10917157 in the WNT4 gene with the lumbar spine BMD (all P < 0.05). We detected an association of rs11830202, rs3809269, rs1029628, and rs6489301 in the WNT5B gene and rs2293303 in the CTNNB1 gene with body composition (all P < 0.05). For the CTNNBL1 gene, six SNPs (rs6126098, rs6091103, rs238303, rs6067647, rs8126174, and rs4811144) were associated with peak BMD of the lumbar spine, femoral neck, or total hip (all P < 0.05). Furthermore, two of the six SNPs (rs8126174 and rs4811144) were associated with body composition.

CONCLUSIONS

This study identified WNT5B and CTNNBL1 for peak BMD and body composition in males from the Han Chinese ethnic group, and the results suggest a site-specific gene regulation. The WNT4 and CTNNB1 gene polymorphisms contribute to the variation in peak BMD and body composition, respectively.

Polymorphisms in inflammation associated genes ALOX15 and IL-6 are associated with bone properties in young women and fracture in elderly

PURPOSE

ALOX12 and ALOX15 encode arachidonate lipoxygenases which produce lipid metabolites involved in inflammatory processes. Metabolites generated by ALOX12 and ALOX15 can activate the expression of the potent pro-inflammatory cytokine IL-6, and produce endogenous ligands for PPARG. In this study, polymorphisms in ALOX12, ALOX15, IL6 and PPARG were investigated for association with bone properties in young and elderly Swedish women.

METHODS

Three SNPs in ALOX12, five in ALOX15, one each in IL6 and PPARG were genotyped in the cohorts PEAK-25 (n=1061 women; all 25y) and OPRA (n=1044 women; all 75y). Bone mineral density (BMD) and quantitative ultrasound (QUS) were analyzed in both cohorts; trabecular bone score (TBS) in PEAK-25; bone loss, fracture incidence and serum C-reactive protein (CRP) were assessed in OPRA.

RESULTS

In the elderly women ALOX15 (rs2619112) was associated with CRP levels (p=0.004) and incident fracture of any type (p=0.014), although not with BMD or ultrasound. In young women, carrying the common T allele (ALOX 15 rs748694) was associated with lower QUS values (p=0.002-0.006). The IL6 SNP was associated with lower BMD in PEAK-25 (femoral neck p=0.034; hip p=0.012). TBS was not associated with variation in any gene. Variants in the ALOX12 and PPARγ were not associated with BMD in either cohort.

CONCLUSIONS

This study suggests that variation in inflammation related genes ALOX15 and IL6 was associated with bone microarchitecture and density in young adult women, but appears to be less important in the elderly, despite an observed association with CRP as a marker of inflammation and incident fracture.