Galanin preproprotein is associated with elevated plasma triglycerides.

Area of Science:

• Genetics
• Molecular Biology
• Metabolic Disorders

Background:

• Rodent studies suggest a link between the neuropeptide galanin and triglyceride levels.
• Human genetic variation in the galanin preproprotein (GAL) gene is a potential factor in hypertriglyceridemia (HTG).

Purpose of the Study:

• To investigate the GAL gene as a candidate gene for hypertriglyceridemia.
• To determine if variations in the GAL gene are associated with altered triglyceride levels in humans.

Main Methods:

• Genotyping of 4 tag single nucleotide polymorphisms (tagSNPs) in the GAL gene within familial combined hyperlipidemia (FCHL) families and hyperlipidemia cases/controls.
• Association analysis of SNPs with hypertriglyceridemia and triglyceride levels in Dutch, Finnish, Mexican, and white populations.
• In vitro reporter gene assays to assess the functional impact of SNP rs2187331 on gene expression and nuclear factor binding.
• Analysis of differential gene expression in adipose tissue based on rs2187331 genotypes.

Main Results:

• The common allele of rs2187331 in the GAL promoter region was significantly associated with hypertriglyceridemia (P=0.00038).
• In a Finnish male population, the rare allele of rs2187331 correlated with higher triglyceride levels (P=0.0028 to 0.00016).
• In vitro studies demonstrated allele-specific cis-regulatory function for rs2187331, affecting gene expression and nuclear factor binding.
• Differential expression of key lipid genes in adipose tissue was observed based on rs2187331 genotypes.

Conclusions:

• The single nucleotide polymorphism rs2187331 is associated with hypertriglyceridemia in FCHL and hyperlipidemia cohorts.
• rs2187331 influences population triglyceride levels and exhibits allele-specific regulatory function.
• Functional evidence supports rs2187331's role in modulating lipid gene expression in adipose tissue, warranting further investigation into allelic differences.