👤 Suzanne A Al-Bustan

Lipoprotein lipase (LPL) is a key enzyme that hydrolyzes triglycerides (TGs) into free fatty acids. Several genetic variants of LPL are directly or indirectly associated with variations in lipid levels, causing different lipid metabolic disorders. Previous studies on the LPL gene have shown that exons and introns are essential for gene expression and regulation. However, mechanisms through which introns regulate gene expression and function remain unclear. In this study, we successfully designed a protocol to assess the function of LPL intron 3 in LPL regulation. This was accomplished by constructing luciferase reporter vectors, containing full and partial intron 3 fragments from a healthy human DNA sample. These recombinant constructs facilitated the analysis of transcriptional activity using dual-luciferase reporter assays in cell lines. The results showed that the luciferase activity of the chimeric firefly luciferase reporter construct containing the full-length LPL intron 3 was higher than that of other constructs. In this study, a successful protocol was developed to assess the function of LPL intron 3 in regulation of the LPL gene. This protocol provides a novel method for functional analysis of introns and intronic variants that can be applied to other genes. Show less

Lipoprotein lipase (LPL) is a multifunctional protein that catalyzes the hydrolysis of plasma triglycerides, releasing free fatty acids, which play critical roles in the metabolism and transport of lipids. The transcription of Show less

APOC3 is important in lipid transport and metabolism with limited studies reporting genetic sequence variations in specific ethnic groups. The present study aimed to analyze the full APOC3 sequence among Kuwaiti Arabs and test the association of selected variants with lipid levels and BMI. Variants were identified by Sanger sequencing the entire APOC3 gene in 100 Kuwaiti Arabs. Variants and their genotypes were fully characterized and used to construct haplotype blocks. Four variants (rs5128, rs2854117, rs2070668, KUAPOC3N3 g.5196 A > G) were selected for testing association with serum lipid levels and BMI in a cohort (n = 733). APOC3 sequence (4.3 kb) of a Kuwaiti Arab was deposited in Genbank (accession number KJ437193). Forty-two variants including 3 novels were identified including an "A" insertion at genomic positions 116,700,599-116,700,600 (promoter region) and two substitutions in intron 1 at genomic positions 116,700,819 and 116,701,159. Only three variants, (rs5128, rs2854117, and rs2070668) were analyzed for association of which rs5128 showed a trend for association with increased BMI, TG and VLDL levels that was further investigated using multivariate analysis. A significant association of rs5128 with BMI (p <  0.05) was observed following a dominant genetic model with increased risk by an OR of 4.022 (CI: 1.13-14.30). The present study is the first to report sequence analysis of APOC3 in an Arab ethnic group. This study supports the inclusion of rs5128 as a marker for assessing genetic risk to dyslipidemia and obesity and the inclusion of the novel variant g.5196 A > G for population stratification of Arabs. Show less