Polymorphism of the FABP2 gene: a population frequency analysis and an association study with cardiovascular risk markers in Argentina

Postprandial Hypertriglyceridemia Is Associated with the Variant 54 Threonine FABP2 Gene

Purpose: Fasting or postprandial hypertriglyceridemia is considered an independent cardiovascular disease (CVD) risk factor. The intestinal fatty acid binding protein (FABP2) is involved in the intracellular transport and metabolism of fatty acids. The presence of the Ala54Thr polymorphism of the FABP2 gene appears to be involved in postprandial hypertriglyceridemia. We explored the possible association of the Ala54Thr polymorphism with fat intolerance in apparently healthy, fasting, normolipidemic subjects with normal body-mass index and without diabetes. Methodology: A total of 158 apparently healthy individuals were classified as fat tolerant (n = 123) or intolerant (n = 35) according to their response (plasma triglycerides) to an oral abbreviated tolerance test with blood samples taken at 0, 2 and 4 h. At 0 h, all subjects ingested 26.3 g of fats. Presence of the Ala54Thr polymorphism of the FABP2 gene was evaluated by polymerase chain reaction⁻restriction fragment length (PCR⁻RFLP). Results: The group with fat intolerance (postprandial hypertriglyceridemia group) showed an increased frequency of the Thr54Thr genotype when compared with the group with normal fat tolerance (control group) (23% vs. 4%, respectively, OR: 16.53, 95% CI: 4.09⁻66.82, p: 0.0001, pc: 0.0003). Carriers of at least one Thr54 allele were up to six times more prevalent in the fat intolerant group than in the non-carriers. (OR: 6.35; 95% CI: 1.86⁻21.59, p: 0.0003, pc: 0.0009). The levels of plasma triglycerides (Tg) at 4 h after the test meal were higher in carriers of at least one 54Thr allele than in carriers of the Ala54 allele (p < 0.05). Conclusions: There is a significant association between postprandial hypertriglyceridemia and the presence of at least one 54Thr allele of the FABP2 gene. In addition, subjects with this genotype showed an increased ratio of Tg/HDL-cholesterol. This parameter is a marker of increased CVD risk and insulin resistance.

Development and characterization of 2-dimensional culture for buffalo intestinal cells

Small intestinal epithelial cells (IEC) play a major role in the absorption of nutrients and toxins. Due to the similarity of genome-wide single copy protein orthologues between cattle and human, establishment of ruminant's primary small IEC culture could be a valuable tool for toxicity studies. Therefore, the current study focused on the development and characterization of buffalo IEC culture, as cattle slaughter is banned in India. The buffalo jejunum fragments were washed consecutively several times in saline, warm phosphate buffered saline (PBS), PBS with 5 mM dithiothreitol, digesting solution and 2% sorbitol in PBS. The cells were cultured on 17 µg/cm² collagen coated plates and transwell plates with serum (2% Fetal bovine serum (FBS) and 10% FBS) and serum-free culture conditions. The cells were differentiated into typical epithelial cobblestone morphology from day 5 onwards in 50% successful cultures. The cultured IEC were characterized by gene expression of epithelial cell markers, cytokeratin and vimentin, and enterocyte markers like villin, zonula occluden (ZO1), fatty acid binding protein 2 (FABP2) and small intestinal peptidase (IP). Based on the morphology and gene expression profile, 10% FBS has been recommended for culturing primary buffalo IEC on collagen coated plates for 10 days. However, 50% of the successful cultures could not show epithelial phenotype on 10% FBS culture conditions even on collagen coated plates. Interestingly, undifferentiated IEC showed an increasing expression of FABP2, IP and ZO1 transcripts compared to differentiated intestinal cells with 10% FBS on collagen plates. Therefore, future studies are needed to understand the role of FABP2, IP and ZO1 in differentiation of buffalo IEC.

Intestinal fatty acid binding protein Ala54Thr polymorphism is associated with peripheral atherosclerosis combined with type 2 diabetes mellitus

BACKGROUND

Intestinal fatty acid-binding protein 2 (FABP2) is expressed in enterocytes and binds saturated and unsaturated long-chain fatty acids. The FABP2 Ala54Thr polymorphism has been reported to effect lipid metabolism. The aim of the present study was to assess the relationship between this polymorphism and peripheral atherosclerosis combined with type 2 diabetes mellitus (T2DM) in an Egyptian population.

METHODS

The study was performed on 100 T2DM patients with peripheral atherosclerosis and 100 control subjects. The Ala54Thr polymorphism was analyzed by polymerase chain reaction-restriction fragment length polymorphism, whereas serum FABP2 levels were determined using ELISA. Fasting blood glucose, fasting serum insulin concentrations, HbA1c, lipid profile, body mass index (BMI) and systolic and diastolic blood pressure (SBP and DBP, respectively) were determined.

RESULTS

There was a higher frequency of the Thr54 allele among the patient group (P = 0.002). In Ala54/Thr54 heterozygotes and carriers of the rare Thr54/Thr54 genotype, there were significant increases in BMI and FABP2. Those with the Thr54/Thr54 genotype had significantly decreased high-density lipoprotein cholesterol (HDL-C) concentrations; in addition, those with the Thr54/Thr54 genotype had significantly higher SBP and DBP than subjects with the Ala54/Ala54 and Ala54/Thr54 genotypes. There was a positive correlation between FABP2 levels and BMI, SBP and DBP, and a negative correlation with HDL-C.

CONCLUSIONS

The Thr54 allele of the FABP2 Ala54Thr polymorphism was associated with an increased incidence of peripheral atherosclerosis combined with T2DM in the population studied.