Role of interleukin-15 receptor alpha polymorphisms in normal weight obese syndrome.
Previous published studies have identified a class of women, Normal Weight Obese women (NWO) with normal BMI and high fat content. An important role of Interleukin-15 (IL-15) has been documented in facilitating muscle proliferation and promoting fat depletion. Indeed the presence of three types of IL-15 receptor subunits in fat tissue suggests a direct effect on adipose tissue. We studied three single nucleotide polymorphisms (SNP) of IL-15R-alpha receptor gene and investigated their relationship with NWO phenotype. We considered two classes of women according to their BMI and percent fat mass (percent FAT), class 1: including 72 overweight-obese women (high BMI-high fat mass) and class 2: including 36 NWO (normal BMI, high fat mass). Three sites of Interleukin-15 receptor subunit á gene were examined, located respectively in exon4, exon5 intron-exon border and exon7. Genotyping of the identified polymorphisms was performed by restriction fragment length polymorphism. Haplotype frequency estimation was performed by using the Mendel-University of Chicago program. Odds ratio analyses were calculated by EPISTAT program. Highly significant differences were observed for exon 7- exon5 intron-exon border and exon 4-exon 7 haplotype distribution between class 1 and class 2 women. These results strongly support the hypothesis that genetic variability of the IL-15 receptor has an important role in body fat composition. Our data underscore previous findings that suggest a potential role of IL-15 cytokine in NWO syndrome.
Di Renzo
L
L
Department of Neuroscience, Division of Human Nutrition, University of Tor Vergata, Rome, Italy.
Gloria-Bottini
F
F
Saccucci
P
P
Bigioni
M
M
Abenavoli
L
L
Gasbarrini
G
G
De Lorenzo
A
A
D000328:Adult; D015992:Body Mass Index; D001835:Body Weight / Q000502:physiology*; D005091:Exons; D005260:Female; D006239:Haplotypes; D006801:Humans; D019409:Interleukin-15 / Q000235:genetics; D053720:Interleukin-15 Receptor alpha Subunit / Q000235:genetics*; D008875:Middle Aged; D009765:Obesity / Q000235:genetics*; D020641:Polymorphism, Single Nucleotide; D013577:Syndrome
D019409:Interleukin-15; D053720:Interleukin-15 Receptor alpha Subunit