The PEA15 gene is overexpressed and related to insulin resistance in healthy first-degree relatives of patients with type 2 diabetes.
OBJECTIVE
Overexpression of the gene encoding phosphoprotein enriched in astrocytes 15 (PEA15), also known as phosphoprotein enriched in diabetes (PED), causes insulin resistance and diabetes in transgenic mice and has been observed in type 2 diabetic individuals. The aim of this study was to investigate whether PEA15 overexpression occurs in individuals at high risk of diabetes and whether it is associated with specific type 2 diabetes subphenotypes.


METHODS
We analysed PEA15 expression in euglycaemic first-degree relatives (FDR) of type 2 diabetic subjects.


RESULTS
The expression of PEA15 in peripheral blood leucocytes (PBLs) paralleled that in fat and skeletal muscle tissues. In PBLs from the FDR, PEA15 expression was two-fold higher than in euglycaemic individuals with no family history of diabetes (control subjects), both at the protein and the mRNA level (p < 0.001). The expression of PEA15 was comparable in FDR and type 2 diabetic subjects and in each group close to one-third of the subjects expressed PEA15 levels more than 2 SD higher than the mean of control subjects. Subjects with IFG with at least one type 2 diabetes-affected FDR also overexpressed PEA15 (p < 0.05). In all the groups analysed, PEA15 expression was independent of sex and unrelated to age, BMI, waist circumference, systolic and diastolic BP, and fasting cholesterol, triacylglycerol and glucose levels. However, in euglycaemic FDR of type 2 diabetic subjects, PEA15 expression was inversely correlated with insulin sensitivity (r = -557, p = 0.01).


CONCLUSIONS
We conclude that PEA15 overexpression represents a common defect in FDR of patients with type 2 diabetes and is correlated with reduced insulin sensitivity in these individuals.
Valentino
R
R
Department of Cellular and Molecular Biology, University of Naples Federico II, Naples, Italy.
Lupoli
G A
GA
Raciti
G A
GA
Oriente
F
F
Farinaro
E
E
Della Valle
E
E
Salomone
M
M
Riccardi
G
G
Vaccaro
O
O
Donnarumma
G
G
Sesti
G
G
Hribal
M L
ML
Cardellini
M
M
Miele
C
C
Formisano
P
P
Beguinot
F
F
D000328:Adult; D051017:Apoptosis Regulatory Proteins; D001786:Blood Glucose / Q000378:metabolism; D017931:DNA Primers; D003924:Diabetes Mellitus, Type 2 / Q000235:genetics* / Q000503:physiopathology; D005190:Family; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D007333:Insulin Resistance / Q000235:genetics*; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics*; D008297:Male; D010750:Phosphoproteins / Q000235:genetics* / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction
D051017:Apoptosis Regulatory Proteins; D001786:Blood Glucose; D017931:DNA Primers; D047908:Intracellular Signaling Peptides and Proteins; C092039:PEA15 protein, human; D010750:Phosphoproteins; D012313:RNA