Short-term type-1 diabetes differentially modulates 14-3-3 proteins in rat brain and liver.
BACKGROUND
The 14-3-3 proteins family consists of seven proteins that are highly conserved molecular chaperones with roles in the regulation of metabolism, signal transduction, cell cycle control, protein trafficking and apoptosis. Their role in several pathologies has been reported. In this study, we investigated the mRNA and protein expression of the 14-3-3s in rat brain and liver in the early stage of Type-1 diabetes (T1D).


METHODS
Diabetes was induced by a single intraperitoneal injection (70 mg/kg bw) of freshly prepared streptozotocin (STZ), and, after 3 weeks of treatment, brain and liver nuclei and cytosolic extracts were prepared. Quantitative real-time PCR and Western blotting analyses were performed to evaluate mRNA and protein expression for each of the seven 14-3-3s.


RESULTS
In nondiabetic control rats, the expression profile of 14-3-3s revealed a tissue-specific distribution, and the expression level of each isoform was found higher in the brain than in the liver. In the diabetic brain, mRNA and protein levels of the 14-3-3β, ε, ζ, η and θ were lower; 14-3-3σ mRNA significantly increased while its protein level decreased. In the diabetic liver, the mRNA of 14-3-3γ, 14-3-3θ and 14-3-3σ significantly increased, but only the 14-3-3γ protein level increased. Overall, in diabetic animals, the changes in the expression levels of brain 14-3-3s were much more pronounced than in the liver.


CONCLUSIONS
Our results indicate that during the early phase of STZ-induced T1D, the 14-3-3 proteins are affected in an isoform- and tissue-specific way.
Department of Basical Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Bari, Italy.
Federica
F
Taurino
Eleonora
E
Stanca
Luisa
L
Vonghia
Luisa
L
Siculella
Anna Maria
AM
Sardanelli
Sergio
S
Papa
Franco
F
Zanotti
Antonio
A
Gnoni
D048948:14-3-3 Proteins / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar
D048948:14-3-3 Proteins; D012333:RNA, Messenger
14-3-3 proteins; brain; diabetes; liver; streptozotocin; type-1 diabetes