Correlation between ROS production and InsP3 released by granulocytes from type 1 diabetic patients in a cAMP-dependent manner.
BACKGROUND
Diabetes is associated with a pro-inflammatory status characterized by an increased production of inflammatory molecules. Reactive oxygen species (ROS) and cAMP elevating agents represent two molecular systems, normally generated during inflammation. These molecules could be responsible for the alteration of signaling pathways. In the present paper we have studied the correlation between ROS generation and inositolpolyphosphates (InsP(1), InsP(2) InsP(3) and InsP(4)) released by granulocytes from Type 1 diabetic patients (DM1) in the presence or in the absence of cyclic AMP-elevating agents.


METHODS
The effect of cAMP on ROS production was quantified in a chemoluminescence assay luminol-dependent (RLU/min). InsP(1), InsP(2) InsP(3) and InsP(4) were quantified by inositol-H(3) in a Beta-counter and the results were expressed as count per minute (CPM).


RESULTS
The elevation of intracellular level of cAMP inhibited both InsP(3) and ROS production in granulocytes from healthy subjects and activated in the cells from Type 1 diabetic patients. InsP(1), InsP(2) and InsP(4) did not show significant alteration in both studied cells. There was a significant correlation between InsP(3) and ROS in the presence of elevated content of cAMP. This correlation was observed in a 15 minutes reaction for healthy subjects and in 120 minutes for DM1.


CONCLUSIONS
The importance of both InsP(3) release and ROS production in an inflammatory process and tissue pathophysiology in Type 1 diabetic patients is still under debate because hyperglycemia accelerates generation of oxidative stress and may play an important role in the development of complications in diabetes. Thus, our results demonstrated alteration in metabolic response in granulocytes from Type 1 diabetic patients and it may be important for the development of therapeutic processes and drugs that interfere with signaling of ROS generation and may contribute to the improvement of the severe complications of diabetes.
Chaves
Míriam Martins
MM
Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais - Caixa Postal 486, 30161-970, Belo Horizonte, Minas Gerais, Brazil. chavesmm@icb.ufmg.br
Costa
Daniela Caldeira
DC
Souza
Denniece Adriana da Costa
DA
Lima e Silva
Francisco das Chagas
Fd
Machado
José Augusto Nogueira
JA
D000328:Adult; D016022:Case-Control Studies; D000242:Cyclic AMP / Q000378:metabolism*; D003563:Cyclic CMP / Q000031:analogs & derivatives / Q000494:pharmacology; D003922:Diabetes Mellitus, Type 1 / Q000378:metabolism*; D006098:Granulocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism*; D007700:Kinetics; D008875:Middle Aged; D017382:Reactive Oxygen Species / Q000378:metabolism*
D017382:Reactive Oxygen Species; D003563:Cyclic CMP; C053441:dibutyryl cyclic-3',5'-cytidine monophosphate; D015544:Inositol 1,4,5-Trisphosphate; D000242:Cyclic AMP