INVESTIGADORES
HONORE Stella Maris
congresos y reuniones científicas
Título:
Signaling pathways in diabetic gut
Autor/es:
HONORÉ S. M.; GENTA S. B.; SANCHEZ S. S.
Lugar:
Guaruja, Sao Paulo
Reunión:
Congreso; 2nd LASDB (Latin American of Developmental Biology) meeting; 2005
Institución organizadora:
Latin American of Developmental Biology (LASDB)
Resumen:
Gastrointestinal
disorders are common complications in diabetic state. At the present
the causes of the abnormal functions of the diabetic gut have not yet
been completely understood. Inmunohistochemical, inmunoblotting, and
electron microscopy techniques demonstrated alterations in the
expression of extracellular matrix (ECM) and basement membrane
molecules in muscular layer of induced-streptozotocin diabetic mice.
The presence of fibronectin, vitronectin, collagen type III, IV and
laminin 1 were higher than normal animals. In addition the expression
of TGFb mRNA was signifigatly increased in the diabetic animals compared to controls This result suggest that TGFb play a role in the abnormal secretion of ECM components during hyperglycemic state.
Moreover
an increment in apoptosis level in the gut and a decrease in the
myenteric ganglia density were observed under our experimental
conditions. This results are in correlation with a significant decrease
in the expression of Vasoactive intestinal polypeptide (VIP) mRNA, an
inhibitory transmitter which mediate in the relaxation of the
gastrointestinal muscle layer. A low tissue level of VIP in the jejunum
of diabetic mice may contribute in part to the abnormal gut motility
observed in diabetes. Considering
that Bone morphogenetic proteins (BMPs) play important role in gut
morphogenesis and regulate the specification and diferentiation of the
developing Enteric Nervous System, the possible involvement of BMPs
signaling in the observed changes was analyzed. Semicuantitative
reverse transcription- polymerase chain reaction (RT-PCR) and in situ
hybridization was performed for BMP2, BMP4, BMP type II, I receptors
and Smad1. Changes were observed in levels of BMPs and in the type II
receptor. This preliminary results raise the possibility that diabetic
intestine could be under the influence of BMP during the pathogenesis