| Autor(es): |
Guimaraes, Paola Bianchi
[1]
;
da Silva, Rafael Filippelli
[1]
;
Hoff, Carolina Caldas
[2]
;
Fernandes, Liliam
[3]
;
Nakaie, Clovis Ryuichi
[1]
;
Chagas, Jair Ribeiro
[1]
;
Carmona, Adriana Karaoglanovic
[1]
;
Bader, Michael
[4]
;
Pesquero, Joao Bosco
[1]
Número total de Autores: 9
|
| Afiliação do(s) autor(es): | [1] Univ Fed Sao Paulo, Dept Biofis, Rua Pedro Toledo 669, 9 Andar Fundos, BR-04039032 Sao Paulo, SP - Brazil
[2] Univ Fed Sao Paulo, Dept Biociencias, Santos, SP - Brazil
[3] Univ Fed Sao Paulo, ICAQF, Diadema, SP - Brazil
[4] Max Delbruck Ctr Mol Med, Berlin - Germany
Número total de Afiliações: 4
|
Introduction Carboxypeptidase M (CPM) is a glycosylphosphatidylinositol anchored enzyme that plays an important role in the kallikrein-kinin system (KKS). CPM catalytic domain hydrolyzes Arg from C-terminal peptides (i.e., bradykinin and kallidin), generating des-Arg-kinins, the agonists of B-1 receptor (B1R). It is known that CPM and kinin B1R are co-localized in the plasma membrane microdomains, where they interact with each other, facilitating receptor signaling. Aims We hypothesized here that this CPM-B1R interaction could also affect the activity of the enzyme. Methods Thus, in this work, we evaluated the impact of B1R presence or absence on CPM activity and expression, using primary culture of microvascular endothelial cells from wild-type, kinin B1R knockout mice (B1-/-), and transgenic rats overexpressing B-1 receptor exclusively in the endothelium. In addition, HEK293T cells, as wells as B1-/- primary culture of endothelial cells, both transfected with B1R, were also used. Results CPM expression and activity were downregulated in cells of knockout mice compared to control and this reduction was rescued after B1R transfection. Cells overexpressing B1R presented higher levels of CPM mRNA, protein, and activity. This profile was reverted by pre-incubation with the B1R antagonist, R715, in highly expressing receptor cells. Conclusions Our data show that kinin B1R positively modulates both CPM expression and activity, suggesting that CPM-B1R interaction in membrane microdomains might affect enzyme activity, beyond interfering in receptors signaling. This work highlights the interactions among different components of KKS and contributes to a better understanding of its patho-physiological role. (AU) |