| First Author | Asai S | Year | 2004 |
| Journal | J Immunol | Volume | 173 |
| Issue | 7 | Pages | 4669-74 |
| PubMed ID | 15383602 | Mgi Jnum | J:93733 |
| Mgi Id | MGI:3505629 | Doi | 10.4049/jimmunol.173.7.4669 |
| Citation | Asai S, et al. (2004) Absence of procarboxypeptidase R induces complement-mediated lethal inflammation in lipopolysaccharide-primed mice. J Immunol 173(7):4669-74 |
| abstractText | Carboxypeptidase R (CPR) is a heat-labile enzyme found in serum in addition to stable carboxypeptidase N. CPR cleaves the C-terminal basic amino acids, arginine and lysine, from inflammatory peptides such as complement C3a and C5a, bradykinin, and enkephalin. This enzyme is generated from procarboxypeptidase R (proCPR), also known as thrombin-activatable fibrinolysis inhibitor, following cleavage by proteolytic enzymes such as thrombin, plasmin, and trypsin. We generated proCPR-deficient mice by knocking out exons 4 and 5 of the proCPR gene, which are regarded as essential for CPR function. At LPS challenge, there was virtually no difference in lethality among proCPR(+/+), proCPR(+/-), and proCPR(-/-) mice. However, challenge with cobra venom factor, which can activate and deplete almost all complement in vivo, induced a lethal effect on proCPR(-/-) mice following LPS sensitization which up-regulates C5a receptor expression. In contrast, proCPR(+/+) and proCPR(+/-) mice were able to tolerate the cobra venom factor challenge with the limited dose (30 U). Although carboxypeptidase N plays a role in inactivation of inflammatory peptides in vivo, CPR may also be important in the regulation of hyperinflammation. |
