Estudio de los polimorfismos de los genes transforming growth factor-beta-1, enzima de conversión de la angiotensina, y Par1/Emk1 como marcadores moleculares para el diagnóstico precoz de la nefropatía crónica del transplante.
SUMMARY: "Polymorphisms of Transforming growth factor-beta1 (TGF-beta1), Angiotensing converting enzyme (ACE) and Par1/Emk1 as molecular markers in the diagnoses of chronic allograft nephropathy (CAN)." TGF-beta1 and renin-angiotensin system have been suggested as the common pathway leading to CAN, a yet poorly known disease characterized by fibrosis and inflammation. Other proteins related with inflammation such as Par1/Emk1, may have also a role. Polymorphisms in these genes have been associated with diseases characterized by fibrosis and inflammation. AIM: To associate polymorphisms of TGF-beta1, ACE and Par1/Emk1 genes with allograft lesions in protocol biopsies. METHODS: Protocol biopsies. TGF-beta1 genotype was analysed by PCR-RFLP. ACE genotype and expression pattern of Par1/Emk1 were analysed by PCR. Intragraft TGF-beta1 and ACE mRNA levels were measured by real-time PCR and TGF-beta1 plasma levels by ELISA. Results: CAN prevalence was 38,3% and CAN incidence 22,6%. TGF-beta1 allele T at codon 10 and a previous acute rejection episode were independent predictors of subclinical rejection (SCR). TGF-beta1 plasma levels were increased in patients with SCR (2.59±0.91, n=22 vs. 2.05±0.76 ng/mL, n=43; p=0.01) but not intragraft mRNA TGF-beta1 levels. However, there were no association among allele T and TGF-beta1 levels. Otherwise, ACE-DD genotype was more frequent in transplanted patients than in controls (43,3% vs 30,1%, p=0,026), but prevalence or incidence was not different regarding recipient ACE genotype. Furthermore, patients with the ACE-DD genotype and CAN had the poorest graft survival and higher ACE mRNA levels than non-DD and CAN. Finally, we detected alterations in the normal pattern of alternative splicing of the Par1/Emk1 transcript. Expression of Emk1C was associated with an increased interstitial infiltrate, higher interstitial scarring and higher mean arterial pressure. Conclusions: 1) Protocol biopsies reduce the number of patients required in clinical studies. 2) Allele T at codon 10 of the TGF-beta1 gene was associated with higher incidence of SCR 3) ACE-DD genotype was not associated with an increased prevalence or incidence of CAN but was associated with higher ACE mRNA levels and poorer graft survival in patients who already display CAN. 4) Par1/Emk1 could have a role in the development of CAN. 5) Polymorphisms seem to contribute in the individual variability of CAN. 6) Polymorphisms of TGF-beta1 and Par1/Emk1 may be useful as molecular markers in the diagnosis of CAN.
Advisor:Seron Micas, Daniel; Grinyó Boira, Josep Maria
School:Universitat de Barcelona
Source Type:Master's Thesis
Date of Publication:03/03/2006