Participation of RANTES and T-Cell Apoptosis in Human Renal Allograft

5-Pyrrolidinylsulfonyl Isatins as a Potential Tool for the Molecular Imaging of Caspases in Apoptosis

Caspases are the unique enzymes responsible for the execution of the cell death program and may represent an exclusive target for the specific molecular imaging of apoptosis in vivo. 5-Pyrrolidinylsulfonyl isatins represent potent nonpeptidyl caspase inhibitors that may be suitable for the development of caspase binding radioligands (CBRs). (S)-5-[1-(2-Methoxymethylpyrrolidinyl)sulfonyl]isatin (7) served as a lead compound for modification of its N-1-position. Corresponding pairs of N-1-substituted 2-methoxymethyl- and 2-phenoxymethylpyrrolidinyl derivatives were examined in vitro by biochemical caspase inhibition assays. All target compounds possess high in vitro caspase inhibition potencies in the nanomolar to subnanomolar range for caspase-3 (Ki=0.2-56.1 nM). As shown for compound (S)-1-(4-(2-fluoroethoxy)benzyl)-5-[1-(2-methoxymethylpyrrolidinyl)sulfonyl]isatin (35), the class of N-1-substituted 5-pyrrolidinylsulfonyl isatins competitively inhibits caspase-3. All caspase inhibitors show selectivity for the effector caspases-3 and -7 in vitro. The 2-methoxymethylpyrrolidinyl versions of the isatins appear to possess superior caspase inhibition potencies in cellular apoptosis inhibition assays compared with the 2-phenoxymethylpyrrolidinyl inhibitors.

Lack of association between the -403G/A promoter polymorphism in the human CCL5/RANTES chemokine gene in liver transplant outcome

Chemokines play a major role in the inflammatory and immune responses that mediate allograft outcome. CCL5/RANTES expansion chemokine is potent eosinophil, monocyte, basophils and lymphocyte chemoattractant and has recently been studied in transplantation with discrepant results, but systemic concentrations have been correlated to liver graft survival and incidence of rejection. Recent studies revealed that a functional mutation at -403 in the promoter may have a significance for inflammatory and infectious immune responses. Our objective was to investigate CCL5/RANTES promoter polymorphism in rejection and graft survival in liver transplant. We examined the CCL5/RANTES polymorphism in a series of 218 liver transplants and 101 healthy Caucasian subjects. CCL5/RANTES genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). After comparing recipients (with acute rejection episodes versus without rejection) with the control population, we found no significant deviation in the distribution of the alleles or genotypes of CCL5/RANTES dimorphism in any comparison (P > 0.05). Indeed, 5 years allograft survival was 61.3% in recipients with the GG genotype against 58.8% in recipients with the GA and AA genotypes. These differences were also not statistically significant. In conclusion, human CCL5/RANTES gene promoter polymorphism does not seem to influence acute rejection development and allograft survival in liver recipients.