Human SENP6 blocking peptide

Purpose: Protein Sumoylation is one of the most important and prevalent posttranscriptional modification. Increasing evidence have shown that the SENPs (sentrin/SUMOspecific proteases) are critical for steady-state levels of SUMO modification of target proteins, and protein de-sumoylation modulates a great diversity of biological processes including transcription, development, differentiation, neuroprotection, as well as pathogenesis. In the vertebrate eye, we and others have previously shown that sumoylation participated in the differentiation of major ocular tissues including retina and lens. However, the biological significance of seven SENP enzymes: SENP1 to 3 and SENP5 to 8 have not be fully investigated in the ocular tissues. Methods: The 5 major ocular cell lines were cultured in Dulbecco's modified Eagle's medium (DMEM) containing fetal bovine serum (FBS) or rabbit serum (RBS) and 1% Penicillin-Streptomycin. The mRNA levels were analysed with qRT-PCR. The protein levels were determined with western blot analysis and quantitated with Image J. Results: At the mRNA level, all SENPs were highly expressed in retina, and much reduced expression patterns in cornea, lens epithelium and lens fiber. At the protein level, SENP1 to -3, and SENP6 were highly abundant in cornea, while SENP5, SENP7 and SENP8 were enriched in retina, and these SENPs were relatively less abundant in lens tissues. Conclusion: Our results for the first time established the differentiation expression patterns of the 7 de-sumoylation enzymes (SENPs), which provides a basis for further investigation of protein desumoylation functions in vertebrate eye.

Background. Numerous studies have emphasized the genetic and phenotypic profiles of tolerant transplant patients. Moreover, different groups have defined several biomarkers, trying to distinguish patients who are going to be tolerant from those who are going to reject. However, most of these biomarkers have not been validated by other groups or even established for clinical practice. Methods. We reanalyzed and stratified the predictive capacity of 20 previously described biomarkers for liver transplantation tolerance in a cohort of 17 liver transplant patients subjected to an independent, nonrandomized, prospective study of immunosuppression drug withdrawal. Results. Only 4 of the 20 studied biomarkers (expression of SENP6, FEM1C, miR31, and miR95) showed a strong predictive capacity in the present study. miR31 and FEM1C presented an area under the ROC curve of 96.7%, followed by SENP1 with 93.3%. Finally, miR95 had an area under the ROC curve value Conclusions. Even though this independent analysis seems to confirm the predictive strength of SENP6 and FEM1C in liver transplantation tolerance, there are also risks in establishing biomarkers for clinical phenotypes without an understanding of how they are biologically relevant. Future collaborations between groups should be promoted so that the most promising biomarkers can be validated and implemented in daily clinical practice.