Longitudinal genome-wide DNA methylation changes in response to kidney failure replacement therapy

Chronic kidney disease (CKD) is an emerging public health priority associated with high mortality rates and demanding treatment regimens, including life-style changes, medications or even dialysis or renal transplantation. Unavoidably, the uremic milieu disturbs homeostatic processes such as DNA methylation and other vital gene regulatory mechanisms. Here, we aimed to investigate how dialysis or kidney transplantation modifies the epigenome-wide methylation signature over 12 months of treatment. We used the Infinium HumanMethylation450 BeadChip on whole blood samples from CKD-patients undergoing either dialysis (n = 11) or kidney transplantation (n = 12) and 24 age- and sex-matched population-based controls. At baseline, comparison between patients and controls identified several significant (P_FDR < 0.01) CpG methylation differences in genes with functions relevant to inflammation, cellular ageing and vascular calcification. Following 12 months, the global DNA methylation pattern of patients approached that seen in the control group. Notably, 413 CpG sites remained differentially methylated at follow-up in both treatment groups compared to controls. Together, these data indicate that the uremic milieu drives genome-wide methylation changes that are partially reversed with kidney failure replacement therapy. Differentially methylated CpG sites unaffected by treatment may be of particular interest as they could highlight candidate genes for kidney disease per se.

Psoralen derivatives as inhibitors of NF-κB interaction: the critical role of the furan ring

Simplified analogues of previously reported NF-κB interaction inhibitors, lacking the furan moiety, were synthesized and evaluated by performing experiments based on electrophoretic mobility shift assay (EMSA). The synthetic modifications led to simpler coumarin derivatives with lower activity allowing to better understand the minimal structural requirement for the binding to NF-κB.

Gene expression of tumor necrosis factor receptor associated-factor (TRAF)-1 and TRAF-2 in inflammatory bowel disease

OBJECTIVE

This study aimed to investigate the expression of tumor necrosis factor receptor-associated factor (TRAF)-1 and TRAF-2 in patients with inflammatory bowel disease (IBD).

METHODS

Immunostaining, western blot and real-time polymerase chain reaction (PCR) were used to detect the expression of TRAF-1 and TRAF-2 in colonic mucosa of IBD patients and control. Furthermore, serum protein levels of TRAF-1 and TRAF-2 were measured by ELISA and the receiver operating characteristic (ROC) curve was used to determine their diagnostic value.

RESULTS

The expression of TRAF-1 and TRAF-2 was significantly higher in inflamed and non-inflamed tissues of IBD patients than those in control (P < 0.05). Moreover, inflamed tissues had higher TRAF-1 and TRAF-2 expression than non-inflamed tissues (P < 0.05). Both TRAF-1 and TRAF-2 were shown to have a fair to excellent value in the differentiation of control and IBD patients with the area under the ROC curve (AUROC) of 0.680-1.000 (P < 0.001).

CONCLUSION

The activation of TRAF-1 and TRAF-2 may be early events in the pathogenesis of IBD and their functions are not quite the same.

Parkin induces apoptotic cell death in TNF-α-treated cervical cancer cells

Many malignant tumors become resistant to tumor necrosis factor-alpha (TNF-α)-induced cell death during carcinogenesis. In the present study, we examined whether parkin acts as a tumor suppressor in HeLa cells, a human cervical cancer cell line resistant to TNF-α-induced cell death. TNF-α-treatment alone did not affect HeLa cell viability. However, expression of parkin restored TNF-α-induced apoptosis in HeLa cells. Increased cell death was due to the activation of the apoptotic pathway. Expression of parkin in TNF-α-treated HeLa cells stimulated cleavage of the pro-apoptotic proteins caspase-8, -9, -3, -7 and poly ADP ribose polymerase (PARP). In addition, parkin expression resulted in decreased expression of the caspase inhibitory protein, survivin. These results suggest that parkin acts as a tumor suppressor in human cervical cancer cells by modulating survivin expression and caspase activity. We propose that this pathway is a novel molecular mechanism by which parkin functions as a tumor suppressor.

CopA3 peptide from Copris tripartitus induces apoptosis in human leukemia cells via a caspase-independent pathway

Our previous study demonstrated that CopA3, a disulfide dimer of the coprisin peptide analogue (LLCIALRKK), has antibacterial activity. In this study, we assessed whether CopA3 caused cellular toxicity in various mammalian cell lines. CopA3 selectively caused a marked decrease in cell viability in Jurkat T, U937, and AML-2 cells (human leukemia cells), but was not cytotoxic to Caki or Hela cells. Fragmentation of DNA, a marker of apoptosis, was also confirmed in the leukemia cell lines, but not in the other cells. CopA3-induced apoptosis in leukemia cells was mediated by apoptosis inducing factor (AIF), indicating induction of a caspase-independent signaling pathway.