The NLRP3 inflammasome has a major role in regulating innate immunity. Deregulated inflammasome activity is associated with several inflammatory diseases, yet little is known about the signaling pathways that lead to its activation. Here we show that NLRP3 interacted with thioredoxin (TRX)-interacting protein (TXNIP), a protein linked to insulin resistance. Inflammasome activators such as uric acid crystals induced the dissociation of TXNIP from thioredoxin in a reactive oxygen species (ROS)-sensitive manner and allowed it to bind NLRP3. TXNIP deficiency impaired activation of the NLRP3 inflammasome and subsequent secretion of interleukin 1beta (IL-1beta). Akin to Txnip(-/-) mice, Nlrp3(-/-) mice showed improved glucose tolerance and insulin sensitivity. The participation of TXNIP in the NLRP3 inflammasome activation may provide a mechanistic link to the observed involvement of IL-1beta in the pathogenesis of type 2 diabetes.

Vitamin D 3 upregulated protein 1 (VDUP1) is a 1,25-dihydroxyvitamin D 3 (1,25(OH) 2 D 3 ) upregulated protein, and it is induced by various stresses. In human tumor tissues, VDUP1 expression was downregulated. Upon stimulation by growth-inhibitory signals such as TGF-b1 and 1,25(OH) 2 D 3 , its expression was rapidly upregulated as the cell growth was retarded. The transfection of VDUP1 in tumor cells reduced cell growth. The VDUP1 expression was also increased when the cell-cycle progression was arrested. Transfection of VDUP1 induced cellcycle arrest at the G0/G1 phase, indicating that VDUP1 possesses a tumor-suppressive activity. In addition, it was found that VDUP1 interacted with promyelocytic leukemia zinc-finger, Fanconi anemia zinc-finger, and histone deacetylase 1, which are known to be transcriptional corepressors. VDUP1 itself suppressed IL-3 receptor and cyclin A2 promoter activity. Taken together, these results suggest that VDUP1 is a novel antitumor gene which forms a transcriptional repressor complex.

Post transplant infusion of donor-type natural killer (NK) cells has been shown to have an anti-leukemia-enhancing effect without evoking GVHD in murine hematopoietic cell transplantation (HCT) models. Here, we tested 14 patients (age, 23-65 years), 12 with acute leukemia and 2 with myelodysplastic syndrome, who underwent HLAmismatched HCT and subsequently received donor NK cell infusions. Cell donors (age, 16-51 years), comprising seven siblings, five offspring, and two mothers of the patients, underwent growth factor-mobilized leukapheresis for 3-5 days. Cells collected on the first 2-4 days were used for HCT, whereas those collected on the last day were CD34 selected by magnetic-activated cell sorting (median, 2.22 Â 10 6 cells/kg; range, 0.29-5.66). Donor NK cells were generated from the CD34 þ cells by ex vivo cell culture over a 6-week period (median, 9.28 Â 10 6 cells/ kg; range, 0.33-24.50; CD122/CD56 þ 64%; CD3 þ 1.0%; and viability 88%). There were no signs of acute toxicity in patients infused with these cells 6-7 weeks post transplant. Overall, one and five patients developed acute and chronic GVHD during post transplant period, respectively. These results showed that clinical-grade donor NK cell production from CD34 þ cells is feasible.

The redox-dependent inhibition of thioredoxin (TRX) by thioredoxin-interacting protein (TXNIP) plays a pivotal role in various cancers and metabolic syndromes. However, the molecular mechanism of this regulation is largely unknown. Here, we present the crystal structure of the TRX–TXNIP complex and demonstrate that the inhibition of TRX by TXNIP is mediated by an intermolecular disulphide interaction resulting from a novel disulphide bond-switching mechanism. Upon binding to TRX, TXNIP undergoes a structural rearrangement that involves switching of a head-to-tail interprotomer Cys63-Cys247 disulphide between TXNIP molecules to an interdomain Cys63-Cys190 disulphide, and the formation of a de novo intermolecular TXNIP Cys247-TRX Cys32 disulphide. This disulphide-switching event unexpectedly results in a domain arrangement of TXNIP that is entirely different from those of other arrestin family proteins. We further show that the intermolecular disulphide bond between TRX and TXNIP dissociates in the presence of high concentrations of reactive oxygen species. This study provides insight into TRX and TXNIP-dependent cellular regulation.

Vitamin D 3 up-regulated protein 1 (VDUP1) is a stressresponse gene that is up-regulated by 1,25(OH) 2 D 3 in many cells. It has been reported that VDUP1 expression is reduced in many tumor cells and the enforced expression of VDUP1 inhibits cell proliferation by arresting cell cycle progression. Here, we found that VDUP1 À/À fibroblast cells proliferated more rapidly compared with wild-type cells with reduced expression of p27 kip1 , a cyclin-dependent kinase inhibitor. JAB1 is known to interact with p27 kip1 and to decrease the stability of p27 kip1 . VDUP1 interacted with JAB1 and restored JAB1-induced suppression of p27 kip1 stability. In this process, VDUP1 blocked the JAB1-mediated translocation of p27 kip1 from the nucleus to the cytoplasm. In addition, VDUP1 inhibited JAB1-mediated activator protein-1 activation and cell proliferation. Taken together, these results indicate that VDUP1 is a novel factor of p27 kip1 stability via regulating JAB1. (Cancer Res 2005; 65(11): 4485-9)