SUMMARY Recent clinical and experimental evidence suggests that endoplasmic reticulum (ER) stress contributes to the life-and-death decisions of β cells during the progression of type 1 and type 2 diabetes. Although crosstalk between inflammation and ER stress has been suggested to play a significant role in β cell dysfunction and death, a key molecule connecting ER stress to inflammation has not been identified. Here we report that thioredoxin-interacting protein (TXNIP) is a critical signaling node that links ER stress and inflammation. TXNIP is induced by ER stress through the PERK and IRE1 pathways, induces IL-1β mRNA transcription, activates IL-1β production by the NLRP3 inflammasome, and mediates ER stress-mediated β cell death. Collectively, our results suggest that TXNIP is a potential therapeutic target for diabetes and ER stress-related human diseases such as Wolfram syndrome.

Wolfram syndrome is an autosomal-recessive disorder characterized by insulin-dependent diabetes mellitus, caused by nonautoimmune loss of β cells, and neurological dysfunctions. We have previously shown that mutations in the Wolfram syndrome 1 (WFS1) gene cause Wolfram syndrome and that WFS1 has a protective function against ER stress. However, it remained to be determined how WFS1 mitigates ER stress. Here we have shown in rodent and human cell lines that WFS1 negatively regulates a key transcription factor involved in ER stress signaling, activating transcription factor 6α (ATF6α), through the ubiquitin-proteasome pathway. WFS1 suppressed expression of ATF6α target genes and repressed ATF6α-mediated activation of the ER stress response element (ERSE) promoter. Moreover, WFS1 stabilized the E3 ubiquitin ligase HRD1, brought ATF6α to the proteasome, and enhanced its ubiquitination and proteasome-mediated degradation, leading to suppression of ER stress signaling. Consistent with these data, β cells from WFS1-deficient mice and lymphocytes from patients with Wolfram syndrome exhibited dysregulated ER stress signaling through upregulation of ATF6α and downregulation of HRD1. These results reveal a role for WFS1 in the negative regulation of ER stress signaling and in the pathogenesis of diseases involving chronic, unresolvable ER stress, such as pancreatic β cell death in diabetes.

The enhanced AER in ADH1B*2 carriers and the increased sAcH levels in ALDH2*1/*2 carriers among intoxicated alcoholics provide possible mechanisms explaining how each genetic polymorphism affects the risk of alcoholism and upper aerodigestive tract cancer.

Undifferentiated (anaplastic) carcinoma with rhabdoid features is a rare and aggressive subtype of pancreatic carcinoma. Here, we report the clinical, histological, and immunohistochemical phenotypes in six autopsy cases of anaplastic carcinoma with rhabdoid features. The patients ranged between 44 and 76 years of age (median, 61 years) and consisted of four males and two females. All patients except one case died within 3 months of diagnosis, as these tumors were found at an advanced stage and were chemoresistant. At autopsy, tumor masses measuring 4-22 cm in maximum diameter were mainly located in the pancreatic body and tail. Microscopically, all cases showed anaplastic carcinoma with rhabdoid features that were discohesive with round to polygonal eosinophilic cytoplasm with occasional inclusions, and that had vesicular nuclei, and prominent nucleoli. Immunohistochemistry showed that the rhabdoid cells, particularly the inclusions, were strongly positive for pan-cytokeratin (AE1/AE3) and vimentin. Meanwhile, downregulation or aberrant cytoplasmic localization with focal aggregation of E-cadherin, β-catenin, and EMA were frequently observed in the rhabdoid cells. Moreover, the intracytoplasmic inclusions were labeled with selective autophagy-related molecules including p62/SQSTM1, ubiquitin, and kelch-like ECH-associated protein 1 (KEAP1). In addition, nuclear factor erythroid 2-related factor 2 (NRF2) and overexpression of its target molecule multidrug resistance-associated protein 1 (MRP1) were commonly observed in the rhabdoid cells. Therefore, these results suggest that p62-mediated aggregation of ubiquitinated intermediate filaments and membranous proteins is an important phenomenon in the rhabdoid phenotype. Indeed, the ubiquitinated aggregates of p62 and KEAP1 would induce activation of NRF2 and upregulation of MRP1, leading to potential chemoresistance of anaplastic carcinoma with rhabdoid features.

Purpose: Cancer-testis antigens are promising targets for cancer immunotherapy. Identification of additional cancer-testis antigens with frequent expression in various cancers was attempted using representational differential analysis (RDA) and immunogenicity evaluation. Experimental Design: cDNAs preferentially expressed in testis were enriched using RDA by subtraction between testis and normal tissues. Thirty clones showing cancer-testis^like expression based on EST database analysis were evaluated by reverse transcription-PCR. A potential antigen, CRT2, was identified and its expression was analyzed with a newly generated anti-CRT2 antibody. The immunogenicity of CRT2 was examined based on reactivity with serum immunoglobulin G (IgG) from cancer patients, using Western blot and ELISA analysis, and on in vitro induction of tumor-reactive CTLs from HLA-A24 transgenic mice and human peripheral blood lymphocytes. Results: CRT2 was expressed in elongated spermatids of testis among normal tissues and in various cancer cell lines and tissues. The recombinant CRT2 protein was recognized by serum IgG from patients with various cancers inWestern blot and ELISA analyses. A CRT2-derived peptide was identified as an HLA-A24^restricted T-cell epitope that induced tumor-reactive CTLs. Conclusion: CRT2 was identified as a new cancer-testis antigen expressed in elongated spermatids of testis and in cancer tissues (particularly melanoma) that is recognized by serum IgG from cancer patients. An HLA-A24^restricted T-cell epitope capable of inducing tumor-reactive CTLs was identified, suggesting that CRT2 may be useful for cancer diagnosis and immunotherapy.