The deubiquitinase USP11 regulates cell proliferation and ferroptotic cell death via stabilization of NRF2 USP11 deubiquitinates and stabilizes NRF2.

The transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF2) plays a key role in cancer progression and is tightly regulated by the proteasome pathway. E3 ligases that mediate NRF2 ubiquitination have been widely reported, but the mechanism of NRF2 deubiquitination remains largely unclear. Here, we identified ubiquitin-specific-processing protease 11 (USP11) in NRF2 complexes and confirmed an interaction between these two proteins. We further found that USP11 deubiquitinates NRF2; this modification stabilizes NRF2. Functionally, USP11 depletion contributes to the suppression of cell proliferation and induction of ferroptotic cell death due to ROS-mediated stress, which can be largely abrogated by overexpression of NRF2. Finally, immunohistochemical staining of USP11 and NRF2 was performed using a lung tissue microarray, which revealed that USP11 is highly expressed in patients with NSCLC and positively correlated with NRF2 expression. Together, USP11 stabilizes NRF2 and is thus an important player in cell proliferation and ferroptosis.

Genetic testing of 248 Chinese aortopathy patients using a panel assay.

Inherited aortopathy, which is characterized by a high risk of fatal aortic aneurysms/dissections, can occur secondarily to several syndromes. To identify genetic mutations and help make a precise diagnosis, we designed a gene panel containing 15 genes responsible for inherited aortopathy and tested 248 probands with aortic disease or Marfan syndrome. The results showed that 92 individuals (37.1%) tested positive for a (likely) pathogenic mutation, most of which were FBN1 mutations. We found that patients with a FBN1 truncating or splicing mutation were more prone to developing severe aortic disease or valvular disease. To date, this is the largest reported cohort of Chinese patients with aortic disease who have undergone genetic testing. Therefore, it can serve as a considerable dataset of next generation sequencing data analysis of Chinese population with inherited aortopathy. Additionally, according to the accumulated data, we optimized the analysis pipeline by adding quality control steps and lowering the false positive rate.

Regulation of cytochrome P450 3A4 by small vault RNAb derived from the non-coding vault RNA1 of multidrug resistance-linked vault particle.

Cytochrome P450 3A4 (CYP3A4) is the most abundant cytochrome P450 enzyme in human liver and intestine, contributing to the metabolism of >60% of all pharmaceuticals. The expression levels of hepatic CYP3A4 show great inter­individual variation. However, the detailed regulatory mechanism of CYP3A4 expression has remained largely elusive. It has been reported that the non­coding RNA small vault (sv)RNAb targets the 3' untranslated region (3'UTR) of CYP3A4 in MCF7 cells. However, to date, the role of svRNAb has not been examined in human liver tissue and hepatic cell lines such as HepG2, which was the aim of the present study. Polymerase chain reaction analysis indicated that the expression of CYP3A4 was significantly different within a study cohort (n=19). In addition, a significant negative correlation was observed between svRNAb and CYP3A4 expression in human liver tissue samples. Furthermore, a luciferase assay on HepG2 cells verified that svRNAb directly targets CYP3A4 and regulates the expression of CYP3A4 by interacting with the validated binding sites of the CYP3A4 3'UTR. The results provided insight into the variation of the expression of CYP3A4 among individuals and provided a novel method for the adjustment of personalized drug treatment. Furthermore, the present study provided a mechanism of the regulatory role of svRNAb in multidrug­resistant cells.

Research on Susceptible Genes and Immunological Pathogenesis of Cutaneous Adverse Drug Reactions in Chinese Hans.

Cutaneous adverse drug reactions (cADRs) include mild maculopapular exanthems (MPE), Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), drug reaction with eosinophilia and systemic symptoms (DRESS) and acute generalized exanthematous pustulosis (AGEP). We used HLA high-resolution genotyping and genome wide association analysis (GWAS) to identify the genetic markers for cADRs induced by common culprit drugs in Han Chinese population. To further understand the immunopathogenesis of cADRs, and with the goal of developing treatment strategies, we compared the expression of cytoxic cytokines between the patients with cADRs and normal controls. Our data suggested that the carbamazepine induced SJS/TEN, allopurinol induced CADRs, methazolamide induced SJS/TEN and SASP induced DRESS were respectively strongly associated with HLA-B*15:02, HLA-B*58:01, HLA-B*59:01 and HLA-B*13:01. In addition, increased expression of cytotoxic cytokines in sera and tissues of cADRs patients were found, compared with healthy controls. Our findings may shed light on prediction and prevention of cADRs, provide clues to pathogenesis, and guide treatment strategies of these reactions.

The effect of microRNAs in the regulation of human CYP3A4: a systematic study using a mathematical model.

CYP3A4 metabolizes more than 50% of the drugs on the market. The large inter-individual differences of CYP3A4 expression may contribute to the variability of human drug responses. Post-transcriptional regulation of CYP3A4 is poorly understood, whereas transcriptional regulation has been studied much more thoroughly. In this study, we used multiple software programs to predict miRNAs that might bind to CYP3A4 and identified 112 potentially functional miRNAs. Then a luciferase reporter system was used to assess the effect of the overexpression of each potentially functional miRNA in HEK 293T cells. Fourteen miRNAs that significantly decreased reporter activity were measured in human liver samples (N = 27) as candidate miRNAs. To establish a more effective way to analyze in vivo data for miRNA candidates, the relationship between functional miRNA and target mRNA was modeled mathematically. Taking advantage of this model, we found that hsa-miR-577, hsa-miR-1, hsa-miR-532-3p and hsa-miR-627 could significantly downregulate the translation efficiency of CYP3A4 mRNA in liver. This study used in silico, in vitro and in vivo methods to progressively screen functional miRNAs for CYP3A4 and to enhance our understanding of molecular events underlying the large inter-individual differences of CYP3A4 expression in human populations.