Progress in the function of nucleoporin 50 and its relationship with viral infection / 中华微生物学和免疫学杂志

Nucleoporin 50 (Nup50) is a component of nuclear basket in nuclear pore complex. It includes three main domains: N domain binding to importin α, F domain binding to importin β and R domain binding to Ran. The N domain has two importin α-binding segments. There are mainly two models for explaining the role of Nup50 in nuclear import: tri-stable switch and disassemble-recycle model. Nup50 not only participates in nuclear import, but also regulates genome organization and gene expression. In addition, Nup50 is involved in the process of viral infection and replication. There is some evidence that Nup50 is related to hepatitis B virus and human immunodeficiency virus 1 infections. However, there are few researches on the relationship between Nup50 and viral infection. This article summarized the progress in the function of Nup50 and its relationship with viral infection, aiming to provide new ideas for the following in-depth study.

Detection of Autoantibodies Against Nucleoporin p62 in Sera of Patients With Primary Biliary Cholangitis

BACKGROUND: Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by specific autoantibodies. We evaluated the prevalence of autoantibodies against nucleoporin p62 (anti-p62) in PBC patients' sera to determine whether it can be a marker for PBC, in comparison with other immunological and biochemical parameters. We validated the performance of our in-house ELISA technique. METHODS: Serum samples were collected from 135 PBC patients. Thirty patients with primary sclerosing cholangitis (PSC) and 30 with autoimmune hepatitis (AIH) were included as pathological controls, and 40 healthy blood donors served as healthy controls. The presence of anti-p62 was determined by an in-house ELISA using a recombinant protein. We calculated the sensitivity, specificity, positive and negative predictive values (PPV and NPV), and positive and negative likelihood ratio (LR+ and LR−) of our in-house ELISA for diagnosing PBC based on anti-p62. Findings were correlated with biochemical data and survival. RESULTS: Anti-p62 was detected in 32 PBC patients (23.7%). Specificity and PPV of anti-p62 for PBC were 99% and 97%, respectively. The difference between proportions of anti-p62-positive patients and controls was 0.23 (95% confidence interval [CI]: 0.03–0.40; P < 0.0001); LR+ and LR− were 23.7 and 0.77, respectively. The presence of anti-p62 was associated with higher levels of bilirubin and alkaline phosphatase (P < 0.001). The odds ratio for survival was 2.44 (95% CI: 0.87–6.87; P=0.091). CONCLUSIONS: Anti-p62 may be regarded as a significant serological marker of PBC.

Impaired Nucleoporins Are Present in Sporadic Amyotrophic Lateral Sclerosis Motor Neurons that Exhibit Mislocalization of the 43-kDa TAR DNA-Binding Protein

BACKGROUND AND PURPOSE: Disruption of nucleoporins has been reported in the motor neurons of patients with sporadic amyotrophic lateral sclerosis (sALS). However, the precise changes in the morphology of nucleoporins associated with the pathology of the 43-kDa TAR DNA-binding protein (TDP-43) in the disease process remain unknown. We investigated the expression of nucleoporins that constitute the nuclear pore complex (NPC) in spinal motor neurons that exhibit sALS in relation to TDP-43 pathology, which is a reliable neuropathological hallmark of sALS. METHODS: Paraffin-embedded sections of the lumbar spinal cord were obtained for immunofluorescence analysis from seven control subjects and six sALS patients. Anti-TDP-43 antibody, anti-nucleoporin p62 (NUP62) antibody, and anti-karyopherin beta 1 (KPNB1) antibody were applied as primary antibodies, and then visualized using appropriate secondary antibodies. The sections were then examined under a fluorescence microscope. RESULTS: NUP62 and KPNB1 immunoreactivity appeared as a smooth round rim bordering the nuclear margin in normal spinal motor neurons that exhibited nuclear TDP-43 immunoreactivity. sALS spinal motor neurons with apparent TDP-43 mislocalization demonstrated irregular, disrupted nuclear staining for NUP62 or KPNB1. Some atrophic sALS spinal motor neurons with TDP-43 mislocalization presented no NUP62 immunoreactivity. CONCLUSIONS: Our findings suggest a close relationship between NPC alterations and TDP-43 pathology in the degenerative process of the motor neurons of sALS patients.