Poliovirus disrupts nucleocytoplasmic trafficking and results in the cleavage of two nuclear pore complex (NPC) proteins, Nup153 and Nup62. The NPC is a 125-MDa complex composed of multiple copies of 30 different proteins. Here we have extended the analysis of the NPC in infected cells by examining the status of Nup98, an interferon-induced NPC protein with a major role in mRNA export. Our results indicate that Nup98 is targeted for cleavage after infection but that this occurs much more rapidly than it does for Nup153 and Nup62. In addition, we find that cleavage of these NPC proteins displays differential sensitivity to the viral RNA synthesis inhibitor guanidine hydrochloride. Inhibition of nuclear import and relocalization of host nuclear proteins to the cytoplasm were only apparent at later times after infection when all three nucleoporins (Nups) were cleaved. Surprisingly, analysis of the distribution of mRNA in infected cells revealed that proteolysis of Nup98 did not result in an inhibition of mRNA export. Cleavage of Nup98 could be reconstituted by the addition of purified rhinovirus type 2 2Apro to whole-cell lysates prepared from uninfected cells, suggesting that the 2A protease has a role in this process in vivo. These results indicate that poliovirus differentially targets subsets of NPC proteins at early and late times postinfection. In addition, targeting of interferon-inducible NPC proteins, such as Nup98, may be an additional weapon in the arsenal of poliovirus and perhaps other picornaviruses to overcome host defense mechanisms.Poliovirus is a positive-strand RNA virus belonging to the family Picornaviridae. Poliovirus, like other members of this family, encodes a single large polyprotein that is co-and posttranslationally processed by virus-encoded proteases to produce the individual viral gene products (reviewed in reference 40). After the production of viral proteins, RNA synthesis ensues on virus-induced vesicles in the cell cytoplasm. Despite the fact that viral translation, RNA synthesis, and assembly occur in the cytoplasm, a number of host nuclear proteins have been attributed roles in the viral life cycle (3,6,27,32,33,51). Consistent with their having a role in the replication of poliovirus in the cytoplasm, several host nuclear factors have been shown to redistribute to the cytoplasm after infection (3,5,32,33,51).For nuclear factors to move from the nucleus to the cytoplasm they must transit the nuclear pore complex (NPC), a large protein channel found embedded in the nuclear envelope. The vertebrate NPC has a molecular mass of 125 MDa and is composed of multiple copies of roughly 30 different proteins that are collectively called nucleoporins (Nups; reviewed in reference 18). A number of findings have suggested that the redistribution of host nuclear factors to the cytoplasm in poliovirus-infected cells is due to alterations of the NPC and a disruption in nucleocytoplasmic trafficking. Previous work has shown that two NPC proteins, Nup153 and Nup62, are targeted for degradation in ...

Hydrogen sulfide (H2S) has emerged as an important physiological and pathophysiological signaling molecule in the cardiovascular system influencing vascular tone, cytoprotective responses, redox reactions, vascular adaptation, and mitochondrial respiration. However, bioavailable levels of H2S in its various biochemical metabolite forms during clinical cardiovascular disease remain poorly understood. We performed a case-controlled study to quantify and compare the bioavailability of various biochemical forms of H2S in patients with and without cardiovascular disease (CVD). In our study, we used the reverse-phase high performance liquid chromatography monobromobimane assay to analytically measure bioavailable pools of H2S. Single nucleotide polymorphisms (SNPs) were also identified using DNA Pyrosequencing. We found that plasma acid labile sulfide levels were significantly reduced in Caucasian females with CVD compared with those without the disease. Conversely, plasma bound sulfane sulfur levels were significantly reduced in Caucasian males with CVD compared with those without the disease. Surprisingly, gender differences of H2S bioavailability were not observed in African Americans, although H2S bioavailability was significantly lower overall in this ethnic group compared to Caucasians. We also performed SNP analysis of H2S synthesizing enzymes and found a significant increase in cystathionine gamma-lyase (CTH) 1364 G-T allele frequency in patients with CVD compared to controls. Lastly, plasma H2S bioavailability was found to be predictive for cardiovascular disease in Caucasian subjects as determined by receiver operator characteristic analysis. These findings reveal that plasma H2S bioavailability could be considered a biomarker for CVD in an ethnic and gender manner. Cystathionine gamma-lyase 1346 G-T SNP might also contribute to the risk of cardiovascular disease development.

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Anthracycline‐based chemotherapy is widely used in the management of breast cancer. Despite the lack of clinical evidence, obtaining prechemotherapy left ventricular ejection fraction (LVEF) by echocardiogram or multigated acquisition scan is a widely adopted practice throughout the world. We present here the results of a retrospective analysis of breast cancer patients who had LVEF measurements in anticipation of an anthracycline chemotherapy to determine whether predefined cardiac risk factors predicted for poor cardiac function. Retrospective data were analyzed from 482 female breast cancer patients in whom LVEF was measured before starting anthracycline‐based chemotherapy. Baseline demographics and multiple risk factors associated with congestive heart failure were collected. Twenty‐six possible risk factors for CHF were defined, and the frequency of finding an abnormal LVEF as a function of total risk factors was assessed. Statistical tests include chi‐squared and logistic regression analysis. The median age of the study population was 52 years. The original chemotherapy plan was changed in 7 patients (1.45%) based on LVEF findings, all of which had asymptomatic LV dysfunction (LVEF ranging 40%‐50%). In 32 patients, despite normal LVEF results, anthracyclines were omitted secondary to prior cardiac issues. In 17 patients where LVEF was reported normal, anthracyclines were skipped based on patient's preference, tumor characteristics, or upstaging of the cancer based on imaging studies. No patient with ≤2 risk factors had an abnormal LVEF (N = 350). The probability of finding an abnormal LVEF in patients without any cardiac risk factors is extremely rare. Skipping baseline LVEF assessment may be an option in some patients with no cardiac risk factors undergoing anthracycline‐based chemotherapy.

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