HPVE6-USP46 Mediated Cdt2 Stabilization Reduces Set8 Mediated H4K20-Methylation to Induce Gene Expression Changes.

E6 from high-risk strains of HPV is well known to transform cells by deregulating p53. We reported that in HPV transformed cell-lines E6 from high-risk HPV can recruit the USP46 deubiquitinase to substrates such as Cdt2 and stabilize the latter, and that USP46 is important for growth of HPV induced tumors in xenografts. Here we show that in cervical cancer biopsies the stabilization of Cdt2 in the HPV-induced cancers leads to the decrease of a CRL4-Cdt2 substrate, the histone H4K20 mono-methyltransferase Set8, and decrease in H4K20me1 or H4K20me3 that can be detected by immunohistochemistry. In HPV-transformed cancer cell lines in vitro, knockdown of E6 decreases Cdt2 and increases Set8. Co-knockdown of Set8 shows that some of the gene expression changes produced by E6 knockdown is due to the increase of Set8. EGFR and EGFR regulated genes were identified in this set of genes. Turning to the mechanism by which E6 stabilizes Cdt2, we find that a purified E6:USP46 complex has significantly more de-ubiquitinase activity in vitro than USP46 alone, demonstrating that E6 can directly interact with USP46 in the absence of other proteins and that it can substitute for the known activators of USP46, UAF1 and WDR20. Deletion mapping of Cdt2 shows that there are three discrete, but redundant, parts of the substrate that are essential for stabilization by E6: USP46. The helix-loop-helix region or the WD40 repeat driven beta-propeller structure of Cdt2 are dispensable for the stabilization implying that interaction with DDB1 (and the rest of the CRL4 complex) or with the substrate of the CRL4-Cdt2 E3 ligase is not necessary for E6:USP46 to interact with and stabilize Cdt2. The identification of 50 amino acid stretches in the 731 amino acid Cdt2 protein as being important for the stabilization by E6 underlines the specificity of the process. In summary, E6 activates the deubiquitinase activity of USP46, stabilizes Cdt2 utilizing multiple sites on Cdt2, and leads to degradation of Set8 and changes in gene-expression in HPV-transformed cells.

Corrigendum to "Iatrogenic Superior Vena Cava Syndrome after Cardiopulmonary Bypass Diagnosed by Intraoperative Echocardiography".

[This corrects the article DOI: 10.1155/2020/8813065.].

Iatrogenic Superior Vena Cava Syndrome after Cardiopulmonary Bypass Diagnosed by Intraoperative Echocardiography.

A 73-year-old female patient presented for mitral valve replacement and coronary artery bypass grafting secondary to multivessel coronary disease and severe mitral valve regurgitation with moderate stenosis. After bypass, the patient developed refractory hypotension with decreased biventricular volume and elevated central venous pressure (CVP). Transesophageal echocardiography (TEE) was utilized to make the diagnosis of acute intraoperative superior vena cava (SVC) syndrome. The SVC cannulation site was revised, resulting in resolution of the hypotension and a decrease in the CVP. Intraoperative TEE was vital in recognizing, managing, and ultimately repairing the acute intraoperative SVC stenosis.

Harmonizing disease prevention and police practice in the implementation of HIV prevention programs: Up-stream strategies from Wilmington, Delaware.

INTRODUCTION: Improving access to sterile injection equipment is a key component in community-based infectious disease prevention. Implementation of syringe access programs has sometimes been complicated by community opposition and police interference. CASE DESCRIPTION: In 2006, the Delaware legislature authorized a pilot syringe exchange program (SEP). A program designed to prevent, monitor, and respond to possible policing and community barriers before they had a chance to effect program implementation and operation. A program designed to prevent, monitor, and respond to these barriers was planned and implemented by a multidisciplinary team of legal practitioners and public health professionals. DISCUSSION: We report on an integrated intervention to address structural barriers to syringe exchange program utilization. This intervention employs community, police and client education combined with systematic surveillance of and rapid response to police interference to preempt the kinds of structural barriers to implementation observed elsewhere. The intervention addresses community concerns and stresses the benefits of syringe exchange programs to officer occupational safety. CONCLUSIONS: A cohesive effort combining collaboration with and educational outreach to police and community members based on the needs and concerns of these groups as well as SEP clients and potential clients helped establish a supportive street environment for the SEP. Police-driven structural barriers to implementation of public health programs targeting populations engaged in drug use and other illicit behavior can be addressed by up-stream planning, prevention, monitoring and intervention strategies. More research is needed to inform the tailoring of interventions to address police-driven barriers to HIV prevention services, especially among marginalized populations.