Multi-functional regulation of cGAS by the nuclear localization signal2 (NLS2) motif: Nuclear localization, enzyme activity and protein degradation.

Cyclic GMP-AMP synthase (cGAS), which recognizes double-stranded DNA (dsDNA) and activates the innate immune system, is mainly localized in the cytosol, but also shows nuclear localization. Here, we sought to determine the role of nuclear cGAS by mutating known nuclear localization signal (NLS) motifs in cGAS and assessing its functionality by monitoring phosphorylation of the downstream target, interferon regulatory factor-3 (IRF3). Interestingly, NLS2-mutated cGAS failed to promote phosphorylation of IRF3, reflecting the loss of its ability to produce cyclic GMP-AMP (cGAMP). We further found that insertion of an NLS from SV40 large T antigen could not restore this loss of activity, indicating that this loss was attributable to the mutation of NLS2 itself, but not dependent on the inability of cGAS to enter the nucleus. NLS2-mutant cGAS protein also showed decreased stability dependent on polyubiquitination, an effect that was independent of both its loss of catalytic function and its inability to enter into the nucleus. Collectively, these findings indicate that the NLS2 motif of cGAS is not only involved in regulating the subcellular localization of cGAS protein but also influences its stability and enzymatic activity through independent mechanisms, highlighting the novel roles of NLS2 in regulating the intracellular functions of cGAS.

Comparison of mid- to long-term clinical outcomes between anatomical testing and usual care in patients with suspected coronary artery disease: A meta-analysis of randomized trials.

BACKGROUND: Controversies remain regarding clinical outcomes following initial strategies of coronary computed tomography angiography (CCTA) vs usual care with functional testing in patients with suspected coronary artery disease (CAD). HYPOTHESIS: CCTA as initial diagnostic strategy results in better mid- to long-term outcomes than usual care in patients with suspected CAD. METHODS: We searched PubMed, Embase, and Cochrane Library for randomized controlled trials comparing clinical outcomes during ≥6 months' follow-up between initial anatomical testing by CCTA vs usual care with functional testing in patients with suspected CAD. Occurrence of all-cause mortality, nonfatal myocardial infarction (MI), and major adverse cardiovascular events (MACE), and use of invasive coronary angiography and coronary revascularization, were compared between the 2 diagnostic strategies. RESULTS: Twelve trials were included (20 014 patients; mean follow-up, 20.5 months). Patients undergoing CCTA as initial noninvasive testing had lower risk of nonfatal MI compared with those treated with usual care (risk ratio [RR]: 0.70, 95% confidence interval [CI]: 0.52-0.94, P = 0.02). There was a tendency for reduced MACE following initial CCTA strategy, but not for risk of all-cause mortality. Compared with functional testing, the CCTA strategy increased use of invasive coronary angiography (RR: 1.53, 95% CI: 1.12-2.09, P = 0.007) and coronary revascularization (RR: 1.49, 95% CI: 1.11-2.00, P = 0.007). CONCLUSIONS: Anatomical testing with CCTA as the initial noninvasive diagnostic modality in patients with suspected CAD resulted in lower risk of nonfatal MI than usual care with functional testing, at the expense of more frequent use of invasive procedures.

Cell chip with a thiolated chitosan self-assembled monolayer to detect the effects of anticancer drugs on breast normal and cancer cells.

Cell-based chips are an effective in vitro analysis tool; however, the sensitivity of the cell chip to biomaterials is high, which is crucial for immobilizing cells on the electrode surface without conductivity. In this study, we report on a cell chip with a thiolated chitosan monolayer that was easy to fabricate, highly adhesive to cells, and enhanced electrochemical signals. Thiolated chitosan containing thiol groups was synthesized and self-assembled on a gold electrode to immobilize cells, and showed superior electrochemical performance to that of poly-l-lysine and collagen. Cyclic voltammetry (CV) was performed to distinguish the redox characteristics of normal (HMEC) and breast cancer cells (MCF-7); then, two anticancer drugs (doxorubicin and cyclophosphamide) were added to the cell cultures to analyze their effects on the redox environment of normal and cancer cells derived from the same origin. As a result, the CV cathode peaks decreased differently with respect to the cell line (normal and cancer) and anticancer drug, which was validated by a conventional MTT viability assay. Hence, the proposed cell chip with a thiolated chitosan modified layer could be used in various fields, including discriminating normal from cancer cells, to evaluating the efficiency of newly developed drugs, and to assessing cytotoxicity of various chemicals.

Nanoscale film fabrication of various peptides on neural stem cell chip.

Modification of peptide on the electrode surface is very important issue for achieving valuable information from cell chip. In this study, various kinds of cysteine-containing peptide were fabricated on the electrode surface to enhance the electrochemical signals, cell spreading, and proliferation of rat neural stem cells. Different kinds of lysine-rich and RGD peptides were self-assembled on the gold nanoparticle modified ITO surfaces via strong Au-S chemical bond, followed by seeding neural stem cells (NE-4C) on its surface. As a result, K-MAP-C peptide consists of the quadruple branches of lysine chains and cysteine terminal showed outstanding characteristics respect to the improvement of redox signals, cell spreading and proliferation on electrode surface. Hence, our stem cell chip composed of lysine-rich peptide modified electrode can be usefully applied as efficient stem cell research tool.

Race and correlations between lymph node number and survival for patients with gastric cancer.

BACKGROUND: There is ongoing debate whether extended lymphadenectomy improves survival in gastric cancer patients who undergo surgical resection. We previously observed that Korean-American patients had the highest overall survival in Los Angeles County. Our objective was to assess lymph node (LN) number and its impact on survival for Korean-American gastric cancer patients. METHODS: We utilized the National Cancer Institute's Surveillance, Epidemiology, and End Results registry to identify Korean-Americans with gastric adenocarcinoma treated with curative-intent gastrectomy between 1988 and 2008. We grouped patients according to examined LN number (1-15 and 16+) and compared characteristics. We performed similar analysis for white patients. RESULTS: Out of 982 Korean-American patients with gastric adenocarcinoma, most patients had 1-15 examined LNs (60 %). When we compared LN groups, we observed higher overall survival in the 1-15 group than the 16+ group (5-year survival, 59 % vs 52 %, respectively; p = 0.04). However, LN number was not prognostic of overall survival on stepwise Cox proportional hazards analysis. In contrast, LN number was prognostic for white patients. CONCLUSIONS: Although examined LN number may impact survival for white patients, outcomes of Korean-American gastric cancer patients were independent of LN number. Our data suggest that survival of Korean-American gastric cancer patients are comparable with outcomes from East Asian hospitals and may be independent of surgical technique.