Signal processing and generation of bioactive nitric oxide in a model prototissue

The design and construction of synthetic prototissues from integrated assemblies of artificial protocells is an important challenge for synthetic biology and bioengineering. Here we spatially segregate chemically communicating populations of enzyme-decorated phospholipid-enveloped polymer/DNA coacervate protocells in hydrogel modules to construct a tubular prototissue-like vessel capable of modulating the output of bioactive nitric oxide (NO). By decorating the protocells with glucose oxidase, horseradish peroxidase or catalase and arranging different modules concentrically, a glucose/hydroxyurea dual input leads to logic-gate signal processing under reaction-diffusion conditions, which results in a distinct NO output in the internal lumen of the model prototissue. The NO output is exploited to inhibit platelet activation and blood clot formation in samples of plasma and whole blood located in the internal channel of the device, thereby demonstrating proof-of-concept use of the prototissue-like vessel for anticoagulation applications. Our results highlight opportunities for the development of spatially organized synthetic prototissue modules from assemblages of artificial protocells and provide a step towards the organization of biochemical processes in integrated micro-compartmentalized media, micro-reactor technology and soft functional materials

Using force spectroscopy analysis to improve the properties of the hairpin probe

The sensitivity of hairpin-probe-based fluorescence resonance energy transfer (FRET) analysis was sequence-dependent in detecting single base mismatches with different positions and identities. In this paper, the relationship between the sequence-dependent effect and the discrimination sensitivity of a single base mismatch was systematically investigated by fluorescence analysis and force spectroscopy analysis. The same hairpin probe was used. The uneven fluorescence analysis sensitivity was obviously influenced by the guanine-cytosine (GC) contents as well as the location of the mismatched base. However, we found that force spectroscopy analysis distinguished itself, displaying a high and even sensitivity in detecting differently mismatched targets. This could therefore be an alternative and novel way to minimize the sequence-dependent effect of the hairpin probe. The advantage offered by force spectroscopy analysis could mainly be attributed to the percentage of rupture force reduction, which could be directly and dramatically influenced by the percentage of secondary structure disruption contributed by each mismatched base pair, regardless of its location and identity. This yes-or-no detection mechanism should both contribute to a comprehensive understanding of the sensitivity source of different mutation analyses and extend the application range of hairpin probes

NAT10 is upregulated in hepatocellular carcinoma and enhances mutant p53 activity

Abstract Background N-acetyltransferase 10 (NAT10) is a histone acetyltransferase which is involved in a wide range of cellular processes. Recent evidences indicate that NAT10 is involved in the development of human cancers. Previous study showed that NAT10 acetylates the tumor suppressor p53 and regulates p53 activation. As Tp53 gene is frequently mutated in hepatocellular carcinoma (HCC) and associates with the occurrence and development of HCC, the relationship between NAT10 and HCC was investigated in this study. Methods Immunohistochemistry (IHC) and western blot analysis were performed to evaluate the NAT10 expression in HCC. Immunoprecipitation experiments were performed to verify the interaction of NAT10 with mutant p53 and Mdm2. RNA interference and Western blot were applied to determine the effect of NAT10 on mutant p53. Cell growth curve was used to examine the effect of NAT10 on HCC cell proliferation. Results NAT10 was upregulated in HCC and increased NAT10 expression was correlated with poor overall survival of the patients. NAT10 protein levels were significantly correlated with p53 levels in human HCC tissues. Furthermore, NAT10 increased mutant p53 levels by counteracting Mdm2 action in HCC cells and promoted proliferation in cells carrying p53 mutation. Conclusion Increased NAT10 expression levels are associated with shortened patient survival and correlated with mutant p53 levels. NAT10 upregulates mutant p53 level and might enhance its tumorigenic activity. Hence, we propose that NAT10 is a potential prognostic and therapeutic candidate for p53-mutated HCC

Association of Lp-PLA2 Mass and Aysmptomatic Intracranial and Extracranial Arterial Stenosis in Hypertension Patients.

Intracranial arterial stenosis (ICAS) is a common cause of ischemic stroke in Asians, whereas whites tend to have more extracranial lesions. Lipoprotein-associated phospholipase A2 (Lp-PLA2) has been associated with ischemic stroke by a large amount of work. However, there are few studies focusing on the relationship of Lp-PLA2 and asymptomatic ICAS or extracranial arterial stenosis (ECAS). Wehereby sought to explore the relationship of Lp-PLA2 and ICAS, ECAS and concurrent stenosis in stroke-free hypertensive patients in Chinese population.All the subjects were evaluated for the presence and severity of ICAS and ECAS through computerized tomographic angiography (CTA) covered the whole brain down to the level of aortic arch. Lp-PLA2 mass was measured by enzyme linked immunoassay. The association of Lp-PLA2 and vascular stenosis was analyzed through multivariate logistic regression.Among 414 participants, 163 (39.4%) had no ICAS or ECAS, 63 (15.2%) had ECAS only, 111 (26.8%) had ICAS only and 77 (18.6%) had concurrent extraintracranial stenosis. Lp-PLA2 mass was significantly associated with isolated ICAS (OR: 2.3; 95% CI: 1.14-4.64), and concurrent stenosis (OR: 3.93; 95% CI: 1.62-9.51), but was not related to isolated ECAS (OR: 1.54; 95% CI: 0.68-3.48). Lp-PLA2 mass was also associated with moderate to severe ICAS no matter how was the ECAS. Moreover, patients with higher Lp-PLA2 mass showed more sever ICAS and had more intracranial arterial lesions.This study revealed the association of Lp-PLA2 mass with ICAS in stroke-free hypertensive patients in Chinese population. The further long-term cohort study was warranted to elucidate the concrete effect of Lp-PLA2 on the asymptomatic ICAS