RAP80 phase separation at DNA double-strand break promotes BRCA1 recruitment.

RAP80 has been characterized as a component of the BRCA1-A complex and is responsible for the recruitment of BRCA1 to DNA double-strand breaks (DSBs). However, we and others found that the recruitment of RAP80 and BRCA1 were not absolutely temporally synchronized, indicating that other mechanisms, apart from physical interaction, might be implicated. Recently, liquid-liquid phase separation (LLPS) has been characterized as a novel mechanism for the organization of key signaling molecules to drive their particular cellular functions. Here, we characterized that RAP80 LLPS at DSB was required for RAP80-mediated BRCA1 recruitment. Both cellular and in vitro experiments showed that RAP80 phase separated at DSB, which was ascribed to a highly disordered region (IDR) at its N-terminal. Meanwhile, the Lys63-linked poly-ubiquitin chains that quickly formed after DSBs occur, strongly enhanced RAP80 phase separation and were responsible for the induction of RAP80 condensation at the DSB site. Most importantly, abolishing the condensation of RAP80 significantly suppressed the formation of BRCA1 foci, encovering a pivotal role of RAP80 condensates in BRCA1 recruitment and radiosensitivity. Together, our study disclosed a new mechanism underlying RAP80-mediated BRCA1 recruitment, which provided new insight into the role of phase separation in DSB repair.

Mechanistic insights into the improving effects of germination on physicochemical properties and antioxidant activity of protein isolate derived from black and white sesame.

Germination is a natural green technology to improve the nutritional and techno-functional quality of plant-based proteins. In this study, the mechanism of improving the functional and antioxidant properties of black and white sesame protein isolates (SPI) through germination process was investigated. Results showed that the surface hydrophobicity and sulfhydryl content increased significantly after germination, which were supported by multispectral analysis suggesting the exposed and unfolded conformational transition of germinated SPI. Moreover, the increased particle size was observed by microscopy analysis and reducing electrophoresis, which indicated that depolymerized protein molecules were rearranged to form protein aggregates during germination. The structural modification induced by germination contributed to the superior solubility (increased to 3.15-fold and 2.36-fold at pH 8 for black and white SPI, respectively), foaming capacity (increased to 3.99-fold and 1.69-fold, respectively), emulsifying ability (increased to 2.84-fold and 2.71-fold, respectively), and diverse chemical antioxidant activities (increased up to 5.60-fold) of SPI in both varieties. This was the first comprehensive study to investigate germination as a promising technology for obtaining high-quality SPI.

Association of PCSK9 with inflammation and platelet activation markers and recurrent cardiovascular risks in STEMI patients undergoing primary PCI with or without diabetes.

BACKGROUND: Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been shown to be predictive of cardiovascular outcomes in stable coronary artery disease with diabetes. We aimed to assess the relationship between PCSK9 and major adverse cardiovascular events (MACEs) in ST-segment elevation myocardial infarction (STEMI) patients with or without diabetes, as well as the relationships between PCSK9 and metabolism, inflammation and platelet activation markers. METHODS: A total of 1027 patients with STEMI undergoing primary percutaneous coronary intervention (PCI) and without prior lipid-lowering therapy were consecutively enrolled and the baseline plasma PCSK9 levels were determined by ELISA. Patients were divided into high and low PCSK9 groups according to PCSK9 median. All patients were followed up for the occurrence of MACEs. The associations of PCSK9 with metabolism, inflammation and platelet activation markers and MACEs were evaluated. RESULTS: PCSK9 levels were positively correlated with triglycerides, high-sensitivity C reactive protein, soluble CD40 ligand and soluble P-selectin levels, and the correlations were stronger in diabetic patients than in non-diabetic patients. In diabetic patients receiving ticagrelor, PCSK9 levels were positively correlated with maximal platelet aggregation measured by light transmittance aggregometry and maximum amplitude of adenosine diphosphate-induced platelet-fibrin clots measured by thrombelastography in the maintenance phase of treatment, whereas no correlations were found in non-diabetic patients. During a median follow-up of 2.0 years, 155 (15.1%) MACEs occurred. The Kaplan-Meier analysis displayed that the patients with high PCSK9 levels had lower event-free survival rate than those with low PCSK9 levels (P = 0.030). When participants were categorized into 4 subgroups according to PCSK9 levels and diabetes status, high PCSK9 levels plus diabetes subgroup had the lowest cumulative event-free survival rate (P = 0.043). Multivariable Cox regression analysis revealed that high PCSK9 levels were independently associated with MACEs in diabetic patients (hazard ratio 2.283, 95% confidence interval: 1.094-4.764, P = 0.028), but not in the whole cohort or non-diabetic patients. CONCLUSIONS: The study showed that high PCSK9 levels were independently associated with MACEs in STEMI patients with diabetes undergoing primary PCI, and the association may be due to stronger correlations of PCSK9 with inflammation and platelet activation markers in diabetic patients.

Effect of extrusion on physicochemical properties and antioxidant potential of protein isolate derived from Baijiu vinasse.

Extrusion cooking is a green technology to manufacture distiller's grain food. In this study, effects of extrusion on the physicochemical properties and antioxidant potential of Baijiu vinasse protein isolate were investigated. Results showed that extrusion could effectively reduce the particle size (reduced from 275.07 ± 3.60 to 120.30 ± 1.13 nm), zeta potential, and surface hydrophobicity but increase the free sulfhydryl group of Baijiu vinasse protein isolate. Moreover, the unfolding, porous and amorphous structure was observed after extrusion by spectral analysis and X-Ray diffraction, endowing good solubility (increased from 59.26 ± 5.64% to 102.26 ± 3.21% at pH 7), foaming, and emulsifying stability. The in vitro protein digest of Baijiu vinasse protein isolates from extruded samples (200 °C, 150 rpm) exhibited most potent antioxidant activities. This study is the first to exploit extrusion as a feasible technology to produce Baijiu vinasse protein-based food. The results will be of great potential in future industrial application of Baijiu vinasse as a sustainable source of food proteins.

Ticagrelor Versus Clopidogrel in Patients with Late or Very Late Stent Thrombosis.

PURPOSE: To compare the effect of ticagrelor with clopidogrel in reducing the risk of ischemic cardiovascular events in patients with late or very late stent thrombosis (LST/VLST) after primary percutaneous coronary intervention (PCI). METHODS: A total of 4538 patients with acute coronary syndrome were screened for angiographically determined LST/VLST. Two hundred and forty-one patients were included in the analysis and grouped according to ticagrelor (n = 81) or clopidogrel (n = 160) at discharge. The clinical outcome was major adverse cardiovascular events (MACE) defined as death, myocardial infarction (MI), ischemic stroke, and revascularization during the 1-yr follow-up period. RESULTS: After propensity score matching, 65 pairs were generated. The incidence of MACE was significantly lower in the ticagrelor group compared with the clopidogrel group (9.3% vs. 21.5%, log-rank p = 0.048). However, no difference was observed in event rates of death, MI, ischemic stroke, and revascularization between the ticagrelor group and the clopidogrel group. CONCLUSION: Following successful primary PCI, patients with LST/VLST who received ticagrelor had fewer ischemic cardiovascular events at 1-yr follow-up, compared with those who received clopidogrel.

Identification of Novel LncRNA Biomarkers and Construction of LncRNA-Related Networks in Han Chinese Patients with Ischemic Stroke.

BACKGROUND/AIMS: Long non-coding RNAs (lncRNAs) are potential biomarkers of tumors, cardiac disease, and cerebral disease because of their interaction with coding RNAs. This work focused on ischemic stroke (IS) and aimed to identify novel lncRNA biomarkers and construct lncRNA-related networks in IS. METHODS: Differentially expressed lncRNAs were identified using Arraystar Human LncRNA Microarray v4.0, and validated with qRT-PCR. A lncRNA-mRNA co-expression network and a lncRNA-miRNA-mRNA regulatory network were constructed. Functional and pathway analyses were then performed. RESULTS: In total, 560 up-regulated and 690 down-regulated differentially expressed lncRNAs were found (P < 0.05, false discovery rate < 0.05, absolute fold change ≥ 2). qRT-PCR results confirmed that lncRNA-ENST00000568297, lncRNA-ENST00000568243, and lncRNA-NR_046084 exhibited significant differential expression between IS and controls (all P < 0.05). Areas under the curves (AUCs) for these lncRNAs were 0.733, 0.743, and 0.690, respectively, and the combined AUC was 0.843. A coding-noncoding co-expression (CNC) network was constructed based on Pearson's correlation coefficient. A specific lncRNA-miRNA-mRNA regulatory network of ENST00000568297, ENST00000568243, and NR_046084 was also constructed. Functional annotation of the up- and down-regulated mRNAs was performed. Pathway analysis enriched IS-related pathways with mRNAs in the lncRNA-miRNA-mRNA regulatory network. CONCLUSION: LncRNA and mRNA expression profiles in human peripheral blood were altered after IS. ENST00000568297, ENST00000568243, and NR_046084 were identified as novel potential diagnostic biomarkers of IS. Analysis of the CNC network and lncRNA-miRNA-mRNA regulatory network suggested that lncRNAs may participate in IS pathophysiology by regulating pivotal miRNAs, mRNAs, or IS-related pathways.

Aqueous synthesized quantum dots interfere with the NF-κB pathway and confer anti-tumor, anti-viral and anti-inflammatory effects.

The NF-κB pathway plays crucial roles in inflammatory responses and cell survival. Aberrant constitutive NF-κB activation is associated with various human diseases including cancer and inflammatory and auto-immune diseases. Consequently, it is highly desirable to develop new kinds of inhibitors, which are highly efficacious for blocking the NF-κB pathway. In this study, by using a typical kind of aqueous synthesized quantum dots (QDs), i.e., CdTe QDs, as a model, we for the first time demonstrated that the QDs could selectively affect the cellular nuclear factor-κB (NF-κB) signaling pathway, but do not affect the AKT or ERK pathways. Typically, the QDs efficiently inhibited the activation of IKKα and IKKß, resulting in the suppression of both the canonical and the non-canonical NF-κB signaling pathways. Inhibition of NF-κB by QDs downregulates anti-apoptotic genes and promotes apoptosis in cancer cells. The QDs induced NF-κB inhibition and cytotoxicity could be blocked by N-acetylcysteine due to the reduced cellular uptake of QDs. Importantly, inhibition of NF-κB by QDs displayed promising effects against the viral replication and in vivo bacterial endotoxin-induced inflammatory responses. These data suggest the QDs as potent inhibitors of the NF-κB signaling pathway, both in vitro and in vivo. Our findings highlight the potential of using QDs in the development of anti-cancer, anti-viral, and anti-inflammatory approaches, and also facilitate better understanding of QDs-related cellular behavior under the molecular level.

Herpes Simplex Virus 1 (HSV-1) and HSV-2 Mediate Species-Specific Modulations of Programmed Necrosis through the Viral Ribonucleotide Reductase Large Subunit R1.

UNLABELLED: Receptor-interacting protein kinase 3 (RIP3) and its substrate mixed-lineage kinase domain-like protein (MLKL) are core regulators of programmed necrosis. The elimination of pathogen-infected cells by programmed necrosis acts as an important host defense mechanism. Here, we report that human herpes simplex virus 1 (HSV-1) and HSV-2 had opposite impacts on programmed necrosis in human cells versus their impacts in mouse cells. Similar to HSV-1, HSV-2 infection triggered programmed necrosis in mouse cells. However, neither HSV-1 nor HSV-2 infection was able to induce programmed necrosis in human cells. Moreover, HSV-1 or HSV-2 infection in human cells blocked tumor necrosis factor (TNF)-induced necrosis by preventing the induction of an RIP1/RIP3 necrosome. The HSV ribonucleotide reductase large subunit R1 was sufficient to suppress TNF-induced necrosis, and its RIP homotypic interaction motif (RHIM) domain was required to disrupt the RIP1/RIP3 complex in human cells. Therefore, this study provides evidence that HSV has likely evolved strategies to evade the host defense mechanism of programmed necrosis in human cells. IMPORTANCE: This study demonstrated that infection with HSV-1 and HSV-2 blocked TNF-induced necrosis in human cells while these viruses directly activated programmed necrosis in mouse cells. Expression of HSV R1 suppressed TNF-induced necrosis of human cells. The RHIM domain of R1 was essential for its association with human RIP3 and RIP1, leading to disruption of the RIP1/RIP3 complex. This study provides new insights into the species-specific modulation of programmed necrosis by HSV.

Spectroscopy study on the noncovalent interactions in the binary and ternary systems of L-lysine, adenosine 5'-triphosphate and magnesium ions.

Intermolecular interactions of adenosine 5'-triphosphate (ATP) with Lysine (Lys) and Mg(2+) were studied in aqueous solution by (1)H and (31)P NMR spectra. In the metal-free system, the N-1 atom of the purine ring of ATP and carboxyl group of Lys are the interaction sites at low pH conditions. With increasing pH, the interaction efficiency between the phosphate group of ATP and the protonated ammonium group of Lys increased significantly, while that with carboxyl group in Lys decreased. In the Mg(2+)-Lys-ATP system, multi-interactions, such as coordination, cations (Mg(2+), NH(3)(+))-π, hydrogen bonding, ion-pairing interactions and electrostatic interactions co-existed. In addition, the recognition of ATP by the amino acid cation (Lys) was significantly promoted by the addition of magnesium ion, which led to the coordination competition between Lys and ATP.