Sijunzi Decoction Inhibits Stemness by Suppressing ß-Catenin Transcriptional Activity in Gastric Cancer Cells.

OBJECTIVE: To investigate a previously uncharacterized function of Sijunzi Decoction (SJZD) in inhibition of gastric cancer stem cells (GCSCs). METHODS: MKN74 and MKN45, two CD44 positive gastric cancer cell lines with stem cell properties were used. The cells were divided into 2 groups. Treatment group was treated with SJZD (1-5 mg/mL) for indicated time (48 h-14 days). The control group was treated with equal volume of phosphate buffered saline. Cell Counting Assay Kit-8 were used to measure cell viability. Spheroid colony formation and GCSCs marker expression were performed to determine GCSCs stemness. Cell fractionation and chromatin immunoprecipitation assays were used to assess the distribution and DNA-binding activity of ß-catenin after SJZD treatment, respectively. RESULTS: SJZD treatment repressed cell growth and induced apoptosis in MKN74 and MKN45 cell lines (P<0.05). Moreover, SJZD dramatically inhibited formation of spheroid colony and expression of GCSC markers in GC cells (P<0.05). Mechanistically, SJZD reduced nuclear accumulation and DNA binding activity of ß-catenin (P<0.05), the key regulator for maintaining CSC stemness. CONCLUSION: SJZD inhibits GCSCs by attenuating the transcriptional activity of ß-catenin.

Tripterygium Glycosides Combined with Leflunomide for Rheumatoid Arthritis: A Systematic Review and Meta-Analysis.

OBJECTIVE: To undertake an overview on the overall effects of Tripterygium glycosides (TG) combined with Leflunomide (LEF) for rheumatoid arthritis (RA). METHODS: We searched electronic databases from database establishment time to December 1, 2019. The clinical trial data of TG combined with LEF (trial group) and control group in the treatment of RA were collected. The Cochrane system was used to evaluate the quality of the literature. RevMan 5.3 software was used to conduct a meta-analysis of the eligible studies. RESULTS: A total of 12 randomized controlled trials (RCTs) involving 834 patients with RA were included in this study. The meta-analysis results showed that morning stiffness (mean difference (MD) = -0.29, 95% confidential interval (CI) (-0.45, -0.12), P=0.0005), tender joint count (MD = -1.51, 95% CI (-2.20, -0.83), P=0.0001), swollen joint count (MD = -1.24, 95% CI (-1.59, -0.88), P=0.0001), erythrocyte sedimentation rate (MD = -7.26, 95% CI (-9.92, -4.61), P=0.0001), C-reactive protein (MD = -4.04, 95% CI (-4.93, -3.14), P=0.0001), and rheumatoid factor (MD = -50.88, 95% CI (-72.30, -29.45), P = 0.0001) in the trial groups were lower than those in the control groups. The total effective rate in the trial group was better than that in the control group (risk ratio (RR) = 1.20, 95% CI (1.13, 1.28), P=0.00001). However, there was no significant difference of adverse events (RR = 0.83, 95% CI (0.61, 1.13), P=0.23) while comparing the trial groups with the control groups. CONCLUSION: Our results were found to be superior but limited evidence on the effectiveness of TG combined with LEF in the treatment of RA is available.

Sensitive immunosensor based on high effective resonance energy transfer of lucigenin to the cathodic electrochemiluminescence of tris(bipyridine) Ru(II) complex.

Electrochemiluminescence resonance energy transfer (ECL-RET) has been attracting much focus as an effective approach for great ECL enhancement. Here, we found that lucigenin (Luc) could serve as a new energy transfer donor and greatly improve the cathodic ECL of bis(2,2'-bipyridyl)(4'-methyl-[2,2']bipyridinyl-4-carboxylicacid) ruthenium(II) (Ru(Bpy)2(Mcbpy)2+, acceptor). Then, both Luc and Ru(Bpy)2(Mcbpy)2+ were largely co-immobilized onto the PdCu nanocrystals and polyethyleneimine (PEI) modified single-walled carbon nanohorns (SWCNHs-PdCuNCs-PEI) through π-π stacking and crosslinking reaction, respectively. By this way, the excellent electrocatalytic behavior and high loading capability for both Luc and Ru(Bpy)2(Mcbpy)2+ of SWCNHs-PdCuNCs-PEI effectively facilitated the ECL reaction. Particularly, the co-immobilization strategy making the donor (Luc)/acceptor (Ru(Bpy)2(Mcbpy)2+) pairs co-exist in the same nano-composite could obviously increase the ECL-RET efficiency by shortening the electron-transfer path and reducing energy loss, further significantly improving the ECL signal. Combining the obtained nano-composite (Luc-SWCNHs-PdCuNCs-PEI-Ru(Bpy)2(Mcbpy)2+) with sandwiched immunoreaction, an ECL immunosensor was constructed for ß2-microglobulin (ß2-M) measurement. And as a result, it exhibited excellent performance in sensitivity, stability and selectivity. The establishment of the new effective donor/acceptor pairs for ECL-RET and the co-immobilization strategy of making those donor/acceptor pairs largely co-exist in the same nano-composite would greatly improve the ECL efficiency and motivate the wider application of ECL technology.

Generation of Stable Influenza Virus Hemagglutinin through Structure-Guided Recombination.

Hemagglutinin (HA) is the major surface antigen of influenza virus and the most promising influenza vaccine immunogen. In 2013, the devastating H7N9 influenza virus was identified in China, which induced high mortality. The HA of this virus (H7) is relatively unstable, making it challenging to produce an effective vaccine. To improve the stability of HA protein from H7N9 influenza virus for better vaccine antigens without impairing immunogenicity, we recombined the HA from H7N9 (H7) with a more stable HA from H3N2 (H3) by structure-guided recombination, resulting in six chimeric HAs, FrA-FrF. Two of these chimeric HAs, FrB and FrC, exhibited proper hemagglutination activity and presented improved thermal stability compared to the original H7. Mice immunized with FrB and FrC elicited H7-specific antibodies comparable to those induced by parental H7, and the antisera collected from these immunized mice successfully inhibited H7N9 infection in a microneutralization assay. These results suggest that our structural-recombination approach can create stabilizing chimeric antigens while maintaining proper immunogenicity, which may not only benefit the construction of more stable HA vaccines to fight against H7N9 infection, but also facilitate effective vaccine improvements for other influenza viruses or infectious pathogens. In addition, this study also demonstrates the potential for better engineering of multimeric protein complexes like HA to achieve improved function, which are often immunologically or pharmaceutically important but difficult to modify.

Global Screening of Antiviral Genes that Suppress Baculovirus Transgene Expression in Mammalian Cells.

Although baculovirus has been used as a safe and convenient gene delivery vector in mammalian cells, baculovirus-mediated transgene expression is less effective in various mammalian cell lines. Identification of the negative regulators in host cells is necessary to improve baculovirus-based expression systems. Here, we performed high-throughput shRNA library screening, targeting 176 antiviral innate immune genes, and identified 43 host restriction factor genes in a human A549 lung carcinoma cell line. Among them, suppression of receptor interaction protein kinase 1 (RIP1, also known as RIPK1) significantly increased baculoviral transgene expression without resulting in significant cell death. Silencing of RIP1 did not affect viral entry or cell viability, but it did inhibit nuclear translocation of the IRF3 and NF-κB transcription factors. Also, activation of downstream signaling mediators (such as TBK1 and IRF7) was affected, and subsequent interferon and cytokine gene expression levels were abolished. Further, Necrostatin-1 (Nec-1)-an inhibitor of RIP1 kinase activity-dramatically increased baculoviral transgene expression in RIP1-silenced cells. Using baculovirus as a model system, this study presents an initial investigation of large numbers of human cell antiviral innate immune response factors against a "nonadaptive virus." In addition, our study has made baculovirus a more efficient gene transfer vector for some of the most frequently used mammalian cell systems.

Ultrasensitive Electrochemiluminescence Biosensor for MicroRNA Detection by 3D DNA Walking Machine Based Target Conversion and Distance-Controllable Signal Quenching and Enhancing.

In this study, an electrochemiluminescence (ECL) regenerated biosensor was reported to sensitively detect microRNA through 3D DNA walking machine and "on-off-super on" strategy. First, 3D DNA walking machine with higher efficiency of payload releasing and superior signal amplification than those of the traditional DNA walking machine was initially introduced in the ECL system for converting target microRNA to intermediate DNA and achieving significant signal amplification. Second, the distance between CdS:Mn quantum dots and Au nanoparticles was increased with the hybridization of intermediate DNA and Au nanoparticles modified S2, which weakened the energy transfer for ECL signal recovering and excited the surface plasma resonance for further enhancing the signal to construct the on-off-super on biosensor. Such an on-off-super on strategy not only reduced the ECL background signal but also increased the detection sensitivity. Impressively, the elaborately designed biosensor could be regenerated by Lambda exonuclease hydrolyzing the intermediate DNA to make Au nanoparticles modified S2 recover to their original hairpin structure. With the amazing signal amplification of 3D DNA walking machine and sensitive distance control of the on-off-super on strategy, the biosensor showed excellent performance for microRNA-141 detection with a low detection limit of 3.3 fM and could be applied to human prostate cancer cells analysis. Furthermore, this work established a foundation to apply 3D walker in ECL methodology and provided an effective way for analysis of other microRNA or cancer cells.