Analysis of the immune function of Caspase-3 in Cristaria plicata.

Caspase-3 is generally considered to be the most important terminal shear enzyme in the process of apoptosis, as well as an important part of cytotoxic T lymphocytes (CTL) killing mechanism, which is confirmed to play an important role in vertebrate cell apoptosis and immune system, and is poorly reported in invertebrates. In this paper, we used bioinformatics to perform amino acid multiple sequence alignment and protein structural domain analysis, and constructed a phylogenetic tree to identify the full-length cDNA of the cloned caspase-3 of Cristaria plicata (Named CpCaspase-3). The expression of caspase-1, caspase-7, caspase-8, and caspase-9 was found to be down-regulated by double-stranded RNA interference of CpCaspase-3 in C. plicata. Some degree of disruption of the caspase signaling pathway occurs. The expression of CpCaspase-3 was affected after injection of Lipopolysaccharide (LPS), Peptidoglycan (PGN), polyinosinic-polycytidylic acid (poly(I:C)), and Aeromonas hydrophila. These results were suggested that CpCaspase-3 was involved in the immune response of C. plicata. The wound recovery process of C. plicata was simulated and CpCaspase-3 was found to promote wound recovery. An autophagy inhibition and autophagy activation model of mussels was constructed, where apoptosis and autophagy undergo crosstalk, and inhibition of autophagy induces the onset of apoptosis, and similarly autophagy activation inhibits the process of apoptosis instead. In addition, a recombinant CpCaspase-3-pEGFP-C1 plasmid was constructed for subcellular localization experiments and found that CpCaspase-3 was distributed in both the nucleus and the cytoplasm. This paper aims to unveil the immune mechanism of C. plicata and provide a theoretical basis for the healthy culture of shellfish.

GST-Mu of Cristaria plicata is regulated by Nrf2/Keap1 pathway in detoxification microcystin and has antioxidant function.

Glutathione S-transferase is a crucial phase II metabolic enzyme involved in detoxification and metabolism in aquatic organisms. This study aimed to investigate the regulation of Nrf2/Keap1 pathway on microcystin-induced CpGST-Mu expression and CpGST-Mu resistance to hydrogen peroxide. A mu class GST from Cristaria plicata (CpGST-Mu) was identified. The full-length cDNA was 1026 bp, with an open reading frame of 558 bp. Subcellular localization revealed that CpGST-Mu was localized in cytoplasm. The optimum pH and temperature for the catalytic activity of CpGST-Mu protein was pH 6 and 40 °C, respectively. The results of Real-time quantitative PCR showed that CpGST-Mu mRNA was constitutively expressed in tissues, with the highest expression level in hepatopancreas and the lowest expression level in gill. The mRNA level of CpGST-Mu was significantly increased under the stress of microcystins and hydrogen peroxide. CpGST-Mu had an antagonistic effect on hydrogen peroxide. In the knockdown experiments, the mRNA levels of CpGST-Mu exhibited corresponding changes while Nrf2 and Keap1 genes were individually knocked down. These findings indicated that GST-Mu exhibited antioxidant properties and its expression was regulated by Nrf2/Keap1 signaling pathway. The study provided new information on the function of GST-Mu and could contribute to future studies on how to excrete microcystins in molluscs.

A novel O2- (2,4-dinitrophenyl) diazeniumdiolate inhibits hepatocellular carcinoma migration, invasion, and EMT through the Wnt/ß-catenin pathway.

Targeted Wnt/ß-catenin pathway is considered to be a promising therapy for cancer metastasis. The novel O2 -(2,4-dinitrophenyl) diazeniumdiolate (JS-K) plays a potent inhibitory role in the proliferation of cancers. In this study, HepG2 and SMMC7721 were used to clarify the efficacy of JS-K inhibition of HCC metastasis. JS-K significantly inhibited cell motility through a wound-healing assay and restrained cell migration and invasion at noncytotoxic concentrations. However, the inhibitory effects of migration and invasion were abolished after the addition of NO scavenger, Carboxy-PTIO. In addition, JS-K inhibited the Wnt/ß-catenin pathway by a decrease of p-GSK-3ß at Ser9, cytosolic ß-catenin, and nuclear ß-catenin accumulation whereas an increase of p-ß-catenin. Furthermore, the transcription regulators c-Myc, survivin, and Cyclin D1 were down-regulated after treating with JS-K. The inhibitory of the Wnt/ß-catenin pathway was reversed after the addition of Carboxy-PTIO or LiCl. Meanwhile, JS-K also inhibited the epithelial-mesenchymal transition (EMT)-mediated cell migration and invasion. The characteristics of the inhibition were reflected by the upregulation of E-cadherin whereas the downregulation of Vimentin, Snail, and Slug. Taking together, these results demonstrated that JS-K inhibited HepG2 and SMMC7721 cells migration and invasion by reversing EMT via the Wnt/ß-catenin pathway.

Investigations into the Role of Friction for Rigid Penetration into Concrete-Like Material Targets.

Currently, it appears that there is a lack of understanding related to the role of SSF, in the two-phase behavior of the deceleration history, which is an issue discussed recently in the impact dynamics field. This paper analytically and numerically focuses on the effect of SSF on the projectile deceleration characteristic of concrete-like targets. Firstly, the penetration process according to the two-phase feature of the projectile deceleration is revised, where analytical results indicate that the SSF has a phased feature corresponding to the two-phase behavior of the deceleration history. Furthermore, a series of numerical simulations are conducted to understand the role of SSF more clearly. Simulation results show a similar conclusion to the analyses of the two-phase penetration process; at the range below a certain critical striking velocity, adding friction can reproduce the experimental data; when exceeding the critical striking velocity, the simulated results without considering friction are closest to the experimental data. Hence, it could be gained that the role exchange between the SSF and the dynamic term contributes to the two-phase penetration behavior for concrete-like materials. This indicates that the sensitivity of SSF to the penetration process is one of the factors driving the two-phase feature.