LTA4H extensively associates with mRNAs and lncRNAs indicative of its novel regulatory targets.

The RNA-binding metabolic enzyme LTA4H is a novel target for cancer chemoprevention and chemotherapy. Recent research shows that the increased expression of LTA4H in laryngeal squamous cell carcinoma (LSCC) promotes tumor proliferation, migration, and metastasis. However, its mechanism remains unclear. To investigate the potential role of LTA4H in LSCC, we employed the improved RNA immunoprecipitation and sequencing (iRIP-Seq) experiment to get the expression profile of LTA4H binding RNA in HeLa model cells, a cancer model cell that is frequently used in molecular mechanism research. We found that LTA4H extensively binds with mRNAs/pre-mRNAs and lncRNAs. In the LTA4H binding peak, the frequency of the AAGG motif reported to interact with TRA2ß4 was high in both replicates. More notably, LTA4H-binding genes were significantly enriched in the mitotic cell cycle, DNA repair, RNA splicing-related pathways, and RNA metabolism pathways, which means that LTA4H has tumor-related alternative splicing regulatory functions. QRT-PCR validation confirmed that LTA4H specifically binds to mRNAs of carcinogenesis-associated genes, including LTBP3, ROR2, EGFR, HSP90B1, and lncRNAs represented by NEAT1. These results suggest that LTA4H may combine with genes associated with LSCC as an RNA-binding protein to perform a cancer regulatory function. Our study further sheds light on the molecular mechanism of LTA4H as a clinical therapy target for LSCC.

Study on mechanical properties and energy change of rock materials in whole splitting process based on peridynamics.

Aiming to bypass the inability to directly observe the evolution process of rock internal deformation and fracture, this paper proposes that rock samples with different inclination angles can be analyzed from the standpoint of energy, using the bond-base peridynamic theory and the PMB model of brittle materials, combined with laboratory experiments. The whole process of shearing is analyzed, and the LAMMPS software is used to simulate the internal energy change of rock-like materials under shear conditions, while the damage evolution law of samples with different dip angles is studied from macro and micro perspectives. The result shows that prefabricated cracks and the inclination of cracks are important factors for specimen damage, a finding that has important theoretical value for rock mechanics research. The research results can reduce the occurrence of rock burst accidents, the difficulty of mine support, and the cost of mining engineering, as well as improve mine safety levels.

Cloning and expression of two anti-lipopolysaccharide factors in Eriocheir hepuensis under Vibrio alginolyticus-induced stress.

Anti-lipopolysaccharide factors (ALFs) are small basic proteins that exhibit broad-spectrum antiviral properties and antibacterial activity. In this research, we cloned and studied two Eriocheir hepuensis ALFs, EhALF2 and EhALF3. The results showed that the open reading frame lengths of EhALF2 and EhALF3 were 363 and 372 bp, encoding 120 and 123 amino acids, respectively. Their sequences both contained an Lipopolysaccharide-binding (LPS) domain and were highly similarity to other crab ALFs. qRT-PCR showed that EhALF2 and EhALF3 were detected in nine examined tissues and were expressed the highest in the haemocytes. After challenge with Vibrio alginolyticus, in the hepatopancreas, the expression levels of EhALF2 and EhALF3 reached the highest levels at 48 and 3 h, respectively. In the heart, the expression levels of the two genes were highest at 12 h. These results indicate that EhALF2 and EhALF3 could participate in the resistance of E. hepuensis to V. alginolyticus stress within a short time. They have potential applications in the study of environmental stress markers and disease-resistance factors in E. hepuensis.

The characterization, expression and activity analysis of three superoxide dismutases in Eriocheir hepuensis under azadirachtin stress.

Superoxide dismutase (SOD) can effectively eliminate of excess ROS, which causes oxidative damage to lipids, proteins, and DNA. In this study, we cloned the CuZn-SOD, cMn-SOD1, and cMn-SOD2 genes in Eriocheir hepuensis, and found that the coding sequence (CDS) lengths were 627 bp, 861 bp and 1062 bp, which encoded 208, 286, and 353 amino acids, respectively. Phylogenetic analysis indicated that all SOD genes were evolutionarily conserved, while cMn-SOD2 had an extra gap (67 amino acids) in the conserved domain compared with cMn-SOD1 without huge changes in the tertiary structure of the conserved domain, suggesting that cMn-SOD2 may be a duplicate of cMn-SOD1. qRT-PCR showed that the three SOD genes were widely expressed in all the tested tissues, CuZn-SOD and cMn-SOD1 were mostly expressed in the hepatopancreas, while cMn-SOD2 was mostly expressed in thoracic ganglia. Under azadirachtin stress, the oxidation index of surviving individuals, including the T-AOC, SOD activity, and MDA contents increased in the early stage and then remained steady except for a decrease in MDA contents in the later stage. qRT-PCR showed that the three SOD genes displayed the same trends as SOD activity in surviving individuals, and the highest expressions of CuZn-SOD in the hepatopancreas, heart, and gill were 14.16, 1.41, and 30.87 times that of the corresponding control group, respectively. The changes were 1.35, 5.77 and 3.33 fold for cMn-SOD1 and 1.62, 1.71 and 1.79 fold for cMn-SOD2, respectively. However, the activity and expression of SOD genes in dead individuals were lower than that observed in surviving individuals. These results reveal that SOD plays a significant role in the defence against azadirachtin-induced oxidative stress.