CXCL14 is one of the most evolutionarily conserved members of the chemokine family and is constitutionally expressed in multiple organs, suggesting that it is involved in the homeostasis maintenance of the system. CXCL14 is highly expressed in colon epithelial cells and shows obvious gene silencing in clinical colon cancer samples, suggesting that its silencing is related to the immune escape of cancer cells. In this paper, we analyzed the expression profiles of multiple human clinical colon cancer datasets and mouse colon cancer models to reveal the variation trend of CXCL14 expression during colitis, colon polyps, primary colon cancer, and liver metastases. The relationship between CXCL14 gene silencing and promoter hypermethylation was revealed through the colorectal carcinoma methylation database. The results suggest that CXCL14 is a tumor suppressor gene in colorectal carcinoma, which is activated first and then silenced during the process of tumor occurrence and deterioration. Promoter hypermethylation is the main cause of CXCL14 silencing. The methylation level of CXCL14 is correlated with the anatomic site of tumor occurrence and positively correlated with patient age, and associated with prognosis. Reversing the hypermethylation of CXCL14 may be an epigenetic therapy for colon cancer.

In this work, oxygen-doped g-C3N4 mesoporous nanosheets (O-CNS) were synthesized via a facile recrystallization method with the assistance of H2O2. The crystal phase, chemical composition, morphological structure, optical property, electronic structure and electrochemical property of the prepared O-CNS samples were well investigated. The morphological observation combining with nitrogen adsorption-desorption results demonstrated that the prepared O-CNS samples possessed nanosheets-like morphology with porous structure. The O doping into g-C3N4 resulted in the augment of specific surface area, which could provide more active sites for photocatalytic reaction. Simultaneously, the visible-light absorption capacity of O-CNS samples was boosted owing to the regulation of O doping. The built energy level induced by the O doping could accelerate the migration rate of photoinduced carriers, and the porous structure was most likely to speed up the release of hydrogen during photocatalyic hydrogen process. Resultantly, the photocatalytic hydrogen production rate of the optimized oxygen-doped g-C3N4 nanosheets reached up to 2012.9 μmol•h-1•g-1, which was 13.4 times higher than that of bulk g-C3N4. Thus, the significantly improved photocatalytic behavior was imputed to the porous structure, the augment of active sites, and the enhancement of visible light absorption and charge separation efficiency.

In organisms that use reduced sulfur compounds as alternative or additional electron donors to organic compounds, transcriptional regulation of genes for enzymes involved in sulfur oxidation is needed to adjust metabolic flux to environmental conditions. However, little is known about the sensing and response to inorganic sulfur compounds such as thiosulfate in sulfur-oxidizing bacteria. In the Alphaproteobacterium Hyphomicrobium denitrificans, one strategy is the use of the ArsR-SmtB-type transcriptional regulator SoxR. We show that this homodimeric repressor senses sulfane sulfur and that it is crucial for the expression not only of sox genes encoding the com-ponents of a truncated periplasmic thiosulfate-oxidizing enzyme system but also of several other sets of genes for enzymes of sulfur oxidation. DNA binding and transcriptional regulatory activity of SoxR are controlled by polysulfide-dependent cysteine modification. The repressor uses the formation of a sulfur bridge between two conserved cysteines as a trigger to bind and release DNA and can also form a vicinal disulfide bond to orchestrate a response to oxidizing conditions. The importance of the sulfur bridge forming cysteines was confirmed by site directed mutagen-esis, mass spectrometry and gel shift assays. In vivo, SoxR interacts directly or indirectly with a second closely related repressor, sHdrR.

Trichoderma spp. are widely used in plant disease control as biocontrol agents. Inducing plant disease resistance is an important biocontrol mechanism of Trichoderma. It is of great significance to explore the factors involved in the surface recognition and interaction of Trichoderma with plants. Hydrophobin is a small molecular protein rich in cysteine in higher filamentous fungi and has been found to participate in the morphogenesis and interaction of fungi with other organisms. In this study, the type II hydrophobic protein-coding gene Thfb6 from T. harzianum TH33 was cloned and heterologously expressed in Escherichia coli BL21 (DE3). The purified recombinant protein Thfb6 induced a hypersensitive response in tobacco leaves, a burst of reactive oxygen species, and an accumulation of callose, phenolic substances, and lignin in tobacco, indicating that Thfb6 can induce an early defense reaction in tobacco. Thfb6 also enhanced the systemic resistance of tobacco against tobacco mosaic virus. The rate of lesion number reduction by treatment with Thfb6 could be up to 36.02%. Thfb6 increased the activity of tobacco defense-related enzymes, including phenylalanine ammonia-lyase (PAL), polyphenol oxidase, and peroxidase, which were all more than three times the control after 3–5 days post treatment of Thfb6. The transcription of resistance-related genes, including the PAL gene, non-expresser of pathogenesis-related gene1 (NPR1), and basic pathogenesis-related gene 1 (PR1-b), were upregulated after Thfb6 treatment. The relative expression levels of the PAL and NPR1 genes were highest on the third and fourth days after Thfb6 treatment, at 5.5 times and 8.3 times that of the control, respectively. The relative expression level of PR1 on the sixth day after Thfb6 treatment was 5.3 times that of the control. These results indicate that the improvement of defense-related enzyme activity and the induced expression of disease-resistance-related genes were the main mechanisms by which Thfb6 induced systemic resistance in tobacco.

Cell-to-cell distant mechanical communication has been demonstrated by using in-vitro and in-vivo models. However, the molecular mechanisms underlying long-range cell mechanoresponsive interactions remain to be more elucidated. This study further examined the roles of α-Catenin and Piezo in traction force-induced rapid branch assembly of airway smooth muscle (ASM) cells on Matrigel hydrogel containing type I collagen. Our findings demonstrate that siRNA-mediated downregulation of α-Catenin or chemical inhibition of Piezo activity significantly reduced both cell directional movement and branching assembly. In regarding the role of N-cadherin in regulating branch assembly but not directional migration, our results further confirmed that siRNA downregulation of α-Catenin caused a remarked reduction of focal adhesion formation, as assessed by focal Paxillin and Integrin α5 localization. These observations implied that mechanosensitive α-Catenin was involved in both cell-cell and cell-matrix adhesions. Additionally, Piezo showed partial localization with Paxillin in focal adhesions, which was inhibited by α-Catenin downregulation with siRNA. This provides a plausible clue for Piezo mechanosensing traction force in the hydrogel. Collectively, our findings highlight the significance of α-Catenin in regulating cell-matrix interactions along with possible interpretation for Piezo mechanosensation at focal adhesions during cell-cell distant mechanical communication.