ARIH1 inhibits influenza A virus replication and facilitates RIG-I dependent immune signaling by interacting with SQSTM1/p62.

BACKGROUND: Multiple host factors are involved in modulating type I interferon expression induced by viruses; however, the mechanism is not fully elucidated. Influenza A virus infection causes severe respiratory symptoms and triggers a series of signaling cascades and host innate immune responses, including interferon production. The co-IP/MS technology was used to screen several antiviral factors in the early stage. Among these factors, ariadne-1 homolog (ARIH1) caught our attention. METHODS: Western blot assay was performed to detect the level of proteins and software ImageJ was used to analyze the band intensities. Polymerase activity assay was conducted to evaluate the polymerase activity of influenza A virus. Tissue culture infective dose (TCID50) assay was performed to measure influenza A virus titers, and quantitative RT-PCR assay was applied to test the mRNA level of IFN-ß, ISG56, and CXCL10. Luciferase reporter assay was used to confirm the target of ARIH1 in RIG-I signaling. Immunoprecipitation assay was performed to detect the interaction and the ubiquitination of the proteins. All data were analyzed by biostatistical methods and presented as means ± standard deviation from three independent experiments. Statistical significance was determined using two-tailed student's t test. A P value of less than 0.05 was considered statistically significant, and a P value of less than 0.01 was considered highly significant (ns, P ≥ 0.05; *, P < 0.05; and **, P < 0.01). RESULTS: We found that ARIH1, a member of E3 ubiquitin ligases, enhanced cellular antiviral responses. Subsequent study showed that ARIH1 was up-regulated during influenza A virus infection. Further analysis showed that ARIH1 enhanced IFN-ß and downstream gene expression by affecting the degradation of RIG-I through the SQSTM1/p62 signaling pathway. CONCLUSION: This newly revealed mechanism shows that cellular response increases of ARIH1 and promotes IFN-ß expression to boost host survival during viral infection.

Systematic analysis of lysine crotonylation in human macrophages responding to MRSA infection.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most commonly encountered bacteria found in healthcare clinics and has been ranked a priority 2 pathogen. Research is urgently needed to develop new therapeutic approaches to combat the pathogen. Variations in the pattern of protein posttranslational modifications (PTMs) of host cells affect physiological and pathological events, as well as therapeutic effectiveness. However, the role of crotonylation in MRSA-infected THP1 cells remains unknown. In this study, we found that crotonylation profiles of THP1 cells were altered after MRSA infection. It was then confirmed that lysine crotonylation profiles of THP1 cells and bacteria were different; MRSA infection inhibited global lysine crotonylation (Kcro) modification but partially elevated Kcro of host proteins. We obtained a proteome-wide crotonylation profile of THP1 cells infected by MRSA further treated by vancomycin, leading to the identification of 899 proteins, 1384 sites of which were down-regulated, and 160 proteins with 193 sites up-regulated. The crotonylated down-regulated proteins were mainly located in cytoplasm and were enriched in spliceosome, RNA degradation, protein posttranslational modification, and metabolism. However, the crotonylated up-regulated proteins were mainly located in nucleus and significantly involved in nuclear body, chromosome, ribonucleoprotein complex, and RNA processing. The domains of these proteins were significantly enriched on RNA recognition motif, and linker histone H1 and H5 families. Some proteins related to protecting against bacterial infection were also found to be targets of crotonylation. The present findings point to a comprehensive understanding of the biological functions of lysine crotonylation in human macrophages, thereby providing a certain research basis for the mechanism and targeted therapy on the immune response of host cells against MRSA infection.

Molecular mechanisms of the antibacterial activity of polyimide fibers in a skin-wound model with Gram-positive and Gram-negative bacterial infection in vivo.

Recently, the need for antibacterial dressings has amplified because of the increase of traumatic injuries. However, there is still a lack of ideal, natural antibacterial dressings that show an efficient antibacterial property with no toxicity. Polyimide (PI) used as an implantable and flexible material has been recently reported as a mixture of particles showing more desirable antibacterial properties. However, we have identified a novel type of natural polyimide (PI) fiber that revealed antibacterial properties by itself for the first time. The PI fiber material is mainly composed of C, N, and O, and contains a small amount of Ca and Cl; the characteristic peaks of polyimide appear at 1774 cm-1, 1713 cm-1, 1370 cm-1, 1087 cm-1, and 722 cm-1. PI fibers displayed significant antibacterial activities against Escherichia coli (as a Gram-negative bacteria model) and methicillin-resistant Staphylococcus aureus (MRSA, as a Gram-positive bacteria model) according to the time-kill kinetics in vitro, and PI fibers damaged both bacterial cell walls directly. PI fibers efficiently ameliorated a local infection in vivo, inhibited the bacterial burden, decreased infiltrating macrophages, and accelerated wound healing in an E. coli- or MRSA-infected wound model. In conclusion, PI fibers used in the present study may act as potent antibacterial dressings protecting from MRSA or E. coli infections and as promising candidates for antimicrobial materials for trauma and surgical applications.

Transcriptomic analysis and laboratory experiments reveal potential critical genes and regulatory mechanisms in sepsis-associated acute kidney injury.

Background: Sepsis-associated acute kidney injury (SA-AKI) is one of the most frequent and serious complications of sepsis. However, the transcriptional regulatory network of the pathophysiological mechanism of the kidney has not been revealed. This study identified new mechanisms in SA-AKI using bioinformatics analyses and laboratory-based experiments. Methods: We performed transcriptomic profiling of mouse kidneys after cecal ligation and puncture (CLP) to mimic clinical sepsis. RNA from kidney samples from the CLP and control groups was isolated and analyzed using bulk messenger RNA (mRNA)-seq. Differentially expressed genes (DEGs) between the two groups were identified, and GO, KEGG and GSEA pathway enrichment analyses were performed. The protein-protein interaction (PPI) network of DEGs and hub genes was analyzed. The hub genes were verified using quantitative real-time polymerase chain reaction (qPCR) or Western blotting. The interaction network, targeted microRNAs (miRNAs) and long noncoding RNAs (lncRNAs) of hub genes were predicted, and the critical miRNA-hub gene regulatory axis was verified using qPCR, Western blotting, malondialdehyde (MDA) determination and flow cytometry. Correlation analyses of N6-adenosine methylation (m6A) RNA methylation regulators and hub genes and m6A modification analysis were performed. Results: A total of 4,754 DEGs were identified between the two groups using high-throughput sequencing. The pathways in which DEGs were enriched included ferroptosis (the highest enrichment score), apoptosis, and the PI3K-Akt, NF-kappa B and IL-17 signaling pathways. Seven (Hmox1, Spp1, Socs3, Mapk14, Lcn2, Cxcl1 and Cxcl12) of the 15 hub genes were involved in the KEGG pathway. mmu-miR-7212-5p-Hmox1 was a key RNA regulatory axis in ferroptosis. m6A RNA methylation modifications were involved in SA-AKI. The correlation analyses showed the close interactions among the m6A RNA methylation regulators and important hub genes. Conclusions: The findings of this study provide new insights into the mechanism regulating the occurrence and progression of SA-AKI. The mmu-miR-7212-5p-Hmox1 axis in ferroptosis and m6A RNA methylation regulators may have potential clinical significance for the future treatment of SA-AKI. The datasets generated for this study can be found in the repository of the GEO database (Series number: GSE186822).

Carpel-specific down-regulation of GhCKXs in cotton significantly enhances seed and fiber yield.

Cytokinin is considered to be an important driver of seed yield. To increase the yield of cotton while avoiding the negative consequences caused by constitutive overproduction of cytokinin, we down-regulated specifically the carpel genes for cytokinin oxidase/dehydrogenase (CKX), a key negative regulator of cytokinin levels, in transgenic cotton. The carpel-specific down-regulation of CKXs significantly enhanced cytokinin levels in the carpels. The elevated cytokinin promoted the expression of carpel- and ovule-development-associated genes, GhSTK2, GhAG1, and GhSHP, boosting ovule formation and thus producing more seeds in the ovary. Field experiments showed that the carpel-specific increase of cytokinin significantly increased both seed yield and fiber yield of cotton, without resulting in detrimental phenotypes. Our study details the regulatory mechanism of cytokinin signaling for seed development, and provides an effective and feasible strategy for yield improvement of seed crops.

Impacts of Spatial Components on Outdoor Thermal Comfort in Traditional Linpan Settlements.

Traditional settlements have received increasing attention because of China's rural revitalization. Traditional settlements with excellent thermal comfort in rural areas can attract urban residents, so it is vital to explore the thermal comfort of traditional settlements. For this paper, we studied Linpan settlements, which are scattered traditional settlements that are mainly composed of buildings and trees. Firstly, we visually interpreted Linpan settlements by ArcGIS. A total of 1194 Linpan settlements were classified to obtain the spatial components. The statistical results of Linpan were used in the subsequent experimental design. Then ENVI-met was used to simulate 25 different spatial forms of Linpan obtained by statistical results and orthogonal experiment to explore the most comfortable Linpan layout. The results showed the following: (1) Linpan could improve thermal comfort in both winter and summer. Adjusting the spatial arrangement could maximally increase the mean physiological equivalent temperature (PET) of the whole Linpan area by 1.03 °C in winter and reduce it by 3.02 °C in the summer. (2) At different time points, the influence of different space factors on thermal comfort was also different. The overall significance of each factor on thermal comfort was addressed as follows: vegetation coverage (highly significant) > building number (highly significant) > building form (highly significant) > vegetation distribution (significant), but the building distribution was not significant. (3) The best spatial arrangement scheme was high vegetation coverage, a large number of buildings, tri-courtyard buildings, surrounding vegetation distribution, and surrounding building distribution. The innovation of this paper lies in introduced thermal comfort into the traditional Linpan settlement, extracted spatial features of buildings and vegetation by visual interpretation combined with GIS software, and the fact that we conducted the experimental design of microclimate and thermal comfort based on spatial features. The research results can guide the outdoor thermal environment renewal design of Linpan and other traditional settlements.

Methylsulfonylmethane protects against lethal dose MRSA-induced sepsis through promoting M2 macrophage polarization.

BACKGROUND: Multi-drug-resistant bacterial infections, which have become a global threat, lack effective treatments. The discoveries of non-antibiotics with different modes of antibacterial action, such as methylsulfonylmethane (MSM), are a promising new treatment for multi-drug-resistant pathogens. METHODS: We constructed a mouse peritonitis infection model to evaluate the effects of MSM against methicillin-resistant Staphylococcus aureus (MRSA) infection. The time-kill kinetics of MSM against MRSA and the effect of MSM on the integrity of bacterial cell membrane were measured. Viability effects of MSM on THP1 cells were performed by CCK-8 cytotoxicity assay. Systematic inflammatory factor levels of mice were detected using ELISA. The immune response of peritoneal macrophages during MRSA-infection was evaluated using RNA sequencing. Gene Ontology function, Kyoto Encyclopedia of Genes and Genomes pathway enrichment analyses, and correlation analyses were applied to analysis RNA sequencing data. RT-qPCR, western blotting and flow cytometry were performed to analysis the gene and protein expression levels of macrophages. RESULTS: In in vitro experiments, MSM did not show significant killing effects on the growth of MRSA directly and did not destroy bacterial membrane integrity. MSM also displayed no significant effects on the proliferative capacity of THP1 cells. However, MSM treatment protected mice against a lethal dose MRSA-infection and decreased systemic inflammation. MSM upregulated metabolic pathway in peritoneal macrophages, especial glycolysis, during MRSA infection. MSM increased the expression of M2 markers (such as Arg1), promoted phosphorylation of STAT3 (which regulates M2 polarization), and decreased the expression of M1 markers in peritoneal macrophages. Additionally, MSM treatment increased the expression of H3K18 lactylation specific target genes, including Arg1. GNE-140, the LDHA-specific inhibitor of glycolysis, blocked the MSM-induced Arg1 expression in this disease model. CONCLUSIONS: MSM protects against MRSA infection through immunomodulation. MSM promotes the expression of Arg1 by lactate-H3K18la pathway to control macrophage to M2 polarization; it firstly provides therapeutic potential for drug-resistant infections and sepsis.

Arabidopsis P4 ATPase-mediated cell detoxification confers resistance to Fusarium graminearum and Verticillium dahliae.

Many toxic secondary metabolites produced by phytopathogens can subvert host immunity, and some of them are recognized as pathogenicity factors. Fusarium head blight and Verticillium wilt are destructive plant diseases worldwide. Using toxins produced by the causal fungi Fusarium graminearum and Verticillium dahliae as screening agents, here we show that the Arabidopsis P4 ATPases AtALA1 and AtALA7 are responsible for cellular detoxification of mycotoxins. Through AtALA1-/AtALA7-mediated vesicle transport, toxins are sequestered in vacuoles for degradation. Overexpression of AtALA1 and AtALA7 significantly increases the resistance of transgenic plants to F. graminearum and V. dahliae, respectively. Notably, the concentration of deoxynivalenol, a mycotoxin harmful to the health of humans and animals, was decreased in transgenic Arabidopsis siliques and maize seeds. This vesicle-mediated cell detoxification process provides a strategy to increase plant resistance against different toxin-associated diseases and to reduce the mycotoxin contamination in food and feed.