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Background Gradually, more researches pay attention to the potential relationship between N6-methyladenosine (m6A) modification of RNA and immunity in tumor microenvironment (TME). Therefore, they developed unique scoring modes through detecting level of m6A in various tumors to learn immune phenotypes. Nevertheless, direct detection always is harmful even fatal to patients. Recent studies demonstrated that exosomes in body fluid would deliver RNA with m6A modification from tumors. Methods Through analyzing datasets from 1066 colon cancer samples, m6A-related exosome genes modification patterns which based on 59 m6A-related exosome genes was classified. Then we used MREGS to calculate modification patterns of each tumor with PCA algorithm. Results In accordance with 59 m6A-related exosome gene, we indicated that there were distinguishing characteristics of TME cell infiltration in three different m6A-related exosome gene modification patterns. Three immune cell infiltration profiles (immune-inflamed, immune-desert and immune-excluded) were pronouncedly relevant with the identified patterns in aspects of immune activation, EMT- and TGFβ-related pathways and activity of stroma in TME. We also discovered that tumor molecular subtypes, genetic aberrant expression and patients’ outcomes could be evaluated by identified modification patterns. Furthermore, patients in lower MREGS group, featured as prolonged lifespan and advantageous immune activation, was associated with high tumor mutation burden (TMB) and good prognosis with anti-PDL1 immune therapy. Conclusion Detecting the level of m6A methylation of exosomes in patients’ serum, MREGS could be utilized for assessing m6A-related exosome gene modification patterns of each patient and their own matching characteristics of TME cell infiltration, and next ascertain immunological classifications of tumors and assist clinicians to tailor optimal treatment for patients.

Graphical abstract, Highlights • PPIX possesses broad antiviral activities in vitro against a panel of enveloped viruses. • PPIX interacts with the lipids of enveloped virions, thereby inhibiting the entry of enveloped viruses into host cells. • PPIX shows the antiviral effect in vivo by testing mice infected with the influenza A/Puerto Rico/8/34 (H1N1) virus., Severe emerging and re-emerging viral infections such as Lassa fever, Avian influenza (AI), and COVID-19 caused by SARS-CoV-2 urgently call for new strategies for the development of broad-spectrum antivirals targeting conserved components in the virus life cycle. Viral lipids are essential components, and viral-cell membrane fusion is the required entry step for most unrelated enveloped viruses. In this paper, we identified a porphyrin derivative of protoporphyrin IX (PPIX) that showed broad antiviral activities in vitro against a panel of enveloped pathogenic viruses including Lassa virus (LASV), Machupo virus (MACV), and SARS-CoV-2 as well as various subtypes of influenza A viral strains with IC50 values ranging from 0.91 ± 0.25 μM to 1.88 ± 0.34 μM. A mechanistic study using influenza A/Puerto Rico/8/34 (H1N1) as a testing strain showed that PPIX inhibits the infection in the early stage of virus entry through biophysically interacting with the hydrophobic lipids of enveloped virions, thereby inhibiting the entry of enveloped viruses into host cells. In addition, the preliminary antiviral activities of PPIX were further assessed by testing mice infected with the influenza A/Puerto Rico/8/34 (H1N1) virus. The results showed that compared with the control group without drug treatment, the survival rate and mean survival time of the mice treated with PPIX were apparently prolonged. These data encourage us to conduct further investigations using PPIX as a lead compound for the rational design of lipid-targeting antivirals for the treatment of infection with enveloped viruses.

Actinobacteria are historically and continued to be an important source for drug discovery. The annual epidemics and periodic pandemics of humans induced by influenza A virus (IAV) prompted us to develop new effective antiviral drugs with different modes of action. An actinobacterium of Streptomyces sp. SMU 03 was identified from the feces of Elephas maximus in Yunnan Province, China. By employing an H5N1 pseudo-typed virus drug screening system, the anti-IAV effect of the dichloromethane extracts (DCME) of this bacterium was investigated. DCME showed broad and potent activities against several influenza viruses, including the H1N1 and H3N2 subtypes and influenza B virus, with IC50 values ranging from 0.37 ± 0.22 to 14.44 ± 0.79 μg/mL. A detailed modes-of-action study indicated that DCME might interact with the HA2 subunit of hemagglutinin (HA) of IAV by interrupting the fusion process between the viral and host cells' membranes thereby inhibiting the entry of the virus into host cells. Furthermore, the in vivo anti-IAV activity test of DCME showed that compared with the no-drug treated group, the survival rates, appearances, weights, lung indices and histopathological changes were all significantly alleviated. Based on these results, the chemical constituent study of DCME was then investigated, from which a number of antiviral compounds with various structural skeletons have been isolated and identified. Overall, these data indicated that the DCME from Streptomyces sp. SMU 03 might represent a good source for antiviral compounds that can be developed as potential antivirus remedies.

BACKGROUND AND PURPOSE: Propionibacterium acnes is a Gram‐positive bacterium associated with the skin disorder acne. In this study, as fatty acids are considered to be important in the life habitat of P. acnes, we tested our lipopeptide library in an attempt to create potent P. acnes‐specific antimicrobial agents. EXPERIMENTAL APPROACH: The antimicrobial activity of various lipopeptides was determined by measuring their minimal inhibitory concentration (MIC). Lipids from P. acnes were used to explore their mode of action. RAW264.7 cells stimulated with LPS and P. acnes respectively were used to measure their anti‐inflammatory activity. Mice ears injected with P. acnes were used to assess the antimicrobial and anti‐inflammatory effects of the peptides tested in vivo. KEY RESULTS: The most potent candidate, C16‐KWKW, was observed to be more active against P. acnes than against other non‐targeted bacterial strains, such as Streptococcus mutans, Staphylococcus aureus, and Escherichia coli. The mode of action of C16‐KWKW was observed to be through interference with the integrity of the bacterial membrane, thereby impairing membrane permeability and causing leakage of inner contents of bacterial cells. Furthermore, C16‐KWKW inhibited the expression of pro‐inflammatory cytokines, such as IL‐1β, TNF‐α, and inducible NOS stimulated by both LPS and P. acnes, thus showing potential anti‐inflammatory activity, which was further verified in the in vivo animal studies. CONCLUSIONS AND IMPLICATIONS: C16‐KWKW is a lipopeptide displaying both anti‐P. acnes and anti‐inflammatory effects in vitro and in vivo and shows potential as a treatment for acne vulgaris induced by P. acnes.

Marine environments are known to be a new source of structurally diverse bioactive molecules. In this paper, we identified a porphyrin derivative of Pyropheophorbide a (PPa) from the mussel Musculus senhousei (M. senhousei) that showed broad anti-influenza A virus activity in vitro against a panel of influenza A viral strains. The analysis of the mechanism of action indicated that PPa functions in the early stage of virus infection by interacting with the lipid bilayer of the virion, resulting in an alteration of membrane-associated functions, thereby blocking the entry of enveloped viruses into host cells. In addition, the anti-influenza A virus activity of PPa was further assessed in mice infected with the influenza A virus. The survival rate and mean survival time of mice were apparently prolonged compared with the control group which was not treated with the drug. Therefore, PPa and its derivatives may represent lead compounds for controlling influenza A virus infection.

Dental plaque is closely related to the occurrence of dental caries, of which the main causative bacterium is Streptococcus mutans (S. mutans). In this study, to create potent antibiofilm agents, we chose a human antimicrobial peptide LL-37 as our starting material and modified it by cutting it shorter and varying its charge and hydrophobicity. The results of anti-S. mutans as well as biofilm inhibitory activity tests indicated that two derivatives, IG-13-1 and IG-13-2, were the most potent one toward both planktonic and biofilm S. mutans cells with the minimal inhibitory concentration of 5.0 μM and minimal biofilm inhibitory concentrations of 5.91 ± 0.91 μM and 7.58 ± 0.23 μM, respectively. The modes of action study showed that IG-13-1 and IG-13-2 were functioned by disrupting the bacterial membrane, causing the leakage of inner contents, thereby leading to the death of bacterial cells eventually. In addition, IG-13-1 and IG-13-2 were able to suppress the expression of proinflammatory cytokine of TNF-α and reduce the level of nuclear transcription factor-κB, which indicated the potential anti-inflammatory activity of these peptides. Conclusively, this study indicated that IG-13-1 and IG-13-2 are potent peptides in both anti-S. mutans and anti-inflammatory activities, therefore, showing a potential application for the prevention and treatment of dental caries.

Influenza A viruses (IAVs) induce acute respiratory disease and cause significant morbidity and mortality throughout the world. With the emergence of drug-resistant viral strains, new and effective anti-IAV drugs with different modes of action are urgently needed. In this study, by conjugating cholesterol to the N-terminus of the short peptide KKWK, a lipopeptide named S-KKWK was created. The anti-IAV test indicated that S-KKWK and its derivatives displayed potent antiviral activities against a broad variety of influenza A viral strains including oseltamivir-resistant strains and clinically relevant isolates with IC50 values ranging from 0.7 to 3.0µM. An extensive mechanistic study showed that these peptides functioned as viral "entry blockers" by inhibiting the conformational rearrangements of HA2 subunit, thereby interrupting the fusion of virus-host cell membranes. Significantly, a computer-aided docking simulation and protein sequence alignment identified conserved residues in the stem region of HA2 as the possible binding site of S-KKWK, which may be employed as a potential drug target for designing anti-IAVs with a broad-spectrum of activity. By targeting this region, a potent anti-IAV agent was subsequently created. In addition, the anti-IAV activity of S-KKWK was assessed by experiments with influenza A virus-infected mice, in which S-KKWK reduced the mortality of infected animals and extended survival time significantly. Overall, in addition to providing a strategy for designing broad-spectrum anti-IAV agents, these results indicate that S-KKWK and its derivatives are prospective candidates for potent antivirals.

Objectives In the past decade, the mobile phone (MP) has become extremely popular among children and the average age at which children own their first MP has decreased. The potential health effects of children’s exposure to MP have been the subject of widespread public concern. The aim of our study is to investigate the associations between MP use and well-being in children. Design Cross-sectional study. Setting The questionnaires were completed in class with items regarding demographics, MP usage, self-reported well-being (symptoms were taken from the questionnaire of the HBSC survey) and possible confounding factors between October 2011 and May 2012 in Chongqing, China. Data were analysed using χ2 tests and logistic regression models. Participants Among the 793 children invited to participate, 781 returned the questionnaires. Results In total, 746 (94.1%) valid questionnaires were received. Fatigue was significantly associated with the years of MP usage (OR 1.85; 95% CI 1.07 to 3.22) and the daily duration of MP calls (OR 2.98; 95% CI 1.46 to 6.12). Headache was significantly associated with the daily duration of MP calls (OR 2.85; 95% CI 1.23 to 6.57). However, after adjusting for confounders only, the association between fatigue and MP usage remained statistically significant. There was no significant association between MP use and other physical symptoms in children. Conclusions The present study indicated that there was a consistent significant association between MP use and fatigue in children. Further in-depth research is needed to explore the potential health effects of MP use in children.