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Clustered regularly interspaced short palindromic repeats interference (CRISPRi) is used to edit eukaryotic genomes. Here, we show that CRISPRi can also be used for fine-tuning prokaryotic gene expression while simultaneously regulating multiple essential gene expression with less labor and time consumption. As a case study, CRISPRi was used to control polyhydroxyalkanoate (PHA) biosynthesis pathway flux and to adjust PHA composition. A pathway was constructed in Escherichia coli for the production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] from glucose. The native gene sad encoding E. coli succinate semi-aldehyde dehydrogenase was expressed under the control of CRISPRi using five specially designed single guide RNAs (sgRNAs) for regulating carbon flux to 4-hydroxybutyrate (4HB) biosynthesis. The system allowed formation of P(3HB-co-4HB) consisting of 1-9mol% 4HB. Additionally, succinate, generated by succinyl-coA synthetase and succinate dehydrogenase (respectively encoded by genes sucC, sucD and sdhA, sdhB) was channeled preferentially to the 4HB precursor by using selected sgRNAs such as sucC2, sucD2, sdhB2 and sdhA1 via CRISPRi. The resulting 4HB content in P(3HB-co-4HB) was found to range from 1.4 to 18.4mol% depending on the expression levels of down-regulated genes. The results show that CRISPRi is a feasible method to simultaneously manipulate multiple genes in E. coli.
Assuntos
Sistemas CRISPR-Cas , Proteínas de Escherichia coli , Escherichia coli , Hidroxibutiratos/metabolismo , Engenharia Metabólica , Poliésteres/metabolismo , Escherichia coli/enzimologia , Escherichia coli/genética , Proteínas de Escherichia coli/biossíntese , Proteínas de Escherichia coli/genéticaRESUMO
Colorectal cancer (CRC), a major global health concern, may be influenced by dietary protein digestibility impacting gut microbiota and metabolites, which is crucial for cancer therapy effectiveness. This study explored the effects of a casein protein diet (CTL) versus a free amino acid (FAA)-based diet on CRC progression, gut microbiota, and metabolites using carcinogen-induced (AOM/DSS) and spontaneous genetically induced (ApcMin/+ mice) CRC mouse models. Comprehensive approaches including 16s rRNA gene sequencing, transcriptomics, metabolomics, and immunohistochemistry were utilized. We found that the FAA significantly attenuated CRC progression, evidenced by reduced colonic shortening and histopathological alterations compared to the CTL diet. Notably, the FAA enriched beneficial gut bacteria like Akkermansia and Bacteroides and reversed CRC-associated dysbiosis. Metabolomic analysis highlighted an increase in ornithine cycle metabolites and specific fatty acids, such as Docosapentaenoic acid (DPA), in FAA-fed mice. Transcriptomic analysis revealed that FAA up-regulated Egl-9 family hypoxia inducible factor 3 (Egln 3) and downregulated several cancer-associated pathways including Hippo, mTOR, and Wnt signaling. Additionally, DPA was found to significantly induce EGLN 3 expression in CRC cell lines. These results suggest that FAA modulate gut microbial composition, enhance protective metabolites, improve gut barrier functions, and inhibit carcinogenic pathways.
Assuntos
Neoplasias Colorretais , Microbioma Gastrointestinal , Animais , Camundongos , RNA Ribossômico 16S , Carcinogênese , Transformação Celular Neoplásica , Carcinógenos , AminoácidosRESUMO
Background: Advanced colorectal adenomas are at a risk of malignant transformation following endoscopic resection, and colonoscopic monitoring interval after polypectomy have been widely used. This study aims to investigate the prevailing state of compliance with postoperative colonoscopic surveillance among patients with advanced colorectal adenomas and its' influencing factors at Affiliated Hospital of Jiangnan University between November 2020 and April 2021. Methods: A retrospective analysis was conducted on patients who underwent endoscopic treatment for ACA at Affiliated Hospital of Jiangnan University from November 2020 to April 2021. Compliance with postoperative colonoscopic surveillance was assessed based on established guidelines. Factors such as sociodemographic features, medical histories, and health beliefs were analyzed to determine their influence on compliance. Univariate analysis, survival analysis, and multi-factor Cox regression analysis were used for statistical evaluation. Results: A total of 511 patients were included in the study. The compliance rate was found to be 43.2%. The univariate analysis indicated that factors such as gender, education level, work status, type of health insurance, place of residence, marital status, type of consultation, presence of gastrointestinal symptoms, number of polyps, and the maximum diameter of polyps significantly affected compliance. Multi-factor Cox regression analysis revealed that female gender, absence of gastrointestinal symptoms, outpatient endoscopic treatment, and solitary polyps were independent factors influencing compliance. Reasons for poor compliance included underestimating the severity of the disease, fear of colonoscopy, and procedural complexities. Conclusion: Patients with advanced colorectal adenomas had poor compliance with postoperative colonoscopy monitoring. Tailored health education programs should be designed, targeting women, outpatients undergoing endoscopic procedures, and patients with solitary polyps to enhance their compliance with colonoscopy monitoring.
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Although excessive salt consumption appears to hasten intestinal aging and increases susceptibility to cardiovascular disease, the molecular mechanism is unknown. In this study, mutual validation of high salt (HS) and aging fecal microbiota transplantation (FMT) in C56BL/6 mice was used to clarify the molecular mechanism by which excessive salt consumption causes intestinal aging. Firstly, we observed HS causes vascular endothelial damage and can accelerate intestinal aging associated with decreased colon and serum expression of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and increased malondialdehyde (MDA); after transplantation with HS fecal microbiota in mice, vascular endothelial damage and intestinal aging can also occur. Secondly, we also found intestinal aging and vascular endothelial damage in older mice aged 14 months; and after transplantation of the older mice fecal microbiota, the same effect was observed in mice aged 6-8 weeks. Meanwhile, HS and aging significantly changed gut microbial diversity and composition, which was transferable by FMT. Eventually, based on the core genera both in HS and the aging gut microbiota network, a machine learning model was constructed which could predict HS susceptibility to intestinal aging. Further investigation revealed that the process of HS-related intestinal aging was highly linked to the signal transduction mediated by various bacteria. In conclusion, the present study provides an experimental basis of potential microbial evidence in the process of HS related intestinal aging. Even, avoiding excessive salt consumption and actively intervening in gut microbiota alteration may assist to delay the aging state that drives HS-related intestinal aging in clinical practice.
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Cereal vinegar sediment (CVS) is a natural precipitate formed during the aging process of traditional grain vinegar. It has been used as Chinese traditional medicine, while its composition and function are reported minimally. In this study, we measured CVS in terms of saccharide, protein, fat and water content, and polyphenol and flavonoid content. Furthermore, we determined the amino acids, organic acids, and other soluble metabolites in CVS using reverse-phase high-performance liquid chromatography (RP-HPLC), HPLC, and liquid chromatography with tandem mass spectrometry (LC-MS/MS) platforms. The hepatoprotective effect of CVS was evaluated in acute CCl4-induced liver injury mice. Administration of CVS for 7 days prior to the CCl4 treatment can significantly decrease liver alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels and reactive oxygen species (ROS) levels, compared with those in the hepatic injury model group. The gut microbiota was changed by CCl4 administration and was partly shifted by the pretreatment of CVS, particularly the Muribaculaceae family, which was increased in CVS-treated groups compared with that in the CCl4 administration group. Moreover, the abundances of Alistipes genus and Muribaculaceae family were correlated with the liver ALT, AST, and malondialdehyde (MDA) levels. Our results illustrated the composition of CVS and its hepatoprotective effect in mice, suggested that CVS could be developed as functional food to prevent acute liver injury.
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OBJECTIVES: This meta-analysis was designed to systematically evaluate whether autologous cytokine-induced killer cells (CIK) or dendritic cells and cytokine-induced killer cells (DC-CIK) immunotherapy combined with chemotherapy can improve the therapeutic effect and safety of chemotherapy in esophageal cancer (EC). MATERIALS AND METHODS: Randomized controlled trials (RCTs) were electronically searched databases including CNKI, WanFang, WeiPu, CBMDisc, PubMed, Web of Science, EMbase, the Cochrane Library, and Clinical Trials. The databases were searched for articles published until June 2019. Two researchers independently screened the literature, extracted data, and evaluated the quality of the included literature. Meta-analysis was performed using RevMan5.3. RESULTS: Seventeen studies (1416 participants) were included. The differences between CIK/DC-CIK combination chemotherapy and chemotherapy alone were significant. The results displayed that the number of CD3+, CD4+, CD4+/CD8+, and NK cells was significantly increased after 1 to 2âweeks of treatment with CIK/DC-CIK cells in the treatment group (all Pâ<â.05). In addition, the results shown that 1-year overall survival was significantly prolonged (Pâ<â.0001) and quality of life was improved (Pâ=â.001) in EC chemotherapy combined with immunotherapy groups compared with conventional treatment. Furthermore, cytokine expression levels of interleukin 2 (IL-2), tumor necrosis factor α (TNF-α), and interleukin 12 (IL-12) were significantly increased (Pâ=â.0003) as well as the levels of immunoglobulins were elevated (Pâ<â.00001). Serum levels of tumor marker molecules, carcinoembryonic antigen (CEA), carbohydrate antigen (CA)-199, and CA-125 were lower in treatment groups than that of control groups (Pâ<â.00001). No fatal adverse reactions were noted (Pâ=â.04). CONCLUSIONS: It is safe and effective for patients to use chemotherapy combined with CIK/DC-CIK immunotherapy. Immunotherapy can simultaneously improve the antitumor immune response. Specifically, DC-CIK cells can increase T lymphocyte subsets, CIK cells, NK cells, and immunoglobulins in peripheral blood to enhance antitumor immunity. Therefore, combination therapy enhances the immune function and improves the therapeutic efficacy of patients with EC.