Exploration of the Regulatory Mechanism of Secondary Metabolism by Comparative Transcriptomics in Aspergillus flavus

Mycotoxins cause a huge threaten to agriculture, food safety, and human and animal life. Among them, aflatoxins (AFs) have always been considered the most potent carcinogens, and filamentous fungi from Aspergillus genus are their major producers, especially A. flavus. Although the biosynthesis path of these chemicals had been well-identified, the regulatory mechanisms controlling expression of AF gene cluster were poorly understood. In this report, genome-wide transcriptome profiles of A. flavus from AF conducing [yeast sucrose media (YES)] and non-conducing [yeast peptone media (YEP)] conditions were compared by using deep RNA sequencing (RNA-seq), and the results revealed that AF biosynthesis pathway and biosynthesis of amino acids were significantly upregulated in YES vs. YEP. Further, a novel LaeA-like methyltransferase AFLA_121330 (Lael1) was identified for the first time, to play a specific role in the regulation of AF biosynthesis. Contrary to LaeA, which gene deletion reduced the level, lael1 deletion resulted in a significant increase in AF production. Further, co-expression network analysis revealed that mitochondrial pyruvate transport and signal peptide processing were potentially involved in AF synthesis for the first time, as well as biological processes of ribosome, branched-chain amino acid biosynthetic process and translation were co-regulated by AfRafA and AfStuA. To sum up, our analyses could provide novel insights into the molecular mechanism for controlling the AF and other secondary metabolite synthesis, adding novel targets for plant breeding and making fungicides

Ultra-Processed Food Consumption and Risk of Type 2 Diabetes:Three Large Prospective U.S. Cohort Studies

OBJECTIVE We examined the relationship between ultra-processed food (UPF) intake and type 2 diabetes (T2D) risk among 3 large U.S. cohorts, conducted a meta-analysis of prospective cohort studies, and assessed meta-evidence quality. RESEARCH DESIGN AND METHODS We included 71,871 women from the Nurses’ Health Study, 87,918 women from the Nurses’ Health Study II, and 38,847 men from the Health Professional Follow-Up Study. Diet was assessed using food frequency questionnaires and UPF was categorized per the NOVA classification. Associations of total and subgroups of UPF with T2D were assessed using Cox proportional hazards models. We subse-quently conducted a meta-analysis of prospective cohort studies on total UPF and T2D risk, and assessed meta-evidence quality using the NutriGrade scoring system. RESULTS Among the U.S. cohorts (5,187,678 person-years; n = 19,503 T2D cases), the haz-ard ratio for T2D comparing extreme quintiles of total UPF intake (percentage of grams per day) was 1.46 (95% CI 1.39–1.54). Among subgroups, refined breads; sauces, spreads, and condiments; artificially and sugar-sweetened beverages; an-imal-based products; and ready-to-eat mixed dishes were associated with higher T2D risk. Cereals; dark and whole-grain breads; packaged sweet and savory snacks; fruit-based products; and yogurt and dairy-based desserts were associated with lower T2D risk. In the meta-analysis (n = 415,554 participants; n = 21,932 T2D cases), each 10% increment in total UPF was associated with a 12% (95% CI 10%–13%) higher risk. Per NutriGrade, high-quality evidence supports this relationship. CONCLUSIONS High-quality meta-evidence shows that total UPF consumption is associated with higher T2D risk. However, some UPF subgroups were associated with lower risk in the U.S. cohorts.</p

Long non-coding RNAs and JAK/STAT signaling pathway regulation in colorectal cancer development

Colorectal cancer (CRC) is one of the main fatal cancers. Cell signaling such as Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling substantially influences the process of gene expression and cell growth. Long non-coding RNAs (lncRNAs) play regulatory roles in cell signaling, cell proliferation, and cancer fate. Hence, lncRNAs can be considered biomarkers in cancers. The inhibitory or activating effects of different lncRNAs on the JAK/STAT pathway regulate cancer cell proliferation or tumor suppression. Additionally, lncRNAs regulate immune responses which play a role in immunotherapy. Mechanisms of lncRNAs in CRC via JAK/STAT regulation mainly include cell proliferation, invasion, metastasis, apoptosis, adhesion, and control of inflammation. More profound findings are warranted to specifically target the lncRNAs in terms of activation or suppression in hindering CRC cell proliferation. Here, to understand the lncRNA cross-talk in CRC through the JAK/STAT signaling pathway, we collected the related in vitro and in vivo data. Future insights may pave the way for the development of novel diagnostic tools, therapeutic interventions, and personalized treatment strategies for CRC patients

Listeriosis in mainland China: A systematic review

Objective: The aim of this study was to conduct a systematic review to better understand the epidemiological and clinical characteristics of listeriosis patients in mainland China. Methods: The six most widely used Chinese and English language databases were searched. The records of patients with listeriosis in mainland China reported during the years 2011–2017 were extracted. The clinical data of patients and information on clinical isolates of Listeria were collected and analyzed. Results: In total, 136 records were identified, reporting 562 patients with listeriosis. The number of patients was much higher than that reported in the previous decade. The 227 non-perinatal listeriosis patients included had a mortality rate of 23.78%. Of the 231 perinatal listeriosis patients, 32.68% resulted in abortion and/or newborn death. All listeriosis cases were reported as being sporadic. The listeriosis was traced to infection via a meat product in only three patients, while 33.12% were healthcare-associated infections. Conclusions: The number of patients with listeriosis in mainland China may have been underestimated previously. Perinatal cases in mainland China account for a much higher proportion than is usually described. Considering the high number of listeriosis patients in China, a comprehensive monitoring system for Listeria is urgently needed. Keywords: Listeriosis, Foodborne disease, China, Revie

Application of similarity analysis to flood forecasting

[Objective] There are plenty of useful information in hydrological observations. Predicting future flood on the basis of similarity information in historical records is an effective and promising approach. [Method] In this paper, a multi-measure similarity analysis method of rainstorms is developed based on “quantity”, “type” similarity indicators, the earth mover’s distance (EMD) and the rainstorm distribution similarity indicator. Search the similar rainstorm and its corresponding typical flood in historical library and then scale the typical flood process according to the ratio of rainfall amounts to achieve flood forecasting. [Result] The method is applied to a case study in Xinmiao station of Kuye River. The results show that with the accelerating information of rainstorm and flood process, the forecasted flood process is updated continuously, and the prediction accuracy is gradually increasing. [Conclusion] The proposed similarity analysis method is effective and applicable to flood forecasting

The Putative Histone Methyltransferase DOT1 Regulates Aflatoxin and Pathogenicity Attributes in Aspergillus flavus

Lysine methyltransferases transfer methyl groups in specific lysine sites, which regulates a variety of important biological processes in eukaryotes. In this study, we characterized a novel homolog of the yeast methyltransferase DOT1 in A. flavus, and observed the roles of dot1 in A. flavus. Deletion of dot1 showed a significant decrease in conidiation, but an increase in sclerotia formation. A change in viability to multiple stresses was also found in the Δdot1 mutant. Additionally, aflatoxin (AF) production was found severely impaired in the Δdot1 mutant. Further analysis by qRT-PCR revealed that the transcription of AF structural genes and their regulator gene aflS were prominently suppressed in the Δdot1 mutant. Furthermore, our data revealed that Dot1 is important for colonizing maize seeds in A. flavus. Our research indicates that Dot1 is involved in fungal development, aflatoxin biosynthesis and fungal virulence in A. flavus, which might provide a potential target for controlling A. flavus with new strategies

G Protein α Subunit GpaB is Required for Asexual Development, Aflatoxin Biosynthesis and Pathogenicity by Regulating cAMP Signaling in Aspergillus flavus

The heterotrimeric G proteins are critical for signal transduction and function in numerous biological processes including vegetative growth, asexual development and fungal virulence in fungi. Here, we identified four G protein alpha subunits (GanA, GpaB, FadA and GaoC) in the notorious Aflatoxin-producing fungus Aspergillus flavus. GanA, GpaB and FadA have homologues in other fungal species, while GaoC is a novel one. Here, we showed that the loss function of gpaB displayed a defect in conidiophore formation and considerably reduced expression levels of conidia-specific genes brlA and abaA. A decreased viability of cell wall integrity stress and oxidative stress were also found in the ∆gpaB mutant. More importantly, aflatoxin (AF) biosynthesis and infection on crop seeds were severely impaired in the gpaB-deficient mutant. Further analyses demonstrated that the intracellular cAMP levels significantly reduced in the gpaB-deficient mutant compared to wildtype strains. Additionally, an alteration of PKA activities in the ∆gpaB mutant was also found. Overall, our results indicated that GpaB played diverse roles in asexual sporulation, AF biosynthesis and virulence by regulating cAMP signaling in Aspergillus flavus

Vaccinia virus viability under different environmental conditions and different disinfectants treatment

Monkeypox (mpox) outbreak in 2022 has caused more than 91,000 cases, has spread to 115 countries, regions, and territories, and has thus attracted much attention. The stability of poxvirus particles in the environment is recognized as an important factor in determining their transmission. However, few studies have investigated the persistence of poxviruses on material surfaces under various environmental conditions, and their sensitivity to biocides. Here, we systematically measured the stability of vaccinia virus (VACV) under different environmental conditions and sensitivity to inactivation methods via plaque assay, quantitative real-time polymerase chain reaction (qPCR), and Gaussia luciferase (G-luciferase) reporter system. The results show that VACV is stable on the surface of stainless steel, glass, clothing, plastic, towel, A4 paper, and tissue and persists much longer at 4 °C and −20 °C, but is effectively inactivated by ultraviolet (UV) irradiation, heat treatment, and chemical reagents. Our study raises the awareness of long persistence of poxviruses in the environment and provides a simple solution to inactivate poxviruses using common disinfectants, which is expected to help the control and prevention of mpox virus and future poxvirus outbreaks