Yeast autolysis affects the flavor and quality of beer. The regulation of yeast autolysis is a need for industrial beer production. Previous studies on brewer's yeast autolysis showed that the citric acid cycle-related genes had a great influence on yeast autolysis. To explore the contribution of isocitrate dehydrogenase genes in autolysis, the IDP1 and IDP2 genes were destroyed or overexpressed in typical lager yeast Pilsner. The destruction of IDP1 gene improved the anti-autolytic ability of yeast, and the anti-autolytic index after 96 h autolysis was 8.40, 1.5 times higher than that of the original strain. The destruction of IDP1 gene increased the supply of nicotinamide adenine dinucleotide phosphate (NADPH) and the NADPH/NADP⁺ ratio was 1.94. After fermentation, intracellular ATP level was 1.8 times higher than that of the original strain, while reactive oxygen species (ROS) was reduced by 10%. The destruction of IDP2 gene resulted in rapid autolysis and a decrease in the supply of NADPH. Anti-autolytic index after 96 h autolysis was 4.03 and the NADPH/NADP⁺ ratio was 0.89. After fermentation, intracellular ATP level was reduced by 8% compared with original strain, ROS was 1.3 times higher than that of the original strain. The results may help understand the regulation mechanism of citric acid cycle-related genes on yeast autolysis and provide a basis for the selection of excellent yeast with controllable anti-autolytic performance.
Humans ; Isocitrate Dehydrogenase/genetics* ; NADP ; Reactive Oxygen Species ; Autolysis ; Adenosine Triphosphate

Mitophagy is a process whereby cells selectively remove mitochondria through the mechanism of autophagy, which plays an important role in maintaining cellular homeostasis. In order to explore the effect of mitophagy genes on the antioxidant activities of Saccharomyces cerevisiae, mutants with deletion or overexpression of mitophagy genes ATG8, ATG11 and ATG32 were constructed respectively. The results indicated that overexpression of ATG8 and ATG11 genes significantly reduced the intracellular reactive oxygen species (ROS) content upon H₂O₂ stress for 6 h, which were 61.23% and 46.35% of the initial state, respectively. Notable, overexpression of ATG8 and ATG11 genes significantly increased the mitochondrial membrane potential (MMP) and ATP content, which were helpful to improve the antioxidant activities of the strains. On the other hand, deletion of ATG8, ATG11 and ATG32 caused mitochondrial damage and significantly decreased cell vitality, and caused the imbalance of intracellular ROS. The intracellular ROS content significantly increased to 174.27%, 128.68%, 200.92% of the initial state, respectively, upon H₂O₂ stress for 6 h. The results showed that ATG8, ATG11 and ATG32 might be potential targets for regulating the antioxidant properties of yeast, providing a new clue for further research.
Mitophagy/genetics* ; Saccharomyces cerevisiae/genetics* ; Antioxidants ; Hydrogen Peroxide/pharmacology* ; Reactive Oxygen Species

ObjectiveTo explore the clinical efficacy of compound Wufengcao liquid （CWL） on tuberculous ulcer and the influence on macrophage polarization. Method① Clinical experiment： A total of 145 patients with tuberculous ulcer who were treated in Nanjing Integrated Traditional Chinese and Western Medicine Hospital were randomized into observation group， control group Ⅰ， and control group Ⅱ according to the random number table method. In addition to the basic anti-tuberculosis chemotherapy， CWL， Kangfuxin liquid， and isoniazid solution （local external application） were respectively used in the observation group， control group Ⅰ， and control group Ⅱ. The treatment lasted 4 weeks for each group. The total effective rate in wound healing， traditional Chinese medicine（TCM） syndrome score， and histopathological morphology of wound were observed and the expression of inducible nitric oxide synthase （iNOS） and arginase-1 （Arg-1） in wound tissue was measured. ② Cell experiment： RAW264.7 cells were cultured in DMEM （10% fetal bovine serum， 1% double-antibody solution） in a cell incubator （37 °C， 5% CO₂）. Phorbol 12-myristate 13-acetate （PMA） was used to induce the differentiation of RAW264.7 cells into macrophages. Lipopolysaccharide （LPS） was employed to stimulate polarization of macrophages into M1 type and interleukin-4 （IL-4） to induce the polarization into M2 type. Kangfuxin solution， isoniazid solution， and CWL were respectively applied to the above cell model for 36 h. The cell supernatant was collected and centrifuged. Western blot was used to detect the protein expression of tumor necrosis factor-α （TNF-α）， transforming growth factor-β （TGF-β）， iNOS， and Arg-1， and flow cytometry （FCM） to detect the expression of CD86 and CD206. Result①Clinical experiment： The total effective rate in the CWL group ［98.0% （48/49）］ was higher than that in the control group Ⅰ ［87.5% （42/48）， χ²=3.962， P<0.05］ and control group Ⅱ ［83.3% （40/48）， χ²=6.162， P<0.05］. After 28 days of treatment， compared with control group Ⅰ and control group Ⅱ， CWL decreased the TCM syndrome score （P<0.05） and obviously improved the histopathological morphology of the wound. Immunohistochemistry results showed that the iNOS expression in local focus tissue was lower （P<0.05） and the expression of Arg-1 was higher （P<0.05， P<0.01） in the CWL group than in the control group Ⅰ and control group Ⅱ after 28 days of treatment. ② Cell experiment： Western blot assay showed that the expression of iNOS and TNF-α in LPS group increased compared with that in the M0 group （P<0.01） and the expression in the LPS+ isoniazid group， LPS+ Kangfuxin group， and LPS+CWL group was lower than that in the LPS group （P<0.05）. The expression of iNOS in LPS+Kangfuxin group and LPS+ CWL group was lower than that in the LPS+isoniazid group （P<0.05， P<0.01）， and the expression of TNF-α in LPS+ CWL group was lower than that in LPS+isoniazid group （P<0.01）. The expression of TNF-α in LPS+ CWL group decreased compared with that in the LPS+ Kangfuxin group （P<0.05）. The expression of Arg-1 and TGF-β in IL-4 group was higher than that in the M0 group （P<0.01）， and the expression in the IL-4+isoniazid group， IL-4+Kangfuxin group， and IL-4+ CWL group was higher than that in the IL-4 group （P<0.05）. The expression of Arg-1 and TGF-β in the IL-4+ Kangfuxin group and IL-4+CWL group was higher than that in the IL-4+isoniazid group （P<0.05， P<0.01）， and the expression was higher in the IL-4+CWL group than in the IL-4+Kangfuxin group （P<0.05， P<0.01）. The FCM result showed that the expression of CD86 and CD206 in LPS group and IL-4 group was higher than that in M0 group （P<0.01）. CD86 expression in LPS+isoniazid group， LPS+ Kangfuxin group， and LPS+CWL group was lower than that in the LPS group （P<0.01）. The expression of CD86 in LPS+Kangfuxin group and LPS+ CWL group increased compared with that in the LPS+isoniazid group （P<0.01）， and the expression was higher in the LPS+ CWL group than in the LPS+Kangfuxin group （P<0.01）. CD206 expression in IL-4+ isoniazid group， IL-4+Kangfuxin liquor group， and IL-4+ CWL group was increased compared with that in the IL-4 group （P<0.01）. CD206 expression in IL-4+Kangfuxin liquid group and IL-4+ CWL group was decreased compared with that in the IL-4+isoniazid group （P<0.01）. CD206 expression in IL-4+CWL group was lower than that in the IL-4+ Kangfuxin group （P<0.05）. ConclusionCWL can promote the healing of tuberculous ulcers， and the mechanism is that it inhibits the expression of iNOS， TNF-α， and CD86 and promotes the expression of Arg-1， TGF-β， and CD206， thereby regulating M1/M2 polarization balance.

Objective:To investigate the value of magnetization transfer imaging (MTI) and fat suppression T 2WI (FS-T 2WI) in predicting the clinical activity of Graves ophthalmopathy (GO). Methods:From October 2020 to July 2021, 64 GO patients were prospectively enrolled in the First Affiliated Hospital of Nanjing Medical University. According to the clinical activity score (CAS), the patients were divided into active group (CAS≥3, 39 patients and 78 eyes) and inactive group (CAS<3, 25 patients and 50 eyes). The coronal MTI and FS-T 2WI were scanned for pre-treatment assessment. Magnetization transfer ratio (MTR) of extraocular muscles, and signal intensity ratio (SIR) between extraocular muscles and temporalis were measured, respectively. The independent-sample t-test was used to compare the MTR and SIR between two groups. The correlations between MRI parameters and CAS were analyzed using Spearman correlation analysis. The receiver operating characteristic (ROC) curve was performed to evaluate the value of each and combined parameters for predicting the clinical activity of GO. The DeLong test was used to compare the area under the curve (AUC). Results:The MTR of active group and inactive group were 0.45±0.04 and 0.51±0.04, respectively, the difference was statistically significant ( t=7.62, P<0.001). The SIR were 3.4±0.6 and 2.6±0.5, respectively, and the difference was also statistically significant ( t=-8.20, P<0.001). MTR was negatively correlated with CAS ( r=-0.46, P<0.001), while SIR was positively correlated with CAS ( r=0.63, P<0.001). The AUC of MTR, SIR and the combination of MTR and SIR for predicting the clinical activity of GO were 0.840, 0.845 and 0.905, respectively. The combination of MTR and SIR showed higher performance than MTR or SIR alone, and the differences were statistically significant ( Z=2.61, P=0.009; Z=2.15, P=0.032). Conclusions:The quantitative parameters of MTI and FS-T 2WI, namely MTR and SIR, can be used to evaluate the clinical activity of GO. Integrating MTI and FS-T 2WI can improve the diagnostic efficiency.

Lager yeast is the most popular yeast strain used for beer production in China. The flocculation of yeast plays an important role in cell separation at the end of fermentation. Therefore, appropriately enhancing the flocculation capability of the lager yeast without affecting its fermentation performance would be desirable for beer industry. Our previous study showed that the defect of gene RIM21 might contribute to the enhanced flocculation capability of a lager yeast G03. To further investigate the role of the RIM21 gene in flocculation of strain G03, this study constructed a RIM21-deleted mutant strain G03-RIM21Δ through homologous recombination. Deletion of RIM21 improved the flocculation capability of strain G03 during wort fermentation at 11 °C without changing its fermentation performance significantly. The expression of FLO5, Lg-FLO1 and some other genes involved in cell wall integrity pathway were up-regulated in strain G03-RIM21Δ. In addition, the disruption of RIM21 enhanced resistance of yeast cells to cell wall inhibitors. These results provide a basis for elucidating the flocculation mechanism of lager yeast under low-temperature fermentation conditions.
Beer ; Fermentation ; Flocculation ; Receptors, Cell Surface ; Saccharomyces/metabolism* ; Saccharomyces cerevisiae/metabolism* ; Saccharomyces cerevisiae Proteins/metabolism*

HuR (human antigen R), an mRNA-binding protein responsible for poor prognosis in nearly all kinds of malignancies, is a potential anti-tumor target for drug development. While screening HuR inhibitors with a fluorescence polarization (FP) based high-throughput screening (HTS) system, the clinically used drug eltrombopag was identified. Activity of eltrombopag on molecular level was verified with FP, electrophoretic mobility shift assay (EMSA), simulation docking and surface plasmon resonance (SPR). Further, we showed that eltrombopag inhibited cell proliferation of multiple cancer cell lines and macrophages, and the anti-tumor activity was also demonstrated in a 4T1 tumor-bearing mouse model. The data showed that eltrombopag was efficient in reducing microvessels in tumor tissues. We then confirmed the HuR-dependent anti-angiogenesis effect of eltrombopag in 4T1 cells and RAW264.7 macrophages with qRT-PCR, HuR-overexpression and HuR-silencing assays, RNA stability assays, RNA immunoprecipitation and luciferase assays. Finally, we analyzed the anti-angiogenesis effect of eltrombopag on human umbilical vein endothelial cells (HUVECs) mediated by macrophages with cell scratch assay and Matrigel angiogenesis assay. With these data, we revealed the HuR-dependent anti-angiogenesis effect of eltrombopag in breast tumor, suggesting that the existing drug eltrombopag may be used as an anti-cancer drug.

1,3-1,4-β-glucanase (E.C.3.2.1.73) is an important industrial enzyme which cleave β-glucans into oligosaccharides through strictly cutting the β-1,4 glycosidic bonds in 3-O-substituted glucopyranose units. Microbial 1,3-1,4-β-glucanase belongs to retaining glycosyl hydrolases of family 16 with a jellyroll β-sandwich fold structure. The present paper reviews the industrial application and protein engineering of microbial β-glucanases in the last decades and forecasts the research prospects of microbial β-glucanases.
Amino Acid Sequence ; Glycoside Hydrolases ; Models, Molecular ; Protein Engineering ; Substrate Specificity

Yeast cell wall plays an important role in the establishment and maintenance of cell morphology upon the cell wall stress. The cell wall of yeast consists of β-glucans, mannoproteins and chitin. The composition and structure remodel due to cell wall stress. Brewer's yeast cell wall exhibits stress response during long-term acclimation in order to adapt to environmental changes. This paper reviews the composition and structure of yeast cell wall and the molecular mechanisms of cell wall remodeling and signal pathway regulation.
Cell Wall ; Chitin ; Saccharomyces cerevisiae

The autolysis of brewer's yeast seriously affects the quality of beer and the quality of yeast is considered as one of the key factors in beer brewing. Previous studies on brewer's yeast autolysis showed that RLM1 gene, an important transcription factor in cell integrity pathway, is closely related to the autolysis of yeast. In this study, RLM1 was knocked out and overexpressed in a haploid brewer's yeast. RLM1 disruption resulted in poor anti-autolysis performance of yeast, whereas overexpression of RLM1 contributed to the anti-autolytic ability of yeast. In addition, RLM1 gene knockout affected the osmotic stress resistance, cell wall damage resistance, nitrogen starvation resistance and temperature tolerance of yeast strain. The transcriptional level of GAS1 involved in cell wall assembly and DNA damage response was regulated along with the expression of RLM1, whereas other genes in CWI pathway did not show apparent regularity. RLM1 might mainly affect the expression of GAS1 so as to improve the stress resistance of lager yeast in harsh environment. The result from this study help further understand the mechanism of yeast autolysis and lay a foundation for breeding brewer's yeast strain with better anti-autolytic ability.
Autolysis ; Beer ; Cell Wall ; Humans ; MADS Domain Proteins ; Saccharomyces cerevisiae ; Saccharomyces cerevisiae Proteins

Biofilms are microbial communities composed of bacteria cells and self-produced extracellular polymeric substances and lead to antibiotic resistance, forming a great threat in the fields of medicine, food industries and so on. The formation of biofilms is a multi-stage dynamic process regulated by multiple mechanisms. Recently, researchers paid much more attention to the related research areas of biofilms, especially the detection methods of biofilms. This paper introduced the characteristics and formation process of biofilms as well as the effects of quorum sensing on biofilms development. Meanwhile, we discussed the detection methods of biofilms, especially electrochemical impedance spectroscopy (EIS) in detection of biofilms in detail. Furthermore, we reviewed and predicted that microfluidic chips based EIS served as an in-situ and online monitoring method for biofilms growth.