Evaluation of Cell Responses of <i>Saccharomyces cerevisiae</i> under Cultivation Using Wheat Bran as a Nutrient Resource by Analyses of Growth Activities and Comprehensive Gene Transcription Levels

Wheat bran has high nutritional values and is also cheaper than yeast nitrogen base as an important component of a medium. Although its use in microbial cultivations is expected, research and development has hardly progressed so far. In this study, with experimental Saccharomyces cerevisiae BY4741, the cell responses to wheat bran as a nutrient were evaluated by analyses of cell growth, ethanol production, and comprehensive gene transcription levels. Comparing wheat bran and yeast nitrogen base, BY4741 showed specific growth rates of 0.277 ± 0.002 and 0.407 ± 0.035 as a significant difference. Additionally, wheat bran could be used as a restricted media component like yeast nitrogen base. However, in 24 h of cultivation with wheat bran and yeast nitrogen base, although conversion ratios of ethanol productions showed no significant difference at 63.0 ± 7.2% and 62.5 ± 8.2%, the ratio of cell production displayed a significant difference at 7.31 ± 0.04% and 4.90 ± 0.16%, indicating a different cell response. In fact, the comprehensive evaluation of transcription levels strongly suggested major changes in glucose metabolism. This study indicated that BY4741 could switch transcription levels efficiently to use wheat bran

Association between &gamma;-Glutamyl Transpeptidase and SARS-CoV-2 Spike Antibody Titers among BNT162b2 Vaccine Recipients

Background: Increased &gamma;-glutamyl transpeptidase (GGT) levels can deplete plasma glutathione, which in turn impairs immune regulation; however, evidence on GGT levels and post-vaccine immunogenicity is lacking. Objective: To examine the association between GGT and SARS-CoV-2 spike IgG antibodies. Methods: Participants were 1479 medical staff (aged 21 to 75 years) who received a SARS-CoV-2 antibody test after their second vaccine and whose GGT levels were measured before the vaccine rollout. Elevated and highly elevated GGT levels were defined as 51&ndash;80 and &ge;81 U/L, respectively. Multivariable linear regression was used to calculate the means of SARS-CoV-2 spike IgG. Results: In a basic model, both elevated and highly elevated GGT levels were associated with significantly lower antibody titers. The ratio of mean (95% CI) was 0.83 (0.72&ndash;0.97) and 0.69 (0.57&ndash;0.84) for elevated and highly elevated GGT levels, respectively. However, these associations were largely attenuated after additional adjustment for potential confounders. An inverse association between GGT levels and antibody titers was found in women [0.70 (0.51&ndash;0.97)], normal-weight adults [0.71 (0.51&ndash;0.98)], and non-drinkers [0.73 (0.46&ndash;1.14)] but not in men, overweight adults, and alcohol drinkers. Conclusions: Circulating GGT concentrations were associated with the humoral immune response after COVID-19 vaccination, but this relationship could be ascribed to confounders such as sex, BMI, and alcohol drinking rather than GGT per se

High diagnostic accuracy of quantitative SARS-CoV-2 spike-binding-IgG assay and correlation with in vitro viral neutralizing activity

Background: Antibody testing can easily evaluate the clinical status of patients, aid in the diagnosis of multisystem inflammatory syndrome, and monitor the immunity level in the population. However, the applicability of serological tests in detecting antibodies against the severe acute respiratory syndrome 2 (SARS-CoV-2) spike-binding protein remains limited. This study aimed to quantify both serum-derived neutralizing immunoglobulin-G (IgG) antibody activity and the amount of anti-SARS-CoV-2 Spike-IgG (S-IgG) in convalescent sera/plasmas and evaluate the direct correlation between the in vitro IgG-EC50 values and S-IgG values. Methods: We evaluated the neutralizing activity of purified IgG (IgG-EC50), quantified S-IgG in the serum/plasma of consecutive COVID-19 convalescent individuals using a cell-based virus-neutralizing assay, and determined the correlation between IgG-EC50 and S-IgG. In addition, we evaluated rational cut-off values using the receiver operating characteristic (ROC) curve and calculated the sensitivity and specificity of the quantitative S-IgG assay for moderate and high IgG-EC50. Results: A high correlation was observed between S-IgG and IgG-EC50 with a Spearman's ρ value of −0.748 (95 % confidence interval [CI]: −0.804–0.678). Using an IgG-EC50 of 50 μg/mL and 20 μg/mL as the cut-off values for moderate and high in vitro neutralizing activity, respectively, the Youden's index values of 287.5 binding antibody units (BAU)/mL and 454.1 BAU/mL determined from the ROC curve showed the highest diagnostic accuracy, with Kappa values of 0.884 (95 % CI: 0.823–0.946) and 0.920 (95 % CI: 0.681–0.979), respectively. Conclusions: Quantitative S-IgG tests are a useful and convenient tool for estimating in vitro virus-neutralizing activity, with a high correlation with IgG-EC50 when the rational cut-off value is carefully determined

Inhibition of DNA Methylation at the <i>MLH1</i> Promoter Region Using Pyrrole–Imidazole Polyamide

Aberrant DNA methylation causes major epigenetic changes and has been implicated in cancer following the inactivation of tumor suppressor genes by hypermethylation of promoter CpG islands. Although methylated DNA regions can be randomly demethylated by 5-azacytidine and 5-aza-2′-deoxycytidine, site-specific inhibition of DNA methylation, for example, in the promoter region of a specific gene, has yet to be technically achieved. Hairpin pyrrole (Py)–imidazole (Im) polyamides are small molecules that can be designed to recognize and bind to particular DNA sequences. In this study, we synthesized the hairpin polyamide MLH1_–16 (Py-Im-β-Im-Im-Py-γ-Im-Py-β-Im-Py-Py) to target a CpG site 16 bp upstream of the transcription start site of the human <i>MLH1</i> gene. <i>MLH1</i> is known to be frequently silenced by promoter hypermethylation, causing microsatellite instability and a hypermutation phenotype in cancer. We show that MLH1_–16 binds to the target site and that CpG methylation around the binding site is selectively inhibited in vitro. MLH1_non, which does not have a recognition site in the <i>MLH1</i> promoter, neither binds to the sequence nor inhibits DNA methylation in the region. When MLH1_–16 was used to treat RKO human colorectal cancer cells in a remethylating system involving the <i>MLH1</i> promoter under hypoxic conditions (1% O₂), methylation of the <i>MLH1</i> promoter was inhibited in the region surrounding the compound binding site. Silencing of the <i>MLH1</i> expression was also inhibited. Promoter methylation and silencing of <i>MLH1</i> were not inhibited when MLH1_non was added. These results indicate that Py–Im polyamides can act as sequence-specific antagonists of CpG methylation in living cells