Background: The COVID-19 infection is a novel virus that mainly targets the respiratory system via specific receptors without any coronavirus-targeted therapies. Many efforts have been made to prepare specific vaccines for COVID-19 or use of prefabricated vaccines of other similar viruses, especially severe acute respiratory syndrome (SARS), Middle East respiratory syndrome (MERS), and influenza (flu). We aimed to evaluate the effects of previous flu vaccine injection on severity of incoming COVID-19 infection. Methods: We conducted a large cross-sectional study of 529 hospitalized Iranian COVID patients to evaluate the severity of disease courses in patients with or without previous flu vaccination history using some main factors like length of hospitalization, need for the intensive care unit (ICU) admission and length of stay in the ICU for comparison between COVID-19 infected patients with or without flu vaccination history. For the quantitative data, we used independent-samples t and Mann-Whitney tests. The qualitative data were calculated using the Fisher exact and chi-square tests in IBM SPSS Statistics version 22 (SPSS Inc) and P value <0.05 was considered statistically significant. Results: There were no significant differences in the demographic data of patients, disease, and severity-related parameters between the 2 groups. It means that there were not any significant differences between patients with and without history of flu vaccination regarding mean days of hospitalization, percentage of needing to be admitted to the ICU, days being admitted to the ICU (8.44±6.36 vs 7.94±8.57; 17% vs 11.5%; and 1.17±3.09 vs 0.92±3.04, retrospectively) (p=0.883, 0.235, and 0.809, respectively). In the laboratory tests, in comparison between patients with and without history of previous flu vaccination, only lymphocytes count in the vaccine positive group was higher than the vaccine negative group (20.82±11.23 vs 18.04±9.71) (p=0.067) and creatine phosphokinase (CPK) levels were higher in the vaccine negative group (146.57±109.72 vs 214.15±332.06) (p=0.006). Conclusion: We did not find any association between flu vaccination and decrease in disease severity in our patients. It seems that patients with previous history of flu vaccination may experience less laboratory abnormalities in some parameters that could be interpreted in favor of lower overall inflammation; however, this study cannot answer this definitely because of its design. As we collected retrospective data from only alive discharged patients and had no healthy control group, we could not discuss the probable effect of the vaccine on the mortality rate or its probable protective role against the infection. We need more well-designed controlled studies with different populations in different geographic areas to address the controversies.

Laccase (EC 1.10.3.2; benzenediol; oxygen oxidoreductases) is a multi-copper oxidase that catalyzes the oxidation of phenols, polyphenols, aromatic amines, and different non-phenolic substrates with concomitant reduction of O2 to H2O. Enzymatic oxidation techniques have the potential of implementation in different areas of industrial fields. In this study, the Cohnella sp. A01 laccase gene was cloned into pET-26 (b+) vector and was transformed to E. coli BL21. Then it was purified using His tag affinity (Ni sepharose resin) chromatography. The estimated molecular weight was approximately 60 kDa using SDS-PAGE. The highest enzyme activity and best pH for 2,6-dimethoxyphenol (DMP) oxidation were recorded as 8 at 90 °C respectively. The calculated half-life and kinetic values including Km, Vmax, turn over number (kcat), and catalytic efficiency (kcat/Km) of the enzyme were 106 min at 90 °C and 686 μM, 10.69 U/ml, 20.3 S−, and 0.029 s−1 μM−1, respectively. The DMP was available as the substrate in all the calculations. Enzyme activity enhanced in the presence of Cu2+, NaCl, SDS, n-hexane, Triton X-100, tween 20, and tween 80, significantly. The binding residues were predicted and mapped upon the modeled tertiary structure of identified laccase. The remaining activity and structural properties of Cohnella sp. A01 laccase in extreme conditions such as high temperatures and presence of metals, detergents, and organic solvents suggest the potential of this enzyme in biotechnological and industrial applications. This process has been patented in Iranian Intellectual Property Centre under License No: 91325.

Hyperglycemia is a hallmark of diabetes, which is associated with protein glycation and misfolding, impaired cell metabolism and altered signaling pathways result in endoplasmic reticulum stress (ERS). We previously showed that L-lysine (Lys) inhibits the nonenzymatic glycation of proteins, and protects diabetic rats and type 2 diabetic patients against diabetic complications. Here, we studied some molecular aspects of the Lys protective role in high glucose (HG)-induced toxicity in C2C12 myotubes and 3T3-L1 adipocytes. C2C12 and 3T3-L1 cell lines were differentiated into myotubes and adipocytes, respectively. Then, they were incubated with normal or high glucose (HG) concentrations in the absence/presence of Lys (1 mM). To investigate the role of HG and/or Lys on cell apoptosis, oxidative status, unfolded protein response (UPR) and autophagy, we used the MTT assay and flow cytometry, spectrophotometry and fluorometry, RT-PCR and Western blotting, respectively. In both cell lines, HG significantly reduced cell viability and induced apoptosis, accompanying with the significant increase in reactive oxygen species (ROS) and nitric oxide (NO). Furthermore, the spliced form of X-box binding protein 1 (XBP1), at both mRNA and protein levels, the phosphorylated eukaryotic translation initiation factor 2α (p-eIf2α), and the Light chain 3 (LC3)II/LC3I ratio was also significantly increased. Lys alone had no significant effects on most of these parameters; but, treatment with HG plus Lys returned them all to, or close to, the normal values. The results indicated the protective role of Lys against glucotoxicity induced by HG in C2C12 myotubes and 3T3-L1 adipocytes.