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BackgroundPrevious studies have reported that the susceptibility to coronavirus disease 2019 (COVID-19) is related to ABO blood group, but the relationship with Rh phenotype and MN blood group is unknown. China had adopted a strict control policy on COVID-19 until December 5, 2022, when local communities were liberalized. Therefore, we aimed to explore the correlation between ABO blood group, Rh phenotype, MN blood group and susceptibility to COVID-19 based on the time sequence of infection during the pandemic.MethodsA total of 870 patients who were routinely hospitalized in Ningbo Medical Center Lihuili Hospital from March 1, 2023 to March 31, 2023 were randomly selected to enroll in this study. Patients were divided into susceptible group and non-susceptible group, according to the time of their previous infection. The demographics and clinical information of the enrolled participants were collected from electronic medical records. The association of ABO blood group, Rh phenotype and MN blood group with susceptibility to COVID-19 was analyzed.ResultsA total of 650 cases (74.7%) had been infected with COVID-19, with 157 cases (18.0%) in the second week and 252 cases (29.0%) in the third week, reaching the peak of infection. Compared with the non-susceptible group, the susceptible group had no statistically significant differences in ABO blood group and Rh phenotype, but the proportion of N+ was higher (75.6% vs 68.9%, P = 0.030) and the proportion of MM was lower (24.4% vs 31.1%, P = 0.030). Consistent with this, ABO blood group and Rh phenotype were not significantly associated with susceptibility to COVID-19 (P>0.05), while N+ and MM were associated with susceptibility to COVID-19 (OR: 1.432, 95% confidence interval [CI]: 1.049, 1.954, P = 0.024; OR: 0.698, 95% CI: 0.512, 0.953, P = 0.024, respectively), after adjusting for age, sex, BMI, basic disease, and vaccination status in multivariate logistic regression analysis.ConclusionOur study showed that ABO blood group and Rh phenotype may not be related to the susceptibility to COVID-19, but MN blood group may be associated with the susceptibility to COVID-19.</div

Consort diagram detailing the selection and exclusion of patients.

Consort diagram detailing the selection and exclusion of patients.</p

Multivariate logistic regression analysis of ABO blood type, Rh phenotype, and MN blood type associated with susceptibility to COVID-19^b'*'.

Multivariate logistic regression analysis of ABO blood type, Rh phenotype, and MN blood type associated with susceptibility to COVID-19b'*'.</p

Comparison of indexes between susceptible group and non-susceptible group^b'*'.

Comparison of indexes between susceptible group and non-susceptible groupb'*'.</p

Demographics and basic clinical characteristics in the study group^b'*'.

Demographics and basic clinical characteristics in the study groupb'*'.</p

The difference in the distribution of ABO blood group between the study group and the control group.

The difference in the distribution of ABO blood group between the study group and the control group.</p

Risk of COVID-19 infection in the study population, according to ABO blood group, Rh phenotype and MN blood group.

A: unadjusted; B: adjusted for age, sex, BMI, basic disease and vaccination status.</p

Graphene oxide significantly inhibits cell growth at sublethal concentrations by causing extracellular iron deficiency

<p>Graphene oxide (GO)-based materials are increasingly being used in medical materials and consumer products. However, their sublethal effects on biological systems are poorly understood. Here, we report that GO (at 10 to 160 mg/L) induced significant inhibitory effects on the growth of different unicellular organisms, including eukaryotes (i.e. <i>Saccharomyces cerevisiae</i>, <i>Candida albicans</i>, and <i>Komagataella pastoris</i>) and prokaryotes (<i>Pseudomonas fluorescens</i>). Growth inhibition could not be explained by commonly reported cytotoxicity mechanisms such as plasma membrane damage or oxidative stress. Based on transcriptomic analysis and measurement of extra- and intracellular iron concentrations, we show that the inhibitory effect of GO was mainly attributable to iron deficiency caused by binding to the O-functional groups of GO, which sequestered iron and disrupted iron-related physiological and metabolic processes. This inhibitory mechanism was corroborated with supplementary experiments, where adding bathophenanthroline disulfonate—an iron chelating agent—to the culture medium exerted similar inhibition, whereas removing surface O-functional groups of GO decreased iron sequestration and significantly alleviated the inhibitory effect. These findings highlight a potential indirect detrimental effect of nanomaterials (i.e. scavenging of critical nutrients), and encourage research on potential biomedical applications of GO-based materials to sequester iron and enhance treatment of iron-dependent diseases such as cancer and some pathogenic infections.</p

Aft2 is required for the oxidative stress response.

<p>(A) Overnight cultures of each strain were resuspended in YPD medium with OD₆₀₀ of 0.1. 5 ul of cells in 10-fold serial dilutions were spotted onto solid YPD or YPD +1 mM Fe³⁺ medium that was supplemented with the indicated concentrations of H₂O₂. The plates were incubated at 30°C for 2 days and photographed. (B, C) Reactive oxygen species (ROS) and superoxide dismutase enzymes (SOD) activity were measured as described in Materials and methods.</p

Aft2, a Novel Transcription Regulator, Is Required for Iron Metabolism, Oxidative Stress, Surface Adhesion and Hyphal Development in <i>Candida albicans</i>

<div><p>Morphological transition and iron metabolism are closely relevant to <i>Candida albicans</i> pathogenicity and virulence. In our previous study, we demonstrated that <i>C. albicans</i> Aft2 plays an important role in ferric reductase activity and virulence. Here, we further explored the roles of <i>C. albicans</i> Aft2 in numerous cellular processes. We found that <i>C. albicans</i> Aft2 exhibited an important role in iron metabolism through bi-directional regulation effects on iron-regulon expression. Deletion of <i>AFT2</i> reduced cellular iron accumulation under iron-deficient conditions. Furthermore, both reactive oxygen species (ROS) generation and superoxide dismutase (SOD) activity were remarkably increased in the <i>aft2Δ/Δ</i> mutant, which were thought to be responsible for the defective responses to oxidative stress. However, we found that over-expression of <i>C. albicans AFT2</i> under the regulation of the strong <i>PGK1</i> promoter could not effectively rescue <i>Saccharomyces cerevisiae aft1Δ</i> mutant defects in some cellular processes, such as cell-wall assembly, ion homeostasis and alkaline resistance, suggesting a possibility that <i>C. albicans</i> Aft2 weakened its functional role of regulating some cellular metabolism during the evolutionary process. Interestingly, deletion of <i>AFT2</i> in <i>C. albicans</i> increased cell surface hydrophobicity, cell flocculation and the ability of adhesion to polystyrene surfaces. In addition, our results also revealed that <i>C. albicans</i> Aft2 played a dual role in regulating hypha-specific genes under solid and liquid hyphal inducing conditions. Deletion of <i>AFT2</i> caused an impaired invasive growth in solid medium, but an increased filamentous aggregation and growth in liquid conditions. Moreover, iron deficiency and environmental cues induced nuclear import of Aft2, providing additional evidence for the roles of Aft2 in transcriptional regulation.</p></div