EQUOL, A SOYBEAN METABOLITE WITH ESTROGEN-LIKE FUNCTIONS, DECREASES LIPOPOLYSACCHARIDE-INDUCED HUMAN NEUTROPHIL EXTRACELLULAR TRAPS IN VITRO

ABSTRACT

Objective: Neutrophil extracellular traps (NETs) defend against acute infections. However, their overexpression causes organ failure during sepsis. Control of NET formation may improve the outcomes of patients with sepsis. Equol, a soybean isoflavone, is a female hormone analog, which prevents inflammation. We evaluated the effects of equol on NET formation in human neutrophils during inflammatory stimulation in vitro . Methods: Healthy volunteers provided blood samples. An enzyme-linked immunosorbent assay assessed serum equol concentrations. Neutrophil extracellular trap formation in neutrophils was induced by lipopolysaccharide treatment. Enzyme-linked immunosorbent assay quantified DNA-binding elastase, and immunostaining assessed NET formation. Reverse-transcription quantitative polymerase chain reaction and Western blotting detected G-protein-coupled receptor 30 (GPR30) or peptidyl arginine deiminase 4 (PAD4) expression. Flow cytometry assessed neutrophil phagocytic ability with inactivated Escherichia coli . Results: In neutrophils derived from males with low-serum equol levels (low-serum equol group), equol significantly decreased DNA-binding elastase levels and NET formation. Equol did not decrease NETs in neutrophils from males with high-serum equol levels. GPR30 expression of neutrophils was higher in the low-serum than in the high-serum equol group. PAD4 mRNA levels and nuclear PAD4 protein expression also decreased more than the vehicle control in the low-serum equol group. Equol did not alter the phagocytic ability of neutrophils. In neutrophils from young females, equol had no inhibitory effect on NET formation. Conclusions: Equol decreases lipopolysaccharide-induced NET formation in neutrophils from males via inhibition of PAD4 expression. Our findings provide a rationale for investigating a new therapeutic approach using equol to control neutrophil activity during sepsis.

Improving residential care amid COVID-19: The link between risk factors and hospitalization

AIM

This study was conducted to investigate the relationship between the hospitalizations and backgrounds of patients with coronavirus disease 2019 to identify specific risk factors.

METHODS

This retrospective study used health observation records to analyze the relationship between certain risk factors and the subsequent hospitalization of 321 patients who were discharged from a residential care facility between January 16 and February 8, 2021. The usefulness of a hospitalization prediction score, created based on the presence of comorbidities and sex, was examined.

RESULTS

Being older, male, and having a history of high blood pressure or vascular disease were all risk factors. A multivariate analysis with age and hospitalization predictive score as independent variables and hospitalization as the dependent variable showed that age (odds ratio: 1.07, 95 percent confidence interval: 1.03-1.11, p < 0.01) significantly increased hospitalization risk by 7 percent for every 1-year age increase. The median time from illness onset to hospitalization for all patients was 9 days (interquartile range: 8-10). Hypoxia was the most common cause of hospitalization. However, hypoxia and other symptoms, such as cough and dyspnea, were not correlated.

CONCLUSION

Given the pandemic, there may come another time when hospitals are not able to accommodate all patients who require care. In such instances, age, sex, the presence of comorbidities, and checking oxygen saturation regularly using a pulse oximeter around 9 days after the onset of the disease should all be considered important, as it may lead to improved and safer operation of overnight care facilities.

Dysfunctional Sars-CoV-2-M protein-specific cytotoxic T lymphocytes in patients recovering from severe COVID-19

Although the importance of virus-specific cytotoxic T lymphocytes (CTL) in virus clearance is evident in COVID-19, the characteristics of virus-specific CTLs related to disease severity have not been fully explored. Here we show that the phenotype of virus-specific CTLs against immunoprevalent epitopes in COVID-19 convalescents might differ according to the course of the disease. We establish a cellular screening method that uses artificial antigen presenting cells, expressing HLA-A^*24:02, the costimulatory molecule 4-1BBL, SARS-CoV-2 structural proteins S, M, and N and non-structural proteins ORF3a and nsp6/ORF1a. The screen implicates SARS-CoV-2 M protein as a frequent target of IFNγ secreting CD8⁺ T cells, and identifies M_198-206 as an immunoprevalent epitope in our cohort of HLA-A^*24:02 positive convalescent COVID-19 patients recovering from mild, moderate and severe disease. Further exploration of M_198-206-specific CD8⁺ T cells with single cell RNA sequencing reveals public TCRs in virus-specific CD8⁺ T cells, and shows an exhausted phenotype with less differentiated status in cells from the severe group compared to cells from the moderate group. In summary, this study describes a method to identify T cell epitopes, indicate that dysfunction of virus-specific CTLs might be an important determinant of clinical outcomes.

Diagnosis and long-term management of hydrolyzed wheat protein wheat-dependent exercise-induced anaphylaxis

Case

A 37-year-old woman was admitted to the emergency room with bilateral periorbital edema, hypotension, and expiratory stridor that developed 30 min after starting to hang out washing following consumption of a jam bun. Despite no food allergies or similar episodes, she had recently developed facial wheals after bathing.

Outcome

She was immediately and repeatedly administered adrenalin and succinic acid hydrocortisone sodium for wheat-dependent exercise-induced anaphylaxis. On the third hospital day, radioallergosorbent testing reactions to wheat, gluten, and omega-5 gliadin were mildly positive; skin-prick tests for hydrolyzed wheat protein and a face-wash challenge were positive. Therefore, we diagnosed hydrolyzed wheat protein wheat-dependent exercise-induced anaphylaxis. Despite advising her about hyposensitization, the episode recurred and an adrenalin auto-injector was prescribed.

Conclusion

Differentiating hydrolyzed wheat protein wheat-dependent exercise-induced anaphylaxis from conventional wheat-dependent exercise-induced anaphylaxis is important owing to their severity and similarities. Each requires long-term management of patients' etiological conditions by advising them about hyposensitization and prescribing adrenalin auto-injectors.