CYP19A1 mediates severe SARS-CoV-2 disease outcome in males

Aromatase, testosterone, TMPRSS2: determinants of COVID-19 severity

BACKGROUND

Male sex has been identified as a risk factor for worse COVID-19 outcomes. This sex difference has been mostly attributed to the complex role of sex hormones. Cell surface entry of SARS-CoV-2 is mediated by the transmembrane protease serine 2 (TMPRSS2) which is under transcriptional regulation by androgens. P450 aromatase enzyme converts androgens to estrogens. This study measured concentrations of aromatase enzyme, testosterone, estradiol, and TMPRSS-2 in plasma of hospitalized COVID-19 patients to elucidate the dynamics of sex-linked disparity in COVID-19 and correlate them with disease severity and mortality.

METHODS

In this prospective cohort study, a total of 265 patients (41% women), age 18 years and older, who had a positive COVID-19 PCR test and were hospitalized for COVID-19 at Memorial Hermann Hospital in Houston, (between May 2020 and May 2021) were enrolled in the study if met inclusion criteria. Plasma concentrations of Testosterone, aromatase, TMPRSS-2, and estradiol were measured by ELISA. COVID-19 patients were dichotomized based on disease severity into moderate-severe (n = 146) or critical (n = 119). Mann Whitney U and logistic regression were used to correlate the analytes with disease severity and mortality.

RESULTS

TMPRSS2 (2.5 ± 0.31 vs. 1.73 ± 0.21 ng/mL, p < 0.01) and testosterone (1.2 ± 0.1 vs. 0.44 ± 0.12 ng/mL, p < 0.01) were significantly higher in men as compared to women with COVID-19 after adjusting for age in a multivariate model. There was no sex difference seen in the level of estradiol and aromatase in COVID-19 patients. TMPRSS2 and aromatase were higher, while testosterone was lower in patients with increased COVID-19 severity. They were independently associated with COVID-19 severity, after adjusting for several baseline risk factors in a multivariate logistic regression model. In terms of mortality, TMPRRS2 and aromatase levels were significantly higher in non-survivors.

CONCLUSIONS

Our study demonstrates that testosterone, aromatase, and TMPRSS2 are markers of COVID-19 severity. Estradiol levels do not change with disease severity in COVID-19. In terms of mortality prediction, higher aromatase and TMPRSS-2 levels can be used to predict mortality from COVID-19 in hospitalized patients. COVID-19 has caused over a million deaths in the U.S., with men often getting sicker than women. Testosterone, a male hormone, helps control a protein called TMPRSS-2, which allows the COVID-19 virus to spread more easily in the body. A protein called aromatase converts the male hormone testosterone into the female hormone estrogen. It is thought that female hormone estrogen helps protect women from getting seriously ill from COVID-19. To understand the role of these hormones in COVID-19 and sex differences, we measured levels of testosterone, estrogen, aromatase (which turns testosterone into estrogen), and TMPRSS-2 in hospitalized COVID-19 patients. We also checked how this level might reflect the severity of the disease. We found that critically ill COVID-19 patients (the ones in ICU) had higher levels of TMPRSS-2 and aromatase, and lower testosterone levels. When we used these hormone levels to predict death in hospitalized COVID-19 patients, higher levels of TMPRSS-2 and aromatase were linked to a lower chance of survival.

Digit ratios and hospitalization for COVID-19: A test of the low-androgen-driven and high-androgen-driven theories of COVID-19 severity

BACKGROUND

Sex hormones are likely to be important determinants of COVID-19 severity, and two opposing explanations regarding severity, the low-androgen-driven and high-androgen-driven theories, seek to explain this pattern. Digit ratios are sex dependent (males < females) and are claimed to be markers for both prenatal and postnatal testosterone.

OBJECTIVES

Here, we use a measure of COVID-19severity (hospitalization), compare digit ratios in patients and controls and consider whether vaccination status changed these associations.

MATERIAL AND METHODS

Four digits were measured (2D, 3D, 4D, 5D). There were 194 participants (94 hospitalized patients [45 men] and 100 controls [53 men]) in Sample I and 162 participants (100 hospitalized [42 men], including 40 vaccinated and 62 controls [32 men]) in Sample II. Six ratios were calculated (2D:3D; 2D:4D; 2D:5D; 3D:4D; 3D:5D, 4D:5D) and compared between COVID-19 hospitalized and non-hospitalized patients and vaccinated and non-vaccinated.

RESULTS

In comparison to controls, we found higher ("feminized") means in patient ratios that included 5D (2D:5D; 3D:5D; 4D:5D) in both samples. The differences were independent of sex and age. Hospitalized patients with COVID-19 have higher (feminized) means and higher standard deviations (SDs) for 5D digit ratios.

DISCUSSION

Digit ratios are sex dependent (males < females) and are considered as markers for both prenatal and postnatal testosterone. If verified in future studies, the results will be helpful in regard to targeting mortality-reducing therapies for COVID-19 in certain groups of patients.

CONCLUSION

We conclude that the association between high (feminized) 5D ratios and hospitalization supports the low-androgen-driven theory of COVID-19 severity.

Sex-specific biphasic alpha-synuclein response and alterations of interneurons in a COVID-19 hamster model

BACKGROUND

Coronavirus disease 2019 (COVID-19) frequently leads to neurological complications after recovery from acute infection, with higher prevalence in women. However, mechanisms by which SARS-CoV-2 disrupts brain function remain unclear and treatment strategies are lacking. We previously demonstrated neuroinflammation in the olfactory bulb of intranasally infected hamsters, followed by alpha-synuclein and tau accumulation in cortex, thus mirroring pathogenesis of neurodegenerative diseases such as Parkinson's or Alzheimer's disease.

METHODS

To uncover the sex-specific spatiotemporal profiles of neuroinflammation and neuronal dysfunction following intranasal SARS-CoV-2 infection, we quantified microglia cell density, alpha-synuclein immunoreactivity and inhibitory interneurons in cortical regions, limbic system and basal ganglia at acute and late post-recovery time points.

FINDINGS

Unexpectedly, microglia cell density and alpha-synuclein immunoreactivity decreased at 6 days post-infection, then rebounded to overt accumulation at 21 days post-infection. This biphasic response was most pronounced in amygdala and striatum, regions affected early in Parkinson's disease. Several brain regions showed altered densities of parvalbumin and calretinin interneurons which are involved in cognition and motor control. Of note, females appeared more affected.

INTERPRETATION

Our results demonstrate that SARS-CoV-2 profoundly disrupts brain homeostasis without neuroinvasion, via neuroinflammatory and protein regulation mechanisms that persist beyond viral clearance. The regional patterns and sex differences are in line with neurological deficits observed after SARS-CoV-2 infection.

FUNDING

Federal Ministry of Health, Germany (BMG; ZMV I 1-2520COR501 to G.G.), Federal Ministry of Education and Research, Germany (BMBF; 03COV06B to G.G.), Ministry of Science and Culture of Lower Saxony in Germany (14-76403-184, to G.G. and F.R.).

Obesity and diabetes mellitus are associated with SARS-CoV-2 outcomes without influencing signature genes of extrapulmonary immune compartments at the RNA level

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which is responsible for eliciting Coronavirus disease 2019 (COVID-19) still challenges healthcare services worldwide. While many patients only suffer from mild symptoms, patients with some pre-existing medical conditions are at a higher risk for a detrimental course of disease. However, the underlying mechanisms determining disease course are only partially understood. One key factor influencing disease severity is described to be immune-mediated. In this report, we describe a post-mortem analysis of 45 individuals who died from SARS-CoV-2 infection. We could show that although sociodemographic factors and premedical conditions such as obesity and diabetes mellitus reduced survival time in our cohort, they were not associated with changes in the expression of immune-related signature genes at the RNA level in the blood, the gut, or the liver between these different groups. Our data indicate that obesity and diabetes mellitus influence SARS-CoV-2-related mortality, without influencing the extrapulmonary gene expression of immunity-related signature genes at the RNA level.