17β-estradiol reduces SARS-CoV-2 infection in vitro

Antiviral, anti-inflammatory and antioxidant effects of curcumin and curcuminoids in SH-SY5Y cells infected by SARS-CoV-2

COVID-19, caused by SARS-CoV-2, affects neuronal cells, causing several symptoms such as memory loss, anosmia and brain inflammation. Curcuminoids (Me08 e Me23) and curcumin (CUR) are derived from Curcuma Longa extract (EXT). Many therapeutic actions have been linked to these compounds, including antiviral action. Given the severe implications of COVID-19, especially within the central nervous system, our study aims to shed light on the therapeutic potential of curcuminoids against SARS-CoV-2 infection, particularly in neuronal cells. Here, we investigated the effects of CUR, EXT, Me08 and Me23 in human neuroblastoma SH-SY5Y. We observed that Me23 significantly decreased the expression of plasma membrane-associated transmembrane protease serine 2 (TMPRSS2) and TMPRSS11D, consequently mitigating the elevated ROS levels induced by SARS-CoV-2. Furthermore, Me23 exhibited antioxidative properties by increasing NRF2 gene expression and restoring NQO1 activity following SARS-CoV-2 infection. Both Me08 and Me23 effectively reduced SARS-CoV-2 replication in SH-SY5Y cells overexpressing ACE2 (SH-ACE2). Additionally, all of these compounds demonstrated the ability to decrease proinflammatory cytokines such as IL-6, TNF-α, and IL-17, while Me08 specifically reduced INF-γ levels. Our findings suggest that curcuminoid Me23 could serve as a potential agent for mitigating the impact of COVID-19, particularly within the context of central nervous system involvement.

Knockout of IRF3 and IRF7 genes by CRISPR/Cas9 technology enhances porcine virus replication in the swine testicular (ST) cell line

Antiviral vaccines for pig diseases are essential to prevent epidemic outbreaks. However, their production is often hindered by inefficient manufacturing processes that yield lower quantities of the vaccine. To accelerate the progress of various areas of bioproduction, we have considered the necessity of enhancing viral replication efficiency by optimizing ST (swine testicular) cell lines that are commonly utilized in virus manufacturing. CRISPR/Cas9 gene-editing technology were utilized to create IRF3 or IRF7 knockout cell lines that facilitate high-titer viral stock production. Compared to the parental cell lines, the ST IRF3/7 KO cell line displayed a compromised antiviral response to a panel of viruses (Porcine epidemic diarrhea virus, Senecavirus A, Parainfluenza virus 5, and Getah virus), as evidenced by decreased expression of interferon and certain antiviral factors. The inhibition of these responses led to heightened viral replication and increased cytopathic effects, ultimately promoting apoptosis. As a result, the development of these cell lines offers a more efficient approach for biopharmaceutical companies to boost their virus production and reduce associated costs.

Removal of Soluble ACE2 in VeroE6 Cells by 17β-Estradiol Reduces SARS-CoV-2 Infectivity

Women are less susceptible than men to coronavirus disease 2019 (COVID-19), which might be due to the female steroid hormone 17β-estradiol. We hypothesized that 17β-estradiol removes the soluble portion of angiotensin-converting enzyme 2 (sACE2) to which severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds in host cells and that sACE2 then binds to the virus, thereby reducing the infectivity. In the present study, VeroE6/serine protease 2 transmembrane protein (TMPRSS2) cells were infected with pseudo SARS-CoV-2 viruses and used as our model system. This infectivity was reduced by the application of 17β-estradiol. After applying 17β-estradiol to the VeroE6/TMPRSS2 cells, we used a sandwich enzyme-linked immunosorbent assay (ELISA) to measure the sACE2 concentration in the culture medium. Our findings revealed that 17β-estradiol removes sACE2 from VeroE6/TMPRSS2 cells. Furthermore, the pseudo SARS-CoV-2 viruses were incubated in culture medium with ACE2 collected from 17β-estradiol-treated VeroE6/TMPRSS2 cells, and the viruses were measured with an ultrasensitive ELISA using anti-spike protein antibodies. The amount of spike proteins decreased according to the concentration of 17β-estradiol applied. These results clearly demonstrated that the soluble portion of ACE2, which was removed from 17β-estradiol-treated VeroE6/TMPRSS2 cells, bound to the spike proteins of SARS-CoV-2, thereby reducing COVID-19 infectivity.

Mapping the Lipid Signatures in COVID-19 Infection: Diagnostic and Therapeutic Solutions

The COVID-19 pandemic ignited research centered around the identification of robust biomarkers and therapeutic targets. SARS-CoV-2, the virus responsible, hijacks the metabolic machinery of the host cells. It relies on lipids and lipoproteins of host cells for entry, trafficking, immune evasion, viral replication, and exocytosis. The infection causes host cell lipid metabolic remodelling. Targeting lipid-based processes is thus a promising strategy for countering COVID-19. Here, we review the role of lipids in the different steps of the SARS-CoV-2 pathogenesis and identify lipid-centric targetable avenues. We discuss lipidome changes in infected patients and their relevance as potential clinical diagnostic or prognostic biomarkers. We summarize the emerging direct and indirect therapeutic approaches for targeting COVID-19 using lipid-inspired approaches. Given that viral protein-targeted therapies may become less effective due to mutations in emerging SARS-CoV-2 variants, lipid-inspired interventions may provide additional and perhaps better means of combating this and future pandemics.

Disruptive 3D in vitro models for respiratory disease investigation: A state-of-the-art approach focused on SARS-CoV-2 infection

COVID-19, along with most respiratory diseases in the medical field, demonstrates significant ability to take its toll on global population. There is a particular difficulty in studying these conditions, which stems especially from the short supply of in vitro models for detailed investigation, the specific therapeutic knowledge required for disease scrutinization and the occasional need of BSL-3 [Biosafety Level 3] laboratories for research. Based on this, the process of drug development is hampered to a great extent. In the scenario of COVID-19, this difficulty is even more substantial on account of the current undefinition regarding the exact role of the ACE2 [Angiotensin-converting enzyme 2] receptor upon SARS-CoV-2 kinetics in human cells and the great level of demand in the investigation process of ACE2, which usually requires the laborious and ethically complicated usage of transgenic animal models overexpressing the receptor. Moreover, the rapid progression of the aforementioned diseases, especially COVID-19, poses a crucial necessity for adequate therapeutic solutions emergence. In this context, the work herein presented introduces a groundbreaking set of 3D models, namely spheroids and MatriWell cell culture inserts, whose remarkable ability to mimic the in vivo environment makes them highly suitable for respiratory diseases investigation, particularly SARS-CoV-2 infection. Using MatriWells, we developed an innovative platform for COVID-19 research: a pulmonary air-liquid interface [ALI] associated with endothelial (HUVEC) cells. Infection studies revealed that pulmonary (BEAS-2B) cells in the ALI reached peak viral load at 24h and endothelial cells, at 48h, demonstrating lung viral replication and subsequent hematogenous dissemination, which provides us with a unique and realistic framework for studying COVID-19. Simultaneously, the spheroids were used to address the understudied ACE2 receptor, aiming at a pronounced process of COVID-19 investigation. ACE2 expression not only increased spheroid diameter by 20% (p<0.001) and volume by 60% (p≤0.0001) but also led to a remarkable 640-fold increase in intracellular viral load (p≤0.01). The previously mentioned finding supports ACE2 as a potential target for COVID-19 treatment. Lastly, we observed a higher viral load in the MatriWells compared to spheroids (150-fold, p<0.0001), suggesting the MatriWells as a more appropriate approach for COVID-19 investigation. By establishing an advanced method for respiratory tract conditions research, this work paves the way toward an efficacious process of drug development, contributing to a change in the course of respiratory diseases such as COVID-19.

Identification of Histopathological Biomarkers in Fatal Cases of Coronavirus Disease: A Study on Lung Tissue

We aimed to evaluate the primary lung postmortem macro- and microscopic biomarkers and factors associated with diffuse alveolar damage in patients with fatal coronavirus (COVID-19). We retrospectively analyzed lung tissue collected from autopsies performed in Cluj-Napoca, Romania, between April 2020 and April 2021 on patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). We examined 79 patients with confirmed SARS-CoV-2 infection, ages 34 to 96 years, split into two groups using the cut-off value of 70 years. Arterial hypertension (38%) and type 2 diabetes mellitus (19%) were the most common comorbidities with similar distribution between groups (p-values > 0.14). Macroscopically, bloody exudate was more frequently observed among patients < 70 years (33/36 vs. 29/43, p-value = 0.0091). Diffuse alveolar damage (53.1%) was similarly observed among the evaluated groups (p-value = 0.1354). Histopathological biomarkers of alveolar edema in 83.5% of patients, interstitial pneumonia in 74.7%, and microthrombi in 39.2% of cases were most frequently observed. Half of the evaluated lungs had an Ashcroft score of up to 2 and an alveolar air capacity of up to 12.5%. Bronchopneumonia (11/43 vs. 3/36, p-value = 0.0456) and interstitial edema (9/43 vs. 2/36, p-value = 0.0493) were significantly more frequent in older patients. Age (median: 67.5 vs. 77 years, p-value = 0.023) and infection with the beta variant of the virus (p-value = 0.0071) proved to be significant factors associated with diffuse alveolar damage.

Hormone Replacement Therapy and COVID-19 Outcomes in Solid Organ Transplant Recipients Compared with the General Population

Exogenous estrogen is associated with reduced COVID mortality in non-immunosuppressed/immunocompromised (non-ISC) post-menopausal females. Here, we examined the association of estrogen or testosterone hormone replacement therapy (HRT) with COVID outcomes in solid organ transplant recipients (SOTR) compared to non-ISC individuals, given known differences in sex-based risk in these populations. SOTR >45y with COVID-19 between 04-01-2020 and 07-31-2022 were identified using the National COVID Cohort Collaborative. The association of HRT use in the last 24 months (exogenous systemic estrogens for females; testosterone for males) with major adverse renal or cardiac events (MARCE) in the 90-days post COVID diagnosis and other secondary outcomes were examined using multivariable cox proportional hazards models and logistic regression. We repeated these analyses in a non-ISC control group for comparison. Our study included 1,135 SOTR and 43,383 immunocompetent patients on HRT with COVID-19. In non-ISC, HRT use was associated with lower risk of MARCE (aHR 0.61, 95% CI 0.57-0.65 for females; aHR 0.70, 0.65-0.77 for males), and all secondary outcomes. In SOTR, HRT reduced the risk of AKI (aHR 0.79, 0.63-0.98) and mortality (aHR 0.49, 0.28-0.85) in males with COVID, but not in females. The potentially modifying effects of immunosuppression on the benefits of HRT requires further investigation.

Sex hormones in SARS-CoV-2 susceptibility: key players or confounders?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has a clear sex disparity in clinical outcomes. Hence, the interaction between sex hormones, virus entry receptors and immune responses has attracted major interest as a target for the prevention and treatment of SARS-CoV-2 infections. This Review summarizes the current understanding of the roles of androgens, oestrogens and progesterone in the regulation of virus entry receptors and disease progression of coronavirus disease 2019 (COVID-19) as well as their therapeutic value. Although many experimental and clinical studies have analysed potential mechanisms by which female sex hormones might provide protection against SARS-CoV-2 infectivity, there is currently no clear evidence for a sex-specific expression of virus entry receptors. In addition, reports describing an influence of oestrogen, progesterone and androgens on the course of COVID-19 vary widely. Current data also do not support the administration of oestradiol in COVID-19. The conflicting evidence and lack of consensus results from a paucity of mechanistic studies and clinical trials reporting sex-disaggregated data. Further, the influence of variables beyond biological factors (sex), such as sociocultural factors (gender), on COVID-19 manifestations has not been investigated. Future research will have to fill this knowledge gap as the influence of sex and gender on COVID-19 will be essential to understanding and managing the long-term consequences of this pandemic.

Proteins in pregnant swine serum promote the African swine fever virus replication: an iTRAQ-based quantitative proteomic analysis

African swine fever (ASF) is a severe infectious disease caused by the African swine fever virus (ASFV), seriously endangering the global pig industry. ASFV possesses a large genome, strong mutation ability, and complex immune escape mechanisms. Since the first case of ASF was reported in China in August 2018, it has had a significant impact on social economy and food safety. In the present study, pregnant swine serum (PSS) was found to promote viral replication; differentially expressed proteins (DEPs) in PSS were screened and identified using the isobaric tags for relative and absolute quantitation technology and compared with those in non-pregnant swine serum (NPSS). The DEPs were analyzed using Gene Ontology functional annotation, Kyoto Protocol Encyclopedia of Genes and Genome pathway enrichment, and protein-protein interaction networks. In addition, the DEPs were validated via western blot and RT-qPCR experiments. And the 342 of DEPs were identified in bone marrow-derived macrophages cultured with PSS compared with the NPSS. The 256 were upregulated and 86 of DEPs were downregulated. The primary biological functions of these DEPs involved signaling pathways that regulate cellular immune responses, growth cycles, and metabolism-related pathways. An overexpression experiment showed that the PCNA could promote ASFV replication whereas MASP1 and BST2 could inhibit it. These results further indicated that some protein molecules in PSS were involved in the regulation of ASFV replication. In the present study, the role of PSS in ASFV replication was analyzed using proteomics, and the study will be provided a basis for future detailed research on the pathogenic mechanism and host interactions of ASFV as well as new insights for the development of small-molecule compounds to inhibit ASFV.

Estrogens as a Possible Therapeutic Strategy for the Management of Neuroinflammation and Neuroprotection in COVID-19

The Coronavirus disease 2019 (COVID-19) affects several tissues, including the central and peripheral nervous system. It has also been related to signs and symptoms that suggest neuroinflammation with possible effects in the short, medium, and long term. Estrogens could have a positive impact on the management of the disease, not only due to its already known immunomodulator effect, but also activating other pathways that may be important in the pathophysiology of COVID-19, such as the regulation of the virus receptor and its metabolites. In addition, they can have a positive effect on neuroinflammation secondary to pathologies other than COVID-19. The aim of this study is to analyze the molecular mechanisms that link estrogens with their possible therapeutic effect for neuroinflammation related to COVID-19. Advanced searches were performed in scientific databases as Pub- Med, ProQuest, EBSCO, the Science Citation index, and clinical trials. Estrogens have been shown to participate in the immune modulation of the response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In addition to this mechanism, we propose that estrogens can regulate the expression and activity of the Angiotensin-converting enzyme 2 (ACE2), reestablishing its cytoprotective function, which may be limited by its interaction with SARS-CoV-2. In this proposal, estrogens and estrogenic compounds could increase the synthesis of Angiotensin-(1-7) (Ang-(1-7)) that acts through the Mas receptor (MasR) in cells that are being attacked by the virus. Estrogens can be a promising, accessible, and low-cost treatment for neuroprotection and neuroinflammation in patients with COVID-19, due to its direct immunomodulatory capacity in decreasing cytokine storm and increasing cytoprotective capacity of the axis ACE2/Ang (1-7)/MasR.

Risk factors for intensive care unit admission and death from COVID-19 in fully vaccinated patients hospitalized for severe COVID-19, Brazil, 2021–2022

Objectives.

To assess factors associated with admission to an intensive care unit (ICU) and death from coronavirus disease 2019 (COVID-19) in fully vaccinated patients with severe COVID-19 in Brazil and the association between ICU admission and death from COVID-19.

Methods.

This was retrospective study of patients hospitalized for COVID-19 from February 12, 2021 to January 10, 2022 across Brazil who were fully vaccinated against COVID-19 before hospitalization. Outcomes were admission in an ICU for COVID-19 and death from COVID-19. Variables evaluated were: sex; age; self-reported skin color; macroregion; comorbidities; time between full vaccination and onset of symptoms; and time between onset of symptoms and hospitalization. A Poisson regression model was used to estimate crude and adjusted risk ratios.

Results.

Of 74 991 patients hospitalized for severe COVID-19, 67.28% were ≥ 70 years and 68.32% had at least one comorbidity. Men, patients aged 60–69 years, and patients aged 18–39 years with obesity had the greatest risk of ICU admission. Patients aged 18–39 years with obesity, diabetes, or renal diseases had the highest risk of death from COVID-19. When age and time between onset of symptoms and hospitalization were considered effect modifiers, patients admitted to an ICU 9–13 days after symptom onset in each age category had the greatest risk of death from COVID-19.

Conclusion.

Although older patients were at greatest risk of ICU admission and death from COVID-19, the difference in the risk of dying from COVID-19 between patients admitted to an ICU and those not admitted was greatest for young adults.

Biofunctional roles of estrogen in coronavirus disease 2019: Beyond a steroid hormone

The coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), epidemic poses a major global public health threat with more than one million daily new infections and hundreds of deaths. To combat this global pandemic, efficient prevention and management strategies are urgently needed. Together with the main characteristics of COVID-19, impaired coagulation with dysfunctions of the immune response in COVID-19 pathophysiology causes high mortality and morbidity. From recent clinical observations, increased expression of specific types of estrogen appears to protect patients from SARS-CoV-2 infection, thereby, reducing mortality. COVID-19 severity is less common in women than in men, particularly in menopausal women. Furthermore, estrogen levels are negatively correlated with COVID-19 severity and mortality. These findings suggest that estrogen plays a protective role in the pathophysiology of COVID-19. In this review, we discuss the potential roles of estrogen in blocking the SARS-CoV-2 from invading alveolar cells and replicating, and summarize the potential mechanisms of anti-inflammation, immune modulation, reactive oxygen species resistance, anti-thrombosis, vascular dilation, and vascular endothelium protection. Finally, the potential therapeutic effects of estrogen against COVID-19 are reviewed. This review provides insights into the role of estrogen and its use as a potential strategy to reduce the mortality associated with COVID-19, and possibly other viral infections and discusses the possible challenges and pertinent questions.

Membrane estrogen receptor ERα activation improves tau clearance via autophagy induction in a tauopathy cell model

Alzheimer's disease (AD) is the most prevalent aging-associated neurodegenerative disease, with a higher incidence in women than men. There is evidence that sex hormone replacement therapy, particularly estrogen, reduces memory loss in menopausal women. Neurofibrillary tangles are associated with tau protein aggregation, a characteristic of AD and other tauopathies. In this sense, autophagy is a promising cellular process to remove these protein aggregates. This study evaluated the autophagy mechanisms involved in neuroprotection induced by 17β-estradiol (E2) in a Tet-On inducible expression tauopathy cell model (EGFP-tau WT or with the P301L mutation, 0N4R isoform). The results indicated that 17β-estradiol induces autophagy by activating AMPK in a concentration-dependent manner, independent of mTOR signals. The estrogen receptor α (ERα) agonist, PPT, also induced autophagy, while the ERα antagonist, MPP, substantially attenuated the 17β-estradiol-mediated autophagy induction. Notably, 17β-estradiol increased LC3-II levels and phosphorylated and total tau protein clearance in the EGFP-tau WT cell line but not in EGPF-tau P301L. Similar results were observed with E2-BSA, a plasma membrane-impermeable estrogen, suggesting membrane ERα involvement in non-genomic estrogenic pathway activation. Furthermore, 17β-estradiol-induced autophagy led to EGFP-tau protein clearance. These results demonstrate that modulating autophagy via the estrogenic pathway may represent a new therapeutic target for treating AD.

SARS-CoV-2 infection and replication kinetics in different human cell types: The role of autophagy, cellular metabolism and ACE2 expression

Aims

This study evaluated SARS-CoV-2 replication in human cell lines derived from various tissues and investigated molecular mechanisms related to viral infection susceptibility and replication.

Main methods

SARS-CoV-2 replication in BEAS-2B and A549 (respiratory tract), HEK-293 T (kidney), HuH7 (liver), SH-SY5Y (brain), MCF7 (breast), Huvec (endothelial) and Caco-2 (intestine) was evaluated by RT-qPCR. Concomitantly, expression levels of ACE2 (Angiotensin Converting Enzyme) and TMPRSS2 were assessed through RT-qPCR and western blot. Proteins related to autophagy and mitochondrial metabolism were monitored in uninfected cells to characterize the cellular metabolism of each cell line. The effect of ACE2 overexpression on viral replication in pulmonary cells was also investigated.

Key findings

Our data show that HuH7, Caco-2 and MCF7 presented a higher viral load compared to the other cell lines. The increased susceptibility to SARS-CoV-2 infection seems to be associated not only with the differential levels of proteins intrinsically related to energetic metabolism, such as ATP synthase, citrate synthase, COX and NDUFS2 but also with the considerably higher TMPRSS2 mRNA expression. The two least susceptible cell types, BEAS-2B and A549, showed drastically increased SARS-CoV-2 replication capacity when ACE2 was overexpressed. These modified cell lines are relevant for studying SARS-CoV-2 replication in vitro.

Significance

Our data not only reinforce that TMPRSS2 expression and cellular energy metabolism are important molecular mechanisms for SARS-CoV-2 infection and replication, but also indicate that HuH7, MCF7 and Caco-2 are suitable models for mechanistic studies of COVID-19. Moreover, pulmonary cells overexpressing ACE2 can be used to understand mechanisms associated with SARS-CoV-2 replication.

17β-Oestradiol Protects from Hepatitis C Virus Infection through Induction of Type I Interferon

Background and Aims: Sex hormones are widely recognised to act as protective factors against several viral infections. Specifically, females infected by the hepatitis C virus display higher clearance rates and reduced disease progression than those found in males. Through modulation of particle release and spread, 17β-oestradiol controls HCV’s life cycle. We investigated the mechanism(s) behind oestrogen’s antiviral effect. Methods: We used cell culture-derived hepatitis C virus in in vitro assays to evaluate the effect of 17β-oestradiol on the innate immune response. Host immune responses were evaluated by enumerating gene transcripts via RT-qPCR in cells exposed to oestrogen in the presence or absence of viral infection. Antiviral effects were determined by focus-forming unit assay or HCV RNA quantification. Results: Stimulation of 17β-oestradiol triggers a pre-activated antiviral state in hepatocytes, which can be maintained for several hours after the hormone is removed. This induction results in the elevation of several innate immune genes, such as interferon alpha and beta, tumour necrosis factor, toll-like receptor 3 and interferon regulatory factor 5. We demonstrated that this pre-activation of immune response signalling is not affected by a viral presence, and the antiviral state can be ablated using an interferon-alpha/beta receptor alpha inhibitor. Finally, we proved that the oestrogen-induced stimulation is essential to generate an antiviral microenvironment mediated by activation of type I interferons. Conclusion: Resulting in viral control and suppression, 17β-oestradiol induces an interferon-mediated antiviral state in hepatocytes. Oestrogen-stimulated cells modulate the immune response through secretion of type I interferon, which can be countered by blocking interferon-alpha/beta receptor alpha signalling.

Effect of Norelgestromin and Ethinylestradiol in Transdermal Patches on the Clinical Outcomes and Biochemical Parameters of COVID-19 Patients: A Clinical Trial Pilot Study

The disease caused by SARS-CoV-2 is still considered a global pandemic. Transdermal patches (TP) with immunoregulators such as estrogen and progesterone compounds could be a feasible option to treat COVID-19 because of their accessibility and relative safety. The objective of the current study was to evaluate the additional treatment with norelgestromin and ethinylestradiol in TP on the clinical and biochemical evolution of COVID-19 patients. The present is a clinical-trial pilot study that included subjects diagnosed with COVID-19, randomized into two groups; the experimental Evra® TP (norelgestromin 6 mg and ethinylestradiol 0.60 mg) was administered such that it was applied on arrival and replaced at day 8 and day 15. The control continued with the conventional COVID-19 treatment protocol. A blood sample was taken each week in order to evaluate relevant biochemical parameters, clinical signs, and evolution. In total, 44 subjects participated in this study, 30 in the experimental group and 14 in the control group. Both groups were homogeneous in terms of age and comorbidities. The experimental group had a significantly lower hospital stay (p = 0.01), high flow supplemental oxygen (p = 0.001), mechanical ventilation (p = 0.003), and intubation (p = 0.01), and the oxygen saturation significantly increased (p = 0.01) in comparison with control group when patients were exposed to room air. A decrease in ferritin (p < 0.05) was observed, with no significant increase in ESR (p > 0.05), D dimer (p > 0.05) and platelets (p > 0.05) in an auto-controlled analysis in the experimental group. Norelgestromin and ethinylestradiol TP could be a safe and effective treatment for moderate and severe COVID-19 patients.

Effect of Androgen Suppression on Clinical Outcomes in Hospitalized Men With COVID-19: The HITCH Randomized Clinical Trial

IMPORTANCE

SARS-CoV-2 entry requires the TMPRSS2 cell surface protease. Antiandrogen therapies reduce expression of TMPRSS2.

OBJECTIVE

To determine if temporary androgen suppression induced by degarelix improves clinical outcomes of inpatients hospitalized with COVID-19.

DESIGN, SETTING, AND PARTICIPANTS

The Hormonal Intervention for the Treatment in Veterans With COVID-19 Requiring Hospitalization (HITCH) phase 2, placebo-controlled, double-blind, randomized clinical trial compared efficacy of degarelix plus standard care vs placebo plus standard care on clinical outcomes in men hospitalized with COVID-19 but not requiring invasive mechanical ventilation. Inpatients were enrolled at 14 Department of Veterans Affairs hospitals from July 22, 2020, to April 8, 2021. Data were analyzed from August 9 to October 15, 2021.

INTERVENTIONS

Patients stratified by age, history of hypertension, and disease severity were centrally randomized 2:1 to degarelix, (1-time subcutaneous dose of 240 mg) or a saline placebo. Standard care included but was not limited to supplemental oxygen, antibiotics, vasopressor support, peritoneal dialysis or hemodialysis, intravenous fluids, remdesivir, convalescent plasma, and dexamethasone.

MAIN OUTCOMES AND MEASURES

The composite primary end point was mortality, ongoing need for hospitalization, or requirement for mechanical ventilation at day 15 after randomization. Secondary end points were time to clinical improvement, inpatient mortality, length of hospitalization, duration of mechanical ventilation, time to achieve a temperature within reference range, maximum severity of COVID-19, and the composite end point at 30 days.

RESULTS

The trial was stopped for futility after the planned interim analysis, at which time there were 96 evaluable patients, including 62 patients randomized to the degarelix group and 34 patients in the placebo group, out of 198 initially planned. The median (range) age was 70.5 (48-85) years. Common comorbidities included chronic obstructive pulmonary disorder (15 patients [15.6%]), hypertension (75 patients [78.1%]), cardiovascular disease (27 patients [28.1%]), asthma (12 patients [12.5%]), diabetes (49 patients [51.0%]), and chronic respiratory failure requiring supplemental oxygen at baseline prior to COVID-19 (9 patients [9.4%]). For the primary end point, there was no significant difference between the degarelix and placebo groups (19 patients [30.6%] vs 9 patients [26.5%]; P = .67). Similarly, no differences were observed between degarelix and placebo groups in any secondary end points, including inpatient mortality (11 patients [17.7%] vs 6 patients [17.6%]) or all-cause mortality (11 patients [17.7%] vs 7 patents [20.6%]). There were no differences between degarelix and placebo groups in the overall rates of adverse events (13 patients [21.0%] vs 8 patients [23.5%) and serious adverse events (19 patients [30.6%] vs 13 patients [32.4%]), nor unexpected safety concerns.

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial of androgen suppression vs placebo and usual care for men hospitalized with COVID-19, degarelix did not result in amelioration of COVID-19 severity.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04397718.

Are sex hormones promising candidates to explain sex disparities in the COVID-19 pandemic?

Emerging evidence suggests that the novel Coronavirus disease-2019 (COVID-19) is deadlier for men than women both in China and in Europe. Male sex is a risk factor for COVID-19 mortality. The meccanisms underlying the reduced morbidity and lethality in women are currently unclear, even though hypotheses have been posed (Brandi and Giustina in Trends Endocrinol Metab. 31:918-27, 2020). This article aims to describe the role of sex hormones in sex- and gender-related fatality of COVID-19. We discuss the possibility that potential sex-specific mechanisms modulating the course of the disease include both the androgen- and the estrogen-response cascade. Sex hormones regulate the respiratory function, the innate and adaptive immune responses, the immunoaging, the cardiovascular system, and the entrance of the virus in the cells. Recommendations for the future government policies and for the management of COVID-19 patients should include a dimorphic approach for males and females. As the estrogen receptor signaling appears critical for protection in women, more studies are needed to translate the basic knowledge into clinical actions. Understanding the etiological bases of sexual dimorphism in COVID-19 could help develop more effective strategies in individual patients in both sexes, including designing a good vaccine.

Association between pharmaceutical modulation of oestrogen in postmenopausal women in Sweden and death due to COVID-19: a cohort study

OBJECTIVE

Determine whether augmentation of oestrogen in postmenopausal women decreases the risk of death following COVID-19.

DESIGN

Nationwide registry-based study in Sweden based on registries from the Swedish Public Health Agency (all individuals who tested positive for SARS-CoV-2); Statistics Sweden (socioeconomical variables) and the National Board of Health and Welfare (causes of death).

PARTICIPANTS

Postmenopausal women between 50 and 80 years of age with verified COVID-19.

INTERVENTIONS

Pharmaceutical modulation of oestrogen as defined by (1) women with previously diagnosed breast cancer and receiving endocrine therapy (decreased systemic oestrogen levels); (2) women receiving hormone replacement therapy (increased systemic oestrogen levels) and (3) a control group not fulfilling requirements for group 1 or 2 (postmenopausal oestrogen levels). Adjustments were made for potential confounders such as age, annual disposable income (richest group as the reference category), highest level of education (primary, secondary and tertiary (reference)) and the weighted Charlson Comorbidity Index (wCCI).

PRIMARY OUTCOME MEASURE

Death following COVID-19.

RESULTS

From a nationwide cohort consisting of 49 853 women diagnosed with COVID-19 between 4 February and 14 September 2020 in Sweden, 16 693 were between 50 and 80 years of age. We included 14 685 women in the study with 11 923 (81%) in the control group, 227 (2%) women in group 1 and 2535 (17%) women in group 2. The unadjusted ORs for death following COVID-19 were 2.35 (95% CI 1.51 to 3.65) for group 1 and 0.45 (0.34 to 0.6) for group 2. Only the adjusted OR for death remained significant for group 2 with OR 0.47 (0.34 to 0.63). Absolute risk of death was 4.6% for the control group vs 10.1% and 2.1%, for the decreased and increased oestrogen groups, respectively. The risk of death due to COVID-19 was significantly associated with: age, OR 1.15 (1.14 to 1.17); annual income, poorest 2.79 (1.96 to 3.97), poor 2.43 (91.71 to 3.46) and middle 1.64 (1.11 to 2.41); and education (primary 1.4 (1.07 to 1.81)) and wCCI 1.13 (1.1 to 1.16).

CONCLUSIONS

Oestrogen supplementation in postmenopausal women is associated with a decreased risk of dying from COVID-19 in this nationwide cohort study. These findings are limited by the retrospective and non-randomised design. Further randomised intervention trials are warranted.

Estradiol reduces ACE2 and TMPRSS2 mRNA levels in A549 human lung epithelial cells

Epidemiologic studies suggest slightly higher risk of severe Covid‐19 symptoms and fatalities following SARS‐CoV‐2 infection in men compared with women from similar age groups. This bias was suggested to reflect differences in the male and female immune system regulation, driven by different sex hormone levels in men and women, in particular, higher plasma estradiol in women. SARS‐CoV‐2 infects respiratory tract epithelial cells by binding to their cell membrane ACE2, followed by priming for cell entry by the host cell membrane serine protease TMPRSS2. The cell protease FURIN facilitates cell exit of mature SARS‐CoV‐2 virions. Our study examined the effects of in vitro treatment of A549 human lung epithelial cells with 17‐β‐estradiol on mRNA expression of genes coding for these proteins. Treatment of A549 human lung epithelial cells with 17‐β‐estradiol reduced the cellular mRNA levels of ACE2 and TMPRSS2 mRNA, while not affecting FURIN expression. Our findings suggest that 17‐β‐estradiol may reduce SARS‐CoV‐2 infection of lung epithelial cells, which may in part explain the reduced incidence of severe Covid‐19 and fatalities among women compared with men of similar age. Studies into the molecular pathways by which 17‐β‐estradiol reduces ACE2 and TMPRSS2 mRNA expression in lung epithelial cells are needed for assessing its potential protective value against severe Covid‐19.

Structural biology of SARS-CoV-2: open the door for novel therapies

Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is the causative agent of the pandemic disease COVID-19, which is so far without efficacious treatment. The discovery of therapy reagents for treating COVID-19 are urgently needed, and the structures of the potential drug-target proteins in the viral life cycle are particularly important. SARS-CoV-2, a member of the Orthocoronavirinae subfamily containing the largest RNA genome, encodes 29 proteins including nonstructural, structural and accessory proteins which are involved in viral adsorption, entry and uncoating, nucleic acid replication and transcription, assembly and release, etc. These proteins individually act as a partner of the replication machinery or involved in forming the complexes with host cellular factors to participate in the essential physiological activities. This review summarizes the representative structures and typically potential therapy agents that target SARS-CoV-2 or some critical proteins for viral pathogenesis, providing insights into the mechanisms underlying viral infection, prevention of infection, and treatment. Indeed, these studies open the door for COVID therapies, leading to ways to prevent and treat COVID-19, especially, treatment of the disease caused by the viral variants are imperative.

Roles of steroid receptors in the lung and COVID-19

COVID-19 symptoms and mortality are largely due to its devastating effects in the lungs. The disease is caused by the SARS (Severe Acute Respiratory Syndrome)-CoV-2 coronavirus, which requires host cell proteins such as ACE2 (angiotensin-converting enzyme 2) and TMPRSS2 (transmembrane serine protease 2) for infection of lung epithelia. The expression and function of the steroid hormone receptor family is important in many aspects that impact on COVID-19 effects in the lung - notably lung development and function, the immune system, and expression of TMPRSS2 and ACE2. This review provides a brief summary of current knowledge on the roles of the steroid hormone receptors [androgen receptor (AR), glucocorticoid receptor (GR), progesterone receptor (PR), mineralocorticoid receptor (MR) and oestrogen receptor (ER)] in the lung, their effects on host cell proteins that facilitate SARS-CoV-2 uptake, and provides a snapshot of current clinical trials investigating the use of steroid receptor (SR) ligands to treat COVID-19.

COVID-19, gender and estroprogestins, what do we know?

The new coronavirus disease-19 (COVID-19) pandemic has rapidly spread all around the world, eliciting many questions and doubts about the pathogenesis of the disease and treatment. Mortality has been related to a prothrombotic state. Risk factors for the infection and for severe forms of COVID-19 have still to be defined. According to data collected, women appear to be less prone to severe forms of the disease and their mortality was lower than for men. The role of female hormones in the modulation of inflammation may be the reason behind this gender gap.Considering the prothrombotic state activated by the virus, hormone therapies have been placed under investigation as possible increasing risk factors for severe forms. Moreover, new vaccines and their rare thrombotic side effects have increased the concern about this issue.The goal of this review is to go over the mechanisms that lead up to thrombosis during COVID-19, trying to explain the possible reasons why women seem to be naturally protected. The expert opinions about whether to continue/discontinue hormonal therapies are reviewed. Moreover, available data about the so-called 'vaccine induced immune thrombotic thrombocytopaenia' caused by vaccines against COVID-19 are discussed.

Endothelial Dysfunction through Oxidatively Generated Epigenetic Mark in Respiratory Viral Infections

The bronchial vascular endothelial network plays important roles in pulmonary pathology during respiratory viral infections, including respiratory syncytial virus (RSV), influenza A(H1N1) and importantly SARS-Cov-2. All of these infections can be severe and even lethal in patients with underlying risk factors.A major obstacle in disease prevention is the lack of appropriate efficacious vaccine(s) due to continuous changes in the encoding capacity of the viral genome, exuberant responsiveness of the host immune system and lack of effective antiviral drugs. Current management of these severe respiratory viral infections is limited to supportive clinical care. The primary cause of morbidity and mortality is respiratory failure, partially due to endothelial pulmonary complications, including edema. The latter is induced by the loss of alveolar epithelium integrity and by pathological changes in the endothelial vascular network that regulates blood flow, blood fluidity, exchange of fluids, electrolytes, various macromolecules and responses to signals triggered by oxygenation, and controls trafficking of leukocyte immune cells. This overview outlines the latest understanding of the implications of pulmonary vascular endothelium involvement in respiratory distress syndrome secondary to viral infections. In addition, the roles of infection-induced cytokines, growth factors, and epigenetic reprogramming in endothelial permeability, as well as emerging treatment options to decrease disease burden, are discussed.

Estradiol and COVID-19: Does 17-Estradiol Have an Immune-Protective Function in Women Against Coronavirus?

Objective: Female sex hormones have a pro-inflammatory effect, which may help to minimize inflammation. Estrogen's immunoregulatory properties play a significant role in the bi-directional neuroendocrine-immune activity in females. As a result, sex hormones can play a role in men's high mortality rate from coronavirus-2019 (COVID-19). It is aimed to clarify the role of 17-estradiol (E2) in the battle against COVID-19.

Materials and methods: Until April 2021, a study on PubMed was performed. COVID-19, 17-estradiol (E2), immunoregulatory properties, pregnancy, menopausal symptoms, hormonal therapy, ER/ expression on immune cells, and mortality were some of the concepts used in the search.

Results: Regulation of pro-inflammatory immune processes against COVID-19 appears to be associated with increased immune function (pro-inflammatory), anti-inflammatory regulation, and antiviral defense. Women with a severe coronavirus infection had higher serum IgG antibody levels than men, and their IgG production was faster in the early stages of infection. 17-estradiol (E2) levels of blood will increase by 100-fold during pregnancy. COVID-19 in pregnant women had a 15-fold lower mortality rate than other women. While menopause replacement therapy (MRT) for pre/post-menopausal women and its effectiveness in reducing COVID-19 infection is debatable.

Conclusion: MRT may be considered as a viable treatment option for pre/post-menopause women with coronavirus, referring to the fact that sex hormones reduce inflammatory responses and modulate ACE2 expression. The task's difficulty and achieving the desired outcome seem to be challenging.

Crosstalk between estrogen, dendritic cells, and SARS-CoV-2 infection

The novel coronavirus disease 2019 (Covid‐19) first appeared in Wuhan and has so far killed more than four million people worldwide. Men are more affected than women by Covid‐19, but the cellular and molecular mechanisms behind these differences are largely unknown. One plausible explanation is that differences in sex hormones could partially account for this distinct prevalence in both sexes. Accordingly, several papers have reported a protective role of 17β‐estradiol during Covid‐19, which might help explain why women appear less likely to die from Covid‐19 than men. 17β‐estradiol is the predominant and most biologically active endogenous estrogen, which signals through estrogen receptor α, estrogen receptor β, and G protein‐coupled estrogen receptor 1. These receptors are expressed in mature cells from the innate and the adaptive immune system, particularly on dendritic cells (DCs), suggesting that estrogens could modulate their effector functions. DCs are the most specialized and proficient antigen‐presenting cells, acting at the interface of innate and adaptive immunity with a powerful capacity to prime antigen‐specific naive CD8+ T cells. DCs are richly abundant in the lung where they respond to viral infection. A relative increase of mature DCs in broncho‐alveolar lavage fluids from Covid‐19 patients has already been reported. Here we will describe how SARS‐CoV‐2 acts on DCs, the role of estrogen on DC immunobiology, summarise the impact of sex hormones on the immune response against Covid‐19, and explore clinical trials regarding Covid‐19

Long-term side effects and lingering symptoms post COVID-19 recovery

Since the Coronavirus disease 2019 (COVID‐19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2), our understanding regarding the pathophysiology and clinical manifestations of this disease have been improving. However, we still have limited data on long‐term effects and lingering symptoms of post COVID‐19 recovery. Despite predilection of COVID‐19 for lungs, multiple extra‐pulmonary manifestations appear in multiple organs and biological systems and with continued infection and recovery worldwide. It is necessary that clinicians provide patients with previous SARS‐CoV‐2 infection with expectations of long‐term effects during or after recovery from COVID‐19. Herein, we review the long‐term impact of COVID‐19 on different organ systems reported from different clinical studies. Understanding risk factors and signs and symptoms of long‐term consequences after recovery from COVID‐19 will allow for proper follow‐up and management of the disease post recovery.

A Review on Expression, Pathological Roles, and Inhibition of TMPRSS2, the Serine Protease Responsible for SARS-CoV-2 Spike Protein Activation

SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, uses the host cell membrane receptor angiotensin-converting enzyme 2 (ACE2) for anchoring its spike protein, and the subsequent membrane fusion process is facilitated by host membrane proteases. Recent studies have shown that transmembrane serine protease 2 (TMPRSS2), a protease known for similar role in previous coronavirus infections, severe acute respiratory syndrome (SARS), and Middle East respiratory syndrome (MERS), is responsible for the proteolytic cleavage of the SARS-CoV-2 spike protein, enabling host cell fusion of the virus. TMPRSS2 is known to be expressed in the epithelial cells of different sites including gastrointestinal, respiratory, and genitourinary system. The infection site of the SARS-CoV-2 correlates with the coexpression sites of ACE2 and TMPRSS2. Besides, age-, sex-, and comorbidity-associated variation in infection rate correlates with the expression rate of TMPRSS2 in those groups. These findings provide valid reasons for the assumption that inhibiting TMPRSS2 can have a beneficial effect in reducing the cellular entry of the virus, ultimately affecting the infection rate and case severity. Several drug development studies are going on to develop potential inhibitors of the protease, using both conventional and computational approaches. Complete understanding of the biological roles of TMPRSS2 is necessary before such therapies are applied.

Estrogen Receptor Modulators in Viral Infections Such as SARS-CoV-2: Therapeutic Consequences

COVID-19 is a pandemic respiratory disease caused by the SARS-CoV-2 coronavirus. The worldwide epidemiologic data showed higher mortality in males compared to females, suggesting a hypothesis about the protective effect of estrogens against severe disease progression with the ultimate end being patient's death. This article summarizes the current knowledge regarding the potential effect of estrogens and other modulators of estrogen receptors on COVID-19. While estrogen receptor activation shows complex effects on the patient's organism, such as an influence on the cardiovascular/pulmonary/immune system which includes lower production of cytokines responsible for the cytokine storm, the receptor-independent effects directly inhibits viral replication. Furthermore, it inhibits the interaction of IL-6 with its receptor complex. Interestingly, in addition to natural hormones, phytestrogens and even synthetic molecules are able to interact with the estrogen receptor and exhibit some anti-COVID-19 activity. From this point of view, estrogen receptor modulators have the potential to be included in the anti-COVID-19 therapeutic arsenal.

The role of sexual dimorphism in susceptibility to SARS-CoV-2 infection, disease severity, and mortality: facts, controversies and future perspectives

Former studies have revealed intersex variability in immune response to infectious diseases, including Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Epidemiological surveillance of the ongoing pandemic has demonstrated a male vulnerability to morbidity and mortality, despite similar infection rates between the two sexes. Divergence in the frequency of comorbidities between males and females, differences in hormonal profile, chromosomal composition and gender behavior have all been proposed as potential causative factors. Data deriving from the immunization process indirectly support the existence of a sex-specific response to SARS-CoV-2, since females apparently produce higher numbers of antibodies while simultaneously exhibiting higher rates of side effects, indicating a stronger immune reactivity to the vaccine's elements. Interpreting intersex differences in immune response to SARS-CoV-2 could lead to a deeper understanding of the COVID-19 pathophysiology and enable healthcare professionals to conduct a more accurate patient risk assessment and better predict the clinical outcome of the disease. This narrative review aims to discuss the pathophysiological and behavioral basis of the disproportionate male morbidity and mortality observed in COVID-19, in the context of most research findings in the field.

Immunological aspects and gender bias during respiratory viral infections including novel Coronavirus disease-19 (COVID-19): A scoping review

The human immune system is not adequately equipped to eliminate new microbes and could result in serious damage on first exposure. This is primarily attributed to the exaggerated immune response (inflammatory disease), which may prove detrimental to the host, as evidenced by SARS‐CoV‐2 infection. From the experiences of Novel Coronavirus Disease‐19 to date, male patients are likely to suffer from high‐intensity inflammation and disease severity than the female population. Hormones are considered the significant pillars of sex differences responsible for the discrepancy in immune response exhibited by males and females. Females appear to be better equipped to counter invading respiratory viral pathogens, including the novel SARS‐CoV‐2, than males. It can be hypothesized that females are more shielded from disease severity, probably owing to the diverse action/influence of estrogen and other sex hormones on both cellular (thymus‐derived T lymphocytes) and humoral immunity (antibodies).

Hormones are considered as significant pillars of sex differences and influence both the innate as well as adaptive immune responses.

Sex hormones and their potential role in the immune responses has not been completely understood.

Females are more shielded from disease severity probably owing to their unique hormonal constitution.

In females, the immunological cells have been noted to restrict the spread of infections as compared to males.

Males suffer from increased severity of respiratory infections and are less prone to autoimmune disorders as compared to the female counterparts.

Estrogen and other sex hormones play a key role both in restricting the inflammatory responses and in effective clearance of pathogens including the novel Coronairus.

Pharmacological Modulators of Autophagy as a Potential Strategy for the Treatment of COVID-19

The family of coronaviruses (CoVs) uses the autophagy machinery of host cells to promote their growth and replication; thus, this process stands out as a potential target to combat COVID-19. Considering the different roles of autophagy during viral infection, including SARS-CoV-2 infection, in this review, we discuss several clinically used drugs that have effects at different stages of autophagy. Among them, we mention (1) lysosomotropic agents, which can prevent CoVs infection by alkalinizing the acid pH in the endolysosomal system, such as chloroquine and hydroxychloroquine, azithromycin, artemisinins, two-pore channel modulators and imatinib; (2) protease inhibitors that can inhibit the proteolytic cleavage of the spike CoVs protein, which is necessary for viral entry into host cells, such as camostat mesylate, lopinavir, umifenovir and teicoplanin and (3) modulators of PI3K/AKT/mTOR signaling pathways, such as rapamycin, heparin, glucocorticoids, angiotensin-converting enzyme inhibitors (IECAs) and cannabidiol. Thus, this review aims to highlight and discuss autophagy-related drugs for COVID-19, from in vitro to in vivo studies. We identified specific compounds that may modulate autophagy and exhibit antiviral properties. We hope that research initiatives and efforts will identify novel or "off-label" drugs that can be used to effectively treat patients infected with SARS-CoV-2, reducing the risk of mortality.