The androgen-regulated type II serine protease TMPRSS2 is differentially expressed and mislocalized in prostate adenocarcinoma

Updates in the pathophysiology of COVID-19 infection in male reproductive and sexual health: a literature review

This extensive comprehensive review explores the impact of the Coronavirus disease 2019 (COVID-19) pandemic on men's sexual and reproductive health. We conducted a literature review focusing on the possible pathophysiology by which severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) affects men's sexual and reproductive systems. We reviewed most of the studies that reported the impact of SARS-CoV-2 infection on the Testicular, Epididymal, Prostatic, and Penile tissue. Also, we focused on evaluating the SARS-CoV-2 infection on semen parameters and male reproductive hormones. Finally, we reviewed the COVID-19 vaccine's effect on male reproductive and sexual health. Findings revealed the adverse consequences of SARS-CoV-2 at cellular and organ levels on the male genital tract. However, the reported data are still controversial. The initial data regarding COVID-19 vaccination was promising promoted safety for men's reproductive and sexual health. We conclude this paper by offering recommendations to address these adverse consequences and potentially improve sexual and reproductive health among men in the post-COVID-19 pandemic era.

Antiandrogens as Therapies for COVID-19: A Systematic Review

BACKGROUND

In 2019, the breakthrough of the coronavirus 2 disease (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represented one of the major issues of our recent history. Different drugs have been tested to rapidly find effective anti-viral treatments and, among these, antiandrogens have been suggested to play a role in mediating SARS-CoV-2 infection. Considering the high heterogeneity of studies on this topic, we decided to review the current literature.

METHODS

We performed a systematic review according to PRISMA guidelines. A search strategy was conducted on PUBMED and Medline. Only original articles published from March 2020 to 31 August 2023 investigating the possible protective role of antiandrogens were included. In vitro or preclinical studies and reports not in the English language were excluded. The main objective was to investigate how antiandrogens may interfere with COVID-19 outcomes.

RESULTS

Among 1755 records, we selected 31 studies, the majority of which consisted of retrospective clinical data collections and of randomized clinical trials during the first and second wave of the COVID-19 pandemic.

CONCLUSIONS

In conclusion, we can state that antiandrogens do not seem to protect individuals from SARS-CoV-2 infection and COVID-19 severity and, thus, their use should not be encouraged in this field.

Significance of Furin Expression in Thyroid Neoplastic Transformation

Angiotensin-Converting Enzyme 2 (ACE2), Transmembrane Serine Protease 2 (TMPRSS2), and Furin were known to be key players in the SARS-CoV-2 infection, and the thyroid gland was revealed to be one of the relevant targets of the virus. Regardless of the viral infection, the expression of these molecules in the thyroid gland and their putative role in the neoplastic transformation of the thyrocytes has not been thoroughly explored. In this work, we aimed to characterize the mRNA and protein expression pattern of ACE2, TMPRSS2, and Furin in a series of patients with thyroid lesions. Our main results revealed a significantly decreased expression of ACE2 mRNA in the thyroid neoplasms in comparison to normal adjacent tissue. Furin mRNA was significantly increased in thyroid neoplasms when compared to normal adjacent tissue. In addition, a higher Furin mRNA level in thyroid carcinomas was associated with the presence of lymph node metastasis. Furin mRNA expression revealed a high discriminatory power between adjacent tissue and neoplasms. Protein expression of these molecules did not correlate with mRNA expression. Our study shows the mRNA downregulation of ACE2 and overexpression of Furin in thyroid neoplasms. Further studies are required to clarify if Furin expression can be a potential diagnostic indicator in thyroid neoplasia.

Androgen receptor, a possible anti-infective therapy target and a potent immune respondent in SARS-CoV-2 spike binding: a computational approach

BACKGROUND

Although androgen in gender disparity of COVID-19 has been implied, no direct link has been provided.

RESEARCH DESIGN AND METHODS

Here, we applied AlphaFold multimer, network and single cells database analyses to highlight specificity of Androgen receptor (AR) against spike receptor binding protein (RBD) of SARS-CoV-2.

RESULTS

LXXL motifs in spike RBD are essential for AR binding. RBD LXXA mutation complex with the AR depicting slightly reduced binding energy, as LXXLL motif usually mediates nuclear receptor binding to coregulators. Moreover, AR preferred to bind a LYRL motif in specificity and interaction interface, and showed reduced affinity against Omicron compared to other variants (alpha, beta, gamma, and delta). Importantly, RBD LYRL motif is a conserved antigenic epitope (9 residues) for T-cell response. Network analysis of AR-related genes against COVID-19 database showed T-cell signaling regulation, and CD8+ T-cell spatial location in AR+ single cells, which is consistent with the AR binding motif LYRL in epitope function.

CONCLUSIONS

We provided the potent mechanisms of AR binding to RBD linking to immune response and vaccination shift. AR could be an anti-infective therapy target for anti-Omicron new lineages.

Apalutamide Prevents SARS-CoV-2 Infection in Lung Epithelial Cells and in Human Nasal Epithelial Cells

In early 2020, the novel pathogenic severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, and rapidly propagated worldwide causing a global health emergency. SARS-CoV-2 binds to the angiotensin-converting enzyme 2 (ACE2) protein for cell entry, followed by proteolytic cleavage of the Spike (S) protein by the transmembrane serine protease 2 (TMPRSS2), allowing fusion of the viral and cellular membranes. Interestingly, TMPRSS2 is a key regulator in prostate cancer (PCa) progression which is regulated by androgen receptor (AR) signaling. Our hypothesis is that the AR signaling may regulate the expression of TMPRSS2 in human respiratory cells and thus influence the membrane fusion entry pathway of SARS-CoV-2. We show here that TMPRSS2 and AR are expressed in Calu-3 lung cells. In this cell line, TMPRSS2 expression is regulated by androgens. Finally, pre-treatment with anti-androgen drugs such as apalutamide significantly reduced SARS-CoV-2 entry and infection in Calu-3 lung cells but also in primary human nasal epithelial cells. Altogether, these data provide strong evidence to support the use of apalutamide as a treatment option for the PCa population vulnerable to severe COVID-19.

TMPRSS2 Impacts Cytokine Expression in Murine Dendritic Cells

BACKGROUND

The transmembrane protease serine 2 (TMPRSS2) proteolytically activates the envelope proteins of several viruses for viral entry via membrane fusion and is therefore an interesting and promising target for the development of broad-spectrum antivirals. However, the use of a host protein as a target may lead to potential side effects, especially on the immune system. We examined the effect of a genetic deletion of TMPRSS2 on dendritic cells.

METHODS

Bone marrow cells from wild-type (WT) and TMPRSS2-deficient mice (TMPRSS2^-/-) were differentiated to plasmacytoid dendritic cells (pDCs) and classical DCs (cDCs) and activated with various toll-like receptor (TLR) agonists. We analyzed the released cytokines and the mRNA expression of chemokine receptors, TLR7, TLR9, IRF7 and TCF4 stimulation.

RESULTS

In cDCs, the lack of TMPRSS2 led to an increase in IL12 and IFNγ in TLR7/8 agonist resiquimod or TLR 9 agonist ODN 1668-activated cells. Only IL-10 was reduced in TMPRSS2^-/- cells in comparison to WT cells activated with ODN 1668. In resiquimod-activated pDCs, the lack of TMPRSS2 led to a decrease in IL-6, IL-10 and INFγ. ODN 1668 activation led to a reduction in IFNα. The effect on receptor expression in pDCs and cDCs was low.

CONCLUSION

The effect of TMPRSS2 on pDCS and cDCs depends on the activated TLR, and TMPRSS2 seems to affect cytokine release differently in pDCs and cDCs. In cDCs, TMPRSS2 seems to suppress cytokine release, whereas in pDCS TMPRSS2 possibly mediates cytokine release.

The role of oxidative stress in the pathogenesis of infections with coronaviruses

Coronaviruses can cause serious respiratory tract infections and may also impact other end organs such as the central nervous system, the lung and the heart. The coronavirus disease 2019 (COVID-19) has had a devastating impact on humanity. Understanding the mechanisms that contribute to the pathogenesis of coronavirus infections, will set the foundation for development of new treatments to attenuate the impact of infections with coronaviruses on host cells and tissues. During infection of host cells, coronaviruses trigger an imbalance between increased production of reactive oxygen species (ROS) and reduced antioxidant host responses that leads to increased redox stress. Subsequently, increased redox stress contributes to reduced antiviral host responses and increased virus-induced inflammation and apoptosis that ultimately drive cell and tissue damage and end organ disease. However, there is limited understanding how different coronaviruses including SARS-CoV-2, manipulate cellular machinery that drives redox responses. This review aims to elucidate the redox mechanisms involved in the replication of coronaviruses and associated inflammation, apoptotic pathways, autoimmunity, vascular dysfunction and tissue damage that collectively contribute to multiorgan damage.

The roles of proteases in prostate cancer

Since the proposition of the pro-invasive activity of proteolytic enzymes over 70 years ago, several roles for proteases in cancer progression have been established. About half of the 473 active human proteases are expressed in the prostate and many of the most well-characterized members of this enzyme family are regulated by androgens, hormones essential for development of prostate cancer. Most notably, several kallikrein-related peptidases, including KLK3 (prostate-specific antigen, PSA), the most well-known prostate cancer marker, and type II transmembrane serine proteases, such as TMPRSS2 and matriptase, have been extensively studied and found to promote prostate cancer progression. Recent findings also suggest a critical role for proteases in the development of advanced and aggressive castration-resistant prostate cancer (CRPC). Perhaps the most intriguing evidence for this role comes from studies showing that the protease-activated transmembrane proteins, Notch and CDCP1, are associated with the development of CRPC. Here, we review the roles of proteases in prostate cancer, with a special focus on their regulation by androgens.

Transmembrane serine protease 2 cleaves nidogen 1 and inhibits extrahepatic liver cancer cell migration and invasion

We aimed to confirm whether transmembrane serine protease 2 (TMPRSS2) regulates nidogen 1 (NID1) expression in extracellular vesicles (EVs) and metastatic hepatocellular carcinoma (HCC) cells. HCC cells, HUVEC cells, MRC-5 cells, HLE cells, MHCCLM3 cells, MHCC97L cells, H2P cells, H2M cells, as well as LO2 cells were cultured according to providers' instruction and EV models were established by using BALB/cAnN-nu mice to facilitate the verifications. We found that TMPRSS2 expression was inversely correlated with the metastatic potential of HCC cell lines. The expression of TMPRSS2 decreased in a time-dependent manner in tumor-bearing model mice implanted with MHCCLM3 cells compared with uninoculated mice. TMPRSS2 overexpression in MHCCLM3 and MHCC97L cells led to the significant downregulation of NID1 expression in total cell lysates and isolated EVs. In contrast, TMPRSS2 silencing resulted in the elevation of NID1 expression in cells and EVs. Administration of EVs from MHCCLM3 and MHCC97L cells with overexpressed or silenced TMPRSS2 inhibited or strengthened, respectively, the invasion, proliferation, and migration of LO2 tumor cells. EVs derived from MHCCLM3 and MHCC97L cells with overexpressed or depleted TMPRSS2 also deactivated or activated fibroblasts, respectively. These EVs secrete inflammatory cytokines and phosphorylated p65, facilitate the colonization of fibroblasts, and augment fibroblast growth and motility. These findings provide evidence for a new candidate drug targeting tumorigenic EV-NID1 to treat HCC.

COVID-19 and Acute Kidney Injury - Direct and Indirect Pathophysiological Mechanisms Underlying Lesion Development

COVID-19 is a pandemic disease caused by the SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) responsible for millions of deaths worldwide. Although the respiratory system is the main target of COVID-19, the disease can affect other organs, including the kidneys. Acute Kidney Injury (AKI), commonly seen in patients infected with COVID-19, has a multifactorial cause. Several studies associate this injury with the direct involvement of the virus in renal cells and the indirect damage stimulated by the infection. The direct cytopathic effects of SARS-CoV-2 are due to the entry and replication of the virus in renal cells, changing several regulatory pathways, especially the renin-angiotensin-aldosterone system (RAAS), with repercussions on the kallikrein-kinin system (KKS). Furthermore, the virus can deregulate the immune system, leading to an exaggerated response of inflammatory cells, characterizing the state of hypercytokinemia. The such exaggerated inflammatory response is commonly associated with hemodynamic changes, reduced renal perfusion, tissue hypoxia, generation of reactive oxygen species (ROS), endothelial damage, and coagulopathies, which can result in severe damage to the renal parenchyma. Thereby, understanding the molecular mechanisms and pathophysiology of kidney injuries induced by SARS-COV-2 is of fundamental importance to obtaining new therapeutic insights for the prevention and management of AKI.

A systemic study on the vulnerability and fatality of prostate cancer patients towards COVID-19 through analysis of the TMPRSS2, CXCL10 and their co-expressed genes

A pandemic of respiratory disease named coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It is reported prostate cancer patients are susceptible to COVID-19 infection. To understand the possible causes of prostate cancer patients' increased vulnerability and mortality from COVID-19 infection, we focused on the two most important agents, transmembrane protease serine subtype 2 (TMPRSS2) and the C-X-C motif 10 (CXCL10). When SARS-CoV-2 binds to the host cell via S protein–angiotensin-converting enzyme-2 receptor interaction, TMPRSS2 contributes in the proteolytic cleavage of the S protein, allowing the viral and cellular membranes to fuse. CXCL10 is a cytokine found in elevated level in both COVID-19 and cancer-causing cytokine storm. We discovered that TMPRSS2 and CXCL10 are overexpressed in prostate cancer and COVID-19 using the UALCAN and GEPIA2 datasets. The functional importance of TMPRSS2 and CXCL10 in prostate cancer development was then determined by analyzing the frequency of genetic changes in their amino acid sequences using the cBioPortal online portal. Finally, we used the PANTHER database to examine the pathology of the targeted genes. We observed that TMPRSS2 and CXCL10, together with their often co-expressed genes, are important in the binding activity and immune responses in prostate cancer and COVID-19 infection, respectively. Finally, we found that TMPRSS2 and CXCL10 are two putative biomarkers responsible for the increased vulnerability and fatality of prostate cancer patients to COVID-19.

Reformation of the chondroitin sulfate glycocalyx enables progression of AR-independent prostate cancer

Lineage plasticity of prostate cancer is associated with resistance to androgen receptor (AR) pathway inhibition (ARPI) and supported by a reactive tumor microenvironment. Here we show that changes in chondroitin sulfate (CS), a major glycosaminoglycan component of the tumor cell glycocalyx and extracellular matrix, is AR-regulated and promotes the adaptive progression of castration-resistant prostate cancer (CRPC) after ARPI. AR directly represses transcription of the 4-O-sulfotransferase gene CHST11 under basal androgen conditions, maintaining steady-state CS in prostate adenocarcinomas. When AR signaling is inhibited by ARPI or lost during progression to non-AR-driven CRPC as a consequence of lineage plasticity, CHST11 expression is unleashed, leading to elevated 4-O-sulfated chondroitin levels. Inhibition of the tumor cell CS glycocalyx delays CRPC progression, and impairs growth and motility of prostate cancer after ARPI. Thus, a reactive CS glycocalyx supports adaptive survival and treatment resistance after ARPI, representing a therapeutic opportunity in patients with advanced prostate cancer.

Chondroitin sulfate (CS) is one of the most abundant glycosaminoglycans in prostate cancers. Here the authors show that inhibition of the androgen receptor pathway leads to the upregulation of CS, which promotes prostate cancer growth and metastasis.

TMPRSS2 Serves as a Prognostic Biomarker and Correlated With Immune Infiltrates in Breast Invasive Cancer and Lung Adenocarcinoma

TMPRSS2 is a transmembrane serine protease and plays a pivotal role in coronavirus disease 2019 (COVID-19). However, the correlation of TMPRSS2 with prognosis and immune infiltration in tumors has not yet been explored. Here, we analyzed the expression of TMPRSS2 in Oncomine and TIMER databases, the correlation between TMPRSS2 and overall survival in the PrognoScan, Kaplan-Meier plotter, and GEPIA databases. The association between TMPRSS2 and immune infiltration levels was investigated in the TIMER database. In addition, the prognosis of TMPRSS2 related to immune cells in cancers was analyzed. Quantitative real-time PCR (qRT-PCR) confirmed that TMPRSS2 was upregulated in lung adenocarcinoma (LUAD) and downregulated in breast invasive carcinoma (BRCA). We demonstrated that high TMPRSS2 expression was associated with favorable prognosis in LUAD, but it was associated with poor prognosis in BRCA. Interestingly, we found that TMPRSS2 expression was significantly correlated with immune infiltration of B cells, CD4+ T cells, macrophages, and dendritic cells in LUAD, and it was positively correlated with the infiltrating levels of CD8+ T cells, CD4+ T cells, neutrophils, and dendric cells in BRCA. Consistent with the prognosis of TMPRSS2 in LUAD and BRCA, the high expression level of TMPRSS2 has a favorable prognosis in enriched immune cells such as B cells, macrophages, and CD4+ T cells in LUAD, and it has a poor prognosis in CD4+ T cells and CD8+ T cells in BRCA. In conclusion, our results indicate that the prognosis of TMPRSS2 in LUAD and BRCA is significantly correlated with immune cells infiltration. Our study comprehensively revealed the relationship between the prognosis of TMPRSS2 in pan-cancers and tumor immunity.

The Transmembrane Protease TMPRSS2 as a Therapeutic Target for COVID-19 Treatment

TMPRSS2 is a type II transmembrane protease with broad expression in epithelial cells of the respiratory and gastrointestinal tract, the prostate, and other organs. Although the physiological role of TMPRSS2 remains largely elusive, several endogenous substrates have been identified. TMPRSS2 serves as a major cofactor in SARS-CoV-2 entry, and primes glycoproteins of other respiratory viruses as well. Consequently, inhibiting TMPRSS2 activity is a promising strategy to block viral infection. In this review, we provide an overview of the role of TMPRSS2 in the entry processes of different respiratory viruses. We then review the different classes of TMPRSS2 inhibitors and their clinical development, with a focus on COVID-19 treatment.

Decreased TMPRSS2 expression by SARS-CoV-2 predicts the poor prognosis of lung cancer patients through metabolic pathways and immune infiltration

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread around the world and became a global pandemic in 2020. One promising drug target for SARS-CoV-2 is the transmembrane protease serine 2 (TMPRSS2). This study was designed to explore the expression status, prognostic significance and molecular functions of TMPRSS2 in lung cancer. TMPRSS2 expression was investigated using the TIMER, Oncomine, UALCAN, GEO, HPA and TCGA databases. The prognostic value of TMPRSS2 was examined using Cox regression and a nomogram. KEGG, GO and GSEA were performed to investigate the cellular function of TMPRSS2 in lung cancer. The relationship between TMPRSS2 and immune infiltration was determined using the TIMER and CIBERSORT algorithms. TMPRSS2 mRNA and protein expression was significantly reduced in lung cancer. Decreased TMPRSS2 expression and increased DNA methylation of TMPRSS2 were associated with various clinicopathological parameters in patients with lung cancer. Low TMPRSS2 mRNA expression also correlated with poor outcome in lung cancer patients. Moreover, a nomogram was constructed and exhibited good predictive power for the overall survival of lung cancer patients. KEGG and GO analyses and GSEA implied that multiple immune- and metabolism-related pathways were significantly linked with TMPRSS2 expression. Intriguingly, TMPRSS2 expression associated with immune cell infiltration in lung cancer. More importantly, TMPRSS2 expression was markedly decreased in SARS-CoV-infected cells. These findings indicate that TMPRSS2 may be a promising prognostic biomarker and therapeutic target for lung cancer through metabolic pathways and immune cell infiltration.

Influence of androgen deprivation therapy on the severity of COVID-19 in prostate cancer patients

BACKGROUND

The TMPRSS2 protein has been involved in severe acute respiratory syndrome caused by coronavirus 2 (SARS-CoV-2). The production is regulated by the androgen receptor (AR). It is speculated that androgen deprivation therapy (ADT) may protect patients affected by prostate cancer (PC) from SARS-CoV-2 infection.

METHODS

This is a retrospective study of patients treated for COVID-19 in our institution who had a previous diagnosis of PC. We analyzed the influence of exposure of ADT on the presence of severe course of COVID-19.

RESULTS

A total of 2280 patients were treated in our center for COVID-19 with a worse course of disease in males (higher rates of hospitalization, intense care unit [ICU] admission, and death). Out of 1349 subjects registered in our PC database, 156 were on ADT and 1193 were not. Out of those, 61 (4.52%) PC patients suffered from COVID-19, 11 (18.0%) belonged to the ADT group, and 50 (82.0%) to the non-ADT group. Regarding the influence of ADT on the course of the disease, statistically significant differences were found neither in the death rate (27.3% vs. 34%; p = 0.481), nor in the presence of severe COVID-19: need for intubation or ICU admission (0% vs. 6.3%; p = 0.561) and need for corticoid treatment, interferon beta, or tocilizumab (60% vs. 34.7%; p = 0.128). Multivariate analysis adjusted for clinically relevant comorbidities did not find that ADT was a protective factor for worse clinical evolution (risk ratio [RR] 1.08; 95% confidence interval [CI], 0.64-1.83; p = 0.77) or death (RR, 0.67; 95% CI, 0.26-1.74; p = 0.41).

CONCLUSIONS

Our study confirms that COVID-19 is more severe in men. However, the use of ADT in patients with PC was not shown to prevent the risk of severe COVID-19.

PFOA induces alteration in DNA methylation regulators and SARS-CoV-2 targets Ace2 and Tmprss2 in mouse lung tissues

Perfluorooctanoic acid (PFOA), a ubiquitous environmental toxicant from the Per- and polyfluoroalkyl substances (PFAS) family has been implicated in toxicity of various organs. Several epidemiological studies have linked PFOA to different lung injuries and diseased conditions. However, the implication of PFOA in affecting epigenetic regulators and SARS-CoV-2 infection pathways in the lung are unknown. The present work explores the accumulation of PFOA in lungs and changes in mRNA expression of DNA methylation regulator genes DNA methyltransferases (Dnmts) and ten-eleven translocation (Tets) along with the membrane proteins angiotensin converting enzyme 2 (Ace2) and transmembrane Serine Protease 2 (Tmprss2) genes involved in the SARS-CoV-2 virus infection. CD1 mice were orally exposed to 5 and 20 mg/kg/day PFOA for 10 days and the lung tissues were analyzed using LCMS, qPCR, and pyrosequencing techniques. PFOA was shown to accumulate in the lung tissues and increase in a dose-dependent manner. Dnmts and Tets were significantly downregulated upon at least one of the PFOA dosing concentration, whereas Ace2 and Tmprss2 show significant increase in their expression level. Further, CpG islands in the promotor region of Tmprss2 exhibited significant hypomethylation in PFOA treated groups, which supports its increased gene expression level. Current study reveals the implication of PFOA induced DNA methylation changes in lungs and their possible role in upregulation of Ace2 and Tmprss2. It is possible that increased expression of these membrane receptors due to PFOA exposure can lead to higher susceptibility of SARS-CoV-2 infections.

COVID-19 pandemic: Insights into genetic susceptibility to SARS-CoV-2 and host genes implications on virus spread, disease severity and outcomes

The outbreak of the newly emerging severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) all over the world has caused global public health emergencies, international concern and economic crises. The systemic SARS-CoV-2 disease (COVID-19) can lead to death through causing unrestrained cytokines-storm and subsequent pulmonary shutdown among the elderly and patients with pre-existing comorbidities. Additionally, in comparison with poor nations without primary health care services, in developed countries with advanced healthcare system we can witness higher number of infections per one million people. In this review, we summarize the latest studies on genes associated with SARS-CoV-2 pathogenesis and propose possible mechanisms of the virus replication cycle and its triggered signaling pathways to encourage researchers to investigate genetic and immune profiles of the disease and try strategies for its treatment. Our review shows that immune response in people with different genetic background might vary as African and then Asian populations have lowest number of affected cases compared with European and American nations. Considering SARS-CoV-2 pathogenesis, we put forward some potentially important genetic gateways to COVID-19 infection including genes involved in the entry and replication of SARS-CoV-2 and the regulation of host immune response which might represent explanation for its spread, severity, and morality. Finally, we suggest that genetic alterations within these gateways could be critical factors in influencing geographical discrepancies of the virus, so it is essential to fully study them and design appropriated and reliable therapeutic agents against COVID-19.

A novel class of TMPRSS2 inhibitors potently block SARS-CoV-2 and MERS-CoV viral entry and protect human epithelial lung cells

The host cell serine protease TMPRSS2 is an attractive therapeutic target for COVID-19 drug discovery. This protease activates the Spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and of other coronaviruses and is essential for viral spread in the lung. Utilizing rational structure-based drug design (SBDD) coupled to substrate specificity screening of TMPRSS2, we have discovered covalent small-molecule ketobenzothiazole (kbt) TMPRSS2 inhibitors which are structurally distinct from and have significantly improved activity over the existing known inhibitors Camostat and Nafamostat. Lead compound MM3122 (4) has an IC50 (half-maximal inhibitory concentration) of 340 pM against recombinant full-length TMPRSS2 protein, an EC50 (half-maximal effective concentration) of 430 pM in blocking host cell entry into Calu-3 human lung epithelial cells of a newly developed VSV-SARS-CoV-2 chimeric virus, and an EC50 of 74 nM in inhibiting cytopathic effects induced by SARS-CoV-2 virus in Calu-3 cells. Further, MM3122 blocks Middle East respiratory syndrome coronavirus (MERS-CoV) cell entry with an EC50 of 870 pM. MM3122 has excellent metabolic stability, safety, and pharmacokinetics in mice, with a half-life of 8.6 h in plasma and 7.5 h in lung tissue, making it suitable for in vivo efficacy evaluation and a promising drug candidate for COVID-19 treatment.

The probable mechanism of reduced androgen level in COVID-19 patients

COVID-19, caused by the SARS-CoV-2, has challenged the health care systems of the world. Although the pulmonary complications of the infection have received extensive attention, addressing the other complications (e.g., changes in androgen levels) could further provide a more efficient understanding of the disease, which might aid in combating it. Since the association between androgens and the expression and activity of SARS-CoV-2 receptors has been proven and anti-androgen-based therapies have been considered in this regard, addressing various aspects of androgen level changes can be constructive. The present paper examines the possible mechanisms of changes in androgen levels by the virus. It seems that the infection of the gonads by the SARS-CoV-2 could reduce the androgen levels by affecting different cellular pathways.

Determinants of SARS-CoV-2 entry and replication in airway mucosal tissue and susceptibility in smokers

Understanding viral tropism is an essential step toward reducing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission, decreasing mortality from coronavirus disease 2019 (COVID-19) and limiting opportunities for mutant strains to arise. Currently, little is known about the extent to which distinct tissue sites in the human head and neck region and proximal respiratory tract selectively permit SARS-CoV-2 infection and replication. In this translational study, we discover key variabilities in expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), essential SARS-CoV-2 entry factors, among the mucosal tissues of the human proximal airways. We show that SARS-CoV-2 infection is present in all examined head and neck tissues, with a notable tropism for the nasal cavity and tracheal mucosa. Finally, we uncover an association between smoking and higher SARS-CoV-2 viral infection in the human proximal airway, which may explain the increased susceptibility of smokers to developing severe COVID-19. This is at least partially explained by differences in interferon (IFN)-β1 levels between smokers and non-smokers.

In silico identification of widely used and well-tolerated drugs as potential SARS-CoV-2 3C-like protease and viral RNA-dependent RNA polymerase inhibitors for direct use in clinical trials

Despite strict measures taken by many countries, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to be an issue of global concern. Currently, there are no clinically proven pharmacotherapies for coronavirus disease 2019, despite promising initial results obtained from drugs such as azithromycin and hydroxychloroquine. Therefore, the repurposing of clinically approved drugs for use against SARS-CoV-2 has become a viable strategy. Here, we searched for drugs that target SARS-CoV-2 3C-like protease (3CLpro) and viral RNA-dependent RNA polymerase (RdRp) by in silico screening of the U.S. Food and Drug Administration approved drug library. Well-tolerated and widely used drugs were selected for molecular dynamics (MD) simulations to evaluate drug-protein interactions and their persistence under physiological conditions. Tetracycline, dihydroergotamine, ergotamine, dutasteride, nelfinavir, and paliperidone formed stable interactions with 3CLpro based on MD simulation results. Similar analysis with RdRp showed that eltrombopag, tipranavir, ergotamine, and conivaptan bound to the enzyme with high binding free energies. Docking results suggest that ergotamine, dihydroergotamine, bromocriptine, dutasteride, conivaptan, paliperidone, and tipranavir can bind to both enzymes with high affinity. As these drugs are well tolerated, cost-effective, and widely used, our study suggests that they could potentially to be used in clinical trials for the treatment of SARS-CoV-2-infected patients.Communicated by Ramaswamy H. Sarma.

Host variations in SARS-CoV-2 infection

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the zoonotic pathogen that causes the "Coronavirus Disease of 2019 (COVID-19)", and COVID-19 itself is yet to be thoroughly understood. Both the disease as well as the mechanisms by which the host interacts with the SARS-CoV-2 have not been fully enlightened. The epidemiological factors -e.g. age, sex, race-, the polymorphisms of the host proteins, the blood types and individual differences have all been in discussions about affecting the progression and the course of COVID-19 both individually and collectively, as their effects are mostly interwoven. We focused mainly on the effect of polymorphic variants of the host proteins that have been shown to take part in and/or affect the pathogenesis of COVID-19. Additionally, how the procedures of diagnosing and treating COVID-19 are affected by these variants and what possible changes can be implemented are the other questions, which are sought to be answered.

Host Serine Proteases: A Potential Targeted Therapy for COVID-19 and Influenza

The ongoing pandemic illustrates limited therapeutic options for controlling SARS-CoV-2 infections, calling a need for additional therapeutic targets. The viral spike S glycoprotein binds to the human receptor angiotensin-converting enzyme 2 (ACE2) and then is activated by the host proteases. Based on the accessibility of the cellular proteases needed for SARS-S activation, SARS-CoV-2 entrance and activation can be mediated by endosomal (such as cathepsin L) and non-endosomal pathways. Evidence indicates that in the non-endosomal pathway, the viral S protein is cleaved by the furin enzyme in infected host cells. To help the virus enter efficiently, the S protein is further activated by the serine protease 2 (TMPRSS2), provided that the S has been cleaved by furin previously. In this review, important roles for host proteases within host cells will be outlined in SARS-CoV-2 infection and antiviral therapeutic strategies will be highlighted. Although there are at least five highly effective vaccines at this time, the appearance of the new viral mutations demands the development of therapeutic agents. Targeted inhibition of host proteases can be used as a therapeutic approach for viral infection.

The secret identities of TMPRSS2: Fertility factor, virus trafficker, inflammation moderator, prostate protector and tumor suppressor

The human TMPRSS2 gene is pathogenetically implicated in both coronaviral lung infection and prostate cancer, suggesting its potential as a drug target in both contexts. SARS-COV-2 spike polypeptides are primed by the host transmembrane TMPRSS2 protease, triggering virus fusion with epithelial cell membranes followed by an endocytotic internalisation process that bypasses normal endosomal activation of cathepsin-mediated innate immunity; viral co-opting of TMPRSS2 thus favors microbial survivability by attenuating host inflammatory responses. In contrast, most early hormone-dependent prostate cancers express TMPRSS2:ERG fusion genes arising from deletions that eliminate the TMPRSS2 coding region while juxtaposing its androgen-inducible promoter and the open reading frame of ERG, upregulating pro-inflammatory ERG while functionally disabling TMPRSS2. Moreover, inflammatory oxidative DNA damage selects for TMPRSS2:ERG-fused cancers, whereas patients treated with antiinflammatory drugs develop fewer of these fusion-dependent tumors. These findings imply that TMPRSS2 protects the prostate by enabling endosomal bypass of pathogens which could otherwise trigger inflammation-induced DNA damage that predisposes to TMPRSS2:ERG fusions. Hence, the high oncogenic selectability of TMPRSS2:ERG fusions may reflect a unique pro-inflammatory synergy between androgenic ERG gain-of-function and fusogenic TMPRSS2 loss-of-function, cautioning against the use of TMPRSS2-inhibitory drugs to prevent or treat early prostate cancer.

Can Host Cell Proteins Like ACE2, ADAM17, TMPRSS2, Androgen Receptor be the Efficient Targets in SARS-CoV-2 Infection?

A novel betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV- -2), which caused a large disease outbreak in Wuhan, China in December 2019, is currently spreading across the world. Along with binding of the virus spike with the host cell receptor, fusion of the viral envelope with host cell membranes is a critical step in establishing successful infection of SARS-CoV-2. In this entry process, a diversity of host cell proteases and androgen receptor play a very important role directly or indirectly. These features of SARS-CoV-2 entry contribute to its rapid spread and severe symptoms, high fatality rates among infected patients. This review is based on the latest published literature including review articles, research articles, hypothetical manuscript, preprint articles and official documents. The literature search was made from various published papers on physiological aspects relevant to SARS-CoV and SARS-CoV-2. In this report, we focus on the role of host cell proteases (ACE2, ADAM17, TMPRSS2) and androgen receptor (AR) in SARS-CoV-2 infection. The hypotheses put forth by us are based on the role played by the proteases ACE2, ADAM17, TMPRSS2 and AR in SARS-CoV-2 infection, which were deduced based on various studies. We have also summarized how these host proteins increase the pathology and the infective ability of SARS-CoV-2 and we posit that their inhibition may be a therapeutic option for preventing SARS-CoV-2 infection.

The intersection of COVID-19 and cancer: signaling pathways and treatment implications

The outbreak of the novel coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as a serious public health concern. Patients with cancer have been disproportionately affected by this pandemic. Increasing evidence has documented that patients with malignancies are highly susceptible to severe infections and mortality from COVID-19. Recent studies have also elucidated the molecular relationship between the two diseases, which may not only help optimize cancer care during the pandemic but also expand the treatment for COVID-19. In this review, we highlight the clinical and molecular similarities between cancer and COVID-19 and summarize the four major signaling pathways at the intersection of COVID-19 and cancer, namely, cytokine, type I interferon (IFN-I), androgen receptor (AR), and immune checkpoint signaling. In addition, we discuss the advantages and disadvantages of repurposing anticancer treatment for the treatment of COVID-19.

A novel class of TMPRSS2 inhibitors potently block SARS-CoV-2 and MERS-CoV viral entry and protect human epithelial lung cells

The host cell serine protease TMPRSS2 is an attractive therapeutic target for COVID-19 drug discovery. This protease activates the Spike protein of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and of other coronaviruses and is essential for viral spread in the lung. Utilizing rational structure-based drug design (SBDD) coupled to substrate specificity screening of TMPRSS2, we have discovered a novel class of small molecule ketobenzothiazole TMPRSS2 inhibitors with significantly improved activity over existing irreversible inhibitors Camostat and Nafamostat. Lead compound MM3122 ( 4 ) has an IC ₅₀ of 340 pM against recombinant full-length TMPRSS2 protein, an EC ₅₀ of 430 pM in blocking host cell entry into Calu-3 human lung epithelial cells of a newly developed VSV SARS-CoV-2 chimeric virus, and an EC ₅₀ of 74 nM in inhibiting cytopathic effects induced by SARS-CoV-2 virus in Calu-3 cells. Further, MM3122 blocks Middle East Respiratory Syndrome Coronavirus (MERS-CoV) cell entry with an EC ₅₀ of 870 pM. MM3122 has excellent metabolic stability, safety, and pharmacokinetics in mice with a half-life of 8.6 hours in plasma and 7.5 h in lung tissue, making it suitable for in vivo efficacy evaluation and a promising drug candidate for COVID-19 treatment.

SARS-CoV-2 Entry Related Viral and Host Genetic Variations: Implications on COVID-19 Severity, Immune Escape, and Infectivity

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evolved to display particular patterns of genetic diversity in the genome across geographical regions. These variations in the virus and genetic variation in human populations can determine virus transmissibility and coronavirus disease 2019 (COVID-19) severity. Genetic variations and immune differences in human populations could be the driving forces in viral evolution. Recently emerged SARS-CoV-2 variants show several mutations at the receptor binding domain in the spike (S) glycoprotein and contribute to immune escape and enhanced binding with angiotensin 1-converting enzyme 2 (ACE2). Since ACE2 and transmembrane protease serine 2 (TMPRSS2) play important roles in SARS-CoV-2 entry into the cell, genetic variation in these host entry-related proteins may be a driving force for positive selection in the SARS-CoV-2 S glycoprotein. Dendritic or liver/lymph cell-specific intercellular adhesion molecule (ICAM)-3-grabbing non-integrin is also known to play vital roles in several pathogens. Genetic variations of these host proteins may affect the susceptibility to SARS-CoV-2. This review summarizes the latest research to describe the impacts of genetic variation in the viral S glycoprotein and critical host proteins and aims to provide better insights for understanding transmission and pathogenesis and more broadly for developing vaccine/antiviral drugs and precision medicine strategies, especially for high risk populations with genetic risk variants.

Coronaviruses in children: A review of potential mechanisms of childhood protection

Aim

The 2019 coronavirus disease (COVID‐19) has spread worldwide and the number of cases continues to rise exponentially. Epidemiologic reports indicate that severity of illness increases with age. However, the reasons behind the relative protection of children and infants are unclear. Whether the rationale is host‐related or virus dependent is important to determine since the latter could change with viral mutations. We review factors that could affect the susceptibility of children to the novel coronavirus.

Methods

We search publications indexed on PUBMED.

Results

Descriptions of the pathophysiology of current and previous coronavirus infections suggest several viral targets and immunomodulatory pathways affecting the severity of illness. There is limited evidence to suggest age‐variability of viral cell receptors and transmembrane co‐factors required for coronavirus entry and replication. However, the ensuing cytokine storm and the effect of higher melatonin in children are age‐dependent and could explain decreased disease variability in children.

Conclusion

We believe that current evidence suggests host factors can play a role in disease severity in children and thus may remain protective despite potential virus mutation in the future. However, we recognise and discuss avenues of future research that can further illuminate the reasons children are protected from severe COVID‐19 illness.

SARS-CoV-2 infects and replicates in cells of the human endocrine and exocrine pancreas

Infection-related diabetes can arise as a result of virus-associated β-cell destruction. Clinical data suggest that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causing the coronavirus disease 2019 (COVID-19), impairs glucose homoeostasis, but experimental evidence that SARS-CoV-2 can infect pancreatic tissue has been lacking. In the present study, we show that SARS-CoV-2 infects cells of the human exocrine and endocrine pancreas ex vivo and in vivo. We demonstrate that human β-cells express viral entry proteins, and SARS-CoV-2 infects and replicates in cultured human islets. Infection is associated with morphological, transcriptional and functional changes, including reduced numbers of insulin-secretory granules in β-cells and impaired glucose-stimulated insulin secretion. In COVID-19 full-body postmortem examinations, we detected SARS-CoV-2 nucleocapsid protein in pancreatic exocrine cells, and in cells that stain positive for the β-cell marker NKX6.1 and are in close proximity to the islets of Langerhans in all four patients investigated. Our data identify the human pancreas as a target of SARS-CoV-2 infection and suggest that β-cell infection could contribute to the metabolic dysregulation observed in patients with COVID-19.

Sex differences in COVID-19: the role of androgens in disease severity and progression

PURPOSE

Throughout the SARS-CoV2 pandemic, multiple reports show higher percentages of hospitalization, morbidity, and mortality among men than women, indicating that men are more affected by COVID-19. The pathophysiology of this difference is yet not established, but recent studies suggest that sex hormones may influence the viral infectivity process. Here, we review the current evidence of androgen sensitivity as a decisive factor for COVID-19 disease severity.

METHODS

Relevant literature investigating the role of androgens in COVID-19 was assessed. Further, we describe several drugs suggested as beneficial for COVID-19 treatment related to androgen pathways. Lastly, we looked at androgen sensitivity as a predictor for COVID-19 progression and ongoing clinical trials on androgen suppression therapies as a line of treatment.

RESULTS

SARS-COV2 virus spike proteins utilize Transmembrane protease serine 2 (TMPRSS2) for host entry. Androgen receptors are transcription promoters for TMPRSS2 and can, therefore, facilitate SARS-COV2 entry. Variants in the androgen receptor gene correlate with androgen sensitivity and are implicated in diseases like androgenetic alopecia and prostate cancer, conditions that have been associated with worse COVID-19 outcomes and hospitalization.

CONCLUSION

Androgen's TMPRSS2-mediated actions might explain both the low fatalities observed in prepubertal children and the differences between sexes regarding SARS-COV2 infection. Androgen sensitivity may be a critical factor in determining COVID-19 disease severity, and sensitivity tests can, therefore, help in predicting patient outcomes.

The PIKfyve Inhibitor Apilimod: A Double-Edged Sword against COVID-19

The PIKfyve inhibitor apilimod is currently undergoing clinical trials for treatment of COVID-19. However, although apilimod might prevent viral invasion by inhibiting host cell proteases, the same proteases are critical for antigen presentation leading to T cell activation and there is good evidence from both in vitro studies and the clinic that apilimod blocks antiviral immune responses. We therefore warn that the immunosuppression observed in many COVID-19 patients might be aggravated by apilimod.

SARS-CoV-2 and Viral Sepsis: Immune Dysfunction and Implications in Kidney Failure

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of coronavirus disease 2019 (COVID-19), first emerged in Wuhan, China. The clinical manifestations of patients infected with COVID-19 include fever, cough, and dyspnea, up to acute respiratory distress syndrome (ARDS) and acute cardiac injury. Thus, a lot of severe patients had to be admitted to intensive care units (ICU). The pathogenic mechanisms of SARS-CoV-2 infection are mediated by the binding of SARS-CoV-2 spikes to the human angiotensin-converting enzyme 2 (ACE-2) receptor. The overexpression of human ACE-2 is associated with the disease severity in SARS-CoV-2 infection, demonstrating that viral entry into cells is a pivotal step. Although the lung is the organ that is most commonly affected by SARS-CoV-2 infection, acute kidney injury (AKI), heart dysfunction and abdominal pain are the most commonly reported co-morbidities of COVID-19. The occurrence of AKI in COVID-19 patients might be explained by several mechanisms that include viral cytopathic effects in renal cells and the host hyperinflammatory response. In addition, kidney dysfunction could exacerbate the inflammatory response started in the lungs and might cause further renal impairment and multi-organ failure. Mounting recent evidence supports the involvement of cardiovascular complications and endothelial dysfunction in COVID-19 syndrome, in addition to respiratory disease. To date, there is no vaccine, and no specific antiviral medicine has been shown to be effective in preventing or treating COVID-19. The removal of pro-inflammatory cytokines and the shutdown of the cytokine storm could ameliorate the clinical outcome in severe COVID-19 cases. Therefore, several interventions that inhibit viral replication and the systemic inflammatory response could modulate the severity of the renal dysfunction and increase the probability of a favorable outcome.

Priming of SARS-CoV-2 S protein by several membrane-bound serine proteinases could explain enhanced viral infectivity and systemic COVID-19 infection

The ongoing COVID-19 pandemic has already caused over a million deaths worldwide, and this death toll will be much higher before effective treatments and vaccines are available. The causative agent of the disease, the coronavirus SARS-CoV-2, shows important similarities with the previously emerged SARS-CoV-1, but also striking differences. First, SARS-CoV-2 possesses a significantly higher transmission rate and infectivity than SARS-CoV-1 and has infected in a few months over 60 million people. Moreover, COVID-19 has a systemic character, as in addition to the lungs, it also affects the heart, liver, and kidneys among other organs of the patients and causes frequent thrombotic and neurological complications. In fact, the term "viral sepsis" has been recently coined to describe the clinical observations. Here I review current structure-function information on the viral spike proteins and the membrane fusion process to provide plausible explanations for these observations. I hypothesize that several membrane-associated serine proteinases (MASPs), in synergy with or in place of TMPRSS2, contribute to activate the SARS-CoV-2 spike protein. Relative concentrations of the attachment receptor, ACE2, MASPs, their endogenous inhibitors (the Kunitz-type transmembrane inhibitors, HAI-1/SPINT1 and HAI-2/SPINT2, as well as major circulating serpins) would determine the infection rate of host cells. The exclusive or predominant expression of major MASPs in specific human organs suggests a direct role of these proteinases in e.g., heart infection and myocardial injury, liver dysfunction, kidney damage, as well as neurological complications. Thorough consideration of these factors could have a positive impact on the control of the current COVID-19 pandemic.

Hepsin Promotes Epithelial-Mesenchymal Transition and Cell Invasion Through the miR-222/PPP2R2A/AKT Axis in Prostate Cancer

Purpose

To determine the role and underlying mechanism of hepsin in epithelial–mesenchymal transition (EMT) and cell invasion in prostate cancer.

Methods

The expression of hepsin in prostate cancer tissue samples and cell lines was measured by immunohistochemical staining and Western blotting. The EMT and cell invasion abilities of prostate cancer cells were detected by Western blot and transwell assays. RNA transfection was used to inhibit or overexpress related genes. The expression of miR-222 was detected by RT-qPCR. A dual‑luciferase reporter gene assay was performed to determine the target of miR-222.

Results

Hepsin expression was upregulated in prostate cancer tissue samples and cell lines. Inhibition of hepsin attenuated EMT and cell invasion and downregulated the expression of miR-222. Decreased miR-222 expression enhanced the level of PPP2R2A, which in turn attenuated the AKT signaling. Activation of miR-222 or AKT could block the inhibitory effects on EMT and cell invasion induced by hepsin deficiency.

Conclusion

Hepsin promotes EMT and cell invasion through the miR-222/PPP2R2A/AKT axis in prostate cancer.

Is Spironolactone the Preferred Renin-Angiotensin-Aldosterone Inhibitor for Protection Against COVID-19?

ABSTRACT

The high mortality of specific groups from COVID-19 highlights the importance of host-viral interactions and the potential benefits from enhancing host defenses. SARS-CoV-2 requires angiotensin-converting enzyme (ACE) 2 as a receptor for cell entry and infection. Although both ACE inhibitors and spironolactone can upregulate tissue ACE2, there are important points of discrimination between these approaches. The virus requires proteolytic processing of its spike protein by transmembrane protease receptor serine type 2 (TMPRSS2) to enable binding to cellular ACE2. Because TMPRSS2 contains an androgen promoter, it may be downregulated by the antiandrogenic actions of spironolactone. Furin and plasmin also process the spike protein. They are inhibited by protease nexin 1 or serpin E2 (PN1) that is upregulated by angiotensin II but downregulated by aldosterone. Therefore, spironolactone should selectively downregulate furin and plasmin. Furin also promotes pulmonary edema, whereas plasmin promotes hemovascular dysfunction. Thus, a downregulation of furin and plasmin by PN1 could be a further benefit of MRAs beyond their well-established organ protection. We review the evidence that spironolactone may be the preferred RASSi to increase PN1 and decrease TMPRSS2, furin, and plasmin activities and thereby reduce viral cell binding, entry, infectivity, and bad outcomes. This hypothesis requires direct investigation.

Review of COVID-19 and male genital tract

COVID‐19 pandemic leads to health challenges globally, and its diverse aspects need to be uncovered. Multi‐organ injuries have been reported by describing potential SARS‐CoV‐2 entrance routes: ACE2 and TMPRSS2. Since these cell surface receptors’ expression has been disclosed within the male reproductive system, its susceptibility to being infected by SARS‐CoV‐2 has been summarised through this literature review. Expression of ACE2 and TMPRSS2 at RNA or protein level has been reported across various investigations indicates that the male genitalia potentially is vulnerable to SARS‐CoV‐2 infection. Presence of SARS‐CoV‐2 within semen samples and following direct viral damage, secondary inflammatory response causing orchitis or testicular discomfort and finally the amount of viral load leading testicular damage and immune response activation are among probable underlying mechanisms. Therefore, genital examination and laboratory tests should be considered to address the male reproductive tract complications and fertility issues.

A rational roadmap for SARS-CoV-2/COVID-19 pharmacotherapeutic research and development: IUPHAR Review 29

In this review, we identify opportunities for drug discovery in the treatment of COVID-19 and, in so doing, provide a rational roadmap whereby pharmacology and pharmacologists can mitigate against the global pandemic. We assess the scope for targeting key host and viral targets in the mid-term, by first screening these targets against drugs already licensed, an agenda for drug repurposing, which should allow rapid translation to clinical trials. A simultaneous, multi-pronged approach using conventional drug discovery methods aimed at discovering novel chemical and biological means of targeting a short list of host and viral entities which should extend the arsenal of anti-SARS-CoV-2 agents. This longer term strategy would provide a deeper pool of drug choices for future-proofing against acquired drug resistance. Second, there will be further viral threats, which will inevitably evade existing vaccines. This will require a coherent therapeutic strategy which pharmacology and pharmacologists are best placed to provide. LINKED ARTICLES: This article is part of a themed issue on The Pharmacology of COVID-19. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v177.21/issuetoc.

The role of androgens in COVID-19

BACKGROUND AND AIM

The coronavirus disease 2019 (COVID-19) pandemic is a global health emergency. According to the findings, male patients with COVID-19 infection are at an increased risk for severe complications than females. The causes of this issue are unknown and are most probably multifactorial. Sexual hormones affect the immune system, so estrogen strengthens the immune system, and testosterone suppresses it. Due to the reports of the high prevalence of androgenic alopecia in hospitalized patients with COVID-19 and a higher risk of respiratory disease and increased use of allergy/asthma medications among patients with polycystic ovary syndrome (PCOS) as a hyperandrogenism condition compared with non-PCOS women, this review aimed to evaluate androgens role in COVID-19.

METHODS

42 related articles from 2008 to 2020 were reviewed with the keywords of androgens, hormonal factors, and hair loss in combination with COVID-19 in medical research databases.

RESULTS

The evidence of transmembrane protease, serine 2 (TMPRSS2) expression in lung tissue, which is an androgen-regulated gene and expressed mainly in the adult prostate may interpret the increased susceptibility of the male gender to severe COVID-19 complications. Moreover, angiotensin-converting enzyme 2 (ACE-2) acts as a functional receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and male hormones are effective in the ACE-2 passageway and simplify SARS-CoV-2 entry into host cells.

CONCLUSION

Further studies on the severity of symptoms in patients with COVID-19 in other hyperandrogenism conditions compared to the control group are recommended.

Testosterone in COVID-19 - Foe, Friend or Fatal Victim?

The evidence derived from observational studies suggests male gender, diabetes and central obesity to be risk factors associated with an increased COVID-19-related case fatality. The precise pathophysiology behind this gender difference in mortality outcomes remains unclear at this stage, although it is worth exploring a possible role of testosterone as one of the contributory factors. The observed role of androgens in transcription of transmembrane protease serine-2, which facilitates COVID-19 anchoring to angiotensin-converting enzyme 2 cell surface receptors, seems to suggest that higher testosterone levels might be detrimental for outcomes. On the other hand, men with type 2 diabetes mellitus and central obesity have an increased prevalence of hypogonadotropic hypogonadism, with inhibition of gonadotropin-releasing hormone secretion induced by inflammatory cytokines being one of the postulated mechanisms. The increased COVID-19 case fatality in this cohort might perhaps reflect an underlying pro-inflammatory state, with low testosterone levels being either a surrogate marker of a poor metabolic state or playing a more active role in propagation of inflammation and thrombosis.

Angiotensin-converting enzyme 2 (ACE2) receptor and SARS-CoV-2: Potential therapeutic targeting

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a beta coronavirus that uses the human angiotensin-converting enzyme 2 (ACE2) receptor as a point of entry. The present review discusses the origin and structure of the virus and its mechanism of cell entry followed by the therapeutic potentials of strategies directed towards SARS-CoV2-ACE2 binding, the renin-angiotensin system, and the kinin-kallikrein system. SARS-CoV2-ACE2 binding-directed approaches mainly consist of targeting receptor binding domain, ACE2 blockers, soluble ACE2, and host protease inhibitors. In conclusion, blocking or manipulating the SARS-CoV2-ACE2 binding interface perhaps offers the best tactic against the virus that should be treated as a fundamental subject of future research.

Renin Angiotensin System, COVID-19 and Male Fertility: Any Risk for Conceiving?

The current knowledge concerning the connection between severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the renin-angiotensin system (RAS) system in the male reproductive apparatus is still limited, so dedicated studies are urgently required. Concerns about the male fertility consequences of SARS-CoV-2 infection have started to emerge, since epidemiologic studies observed that this coronavirus affects male patients more frequently and with increased severity, possibly because of the hormone-regulated expression of angiotensin-converting enzyme 2 (ACE2) receptor. A disturbance in fertility is also expected based on studies of the previous SARS-CoV infection, which targets the same ACE2 receptor when entering the host cells. In addition, bioinformatics analyses reveal the abundant expression of ACE2 receptor in the male reproductive tissues, particularly in the testis. It has been proposed that pharmacological intervention favoring the angiotensin-(1-7)/ACE2/Mas receptor pathway and increasing ACE2 expression and activity could greatly prevent inflammatory lesions in this area. Finally, in laboratories performing assisted reproductive technologies it is recommended that more attention should be paid not only to sperm quality but also to safety aspects. Data about the potential infectivity of seminal fluid are in fact conflicting and do not exclude risks for both personnel and patients. The potential infectivity of SARS-CoV-2 in reproductive male tissues should be strongly considered and further investigated for the proper management of in vitro fertilization procedures.

Identification of Novel Hypothalamic MicroRNAs as Promising Therapeutics for SARS-CoV-2 by Regulating ACE2 and TMPRSS2 Expression: An In Silico Analysis

BACKGROUND

Neuroinvasion of severe acute respiratory syndrome coronavirus (SARS-CoV) is well documented and, given the similarities between this virus and SARS-CoV-2, it seems that the neurological impairment that is associated with coronavirus disease 2019 (COVID-19) is due to SARS-CoV-2 neuroinvasion. Hypothalamic circuits are exposed to the entry of the virus via the olfactory bulb and interact centrally with crucial respiratory nuclei. Hypothalamic microRNAs are considered as potential biomarkers and modulators for various diseases and future therapeutic targets. The present study aims to investigate the microRNAs that regulate the expression of hypothalamic angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2), essential elements for SARS-CoV-2 cell entry.

METHODS

To determine potential hypothalamic miRNAs that can directly bind to ACE2 and TMPRSS2, multiple target bioinformatics prediction algorithms were used, including miRBase, Target scan, and miRWalk2.029.

RESULTS

Our in silico analysis has revealed that, although there are over 5000 hypothalamic miRNAs, around 31 miRNAs and 29 miRNAs have shown binding sites and strong binding capacity against ACE2 and TMPRSS2, respectively.

CONCLUSION

These novel potential hypothalamic miRNAs can be used to identify new therapeutic targets to treat neurological symptoms in COVID-19 patients via regulation of ACE2 and TMPRSS2 expression.

COVID-19 and the male susceptibility: the role of ACE2, TMPRSS2 and the androgen receptor

COVID-19 is the pandemic that hit the world starting December 2019. Recent studies and international statistics have shown an increased prevalence, morbidity as well as mortality of this disease in male patients compared to female patients. The aim of this brief communication is to describe the pathophysiology of this sex-discrepancy, based on the infectivity mechanism of the coronavirus including the Angiotensin-Converting Enzyme 2 (ACE2), the Type II transmembrane Serine Protease (TMPRSS2), and the androgen receptor. This could help understand the susceptibility of urological patients, especially those receiving androgen deprivation therapy for prostate cancer, and testosterone replacement therapy.

Existence of SARS-CoV-2 Entry Molecules in the Oral Cavity

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) receptor, angiotensin-converting enzyme 2 (ACE2), transmembrane protease serine 2 (TMPRSS2), and furin, which promote entry of the virus into the host cell, have been identified as determinants of SARS-CoV-2 infection. Dorsal tongue and gingiva, saliva, and tongue coating samples were examined to determine the presence of these molecules in the oral cavity. Immunohistochemical analyses showed that ACE2 was expressed in the stratified squamous epithelium of the dorsal tongue and gingiva. TMPRSS2 was strongly expressed in stratified squamous epithelium in the keratinized surface layer and detected in the saliva and tongue coating samples via Western blot. Furin was localized mainly in the lower layer of stratified squamous epithelium and detected in the saliva but not tongue coating. ACE2, TMPRSS2, and furin mRNA expression was observed in taste bud-derived cultured cells, which was similar to the immunofluorescence observations. These data showed that essential molecules for SARS-CoV-2 infection were abundant in the oral cavity. However, the database analysis showed that saliva also contains many protease inhibitors. Therefore, although the oral cavity may be the entry route for SARS-CoV-2, other factors including protease inhibitors in the saliva that inhibit viral entry should be considered.

Inhibition of TMPRSS2 by HAI-2 reduces prostate cancer cell invasion and metastasis

TMPRSS2 is an important membrane-anchored serine protease involved in human prostate cancer progression and metastasis. A serine protease physiologically often comes together with a cognate inhibitor for execution of proteolytically biologic function; however, TMPRSS2's cognate inhibitor is still elusive. To identify the cognate inhibitor of TMPRSS2, in this study, we applied co-immunoprecipitation and LC/MS/MS analysis and isolated hepatocyte growth factor activator inhibitors (HAIs) to be potential inhibitor candidates for TMPRSS2. Moreover, the recombinant HAI-2 proteins exhibited a better inhibitory effect on TMPRSS2 proteolytic activity than HAI-1, and recombinant HAI-2 proteins had a high affinity to form a complex with TMPRSS2. The immunofluorescence images further showed that TMPRSS2 was co-localized to HAI-2. Both KD1 and KD2 domain of HAI-2 showed comparable inhibitory effects on TMPRSS2 proteolytic activity. In addition, HAI-2 overexpression could suppress the induction effect of TMPRSS2 on pro-HGF activation, extracellular matrix degradation and prostate cancer cell invasion. We further determined that the expression levels of TMPRSS2 were inversely correlated with HAI-2 levels during prostate cancer progression. In orthotopic xenograft animal model, TMPRSS2 overexpression promoted prostate cancer metastasis, and HAI-2 overexpression efficiently blocked TMPRSS2-induced metastasis. In summary, the results together indicate that HAI-2 can function as a cognate inhibitor for TMPRSS2 in human prostate cancer cells and may serve as a potential factor to suppress TMPRSS2-mediated malignancy.

SARS-CoV-2 Infection and Lung Cancer: Potential Therapeutic Modalities

Human coronaviruses, especially SARS-CoV-2, are emerging pandemic infectious diseases with high morbidity and mortality in certain group of patients. In general, SARS-CoV-2 causes symptoms ranging from the common cold to severe conditions accompanied by lung injury, acute respiratory distress syndrome in addition to other organs' destruction. The main impact upon SARS-CoV-2 infection is damage to alveolar and acute respiratory failure. Thus, lung cancer patients are identified as a particularly high-risk group for SARS-CoV-2 infection and its complications. On the other hand, it has been reported that SARS-CoV-2 spike (S) protein binds to angiotensin-converting enzyme 2 (ACE-2), that promotes cellular entry of this virus in concert with host proteases, principally transmembrane serine protease 2 (TMPRSS2). Today, there are no vaccines and/or effective drugs against the SARS-CoV-2 coronavirus. Thus, manipulation of key entry genes of this virus especially in lung cancer patients could be one of the best approaches to manage SARS-CoV-2 infection in this group of patients. We herein provide a comprehensive and up-to-date overview of the role of ACE-2 and TMPRSS2 genes, as key entry elements as well as therapeutic targets for SARS-CoV-2 infection, which can help to better understand the applications and capacities of various remedial approaches for infected individuals, especially those with lung cancer.