The role of Interleukin-4 in COVID-19 associated male infertility - A hypothesis

NFκB and NLRP3/NLRC4 inflammasomes regulate differentiation, activation and functional properties of monocytes in response to distinct SARS-CoV-2 proteins

Increased recruitment of transitional and non-classical monocytes in the lung during SARS-CoV-2 infection is associated with COVID-19 severity. However, whether specific innate sensors mediate the activation or differentiation of monocytes in response to different SARS-CoV-2 proteins remain poorly characterized. Here, we show that SARS-CoV-2 Spike 1 but not nucleoprotein induce differentiation of monocytes into transitional or non-classical subsets from both peripheral blood and COVID-19 bronchoalveolar lavage samples in a NFκB-dependent manner, but this process does not require inflammasome activation. However, NLRP3 and NLRC4 differentially regulated CD86 expression in monocytes in response to Spike 1 and Nucleoprotein, respectively. Moreover, monocytes exposed to Spike 1 induce significantly higher proportions of Th1 and Th17 CD4 + T cells. In contrast, monocytes exposed to Nucleoprotein reduce the degranulation of CD8 + T cells from severe COVID-19 patients. Our study provides insights in the differential impact of innate sensors in regulating monocytes in response to different SARS-CoV-2 proteins, which might be useful to better understand COVID-19 immunopathology and identify therapeutic targets.

Safety, immunogenicity and efficacy of Relcovax®, a dual receptor binding domain (RBD) and nucleocapsid (N) subunit protein vaccine candidate against SARS-CoV-2 virus

SARS-CoV-2, severe acute respiratory syndrome coronavirus-2, causes coronavirus disease- 2019 (COVID-19). Mostly, COVID-19 causes respiratory symptoms that can resemble those of a cold, the flu, or pneumonia. COVID-19 may harm more than just lungs and respiratory systems. It may also have an impact on other parts of the body and debilitating effects on humans, necessitating the development of vaccines at an unprecedented rate in order to protect humans from infections. In response to SARS-CoV-2 infection, mRNA, viral vector-based carrier and inactivated virus-based vaccines, as well as subunit vaccines, have recently been developed. We developed Relcovax®, a dual antigen (Receptor binding domain (RBD) and Nucleocapsid (N) proteins) subunit protein vaccine candidate. Preliminary mouse preclinical studies revealed that Relcovax® stimulates cell-mediated immunity and provides broader protection against two SARS-CoV-2 variants, including the delta strain. Before conducting human studies, detailed preclinical safety assessments are required, so Relcovax® was tested for safety, and immunogenicity in 28-day repeated dose toxicity studies in rats and rabbits. In the toxicity studies, there were no mortality or morbidity, abnormal clinical signs, abnormalities in a battery of neurobehavioral observations, abnormalities in detailed clinical and ophthalmological examinations, or changes in body weights or feed consumption. In any of the studies, no abnormal changes in organ weights, haematology, clinical chemistry, urinalysis parameters, or pathological findings were observed. Immunogenicity tests on rats and rabbits revealed 100 % seroconversion. Relcovax® was therefore found to be safe in animals, with a No Observed Adverse Effect Level (NOAEL) of 20 µg/protein in rats and rabbits. In efficacy studies, Relcovax® immunised hamsters demonstrated dose-dependent protection against SARS-CoV-2 infection, with a high dose (20 µg/protein) being the most protective, while in cynomolgus macaque monkey study, lowest dose 5 µg/protein had the highest efficacy. In conclusion, Relcovax® was found to be safe, immunogenic, and efficacious in in vivo studies.

Effects of COVID-19 or vaccines for SARS-COV-2 on sperm parameters: A systematic review and meta-analysis

This systematic review and meta-analysis assessed the effects of SARS-Cov-2 and mRNA vaccines on male reproduction. We conducted a comprehensive search using terms such as "COVID-19," "vaccine," and "sperm parameters" on various electronic databases, including MEDLINE (PubMed), BVS (LILACS and others), Embase (Elsevier), and Cochrane Library. We included observational studies, including cohort, case-control, and cross-sectional studies. Of the 2054 records initially identified, we carefully examined 47 full-text articles and excluded 26 articles for specific reasons, ultimately including 21 studies for our analysis. Among these, 16 studies focused on assessing seminal parameters in patients with COVID-19, while five studies investigated the effects of COVID vaccines on seminal parameters. A meta-analysis of seminal parameters in men before and after the COVID-19 pandemic revealed significant differences in seminal concentration, progressive motility, total motility, and normal morphology. These findings indicate a positive impact of the analyzed parameters before the onset of COVID-19. However, the quality of the evidence was considered low. In contrast, a meta-analysis of five studies evaluating seminal parameters before and after the SARS-Cov-2 vaccine did not show any significant differences in total motility. This analysis, involving 256 men from four studies, provided low-quality evidence, suggesting that mRNA vaccines do not affect male reproduction. Overall, our findings suggest that seminal parameters exhibit considerable variability depending on specific outcomes and the study design. However, based on available evidence, it appears that mRNA vaccines do not have detrimental effects on male reproductive function.

Circulating Inflammatory Factor Levels in the Early Phase of COVID-19 are Associated with the Progression of Respiratory Failure: A Single-Center Retrospective Study

Purpose

To evaluate the potential relationships between serum interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α levels and occurrence of respiratory failure in patients with early-stage COVID-19 disease.

Patients and Methods

We analyzed clinical characteristics, laboratory parameters, and immunoinflammatory markers in 302 patients diagnosed with SARS-CoV-2 infection who required hospitalization at Changshu Hospital of Nantong University. IL-2, IL-4, IL-6, IL-10, IL-17, IFN-γ, and TNF-α levels in the peripheral blood of patients hospitalized five days after disease onset were measured using multiplex bead-based flow fluorescent immunoassay (MBFFI).

Results

Patients with respiratory failure had higher serum IL-4 [0 (0, 0.54) pg/mL], IL-6 [40.76 (12.33, 90.28) pg/mL], IL-10 [6.65 (4.12, 11.34) pg/mL], and IL-17 [9.48 (4.31, 12.13) pg/mL] levels than patients without respiratory failure (P=0.042, P<0.0001, P=0.012, and P=0.036, respectively). Serum IL-2, IFN-γ, and TNF-α levels were not significantly different between the two groups. The occurrence of respiratory failure was positively correlated with sex (R=0.122, P=0.034), lactic acid (R=0.193, P=0.007), white blood cell count (R=0.121, P=0.038), erythrocyte distribution width (R=0.131, P=0.024), thyrocalcitonin (R=0.280, P<0.0001), and D-dimer levels (R=0.214, P<0.0001) but negatively correlated with oxygen partial pressure (R=-0.208, P=0.004), oxygen saturation (R=-0.220, P=0.002), lymphocyte count (R=-0.129, P=0.026), and calcium (R=-0.152, P=0.042). Among the immunoinflammatory biomarkers, the occurrence of respiratory failure was positively correlated with IL-4 (R=-0.117, P=0.042), IL-6 (R=0.206, P<0.0001), IL-10 (R=0.145, P=0.012), and IL-17 (R=0.121, P=0.036) levels.

Conclusion

Serum levels of pro-inflammatory cytokines IL-6 and IL-17 and anti-inflammatory cytokines IL-4 and IL-10 were significantly elevated in patients with respiratory failure and weakly positively correlated with the occurrence of respiratory failure. Further studies are required to explore these key immune mechanisms to help clinicians better manage acute complications, long-term sequelae, and possible future COVID-19 variants and be flexible in managing future epidemics and similar public health threats.

Interleukin-4 Promotes Human Metapneumovirus Replication Through the JAK/STAT6 Pathway

Respiratory virus infections are the main causes of pediatric diseases. Human metapneumovirus (hMPV) is an enveloped RNA virus similar to severe acute respiratory syndrome coronavirus type 2, both of which have emerged as important new respiratory viruses. Recent studies have found that interleukin-4 (IL-4) is involved in the replication of a variety of viruses, and its role differs in different viruses. The purpose of this study was to investigate the effect of IL-4 on hMPV and to elucidate its mechanism of action. We found that hMPV infection promoted the expression of IL-4 in human bronchial epithelial cells. The replication of the virus was reduced using small interfering RNA knockdown of IL-4 expression, while the addition of exogenous recombinant human IL-4 to IL-4 knockdown cells restored viral replication ability. These results demonstrate that the expression of IL-4 is closely related to the replication of hMPV; moreover, further experiments revealed that IL-4 promotes the replication of hMPV through a mechanism dependent on the Janus kinase/signal transductor and transcription activator 6 signaling pathway. Therefore, anti-IL-4 strategies may be a promising avenue for the treatment of hMPV infection, representing an important breakthrough for children at risk from hMPV infection.

Early Cytokine Signatures of Hospitalized Mild and Severe COVID-19 Patients: A Prospective Observational Study

Background

The severe manifestation of coronavirus disease 2019 (COVID-19) is known to be mediated by several cytokines and chemokines. The study aimed to compare the early cytokine profile of mild and severe COVID-19 patients to that with COVID-19-like symptoms and tested negative for Severe Acute Respiratory Syndrome Coronavirus-2 in the Reverse-Transcriptase Polymerase Chain Reaction (RT-PCR) test.

Methods

This was a prospective, observational study on COVID-19 patients admitted to King Khalid University Hospital, King Saud University Medical City from June to November 2020. Clinical and biochemical data were collected from hospital charts. Blood samples were collected at the time of hospital admission to measure cytokines. A Cytokine and Growth Factor High-Sensitivity Array was used to quantitatively measure cytokines.

Results

The study included 202 RT-PCR-positive individuals and 61 RT-PCR-negative individuals. C-Reactive protein (CRP) and Interleukin-10 (IL-10) levels were found significantly elevated in the RT-PCR positive group compared to the RT-PCR negative group (p=0.001). Patients with severe COVID-19 had significantly longer median hospital stays than those with mild COVID-19 cases (7 vs 6 days). They also had higher CRP and Vascular Endothelial Growth Factor (VEGF) levels and lower Interleukin-4 (IL-4) levels compared to the mild cases. CRP, interleukin-6, IL-10, VEGF, and Monocyte Chemoattractant Protein-1 (MCP-1) levels were significantly elevated in men and IL-10 was significantly higher and interleukin-8 was significantly lower in women compared to negative controls. Elevated Interferon-ɣ (IFN-γ) and IL-10 levels were seen in mild COVID-19 cases and elevated level of MCP-1 was seen in severe COVID-19 cases when categorized according to the length of stay in the hospital.

Conclusion

CRP and IL-10 levels were elevated in the RT-PCR positive group. People with severe COVID-19 had higher CRP and VEGF levels and lower IL-4 levels. Elevated IFN-γ and IL-10 levels were seen in mild COVID-19 cases and elevated level of MCP-1 was seen in severe COVID-19 cases when categorized according to the length of stay in the hospital.

A mathematical model of protein subunits COVID-19 vaccines

We consider a general mathematical model for protein subunit vaccine with a focus on the MF59-adjuvanted spike glycoprotein-clamp vaccine for SARS-CoV-2, and use the model to study immunological outcomes in the humoral and cell-mediated arms of the immune response from vaccination. The mathematical model is fit to vaccine clinical trial data. We elucidate the role of Interferon-γ and Interleukin-4 in stimulating the immune response of the host. Model results, and results from a sensitivity analysis, show that a balance between the T_H1 and T_H2 arms of the immune response is struck, with the T_H1 response being dominant. The model predicts that two-doses of the vaccine at 28 days apart will result in approximately 85% humoral immunity loss relative to peak immunity approximately 6 months post dose 1.

From Immunogen to COVID-19 vaccines: Prospects for the post-pandemic era

The COVID-19 pandemic has affected millions of people and posed an unprecedented burden on healthcare systems and economies worldwide since the outbreak of the COVID-19. A considerable number of nations have investigated COVID-19 and proposed a series of prevention and treatment strategies thus far. The pandemic prevention strategies implemented in China have suggested that the spread of COVID-19 can be effectively reduced by restricting large-scale gathering, developing community-scale nucleic acid testing, and conducting epidemiological investigations, whereas sporadic cases have always been identified in numerous places. Currently, there is still no decisive therapy for COVID-19 or related complications. The development of COVID-19 vaccines has raised the hope for mitigating this pandemic based on the intercross immunity induced by COVID-19. Thus far, several types of COVID-19 vaccines have been developed and released to into financial markets. From the perspective of vaccine use in globe, COVID-19 vaccines are beneficial to mitigate the pandemic, whereas the relative adverse events have been reported progressively. This is a review about the development, challenges and prospects of COVID-19 vaccines, and it can provide more insights into all aspects of the vaccines.

In silico design of a multi-epitope vaccine against the spike and the nucleocapsid proteins of the Omicron variant of SARS-CoV-2

Computational studies can comprise an effective approach to treating and preventing viral infections. Since 2019, the world has been dealing with the outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The most important achievement in this short period of time in the effort to reduce morbidity and mortality was the production of vaccines and effective antiviral drugs. Although the virus has been significantly suppressed, it continues to evolve, spread, and evade the host's immune system. Recently, researchers have turned to immunoinformatics tools to reduce side effects and save the time and cost of traditional vaccine production methods. In the present study, an attempt has been made to design a multi-epitope vaccine with humoral and cellular immune response stimulation against the Omicron variant of SARS-CoV-2 by investigating new mutations in spike (S) and nucleocapsid (N) proteins. The population coverage of the vaccine was evaluated as appropriate compared to other studies. The results of molecular dynamics simulation and molecular mechanics/generalized Born surface area (MM/GBSA) calculations predict the stability and proper interaction of the vaccine with Toll-like receptor 4 (TLR-4) as an innate immune receptor. The results of the immune simulation show a significant increase in the coordinated response of IgM and IgG after the third injection of the vaccine. Also, in the continuation of the research, spike proteins from BA.4 and BA.5 lineages were screened by immunoinformatics filters and effective epitopes were suggested for vaccine design. Despite the high precision of computational studies, in-vivo and in-vitro research is needed for final confirmation.Communicated by Ramaswamy H. Sarma.

Bronchodilator Reversibility Testing in Long-Term Cough and Dyspnea after Covid-19 Viral Infection: A Trigger for Asthma?

Objective: This study aims to investigate the presence of underlying chronic airway disease in individuals with chronic cough and dyspnea lasting longer than eight weeks and who had previously Coronavirus disease 2019 (COVID-19) and had no known lung disease.Methods: A total of 151 patients admitted to the respiratory diseases outpatient room with the complaint of cough and/or dyspnea that persisted for at least eight weeks following COVID-19 infection were accrued to the study. Demographic characteristics, smoking history, the severity of lung involvement on chest computed tomography in the acute phase of Covid-19 infection, and bronchodilator reversibility test results were recorded. Smoking history and forced expiratory volume in the first second (FEV1) were compared.Results: FEV1 increase ≥ 200 ml was observed in 40 (26.5%) patients. In 24 (15.9%) patients, an increase in FEV1 was found to be 200 ml and above, and the percentage of FEV1 was 12% or more. While 14 (9.3%) patients were diagnosed with asthma, 13 (8.6%) patients were diagnosed with nonreversible airflow obstruction (NRAO), and 1 (0.7%) patient was diagnosed with chronic obstructive pulmonary disease (COPD).Conclusions: COVID-19 infection may play a vital role in initiating asthma pathogenesis. It should be kept in mind that viral infection-related asthma may be the underlying cause of prolonged cough and dyspnea after COVID-19 infection.

Concentrations of matrix metallopeptidase 9, interleukin 4, and interleukin 8 in follicular fluid, and the results of in vitro fertilization

Objective

Cytokines and enzymes in follicular fluid (FF) may have a crucial role in fertility. This study aimed to analyse the results of in vitro fertilization/embryo transfer (IVF/ET) and compare them with matrix metalloproteinase 9 (MMP-9) and cytokine concentrations in FF.

Methods

This case–control study included 20 randomly selected patients with a positive pregnancy (PPG) test and 20 with a negative pregnancy (NPG) test after IVF/ET. In FF obtained during oocyte retrieval, the concentrations of soluble forms of MMP-9, interleukin 1 (IL-1) alpha, IL-1 beta, interferon gamma, IL-2, IL-4, IL-6, IL-8, and IL-10 were measured. Their effect on the characteristics of follicles, embryos, and the efficiency of IVF and ET were analysed.

Results

High-sensitivity IL-4 concentrations were significantly higher in patients with a PPG test than in those with an NPG test (3.15 ± 3.23 vs 1.91 ± 0.35 pg/mL). The number of top-quality embryos achieved was significantly higher in patients with a PPG test than in those with an NPG test (2.6 ± 1.39 vs 1.75 ± 1.21), and they were negatively correlated with IL-8 concentrations in FF.

Conclusion

Further research on the role of IL-4 and IL-8 in FF is required to establish any clinical benefit of determining their concentrations in FF of infertile women.

The potential impact of COVID-19 on male reproductive health

The SARS-CoV-2 virus continues to overwhelm health care systems impairing human to human social and economic interactions. Invasion or damage to the male reproductive system is one of the documented outcomes of viral infection. Existing studies have reported that SARS-CoV-2 may contribute to this loss in relation to inflammatory responses and the formation of cytokine storms in COVID-19 patients. Although direct infection of the testes and entry of SARS-CoV-2 into semen as well as subsequent consequences on the male reproductive system need to be studied more systematically, warnings from two organising ASRM and SART for prospective parents when infected with SARS-CoV-2 should be considered. In the context of an increasingly complex pandemic, this review provides preliminary examples of the potential impact of COVID-19 on male reproductive health and guidance for prospective parents currently infected with or recovering from SARS-CoV-2.

COVID-19 and the role of cytokines in this disease

Studies have shown that SARS-CoV-2 has the ability to activate and mature proinflammatory cytokines in the body. Cytokine markers are a group of polypeptide signalling molecules that can induce and regulate many cellular biological processes by stimulating cell receptors at the surface. SARS-CoV-2 has been shown to be associated with activation of innate immunity, and an increase in neutrophils, mononuclear phagocytes, and natural killer cells has been observed, as well as a decrease in T cells including CD4+ and CD8. It is noteworthy that during the SARS-CoV-2 infection, an increase in the secretion or production of IL-6 and IL-8 is seen in COVID-19 patients along with a decrease in CD4+ and CD8+ and T cells in general. SARS-CoV-2 has been shown to significantly increase Th2, Th1/Th17 cells and antibody production in the body of patients with COVID-19. Specific immune profiles of SARS-CoV-2 infection can lead to secondary infections and dysfunction of various organs in the body. It has been shown that Interleukins (such as IL-1, IL-4, IL-6, IL-7, IL-10, IL-12, IL-17, and IL-18), IFN-γ, TNF-α,TGF-β and NF-κB play major roles in the body's inflammatory response to SARS-CoV-2 infection. The most important goal of this review is to study the role of inflammatory cytokines in COVID-19.

Heavy metal and metalloid - induced reproductive toxicity

Heavy metals and metalloid exposure are among the most common factors responsible for reproductive toxicity in human beings. Several studies have indicated that numerous metals and metalloids can display severe adverse properties on the human reproductive system. Metals like lead, silver, cadmium, uranium, vanadium, and mercury and metalloids like arsenic have been known to induce reproductive toxicity. Moderate to minute quantities of lead may affect several reproductive parameters and even affect semen quality. The ecological and industrial exposures to the various heavy metals and metalloids have disastrous effects on the reproductive system ensuing in infertility. This work emphasizes the mechanism and pathophysiology of the aforementioned heavy metals and metalloids in reproductive toxicity. Additionally, this work aims to cover the classical protective mechanisms of zinc, melatonin, chelation therapy, and other trending methods to prevent heavy metal-induced reproductive toxicity.

Omicron variant infection and the associated immunological scenario

The million-dollar question that has been the talk of the day is how effective the COVID 19 vaccines are against the Omicron variant. Still, there is no clear-cut answer to this question but several studies have concluded that this Variant of Concern (VOC) successfully weakens the neutralizing capability of the antibodies acquired from the COVID 19 vaccines and prior infections, which indicates that Omicron can easily bypass an individual’s humoral immune response. However, the most significant confusion revolves around cell-mediated immunity tackling the Omicron variant. This paper aims to provide a clear idea about the status of the body’s immune surveillance concerning the infection caused by the Omicron variant by producing the effectivity of the humoral and cell-mediated immunity in handling the same. This work also provides complete detail of the various characteristics of the Omicron variant and how it may be a blessing in disguise. The effectiveness of the current vaccines, the transmissibility rate of the variant compared to the other variants, and the importance of administering a booster dose to prevent the spread of this variant are also discussed. Finally, this work aims to bridge the gap between the past and the current status of the Omicron infection and sheds light on the hypothetical idea that herd immunity developed from the SARS-COV2 infection may help tackle other dangerous variants.

Increased odds ratio for erectile dysfunction in COVID-19 patients

PURPOSE

Erectile dysfunction and COVID-19 share similar risk factors, including vascular disruption of integrity, cytokine release, cardiovascular disease, diabetes and obesity. The aim of this study was to investigate the association between erectile dysfunction and COVID-19 patients.

METHODS

Odds ratio for erectile dysfunction in patients with a history of COVID-19 with and without comorbidities were calculated using a patients' registry platform i2b2. ICD-10 diagnoses codes were accessed for queries and data were analyzed using logistic regression.

RESULTS

Patients with COVID-19 were 3.3 times more likely to have erectile dysfunction with 95% CI (2.8, 3.8). The association became stronger with odds ratio 4.8 (95% CI (4.1, 5.7)) after adjusting for age groups. The odds ratio remained the same after adjusting for smoking status with 3.5 (95% CI (3.0, 4.1)). After adjusting for race, COVID-19 patients were 2.6 (95% CI (2.2, 3.1)) times more likely to have erectile dysfunction. The odds ratio were 1.6, 1.8, 1.9 and 2.3 after adjusting for respiratory disease, obesity, circulatory disease and diabetes, respectively.

CONCLUSION

COVID-19 and erectile dysfunction are strongly associated even after adjustment for known risk factors and demographics.

Diagnostic cytokine marker of male infertility - interleukin 4

Analysis of the study is to assess the diagnostic significance of cytokines in the sperm plasma of men of reproductive age (20 - 45 years) of two groups: of patients with chronic bacterial prostatitis, not complicated by infertility and with loss of fertility. The study of sperm plasma - the WHO standard. Determination of the level of cytokines in seminal plasma - by enzyme immunoassay («Cytokine», Russia). Two methods of mathematical statistics were used: discriminant analysis and classification trees (decision trees).The similarity of interpretations of discriminant analysis and decision tree was noted, where the main role in both cases belongs to the cytokine IL-4. The level of sperm IL-4 in combination with therapeutic monitoring can be used for the medical management of patients with chronic prostatitis in order to prevent the development of infertility and to develop methods for screening diagnostics of fertility disorders in men.

Bach2: A Key Regulator in Th2-Related Immune Cells and Th2 Immune Response

Th2 immune response is essential for providing protection against pathogens and orchestrating humoral immunity. However, excessive Th2 immune response leads to the pathogenesis of Th2 inflammation diseases, including asthma, allergic rhinitis, and atopic dermatitis. Emerging evidence suggest a critical role of the transcription factor Bach2 in regulating Th2 immune responses. Bach2 serves as a super enhancer and transcriptional repressor to control the differentiation and maturation of Th2-related immune cells such as B cell lineages and T cell lineages. In B cells, Bach2 is required for every stage of B cell development and can delay the class switch recombination and antibody-producing plasma cell differentiation. In T cell lineages, Bach2 suppresses the CD4⁺ T cell differentiation into Th2 cells, restrains Th2 cytokine production, and promotes the generation and function of regulatory T (Treg) cells to balance the immune activity. Furthermore, studies in various animal models show that Bach2 knockout animals spontaneously develop Th2 inflammation in the airway and gastrointestinal tract. Genome-wide association studies have identified various susceptibility loci of Bach2 which are linked with Th2 inflammatory diseases such as asthma and inflammatory bowel disease. Here, we discuss the critical role of Bach2 involved in the Th2 immune response and associated inflammatory diseases.

Integrative COVID-19 biological network inference with probabilistic core decomposition

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for millions of deaths around the world. To help contribute to the understanding of crucial knowledge and to further generate new hypotheses relevant to SARS-CoV-2 and human protein interactions, we make use of the information abundant Biomine probabilistic database and extend the experimentally identified SARS-CoV-2-human protein-protein interaction (PPI) network in silico. We generate an extended network by integrating information from the Biomine database, the PPI network and other experimentally validated results. To generate novel hypotheses, we focus on the high-connectivity sub-communities that overlap most with the integrated experimentally validated results in the extended network. Therefore, we propose a new data analysis pipeline that can efficiently compute core decomposition on the extended network and identify dense subgraphs. We then evaluate the identified dense subgraph and the generated hypotheses in three contexts: literature validation for uncovered virus targeting genes and proteins, gene function enrichment analysis on subgraphs and literature support on drug repurposing for identified tissues and diseases related to COVID-19. The major types of the generated hypotheses are proteins with their encoding genes and we rank them by sorting their connections to the integrated experimentally validated nodes. In addition, we compile a comprehensive list of novel genes, and proteins potentially related to COVID-19, as well as novel diseases which might be comorbidities. Together with the generated hypotheses, our results provide novel knowledge relevant to COVID-19 for further validation.

Could Lower Testosterone in Older Men Explain Higher COVID-19 Morbidity and Mortalities?

The health scourge imposed on humanity by the COVID-19 pandemic seems not to recede. This fact warrants refined and novel ideas analyzing different aspects of the illness. One such aspect is related to the observation that most COVID-19 casualties were older males, a tendency also noticed in the epidemics of SARS-CoV in 2003 and the Middle East respiratory syndrome in 2012. This gender-related difference in the COVID-19 death toll might be directly involved with testosterone (TEST) and its plasmatic concentration in men. TEST has been demonstrated to provide men with anti-inflammatory and immunological advantages. As the plasmatic concentration of this androgen decreases with age, the health benefit it confers also diminishes. Low plasmatic levels of TEST can be determinant in the infection’s outcome and might be related to a dysfunctional cell Ca²⁺ homeostasis. Not only does TEST modulate the activity of diverse proteins that regulate cellular calcium concentrations, but these proteins have also been proven to be necessary for the replication of many viruses. Therefore, we discuss herein how TEST regulates different Ca²⁺-handling proteins in healthy tissues and propose how low TEST concentrations might facilitate the replication of the SARS-CoV-2 virus through the lack of modulation of the mechanisms that regulate intracellular Ca²⁺ concentrations.

Male reproductive system inflammation after healing from coronavirus disease 2019

BACKGROUND

There is evidence that, after severe acute respiratory syndrome coronavirus 2 infection, male reproductive function and semen quality may be damaged OBJECTIVES: To evaluate a panel of inflammatory mediators in semen in patients recovered from coronavirus disease 2019.

MATERIAL AND METHODS

Sexually active men with previous severe acute respiratory syndrome coronavirus 2 infection and proven recovery from coronavirus disease 2019 were enrolled in a prospective cohort study. Clinical, uro-andrological data and semen specimens were prospectively collected. For previously hospitalized coronavirus disease 2019 patients, data on serum inflammatory markers were retrospectively collected.

RESULTS

A total of 43 men were enrolled in the study. Of these, 32 men were normozoospermic, three were oligozoospermic, and eight were crypto-azoospermic. Serum inflammatory markers (procalcitonin and C-reactive protein) were analyzed in previously hospitalized patients both at admission and at peak of infection. Levels at admission were statistically significantly higher in patients resulting in crypto-azoospermic with respect to those resulting in normozoospermic (p = 0.05; p = 0.03 and p = 0.02, respectively) after healing. Seminal cytokine levels were similar among all groups. Interleukin-1β and tumor necrosis factor-α levels were significantly negatively related to sperm total number and concentration, whereas interleukin-4 was correlated with sperm motility.

DISCUSSION AND CONCLUSION

Negative correlations between interleukin-1β and tumor necrosis factor-α and sperm number and the overall high levels of semen cytokines indicate a potential detrimental role of severe acute respiratory syndrome coronavirus 2 driven inflammation on spermatogenesis. Overall, our results indicate that male patients recovering from coronavirus disease 2019 deserve accurate follow-up for their fertility status.

COVID-19 disrupts the blood-testis barrier through the induction of inflammatory cytokines and disruption of junctional proteins

OBJECTIVE

Junctional proteins are the most important component of the blood-testis barrier and maintaining the integrity of this barrier is essential for spermatogenesis and male fertility. The present study elucidated the effect of SARS-CoV-2 infection on the blood-testis barrier (BTB) in patients who died from severe acute respiratory syndrome coronavirus 2 (COVID-19) complications.

METHODS

In this study, lung and testis tissue was collected from autopsies of COVID-19 positive (n = 10) and negative men (n = 10) and was taken for stereology, immunocytochemistry, and RNA extraction.

RESULTS

Evaluation of the lung tissue showed that the SARS-CoV-2 infection caused extensive damage to the lung tissue and also increases inflammation in testicular tissue and destruction of the testicular blood barrier. Autopsied testicular specimens of COVID-19 showed that COVID-19 infection significantly changes the spatial arrangement of testicular cells and notably decreased the number of Sertoli cells. Moreover, the immunohistochemistry results showed a significant reduction in the protein expression of occluding, claudin-11, and connexin-43 in the COVID-19 group. In addition, we also observed a remarkable enhancement in protein expression of CD68 in the testes of the COVID-19 group in comparison with the control group. Furthermore, the result showed that the expression of TNF-α, IL1β, and IL6 was significantly increased in COVID-19 cases as well as the expression of occludin, claudin-11, and connexin-43 was decreased in COVID-19 cases.

CONCLUSIONS

Overall, the present study demonstrated that SARS-CoV-2 could induce the up-regulation of the pro-inflammatory cytokine and down-regulation of junctional proteins of the BTB, which can disrupt BTB and ultimately impair spermatogenesis.

SARS-CoV-2 effect on male infertility and its possible pathophysiological mechanisms

First case of COVID-19 was reported in Wuhan, China in December 2019. As of now, May 2021, a total of 164,189,004 people were infected, and 3,401,990 deaths have occurred caused by SARS-CoV-2. As SARS-CoV-2 virus cell entry mainly depends on the ACE2 and TMPRSS2 proteins, the presence of high expression levels of both ACE2 and TMPRSS2 in testes highlights the possible vulnerability of men to the virus. Other RNA viruses frequently induce orchitis and result in male infertility. This review evaluates the decline in male fertility and a total of 48 original articles were included for the analysis. We investigated the effects of COVID-19 on male reproductive health and male fertility.  There is a strong association between the high number of ACE2 receptors in the testes and the COVID-19 viral loads. SARS-CoV-2 infection negatively affects the male reproductive tract. Human biological tissues, including body fluids and excretions, tissues, and organs showed positive results tests for SARS-CoV-2. A disruption in the balance of male reproductive system hormones is also observed. Male gonads may be potentially vulnerable to SARS-CoV-2 infection, suggesting caution to follow-up and evaluate infected men that have plans to conceive. Further studies are required to determine if this impairment is temporary or permanent, elucidate SARS-CoV-2’s entrance strategies into the testis and how it can affect the semen quality and quantity. We recommend a post-infection follow-up, especially in male patients of reproductive age already having fertility issues.

Human semen quality as affected by SARS-CoV-2 infection: An up-to-date review

Revealing the effect of SARS‐CoV‐2 infection on semen quality is a dynamic priority for many healthcare providers in the field as well as subfertile patients. Therefore, the collective summary in this research approach is still highly needed, especially with the continuous increase in original publications. Here, we provide an up‐to‐date review and discussion to collectively reveal the effect of SARS‐CoV‐2 infection on human semen quality. To do this, we reviewed all articles and abstracts published in Scopus and PubMed using the keywords ‘SARS‐CoV‐2’ and ‘COVID’ versus ‘sperm’ and ‘semen’. In summary, it can be revealed that, at both symptomatic and recovery stages of infection, no investigational evidence of SARS‐CoV‐2 shedding in human semen. Also, the mainstream of the up‐to‐date published work reveals a negative impact of SARS‐CoV‐2 infection on semen quality parameters, particularly sperm count and motility. However, long‐term post‐recovery comparative studies seem very important in this particular setting.

Multi-omic approach identifies a transcriptional network coupling innate immune response to proliferation in the blood of COVID-19 cancer patients

Clinical outcomes of COVID-19 patients are worsened by the presence of co-morbidities, especially cancer leading to elevated mortality rates. SARS-CoV-2 infection is known to alter immune system homeostasis. Whether cancer patients developing COVID-19 present alterations of immune functions which might contribute to worse outcomes have so far been poorly investigated. We conducted a multi-omic analysis of immunological parameters in peripheral blood mononuclear cells (PBMCs) of COVID-19 patients with and without cancer. Healthy donors and SARS-CoV-2-negative cancer patients were also included as controls. At the infection peak, cytokine multiplex analysis of blood samples, cytometry by time of flight (CyTOF) cell population analyses, and Nanostring gene expression using Pancancer array on PBMCs were performed. We found that eight pro-inflammatory factors (IL-6, IL-8, IL-13, IL-1ra, MIP-1a, IP-10) out of 27 analyzed serum cytokines were modulated in COVID-19 patients irrespective of cancer status. Diverse subpopulations of T lymphocytes such as CD8+T, CD4+T central memory, Mucosal-associated invariant T (MAIT), natural killer (NK), and γδ T cells were reduced, while B plasmablasts were expanded in COVID-19 cancer patients. Our findings illustrate a repertoire of aberrant alterations of gene expression in circulating immune cells of COVID-19 cancer patients. A 19-gene expression signature of PBMCs is able to discriminate COVID-19 patients with and without solid cancers. Gene set enrichment analysis highlights an increased gene expression linked to Interferon α, γ, α/β response and signaling which paired with aberrant cell cycle regulation in cancer patients. Ten out of the 19 genes, validated in a real-world consecutive cohort, were specific of COVID-19 cancer patients independently from different cancer types and stages of the diseases, and useful to stratify patients in a COVID-19 disease severity-manner. We also unveil a transcriptional network involving gene regulators of both inflammation response and proliferation in PBMCs of COVID-19 cancer patients.

The Relation of the Viral Structure of SARS-CoV2, High-Risk Condition, and Plasma Levels of IL-4, IL-10, and IL-15 in COVID-19 Patients compared to SARS and MERS Infections

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has high mortality due to the widespread infection and the strong immune system reaction. Interleukins (ILs) are among the main immune factors contributing to the deterioration of the immune response and the formation of cytokine storms in coronavirus disease 2019 (COVID-19) infections.

INTRODUCTION

This review article investigated the relationship between virus structure, risk factors, and patient plasma interleukin levels in infections caused by the coronavirus family.

METHOD

The keywords "interleukin," "coronavirus structure," "plasma," and "risk factors" were the main words searched to find a relationship among different interleukins, coronavirus structures, and risk factors in ISI, PUBMED, SCOPUS, and Google Scholar databases.

RESULT

Patients with high-risk conditions with independent panels of immune system markers are more susceptible to death caused by SARS-CoV2. IL-4, IL-10, and IL-15 are probably secreted at different levels in patients with coronavirus infections despite the similarity of inflammatory markers during coronavirus infections. SARS-CoV2 and SARS-CoV increase the secretion of IL-4 in the Middle East respiratory syndrome coronavirus (MERS-CoV) infection, while it remains unchanged in MERS-CoV infection. MERS-CoV infection demonstrates increased IL-10 levels. However, IL-10 levels increase during SARS-CoV infection, and different levels are recorded in SARS-CoV2. MERS-CoV increases IL-15 secretion while its levels remain unchanged in SARS-CoV2.

CONCLUSION

In conclusion, the different structures of SARS-CoV2, such as length of spike or nonstructural proteins (NSPs), and susceptibility of patients based on their risk factors may lead to differences in immune marker secretion and pathogenicity. Therefore, identifying and controlling interleukin levels can play a significant role in controlling the symptoms and the development of individual-specific treatments.

Mucormycosis: An opportunistic pathogen during COVID-19

The pandemic of coronavirus disease 2019 (COVID-19) still remains on an upsurge trend. The second wave of this disease has led to panic in many countries, including India and some parts of the world suffering from the third wave. As there are no proper treatment options or remedies available for this deadly infection, supportive care equipment's such as oxygen cylinders, ventilators and heavy use of steroids play a vital role in the management of COVID-19. In the midst of this pandemic, the COVID-19 patients are acquiring secondary infections such as mucormycosis also known as black fungus disease. Mucormycosis is a serious, but rare opportunistic fungal infection that spreads rapidly, and hence prompt diagnosis and treatment are necessary to avoid high rate of mortality and morbidity rates. Mucormycosis is caused by the inhalation of its filamentous (hyphal form) fungi especially in the patients who are immunosuppressed. Recent studies have documented alarming number of COVID-19 patients with mucormycosis infection. Most of these patients had diabetes and were administered steroids for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection and were consequently more prone to mucormycosis. Hence, the present review emphasizes mucormycosis and its related conditions, its mechanism in normal and COVID-19 affected individuals, influencing factors and challenges to overcome this black mold infection. Early identification and further investigation of this fungus will significantly reduce the severity of the disease and mortality rate in COVID-19 affected patients.

The probable destructive mechanisms behind COVID-19 on male reproduction system and fertility

PURPOSE

The present study aims to summarize the current understanding of probable mechanisms and claims of adverse effects of SARS-CoV-2 on male fertility potential.

METHODS

Our search was including original articles, reviews, guidelines, letters to the editor, comments on guidelines, and editorials, regarding the male reproductive system. We used the words SARS-CoV-2, coronavirus, severe acute respiratory syndrome coronavirus 2, "2019 ncov," testis, sperm, male factor infertility, fertility treatment, semen, assisted reproductive technology (ART), sexual transmission, and ACE2.

RESULTS

Data showed coronavirus affects men more than women because of more expression of 2019 nCoV receptors (ACE2 and TMPRSS2) in testicular cells. Also, "Bioinformatics Analysis" suggests that sperm production may be damaged, since "Pseudo Time Analysis" has shown disruption in spermatogenesis. "Gene Ontology" (GO) showed an increase in viral reproduction and a decrease in sperm production-related terms. Recently, SARS-COV-2 mRNA and protein were detected in the semen of patients that had recovered from SARS-CoV-2 infection. Therefore, the probable disruption of blood-testis barrier (BTB) in febrile diseases is suspected in the acute phase of the disease enabling viral entry into the testes. Not only is spermatogenesis disturbed, but also disturbs gonadotropin, androgens, and testosterone secretion during SARS-CoV-2 infection. No sexual transmission has been reported yet; however, detection of the virus in semen still makes the sexual transmission an open question.

CONCLUSION

There is a concern that male fertility may be disturbed after the SARS-CoV-2 infection. Therefore, follow-up of the reproductive functions and male fertility may be necessary in recovered cases, especially in aged men.