Azithromycin inhibits interleukin-6 but not fibrinogen production in hepatocytes infected with cytomegalovirus and chlamydia pneumoniae

Mucormycosis in the COVID-19 Environment: A Multifaceted Complication

The second wave of coronavirus disease 2019 (COVID-19) caused severe infections with high mortality. An increase in the cases of COVID-19-associated mucormycosis (CAM) was reported predominantly in India. Commonly present in immunocompromised individuals, mucormycosis is often a life-threatening condition. Confounding factors and molecular mechanisms associated with CAM are still not well understood, and there is a need for careful research in this direction. In this review, a brief account of the diagnosis, management, and advancement in drug discovery for mucormycosis has been provided. Here, we summarize major factors that dictate the occurrence of mucormycosis in COVID-19 patients through the analysis of published literature and case reports. Major predisposing factors to mucormycosis appear to be uncontrolled diabetes, steroid therapy, and certain cancers. At the molecular level, increased levels of iron in COVID-19 might contribute to mucormycosis. We have also discussed the potential role and regulation of iron metabolism in COVID-19 patients in establishing fungal growth. Other factors including diabetes prevalence and fungal spore burden in India as contributing factors have also been discussed.

The roles of Eph receptors, neuropilin-1, P2X7, and CD147 in COVID-19-associated neurodegenerative diseases: inflammasome and JaK inhibitors as potential promising therapies

The novel coronavirus disease 2019 (COVID-19) pandemic has spread worldwide, and finding a safe therapeutic strategy and effective vaccine is critical to overcoming severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Therefore, elucidation of pathogenesis mechanisms, especially entry routes of SARS-CoV-2 may help propose antiviral drugs and novel vaccines. Several receptors have been demonstrated for the interaction of spike (S) protein of SARS-CoV-2 with host cells, including angiotensin-converting enzyme (ACE2), ephrin ligands and Eph receptors, neuropilin 1 (NRP-1), P2X7, and CD147. The expression of these entry receptors in the central nervous system (CNS) may make the CNS prone to SARS-CoV-2 invasion, leading to neurodegenerative diseases. The present review provides potential pathological mechanisms of SARS-CoV-2 infection in the CNS, including entry receptors and cytokines involved in neuroinflammatory conditions. Moreover, it explains several neurodegenerative disorders associated with COVID-19. Finally, we suggest inflammasome and JaK inhibitors as potential therapeutic strategies for neurodegenerative diseases.

Reinforcing our defense or weakening the enemy? A comparative overview of defensive and offensive strategies developed to confront COVID-19

Developing effective strategies to confront coronavirus disease 2019 (COVID-19) has become one of the greatest concerns of the scientific community. In addition to the vast number of global mortalities due to COVID-19, since its outbreak, almost every aspect of human lives has changed one way or another. In the present review, various defensive and offensive strategies developed to confront COVID-19 are illustrated. The Administration of immune-boosting micronutrients/agents, as well as the inhibition of the activity of incompetent gatekeepers, including some host cell receptors (e.g. ACE2) and proteases (e.g. TMPRSS2), are some efficient defensive strategies. Antibody/phage therapies and specifically vaccines also play a prominent role in the enhancement of host defense against COVID-19. Nanotechnology, however, can considerably weaken the virulence of SARS-CoV-2, utilizing fake cellular locks (compounds mimicking cell receptors) to block the viral keys (spike proteins). Generally, two strategies are developed to interfere with the binding of spike proteins to the host cell receptors, either utilizing fake cellular locks to block the viral keys or utilizing fake viral keys to block the cellular locks. Due to their evolutionary conserved nature, viral enzymes, including 3CLpro, PLpro, RdRp, and helicase are highly potential targets for drug repurposing strategy. Thus, various steps of viral replication/transcription can effectively be blocked by their inhibition, leading to the elimination of SARS-CoV-2. Moreover, RNA decoy and CRISPR technologies likely offer the best offensive strategies after viral entry into the host cells, inhibiting the viral replication/assembly in the infected cells and substantially reducing the quantity of viral progeny.

Insights Into Host Cell Cytokines in Chlamydia Infection

Chlamydial infection causes a number of clinically relevant diseases and induces significant morbidity in humans. Immune and inflammatory responses contribute to both the clearance of Chlamydia infection and pathology in host tissues. Chlamydia infection stimulates host cells to produce a large number of cytokines that trigger and regulate host immune responses against Chlamydia. However, inappropriate responses can occur with excessive production of cytokines, resulting in overreactive inflammatory responses and alterations in host or Chlamydia metabolism. As a result, Chlamydia persists and causes wound healing delays, leading to more severe tissue damage and triggering long-lasting fibrotic sequelae. Here, we summarize the roles of cytokines in Chlamydia infection and pathogenesis, thus advancing our understanding chlamydial infection biology and the pathogenic mechanisms involved.

Latest evidences on meibomian gland dysfunction diagnosis and management

Meibomian gland dysfunction (MGD) can be considered the leading cause of dry eye disease (DED) and one of the most common ophthalmic disorders found in clinical practice. The growing body of literature provides a substantial amount of information on this condition, but more efforts are needed to better interpret research data and to properly apply them to daily clinical practice., In this article, we reviewed the most recent publications on MGD diagnosis and management, focusing on the highest available level of evidence, provided by well-designed and well-reported studies on humans., Latest evidences on MGD diagnosis are mainly focused on imaging techniques, including meibography, optical coherence tomography (OCT), and in vivo confocal microscopy. Meibographic parameters, such as drop-out and glands' distortion, show great diagnostic accuracy, which accounts for their widespread use in clinical practice and research., Recent randomized controlled clinical trials on MGD treatment provided data on the role of antibiotics, steroids, essential fatty acids, intraductal meibomian gland probing, electronic heating devices and intense pulsed light therapy.

Drugs against SARS-CoV-2: What do we know about their mode of action?

The health emergency caused by the recent Covid-19 pandemic highlights the need to identify effective treatments against the virus causing this disease (SARS-CoV-2). The first clinical trials have been testing repurposed drugs that show promising anti-SARS-CoV-2 effects in cultured cells. Although more than 2400 clinical trials are already under way, the actual number of tested compounds is still limited to approximately 20, alone or in combination. In addition, knowledge on their mode of action (MoA) is currently insufficient. Their first results reveal some inconsistencies and contradictory results and suggest that cohort size and quality of the control arm are two key issues for obtaining rigorous and conclusive results. Moreover, the observed discrepancies might also result from differences in the clinical inclusion criteria, including the possibility of early treatment that may be essential for therapy efficacy in patients with Covid-19. Importantly, efforts should also be made to test new compounds with a documented MoA against SARS-CoV-2 in clinical trials. Successful treatment will probably be based on multitherapies with antiviral compounds that target different steps of the virus life cycle. Moreover, a multidisciplinary approach that combines artificial intelligence, compound docking, and robust in vitro and in vivo assays will accelerate the development of new antiviral molecules. Finally, large retrospective studies on hospitalized patients are needed to evaluate the different treatments with robust statistical tools and to identify the best treatment for each Covid-19 stage. This review describes different candidate antiviral strategies for Covid-19, by focusing on their mechanism of action.

Azithromycin decreases Chlamydia pneumoniae-mediated Interleukin-4 responses but not Immunoglobulin E responses

BACKGROUND

Chlamydia pneumoniae is an obligate intracellular bacterium that causes respiratory infection. There may exist an association between C. pneumoniae, asthma, and production of immunoglobulin (Ig) E responses in vitro. Interleukin (IL-4) is required for IgE production.

OBJECTIVE

We previously demonstrated that doxycycline suppresses C. pneumoniae-induced production of IgE and IL-4 responses in peripheral blood mononuclear cells (PBMC) from asthmatic subjects. Whereas macrolides have anti-chlamydial activity, their effect on in vitro anti-inflammatory (IgE) and IL-4 responses to C. pneumoniae have not been studied.

METHODS

PBMC from IgE- adult atopic subjects (N = 5) were infected +/- C. pneumoniae BAL69, +/- azithromycin (0.1, 1.0 ug/mL) for 10 days. IL-4 and IgE levels were determined in supernatants by ELISA. IL-4 and IgE were detected in supernatants of PBMC (day 10).

RESULTS

When azithromycin (0.1, 1.0 ug/ml) was added, IL-4 levels decreased. At low dose, IgE levels increased and at high dose, IgE levels decreased. When PBMC were infected with C. pneumoniae, both IL-4 and IgE levels decreased. Addition of azithromycin (0.1, 1.0 ug/mL) decreased IL-4 levels and had no effect on IgE levels.

CONCLUSIONS

These findings indicate that azithromycin decreases IL-4 responses but has a bimodal effect on IgE responses in PBMC from atopic patients in vitro.

CD147 as a Target for COVID-19 Treatment: Suggested Effects of Azithromycin and Stem Cell Engagement

The expressive number of deaths and confirmed cases of SARS-CoV-2 call for an urgent demand of effective and available drugs for COVID-19 treatment. CD147, a receptor on host cells, is a novel route for SARS-CoV-2 invasion. Thus, drugs that interfere in the spike protein/CD147 interaction or CD147 expression may inhibit viral invasion and dissemination among other cells, including in progenitor/stem cells. Studies suggest beneficial effects of azithromycin in reducing viral load of hospitalized patients, possibly interfering with ligand/CD147 receptor interactions; however, its possible effects on SARS-CoV-2 invasion has not yet been evaluated. In addition to the possible effect in invasion, azithromycin decreases the expression of some metalloproteinases (downstream to CD147), induces anti-viral responses in primary human bronchial epithelial infected with rhinovirus, decreasing viral replication and release. Moreover, resident lung progenitor/stem are extensively differentiated into myofibroblasts during pulmonary fibrosis, a complication observed in COVID-19 patients. This process, and the possible direct viral invasion of progenitor/stem cells via CD147 or ACE2, could result in the decline of these cellular stocks and failing lung repair. Clinical tests with allogeneic MSCs from healthy individuals are underway to enhance endogenous lung repair and suppress inflammation.

Image-guided evaluation and monitoring of treatment response in patients with dry eye disease

BACKGROUND

Dry eye disease (DED) is one of the most common ocular disorders worldwide. The pathophysiological mechanisms involved in the development of DED are not well-understood, and thus treating DED has been a significant challenge for ophthalmologists. Most of the currently available diagnostic tests demonstrate low correlation to patient symptoms and have low reproducibility.

METHODS

Recently, sophisticated in vivo imaging modalities have become available for patient care, namely, in vivo confocal microscopy (IVCM) and optical coherence tomography (OCT). These emerging modalities are powerful and non-invasive, allowing real-time visualization of cellular and anatomical structures of the cornea and ocular surface. Here we discuss how, by providing both qualitative and quantitative assessment, these techniques can be used to demonstrate early subclinical disease, grade layer-by-layer severity, and allow monitoring of disease severity by cellular alterations. Imaging-guided stratification of patients may also be possible in conjunction with clinical examination methods.

CONCLUSIONS

Visualization of subclinical changes and stratification of patients in vivo allows objective image-guided evaluation of tailored treatment response based on cellular morphological alterations specific to each patient. This image-guided approach to DED may ultimately improve patient outcomes and make it possible to study the efficacy of novel therapies in clinical trials.

Macrolide antibiotics like azithromycin increase lipopolysaccharide-induced IL-8 production by human gingival fibroblasts

Objective

Macrolide antibiotics are reported to modulate the production of cytokines in various type of cells. We examined the effect of macrolide antibiotics on inflammatory cytokines (IL-6 and IL-8) and chemical mediator (PGE₂) and also matrix metalloproteinases (MMPs) productions by human gingival fibroblasts (HGFs) treated with lipopolysaccharide (LPS).

Methods

The effect of macrolide antibiotics [erythromycin (EM), azithromycin (AZM) and josamycin (JOM)] on HGFs proliferation were examined by MTT assay. HGFs were treated with LPS from Porphyromonas gingivalis (PgLPS) and macrolide antibiotics, and IL-6, IL-8 and PGE₂ levels were evaluated by ELISA. MMPs were detected by gelatin zymography.

Results

AZM slightly but significantly decreased HGFs proliferation, while EM and JOM did not affected. AZM increased PgLPS-induced IL-8 production dose-dependently, while AZM did not alter IL-6 and PGE₂ productions. EM and JOM did not altered PgLPS-induced IL-6, IL-8 and PGE₂ productions. All macrolide antibiotics did not alter MMPs production. These results indicate that macrolide antibiotics have no direct anti-inflammatory effect. However, the use of the inhibitors of cell signaling pathway failed to reveal the mechanism that AZM enhanced PgLPS-induced IL-8 production.

Conclusion

These results suggest macrolide antibiotics have an indirect anti-inflammatory effect as a result of their antimicrobial properties. Because AZM increased LPS-induced IL-8 production by HGFs, the possibility is considered that neutrophils may be migrated to periodontal tissue and phagocytize the periodontopathic bacteria more efficiently.

Infection-induced inflammatory response of adipocytes in vitro

BACKGROUND

Abdominal obesity plays an important role in the development of insulin resistance, diabetes mellitus and atherosclerosis. The exact pathophysiological mechanisms are unclear but adipocyte dysfunction is thought to be crucial. Infections are associated with the development of atherosclerosis as well as diabetes. In this study we investigated whether adipocytes can be infected and whether this results in production of inflammatory cytokines relevant for the development of atherosclerosis and diabetes.

METHODS

Pre-adipocytes were cultured and differentiated into mature adipocytes in vitro. Adipocytes and pre-adipocytes were incubated with infective and heat-inactivated Chlamydia pneumoniae, cytomegalovirus (CMV), adenovirus (Ad) subtypes 2 and 36, influenza A and respiratory syncitial virus (RSV). After 48 h, adiponectin, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and plasminogen activator inhibitor-1 (PAI-1) were measured in supernatants.

RESULTS

Infection of adipocytes with Ad-36, CMV and RSV resulted in increased IL-6 production from 192+/-22 pg ml(-1) (uninfected) to 1030+/-86 pg ml(-1), 838+/-59 pg ml(-1) and 1241+/-191 pg ml(-1), respectively (all P<0.01 vs control). In addition, Ad-36 infection slightly reduced PAI production in adipocytes (285+/-26.8 ng ml(-1) vs uninfected: 477+/-71.2 ng ml(-1); P=0.05) and pre-adipocytes (709+/-43.3 ng ml(-1) vs uninfected: 1071+/-71.8 ng ml(-1); P<0.01). In contrast, human Ad type 2 did not exert any effect on IL-6 or PAI production. None of the microorganisms induced significant changes in adiponectin and/or TNF-alpha production.

CONCLUSIONS

Adipocytes can be infected with several microorganisms in vitro. Infection of adipocytes with Ad-36, but not Ad-2 leads to increased production of IL-6 which might contribute to chronic low-grade inflammation, a process known to be involved in the development of cardiovascular diseases and type 2 diabetes.

Assessment of B-type natriuretic peptide in patients with pneumonia

The mammalian heart synthesises and secretes B-type natriuretic peptide (BNP), which has potent diuretic, natriuretic and vascular smooth muscle-relaxing effects as well as complex interactions with the hormonal and nervous systems. Recent studies described that BNP was acute phase reactant. In this study, we aimed to evaluate BNP levels in patients with pneumonia. Twenty-one patients with pneumonia and 21 healthy control subjects were enrolled in this study. Their serum levels of BNP were measured in addition to the standard evaluations. Leucocyte count [19.3 (13.2-25.7) 10(6)/ml vs. 9.55 (3.7-13.9) 10(6)/ml, p < 0.001], erythrocyte sedimentation rate [73 (57-81) mm/h vs. 35 (4-55) mm/h, p < 0.001], C-reactive protein (CRP) [127.72 (27-290) mg/l vs. 13.19 (3-41) mg/l, p < 0.001] and BNP [53.1 (17-91) pg/ml vs. 16.24 (1-38) pg/ml, p < 0.001] levels significantly decreased after treatment period. Initial BNP levels were significantly higher than control groups (53.10 +/- 15.07 pg/ml vs. 18.62 +/- 14.05 pg/ml, p < 0.001) and decreased after treatment to the levels comparable with control subjects. BNP levels correlated with CRP levels at admission (r = 0.716, p < 0.001). We have shown that BNP levels show a transient increase in patients with pneumonia and correlate well with CRP.

Azithromycin reduces Chlamydia pneumoniae-induced attenuation of eNOS and cGMP production by endothelial cells

BACKGROUND

Intracellular infections with cytomegalovirus (CMV) or Chlamydia pneumoniae (Cp) may play a role in the aetiology of atherosclerosis. Nitric oxide (NO) is a key regulator of endothelial function. Under pathological conditions uncoupling of endothelial nitric oxide synthase (eNOS) leads to vessel damage as a result of production of oxygen radicals instead of NO. We hypothesized that infection-induced atherosclerosis is initiated by changes in NO metabolism and may be reversed by azithromycin treatment.

METHODS

Confluent human umbilical vein endothelial cells (HUVECs) were infected with Cp or CMV. After 48 h of infection, production of eNOS, cyclic guanosine monophosphate (cGMP) and reactive oxygen species (ROS) was measured. Detection of cGMP was used as a reporter assay for the bioavailability of NO. Subsequently, Cp- and CMV-infected HUVECs were coincubated with 0.016 mg L(-1) and 1 mg L(-1) azithromycin.

RESULTS

Infection with Cp (MOI 1 and MOI 0.1) and CMV (MOI 1) caused a dose- and time-dependent reduction of eNOS production in the HUVECs: Cp MOI 1: 1141 +/- 74 pg mL(-1) (P < 0.01); Cp MOI 0.1: 3189 +/- 30 pg mL(-1) (P < 0.01); CMV: 3213 +/- 11 pg mL(-1) (P < 0.01) vs. 3868 +/- 83 pg mL(-1) for uninfected HUVECs. Chlamydia pneumoniae- but not CMV-infection also reduced cGMP-production (Cp: 0.195 +/- 0.030 pmol mL(-1) (P < 0.01); CMV: 0.371 +/- 27 pmol mL(-1) (P > 0.05) vs. 0.378 +/- 0.019 pmol mL(-1) for uninfected HUVECs). CMV-infection did not affect ROS production either, but Cp-infection reduced ROS-production by 21% (P > 0.05; Cp MOI 0.1) to 68% (P < 0.01; Cp MOI 1). Azithromycin treatment restored Cp-induced eNOS, cGMP and ROS production in a dose-dependent manner.

CONCLUSIONS

Infection with Cp in endothelial cells in vitro attenuates eNOS, cGMP and ROS production in HUVECs and azithromycin reverses Cp-induced effects on eNOS, cGMP and ROS-production. The results from our in vitro research support the role of antibiotic therapy for infection-induced atherosclerosis by indicating that azithromycin does actually improve endothelial function.

High rate of seropositivity of Chlamydia pneumoniae IgA in male patients with nonalcoholic steatohepatitis

The aim of this study was to investigate if there was any relationship between nonalcoholic steatohepatitis and the rate of Chlamydia pneumoniae seropositivity in a male population. Fifteen men with nonalcoholic steatohepatitis and 20 healthy men were enrolled in the study. The seropositivity rate of Chlamydia pneumoniae immunoglobulin A in the nonalcoholic steatohepatitis and control groups was 53.3 and 5%, respectively. The rate of Chlamydia pneumoniae immunoglobulin A positivity was significantly higher in the nonalcoholic steatohepatitis group than the controls (P = 0.002), while such a difference did not occur for Chlamydia pneumoniae immunoglobulin G positivity (P > 0.05). There is an association between nonalcoholic steatohepatitis and persistent Chlamydia pneumoniae infection as a probable causative or triggering agent. These findings suggest that further studies are necessary to clarify this association.