Excessive Production Of Proinflammatory Cytokines Research Articles

Inflammasomes and SARS-CoV-2 Infection.

SARS-CoV-2 is a new type of coronavirus that has caused worldwide pandemic. The disease induced by SARS-CoV-2 is called COVID-19. A majority of people with COVID-19 have relatively mild respiratory symptoms. However, a small percentage of COVID-19 patients develop a severe disease where multiple organs are affected. These severe forms of SARS-CoV-2 infections are associated with excessive production of pro-inflammatory cytokines, so called “cytokine storm”. Inflammasomes, which are protein complexes of the innate immune system orchestrate development of local and systemic inflammation during virus infection. Recent data suggest involvement of inflammasomes in severe COVID-19. Activation of inflammasome exerts two major effects: it activates caspase-1-mediated processing and secretion of pro-inflammatory cytokines IL-1β and IL-18, and induces inflammatory cell death, pyroptosis, via protein called gasdermin D. Here, we provide comprehensive review of current understanding of the activation and possible functions of different inflammasome structures during SARS-CoV-2 infection and compare that to response caused by influenza A virus. We also discuss how novel SARS-CoV-2 mRNA vaccines activate innate immune response, which is a prerequisite for the activation of protective adaptive immune response.

IL-1β, IL-17A, and IL-10: A Novel Axis Linked to Immunological Dysfunction May Pre-Empt Early Diagnosis of Sepsis after Cardiac Surgery

INTRODUCTIONSepsis caused by a dysregulated host response to infection, is a serious healthcare problem that results in very high mortality every year-round the globe. When left untreated, sepsis can potentially turn fulminant, making early diagnosis and intervention an essential component of the therapeutic strategy. Proinflammatory cytokines are necessary for initiating an effective inflammatory response against infection, whereas their excess production has been associated with tissue injury in multiple organ systems leading to increased mortality. In contrast, anti-inflammatory cytokines seem to be a prerequisite for controlling and down regulating the initial inflammatory response. But a sustained release of these biomolecules leads to a turn-down of immune activation within the host organism. In the clinical conundrums associated with sepsis, it was often observed that pathogen-responsive cells were exposed to a complex cytokine milieu. The excess production of proinflammatory cytokines is essential for the survival, replication and activation of phagocytic and cytotoxic immune cells. In conjunction with this proinflammatory activity, anti-inflammatory cytokines are also released which are involved in the occurrence of cellular anergy and impaired response to aetiologic agents, causing a compensatory anti-inflammatory response syndrome (CARS).Current practice in cardiac surgery is to review laboratory test results (CRP, PCT, blood culture) and clinical criteria (SOFA and STS) 48 h after surgery to diagnose sepsis. CRP and PCT lack sensitivity and specificity, whereas blood culture requires a long turnaround time and lacks sensitivity. Sepsis being an interplay between pro and anti-inflammatory response, the relative expression of immune biomarkers may provide a useful criterion for early diagnosis of sepsis. Thus, we aimed at investigating the variations in circulating levels of prominent cytokines and their potential use as a diagnostic marker of adult sepsis post cardiac surgery.MATERIALS AND METHODSIn this double-blinded cohort study, blood samples of adult patients undergoing cardiac surgery were collected before surgery (D -1), and on the post-operative day 1 (D +1) after the approval from the appropriate Institutional Ethics Committee. Patients who were deemed risky by EuroSCORE II risk stratification were included and immuno-compromised as well as patients with active infection before surgery were excluded. Plasma levels of IL-1β, IL-5, IL-6, IL-10, IL-17A and TNFα were determined using cytometric bead assay by flow cytometry and the results were analyzed using FCAP Array™ software. The data sets were analyzed (GraphPad Prism 5.02) and a p value of < 0.05 was considered statistically significant.RESULTSThe study was conducted with 34 patients (n=34) and un-blinded after retrieval of data. The cohort has 8 patients diagnosed with sepsis and 26 without sepsis based on STS criteria. Demographic details for both groups are summarized in Table 1. Cytokine and other biomarker expression levels before (D-1) and after (D+1) Surgery is summarized in Table 2. At D +1, IL-1β, TNF-α, IL-17A and IL-10 showed significantly higher concentration in sepsis group compared to non-sepsis group (Fig 1B). CRP, PCT, WBC and differential blood count were not showing any discriminatory potential between sepsis and non-sepsis patients at D +1. The ROC curves of the above four cytokine expression levels at D+1 was analyzed between sepsis and non-sepsis groups. A plasma IL-1β level of 0.25 pg/ml had a sensitivity of 87.5 % and a specificity of 53.8 % and a plasma IL-17A level of 1.78 pg/ml had a sensitivity of 75 % and specificity of 46.2 %. In addition, IL-10 level of 8.99 pg/ml in plasma showed a diagnostic sensitivity of 87.5 % and a specificity of 53.8% (Fig 1C). Based on the current observation we proposed a model of inflammatory cytokine dynamics involving IL-1β, IL-17A and IL-10 suggesting their role, which may lead to the development of sepsis (Fig 1D).CONCLUSIONWe identified a significant up regulation of circulating inflammatory cytokines at 24 h in patients who developed sepsis after cardiac surgery, earlier than any noticeable changes in conventional sepsis biomarkers. These results suggest the possibility of inflammatory cytokines as a diagnostic marker and may be a potential therapeutic target as well. The study needs to be validated further on a larger cohort of patients. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

A RARE AND COMPLEX CAUSE OF IMPOTENCE POEMS SYNDROME

Although plasma cell neoplasms occupy a large place in hematology practice, POEMS syndrome is very rare. Serum lambda light chain elevation and polyneuropathy, together with organomegaly, endocrinopathy, and skin lesions are the main components of the syndrome. We share our case, which we diagnosed in our clinic, with the belief that it will contribute to the literature. A 51-year-old male patient, who had no history of co-morbidity, drug use, or exposure to toxic substances, was started on supportive treatment in February 2021, who first developed the complaint of impotence. Later, he applied to the neurology outpatient clinic with complaints of weakness and weakness in the feet. After detecting polyneuropathy in his evaluation, IgG Lambda monoclonal gammopathy was detected in serum immune electrophoresis in his evaluation for etiology. Thereupon, it started to be investigated in terms of plasma cell neoplasms. In the examinations performed, immunoglobulin levels, serum-urine kappa and lambda light chain levels, plasma increase in the bone marrow biopsies and a solitary 3.3 cm sclerotic lesion in the sacral region were detected in the PET-CT of the patient, whose ethology could not be diagnosed. A tru-cut biopsy was taken from the sclerotic lesion of the patient, who was thought to be a plasmacytoma and a 20% monoclonal IgG lambda plasma increase was detected. In his physical examination, it was seen that he had increased lesions (Figure-1) and acrocyanosis (Figure-2) on the skin for the last 3-4 months. The patient's current complaints and laboratory results were evaluated with a preliminary diagnosis of POEMS syndrome (Table-1). POEMS syndrome is a rare disease and its exact incidence is unknown. It is frequently seen in 5-6 decades, with a median age of 51 years, and 63% of cases are male patients [1]. Chronic and excessive production of proinflammatory and other cytokines (IL-1β, TNFα, IL-6, vascular endothelial growth factor (VEGF) etc.), microangiopathy, edema, effusions, increase in vascular permeability, increase in neovascularization are important in the pathophysiology of the disease.

Protein PGLYRP1/Tag7 Peptides Decrease the Proinflammatory Response in Human Blood Cells and Mouse Model of Diffuse Alveolar Damage of Lung through Blockage of the TREM-1 and TNFR1 Receptors.

Infection caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2) in many cases is accompanied by the release of a large amount of proinflammatory cytokines in an event known as “cytokine storm”, which is associated with severe coronavirus disease 2019 (COVID-19) cases and high mortality. The excessive production of proinflammatory cytokines is linked, inter alia, to the enhanced activity of receptors capable of recognizing the conservative regions of pathogens and cell debris, namely TLRs, TREM-1 and TNFR1. Here we report that peptides derived from innate immunity protein Tag7 inhibit activation of TREM-1 and TNFR1 receptors during acute inflammation. Peptides from the N-terminal fragment of Tag7 bind only to TREM-1, while peptides from the C-terminal fragment interact solely with TNFR1. Selected peptides are capable of inhibiting the production of proinflammatory cytokines both in peripheral blood mononuclear cells (PBMCs) from healthy donors and in vivo in the mouse model of acute lung injury (ALI) by diffuse alveolar damage (DAD). Treatment with peptides significantly decreases the infiltration of mononuclear cells to lungs in animals with DAD. Our findings suggest that Tag7-derived peptides might be beneficial in terms of the therapy or prevention of acute lung injury, e.g., for treating COVID-19 patients with severe pulmonary lesions.

Effect of Tilorone on the Dynamics of Viral Load and the Levels of Interferons and Interleukin-1β in the Lung Tissue and Blood Serum of Mice with Experimental Influenza.

We studied the effect of tilorone on the dynamics of IFNα, IFNγ, and IL-1β levels in the lung tissue and blood serum in relation to viral load in the lungs of BALB/c mice with pneumonia caused by influenza virus A/Aichi/2/68 (H3N2). Tilorone was administered per os in doses of 40, 150, and 540 μg per mouse 6, 30, and 78 h postinfection, which simulated the drug regimen used in the clinic for the treatment of influenza and acute respiratory viral infections in Russia and post-Soviet countries. Tilorone reduced viral load with the maximum amplitude (2-3 lg) after 1-2 administrations. The results of studying the dynamics of the cytokine levels in the infected animals in general support the previous hypothesis that, in repeated dosing, tilorone enhances the IFN response (compensates for its deficiency) at the early stages of acute respiratory viral infections and suppresses (damps) excessive production of IFN and proinflammatory cytokines at the later stages.

Targeting the Gut Microbiota in Coronavirus Disease 2019: Hype or Hope?

Targeting the Gut Microbiota in Coronavirus Disease 2019: Hype or Hope?

Mycobacterial disease in patients with chronic granulomatous disease

Chronic granulomatous disease (CGD) is an inborn error of immunity that affects the functionality of phagocytosis; specifically, there's lack of production of oxygen-free radicals by NADPH oxidase. CGD manifests as severe and recurring bacterial and fungal infections, as well as local and systemic hyperinflammation. In countries where tuberculosis is endemic and the BCG vaccine is mandatory at birth, patients with CGD may present local or systemic reactions to this vaccine as first manifestation; besides, recurrent infections by M. tuberculosis may be present throughout their life. The susceptibility of these patients to mycobacteria is due to the excessive production of pro-inflammatory cytokines and the formation of granulomas that are inefficient in containing mycobacteria. In developed countries, patients with CGD do not present this type of infectious manifestations, except for migrants who come from developing countries. In this review, we present the characteristics of infections by BCG, M. tuberculosis, and other types of mycobacteria. Interestingly, there are no guidelines regarding anti-tuberculosis treatments in patients with CGD, so we propose the realization of a consensus by experts in order to establish guidelines for the treatment of mycobacterial disease in CGD.

Thrombotic and Hypercoagulability Complications of COVID-19: An Update

The current COVID-19 pandemic emerged in December 2019, in China, affecting millions of people worldwide. COVID-19 is mainly a disease of the respiratory system, yet systematic complications have also been reported among SARS-CoV-2 infected patients. Thrombotic complications are one of the severe clinical outcomes of COVID-19, especially among critically ill patients, and are associated with poor prognosis. To date, many studies have concluded that COVID-19 increases the incidence of thrombotic events and coagulopathies; however, the exact mechanism behind such a disease outcome is not well known. Various pathophysiological mechanisms for thrombotic events in COVID-19 have been proposed, these include virus-induced endothelial cell damage, inflammation, and excess production of pro-inflammatory cytokines. As a result, most critically diseased COVID-19 patients are managed with prophylactic anticoagulant, yet some still develop thrombotic episodes. Therefore, better understanding of the mechanisms behind the thrombotic complications is needed to develop treatments that specifically target such pathways, which may aid in better disease management and improve the prognosis.

Gut Microbiota in NSAID Enteropathy: New Insights From Inside.

As a class of the commonly used drugs in clinical practice, non-steroidal anti-inflammatory drugs (NSAIDs) can cause a series of adverse events including gastrointestinal injuries. Besides upper gastrointestinal injuries, NSAID enteropathy also attracts attention with the introduction of capsule endoscopy and double balloon enteroscopy. However, the pathogenesis of NSAID enteropathy remains to be entirely clarified. Growing evidence from basic and clinical studies presents that gut microbiota is a critical factor in NSAID enteropathy progress. We have reviewed the recent data about the interplay between gut microbiota dysbiosis and NSAID enteropathy. The chronic medication of NSAIDs could change the composition of the intestinal bacteria and aggravate bile acids cytotoxicity. Meanwhile, NSAIDs impair the intestinal barrier by inhibiting cyclooxygenase and destroying mitochondria. Subsequently, intestinal bacteria translocate into the mucosa, and then lipopolysaccharide released from gut microbiota combines to Toll-like receptor 4 and induce excessive production of nitric oxide and pro-inflammatory cytokines. Intestinal injuries present in the condition of intestinal inflammation and oxidative stress. In this paper, we also have reviewed the possible strategies of regulating gut microbiota for the management of NSAID enteropathy, including antibiotics, probiotics, prebiotics, mucosal protective agents, and fecal microbiota transplant, and we emphasized the adverse effects of proton pump inhibitors on NSAID enteropathy. Therefore, this review will provide new insights into a better understanding of gut microbiota in NSAID enteropathy.

COVID-19-related cardiac complications from clinical evidences to basic mechanisms: opinion paper of the ESC Working Group on Cellular Biology of the Heart.

The pandemic of coronavirus disease (COVID)-19 is a global threat, causing high mortality, especially in the elderly. The main symptoms and the primary cause of death are related to interstitial pneumonia. Viral entry also into myocardial cells mainly via the angiotensin converting enzyme type 2 (ACE2) receptor and excessive production of pro-inflammatory cytokines, however, also make the heart susceptible to injury. In addition to the immediate damage caused by the acute inflammatory response, the heart may also suffer from long-term consequences of COVID-19, potentially causing a post-pandemic increase in cardiac complications. Although the main cause of cardiac damage in COVID-19 remains coagulopathy with micro- (and to a lesser extent macro-) vascular occlusion, open questions remain about other possible modalities of cardiac dysfunction, such as direct infection of myocardial cells, effects of cytokines storm, and mechanisms related to enhanced coagulopathy. In this opinion paper, we focus on these lesser appreciated possibilities and propose experimental approaches that could provide a more comprehensive understanding of the cellular and molecular bases of cardiac injury in COVID-19 patients. We first discuss approaches to characterize cardiac damage caused by possible direct viral infection of cardiac cells, followed by formulating hypotheses on how to reproduce and investigate the hyperinflammatory and pro-thrombotic conditions observed in the heart of COVID-19 patients using experimental in vitro systems. Finally, we elaborate on strategies to discover novel pathology biomarkers using omics platforms.

Control of Innate Immune Activation by Severe Acute Respiratory Syndrome Coronavirus 2 and Other Coronaviruses.

The ongoing coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), represents a public health crisis of unprecedented proportions. After the emergence of SARS-CoV-1 in 2002, and Middle East respiratory syndrome coronavirus (MERS-CoV) in 2012, this is the third outbreak of a highly pathogenic zoonotic coronavirus (CoV) that the world has witnessed in the last 2 decades. Infection with highly pathogenic human CoVs often results in a severe respiratory disease characterized by a delayed and blunted interferon (IFN) response, accompanied by an excessive production of proinflammatory cytokines. This indicates that CoVs developed effective mechanisms to overcome the host innate immune response and promote viral replication and pathogenesis. In this review, we describe the key innate immune signaling pathways that are activated during infection with SARS-CoV-2 and other well studied pathogenic CoVs. In addition, we summarize the main strategies that these viruses employ to modulate the host immune responses through the antagonism of IFN induction and effector pathways.

Nargenicin A1 attenuates lipopolysaccharide-induced inflammatory and oxidative response by blocking the NF-κB signaling pathway.

Inflammation caused by the excessive production of pro-inflammatory mediators and cytokines in abnormally activated macrophages promotes the initiation and progression of many diseases along with oxidative stress. Previous studies have suggested that nargenicin A1, an antibacterial macrolide isolated from Nocardia sp. may be a potential treatment for inflammatory responses and oxidative stress, but the detailed mechanisms are still not well studied. In this study, we investigated the inhibitory effect of nargenicin A1 on inflammatory and oxidative stress in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages and zebrafish (Danio rerio) models. Our results indicated that nargenicin A1 treatment significantly inhibited LPS-induced release of pro-inflammatory mediators including nitric oxide (NO) and prostaglandin E2, which was associated with decreased inducible NO synthase and cyclooxygenase-2 expression. In addition, nargenicin A1 attenuated the LPS-induced expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and monocyte chemotactic protein-1, reducing their extracellular secretion. Nargenicin A1 also suppressed LPS-induced generation of reactive oxygen species. Moreover, nargenicin A1 abolished the LPS-mediated nuclear translocation of nuclear factor-kappa B (NF-κB) and the degradation of inhibitor IκB-α, indicating that nargenicin A1 exhibited anti-inflammatory effects by inhibiting the NF-κB signaling pathway. Furthermore, nargenicin A1 showed strong protective effects against NO and ROS production in LPS-injected zebrafish larvae. In conclusion, our findings suggest that nargenicin A1 ameliorates LPS-induced anti-inflammatory and antioxidant effects by downregulating the NF-κB signaling pathway, and that nargenicin A1 can be a potential functional agent to prevent inflammatory- and oxidative-mediated damage.

Decreased microRNA-155 in Behcet\u2019s disease leads to defective control of autophagy thereby stimulating excessive proinflammatory cytokine production

BackgroundEarlier, we reported that the microRNA (miR)-155 expression in dendritic cells (DCs) from Behcet’s disease (BD) patients was decreased and affected cytokine production of DCs. In this study, we investigated the mechanisms whereby miR-155 regulates cytokine production by DCs.MethodsThe formation of autophagosomes in DCs was detected by transmission electron microscopy. Western blotting was used to detect the protein levels of LC3, Beclin-1, P62, p-mTOR, and p-Akt in DCs. TNF-α, IL-6, and IL-1β expression were investigated by ELISA. MiR-155 mimics were transfected to DCs to evaluate its effects on autophagy and cytokine production. RNA interference was used to downregulate the expression of TAB2.ResultsThe formation of autophagosomes was found in DCs of active BD patients. The expressions of LC3-II, Beclin-1, and P62 were significantly increased in DCs of active BD patients compared to that of inactive BD patients and healthy controls. The expressions of IL-6, IL-1β, and TNF-α were significantly increased in DCs of active BD patients compared to that of healthy controls. The autophagy promoter (3-MA) and inhibitor (rapamycin) significantly decreased or increased the expression of TNF-α, IL-6, and IL-1β by DCs. The expression of LC3-II and Beclin-1 was significantly increased, but the expression of P62 proteins was decreased in DCs transfected with miR-155 mimics or after TAB2 was downregulated. The expression of TNF-α, IL-6, and IL-1β was decreased in DCs after miR-155 was upregulated or TAB2 was downregulated. The ratios of p-Akt/Akt and p-mTOR/mTOR were decreased in DCs after miR-155 was upregulated.ConclusionsThese results suggest that miR-155 affects the production of TNF-α, IL-6, and IL-1β by DCs through activation of the Akt/mTOR signaling pathway and by affecting the process of autophagy.

Cytokine profile in women with threatened miscarriage and intestinal dysbiosis

Hypothesis/Aims of study: Systemic endotoxinemia resulting from intestinal dysbiosis activates the Th1 immune response and excessive production of proinflammatory cytokines, which can cause abortion. This study was aimed at assessing interleukin levels in women with the threat of miscarriage and exploring their dependence on intestinal microbiocenosis and the level of endotoxinemia.&#x0D; Study design, materials and methods: The study involved 87 women aged 18 to 43 years in pregnancy from six to 22 weeks. The main group consisted of 50 women with a threatened miscarriage. The control group included 37 women with normal pregnancy. A qualitative and quantitative analysis of intestinal microbiocenosis was performed by real-time PCR, with endotoxin and interleukin levels evaluated using conventional methods.&#x0D; Results: In patients of the main group, intestinal dysbiosis of grade I was detected in 30 % (n = 15), of grade II in 46 % (n = 23), and of grade III in 24 % (n = 12) of cases. In the control group, intestinal microflora disorders corresponded to grade I dysbiosis in 67.6 % (n = 25) and grade II dysbiosis in 32.4 % (n = 12) of cases, there being no cases of severe dysbiosis revealed. The level of endotoxin in pregnant women of the main group was 0.57 0.02 nmol / ml and was classified as increased. The endotoxin level in the blood serum of pregnant women of the control group was 0.34 0.02 nmol / ml and was characterized as low (p 0.001). A strong correlation was found (r = 0.8, p 0.001) between the grade of intestinal dysbiosis and the level of endotoxinemia. The cytokine profile in patients of the main group was characterized by increased concentrations of pro-inflammatory cytokines (IL-1 4.9 1.6 pg / ml, IL-6 4.8 1.5 pg / ml) and a decreased concentration of anti-inflammatory cytokine (IL-10 18.0 4.5 pg / ml), when compared to the control group (IL-1 1.8 0.2 pg / ml, IL-6 2.1 0.2 pg / ml, IL-10 30.3 4.4 pg/ml). There were a statistically significant moderate positive correlation between the level of endotoxinemia and the concentration of pro-inflammatory cytokines and a weak negative correlation between the endotoxin level and the concentration of anti-inflammatory IL-10.&#x0D; Conclusion: Endotoxinemia, which occurs as a result of intestinal microflora dysbiosis and activates pro-inflammatory pathways, can really be as a triggering factor in the pathogenesis of miscarriage in pregnant women.

Lgals3bp suppresses colon inflammation and tumorigenesis through the downregulation of TAK1-NF-\u03baB signaling

Galectin 3-binding protein (LGALS3BP, also known as 90K) is a multifunctional glycoprotein involved in immunity and cancer. However, its precise role in colon inflammation and tumorigenesis remains unclear. Here, we showed that Lgals3bp−/− mice were highly susceptible to colitis and colon tumorigenesis, accompanied by the induction of inflammatory responses. In acute colitis, NF-κB was highly activated in the colon of Lgals3bp−/− mice, leading to the excessive production of pro-inflammatory cytokines, such as IL-6, TNFα, and IL-1β. Mechanistically, Lgals3bp suppressed NF-κB through the downregulation of TAK1 in colon epithelial cells. There was no significant difference in the pro-inflammatory cytokine levels between wild-type and Lgals3bp−/− mice in a chronic inflammatory state, during colon tumorigenesis. Instead, Lgals3bp−/− mice showed elevated levels of GM-CSF, compared to those in WT mice. We also found that GM-CSF promoted the accumulation of myeloid-derived suppressor cells and ultimately increased colon tumorigenesis in Lgals3bp−/− mice. Taken together, Lgals3bp plays a critical role in the suppression of colitis and colon tumorigenesis through the downregulation of the TAK1-NF-κB-cytokine axis. These findings suggest that LGALS3BP is a novel immunotherapeutic target for colon inflammation and tumorigenesis.

Oleanolic Acid, Ursolic Acid and Apigenin from Ocimum basilicum as Potential Inhibitors of the SARS-CoV-2 Main Protease: A Molecular Docking Study

Aim: The present study aims at identifying potential inhibitors from a set of ten compounds from Ocimum basilicum against the SARS-CoV-2 main protease, the chymotrypsin-like protease (3CLpro).&#x0D; Materials and Methods: Computational studies by molecular docking (Autodock tool) were used to obtain the scoring function of ten phytochemicals in interaction with the SARS-CoV-2 main protease. The pharmacokinetic behavior of the high-docking score compounds was addressed by using SwissADME and pkCSM webservers.&#x0D; Results: Three high-docking score ligands were identified as hit compounds mainly the oleanolic acid (-8.55 kcal/mol), the ursolic acid (-8.21 kcal/mol) and apigenin (-7.52 kcal/mol). Their pharmacokinetic profile revealed that they have good therapeutic profile of druggability and safe. The biological activities of the three compounds especially their anti-inflammatory properties in relation with the excessive production of proinflammatory cytokines in the most severe form of the COVID-19 were also highlighted. &#x0D; Conclusion: COVID-19 outbreak is a serious public health threat that requires immediate action. In order to combat this pandemic, several strategies are used and the identification of potential inhibitors of the main protease of the virus is one of the widely used strategies. Here, three potential inhibitors from Ocimum basilicum plant (leaves) were pinpointed. Further in-vitro and in-vivo studies are needed that will clarify the role of Ocimum basilicum for the management of COVID-19 disease.

Apigetrin inhibits cytotoxicity and dysregulation of ACE2, IL1α and TGFβ expression induced by recombinant spike protein of SARS-CoV-2

SARS-CoV-2 virus is a novel coronavirus that was first identified in Wuhan, China in December 2019 and has caused an ongoing global health crisis. It has been a worldwide focus in research to understand viral pathogenesis and discover effective therapies. SARS-CoV-2 belongs to the same genus as the viruses responsible for Severe Acute Respiratory Syndrome (SARS) and the Middle East Respiratory Syndrome (MERS). Spike protein (SP) on SARS-CoV-2 plays a key role in the pathogenesis of SARS-CoV-2. The virus enters human cells via the binding of SP to the angiotensin-converting enzyme 2 (ACE2) on human cells. The binding of SP inhibits ACE2 function by reducing formation of angiotensin-(1-7), a compound that has inhibitory effects on inflammation. In addition, SARS-CoV-2 induces excessive proinflammatory cytokine production through various other signaling pathways such as the NFκB and NLRP3 inflammasome pathways. Previous evidence showed that apigenin (APG), a plant phenolic compound, can bind to SP. However, whether or not apigetrin (APT), the glucoside conjugate of APG, can protect human cells against cell injury caused by SARS-CoV-2 is still unknown. Studies have shown that SARS-CoV-2 induced dysregulation of host cell ACE2 expression is one of the major pathophysiological factors of COVID-19 infection. Our current study demonstrated that recombinant SP significantly reduced ACE2 level in human neuronal cells in a dose dependent manner using ELISA assay. Interestingly, APT reversed the SP induced ACE2 downregulation in these cells. In this study, the effect of SP on cell proliferation and immune regulation was also investigated. Using MTT and LDH assays, I discovered that SP had a cytotoxic effect on these cells and significantly inhibited cell proliferation. This cytotoxic effect was mitigated by adding APT treatment. Furthermore, APT reduced SP induced cytokine production such as IL1α and TGFβ . In sum, my study demonstrated that APT inhibited SARS-CoV-2 SP induced dysregulation of human cells and reduced its cytotoxic effects on cells. APT significantly upregulated ACE2 expression and inhibited the production of cytokines IL1α and TGFβ in the cells treated with SP. My study indicated that APT has potential to be a novel therapy for COVID-19 infection. More experiments to further elucidate molecular mechanisms of how APT modulates pathological effect of SP with different in vitro models including other human cell lines and in vivo animal models are currently being performed.

Facing COVID-19 Via Anti-Inflammatory Mechanism of Action: Molecular Docking and Pharmacokinetic Studies of Six Anti-Inflammatory Compounds Derived from Passiflora edulis

Aim: In the most severe case of the COVID-19, there is an excessive production of proinflammatory cytokines, being the main cause of mortality and morbidity. The present study aims at assessing the potential inhibitor effect of six phytochemicals with anti-inflammatory activity derived from Passiflora edulis, against the SARS-CoV-2 main protease.&#x0D; Materials and Methods: Virtual screening by molecular docking (Autodock tool) was used to obtain the binding energies of ligand-protein complexes formed between each of the six ligands and the SARS-CoV-2 main protease. The six ligands were then submitted to ADME (absorption, distribution, metabolism and excretion) and toxicity analyses to understand their pharmacokinetic behavior, using SwissADME, preADMET and pkCSM webservers.&#x0D; Results: Four high-docking score compounds were identified (both flavonoids) as hits, with the trend: ligand 4 (quercetin, -8.2 kcal/mol ) &gt; ligand 1 (chrysin, -8.0 kcal/mol) &gt; ligand 2 (kaempferol, -7.9 kcal/mol) &gt; ligand 3 (luteolin, -7.7 kcal/mol)&gt; ligand 5 (harmol, -6.7 kcal/mol) &gt; ligand 6 (harmine, -6.4 kcal/mol). The pharmacokinetic behavior of the six ligands revealed that they can be easily absorbed and have good permeability and bioavailability. The toxicity predictions of the six compounds from P. edulis which is an editable fruit confirm that they are safe.&#x0D; Conclusion: Several approaches are currently being used to tackle the COVID-19. Given the cytokine storm in the most severe case of the COVID-19, we adopted the strategy of combatting the disease by compounds that exhibit anti-inflammatory activity. The assessment of the efficiency of six phytochemicals from P. edulis against the SARS-CoV-2 Mpro and their pharmacokinetic profile revealed their potential inhibitor effect against the COVID-19 protein.

Activation of the cholinergic antiinflammatory reflex by occipitoatlantal decompression and transcutaneous auricular vagus nerve stimulation.

The parasympathetic-mediated inflammatory reflex inhibits excessive proinflammatory cytokine production. Noninvasive techniques, including occipitoatlantal decompression (OA-D) and transcutaneous auricular vagus nerve stimulation (taVNS), have been demonstrated to increase parasympathetic tone. To test the hypothesis that OA-D and taVNS increase parasympathetic nervous system activity and inhibit proinflammatory cytokine mobilization and/or production. Healthy adult participants were randomized to receive OA-D (5min of OA-D followed by 10min of rest; n=8), taVNS (15min; n=9), or no intervention (15min, time control; n=10) on three consecutive days. Before and after these interventions, saliva samples were collected for determination of the cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor α (TNF-α). Arterial blood pressure and the electrocardiogram were recorded for a 30-min baseline, throughout the intervention, and during a 30-min recovery period to derive heart rate and blood pressure variability markers as indices of vagal and sympathetic control. OA-D and taVNS increased root mean square of successive RR interval differences (RMSSD) and high frequency heart rate variability, which are established markers for parasympathetic modulation of cardiac function. In all three groups, the experimental protocol was associated with a significant increase in salivary cytokine concentrations. However, the increase in IL-1β was significantly less in the taVNS group (+66±13pg/mL; p<0.05) than in the time control group (+142±24pg/mL). A similar trend was observed in the taVNS group for TNF-α (+1.7±0.3pg/mL vs. 4.1±1.3pg/mL; p<0.10). In the OA-D group baseline IL-6, IL-8, and TNF-α levels on the third study day were significantly lower than on the first study day (IL-6: 2.3±0.4 vs. 3.2±0.6pg/mL, p<0.05; IL-8: 190±61 vs. 483±125pg/mL, p <0.05; TNF-α: 1.2±0.3 vs. 2.3±0.4pg/mL, p<0.05). OA-D decreased mean blood pressure from the first (100±8mmHg) to the second (92±6mmHg; p<0.05) and third (93±8mmHg; p<0.05) study days and reduced low frequency spectral power of systolic blood pressure variability (19±3mmHg2 after OA-D vs. 28±5mmHg2 before OA-D; p<0.05), a marker of sympathetic modulation of vascular tone. OA-D also increased baroreceptor-heart rate reflex sensitivity from the first (13.7±3.0ms/mmHg) to the second (18.4±4.3ms/mmHg; p<0.05) and third (16.9±4.2ms/mmHg; p<0.05) study days. Both OA-D and taVNS elicited antiinflammatory responses that were associated with increases in heart rate variability-derived markers for parasympathetic function. These findings suggest that OA-D and taVNS activate the parasympathetic antiinflammatory reflex. Furthermore, an antihypertensive effect was observed with OA-D that may be mediated by reduced sympathetic modulation of vascular tone and/or increased baroreceptor reflex sensitivity.

The age-related alerations in the enteric nervous system and their impact on peristalsis of the gastrointestinal tract.

Constipation occurs more often in old patients, because the intestinal peristalsis decreases with aging. Constipation is caused due to impaired motility of the intestines, intestinal barrier damage and the imbalance between the absorption and secretion of water and electrolytes, as well as disturbed production and release of intestinal hormones, infiltration of the gastrointestinal tract with immune cells, excessive production of pro-inflammatory cytokines and the alterations in the functions of enteric nervous system. In this review we will discuss the most important issues associated with the process of aging of the digestive tract, focusing on the enteric nervous system.