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Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) represent a significant global burden of morbidity and mortality, with lung injury being the primary cause of death in affected patients. The pathogenesis of lung injury, however, remains a complex issue. In recent years, the role of the immune system in lung injury has attracted extensive attention worldwide. Despite advancements in our understanding of various lung injury subtypes, significant limitations persist in both prevention and treatment. This review investigates the immunopathogenesis of ALI/ARDS, aiming to elucidate the pathological processes of lung injury mediated by dendritic cells (DCs), natural killer (NK) cells, phagocytes, and neutrophils. Furthermore, the article expounds on the critical contributions of gut microbiota, inflammatory pathways, and cytokine storms in the development of ALI/ARDS. [Display omitted] • Damage to lung tissue caused by immune cell dysfunction. • The ecological stability of intestinal flora is important in protecting lung tissue. • The inflammatory pathway plays a crucial role in regulating and mediating lung injury. • The impact of cytokine storm on lung injury is severe. [ABSTRACT FROM AUTHOR]

An archetypal anti-inflammatory compound against cytokine storm would inhibit it without suppressing the innate immune response. AG5, an anti-inflammatory compound, has been developed as synthetic derivative of andrographolide, which is highly absorbable and presents low toxicity. We found that the mechanism of action of AG5 is through the inhibition of caspase-1. Interestingly, we show with in vitro generated human monocyte derived dendritic cells that AG5 preserves innate immune response. AG5 minimizes inflammatory response in a mouse model of lipopolysaccharide (LPS)-induced lung injury and exhibits in vivo anti-inflammatory efficacy in the SARS-CoV-2-infected mouse model. AG5 opens up a new class of anti-inflammatories, since contrary to NSAIDs, AG5 is able to inhibit the cytokine storm, like dexamethasone, but, unlike corticosteroids, preserves adequately the innate immunity. This is critical at the early stages of any naïve infection, but particularly in SARS-CoV-2 infections. Furthermore, AG5 showed interesting antiviral activity against SARS-CoV-2 in humanized mice. [Display omitted] • AG5, a synthetic derivative of andrographolide, is a novel anti-inflammatory drug • AG5 minimizes inflammatory response by inhibition of caspase-1 route • AG5 inhibits cytokine storm and preserves adequately the innate immunity • AG5 shows antiviral activity against SARS-CoV-2. [ABSTRACT FROM AUTHOR]

Cytokine storm (CS) is a major contributor to the fatal outcome of severe infectious diseases, including Covid-19. Treatment with the complement (C) C5 inhibitor eculizumab was beneficial in end-stage Covid-19, however, the mechanism of this effect is unknown. To clarify this, we analyzed the relationship between C activation and production of pro-inflammatory cytokines in a PBMC model. Human PBMC with or without 20 % autologous serum was incubated with C3a, C5a, zymosan or zymosan-pre-activated serum (ZAS) for 24 h with or without eculizumab or the C5a receptor antagonist, DF2593A. C activation (sC5b-9) and 9 inflammatory cytokines were measured by ELISA. In serum-free unstimulated PBMC only IL-8 release could be measured during incubation. Addition of C5a increased IL-8 secretion only, ZAS induced both IL-2 and IL-8, while zymosan led to significant production of all cytokines, most abundantly IL-8. In the presence of serum the above effects were greatly enhanced, and the zymosan-induced rises of IL-1α, IL-1β IFN-γ and IL-2 were significantly attenuated by eculizumab but not by DF2593a. These data highlight the complexity of interrelationships between C activation and cytokine secretion under different experimental conditions. The clinically relevant findings include the abundant formation of the chemokine IL-8, which was stimulated by C5a, and the suppression of numerous inflammatory cytokines by eculizumab, which explains its therapeutic efficacy in severe Covid-19. These data strengthen the clinical relevance of the applied PBMC model for drug screening against CS, enabling the separation of complex innate immune cross-talks. • In serum-free unstimulated human PBMC culture only IL-8 release could be measured. • Serum increased the release of all cytokines measured. • Zymosan increased the release of all cytokines much more in the presence of serum. • Eculizumab suppressed zymosan-induced secretion of IL-1a, IL-1b, IFγ and IL-2. • A differential relationship between C activation and cytokine release was revealed. [ABSTRACT FROM AUTHOR]

Coronavirus disease 2019 (COVID-19) is a worldwide health threat that has long-term effects on the patients and there is currently no efficient cure prescribed for the treatment and the prolonging effects. Traditional Chinese medicines (TCMs) have been reported to exert therapeutic effect against COVID-19. In this study, the therapeutic effects of Jing Si herbal tea (JSHT) against COVID-19 infection and associated long-term effects were evaluated in different in vitro and in vivo models. The anti-inflammatory effects of JSHT were studied in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and in Omicron pseudotyped virus-induced acute lung injury model. The effect of JSHT on cellular stress was determined in HK-2 proximal tubular cells and H9c2 cardiomyoblasts. The therapeutic benefits of JSHT on anhedonia and depression symptoms associated with long COVID were evaluated in mice models for unpredictable chronic mild stress (UCMS). JSHT inhibited the NF-ƙB activities, and significantly reduced LPS-induced expression of TNFα, COX-2, NLRP3 inflammasome, and HMGB1. JSHT was also found to significantly suppress the production of NO by reducing iNOS expression in LPS-stimulated RAW 264.7 cells. Further, the protective effects of JSHT on lung tissue were confirmed based on mitigation of lung injury, repression in TMRRSS2 and HMGB-1 expression and reduction of cytokine storm in the Omicron pseudotyped virus-induced acute lung injury model. JSHT treatment in UCMS models also relieved chronic stress and combated depression symptoms. The results therefore show that JSHT attenuates the cytokine storm by repressing NF-κB cascades and provides the protective functions against symptoms associated with long COVID-19 infection. [ABSTRACT FROM AUTHOR]

Interleukin-6 (IL-6) is a multi-tasking cytokine that represents high activity in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and cancer. High concentration of this pleiotropic cytokine accounts for hyperinflammation and cytokine storm, and is related to multi-organ failure in patients with SARS-CoV-2 induced disease. IL-6 promotes lymphopenia and increases C-reactive protein (CRP) in such cases. However, blockade of IL-6 is not a full-proof of complete response. Hypoxia, hypoxemia, aberrant angiogenesis and chronic inflammation are inter-related events occurring as a response to the SARS-CoV-2 stimulatory effect on high IL-6 activity. Taking both pro- and anti-inflammatory activities will make complex targeting IL-6 in patient with SARS-CoV-2 induced disease. The aim of this review was to discuss about interactions occurring within the body of patients with SARS-CoV-2 induced disease who are representing high IL-6 levels, and to determine whether IL-6 inhibition therapy is effective for such patients or not. We also address the interactions and targeted therapies in cancer patients who also have SARS-CoV-2 induced disease. • IL-6 is a hallmark of inflammatory feature in severe/critical SARS-CoV-2 induced disease. • CRP level is a predictor of response to IL-6 inhibitor therapy. • The efficacy of tocilizumab is moderate in severe SARS-CoV-2 induced disease. • SARS-CoV-2-induced IL-6 seemingly strengthens cancer aggression. • IL-6 inhibitors can go with ICI in cancer (not in SARS-CoV-2 induced disease). [ABSTRACT FROM AUTHOR]

One of the hallmarks of COVID-19 is the cytokine storm that provokes primarily pneumonia followed by systemic inflammation. Emerging evidence has identified a potential link between elevated interleukin-17A (IL-17A) levels and disease severity and progression. Considering that per se, IL-17A can activate several inflammatory pathways, it is plausible to hypothesize an involvement of this cytokine in COVID-19 clinical outcomes. Thus, IL-17A could represent a marker of disease progression and/or a target to develop therapeutic strategies. This hypothesis paper aims to propose this "unique" cytokine as a silent amplifier of the COVID-19 immune response and (potentially) related therapy. [Display omitted] • One of the hallmarks of COVID-19 is the cytokine storm that provokes systemic inflammation. • Elevated levels of interleukin-17A (IL-17A) are associated to disease severity and progression. • We propose IL-17A as a silent amplifier of the COVID-19 immune response and (potentially) related therapy. [ABSTRACT FROM AUTHOR]

It has become evident that the actions of pro-inflammatory cytokines and/or the development of a cytokine storm are responsible for the occurrence of severe COVID-19 during SARS-CoV-2 infection. Although immunomodulatory mechanisms vary among viruses, the activation of multiple TLRs that occurs primarily through the recruitment of adapter proteins such as MyD88 and TRIF contributes to the induction of a cytokine storm. Based on this, controlling the robust production of pro-inflammatory cytokines by macrophages may be applicable as a cellular approach to investigate potential cytokine-targeted therapies against COVID-19. In the current study, we utilized TLR2/MyD88 and TLR3/TRIF co-activated macrophages and evaluated the anti-cytokine storm effect of the traditional Chinese medicine (TCM) formula Babaodan (BBD). An RNA-seq-based transcriptomic approach was used to determine the molecular mode of action. Additionally, we evaluated the anti-inflammatory activity of BBD in vivo using a mouse model of post-viral bacterial infection-induced pneumonia and seven severely ill COVID-19 patients. Our study reveals the protective role of BBD against excessive immune responses in macrophages, where the underlying mechanisms involve the inhibition of the NF-κB and MAPK signaling pathways. In vivo, BBD significantly inhibited the release of IL-6, thus resulting in increased survival rates in mice. Based on limited data, we demonstrated that severely ill COVID-19 patients benefited from BBD treatment due to a reduction in the overproduction of IL-6. In conclusion, our study indicated that BBD controls excessive immune responses and may thus represent a cytokine-targeted agent that could be considered to treating COVID-19. [Display omitted] • Cytokine-targeted therapeutic strategies to reduce lung inflammatory injury have been proposed for the treatment of patients with severe COVID-19. • TCM within the "heat-clearing and detoxifying (qingre jiedu)" category have been demonstrated to exert strong anti-inflammatory activities. • Baobadan (BBD) exerts pronounced anti-inflammatory effects on TLR1/2 and TLR3 dual activated macrophages that are associated with NF-κB and MAPKs. • BBD protects mice from excessive cytokine production and inflammatory lung injury. • Based on limited data, BBD appears to reduce the overproduction of IL-6 in severely ill COVID-19 patients. [ABSTRACT FROM AUTHOR]

Hyperinflammatory response caused by infections such as Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) increases organ failure, intensive care unit admission, and mortality. Cytokine storm in patients with Coronavirus Disease 2019 (COVID-19) drives this pattern of poor clinical outcomes and is dependent upon the activity of the transcription factor complex nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB) and its downstream target gene interleukin 6 (IL6) which interacts with IL6 receptor (IL6R) and the IL6 signal transduction protein (IL6ST or gp130) to regulate intracellular inflammatory pathways. In this study, we compare transcriptomic signatures from a variety of drug-treated or genetically suppressed (i.e. knockdown) cell lines in order to identify a mechanism by which antidepressants such as fluoxetine demonstrate non-serotonergic, anti-inflammatory effects. Our results demonstrate a critical role for IL6ST and NF-kappaB Subunit 1 (NFKB1) in fluoxetine's ability to act as a potential therapy for hyperinflammatory states such as asthma, sepsis, and COVID-19. [Display omitted] • Fluoxetine treatment elicits genetic changes which parallel those caused by IL6ST or NFKB1 knockdown. • Fluoxetine's anti-inflammatory mechanism of action may depend upon NF-kappaB/IL6ST signaling. • The anti-inflammatory effects of fluoxetine are likely independent of its monoaminergic mechanism. • The anti-inflammatory effects of fluoxetine may prevent cytokine storm associated with COVID-19. [ABSTRACT FROM AUTHOR]

Cytokines, the main players in the cytokine storm, can act as immunomodulators regulating inflammatory responses. S. baicalensis active components (SBACs) can act directly on immune cells such as lymphocytes, macrophages, mast cells, dendritic cells, monocytes, and neutrophils, and inhibit the production of inflammatory cytokines and alleviate inflammatory damage to organ tissues. "→", promotion; " ", inhibition. • Infection-associated cytokine storms can readily lead to organ failure or death. • The bioactive substances of S. baicalensis act directly on multiple immune cells. • The bioactive substances inhibit the production of diverse inflammatory cytokines. • The immunomodulatory mechanisms include multiple inflammatory signaling pathways. • S. baicalensis active components are potential drugs for cytokine storm treatment. Scutellaria baicalensis Georgi., a plant used in traditional Chinese medicine, has multiple biological activities, including anti-inflammatory, antiviral, antitumor, antioxidant, and antibacterial effects, and can be used to treat respiratory tract infections, pneumonia, colitis, hepatitis, and allergic diseases. The main active substances of S. baicalensis , baicalein, baicalin, wogonin, wogonoside, and oroxylin A, can act directly on immune cells such as lymphocytes, macrophages, mast cells, dendritic cells, monocytes, and neutrophils, and inhibit the production of the inflammatory cytokines IL-1β, IL-6, IL-8, and TNF-α, and other inflammatory mediators such as nitric oxide, prostaglandins, leukotrienes, and reactive oxygen species. The molecular mechanisms underlying the immunomodulatory and anti-inflammatory effects of the active compounds of S. baicalensis include downregulation of toll-like receptors, activation of the Nrf2 and PPAR signaling pathways, and inhibition of the nuclear thioredoxin system and inflammation-associated pathways such as those of MAPK, Akt, NFκB, and JAK-STAT. Given that in addition to the downregulation of cytokine production, the active constituents of S. baicalensis also have antiviral and antibacterial effects, they may be more promising candidate therapeutics for the prevention of infection-related cytokine storms than are drugs having only antimicrobial or anti-inflammatory activities. [ABSTRACT FROM AUTHOR]

• CS triggered by excessive inflammatory response drives the pathogenesis of COVID-19. • ASX inhibits TNFα, IL1β, IL6 via regulation of NF-kB & JAK/STAT; prevents CS & ALI/ARDS. • ASX suppresses plasma CRP, iNOS, COX2, PGE2 & ICAM-1; prevents oxidative damages. • ASX inhibits NLRP3, HIF1α, activates Nrf2, Sirtuin pathways; exerts antioxidant effect. • ASX enhances immune responses, NK cell activity, T- & B- cell population. Host excessive inflammatory immune response to SARS-CoV-2 infection is thought to underpin the pathogenesis of COVID-19 associated severe pneumonitis and acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). Once an immunological complication like cytokine storm occurs, anti-viral based monotherapy alone is not enough. Additional anti-inflammatory treatment is recommended. It must be noted that anti-inflammatory drugs such as JAK inhibitors, IL-6 inhibitors, TNF-α inhibitors, colchicine, etc., have been either suggested or are under trials for managing cytokine storm in COVID-19 infections. Natural astaxanthin (ASX) has a clinically proven safety profile and has antioxidant, anti-inflammatory, and immunomodulatory properties. There is evidence from preclinical studies that supports its preventive actions against ALI/ARDS. Moreover, ASX has a potent PPARs activity. Therefore, it is plausible to speculate that ASX could be considered as a potential adjunctive supplement. Here, we summarize the mounting evidence where ASX is shown to exert protective effect by regulating the expression of pro-inflammatory factors IL-1β, IL-6, IL-8 and TNF-α. We present reports where ASX is shown to prevent against oxidative damage and attenuate exacerbation of the inflammatory responses by regulating signaling pathways like NF-ĸB, NLRP3 and JAK/STAT. These evidences provide a rationale for considering natural astaxanthin as a therapeutic agent against inflammatory cytokine storm and associated risks in COVID-19 infection and this suggestion requires further validation with clinical studies. [ABSTRACT FROM AUTHOR]

• Effect of sex hormones on COVID-19 outcome bias in males and females. • Effect of immunological factors on COVID-19 outcome bias in males and females. • Angiotensin-converting enzyme-2 (ACE2) system and COVID-19 outcome in males and females. • Correlation between smoking and COVID-19 incidence in males and females. • Possible therapeutic options for COVID-19. The severe form of COVID-19 has significant sex disparities, with high fatalities commonly reported among males than females. The incidence of COVID-19 has also been higher in males compared with their female counterparts. This trend could be attributed to a better responsive and robust immune system in females. Cytokine storm is one of the pathophysiological features of severe COVID-19, and it occurs as a result of over-activation of immune cells leading to severe inflammation and tissue damage. Nevertheless, it is well modulated in females compared to their male counterparts. Severe inflammation in males is reported to facilitate progression of mild to severe COVID-19. The sex hormones, estrogens and androgens which exist in varying functional levels respectively in females and males are cited as the underlying cause for the differential immune response to COVID-19. Evidence abounds that estrogen modulate the immune system to protect females from severe inflammation and for that matter severe COVID-19. On the contrary, androgen has been implicated in over-activation of immune cells, cytokine storm and the attendant severe inflammation, which perhaps predispose males to severe COVID-19. In this review efforts are made to expand understanding and explain the possible roles of the immune system, the sex hormones and the angiotensin-converting enzyme (ACE) systems in male bias to severe COVID-19. Also, this review explores possible therapeutic avenues including androgen deprivation therapy (ADT), estrogen-based therapy, and ACE inhibitors for consideration in the fight against COVID-19. [ABSTRACT FROM AUTHOR]

• Candesartan downregulates expression of many glutamate upregulated genes in cultured neurons. • Glutamate upregulated genes in neurons positively correlate with COVID-19 upregulated genes. • Candesartan gene downregulation negatively correlates with COVID-19 upregulated genes. • Candesartan downregulates genes involved in the COVID-19 cytokine storm. Angiotensin receptor blockers (ARBs) reducing inflammation and protecting lung and brain function, could be of therapeutic efficacy in COVID-19 patients. Using GSEA, we compared our previous transcriptome analysis of neurons injured by glutamate and treated with the ARB Candesartan (GSE67036) with transcriptional signatures from SARS-CoV-2 infected primary human bronchial epithelial cells (NHBE) and lung postmortem (GSE147507), PBMC and BALF samples (CRA002390) from COVID-19 patients. Hundreds of genes upregulated in SARS-CoV-2/COVID-19 transcriptomes were similarly upregulated by glutamate and normalized by Candesartan. Gene Ontology analysis revealed expression profiles with greatest significance and enrichment, including proinflammatory cytokine and chemokine activity, the NF-kappa B complex, alterations in innate and adaptive immunity, with many genes participating in the COVID-19 cytokine storm. There are similar injury mechanisms in SARS-CoV-2 infection and neuronal injury, equally reduced by ARB treatment. This supports the hypothesis of a therapeutic role for ARBs, ameliorating the COVID-19 cytokine storm. [ABSTRACT FROM AUTHOR]

• Entecavir and imipenem alleviated LPS-induced cytokine storm syndrome. • Entecavir and imipenem mitigated LPS-induced acute lung injury. • Entecavir and imipenem inhibited LPS-stimulated TNF-α and IL-10 in hPBMC. • Entecavir and imipenem attenuated LPS-activated NF-κB. Coronavirus Disease 2019 (COVID-19) caused by Severe Acute Respiratory Syndrome Coronavirus -2 (SARS-CoV-2) has been widely spread in the world with a high mortality. Cytokine storm syndrome (CSS) and acute lung injury caused by SARS-CoV-2 infection severely threaten the patients. With the purpose to find effective and low-toxic drugs to mitigate CSS, entecavir and imipenem were identified to reduce TNF-α using a LPS-induced macrophage model from the anti-infective drug library. Entecavir and imipenem efficiently suppressed the release of inflammatory cytokines by partly intervention of NF-κB activity. The acute lung injury was also alleviated and the survival time was prolonged in mice. In addition, entecavir and imipenem inhibited the release of TNF-α and IL-10 in human peripheral blood mononuclear cells (hPBMCs). Collectively, we proposed that entecavir and imipenem might be candidates for the treatment of CSS. [ABSTRACT FROM AUTHOR]