COVID-19: Inflammatory Profile

Statin Therapy, Inflammation, and Outcomes in Patients Hospitalized for COVID-19: A Prospective Multicenter Cohort Study

BACKGROUND

Statins are lipid-lowering agents with anti-inflammatory effects. Data surrounding the benefits of statins in patients with coronavirus disease 2019 (COVID-19) are conflicting. We sought to better understand the impact of statins in the context of COVID-19-related inflammation.

METHODS

We leveraged the International Study of Inflammation in COVID-19, a prospective multicenter cohort of patients hospitalized for COVID-19 between February 2020 and October 2022. Participants underwent systematic assessment of biomarkers of inflammation. We used logistic regression modeling and inverse probability-of-treatment weighting (IPTW) to examine the association between prior statin use and the composite outcome of in-hospital death, need for mechanical ventilation, and need for renal replacement therapy.

RESULTS

A total of 4464 patients were included in the study, of whom 1364 (27.5%) were taking a statin prior to admission. There were 1061 primary outcome events, including 540 deaths, 854 mechanical ventilation and 313 renal replacement therapy. Amongst biomarkers of inflammation, statin use was associated solely with lower levels of soluble urokinase plasminogen activator receptor (suPAR) after adjusting for known confounders. In multivariable logistic regression analysis, statin use was associated with lower odds of the composite outcome (adjusted odds ratio (aOR) 0.63, 95% CI [0.53-0.76]) compared to patients not on statins. Findings were consistent with IPTW (aOR 0.92, 95% CI [0.89- 0.95]). The proportion of the effect of statin on the primary outcome mediated by suPAR was estimated at 31.5%.

CONCLUSION

Prior-statin use is associated with improved outcomes and lower inflammation as measured by suPAR levels in patients hospitalized for COVID-19.

Pericoronary Fat Attenuation: Diagnosis and Clinical Implications

PURPOSE OF THE REVIEW

The purpose of this review is to evaluate the current state of knowledge regarding the technical challenges associated with the Post-Acquisition Fat Attenuation Index (PFAI). By examining the limitations and gaps in the current methodologies, this review aims to provide a comprehensive understanding of how various factors impact the accuracy and reliability of PFAI measurements.

RECENT FINDINGS

PFAI correlates with plaque instability, as inflammation in coronary plaque alters surrounding adipose tissue composition, increasing its water content and reducing lipid content, which is detectable via cardiac CT as increased attenuation. Recent studies have demonstrated PFA's prognostic value, with elevated levels linked to higher risks of cardiac events and plaque instability. A 2022 meta-analysis confirmed its association with major adverse cardiac events. Machine learning algorithms incorporating PFA and additional imaging features have further enhanced risk prediction beyond traditional metrics. Pericoronary fat attenuation is a promising marker for assessing coronary inflammation and could be useful in predicting plaque development, rupture, and monitoring treatment response, though further prospective studies and technical standardization are needed to fully establish its clinical benefits.

Correlation of Triethylamine N-oxide (TMAO), LPS, and TNF-Alpha Levels With Clinical Features of the Disease in Patients With and Without Septic Shock Infected With COVID-19 Virus

BACKGROUND

Inflammation is a response of the immune system to protect the body against various diseases or injuries. Serum trimethylamine N-oxide (TMAO) levels may vary depending on age, gender, habits, comorbidities, and microbiota.

AIMS

In this study, we investigated whether TMAO levels have diagnostic significance and their potential as a marker in the early diagnosis of the disease. Another aim of the research was to identify changes in TMAO levels as a reflection of the deterioration in the microflora, and IL-6, IL-10, IL-1β, TNF-alpha, and LPS levels in patient groups. Then, we recognized relationships between these parameters in patients infected with COVID-19 without septic shock and with COVID-19 who were without transmission of COVID-19 in septic shock.

STUDY DESIGN

A total of 160 patients were investigated, including 40 patients infected with COVID-19 without septic contact, 40 patients with COVID-19 positive septic shock, 40 patients with COVID-19 negative septic shock, and 40 healthy individuals as the control group.

RESULTS

TNF-α and IL-1β levels were significantly lower (P < 0.001) and IL-6 and IL-10 levels were significantly higher (P < 0.001) in patient groups than in control groups. IL-1β showed a significant decrease, especially in the groups infected with COVID-19. Although IL-6, increased even more in the groups infected with COVID-19.

CONCLUSIONS

LPS level was remarkably high in the sepsis group infected with COVID-19 compared to the other groups. TMAO level was significantly higher (P < 0.001) in the sepsis group. Therefore, TMAO is a potential biomarker in sepsis and septic shock.

SARS-CoV-2 ORF3a induces COVID-19-associated kidney injury through HMGB1-mediated cytokine production

The primary challenge posed by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is COVID-19-related mortality, often exacerbated by additional medical complications, such as COVID-19-associated kidney injuries (CAKIs). Up to half of COVID-19 patients experience kidney complications, with those facing acute respiratory failure and kidney injury having the worst overall prognosis. Despite the significant impact of CAKI on COVID-19-related mortality and its enduring effects in long COVID, the underlying causes and molecular mechanisms of CAKI remain elusive. In this study, we identified a functional relationship between the expression of the SARS-CoV-2 ORF3a protein and inflammation-driven apoptotic death of renal tubular epithelial cells in patients with CAKI. We demonstrate in vitro that ORF3a independently induces renal cell-specific apoptotic cell death, as evidenced by the elevation of kidney injury molecule-1 (KIM-1) and the activation of NF-kB-mediated proinflammatory cytokine (TNFα and IL-6) production. By examining kidney tissues of SARS-CoV-2-infected K18-ACE2 transgenic mice, we observed a similar correlation between ORF3a-induced cytopathic changes and kidney injury. This correlation was further validated through reconstitution of the ORF3a effects via direct adenoviral injection into mouse kidneys. Through medicinal analysis, we identified a natural compound, glycyrrhizin (GL4419), which not only blocks viral replication in renal cells, but also mitigates ORF3a-induced renal cell death by inhibiting activation of a high mobility group box 1 (HMGB1) protein, leading to a reduction of KIM-1. Moreover, ORF3a interacts with HMGB1. Overproduction or downregulation of hmgb1 expression results in correlative changes in renal cellular KIM-1 response and respective cytokine production, implicating a crucial role of HMGB1 in ORF3a-inflicted kidney injuries. Our data suggest a direct functional link between ORF3a and kidney injury, highlighting ORF3a as a unique therapeutic target contributing to CAKI.

IMPORTANCE

The major challenge of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during the pandemic is COVID-19-related mortality, which has tragically claimed millions of lives. COVID-19-associated morbidity and mortality are often exacerbated by pre-existing medical conditions, such as chronic kidney diseases (CKDs), or the development of acute kidney injury (AKI) due to COVID-19, collectively known as COVID-19-associated kidney injuries (CAKIs). Patients who experience acute respiratory failure with CAKI have the poorest clinical outcomes, including increased mortality. Despite these alarming clinical findings, there is a critical gap in our understanding of the underlying causes of CAKI. Our study establishes a direct correlation between the expression of the SARS-CoV-2 viral ORF3a protein and kidney injury induced by ORF3a linking to CAKI. This functional relationship was initially observed in our clinical studies of COVID-19 patients with AKI and was further validated through animal and in vitro cellular studies, either by expressing ORF3a alone or in the context of viral infection. By elucidating this functional relationship and its underlying mechanistic pathways, our research deepens the understanding of COVID-19-associated kidney diseases and presents potential therapeutic avenues to address the healthcare challenges faced by individuals with underlying conditions.

p70S6K as a Potential Anti-COVID-19 Target: Insights from Wet Bench and In Silico Studies

The onset of SARS-CoV-2 infection in 2019 sparked a global COVID-19 pandemic. This infection is marked by a significant rise in both viral and host kinase activity. Our primary objective was to identify a pivotal host kinase essential for COVID-19 infection and the associated phenomenon of the cytokine storm, which may lead to long-term COVID-19 complications irrespective of viral genetic variations. To achieve this, our study tracked kinase phosphorylation dynamics in RAW264.7 macrophages following SPIKE transfection over time. Among the kinases surveyed, p70S6K (RPS6KB1) exhibited a 3.5-fold increase in phosphorylation at S418. This significant change prompted the selection of p70S6K for in silico investigation, utilizing its structure bound to M2698 (PDB: 7N93). M2698, an oral dual Akt/p70S6K inhibitor with an IC50 of 1.1 nM, exhibited psychosis side effects in phase I clinical trials, potentially linked to its interaction with Akt2. Our secondary objective was to discover a small-molecule analogue of M2698 that exhibits a distinct binding preference for p70S6K over Akt2 through computational modeling and analysis. The in silico part of our project began with validating the prediction accuracy of the docking algorithm, followed by an OCA analysis pinpointing specific atoms on M2698 that could be modified to enhance selectivity. Subsequently, our investigation led to the identification of an analog of M2698, designated as S34, that showed a superior docking score towards p70S6K compared to Akt2. To further assess the stability of S34 in its protein-ligand (PL) complexes with p70S6K and Akt2, MD simulations were conducted. These simulations suggest that S34, on average, forms two hydrogen bond interactions with p70S6K, whereas it only forms one hydrogen bond interaction with Akt2. This difference in hydrogen bond interactions likely contributed to the observed larger root mean square deviation (RMSD) of 0.3 nm in the S34-Akt2 complex, compared to 0.1 nm in the S34-p70S6K complex. Additionally, we calculated free binding energy to predict the strength of the binding interactions of S34 to p70S6K and Akt2, which showed ~2-fold favorable binding affinity of S34 in the p70S6K binding pocket compared to that in the Akt2 binding pocket. These observations may suggest that the S34-p70S6K complex is more stable than the S34-Akt2 complex. Our work focused on identifying a host kinase target and predicting the binding affinity of a novel small molecule to accelerate the development of effective treatments. The wet bench results specifically highlight p70S6K as a compelling anti-COVID-19 target. Meanwhile, our in silico investigations address the known off-target effects associated with M2698 by identifying a close analog called S34. In conclusion, this study presents novel and intriguing findings that could potentially lead to clinical applications with further investigations.

SARS-CoV-2 spike protein induces the cytokine release syndrome by stimulating T cells to produce more IL-2

Introduction

Cytokine release syndrome (CRS) is one of the leading causes of mortality in patients with COVID-19 caused by the SARS-CoV-2 coronavirus. However, the mechanism of CRS induced by SARS-CoV-2 is vague.

Methods

Using spike protein combined with IL-2, IFN-γ, and TNF-α to stimulate human peripheral blood mononuclear cells (PBMCs) to secrete CRS-related cytokines, the content of cytokines in the supernatant was detected, and the effects of NK, T, and monocytes were analyzed.

Results

This study shows that dendritic cells loaded with spike protein of SARS-CoV-2 stimulate T cells to release much more interleukin-2 (IL-2,) which subsequently cooperates with spike protein to facilitate PBMCs to release IL-1β, IL-6, and IL-8. These effects are achieved via IL-2 stimulation of NK cells to release tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), as well as T cells to release IFN-γ Mechanistically, IFN-γ and TNF-α enhance the transcription of CD40, and the interaction of CD40 and its ligand stabilizes the membrane expression of toll-like receptor 4 (TLR4) that serves as a receptor of spike protein on the surface of monocytes. As a result, there is a constant interaction between spike protein and TLR4, leading to continuous activation of nuclear factor-κ-gene binding (NF-κB). Furthermore, TNF-α also activates NF-κB signaling in monocytes, which further cooperates with IFN-γ and spike protein to modulate NF-κB-dependent transcription of CRS-related inflammatory cytokines.

Discussion

Targeting TNF-α/IFN-γ in combination with TLR4 may represent a promising therapeutic approach for alleviating CRS in individuals with COVID-19.

Activation of alveolar epithelial ER stress by β-coronavirus infection disrupts surfactant homeostasis in mice: implications for COVID-19 respiratory failure

COVID-19 syndrome is characterized by acute lung injury, hypoxemic respiratory failure, and high mortality. Alveolar type 2 (AT2) cells are essential for gas exchange, repair, and regeneration of distal lung epithelium. We have shown that the causative agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and other members of the β-coronavirus genus induce an endoplasmic reticulum (ER) stress response in vitro; however, the consequences for host AT2 cell function in vivo are less understood. To study this, two murine models of coronavirus infection were used-mouse hepatitis virus-1 (MHV-1) in A/J mice and a mouse-adapted SARS-CoV-2 strain. MHV-1-infected mice exhibited dose-dependent weight loss with histological evidence of distal lung injury accompanied by elevated bronchoalveolar lavage fluid (BALF) cell counts and total protein. AT2 cells showed evidence of both viral infection and increased BIP/GRP78 expression, consistent with activation of the unfolded protein response (UPR). The AT2 UPR included increased inositol-requiring enzyme 1α (IRE1α) signaling and a biphasic response in PKR-like ER kinase (PERK) signaling accompanied by marked reductions in AT2 and BALF surfactant protein (SP-B and SP-C) content, increases in surfactant surface tension, and emergence of a reprogrammed epithelial cell population (Krt8+ and Cldn4+). The loss of a homeostatic AT2 cell state was attenuated by treatment with the IRE1α inhibitor OPK-711. As a proof-of-concept, C57BL6 mice infected with mouse-adapted SARS-CoV-2 demonstrated similar lung injury and evidence of disrupted surfactant homeostasis. We conclude that lung injury from β-coronavirus infection results from an aberrant host response, activating multiple AT2 UPR stress pathways, altering surfactant metabolism/function, and changing AT2 cell state, offering a mechanistic link between SARS-CoV-2 infection, AT2 cell biology, and acute respiratory failure.NEW & NOTEWORTHY COVID-19 syndrome is characterized by hypoxemic respiratory failure and high mortality. In this report, we use two murine models to show that β-coronavirus infection produces acute lung injury, which results from an aberrant host response, activating multiple epithelial endoplasmic reticular stress pathways, disrupting pulmonary surfactant metabolism and function, and forcing emergence of an aberrant epithelial transition state. Our results offer a mechanistic link between SARS-CoV-2 infection, AT2 cell biology, and respiratory failure.

Single-cell transcriptomic analysis of B cells reveals new insights into atypical memory B cells in COVID-19

Here, we performed single-cell RNA sequencing of S1 and receptor binding domain protein-specific B cells from convalescent COVID-19 patients with different clinical manifestations. This study aimed to evaluate the role and developmental pathway of atypical memory B cells (MBCs) in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The results revealed a proinflammatory signature across B cell subsets associated with disease severity, as evidenced by the upregulation of genes such as GADD45B, MAP3K8, and NFKBIA in critical and severe individuals. Furthermore, the analysis of atypical MBCs suggested a developmental pathway similar to that of conventional MBCs through germinal centers, as indicated by the expression of several genes involved in germinal center processes, including CXCR4, CXCR5, BCL2, and MYC. Additionally, the upregulation of genes characteristic of the immune response in COVID-19, such as ZFP36 and DUSP1, suggested that the differentiation and activation of atypical MBCs may be influenced by exposure to SARS-CoV-2 and that these genes may contribute to the immune response for COVID-19 recovery. Our study contributes to a better understanding of atypical MBCs in COVID-19 and the role of other B cell subsets across different clinical manifestations.

Functional and epigenetic changes in monocytes from adults immunized with an AS01-adjuvanted vaccine

The adjuvant AS01 plays a key role in the immunogenicity of several approved human vaccines with demonstrated high efficacy. Its adjuvant effect relies on activation of the innate immune system. However, specific effects of AS01-adjuvanted vaccines on innate cell function and epigenetic remodeling, as described for Bacille Calmette-Guérin (BCG) and influenza vaccines, are still unknown. We assessed the long-term functional and epigenetic changes in circulating monocytes and dendritic cells induced by a model vaccine containing hepatitis B surface antigen and AS01 in healthy adults (NCT01777295). The AS01-adjuvanted vaccine, but not an Alum-adjuvanted vaccine, increased the number of circulating monocytes and their expression of human leukocyte antigen (HLA)-DR, which correlated with the magnitude of the memory CD4+ T cell response. Single-cell analyses revealed epigenetic alterations in monocyte and dendritic cell subsets, affecting accessibility of transcription factors involved in cell functions including activator protein-1 (AP-1), GATA, C/EBP, and interferon regulatory factor. The functional changes were characterized by a reduced proinflammatory response to Toll-like receptor activation and an improved response to interferon-γ, a cytokine critical for the adjuvant's mode of action. Epigenetic changes were most evident shortly after the second vaccine dose in CD14+ monocytes, for which accessibility differences of some transcription factors could persist for up to 6 months postvaccination. Together, we show that reprogramming of monocyte subsets occurs after vaccination with an AS01-adjuvanted vaccine, an effect that may contribute to the impact of vaccination beyond antigen-specific protection.

COVID-19 Diarrhea Is Inflammatory, Caused by Direct Viral Effects Plus Major Role of Virus-induced Cytokines

BACKGROUND & AIMS

Diarrhea occurs in up to 50% of cases of COVID-19. Nonetheless, the pathophysiologic mechanism(s) have not been determined.

METHODS

This was examined using normal human enteroid monolayers exposed apically to live SARS-CoV-2 or non-replicating virus-like particles (VLPs) bearing the 4 SARS-CoV-2 structural proteins or irradiated virus, all of which bound and entered enterocytes.

RESULTS

Live virus and VLPs incrieased secretion of multiple cytokines and reduced mRNAs of ACE2, NHE3, and DRA. Interleukin (IL)-6 plus IL-8 alone reduced NHE3 mRNA and protein and DRA mRNA and protein. Neither VLPs nor IL-6 plus IL-8 alone altered Cl- secretion, but together they caused Cl- secretion, which was Ca2+-dependent, CFTR-independent, blocked partially by a specific TMEM16A inhibitor, and entirely by a general TMEM16 family inhibitor. VLPs and irradiated virus, but not IL-6 plus IL-8, produced Ca2+ waves that began within minutes of VLP exposure, lasted for at least 60 minutes, and were prevented by pretreatment with apyrase, a P2Y1 receptor antagonist, and general TMEM16 family inhibitor but not by the specific TMEM16A inhibitor.

CONCLUSIONS

The pathophysiology of COVID-19 diarrhea appears to be a unique example of a calcium-dependent inflammatory diarrhea that is caused by direct viral effects plus the virus-induced intestinal epithelial cytokine secretion.

Initiator cell death event induced by SARS-CoV-2 in the human airway epithelium

Virus-induced cell death is a key contributor to COVID-19 pathology. Cell death induced by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is well studied in myeloid cells but less in its primary host cell type, angiotensin-converting enzyme 2 (ACE2)-expressing human airway epithelia (HAE). SARS-CoV-2 induces apoptosis, necroptosis, and pyroptosis in HAE organotypic cultures. Single-cell and limiting-dilution analysis revealed that necroptosis is the primary cell death event in infected cells, whereas uninfected bystanders undergo apoptosis, and pyroptosis occurs later during infection. Mechanistically, necroptosis is induced by viral Z-RNA binding to Z-DNA-binding protein 1 (ZBP1) in HAE and lung tissues from patients with COVID-19. The Delta (B.1.617.2) variant, which causes more severe disease than Omicron (B1.1.529) in humans, is associated with orders of magnitude-greater Z-RNA/ZBP1 interactions, necroptosis, and disease severity in animal models. Thus, Delta induces robust ZBP1-mediated necroptosis and more disease severity.

Recent Advances of Engineered Cell Membrane-Based Nanotherapeutics to Combat Inflammatory Diseases

An immune reaction known as inflammation serves as a shield from external danger signals, but an overactive immune system may additionally lead to tissue damage and even a variety of inflammatory disorders. By inheriting biological functionalities and serving as both a therapeutic medication and a drug carrier, cell membrane-based nanotherapeutics offer the potential to treat inflammatory disorders. To further strengthen the anti-inflammatory benefits of natural cell membranes, researchers alter and optimize the membranes using engineering methods. This review focuses on engineered cell membrane-based nanotherapeutics (ECMNs) and their application in treating inflammation-related diseases. Specifically, this article discusses the methods of engineering cell membranes for inflammatory diseases and examines the progress of ECMNs in inflammation-targeted therapy, inflammation-neutralizing therapy, and inflammation-immunomodulatory therapy. Additionally, the article looks into the perspectives and challenges of ECMNs in inflammatory treatment and offers suggestions as well as guidance to encourage further investigations and implementations in this area.

Differences and similarities between innate immune evasion strategies of human coronaviruses

So far, seven coronaviruses have emerged in humans. Four recurring endemic coronaviruses cause mild respiratory symptoms. Infections with epidemic Middle East respiratory syndrome-related coronavirus or severe acute respiratory syndrome coronavirus (SARS-CoV)-1 are associated with high mortality rates. SARS-CoV-2 is the causative agent of the coronavirus disease 2019 pandemic. To establish an infection, coronaviruses evade restriction by human innate immune defenses, such as the interferon system, autophagy and the inflammasome. Here, we review similar and distinct innate immune manipulation strategies employed by the seven human coronaviruses. We further discuss the impact on pathogenesis, zoonotic emergence and adaptation. Understanding the nature of the interplay between endemic/epidemic/pandemic coronaviruses and host defenses may help to better assess the pandemic potential of emerging coronaviruses.

Anti-Coronavirus Potential of Polyether Ionophores: The New Application of Veterinary Antibiotics in Livestock

Coronaviruses have consistently posed a major global concern in the field of livestock industry and public health. However, there is currently a lack of efficient drugs with broad-spectrum antiviral activity to address the challenges presented by emerging mutated strains or drug resistance. Additionally, the method for identifying multitarget drugs is also insufficient. Aminopeptidase N (APN) and 3C-like proteinase (3CLpro) represent promising targets for host-directed and virus-directed strategies, respectively, in the development of effective drugs against various coronaviruses. In this study, maduramycin ammonium demonstrated a broad-spectrum antiviral effect by targeting both of the proteins. The binding domains 4 Å from the ligand of both target proteins shared a structural similarity, suggesting that screening and designing drugs based on these domains might exhibit broad-spectrum and highly effective antiviral activity. Furthermore, it was identified that the polyether ionophores' ability to carry zinc ion might be one of the reasons why they were able to target APN and exhibit antiviral effect. The findings of this experiment provide novel perspectives for future drug screening and design, while also offering valuable references for the utilization of polyether ionophores in the management of livestock health.

Inhibitory effect of food-functioned phytochemicals on dysregulated inflammatory pathways triggered by SARS-CoV-2: a mechanistic review

Inflammatory cascades of the dysregulated inflammatory pathways in COVID-19 can cause excessive production of pro-inflammatory cytokines and chemokines leading to cytokine storm syndrome (CSS). The molecular cascades involved in the pathways may be targeted for discovery of new anti-inflammatory agents. Many plant extracts have been used clinically in the management of COVID-19, however, their immunosuppressive activities were mainly investigated based on in silico activity. Dietary flavonoids of the extracts such as quercetin, luteolin, kaempferol, naringenin, isorhamnetin, baicalein, wogonin, and rutin were commonly identified as responsible for their inhibitory effects. The present review critically analyzes the anti-inflammatory effects and mechanisms of phytochemicals, including dietary compounds against cytokine storm (CS) and hyperinflammation via inhibition of the altered inflammatory pathways triggered by SARS-CoV-2, published since the emergence of COVID-19 in December 2019. Only a few phytochemicals, mainly dietary compounds such as nanocurcumin, melatonin, quercetin, 6-shagoal, kaempferol, resveratrol, andrographolide, and colchicine have been investigated either in in silico or preliminary clinical studies to evaluate their anti-inflammatory effects against COVID-19. Sufficient pre-clinical studies on safety and efficacy of anti-inflammatory effects of the phytochemicals must be performed prior to proper clinical studies to develop them into therapeutic adjuvants in the prevention and treatmemt of COVID-19 symptoms.

Nebulized pH-Responsive Nanospray Combined with Pentoxifylline and Edaravone to Lungs for Efficient Treatments of Acute Respiratory Distress Syndrome

The COVID-19 pandemic has become an unprecedented global medical emergency, resulting in more than 5 million deaths. Acute respiratory distress syndrome (ARDS) caused by COVID-19, characterized by the release of a large number of pro-inflammatory cytokines and the production of excessive toxic ROS, is the most common serious complication leading to death. To develop new strategies for treating ARDS caused by COVID-19, a mouse model of ARDS was established by using lipopolysaccharide (LPS). Subsequently, we have constructed a novel nanospray with anti-inflammatory and antioxidant capacity by loading pentoxifylline (PTX) and edaravone (Eda) on zeolite imidazolate frameworks-8 (ZIF-8). This nanospray was endowed with synergetic therapy, which could kill two birds with one stone: (1) the loaded PTX played a powerful anti-inflammatory role by inhibiting the activation of inflammatory cells and the synthesis of pro-inflammatory cytokines; (2) Eda served as a free radical scavenger in ARDS. Furthermore, compared with the traditional intravenous administration, nanosprays can be administered directly and inhaled efficiently and reduce the risk of systemic adverse reactions greatly. This nanospray could not only coload two drugs efficiently but also realize acid-responsive release on local lung tissue. Importantly, ZIF8-EP nanospray showed an excellent therapeutic effect on ARDS in vitro and in vivo, which provided a new direction for the treatment of ARDS.

Association of dietary inflammatory index and the SARS-CoV-2 infection incidence, severity and mortality of COVID-19: a systematic review and dose-response meta-analysis

BACKGROUND

Several studies have reported the association between dietary inflammatory index (DII) and the SARS-CoV-2 infection risk, severity or mortality of COVID-19, however, the outcomes remain controversial.

OBJECTIVE

We sought to examine whether a dose-response association of DII and SARS-CoV-2 infection exists.

DESIGN

A dose-response meta-analysis was performed to investigate the association of DII and SARS-CoV-2 infection. We conducted a systematic search of PubMed, Embase and Web of Science up to March 15th, 2023. The odds ratios (OR) of DII and COVID-19 risk and severity were computed.

RESULTS

Totally, 5 studies were included (1 from UK and 4 from Iran), consisting of 197,929 participants with 12,081 COVID-19 cases. Although there was heterogeneity among studies, the results indicated that higher DII was independently related to higher SARS-CoV-2 infection incidence (OR = 1.57, 95% CI: 1.14, 2.17) and COVID-19 severity (OR = 1.11, 95% CI: 1.07, 1.15) but not COVID-19 mortality (risk ratio = 1.13, 95% CI: 1.00, 1.27). The incidence of SARS-CoV-2 infection increased by 31% for each 1-point increase in the E-DII (OR = 1.31, 95% CI: 1.20, 1.43).

CONCLUSIONS

This meta-analysis suggests that an elevated DII score is associated with increased SARS-CoV-2 infectious risk and severity of COVID-19. There were not enough studies on COVID-19 mortality. Further large prospective studies in different countries are warranted to validate our results.

Erdr1 Drives Macrophage Programming via Dynamic Interplay with YAP1 and Mid1

Erythroid differentiation regulator 1 (Erdr1) is a stress-induced, widely expressed, highly conserved secreted factor found in both humans and mice. Erdr1 is linked with the Hippo-YAP1 signaling. Initially identified as an inducer of hemoglobin synthesis, Erdr1 emerged as a multifunctional protein, especially in immune cells. Although Erdr1 has been implicated in regulating T cells and NK cell function, its role in macrophage remains unclear. This study explored the function and mechanism of Erdr1 in macrophage inflammatory response. The data demonstrated that Erdr1 could promote anti-inflammatory cytokine production, a function that also has been reported by previous research. However, I found Erdr1 also could play a proinflammatory role. The function of Erdr1 in macrophages depends on its dose and cell density. I observed that Erdr1 expression was inhibited in M1 macrophages but was upregulated in M2 macrophages compared with unpolarized macrophages. I hypothesized that Erdr1 balances the inflammatory response by binding with distinct adaptors dependent on varying concentrations. Mechanistically, I demonstrated YAP1 and Mid1 as the two adaptor proteins of Erdr1. The Erdr1-YAP1 interaction promotes anti-inflammatory cytokine production when Erdr1 levels are elevated, whereas the Erdr1-Mid1 interaction induces proinflammatory cytokine production when Erdr1 levels are decreased. This study highlights the effects of Erdr1 on regulating cytokine production from polarized macrophages potentially by regulating YAP1 in the nonclassical Hippo pathway.

Role of PCSK9 inhibition during the inflammatory stage of SARS-COV-2: an updated review

The potential role of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition in the management of COVID-19 and other medical conditions has emerged as an intriguing area of research. PCSK9 is primarily known for its impact on cholesterol metabolism, but recent studies have unveiled its involvement in various physiological processes, including inflammation, immune regulation, and thrombosis. In this abstract, the authors review the rationale and potential implications of PCSK9 inhibition during the inflammatory stage of SARS-CoV-2 infection. Severe cases of COVID-19 are characterized by an uncontrolled inflammatory response, often referred to as the cytokine storm, which can lead to widespread tissue damage and organ failure. Preclinical studies suggest that PCSK9 inhibition could dampen this inflammatory cascade by reducing the production of pro-inflammatory cytokines. Additionally, PCSK9 inhibition may protect against acute respiratory distress syndrome (ARDS) through its effects on lung injury and inflammation. COVID-19 has been linked to an increased risk of cardiovascular complications, especially in patients with pre-existing cardiovascular conditions or dyslipidemia. PCSK9 inhibitors are known for their ability to lower low-density lipoprotein (LDL) cholesterol levels by enhancing the recycling of LDL receptors in the liver. By reducing LDL cholesterol, PCSK9 inhibition might protect blood vessels from further damage and lower the risk of atherosclerotic plaque formation. Moreover, PCSK9 inhibitors have shown potential antithrombotic effects in preclinical studies, making them a potential avenue to mitigate the increased risk of coagulation disorders and thrombotic events observed in COVID-19. While the potential implications of PCSK9 inhibition are promising, safety considerations and possible risks need careful evaluation. Hypocholesterolemia, drug interactions, and long-term safety are some of the key concerns that should be addressed. Clinical trials are needed to establish the efficacy and safety of PCSK9 inhibitors in COVID-19 patients and to determine the optimal timing and dosing for treatment. Future research opportunities encompass investigating the immune response, evaluating long-term safety, exploring combination therapy possibilities, and advancing personalized medicine approaches. Collaborative efforts from researchers, clinicians, and policymakers are essential to fully harness the therapeutic potential of PCSK9 inhibition and translate these findings into meaningful clinical outcomes.

All-trans retinoic acid acts as a dual-purpose inhibitor of SARS-CoV-2 infection and inflammation

Coronavirus disease 2019 (COVID-19) was an epidemic that effected human health caused by SARS-CoV-2 infection. All-trans retinoic acid (ATRA) has anti-inflammatory capability. In this article, we evaluated the effectiveness and revealed the molecular mechanism of ATRA for treating SARS-CoV-2 using deep learning, in vitro studies, multi-scale molecular modeling, and network pharmacology. The DeepDTA model suggested that ATRA would be effective against COVID-19. In vitro studies confirmed the antiviral activity of ATRA. Subsequently, multi-scale molecular modeling indicated that ATRA could binding to angiotensin converting enzyme 2 (ACE2), 3C-like protease (3CLpro), RNA dependent RNA polymerase (RdRp), helicase, and 3'-to-5' exonuclease by non-covalent interactions. Additionally, network pharmacology suggested that ATRA alleviated inflammatory response by regulating the IL-17 signaling pathway and binding with TNF, PTGS2, and MAPK1 directly. In summary, our findings provide the first evidence that ATRA suppresses the entry and replication of SARS-CoV-2, and regulates inflammatory response of host cells.

Identification of shared pathogenetic mechanisms between COVID-19 and IC through bioinformatics and system biology

COVID-19 increased global mortality in 2019. Cystitis became a contributing factor in SARS-CoV-2 and COVID-19 complications. The complex molecular links between cystitis and COVID-19 are unclear. This study investigates COVID-19-associated cystitis (CAC) molecular mechanisms and drug candidates using bioinformatics and systems biology. Obtain the gene expression profiles of IC (GSE11783) and COVID-19 (GSE147507) from the Gene Expression Omnibus (GEO) database. Identified the common differentially expressed genes (DEGs) in both IC and COVID-19, and extracted a number of key genes from this group. Subsequently, conduct Gene Ontology (GO) functional enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis on the DEGs. Additionally, design a protein-protein interaction (PPI) network, a transcription factor gene regulatory network, a TF miRNA regulatory network, and a gene disease association network using the DEGs. Identify and extract hub genes from the PPI network. Then construct Nomogram diagnostic prediction models based on the hub genes. The DSigDB database was used to forecast many potential molecular medicines that are associated with common DEGs. Assess the precision of hub genes and Nomogram models in diagnosing IC and COVID-19 by employing Receiver Operating Characteristic (ROC) curves. The IC dataset (GSE57560) and the COVID-19 dataset (GSE171110) were selected to validate the models' diagnostic accuracy. A grand total of 198 DEGs that overlapped were found and chosen for further research. FCER1G, ITGAM, LCP2, LILRB2, MNDA, SPI1, and TYROBP were screened as the hub genes. The Nomogram model, built using the seven hub genes, demonstrates significant utility as a diagnostic prediction model for both IC and COVID-19. Multiple potential molecular medicines associated with common DEGs have been discovered. These pathways, hub genes, and models may provide new perspectives for future research into mechanisms and guide personalised and effective therapeutics for IC patients infected with COVID-19.

The immune inflammation factors associated with disease severity and poor prognosis in patients with COVID-19: A retrospective cohort study

Coronavirus disease 2019 (COVID-19) is associated with immune dysregulation and cytokine storm. It is essential to explore the immune response characteristics of peripheral circulation in COVID-19 patients to reveal pathogenesis and predict disease progression. In this study, the levels of total immunoglobulins (IgG, IgM, IgA), complement (C3, C4)，lymphocyte subsets (CD3+ cell，CD4+ cell，CD8+ cell, NK cell, CD19+ cell and CD45+ cell) and cytokines (IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-17, IL-12p, IL-1β, TNF-α, IFN-α and IFN-γ) were retrospectively analyzed in COVID-19 patients. A total of 513 patients were enrolled in this study, cases were distributed according to clinical status as mild or moderate (n = 212), severe survivors (n = 197) and severe non-survivors (n = 104). IL-6, IL-8, IL-10 and IFN-γ were increased in severe patients compared with non-severe patients, despite decreased CD45+ cell, CD3+ cell, CD4+ cell, CD8+ cell, CD19+ cell, and NK cell. Compared with severe survivors, the levels of L-6, IL-8 and IL-10 in non-survivors increased significantly, and levels of C3, CD45+ cell, CD3+ cell，CD4+ cell，CD8+ cell, and NK cell decreased. Moreover, age, IL-8, IL-10, CD8+cells and NK cell were independent risk factors for the severity of COVID-19. Multivariable regression showed increasing odds ratio of in-hospital death associated with tumor, older age, higher IL-8 level, and decreasing odds ratio of in-hospital death associated with increased levels of CD8+cell and NK cell. Finally, patients with tumor, or high IL-6 or high IL-10 expression and lower CD8+ or lower NK levels exhibited a significantly shorter survival time. In conclusion, our study provides findings of the immunological characteristics associated with disease severity to predict the progression of COVID-19. The immune inflammation factors, such as IL-6, IL-8, IL-10, CD8+ cell and NK cell, could serve as excellent biomarkers for monitoring or predicting COVID-19 progression therapeutic to COVID-19 patients.

Decellularized diseased tissues: current state-of-the-art and future directions

Decellularized matrices derived from diseased tissues/organs have evolved in the most recent years, providing novel research perspectives for understanding disease occurrence and progression and providing accurate pseudo models for developing new disease treatments. Although decellularized matrix maintaining the native composition, ultrastructure, and biomechanical characteristics of extracellular matrix (ECM), alongside intact and perfusable vascular compartments, facilitates the construction of bioengineered organ explants in vitro and promotes angiogenesis and tissue/organ regeneration in vivo, the availability of healthy tissues and organs for the preparation of decellularized ECM materials is limited. In this paper, we review the research advancements in decellularized diseased matrices. Considering that current research focuses on the matrices derived from cancers and fibrotic organs (mainly fibrotic kidney, lungs, and liver), the pathological characterizations and the applications of these diseased matrices are mainly discussed. Additionally, a contrastive analysis between the decellularized diseased matrices and decellularized healthy matrices, along with the development in vitro 3D models, is discussed in this paper. And last, we have provided the challenges and future directions in this review. Deep and comprehensive research on decellularized diseased tissues and organs will promote in-depth exploration of source materials in tissue engineering field, thus providing new ideas for clinical transformation.

Microglia influence immune responses and restrict neurologic disease in response to central nervous system infection by a neurotropic murine coronavirus

Intracranial (i.c.) inoculation of susceptible mice with a glial-tropic strain of mouse hepatitis virus (JHMV), a murine coronavirus, results in an acute encephalomyelitis followed by viral persistence in white matter tracts accompanied by chronic neuroinflammation and demyelination. Microglia serve numerous functions including maintenance of the healthy central nervous system (CNS) and are among the first responders to injury or infection. More recently, studies have demonstrated that microglia aid in tailoring innate and adaptive immune responses following infection by neurotropic viruses including flaviviruses, herpesviruses, and picornaviruses. These findings have emphasized an important role for microglia in host defense against these viral pathogens. In addition, microglia are also critical in optimizing immune-mediated control of JHMV replication within the CNS while restricting the severity of demyelination and enhancing remyelination. This review will highlight our current understanding of the molecular and cellular mechanisms by which microglia aid in host defense, limit neurologic disease, and promote repair following CNS infection by a neurotropic murine coronavirus.

Human Placental Mesenchymal Stem Cells and Derived Extracellular Vesicles Ameliorate Lung Injury in Acute Respiratory Distress Syndrome Murine Model

This study investigates the therapeutic potential of human placental mesenchymal stem cells (P-MSCs) and their extracellular vesicles (EVs) in a murine model of acute respiratory distress syndrome (ARDS), a condition with growing relevance due to its association with severe COVID-19. We induced ARDS-like lung injury in mice using intranasal LPS instillation and evaluated histological changes, neutrophil accumulation via immunohistochemistry, bronchoalveolar lavage fluid cell count, total protein, and cytokine concentration, as well as lung gene expression changes at three time points: 24, 72, and 168 h. We found that both P-MSCs and EV treatments reduced the histological evidence of lung injury, decreased neutrophil infiltration, and improved alveolar barrier integrity. Analyses of cytokines and gene expression revealed that both treatments accelerated inflammation resolution in lung tissue. Biodistribution studies indicated negligible cell engraftment, suggesting that intraperitoneal P-MSC therapy functions mostly through soluble factors. Overall, both P-MSC and EV therapy ameliorated LPS-induced lung injury. Notably, at the tested dose, EV therapy was more effective than P-MSCs in reducing most aspects of lung injury.

Differences in leucocytes and inflammation-based indices among critically ill patients owing to SARS-CoV-2 variants during several successive waves of COVID-19 pandemic

BACKGROUND/AIM

Inflammatory indices are useful informative markers in assessing the severity of the COVID-19 disease course; however, their involvements during series waves of SARS-CoV-2 virus outbreaks in critical patients with COVID-19 remain unclear. Hence, we aimed to ascertain the changing dynamics of the combined inflammatory indices (NLR, dNLR, CLR, LMR, PLR, SII, and SIRI) and their associations with clinical outcomes in severe COVID-19 patients during serial waves of SARS-CoV-2.

PATIENTS AND METHODS

We retrospectively enrolled 163 severe COVID-19 patients admitted to the ICU during six SARS-CoV-2 waves.

RESULTS

We found that most of patients admitted to the ICU were from the fourth wave. Patients in the fourth wave were considerably younger and had the highest percentage of ARDS than other waves. The highest CRP was found in the first wave, while the lowest in patients admitted in the sixth wave. Although most of the COVID-19 waves were marked with leukocytosis, neutrophilia, and lymphocytopenia, the lowest of both NLR and dNLR were found in the fourth wave "Delta wave" and the lowest of both CLR and SII were observed in "Omicron wave". Interestingly, during most of the COVID-19 waves, the derived combined inflammatory ratio NLR, dNLR, CLR, SII and SIRI were sustained at high levels in fatal cases at the last day of hospitalization, while these indices declined in the alive group at the end of ICU hospitalization. No major difference was identified in lymphocyte count between admission and the last day of hospitalization in both deceased and recovered COVID-19 patients during Delta and Omicron waves. Moreover, patients admitted in the Omicron wave had less severe disease compared to those admitted in the Delta wave. The Kaplan-Meier analysis revealed no significant difference in survival rates or the probability of respiratory failure between six successive COVID-19 waves.

CONCLUSION

Taken together, our results showed marked differences in the alteration of nonspecific inflammation and damage in the adaptive immune response during the six serial SARS-CoV-2 waves. Considering the inflammatory response of infectious diseases, embedding inflammatory indices informative markers into routine clinical testing offers the potential to mitigate the impact of future pandemics of COVID-19 and other infectious diseases.

Functional principal component analysis and sparse-group LASSO to identify associations between biomarker trajectories and mortality among hospitalized SARS-CoV-2 infected individuals

BACKGROUND

A substantial body of clinical research involving individuals infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has evaluated the association between in-hospital biomarkers and severe SARS-CoV-2 outcomes, including intubation and death. However, most existing studies considered each of multiple biomarkers independently and focused analysis on baseline or peak values.

METHODS

We propose a two-stage analytic strategy combining functional principal component analysis (FPCA) and sparse-group LASSO (SGL) to characterize associations between biomarkers and 30-day mortality rates. Unlike prior reports, our proposed approach leverages: 1) time-varying biomarker trajectories, 2) multiple biomarkers simultaneously, and 3) the pathophysiological grouping of these biomarkers. We apply this method to a retrospective cohort of 12, 941 patients hospitalized at Massachusetts General Hospital or Brigham and Women's Hospital and conduct simulation studies to assess performance.

RESULTS

Renal, inflammatory, and cardio-thrombotic biomarkers were associated with 30-day mortality rates among hospitalized SARS-CoV-2 patients. Sex-stratified analysis revealed that hematogolical biomarkers were associated with higher mortality in men while this association was not identified in women. In simulation studies, our proposed method maintained high true positive rates and outperformed alternative approaches using baseline or peak values only with respect to false positive rates.

CONCLUSIONS

The proposed two-stage approach is a robust strategy for identifying biomarkers that associate with disease severity among SARS-CoV-2-infected individuals. By leveraging information on multiple, grouped biomarkers' longitudinal trajectories, our method offers an important first step in unraveling disease etiology and defining meaningful risk strata.

Antrodia cinnamomea May Interfere with the Interaction Between ACE2 and SARS-CoV-2 Spike Protein in vitro and Reduces Lung Inflammation in a Hamster Model of COVID-19

Purpose

Coronavirus disease 2019 (COVID-19) poses a global health challenge with widespread transmission. Growing concerns about vaccine side effects, diminishing efficacy, and religious-based hesitancy highlight the need for alternative pharmacological approaches. Our study investigates the impact of the ethanol extract of Antrodia cinnamomea (AC), a native medicinal fungus from Taiwan, on COVID-19 in both in vitro and in vivo contexts.

Methods

We measured the mRNA and protein levels of angiotensin-converting enzyme-2 (ACE2) in human lung cells using real-time reverse transcriptase-polymerase chain reaction and Western blotting, respectively. Additionally, we determined the enzymatic activity of ACE2 using the fluorogenic peptide substrate Mca-YVADAPK(Dnp)-OH. To assess the impact of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection, we used SARS-CoV-2 pseudovirus infections in human embryonic kidney 293T cells expressing ACE2 to measure infection rates. Furthermore, we evaluated the in vivo efficacy of AC in mitigating COVID-19 by conducting experiments on hamsters infected with the Delta variant of SARS-CoV-2.

Results

AC effectively decreased ACE2 mRNA and protein levels, a critical host receptor for the SARS-CoV-2 spike protein, in human lung cells. It also prevented the spike protein from binding to human lung cells. Dehydrosulphurenic acid, an isolate from AC, directly inhibited ACE2 protease activity with an inhibitory constant of 1.53 µM. In vitro experiments showed that both AC and dehydrosulphurenic acid significantly reduced the infection rate of SARS-CoV-2 pseudovirus. In hamsters infected with the Delta variant of SARS-CoV-2, oral administration of AC reduced body weight loss and improved lung injury. Notably, AC also inhibited IL-1β expression in both macrophages and the lung tissues of SARS-CoV-2-infected hamsters.

Conclusion

AC shows potential as a nutraceutical for reducing the risk of SARS-CoV-2 infection by disrupting the interaction between ACE2 and the SARS-CoV-2 spike protein, and for preventing COVID-19-associated lung inflammation.

The Inflammatory Profile Correlates with COVID-19 Severity and Mortality in Cancer Patients

BACKGROUND

The correlation of the inflammatory profile with the severity of the disease in neoplastic patients with SARS-CoV-2 infection was addressed.

METHODS

A database of 1537 patients hospitalized in the pneumology department was analyzed. After applying the inclusion and exclusion criteria, 83 patients (67% males, 33% females) were included.

RESULTS

Most of the analyzed patients were hospitalized with a moderate form of disease, explaining the significant percentage of 25% mortality. The frequency of the type of neoplasm was higher for lung cancer, followed by malignant colon tumor. We identified a significant association between the increased value of ferritin (p < 0.0001, OR = 22.31), fibrinogen (p = 0.009, OR = 13.41), and C-reactive protein (p = 0.01, OR = 7.65), respectively, and the level of severity of COVID-19. The results of the univariate logistic regression analysis for predicting the severity of the disease revealed that the increased values of ferritin (p = 0.001, OR = 22.31) and fibrinogen (p = 0.02, OR = 13.41) represent a risk for a serious negative prognosis of COVID-19.

CONCLUSIONS

Our study demonstrated that the value of the analyzed inflammatory parameters increased in direct proportion to the severity of the disease and that higher values were associated with increased mortality in the study group.

The emergence of SARS-CoV-2 lineages and associated saliva antibody responses among asymptomatic individuals in a large university community

SARS-CoV-2 (CoV2) infected, asymptomatic individuals are an important contributor to COVID transmission. CoV2-specific immunoglobulin (Ig)-as generated by the immune system following infection or vaccination-has helped limit CoV2 transmission from asymptomatic individuals to susceptible populations (e.g. elderly). Here, we describe the relationships between COVID incidence and CoV2 lineage, viral load, saliva Ig levels (CoV2-specific IgM, IgA and IgG), and ACE2 binding inhibition capacity in asymptomatic individuals between January 2021 and May 2022. These data were generated as part of a large university COVID monitoring program in Ohio, United States of America, and demonstrate that COVID incidence among asymptomatic individuals occurred in waves which mirrored those in surrounding regions, with saliva CoV2 viral loads becoming progressively higher in our community until vaccine mandates were established. Among the unvaccinated, infection with each CoV2 lineage (pre-Omicron) resulted in saliva Spike-specific IgM, IgA, and IgG responses, the latter increasing significantly post-infection and being more pronounced than N-specific IgG responses. Vaccination resulted in significantly higher Spike-specific IgG levels compared to unvaccinated infected individuals, and uninfected vaccinees' saliva was more capable of inhibiting Spike function. Vaccinees with breakthrough Delta infections had Spike-specific IgG levels comparable to those of uninfected vaccinees; however, their ability to inhibit Spike binding was diminished. These data are consistent with COVID vaccines having achieved hoped-for effects in our community, including the generation of mucosal antibodies that inhibit Spike and lower community viral loads, and suggest breakthrough Delta infections were not due to an absence of vaccine-elicited Ig, but instead limited Spike binding activity in the face of high community viral loads.

COVID-19 inactivated and non-replicating viral vector vaccines induce regulatory training phenotype in human monocytes under epigenetic control

Background

Trained immunity is the enhanced innate immune response resulting from exposure to pathogens or vaccines against an unrelated pathogen stimulus. Certain vaccines induce a memory like response in monocytes and NK cells, leading to modulation in cytokine production, metabolic changes, and modifications in histone patterns. Here, we hypothesized that vaccination against SARS-CoV-2 could induce the training of monocytes in addition to stimulating the adaptive immune response.

Methods

Therefore, we aimed to investigate the immunophenotyping, cytokine and metabolic profile of monocytes from individuals who were completely immunized with two doses of inactivated COVID-19 vaccine or non-replicating viral vector vaccine. Subsequently, we investigated the epigenetic mechanisms underlying monocyte immune training. As a model of inflammatorychallenge, to understand if the monocytes were trained by vaccination and how they were trained, cells were stimulated in vitro with the endotoxin LPS, an unrelated stimulus that would provoke the effects of training.

Results

When challenged in vitro, monocytes from vaccinated individuals produced less TNF-α and those who received inactivated vaccine produced less IL-6, whereas vaccination with non-replicating viral vector vaccine induced more IL-10. Inactivated vaccine increased classical monocyte frequency, and both groups showed higher CD163 expression, a hallmark of trained immunity. We observed increased expression of genes involved in glycolysis and reduced IRG1 expression in vaccinated subjects, a gene associated with the tolerance phenotype in monocytes. We observed that both vaccines reduced the chromatin accessibility of genes associated with the inflammatory response, the inactivated COVID-19 vaccine trained monocytes to a regulatory phenotype mediated by histone modifications in the IL6 and IL10 genes, while the non-replicating viral vector COVID-19 vaccine trained monocytes to a regulatory phenotype, mediated by histone modifications in the IL6, IL10, TNF, and CCL2 genes.

Conclusions

Our findings support the recognized importance of adopting vaccination against SARS CoV-2, which has been shown to be effective in enhancing the adaptive immune response against the virus and reducing mortality and morbidity rates. Here, we provide evidence that vaccination also modulates the innate immune response by controlling the detrimental inflammatory response to unrelated pathogen stimulation.

Potential interaction between the oral microbiota and COVID-19: a meta-analysis and bioinformatics prediction

Objectives

The purpose of this study was to evaluate available evidence on the association between the human oral microbiota and coronavirus disease 2019 (COVID-19) and summarize relevant data obtained during the pandemic.

Methods

We searched EMBASE, PubMed, and the Cochrane Library for human studies published up to October 2022. The main outcomes of the study were the differences in the diversity (α and β) and composition of the oral microbiota at the phylum and genus levels between patients with laboratory-confirmed SARS-CoV-2 infection (CPs) and healthy controls (HCs). We used the Human Protein Atlas (HPA), Gene Expression Profiling Interactive Analysis (GEPIA) database, Protein-protein interaction (PPI) network (STRING) and Gene enrichment analysis (Metascape) to evaluate the expression of dipeptidyl peptidase 4 (DPP4) (which is the cell receptor of SARS CoV-2) in oral tissues and evaluate its correlation with viral genes or changes in the oral microbiota.

Results

Out of 706 studies, a meta-analysis of 9 studies revealed a significantly lower alpha diversity (Shannon index) in CPs than in HCs (standardized mean difference (SMD): -0.53, 95% confidence intervals (95% CI): -0.97 to -0.09). Subgroup meta-analysis revealed a significantly lower alpha diversity (Shannon index) in older than younger individuals (SMD: -0.54, 95% CI: -0.86 to -0.23/SMD: -0.52, 95% CI: -1.18 to 0.14). At the genus level, the most significant changes were in Streptococcus and Neisseria, which had abundances that were significantly higher and lower in CPs than in HCs based on data obtained from six out of eleven and five out of eleven studies, respectively. DPP4 mRNA expression in the oral salivary gland was significantly lower in elderly individuals than in young individuals. Spearman correlation analysis showed that DPP4 expression was negatively correlated with the expression of viral genes. Gene enrichment analysis showed that DPP4-associated proteins were mainly enriched in biological processes, such as regulation of receptor-mediated endocytosis of viruses by host cells and bacterial invasion of epithelial cells.

Conclusion

The oral microbial composition in COVID-19 patients was significantly different from that in healthy individuals, especially among elderly individuals. DPP4 may be related to viral infection and dysbiosis of the oral microbiome in elderly individuals.

A novel hACE2 knock-in mouse model recapitulates pulmonary and intestinal SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission is responsible for the coronavirus disease 2019 (COVID-19) pandemic. SARS-CoV-2 uses the angiotensin-converting enzyme 2 (ACE2) receptor to enter the host, and the gastrointestinal tract is a potential infection site as this receptor is expressed on it. Multiple studies have indicated that an increasing number of COVID-19 patients presented with gastrointestinal symptoms that are highly associated with disease severity. Moreover, emerging evidence has demonstrated that alterations in the gut immune microenvironment induced by intestinal SARS-CoV-2 infection can regulate respiratory symptoms. Therefore, targeting the intestines may be a candidate therapeutic strategy in patients with COVID-19; however, no mouse model can serve as an appropriate infection model for the development of fatal pneumonia while mimicking intestinal infection. In this study, a novel human ACE2 knock-in (KI) mouse model (or hACE2-KI) was systemically compared with the popular K18-hACE2 mice; it showed differences in the distribution of lung and intestinal infections and pathophysiological characteristics. These newly generated hACE2-KI mice were susceptible to intranasal infection with SARS-CoV-2, and not only developed mild to severe lung injury, but also acquired intestinal infection. Consequently, this model can be a useful tool for studying intestinal SARS-CoV-2 infection and developing effective therapeutic strategies.

What's what in a pandemic? Virus, disease, and societal disaster must be differentiated

Viruses, the diseases they can trigger, and the possible associated societal disaster represent different entities. To engage with the complexities of viral pandemics, we need to recognize each entity by using a distinctive name.

Cellular and Molecular Mechanisms of Pathogenic and Protective Immune Responses to SARS-CoV-2 and Implications of COVID-19 Vaccines

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has devastated the world with coronavirus disease 2019 (COVID-19), which has imparted a toll of at least 631 million reported cases with 6.57 million reported deaths. In order to handle this pandemic, vaccines against SARS-CoV-2 have been developed and billions of doses of various vaccines have been administered. In the meantime, several antiviral drugs and other treatment modalities have been developed to treat COVID-19 patients. At the end of the day, it seems that anti-SARS-CoV-2 vaccines and newly developed antiviral drugs may be improved based on various new developments. COVID-19 represents a virus-induced, immune-mediated pathological process. The severity of the disease is related to the nature and properties of the host immune responses. In addition, host immunity plays a dominant role in regulating the extent of COVID-19. The present reality regarding the role of anti-SARS-CoV-2 vaccines, persistence of SARS-CoV-2 infection even three years after the initiation of the pandemic, and divergent faces of COVID-19 have initiated several queries among huge populations, policy makers, general physicians, and scientific communities. The present review aims to provide some information regarding the molecular and cellular mechanisms underlying SARS-CoV-2 infection.

Beneficial Effects of L-Arginine in Patients Hospitalized for COVID-19: New Insights from a Randomized Clinical Trial

We have recently demonstrated in a double-blind randomized trial the beneficial effects of L-Arginine in patients hospitalized for COVID-19. We hypothesize that one of the mechanisms underlying the favorable effects of L-Arginine is its action on inflammatory cytokines. To verify our hypothesis, we measured longitudinal plasma levels of pro-inflammatory and anti-inflammatory cytokines implied in the pathophysiology of COVID-19 in patients randomized to receive oral L-Arginine or placebo. The study was successfully completed by 169 patients. Patients in the L-Arginine arm had a reduced respiratory support evaluated at 10 and 20 days; moreover, the time to hospital discharge was significantly shorter in the L-Arginine group. The assessment of circulating cytokines revealed that L-Arginine significantly reduced the circulating levels of pro-inflammatory IL-2, IL-6, and IFN-γ and increased the levels of the anti-inflammatory IL-10. Taken together, these findings indicate that adding L-Arginine to standard therapy in COVID-19 patients markedly reduces the need of respiratory support and the duration of in-hospital stay; moreover, L-Arginine significantly regulates circulating levels of pro-inflammatory and anti-inflammatory cytokines.

Periodontitis and COVID-19: Immunological Characteristics, Related Pathways, and Association

Both periodontitis and Coronavirus disease 2019 (COVID-19) pose grave threats to public health and social order, endanger human life, and place a significant financial strain on the global healthcare system. Since the COVID-19 pandemic, mounting research has revealed a link between COVID-19 and periodontitis. It is critical to comprehend the immunological mechanisms of the two illnesses as well as their immunological interaction. Much evidence showed that there are many similar inflammatory pathways between periodontitis and COVID-19, such as NF-κB pathway, NLRP3/IL-1β pathway, and IL-6 signaling pathway. Common risk factors such as gender, lifestyle, and comorbidities contribute to the severity of both diseases. Revealing the internal relationship between the two diseases is conducive to the treatment of the two diseases in an emergency period. It is also critical to maintain good oral hygiene and a positive attitude during treatment. This review covers four main areas: immunological mechanisms, common risk factors, evidence of the association between the two diseases, and possible interventions and potential targets. These will provide potential ideas for drug development and clinical treatment of the two diseases.

Prognostic Value of Serum Interleukin-6 Level in Hypertensive Patients with COVID-19-Associated Pneumonia

Background. An interleukin-6 (IL-6) is a proinflammatory cytokine which plays an important role in COVID-19-associated hyperinflammation. Aim. This study aimed to assess the predictive ability of serum IL-6 levels for the development of severe/critical clinical conditions, a hypoxemic state requiring supplemental oxygen, and lethal outcomes in patients with COVID-19-associated pneumonia and arterial hypertension (AH). Materials and Methods. One hundred and thirty-five unvaccinated patients hospitalized for COVID-19-associated pneumonia were enrolled in the study. AH was diagnosed in 78.5% of cases. Pneumonia was confirmed radiologically. SARS-COV-2 as an etiological factor was confirmed by either PCR or ELISA. In addition to conventional laboratory tests, IL-6, ferritin, and soluble interleukin-2 levels were measured. Results. Among AH patients, the median levels of IL-6 were higher in non-survivors (95.1 [37.8 - 158.8] pg/mL) as compared to survivors (39.5 [13.6 - 81.1] pg/mL) (p=0.04). Among AH patients, the median serum level of IL-6 was 98.3 [37.8 - 158.8] pg/mL in critically ill patients, 41.7 [11.8 - 83.4] pg/mL in severely ill patients, 37.8 [13.6 - 74.4] pg/mL in moderately ill patients (p=0.051). The median serum level of IL-6 was lower at the time of discharge (6.5 [2.0 - 21.5] pg/mL) as compared to that on admission (43.2 [16.1 - 92.0] pg/mL) (p< 0.001). IL-6 level failed to predict severe/critical condition (AUC=0.59, p=0.13) and the need for supplemental oxygen (AUC=0.61, p=0.06); however, it might be used for the prediction of the lethal outcome (AUC=0.69, p=0.03). The cut-off value of IL-6 level for lethal outcome prediction of 91.0 pg/mL showed a sensitivity of 58.3% and a specificity of 78.7%. Patients with IL-6 levels > 91.0 pg/mL on admission had higher odds of lethal outcomes (OR = 4.87 [1.40 - 16.92], p=0.01). Conclusions. Serum IL-6 level on admission did not show significant predictive ability for severe/critical conditions and hypoxemic states requiring supplemental oxygen in AH patients. However, serum IL-6 levels on admission were higher in non-survivors and might be used for the prediction of lethal outcomes with a cut-off value of 91.0 pg/mL in AH patients.

Palmitoylethanolamide Reduces Proinflammatory Markers in Unvaccinated Adults Recently Diagnosed with COVID-19: A Randomized Controlled Trial

BACKGROUND

Inflammation is at the core of many chronic conditions and exacerbates infectious conditions, including the severity of coronavirus disease 2019 (COVID-19) infections.

OBJECTIVES

This study aimed to examine the effects of a novel food supplement, palmitoylethanolamide (PEA), specifically Levagen+, as compared with a placebo on proinflammatory biomarkers in adults recently diagnosed with COVID-19 who were unvaccinated and nonhospitalized.

METHODS

This study was a double-blind randomized placebo-controlled trial conducted October 2020-March 2021 (clinicaltrials.gov: NCT04912921). Participants aged 19-53 y were unvaccinated and recently infected with COVID-19 as indicated by a positive test result per RT-PCR or antigen test, and they reported to the test site following diagnosis as allowed by the CDC's return-to-work policy. Participants were stratified by age, sex, and BMI and randomly assigned by coin toss to receive 600 mg Levagen+ twice daily (LEV) or placebo tablets twice daily (CON) for 4 wk. At baseline and week 4, participants completed health histories, 24-h dietary recalls, anthropometrics, and nonfasting blood sampling. The primary outcomes were the 4-wk change between groups for IL-6, C-reactive protein, ferritin, intercellular adhesion molecule 1, soluble P-selectin (sP-selectin), and neutrophil/lymphocyte ratio. Multiple linear regression models were utilized to assess treatment effects on outcomes, adjusting for covariates.

RESULTS

A total of 60 participants completed the study (LEV: n = 30; CON: n = 30). After 4 wk of supplementation, sP-selectin (β = -11.5; 95% CI: -19.8, -3.15; P = 0.0078), IL-1β (β = -22.9; 95% CI: -42.4, -3.40; P = 0.0222), and IL-2 (β = -1.73; 95% CI: -3.45, -0.065; P = 0.0492) concentrations were significantly reduced in the LEV group compared with the CON group.

CONCLUSIONS

Inflammatory mechanisms are crucial to optimal resolution of infectious conditions, yet unchecked secretion of inflammatory mediators can promote the dysregulated immune response implicated in COVID-19 complications. Overall, PEA supplementation produced anti-inflammatory effects in individuals recently diagnosed with COVID-19 who were nonhospitalized.

Recent clinical findings on the role of kinase inhibitors in COVID-19 management

The highly pathogenic, novel coronavirus disease (COVID-19) outbreak has emerged as a once-in-a-century pandemic with poor consequences, urgently calling for new therapeutics, cures, and supportive interventions. It has already affected over 250 million people worldwide; thereby, there is a need for novel therapies to alleviate the related complications. There is a paradigm shift in developing drugs and clinical practices to combat COVID-19. Several clinical trials have been performed or are testing diverse pharmacological interventions to alleviate viral load and complications such as cytokine release storm (CRS). Kinase-inhibitors have appeared as potential antiviral agents for COVID-19 patients due to their efficacy against CRS. Combination of kinase inhibitors with other therapies can achieve more efficacy against COVID-19. Based on the pre-clinical trials, kinase inhibitors such as Janus kinase-signal transducer and activator of transcription (JAK/STAT) inhibitors, Brutton's tyrosin kinase (BTK) inhibitors, p38 mitogen-activated protein kinases (p38 MAPK) inhibitors, Glycogen synthase kinase 3 (GSK-3) inhibitors can be a promising strategy against COVID-19. Kinase inhibitors possess crucial pharmacological properties for a successful re-purposing in terms of dual anti-inflammatory and anti-viral effects. This review will address the current clinical evidence and the newest discovery regarding the application of kinase inhibitors in COVID-19. An outlook on ongoing clinical trials (clinicaltrials.gov) and unpublished data is also presented here. Besides, Kinase inhibitors' function on COVID-19-mediated CRS is discussed.

Coronavirus Infection 2019 (COVID-19) and Autoimmunity

The pandemic of coronavirus disease 2019, etiologically associated with the SARS-CoV-2 virus, has drawn the attention of the medical community to new clinical and fundamental problems in the immunopathology of human diseases. During a detailed analysis of the clinical manifestations and immunopathological disorders in COVID-19, it became apparent that SARS-CoV-2 infection is accompanied by the development of a wide range of extrapulmonary clinical and laboratory disorders, some of which are characteristic of immunoinflammatory rheumatic diseases and other human autoimmune and autoinflammatory diseases. All this taken together served as a theoretical justification for the repositioning of anti-inflammatory drugs in COVID-19, previously specifically designed for the treatment of immunoinflammatory rheumatic diseases. The prospects for studying the autoimmune mechanisms of COVID-19 and the possibility of anti-inflammatory therapy are discussed.

Pathogenic Mechanism and Multi-omics Analysis of Oral Manifestations in COVID-19

Coronavirus disease 2019 (COVID-19) is a respiratory infectious disease that seriously threatens human life. The clinical manifestations of severe COVID-19 include acute respiratory distress syndrome and multiple organ failure. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causal agent of COVID-19, spreads through contaminated droplets. SARS-CoV-2 particles have been detected in the saliva of COVID-19 patients, implying that the virus can infect and damage the oral cavity. The oral manifestations of COVID-19 include xerostomia and gustatory dysfunction. Numerous studies showed that the four structural proteins of SARS-CoV-2 are its potential pathogenic factors, especially the S protein, which binds to human ACE2 receptors facilitating the entry of the virus into the host cells. Usually, upon entry into the host cell, a pathogen triggers the host’s immune response. However, a mount of multi-omics and immunological analyses revealed that COVID-19 is caused by immune dysregulation. A decrease in the number and phenotypes of immune cells, IFN-1 production and excessive release of certain cytokines have also been reported. In conclusion, this review summarizes the oral manifestations of COVID-19 and multi-omics analysis of SARS-CoV-2 infection.

The AI-Assisted Identification and Clinical Efficacy of Baricitinib in the Treatment of COVID-19

During the current pandemic, the vast majority of COVID-19 patients experienced mild symptoms, but some had a potentially fatal aberrant hyperinflammatory immune reaction characterized by high levels of IL-6 and other cytokines. Modulation of this immune reaction has proven to be the only method of reducing mortality in severe and critical COVID-19. The anti-inflammatory drug baricitinib (Olumiant) has recently been strongly recommended by the WHO for use in COVID-19 patients because it reduces the risk of progressive disease and death. It is a Janus Kinase (JAK) 1/2 inhibitor approved for rheumatoid arthritis which was suggested in early 2020 as a treatment for COVID-19. In this review the AI-assisted identification of baricitinib, its antiviral and anti-inflammatory properties, and efficacy in clinical trials are discussed and compared with those of other immune modulators including glucocorticoids, IL-6 and IL-1 receptor blockers and other JAK inhibitors. Baricitinib inhibits both virus infection and cytokine signalling and is not only important for COVID-19 management but is “non-immunological”, and so should remain effective if new SARS-CoV-2 variants escape immune control. The repurposing of baricitinib is an example of how advanced artificial intelligence (AI) can quickly identify new drug candidates that have clinical benefit in previously unsuspected therapeutic areas.

Janus kinase inhibitors in immunoinflammatory diseases: 10 years of clinical practice in rheumatology

Despite great advances in the diagnosis and treatment of Immune-mediated inflammatory diseases (IMIDs), which have led to a significant improvement in the prognosis in many patients, the central medical problems of this pathology – restoring the quality of life and reducing mortality to the population level – are far from being resolved. This served as a powerful stimulus for the study of new approaches to the pharmacotherapy of IMIDs, one of which is associated with the discovery of targets for small-molecule therapeutics that inhibit intracellular “signaling” molecules JAKs (Janus kinases). The current achievements, trends and recommendations regarding the use of JAK inhibitors in the treatment of IMIDs and also in the hyper-response phase of COVID-19 are reviewed.

Skeletal Muscle and COVID-19: The Potential Involvement of Bioactive Sphingolipids

SARS-CoV-2 virus infection is the cause of the coronavirus disease 2019 (COVID-19), which is still spreading over the world. The manifestation of this disease can range from mild to severe and can be limited in time (weeks) or persist for months in about 30–50% of patients. COVID-19 is considered a multiple organ dysfunction syndrome and the musculoskeletal system manifestations are beginning to be considered of absolute importance in both COVID-19 patients and in patients recovering from the SARS-CoV-2 infection. Musculoskeletal manifestations of COVID-19 and other coronavirus infections include loss of muscle mass, muscle weakness, fatigue or myalgia, and muscle injury. The molecular mechanisms by which SARS-CoV-2 can cause damage to skeletal muscle (SkM) cells are not yet well understood. Sphingolipids (SLs) represent an important class of eukaryotic lipids with structural functions as well as bioactive molecules able to modulate crucial processes, including inflammation and viral infection. In the last two decades, several reports have highlighted the role of SLs in modulating SkM cell differentiation, regeneration, aging, response to insulin, and contraction. This review summarizes the consequences of SARS-CoV-2 infection on SkM and the potential involvement of SLs in the tissue responses to virus infection. In particular, we highlight the role of sphingosine 1-phosphate signaling in order to aid the prediction of novel targets for preventing and/or treating acute and long-term musculoskeletal manifestations of virus infection in COVID-19.

COVID-19 Critical Illness: A Data-Driven Review

The coronavirus disease 2019 (COVID-19) pandemic has posed unprecedented challenges in critical care medicine, including extreme demand for intensive care unit (ICU) resources and rapidly evolving understanding of a novel disease. Up to one-third of hospitalized patients with COVID-19 experience critical illness. The most common form of organ failure in COVID-19 critical illness is acute hypoxemic respiratory failure, which clinically presents as acute respiratory distress syndrome (ARDS) in three-quarters of ICU patients. Noninvasive respiratory support modalities are being used with increasing frequency given their potential to reduce the need for intubation. Determining optimal patient selection for and timing of intubation remains a challenge. Management of mechanically ventilated patients with COVID-19 largely mirrors that of non-COVID-19 ARDS. Organ failure is common and portends a poor prognosis. Mortality rates have improved over the course of the pandemic, likely owing to increasing disease familiarity, data-driven pharmacologics, and improved adherence to evidence-based critical care.