Neutrophil degranulation and myocardial infarction

Investigating the Correlation between Serum Amyloid A and Infarct-Related Artery Patency Prior to Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction Patients

Serum amyloid A (SAA) is a cardiovascular risk factor and may serve as a predictor of infarct-related artery (IRA) patency in patients with ST-segment elevation myocardial infarction (STEMI). We measured SAA levels in STEMI patients who underwent percutaneous coronary intervention (PCI) and investigated their association with IRA patency. According to the Thrombolysis in Myocardial Infarction (TIMI) flow grade, 363 STEMI patients undergoing PCI in our hospital were divided into an occlusion group (TIMI 0-2) and a patency group (TIMI 3). The SAA level before PCI was significantly higher in STEMI patients with IRA occluded than in those with patent ones. At a cutoff value of 36.9 mg/L, SAA had a sensitivity of 63.0% and a specificity of 90.6% (area under the ROC curve [AUC] = .833, 95% CI: .793-.873, P < .001). Multivariate logistic regression analysis showed that SAA was an independent predictor of IRA patency in STEMI patients before PCI (odds ratio [OR] = 1.041, 95% CI: 1.020-1.062, P < .001). SAA can be used as a potential predictor of IRA patency in STEMI patients before PCI.

Blood Cell Ratios Unveiled: Predictive Markers of Myocardial Infarction Prognosis

BACKGROUND

Even if the management and treatment of patients with non-ST-elevation myocardial infarction (NSTEMI) have significantly evolved, it is still a burgeoning disease, an active volcano with very high rates of morbidity and mortality. Therefore, novel management and therapeutic strategies for this condition are urgently needed. Lately, theories related to the role of various blood cells in NSTEMI have emerged, with most of this research having so far been focused on correlating the ratios between various leukocyte types (neutrophil/lymphocyte ratio-NLR, neutrophil/monocyte ratio-NMR). But what about erythrocytes? Is there an interaction between these cells and leukocytes, and furthermore, can this relationship influence NSTEMI prognosis? Are they partners in crime?

METHODS

Through the present study, we sought, over a period of sixteen months, to evaluate the neutrophil/red blood cell ratio (NRR), monocyte/red blood cell ratio (MRR) and lymphocyte/red blood cell ratio (LRR), assessing their potential role as novel prognostic markers in patients with NSTEMI.

RESULTS

There was a statistically significant correlation between the NRR, LRR, MRR and the prognosis of NSTEMI patients.

CONCLUSIONS

These new predictive markers could represent the start of future innovative therapies that may influence crosstalk pathways and have greater benefits in terms of cardiac repair and the secondary prevention of NSTEMI.

MiRNA-miRNA interaction network in peripheral blood of patients with myocardial infarction: a gene expression meta-analysis

In recent years, investigations have revealed that microRNAs (miRNAs) can bind together and form a miRNA-miRNA-mRNA regulatory network that alters the consequence of miRNA-mRNA interaction. If we consider the miRNA that binds to mRNA as the primary miRNA and the miRNA that binds to the primary miRNA as the secondary one, secondry miRNAs can act as master regulators upstream of primary miRNAs and their target mRNAs. One of the distinguishing characteristics of secondary miRNAs as master regulators within a diverse set of differentially expressed genes is the absence of direct target mRNA for them. Instead, these master regulators exclusively govern the regulation of miRNAs that target specific mRNAs. Through in silico analysis, we identified 18 miRNAs among 385 differentially expressed miRNAs (DEmiRNAs) with no direct target mRNAs among 58 differentially expressed mRNAs (DEmRNAs) in peripheral blood of patients with myocardial infarction (MI). Instead, these secondary miRNAs targeted 9 primary miRNAs that had 36 direct targets among 58 DEmRNAs. We found that one primary miRNA might be regulated by more than one secondary miRNAs and each secondary miRNA can target more than one primary miRNAs. Among identified miRNA-miRNA-mRNA networks miR-188-5p/miR-299-3p/natural killer cell granule protein (NKG7), miR-200a-3p/miR-199b-5p/granzyme B (GZMB), and miR-377-3p/miR-581/oviductal glycoprotein 1 (OVGP1) exhibited higher scors in terms of expression levels (>2-fold increase or decrease) and strengh of interactions (ΔG < -5). Given the extensive network of miRNA interactions, focusing on master regulators opens up avenues for identifying key regulatory nodes for more effective therapeutic strategies.

Yohimbine Treatment Alleviates Cardiac Inflammation/Injury and Improves Cardiac Hemodynamics by Modulating Pro-Inflammatory and Oxidative Stress Indicators

Acute myocarditis, also known as myocardial inflammation, is a self-limited condition caused by systemic infection with cardiotropic pathogens, primarily viruses, bacteria, or fungi. Despite significant research, inflammatory cardiomyopathy exacerbated by heart failure, arrhythmia, or left ventricular dysfunction and it has a dismal prognosis. In this study, we aimed to evaluate the therapeutic effect of yohimbine against lipopolysaccharide (LPS) induced myocarditis in rat model. The anti-inflammatory activity of yohimbine was assessed in in-vitro using RAW 264.7 and H9C2 cells. Myocarditis was induced in rats by injecting LPS (10 mg/kg), following the rats were treated with dexamethasone (2 mg/kg) or yohimbine (2.5, 5, and 10 mg/kg) for 12 h and their therapeutic activity was examined using various techniques. Yohimbine treatment significantly attenuated the LPS-mediated inflammatory markers expression in the in-vitro model. In-vivo studies proved that yohimbine treatment significantly reduced the LPS-induced increase of cardiac-specific markers, inflammatory cell counts, and pro-inflammatory markers expression compared to LPS-control samples. LPS administration considerably affected the ECG, RR, PR, QRS, QT, ST intervals, and hemodynamic parameters, and caused abnormal pathological parameters, in contrast, yohimbine treatment substantially improved the cardiac parameters, mitigated the apoptosis in myocardial cells and ameliorated the histopathological abnormalities that resulted in an improved survival rate. LPS-induced elevation of cardiac troponin-I, myeloperoxidase, CD-68, and neutrophil elastase levels were significantly attenuated upon yohimbine treatment. Further investigation showed that yohimbine exerts an anti-inflammatory effect partly by modulating the MAPK pathway. This study emphasizes yohimbine's therapeutic benefit against LPS-induced myocarditis and associated inflammatory markers response by regulating the MAPK pathway.

Differential gene expression patterns in ST-elevation Myocardial Infarction and Non-ST-elevation Myocardial Infarction

The ST-elevation Myocardial Infarction (STEMI) and Non-ST-elevation Myocardial Infarction (NSTEMI) might occur because of coronary artery stenosis. The gene biomarkers apply to the clinical diagnosis and therapeutic decisions in Myocardial Infarction. The aim of this study was to introduce, enrich and estimate timely the blood gene profiles based on the high-throughput data for the molecular distinction of STEMI and NSTEMI. The text mining data (50 genes) annotated with DisGeNET data (144 genes) were merged with the GEO gene expression data (5 datasets) using R software. Then, the STEMI and NSTEMI networks were primarily created using the STRING server, and improved using the Cytoscape software. The high-score genes were enriched using the KEGG signaling pathways and Gene Ontology (GO). Furthermore, the genes were categorized to determine the NSTEMI and STEMI gene profiles. The time cut-off points were identified statistically by monitoring the gene profiles up to 30 days after Myocardial Infarction (MI). The gene heatmaps were clearly created for the STEMI (high-fold genes 69, low-fold genes 45) and NSTEMI (high-fold genes 68, low-fold genes 36). The STEMI and NSTEMI networks suggested the high-score gene profiles. Furthermore, the gene enrichment suggested the different biological conditions for STEMI and NSTEMI. The time cut-off points for the NSTEMI (4 genes) and STEMI (13 genes) gene profiles were established up to three days after Myocardial Infarction. The study showed the different pathophysiologic conditions for STEMI and NSTEMI. Furthermore, the high-score gene profiles are suggested to measure up to 3 days after MI to distinguish the STEMI and NSTEMI.

Identification and Validation of Hub Genes Related to Neutrophil Extracellular Traps-Mediated Cell Damage During Myocardial Infarction

Purpose

Studies have shown that neutrophil-mediated formation of neutrophil extracellular traps (NETs) leads to increased inflammatory response and cellular tissue damage during myocardial infarction (MI). We aimed to identify and validate possible hub genes in the process of NETs-mediated cell damage.

Methods

We performed an immune cell infiltration analysis of the MI transcriptome dataset based on CIBERSORT and ssGSEA algorithms. Gene expression profiles of NETs formation (GSE178883) were used to analyze the physiological processes of peripheral blood neutrophils after phorbol myristate acetate (PMA) stimulation. Bioinformatics and machine learning algorithms were utilized to find candidate hub genes based on NETs-related genes and transcriptome datasets (GSE66360 and GSE179828). We generated the receiver operating curve (ROC) to evaluate the diagnostic value of hub genes. Next, the correlation between hub genes and immune cells was analyzed using CIBERSORT, ssGSEA and xCell algorithms. Finally, we used quantitative real-time PCR (qRT-PCR) and immunohistochemistry to verify gene expression.

Results

Immune cell infiltration analysis revealed that inflammatory cells such as neutrophils were highly expressed in the peripheral blood of patients with MI. Functional analysis of differentially expressed genes (DEGs) in GSE178883 indicated that the potential pathogenesis lies in immune terms. Using weighted gene co-expression network analysis (WGCNA) and machine learning algorithms, we finally identified the seven hub genes (FCAR, IL1B, MMP9, NFIL3, CXCL2, ICAM1, and ZFP36). The qRT-PCR results showed that IL-1B, MMP9, and NFIL3 mRNA expression was up-regulated in the MI group compared to the control. Immunohistochemical results showed high MMP9, IL-1B, and NFIL3 expression in the infarcted area compared to the non-infarcted area and sham-operated groups.

Conclusion

We identified seven hub genes associated with NETs-mediated cellular damage during MI. Our results may provide insights into the mechanisms of neutrophil-mediated cell injury during MI.

Circulating myeloid-derived MMP8 in stress susceptibility and depression

Psychosocial stress has profound effects on the body, including the immune system and the brain1,2. Although a large number of pre-clinical and clinical studies have linked peripheral immune system alterations to stress-related disorders such as major depressive disorder (MDD)3, the underlying mechanisms are not well understood. Here we show that expression of a circulating myeloid cell-specific proteinase, matrix metalloproteinase 8 (MMP8), is increased in the serum of humans with MDD as well as in stress-susceptible mice following chronic social defeat stress (CSDS). In mice, we show that this increase leads to alterations in extracellular space and neurophysiological changes in the nucleus accumbens (NAc), as well as altered social behaviour. Using a combination of mass cytometry and single-cell RNA sequencing, we performed high-dimensional phenotyping of immune cells in circulation and in the brain and demonstrate that peripheral monocytes are strongly affected by stress. In stress-susceptible mice, both circulating monocytes and monocytes that traffic to the brain showed increased Mmp8 expression following chronic social defeat stress. We further demonstrate that circulating MMP8 directly infiltrates the NAc parenchyma and controls the ultrastructure of the extracellular space. Depleting MMP8 prevented stress-induced social avoidance behaviour and alterations in NAc neurophysiology and extracellular space. Collectively, these data establish a mechanism by which peripheral immune factors can affect central nervous system function and behaviour in the context of stress. Targeting specific peripheral immune cell-derived matrix metalloproteinases could constitute novel therapeutic targets for stress-related neuropsychiatric disorders.

Prognostic implications of systemic immune-inflammation index in myocardial infarction patients with and without diabetes: insights from the NOAFCAMI-SH registry

BACKGROUND

It is well-known that systemic inflammation plays a crucial role in the pathogenesis and prognosis of acute myocardial infarction (AMI). The systemic immune-inflammation index (SII, platelet × neutrophil/lymphocyte ratio) is a novel index that is used for the characterization of the severity of systemic inflammation. Recent studies have identified the high SII level as an independent predictor of poor outcomes in patients with AMI. We aimed to investigate the prognostic implications of SII in AMI patients with and without diabetes mellitus (DM).

METHODS

We included 2111 patients with AMI from February 2014 to March 2018. Multivariable Cox regression analyses were performed to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) of all-cause death and cardiovascular (CV) death. Multiple imputation was used for missing covariates.

RESULTS

Of 2111 patients (mean age: 65.2 ± 12.2 years, 77.5% were males) analyzed, 789 (37.4%) had DM. Generalized additive model analyses showed that as the SII increased, the C-reactive protein and peak TnT elevated while the LVEF declined, and these associations were similar in patients with and without DM. During a median of 2.5 years of follow-up, 210 all-cause deaths and 154 CV deaths occurred. When treating the SII as a continuous variable, a higher log-transformed SII was significantly associated with increased all-cause mortality (HR: 1.57, 95%CI: 1.02-2.43) and CV mortality (HR: 1.85, 95%CI 1.12-3.05), and such an association was also significant in the diabetics (HRs and 95%CIs for all-cause death and CV death were 2.90 [1.40-6.01] and 3.28 [1.43-7.57], respectively) while not significant in the nondiabetics (Pinteraction for all-cause death and CV death were 0.019 and 0.049, respectively). Additionally, compared to patients with the lowest tertiles of SII, those with the highest tertiles of SII possessed significantly higher all-cause mortality (HR: 1.82, 95%CI 1.19-2.79) and CV mortality (HR: 1.82, 95%CI 1.19-2.79) after multivariable adjustment, and this relationship remained pronounced in the diabetics (HRs and 95%CIs for all-cause death and CV death were 2.00 [1.13-3.55] and 2.09 [1.10-3.98], respectively) but was not observed in the nondiabetics (HRs and 95%CIs for all-cause death and CV death were 1.21 [0.75-1.97] and 1.60 [0.89-2.90], respectively). Our restricted cubic splines analyses indicated a pronounced linear association between SII and mortality only in diabetics.

CONCLUSIONS

In AMI patients with DM, high SII is an independent predictor of poor survival and may be helpful for patient's risk stratification.

Induction of Collagenolytic MMP-8 and -9 Tissue Destruction Cascade in Mouth by Head and Neck Cancer Radiotherapy: A Cohort Study

The effect of head and neck cancer (HNC) radiotherapy (RT) on biomarkers is not known but there is a lot of potential for gaining more precise cancer treatments and less side effects. This cohort study investigated the levels and molecular forms of the matrix metalloproteinase (MMP) -8 and -9, tissue inhibitor of metalloproteinase (TIMP)-1, myeloperoxidase (MPO) and interleukin (IL)-6 in mouth-rinse samples as well as the clinical periodontal status in HNC patients (n = 21) receiving RT. Complete periodontal examinations were performed pre-RT and one month after RT. Mouth-rinse samples (pre-RT, after six weeks of RT and one month after RT) were assayed using a point-of-care-kit (PerioSafe®/ORALyzer® (Dentognostics GmbH, Jena, Germany)) for active MMP-8 and ELISA analysis for total MMP-8 and -9, MPO, TIMP-1, and IL-6 levels. Molecular forms of MMP-9 were assessed by gelatinolytic zymography and MMP-8 by western immunoblot. Significant changes were observed between the three time points in the mean levels of active and total MMP-8, active MMP-9, and IL-6. Their levels increased during the RT and decreased after the RT period. The aMMP-8 levels stayed elevated even one month after RT compared to the pre-RT. Clinical attachment loss, probing depths, and bleeding on probing were increased between pre- and post-calculations in periodontal status. Elevated inflammatory biomarker levels together with clinical recordings strongly suggest that RT eventually increases the risk to the periodontal tissue destruction by inducing the active proteolytical MMP-cascade, and especially by prolonged activity of collagenolytic aMMP-8. Eventually, the aMMP-8 point-of-care mouth-rinse test could be an easy, early detection tool for estimating the risk for periodontal damage by the destructive MMP-cascade in HNC patients with RT treatment.

The effect and mechanism of Huangqin-Baishao herb pair in the treatment of dextran sulfate sodium-induced ulcerative colitis

Background

The haungqing (Scutellariae Radix) and baishao (Paeoniae Radix Alba) herb pair (HBHP) is a common prescribed herbal formula or is added to other traditional Chinese medicine (TCM) prescriptions to treat ulcerative colitis (UC). However, the underlying mechanism is unclear.

Purpose

Elucidate the efficacy and potential mechanism of HBHP against UC.

Methods

First, The UC model of mice induced by dextran sulfate sodium (DSS) was established. The mice were randomly divided into Control group, DSS group, SASP group (390 mg/kg), and HPHP group (1.95 g/kg), with 8 mice per group. Drugs were administrated via oral gavage for 7 days. Then, Disease activity index (DAI), length of the colon, histopathology, and changes in inflammatory cytokines in colonic tissues were analyzed to assess the effect of HBHP on UC. Besides, Network pharmacology was applied to identify the active compounds, core targets of HBHP in the treatment of UC, and the corresponding signaling pathways to explore the underlying mechanisms. Finally, Western blot (WB), immunohistochemistry (IHC) and molecular docking were performed to validate the results.

Results

HBHP significantly reduced DAI score and decreased colon length shortening in DSS-induced UC mice. The administration of HBHP was able to effectively alleviated mucosal ulceration and epithelial destruction. In addition, HBHP treatment obviously - reduced the expressions of TNF-α, IL-6, and IL-1β in colon tissues (p < 0.05 or p < 0.01). 35 bioactive compounds and 290 HBHP targets related to UC were obtained. Among them 3 key active compounds (baicalein, panicolin, and norwogonin) with higher degree values in the drug-compound-target network and 21 hub genes (STAT3, JAK2, SRC, AKT1, PIK3CA, and VEGFA, etc.) were identified. KEGG enrichment analysis suggested that HBHP's mechanisms mainly involve the JAK-STAT pathway. Abnormal activation of JAK/STAT signaling is believed to be involved in the pathogeneses of UC. Notably, WB and IHC showed that HBHP significantly down-regulated the protein expression levels of p-JAK2 (p < 0.05) and p-STAT3 (p < 0.05 or p < 0.01). JAK2 and STAT3 might be core targets for the action of HBHP; this possibility was also supported by molecular docking.

Conclusions

HBHP could alleviate DSS-induced UC, reduce tissue inflammation, and its mechanism might primarily be achieved by inhibiting JAK2/STAT3 signaling pathway. Meanwhile, our work revealed that network pharmacology combined with experimental verification is a cogent means of studying the mechanism of TCM.

Lead activates neutrophil degranulation to induce early myocardial injury in mice

Lead (Pb) is a pervasive toxic metal contaminant associated with a high risk of myocardial injury. However, the precise mechanism underlying Pb-induced myocardial injury has yet to be fully elucidated. In this study, a murine model of Pb exposure (0, 1, 5, and 10 mg/kg) was employed to investigate the involvement of neutrophil degranulation in the induction of myocardial injury. Notably, serum levels of cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) increased significantly in Pb-exposed mice, whereas cTnI levels in cardiomyocytes decreased, suggesting that Pb exposure may cause early myocardial injury. Moreover, Pb exposure was found to promote neutrophil degranulation, as evidenced by elevated myeloperoxidase (MPO) and neutrophil elastase (NE) concentrations in both the serum of Pb-exposed workers and Pb-exposed mice, as well as the extracellular supernatant of neutrophils following exposure. However, we found that serum level of cTnI enhanced by Pb exposure is associated with increased NE levels in the serum, but not with MPO levels. Upon treatment with NE inhibitor (sivelestat), the serum level of cTnI markedly reduced in Pb-exposed mice, we found that early myocardial injury is associated with NE levels in the serum. At the molecular level, western blotting analysis revealed an upregulation of ERK1/2 expression in vitro following Pb exposure, suggesting that the activation of the ERK1/2 signaling pathway may underlie the participation of neutrophil degranulation in Pb-induced myocardial injury. In summary, our findings demonstrate that Pb exposure can initiate early myocardial injury by promoting the neutrophil degranulation process, thereby highlighting the potential role of this process in the pathogenesis of Pb-associated myocardial injury.

Single-Cell Meta-Analysis of Neutrophil Activation in Kawasaki Disease and Multisystem Inflammatory Syndrome in Children Reveals Potential Shared Immunological Drivers

BACKGROUND

Kawasaki disease (KD) and multisystem inflammatory syndrome in children (MIS-C) share similar clinical manifestations, including cardiovascular complications, suggesting similar underlying immunopathogenic processes. Aberrant neutrophil activation may play a crucial role in the shared pathologies of KD and MIS-C; however, the associated pathogenic mechanisms and molecular drivers remain unknown.

METHODS

We performed a single-cell meta-analysis of neutrophil activation with 103 pediatric single-cell transcriptomic peripheral blood mononuclear cell data across 9 cohorts, including healthy controls, KD, MIS-C, compared with dengue virus infection, juvenile idiopathic arthritis, and pediatric celiac disease. We used a series of computational analyses to investigate the shared neutrophil transcriptional programs of KD and MIS-C that are linked to systemic damage and cardiac pathologies, and suggested Food and Drug Administration-approved drugs to consider as KD and MIS-C treatment.

RESULTS

We meta-analyzed 521 950 high-quality cells. We found that blood signatures associated with risks of cardiovascular events are enriched in neutrophils of KD and MIS-C. We revealed the expansion of CD177+ neutrophils harboring hyperactivated effector functions in both KD and MIS-C, but not in healthy controls or in other viral-, inflammatory-, or immune-related pediatric diseases. KD and MIS-C CD177+ neutrophils had highly similar transcriptomes, marked by conserved signatures and pathways related to molecular damage. We found the induction of a shared neutrophil expression program, potentially regulated by SPI1 (Spi-1 proto-oncogene), which confers enhanced effector functions, especially neutrophil degranulation. CD177 and shared neutrophil expression program expressions were associated with acute stages and attenuated during KD intravenous immunoglobulin treatment and MIS-C recovery. Network analysis identified hub genes that correlated with the high activation of CD177+ neutrophils. Disease-gene association analysis revealed that the KD and MIS-C CD177+ neutrophils' shared expression program was associated with the development of coronary and myocardial disorders. Last, we identified and validated TSPO (translocator protein) and S100A12 (S100 calcium-binding protein A12) as main molecular targets, for which the Food and Drug Administration-approved drugs methotrexate, zaleplon, metronidazole, lorazepam, clonazepam, temazepam, and zolpidem, among others, are primary candidates for drug repurposing.

CONCLUSIONS

Our findings indicate that CD177+ neutrophils may exert systemic pathological damage contributing to the shared morbidities in KD and MIS-C. We uncovered potential regulatory drivers of CD177+ neutrophil hyperactivation and pathogenicity that may be targeted as a single therapeutic strategy for either KD or MIS-C.

P2X7 accelerate tissue fibrosis via metalloproteinase 8-dependent macrophage infiltration in a murine model of unilateral ureteral obstruction

Renal fibrosis is tightly associated with chronic kidney disease, irrespective of the underlying pathogenesis. We previously demonstrated mild antifibrotic effects of targeting the P2X7 receptor in a pyelonephritis model. Reduced P2X7 R-activation elevated the neutrophil-to-macrophage ratio, resulting in less matrix accumulation without affecting the initial tissue healing. Here, we test if this P2X7 R-dependent modification of matrix accumulation also applies to a noninfectious fibrosis model of unilateral ureteral obstruction (7dUUO) and whether the response is gender-dependent. We found that P2X7 -/- mice show reduced fibrosis compared to wild type after 7dUUO: the effect was most pronounced in females, with a 55% decrease in collagen deposition after 7dUUO (p < 0.0068). P2X7 R deficiency did not affect early fibrosis markers (TGF-β, α-SMA) or the renal infiltration of neutrophils. However, a UUO-induced increase in macrophages was observed in wildtypes only (p < 0.001), leaving the P2X7 -/- mice with ≈50% fewer CD68+ cells in the renal cortex (p = 0.018). In males, 7dUUO triggered an increase in diffusely interstitial scattering of the profibrotic, macrophage-attracting metalloproteinase MMP8 and showed significantly lower MMP8 tissue expression in both male and female P2X7 -/- mice (p < 0.0008). Thus, the P2X7 R is advocated as a late-stage fibrosis moderator by reducing neutrophil-dependent interstitial MMP8 release, resulting in less macrophage infiltration and reduced matrix accumulation.

Single-cell RNA sequencing reveals the effects of capsaicin in the treatment of sepsis-induced liver injury

Sepsis is a difficult-to-treat systemic condition in which liver dysfunction acts as both regulator and target. However, the dynamic response of diverse intrahepatic cells to sepsis remains poorly characterized. Capsaicin (CAP), a multifunctional chemical derived from chilli peppers, has recently been shown to potentially possess anti-inflammatory effects, which is also one of the main approaches for drug discovery against sepsis. We performed single-cell RNA transcriptome sequencing on 86,830 intrahepatic cells isolated from normal mice, cecal ligation and puncture-induced sepsis model mice and CAP-treated mice. The transcriptional atlas of these cells revealed dynamic changes in hepatocytes, macrophages, neutrophils, and endothelial cells in response to sepsis. Among the extensive crosstalk across these major subtypes, KC_Cxcl10 shared strong potential interaction with other cells when responding to sepsis. CAP mitigated the severity of inflammation by partly reversing these pathophysiologic processes. Specific cell subpopulations in the liver act collectively to escalate inflammation, ultimately causing liver dysfunction. CAP displays its health-promoting function by ameliorating liver dysfunction induced by sepsis. Our study provides valuable insights into the pathophysiology of sepsis and suggestions for future therapeutic gain.

Interferon-β decreases LPS-induced neutrophil recruitment to cardiac fibroblasts

Introduction: Cardiac fibroblasts (CF) are crucial cells in damaged heart tissues, expressing TLR4, IFN-receptor and responding to lipopolysaccharide (LPS) and interferon-β (IFN-β) respectively. While CF interact with immune cells; however, their relationship with neutrophils remains understudied. Additionally, theimpact of LPS and IFN-β on CF-neutrophil interaction is poorly understood. Methods: Isolated CF from adult rats were treated with LPS, with or without IFN-β. This study examined IL-8 secretion, ICAM-1 and VCAM-1 expression, and neutrophil recruitment, as well as their effects on MMPs activity. Results: LPS triggered increased IL-8 expression and secretion, along with elevated ICAM-1 and VCAM-1 expression, all of which were blocked by TAK-242. Pre-treatment with IFN-β countered these LPS effects. LPS treated CF showed higher neutrophil recruitment (migration and adhesion) compared to unstimulated CF, an effect prevented by IFN-β. Ruxolitinib blocked these IFN-β anti-inflammatory effects, implicating JAK signaling. Analysis of culture medium zymograms from CF alone, and CF-neutrophils interaction, revealed that MMP2 was mainly originated from CF, while MMP9 could come from neutrophils. LPS and IFN-β boosted MMP2 secretion by CF. MMP9 activity in CF was low, and LPS or IFN-β had no significant impact. Pre-treating CF with LPS, IFN-β, or both before co-culture with neutrophils increased MMP2. Neutrophil co-culture increased MMP9 activity, with IFN-β pre-treatment reducing MMP9 compared to unstimulated CF. Conclusion: In CF, LPS induces the secretion of IL-8 favoring neutrophils recruitment and these effects were blocked by IFN-. The results highlight that CF-neutrophil interaction appears to influence the extracellular matrix through MMPs activity modulation.

Neutrophils: a subgroup of neglected immune cells in ALS

Amyotrophic lateral sclerosis (ALS) is a chronic, progressive neurodegenerative disease characterized by the loss of motor neurons. Dysregulated peripheral immunity has been identified as a hallmark of ALS. Neutrophils, as the front-line responders of innate immunity, contribute to host defense through pathogen clearance. However, they can concurrently play a detrimental role in chronic inflammation. With the unveiling of novel functions of neutrophils in neurodegenerative diseases, it becomes essential to review our current understanding of neutrophils and to recognize the gap in our knowledge about their role in ALS. Thus, a detailed comprehension of the biological processes underlying neutrophil-induced pathogenesis in ALS may assist in identifying potential cell-based therapeutic strategies to delay disease progression.

Identifying immune cell infiltration and effective diagnostic biomarkers in Crohn's disease by bioinformatics analysis

Background

Crohn's disease (CD) has an increasing incidence and prevalence worldwide. It is currently believed that both the onset and progression of the disease are closely related to immune system imbalance and the infiltration of immune cells. The aim of this study was to investigate the molecular immune mechanisms associated with CD and its fibrosis through bioinformatics analysis.

Methods

Three datasets from the Gene Expression Omnibus data base (GEO) were downloaded for data analysis and validation. Single sample gene enrichment analysis (ssGSEA) was used to evaluate the infiltration of immune cells in CD samples. Immune cell types with significant differences were identified by Wilcoxon test and Least Absolute Shrinkage and Selection Operator (LASSO) regression analysis. Differentially expressed genes (DEGs) were screened and then subjected to Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional correlation analysis, as well as protein-protein interaction (PPI) network analysis. The cytoHubba program and the GSE75214 dataset were used to screen for hub genes and plot Receiver operating characteristic (ROC)curves to screen for possible biomarkers of CD based on diagnostic efficacy. The hub genes of CD were correlated with five significantly different immune cells. In addition, validation was performed by real time quantitative PCR (RT-qPCR) experiments in colonic tissue of CD intestinal fibrosis rats to further identify hub genes that are more related to CD intestinal fibrosis.

Results

The DEGs were analyzed separately by 10 algorithms and narrowed down to 9 DEGs after taking the intersection. 4 hub genes were further screened by the GSE75214 validation set, namely COL1A1, CXCL10, MMP2 and FGF2. COL1A1 has the highest specificity and sensitivity for the diagnosis of CD and is considered to have the potential to diagnose CD. Five immune cells with significant differences were screened between CD and health controls (HC). Through the correlation analysis between five kinds of immune cells and four biomarkers, it was found that CXCL10 was positively correlated with activated dendritic cells, effector memory CD8+ T cells. MMP2 was positively correlated with activated dendritic cells, gamma delta T cells (γδ T) and mast cells. MMP2 and COL1A1 were significantly increased in colon tissue of CD fibrosis rats.

Conclusion

MMP2, COL1A1, CXCL10 and FGF2 can be used as hub genes for CD. Among them, COL1A1 can be used as a biomarker for the diagnosis of CD. MMP2 and CXCL10 may be involved in the development and progression of CD by regulating activated dendritic cell, effector memory CD8+ T cell, γδ T cell and mast cell. In addition, MMP2 and COL1A1 may be more closely related to CD intestinal fibrosis.

Control of the post-infarct immune microenvironment through biotherapeutic and biomaterial-based approaches

Ischemic heart failure (IHF) is a leading cause of morbidity and mortality worldwide, for which heart transplantation remains the only definitive treatment. IHF manifests from myocardial infarction (MI) that initiates tissue remodeling processes, mediated by mechanical changes in the tissue (loss of contractility, softening of the myocardium) that are interdependent with cellular mechanisms (cardiomyocyte death, inflammatory response). The early remodeling phase is characterized by robust inflammation that is necessary for tissue debridement and the initiation of repair processes. While later transition toward an immunoregenerative function is desirable, functional reorientation from an inflammatory to reparatory environment is often lacking, trapping the heart in a chronically inflamed state that perpetuates cardiomyocyte death, ventricular dilatation, excess fibrosis, and progressive IHF. Therapies can redirect the immune microenvironment, including biotherapeutic and biomaterial-based approaches. In this review, we outline these existing approaches, with a particular focus on the immunomodulatory effects of therapeutics (small molecule drugs, biomolecules, and cell or cell-derived products). Cardioprotective strategies, often focusing on immunosuppression, have shown promise in pre-clinical and clinical trials. However, immunoregenerative therapies are emerging that often benefit from exacerbating early inflammation. Biomaterials can be used to enhance these therapies as a result of their intrinsic immunomodulatory properties, parallel mechanisms of action (e.g., mechanical restraint), or by enabling cell or tissue-targeted delivery. We further discuss translatability and the continued progress of technologies and procedures that contribute to the bench-to-bedside development of these critically needed treatments.

Peripheral immune-derived matrix metalloproteinase promotes stress susceptibility

Psychosocial stress has profound effects on the body, including the peripheral immune system and the brain1,2. Although a large number of pre-clinical and clinical studies have linked peripheral immune system alterations to stress-related disorders such as major depressive disorder (MDD)3,4,5, the underlying mechanisms are not well understood. Here we show that a peripheral myeloid cell-specific proteinase, matrix metalloproteinase 8 (MMP8), is elevated in serum of subjects with MDD as well as in stress-susceptible (SUS) mice following chronic social defeat stress (CSDS). In mice, we show that this increase leads to alterations in extracellular space and neurophysiological changes in the nucleus accumbens (NAc), thereby altering social behaviour. Using a combination of mass cytometry and single-cell RNA-sequencing, we performed high-dimensional phenotyping of immune cells in circulation and brain and demonstrate that peripheral monocytes are strongly affected by stress. Both peripheral and brain-infiltrating monocytes of SUS mice showed increased Mmp8 expression following CSDS. We further demonstrate that peripheral MMP8 directly infiltrates the NAc parenchyma to control the ultrastructure of the extracellular space. Depleting MMP8 prevented stress-induced social avoidance behaviour and alterations in NAc neurophysiology and extracellular space. Collectively, these data establish a novel mechanism by which peripheral immune factors can affect central nervous system function and behaviour in the context of stress. Targeting specific peripheral immune cell-derived matrix metalloproteinases could constitute novel therapeutic targets for stress-related neuropsychiatric disorders.

The Innate Immune System in Cardiovascular Diseases and Its Role in Doxorubicin-Induced Cardiotoxicity

Innate immune cells are the early responders to infection and tissue damage. They play a critical role in the initiation and resolution of inflammation in response to insult as well as tissue repair. Following ischemic or non-ischemic cardiac injury, a strong inflammatory response plays a critical role in the removal of cell debris and tissue remodeling. However, persistent inflammation could be detrimental to the heart. Studies suggest that cardiac inflammation and tissue repair needs to be tightly regulated such that the timely resolution of the inflammation may prevent adverse cardiac damage. This involves the recognition of damage; activation and release of soluble mediators such as cytokines, chemokines, and proteases; and immune cells such as monocytes, macrophages, and neutrophils. This is important in the context of doxorubicin-induced cardiotoxicity as well. Doxorubicin (Dox) is an effective chemotherapy against multiple cancers but at the cost of cardiotoxicity. The innate immune system has emerged as a contributor to exacerbate the disease. In this review, we discuss the current understanding of the role of innate immunity in the pathogenesis of cardiovascular disease and dox-induced cardiotoxicity and provide potential therapeutic targets to alleviate the damage.

Severe, but not moderate asthmatics share blood transcriptomic changes with post-traumatic stress disorder and depression

Asthma, an inflammatory disorder of the airways, is one of the most common chronic illnesses worldwide and is associated with significant morbidity. There is growing recognition of an association between asthma and mood disorders including post-traumatic stress disorder (PTSD) and major depressive disorder (MDD). Although there are several hypotheses regarding the relationship between asthma and mental health, there is little understanding of underlying mechanisms and causality. In the current study we utilized publicly available datasets of human blood mRNA collected from patients with severe and moderate asthma, MDD, and PTSD. We performed differential expression (DE) analysis and Gene Set Enrichment Analysis (GSEA) on diseased subjects against the healthy subjects from their respective datasets, compared the results between diseases, and validated DE genes and gene sets with 4 more independent datasets. Our analysis revealed that commonalities in blood transcriptomic changes were only found between the severe form of asthma and mood disorders. Gene expression commonly regulated in PTSD and severe asthma, included ORMDL3 a gene known to be associated with asthma risk and STX8, which is involved in TrkA signaling. We also identified several pathways commonly regulated to both MDD and severe asthma. This study reveals gene and pathway regulation that potentially drives the comorbidity between severe asthma, PTSD, and MDD and may serve as foci for future research aimed at gaining a better understanding of both the relationship between asthma and PTSD, and the pathophysiology of the individual disorders.

Doxorubicin-induced cardiotoxicity is mediated by neutrophils through release of neutrophil elastase

The mechanisms by which Doxorubicin (Dox) causes acute and late cardiotoxicity are not completely understood. One understudied area is the innate immune response, and in particular the role of neutrophils in Dox-induced cardiotoxicity. Here, using echocardiography, flow cytometry and immunofluorescence staining, we demonstrated increased infiltration of neutrophils that correlated with decreased heart function, disruption of vascular structures and increased collagen deposition in the heart after Dox treatment. Depleting neutrophils protected the heart from Dox-induced cardiotoxicity and changes in vascular structure. Furthermore, our data using neutrophil elastase (NE) knock-out mice and the NE inhibitor AZD9668 suggest that neutrophils cause this damage by releasing NE and that inhibiting NE can prevent Dox-induced cardiotoxicity. This work shows the role of neutrophils and NE in Doxorubicin-induced cardiotoxicity for the first time and suggests a new possible therapeutic intervention.

Approaches for neutrophil imaging: an important step in personalized medicine

Neutrophils are the most abundant circulating leukocytes and the first line of defense against invading pathogens. They are key components of the innate immune system. Neutrophils also cause tissue damage in various autoimmune and inflammatory diseases and play an important role in cancer progression. Due to the complex relationship between various diseases and neutrophils, these cells have become potentially important targets for therapeutic interventions. Monitoring neutrophils in the tumor microenvironment is critical for tumor treatment and prognostic analysis but remains challenging. Molecular imaging technology has made great progress as a valuable tool for noninvasively visualizing biological events and establishing effective cancer diagnoses and treatment methods. Molecular probes designed based on the characteristics of neutrophils, such as their flexible morphology, the abundance of surface receptors, and the absence of immunogenicity, have shown great potential. This has created an opportunity for novel ideas and research methods for the diagnosis and targeted therapy of inflammatory diseases and tumors, with the goal of integrated diagnosis and treatment. This review discusses the diverse tumor detection and diagnostic imaging strategies based on neutrophils. It is anticipated that neutrophil-based imaging will soon be gradually integrated into clinical applications.