Dysregulated Inflammatory Response Research Articles

CD5L as a promising biological therapeutic for treating sepsis

Sepsis results from systemic, dysregulated inflammatory responses to infection, culminating in multiple organ failure. Here, we demonstrate the utility of CD5L for treating experimental sepsis caused by cecal ligation and puncture (CLP). We show that CD5L’s important features include its ability to enhance neutrophil recruitment and activation by increasing circulating levels of CXCL1, and to promote neutrophil phagocytosis. CD5L-deficient mice exhibit impaired neutrophil recruitment and compromised bacterial control, rendering them susceptible to attenuated CLP. CD5L-/- peritoneal cells from mice subjected to medium-grade CLP exhibit a heightened pro-inflammatory transcriptional profile, reflecting a loss of control of the immune response to the infection. Intravenous administration of recombinant CD5L (rCD5L) in immunocompetent C57BL/6 wild-type (WT) mice significantly ameliorates measures of disease in the setting of high-grade CLP-induced sepsis. Furthermore, rCD5L lowers endotoxin and damage-associated molecular pattern (DAMP) levels, and protects WT mice from LPS-induced endotoxic shock. These findings warrant the investigation of rCD5L as a possible treatment for sepsis in humans.

Diagnostic accuracy of pancreatic stone protein in patients with sepsis: a systematic review and meta-analysis

BackgroundSepsis is a common syndrome of multiorgan system dysfunction secondary to the dysregulated inflammatory response to infection. The role of pancreatic stone protein (PSP) in diagnosing sepsis has been investigated in previous studies. The meta-analysis aimed to comprehensively investigate the diagnostic value of PSP in identifying sepsis.MethodsPubMed, Web of Science, Embase, Cochrane Library, and China National Knowledge Infrastructure (CNKI), were systematically searched. Studies investigating the diagnostic performance of PSP were included. Pooled sensitivity, specificity, positive Likelihood Ratio (+ LR) and negative Likelihood Ratio (-LR), diagnostic odds ratio (DOR), and area under the curve (AUC) of summary receiver operating characteristic (SROC) were calculated.ResultsThe sensitivity of PSP was 0.88 (95% CI: 0.77–0.94), and the pooled specificity was 0.78 (95% CI: 0.65–0.87). Pooled + LR, -LR, and DOR were 4.1 (2.3, 7.3), 0.16 (0.07, 0.34), and 26 (7, 98). The AUC value for the SROC of PSP was 0.90 (0.87, 0.92). The pooled sensitivity, specificity, + LR and - LR, and DOR for PSP among neonates were 0.91 (95% CI: 0.84, 0.96), 0.66 (95% CI: 0.58, 0.74), 3.97 (95% CI: 0.53, 29.58), 0.13 (95% CI: 0.02, 1.00), and 31.27 (95% CI: 0.97, 1004.60).ConclusionsThis study indicates that PSP demonstrated favorable diagnostic accuracy in detecting sepsis. Well-designed studies are warranted to ascertain the value of PSP measurement to guide early empirical antibiotic treatment, particularly in neonates.

NLRP6 negatively regulates host defense against polymicrobial sepsis.

Sepsis remains a major cause of death in Intensive Care Units. Sepsis is a life-threatening multi-organ dysfunction caused by a dysregulated systemic inflammatory response. Pattern recognition receptors, such as TLRs and NLRs contribute to innate immune responses. Upon activation, some NLRs form multimeric protein complexes in the cytoplasm termed "inflammasomes" which induce gasdermin d-mediated pyroptotic cell death and the release of mature forms of IL-1β and IL-18. The NLRP6 inflammasome is documented to be both a positive and a negative regulator of host defense in distinct infectious diseases. However, the role of NLRP6 in polymicrobial sepsis remains elusive. We have used NLRP6 KO mice and human septic spleen samples to examine the role of NLRP6 in host defense in sepsis. NLRP6 KO mice display enhanced survival, reduced bacterial burden in the organs, and reduced cytokine/chemokine production. Co-housed WT and KO mice following sepsis show decreased bacterial burden in the KO mice as observed in singly housed groups. NLRP6 is upregulated in CD3, CD4, and CD8 cells of septic patients and septic mice. The KO mice showed a higher number of CD3, CD4, and CD8 positive T cell subsets and reduced T cell death in the spleen following sepsis. Furthermore, administration of recombinant IL-18, but not IL-1β, elicited excessive inflammation and reversed the survival advantages observed in NLRP6 KO mice. These results unveil NLRP6 as a negative regulator of host defense during sepsis and offer novel insights for the development of new treatment strategies for sepsis.

Clomiphene citrate administered in peri-conception phase causes fetal loss and developmental impairment in mice.

Clomiphene citrate is a common treatment for ovulation induction in subfertile women, but its use is associated with elevated risk of adverse perinatal outcomes and birth defects. To investigate the biological plausibility of a causal relationship, this study investigated in mice the consequences for fetal development and pregnancy outcome of peri-conception clomiphene citrate administration at doses approximating human exposures. A dose-dependent adverse effect of clomiphene citrate given twice in the 36 h after mating was seen, with a moderate dose of 0.75 mg/kg sufficient to cause altered reproductive outcomes in three independent cohorts. Viable pregnancy was reduced by 30%, late gestation fetal weight was reduced by 16%, and ∼30% of fetuses exhibited delayed development and/or congenital abnormalities not seen in control dams, including defects of the lung, kidney, liver, eye, skin, limbs, and umbilicus. Clomiphene citrate also caused a 30 h average delay in time of birth, and elevated rate of pup death in the early postnatal phase. In surviving offspring, growth trajectory tracking and body morphometry analysis at 20 weeks of age showed post-weaning growth and development comparable to controls. A dysregulated inflammatory response in the endometrium was observed and may contribute to the underlying pathophysiological mechanism. These results demonstrate that in utero exposure to clomiphene citrate during early pregnancy can inhibit implantation and impact fetal growth and development, causing adverse perinatal outcomes. The findings raise the prospect of similar iatrogenic effects in women where clomiphene citrate may be present in the peri-conception phase unless its use is well-supervised.

Recent alcohol intake impacts microbiota in adult burn patients

Alcohol use is associated with an increased incidence of negative health outcomes in burn patients due to biological mechanisms that include a dysregulated inflammatory response and increased intestinal permeability. This study used phosphatidylethanol (PEth) in blood, a direct biomarker of recent alcohol use, to investigate associations between a recent history of alcohol use and the fecal microbiota, short chain fatty acids, and inflammatory markers in the first week after a burn injury for nineteen participants. Burn patients were grouped according to PEth levels of low or high and differences in the overall fecal microbial community were observed between these cohorts. Two genera that contributed to the differences and had higher relative abundance in the low PEth burn patient group were Akkermansia, a mucin degrading bacteria that improves intestinal barrier function, and Bacteroides, a potentially anti-inflammatory bacteria. There was no statistically significant difference between levels of short chain fatty acids or intestinal permeability across the two groups. To our knowledge, this study represents the first report to evaluate the effects of burn injury and recent alcohol use on early post burn microbiota dysbiosis, inflammatory response, and levels of short chain fatty acids. Future studies in this field are warranted to better understand the factors associated with negative health outcomes and develop interventional trials.

Macrophage Polarization and Crosstalk between Macrophages and Other Cells in Hidradenitis Suppurativa

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic inflammatory disease characterized by the development of inflammatory nodules, abscesses, and pus-discharging tunnels in areas such as the axillary, inguinal, gluteal, and perianal regions. The pathogenesis of HS remains unclear, but it is being increasingly recognized to rely on the dysregulation of inflammatory responses. Central to this process are macrophages, which have emerged as key players in the inflammatory milieu of HS. These cells orchestrate inflammation via polarization and significantly influence the functions of neighboring cells. This review briefly describes macrophage polarization and crosstalk between macrophages and other cells in patients with HS with the aim of providing new therapeutic strategies for the clinical management of HS.

Therapeutic potential of procathepsin L-inhibiting and progesterone-entrapping dimethyl-β-cyclodextrin nanoparticles in treating experimental sepsis.

The pathogenic mechanisms of bacterial infections and resultant sepsis are partly attributed to dysregulated inflammatory responses sustained by some late-acting mediators including the procathepsin-L (pCTS-L). It was entirely unknown whether any compounds of the U.S. Drug Collection could suppress pCTS-L-induced inflammation, and pharmacologically be exploited into possible therapies. Here, we demonstrated that a macrophage cell-based screening of a U.S. Drug Collection of 1360 compounds resulted in the identification of progesterone (PRO) as an inhibitor of pCTS-L-mediated production of several chemokines [e.g., Epithelial Neutrophil-Activating Peptide (ENA-78), Monocyte Chemoattractant Protein-1 (MCP-1) or MCP-3] and cytokines [e.g., Interleukin-10 (IL-10) or Tumor Necrosis Factor (TNF)] in primary human peripheral blood mononuclear cells (PBMCs). In vivo, these PRO-entrapping 2,6-dimethal-β-cyclodextrin (DM-β-CD) nanoparticles (containing 1.35 mg/kg PRO and 14.65 mg/kg DM-β-CD) significantly increased animal survival in both male (from 30% to 70%, n = 20, P = 0.041) and female (from 50% to 80%, n = 30, P = 0.026) mice even when they were initially administered at 24h post the onset of sepsis. This protective effect was associated with a reduction of sepsis-triggered accumulation of three surrogate biomarkers [e.g., Granulocyte Colony Stimulating Factor (G-CSF) by 40%; Macrophage Inflammatory Protein-2 (MIP-2) by 45%; and Soluble Tumor Necrosis Factor Receptor I (sTNFRI) by 80%]. Surface Plasmon Resonance (SPR) analysis revealed a strong interaction between PRO and pCTS-L (KD = 78.2 ± 33.7 nM), which was paralleled with a positive correlation between serum PRO concentration and serum pCTS-L level (ρ = 0.56, P = 0.0009) or disease severity (Sequential Organ Failure Assessment, SOFA; ρ = 0.64, P = 0.0001) score in septic patients. Our observations support a promising opportunity to explore DM-β-CD nanoparticles entrapping lipophilic drugs as possible therapies for clinical sepsis.

Rapid Electrochemical Detection of Bacterial Sepsis in Cirrhotic Patients: A Microscaffold-Based Approach for Early Intervention.

Sepsis is a dysregulated inflammatory response leading to multiple organ failure. Current methods of sepsis detection are time-consuming, involving nonspecific clinical signs, biomarkers, and blood cultures. Hence, efficient and rapid sepsis detection platforms are of utmost need for immediate antibiotic treatment. In the current study, a noninvasive rapid monitoring electrochemical sensing (ECS) platform was developed for the detection and classification of plasma samples of patients with liver cirrhosis by measuring the current peak shifts using the cyclic voltammetry (CV) technique. A total of 61 hospitalized cirrhotic patients with confirmed (culture-positive) or suspected (culture-negative) sepsis were enrolled. The presence of bacteria in the plasma was observed by growth kinetics, and for rapidness, the samples were co-encapsulated in microscaffolds with carbon nanodots that were sensitive enough to detect redox changes occurring due to the change in the pH of the surrounding medium, causing shifts in current peaks in the voltammograms within 2 h. The percentage area under the curve for confirmed infections was 94 and that with suspected cases was 87 in comparison to 69 and 71 with PCT, respectively. Furthermore, the charge was measured for class identification. The charge for LPS-absent bacteria ranged from -400 to -600 μC, whereas the charge for LPS-containing bacteria class ranged from -290 to -300 μC. Thus, the developed cost-effective system was sensitive enough to detect and identify bacterial sepsis.

Pediatric sepsis inflammatory blood biomarkers that correlate with clinical variables and severity of illness scores

BackgroundSepsis is a dysregulated systemic inflammatory response triggered by infection, resulting in organ dysfunction. A major challenge in clinical pediatrics is to identify sepsis early and then quickly intervene to reduce morbidity and mortality. As blood biomarkers hold promise as early sepsis diagnostic tools, we aimed to measure a large number of blood inflammatory biomarkers from pediatric sepsis patients to determine their predictive ability, as well as their correlations with clinical variables and illness severity scores.MethodsPediatric patients that met sepsis criteria were enrolled, and clinical data and blood samples were collected. Fifty-eight inflammatory plasma biomarker concentrations were determined using immunoassays. The data were analyzed with both conventional statistics and machine learning.ResultsTwenty sepsis patients were enrolled (median age 13 years), with infectious pathogens identified in 75%. Vasopressors were administered to 85% of patients, while 55% received invasive ventilation and 20% were ventilated non-invasively. A total of 24 inflammatory biomarkers were significantly different between sepsis patients and age/sex-matched healthy controls. Nine biomarkers (IL-6, IL-8, MCP-1, M-CSF, IL-1RA, hyaluronan, HSP70, MMP3, and MMP10) yielded AUC parameters > 0.9 (95% CIs: 0.837-1.000; p < 0.001). Boruta feature reduction yielded 6 critical biomarkers with their relative importance: IL-8 (12.2%), MCP-1 (11.6%), HSP70 (11.6%), hyaluronan (11.5%), M-CSF (11.5%), and IL-6 (11.5%); combinations of 2 biomarkers yielded AUC values of 1.00 (95% CI: 1.00–1.00; p < 0.001). Specific biomarkers strongly correlated with illness severity scoring, as well as other clinical variables. IL-3 specifically distinguished bacterial versus viral infection (p < 0.005).ConclusionsSpecific inflammatory biomarkers were identified as markers of pediatric sepsis and strongly correlated to both clinical variables and sepsis severity.

Suppressing the Substance P-NK1R Signalling Protects Mice against Sepsis-Associated Acute Inflammatory Injury and Ferroptosis in the Liver and Lungs.

Substance P (SP), encoded by the TAC1/Tac1 gene, acts as a significant mediator in dysregulated systemic inflammatory response and associated organ injury in sepsis by activating the neurokinin-1 receptor (NK1R). This study investigated the impact of SP-NK1R signaling on ferroptosis in the liver and lungs of mice with sepsis. Sepsis was induced by caecal ligation puncture (CLP) surgery in mice. The SP-NK1R signaling was suppressed by Tac1 gene deletion, NK1R blockade, and a combination of these two approaches. The physiological conditions of mice were recorded. The profile of the SP-NK1R cascade, inflammatory response, ferroptosis, and tissue histology were investigated in the liver and lungs. Several manifestations of sepsis occurred in Tac1+/+ mice during the development of sepsis. Notably, hypothermia became significant four hours after the induction of sepsis. In the liver and lungs of mice subjected to CLP surgery, the concentrations of SP and NK1R were upregulated. Additionally, the concentrations of pro-inflammatory mediators, including cytokines (IL-1β, IL-6, and TNF-α) and chemokines (MCP-1 and MIP-2), were increased. Moreover, ferroptosis was elevated, as evidenced by increased concentrations of iron and MDA and reduced concentrations of GSH, Nrf2, and Gpx4. Suppressing the SP-NK1R cascade significantly mitigated CLP-surgery-induced alterations in mice. Importantly, these three approaches used to suppress SP-NK1R signaling showed similar effects on protecting mice against sepsis. In conclusion, increased SP-mediated acute inflammatory response and injury in the liver and lungs in mice with CLP-surgery-induced sepsis was associated with elevated ferroptosis. The detrimental effect of SP on sepsis was predominantly mediated by NK1R. Therefore, the suppression of increased SP-NK1R signaling and ferroptosis may be a promising adjuvant therapeutic candidate for sepsis and associated acute liver and lung injury.

Abstract 146: Trained Immunity Induced by Dietary Salt Impedes Long-Term Brain Recovery in Experimental Intracerebral Hemorrhage

Introduction: Excessive sodium intake is the top dietary risk factor for mortality and non-communicable diseases such as stroke. However, whether and how a high salt diet (HSD) impacts long-term stroke outcomes - even after salt reduction/withdrawal prior to a stroke is unknown. Methods: Intracerebral hemorrhage (ICH) was modeled by blood or collagenase injections in mice. Bone marrow (BM) progenitor and immune cell compositions as well as monocyte-derived macrophage (MDM) and microglial phenotypes were profiled using flow cytometry. BM chimeras were created to test innate immune memory. Glycolysis and OXPHOS were measured by Seahorse assays. Macrophage phagocytosis was evaluated using in vivo and in vitro erythrophagocytosis assays. RNA-seq was used to analyze the progenitor transcriptome. Hematoma, neuron loss, and astrogliosis were assessed with immunofluorescence. LysM Cre/+ : NR4a1 fl/fl ; Nr4a2 fl/fl ; NR4a3 -/- mice, LysM Cre/+ : NR4a1 fl/fl mice, and celastrol treatment were used to elucidate the mechanism underlying HSD-induced trained immunity. Results: HSD impaired long-term ICH recovery despite prior salt withdrawal. HSD triggered innate immune training in BM progenitor cells by downregulating the NR4a family and OXPHOS. This training selectively compromised MDM reparative polarization without altering their initial inflammatory response in the ICH brain. Healthy mice transplanted with BM from HSD-fed mice retained training signatures, confirming a persistent form of trained immunity that originates in the BM. Lack of NR4a1 in MDMs recapitulated HSD-induced negative impacts on ICH outcomes. Notably, transplantation of healthy BM and gain of NR4a1 function enabled stroke recovery in the HSD animals. Conclusions: These findings provide the first evidence that links HSD-induced trained immunity to the acquisition of persistent dysregulated inflammatory responses and unveil NR4a1 as a potential therapeutic target.

Systemic inflammatory response syndrome in patients with severe fever with thrombocytopenia syndrome: prevalence, characteristics, and impact on prognosis

BackgroundSevere fever with thrombocytopenia syndrome (SFTS) is an emerging zoonosis with a high fatality rate in China. Previous studies have reported that dysregulated inflammatory response is associated with disease pathogenesis and mortality in patients with SFTS. This investigation aimed to evaluate the prevalence and characteristics of systemic inflammatory response syndrome (SIRS), and its impact on prognosis.MethodsData on demographic characteristics, comorbid conditions, clinical manifestations, laboratory parameters, and survival time of patients with SFTS were collected. Patients were divided into the non-SIRS and SIRS groups according to the presence of SIRS, then their clinical data were compared.ResultsA total of 290 patients diagnosed with SFTS were retrospectively enrolled, including 126(43.4%) patients with SIRS. Patients in the non-survivor group had more prevalence of SIRS than patients in the survivor group (P < 0.001), and SIRS (adjusted OR 2.885, 95% CI 1.226–6.786; P = 0.005) was shown as an independent risk factor for prognosis of patients with SFTS. Compared with patients without SIRS, patients with SIRS had lower WBC and neutrophils counts, and fibrinogen levels, but higher AST, LDH, amylase, lipase, CK, CK-MB, troponin I, APTT, thrombin time, D-dimer, CRP, IL-6, SAA levels, and viral load. The cumulative survival rate of patients with SIRS was significantly lower than that of patients without SIRS. Patients with SIRS also showed a higher incidence of bacterial or fungal infections than patients without SIRS.ConclusionsSIRS is highly frequent in patients with SFTS, and it is associated with high mortality.

Association between altered tryptophan metabolism, plasma aryl hydrocarbon receptor agonists, and inflammatory Chagas disease.

Chagas disease causes a cardiac illness characterized by immunoinflammatory reactions leading to myocardial fibrosis and remodeling. The development of Chronic Chagas Cardiomyopathy (CCC) in some patients while others remain asymptomatic is not fully understood, but dysregulated inflammatory responses are implicated. The Aryl hydrocarbon receptor (AhR) plays a crucial role in regulating inflammation. Certain tryptophan (Trp) metabolites have been identified as AhR ligands with regulatory functions. We investigated AhR expression, agonist response, ligand production, and AhR-dependent responses, such as IDO activation and regulatory T (Treg) cells induction, in two T. cruzi-infected mouse strains (B6 and Balb/c) showing different polymorphisms in AhR. Furthermore, we assessed the metabolic profile of Trp catabolites and AhR agonistic activity levels in plasma samples from patients with chronic Chagas disease (CCD) and healthy donors (HD) using a luciferase reporter assay and liquid chromatography-mass spectrophotometry (LC-MS) analysis. T. cruzi-infected B6 mice showed impaired AhR-dependent responses compared to Balb/c mice, including reduced IDO activity, kynurenine levels, Treg cell induction, CYP1A1 up-regulation, and AhR expression following agonist activation. Additionally, B6 mice exhibited no detectable AhR agonist activity in plasma and displayed lower CYP1A1 up-regulation and AhR expression upon agonist activation. Similarly, CCC patients had decreased AhR agonistic activity in plasma compared to HD patients and exhibited dysregulation in Trp metabolic pathways, resulting in altered plasma metabolite profiles. Notably, patients with severe CCC specifically showed increased N-acetylserotonin levels in their plasma. The methods and findings presented here contribute to a better understanding of CCC development mechanisms and may identify potential specific biomarkers for T. cruzi infection and the severity of associated heart disease. These insights could be valuable in designing new therapeutic strategies. Ultimately, this research aims to establish the AhR agonistic activity and Trp metabolic profile in plasma as an innovative, non-invasive predictor of prognosis for chronic Chagas disease.

Safety and Reactogenicity of COVID-19 Vaccination in Severe Alpha-1 Antitrypsin Deficiency.

Patients with alpha-1 antitrypsin deficiency (AATD) exhibit dysregulated inflammatory responses and a predilection for autoimmunity. While the adverse event (AE) profiles of COVID-19 vaccines in several chronic inflammatory conditions are now available, safety and tolerability data for patients with severe AATD have yet to be described. The feasibility of coadministering vaccines against COVID-19 and influenza in this population is similarly unclear. We conducted a prospective study of 170 patients with Pi*ZZ genotype AATD receiving their initial vaccination series with ChAdOx1 nCoV-19 (AstraZeneca). Patients were monitored clinically for AEs over the week that followed their first and second doses. In parallel, we conducted the same assessments in patients with Pi*MM genotype chronic obstructive pulmonary disease (COPD) (n=160) and Pi*MM individuals without lung disease (n=150). The Pi*ZZ cohort was subsequently followed through 2 consecutive mRNA-based booster vaccines (monovalent and bivalent BNT162b2, Pfizer/BioNTech). To assess the safety of combined vaccination against COVID-19 and influenza, the quadrivalent influenza vaccine was administered to participants attending for their second COVID-19 booster vaccination, either on the same day or following a 1-week interval. Pi*ZZ AATD participants did not display increased AEs compared to Pi*MM COPD or Pi*MM non-lung disease controls. Although unexpected and serious vaccine-associated AEs did occur, the majority of AEs experienced across the 3 groups were mild and self-limiting. The AATD demographic at highest risk for AEs (especially systemic and prolonged AEs) was young females. No increase in AE risk was observed in patients with established emphysema, sonographic evidence of liver disease, or in those receiving intravenous augmentation therapy. AE incidence declined sharply following the initial vaccine series. Same-day coadministration of the COVID-19 mRNA bivalent booster vaccine and the annual influenza vaccine did not result in increased AEs compared to sequential vaccines 1 week apart. Despite their pro-inflammatory state, patients with severe AATD are not at increased risk of AEs or serious AEs compared to patients with nonhereditary COPD and patients without lung disease. Same-day coadministration of COVID-19 booster vaccines with the annual influenza vaccine is feasible, safe, and well-tolerated in this population.

Backpack-mediated anti-inflammatory macrophage cell therapy for the treatment of traumatic brain injury.

Traumatic brain injury (TBI) is a debilitating disease with no current therapies outside of acute clinical management. While acute, controlled inflammation is important for debris clearance and regeneration after injury, chronic, rampant inflammation plays a significant adverse role in the pathophysiology of secondary brain injury. Immune cell therapies hold unique therapeutic potential for inflammation modulation, due to their active sensing and migration abilities. Macrophages are particularly suited for this task, given the role of macrophages and microglia in the dysregulated inflammatory response after TBI. However, maintaining adoptively transferred macrophages in an anti-inflammatory, wound-healing phenotype against the proinflammatory TBI milieu is essential. To achieve this, we developed discoidal microparticles, termed backpacks, encapsulating anti-inflammatory interleukin-4, and dexamethasone for ex vivo macrophage attachment. Backpacks durably adhered to the surface of macrophages without internalization and maintained an anti-inflammatory phenotype of the carrier macrophage through 7 days in vitro. Backpack-macrophage therapy was scaled up and safely infused into piglets in a cortical impact TBI model. Backpack-macrophages migrated to the brain lesion site and reduced proinflammatory activation of microglia in the lesion penumbra of the rostral gyrus of the cortex and decreased serum concentrations of proinflammatory biomarkers. These immunomodulatory effects elicited a 56% decrease in lesion volume. The results reported here demonstrate, to the best of our knowledge, a potential use of a cell therapy intervention for a large animal model of TBI and highlight the potential of macrophage-based therapy. Further investigation is required to elucidate the neuroprotection mechanisms associated with anti-inflammatory macrophage therapy.

Prevention of lipid droplet accumulation by DGAT1 inhibition ameliorates sepsis-induced liver injury and inflammation

Lipid droplet (LD) accumulation in cells and tissues is understood to be an evolutionarily conserved tissue tolerance mechanism to prevent lipotoxicity caused by excess lipids; however, the presence of excess LDs has been associated with numerous diseases. Sepsis triggers the reprogramming of lipid metabolism and LD accumulation in cells and tissues, including the liver. The functions and consequences of sepsis-triggered liver LD accumulation are not well known. Experimental sepsis was induced by CLP (caecal ligation and puncture) in mice. Markers of hepatic steatosis, liver injury, hepatic oxidative stress, and inflammation were analysed using a combination of functional, imaging, lipidomic, protein expression and immune-enzymatic assays. To prevent LD formation, mice were treated orally with A922500, a pharmacological inhibitor of DGAT1. We identified that liver LD overload correlates with liver injury and sepsis severity. Moreover, the progression of steatosis from 24h to 48h post-CLP occurs in parallel with increased cytokine expression, inflammatory cell recruitment and oxidative stress. Lipidomic analysis of purified LDs demonstrated that sepsis leads LDs to harbour increased amounts of unsaturated fatty acids, mostly 18:1 and 18:2. An increased content of lipoperoxides within LDs was also observed. Conversely, the impairment of LD formation by inhibition of the DGAT1 enzyme reduces levels of hepatic inflammation and lipid peroxidation markers and ameliorates sepsis-induced liver injury. Our results indicate that sepsis triggers lipid metabolism alterations that culminate in increased liver LD accumulation. Increased LDs are associated with disease severity and liver injury. Moreover, inhibition of LD accumulation decreased the production of inflammatory mediators and lipid peroxidation while improving tissue function, suggesting that LDs contribute to the pathogenesis of liver injury triggered by sepsis. Sepsis is a complex life-threatening syndrome caused by dysregulated inflammatory and metabolic host responses to infection. The observation that lipid droplets may contribute to sepsis-associated organ injury by amplifying lipid peroxidation and inflammation provides a rationale for therapeutically targeting lipid droplets and lipid metabolism in sepsis.

Immunological and biochemical biomarker alterations among SARS-COV-2 patients with varying disease phenotypes in Uganda

Every novel infection requires an assessment of the host response coupled with identification of unique biomarkers for predicting disease pathogenesis, treatment targets and diagnostic utility. Studies have exposed dysregulated inflammatory response induced by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as significant predictor or cause of disease severity/prognosis and death. This study evaluated inflammatory biomarkers induced by SARS-CoV-2 in plasma of patients with varying disease phenotypes and healthy controls with prognostic or therapeutic potential. We stratified SARS-CoV-2 plasma samples based on disease status (asymptomatic, mild, severe, and healthy controls), as diagnosed by RT-PCR SARS-CoV-2. We used a solid phase sandwich and competitive Enzyme-Linked Immunosorbent Assay (ELISA) to measure levels of panels of immunological (IFN-γ, TNF-α, IL-6, and IL-10) and biochemical markers (Ferritin, Procalcitonin, C-Reactive Protein, Angiotensin II, Homocysteine, and D-dimer). Biomarker levels were compared across SARS-CoV-2 disease stratification. Plasma IFN-γ, TNF-α, IL-6, and IL-10 levels were significantly (P < 0.05) elevated in the severe SARS-CoV-2 patients as compared to mild, asymptomatic, and healthy controls. Ferritin, Homocysteine, and D-dimer plasma levels were significantly elevated in severe cases over asymptomatic and healthy controls. Plasma C-reactive protein and Angiotensin II levels were significantly (P < 0.05) higher in mild than severe cases and healthy controls. Plasma Procalcitonin levels were significantly higher in asymptomatic than in mild, severe cases and healthy controls. Our study demonstrates the role of host inflammatory biomarkers in modulating the pathogenesis of COVID-19. The study proposes a number of potential biomarkers that could be explored as SARS-CoV-2 treatment targets and possible prognostic predictors for a severe outcome. The comprehensive analysis of prognostic biomarkers may contribute to the evidence-based management of COVID-19 patients.

The potential role of extracorporeal cytokine removal with CytoSorb® as an adjuvant therapy in Acute Respiratory Distress Syndrome.

Management of acute respiratory distress syndrome (ARDS) represents one of the greatest challenges in intensive care and despite all efforts mortality remains high. One common phenotype of ARDS is that of a secondary injury to a dysregulated inflammatory host response resulting in increased capillary congestion, interstitial lung edema, atelectasis, pulmonary embolism, muscle wasting, recurring infectious episodes, and multiple organ failure. In cases of hyperinflammation, immunomodulation by extracorporeal cytokine removal such as the CytoSorb hemoadsorption cartridge could conceptually enhance lung recovery during the early course of the disease. The aim of this narrative review is to summarize the currently available data in this field and to provide an overview of pathophysiology and rationale for the use of CytoSorb hemoadsorption in patients with hyperinflammatory ARDS.

Proteomic Profiling and Cytokine Analysis Reveals Molecular Signatures and Inflammatory Factors Associated with Thrombosis in JAK2-V617F Positive Myeloproliferative Neoplasm (MPN) Cohorts

Background: Myeloproliferative neoplasms (MPNs), a hematological malignancy commonly associated with the JAK2-V617F mutation, exhibit a considerable burden of comorbidities resulting from inflammation-mediated processes. The JAK2-V617F malignant clones instigate systemic inflammation by upregulating various pro-inflammatory cytokines. This leads to dysregulated immune and inflammatory responses, thereby driving a process called thrombo-inflammation. Neutrophils play a crucial role as inflammatory mediators and effectors of pro-thrombotic activity in MPNs. We, therefore, hypothesize that perturbations in the neutrophil proteome may alter the molecular communication networks within neutrophils, thereby potentially contributing to the pathological thrombus formation in veins and arteries. Aim: The study was aimed to elucidate (i) the pathological significance of dysregulated protein expression profile of neutrophils carrying the JAK2-V617F mutation, and (ii) the impact of pro-inflammatory cytokines on neutrophils during thrombo-inflammation. Methods: In this study, which was conducted at the University Hospital Magdeburg, Germany, 11 patients carrying the JAK2-V617F mutation (6 with thrombosis; 5 without thrombosis) and 9 healthy volunteers were enrolled. Neutrophils were isolated from freshly collected whole blood using a negative selection kit. The isolated neutrophils were then lysed, and protein extraction was performed. High-resolution liquid chromatography - mass spectrometry (LC-MS/MS) was employed to investigate the protein inventory of neutrophils. Furthermore, platelet-poor plasma was isolated from the same cohort to analyse plasma cytokine/chemokine levels using a bead-based multiplex assay. Results: LC-MS/MS identified 2,006 proteins in neutrophils, which were then used for quantitative comparative analysis. Amongst these, 28 and 26 proteins exhibited significant up-regulation in the JAK2-V617F positive patients ‘with thrombosis’ and ‘without thrombosis’, respectively. Notably, ATP2A3 and ROCK1 were significantly upregulated in the JAK2-V617F thrombotic group, ranking among the top 10-upregulated proteins. Of note, ROCK1 activation has previously been implicated in cell proliferation, survival and cell cycle control. Functional annotation analysis using Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) revealed that upregulated proteins in the JAK2-V617F cohorts were significantly enriched for proteins involved in the calcium and TGF-ß signaling pathways. Furthermore, we assessed the levels of 60 cytokines/chemokines and soluble adhesion molecules in the same cohort, wherein significantly increased levels of ALCAM, ICAM-2 and VCAM-1 were observed in the JAK2-V617F thrombotic group. These molecules are known to play a critical role in vasculature-related inflammation and endothelial cell activation. Additionally, the JAK2-V617F thrombotic group exhibited significant upregulation of free active TGF-ß and pro-inflammatory cytokines such as IL-6 and IL-8 compared to both healthy subjects and JAK2-V617F non-thrombotic patients, indicating their contribution to the thrombo-inflammatory response. Moreover, the thrombotic cohort displayed elevated plasma levels of CXC chemokines and myeloperoxidase (MPO), a key enzyme linked to NETosis for neutrophil extracellular trap (NET) formation. Conclusions: The proteomic profile of neutrophils in MPN patients exhibit significant alterations, particularly between JAK2-V617F patients with and without thrombosis. The observed elevated expression of markers related to NETosis and calcium signaling pathways point towards the underlying mechanisms that could potentially contribute to the differential behavior of neutrophils, thereby facilitating the development of a thrombotic state in MPN patients.

Sepsis in cardiothoracic surgery

Sepsis is a life-changing condition that can occur in patients undergoing cardiothoracic surgery. It is characterized by a dysregulated inflammatory response to infection, often leading to higher rates of organ dysfunction and mortality. The importance of early recognition and prompt intervention in managing sepsis-related complications in cardiothoracic surgery is pivotal to adequate surgical practice. Due to the multiple subsections that construct the broad spectrum of cardiothoracic surgery, it is important to address the presence of sepsis in elective cardiothoracic surgery, urgent/emergency cardiothoracic surgery, solid organ transplantation, and both temporary and permanent mechanical circulatory support (ie, left ventricular assist devices, extracorporeal membrane oxygenation, and percutaneous temporary devices [eg, Impella series]). Exploring the incidence, prevalence, and risk factors of said subsections can lead to improvement in postoperative outcomes. The impact of accompanying infections can progress into further operative morbidity and mortality. To this effect, the perioperative management of cardiothoracic surgery transcends surgical techniques and should undergo additional recognition of other occurrences such as wound infections, bloodstream infections, urinary tract infections, and pneumonia. Sepsis remains a concern in cardiothoracic surgery, as it can lead to devastating consequences. Hence, there is an evident need for heightened vigilance, early recognition, and effective management strategies to mitigate the risk of sepsis in this patient population. The purpose of this article is to provide an overview of sepsis in the different cardiothoracic surgery areas.