ErbB3 signaling prevents cardiac fibrosis after isoproterenol-induced myocardial injury

We generate a new tamoxifen-inducible mice model of EC-specific ErbB3 overexpression to investigate the role of ErbB3 in myocardial ischemia and heart failure. In the present study, we compared cardiac function and fibrosis development in EC cell-specific ErbB3 overexpressing mice versus control after the Isoproterenol (ISO)-induced model of cardiac injury, which culminates in cardiac fibrosis development.https://knowledgeconnection.mainehealth.org/lambrew-retreat-2023/1011/thumbnail.jp

Cytokine CXCL2 concentration in the cerebrospinal fluid of patients with aneurysmal subarachnoid hemorrhage is associated with patient-reported headache pain

Subarachnoid hemorrhage (SAH) is a severe type of stroke categorized by a sharp, sudden, and persistent headache. The mechanism of headache after SAH is currently poorly understood but the neuro-inflammatory response has been identified as a target in understanding the causes of headache after SAH. A better understanding of this mechanism may lead to identification of molecular targets for therapeutic reduction of headache pain and improving outcomes after SAH. In this study, we collected cerebrospinal fluid (CSF) from patients hospitalized with SAH and conducted a cytokine array to screen for soluble factors involved in SAH-associated headache Introductionhttps://knowledgeconnection.mainehealth.org/lambrew-retreat-2022/1012/thumbnail.jp

Level of circulating Interleukin-21 after cardiac arrest

Purpose/Background: Patients resuscitated from cardiac arrest (CA) have highly variable neurological, circulatory, and systemic ischemia-reperfusion injuries. The initial ischemic insult triggers immune and inflammatory responses, and results in a cascade of secondary injuries that are often fatal. Previous studies using animal’s model of cardiac arrest/cardiopulmonary resuscitation have demonstrated that interleukin-21 (IL-21) promotes brain injury through stimulation of lymphocytes accumulation. However, the role of IL-21 in neurological injury in humans has not been well characterized. The goal of this project was to determine the level of IL-21 in patients with cardiac arrest and resuscitation. Methods/Approach: Post-cardiac arrest subjects underwent phlebotomy at 24, 48, and 72 hours after resuscitation. The blood plasma was then analyzed using a enzyme-linked immunosorbent assay (ELISA) to measure the levels of circulating IL-21 in 50 patients with cardiac arrest and resuscitation.Thirty one patients underwent coronary artery bypass grafting (CABG) surgery served as a control group. The level of IL-21 was read using a Biotek Epoch Plate Reader. The values of IL-21 were calculated using standard curve (R&D Systems test kit). The correlation analysis between the level of IL-21 and various clinical parameters, including time to return of spontaneous circulation, survival, and cerebral performance category (CPC) score was performed using Spearman\u27s rank-order correlation. Results: We found large inter-individual variability in the levels of IL-21 in both control subjects and post-cardiac arrest patients. However, no significant changes were found in the levels of IL-21 between CABG and cardiac arrest. The level of IL-21 remained stable at different time points after cardiac arrest. A positive trend was found between the level of IL-21 at 24 hours post-cardiac arrest and survival at day 7 (p=0.100). Conclusion: Our study identified significant inter-individual variability in the level of circulating IL-21, signifying the potential involvement of this cytokine into a variety of clinical phenotypes after cardiac arrest. A positive trend between the level of IL-21 and survival may indicate that high level of IL-21 is associated with a better chance to survive after cardiac arrest. However, further studies at early time points e.g., 6 hours or 12 hours post-cardiac arrest, are warranted

The number of circulating CD26 expressing cells is decreased in critical COVID-19 illness

We evaluated the number of CD26 expressing cells in peripheral blood of patients with COVID-19 within 72 h of admission and on day 4 and day 7 after enrollment. The majority of CD26 expressing cells were presented by CD3 CD4 lymphocytes. A low number of CD26 expressing cells were found to be associated with critical-severity COVID-19 disease. Conversely, increasing numbers of CD26 expressing T cells over the first week of standard treatment was associated with good outcomes. Clinically, the number of circulating CD26 cells might be a marker of recovery or the therapeutic efficacy of anti-COVID-19 treatment. New therapies aimed at preserving and increasing the level of CD26 expressing T cells may prove useful in the treatment of COVID-19 disease

Decreased circulating CD73 and adenosine deaminase are associated with disease severity in hospitalized patients with COVID-19

OBJECTIVE: SARS-CoV-2 infection has been shown to result in increased circulating levels of adenosine triphosphate and adenosine diphosphate and decreased levels of adenosine, which has important anti-inflammatory activity. The goal of this pilot project was to assess the levels of soluble CD73 and soluble Adenosine Deaminase (ADA) in hospitalized patients with COVID-19 and determine if levels of these molecules are associated with disease severity. METHODS: Plasma from 28 PCR-confirmed hospitalized COVID-19 patients who had varied disease severity based on WHO classification (6 mild/moderate, 10 severe, 12 critical) had concentrations of both soluble CD73 and ADA determined by ELISA. These concentrations were compared to healthy control plasma that is commercially available and was biobanked prior to the start of the pandemic. Additionally, outcomes such as WHO ordinal scale for disease severity, ICU admission, needed for invasive ventilation, hospital length of stay, and development of thrombosis during admission were used as markers of disease severity. RESULTS: Our results show that both CD73 and ADA are decreased during SARS-CoV-2 infection. The level of circulating CD73 is directly correlated to the severity of the disease defined by the need for ICU admission, invasive ventilation, and hospital length of stay. Low level of CD73 is also associated with clinical thrombosis, a severe complication of SARS-CoV-2 infection. CONCLUSION: Our study indicates that adenosine metabolism is down-regulated in patients with COVID-19 and associated with severe infection. Further large-scale studies are warranted to investigate the role of the adenosinergic anti-inflammatory CD73/ADA axis in protection against COVID-19

High ErbB3 activating activity in human blood is not due to circulating neuregulin-1 beta

Neuregulin-1β (NRG-1) is a membrane-bound or secreted growth and differentiation factor that mediates its action by binding to ErbB receptors. Circulating levels of NRG-1 are characterized by large inter-individual variability with the range of absolute values covering two orders of magnitude, from hundreds to tens of thousands of picograms per milliliter of blood. NRG-1 signaling via ErbB receptors contributes to the cell survival and downregulation of the inflammatory response. A higher level of circulating NRG-1 may indicate increased shedding of membrane-bound NRG-1, which in turn can contribute to better protection against cardiovascular stress or injury. However, it is unknown whether circulating NRG-1 can induce activation of ErbB receptors. In the current study, we performed an analysis of circulating NRG-1 functional activity using a cell-based ELISA measuring phosphorylation of ErbB3 induced by blood plasma obtained from healthy donors. We found high levels of ErbB3 activating activity in human plasma. No correlations were found between the levels of circulating NRG-1 and plasma ErbB3 activating activity. To determine the direct effect of circulating NRG-1, we incubated plasma with neutralizing antibody, which prevented the stimulatory effect of recombinant NRG-1 on activation of ErbB3. No effect of the neutralizing antibody was found on plasma-induced phosphorylation of ErbB3. We also found that a significant portion of circulating NRG-1 is comprised of full-length NRG-1 associated with large extracellular vesicles. Our results demonstrate that circulating NRG-1 does not contribute to plasma-induced ErbB3 activating activity and emphasizes the importance of functional testing of NRG-1 proteins in biological samples

Protective role of ErbB3 signaling in myeloid cells during adaptation to cardiac pressure overload

BACKGROUND: Myeloid cells play an important role in a wide variety of cardiovascular disorders, including both ischemic and non-ischemic cardiomyopathies. Neuregulin-1 (NRG-1)/ErbB signaling has recently emerged as an important factor contributing to the control of inflammatory activation of myeloid cells after an ischemic injury. However, the role of ErbB signaling in myeloid cells in non-ischemic cardiomyopathy is not fully understood. This study investigated the role of ErbB3 receptors in the regulation of early adaptive response using a mouse model of transverse aortic constriction (TAC) for non-ischemic cardiomyopathy. METHODS AND RESULTS: TAC surgery was performed in groups of age- and sex-matched myeloid cell-specific ErbB3-deficient mice (ErbB3) and control animals (ErbB3). The number of cardiac CD45 immune cells, CD11b myeloid cells, Ly6G neutrophils, and Ly6C monocytes was determined using flow cytometric analysis. Five days after TAC, survival was dramatically reduced in male but not female ErbB3 mice or control animals. The examination of lung weight to body weight ratio suggested that acute pulmonary edema was present in ErbB3 male mice after TAC. To determine the cellular and molecular mechanisms involved in the increased mortality in ErbB3 male mice, cardiac cell populations were examined at day 3 post-TAC using flow cytometry. Myeloid cells accumulated in control but not in ErbB3 male mouse hearts. This was accompanied by increased proliferation of Sca-1 positive non-immune cells (endothelial cells and fibroblasts) in control but not ErbB3 male mice. No significant differences in intramyocardial accumulation of myeloid cells or proliferation of Sca-1 cells were found between the groups of ErbB3 and ErbB3 female mice. An antibody-based protein array analysis revealed that IGF-1 expression was significantly downregulated only in ErbB3 mice hearts compared to control animals after TAC. CONCLUSION: Our data demonstrate the crucial role of myeloid cell-specific ErbB3 signaling in the cardiac accumulation of myeloid cells, which contributes to the activation of cardiac endothelial cells and fibroblasts and development of an early adaptive response to cardiac pressure overload in male mice

Chemokine dynamics and the inflammatory response after cardiac injury

Problem/Background: The initial ischemic insult of a cardiac arrest (CA) episode triggers the inflammatory response, resulting in neurological, circulatory, and systemic ischemia-reperfusion injuries that are frequently fatal. More than 500,000 Americans suffer cardiac arrest annually, and despite improved cardiopulmonary resuscitation, post-resuscitation therapy, and cardiovascular systems of care, outcomes remain poor. Understanding molecular mechanisms contributing to survival after CA may lead to identification of therapeutic targets and improvement of outcomes. Chemotactic cytokines (chemokines) are secreted soluble or membrane-bound proteins that signal through G-protein coupled receptors to stimulate immune cell migration to the site of injury, acting as the first mobilizers of the inflammatory response. To our knowledge chemokine expression and function in cardiac arrest has not been examined. We measured levels of circulating chemokines in CA subjects as well as in Coronary Artery Bypass Graft (CABG) subjects before surgery. Approach: Study subjects admitted to intensive care after a CA episode and treated with therapeutic temperature management underwent phlebotomy at 6, 12, 24, 48, and 72 hours, and 7 days after return of spontaneous circulation (ROSC). Control subjects underwent CABG surgery with phlebotomy at pre-op, surgery, 4-8 hours, 24 hours, and 4 days postop. Blood samples were processed within 4 to 6 hours of collection. Platelets free plasma (PFP) was obtained from venous blood via consecutive centrifugations and stored at -800C. CCL2, CCL4, and CCL23 protein levels were determined using Human CCL2, CCL4, and CCL23 DuoSet ELISA (R&D Systems/biotechne) kits. Data analysis was performed with GraphPad Prism. Results: Each chemokine demonstrated unique dynamics in the context of cardiac arrest. Our results revealed large inter-individual variability, in accord with other analyte testing in this study group. All three chemokines were found at significantly elevated levels 24 hours post-ROSC as compared to control. CCL23 (MPIF-1, myeloid progenitor inhibitory factor-1), emerged as a protein of interest. This chemokine exhibits a specific time-dependent pattern associated with increased circulating levels at 24 to 48 hours post-ROSC. In our cohort, CCL23 levels are statistically significantly different between non-survivors (n=19) and survivors (n=23) at 48 hours post-ROSC, with non-survivor median CCL23 levels twice that seen in survivors. We also observed positive correlation between the number of white blood cells (WBCs) and CCL23 levels at 48 hours post-ROSC. Conclusion: Chemokine dynamics may provide insight into potential targets for treatment after cardiac arrest with focus on the inflammatory response in the first two days after injury. The current study provides an important contribution to our understanding of the role of chemokines and the inflammatory response after cardiac arrest. Further investigation into the expression locations and mechanisms of action of chemokines is warranted

Ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arresT (PROTECT): study protocol for a randomized, placebo-controlled trial

BACKGROUND: Pneumonia is the most common infection after out-of-hospital cardiac arrest (OHCA) occurring in up to 65% of patients who remain comatose after return of spontaneous circulation. Preventing infection after OHCA may (1) reduce exposure to broad-spectrum antibiotics, (2) prevent hemodynamic derangements due to local and systemic inflammation, and (3) prevent infection-associated morbidity and mortality. METHODS: The ceftriaxone to PRevent pneumOnia and inflammaTion aftEr Cardiac arrest (PROTECT) trial is a randomized, placebo-controlled, single-center, quadruple-blind (patient, treatment team, research team, outcome assessors), non-commercial, superiority trial to be conducted at Maine Medical Center in Portland, Maine, USA. Ceftriaxone 2 g intravenously every 12 h for 3 days will be compared with matching placebo. The primary efficacy outcome is incidence of early-onset pneumonia occurring \u3c 4 days after mechanical ventilation initiation. Concurrently, T cell-mediated inflammation bacterial resistomes will be examined. Safety outcomes include incidence of type-one immediate-type hypersensitivity reactions, gallbladder injury, and Clostridioides difficile-associated diarrhea. The trial will enroll 120 subjects over approximately 3 to 4 years. DISCUSSION: The PROTECT trial is novel in its (1) inclusion of OHCA survivors regardless of initial heart rhythm, (2) use of a low-risk antibiotic available in the USA that has not previously been tested after OHCA, (3) inclusion of anti-inflammatory effects of ceftriaxone as a novel mechanism for improved clinical outcomes, and (4) complete metagenomic assessment of bacterial resistomes pre- and post-ceftriaxone prophylaxis. The long-term goal is to develop a definitive phase III trial powered for mortality or functional outcome. TRIAL REGISTRATION: ClinicalTrials.gov NCT04999592 . Registered on August 10, 2021