Copley, E A

Abstract Metabolic reprogramming is a fundamental determinant of immune cell fate and effector function during inflammation, yet how distinct metabolic pathways regulate pathogenic lung macrophage activity and contribute to fibrotic remodeling remains incompletely understood. Here, we integrated single-cell RNA sequencing, lineage-specific genetic mouse models, and fate-mapping approaches to define the metabolic pathways that regulate the pro-fibrotic activity of lung macrophages. We found that such cells undergo pronounced aerobic glycolysis in the bleomycin-induced mouse model of pulmonary fibrosis. Myeloid cell-specific depletion of lactate dehydrogenase A (Ldha), but not of mitochondrial pyruvate carrier (Mpc), markedly attenuated lung fibrosis and improved survival. Mechanistically, enhanced glycolytic flux increased lactate production, which promoted histone lysine lactylation and facilitated Arginase 1 (Arg1) expression in lung macrophages, thereby driving fibrotic progression. Using monocyte fate-mapping, we further demonstrated that Arg1 expression is largely restricted to recruited monocyte-derived macrophages rather than lung-resident macrophages. Notably, selective deletion of Ldha in granulocyte-monocyte progenitors and their progeny was sufficient to suppress Arg1 expression and reduce fibrosis severity. In human lung samples, we observed significantly elevated expression of ARG1 and key glycolytic enzymes in patients with idiopathic pulmonary fibrosis, despite species-specific differences in the immune cell types expressing ARG1. Together, these findings identify an aerobic glycolysis–lactate–histone lactylation axis that regulates pro-fibrotic myeloid cell function and represents a potential therapeutic target in pulmonary fibrosis.

Background α‐Klotho is a multifunctional protein implicated in vascular aging. Declining Klotho levels are associated with arterial stiffness, endothelial dysfunction, and vascular calcification. We investigated the associations between circulating klotho, aortoiliac calcification, endothelial progenitor cells, and 10‐year survival. Methods In this retrospective cohort, blinded clinicians scored calcification on computed tomography (0–10 scale: aorta 6 points, iliac 4 points). Plasma klotho was measured by ELISA; endothelial progenitor cell subsets were quantified via flow cytometry. Mortality data were obtained from the Minnesota Death Registry. Results This study included 148 participants (mean age 72.4±9.6 years; 41% female). Median calcification score was 3 (interquartile range, 1–5). Patients with low calcification had higher Klotho levels (669 [567–841] versus 556 [457–678] pg/mL; P <0.01), with Klotho inversely correlated with calcification (r=−0.315, P <0.01). Stratified by calcification location and severity, the highest Klotho levels were seen in patients without aortic or iliac calcification ( P =0.015). Over 10 years, low Klotho was independently associated with higher mortality (hazard ratio [HR], 3.056 [95% CI 1.288–7.878]; P =0.014). Klotho inversely correlated with mature osteocalcin‐positive EPCs; B=−0.16 (95% CI, −0.29 to −0.02; P =0.027). Immunohistochemistry and immunofluorescence confirmed endothelial Klotho expression in internal mammary artery. Conclusions Lower circulating Klotho levels are associated with increased aortoiliac calcification and higher 10‐year mortality, supporting a role for Klotho in vascular aging.

e24015 Background: Anthracyclines are effective cancer therapeutics but can cause cardiotoxicity. Recent studies suggest a connection between efficacy and toxicity in that the effects of anthracyclines on cancer cells leads to the release of interleukin 1-alpha (IL-1⍺), which negatively impacts cardiomyocyte metabolism and thereby cardiac function. This observation was made in in vivo and in vitro models of acute myeloid leukemia (AML); whether this holds true for other cancer cell lines remains unclear. Methods: Herein we characterized the cytokine profile of 9 cancer cell lines exposed to doxorubicin (1 µM for 24 hours) and then tested the effects of interleukin 1-alpha (IL-1⍺, 50-150 ng/mL) on the viability and metabolism of neonatal cardiomyocyte. We used Seahorse to assess cardiomyocyte glycolysis via extracellular acidification rate (ECAR) and mitochondrial oxidative phosphorylation based on the oxygen consumption rate (OCR). Results: As outlined in Table 1, different hematological and breast cancer cell lines showed a range of cytokine profile in response to doxorubicin exposure. Of the cytokines with putative action on cardiomyocyte metabolism IL-1⍺was one of the most induced in 3 out of 5 murine breast cancer, murine B- and T-cell lymphoma, as well as murine and human AML human and murine cell lines. Doxorubicin did not induce IL-1⍺ expression in macrophage cell lines (RAW) or directly in cardiomyocytes. Exposing neonatal cardiomyocytes to different concentrations of IL-1⍺ did not decrease but rather increased OCR and especially ECAR. Conclusions: These data confirm the release of IL-1⍺ from AML as well as several, but not all breast cancer cell lines. Furthermore, purified IL-1⍺ increased oxidative phosphorylation and glycolysis in murine neonatal cardiomyocytes. These data point out heterogeneity in the cytokine release pattern from anthracycline-treated cancer cell lines and their impact on cardiomyocyte metabolism. Further studies are required to define the nuances of crosstalk between cancer and the heart and its contribution to the variation in cardiotoxicity risk. Cytokine profile of cancer cell lines. Cytokines RAW Neonatal MC38HuPD-L1 EMT6 JC E0771 4T1 B Lymphoma: A20 T Lymphoma: E.G7-OVA AML Human: THP-1 AML mouse: C1498 ICAM-1, CD54 ++ ++ ++ ++ ++ ++ IL-1α IL-1F1 + + + + + + + IL-10 + + IL-16 ++ ++ ++ CXCL10/CRG-2 ++ + ++ ++ ++ ++ ++ ++ ++ M-CSF ++ ++ ++ + ++ ++ ++ ++ + RANTES CCL5 + ++ ++ ++ ++ TNF-α +++ + ++ + + + + +

Introduction: Atrial fibrillation (AF) is prevalent in patients with atherosclerotic coronary and carotid artery disease and is associated with elevated plasma inflammatory markers, such as Interleukin (IL)-6. In carotid artery atherosclerosis, macrophages are considered a local marker of inflammation. Hypothesis: We hypothesize that AF is independently associated with carotid plaque inflammation. Aims: In patients undergoing carotid endarterectomy (CEA), we aimed to determine whether carotid plaques inflammation is associated with AF. Approach: In this prospective cohort study, consecutive patients with carotid artery disease undergoing CEA were enrolled. From the plaques removed during surgery, fixed in formalin and embedded in paraffin blocks, sections were stained with antibodies against CD68 to detect macrophages (Fig.1A) . Digital copies of the slides were created by Motic Easy Scan and histologically annotated with QuPath. The percentage of CD68+ cells was defined as (CD68+ positive cells/total nuclei) x 100. Flash-frozen plaque segments were analyzed by ELISA for IL-6 concentration. Baseline demographics and clinical data, including AF diagnosis, were extracted from the electronic health records. Results: A total of 106 patients undergoing CEA, with a median age of 73 [67-78] years and comprising 83 (78.3%) males, were included in the study. AF was diagnosed prior to CEA in 13 (12.3%) patients. Univariate logistic regression showed that plaque CD68+ cell content was associated with AF (OR 1.048 [95% CI 1.010 – 1.088]; p = 0.013). Additionally, in Mann-Whitney test IL-6 levels were significantly over twofold higher in plaques of patients with AF compared to those without AF (82.4 [64.9-111.7] pg/mg vs 37.0 [18.4-93.3] pg/mg; p=0.020) (Fig. 1B) . Conclusions: The current study demonstrates an association between carotid atherosclerotic plaque macrophage content, IL6 levels and AF, supporting the role of inflammation in the pathogenesis of AF in these patients. Further studies are needed to determine the potential of plaque inflammation as a therapeutic target in AF.

Abstract Background Patients with carotid artery disease undergoing carotid endarterectomy (CEA) appear to be at high risk of all-cause mortality during their follow-up. However, the possible predictors of this adverse outcome are not elucidated yet. Purpose We aimed to test cardiovascular (CV) risk factors as possible predictors of all-cause mortality in patients undergoing CEA and to determine whether there is a difference between the mortality rate of our study cohort and the general population. We hypothesize that CEA-treated patients have a higher mortality rate during follow-up after surgery than the general population, which is not related to the presence of CV risk factors. Methods We prospectively enrolled and followed up patients undergoing CEA. Univariate and multivariable Cox regression were performed to test whether common CV risk factors (demographics, laboratory values, comorbidities, and events before CEA) were predictive of all-cause mortality. We then compared the standardized mortality ratio (SMR) of our population and the age-sex-matched Minnesota (MN) general population at 5,10, and 21 years of follow-up after CEA. Results A total of 710 patients were followed for a median of 7.1 [2.9-11.9] years after CEA. Mortality occurred in 198 (27.0%) patients during the follow-up. The median time to event was 11.0 [10.0-12.0] years. Age was the only predictor of all-cause mortality in CEA-treated patients in multivariable models adjusted for known CV risk factors (Model 1: HR 1.03 [95%CI 1.01-1.06]; p=0.004; Model 2: HR 1.02 [95%CI 1.00-1.04]; p=0.023) (Table 1). However, the CEA-treated group had a higher mortality rate than would have been expected in the MN population (log-rank p&lt;0.001) (Fig.1A). Compared to the MN population, at 5 years of follow-up only patients &lt;60 years old had a higher SMR (4.53 [1.95-8.92]; p=0.001), whereas, at 10 years and 21 years of follow-up, our study population had a higher mortality rate at any age (Fig.1B). Conclusions The elevated mortality risk post-CEA in our cohort cannot be solely attributed to chronological aging. The underlying process of atherosclerosis likely contributes to all-cause mortality, and plaque characteristics may offer additional insight into the risk stratification of this patient group.All cause mortality predictors after CEAStudy population vs. MN population SMR

Abstract Background Patients with carotid artery disease undergoing carotid endarterectomy (CEA) have a high risk of experiencing Major Adverse Cardiovascular Events (MACE) after surgery. The occurrence of MACE in CEA-treated patients is not predicted by common cardiovascular (CV) risk factors. Purpose We aimed to identify the association between plasma and plaque inflammatory cytokines and the incidence of MACE in the follow-up after CEA. We hypothesized that MACE is related to a higher level of circulating inflammatory cytokines at the time of surgery. Methods We prospectively enrolled patients with carotid artery disease undergoing CEA. Plasma and carotid plaques were collected during the surgery. Inflammatory cytokines (MCP-1/CCL2, IL-8/CXCL8, IFN-gamma, IL-10, IL-1beta/IL-1F2, IL-6, PDGF-AA, PDGF-AB/BB, TNF-alpha, VEGF) were measured in plasma and tissue homogenates using a customized 10-plex Luminex assay. Baseline demographics and clinical data for all the patients were extracted from electronic health records. MACE after CEA was defined as a composite measure of nonfatal cardiac events such as myocardial infarction with or without revascularization, cerebrovascular events (ischemic stroke, TIA, and amaurosis fugax), and all-cause mortality. Results Of 107 patients who underwent CEA with a median age of 73 (67-78) years, 57 (53.2%) experienced MACE during a median follow-up of 5.2 [2.2-9.3] years: 23 (40.3%) cardiac events, 9 (15.7%) CVA, and 25 (43.8%) all-cause mortality. Plaque cytokines levels did not differ between the groups with and without MACE in the follow-up after CEA. Instead, plasma cytokines were associated with MACE in the follow-up after CEA, as summarized in Figure 1. In the logistic regression analysis, plasma levels of MCP-1/CCL2, IFN-gamma, and TNF-alpha were independent predictors of MACE in follow-up post-CEA in univariate and multivariable models adjusted for CV risk factors such as age, BMI, systolic and diastolic blood pressure, low-density lipoprotein, high-density lipoprotein, and glucose level: MCP1/CCL2 (HR 1.009 [1.002-1.015]; p=0.007), IFN-gamma (HR 1.368 [1.014-1.845]; p=0.040), and TNF-alpha (HR 1.121 [1.022-1.228]; p=0.015) (Table 1). Conclusions Plasma levels of CCL2, IFN-gamma, and TNF-alpha are associated with the high incidence of MACE in the follow-up after CEA, indicating that these are potential biomarkers of MACE in this patient population and potential therapeutic targets in patients' progression of systemic atherosclerosis.Plasma cytokines and MACE after CEACytokines logistic regression analysis

Abstract Background One of the main features of vulnerability in atherosclerotic carotid plaques is intraplaque hemorrhage (IPH), which is related to a higher incidence of cerebrovascular events in patients with carotid artery disease. Additionally, inflammation plays a pivotal role in the progression of atherosclerotic disease. Purpose We aimed to determine plasma and tissue levels of inflammatory cytokines in patients with carotid artery disease hypothesizing that plaques with IPH are characterized by the presence of a more inflamed environment. Methods We retrospectively enrolled 104 consecutive patients undergoing carotid endarterectomy (CEA) with symptomatic (ischemic stroke, TIA, amaurosis fugax) or asymptomatic ipsilateral carotid artery disease. Plasma and carotid plaque specimens were collected at CEA. The tissue samples were stained with H&E to identify IPH and classified as specimens with and without IPH. Frozen homogenates of both plasma and tissue were analyzed using a customized 10-plex Luminex assay to determine the levels of inflammatory cytokines such as MCP-1/CCL2, IL-8/CXCL8, IFN-gamma, IL-10, IL-1beta/IL-1F2, IL-6, PDGF-AA, PDGF-AB/BB, TNF-alpha, and VEGF. Results IPH was identified in 53 patients (51.0 %). Cytokine levels in plasma and tissue from patients with and without IPH are reported in Table 1. In the univariate logistic regression MCP-1/CCL2, IL-8/CXCL8, IFN-gamma, IL-10, IL6, PDGF-AA, and PDGF-AB/BB were associated with IPH (Table 2). In the multivariate logistic regression, IL-6 was an independent predictor of IPH (HR 1.026 [95% CI 1.005-1.047]; p=0.014) after adjusting for cardiovascular risk factors such as age, BMI, sex, hypertension, diabetes mellitus, hyperlipidemia, ipsilateral carotid stenosis %. Conclusions Carotid plaques with IPH have an elevated inflammatory burden, potentially impacting adverse outcomes in this patient cohort. The local inflammatory cytokines in carotid plaques with IPH might serve as biomarkers and therapeutic targets in patients with carotid artery disease.