Prospective assessment of cytokine IL-15 activity in patients with refractory atrial fibrillation episodes

Comprehensive Analysis of Immune Cell Infiltration and M2-Like Macrophage Biomarker Expression Patterns in Atrial Fibrillation

Background

Macrophages play a crucial role in the progression of AF, closely linked to atrial inflammation and myocardial fibrosis. However, the functions and molecular mechanisms of different phenotypic macrophages in AF are not well understood. This study aims to analyze the infiltration characteristics of atrial immune cells in AF patients and further explore the role and molecular expression patterns of M2 macrophage-related genes in AF.

Methods

This study integrates single-cell and large-scale sequencing data to analyze immune cell infiltration and molecular characterization of the LAA in patients with AF, using SR as a control group. CIBERSORT assesses immune cell types in LAA tissues; WGCNA identifies signature genes; cell clustering analyzes cell types and subpopulations; cell communication explores macrophage interactions; hdWGCNA identifies M2 macrophage gene modules in AF. AF biomarkers are identified using LASSO and Random Forest, validated with ROC curves and RT-qPCR. Potential molecular mechanisms are inferred through TF-miRNA-mRNA networks and single-gene enrichment analyses.

Results

Myeloid cell subsets varied considerably between the AF and SR groups, with a significant increase in M2 macrophages in the AF group. Signals of inflammation and matrix remodeling were observed in AF. M2 macrophage-related genes IGF1, PDK4, RAB13, and TMEM176B were identified as AF biomarkers, with RAB13 and TMEM176B being novel markers. A TF-miRNA-mRNA network was constructed using target genes, which are enriched in the PPAR signaling pathway and fatty acid metabolism.

Conclusion

Over infiltration of M2 macrophages may be an important factor in the progression of AF. The M2 macrophage-related genes IGF1, RAB13, TMEM176B and PDK4 may regulate the progression of AF through the PPAR signaling pathway and fatty acid metabolism.

Pretreatment with interleukin-15 attenuates inflammation and apoptosis by inhibiting NF-κB signaling in sepsis-induced myocardial dysfunction

Sepsis-induced myocardial dysfunction (SIMD) is associated with poor prognosis and increased mortality in patients with sepsis. Cytokines are important regulators of both the initiation and progression of sepsis. Interleukin-15 (IL-15), a pro-inflammatory cytokine, has been linked to protective effects against myocardial infarction and myocarditis. However, the role of IL-15 in SIMD remains unclear. We established a mouse model of SIMD via cecal ligation puncture (CLP) surgery and a cell model of myocardial injury via lipopolysaccharide (LPS) stimulation. IL-15 expression was prominently upregulated in septic hearts as well as cardiomyocytes challenged with LPS. IL-15 pretreatment attenuated cardiac inflammation and cell apoptosis and improved cardiac function in the CLP model. Similar cardioprotective effects of IL-15 pretreatment were observed in vitro. As expected, IL-15 knockdown had the opposite effect on LPS-stimulated cardiomyocytes. Mechanistically, we found that IL-15 pretreatment reduced the expression of the pro-apoptotic proteins cleaved caspase-3 and Bax and upregulated the anti-apoptotic protein Bcl-2. RNA sequencing and Western blotting further confirmed that IL-15 pretreatment suppressed the activation of nuclear factor kappa B (NF-κB) signaling in mice with sepsis. Besides, the addition of NF-κB inhibitor can significantly attenuate cardiomyocyte apoptosis compared to the control findings. Our results suggest that IL-15 pretreatment attenuated the cardiac inflammatory responses and reduced cardiomyocyte apoptosis by partially inhibiting NF-κB signaling in vivo and in vitro, thereby improving cardiac function in mice with sepsis. These findings highlight a promising therapeutic strategy for SIMD.

Cytokines and their role in cardiovascular diseases

The evaluation of diagnostic and prognostic biomarkers has always been a hot topic in various diseases. Considering that cardiovascular diseases (CVDs) have the highest mortality and morbidity rates in the world, various studies have been conducted so far to find CVD associated biomarkers, including cardiac troponin (cTn) and NT-proBNP. Cytokines are components of the immune system that are involved in the pathogenesis of CVD due to their contribution to the inflammation process. The level of cytokines varies in many cardiovascular diseases. For instance, the plasma level of IL-1α, IL-18, IL-33, IL-6 and IL-8 is positively correlated with atherosclerosis and that of some other interleukins such as IL-35 is negatively correlated with acute myocardial infarction or cardiac angina. Due to its pivotal role in the inflammation process, IL-1 super family is involved in many CVDs, including atherosclerosis. IL-20 among the interleukins of IL-10 family has a pro-atherogenic role, while others, such as IL-10 and IL-19, play an anti-atherogenic role. In the present review, we have collected the latest published evidence in this respect to discuss valuable cytokines from the diagnostic and prognostic stand point in CVDs.

Cardiac and inflammatory biomarker differences in adverse cardiac events after chimeric antigen receptor T-Cell therapy: an exploratory study

BACKGROUND

Chimeric antigen receptor T- Cell (CAR-T) immunotherapy has been a breakthrough treatment for various hematological malignancies. However, cardiotoxicities such as new-onset heart failure, arrhythmia, acute coronary syndrome and cardiovascular death occur in 10-15% of patients treated with CAR-T. This study aims to investigate the changes in cardiac and inflammatory biomarkers in CAR-T therapy to determine the role of pro-inflammatory cytokines.

METHODS

In this observational study, ninety consecutive patients treated with CAR-T underwent baseline cardiac investigation with electrocardiogram (ECG), transthoracic echocardiogram (TTE), troponin-I, and B-type natriuretic peptide (BNP). Follow-up ECG, troponin-I and BNP were obtained five days post- CAR-T. In a subset of patients (N = 53), serum inflammatory cytokines interleukin (IL)-2, IL-6, IL-15, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, granulocyte-macrophage colony-stimulating factor (GM-CSF), and angiopoietin 1 & 2 were tested serially, including baseline and daily during hospitalization. Adverse cardiac events were defined as new-onset cardiomyopathy/heart failure, acute coronary syndrome, arrhythmia and cardiovascular death.

RESULTS

Eleven patients (12%) had adverse cardiac events (one with new-onset cardiomyopathy and ten with new-onset atrial fibrillation). Adverse cardiac events appear to have occurred among patients with advanced age (77 vs. 66 years; p = 0.002), higher baseline creatinine (0.9 vs. 0.7 mg/dL; 0.007) and higher left atrial volume index (23.9 vs. 16.9mL/m²; p = 0.042). Day 5 BNP levels (125 vs. 63pg/mL; p = 0.019), but not troponin-I, were higher in patients with adverse cardiac events, compared to those without. The maximum levels of IL-6 (3855.0 vs. 254.0 pg/mL; p = 0.021), IFN-γ (474.0 vs. 48.8pg/mL; p = 0.006) and IL-15 (70.2 vs. 39.2pg/mL; p = 0.026) were also higher in the adverse cardiac events group. However, cardiac and inflammatory biomarker levels were not associated with cardiac events. Patients who developed cardiac events did not exhibit worse survival compared to patients without cardiac events (Log-rank p = 0.200).

CONCLUSION

Adverse cardiac events, predominantly atrial fibrillation, occur commonly after CAR-T (12%). The changes in serial inflammatory cytokine after CAR-T in the setting of adverse cardiac events suggests pro-inflammation as a pathophysiology and require further investigation for their role in adverse cardiac events.

TWEET BRIEF HANDLE

CAR-T related Cardiotoxicity has elevated cardiac and inflammatory biomarkers. #CARTCell #CardioOnc #CardioImmunology.

Effects of the Chinese herbal medicine Hong Huang decoction, on myocardial injury in breast cancer patients who underwent anthracycline-based chemotherapy

Objective

To assess the effects of Hong Huang Decoction (HHD), a Chinese herbal medicine, on myocardial injury in breast cancer patients who underwent anthracycline (ANT)-based chemotherapy.

Methods

A total of 51 patients with breast cancer who underwent an ANT-based chemotherapy program and met the inclusion/exclusion criteria were allocated to the treatment or placebo groups using a random number generation process. Patients in the treatment group received liquid HHD twice a day. Treatment was given from 1 day prior to chemotherapy up to the end of chemotherapy (after 6 months). Participants in the placebo group received a placebo over the same schedule. Left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), diagnostic markers of acute myocardial infarction [e.g., lactate dehydrogenase (LDH), creatine kinase-MB (CK-MB), and B-type natriuretic peptide (BNP)], nitric oxide (NO), superoxide dismutase (SOD), as well as pro-inflammatory cytokines [e.g., tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and human C-reactive protein (CRP)], and anti-inflammatory cytokine interleukin-10 (IL-10), were outcome measures assessed before chemotherapy, 3 and 6 months after chemotherapy.

Results

Compared to the placebo group, the GLS value was significantly higher in the treatment group (19.95 ± 1.16 vs. 19.06 ± 1.64, P ≤ 0.001). Significant differences were also noted for levels of SOD (689.71 ± 203.60 vs. 807.88 ± 182.10, P < 0.05), IL-6 (58.04 ± 22.06 vs. 194.20 ± 40.14, P ≤ 0.001), IL-10 (237.90 ± 94.98 vs. 68.81 ± 32.92, P ≤ 0.001), NO (75.05 ± 26.39 vs. 55.83 ± 19.37, P ≤ 0.005), and TNF-α (301.80 ± 134.20 vs. 680.30 ± 199.60, P ≤ 0.001) in the patients before chemotherapy compared to 6 months after initiating chemotherapy.

Conclusion

HHD regulated the levels of IL-6, IL-10, SOD, NO, and TNF-α. The results demonstrated that GLS is a better indicator of early myocardial injury compared to LVEF, and HHD could modulate oxidative stress to protect against ANT cardio toxicity.

Clinical trial registration

Chinese Clinical Trial Registry, identifier ChiCTR1900022394. Date of registration: 2019-04-09.

Role of interleukin-15 in cardiovascular diseases

Interleukin (IL)‐15 is a recently identified cytokine, which belongs to the interleukin‐2(IL‐2) family, and plays an important role in innate and adaptive immunoreaction. Given the fact that the structure of IL‐15 is partially similar to IL‐2, they share some common biological effects, including immunoregulation. IL‐2 was proven to protect cardiac function in mouse myocardial infarction models. Cardiovascular diseases (CVDs) dominate the cause of mortality worldwide. Besides atherosclerosis, inflammation is also widely involved in the pathogenesis of many CVDs including hypertension, heart failure (HF) and aneurysm. IL‐15, as a pro‐inflammatory cytokine, is up‐regulated in some cardiovascular diseases, such as myocardial infarction and atherosclerosis. The current understanding of IL‐15, including its signal pathway and cellular function, was described. Furthermore, IL‐15 has a protective effect in myocardial infarction and myocarditis by decreasing cardiomyocyte death and improving heart function. The inhibited effect of IL‐15 in ductus arteriosus (DA) should be focused on. IL‐15 promoted atherogenesis. IL‐15 may be a good target in treatment of cardiovascular diabetology. Finally, future research direction of IL‐15 deserves attention. Since IL‐15 plays several roles in CVDs, understanding the role of the IL‐15/IL‐15R system may provide a scientific basis for the development of new approaches that use IL‐15 for the treatment of CVDs.

TNF-α induces Drp1-mediated mitochondrial fragmentation during inflammatory cardiomyocyte injury

Dynamin-related peptide 1 (Drpl)-mediated mitochondrial fission is an important process associated with cardiac dysfunction under different pathological conditions. The aim of the present study was to investigate the expression of Drpl during inflammatory myocardial injury. Sprague‑Dawley rats were treated intraperitoneally with lipopolysaccharides (LPS). Furthermore, cultured H9C2 cardiomyocytes were treated with LPS, interleukin‑6 (IL‑6) and tumor necrosis factor‑α (TNF‑α). Total and mitochondrial proteins were isolated from the heart tissue of rats and from the H9C2 cardiomyocytes. Expression levels of Drp1 and RhoA were analyzed by western blotting. Mitochondrial morphology was determined using confocal laser microscopy. The levels of mitochondrial Drp1 and phosphorylated‑Drp1 (p‑Drp1) Ser616 were revealed to be increased in rats 6 h after injection with LPS (5, 10 or 20 mg/kg). Furthermore, treatment with LPS and IL‑6 did not demonstrate a significant effect on the expression of total and mitochondrial Drp1 in H9C2 cardiomyocytes in vitro; however, treatment with TNF‑α (20 ng/ml) significantly enhanced the levels of mitochondrial Drp1 and p‑Drp1 Ser616. Following TNF‑α treatment, the expression of Ras homolog gene family member A (RhoA) was also revealed to increase. Treatment with both Y‑27632 and fasudil, [Rho kinase (ROCK) inhibitors], was demonstrated to attenuate the otherwise TNF‑α‑induced increase in p‑Drp1 Ser616 and mitochondrial Drp1. In addition, it was revealed that Y‑27632 and fasudil may also attenuate the TNF‑α‑induced increase in mitochondrial fragmentation and cell viability. Therefore, the findings of the present study suggest that TNF‑α is the predominant inducer of Drp1 S616 phosphorylation during sepsis. The results of the present study also suggest that the RhoA/ROCK pathway may be involved in the phosphorylation and mitochondrial translocation of Drp1, which leads to mitochondrial fragmentation.