Microarray Analysis for Transcriptomic Profiling of Myocardium in Patients with Fatal Myocardial Infarction

Transcriptomic evidence from human myocardium in myocardial infarction (MI) is still not sufficient. Thus, there is a need for studies on human cardiac samples in relation to the clinical data of patients. The purpose of our pilot study was to investigate the transcriptomic profile of myocardium in the infarct zone, in comparison to the remote myocardium, in patients with fatal MI, via microarray analysis. This study included four patients with fatal MI type 1. We selected histologically verified samples from within the infarct area (n = 4) and remote myocardium (n = 4). The whole transcriptome was evaluated using microarray analysis. Differentially expressed genes (DEGs) clustered in the infarct area and in the remote myocardium allowed their differentiation. We identified a total of 1785 DEGs (8.32%) in the infarct area, including 1692 up-regulated (94.79%) and 93 down-regulated (5.21%) genes. The top 10 up-regulated genes were TRAIL, SUCLA2, NAE1, PDCL3, OSBPL5, FCGR2C, SELE, CEP63, ST3GAL3 and C4orf3. In the infarct area, we found up-regulation of seventeen apoptosis-related genes, eleven necroptosis-related, and six necrosis-related genes. Transcriptome profiling of the myocardium in patients with MI remains a relevant area of research for the formation of new scientific hypotheses and a potential way to increase the translational significance of studies into myocardial infarction.

Chemically Modified Biomimetic Carbon-Coated Iron Nanoparticles for Stent Coatings: In Vitro Cytocompatibility and In Vivo Structural Changes in Human Atherosclerotic Plaques

Atherosclerosis, a systematic degenerative disease related to the buildup of plaques in human vessels, remains the major cause of morbidity in the field of cardiovascular health problems, which are the number one cause of death globally. Novel atheroprotective HDL-mimicking chemically modified carbon-coated iron nanoparticles (Fe@C NPs) were produced by gas-phase synthesis and modified with organic functional groups of a lipophilic nature. Modified and non-modified Fe@C NPs, immobilized with polycaprolactone on stainless steel, showed high cytocompatibility in human endothelial cell culture. Furthermore, after ex vivo treatment of native atherosclerotic plaques obtained during open carotid endarterectomy surgery, Fe@C NPs penetrated the inner structures and caused structural changes of atherosclerotic plaques, depending on the period of implantation in Wistar rats, serving as a natural bioreactor. The high biocompatibility of the Fe@C NPs shows great potential in the treatment of atherosclerosis disease as an active substance of stent coatings to prevent restenosis and the formation of atherosclerotic plaques.

Association of actin-myosin interaction biomarkers and fibrosis with myocardial inflammatory changes in patients with idiopathic atrial fibrillation

Introduction

Myocarditis and inflammatory changes in the myocardium are causes of the development and progression of atrial fibrillation (AF). Inflammatory processes may also lead to the development of fibrosis, electrical and structural myocardial remodeling, adversely affecting the effectiveness of interventional treatment.

Purpose

To assess the dynamics and to identify relationships between serum levels of tropomyosin I, myosin light chain kinase (MLCK), myosin heavy (MYH7) and light chains (CMLC), transforming growth factor (TGF-β1) and myocardial inflammatory changes in patients with idiopathic AF.

Methods

Subjects were 40 patients (41.0±9.2 y.o.) with idiopathic AF (arrhythmic history constituted 4.9±3.9 years). Paroxysmal AF (ParAF) was detected in 37% (n=15), persistent AF (PerAF)–30% (n=12), and long-standing persistent (LPerAF)–33% (n=13). All patients underwent radiofrequency ablation (RFA) of the pulmonary veins and endomyocardial byopsy with histologic and immunohistochemical studies. Depending on the results of histological study, the patients were divided into 2 groups: 1–with active lymphocytic myocarditis (ALM) (n=22); 2–with lymphocytic infiltration (IL) (n=18). Blood for biomarkers evaluation was collected prior to RFA and in 6 months after RFA.

Results

In patients with ALM levels of biomarkers significant differed depending on the form of AF. In patients with PerAF, the levels of MYH7, MLCK and tropomyosin I were significantly lower than in patients with ParAF (p<0.005). In 6 months the levels of MLCK, tropomyosin I, and CMLC significantly differed in patients with ALM depending on the form of AF (p<0.05). In patients with PerAF in the group 1, the concentrations of MYH7, CMLC, and tropomyosin I were lower, than the group 2 (p<0.05). In 6 months in patients with PerAF, the TGF-β1 levels also differed between groups 1 and 2 (Me: 24.09 and 40.34 ng/ml, p<0.05). The content of TGF-β1 before the RFA and in 6 months in patients with PerAF was associated with the development of infiltration in 6 months after RFA (R=0.696, p=0.025). In LPerAF patients we showed correlation between the content of TGF-β1 and the severity of fibrosis in 6 months after RFA (R=0.607, p=0.047). At LPerAF TGF-β1 content correlated with degree of fibrosis in 6 months after RFA (R=0.607, p=0.047). The relationship between the form of AF and the inflammatory changes were identified (r=0.32, p=0.049). Thus, in patients with LPerAF and PerAF, ALM was diagnosed in 69% and 50% of cases, while in patients with ParAF the frequency of ALM detection constituted 33%.

Conclusion

Our study showed that ALM was detected in 55% of patients, and IL–in 45% of cases. Significant differences in the levels of MYH7, MLCK, CLCK, tropomyosin I in patients with PerAF and various forms of inflammatory myocardial changes were revealed. The content of the TGF-β1 is reduced in ALM in patients with PerAFP. The incidence of ALM was higher in patients with long-term persistent AF.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): Cardiology Research Institute, Tomsk NRMC

Stabilin-1+/SMA- macrophages in diagnostics of postinfarction tissue inflammation associated with adverse cardiac remodeling in patients with myocardial infarction

Introduction

Molecular biomarkers of monocytes/macrophages identified to date have provided advanced diagnostic capabilities. We have accumulated a large amount of knowledge related to the role of innate immune response in the development of postinfarction cardiac remodeling. However, there is no significant advancement in clinical studies.

Purpose

The purpose was to assess prospects of macrophage biomarkers in diagnostics of postinfarction tissue inflammation associated with adverse cardiac remodeling in patients with myocardial infarction (MI).

Methods

The study included 41 patients with MI type 1, died in 2013–2014. We used a biobank of tissue samples for analysis. Group 1 (n=24) comprised patients who died within 72 hours of MI (the inflammatory phase), group 2 (n=17) comprised patients who died 4–28 days after MI (the regenerative phase). Macrophage infiltration in the heart was assessed by double immunofluorescence. We used stabilin-1 as a marker of M2 macrophages, while α-smooth muscle actin (α-SMA) was considered as a marker of cell transdifferentiation. Cells were counted in the infarct (IA) and non-infarct area (NIA). Morphological determination of adverse cardiac remodeling was based on the ratio of heart size, in particular, length/width ratio that was <1.1.

Results

We identified subpopulations of stabilin-1+/α-SMA− and stabilin-1+/α-SMA+ macrophages. In the IA the number of stabilin-1+/α-SMA− macrophages was lower during the inflammatory phase than during the regenerative phase (Table 1). The calculation of sensitivity and specificity of stabilin-1+/α-SMA− macrophages in the NIA for predicting of adverse cardiac remodeling has shown following: AUC=0.96, p<0.001. The cut-off value was 18 cells/mm2. The ROC curve is presented in Figure 1.

Conclusions

We identified that number of stabilin-1+/α-SMA− macrophages in the NIA ranged from 0 to 18 cells/mm2 was associated with adverse cardiac remodeling. The presence of stabilin-1+/α-SMA+ macrophages could indicate persistent tissue inflammation and possibility of macrophage transdifferentiation and plasticity. Our study supports prospects for implementation of macrophage biomarkers in clinical practice that might become a breakthrough in the development of new methods for management of MI and following complications.

Figure 1

Funding Acknowledgement

Type of funding source: None

P6390Macrophages as contributors to chronic inflammation and cardiac fibrosis in patients with myocardial infarction

Introduction

The functional characteristics of tissue macrophages associated with the progression of cardiac fibrosis in clinic are still unknown.

Purpose

The purpose was to study cardiac macrophage phenotypes contributing to the development of chronic inflammation and fibrosis in patients with myocardial infarction (MI).

Methods

The study included 41 patients with fatal MI type 1. Group 1 (n=24) comprised patients who died within 72 hours of MI (the inflammatory phase) and group 2 (n=17) comprised patients who died 4–28 days after MI (the regenerative phase). Macrophage infiltration (number of cells) in the heart was assessed by double immunofluorescence in the non-infarct area. Each area was evaluated in 20 random fields. We used CD163, CD206, stabilin-1, α-smooth muscle actin (α-SMA), interleukin-10 (IL-10) as markers of M2-like macrophages.

Results

The number of CD163+/CD206− (p=0.087) and CD163+/206+ (p=0.072) macrophages was higher during the regenerative phase of MI. The number of CD163-/CD206+, stabilin-1+/α-SMA-, stabilin-1+/α-SMA+, stabilin-1+/IL-10−, stabilin-1+/IL-10+, stabilin-1-/IL-10+ did not significantly change throughout the entire period of MI. The comparison of various M2 macrophage subpopulations into groups revealed following. In group 1 the number of CD163+/CD206− and CD163+/CD206+ cells prevailed over CD163−/CD206+ (p=0.033 and p=0.003, respectively), stabilin1+/α-SMA− cells over stabilin-1+/α-SMA+ (p<0.001), and stabilin-1+/IL-10+ cells over stabilin-1+/IL-10− (p=0.018). In group 2 the quantity of stabilin-1+/α-SMA− macrophages prevailed over stabilin-1+/α-SMA+ (p=0.005) and stabilin-1+/IL-10+ over stabilin-1−/IL-10+ (p=0.028). In group 1 the number of CD163+/CD206+ cells correlated with the absolute and the relative number of peripheral blood monocytes prior to the onset of death (R=0.97), while the quantity of stablin-1+/α-SMA+ cells correlated with the absolute number of peripheral blood monocytes at admission (R=-0.53). In group 2 the quantity of CD206+/CD163− cells correlated with the absolute and the relative number of monocytes in the peripheral blood at admission (R=0.73 and R=0.59, respectively), the quantity of CD163+/CD206− macrophages with the incidence of recurrent MI (R= 0.54), and the number of stabilin-1+/α-SMA+ macrophages with the age of patients (R=-0.58).

Conclusions

We have suggested that the key cardiac macrophage phenotypes contributing to the development of chronic inflammation and cardiac fibrosis in the regenerative phase of MI were stabilin-1+/α-SMA− and stabilin-1+/IL-10+. We revealed subpopulation of stabilin-1+/α-SMA+ macrophages, that indicated the possibility of cellular transdifferentiation and macrophage plasticity. Thus, our results supports that understanding the role of macrophages in initiation, progression, and resolution of cardiac fibrosis is one of the most promising goal in the design of anti-fibrotic treatment strategies for patients with MI.