Myocardial remodeling is an inevitable risk factor for cardiac arrhythmias and can potentially be corrected with cell therapy. Although the generation of cardiac cells ex vivo is possible, specific approaches to cell replacement therapy remain unclear. On the one hand, adhesive myocyte cells must be viable and conjugated with the electromechanical syncytium of the recipient tissue, which is unattainable without an external scaffold substrate. On the other hand, the outer scaffold may hinder cell delivery, for example, making intramyocardial injection difficult. To resolve this contradiction, we developed molecular vehicles that combine a wrapped (rather than outer) polymer scaffold that is enveloped by the cell and provides excitability restoration (lost when cells were harvested) before engraftment. It also provides a coating with human fibronectin, which initiates the process of graft adhesion into the recipient tissue and can carry fluorescent markers for the external control of the non-invasive cell position. In this work, we used a type of scaffold that allowed us to use the advantages of a scaffold-free cell suspension for cell delivery. Fragmented nanofibers (0.85 µm ± 0.18 µm in diameter) with fluorescent labels were used, with solitary cells seeded on them. Cell implantation experiments were performed in vivo. The proposed molecular vehicles made it possible to establish rapid (30 min) electromechanical contact between excitable grafts and the recipient heart. Excitable grafts were visualized with optical mapping on a rat heart with Langendorff perfusion at a 0.72 ± 0.32 Hz heart rate. Thus, the pre-restored grafts’ excitability (with the help of a wrapped polymer scaffold) allowed rapid electromechanical coupling with the recipient tissue. This information could provide a basis for the reduction of engraftment arrhythmias in the first days after cell therapy.

электронный журнал: Клиническая и экспериментальная морфология

Background: The systemic inflammatory response to coronary artery bypass grafting (CABG) is highly variable and a key driver of complications. We hypothesised that a pre-existing pro-inflammatory immune state, characterised by a skewed monocyte profile, ‘primes’ patients for an exaggerated response. This pilot prospective study aimed to test this hypothesis and to evaluate the Neutrophil-to-Albumin Ratio (NAR) as an integrated biomarker of this response, comparing it against the established Neutrophil-to-Lymphocyte Ratio (NLR). Methods: In this pilot prospective, single-centre pilot study, we enrolled 34 patients with multivessel coronary artery disease (CAD) scheduled for off-pump CABG and 20 control subjects. Preoperatively, peripheral blood monocyte subsets were quantified by flow cytometry. Neutrophil, lymphocyte, and albumin levels were measured before and after surgery to calculate NAR and NLR. Multivariable linear regression was used to test for independent predictors of the inflammatory response. Results: Preoperatively, CAD patients exhibited a reduced percentage of the classical monocyte subpopulation (p < 0.001), with a skew toward intermediate and non-classical subpopulations. Postoperatively, both NAR and NLR increased significantly (p < 0.001) and performed comparably in discriminating the postoperative state (AUC: 0.89 vs. 0.86, p > 0.05). Critically, in multivariable linear regression analysis, the preoperative percentage of classical monocytes remained a significant and independent predictor of the magnitude of the postoperative NAR surge (β = −0.028, p = 0.007), after adjusting for clinical confounders including atherosclerotic burden. Conclusion: A patient’s preoperative immune profile, specifically the degree of monocyte skew, is an independent predictor of the acute inflammatory response to CABG. This finding supports a ‘priming’ mechanism in high-risk patients. While NAR and NLR perform similarly as monitoring tools, the independent link between the underlying immunology and the postoperative outcome suggests that combining preoperative immunophenotyping with simple biomarker monitoring could offer a powerful new strategy for personalised risk stratification in cardiac surgery.

Currently, the analysis of the fibrosis severity during the restructuring of the surrounding extracellular matrix (ECM) is studied in most of the research works devoted to “cardiac remodeling”. At the same time, the role of the basal membrane of cardiomyocytes in heart diseases was not studied. The basal membrane of cardiomyocytes is a highly organized layer of the ECM which is located on the outer side of the sarcolemma. Degradation of ECM components is carried out by different types of matrix metalloproteinases (MMP), which have proteolytic activity and are actively involved in the process of ECM remodeling, destroying its components such as collagen, elastin, fibronectin, glycosaminoglycans and other structural components.Aim. To evaluate the ECM status in patients with coronary artery disease and its effect on left ventricular myocardial remodeling.Material and methods. Morphological and immunohistochemical (IHC) examination of left ventricular myocardial biopsies was performed in 16 patients undergoing left ventricular reconstruction in combination with coronary artery bypass grafting.Results. The IHC study revealed the accumulation of matrix metalloproteinase-9 in the cytoplasm of cardiomyocytes. This accumulation was combined with partial or complete destruction of the basal membranes (BM) of cardiomyocytes formed by type IV collagen.Conclusion. Type IV collagen destruction in basal membranes of left ventricular cardiomyocyteswasrevealed. It iscausedbytheactionofmatrixmetalloproteinase-9, which accumulates in the cell cytoplasm.

Endotoxin tolerance in monocytes is a mechanism that reduces the secretion of inflammatory cytokines upon repeated pathogen exposure, thereby protecting tissues from hyperinflammation. Previously, we demonstrated that monocytes from patients with asymptomatic carotid atherosclerosis exhibit impaired LPS tolerance. In this study, we aimed to investigate monocyte tolerance impairments in coronary atherosclerosis in greater detail. The study included 46 male patients with ischemic heart disease, divided into two groups based on coronary angiography results with and without coronary atherosclerosis. CD14 + monocytes were isolated from patients' blood and subjected to LPS stimulation on days 1 and 7 of culture. Transcriptomic analysis of monocytes was conducted. Monocyte subpopulations were assessed and sorted based on CD14 and CD16 expression. Patients with coronary atherosclerosis exhibited disrupted inflammatory responses in monocytes, characterized by elevated basal and LPS-induced IL-1β secretion. These patients demonstrated impaired LPS tolerance, as evidenced by increased CCL2 secretion upon repeated stimulation. Transcriptomic analysis revealed upregulation of inflammatory genes, particularly those associated with minor CD16 + monocyte subpopulations. The proportions of non-classical and intermediate monocytes were elevated in patients with atherosclerosis, with IL-1β and CCL2 secretion levels correlating predominantly with the intermediate monocyte subset. Functional analysis revealed that non-classical monocytes from healthy donors developed stable endotoxin tolerance. In contrast, intermediate and classical monocytes from some donors exhibited a non-tolerant response to LPS, as evidenced by secretion of IL-1β, IL-6, and CCL2. The differentiation of classical monocytes into intermediate monocytes may play a key role in the impaired endotoxin tolerance observed in atherosclerosis.

Platelets are one of the main participants in vascular accidents in cases of coronary heart disease (CHD). In this study, we sought to detect platelet apoptosis in patients with coronary artery disease who underwent scheduled myocardial revascularization surgery. To identify apoptotic events, we analyzed phosphatidylserine (PS) expression on the surface of platelets and mitochondrial membrane potential (ΔΨm) by flow cytometry in two groups of 30 patients aged 45–60 years: Group 1—patients before myocardial revascularization surgery and group 2—patients after myocardial revascularization surgery. The control group consisted of 10 healthy volunteers aged 45–60 years. According to our data, the percentage levels of PS expression in patients greatly decreased after surgery. We confirmed platelet apoptosis by recording depolarization of ΔΨm in pre- and postoperative patients. ΔΨm readings were considerably improved after surgery. Our data indicated that the functional parameters of platelets in patients with coronary heart disease differed from the characteristics of platelets in patients who underwent myocardial revascularization, and from those of patients in a control group. Future studies of platelet phenotypic characteristics and platelet apoptosis biomarkers should greatly advance our understanding of the pathophysiology of coronary heart disease, and further promote the development of methods for predicting adverse outcomes after surgery.