Pangonytė, Dalia

The formation of extracellular traps (ETs) through ETosis has emerged as a key mechanism in immunothrombosis. However, the temporal dynamics and clinical significance of ETosis in coronary thrombi of ST-elevation myocardial infarction (STEMI) patients remain incompletely understood. We investigated whether ETosis burden increases with thrombus age and is associated with DNASE1 and TREX1 genetic variants as well as impaired myocardial reperfusion. Thrombus aspirates from 81 STEMI patients undergoing primary percutaneous coronary intervention were histologically classified as fresh (n = 41) or lytic (n = 40). ETosis was quantified by citrullinated histone H3 (CitH3) immunohistochemistry and digital image analysis, complemented by multiplex staining for myeloperoxidase (MPO), CD68, caspase 3, and CD61. Plasma ET-related markers and genotyping of DNASE1 (rs1053874) and TREX1 (rs11797) were also performed. CitH3-positive cells were present in all thrombi but were more abundant in lytic (older) thrombi compared with fresh thrombi (1348 vs. 591 cells/mm2, p < 0.001). Increased ETosis was associated with neutrophil and macrophage infiltration, apoptosis, prolonged ischemia time, elevated systemic inflammation (neutrophil–lymphocyte ratio and C-reactive protein), and impaired myocardial reperfusion (lower TIMI flow grades). Moreover, the DNASE1 GG genotype was associated with higher densities of MPO- and CD68-positive cells, whereas the TREX1 CC genotype was associated with increased densities of CitH3-, MPO-, and CD68-positive cells. This study demonstrates that ETosis increases with coronary thrombus maturation and is associated with local inflammation and impaired reperfusion in STEMI. Genetic variants in DNASE1 and TREX1 may modulate inflammatory cell accumulation within thrombi. These findings suggest ETosis as a potential therapeutic target, particularly in patients with delayed presentation.

Matrix metalloproteinase 3 (MMP3), in conjunction with other MMPs, plays a key role in myocardial remodeling by breaking down the extracellular matrix of the heart and the development of heart failure (HF). However, the existing data on MMP3 protein expression in human myocardium remains insufficient. The objective of the present study was to determine the expression of MMP3 protein in left ventricular myocardial cells at varying stages of ischemic HF. To this end, a quantitative and semi-quantitative immunohistochemical analysis was performed on 113 samples of left ventricular myocardium. A non-selective digital myocardial image analysis revealed that the stage A HF group exhibited higher MMP3 protein expression compared to the control group (p < 0.001). Subsequent increases in immunostaining intensity of MMP3 were observed in the stage B HF group (p < 0.001). In the stage C/D HF group, MMP3 expression reached its highest level (p < 0.001). The intensity of immunostaining exhibited comparable tendencies in both cardiomyocytes and non-cardiomyocytes. Increased levels of MMP3 immunostaining in both types of cells were associated with increased left ventricular mass. Subjects who carried the 5A allele and patients with the 5A homozygous genotype exhibited a higher propensity for increased immunostaining levels in both cardiomyocytes and non-cardiomyocytes when compared to those with the 6A/6A and 5A/6A genotype. These changes in MMP3 protein expression were associated with left ventricular myocardial remodeling in the progression of ischemic HF.

Background & Objectives: Early protein expression and corresponding shape changes within cardiomyocytes exposed to ischemia can eventually exhaust their potential during remodelling, leading to HF. Study objective is to determine morphometric and immunohistochemical criteria for early cardiomyocyte remodelling and pre-symptomatic ischemic HF. Methods: 84 male patients of study were classified as risk HF (n=25), pre-HF (n=23), and symptomatic/advanced HF (n=34) groups according to ACC / AHA classification. Men who died suddenly with no prior cardiovascular diseases were a control group (n=25). Left cardiac ventricular myocardium of selected cases stained by Heidenhain’s azan trichrome were analysed by light microscopy, calculating cardiomyocytes‘ volume. Immunohistochemical reactions with antibodies against desmin, osteopontin, gremlin 1, and iRNA heterogenous nucleic ribonucleoprotein C were performed and evaluated in cardiomyocytes. Statistical analysis was applied (p<0.05). Local bioethical committee approval no. BE-2-77. Results: Volume of cardiomyocytes was already increasing in a risk HF group compared to the control group (p<0.001). This parameter continued to increase in pre-HF group, comparing to the risk HF (p<0.001) and control groups. Volume of cardiomyocytes was the greatest in the symptomatic / advanced HF group, compared to the pre-HF (p<0.001), risk HF (p<0.001), and the control groups (p<0.001). Strong correlation was detected between the volume of cardiomyocyte and intensity of immunohistochemical reaction against desmin (rS=0.681; p<0.001), osteopontin (rP=0.524; p<0.001), and gremlin 1 (rP=0.701; p<0.001). Correlation between cardiomyocytes‘ volume and iRNA heterogenous nucleic ribonucleoprotein C was weak (rS=0.248; p<0.05). Conclusion: Volume of cardiomyocytes already increases in the early remodelling during at risk HF of ischemic origin and continues to increase significantly in pre-HF of ischemic origin compared to control group. Changes of cardiomyocytic geometry correlate significantly with protein expression changes within cardiomyocytes. Therefore, morphometric and immunohistochemical data reflecting the earliest cardiomyocytic geometry and protein expression shifts during remodelling can contribute to ancillary diagnostics detecting early pathological remodelling before symptomatic ischemic HF.

Širdies nepakankamumas (ŠN) yra klinikinis sindromas, pasireiškiantis susilpnėjusia širdies funkcija dėl struktūrinių ir funkcinių pažeidimų. ŠN patogeneziniai mechanizmai yra plačiai apibūdinti, tačiau kardiomiocitų ankstyvieji kompensaciniai struktūriniai pakitimai dar nėra pakankamai ištirti. Įvertinus kardiomiocitų įtaką širdies raumens remodeliavimosi procesui ir šiose ląstelėse vykstančius baltymų raiškos persitvarkymus, vis daugiau dėmesio skiriama diagnostikos kriterijų ir žymenų, atspindinčių širdies raumens persitvarkymo metu vykstančių baltymų raiškos dinamiką ir sąsajas su kardiomiocitų formos bei funkcijos pokyčiais, paieškai. Atlikus detalų morfometrinį ir imunohistocheminį širdies kairiojo skilvelio tyrimą, pirmą kartą pateikiama kardiomiocitų struktūrinių pokyčių įvairovė, detaliai apibūdinami kardiomiocitų citoskeleto tarpinio filamento desmino, osteopontino, gremlino 1 ir iRNR potranskripcinį brendimą reguliuojančio heterogeninio ribonukleoproteino C raiškos pokyčiai remodeliavimosi metu, kai buvo A, B ir C–D stadijų išeminės kilmės ŠN pagal Amerikos kardiologijos kolegijos / Amerikos širdies asociacijos klasifikaciją. Išsamių morfometrinio ir imunohistocheminio kardiomiocitų tyrimų rezultatais įrodyta kardiomiocitų remodeliavimosi svarba išeminės kilmės ŠN patogenezei dar iki atsirandant pirmiesiems ŠN simptomams. Šie rezultatai gali būti taikomi ieškant naujų ŠN diagnostikos ir gydymo taikinių.

A relevant role of osteopontin (OPN) and gremlin 1 (Grem1) in regulating cardiac tissue remodeling and formation of heart failure (HF) are documented, with the changes of OPN and Grem1 levels in blood plasma due to acute ischemia, ischemic heart disease-induced advanced HF or dilatative cardiomyopathy being the primary focus in most of these studies. However, knowledge on the early OPN and Grem1 proteins expression changes within cardiomyocytes during remodeling due to chronic ischemia remains insufficient. The aim of this study was to determine the OPN and Grem1 proteins expression changes in human cardiomyocytes at different stages of ischemic HF. A semi-quantitative immunohistochemical analysis was performed in 105 myocardial tissue samples obtained from the left cardiac ventricles. Increased OPN immunostaining intensity was already detected in the stage A HF group, compared to the control group (p < 0.001), and continued to increase in the stage B HF (p < 0.001), achieving the peak of immunostaining in the stages C/D HF group (p < 0.001). Similar data of Grem1 immunostaining intensity changes in cardiomyocytes were documented. Significantly positive correlations were detected between OPN, Grem1 expression in cardiomyocytes and their diameter as well as the length, in addition to positive correlation between OPN and Grem1 expression changes within cardiomyocytes. These novel findings suggest that OPN and Grem1 contribute significantly to reorganization of cellular geometry from the earliest stage of cardiomyocyte remodeling, providing new insights into the ischemic HF pathogenesis.

Background and Objectives: The combination of aortic valve stenosis (AS) and ischemic heart disease (IHD) is quite common and is associated with myocardial fibrosis (MF). The purpose of this study was to evaluate the association between the histologically verified left ventricular (LV) MF and its geometry and function in isolated AS and AS within IHD groups. Materials and Methods: In a single-center, prospective trial, 116 patients underwent aortic valve replacement (AVR) with/without concomitant surgery. The study population was divided into groups of isolated AS with/without IHD. Echocardiography was used, and LV measurements and aortic valve parameters were obtained from all patients. Myocardial tissue was procured from all study patients undergoing elective surgery. Results: There were no statistical differences between isolated AS and AS+IHD groups in LV parameters or systolic and diastolic functions during the study periods. The collagen volume fraction was significantly different between the isolated AS and AS+IHD groups and was 7.3 ± 5.6 and 8.3 ± 6.4, respectively. Correlations between MF and left ventricular end-diastolic diameter (LVEDD) (r = 0.59, p = < 0.001), left ventricular mass (LVM) (r = 0.42, p = 0.011), left ventricular ejection fraction (LVEF) (r = −0.67, p < 0.001) and an efficient orifice area (EOA) (r = 0.371, p = 0.028) were detected in isolated AS during the preoperative period; the same was observed for LVEDD (r = 0.45, p = 0.002), LVM (r = 0.36, p = 0.026), LVEF (r = −0.35, p = 0.026) and aortic annulus (r = 0.43, p = 0.018) in the early postoperative period; and LVEDD (r = 0.35, p ≤ 0.05), LVM (r = 0.43, p = 0.007) and EOA (r = 0.496, p = 0.003) in the follow-up period. In the group of AS and IHD, correlations were found only with LV posterior wall thickness (r = 0.322, p = 0.022) in the follow-up period. Conclusions: Histological MF in AS was correlated with LVM and LVEDD in all study periods. No correlations between MF and LV parameters were found in aortic stenosis in the ischemic heart disease group across all study periods.

The angiotensin-converting enzyme 2 (ACE2)-angiotensin-(1-7)-Mas receptor axis plays a significant role in regulating myocardial remodeling and the development of heart failure (HF), with ACE2 being the primary focus. However, contemporary understanding of the membrane-bound form of the human ACE2 protein remains insufficient. The purpose of this study was to determine the expression of ACE2 protein in different cells of the left ventricular myocardium in non-diseased hearts and at various stages of ischemic HF. A total of 103 myocardial tissue samples from the left ventricle underwent quantitative and semi-quantitative immunohistochemical analysis. Upon assessing ACE2 immunostaining in all myocardial cells through unselective digital image analysis, there was no change in the stage A HF group. Nevertheless, the expression of ACE2 membrane protein in cardiomyocytes showed a tendency to increase, while non-cardiomyocyte ACE2 expression decreased significantly (p < 0.001). In the stage B HF group, the intensity of ACE2 immunostaining continued to increase with rising cardiomyocyte ACE2 expression (p < 0.001). Non-cardiomyocyte expression, in contrast, remained similar to that observed in the stage A HF group. In the stages C/D HF group, ACE2 expression reached its highest level in cardiomyocytes (p < 0.001), while ACE2 expression in non-cardiomyocytes was the lowest (p < 0.001). These changes in ACE2 protein levels are associated with left ventricular remodeling in ischemic HF.

This study investigates the therapeutic potential of human placental mesenchymal stem cells (P-MSCs) and their extracellular vesicles (EVs) in a murine model of acute respiratory distress syndrome (ARDS), a condition with growing relevance due to its association with severe COVID-19. We induced ARDS-like lung injury in mice using intranasal LPS instillation and evaluated histological changes, neutrophil accumulation via immunohistochemistry, bronchoalveolar lavage fluid cell count, total protein, and cytokine concentration, as well as lung gene expression changes at three time points: 24, 72, and 168 h. We found that both P-MSCs and EV treatments reduced the histological evidence of lung injury, decreased neutrophil infiltration, and improved alveolar barrier integrity. Analyses of cytokines and gene expression revealed that both treatments accelerated inflammation resolution in lung tissue. Biodistribution studies indicated negligible cell engraftment, suggesting that intraperitoneal P-MSC therapy functions mostly through soluble factors. Overall, both P-MSC and EV therapy ameliorated LPS-induced lung injury. Notably, at the tested dose, EV therapy was more effective than P-MSCs in reducing most aspects of lung injury.

Elsholtzia ciliata essential oil (E. ciliata) has been reported to have an impact on the cardiovascular system. However, its toxicity remains unknown. Therefore, the objective of this investigation was to evaluate the toxicological aspects of the E. ciliata extract. Male Balb/c mice were subjected to either acute (a single dose administered for 24 h) or sub-chronic (daily dose for 60 days) intraperitoneal injections of the E. ciliata extract. The mice were assessed for blood hematological/biochemical profiles, mitochondrial functions, and histopathological changes. Additionally, in vitro cytotoxicity assessments of the E. ciliata extract were performed on immobilized primate kidney cells (MARC-145, Vero) and rat liver cells (WBF344) to evaluate cell viability. The control groups received an equivalent volume of olive oil or saline. Our results demonstrated no significant detrimental effects on hematological and biochemical parameters, mitochondrial functions, cellular cytotoxicity, or pathological alterations in vital organs following the intraperitoneal administration of the E. ciliata extract over the 60-day sub-chronic toxicity study. In general, E. ciliata displayed no indications of toxicity, suggesting that the E. ciliata extract is a safe natural product with a well-defined therapeutic and protective index (found to be 90 and 54, respectively) in Balb/c mice.

Although major pathogenesis mechanisms of heart failure (HF) are well established, the significance of early (mal)adaptive structural changes of cardiomyocytes preceding symptomatic ischemic HF remains ambiguous. The aim of this study is to present the morphological characterization of changes in cardiomyocytes and their reorganization of intermediate filaments during remodeling preceding symptomatic ischemic HF in an adult human heart. A total of 84 myocardial tissue samples from middle-left heart ventricular segments were analyzed histomorphometrically and immunohistochemically, observing the cardiomyocyte’s size, shape, and desmin expression changes in the remodeling process: Stage A of HF, Stage B of HF, and Stages C/D of HF groups (ACC/AHA classification). Values p < 0.05 were considered significant. The cellular length, diameter, and volume of Stage A of HF increased predominantly by the diameter vs. the control group (p < 0.001) and continued to increase in Stage B of HF in a similar pattern (p < 0.001), increasing even more in the C/D Stages of HF predominantly by length (p < 0.001). Desmin expression was increased in Stage A of HF vs. the control group (p < 0.001), whereas it was similar in Stages A and B of HF (p > 0.05), and most intense in Stages C/D of HF (p < 0.001). Significant morphological changes of cardiomyocytes and their cytoskeletal reorganization were observed during the earliest remodeling events preceding symptomatic ischemic HF.