Late persistent expressions of ICAM-1 and VCAM-1 on myocardial tissue in children with lymphocytic myocarditis

Myocarditis: A multi-omics approach

Myocarditis, an inflammatory condition of weakened heart muscles often triggered by a variety of causes, that can result in heart failure and sudden death. Novel ways to enhance our understanding of myocarditis pathogenesis is available through newer modalities (omics). In this review, we examine the roles of various biomolecules and associated functional pathways across genomics, transcriptomics, proteomics, and metabolomics in the pathogenesis of myocarditis. Our analysis further explores the reproducibility and variability intrinsic to omics studies, underscoring the necessity and significance of employing a multi-omics approach to gain profound insights into myocarditis pathogenesis. This integrated strategy not only enhances our understanding of the disease, but also confirms the critical importance of a holistic multi-omics approach in disease analysis.

Interaction Between Blood Vasculatures and Lymphatic Vasculatures During Inflammation

Physiological activity cannot be regulated without the blood and lymphatic vasculatures, which play complementary roles in maintaining the body's homeostasis and immune responses. Inflammation is the body's initial response to pathological injury and is responsible for protecting the body, removing damaged tissues, and restoring and maintaining homeostasis in the body. A growing number of researches have shown that blood and lymphatic vessels play an essential role in a variety of inflammatory diseases. In the inflammatory state, the permeability of blood vessels and lymphatic vessels is altered, and angiogenesis and lymphangiogenesis subsequently occur. The blood vascular and lymphatic vascular systems interact to determine the development or resolution of inflammation. In this review, we discuss the changes that occur in the blood vascular and lymphatic vascular systems of several organs during inflammation, describe the different scenarios of angiogenesis and lymphangiogenesis at different sites of inflammation, and demonstrate the prospect of targeting the blood vasculature and lymphatic vasculature systems to limit the development of inflammation and promote the resolution of inflammation in inflammatory diseases.

Up-regulation of miR-27 extenuates lipopolysaccharide-induced injury in H9c2 cells via modulating ICAM1 expression

BACKGROUND

MiR-27 has been found to present an overt myocardial expression during cardiogenesis. However, whether miR-27 involves in myocarditis development and the possible molecular mechanism remain unknown. The purpose of this study was to investigate the biological characteristic of miR-27 in LPS-damaged H9c2 cells.

METHODS

H9c2 cells were treated with lipopolysaccharide (LPS, 10 µg/ml) for 12 h to form cell injury. MiR-27 mimic and inhibitor were used to up-regulate or down-regulate miR-27 expression. MTT assay and flow cytometry analysis were conducted to test cell viability and apoptosis. The relative RNA expression level of miR-27 and intercellular adhesion molecule 1 (ICAM1) was determined by qRT-PCR. Luciferase reporter gene assay was utilized to confirm the interaction between miR-27 and ICAM1. Western blot was used to determine the protein expression levels.

RESULTS

We observed that LPS treatment significantly decreased the level of miR-27 in H9c2 cells. Moreover, LPS exposure suppressed cell viability, promoted cell apoptosis and increased the relative expression of p-NF-κB p65/NF-κB p65 and p-IκBα/IκBα. Up-regulation of miR-27 increased cell proliferation and reduced cell apoptosis, while down-regulation of miR-27 suppressed cell growth and promoted cell apoptosis. ICAM1 was predicted and verified as a target of miR-27, and the expression of ICAM1 is negatively regulated by miR-27. The relative expression of p-NF-κB p65/NF-κB p65 and p-IκBα/IκBα was dramatically decreased by miR-27 mimic and increased by miR-27 inhibitor.

CONCLUSION

Our study illustrated that up-regulation of miR-27 exhibits a protective effect on LPS-damaged H9c2 cells, which may be achieved by regulating ICAM1 and NF-κB signaling.

Infectious myocarditis: the role of the cardiac vasculature

Infectious myocarditis is the result of an immune response to a microbial infection of the heart. The blood vessels of the heart, both the intramyocardial microvasculature and the large epicardial coronary arteries, play an important role in the pathogenesis of infectious myocarditis. First of all, in addition to cardiomyocytes, endothelial cells of the cardiac (micro)vasculature are direct targets for infection. Moreover, through the expression of adhesion molecules and antigen presenting Major Histocompatibility Complex molecules, the blood vessels assist in shaping the cellular immune response in infectious myocarditis. In addition, damage and dysfunction of the cardiac (micro)vasculature are associated with thrombus formation as well as aberrant regulation of vascular tone including coronary vasospasm. These in turn can cause cardiac perfusion abnormalities and even myocardial infarction. In this review, we will discuss the role of the cardiac (micro)vasculature in the pathogenesis of infectious myocarditis.

Circulating adhesion molecules in patients with Keshan disease and their relationship with Coxsackie B virus infection

This study determined the levels of serum soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecular-1 (sVCAM-1) in patients with different types of Keshan disease (KD), examined the relationship between Coxsackie B virus-specific IgM antibody (CBV-IgM) and sICAM-1 or sVCAM-1 in KD patients, and investigated the role of these adhesion molecules in the pathogenesis of KD and their clinical implications. The levels of serum sICAM-1, sVCAM-1 and CBV-IgM were measured by using enzyme-linked immunosorbent assay in 22 patients with chronic Keshan disease (CKD), 27 with latent Keshan disease (LKD) and 28 healthy controls. The subjects in different groups were adjusted for sex and age. Echocardiography was adopted to determine left ventricular ejection fraction (LVEF) in 22 patients with CKD. The results showed that CKD patients had significantly higher levels of sICAM-1 and sVCAM-1 than LKD patients and healthy controls (P<0.01 for all). And there was significant difference in the levels of the 2 adhesion molecules between LKD patients and healthy controls (P<0.05). A negative correlation was found between LVEF and sICAM-1 or sVCAM-1 in CKD patients. The percentage of CBV-specific IgM positive individuals in KD patients was significantly higher than that of healthy controls. In CVB-specific IgM positive patients, the levels of serum sICAM-1 and sVCAM-1 were significantly greater than those in CBV-specific IgM negative counterpart. It was concluded that the increase in the levels of sICAM-1 and sVCAM-1 suggests the progression of inflammation in KD. sICAM-1 and sVCAM-1 can promote the development of myocardial pathology and lead to poor myocardial function. The increased serum sICAM-1 and sVCAM-1 in KD patients may be related to CBV infection.

Noninvasive imaging in myocarditis

Increased recognition of the role of inflammation in acute and chronic dilated cardiomyopathy has revived an interest in noninvasive imaging for detection of myocarditis. Diagnostic strategies that are based on molecular imaging promise to further advance our understanding and improve diagnostic precision. This article reviews the strengths and limitations of common clinical tests used for the diagnosis of myocarditis, with a focus on the emerging role of cardiovascular magnetic resonance imaging. Novel imaging modalities that are currently in preclinical development are discussed with recommendations for future clinical research.

Sudden infant death syndrome (SIDS)--standardised investigations and classification: recommendations

Sudden infant death syndrome (SIDS) still accounts for considerable numbers of unexpected infant deaths in many countries. While numerous theories have been advanced to explain these events, it is increasingly clear that this group of infant deaths results from the complex interaction of a variety of heritable and idiosyncratic endogenous factors interacting with exogenous factors. This has been elegantly summarised in the "three hit" or "triple risk" model. Contradictions and lack of consistencies in the literature have arisen from diverse autopsy approaches, variable applications of diagnostic criteria and inconsistent use of definitions. An approach to sudden infant death is outlined with discussion of appropriate tissue sampling, ancillary investigations and the use of controls in research projects. Standardisation of infant death investigations with the application of uniform definitions and protocols will ensure optimal investigation of individual cases and enable international comparisons of trends.

Successful implantation of intravenously administered stem cells correlates with severity of inflammation in murine myocarditis

The present study was designed to determine whether cardiac inflammation is important for the successful homing of stem cells to the heart after intravenous injection in a murine myocarditis model. Male Bagg albino/c mice were infected with encephalomyocarditis virus (EMCV) to produce myocarditis. Subgroups of mice received single injections by tail vein of embryonic stem cells (ESCs) transfected with green fluorescent protein (GFP) as a marker at days 3, 14, or 60 after infection; other subgroups without stem cell injections were killed at each of these time points to assess the degree of inflammation present. The surviving mice were killed at day 90 after virus infection and hemodynamics, gross pathology, histology, and inflammatory cytokine production in the hearts were measured. Our results indicate that myocardial inflammation was most severe and cytokine production highest at day 14 after EMCV inoculation, and in particular, was strongly positive for interleukin 6. Mice receiving intravenous ESC injections on day 14 after EMCV inoculation showed the largest number of GFP-positive cells at the time of death and the greatest functional improvement compared to uninfected controls without inflammation. We conclude that factors released from myocardium during inflammation are important for enhancing the homing, migration, and implantation of systemically infused stem cells.

Immunomodulatory treatment strategies in inflammatory cardiomyopathy: current status and future perspectives

Chronic autoimmunity and viral persistence constitute prognostic factors for adverse outcome in dilated cardiomyopathy patients. Inflammatory cardiomyopathy is a specific cardiomyopathy entity diagnosed in approximately 50% of dilated cardiopmyopathy patients by immunohistological quantification of immunocompetent infiltrates and cell adhesion molecule abundance. Patients with autoimmune inflammatory cardiomyopathy benefit from immunosuppressive treatment and immunoadsorption by improvement of left ventricular ejection fraction and heart failure symptoms, paralleled by a significant suppression of intramyocardial inflammation. However, dilated cardiomyopathy patients with viral persistence do not respond favorably to immunosuppression.

sICAM-1 correlates with myocardial ICAM-1 expression in dilated cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is etiopathogenically linked to intramyocardial inflammation, which is reflected by ICAM-1 abundance. We investigated whether soluble ICAM-1 (sICAM-1) levels in the sera of DCM patients are associated with intramyocardial ICAM-1 expression.

METHODS

Immunohistochemically detected ICAM-1 expression was quantified semiquantitatively in endomyocardial biopsies from DCM patients (n=45; n=17 females; age: 48+/-15 years) and from n=12 donor hearts (controls) by a human observer (baseline vs. enhanced expression) and quantitatively by a digital image analysis (DIA) system. The DIA-measured qualities were area fraction (AF), surface-volume ratio (SVR) and integral optical density (ID). The sICAM-1 levels of the DCM patients and n=12 healthy volunteers (controls) were measured by ELISA (means of duplicate measurements). Intramyocardial ICAM-1 expression and sICAM-1 levels were compared in these DCM patients.

RESULTS

Of the DCM patients, n=24 (53%) demonstrated statistically higher sICAM-1 levels compared to controls (>198 ng/ml). By semiquantitative and quantitative DIA evaluation, endothelial ICAM-1 abundance was present in n=25 (56%) of the DCM biopsies. sICAM-1 correlated significantly (P<0.001) both with the semiquantitatively assessed and the DIA-measured ICAM-1-AF, the ICAM-1-SVR and the ICAM-1-ID. The positive predictive value of sICAM-1 measurements for intramyocardial ICAM-1 abundance was 96%, and the negative predictive value was 71%, with a receiver operating characteristic area under the curve of 0.93. Furthermore, sICAM-1 levels correlated with intramyocardial T-lymphocytic (CD2+/CD3+) infiltrates (P<0.03).

CONCLUSIONS

Measurement of non-invasively obtained sICAM-1 reliably reflects intramyocardial ICAM-1 expression and may therefore serve as a non-invasive marker of inflammatory activity in DCM.

Cytotoxic perforin+ and TIA-1+ infiltrates are associated with cell adhesion molecule expression in dilated cardiomyopathy

OBJECTIVE

To phenotypically characterize cytotoxic T-lymphocytes (CTLs: Perforin+ and TIA-1+ phenotypes) and to study the interactions with cell adhesion molecules (CAMs) in dilated cardiomyopathy (DCM).

BACKGROUND

DCM is linked to intramyocardial inflammation, being characterized by T-lymphocytic infiltration and CAMs abundance. However, the pathogenic significance of increased CD3+ lymphocytes remains obscure as these do not correlate with CTLs (perforin+ and TIA1+ phenotypes). CAMs participate in the phenotypic repertoire and effector pathways of CTLs.

METHODS

CAMs-expression (ICAM-1, VCAM-1, LFA-3, CD29, CD62E and CD62P and beta(2)-integrins), CD3+ (T-lymphocytes), CD57+ (NK-cells) and adhesion related (CD18+, CD11a+, CD11b+, CDw49d+) phenotyped infiltrates were investigated in endomyocardial biopsies (EMBs) from 89 DCM patients (33 female; LVEF<40%) using immunohistochemisty. The enteroviral genome was identified by nested RT-PCR.

RESULTS

CAMs abundance was confirmed in 55 DCM patients (62%) and 29 EMBs (33%) were graded CTLs+ (>1.5 TIA-1+ and/or >2.0 perforin+ infiltrates/hpf). CTLs correlated with all endothelial CAMs-markers studied (P<0.01), the adhesion related phenotypes of infiltrates (LFA-1, VLA-4, CD18) and CD57+ NK-cells (P<0.02). There was no correlation of CTLs with CD3+ T-lymphocytes, CD11b+ macrophages, enteroviral infection (present in n=16/18%), clinical history and LVEF (P>0.05). Phenomena suggestive of CTLs mediated myocytolysis were observed in 10 patients (11%).

CONCLUSIONS

CTLs-infiltrates are associated with endothelial CAMs-abundance and co-express adhesion related (beta2-integrins, VLA-4) and NK-cellular antigens (CD57) in DCM. Endothelial CAMs expression also reflects cytotoxic activation of intramyocardial infiltrates, which is not reflected by immunologically nai;ve CD3 T-lymphocytes.

Early elevation of plasma soluble intercellular adhesion molecule-1 in pediatric acute lung injury identifies patients at increased risk of death and prolonged mechanical ventilation

OBJECTIVE

To determine whether soluble intercellular adhesion molecule (sICAM)-1, a biological marker of alveolar epithelial and lung endothelial injury and alveolar macrophage activation, is elevated in the plasma of pediatric patients with acute lung injury and to examine whether elevated plasma sICAM-1 levels correlate with two clinically relevant outcomes, mortality and the duration of mechanical ventilation.

DESIGN

Prospective cohort study.

SETTING

Pediatric intensive care units at an urban children's hospital and a tertiary university medical center.

PATIENTS

Eighty-three pediatric patients with acute lung injury and five intubated controls.

INTERVENTIONS

Plasma sICAM-1 levels were measured on days 1 and 2 of acute lung injury in pediatric patients and on day 1 of mechanical ventilation in control patients.

MEASUREMENTS AND MAIN RESULTS

Plasma sICAM-1 levels were significantly higher in patients with acute lung injury compared with controls (966 +/- 830 vs. 251 +/- 168 ng/mL, p <.05). Levels of sICAM-1 were also significantly higher on days 1 and 2 of acute lung injury in nonsurvivors and in patients requiring prolonged duration of mechanical ventilation. Also, plasma sICAM-1 levels >1000 ng/mL had a high specificity for identifying nonsurvivors of acute lung injury.

CONCLUSIONS

Early elevation of sICAM-1 in the plasma of pediatric patients with acute lung injury is associated with increased risk of death or prolonged duration of mechanical ventilation.

Targeted disruption of ICAM-1, P-selectin genes improves cardiac function and survival in TNF-alpha transgenic mice

We have developed a transgenic mouse model in which tumor necrosis factor (TNF)-alpha is overexpressed exclusively in the heart under the regulation of the alpha-myosin heavy chain promoter. These animals develop chronic heart failure associated with severe leukocyte infiltration in both the atria and the ventricles. The purpose of this study was to investigate the role of adhesion molecules in mediating cardiac dysfunction in the TNF-alpha transgenic model. TNF-alpha transgenic mice were bred with mice null for intercellular adhesion molecule (ICAM)-1 and P-selectin genes to obtain a lineage of ICAM-1 and P-selectin null mice with selective overexpression of TNF-alpha in the heart. TNF-alpha transgenic animals showed marked upregulation of ICAM-1 mRNA and protein; however, P-selectin mRNA and protein remained undetectable despite chronic TNF overexpression. Cardiac function was markedly improved in the ICAM-1(-/-), P-selectin(-/-), TNF-alpha transgenic group versus the ICAM(+/+), P-selectin(+/+), TNF-alpha transgenic group. Kaplan-Meier survival curves showed statistically significant prolonged survival in the ICAM-1(-/-), P-selectin(-/-), TNF-alpha transgenic animals. These data suggest that ICAM-1 mediates at least in part the cardiac dysfunction induced by TNF-alpha expression by cardiac myocytes.

Upregulation of adhesion molecules and class I HLA in the myocardium of chronic chagasic cardiomyopathy and heart allograft rejection, but not in dilated cardiomyopathy

The immunohistochemical expression of adhesion molecules and class I HLA in chronic chagasic cardiomyopathy were compared with heart allograft rejection and dilated cardiomyopathy, to obtain new knowledge on the occurrence of autoimmunity and inflammation in the pathogenesis of chronic chagasic cardiomyopathy. Semiquantitative immunohistochemistry was performed for CD8+ T cells, ICAM-1, VCAM-1, LFA-1, and class I HLA in frozen sections of myocardial biopsies from patients presenting chronic chagasic cardiomyopathy (group I, n = 12), heart allograft rejection (group II, n = 9) or dilated cardiomyopathy (group III, n = 9). A high mean number of CD8+ T cells/mm(2) was present in group I (18.26) and group II (28.60), but not in group III (0.83). The frequency of high expression for ICAM-1 and VCAM-1 on the endothelial and interstitial cells, and for class I HLA on the cardiomyocytes was greater in group I (100%, 33.3%, and 83.3%, respectively) and group II (100%, 66.7%, and 77.8%, respectively), compared to group III (66.7%, 0%, and 0%, respectively). ICAM-1 and VCAM-1 probably participate in the development of the lymphocytic inflammatory infiltrate present in chronic chagasic cardiomyopathy, as seen in heart allograft rejection. The overexpression of adhesion molecules and the induction of class I HLA on the cardiomyocytes are probably related to the high cytokine levels at the inflammatory sites in chronic chagasic cardiomyopathy. Although the induction of class I HLA on the cardiomyocytes is consistent with an autoimmune reaction, it should not be considered as irrefutable evidence for autoimmunity in chronic chagasic cardiomyopathy. The differential expression of adhesion molecules and class I HLA in dilated cardiomyopathy compared to chronic chagasic cardiomyopathy suggests differences in the pathogenesis of these cardiomyopathies.

Expression of cell adhesion molecules in dilated cardiomyopathy: evidence for endothelial activation in inflammatory cardiomyopathy

BACKGROUND

Dilated cardiomyopathy (DCM) is pathogenically linked to inflammatory cardiomyopathy (InfCM), which is characterized by intramyocardial infiltration. The transendothelial migration of immunocompetent cells is mediated by cell adhesion molecules (CAMs).

METHODS AND RESULTS

We investigated the expression pattern of CAMs (immunoglobulin superfamily, 32 selectins, and beta1- and beta2-integrins) in endomyocardial biopsies from DCM patients (n=152; left ventricular ejection fraction <40%) using immunohistochemistry. Whereas few specimens obtained at autopsy (controls; n=14) presented enhanced expression regarding single endothelial CAMs (human leukocyte antigen [HLA] class I, 7%; HLA-DR, 14%; CD29, 14%), none demonstrated concurrent abundance of >3 CAMs (inflammatory endothelial activation), nor did any control tissue prove positive for InfCM (>7.0 CD3+ lymphocytes per 1 mm2). In comparison, 64% (n=97) of the DCM biopsies were evaluated positive for InfCM and 67% (n=101) for inflammatory endothelial activation, respectively. Whereas expression of HLA class I, HLA-DR, intercellular cell adhesion molecule-1, and CD29 was distributed homogeneously within a patient's serial sections, immunoreactivity of vascular cell adhesion molecule-1, lymphocyte function antigen-3, and the selectins was accentuated on single vascular endothelia. Sixty-six percent of the DCM biopsies presented CD29 abundance also within the extracellular matrix and the sarcolemma. CD62P and CD62E were present in 16% and 40% of the DCM patients, respectively. Endothelial CAM representatives correlated with one another (P<0.05), except for CD62P with HLA. Endothelial CAM expression correlated with intramyocardial infiltrates phenotyped by the corresponding counterreceptors.

CONCLUSIONS

Inflammatory endothelial activation is present in 67% of DCM patients. Because CAM expression correlates with the immunohistological diagnosis of InfCM and counterreceptor-bearing intramyocardial infiltrates, evaluation of endothelial CAMs might be of diagnostic significance in InfCM.