Relationship Between Peripheral Monocytosis and Nonrecovery of Left Ventricular Function in Patients With Left Ventricular Dysfunction Complicated With Acute Myocardial Infarction

Identification and validation of lipid metabolism-related key genes as novel biomarkers in acute myocardial infarction and pan-cancer analysis

BACKGROUND

Acute myocardial infarction (AMI) is associated with high morbidity and mortality, and is associated with abnormal lipid metabolism. We identified lipid metabolism related genes as biomarkers of AMI, and explored their mechanisms of action.

METHODS

Microarray datasets were downloaded from the GEO database and lipid metabolism related genes were obtained from Molecular Signatures Database. WGCNA was performed to identify key genes. We evaluated differential expression and performed ROC and ELISA analyses. We also explored the mechanism of AMI mediated by key genes using gene enrichment analysis. Finally, immune infiltration and pan-cancer analyses were performed for the identified key genes.

RESULTS

TRL2, S100A9, and HCK were identified as key genes related to lipid metabolism in AMI. Internal and external validation (including ELISA) showed that these were good biomarkers of AMI. In addition, the results of gene enrichment analysis showed that the key genes were enriched in inflammatory response, immune system process, and tumor-related pathways. Finally, the results of immune infiltration showed that key genes were concentrated in neutrophils and macrophages, and pan-cancer analysis showed that the key genes were highly expressed in most tumors and were associated with poor prognosis.

CONCLUSIONS

TLR2, S100A9, and HCK were identified as lipid metabolism related novel diagnostic biomarkers of AMI. In addition, AMI and tumors may be related through the inflammatory immune response.

Features of metabolic syndrome and inflammation independently affect left ventricular function early after first myocardial infarction

BACKGROUND

A high body mass index (BMI) is often associated with metabolic syndrome, which is accompanied by systemic low-grade chronic inflammation. Here, we analyzed whether BMI, other components of metabolic syndrome, and/or inflammatory markers correlate with left ventricular geometry, function, and infarct size as assessed by serial cardiac magnetic resonance imaging (MRI) after a first (clinically evident) ST-elevation MI (STEMI).

METHODS

Within the Etiology, Titre-Course, and effect on Survival (ETiCS) study, cardiac MRI conducted 7-9 days and 12 months after MI enabled longitudinal characterization of patients with a first STEMI along with serial routine blood counts and multiplex cytokine measurements.

RESULTS

Of 91 locally included STEMI patients, 47% were overweight (25 kg/m² < BMI < 30 kg/m²) and 24% were obese (BMI ≥ 30 kg/m²). No patient died during 12 months of follow-up. Left ventricular ejection fraction (LVEF), measured 7-9 days after STEMI, was significantly lower in overweight (49.5 ± 7.1%) and obese (45.8 ± 12.0%) patients than in the normal weight group (56.2 ± 7.7%). Along with BMI (T = -3.8; p < 0.001), hemoglobin A1c (HbA1c; T = -3.1; p = 0.004) and peak C-reactive protein (T = -2.6; p = 0.013) emerged as independent predictors of worse LVEF 7-9 days post MI (R² = 0.45). Only peak C-reactive protein (T = -4.4; p < 0.001), but not parameters of the metabolic syndrome, predicted worse LVEF 12 months after STEMI (R² = 0.20).

CONCLUSION

Both BMI and HbA1c correlated negatively with LVEF only early, but not late after STEMI. Peak CRP evolved as strongest predictor of cardiac function at all time points independent of the metabolic syndrome.

Leukocyte-Associated Immunoglobulin-like Receptor-1 is regulated in human myocardial infarction but its absence does not affect infarct size in mice

Heart failure after myocardial infarction (MI) depends on infarct size and adverse left ventricular (LV) remodelling, both influenced by the inflammatory response. Leukocyte-associated immunoglobulin-like receptor 1 (LAIR-1) is an inhibitory receptor of ITAM-dependent cell activation, present on almost all immune cells. We investigated regulation of LAIR-1 leukocyte expression after MI in patients and hypothesized that its absence in a mouse model of MI would increase infarct size and adverse remodelling. In patients, LAIR-1 expression was increased 3 days compared to 6 weeks after MI on circulating monocytes (24.8 ± 5.3 vs. 21.2 ± 5.1 MFI, p = 0.008) and neutrophils (12.9 ± 4.7 vs. 10.6 ± 3.1 MFI, p = 0.046). In WT and LAIR-1^-/- mice, infarct size after ischemia-reperfusion injury was comparable (37.0 ± 14.5 in WT vs. 39.4 ± 12.2% of the area at risk in LAIR-1^-/-, p = 0.63). Remodelling after permanent left coronary artery ligation did not differ between WT and LAIR-1^-/- mice (end-diastolic volume 133.3 ± 19.3 vs. 132.1 ± 27.9 μL, p = 0.91 and end-systolic volume 112.1 ± 22.2 vs. 106.9 ± 33.5 μL, p = 0.68). Similarly, no differences were observed in inflammatory cell influx or fibrosis. In conclusion, LAIR-1 expression on monocytes and neutrophils is increased in the acute phase after MI in patients, but the absence of LAIR-1 in mice does not influence infarct size, inflammation, fibrosis or adverse cardiac remodelling.

Peripheral monocytosis as a predictive factor for adverse outcome in the emergency department: Survey based on a register study

Monocytosis is associated with chronic infections such as tuberculosis or endocarditis as well as rheumatic and myeloproliferative disorders. Monocytes are also involved in the pathogenesis of atherosclerosis, coronary artery disease, and stroke. The value of monocytosis as a prognostic marker in different diagnostic groups in the emergency setting, however, has not been investigated so far.The aim of the article is to study monocytosis as an outcome factor in the emergency setting.In a Swiss register study, we analyzed monocyte counts in 4238 patients aged >18 years who were admitted to the emergency department of a regional tertiary care hospital. Monocytosis was defined as 0.8×10 cells/L. Diagnoses were grouped into infection, cardiovascular, neurological, metabolic, gastrointestinal, pulmonary, or other. Thirty-day mortality was defined as the primary endpointA total of 1217 patients with monocytosis were identified. Patients with monocytosis at admission suffered more frequently from respiratory symptoms (17.7% vs 8.9%, P <.001) and infection as the final diagnosis (20.8% vs 10.3%, P <.001) while neurological diagnoses were significantly lower in the monocytosis group (15.3% vs 30.9%, P <.001). Patients with monocytosis suffered from more comorbidities such as congestive heart failure, chronic obstructive pulmonary disease, tumor, diabetes, or renal failure but not dementia. When adjusted for age, gender, comorbidities, and main diagnosis, the 30-day mortality (P = .002) and length of stay (P = .001) were significantly higher in patients with monocytosis. The 30-day mortality in patients with monocytosis was most notably influenced by a cardiological diagnosis (odds ratio 3.91).An increased monocyte count predicts adverse outcome in patients admitted to the emergency department. Mechanistic studies will be necessary to specify the potentially detrimental role of monocytosis in critical illness.

Monocytes increase human cardiac myofibroblast-mediated extracellular matrix remodeling through TGF-β1

Following myocardial infarction (MI), cardiac myofibroblasts remodel the extracellular matrix (ECM), preventing mechanical complications. However, prolonged myofibroblast activity leads to dysregulation of the ECM, maladaptive remodeling, fibrosis, and heart failure (HF). Chronic inflammation is believed to drive persistent myofibroblast activity; however, the mechanisms are unclear. We assessed the influence of peripheral blood monocytes on human cardiac myofibroblast activity in a three-dimensional (3D) ECM microenvironment. Human cardiac myofibroblasts isolated from surgical biopsies of the right atrium and left ventricle were seeded into 3D collagen matrices. Peripheral blood monocytes were isolated from healthy human donors and cocultured with myofibroblasts. Monocytes increased myofibroblast activity measured by collagen gel contraction (baseline: 57.6 ± 5.9% vs. coculture: 65.2 ± 7.1% contraction; P < 0.01) and increased local ECM remodeling quantified by confocal microscopy. Under coculture conditions that allow indirect cellular interaction via paracrine factors but prevent direct cell-cell contact, monocytes had minimal effects on myofibroblast activity (17.9 ± 11.1% vs. 6.4 ± 7.0% increase, respectively; P < 0.01). When cells were cultured under direct contact conditions, multiplex analysis of the coculture media revealed an increase in the paracrine factors TGF-β1 and matrix metalloproteinase 9 compared with baseline (122.9 ± 10.1 pg/ml and 3,496.0 ± 190.4 pg/ml, respectively, vs. 21.5 ± 16.3 pg/ml and 183.3 ± 43.9 pg/ml; P < 0.001). TGF-β blockade abolished the monocyte-induced increase in cardiac myofibroblast activity. These data suggest that direct cell-cell interaction between monocytes and cardiac myofibroblasts stimulates TGF-β-mediated myofibroblast activity and increases remodeling of local matrix. Peripheral blood monocyte interaction with human cardiac myofibroblasts stimulates myofibroblast activity through release of TGF-β1. These data implicate inflammation as a potential driver of cardiac fibrosis.

Time course of cardiac inflammation during nitric oxide synthase inhibition in SHR: impact of prior transient ACE inhibition

We have previously demonstrated that angiotensin-converting enzyme (ACE) inhibition with enalapril produces persistent effects that protect against future nitric oxide synthase (NOS) inhibitor (L-arginine methyl ester, L-NAME)-induced cardiac dysfunction and outer wall collagen deposition in spontaneously hypertensive rats (SHR). In the present study, we dissect the cytokine/chemokine release profile during NOS inhibition, its correlation to pathological cardiac remodeling and the impact of transient ACE inhibition on these effects. Adult male SHR were treated with enalapril (E+L) or tap water (C+L) for 2 weeks followed by a 2-week washout period. Rats were then subjected to 0, 3, 7 or 10 days of L-NAME treatment. The temporal response to NOS inhibition was evaluated by measuring arterial pressure, cardiac remodeling and cytokine/chemokine levels. L-NAME equivalently increased blood pressure and myocardial and vascular injury in C+L and E+L rats. However, pulse pressure (PP) was only transiently altered in C+L rats. The levels of several inflammatory mediators were increased during L-NAME treatment. However, interleukin-6 (IL-6) and IL-10 and monocyte chemoattractant protein-1 were uniquely increased in C+L hearts; whereas IL-4 and fractalkine were only elevated in E+L hearts. By days 7 and 10 of L-NAME treatment, there was a significant increase in the cardiac density of macrophages and proliferating cells, respectively only in C+L rats. Although myocardial injury was similar in both treatment groups, PP was not changed and there was a distinct cardiac chemokine/cytokine signature in rats previously treated with enalapril that may be related to the lack of proliferative response and macrophage infiltration in these hearts.

Systemic inflammatory response following acute myocardial infarction

Acute cardiomyocyte necrosis in the infarcted heart generates damage-associated molecular patterns, activating complement and toll-like receptor/interleukin-1 signaling, and triggering an intense inflammatory response. Inflammasomes also recognize danger signals and mediate sterile inflammatory response following acute myocardial infarction (AMI). Inflammatory response serves to repair the heart, but excessive inflammation leads to adverse left ventricular remodeling and heart failure. In addition to local inflammation, profound systemic inflammation response has been documented in patients with AMI, which includes elevation of circulating inflammatory cytokines, chemokines and cell adhesion molecules, and activation of peripheral leukocytes and platelets. The excessive inflammatory response could be caused by a deregulated immune system. AMI is also associated with bone marrow activation and spleen monocytopoiesis, which sustains a continuous supply of monocytes at the site of inflammation. Accumulating evidence has shown that systemic inflammation aggravates atherosclerosis and markers for systemic inflammation are predictors of adverse clinical outcomes (such as death, recurrent myocardial infarction, and heart failure) in patients with AMI.

The immunological axis in heart failure: importance of the leukocyte differential

The important role of the immune system and inflammation in the pathophysiology of heart failure (HF) is becoming increasingly appreciated. We have reviewed the prognostic significance of under-recognized aspects of the leukocyte differential in HF, including lymphocytes, monocytes, eosinophils and mast cells. Studies to date evaluating lymphocyte counts in both chronic and hospitalized HF patients have consistently shown worse prognosis associated with low lymphocyte counts, despite widely heterogeneous study designs. Limited data suggest elevations in monocyte-derived cytokines and serum monocyte count may be predictive of poor outcomes in HF. Further data are required to better define the relationship between eosinophils, mast cells and HF. Leukocyte differentials are widely available, simple, inexpensive and appear to have independent prognostic significance, beyond traditional risk factors. Enhanced sympathetic activation and increased circulating cytokine levels (particularly tumor necrosis factor) have been implicated in the variability of leukocyte subpopulations. To date, immune-modulators targeting these mediators have been largely unsuccessful in improving cardiovascular outcomes in HF. Given the potential role of the immunological axis in HF, there may be an unmet need for novel therapeutic agents that can safely and effectively ameliorate these leukocyte derangements and perhaps improve the unacceptably high event rate in this population. Variations in leukocyte differentials may identify a high-risk subset of patients that may benefit from tailored immune therapies.

Endobiogeny: a global approach to systems biology (part 2 of 2)

ENDOBIOGENY AND THE BIOLOGY OF FUNCTIONS ARE BASED ON FOUR SCIENTIFIC CONCEPTS THAT ARE KNOWN AND GENERALLY ACCEPTED: (1) human physiology is complex and multifactorial and exhibits the properties of a system; (2) the endocrine system manages metabolism, which is the basis of the continuity of life; (3) the metabolic activity managed by the endocrine system results in the output of biomarkers that reflect the functional achievement of specific aspects of metabolism; and (4) when biomarkers are related to each other in ratios, it contextualizes one type of function relative to another to which is it linked anatomically, sequentially, chronologically, biochemically, etc.

Blood monocyte count may be a predictor of vascular access failure in hemodialysis patients

It has been reported that an increase in the counts of white blood cells (WBC) and their subpopulations is an independent predictor of atherosclerotic events and mortality. On the other hand, vascular access (VA) stenosis is caused by a progressive development of neointimal hyperplasia. We examined the relationship between VA failure and counts of peripheral WBC and their subpopulations in hemodialysis (HD) patients. The study population consisted of 82 patients undergoing regular HD. Twenty-two patients, who were unstable, were excluded from the study. After one year, we examined the relationship between VA failure and the counts of peripheral WBC and their subpopulations. In the follow-up period, 21 patients had complicated VA failure. The counts of WBC, neutrophils, lymphocytes, eosinophils, and basophils did not show a significant difference, but a monocyte count of ≥ 400/μL was shown to indicate a high probability of VA failure. Logistic regression analysis revealed that monocyte count was an independent risk factor of VA failure. The peripheral blood monocyte count may be a predictor of VA failure in HD patients.

Elevated peripheral blood mononuclear cell count is an independent predictor of left ventricular remodeling in patients with acute myocardial infarction

OBJECTIVES

Peripheral blood mononuclear cells (PBMCs) increase after acute myocardial infarction (AMI) and infiltrate to the infarct region. However, its impact on left ventricular (LV) remodeling remains unclear. The purpose of the present study was to clarify whether elevated PBMC count contributed to LV remodeling in patients with AMI.

SUBJECTS AND METHODS

A total of 131 patients with AMI were recruited. White blood cell (WBC), monocyte, and lymphocyte counts were measured at presentation and every 24h for five days after presentation. The correlation between PBMC count and LV remodeling was evaluated. LV remodeling was defined as an increase of LV end-diastolic volume index ≥ 10% at the 6-month follow-up left ventriculography.

RESULTS

Forty-eight patients had LV remodeling. Peak WBC (p=0.008), peak monocyte (p=0.001), and peak PBMC (p<0.001) counts were significantly greater in patients with LV remodeling than those without remodeling. Multivariate analysis revealed the peak PBMC count ≥ 3600/mm(3) was an independent predictor of LV remodeling [relative risk (RR) 3.243, p=0.011].

CONCLUSION

Increased PBMC count is significantly correlated with LV remodeling, thus suggesting that PBMCs play a pivotal role for the development of LV remodeling after AMI.

Significance of white blood cell count and its subtypes in patients with acute coronary syndrome

BACKGROUND

Inflammation plays a role in the pathogenesis of coronary atherosclerosis.

MATERIALS AND METHODS

Six hundred twenty-three patients with acute coronary syndrome (ACS) referred for coronary angiography for the first time in our hospital were enrolled in this study. White blood cell and its subtypes were measured on admission. The study population was divided into three groups based on total white blood cell count and followed up. Clinical end points were major adverse cardiac events (MACEs), including cardiogenic death, stroke, heart failure, non-fatal myocardial infarction, rehospitalization for angina pectoris.

RESULTS

The median age was 68 years (range 31-92) and 64.2% of the patients were men. The median white blood cell count was 6.48 x 10(9 )L(-1) (range 2.34-27.10 x 10(9 )L(-1)). The median follow-up duration was 21 months (range 1-116) and MACEs occurred in 167 patients. The multivariable Cox proportional hazards regression model revealed that neutrophil count [Relative risk = 1.098, 95% Confidence interval (CI): 1.010-1.193, P = 0.029) was a risk factor for MACEs. The logistic regression model revealed that lymphocyte count [Odds ratio (OR) = 1.075, 95% CI: 1.012-1.142, P = 0.018] and monocyte count (OR = 8.578, 95% CI: 2.687-27.381, P < 0.001) were predictive of stenosis >or= 75%; Neutrophil proportion (OR = 1.060, 95% CI: 1.007-1.115, P = 0.026), monocyte count (OR = 12.370, 95% CI: 1.298-118.761, P = 0.029) were predictive of the presence of multivessel disease. Kaplan-Meier analysis of short-term and long-term cumulative survival showed no significant statistical differences among three groups.

CONCLUSIONS

Neutrophil count adds prognostic information to MACEs in ACS. Monocyte count and lymphocyte count are predictive of severity of coronary atherosclerosis.

Relationship of admission neutrophil count to microvascular injury, left ventricular dilation, and long-term outcome in patients treated with primary angioplasty for acute myocardial infarction

BACKGROUND

The relationship of admission neutrophil count to the degree of microvascular injury, left ventricular (LV) volume, and long-term outcome after acute myocardial infarction (AMI) was examined in the present study.

METHODS AND RESULTS

The study group comprised 228 consecutive patients with a first anterior wall AMI who underwent primary angioplasty within 12 h of onset. The degree of microvascular injury was evaluated by Doppler guidewire. Adverse cardiac events were recorded during an average follow-up of 52+/-28 months. Using a receiver-operating characteristic analysis, a neutrophil count >or=7,260 cells/mm(3) was the best predictor of future cardiac events. By regression analysis, the neutrophil count significantly correlated with diastolic deceleration time (r=-0.40, p<0.0001), coronary flow reserve (r=-0.43, p<0.0001), and LV end-diastolic volume at 4 weeks (r=0.32, p<0.0001). Kaplan-Meier survival analysis showed a higher incidence of adverse cardiac events in patients with a high neutrophil count (p=0.002). By multivariate analysis, a neutrophil count >or=7,260 cells/mm(3) was an independent predictor of long-term adverse cardiac events (odds ratio 3.8, p=0.002).

CONCLUSION

Neutrophilia on admission is associated with impaired microvascular perfusion, LV dilation, and long-term adverse cardiac events in patients treated with primary angioplasty for AMI.