Blood Milieu in Acute Myocardial Infarction Reprograms Human Macrophages for Trauma Repair.

Acute myocardial infarction (AMI) is accompanied by a systemic trauma response that impacts the whole body, including blood. This study addresses whether macrophages, key players in trauma repair, sense and respond to these changes. For this, healthy human monocyte-derived macrophages are exposed to 20% human AMI (n = 50) or control (n = 20) serum and analyzed by transcriptional and multiparameter functional screening followed by network-guided data interpretation and drug repurposing. Results are validated in an independent cohort at functional level (n = 47 AMI, n = 25 control) and in a public dataset. AMI serum exposure results in an overt AMI signature, enriched in debris cleaning, mitosis, and immune pathways. Moreover, gene networks associated with AMI and with poor clinical prognosis in AMI are identified. Network-guided drug screening on the latter unveils prostaglandin E2 (PGE2) signaling as target for clinical intervention in detrimental macrophage imprinting during AMI trauma healing. The results demonstrate pronounced context-induced macrophage reprogramming by the AMI systemic environment, to a degree decisive for patient prognosis. This offers new opportunities for targeted intervention and optimized cardiovascular disease risk management.

TIMP-1 expression in coronary thrombi associate with myocardial injury in ST-elevation myocardial infarction patients.

BACKGROUND: Matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) are considered important both in atherosclerosis and remodeling after acute myocardial infarction (AMI). We aimed to study genetic expression and presence of MMP-2, MMP-9, TIMP-1, TIMP-2 and the extracellular MMP-inducer (EMMPRIN) in coronary thrombi. Circulating levels and genetic expression in circulating leukocytes were also assessed, and relations to degree of myocardial injury measured by troponin T and time from symptom to PCI were explored. Expression of cell markers were also analyzed, indicating relations to cell types. METHODS: Intracoronary thrombi were aspirated from 33 patients with ST-elevation myocardial infarction (STEMI). Blood samples with Pax-gene tubes were drawn at end of PCI and the next day. RNA was isolated from thrombi and leukocytes, and genes were relatively quantified by RT-PCR. Each thrombus was preserved for histology and immunohistochemistry analyzes. RESULTS: Genes coding for the five markers were present in 84-100% of thrombi and immunohistochemically stained in 96-100%. Expression of TIMP-1 in thrombi and in leukocytes correlated significantly to peak troponin T ( r = 0.393 P = 0.026, r = 0.469 P = 0.006, respectively). No significant correlations between genes expressed in thrombi and time from symptom to PCI were observed. TIMP-1 was connected mainly to monocytes/macrophages in the thrombi. CONCLUSION: MMP-2, MMP-9, TIMP-1, TIMP-2 and EMMPRIN were highly expressed in human coronary thrombi. The correlation between troponin T and the expression of TIMP-1 both in thrombi and in leukocytes at time of PCI indicates that TIMP-1 plays a role in myocardial damage early post-MI.

The Inflammasome Signaling Pathway Is Actively Regulated and Related to Myocardial Damage in Coronary Thrombi from Patients with STEMI.

BACKGROUND: The Nod-Like-Receptor-Protein-3 (NLRP3) inflammasome and the Interleukin-6 (IL-6) pathways are central mechanisms of the inflammatory response in myocardial reperfusion injury. Expanding our knowledge about the inflammasome signaling axis is important to improve treatment options. In a cross-sectional study, we aimed to study presence, localization, and genetic expression of inflammasome- and IL-6- signaling-related proteins in coronary thrombi and circulating leukocytes from ST-elevation myocardial infarction (STEMI) patients, with relation to myocardial injury and time from symptoms to PCI. METHODS: Intracoronary thrombi were aspirated from 33 STEMI patients. Blood samples were drawn. mRNA of Toll-Like-Receptor-4 (TLR4), NLRP3, caspase 1, Interleukin-1ß (IL1-ß), Interleukin-18 (IL-18), IL-6, IL-6-receptor (IL-6R), and glycoprotein 130 (gp130) were isolated from thrombi and circulating leukocytes and relatively quantified by RT-PCR. A part of each thrombus was embedded in paraffin for histology and immunohistochemistry analyses. RESULTS: Genes encoding the 8 markers were present in 76-100% of thrombi. Expression of TLR4 in thrombi significantly correlated to troponin T (r = 0.455, p = 0.013), as did NLRP3 (r = 0.468, p = 0.024). Troponin T correlated with expression in circulating leukocytes of TLR4 (r = 0.438, p = 0.011), NLRP3 (r = 0.420, p = 0.0149), and IL-1ß (r = 0.394, p = 0.023). IL-6R expression in thrombi correlated significantly to troponin T (r = 0.434, p = 0.019), whereas gp130 was inversely correlated (r = -0.398, p = 0.050). IL-6 in circulating leukocytes correlated inversely to troponin T (r = -0.421, p = 0.015). There were no significant correlations between genes expressed in thrombi and time from symptom to PCI. CONCLUSIONS: The inflammasome signaling pathway was actively regulated in coronary thrombi and in circulating leukocytes from patients with STEMI, in association with myocardial damage measured by troponin T. This supports the strategy of medically targeting this pathway in treating myocardial infarction and contributes to sort out optimal timing and targets for anti-inflammatory treatment. The study is registered at clinicaltrials.gov with identification number NCT02746822.

The randomised Oslo study of renal denervation vs. Antihypertensive drug adjustments: efficacy and safety through 7 years of follow-up.

PURPOSE: The blood pressure (BP) lowering effect of renal sympathetic denervation (RDN) in treatment-resistant hypertension shows variation amongst the existing randomised studies. The long-term efficacy and safety of RDN require further investigation. For the first time, we report BP changes and safety up to 7 years after RDN, compared to drug adjustment in the randomised Oslo RDN study. MATERIALS AND METHODS: Patients with treatment-resistant hypertension, defined as daytime systolic ambulatory BP ≥135 mmHg after witnessed intake of ≥3 antihypertensive drugs including a diuretic, were randomised to either RDN (n = 9) or drug adjustment (n = 10). The initial primary endpoint was the change in office BP after 6 months. The RDN group had their drugs adjusted after 1 year using the same principles as the Drug Adjustment group. Both groups returned for long-term follow-up after 3 and 7 years. RESULTS: The decrease in office BP and ambulatory BP (ABPM) after 6 months did not persist, but gradually increased in both groups. From 6 months to 7 years follow-up, mean daytime systolic ABPM increased from 142 ± 10 to 145 ± 15 mmHg in the RDN group, and from 133 ± 11 to 137 ± 13 mmHg in the Drug Adjustment group, with the difference between them decreasing. In a mixed factor model, a significantly different variance was found between the groups in daytime systolic ABPM (p = .04) and diastolic ABPM (p = .01) as well as office diastolic BP (p<.01), but not in office systolic BP (p = .18). At long-term follow-up we unveiled no anatomical- or functional renal impairment in either group. CONCLUSIONS: BP changes up to 7 years show a tendency towards a smaller difference in BPs between the RDN and drug adjustment patients. Our data support RDN as a safe procedure, but it remains non-superior to intensive drug adjustment 7 years after the intervention.