Whole blood transcriptome in long-COVID patients reveals association with lung function and immune response.

BACKGROUND: Months after infection with SARS-CoV-2, at least 10% of patients still experience complaints. Long-COVID is a heterogeneous disease and clustering efforts revealed multiple phenotypes on a clinical level. However, the molecular pathways underlying long-COVID phenotypes are still poorly understood. OBJECTIVES: This study aims to cluster patients according to their blood transcriptomes and uncover the pathways underlying their disease. METHODS: Blood was collected from 77 patients with long-COVID from the P4O2 COVID-19 study. Unsupervised hierarchical clustering was performed on the whole blood transcriptome. These clusters were analysed for differences in clinical features, pulmonary function tests and gene ontology (GO) term enrichment. RESULTS: Clustering revealed two distinct clusters on a transcriptome level. Compared to cluster 2 (n=65), patients in cluster 1 (n=12) showed a higher rate of pre-existing cardiovascular disease (58% vs 22%), higher prevalence of gastrointestinal symptoms (58% vs 29%), shorter hospital duration during SARS-CoV-2 infection (median: 3 vs 8 days), lower Tiffeneau index (72% vs 81%) and lower diffusion capacity of the lung for carbon monoxide (DLCO) (68% vs 85% predicted). GO-term enrichment analysis revealed upregulation of genes involved in the antiviral innate immune response in cluster 1, while genes involved with the adaptive immune response were upregulated in cluster 2. CONCLUSION: This study provides a start in uncovering the pathophysiological mechanisms underlying long-COVID. Further research is required to unravel why the immune response is different in these clusters, and to identify potential therapeutic targets to create an optimized treatment or monitoring strategy for the individual long-COVID patient.

MiR-223-3p and miR-122-5p as circulating biomarkers for plaque instability.

BACKGROUND: In this study, we discovered and validated candidate microRNA (miRNA) biomarkers for coronary artery disease (CAD). METHOD: Candidate tissue-derived miRNAs from atherosclerotic plaque material in patients with stable coronary artery disease (SCAD) (n=14) and unstable coronary artery disease (UCAD) (n=25) were discovered by qPCR-based arrays. We validated differentially expressed miRNAs, along with seven promising CAD-associated miRNAs from the literature, in the serum of two large cohorts (n=395 and n=1000) of patients with SCAD and UCAD and subclinical atherosclerosis (SubA) and controls, respectively. RESULT: From plaque materials (discovery phase), miR-125b-5p and miR-193b-3p were most upregulated in SCAD, whereas miR-223-3p and miR-142-3p were most upregulated in patients with UCAD. Subsequent validation in serum from patients with UCAD, SCAD, SubA and controls demonstrated significant upregulation of miR-223-3p, miR-133a-3p, miR-146-3p and miR-155-5p. The ischaemia-related miR-499-5p was also highly upregulated in patients with UCAD compared with the other groups (SCAD OR 20.63 (95% CI 11.16 to 38.15), SubA OR 96.10 (95% CI 40.13 to 230.14) and controls OR 15.73 (95% CI 7.80 to 31.72)). However, no significant difference in miR-499-5p expression was observed across SCAD, SubA and controls. MiR-122-5p was the only miRNA to be significantly upregulated in the serum of both patients with UCAD and SCAD. CONCLUSION: In conclusion, miR-122-5p and miR-223-3p might be markers of plaque instability.

Subthalamic nucleus stimulation does not influence basal glucose metabolism or insulin sensitivity in patients with Parkinson's disease.

Animal studies have shown that central dopamine signaling influences glucose metabolism. As a first step to show this association in an experimental setting in humans, we studied whether deep brain stimulation (DBS) of the subthalamic nucleus (STN), which modulates the basal ganglia circuitry, alters basal endogenous glucose production (EGP) or insulin sensitivity in patients with Parkinson's disease (PD). We studied 8 patients with PD treated with DBS STN, in the basal state and during a hyperinsulinemic euglycemic clamp using a stable glucose isotope, in the stimulated and non-stimulated condition. We measured EGP, hepatic insulin sensitivity, peripheral insulin sensitivity (Rd), resting energy expenditure (REE), glucoregulatory hormones, and Parkinson symptoms, using the Unified Parkinson's Disease Rating Scale (UPDRS). Basal plasma glucose and EGP did not differ between the stimulated and non-stimulated condition. Hepatic insulin sensitivity was similar in both conditions and there were no significant differences in Rd and plasma glucoregulatory hormones between DBS on and DBS off. UPDRS was significantly higher in the non-stimulated condition. DBS of the STN in patients with PD does not influence basal EGP or insulin sensitivity. These results suggest that acute modulation of the motor basal ganglia circuitry does not affect glucose metabolism in humans.

Non-HDL cholesterol vs. apo B for risk of coronary heart disease in healthy individuals: the EPIC-Norfolk prospective population study.

BACKGROUND: There is an ongoing debate about the performance of non-high-density lipoprotein cholesterol (non-HDL-C) compared with apolipoprotein B (apo B) in the prediction of coronary heart disease (CHD) risk. Therefore, we compared the associations between non-HDL-C and apo B in regard to CHD among apparently healthy Western European individuals. DESIGN: In the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk prospective population study, 25,639 men and women aged 45-79 years were followed for 11·4 ± 2·8 years. Those with diabetes or prevalent CHD at baseline were excluded. A total of 2066 (12·1%) participants developed CHD during 195 692 person-years follow-up. RESULTS: The multivariable-adjusted hazard ratio [HR] of future CHD per one standard deviation increase was 1·22 [95% confidence interval (CI): 1·17-1·27] for LDL-C, 1·26 (95% CI 1·20-1·31) for non-HDL-C and 1·19 (95% CI 1·14-1·24) for apo B, respectively. The multivariable-adjusted HR of future CHD in the highest quartile LDL-C was 1·67 (95% CI: 1·47-1·91). For non-HDL-C and apo B, these respective HRs were 1·87 (95% CI: 1·62-2·15) and 1·56 (95% CI: 1·36-1·78). Kaplan-Meier survival analyses showed that there was incremental and comparable increase in risk of CHD with increasing quartiles of both non-HDL-C and apo B. CONCLUSIONS: In this prospective study, non-HDL-C and apo B were comparable in their ability to predict risk of future CHD.

Lactate increases hepatic secretion of VLDL-triglycerides in humans.

OBJECTIVE: The pathophysiology of hypertriglyceridemia is complex hampering effective therapeutic strategies. Increased central parasympathetic nerve activity was shown to inhibit hepatic triglyceride (TG) excretion via modulation of liver stearyl-CoA desaturase (SCD)-1 activity in rodents. We evaluated the impact of 7-h lactate clamping on VLDL-TG homeostasis in humans. METHODS: Eight normolipidemic, male subjects were subjected to a continuous infusion of l-lactate (target concentration 3 mmol/L) or saline for 7 h in random order on two separate occasions. TG kinetics in very low density lipoproteins (VLDL1 and 2) were measured after a bolus injection of [1,1,2,3,3]-(2)H5-glycerol. Palmitic acid (16:0) and palmitoleic acid (16:1) in VLDL1 and VLDL2 were measured as a reflection of liver SCD1 activity. RESULTS: Plasma TG levels changed by 0.16 ± 0.09 mmol/L during lactate vs -0.15 ± 0.08 mmol/L during saline (P < 0.05). VLDL1 16:1/16:0 ratio increased to 1.2 ± 0.7 during lactate versus a decrease during saline by -1.5 ± 0.6 (p = 0.01). During lactate VLDL1-TG excretion was higher compared to saline (1604 [827-2870] versus 1285 [505-2155] µmol glycerol; p < 0.05), trending toward higher VLDL1-TG pool sizes during lactate (28%; p = 0.07 versus saline). CONCLUSIONS: In normolipidemic men, 7-h l-lactate clamp increases, rather than decreases SCD1 activity and hepatic TG secretion leading to elevated plasma TG levels. These conflicting data between human and rodents on central regulation of hepatic TG excretion illustrate that experimental findings on the role of the central nervous system in lipid metabolism should be interpreted with caution.

Clinical implications of JUPITER in a contemporary European population: the EPIC-Norfolk prospective population study.

AIMS: Justification for the Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) has raised several points of debate. We quantified the proportion of individuals meeting the JUPITER criteria, determined their risk profile, and their risk of coronary heart disease (CHD) events during a long-term follow-up in a contemporary European cohort. METHODS AND RESULTS: A total of 25 639 participants aged between 45 and 79 years were followed for 11.4 ± 2.8 years in EPIC-Norfolk population cohort. A total of 8397 individuals with complete data available were considered potentially eligible for primary prevention. A total of 846 (10.1%) individuals fulfilled the JUPITER criteria [low-density lipoprotein cholesterol-C (LDL-C) <3.4 mmol/L/C-reactive protein ≥ 2 mg]. This group had a 10-person-year event rate of 14.6% compared with 7.0% for those with LDL-C <3.4 mmol/L/C-reactive protein <2 mg (P = 0.001); the corresponding adjusted hazard ratio for future CHD was 1.70 (95% CI: 1.31-2.21). The group fulfilling JUPITER criteria had significantly higher CHD risk compared with those with LDL-C ≥ 3.4 mmol/L and C-reactive protein <2 mg/L. Among individuals who did not qualify for statin therapy based on the Society of Cardiology Systematic COronary Risk Evaluation (SCORE) (n = 4652) or ATP III criteria (n = 4466), 18.1 and 18.9%, respectively, would have qualified using the JUPITER criteria. CONCLUSION: In this European cohort, JUPITER-eligible individuals had significantly higher event rates compared with those with LDL-C <3.4 mmol/L/C-reactive protein <2 mg and LDL-C ≥ 3.4 mmol/L/C-reactive protein <2 mg/L. Application of the JUPITER criteria qualified almost one-fifth of the population for statin therapy that otherwise would not have qualified based on SCORE or ATP III criteria.

Monocyte gene expression signature of patients with early onset coronary artery disease.

The burden of cardiovascular disease (CVD) cannot be fully addressed by therapy targeting known pathophysiological pathways. Even with stringent control of all risk factors CVD events are only diminished by half. A number of additional pathways probably play a role in the development of CVD and might serve as novel therapeutic targets. Genome wide expression studies represent a powerful tool to identify such novel pathways. We compared the expression profiles in monocytes from twenty two young male patients with premature familial CAD with those from controls matched for age, sex and smoking status, without a family history of CVD. Since all patients were on statins and aspirin treatment, potentially affecting the expression of genes in monocytes, twelve controls were subsequently treated with simvastatin and aspirin for 6 and 2 weeks, respectively. By whole genome expression arrays six genes were identified to have differential expression in the monocytes of patients versus controls; ABCA1, ABCG1 and RGS1 were downregulated in patients, whereas ADRB2, FOLR3 and GSTM1 were upregulated. Differential expression of all genes, apart from GSTM1, was confirmed by qPCR. Aspirin and statins altered gene expression of ABCG1 and ADBR2. All finding were validated in a second group of twenty four patients and controls. Differential expression of ABCA1, RSG1 and ADBR2 was replicated. In conclusion, we identified these 3 genes to be expressed differently in CAD cases which might play a role in the pathogenesis of atherosclerotic vascular disease.

Infusion of a lipid emulsion in healthy men decreases the serotonergic response.

Subjects with obesity and insulin resistance display a low response to a serotonergic challenge test. One of the hallmarks of obesity and insulin resistance is elevated plasma free fatty acids (FFAs). We hypothesize that increasing plasma FFA by infusion of a lipid emulsion, may be a contributing component leading to decreased serotonergic responsivity in healthy young men. Ten lean healthy men, 23.6 ± 5.0 years and BMI 22.6 ± 1.9 kg/m(2), were included. Serotonergic responsivity was assessed using the prolactin response to infusion with citalopram, a selective serotonin reuptake inhibitor, which is a validated tool to assess serotonergic tone. All participants received a lipid/heparin emulsion (Intralipid) infusion during 6 h. Saline infusion was used as a control. To evaluate a possible effect of heparin per se on prolactin, four out of the ten subjects also received heparin only during 6 h without the serotonergic challenge test. Plasma prolactin increased by 74.3 ± 15.5% during saline infusion. Intralipid infusion increased plasma FFA from 0.5 ± 0.05 to 2.3 ± 0.2 mmol/l (p < 0.001). The increase in plasma prolactin during Intralipid infusion was significantly lower (39.3 ± 10%; p < 0.001 compared to saline infusion). Heparin infusion per se increased plasma prolactin by 14.0 ± 1.9%. We found that during the Intralipid infusion with concomitant high plasma FFA levels the serotonergic response was decreased in healthy young men. Higher FFA levels may be the mediator of the decreased serotonergic response reported in patients with insulin resistance and obesity.

Microcirculation and atherothrombotic parameters in prolactinoma patients: a pilot study.

Atherothrombosis is a multifactorial process, governed by an interaction between the vessel wall, hemodynamic factors and systemic atherothrombotic risk factors. Recent in vitro, human ex vivo and animal studies have implicated the hormone prolactin as an atherothrombotic mediator. To address this issue, we evaluated the anatomy and function of various microvascular beds as well as plasma atherothrombosis markers in patients with elevated prolactin levels. In this pilot study, involving 10 prolactinoma patients and 10 control subjects, sidestream dark field (SDF) imaging revealed a marked perturbation of the sublingual microcirculation in prolactinoma patients compared to control subjects, as attested to by significant changes in microvascular flow index (2.74 ± 0.12 vs. 2.91 ± 0.05, respectively; P = 0.0006), in heterogeneity index (0.28 [IQR 0.18-0.31] vs. 0.09 [IQR 0.08-0.17], respectively; P = 0.002) and lower proportion of perfused vessels (90 ± 4.0% vs. 95 ± 3.0%, respectively; P = 0.016). In the retina, fluorescein angiography (FAG) confirmed these data, since prolactinoma patients more often have dilatated perifoveal capillaries. In plasma, prolactinoma patients displayed several pro-atherogenic disturbances, including a higher endogenous thrombin potential and prothrombin levels as well as decreased HDL-cholesterol levels. Prolactinoma patients are characterized by microvascular dysfunction as well as plasma markers indicating a pro-atherothrombotic state. Further studies are required to assess if prolactin is causally involved in atherothrombotic disease.

Platelets in patients with premature coronary artery disease exhibit upregulation of miRNA340* and miRNA624*.

BACKGROUND: Coronary artery disease (CAD) is the leading cause of human morbidity and mortality worldwide, underscoring the need to improve diagnostic strategies. Platelets play a major role, not only in the process of acute thrombosis during plaque rupture, but also in the formation of atherosclerosis itself. MicroRNAs are endogenous small non-coding RNAs that control gene expression and are expressed in a tissue and disease-specific manner. Therefore they have been proposed to be useful biomarkers. It remains unknown whether differences in miRNA expression levels in platelets can be found between patients with premature CAD and healthy controls. METHODOLOGY/PRINCIPAL FINDINGS: In this case-control study we measured relative expression levels of platelet miRNAs using microarrays from 12 patients with premature CAD and 12 age- and sex-matched healthy controls. Six platelet microRNAs were significantly upregulated (miR340*, miR451, miR454*, miR545:9.1. miR615-5p and miR624*) and one miRNA (miR1280) was significantly downregulated in patients with CAD as compared to healthy controls. To validate these results, we measured the expression levels of these candidate miRNAs by qRT-PCR in platelets of individuals from two independent cohorts; validation cohort I consisted of 40 patients with premature CAD and 40 healthy controls and validation cohort II consisted of 27 patients with artery disease and 40 healthy relatives. MiR340* and miR624* were confirmed to be upregulated in patients with CAD as compared to healthy controls in both validation cohorts. CONCLUSION/SIGNIFICANCE: Two miRNAs in platelets are significantly upregulated in patients with CAD as compared to healthy controls. Whether the two identified miRNAs can be used as biomarkers and whether they are cause or consequence of the disease remains to be elucidated in a larger prospective study.

Perioperative selective decontamination of the digestive tract (SDD) in elective colorectal surgery.

BACKGROUND: Selective decontamination of the digestive tract (SDD) decreases morbidity and mortality in critically ill patients and morbidity in patients undergoing esophageal resection. This study analyzes the effect of perioperative SDD in patients undergoing elective colorectal surgery on postoperative infections and anastomotic leakage. METHODS: This is a retrospective analysis of prospectively collected data in a 3-year cohort of 162 patients undergoing elective resection of colon and or rectum. Of these patients, 76 (47%) received SDD (polymyxine B sulfate, tobramycin, and amphotericin) perioperatively. The control group consisted of 86 patients who were not treated with SDD. Postoperative complications, hospital stay, and mortality were analyzed. RESULTS: In the SDD group, there were six patients (7.9%) with infectious complications compared with 17 patients (19.8%) in the control group (p = 0.031). The incidence of the combined endpoint infectious complications and anastomotic leakage was 8 (11%) in the SDD group vs. 22 (26%) in the control group (p = 0.014). Multivariate analysis showed that no-SDD, aged above 60 years and diabetes were independent predictors of postoperative complications. CONCLUSION: Perioperative SDD in elective colorectal surgery seems to reduce postoperative surgical complications including infectious complications and anastomotic leakage. Prospective, randomized, placebo-controlled studies are needed to confirm this conclusion.