High levels of stromal cell-derived factor-1α predict secondary cardiac events in stable patients with a history of myocardial infarction

Elevated levels of plasma inactive stromal cell derived factor-1α predict poor long-term outcomes in diabetic patients following percutaneous coronary intervention

BACKGROUND

Since the complication of diabetes mellitus (DM) is a risk for adverse cardiovascular outcomes in patients with coronary artery disease (CAD), appropriate risk estimation is needed in diabetic patients following percutaneous coronary intervention (PCI). However, there is no useful biomarker to predict outcomes in this population. Although stromal cell derived factor-1α (SDF-1α), a circulating chemokine, was shown to have cardioprotective roles, the prognostic impact of SDF-1α in diabetic patients with CAD is yet to be fully elucidated. Moreover, roles of SDF-1α isoforms in outcome prediction remain unclear. Therefore, this study aimed to assess the prognostic implication of three forms of SDF-1α including total, active, and inactive forms of SDF-1α in patients with DM and after PCI.

METHODS

This single-center retrospective analysis involved consecutive patients with diabetes who underwent PCI for the first time between 2008 and 2018 (n = 849). Primary and secondary outcome measures were all-cause death and the composite of cardiovascular death, non-fatal myocardial infarction, and ischemic stroke (3P-MACE), respectively. For determining plasma levels of SDF-1α, we measured not only total, but also the active type of SDF-1α by ELISA. Inactive isoform of the SDF-1α was calculated by subtracting the active isoform from total SDF-1α.

RESULTS

Unadjusted Kaplan-Meier analyses revealed increased risk of both all-cause death and 3P-MACE in patients with elevated levels of inactive SDF-1α. However, plasma levels of total and active SDF-1α were not associated with cumulative incidences of outcome measures. Multivariate Cox hazard analyses repeatedly indicated the 1 higher log-transformed inactive SDF-1α was significantly associated with increased risk of all-cause death (hazard ratio (HR): 2.64, 95% confidence interval (CI): 1.28-5.34, p = 0.008) and 3P-MACE (HR: 2.51, 95% CI: 1.12-5.46, p = 0.02). Moreover, the predictive performance of inactive SDF-1α was higher than that of total SDF-1α (C-statistics of inactive and total SDF-1α for all-cause death: 0.631 vs 0.554, for 3P-MACE: 0.623 vs 0.524, respectively).

CONCLUSION

The study results indicate that elevated levels of plasma inactive SDF-1α might be a useful indicator of poor long-term outcomes in diabetic patients following PCI.

TRIAL REGISTRATION

This study describes a retrospective analysis of a prospective registry database of patients who underwent PCI at Juntendo University Hospital, Tokyo, Japan (Juntendo Physicians' Alliance for Clinical Trials, J-PACT), which is publicly registered (University Medical Information Network Japan-Clinical Trials Registry, UMIN-CTR 000035587).

Distinct Inflammatory Milieu in Patients With Right Heart Failure

BACKGROUND

Right heart failure (RHF) is associated with worse clinical outcomes. In addition to hemodynamic perturbations, the syndrome of RHF involves liver congestion and dysfunction. The mechanisms that underlie heart-liver interactions are poorly understood and may involve secreted factors. As a first step to understand the cardiohepatic axis, we sought to elucidate the circulating inflammatory milieu in patients with RHF.

METHODS

Blood samples were collected from the inferior vena cava and hepatic veins during right heart catheterization from 3 groups of patients: (1) controls with normal cardiac function, (2) patients with heart failure who did not meet all criteria of RHF, and (3) patients who met prespecified criteria for RHF defined by hemodynamic and echocardiographic parameters. We performed a multiplex protein assay to survey levels of several circulating markers and analyzed their association with mortality and the need for a left ventricular assist device or heart transplant. Finally, we leveraged publicly available single-cell RNA sequencing data and performed tissue imaging to evaluate the expression of these factors in the liver.

RESULTS

In this study, RHF was associated with elevated levels of a subset of cytokines/chemokines/growth factors compared with controls. In particular, soluble CD163 (cluster of differentiation 163) and CXCL12 (chemokine [C-X-C motif] ligand 12) were higher in RHF and predicted left ventricular assist device/transplant-free survival in an independent validation cohort. Furthermore, single-cell RNA sequencing and immunohistochemistry of human liver biopsies suggest that these factors are expressed by Kupffer cells and may be liver derived.

CONCLUSIONS

RHF is associated with a distinct circulating inflammatory profile. Soluble CD163 and CXCL12 are novel biomarkers that can prognosticate patient outcomes. Future studies to define how these molecules influence heart failure phenotypes and disease progression may lead to new approaches to the management of patients with RHF.

A Distinct Inflammatory Milieu in Patients with Right Heart Failure

Background

Right heart failure (RHF) is associated with worse clinical outcomes. In addition to hemodynamic perturbations, the syndrome of RHF involves liver congestion and dysfunction. The mechanisms that underlie heart-liver interactions are poorly understood and may involve secreted factors. As a first step to understand the cardiohepatic axis, we sought to elucidate the circulating inflammatory milieu in patients with RHF.

Methods

Blood samples were collected from the IVC and hepatic veins during right heart catheterization from 3 groups of patients: 1) controls with normal cardiac function, 2) patients with heart failure (HF) who did not meet all criteria of RHF, and 3) patients who met prespecified criteria for RHF defined by hemodynamic and echocardiographic parameters. We performed multiplex protein assay to survey levels of several circulating markers and analyzed their association with mortality and need for left ventricular assist device or heart transplant. Finally, we leveraged publicly available single cell RNA sequencing (scRNAseq) data and performed tissue imaging to evaluate expression of these factors in the liver.

Results

In this study of 43 patients, RHF was associated with elevated levels of a subset of cytokines/chemokines/growth factors compared to controls. In particular, soluble CD163 (sCD163) and CXCL12 were higher in RHF and predicted survival in an independent validation cohort. Furthermore, scRNAseq and immunohistochemistry of human liver biopsies suggest that these factors are expressed by Kupffer cells and may be liver derived.

Conclusions

RHF is associated with a distinct circulating inflammatory profile. sCD163 and CXCL12 are novel biomarkers that can prognosticate patient outcomes. Future studies to define how these molecules influence HF phenotypes and disease progression may lead to new approaches to management of patients with RHF.

The role of blood CXCL12 level in prognosis of coronary artery disease: A meta-analysis

Objective

The role of C-X-C motif chemokine 12 (CXCL12) in atherosclerotic cardiovascular diseases (ASCVDs) has emerged as one of the research hotspots in recent years. Studies reported that the higher blood CXCL12 level was associated with increased major adverse cardiovascular events (MACEs), but the results were inconsistent. The objective of this study was to clarify the prognostic value of the blood CXCL12 level in patients with coronary artery disease (CAD) through meta-analysis.

Methods

All related studies about the association between the blood CXCL12 level and the prognosis of CAD were comprehensively searched and screened according to inclusion criteria and exclusion criteria. The quality of the included literature was evaluated using the Newcastle-Ottawa Scale (NOS). The heterogeneity test was conducted, and the pooled hazard risk (HR) or the odds ratio (OR) with a 95% confidence interval (CI) was calculated using the fixed-effect or random-effects model accordingly. Publication bias was evaluated using Begg's funnel plot and Egger's test. Sensitivity analysis and subgroup analysis were also conducted.

Results

A total of 12 original studies with 2,959 CAD subjects were included in the final data combination. The pooled data indicated a significant association between higher CXCL12 levels and MACEs both in univariate analysis (HR 5.23, 95% CI 2.48–11.04) and multivariate analysis (HR 2.53, 95% CI 2.03–3.16) in the CXCL12 level as the category variable group. In the CXCL12 level as the continuous variable group, the result also indicated that the higher CXCL12 level significantly predicted future MACEs (multivariate OR 1.55, 95% CI 1.02–2.35). Subgroup analysis of the CXCL12 level as the category variable group found significant associations in all acute coronary syndrome (ACS) (univariate HR 9.72, 95% CI 4.69–20.15; multivariate HR 2.47, 95% CI 1.79–3.40), non-ACS (univariate HR 2.73, 95% CI 1.65–4.54; multivariate HR 3.49, 95% CI 1.66–7.33), Asian (univariate HR 7.43, 95% CI 1.70–32.49; multivariate HR 2.21, 95% CI 1.71–2.85), Caucasian (univariate HR 3.90, 95% CI 2.73–5.57; multivariate HR 3.87, 95% CI 2.48–6.04), short-term (univariate HR 9.36, 95% CI 4.10–21.37; multivariate HR 2.72, 95% CI 1.97–3.76), and long-term (univariate HR 2.86, 95% CI 1.62–5.04; multivariate HR 2.38, 95% CI 1.76–3.22) subgroups. Subgroup analysis of the CXCL12 level as the continuous variable group found significant associations in non-ACS (multivariate OR 1.53, 95% CI 1.23–1.92), Caucasian (multivariate OR 3.83, 95% CI 1.44–10.19), and long-term (multivariate OR 1.62, 95% CI 1.37–1.93) subgroups, but not in ACS (multivariate OR 1.36, 95% CI 0.67–2.75), Asian (multivariate OR 1.40, 95% CI 0.91–2.14), and short-term (multivariate OR 1.16, 95% CI 0.28–4.76) subgroups. No significant publication bias was found in this meta-analysis.

Conclusion

The higher blood CXCL12 level is associated with increased MACEs in patients with CAD, and the blood CXCL12 level may serve as an important prognostic index for CAD. Integrating the blood CXCL12 level into CAD risk assessment tools may provide more comprehensive messages for evaluating and managing patients with CAD.

Association of SDF1 and MMP12 with Atherosclerosis and Inflammation: Clinical and Experimental Study

BACKGROUND

Atherosclerosis is the main etiology of cardiovascular diseases (CVD), associated to systemic inflammation. Matrix metalloproteinases (MMPs) are related to atherosclerosis progression through the SDF1/CXCR4 axis promoting macrophages recruitment within the vascular wall. The goal was to assess new circulatory inflammatory markers in relation to atherosclerosis.

METHODS

Measurement of SDF1, MMP12 and CRP in blood samples of 298 prospective patients with cardiovascular risk. To explore atherosclerosis progression, CXCR4/SDF1 axis and MMP12 expression were determined by RT-qPCR and by immunohistochemistry in the aorta of accelerated and delayed atherosclerosis mice models (Apoe-/- and Apoe-/-Mmp10-/-).

RESULTS

SDF1, MMP12 and CRP were elevated in patients with clinical atherosclerosis, but after controlling by confounding factors, only SDF1 and CRP remained increased. Having high levels of both biomarkers showed 2.8-fold increased risk of presenting clinical atherosclerosis (p = 0.022). Patients with elevated SDF1, MMP12 and CRP showed increased risk of death in follow-up (HR = 3.2, 95%CI: 1.5-7.0, p = 0.004). Gene and protein expression of CXCR4 and MMP12 were increased in aortas from Apoe-/- mice.

CONCLUSIONS

The combination of high circulating SDF1, MMP12 and CRP identified patients with particular inflammatory cardiovascular risk and increased mortality. SDF1/CXCR4 axis and MMP12 involvement in atherosclerosis development suggests that they could be possible atherosclerotic targets.

Evaluation of renal tubulointerstitial damage as a residual renal risk factor for adverse cardiac events in patients with myocardial infarction

BACKGROUND

Renal dysfunction, defined as a lower estimated glomerular filtration rate (eGFR), has been shown to be related to cardiovascular events in patients with myocardial infarction (MI). However, the contribution of renal tubulointerstitial damage to the predictive value for cardiovascular events has not been established. The aim of this study was to elucidate whether renal tubulointerstitial damage is associated with the occurrence of cardiac death and recurrence of MI in patients who have had MI.

METHODS AND RESULTS

Urinary β2-microglobulin (β2MG) was measured in 681 consecutive patients with MI in our hospital. All patients were followed up for <12 years or until the occurrence of cardiac death and MI. During a median follow-up period of 6 years, the cumulative cardiac death rate was 5.4%, and the MI rate was 3.1%. When outcomes were divided into two groups according to the β2MG levels, cardiac death and MI rates were lower in patients with lower levels of β2MG (<0.319 mg/gCre: determined by receiver operating characteristic analyses) than in those with β2MG ≥0.319 mg/gCre (5.9% versus 17.1%, p<0.01). When outcomes were stratified according to the β2MG levels in combination with eGFR levels, Kaplan-Meier analyses showed that cardiac death and MI rates increased depending on an increase in the β2MG levels (p<0.05). Moreover, multivariate Cox analyses revealed that high levels of β2MG were a significant independent predictor of adverse events (hazard ratio: 1.956; 95% confidence interval: 1.014-3.774; p = 0.045). The addition of high levels of β2MG to conventional risk factors, including eGFR and urinary albumin, improved the net reclassification improvement (NRI) and integrated discrimination improvement (IDI) (NRI 0.5447, p = 0.0002; IDI 0.0126, p = 0.0454).

CONCLUSION

Renal tubulointerstitial damage, as assessed by urinary β2MG, is associated with the occurrence of cardiac death and recurrence of MI independent of renal glomerular function in patients with MI.

The expression and biological function of chemokine CXCL12 and receptor CXCR4/CXCR7 in placenta accreta spectrum disorders

Objectives

Investigation of mechanism related to excessive invasion of trophoblast cells in placenta accreta spectrum disorders (PAS) provides more strategies and ideas for clinical diagnosis and treatment.

Materials and Methods

Blood and placental samples were collected from included patients. The distribution and expression of CXCL12, CXCR4 and CXCR7 proteins in the paraffin of placental tissue in the included cases were analysed, and we analyse the downstream pathways or key proteins involved in cell invasion.

Results

Firstly, our results determined that CXCL12 and CXCR4/CXCR7 were increased in extravillous trophoblastic cell (CXCL12: P < .001; CXCR4: P < .001; CXCR7: P < .001), and the expression levels were closely related to the invasion depth of trophoblastic cells. Secondly, CXCL12 has the potential to become a biochemical indicator of PAS since the high expression of placental trophoblast CXCL12 may be an important source of blood CXCL12. Using lentivirus‐mediated RNA interference and overexpression assay, it was found that both chemokine CXCL12 and receptor CXCR4/CXCR7 are associated with regulation of trophoblast cell proliferation, migration and invasion. Further results proved that through the activating the phosphorylation and increasing the expression of MLC and AKT proteins in the Rho/rock, PI3K/AKT signalling pathway, CXCL12, CXCR4 and CXCR7 could up‐regulate the expression of RhoA, Rac1 and Cdc42 proteins to promote the migration and invasion of extravillous trophoblastic cell and ultimately formate the placenta accrete compare to the normal placenta.

Conclusions

Our research proved that trophoblasts may contribute to a PAS‐associated increase in CXCL12 levels in maternal blood. CXCL12 is not only associated with biological roles of PAS, but may also be potential for prediction of PAS.

Stromal Cell-derived Factor-1 and CXC Chemokine Receptor Type-4 are Associated with Cardiovascular Disease in Patients under Hemodialysis

Background

Cardiovascular disease (CVD) is the most common cause of death among patients with end-stage renal disease especially whom under hemodialysis (HD). Stromal cell-derived factor-1 (SDF-1) and its receptor CXC chemokine receptor type-4 (CXCR4) could contribute to CVD. The main aim of this study was to evaluate the association between SDF-1 and CXCR4 with CVD and its related risk factors in patients under HD.

Methods

Sixty patients under HD and 29 healthy subjects were recruited in the study. The serum levels and relative messenger RNA (mRNA) expressions of SDF-1 and CXCR4 were measured using enzyme-linked immunosorbent assay and real-time polymerase chain reaction in patients and controls, respectively. CVD history of the patients was obtained.

Results

Twenty patients (33.3%) had a history of CVD. The mean levels of serum and relative mRNA expressions of SDF-1 and CXCR4 were higher in patients than controls and also in patients with a history of CVD than patients without it. The serum levels and relative expressions of SDF-1 and CXCR4 were positively correlated with blood urea nitrogen, parathyroid hormone, and high-sensitivity C-reactive protein and inversely correlated with hemoglobin. The history of CVD was the independent predictor of serum levels of SDF-1 and CXCR4 and also relative mRNA expression of CXCR4.

Conclusions

The higher levels of serum and relative mRNA expressions of SDF-1 and CXCR4 were associated with CVD in patients under HD. Furthermore, SDF-1 and CXCR4 were associated with several traditional and uremia-related CVD risk factors in such patients.

Stromal cell derived factor-1 and long-term prognosis in acute coronary syndrome

Aim: To explore long-term prognostic value of SDF-1 in acute coronary syndrome (ACS). Materials & methods: We included 254 patients with ACS. Plasma SDF-1 was measured and patients were classified into tertiles of SDF-1. Results: Multivariate analysis showed third tertile of SDF-1 as an independent predictor of all-cause death (HR: 2.5; 95% CI: 1.2-5.2; p = 0.011) and the composite of major adverse cardiovascular and cerebrovascular events (HR: 1.8; 95% CI: 1.1-3.1; p = 0.031). SDF-1 added to a clinical model can improve all-cause death prediction (net reclassification improvement 0.362; 95% CI: 0.423-0.681; p = 0.027). Conclusion: SDF-1 is an independent predictor of all-cause mortality and major adverse cardiovascular and cerebrovascular events in long-term follow-up of patients with ACS and adds prognostic information beyond traditional cardiovascular risks factors.

High levels of stromal cell-derived factor-1α predict short-term progression of renal dysfunction in patients with coronary artery disease

BACKGROUND

Stromal cell-derived factor-1α (SDF-1α) is an inflammatory chemokine that plays a critical role in cardiovascular disease. Although persistent inflammation causes renal dysfunction, it remains unclear whether SDF-1α is related to progression of chronic kidney disease. This study examined whether high levels of SDF-1α are associated with future declines in renal function in patients with coronary artery disease (CAD).

METHODS

Plasma levels of SDF-1α in the peripheral blood were measured by enzyme-linked immunosorbent assay in 344 patients with CAD. All patients were followed for 24 months or until the occurrence of renal dysfunction, defined as ≥ 25% decrease in estimated glomerular filtration rate (eGFR) from baseline.

RESULTS

During the follow-up period, 36 patients developed renal dysfunction. Multivariate logistic regression analysis showed that high plasma levels of SDF-1α were significantly associated with progression of renal dysfunction (odds ratio 1.65; 95% confidence intervals 1.07-2.35, p = 0.03). In addition, high plasma levels of SDF-1α had a significant incremental effect on the predictive value of known risk factors for renal dysfunction in analyses using net reclassification improvement (NRI) and integrated discrimination improvement (IDI) (NRI 0.58 [0.07-1.02], p < 0.01; and IDI 0.030 [0.001-0.085], p = 0.02).

CONCLUSION

High plasma levels of SDF-1α were associated with the short-term decline of eGFR in patients with CAD. Thus, SDF-1α may be useful for predicting the progression of renal dysfunction in patients with CAD.

Angiotensin II receptor blockers suppress the release of stromal cell-derived factor-1α from infarcted myocardium in patients with acute myocardial infarction

BACKGROUND

Although angiotensin II receptor blockers (ARBs) have been shown to have anti-inflammatory effects on infarcted myocardium in experimental models, little is known in humans. Stromal cell-derived factor-1α (SDF-1α), a pro-inflammatory chemokine, is released from infarcted tissue in patients with acute myocardial infarction (AMI). This study examined whether ARBs suppress SDF-1α production in the infarcted lesion in patients with AMI.

METHODS

SDF-1α levels were measured by enzyme-linked immunosorbent assays in plasma obtained from the aortic root (AO) and the anterior interventricular vein (AIV) in 50 patients with an anterior AMI. Measurement of SDF-1α levels and left ventriculography were repeated at discharge and 6 months after AMI. Patients were divided into 2 groups according to treatment with ARBs, which were administered at the discretion of the attending physician after admission.

RESULTS

The AIV-AO gradient of SDF-1α, reflecting SDF-1α release from the infarcted myocardial region, decreased between the time of discharge and 6 months after AMI in patients taking an ARB. In contrast, the SDF-1α transcardiac gradient did not change in patients not taking an ARB. Among the clinical parameters tested, only the use of ARBs was significantly associated with percent changes in the SDF-1α transcardiac gradient from the time of discharge to 6 months after AMI in a linear regression analysis (r=-0.31, p=0.03). The SDF-1α transcardiac gradient 6 months after AMI was inversely correlated with the percent change in left ventricular (LV) ejection fraction (r=-0.52, p<0.01) and positively correlated with the percent change in LV end-diastolic volume index (r=0.57, p<0.01) and LV end-systolic volume index (r=0.54, p<0.01) during 6 months after AMI.

CONCLUSIONS

ARB treatment suppressed SDF-1α release from the infarcted myocardial region, which was associated with improvement in LV dysfunction and adverse remodeling in AMI survivors.

A novel recombinant antibody specific to full-length stromal derived factor-1 for potential application in biomarker studies

Background

Stromal derived factor-1α (SDF-1α/CXCL12) is a chemokine that is up-regulated in diseases characterised by tissue hypoxia, including myocardial infarction, ischaemic cardiomyopathy and remote ischaemic conditioning (RIC), a technique of cyclical, non-injurious ischaemia applied remote from the heart that protects the heat from lethal ischaemia-reperfusion injury. Accordingly, there is considerable interest in SDF-1α as a potential biomarker of such conditions. However, SDF-1α is rapidly degraded and inactivated by dipeptidyl peptidase 4 and other peptidases, and the kinetics of intact SDF-1α remain unknown.

Methods & results

To facilitate investigation of full-length SDF-1α we established an ELISA using a novel recombinant human antibody we developed called HCI.SDF1. HCI.SDF1 is specific to the N-terminal sequence of all isoforms of SDF-1 and has a comparable K_D to commercially available antibodies. Together with a detection antibody specific to the α-isoform, HCI.SDF1 was used to specifically quantify full-length SDF-1α in blood for the first time. Using RIC applied to the hind limb of Sprague-Dawley rats or the arms of healthy human volunteers, we demonstrate an increase in SDF-1α using a commercially available antibody, as previously reported, but an unexpected decrease in full-length SDF-1α after RIC in both species.

Conclusions

We report for the first time the development of a novel recombinant antibody specific to full-length SDF-1. Applied to RIC, we demonstrate a significant decrease in SDF-1α that is at odds with the literature and suggests a need to investigate the kinetics of full-length SDF-1α in conditions characterised by tissue hypoxia.