Changes in Serum Fibroblast Growth Factor 23 in Patients With Acute Myocardial Infarction

Leonurine pretreatment protects the heart from myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion (I/R), an important complication of reperfusion therapy for myocardial infarction, is characterized by hyperactive oxidative stress and inflammatory response. Leonurine (4-guanidino-n-butyl syringate, SCM-198), an alkaloid extracted from Herbaleonuri, was previously found to be highly cardioprotective both in vitro and in vivo. Our current study aimed to investigate the effect of SCM-198 preconditioning on myocardial I/R injury in vitro and in vivo, respectively, as well as to decipher the mechanism involved. Rats were pretreated with SCM-198 before subjected to 45 min of myocardial ischemia, which was followed by 24 h of reperfusion. Primary neonatal rat cardiac ventricular myocytes (NRCMs) were exposed to hypoxia (95% N2 + 5% CO2) for 12 h, and then to 12 h reoxygenation so as to mimic I/R. The enzymatic measurements demonstrated that SCM-198 reduced the release of infarction-related enzymes, and the hemodynamic and echocardiography measurements showed that SCM-198 restored cardiac functions, which suggested that SCM-198 could significantly reduce infarct size, maintaining cardiomyocyte morphology, and that SCM-198 pretreatment could significantly reduce cardiomyocytes apoptosis. Moreover, we demonstrated that SCM-198 could exert a cardioprotective effect by reducing reactive oxygen species (ROS) level and Akt phosphorylation while reducing the phosphorylation of p38 and JNK. In addition, the upregulation of p-Akt, Bcl-2/Bax induced by SCM-198 treatment were blocked by PI3K inhibitor LY294002, and the total protein level of Akt was not affected by SCM-198 pretreatment. Our experimental results indicated that SCM-198 could have a cardioprotective effect on I/R injury, which confirmed the utility of SCM-198 preconditioning as a strategy to prevent I/R injury.

Baseline fibroblast growth factor 23 is associated with long-term mortality in ST-elevation myocardial infarction-results from the augsburg myocardial infarction registry

Background

The aim of this study was to investigate the association between inflammatory plasma protein concentrations and long-term mortality in patients with ST-elevation myocardial infarction (STEMI).

Methods

For 343 STEMI patients recorded between 2009 and 2013 by the population-based Myocardial Infarction Registry Augsburg, 92 inflammatory plasma proteins were measured at the index event using the OLINK inflammation panel. In multivariable-adjusted Cox regression models, the association between each plasma protein and all-cause long-term mortality was investigated. Median follow-up time was 7.6 (IQR: 2.4) years. For plasma protein that showed a strong association with long-term mortality, a 5-year survival ROC analysis was performed.

Results

One plasma protein, namely Fibroblast Growth Factor 23 (FGF-23), was particularly well associated with long-term mortality in the multivariable-adjusted Cox model with an FDR-adjusted p-value of <0.001 and a Hazard Ratio (HR) of 1.57 [95% CI: 1.29-1.91]. In the 5-years ROC analysis, an AUC of 0.6903 [95% CI: 0.594-0.781] was estimated for FGF-23. All other plasma protein didńt show strong associations, each marker with FDR-adjusted p-values >0.05 in the multivariable-adjusted Cox models.

Conclusions

FGF-23 is independently associated with long-term mortality after STEMI and might play an important role in the response to myocardial injury. The results suggest FGF-23 to be a useful marker in the long-term treatment of STEMI patients and a potential target for drug development.

Direct and indirect effects of fibroblast growth factor 23 on the heart

Fibroblast growth factor (FGF)23 is a bone-derived phosphotropic hormone that regulates phosphate and mineral homeostasis. Recent studies have provided evidence that a high plasma concentration of FGF23 is associated with cardiac disease, including left ventricular hypertrophy (LVH), heart failure, atrial fibrillation, and cardiac death. Experimental studies have shown that FGF23 activates fibroblast growth factor receptor 4 (FGFR4)/phospholipase Cγ/calcineurin/nuclear factor of activated T-cells signaling in cardiomyocytes and induces cardiac hypertrophy in rodents. Activation of FGFR4 by FGF23 normally requires the co-receptor α-klotho, and klotho-independent signaling occurs only under conditions characterized by extremely high FGF23 concentrations. Recent studies have demonstrated that FGF23 activates the renin-angiotensin-aldosterone system (RAAS) and induces LVH, at least in part as a result of lower vitamin D activation. Moreover, crosstalk between FGF23 and RAAS results in the induction of cardiac hypertrophy and fibrosis. In this review, we summarize the results of studies regarding the relationships between FGF23 and cardiac events, and describe the potential direct and indirect mechanisms whereby FGF23 induces LVH.

Fibroblast Growth Factor 23 and Outcome Prediction in Patients with Acute Myocardial Infarction

(1) Background: Fibroblast growth factor 23 (FGF23) is associated with mortality in patients with heart failure (HF); however, less is known about mortality associations in patients with myocardial infarction (MI). (2) Methods: FGF23 was assessed in 180 patients with acute MI, 99 of whom presented with concomitant acute HF. Patients were followed up for one year, and outcome estimates by FGF23 were compared to GRACE score estimates. (3) Results: Log-transformed serum levels of intact FGF23 (logFGF23) did not differ between MI patients with and without HF, and no difference in logFGF23 was observed between 14 MI patients who died and those who survived. However, when only MI patients with concomitant HF were considered, logFGF23 was significantly higher among non-survivors compared to that in survivors. While logFGF23 was not associated with the outcome in the entire cohort, logFGF23 was fairly predictive for one-year mortality in patients with concomitant HF (AUC 0.78; 95%CI 0.61–0.95), where it outperformed GRACE score estimates (AUC 0.70; 95%CI 0.46–0.94). (4) Conclusions: FGF23 was associated with one-year mortality only in MI patients who concomitantly presented with HF, surpassing the predictive ability of GRACE score estimates. No associations were observed in patients without HF despite similar FGF23 levels at admission. Further studies are warranted to investigate whether FGF23 is causal for dismal outcome of HF.

The relationship between Fibroblast Growth Factor 23 (FGF23) and cardiac MRI findings following primary PCI in patients with acute first time STEMI

BACKGROUND

Fibroblast growth factor 23 (FGF23) is a regulator of mineral metabolism, that has been linked to myocardial remodeling including development of left ventricular (LV) hypertrophy and myocardial fibrosis. The aim of this study was to investigate the relationship between intact FGF23 (iFGF23), myocardial infarct size and LV remodeling following a first acute ST-elevation myocardial infarction (STEMI).

METHODS AND RESULTS

Forty-two consecutive patients with first-time STEMI, single vessel disease, successfully treated with primary percutaneous coronary intervention were included. Cardiac magnetic resonance (CMR) imaging was performed at day 2, 1 week, 2 months and 1 year post MI, and blood samples were drawn at admittance and at the same time points as the CMRs. The cohort was divided according to the presence or not of heart failure post MI. In the total cohort, iFGF23 (mean ± SD) was significantly lower at day 0 (33.7 ± 20.6 pg/ml) and day 2 (31.5 ± 23.4 pg/ml) compared with a reference interval based on 8 healthy adults (43.9 pg/ml ± 19.0 pg/ml). iFGF23 increased to normal levels (55.8 ± 23.4 pg/ml) seven days post MI. In the subset of patients with signs of acute heart failure, FGF23 was higher at all measured timepoints, reaching significantly higher FGF23 levels at 2 months and 1 year following revascularization.

CONCLUSION

There was a reduction in iFGF23 levels during the acute phase of MI, with a normalization at seven days following revascularization. During one-year follow-up, there was a gradual increase in iFGF23 levels in patients with heart failure.

An Overview of FGF-23 as a Novel Candidate Biomarker of Cardiovascular Risk

Fibroblast growth factor-23 (FGF)-23 is a phosphaturic hormone involved in mineral bone metabolism that helps control phosphate homeostasis and reduces 1,25-dihydroxyvitamin D synthesis. Recent data have highlighted the relevant direct FGF-23 effects on the myocardium, and high plasma levels of FGF-23 have been associated with adverse cardiovascular outcomes in humans, such as heart failure and arrhythmias. Therefore, FGF-23 has emerged as a novel biomarker of cardiovascular risk in the last decade. Indeed, experimental data suggest FGF-23 as a direct mediator of cardiac hypertrophy development, cardiac fibrosis and cardiac dysfunction via specific myocardial FGF receptor (FGFR) activation. Therefore, the FGF-23/FGFR pathway might be a suitable therapeutic target for reducing the deleterious effects of FGF-23 on the cardiovascular system. More research is needed to fully understand the intracellular FGF-23-dependent mechanisms, clarify the downstream pathways and identify which could be the most appropriate targets for better therapeutic intervention. This review updates the current knowledge on both clinical and experimental studies and highlights the evidence linking FGF-23 to cardiovascular events. The aim of this review is to establish the specific role of FGF-23 in the heart, its detrimental effects on cardiac tissue and the possible new therapeutic opportunities to block these effects.

Limited role for fibroblast growth factor 23 in assessing prognosis in heart failure patients: data from the TIME-CHF trial

AIM

Fibroblast growth factor 23 (FGF23) is an intensively studied biomarker at the crossroads of cardiovascular disease, heart failure (HF) and chronic kidney disease. Independent associations between increasing FGF23 levels and cardiovascular events were found in many, but not all studies. By analysing data from the TIME-CHF cohort, we sought to investigate the prognostic value of FGF23 in an elderly, multimorbid HF patient cohort. We determined differences between intact (iFGF23) and C-terminal FGF23 (cFGF23) regarding their prognostic value and their levels over time in different HF subgroups according to left ventricular ejection fraction (LVEF).

METHODS AND RESULTS

In this multicentre trial of 622 patients with symptomatic HF aged ≥60 years, we determined iFGF23 and cFGF23 at baseline, 3, 6 and 12-month follow-up. In unadjusted analyses, cFGF23 significantly predicted all HF-related outcomes at all time points. The predictive value of iFGF23 was less and not statistically significant at baseline. After multivariable adjustments, the association between both cFGF23 and iFGF23 and outcome lost statistical significance apart from cFGF23 at month 3. Overall, patients with preserved and mid-range LVEF had higher levels of iFGF23 and cFGF23 than those with reduced LVEF. Levels decreased significantly during the first 3 months in mid-range and reduced LVEF patients, but did not significantly change over time in those with preserved LVEF.

CONCLUSIONS

Fibroblast growth factor 23 is of limited value regarding risk prediction in this elderly HF population. Potentially heterogeneous roles of FGF23 in different LVEF groups deserve further investigation.

Cardiac FGF23: a new player in myocardial infarction

Fibroblast Growth Factor 23 (FGF23) is a hormone involved in phosphate metabolism. It is known that FGF23 is increased in different pathologies including chronic kidney disease, heart failure or X-linked hypophosphatemia and directly correlates with negative outcome and mortality in severe diseases. However, the role of FGF23 in cardiovascular pathologies is still under debate. This review summarizes the current knowledge about the role of FGF23 in ischemic heart diseases, such as myocardial infarction.

FGF23: Clinical usefulness and analytical evolution

Fibroblast Growth Factor 23 (FGF23) is a key hormone for the regulation of phosphate homeostasis. Over the past decades, FGF23 was the subject of intense research in the fields of nephrology and the cardiology. It presents a remarkable correlation with well-established biomarkers of cardiovascular disorders in both chronic kidney disease (CKD) and heart failure (HF) patients. The interest of FGF23 lies in its early-onset in the primary course of CKD as well as in the incremental prognosis information it conveys in both CKD and HF. Different types of assays of FGF-23 testing exist, those targeting the intact form (iFGF23), the other one detecting terminal fragments (cFGF23). The issue is still pending which assay suits best for clinical use. Recently, the implementation of this biomarker on multianalyzer platforms, on which other markers of phospho-calcic balance are set up, allows a rapid turn-around-time and a potential financial gain. However, despite the good analytical performances of the automated methods, there is a poor harmonization between assays. The introduction of an international certified reference material should standardize the measurement and improve the harmonization of results from different laboratories. A deeper understanding of physio-pathological mechanisms and processing of FGF-23 should reinforce its clinical indications and might also identify new therapeutic targets for the treatment of CKD and HF.

Towards frailty biomarkers: Candidates from genes and pathways regulated in aging and age-related diseases

OBJECTIVE

Use of the frailty index to measure an accumulation of deficits has been proven a valuable method for identifying elderly people at risk for increased vulnerability, disease, injury, and mortality. However, complementary molecular frailty biomarkers or ideally biomarker panels have not yet been identified. We conducted a systematic search to identify biomarker candidates for a frailty biomarker panel.

METHODS

Gene expression databases were searched (http://genomics.senescence.info/genes including GenAge, AnAge, LongevityMap, CellAge, DrugAge, Digital Aging Atlas) to identify genes regulated in aging, longevity, and age-related diseases with a focus on secreted factors or molecules detectable in body fluids as potential frailty biomarkers. Factors broadly expressed, related to several "hallmark of aging" pathways as well as used or predicted as biomarkers in other disease settings, particularly age-related pathologies, were identified. This set of biomarkers was further expanded according to the expertise and experience of the authors. In the next step, biomarkers were assigned to six "hallmark of aging" pathways, namely (1) inflammation, (2) mitochondria and apoptosis, (3) calcium homeostasis, (4) fibrosis, (5) NMJ (neuromuscular junction) and neurons, (6) cytoskeleton and hormones, or (7) other principles and an extensive literature search was performed for each candidate to explore their potential and priority as frailty biomarkers.

RESULTS

A total of 44 markers were evaluated in the seven categories listed above, and 19 were awarded a high priority score, 22 identified as medium priority and three were low priority. In each category high and medium priority markers were identified.

CONCLUSION

Biomarker panels for frailty would be of high value and better than single markers. Based on our search we would propose a core panel of frailty biomarkers consisting of (1) CXCL10 (C-X-C motif chemokine ligand 10), IL-6 (interleukin 6), CX3CL1 (C-X3-C motif chemokine ligand 1), (2) GDF15 (growth differentiation factor 15), FNDC5 (fibronectin type III domain containing 5), vimentin (VIM), (3) regucalcin (RGN/SMP30), calreticulin, (4) PLAU (plasminogen activator, urokinase), AGT (angiotensinogen), (5) BDNF (brain derived neurotrophic factor), progranulin (PGRN), (6) α-klotho (KL), FGF23 (fibroblast growth factor 23), FGF21, leptin (LEP), (7) miRNA (micro Ribonucleic acid) panel (to be further defined), AHCY (adenosylhomocysteinase) and KRT18 (keratin 18). An expanded panel would also include (1) pentraxin (PTX3), sVCAM/ICAM (soluble vascular cell adhesion molecule 1/Intercellular adhesion molecule 1), defensin α, (2) APP (amyloid beta precursor protein), LDH (lactate dehydrogenase), (3) S100B (S100 calcium binding protein B), (4) TGFβ (transforming growth factor beta), PAI-1 (plasminogen activator inhibitor 1), TGM2 (transglutaminase 2), (5) sRAGE (soluble receptor for advanced glycosylation end products), HMGB1 (high mobility group box 1), C3/C1Q (complement factor 3/1Q), ST2 (Interleukin 1 receptor like 1), agrin (AGRN), (6) IGF-1 (insulin-like growth factor 1), resistin (RETN), adiponectin (ADIPOQ), ghrelin (GHRL), growth hormone (GH), (7) microparticle panel (to be further defined), GpnmB (glycoprotein nonmetastatic melanoma protein B) and lactoferrin (LTF). We believe that these predicted panels need to be experimentally explored in animal models and frail cohorts in order to ascertain their diagnostic, prognostic and therapeutic potential.