Fibroblast growth factors in cardiovascular disease: The emerging role of FGF21

Fibroblast Growth Factor 21 Attenuates Vascular Calcification by Alleviating Endoplasmic Reticulum Stress Mediated Apoptosis in Rats

Fibroblast growth factor 21 (FGF21), a hormone with multiple metabolic properties, has proven to be pleiotropic biological effects and may play pivotal role in numerous cardiovascular and metabolic diseases in the future. Vascular calcification (VC) is a concomitant pathological process of various cardiovascular and metabolic diseases. However, the effects of FGF21 on VC remain unclear. Therefore, in this research, we aimed to explore the roles and mechanisms of FGF21 in VC induced by vitamin D₃ plus nicotine (VDN) treatment rats. After 28 days VDN treatment, the calcium overload was confirmed by blood pressure, ultrasound imaging, calcium content, ALP activity and aortic pathological characteristics. In terms of FGF21, exogenous FGF21 can ameliorate the elevation of blood pressure, aortic calcification and related injury in VC rats. To investigate the mechanisms of FGF21 on VC, the endoplasmic reticulum stress (ERS) mediated apoptosis pathways were tested. As a method to detect apoptosis, the increased positive TUNEL staining cells were alleviated by FGF21 treatment. Furthermore, exogenous FGF21 can suppress the increased ERS chaperone, GRP78, in the calcified aortas. In the three pathways of ERS mediated apoptosis, we found CHOP pathway and caspase-12 pathway were involved in the treatment of FGF21, but not p-JNK/JNK pathway. Our study proved for the first time that FGF21 can inhibit the progress of VC by alleviating ERS mediated apoptosis in rats. FGF21 might be a new target for preventing and treating VC.

Alteration in serum concentrations of FGF19, FGF21, and FGF23 in patients with urothelial carcinoma

Fibroblast growth factors (FGF) 19, 21, and 23 have been reported as functional factors in human metabolic diseases and malignancies. We performed a prospective survey to compare circulating FGF levels in urothelial carcinoma (UC) patients and normal controls. Between 2016 and 2017, 39 patients with UC of the urinary bladder or upper urinary tract who received surgical intervention were included. All the serum samples were obtained before surgeries. The control group included 28 healthy volunteers. Analysis of the circulating FGF19, 21, and 23 levels among all 67 subjects, as well as a subgroup analysis of the 39 UC patients were performed. The median levels of serum FGF19, 21, and 23 in the UC patients were 84.2, 505.3, and 117.6 pg/mL, respectively, which were statistically different from levels found in the healthy controls (P = 0.015, <0.001 and < 0.001, respectively). In the subgroup analysis, the FGF19 and FGF21 levels were significantly higher in end-stage renal disease UC patients, while FGF21 was also higher in the UC patients with cardiovascular diseases and history of recurrent UC. In the receiver operating characteristic (ROC) curve analysis, FGF19, 21, and 23 were all significant predictors of UC [area under the curve (AUC)] 0.674, P = 0.015; AUC 0.918, P < 0.001; AUC 0.897, P < 0.001, respectively). In UC patients, serum FGF19 level was significantly lower, while FGF21 and 23 were significantly higher, than respective levels in healthy controls. All three markers may serve as good predictors of UC occurrence, and FGF21 level was associated with disease recurrence. © 2018 BioFactors, 45(1):62-68, 2019.

Role of fibroblast growth factor 21 in gestational diabetes mellitus: A mini-review

Gestational diabetes mellitus (GDM) is defined as glucose intolerance with onset or first diagnosis during pregnancy, but not to the level of being diagnostic for diabetes in a nonpregnant adult. In GDM, whole-body insulin-dependent glucose disposal decreases by 40%-60% which necessitates a 200%-250% increase in insulin secretion to maintain normoglycaemia. GDM develops when a pregnant woman does not produce sufficient insulin to compensate for the reduced glucose disposal. Fibroblast growth factor 21 (FGF21) is a hormone that is expressed predominantly in the liver, but also in other metabolically active tissues such as pancreas, skeletal muscle and adipose tissue. In animals, FGF21 lowers blood glucose levels and inhibits glucagon secretion. In humans, circulating FGF21 levels are increased in insulin-resistant morbidities such as obesity and type 2 diabetes mellitus (T2DM). An elevated FGF21 level is also an independent predictor of T2DM. GDM and T2DM are proposed to have similar underlying pathophysiologies, raising the question of whether a similar relationship exists between FGF21 and GDM as it does with T2DM. There are a limited number of studies investigating FGF21 levels in patients with GDM. Moreover, recent clinical trials investigating the therapeutic potential of FGF21 have highlighted a major gap in our understanding of the biology of FGF21. This review evaluates what is currently known about FGF21 and GDM and highlights important gaps that warrant further research.

Two-hundred-liter scale fermentation, purification of recombinant human fibroblast growth factor-21, and its anti-diabetic effects on ob/ob mice

Fibroblast growth factor-21 (FGF-21) is a potential cytokine for type II diabetes mellitus. This study aimed to optimize recombinant human FGF-21 (rhFGF-21) production in Escherichia coli BL21 (DE3) employing high cell density fermentation at a 200-L scale and pilot-scale purification. FGF-21 was eventually expressed in E. coli BL21 (DE3) using human FGF-21 synthetic DNA sequence via the introduction of vector pET-3c; the product is used as seed strain during the fermentation of rhFGF-21. Fermentation of rhFGF-21 was performed in a 30-L and 200-L fermenters. rhFGF-21 was primarily expressed in the form of inclusion bodies after IPTG induction. At the 200-L scale, the bacterial production and expression levels of rhFGF-21 were 38.8 ± 0.6 g/L and 30.9 ± 0.7%, respectively. Additionally, the high purification (98%) of rhFGF-21 was tested with HPLC analysis and reducing & non-reducing SDS-PAGE analysis. The final yield of purified rhFGF-21 was 71.1 ± 13.9 mg/L. The activity of rhFGF-21 stock solution reached at 68.67 ± 8.74 IU/mg. Blood glucose controlling and insulin sensitization were improved with treatment of rhFGF-21 in type II diabetic ob/ob mice. Our results showed that the relatively stable and time-saving pilot-scale production process was successfully established, providing an efficient and cost-effective strategy for large-scale and industrial production of rhFGF-21.

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.

Circulating level of fibroblast growth factor 21 is independently associated with the risks of unstable angina pectoris

There is increasing evidence that serum adipokine levels are associated with higher risks of cardiovascular diseases. As an important adipokine, fibroblast growth factor 21 (FGF21) has been demonstrated to be associated with atherosclerosis and coronary artery disease (CAD). However, circulating level of FGF21 in patients with angina pectoris has not yet been investigated. Circulating FGF21 level was examined in 197 patients with stable angina pectoris (SAP, n=66), unstable angina pectoris (UAP, n=76), and control subjects (n=55) along with clinical variables of cardiovascular risk factors. Serum FGF21 concentrations on admission were significantly increased more in patients with UAP than those with SAP (Ln-FGF21: 5.26 ± 0.87 compared with 4.85 ± 0.77, P<0.05) and control subjects (natural logarithm (Ln)-FGF21: 5.26 ± 0.87 compared with 4.54 ± 0.72, P<0.01). The correlation analysis revealed that serum FGF21 concentration was positively correlated with the levels of cardiac troponin I (cTnI) (r²  =  0.026, P=0.027) and creatine kinase-MB (CK-MB) (r²  =  0.023, P= 0.04). Furthermore, FGF21 level was identified as an independent factor associated with the risks of UAP (odds ratio (OR): 2.781; 95% CI: 1.476–5.239; P=0.002), after adjusting for gender, age, and body mass index (BMI). However, there were no correlations between serum FGF21 levels and the presence of SAP (OR: 1.248; 95% CI: 0.703–2.215; P=0.448). The present study indicates that FGF21 has a strong correlation and precise predictability for increased risks of UAP, that is independent of traditional risk factors of angina pectoris.

A high circulating FGF21 level as a prognostic marker in patients with acute myocardial infarction

OBJECTIVE

The purpose of this study was to examine the level of serum FGF21 in acute myocardial infarction (AMI) and to explore the association between serum FGF21 and major adverse cardiovascular events in AMI patients.

METHODS

A total of 238 Chinese patients were recruited for this study between January 2016 and June 2016, including 183 AMI patients and 55 patients without AMI were enrolled in this study. The level of serum FGF21 was measured by ELISA. Patients were followed-up after admission using a standardized protocol that included Outpatient follow-up and telephone contacts to record the Major Adverse Cardiovascular Events (MACEs). Finally, 165 patients were enrolled and followed up during the period of 24 months.

RESULTS

Circulating FGF21 level was elevated in the AMI patients compared to control (P < 0.05). Multivariate linear regression analysis showed that cTnI (β = -0.001, 95% CI = 0.021-0.001, P = 0.002), fibrinogen (β = -0.055, 95% CI = 0.098-0.013, P = 0.011) and hyperlipidemia (β = 0.129, 95% CI = 0.014-0.243, P = 0.011) were the independent risk factors for the serum of FGF21 in AMI patients. After follow-up, A Kaplan-Meier analysis showed that the all-cause mortality rate was not significantly different between the two groups (P = 0.4146). Meanwhile the rate of cardiovascular events was significantly higher in the high-FGF21 group than in the low-FGF21 group (P = 0.0399). In the multivariate Cox proportional hazards regression model suggested that the predictive independent risk factors for the occurrence of MACEs were FGF21 ≥ cut-off (HR: 1.637; 95% CI: 1.357-3.647, P = 0.029) and D-Dimer (HR: 1.420; 95% CI: 1.069-3.014, P = 0.046).

CONCLUSION

Circulating FGF21 level is elevated in the AMI patients. In AMI patients, cTnI, fibrinogen and hyperlipidemia are the inde pendent risk factors for the serum of FGF21. Higher circulating FGF21 level is associated with increased MACEs rate. This study suggests that circulating FGF21 level may be a predictive marker of the clinical outcomes in AMI patients.

Fibroblast growth factor 21 inhibits atherosclerosis in apoE-/- mice by ameliorating Fas-mediated apoptosis

Background

FGF21 is a critical endogenous regulator in energy homeostasis and systemic glucose and lipid metabolism. Despite intensive study of the metabolic functions of FGF21, its important role in heart disease needs further exploration. Apoptosis induced by ox-LDL in vascular endothelial cells is an important step in the progress of atherosclerosis.

Methods

The effects of FGF21 treatment on apoptosis induced by ox-LDL were tested in HUVECs. The role of FGF21 in atherosclerosis was studied by evaluating its function in apolipoprotein E double knockout (apoE−/−) mice.

Results

We found that apoptosis in HUVECs was alleviated by FGF21 treatment. The effects of FGF21 were independent of the ERK1/2 pathway and were mediated through inhibition of the Fas signaling pathway. FGF21 suppressed the development of atherosclerosis, and the administration of FGF21 ameliorated Fas-mediated apoptosis in apoE−/− mice.

Conclusion

FGF21 protects against apoptosis in HUVECs by suppressing the expression of Fas; furthermore, FGF21 alleviated atherosclerosis by ameliorating Fas-mediated apoptosis in apoE−/− mice.

Electronic supplementary material

The online version of this article (10.1186/s12944-018-0846-x) contains supplementary material, which is available to authorized users.

Raspberry Polyphenolic Extract Regulates Obesogenic Signals in Hepatocytes

The aim of this in vitro study was to examine the effect of raspberry polyphenolic extract on the immune-metabolic molecular mechanisms activated by obesity-related signals in hepatocytes (HB-8965^®). Alterations in endosomal/lysosomal activity (neutral red uptake assay, NR), the expression of selected genes involved with lipid oxidation, and metabolism and inflammation processes in the liver were studied. Hepatocytes were treated with plasma collected from Wistar rats that were fed a high-fat diet (HF), raspberry polyphenolic extract (PP), serine-type protease inhibitors as an agonist of TLR4 (TD) or a combination of PP with HF or TD treatments. The PP added to the experimental treatments modulated hepatic immune-metabolic mechanisms through the upregulation of STAT1, ANGPTL4, and CD44, as well as considerably reducing the NR uptake and downregulation of COX-2 and the multifunctional protein AhR. The kinetic analysis of AhR expression revealed that HF-related molecular mechanisms activated AhR mRNA expression earlier than PP initiated the regulatory effect. In conclusion, PP might be considered a valuable dietary agent that regulates obesity-related signals in hepatocytes. Moreover, taking AhR kinetic behavior into consideration, it can be assumed that PP might modulate the severity of the HF-induced downstream metabolic signaling of AhR.

Serum Fibroblast Growth Factor 21 and New-Onset Metabolic Syndrome: KoGES-ARIRANG Study

PURPOSE

Fibroblast growth factor 21 (FGF21) is a crucial metabolic regulator, with multiple favorable effects on glucose homeostasis and lipid metabolism. Since serum FGF21 level has been implicated as a potential marker for the early identification of metabolic syndrome (MetS), we investigated the association between serum FGF21 level and the development of MetS in a population-based prospective study.

MATERIALS AND METHODS

We conducted a prospective study of 221 randomly sampled adults without MetS from a general population-based cohort study who were examined from 2005-2008 (baseline) and from 2008-2011 (follow-up). Baseline serum FGF21 levels were analyzed using enzyme-linked immunosorbent assay.

RESULTS

During the average 2.8-year follow-up period, 82 participants (36.6%) developed new-onset MetS. Serum FGF21 levels were significantly higher in patients with new-onset MetS than in those without MetS (209.56±226.80 vs. 110.09±81.10, p<0.01). In multivariate adjusted models, the odds for MetS development were greater in patients with serum FGF21 levels in the highest quartile, compared to those in the lowest quartile (3.84, 95% confidence interval: 1.59-9.28).

CONCLUSION

Serum FGF21 level was an independent predictor for new-onset MetS in a population-based prospective study.

Hepatic regulation of VLDL receptor by PPARβ/δ and FGF21 modulates non-alcoholic fatty liver disease

Objective

The very low-density lipoprotein receptor (VLDLR) plays an important role in the development of hepatic steatosis. In this study, we investigated the role of Peroxisome Proliferator-Activated Receptor (PPAR)β/δ and fibroblast growth factor 21 (FGF21) in hepatic VLDLR regulation.

Methods

Studies were conducted in wild-type and Pparβ/δ-null mice, primary mouse hepatocytes, human Huh-7 hepatocytes, and liver biopsies from control subjects and patients with moderate and severe hepatic steatosis.

Results

Increased VLDLR levels were observed in liver of Pparβ/δ-null mice and in Pparβ/δ-knocked down mouse primary hepatocytes through mechanisms involving the heme-regulated eukaryotic translation initiation factor 2α (eIF2α) kinase (HRI), activating transcription factor (ATF) 4 and the oxidative stress-induced nuclear factor (erythroid-derived 2)-like 2 (Nrf2) pathways. Moreover, by using a neutralizing antibody against FGF21, Fgf21-null mice and by treating mice with recombinant FGF21, we show that FGF21 may protect against hepatic steatosis by attenuating endoplasmic reticulum (ER) stress-induced VLDLR upregulation. Finally, in liver biopsies from patients with moderate and severe hepatic steatosis, we observed an increase in VLDLR levels that was accompanied by a reduction in PPARβ/δ mRNA abundance and DNA-binding activity compared with control subjects.

Conclusions

Overall, these findings provide new mechanisms by which PPARβ/δ and FGF21 regulate VLDLR levels and influence hepatic steatosis development.

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PPARβ/δ deficiency leads to increased levels of hepatic VLDLR levels.

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FGF21 protects against hepatic steatosis by attenuating ER stress-induced VLDLR upregulation.

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Human hepatic steatosis is accompanied by increased levels of VLDLR and reduced expression of PPARβ/δ.

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PPARβ/δ and FGF21 may influence NAFLD development by regulating VLDLR levels.

The effects of allogenic stem cells in a murine model of hind limb diabetic ischemic tissue

BACKGROUND

Diabetes is one of the major risk factors for peripheral arterial disease. In patients in whom surgery cannot be performed, cell therapy may be an alternative treatment. Since time is crucial for these patients, we propose the use of allogenic mesenchymal cells.

METHODS

We obtained mesenchymal cells derived from the fat tissue of a healthy Sprague-Dawley rat. Previous diabetic induction with streptozotocin in 40 male Sprague-Dawley rats, ligation plus left iliac and femoral artery sections were performed as a previously described model of ischemia. After 10 days of follow-up, macroscopic and histo-pathological analysis was performed to evaluate angiogenic and inflammatory parameters in the repair of the injured limb. All samples were evaluated by the same blind researcher. Statistical analysis was performed using the SPSS v.11.5 program (P < 0.05).

RESULTS

Seventy percent of the rats treated with streptozotocin met the criteria for diabetes. Macroscopically, cell-treated rats presented better general and lower ischemic clinical status, and histologically, a better trend towards angiogenesis, greater infiltration of type 2 macrophages and a shortening of the inflammatory process. However, only the inflammatory variables were statistically significant. No immunological reaction was observed with the use of allogeneic cells.

DISCUSSION

The application of allogeneic ASCs in a hind limb ischemic model in diabetic animals shows no rejection reactions and a reduction in inflammatory parameters in favor of better repair of damaged tissue. These results are consistent with other lines of research in allogeneic cell therapy. This approach might be a safe, effective treatment option that makes it feasible to avoid the time involved in the process of isolation, expansion and production of the use of autologous cells.

Regulation of longevity by FGF21: Interaction between energy metabolism and stress responses

Fibroblast growth factor 21 (FGF21) is a hormone-like member of FGF family which controls metabolic multiorgan crosstalk enhancing energy expenditure through glucose and lipid metabolism. In addition, FGF21 acts as a stress hormone induced by endoplasmic reticulum stress and dysfunctions of mitochondria and autophagy in several tissues. FGF21 also controls stress responses and metabolism by modulating the functions of somatotropic axis and hypothalamic-pituitary-adrenal (HPA) pathway. FGF21 is a potent longevity factor coordinating interactions between energy metabolism and stress responses. Recent studies have revealed that FGF21 treatment can alleviate many age-related metabolic disorders, e.g. atherosclerosis, obesity, type 2 diabetes, and some cardiovascular diseases. In addition, transgenic mice overexpressing FGF21 have an extended lifespan. However, chronic metabolic and stress-related disorders involving inflammatory responses can provoke FGF21 resistance and thus disturb healthy aging process. First, we will describe the role of FGF21 in interorgan energy metabolism and explain how its functions as a stress hormone can improve healthspan. Next, we will examine both the induction of FGF21 expression via the integrated stress response and the molecular mechanism through which FGF21 enhances healthy aging. Finally, we postulate that FGF21 resistance, similarly to insulin resistance, jeopardizes human healthspan and accelerates the aging process.

Macronutrient Intake-Associated FGF21 Genotype Modifies Effects of Weight-Loss Diets on 2-Year Changes of Central Adiposity and Body Composition: The POUNDS Lost Trial

OBJECTIVE

Fibroblast growth factor 21 (FGF21) is involved in the regulation of energy balance and adipose metabolism. Our previous genome-wide association study identified genetic variants in the FGF21 region associated with macronutrient intake preference. We investigated whether the FGF21 genotype modified effects of weight-loss diets varying in macronutrient intake on changes in adiposity in a 2-year randomized diet intervention trial.

RESEARCH DESIGN AND METHODS

We genotyped FGF21 rs838147 in 715 overweight or obese individuals who were assigned to one of four diets varying in macronutrient contents. A DEXA scan was performed to evaluate body composition.

RESULTS

We observed a significant interaction between the FGF21 genotype and carbohydrate/fat intake on 2-year changes in waist circumference (WC), percentage of total fat mass, and percentage of trunk fat (P = 0.049, P = 0.001, and P = 0.003 for interaction, respectively). In response to the low-carbohydrate/high-fat diet, carrying the carbohydrate intake-decreasing C allele of rs838147 was marginally associated with less reduction in WC (P = 0.08) and significantly associated with less reduction of total fat mass (P = 0.01) and trunk fat (P = 0.02). Opposite genetic associations with these outcomes were observed among the high-carbohydrate/low-fat diet group; carrying the C allele was associated with a greater reduction of WC, total body fat mass, and trunk fat.

CONCLUSIONS

Our data suggest that FGF21 genotypes may interact with dietary carbohydrate/fat intake on changes in central adiposity and body fat composition. A low-calorie, high-carbohydrate/low-fat diet was beneficial for overweight or obese individuals carrying the carbohydrate intake-decreasing allele of the FGF21 variant to improve body composition and abdominal obesity.

Roles of FGF Signals in Heart Development, Health, and Disease

The heart provides the body with oxygen and nutrients and assists in the removal of metabolic waste through the blood vessels of the circulatory system. It is the first organ to form during embryonic morphogenesis. FGFs with diverse functions in development, health, and disease are signaling proteins, mostly as paracrine growth factors or endocrine hormones. The human/mouse FGF family comprises 22 members. Findings obtained from mouse models and human diseases with FGF signaling disorders have indicated that several FGFs are involved in heart development, health, and disease. Paracrine FGFs including FGF8, FGF9, FGF10, and FGF16 act as paracrine signals in embryonic heart development. In addition, paracrine FGFs including FGF2, FGF9, FGF10, and FGF16 play roles as paracrine signals in postnatal heart pathophysiology. Although FGF15/19, FGF21, and FGF23 are typical endocrine FGFs, they mainly function as paracrine signals in heart development or pathophysiology. In heart diseases, serum FGF15/19 levels or FGF21 and FGF23 levels decrease or increase, respectively, indicating their possible roles in heart pathophysiology. FGF2 and FGF10 also stimulate the cardiac differentiation of cultured stem cells and cardiac reprogramming of cultured fibroblasts. These findings provide new insights into the roles of FGF signaling in the heart and potential therapeutic strategies for cardiac disorders.

Non-alcoholic fatty liver disease and cardiovascular risk: Pathophysiological mechanisms and implications

Non-alcoholic fatty liver disease (NAFLD) has become one of the most frequent chronic liver diseases in the Western society and its prevalence is likely to rise even further. An increasing body of evidence shows that NAFLD is not only a potentially progressive liver disease, but also has systemic consequences. More specifically, evidence points out that NAFLD has to be considered as a significant independent risk factor for subclinical and clinical cardiovascular disease (CVD). Long-term follow-up studies demonstrate cardiovascular mortality to be the most important cause of death in NAFLD patients. Moreover, ample evidence associates NAFLD with endothelial dysfunction, increased pulse wave velocity, increased coronary arterial calcifications and increased carotid intima media thickness, all established markers for CVD. Despite of all this evidence, the mechanisms by which NAFLD causally contributes to CVD are not fully elucidated. Furthermore, an extensive overview of all potential pathophysiological mechanisms and the corresponding current data are lacking. In this review we summarise current knowledge, originating from fundamental and clinical research, that mechanistically links NAFLD to CVD. Subsequently, the impact of CVD on current clinical practice and future research in the area of NALFD are discussed.