Personalizing biomarker strategies in heart failure with galectin-3

Biomarkers in Peripartum Cardiomyopathy-What We Know and What Is Still to Be Found

Peripartum cardiomyopathy (PPCM) is a form of heart failure, often severe, that occurs in previously healthy women at the end of their pregnancy or in the first few months after delivery. In PPCM, the recovery of heart function reaches 45-50%. However, the all-cause mortality in long-term observation remains high, reaching 20% irrespective of recovery status. The incidence of PPCM is increasing globally; therefore, effort is required to clarify the pathophysiological background of the disease, as well as to discover specific diagnostic and prognostic biomarkers. The etiology of the disease remains unclear, including oxidative stress; inflammation; hormonal disturbances; endothelial, microcirculatory, cardiomyocyte and extracellular matrix dysfunction; fibrosis; and genetic mutations. Currently, antiangiogenic 16-kDa prolactin (PRL), cleaved from standard 23-kDa PRL in the case of unbalanced oxidative stress, is recognized as the main trigger of the disease. In addition, 16-kDa PRL causes damage to cardiomyocytes, acting via microRNA-146a secreted from endothelial cells as a cause of the NF-κβ pathway. Bromocriptine, which inhibits the secretion of PRL from the pituitary gland, is now the only specific treatment for PPCM. Many different phenotypes of the disease, as well as cases of non-responders to bromocriptine treatment, indicate other pathophysiological pathways that need further investigation. Biomarkers in PPCM are not well established. There is a deficiency in specific diagnostic biomarkers. Pro-brain-type natriuretic peptide (BNP) and N-terminal BNP are the best, however unspecific, diagnostic biomarkers of heart failure at the moment. Therefore, more efforts should be engaged in investigating more specific biomolecules of a diagnostic and prognostic manner such as 16-kDa PRL, galectin-3, myeloperoxidase, or soluble Fms-like tyrosine kinase-1/placental growth factor ratio. In this review, we present the current state of knowledge and future directions of exploring PPCM pathophysiology, including microRNA and heat shock proteins, which may improve diagnosis, treatment monitoring, and the development of specific treatment strategies, and consequently improve patients' prognosis and outcome.

Non-natriuretic peptide biomarkers in heart failure with preserved and reduced ejection fraction

Heart failure (HF) with reduced and preserved ejection fraction constitutes two entities with distinct pathogenetic backgrounds sharing common features. Beyond natriuretic peptides, several novel biomarkers have been proven useful in the diagnosis, prognosis and treatment of HF. Biomarkers of myocardial fibrosis have a low diagnostic yield in subjects with acute HF but may add prognostic information, especially in patients with HF and preserved ejection fraction. Biomarkers of renal impairment identify subjects with worse prognosis independently of left ventricle ejection fraction while inflammatory markers have not been proven useful in patients with systolic or diastolic impairment. In this review article, we summarize the main differences and application of non-natriuretic peptide biomarkers in HF patients with preserved and reduced ejection fraction.

Danshen injection prevents heart failure by attenuating post-infarct remodeling

ETHNOPHARMACOLOGICAL RELEVANCE

Danshen Injection (DSI) is a traditional Chinese medicine extracted from Danshen, prepared from the dried root and rhizome of Salvia miltiorrhiza Bunge. Danshen is an ancient antipyretic traditional Chinese medicine which is mostly used to improve blood circulation and dispel blood stasis. Danshen decoction or liquor-fried Danshen (with grain-based liquor) which is cool in nature is traditionally used to 'cool the blood' and reduce the swelling of sores and abscesses.

AIM OF STUDY

The present study aimed to examine the effect and mechanism of DSI in LAD induced heart injury.

MATERIALS AND METHODS

One day after LAD surgery, adult male Sprague-Dawley rats were randomized to 3 groups: MI group; DSI group (1.5ml/kg/d, intramuscular); and Valsartan group (10mg/kg/d, intragastric). Echocardiography and hemodynamic measurements (Pressure-Volume loop) were performed to evaluate cardiac function. Pathological methods (Masson, and Sirus red staining) were used to check myocardial fibrosis. Western blotting assay was used to detect the protein expression of MMP-2. RT-PCR was used to detect the gene expression of MMP-9, MPO, iNOS, Bcl-2 and Bax.

RESULTS

DSI administration to LAD rats resulted in improved cardiac functions, hemodynamic parameters and normalized ventricular mass. Furthermore, DSI-treated group demonstrated potential regulation of myocardial collagen I and III deposition associated with MMP-2 expression. Also, DSI administration decreased gene expression of iNOS, MPO and MMP-9, and increased Bcl-2/Bax ratio.

CONCLUSION

Myocardial fibrosis, cardiac hypertrophy, hemodynamic deterioration as well as systolic and diastolic dysfunctions which characterize a failing hearts were significantly prevented by DSI. Our study may provide future directions to focus on the anti-hypertrophic mechanisms of DSI and pathological roles played by MMP-2 in myocardial hypertrophy. Meanwhile, DSI also performed the effect of anti-inflammation by the way of decreasing iNOS and MPO. The way Danshen Injection increasing Bcl-2/Bax presented the possibility that it may has the effect of inhibiting cell death.

Extracellular galectin-3 programs multidrug resistance through Na+/K+-ATPase and P-glycoprotein signaling

Galectin-3 (Gal-3, LGALS3) is a pleotropic versatile, 29-35 kDa chimeric gene product, and involved in diverse physiological and pathological processes, including cell growth, homeostasis, apoptosis, pre-mRNA splicing, cell-cell and cell-matrix adhesion, cellular polarity, motility, adhesion, activation, differentiation, transformation, signaling, regulation of innate/adaptive immunity, and angiogenesis. In multiple diseases, it was found that the level of circulating Gal-3 is markedly elevated, suggesting that Gal-3-dependent function is mediated by specific interaction with yet an unknown ubiquitous cell-surface protein. Recently, we showed that Gal-3 attenuated drug-induced apoptosis, which is one of the mechanisms underlying multidrug resistance (MDR). Here, we document that MDR could be mediated by Gal-3 interaction with the house-keeping gene product e.g., Na+/K+-ATPase, and P-glycoprotein (P-gp). Gal-3 interacts with Na+/K+-ATPase and induces the phosphorylation of P-gp. We also find that Gal-3 binds P-gp and enhances its ATPase activity. Furthermore Gal-3 antagonist suppresses this interaction and results in a decrease of the phosphorylation and the ATPase activity of P-gp, leading to an increased sensitivity to doxorubicin-mediated cell death. Taken together, these findings may explain the reported roles of Gal-3 in diverse diseases and suggest that a combined therapy of inhibitors of Na+/K+-ATPase and Gal-3, and a disease specific drug(s) might be superior to a single therapeutic modality.

Structural characterisation of human galectin-4 N-terminal carbohydrate recognition domain in complex with glycerol, lactose, 3'-sulfo-lactose, and 2'-fucosyllactose

Galectin-4 is a tandem-repeat galectin with two distinct carbohydrate recognition domains (CRD). Galectin-4 is expressed mainly in the alimentary tract and is proposed to function as a lipid raft and adherens junction stabilizer by its glycan cross-linking capacity. Galectin-4 plays divergent roles in cancer and inflammatory conditions, either promoting or inhibiting each disease progression, depending on the specific pathological condition. The study of galectin-4's ligand-binding profile may help decipher its roles under specific conditions. Here we present the X-ray structures of human galectin-4 N-terminal CRD (galectin-4N) bound to different saccharide ligands. Galectin-4's overall fold and its core interactions to lactose are similar to other galectin CRDs. Galectin-4N recognises the sulfate cap of 3'-sulfated glycans by a weak interaction through Arg45 and two water-mediated hydrogen bonds via Trp84 and Asn49. When galectin-4N interacts with the H-antigen mimic, 2'-fucosyllactose, an interaction is formed between the ring oxygen of fucose and Arg45. The extended binding site of galectin-4N may not be well suited to the A/B-antigen determinants, α-GalNAc/α-Gal, specifically due to clashes with residue Phe47. Overall, galectin-4N favours sulfated glycans whilst galectin-4C prefers blood group determinants. However, the two CRDs of galectin-4 can, to a less extent, recognise each other's ligands.

Clinical use of novel biomarkers in heart failure: towards personalized medicine

Biomarkers play an important role in heart failure. They provide us information about the mechanisms involved in specific types of heart failure and can identify patients at higher risk. Although the majority of biomarker studies in heart failure focus on their prognostic value, the clinical applicability of prognostication in heart failure needs to be established. However, biomarkers can be used for many other purposes. For example, they can help us with the diagnosis of heart failure, and they can be used to select our therapy, leading to personalized tailored therapy. Finally, when biomarkers are causally involved in the disease process, they can even become targets for therapy. The present paper reviews the established and potential value of the novel heart failure biomarkers, mid-regional atrial natriuretic peptide, soluble ST2, growth differentiation factor 15, galectin-3, renal tubular damage markers, and microRNAs. Their potential clinical value will be discussed and compared with the reference markers, the natriuretic peptides.

Old and newer biomarkers in heart failure: from pathophysiology to clinical significance

Heart failure is a complex disease in which a careful clinical examination and the measurement of cardiac function may not always be sufficient for making a correct diagnosis. Measuring plasma levels of natriuretic peptides may assist in this process, also offering a good tool for accurate risk stratification. Other alternative biomarkers may give insight into the different pathways of heart failure genesis and pathophysiology, and may help to identify those patients with overt heart failure and a more adverse outcome, or distinguish between those at risk of developing heart failure. Despite a high number of potentially useful biomarkers, only a few will likely be introduced routinely into clinical practice. However, a multi-marker approach might increase the diagnostic accuracy and it might identify different phenotypes of heart failure patients who might benefit from individualized therapy in the future.

Relationship of galectin-3 to left ventricular geometry and hypertrophy in chronic hemodialysis patients

AIM AND BACKGROUND

Galectin-3 (Gal-3) is used to determine the prognosis of heart failure. Some studies revealed that Gal-3 promoted cardiac hypertrophy but there is no study in which the relationship between Gal-3 and left ventricular hypertrophy (LVH) geometry in patients without diastolic and systolic function impairment has been explored. The aim of the study was to analyze associations between plasma Gal-3 levels, LVH, and LV geometry in maintenance hemodialysis (HD) patients without systolic and diastolic dysfunction.

PATIENTS AND METHODS

The study group included 105 patients (53 women and 52 men)--with an average age of 58.2 ± 12.6 years, treated with HD for an average of 45 ± 32 months--and 60 healthy controls. The Gal-3 and other biochemical parameters were measured and color Doppler echocardiography was performed. For this study LVH was considered present when the LV mass index (LVMI) exceeded 95 g/m(2) in women and 115 g/m(2) in men. Left ventricular geometry was classified into the four groups on the basis of left ventricular mass and relative wall thickness (RWT).

RESULTS

Concentric hypertrophy (CH, 40.9 %, n = 43) was the commonest geometric pattern in our study. The Gal-3 levels in CH patients were not different from the patients with eccentric hypertrophy (EH). Plasma levels of Gal-3 correlated with LVMI (r = 0.617, p < 0.001), parathyroid hormone (PTH, r = 0.408, p < 0.001), uric acid (r = 0.281, p = 0.004), C-reactive protein (CRP, r = 0.412, p < 0.001), and RWT (r = 0.281, p = 0.004) but were inversely correlated with albumin (r = - 0.466, P < 0.001) in the whole group. Plasma levels of Gal-3 were associated with LVMI (r = 0.812, P < 0.001), RWT (r = 0.318, p = 0.001), and CRP(r = 0.381, p < 0.001) in maintenance hemodialysis patients.

CONCLUSION

The Gal-3 level is related to left ventricular hypertrophy and it is independent of left ventricle geometry. The relationship between LVH and Gal-3 might be direct or it may also be inflammation-related.

Molecular imaging of the cardiac extracellular matrix

In almost all cardiac diseases, an increase in extracellular matrix (ECM) deposition or fibrosis occurs, mostly consisting of collagen I. Whereas replacement fibrosis follows cardiomyocyte loss in myocardial infarction, reactive fibrosis is triggered by myocardial stress or inflammatory mediators and often results in ventricular stiffening, functional deterioration, and development of heart failure. Given the importance of ECM deposition in cardiac disease, ECM imaging could be a valuable clinical tool. Molecular imaging of ECM may help understand pathology, evaluate impact of novel therapy, and may eventually find a role in predicting the extent of ECM expansion and development of personalized treatment. In the current review, we provide an overview of ECM imaging including the assessment of ECM volume and molecular targeting of key players involved in ECM deposition and degradation. The targets comprise myofibroblasts, intracardiac renin-angiotensin axis, matrix metalloproteinases, and matricellular proteins.

Novel biomarkers in heart failure: usefulness in clinical practice

Biomarkers have become an increasingly important tool in clinical practice, helping to improve patient care. In heart failure (HF), brain natriuretic peptide and N-terminal prohormone of the brain natriuretic peptide have been widely applied in prognosis, clinical diagnosis and treatment. Recently, several novel biomarkers have been examined on their efficacy to improve diagnosis, determine the pathophysiologic state of HF, improve clinical decision making, clinical outcome, guide treatment and assess prognosis of HF patients. In this special report, the authors summarize the usefulness and significance of the most promising novel biomarkers in patients with HF.

Inhibitors of Galectins and Implications for Structure-Based Design of Galectin-Specific Therapeutics

Galectins are a family of galactoside-specific lectins that are involved in a myriad of metabolic and disease processes. Due to roles in cancer and inflammatory and heart diseases, galectins are attractive targets for drug development. Over the last two decades, various strategies have been used to inhibit galectins, including polysaccharide-based therapeutics, multivalent display of saccharides, peptides, peptidomimetics, and saccharide-modifications. Primarily due to galectin carbohydrate binding sites having high sequence identities, the design and development of selective inhibitors targeting particular galectins, thereby addressing specific disease states, is challenging. Furthermore, the use of different inhibition assays by research groups has hindered systematic assessment of the relative selectivity and affinity of inhibitors. This review summarises the status of current inhibitors, strategies, and novel scaffolds that exploit subtle differences in galectin structures that, in conjunction with increasing available data on multiple galectins, is enabling the feasible design of effective and specific inhibitors of galectins.

Predictive value of serum galectin-3 levels in patients with acute heart failure with preserved ejection fraction

AIMS

This study was conducted to determine whether galectin-3 (Gal3), a β-galactoside-binding lectin, has usefulness to predict outcomes in patients with heart failure (HF) and preserved left ventricular ejection fraction (LVEF).

METHODS AND RESULTS

We measured Gal3, urea, creatinine and natriuretic peptides on admission in 419 selected patients with HF and LVEF over 45%. The primary endpoint was all-cause mortality and/or readmission at one-year follow-up. Multivariable Cox proportional hazards models were generated for Gal3 and classical risk factors. We also evaluated the reclassification of patients on the basis of the different score category after adding Gal3 levels. A total of 219 patients had combined adverse events, and 129 patients died during the follow-up. Kaplan-Meir survival curve showed significantly increased primary endpoint and all-cause mortality according to quartiles of Gal3 (log rank, P<0.001). Serum Gal3 levels above median (13.8 ng/ml) was a significant predictor of primary endpoint risk after adjustment for age, estimated glomerular filtration rate, anemia, diabetes, serum sodium, brain natriuretic peptide levels, NYHA class and urea, respectively (hazard ratio 1.43, 95% CI 1.07-1.91 P=0.015). The reclassification index increased significantly after addition of Gal3 (9.5%, P<0.001) and the integrated discrimination index was 0.022, (P=0.001). The clinical prediction model with Gal3 increased the c-statistic from 0.711 to 0.731 (difference of 0.020, P=0.001).

CONCLUSIONS

Serum Gal3 is a strong and independent predictor of unfavorable outcomes in patients with HF and preserved LVEF. We also demonstrated the improvement of adding the new biomarker to the model.

Myocardial fibrosis and QTc are reduced following treatment with spironolactone or amiloride in stroke survivors: a randomised placebo-controlled cross-over trial

INTRODUCTION

Myocardial fibrosis is dysrhythmogenic and may contribute to the high incidence of cardiac death in stroke survivors, especially if they have long QTc. We tested the hypothesis that procollagen-1-carboxy terminal peptide (P1CP), a biomarker of myocardial fibrosis, might be improved following treatment with spironolactone or amiloride in stroke survivors. We also tested the hypothesis that both drugs would shorten QTc.

METHODS

STUDY DESIGN

randomised, double-blinded, placebo-controlled, cross-over trial (spironolactone vs. amiloride vs. placebo). Duration of Study: 3 months (1 month per drug). Primary endpoints: P1CP, QTc

RESULTS

11 stroke survivors (5 female), aged 71 ± 4, BP 139/81 mmHg ± 20/11 mmHg, completed the study. Both spironolactone and amiloride significantly reduced P1CP [Spironolactone-Placebo = -24 ug/L, 95% CI = -40 to -6.9; Amiloride-Placebo = -28 ug/L, 95% CI = -44 to -11]. Spironolactone and amiloride both shortened QTc [Spironolactone vs. Placebo=-18 ms(1/2), 95% CI = -36 to -0.55; Amiloride vs Placebo = -25 ms(1/2), 95% CI = -42 to -7.5].

CONCLUSIONS

Procollagen-1-carboxy terminal peptide was reduced following treatment with spironolactone within a month. Further, this is the first study demonstrating amiloride could also improve myocardial fibrosis. The beneficial effects of both drugs on myocardial fibrosis, coupled with their effects on raising potassium translated to a shortening of QTc. Future studies should test the hypothesis that these drugs might reduce the risk of sudden cardiac death in stroke survivors.