Insulin-like growth factor binding protein-related protein 1 contributes to hepatic fibrogenesis

Low-affinity insulin-like growth factor binding protein 7 and its association with pulmonary arterial hypertension severity and survival

Insulin-like growth factor (IGF) binding proteins (IGFBPs) are a family of growth factor modifiers, some of which are known to be independently associated with pulmonary arterial hypertension (PAH) survival. IGF factor binding protein 7 (IGFBP7) is a unique low-affinity IGFBP that, independent of IGF, stimulates prostacyclin production. This study proposed to establish associations between IGFBP7 and PAH severity and survival, using enrollment and longitudinal samples. Serum IGFBP7 levels were significantly elevated in patients with PAH compared to controls. After adjusting for age and sex, logarithmic increases in IGFBP7 were associated with a 20 m shorter six-minute walk distance (6MWD; p < 0.001), a 2-3 mmHg higher mean right atrial pressure (p < 0.001 and 0.02), and a higher likelihood of a greater REVEAL 2.0 risk category placement (p < 0.001). Kaplan-Meier analysis demonstrated significantly decreased survival with IGFBP7 above the median and Cox multivariable analysis adjusted for age and sex, demonstrated higher serum IGFBP7 was an independent predictor of survival. Though the exact mechanism is still unknown, given IGFBP7's role as a prostacyclin stimulant, it has potential use as a therapeutic target for disease modulation.

Potential clinical biomarkers and perspectives in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is a serious cardiovascular complication and the leading cause of death in diabetic patients. Patients typically do not experience any symptoms and have normal systolic and diastolic cardiac functions in the early stages of DCM. Because the majority of cardiac tissue has already been destroyed by the time DCM is detected, research must be conducted on biomarkers for early DCM, early diagnosis of DCM patients, and early symptomatic management to minimize mortality rates among DCM patients. Most of the existing implemented clinical markers are not very specific for DCM, especially in the early stages of DCM. Recent studies have shown that a number of new novel markers, such as galactin-3 (Gal-3), adiponectin (APN), and irisin, have significant changes in the clinical course of the various stages of DCM, suggesting that we may have a positive effect on the identification of DCM. As a summary of the current state of knowledge regarding DCM biomarkers, this review aims to inspire new ideas for identifying clinical markers and related pathophysiologic mechanisms that could be used in the early diagnosis and treatment of DCM.

Multiomics study of nonalcoholic fatty liver disease

Nonalcoholic fatty liver (NAFL) and its sequelae are growing health problems. We performed a genome-wide association study of NAFL, cirrhosis and hepatocellular carcinoma, and integrated the findings with expression and proteomic data. For NAFL, we utilized 9,491 clinical cases and proton density fat fraction extracted from 36,116 liver magnetic resonance images. We identified 18 sequence variants associated with NAFL and 4 with cirrhosis, and found rare, protective, predicted loss-of-function variants in MTARC1 and GPAM, underscoring them as potential drug targets. We leveraged messenger RNA expression, splicing and predicted coding effects to identify 16 putative causal genes, of which many are implicated in lipid metabolism. We analyzed levels of 4,907 plasma proteins in 35,559 Icelanders and 1,459 proteins in 47,151 UK Biobank participants, identifying multiple proteins involved in disease pathogenesis. We show that proteomics can discriminate between NAFL and cirrhosis. The present study provides insights into the development of noninvasive evaluation of NAFL and new therapeutic options.

Biomarkers in HFpEF for Diagnosis, Prognosis, and Biological Phenotyping

PURPOSE OF REVIEW

The heterogeneity of heart failure with preserved ejection fraction (HFpEF) is responsible for the limited success of broad management strategies. The role of biomarkers has been evolving helping to provide insight into the diversity of pathophysiology, prognosis, and potential targets for treatments. We will review the role of traditional and novel biomarkers in diagnosing, prognosticating, and evolving the management of patients with HFpEF. As circulating biomarker discovery rapidly evolves, we will explore technology for new biomarker discovery with examples of successful implementation.

RECENT FINDINGS

Besides cardiac-specific biomarkers (natriuretic peptides and troponin), other novel nonspecific biomarkers increasingly identify the diversity of pathophysiological mechanisms of HFpEF including inflammation, fibrosis, and renal dysfunction. Newer approaches have provided increasing granularity providing opportunities to integrate large amounts of information from proteomics and genomics as biomarkers of interest in HFpEF. HFpEF has been marked with failure of many medications to show benefit, whether measuring single targeted biomarkers or broader targeted discovery proteomics or genomic circulating biomarkers are providing increasing opportunities to better understand and manage HFpEF patients.

Associations between blood biomarkers, cardiac function and adverse outcome in a young tetralogy of Fallot cohort

BACKGROUND

To determine the potential prognostic value and clinical correlations of blood biomarkers in a cohort of patients with Tetralogy of Fallot (TOF).

METHODS

In the setting of multicenter prospective research studies TOF patients underwent blood sampling, cardiopulmonary exercise testing and low-dose dobutamine stress cardiac magnetic resonance (CMR) imaging. In the blood sample NT-proBNP, GDF-15, Galectin-3, ST-2, DLK-1, FABP4, IGFBP-1, IGFBP-7, MMP-2, and vWF were assessed. During subsequent follow-up, patients were evaluated for reaching the study endpoint (cardiac death, arrhythmia-related hospitalization or cardioversion/ablation, VO₂ max ≤65% of predicted). Regression analysis was used to explore the correlation between blood biomarkers (corrected for age and gender) and other clinical parameters. The potential predictive value of blood biomarkers and events were assessed with Kaplan-Meier analysis and Cox proportional hazard analysis.

RESULTS

We included 137 Fallot patients, median age 19.2 (interquartile range: 14.6-25.7) years, median age at TOF-repair 0.9 (0.5-1.9) years. After a median follow-up of 8.7 (6.3-10.7) years, 20 (14.6%) patients reached the composite endpoint. In a multivariable cox-regression analysis corrected for age at study baseline, elevated IGFBP-7 and MMP-2 levels were associated with the composite endpoint. We also noted a correlation between DLK-1 and relative change in right ventricular end systolic volume during dobutamine stress CMR (β = -0.27, p = 0.010), a correlation between FABP4 and Max VO₂ (β = -0.41, p ≤0.001 and between MMP-2 and tricuspid valve E/A ratio (β = -0.15, p = 0.037).

CONCLUSIONS

IGFBP-7, MMP-2 and DLK-1 levels are related to cardiac function and long-term outcome in TOF patients.

Role of novel biomarkers in diabetic cardiomyopathy

Diabetic cardiomyopathy (DCM) is commonly defined as cardiomyopathy in patients with diabetes mellitus in the absence of coronary artery disease and hypertension. As DCM is now recognized as a cause of substantial morbidity and mortality among patients with diabetes mellitus and clinical diagnosis is still inappropriate, various expert groups struggled to identify a suitable biomarker that will help in the recognition and management of DCM, with little success so far. Hence, we thought it important to address the role of biomarkers that have shown potential in either human or animal studies and which could eventually result in mitigating the poor outcomes of DCM. Among the array of biomarkers we thoroughly analyzed, long noncoding ribonucleic acids, soluble form of suppression of tumorigenicity 2 and galectin-3 seem to be most beneficial for DCM detection, as their plasma/serum levels accurately correlate with the early stages of DCM. The combination of relatively inexpensive and accurate speckle tracking echocardiography with some of the highlighted biomarkers may be a promising screening method for newly diagnosed diabetes mellitus type 2 patients. The purpose of the screening test would be to direct affected patients to more specific confirmation tests. This perspective is in concordance with current guidelines that accentuate the importance of an interdisciplinary team-based approach.

Galectin-3 is not useful for hepatocellular carcinoma surveillance in cirrhotic patients but it may be a marker of cirrhosis development

Aim of the study

Ultrasound surveillance for hepatocellular carcinoma (HCC) among cirrhotic patients is the currently used modality but it is operator dependent. Combining a tumor marker with ultrasound may improve sensitivity for early HCC detection. Our aim was to assess the galectin-3 level among HCC and cirrhotic patients on top of chronic hepatitis C to evaluate its possible role as a tumor marker for HCC surveillance among cirrhotic patients.

Material and methods

The study was conducted on 160 subjects. They were grouped as follows: group 1: 40 patients with HCC secondary to liver cirrhosis on top of chronic hepatitis C; group 2: 40 patients with cirrhosis secondary to chronic hepatitis C; group 3: 40 patients with chronic hepatitis C without advanced fibrosis; group 4: 40 healthy controls. Serum galectin-3 levels were determined in all subjects using ELISA.

Results

Serum galectin-3 level was significantly higher in HCC patients than in those with chronic hepatitis C (p < 0.001). Also it was significantly higher among cirrhotic patients than in patients with chronic hepatitis C (p < 0.001). But on comparing HCC patients with cirrhotic patients, serum galectin-3 levels were not significantly different (p = 0.926).

Conclusions: Galectin-3 levels cannot be used as an additional method for surveillance of HCC among cirrhotic patients.

Associations Between Blood Biomarkers, Cardiac Function, and Adverse Outcome in a Young Fontan Cohort

Background Patients who have undergone the Fontan procedure are at high risk of circulatory failure. In an exploratory analysis we aimed to determine the prognostic value of blood biomarkers in a young cohort who have undergone the Fontan procedure. Methods and Results In multicenter prospective studies patients who have undergone the Fontan procedure underwent blood sampling, cardiopulmonary exercise testing, and stress cardiac magnetic resonance imaging. Several biomarkers including NT-proBNP (N-terminal pro-B-type natriuretic peptide), GDF-15 (growth differentiation factor 15), Gal-3 (galectin-3), ST2 (suppression of tumorigenicity 2), DLK-1 (protein delta homolog 1), FABP-4 (fatty acid-binding protein 4), IGFBP-1 (insulin-like growth factor-binding protein 1), IGFBP-7, MMP-2 (matrix metalloproteinase 2), and vWF (von Willebrand factor) were assessed in blood at 9.6 (7.1-12.1) years after Fontan completion. After this baseline study measurement, follow-up information was collected on the incidence of adverse cardiac events, including cardiac death, out of hospital cardiac arrest, heart transplantation (listing), cardiac reintervention (severe events), hospitalization, and cardioversion/ablation for arrhythmias was collected and the relation with blood biomarkers was assessed by Cox proportional hazard analyses. The correlation between biomarkers and other clinical parameters was evaluated. We included 133 patients who have undergone the Fontan procedure, median age 13.2 (25th, 75th percentile 10.4-15.9) years, median age at Fontan 3.2 (2.5-3.9) years. After a median follow-up of 6.2 (4.9-6.9) years, 36 (27.1%) patients experienced an event of whom 13 (9.8%) had a severe event. NT-proBNP was associated with (all) events during follow-up and remained predictive after correction for age, sex, and dominant ventricle (hazard ratio, 1.89; CI, 1.32-2.68). The severe event-free survival was better in patients with low levels of GDF-15 (P=0.005) and vWF (P=0.008) and high levels of DLK-1 (P=0.041). There was a positive correlation (β=0.33, P=0.003) between DLK-1 and stress cardiac magnetic resonance imaging functional reserve. Conclusions NT-proBNP, GDF-15, vWF, DLK-1, ST-2 FABP-4, and IGFBP-7 levels relate to long-term outcome in young patients who have undergone the Fontan procedure.

Role of some serum biomarkers in the early detection of diabetic cardiomyopathy

AIM

To assess the role of serum biomarkers in early prediction of diabetic cardiomyopathy.

MATERIALS AND METHODS

The participants were three groups of Type 2 diabetes mellitus (DM) patients having diastolic dysfunction (DM-DD), systolic dysfunction (DM-SD) and normal echocardiography (DM-N) with two control groups: non-DM diastolic dysfunction patients (DD) and healthy controls. AGEs, TNF-α, IL-6, IGFBP-7, creatinine and insulin were assessed.

RESULTS

TNF-α, AGEs, creatinine and insulin panel had area under the curve (AUC) of 0.913 in distinguishing DM-DD from DM-N (78.7% sensitivity and 100% specificity). IL-6 and AGEs panel had AUC 0.795 for differentiating DM-SD from DM-DD (90.6% sensitivity). IL-6, TNF-α and AGEs panel had AUC 0.924 for differentiating diabetic cardiomyopathy from DM-N (85% sensitivity and specificity).

CONCLUSION

A panel of AGEs, IL-6, TNF-α, insulin and creatinine might be used for early detection of DM-DD among T2DM patients.

Insulin-like growth factor-binding protein 7 and risk of congestive heart failure hospitalization in patients with atrial fibrillation

BACKGROUND

The occurrence of congestive heart failure (CHF) hospitalization among patients with atrial fibrillation (AF) is a poor prognostic marker.

OBJECTIVE

The purpose of this study was to assess whether insulin-like growth factor-binding protein 7 (IGFBP-7), a marker of myocardial damage, identifies AF patients at high risk for this complication.

METHODS

We analyzed 2 prospective multicenter observational cohort studies that included 3691 AF patients. Levels of IGFBP-7 and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured from frozen plasma samples at baseline. The primary endpoint was hospitalization for CHF. Multivariable adjusted Cox regression analyses were constructed.

RESULTS

Mean patient age was 69 ± 12 years, 1028 (28%) were female, and 879 (24%) had a history of CHF. The incidence per 1000 patient-years across increasing IGFBP-7 quartiles was 7, 10, 32, and 85. The corresponding multivariable adjusted hazard ratios (aHRs) (95% confidence interval [CI]) were 1.0, 1.05 (0.63-1.77), 2.38 (1.50-3.79), and 4.37 (2.72-7.04) (P for trend <.001). In a subgroup of 2812 patients without pre-existing CHF at baseline, the corresponding aHRs were 1.0, 0.90 (0.47-1.72), 1.69 (0.94-3.04), and 3.48 (1.94-6.24) (P for trend <.001). Patients with IGFBP-7 and NT-proBNP levels above the biomarker-specific median had a higher risk of incident CHF hospitalization (aHR 5.20; 3.35-8.09) compared to those with only 1 elevated marker (elevated IGFBP-7 aHR 2.17; 1.30-3.60); elevated NT-proBNP aHR 1.97; 1.17-3.33); or no elevated marker (reference).

CONCLUSION

Higher plasma levels of IGFBP-7 were strongly and independently associated with CHF hospitalization in AF patients. The prognostic information provided by IGFBP-7 was additive to that of NT-proBNP.

Secretome Analysis of Inductive Signals for BM-MSC Transdifferentiation into Salivary Gland Progenitors

Severe dry mouth in patients with Sjögren's Syndrome, or radiation therapy for patients with head and neck cancer, significantly compromises their oral health and quality of life. The current clinical management of xerostomia is limited to palliative care as there are no clinically-proven treatments available. Previously, our studies demonstrated that mouse bone marrow-derived mesenchymal stem cells (mMSCs) can differentiate into salivary progenitors when co-cultured with primary salivary epithelial cells. Transcription factors that were upregulated in co-cultured mMSCs were identified concomitantly with morphological changes and the expression of acinar cell markers, such as α-amylase (AMY1), muscarinic-type-3-receptor(M3R), aquaporin-5(AQP5), and a ductal cell marker known as cytokeratin 19(CK19). In the present study, we further explored inductive molecules in the conditioned media that led to mMSC reprogramming by high-throughput liquid chromatography with tandem mass spectrometry and systems biology. Our approach identified ten differentially expressed proteins based on their putative roles in salivary gland embryogenesis and development. Additionally, systems biology analysis revealed six candidate proteins, namely insulin-like growth factor binding protein-7 (IGFBP7), cysteine-rich, angiogenetic inducer, 61(CYR61), agrin(AGRN), laminin, beta 2 (LAMB2), follistatin-like 1(FSTL1), and fibronectin 1(FN1), for their potential contribution to mMSC transdifferentiation during co-culture. To our knowledge, our study is the first in the field to identify soluble inductive molecules that drive mMSC into salivary progenitors, which crosses lineage boundaries.

SIRT1/IGFBPrP1/TGF β1 axis involved in cucurbitacin B ameliorating concanavalin A-induced mice liver fibrosis

The present study investigated the improving effect of cucurbitacin B on liver fibrosis induced by concanavalin A in mice and explored its possible mechanism. AST, ALT and TB were detected by kits. ELISA was performed to detect the levels of IL 5, IL 6, IL 13 and TNF-α in serum. Haematoxylin-eosin (HE) staining and Masson's trichrome staining were used to evaluate pathological changes. Western blotting was performed to observe expression levels of sirtuin (SIRT) 1, insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) and TGF β1. The activity of SIRT 1 also was detected. Results showed that cucurbitacin B could effectively improve the abnormal liver function, inhibit liver fibrosis and suppress releases of inflammatory factors in mice induced by concanavalin A. Furthermore, cucurbitacin B could down-regulate the expressions of TGF β1 and IGFBPrP1, increase the expression and activity of SIRT 1. Interestingly, when SIRT1 activity was inhibited by EX 527, a selective inhibitor of SIRT 1, the preventive effect of cucurbitacin B was significantly attenuated. Taken together, the above results showed that cucurbitacin B could significantly suppress releases of inflammatory cytokines and improve liver fibrosis induced by concanavalin A in mice, and those may be achieved through SIRT1/IGFBPrP1/TGF β1 axis.

Echocardiographic assessment of insulin-like growth factor binding protein-7 and early identification of acute heart failure

Aims

Concentrations of insulin‐like growth factor binding protein‐7 (IGFBP7) have been linked to abnormal cardiac structure and function in patients with chronic heart failure (HF), but cardiovascular correlates of the biomarker in patients with more acute presentations are lacking.

We aimed to determine the relationship between IGFBP7 concentrations and cardiac structure and to evaluate the impact of IGFBP7 on the diagnosis of acute HF among patients with acute dyspnoea.

Methods and results

In this pre‐specified subgroup analysis of the International Collaborative of N‐terminal pro‐B‐type Natriuretic Peptide Re‐evaluation of Acute Diagnostic Cut‐Offs in the Emergency Department (ICON‐RELOADED) study, we included 271 patients with and without acute HF. All patients presented to an emergency department with acute dyspnoea, had blood samples for IGFBP7 measurement, and detailed echocardiographic evaluation.

Higher IGFBP7 concentrations were associated with numerous cardiac abnormalities, including increased left atrial volume index (LAVi; r = 0.49, P < 0.001), lower left ventricular ejection fraction (r = −0.27, P < 0.001), lower right ventricular fractional area change (r = −0.31, P < 0.001), and higher tissue Doppler E/e′ ratio (r = 0.44, P < 0.001). In multivariable linear regression analyses, increased LAVi (P = 0.01), lower estimated glomerular filtration rate (P = 0.008), higher body mass index (P = 0.001), diabetes (P = 0.009), and higher concentrations of amino‐terminal pro‐B‐type natriuretic peptide (NT‐proBNP, P = 0.02) were independently associated with higher IGFBP7 concentrations regardless of other variables. Furthermore, IGFBP7 (odds ratio = 12.08, 95% confidence interval 2.42–60.15, P = 0.02) was found to be independently associated with the diagnosis of acute HF in the multivariable logistic regression analysis.

Conclusions

Among acute dyspnoeic patients with and without acute HF, increased IGFBP7 concentrations are associated with a range of cardiac structure and function abnormalities. Independent association with increased LAVi suggests elevated left ventricular filling pressure is an important trigger for IGFBP7 expression and release. IGFBP7 may enhance the diagnosis of acute HF.

Insulin-Like Growth Factor Binding Protein-Related Protein 1 Activates Primary Hepatic Stellate Cells via Autophagy Regulated by the PI3K/Akt/mTOR Signaling Pathway

BACKGROUND

Autophagy is a self-degrading process. Previously, we showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel transforming growth factor β1 (TGFβ1)-interacting factor in liver fibrosis; the role of TGFβ1-mediated autophagy in hepatic stellate cells (HSCs) activation has been investigated. However, whether autophagy is regulated by IGFBPrP1 remains unknown.

AIMS

We investigated the interactions among IGFBPrP1, autophagy, and activation of primary rat HSCs.

METHODS

Primary HSCs were separated from Sprague Dawley rats by two-step enzymatic digestion, and then, we overexpressed or inhibited IGFBPrP1 expression in HSCs under serum-starved condition. Autophagy inducer rapamycin or inhibitor 3-methyladenine (3MA) was used to assess the relationship between autophagy and HSCs activation.

RESULTS

We observed the expression of activation marker α-SMA and autophagy markers such as LC3B and Beclin1, which were significantly increased in HSCs treated with adenovirus vector harboring the IGFBPrP1 gene (AdIGFBPrP1) compared to cells cultured under serum-starved. In comparison, HSCs treated with shIGFBPrP1 showed opposite results. Furthermore, HSCs activation and autophagy increased when cells were treated with rapamycin, whereas opposite results were obtained when cells were treated with 3MA. AdIGFBPrP1 treatment downregulated the phosphorylation of Akt and mTOR.

CONCLUSION

Autophagy was induced in IGFBPrP1-treated primary HSCs, and IGFBPrP1-induced autophagy promoted the activation of HSCs and extracellular matrix expression, the underlying mechanism of which may involve the phosphatidylinositide 3-kinase/Akt/mTOR signaling pathway.

Exercise as A Potential Therapeutic Target for Diabetic Cardiomyopathy: Insight into the Underlying Mechanisms

Diabetes mellitus is associated with cardiovascular, ophthalmic, and renal comorbidities. Among these, diabetic cardiomyopathy (DCM) causes the most severe symptoms and is considered to be a major health problem worldwide. Exercise is widely known as an effective strategy for the prevention and treatment of many chronic diseases. Importantly, the onset of complications arising due to diabetes can be delayed or even prevented by exercise. Regular exercise is reported to have positive effects on diabetes mellitus and the development of DCM. The protective effects of exercise include prevention of cardiac apoptosis, fibrosis, oxidative stress, and microvascular diseases, as well as improvement in cardiac mitochondrial function and calcium regulation. This review summarizes the recent scientific findings to describe the potential mechanisms by which exercise may prevent DCM and heart failure.

Production of insulin-like growth factor-binding proteins during the development of hepatic fibrosis due to chronic hepatitis C

INTRODUCTION AND AIMS

Insulin-like growth factor 1 is modulated by the insulin-like growth factor-binding proteins (IGFBPs) that are synthesized in the liver. The aim of the present study was to evaluate the concentrations of IGFBPs 1-7 in patients with chronic hepatitis C and study their association with fibrosis stage.

PATIENTS AND METHODS

A prospective, cross-sectional study was conducted that included patients with chronic hepatitis C. The stages of fibrosis were determined through FibroTest and FibroScan and the patients were compared with a control group. Serum levels of IGFBPs 1-7 were quantified through multiple suspension arrays. The Kruskal-Wallis test, Mann-Whitney U test, Spearman's correlation, and ROC curves were used for the statistical analysis.

RESULTS

Upon comparing the patients and controls, the highest concentrations were found in IGFBPs 1, 2, 4, and 7 (p=0.02, p=0.002, p=0.008, and p<0.001, respectively). IGFBP-3 levels had a tendency to be lower in the patients (p=0.066), whereas values were similar between patients and controls for IGFBP-5 and 6 (p=0.786 and p=0.244, respectively). Of the seven IGFBPs, IGFBP-3 concentrations were the highest. There were significant differences between fibrosis stages for IGFBP-5 and IGFBP-7.

CONCLUSION

IGFBPs play a relevant role in the fibrotic process in liver damage. IGFBP-7, in particular, differentiates fibrosis stages, making it a potential serum biomarker.

Insulin-like growth factor binding protein 7 accelerates hepatic steatosis and insulin resistance in non-alcoholic fatty liver disease

An association between increased insulin-like growth factor binding protein-7 (IGFBP7) expression and insulin resistance in metabolic diseases has been reported. However, the role and molecular mechanism of IGFBP-7 in non-alcoholic fatty liver disease (NAFLD) remains largely unknown. Therefore, the potential function of IGFBP7 in the pathological progression of NAFLD was explored in this investigation. For in vivo experiments, an animal model of NAFLD was established in C57BL/6 mice by feeding a high-fat diet (HFD), and IGFBP7 was knocked down by injecting adeno-associated adenovirus (AAV)-mediated short-hairpin (sh)-IGFBP7 into the liver. We found that AAV-sh-IGFBP7 treatment significantly alleviated hepatocyte injury and inhibited hepatic lipid accumulation by reducing lipogenesis-associated gene expression. Furthermore, downregulation of IGFBP7 markedly ameliorated IR and restored impaired insulin signalling by elevating the phosphorylation levels of IRS-1, Akt and GSK3β in HFD-treated mice. Similar results were also confirmed by an in vitro study in a palmitic acid (PA)-stimulated HepG2 cell model. In conclusion, our study demonstrates that IGFBP7 contributes to hepatic steatosis and insulin resistance in NAFLD development, which might serve as a novel therapeutic agent for the treatment of NAFLD.

B lymphocytes directly contribute to tissue fibrosis in patients with IgG4-related disease

BACKGROUND

IgG₄-related disease (IgG₄-RD) is a fibroinflammatory condition marked by rapid clinical improvement after selective depletion of B lymphocytes with rituximab. This feature suggests that B cells might participate in fibrogenesis and wound healing.

OBJECTIVE

In the present work we aimed to demonstrate that B lymphocytes contribute directly to tissue fibrosis in patients with IgG₄-RD.

METHODS

Total circulating CD19⁺ B lymphocytes, naive B cells, memory B cells, or plasmablasts from patients with IgG₄-RD were cultivated with human fibroblasts. Profibrotic soluble factors and collagen production in cocultures were assessed by using ELISAs and Luminex assays. RNA sequencing and quantitative RT-PCR were used to assess fibroblast activation in the presence of B cells, as well as induction of profibrotic pathways in B-cell subsets. Relevant profibrotic and inflammatory molecules were confirmed in vitro by using functional experiments and on IgG₄-RD tissue sections by using multicolor immunofluorescence studies.

RESULTS

B cells from patients with IgG₄-RD (1) produced the profibrotic molecule platelet-derived growth factor B and stimulated collagen production by fibroblasts; (2) expressed enzymes implicated in extracellular matrix remodeling, such as lysyl oxidase homolog 2; (3) produced the chemotactic factors CCL4, CCL5, and CCL11; and (4) induced production of these same chemokines by activated fibroblasts. Plasmablasts expressed sets of genes implicated in fibroblast activation and proliferation and therefore represent cells with intrinsic profibrotic properties.

CONCLUSION

We have demonstrated that B cells contribute directly to tissue fibrosis in patients with IgG₄-RD. These unanticipated profibrotic properties of B lymphocytes, particularly plasmablasts, might be relevant for fibrogenesis in patients with other fibroinflammatory disorders and for wound-healing processes in physiologic conditions.

Insulin-like growth factor-binding protein 7 (IGFBP 7) as a new biomarker in coronary heart disease

PURPOSE

The role of insulin-like growth factor-binding protein-7 (IGFBP-7) in atherosclerosis is still not well-known. The objective of this study was to find out the following: 1) whether IGFBP-7 may act as a biomarker of coronary artery disease (CAD) occurrence and extent; 2) whether IGFBP-7 is potentially related to the classical and new markers of cardiovascular risk (carotid intima-media thickness - cIMT); 3) whether IGFBP-7 may be a marker of mortality in the group of patients with myocardial infarction (MI).

MATERIALS/METHODS

The study group consisted of 212 patients with MI and 75 patients with stable CAD, the control group included 100 healthy volunteers. IGFBP-7 serum concentration was measured.

RESULTS

IGFBP-7 value was considerably higher in the study group (MI and CAD patients - 35.1 ng/ml (P = 0.000001) and 32.7ng/ml (P = 0.0001), respectively), than in the controls - 25.2ng/ml. No statistically significant differences between IGFBP-7 concentrations in the MI and CAD group were found. No relationship between IGFBP-7 and the coronary lesions advancement in the study group was observed. No changes in IGFBP-7 concentration in the MI patients during hospitalization were observed. In the group of MI patients who died during follow-up, a considerably higher cIMT values were found whereas no statistically significant difference was observed in relation to IGFBP-7 (34.6 vs. 35.2 ng/ml).

CONCLUSIONS

IGFBP-7 is a good biomarker of CAD occurrence but not of its advancement. We demonstrated the existence of the relation between higher IGFBP-7 concentration and the selected classical risk factors of cardiovascular events as well as cIMT values. IGFBP-7 cannot serve as a marker of acute ischemia. Also, IGFBP-7 was not confirmed as a predictor of mortality in the MI patients.

Insulin-like growth factor binding protein related protein 1 knockdown attenuates hepatic fibrosis via the regulation of MMPs/TIMPs in mice

BACKGROUND

Previous research suggested that insulin-like growth factor binding protein related protein 1 (IGFBPrP1), as a novel mediator, contributes to hepatic fibrogenesis. Matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) play an essential role in hepatic fibrogenesis by regulating homeostasis and remodeling of the extracellular matrix (ECM). However, the interaction between IGFBPrP1 and MMP/TIMP is not clear. The present study was to knockdown IGFBPrP1 to investigate the correlation between IGFBPrP1 and MMP/TIMP in hepatic fibrosis.

METHODS

Hepatic fibrosis was induced by thioacetamide (TAA) in mice. Knockdown of IGFBPrP1 expression by ultrasound-targeted microbubble destruction-mediated CMB-shRNA-IGFBPrP1 delivery, or inhibition of the Hedgehog (Hh) pathway by cyclopamine treatment, was performed in TAA-induced liver fibrosis mice. Hepatic fibrosis was determined by hematoxylin and eosin and Sirius red staining. Hepatic expression of IGFBPrP1, α-smooth muscle actin (α-SMA), transforming growth factor β 1 (TGFβ1), collagen I, MMPs/TIMPs, Sonic Hedgehog (Shh), and glioblastoma family transcription factors (Gli1) were investigated by immunohistochemical staining and Western blotting analysis.

RESULTS

We found that hepatic expression of IGFBPrP1, TGFβ1, α-SMA, and collagen I were increased longitudinally in mice with TAA-induced hepatic fibrosis, concomitant with MMP2/TIMP2 and MMP9/TIMP1 imbalance and Hh pathway activation. Knockdown of IGFBPrP1 expression, or inhibition of the Hh pathway, reduced the hepatic expression of IGFBPrP1, TGFβ1, α-SMA, and collagen I and re-established MMP2/TIMP2 and MMP9/TIMP1 balance.

CONCLUSIONS

Our findings suggest that IGFBPrP1 knockdown attenuates liver fibrosis by re-establishing MMP2/TIMP2 and MMP9/TIMP1 balance, concomitant with the inhibition of hepatic stellate cell activation, down-regulation of TGFβ1 expression, and degradation of the ECM. Furthermore, the Hh pathway mediates IGFBPrP1 knockdown-induced attenuation of hepatic fibrosis through the regulation of MMPs/TIMPs balance.

Cardiometabolic Biomarkers and Their Temporal Patterns Predict Poor Outcome in Chronic Heart Failure (Bio-SHiFT Study)

PURPOSE

Multiple hormonal and metabolic alterations occur in chronic heart failure (CHF), but their proper monitoring during clinically silent progression of CHF remains challenging. Hence, our objective was to explore whether temporal patterns of six emerging cardiometabolic biomarkers predict future adverse clinical events in stable patients with CHF.

METHODS

In 263 patients with CHF, we determined the risk of a composite end point of heart failure hospitalization, cardiac death, left ventricular assist device implantation, and heart transplantation in relation to serially assessed blood biomarker levels and slopes (i.e., rate of biomarker change per year). During 2.2 years of follow-up, we repeatedly measured IGF binding proteins 1, 2, and 7 (IGFBP-1, IGFBP-2, IGFBP-7), adipose fatty acid binding protein 4 (FABP-4), resistin, and chemerin (567 samples in total).

RESULTS

Serially measured IGFBP-1, IGFBP-2, IGFBP-7, and FABP-4 levels predicted the end point [univariable hazard ratio (95% CI) per 1-SD increase: 3.34 (2.43 to 4.87), 2.86 (2.10 to 3.92), 2.45 (1.91 to 3.13), and 2.46 (1.88 to 3.24), respectively]. Independently of the biomarkers' levels, their slopes were also strong clinical predictors [per 0.1-SD increase: 1.20 (1.11 to 1.31), 1.27 (1.14 to 1.45), 1.23 (1.11 to 1.37), and 1.27 (1.12 to 1.48)]. All associations persisted after multivariable adjustment for patient baseline characteristics, baseline N-terminal pro-hormone brain natriuretic peptide and cardiac troponin T, and pharmacological treatment during follow-up.

MAIN CONCLUSIONS

The temporal patterns of IGFBP-1, IGFBP-2, IGFBP-7, and adipose FABP-4 predict adverse clinical outcomes during outpatient follow-up of patients with CHF and may be clinically relevant as they could help detect more aggressive CHF forms and assess patient prognosis, as well as ultimately aid in designing more effective biomarker-guided therapy.

Insulin-Like Growth Factor (IGF) System in Liver Diseases

Hepatocyte differentiation, proliferation, and apoptosis are affected by growth factors produced in liver. Insulin-like growth factor 1 and 2 (IGF1 and IGF2) act in response to growth hormone (GH). Other IGF family components include at least six binding proteins (IGFBP1 to 6), manifested by both IGFs develop due to interaction through the type 1 receptor (IGF1R). The data based on animal models and/or in vitro studies suggest the role of IGF system components in cellular aspects of hepatocarcinogenesis (cell cycle progression, uncontrolled proliferation, cell survival, migration, inhibition of apoptosis, protein synthesis and cell growth), and show that systemic IGF1 administration can reduce fibrosis and ameliorate general liver function. In epidemiologic and clinicopathological studies on chronic liver disease (CLD), lowered serum levels, decreased tissue expression of IGF1, elevated production of IGF1R and variable IGF2 expression has been noted, from the start of preneoplastic alterations up to the developed hepatocellular carcinoma (HCC) stage. These changes result in well-known clinical symptoms of IGF1 deficiency. This review summarized the current data of the complex role of IGF system components in the most common CLD (nonalcoholic fatty liver disease, cirrhosis, and hepatocellular carcinoma). Better recognition and understanding of this system can contribute to discovery of new and improved versions of current preventive and therapeutic actions in CLD.

Interaction between insulin-like growth factor binding protein-related protein 1 and transforming growth factor beta 1 in primary hepatic stellate cells

BACKGROUND

We previously showed that insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) is a novel mediator in liver fibrosis. Transforming growth factor beta 1 (TGFβ1) is known as the strongest effector of liver fibrosis. Therefore, we aimed to investigate the detailed interaction between IGFBPrP1 and TGFβ1 in primary hepatic stellate cells (HSCs).

METHODS

We overexpressed TGFβ1 or IGFBPrP1 and inhibited TGFβ1 expression in primary HSCs for 6, 12, 24, 48, 72, and 96 hours to investigate their interaction and observe the accompanying expressions of α-smooth muscle actin (α-SMA), collagen I, fibronectin, and phosphorylated-mothers against decapentaplegic homolog 2/3 (p-Smad2/3).

RESULTS

We found that the adenovirus vector encoding the TGFβ1 gene (AdTGFβ1) induced IGFBPrP1 expression while that of α-SMA, collagen I, fibronectin, and TGFβ1 increased gradually. Concomitantly, AdIGFBPrP1 upregulated TGFβ1, α-SMA, collagen I, fibronectin, and p-Smad2/3 in a time-dependent manner while IGFBPrP1 expression was decreased at 96 hours. Inhibition of TGFβ1 expression reduced the IGFBPrP1-stimulated expression of α-SMA, collagen I, fibronectin, and p-Smad2/3.

CONCLUSIONS

These findings for the first time suggest the existence of a possible mutually regulation between IGFBPrP1 and TGFβ1, which likely accelerates liver fibrosis progression. Furthermore, IGFBPrP1 likely participates in liver fibrosis in a TGFβ1-depedent manner, and may act as an upstream regulatory factor of TGFβ1 in the Smad pathway.

Insulin-Like Growth Factor-Binding Protein-7 as a Biomarker of Diastolic Dysfunction and Functional Capacity in Heart Failure With Preserved Ejection Fraction: Results From the RELAX Trial

OBJECTIVES

This study sought to investigate relationships between insulin-like growth factor-binding protein-7 (IGFBP7) and parameters of diastolic function or functional capacity in patients with heart failure and preserved ejection fraction (HFpEF) who were randomized to receive sildenafil or placebo.

BACKGROUND

IGFBP7 was previously found to be associated with diastolic function in heart failure with reduced ejection fraction, but it is unclear whether these associations are present in HFpEF.

METHODS

At baseline and 24 weeks, IGFBP7, imaging studies, and peak oxygen consumption (Vo2max) were obtained and compared in 160 patients with HFpEF who were randomized to receive sildenafil or placebo.

RESULTS

Patients with supramedian baseline IGFBP7 concentrations were older, had signs of systemic congestion and worse renal function, and had higher concentrations of prognostic heart failure biomarkers including amino-terminal pro-B-type natriuretic peptide (p < 0.05). Higher baseline IGFBP7 was modestly correlated with worse diastolic function: higher E velocity (Spearman correlation [ρ] = 0.40), E/E' (ρ = 0.40), left atrial volume index (ρ = 0.39), and estimated right ventricular systolic pressure (ρ = 0.41; all p < 0.001) and weakly correlated with transmitral E/A (ρ = 0.26; p = 0.006). Notably, change in IGFBP7 was significantly correlated with change in E, E/A, E/E', and right ventricular systolic pressure. Elevated baseline IGFBP7 was associated with lower baseline Vo2max (13.2 vs. 11.1 ml/min/kg; p < 0.001), and change in IGFBP7 was weakly inversely correlated with change in Vo2max (ρ = -0.19; p = 0.01). Subjects receiving sildenafil had a decrease in IGFBP7 over 24 weeks, in contrast to placebo-treated patients (median change in IGFBP7 -1.5 vs. +13.6 ng/ml; p < 0.001).

CONCLUSIONS

In patients with HFpEF, IGFBP7 may be a novel biomarker of diastolic function and exercise capacity.

Serum insulin-like growth factor-1 and its binding protein-7: potential novel biomarkers for heart failure with preserved ejection fraction

Background

Insulin-like growth factor binding protein-7 (IGFBP-7) modulates the biological activities of insulin-like growth factor-1 (IGF-1). Previous studies demonstrated the prognostic value of IGFBP-7 and IGF-1 among patients with systolic heart failure (HF). This study aimed to evaluate the IGF1/IGFBP-7 axis in HF patients with preserved ejection fraction (HFpEF).

Methods

Serum IGF-1 and IGFBP-7 levels were measured in 300 eligible consecutive patients who underwent comprehensive cardiac assessment. Patients were categorized into 3 groups including controls with normal diastolic function (n = 55), asymptomatic left ventricular diastolic dysfunction (LVDD, n = 168) and HFpEF (n = 77).

Results

IGFBP-7 serum levels showed a significant graded increase from controls to LVDD to HFpEF (median 50.30 [43.1-55.3] vs. 54.40 [48.15-63.40] vs. 61.9 [51.6-69.7], respectively, P < 0.001), whereas IGF-1 levels showed a graded decline from controls to LVDD to HFpEF (120.0 [100.8-144.0] vs. 112.3 [88.8-137.1] vs. 99.5 [72.2-124.4], p < 0.001). The IGFBP-7/IGF-1 ratio increased from controls to LVDD to HFpEF (0.43 [0.33-0.56] vs. 0.48 [0.38-0.66] vs. 0.68 [0.55-0.88], p < 0.001). Patents with IGFB-7/IGF1 ratios above the median demonstrated significantly higher left atrial volume index, E/E’ ratio, and NT-proBNP levels (all P ≤ 0.02).

Conclusion

In conclusion, this hypothesis-generating pilot study suggests the IGFBP-7/IGF-1 axis correlates with diastolic function and may serve as a novel biomarker in patients with HFpEF. A rise in IGFBP-7 or the IGFBP-7/IGF-1 ratio may reflect worsening diastolic function, adverse cardiac remodeling, and metabolic derangement.

Screening for and validation of a hepatic fibrosis-related pathway induced by insulin-like growth factor-binding protein-related protein 1

OBJECTIVE

Our previous studies characterized insulin-like growth factor-binding protein-related protein 1 (IGFBPrP1) as a molecule that promotes hepatic fibrogenesis, but its mechanism has not been fully elucidated. Here, we have investigated the effect of IGFBPrP1 on gene expression in the hepatic fibrosis-related pathway.

MATERIALS AND METHODS

Sprague-Dawley rats received injections of an adenovirus carrying IGFBPrP1 or EGFP cDNA into their tail veins. In hepatic preparations, hepatic stellate cell activation was determined by α-smooth muscle actin expression and hepatic fibrosis by Sirius red staining and hydroxyproline content analysis. IGFBPrP1-inducible genes of the hepatic fibrosis-related pathway were assessed by PCR array. Expression of IGFBPrP1 and transforming growth factor β1 (TGFβ1) and array results were evaluated by quantitative real-time PCR and western blotting.

RESULTS

IGFBPrP1-overexpressing rats showed an increase in α-smooth muscle actin expression and collagen and hydroxyproline content in the liver. The PCR array results indicated that some genes were upregulated and some were downregulated in Ad-IGFBPrP1-infected rats. Among these, Egr1, MAP2K2 (MEK2) and MAPK3 (ERK1) expression increased, whereas PTEN and Hhip mRNA expression decreased. Egr1 protein levels increased and peaked 2 weeks after infection and then decreased gradually. PTEN protein decreased gradually in Ad-IGFBPrP1-infected rats with a concurrent increase in the degree of hepatic fibrosis. TGFβ1 levels increased during hepatic fibrosis development in liver tissues.

CONCLUSION

Egr1, PTEN, Hhip, MAP2K2 (MEK2) and MAPK3 (ERK1) were identified as candidate genes of the IGFBPrP1-induced hepatic fibrosis-related pathway. IGFBPrP1 promoted hepatic fibrosis mainly by enhancing the TGFβ1 expression that it triggered.

Prognostic Value of Insulin-Like Growth Factor-Binding Protein 7 in Patients with Heart Failure and Preserved Ejection Fraction

BACKGROUND

The prognostic merit of insulin-like growth factor-binding protein 7 (IGFBP7) is unknown in heart failure and preserved ejection fraction (HFpEF).

METHODS AND RESULTS

Baseline IGFBP7 (BL-IGFBP7; n = 302) and 6-month change (Δ; n = 293) were evaluated in the Irbesartan in Heart Failure and Preserved Ejection Fraction (I-PRESERVE) trial. Primary outcome was all-cause mortality or cardiovascular hospitalization with median follow-up of 3.6 years; secondary outcomes included HF events. Median BL-IGFBP7 concentration was 218 ng/mL. BL-IGFBP7 was significantly correlated with age (R² = 0.13; P < .0001), amino-terminal pro-B-type NP (R² = 0.22; P < .0001), and estimated glomerular filtration rate (eGFR; R² = 0.14; P < .0001), but not with signs/symptoms of HFpEF. BL-IGFBP7 was significantly associated with the primary outcome (hazard ratio [HR] = 1.007 per ng/mL; P < .001), all-cause mortality (HR = 1.008 per ng/mL; P < .001), and HF events (HR = 1.007 per ng/mL; P < .001). IGFBP7 remained significant for each outcome after adjustment for ln amino-terminal pro-B-type NP and eGFR but not all variables in the I-PRESERVE prediction model. After 6 months, IGFBP7 did not change significantly in either treatment group. ΔIGFBP7 was significantly associated with decrease in eGFR in patients randomized to irbesartan (R² = 0.09; P = .002). ΔIGFBP7 was not independently associated with outcome.

CONCLUSIONS

Higher concentrations of IGFBP7 were associated with increased risk of cardiovascular events, but after multivariable adjustment this association was no longer present. Further studies of IGFBP7 are needed to elucidate its mechanism.

CLINICAL TRIAL REGISTRATION

www.clinicaltrials.gov, NCT00095238.

Role of Serum Biomarkers in Early Detection of Diabetic Cardiomyopathy in the West Virginian Population

OBJECTIVES

Diabetic cardiomyopathy (DCM) is an established complication of diabetes mellitus. In West Virginia, the especially high incidence of diabetes and heart failure validate the necessity of developing new strategies for earlier detection of DCM. Since most DCM patients remain asymptomatic until the later stages of the disease when the fibrotic complications become irreversible, we aimed to explore biomarkers that can identify early-stage DCM.

METHODS

The patients were grouped into 4 categories based on clinical diabetic and cardiac parameters: Control, Diabetes (DM), Diastolic dysfunction (DD), and Diabetes with diastolic dysfunction (DM+DD), the last group being the preclinical DCM group.

RESULTS

Echocardiography images indicated severe diastolic dysfunction in patients with DD+DM and DD compared to DM or control patients. In the DM and DM+DD groups, TNFα, isoprostane, and leptin were elevated compared to control (p<0.05), as were clinical markers HDL, glucose and hemoglobin A1C. Fibrotic markers IGFBP7 and TGF-β followed the same trend. The Control group showed higher beneficial levels of adiponectin and bilirubin, which were reduced in the DM and DM+DD groups (p<0.05).

CONCLUSION

The results from our study support the clinical application of biomarkers in diagnosing early stage DCM, which will enable attenuation of disease progression prior to the onset of irreversible complications.

Insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) contributes to liver inflammation and fibrosis via activation of the ERK1/2 pathway

BACKGROUND AND AIM

Previously, we suggested that IGFBPrP1 played a major role in hepatic stellate cell (HSC) activation, yet the molecular mechanism of IGFBPrP1 in hepatic fibrosis is unclear. The ERK pathway is involved in activation of HSCs. This study investigated the involvement of the ERK1/2 pathway in IGFBPrP1-induced liver inflammation and fibrosis.

METHODS

An adenoviral vector encoding IGFBPrP1 (AdIGFBPrP1) was constructed. Rats received AdIGFBPrP1 or CAd (vector control) via their tail vein injection. One hour prior to adenoviral injections, rats were intraperitoneally administrated with 10 mg/kg U0126 (a specific MEK/ERK1/2 inhibitor) or DMSO (vehicle control). At weeks 2 or 4 post-gene transduction, serum samples were obtained and the levels of liver enzymes and hydroxyproline were determined. Liver tissue were histologically evaluated for inflammation and fibrosis. The expression of α-SMA and ECM were evaluated by qRT-PCR and western blotting.

RESULTS

After transduction, IGFBPrP1 expression significantly increased in livers and transduced cells. MEK/ERK1/2 inhibition administration of AdIGFBPrP1-treated rats and cells significantly blocked AdIGFBPrP1-induced activation of ERK1/2. U0126 significantly down-regulated the number of F4/80-positive cells and CD3-positive cells (markers of liver inflammation), the expression of α-SMA and the concentration of ECM components in vivo. In addition, α-SMA and TGF-β1 levels in AdIGFBPrP1 HSCs were markedly inhibited by a MEK/ERK1/2 inhibitor, indicating that HSC activation was inhibited.

CONCLUSION

These findings suggest that IGFBPrP1 acts as an initiator of liver fibrosis by inducing inflammation, HSC activation and ECM deposition through the ERK1/2 pathway.

Functions of galectin-3 and its role in fibrotic diseases

Fibrotic diseases occur in a variety of organs and lead to continuous organ injury, function decline, and even failure. Currently effective treatment options are limited. Galectin-3 (Gal-3) is a pleiotropic lectin that plays an important role in cell proliferation, adhesion, differentiation, angiogenesis, and apoptosis. Accumulating evidence indicates that Gal-3 activates a variety of profibrotic factors, promotes fibroblast proliferation and transformation, and mediates collagen production. Recent studies have defined key roles for Gal-3 in fibrogenesis in diverse organ systems, including liver, kidney, lung, and myocardial. To help set the stage for future research, we review recent advances about the role played by Gal-3 in fibrotic diseases. Herein we discuss the potential profibrotic role of Gal-3, inhibition of which may represent a promising therapeutic strategy against tissue fibrosis.