Age-related differences in serum MFG-E8, TGF-β1 and correlation to the severity of atherosclerosis determined by ultrasound

Potent CTLs can be induced against tumor cells in an environment of lower levels of systemic MFG-E8

The direction and magnitude of immune responses are critically affected when dead cells are disposed of. Milk fat globule-epidermal growth factor-factor 8 (MFG-E8) promotes the engulfment of apoptotic normal and cancerous cells without inducing inflammation. We have previously reported that a certain proportion of the cancer cells express abundant MFG-E8, and that such expression is associated with the shorter survival of patients with esophageal cancer who had received chemotherapy before surgery. However, the influence of tumor-derived and systemically existing MFG-E8 on antitumor immune responses has not yet been fully investigated. Herein, we showed that CTL-dependent antitumor immune responses were observed in mice with no or decreased levels of systemic MFG-E8, and that such responses were enhanced further with the administration of anti-PD-1 antibody. In mice with decreased levels of systemic MFG-E8, the dominance of regulatory T cells in tumor-infiltrating lymphocytes was inverted to CD8+ T cell dominance. MFG-E8 expression by tumor cells appears to affect antitumor immune responses only when the level of systemic MFG-E8 is lower than the physiological status. We have also demonstrated in the clinical setting that lower levels of plasma MFG-E8, but not MFG-E8 expression in tumor cells, before the treatment was associated with objective responses to anti-PD-1 therapy in patients with non-small cell lung cancer. These results suggest that systemic MFG-E8 plays a critical role during the immunological initiation process of antigen-presenting cells to increase tumor-specific CTLs. Regulation of the systemic level of MFG-E8 might induce efficient antitumor immune responses and enhance the potency of anti-PD-1 therapy.

TGF-β Isoforms and GDF-15 in the Development and Progression of Atherosclerosis

The effect of oxidised lipoproteins on the endothelium, monocytes, platelets, and macrophages is a key factor in the initiation and development of atherosclerosis. Antioxidant action, lipoprotein metabolism, and chronic inflammation are the fields of research interest for better understanding the development of the disease. All the fields are related to inflammation and hence to the secretion of cytokines, which are being investigated as potential diagnostic markers for the onset of atherosclerosis. Pathways of vascular damage are crucial for the development of new laboratory readouts. The very early detection of endothelial cell damage associated with the onset of atherosclerosis, allowing the initiation of therapy, remains a major research goal. This article summarises the latest results on the relationship of tumour growth factor beta (TGF-β) isoforms and growth differentiation factor 15 (GDF-15) to the pathogenesis of atherosclerosis: which cells involved in atherosclerosis produce them, which effectors stimulate their synthesis and secretion, how they influence atherosclerosis development, and the relationship between the levels of TGF-β and GDF-15 in the blood and the development and extent of atherosclerosis.

Remodeling of the Cardiac Extracellular Matrix Proteome During Chronological and Pathological Aging

Impaired extracellular matrix (ECM) remodeling is a hallmark of many chronic inflammatory disorders that can lead to cellular dysfunction, aging, and disease progression. The ECM of the aged heart and its effects on cardiac cells during chronological and pathological aging are poorly understood across species. For this purpose, we first used mass spectrometry-based proteomics to quantitatively characterize age-related remodeling of the left ventricle (LV) of mice and humans during chronological and pathological (Hutchinson-Gilford progeria syndrome (HGPS)) aging. Of the approximately 300 ECM and ECM-associated proteins quantified (named as Matrisome), we identified 13 proteins that were increased during aging, including lactadherin (MFGE8), collagen VI α6 (COL6A6), vitronectin (VTN) and immunoglobulin heavy constant mu (IGHM), whereas fibulin-5 (FBLN5) was decreased in most of the data sets analyzed. We show that lactadherin accumulates with age in large cardiac blood vessels and when immobilized, triggers phosphorylation of several phosphosites of GSK3B, MAPK isoforms 1, 3, and 14, and MTOR kinases in aortic endothelial cells (ECs). In addition, immobilized lactadherin increased the expression of pro-inflammatory markers associated with an aging phenotype. These results extend our knowledge of the LV proteome remodeling induced by chronological and pathological aging in different species (mouse and human). The lactadherin-triggered changes in the proteome and phosphoproteome of ECs suggest a straight link between ECM component remodeling and the aging process of ECs, which may provide an additional layer to prevent cardiac aging.

Inflammatory Role of Milk Fat Globule-Epidermal Growth Factor VIII in Age-Associated Arterial Remodeling

Background Age-associated aortic remodeling includes a marked increase in intimal medial thickness (IMT), associated with signs of inflammation. Although aortic wall milk fat globule-epidermal growth factor VIII (MFG-E8) increases with age, and is associated with aortic inflammation, it is not known whether MFG-E8 is required for the age-associated increase in aortic IMT. Here, we tested whether MFG-E8 is required for the age-associated increase in aortic IMT. Methods and Results To determine the role of MFG-E8 in the age-associated increase of IMT, we compared aortic remodeling in adult (20-week) and aged (96-week) MFG-E8 (-/-) knockout and age matched wild-type (WT) littermate mice. The average aortic IMT increased with age in the WT from 50±10 to 70±20 μm (P<0.0001) but did not significantly increase with age in MFG-E8 knockout mice. Because angiotensin II signaling is implicated as a driver of age-associated increase in IMT, we infused 30-week-old MFG-E8 knockout and age-matched littermate WT mice with angiotensin II or saline via osmotic mini-pumps to determine whether MFG-E8 is required for angiotensin II-induced aortic remodeling. (1) In WT mice, angiotensin II infusion substantially increased IMT, elastic lamina degradation, collagen deposition, and the proliferation of vascular smooth muscle cells; in contrast, these effects were significantly reduced in MFG-E8 KO mice; (2) On a molecular level, angiotensin II treatment significantly increased the activation and expression of matrix metalloproteinase type 2, transforming growth factor beta 1, and its downstream signaling molecule phosphorylated mother against decapentaplegic homolog 2, and collagen type I production in WT mice; however, in the MFG-E8 knockout mice, these molecular effects were significantly reduced; and (3) in WT mice, angiotensin II increased levels of aortic inflammatory markers phosphorylated nuclear factor-kappa beta p65, monocyte chemoattractant protein 1, tumor necrosis factor alpha, intercellular adhesion molecule 1, and vascular cell adhesion molecule 1 molecular expression, while in contrast, these inflammatory markers did not change in knockout mice. Conclusions Thus, MFG-E8 is required for both age-associated proinflammatory aortic remodeling and also for the angiotensin II-dependent induction in younger mice of an aortic inflammatory phenotype observed in advanced age. Targeting MFG-E8 would be a novel molecular approach to curb adverse arterial remodeling.

The functional multipotency of transforming growth factor β signaling at the intersection of senescence and cancer

The transforming growth factor β (TGF-β) family of cytokines comprises a group of proteins, their receptors, and effector molecules that, in a coordinated manner, modulate a plethora of physiological and pathophysiological processes. TGF-β1 is the best known and plausibly most active representative of this group. It acts as an immunosuppressant, contributes to extracellular matrix remodeling, and stimulates tissue fibrosis, differentiation, angiogenesis, and epithelial-mesenchymal transition. In recent years, this cytokine has been established as a vital regulator of organismal aging and cellular senescence. Finally, the role of TGF-β1 in cancer progression is no longer in question. Because this protein is involved in so many, often overlapping phenomena, the question arises whether it can be considered a molecular bridge linking some of these phenomena together and governing their reciprocal interactions. In this study, we reviewed the literature from the perspective of the role of various TGF-β family members as regulators of a complex mutual interplay between senescence and cancer. These aspects are then considered in a broader context of remaining TGF-β-related functions and coexisting processes. The main narrative axis in this work is centered around the interaction between the senescence of normal peritoneal cells and ovarian cancer cells. The discussion also includes examples of TGF-β activity at the interface of other normal and cancer cell types.

Milk Fat Globule Epidermal Growth Factor 8 (MFGE8) Gene Variants in Rheumatoid Arthritis and Sjögren's Syndrome

Milk Fat Globule Epidermal Growth Factor 8 (MFGE8) deficiency and gene polymorphisms have been previously linked to systemic lupus erythematosus (SLE)-like and SLE development. Our aim was to explore whether four MFGE8 variants and MFGE8 serum levels are associated with autoimmunity susceptibility and autoimmune related atherosclerosis. DNA from 107 primary Sjogren's syndrome (SS), 116 rheumatoid arthritis (RA) and 123 SLE patients as well as 199 HC were genotyped for the MFGE8 rs2271715, rs1878326, rs4945, rs3743388 variants by RFLP-PCR. MFGE8 serum levels were measured by ELISA. The CA genotype of rs4945 variant exhibited a protective effect against RA development, a finding not confirmed in the SS and SLE populations. The CACG haplotype exhibited a protective effect in both RA and SS patients compared to HC. Primary SS patients with IMT ≤ 0.9 mm displayed higher MGFE8 serum levels compared to those with ˃0.9 mm. Here, we report a novel association of MFGE8 variants in SS and RA susceptibility, as well as reduced MFGE8 serum levels in SS patients with heightened atherosclerotic risk.

Serum milk fat globule-EGF factor 8 protein as a potential biomarker for metabolic syndrome

Background/Aims

Useful biomarkers for metabolic syndrome have been insufficient. We investigated the performance of serum milk fat globule-EGF factor-8 (MFG-E8), the key mediator of inflammatory pathway, in diagnosis of metabolic syndrome.

Methods

Subjects aged between 30 and 64 years were prospectively enrolled in the Seoul Metabolic Syndrome cohort. Serum MFG-E8 levels were measured at baseline.

Results

A total of 556 subjects were included, comprising 279 women (50.2%) and 277 men (49.8%). Metabolic syndrome was diagnosed in 236 subjects (42.4%), and the mean MFG-E8 level of subjects with metabolic syndrome was significantly higher than that of subjects without metabolic syndrome (P<0.001). MFG-E8 level was significantly correlated with all metabolic syndrome components and pulse wave velocity (all P<0.05). Subjects were categorized into two groups according to the best MFG-E8 cut-off value as follows: group 1, MFG-E8 level <4,745.1 pg/mL (n=401, 72.1%); and group 2, MFG-E8 level ≥4,745.1 (n=155, 27.9%). At baseline, metabolic syndrome in group 2 was significantly more prevalent than in group 1 (63.9% vs. 34.2%, P<0.001). During median follow-up of 17 months, metabolic syndrome developed in 122 (38.1%) subjects among 320 subjects without it at baseline. The incidence of metabolic syndrome in group 2 was significantly higher than that in group 1 (55.4% vs. 34.5%, P=0.003). On multivariate analysis, MFG-E8 level ≥4,745.1 pg/mL was an independent predictor for diagnosis and development of metabolic syndrome after adjusting other factors (all P<0.05).

Conclusions

Serum MFG-E8 level is a potent biomarker for the screening and prediction of metabolic syndrome.

Roles and mechanisms of MFG-E8 in vascular aging-related diseases

The aging of the vasculature plays a crucial role in the pathological progression of various vascular aging-related diseases. As endothelial cells (ECs) and vascular smooth muscle cells (VSMCs) are essential parts in the inner and medial layers of vessel wall, respectively, the structural and functional alterations of ECs and VSMCs are the major causes of vascular aging. Milk fat globule-epidermal growth factor 8 (MFG-E8) is a multifunctional glycoprotein which exerts a regulatory role in the intercellular interactions involved in a variety of biological and pathological processes. Emerging evidence suggests that MFG-E8 is a novel and outstanding modulator for vascular aging via targeting at ECs and VSMCs. In this review, we will summarise the cumulative roles and mechanisms of MFG-E8 in vascular aging and vascular aging-related diseases with special emphasis on the functions of ECs and VSMCs. In addition, we also aim to focus on the promising diagnostic function as a biomarker and the potential therapeutic application of MFG-E8 in vascular aging and the clinical evaluation of vascular aging-related diseases.

MFGE8, ALB, APOB, APOE, SAA1, A2M, and C3 as Novel Biomarkers for Stress Cardiomyopathy

BACKGROUND

Stress cardiomyopathy (SCM) is a transient reversible left ventricular dysfunction that more often occurs in women. Symptoms of SCM patients are similar to those of acute coronary syndrome (ACS), but little is known about biomarkers. The goals of this study were to identify the potentially crucial genes and pathways associated with SCM.

METHODS

We analyzed microarray datasets GSE95368 derived from the Gene Expression Omnibus (GEO) database. Firstly, identify the differentially expressed genes (DEGs) between SCM patients in normal patients. Then, the DEGs were used for Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis. Finally, the protein-protein interaction (PPI) network was constructed and Cytoscape was used to find the key genes.

RESULTS

In total, 25 DEGs were identified, including 10 upregulated genes and 15 downregulated genes. These DEGs were mainly enriched in ECM-receptor interaction, dilated cardiomyopathy (DCM), human papillomavirus infection, and focal adhesion, whereas in GO function classification, they were mainly enriched in the extracellular region, positive regulation of the multicellular organismal process, establishment of localization, and intracellular vesicle.

CONCLUSION

Seven hub genes contained APOE, MFGE8, ALB, APOB, SAA1, A2M, and C3 identified as hub genes of SCM, which might be used as diagnostic biomarkers or molecular targets for the treatment of SCM.

Transforming Growth Factor Beta 1 and Vascular Risk in Alcoholics

INTRODUCTION

Transforming growth factor beta-1 (TGF-β1) is a pleiotropic cytokine. Its relationship with atherosclerosis is debatable, protective or deleterious effects have been described. Alcoholics are at increased vascular risk. Although TGF-β1 is increased in alcoholics, its role on vascular risk factors has not been analyzed. This is the objective of this study.

PATIENTS AND METHODS

79 heavy alcoholics and 34 controls were included. Calcium deposition in the aortic arch was assessed in the plain thorax X-ray film. Ankle-brachial index was recorded in 48 patients. All the patients underwent complete laboratory evaluation, including serum levels of TGF-β1, tumor necrosis factor (TNF)-α, interleukin (IL)-4, IL-6, and interferon-γ (IFN-γ).We analyzed the relationships between TGF-β1 and vascular risk factors by both univariate (parametric or non parametric tests), or multivariate analysis to discern on which variables TGF-β1 levels depend.

RESULTS

Serum TGF-β1 levels were higher among patients (t = 2.73; P = 0.008), but no differences exist among cirrhotics (17246 ± 11,021 pg/mL) and non-cirrhotics (21,340 ± 12,442 pg/mL). TGF-β1 showed significant correlations with total cholesterol (r = 0.28; P = 0.017) and HDL- cholesterol (r = 0.25; P = 0.042), and inverse correlations with body mass index (BMI; ρ = -0.37; P = 0.004), IL-4 (ρ = -0.31; P = 0.009), INF-γ (ρ = -0.28; P = 0.001), and IL-6 (ρ = -0.38; P = 0.001). By multivariate analysis, only BMI, IL-6 and HDL-cholesterol showed independent relationships with TGF-β1. No relationships were observed with ankle-brachial index or calcium in the aortic arch, hypertension, diabetes, left ventricular hypertrophy or atrial fibrillation.

CONCLUSION

TGF-β1 levels are increased in alcoholics, but are unrelated to vessel wall calcification or arterial stiffness.

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.