epidermal-growth-factor and Vascular-Diseases

Medin, a small 50-amino acid peptide, is an internal cleaved product from the second discoidin domain of milk fat globule epidermal growth factor VIII (MFG-E8) protein. Medin has been reported as the most common amylogenic protein in the upper part of the arterial system, including aortic, temporal, and cerebral arterial walls in the elderly. Medin has a high affinity to elastic fibers and is closely associated with arterial degenerative inflammation, elastic fiber fragmentation, calcification, and amyloidosis. In vitro, treating with the medin peptide promotes the inflammatory phenotypic shift of both endothelial cells and vascular smooth muscle cells. In vitro, ex vivo, and in vivo studies demonstrate that medin enhances the abundance of reactive oxygen species and reactive nitrogen species produced by both endothelial cells and vascular smooth muscle cells and promotes vascular endothelial dysfunction and arterial stiffening. Immunostaining and immunoblotting analyses of human samples indicate that the levels of medin are increased in the pathogenesis of aortic aneurysm/dissection, temporal arteritis, and cerebrovascular dementia. Thus, medin peptide could be targeted as a biomarker diagnostic tool or as a potential molecular approach to curbing the arterial degenerative inflammatory remodeling that accompanies aging and disease.

Topics: Aged; Arteries; Endothelial Cells; Epidermal Growth Factor; Glycoproteins; Humans; Vascular Diseases

Most intractable tissue-degenerative disorders share a common pathogenic condition, so-called proteinopathy. Amyloid-related disorders are the most common proteinopathies and are characterized by amyloid fibril deposits in the brain or other organs. Aging is generally associated with the development of these amyloid-related disorders, but we still do not fully understand how functional proteins become pathogenic amyloid deposits during the human aging process. We identified a novel amyloidogenic protein, named epidermal growth factor-containing fibulin-like extracellular matrix protein 1 (EFEMP1), in massive venous amyloid deposits in specimens that we obtained from an autopsied patient who died of gastrointestinal bleeding. Our postmortem analyses of additional patients indicate that EFEMP1 amyloid deposits frequently developed in systemic venous walls of elderly people. EFEMP1 was highly expressed in veins, and aging enhanced venous EFEMP1 expression. In addition, biochemical analyses indicated that these venous amyloid deposits consisted of C-terminal regions of EFEMP1. In vitro studies showed that C-terminal regions formed amyloid fibrils, which inhibited venous tube formation and cell viability. EFEMP1 thus caused a novel age-related venous amyloid-related disorder frequently found in the elderly population. Understanding EFEMP1 amyloid formation provides new insights into amyloid-related disorders occurring during the aging process. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Topics: Aged, 80 and over; Amyloidosis; Biomarkers; Calcium-Binding Proteins; Dose-Response Relationship, Drug; Epidermal Growth Factor; Extracellular Matrix Proteins; Female; Gastrointestinal Hemorrhage; Human Umbilical Vein Endothelial Cells; Humans; Intestine, Large; Vascular Diseases; Veins

Thrombospondin1 (TSP1) participates in numerous signaling pathways critical for vascular physiology and disease. The conserved signature domain of thrombospondin 1 (TSP1-Sig1) comprises three epidermal growth factor (EGF), 13 calcium-binding type 3 thrombospondin (T3) repeats, and one lectin-like module arranged in a stalk-wire-globe topology. TSP1 is known to be present in both calcium-replete (Holo-) and calcium-depleted (Apo-) state, each with distinct downstream signaling effects.. To prepare a homology model of TSP1-Sig1 and investigate the effect of calcium on its dynamic structure and interactions.. A homology model of Holo-TSP1-Sig1 was prepared with TSP2 as template in Swissmodel workspace. The Apo-form of the model was obtained by omitting the bound calcium ions from the homology model. Molecular dynamics (MD) simulation studies (100 ns) were performed on the Holo- and Apo- forms of TSP1 using Gromacs4.6.5.. After simulation, Holo-TSP1-Sig1 showed significant reorientation at the interface of the EGF1-2 and EGF2-3 modules. The T3 wire is predicted to show the maximum mobility and deviation from the initial model. In Apo-TSP1-Sig1 model, the T3 repeats unfolded and formed coils with predicted increase in flexibility. Apo-TSP1-Sig1model also predicted the exposure of the binding sites for neutrophil elastase, integrin and fibroblast growth factor 2. We present a structural model and hypothesis for the role of TSP1-Sig1 interactions in the development of vascular disorders.. The simulated model of the fully calcium-loaded and calcium-depleted TSP1-Sig1 may enable the development of its interactions as a novel therapeutic target for the treatment of vascular diseases.

Topics: Amino Acid Sequence; Binding Sites; Calcium; Epidermal Growth Factor; Humans; Molecular Dynamics Simulation; Protein Conformation; Protein Domains; Signal Transduction; Thrombospondin 1; Thrombospondins; Vascular Diseases

A murine model of vascular injury-induced neointimal hyperplasia was developed by using a photoactive dye, rose bengal. Photoactivation of rose bengal induced vascular injury to the femoral arteries of C57B1/6 mice and resulted in an occlusive neointimal hyperplasia after 4 weeks. The cellular elements of the hyperplastic neointima were found to be alpha-actin-positive vascular smooth muscle cells expressing epidermal growth factor (EGF) receptor at high levels. EGF-Gen, an EGF-R-specific inhibitor with potent anticancer activity, suppressed the formation of hyperplastic neointima. Morphometric analysis of serial tissue sections at 4 weeks after vascular injury showed that in 75% of the EGF-Gen-treated mice, the maximal stenosis index was only 0.44 +/- 0.13, whereas in 75% of phosphate-buffered saline (PBS)-treated mice, the maximal stenosis index was 1.20 +/- 0.25. The mean neointima/media ratios for areas of maximum neointimal hyperplasia were 0.59 +/- 0.16 (n = 24) for the EGF-Gen-treated group, 0.99 +/- 16 (n = 45) for the PBS group (EGF-Gen vs. PBS, p = 0.0017), and 1.03 +/- 18 (n = 8) for group treated with unconjugated genistein (EGF-Gen vs. Gen, p = 0.0088). EGF-Gen treatment of mice with vascular injury to the left femoral artery was not associated with any clinical signs of toxicity or histopathologic lesions in any of the organs, including the uninjured right femoral artery. EGF-Gen also inhibited VSMC migration in vitro, without affecting VSMC proliferation and viability, suggesting that EGF-Gen is blocking neointima formation by inhibiting cellular migration to vascular injury sites. In conclusion, EGF-Gen may be useful as a nontoxic prophylactic agent for prevention of restenosis in clinical settings.

Topics: Animals; Antineoplastic Agents; Cell Movement; Constriction, Pathologic; Disease Models, Animal; Epidermal Growth Factor; ErbB Receptors; Genistein; Hyperplasia; Male; Mice; Mice, Inbred C57BL; Muscle, Smooth, Vascular; Protein-Tyrosine Kinases; Recombinant Proteins; Tunica Intima; Up-Regulation; Vascular Diseases; Vasoconstriction

We evaluated the content of EGF in platelet lysates obtained from 49 patients with non-insulin-dependent diabetes mellitus (NIDDM)(18 males, 31 females, age 58 +/- 13 years) and from 23 clinically healthy control subjects (11 males, 12 females, age 53 +/- 18 years). Platelets were collected from platelet-rich plasma and lysed. EGF was determined by radioimmunoassay. The immunoreactive EGF content in the platelet lysates in diabetic patients significantly exceeded that of control subjects (44.9 +/- 18.5 pg/mm3platelet vs. 34.2 +/- 7.8 pg/mm3platelet, mean +/- SD p < 0.008). In performing multiple regression analysis with ten clinical parameters, urinary albumin excretion (F = 16.1, r = 0.551, p < 0.001), duration of diabetes (F = 13.0, r = 0.511, p < 0.001) and the presence of diabetic proliferative retinopathy (F = 8.8, p < 0.01) were significantly associated with irEGF content in platelet lysates. These observations suggest that the amount of EGF in platelets may increase with the progression of diabetic complications. The mechanism for the increase of EGF in platelets remains to be clarified.

Topics: Adult; Aged; Blood Platelets; Diabetes Mellitus, Type 2; Epidermal Growth Factor; Female; Humans; Male; Middle Aged; Platelet Count; Vascular Diseases

Epidermal growth factor (EGF) receptor binding kinetics and EGF-mediated stimulation of DNA synthesis and cellular proliferation were studied in cultured vascular smooth muscle cells (VSMC) from the equine thoracic aorta. Binding studies, using murine 125I-labeled EGF, indicate the presence of a single class of high-affinity binding sites (apparent KD = 2.8 X 10(-11) M), with an estimated maximal binding capacity of 5,800 sites/cell. EGF stimulated [3H]thymidine uptake in confluent quiescent monolayers in a dose-dependent fashion, half-maximal stimulation occurring at 7.5 X 10(-11) M. Likewise, EGF-mediated cellular proliferation was dose dependent (50% effective dose = 5 X 10(-11) M) under reduced serum concentrations. Equine VSMC contain specific receptors for EGF, and EGF can stimulate DNA synthesis and proliferation in these cultured cells, which suggests that EGF may participate in the proliferative changes observed in equine distal digital peripheral vascular disease.

Topics: Animals; Aorta; Binding, Competitive; Cell Division; Cells, Cultured; Culture Media; DNA Replication; Epidermal Growth Factor; ErbB Receptors; Horse Diseases; Horses; Kinetics; Muscle, Smooth, Vascular; Vascular Diseases