Exploring aortic stiffness in aging mice: a comprehensive methodological overview.

Stiffening of the vascular network is associated with the early stages of vascular aging, leading to cardiovascular disorders (hypertension), renal failures, or neurodegenerative diseases (Alzheimer's). Unfortunately, many people remain undiagnosed because diagnostic methods are either unsuitable for a large population or unfamiliar to clinicians which favor the hypertension evaluation. In preclinical research, stiffness studies are often partially conducted.

Structural and physical basis for the elasticity of elastin.

Elastin function is to endow vertebrate tissues with elasticity so that they can adapt to local mechanical constraints. The hydrophobicity and insolubility of the mature elastin polymer have hampered studies of its molecular organisation and structure-elasticity relationships. Nevertheless, a growing number of studies from a broad range of disciplines have provided invaluable insights, and several structural models of elastin have been proposed.

Prediction, screening and characterization of novel bioactive tetrapeptide matrikines for skin rejuvenation.

Background: Extracellular matrices play a critical role in tissue structure and function and aberrant remodelling of these matrices is a hallmark of many age-related diseases. In skin, loss of dermal collagens and disorganization of elastic fibre components are key features of photoageing. Although the application of some small matrix-derived peptides to aged skin has been shown to beneficially affect in vitro cell behaviour and, in vivo, molecular architecture and clinical appearance, the discovery of new peptides has lacked a guiding hypothesis.

Matrikines as mediators of tissue remodelling.

Extracellular matrix (ECM) proteins confer biomechanical properties, maintain cell phenotype and mediate tissue repair (via release of sequestered cytokines and proteases). In contrast to intracellular proteomes, where proteins are monitored and replaced over short time periods, many ECM proteins function for years (decades in humans) without replacement. The longevity of abundant ECM proteins, such as collagen I and elastin, leaves them vulnerable to damage accumulation and their host organs prone to chronic, age-related diseases.

Early Alterations of Intra-Mural Elastic Lamellae Revealed by Synchrotron X-ray Micro-CT Exploration of Diabetic Aortas.

Diabetes is a major concern of our society as it affects one person out of 11 around the world. Elastic fiber alterations due to diabetes increase the stiffness of large arteries, but the structural effects of these alterations are poorly known. To address this issue, we used synchrotron X-ray microcomputed tomography with in-line phase contrast to image in three dimensions C57Bl6J (control) and db/db (diabetic) mice with a resolution of 650 nm/voxel and a field size of 1.

Investigation of Antiparasitic Activity of 10 European Tree Bark Extracts on Toxoplasma gondii and Bioguided Identification of Triterpenes in Barks.

Toxoplasmosis is a worldwide parasitosis that affects one-third of the population. People at risk, such as immunocompromised patients (AIDS, chemotherapy treatment) or fetuses (maternal-fetal transmission) can develop severe forms of the disease. The antiparasitic activity of extracts of different polarities (-heptane, MeOH, MeOH/HO) of 10 tree species endemic to temperate regions was investigated against Toxoplasma gondii infection .

X-ray microtomography reveals a lattice-like network within aortic elastic lamellae.

The arterial wall consists of three concentric layers: intima, media, and adventitia. Beyond their resident cells, these layers are characterized by an extracellular matrix (ECM), which provides both biochemical and mechanical support. Elastin, the major component of arterial ECM, is present in the medial layer and organized in concentric elastic lamellae that confer resilience to the wall.

Structural Analysis of Nonapeptides Derived from Elastin.

Elastin-derived peptides are released from the extracellular matrix remodeling by numerous proteases and seem to regulate many biological processes, notably cancer progression. The canonical elastin peptide is VGVAPG, which harbors the XGXXPG consensus pattern, allowing interaction with the elastin receptor complex located at the surface of cells. Besides these elastokines, another class of peptides has been identified.

Elastin molecular aging promotes MDA-MB-231 breast cancer cell invasiveness.

Elastin is a long-lived extracellular matrix protein responsible for the structural integrity and function of tissues. Breast cancer elastosis is a complex phenomenon resulting in both the deposition of elastotic masses and the local production of elastin fragments. In invasive human breast cancers, an increase in elastosis is correlated with severity of the disease and age of the patient.

New Insights into Molecular Organization of Human Neuraminidase-1: Transmembrane Topology and Dimerization Ability.

Neuraminidase 1 (NEU1) is a lysosomal sialidase catalyzing the removal of terminal sialic acids from sialyloconjugates. A plasma membrane-bound NEU1 modulating a plethora of receptors by desialylation, has been consistently documented from the last ten years. Despite a growing interest of the scientific community to NEU1, its membrane organization is not understood and current structural and biochemical data cannot account for such membrane localization.

Impact of sialic acids on the molecular dynamic of bi-antennary and tri-antennary glycans.

Sialic acids (SA) are monosaccharides that can be located at the terminal position of glycan chains on a wide range of proteins. The post-translational modifications, such as N-glycan chains, are fundamental to protein functions. Indeed, the hydrolysis of SA by specific enzymes such as neuraminidases can lead to drastic modifications of protein behavior.

Pregnancy outcome following frozen embryo transfer after artificial cycle or treatment by clomiphene citrate.

The optimal method to prepare endometrium before frozen embryo transfer (FET) is not yet established. We retrospectively studied 4496 FET and detailed pregnancy and miscarriage rates in three groups of patients according to the endometrium preparation they have followed before their successive FET: clomifene citrate (CC, group 1), artificial cycle (AC, group 2) or switch between CC and AC (group 3). The overall pregnancy rates per transfer were 24.

Matrix ageing and vascular impacts: focus on elastin fragmentation.

Cardiovascular diseases (CVDs) are the leading cause of death worldwide and represent a major problem of public health. Over the years, life expectancy has considerably increased throughout the world, and the prevalence of CVD is inevitably rising with the growing ageing of the population. The normal process of ageing is associated with progressive deterioration in structure and function of the vasculature, commonly called vascular ageing.

The Elastin Receptor Complex: A Unique Matricellular Receptor with High Anti-tumoral Potential.

Elastin, one of the longest-lived proteins, confers elasticity to tissues with high mechanical constraints. During aging or pathophysiological conditions such as cancer progression, this insoluble polymer of tropoelastin undergoes an important degradation leading to the release of bioactive elastin-derived peptides (EDPs), named elastokines. EDP exhibit several biological functions able to drive tumor development by regulating cell proliferation, invasion, survival, angiogenesis, and matrix metalloproteinase expression in various tumor and stromal cells.

Protein carbamylation is a hallmark of aging.

Aging is a progressive process determined by genetic and acquired factors. Among the latter are the chemical reactions referred to as nonenzymatic posttranslational modifications (NEPTMs), such as glycoxidation, which are responsible for protein molecular aging. Carbamylation is a more recently described NEPTM that is caused by the nonenzymatic binding of isocyanate derived from urea dissociation or myeloperoxidase-mediated catabolism of thiocyanate to free amino groups of proteins.

Autophagy is decreased in triple-negative breast carcinoma involving likely the MUC1-EGFR-NEU1 signalling pathway.

Triple-negative breast carcinoma (TN) is a heterogeneous cancer type expressing EGFR in 75% of cases. MUC1 is a large type I sialylated glycoprotein comprising two subunits (α and β chains, also called respectively MUC1-VNTR and MUC1-CT), which was found to regulate EGFR activity through endocytic internalisation. Endocytosis and autophagy use the lysosome pathway involving NEU1.

Uncoupling of Elastin Complex Receptor during In Vitro Aging Is Related to Modifications in Its Intrinsic Sialidase Activity and the Subsequent Lactosylceramide Production.

Degradation of elastin leads to the production of elastin-derived peptides (EDP), which exhibit several biological effects, such as cell proliferation or protease secretion. Binding of EDP on the elastin receptor complex (ERC) triggers lactosylceramide (LacCer) production and ERK1/2 activation following ERC Neu-1 subunit activation. The ability for ERC to transduce signals is lost during aging, but the mechanism involved is still unknown.

Elastin-derived peptides potentiate atherosclerosis through the immune Neu1-PI3Kγ pathway.

Aims: Elastin is degraded during vascular ageing and its products, elastin-derived peptides (EP), are present in the human blood circulation. EP binds to the elastin receptor complex (ERC) at the cell surface, composed of elastin-binding protein (EBP), a cathepsin A and a neuraminidase 1. Some in vitro functions have clearly been attributed to this binding, but the in vivo implications for arterial diseases have never been clearly investigated.

Elastin-derived peptides are new regulators of insulin resistance development in mice.

Although it has long been established that the extracellular matrix acts as a mechanical support, its degradation products, which mainly accumulate during aging, have also been demonstrated to play an important role in cell physiology and the development of cardiovascular and metabolic diseases. In the current study, we show that elastin-derived peptides (EDPs) may be involved in the development of insulin resistance (IRES) in mice. In chow-fed mice, acute or chronic intravenous injections of EDPs induced hyperglycemic effects associated with glucose uptake reduction and IRES in skeletal muscle, liver, and adipose tissue.

Elastin fragmentation and atherosclerosis progression: the elastokine concept.

Atherosclerosis is a progressive multifaceted inflammatory disease affecting large- and medium-sized arteries. Typical feature of this disease is the formation and build-up of atherosclerotic plaques characterized by vascular extracellular matrix degradation and remodeling. Many studies have documented degradation of native elastin, the main extracellular matrix protein responsible for resilience and elasticity of arteries, by local release of elastases, leading to the production of elastin-derived peptides (EDP).

Elastin peptides in aging and pathological conditions.

Elastin is the protein responsible for the resilience of vertebrate tissue. It is an extremely stable protein deposited during the early stages of life and experiencing almost no renewal. As a consequence, it can be considered that each individual has an elastin capital for life.

Interaction between the elastin peptide VGVAPG and human elastin binding protein.

The elastin binding protein (EBP), a spliced variant of lysosomal β-galactosidase, is the primary receptor of elastin peptides that have been linked to emphysema, aneurysm and cancer progression. The sequences recognized by EBP share the XGXXPG consensus pattern found in numerous matrix proteins, notably in elastin where the VGVAPG motif is repeated. To delineate the elastin binding site of human EBP, we built a homology model of this protein and docked VGVAPG on its surface.