Extraction, Isolation, Characterization, and Biological Activity of Sulfated Polysaccharides Present in Ascidian Viscera .

Ascidians are marine invertebrates that synthesize sulfated glycosaminoglycans (GAGs) within their viscera. Ascidian GAGs are considered analogues of mammalian GAGs and possess great potential as bioactive compounds, presenting antitumoral and anticoagulant activity. Due to its worldwide occurrence and, therefore, being a suitable organism for large-scale mariculture in many marine environments, our main objectives are to study GAGs regarding composition, structure, and biological activity.

Elemental profiles in distant tissues during tumor progression.

Background: Essential elements have functions in tumor progression by promoting protumoral cellular processes, such as proliferation, and migration, among others. Obtaining an understanding of how these elements relate to tumor progression processes is of great importance for research. Elemental profile studies in distant tissues, which can be modulated by tumor cells to promote metastasis, have not been sufficiently investigated.

p53 Signaling on Microenvironment and Its Contribution to Tissue Chemoresistance.

Chemoresistance persists as a significant, unresolved clinical challenge in many cancer types. The tumor microenvironment, in which cancer cells reside and interact with non-cancer cells and tissue structures, has a known role in promoting every aspect of tumor progression, including chemoresistance. However, the molecular determinants of microenvironment-driven chemoresistance are mainly unknown.

Manganese systemic distribution is modulated in vivo during tumor progression and affects tumor cell migration and invasion in vitro.

Metastatic disease remains the leading cause of death in cancer and understanding the mechanisms involved in tumor progression continues to be challenging. This work investigates the role of manganese in tumor progression in an in vivo model of tumor growth. Our data revealed that manganese accumulates within primary tumors and secondary organs as manganese-rich niches.

Metal ions and the extracellular matrix in tumor migration.

In this review, we explore the roles of divalent metal ions in structure and function within the extracellular matrix (ECM), specifically, their interaction with glycosaminoglycans (GAGs) during tumor progression. Metals and GAGs have been individually associated with physiological and pathological processes, however, their combined activities in regulating cell behavior and ECM remodeling have not been fully explored to date. During tumor progression, divalent metals and GAGs participate in central processes, such as cell migration and angiogenesis, either by modulating cell surface molecules, as well as soluble signaling factors.

Expression of potassium channels is relevant for cell survival and migration in a murine bone marrow stromal cell line.

S17 is a clonogenic bone marrow stromal (BMS) cell line derived from mouse that has been extensively used to assess both human and murine hematopoiesis support capacity. However, very little is known about the expression of potassium ion channels and their function in cell survival and migration in these cells. Thus, the present study was designed to characterize potassium ion channels using electrophysiological and molecular biological approaches in S17 BMS cells.

Methods for Isolation and Characterization of Sulfated Glycosaminoglycans from Marine Invertebrates.

Marine invertebrates produce different kinds of sulfated polysaccharides. These glycans play essential roles in several biological processes and the study of these molecules is promising in a variety of fields. In the following sections, we describe the materials and methods used for the extraction, purification, and characterization of marine invertebrate-derived glycosaminoglycans.

Trace elements during primordial plexiform network formation in human cerebral organoids.

Systematic studies of micronutrients during brain formation are hindered by restrictions to animal models and adult post-mortem tissues. Recently, advances in stem cell biology have enabled recapitulation of the early stages of human telencephalon development . In the present work, we analyzed cerebral organoids derived from human pluripotent stem cells by synchrotron radiation X-ray fluorescence in order to measure biologically valuable micronutrients incorporated and distributed into the exogenously developing brain.

Heparan Sulfate Proteoglycans May Promote or Inhibit Cancer Progression by Interacting with Integrins and Affecting Cell Migration.

The metastatic disease is one of the main consequences of tumor progression, being responsible for most cancer-related deaths worldwide. This review intends to present and discuss data on the relationship between integrins and heparan sulfate proteoglycans in health and cancer progression. Integrins are a family of cell surface transmembrane receptors, responsible for cell-matrix and cell-cell adhesion.

Extracellular galectin-3 in tumor progression and metastasis.

Galectin-3, the only chimera galectin found in vertebrates, is one of the best-studied galectins. It is expressed in several cell types and is involved in a broad range of physiological and pathological processes, such as cell adhesion, cell activation and chemoattraction, cell cycle, apoptosis, and cell growth and differentiation. However, this molecule raises special interest due to its role in regulating cancer cell activities.

Heparanase expression and localization in different types of human lung cancer.

Background: Heparanase is the only known mammalian glycosidase capable of cleaving heparan sulfate chains. The expression of this enzyme has been associated with tumor development because of its ability to degrade extracellular matrix and promote cell invasion.

Methods: We analyzed heparanase expression in lung cancer samples to understand lung tumor progression and malignancy.

Valproate reverts zinc and potassium imbalance in schizophrenia-derived reprogrammed cells.

Schizophrenia has been considered a devastating clinical syndrome rather than a single disease. Nevertheless, the mechanisms behind the onset of schizophrenia have been only partially elucidated. Several studies propose that levels of trace elements are abnormal in schizophrenia; however, conflicting data generated from different biological sources prevent conclusions being drawn.

Heparan sulfate and heparanase as modulators of breast cancer progression.

Breast cancer is defined as a cancer originating in tissues of the breast, frequently in ducts and lobules. During the last 30 years, studies to understand the biology and to treat breast tumor improved patients' survival rates. These studies have focused on genetic components involved in tumor progression and on tumor microenvironment.

Matrix-bound heparan sulfate is essential for the growth and pluripotency of human embryonic stem cells.

Human embryonic stem (hES) cell production of heparan sulfate influences cell fate and pluripotency. Human ES cells remain pluripotent in vitro through the action of growth factors signaling, and the activity of these factors depends on interaction with specific receptors and also with heparan sulfate. Here, we tested the hypothesis that matrix-associated heparan sulfate is enough to maintain hES cells under low fibroblast growth factor-2 concentration in the absence of live feeder cells.

Synchrotron radiation X-ray microfluorescence reveals polarized distribution of atomic elements during differentiation of pluripotent stem cells.

The mechanisms underlying pluripotency and differentiation in embryonic and reprogrammed stem cells are unclear. In this work, we characterized the pluripotent state towards neural differentiated state through analysis of trace elements distribution using the Synchrotron Radiation X-ray Fluorescence Spectroscopy. Naive and neural-stimulated embryoid bodies (EB) derived from embryonic and induced pluripotent stem (ES and iPS) cells were irradiated with a spatial resolution of 20 µm to make elemental maps and qualitative chemical analyses.

The renal clearance of dextran sulfate decreases in puromycin aminonucleoside-induced glomerulosclerosis: a puzzle observation.

Background: Puromycin aminonucleoside-induced nephrosis is characterized by increased renal excretion of plasma proteins. We employed this experimental model to study the urinary clearance of dextran sulfate.

Methods: The dextran sulfate eliminated by the urine was determined using a metachromatic assay.

Dermatan sulfate is the predominant antithrombotic glycosaminoglycan in vessel walls: implications for a possible physiological function of heparin cofactor II.

The role of different glycosaminoglycan species from the vessel walls as physiological antithrombotic agents remains controversial. To further investigate this aspect we extracted glycosaminoglycans from human thoracic aorta and saphenous vein. The different species were highly purified and their anticoagulant and antithrombotic activities tested by in vitro and in vivo assays.