scholarly journals Varanid Lizard Venoms Disrupt the Clotting Ability of Human Fibrinogen through Destructive Cleavage

Toxins ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 255 ◽  
Author(s):  
James S. Dobson ◽  
Christina N. Zdenek ◽  
Chris Hay ◽  
Aude Violette ◽  
Rudy Fourmy ◽  
...  
Keyword(s):  
Selection Pressure ◽  
Mechanical Damage ◽  
Bioactive Molecules ◽  
Human Fibrinogen ◽  
Clot Strength ◽  
Functional Activities ◽  
Evolutionary Selection ◽  
Lead Compounds ◽  
Prey Escape

The functional activities of Anguimorpha lizard venoms have received less attention compared to serpent lineages. Bite victims of varanid lizards often report persistent bleeding exceeding that expected for the mechanical damage of the bite. Research to date has identified the blockage of platelet aggregation as one bleeding-inducing activity, and destructive cleavage of fibrinogen as another. However, the ability of the venoms to prevent clot formation has not been directly investigated. Using a thromboelastograph (TEG5000), clot strength was measured after incubating human fibrinogen with Heloderma and Varanus lizard venoms. Clot strengths were found to be highly variable, with the most potent effects produced by incubation with Varanus venoms from the Odatria and Euprepriosaurus clades. The most fibrinogenolytically active venoms belonged to arboreal species and therefore prey escape potential is likely a strong evolutionary selection pressure. The results are also consistent with reports of profusive bleeding from bites from other notably fibrinogenolytic species, such as V. giganteus. Our results provide evidence in favour of the predatory role of venom in varanid lizards, thus shedding light on the evolution of venom in reptiles and revealing potential new sources of bioactive molecules useful as lead compounds in drug design and development.

Catabolism of Human Fibrinogen Fragment D in Normal Subjects and Patients with Liver Cirrhosis

1980 ◽  
Vol 44 (03) ◽  
pp. 146-149 ◽  
Author(s):  
Nicole Ardaillou ◽  
Jeannine Yvart ◽  
Philippe Le Bras ◽  
Marie-José Larrieu
Keyword(s):  
Liver Cirrhosis ◽  
Clearance Rate ◽  
Plasma Clearance ◽  
Normal Subjects ◽  
Fractional Catabolic Rate ◽  
Human Fibrinogen ◽  
Plasma Pool ◽  
Catabolic Rate ◽  
Chloramine T

SummaryThe catabolism of human fragment D, (FgD), obtained by plasmin digestion of fibrinogen has been investigated in normal subjects and patients with liver cirrhosis and the results compared with those obtained for fibrinogen (Fg). Fg was labelled with I-125 and Fg D with I-131 using the chloramine T method. The plasma disappearance curves of both labelled proteins fitted a two exponential curve. In controls the plasma clearance rate of Fg D was greater than that of Fg as shown by the marked difference between the half-lives of these two tracers: 8,9 and 83,5 hours for Fg D and Fg respectively. The fractional catabolic rate of Fg D was 3.38 times the plasma pool per day. In nine patients with liver cirrhosis, catabolism of Fg was not modified. In contrast, catabolism of Fg D was significantly reduced with a half life of 13.0 hours and a low fractional catabolic rate. These results suggest the role of the liver in the catabolism of Fg D in man.

Role of Exosomes in Photodynamic Anticancer Therapy

2020 ◽  
Vol 27 (40) ◽  
pp. 6815-6824 ◽  
Author(s):  
Yuan Jiang ◽  
Chuanshan Xu ◽  
Wingnang Leung ◽  
Mei Lin ◽  
Xiaowen Cai ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Basic Principle ◽  
Photochemical Reaction ◽  
Cell Communication ◽  
Anticancer Therapy ◽  
Bioactive Molecules ◽  
Promising Alternative ◽  
Tumor Tissues ◽  
Significant Attention

Photodynamic Therapy (PDT) is a promising alternative treatment for malignancies based on photochemical reaction induced by Photosensitizers (PS) under light irradiation. Recent studies show that PDT caused the abundant release of exosomes from tumor tissues. It is well-known that exosomes as carriers play an important role in cell-cell communication through transporting many kinds of bioactive molecules (e.g. lipids, proteins, mRNA, miRNA and lncRNA). Therefore, to explore the role of exosomes in photodynamic anticancer therapy has been attracting significant attention. In the present paper, we will briefly introduce the basic principle of PDT and exosomes, and focus on discussing the role of exosomes in photodynamic anticancer therapy, to further enrich and boost the development of PDT.

Potential of Mesenchymal Stem Cells in Anti-Cancer Therapies

2020 ◽  
Vol 15 (6) ◽  
pp. 482-491 ◽  
Author(s):  
Milena Kostadinova ◽  
Milena Mourdjeva
Keyword(s):  
Cancer Cells ◽  
Small Population ◽  
Tumor Formation ◽  
Bioactive Molecules ◽  
Cancer Therapies ◽  
New Methods ◽  
Cycle Arrest ◽  
Anti Cancer ◽  
Blocking Mechanisms

Mesenchymal stem/stromal cells (MSCs) are localized throughout the adult body as a small population in the stroma of the tissue concerned. In injury, tissue damage, or tumor formation, they are activated and leave their niche to migrate to the site of injury, where they release a plethora of growth factors, cytokines, and other bioactive molecules. With the accumulation of data about the interaction between MSCs and tumor cells, the dualistic role of MSCs remains unclear. However, a large number of studies have demonstrated the natural anti-tumor properties inherent in MSCs, so this is the basis for intensive research for new methods using MSCs as a tool to suppress cancer cell development. This review focuses specifically on advanced approaches in modifying MSCs to become a powerful, precision- targeted tool for killing cancer cells, but not normal healthy cells. Suppression of tumor growth by MSCs can be accomplished by inducing apoptosis or cell cycle arrest, suppressing tumor angiogenesis, or blocking mechanisms mediating metastasis. In addition, the chemosensitivity of cancer cells may be increased so that the dose of the chemotherapeutic agent used could be significantly reduced.

scholarly journals Benefits under the Sea: The Role of Marine Compounds in Neurodegenerative Disorders

Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 24
Author(s):  
Mariano Catanesi ◽  
Giulia Caioni ◽  
Vanessa Castelli ◽  
Elisabetta Benedetti ◽  
Michele d’Angelo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Neurodegenerative Disorders ◽  
Extreme Temperature ◽  
Bioactive Molecules ◽  
Neuroprotective Effects ◽  
Physical Conditions ◽  
Adjuvant Therapies ◽  
Marine Habitats ◽  
Marine Compounds

Marine habitats offer a rich reservoir of new bioactive compounds with great pharmaceutical potential; the variety of these molecules is unique, and its production is favored by the chemical and physical conditions of the sea. It is known that marine organisms can synthesize bioactive molecules to survive from atypical environmental conditions, such as oxidative stress, photodynamic damage, and extreme temperature. Recent evidence proposed a beneficial role of these compounds for human health. In particular, xanthines, bryostatin, and 11-dehydrosinulariolide displayed encouraging neuroprotective effects in neurodegenerative disorders. This review will focus on the most promising marine drugs’ neuroprotective potential for neurodegenerative disorders, such as Parkinson’s and Alzheimer’s diseases. We will describe these marine compounds’ potential as adjuvant therapies for neurodegenerative diseases, based on their antioxidant, anti-inflammatory, and anti-apoptotic properties.

scholarly journals Emerging Roles for Browning of White Adipose Tissue in Prostate Cancer Malignant Behaviour

2021 ◽  
Vol 22 (11) ◽  
pp. 5560
Author(s):  
Alejandro Álvarez-Artime ◽  
Belén García-Soler ◽  
Rosa María Sainz ◽  
Juan Carlos Mayo
Keyword(s):  
Prostate Cancer ◽  
Adipose Tissue ◽  
White Adipose Tissue ◽  
Tumor Development ◽  
Cell Types ◽  
Protective Role ◽  
Bioactive Molecules ◽  
Brown Adipose ◽  
Endocrine Organs

In addition to its well-known role as an energy repository, adipose tissue is one of the largest endocrine organs in the organism due to its ability to synthesize and release different bioactive molecules. Two main types of adipose tissue have been described, namely white adipose tissue (WAT) with a classical energy storage function, and brown adipose tissue (BAT) with thermogenic activity. The prostate, an exocrine gland present in the reproductive system of most mammals, is surrounded by periprostatic adipose tissue (PPAT) that contributes to maintaining glandular homeostasis in conjunction with other cell types of the microenvironment. In pathological conditions such as the development and progression of prostate cancer, adipose tissue plays a key role through paracrine and endocrine signaling. In this context, the role of WAT has been thoroughly studied. However, the influence of BAT on prostate tumor development and progression is unclear and has received much less attention. This review tries to bring an update on the role of different factors released by WAT which may participate in the initiation, progression and metastasis, as well as to compile the available information on BAT to discuss and open a new field of knowledge about the possible protective role of BAT in prostate cancer.

scholarly journals The Dual Role of Vitamin K2 in “Bone-Vascular Crosstalk”: Opposite Effects on Bone Loss and Vascular Calcification

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1222
Author(s):  
Domitilla Mandatori ◽  
Letizia Pelusi ◽  
Valeria Schiavone ◽  
Caterina Pipino ◽  
Natalia Di Pietro ◽  
...  
Keyword(s):  
Bone Loss ◽  
Vascular Calcification ◽  
Vascular System ◽  
The Elderly ◽  
Food Supplement ◽  
Vitamin K2 ◽  
Bioactive Molecules ◽  
Calcium Deposition ◽  
Age Related

Osteoporosis (OP) and vascular calcification (VC) represent relevant health problems that frequently coexist in the elderly population. Traditionally, they have been considered independent processes, and mainly age-related. However, an increasing number of studies have reported their possible direct correlation, commonly defined as “bone-vascular crosstalk”. Vitamin K2 (VitK2), a family of several natural isoforms also known as menaquinones (MK), has recently received particular attention for its role in maintaining calcium homeostasis. In particular, VitK2 deficiency seems to be responsible of the so-called “calcium paradox” phenomenon, characterized by low calcium deposition in the bone and its accumulation in the vessel wall. Since these events may have important clinical consequences, and the role of VitK2 in bone-vascular crosstalk has only partially been explained, this review focuses on its effects on the bone and vascular system by providing a more recent literature update. Overall, the findings reported here propose the VitK2 family as natural bioactive molecules that could be able to play an important role in the prevention of bone loss and vascular calcification, thus encouraging further in-depth studies to achieve its use as a dietary food supplement.

scholarly journals Mutational escape from CD8+ T cell immunity

2005 ◽  
Vol 201 (11) ◽  
pp. 1709-1714 ◽  
Author(s):  
David G. Bowen ◽  
Christopher M. Walker
Keyword(s):  
Mhc Class I ◽  
T Lymphocyte ◽  
Selection Pressure ◽  
Cytotoxic T Lymphocyte ◽  
Viral Persistence ◽  
Cd8 T Cell ◽  
Viral Escape ◽  
Immune Selection ◽  
Cell Immunity

The mechanisms by which the hepatitis C virus (HCV) establishes persistence are not yet fully understood. Previous chimpanzee and now human studies suggest that mutations within MHC class I–restricted HCV epitopes might contribute to viral escape from cytotoxic T lymphocyte (CTL) responses. However, there are several outstanding questions regarding the role of escape mutations in viral persistence and their fate in the absence of immune selection pressure.

scholarly journals The State of the Art and Prospects for Osteoimmunomodulatory Biomaterials

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1357
Author(s):  
Andreea-Mariana Negrescu ◽  
Anisoara Cimpean
Keyword(s):  
Foreign Bodies ◽  
Structural Characteristics ◽  
Critical Role ◽  
Fibrous Tissue ◽  
Bioactive Molecules ◽  
New Bone Formation ◽  
Recent Developments

The critical role of the immune system in host defense against foreign bodies and pathogens has been long recognized. With the introduction of a new field of research called osteoimmunology, the crosstalk between the immune and bone-forming cells has been studied more thoroughly, leading to the conclusion that the two systems are intimately connected through various cytokines, signaling molecules, transcription factors and receptors. The host immune reaction triggered by biomaterial implantation determines the in vivo fate of the implant, either in new bone formation or in fibrous tissue encapsulation. The traditional biomaterial design consisted in fabricating inert biomaterials capable of stimulating osteogenesis; however, inconsistencies between the in vitro and in vivo results were reported. This led to a shift in the development of biomaterials towards implants with osteoimmunomodulatory properties. By endowing the orthopedic biomaterials with favorable osteoimmunomodulatory properties, a desired immune response can be triggered in order to obtain a proper bone regeneration process. In this context, various approaches, such as the modification of chemical/structural characteristics or the incorporation of bioactive molecules, have been employed in order to modulate the crosstalk with the immune cells. The current review provides an overview of recent developments in such applied strategies.

scholarly journals Hunting Bioactive Molecules from the Agave Genus: An Update on Extraction and Biological Potential

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 6789
Author(s):  
Misael Bermúdez-Bazán ◽  
Gustavo Adolfo Castillo-Herrera ◽  
Judith Esmeralda Urias-Silvas ◽  
Antonio Escobedo-Reyes ◽  
Mirna Estarrón-Espinosa
Keyword(s):  
Secondary Metabolites ◽  
Biological Activities ◽  
Waste Product ◽  
Bioactive Molecules ◽  
Alcoholic Beverages ◽  
Therapeutic Benefits ◽  
Biological Potential ◽  
Novel Drugs ◽  
Ancient Times

Agaves are plants used in the production of alcoholic beverages and fibers. Ever since ancient times, pre-Hispanic cultures in Mexico have used them in traditional medicine to cure different ailments. Over the years, studies of the active principles responsible for the therapeutic benefits of agaves have increased. Leaves and fibers are the main agro-wastes generated in tequila and mezcal production, while fibers are the main waste product in the textile sector. Different investigations have referred to the agro-waste from agave processing as a source of bioactive molecules called secondary metabolites (SM). Among them, phenols, flavonoids, phytosterols, and saponins have been extracted, identified, and isolated from these plants. The role of these molecules in pest control and the prospect of metabolites with the biological potential to develop novel drugs for chronic and acute diseases represent new opportunities to add value to these agro-wastes. This review aims to update the biological activities and recent applications of the secondary metabolites of the genus Agave.

scholarly journals Melatonin in yeast and fermented beverages: analytical tools for detection, physiological role and biosynthesis

2020 ◽  
Vol 3 (2) ◽  
pp. 144-160 ◽  
Author(s):  
Sara Muñiz-Calvo ◽  
Ricardo Bisquert ◽  
José M. Guillamón
Keyword(s):  
Biosynthetic Pathway ◽  
Physiological Role ◽  
Aromatic Amino Acids ◽  
Bioactive Molecules ◽  
Research Topics ◽  
Fermented Beverages ◽  
Potential Benefits ◽  
Analytical Tools ◽  
Melatonin Production

The recently established relation between the metabolism of aromatic amino acids of yeast and the production of different bioactive molecules during fermentation opens up new and interesting research topics. Among these molecules, melatonin has drawn researchers’ attention in the last decade given its potential benefits for human health. This review summarizes melatonin production in fermented beverages, and conventional and current methods for detecting melatonin in yeast-derived samples. In addition, the role of melatonin in yeast is discussed and the biosynthetic pathway of melatonin is presented in Saccharomyces cerevisiae.

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