Amyloidogenic properties of the artificial protein albebetin and its biologically active derivatives. The role of electrostatic interactions in fibril formation

2006 ◽  
Vol 71 (3) ◽  
pp. 306-314 ◽  
Author(s):  
M. A. Lavrikova ◽  
V. V. Zamotin ◽  
M. Malisauskas ◽  
R. V. Chertkova ◽  
I. A. Kostanyan ◽  
...  
2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Sudipta Biswas ◽  
Liang Xin ◽  
Soumya Panigrahi ◽  
Alejandro Zimman ◽  
Valentin Yakubenko ◽  
...  

A prothrombotic state and increased platelet reactivity are common in hyperlipidemia and oxidative stress. Lipid peroxidation, a major consequence of oxidative stress, generates highly reactive products including hydroxy-w-oxoalkenoic acids that modify autologous proteins generating biologically active derivatives. Phosphatidylethanolamine, the second most abundant eukaryotic phospholipid can also be modified by hydroxy-w-oxoalkenoic acids. However, the conditions leading to accumulation of such derivatives in circulation and their biological activities remain poorly understood. We now show that carboxyalkylpyrrole-phosphatidylethanolamine derivatives (CAP-PE) accumulate in plasma of hyperlipidemic ApoE -/- mice. CAP-PE directly bind to TLR2 and induce platelet integrin alpha 2b beta 3 activation and P-selectin expression in TLR2 dependent manner. Platelet activation by CAP-PE includes assembly of TLR2/TLR1 receptor complex, induction of downstream signaling via MyD88/TIRAP, phosphorylation of IRAK4, and subsequent activation of TRAF6. This in turn activates the Src family kinases, Syk and PLC gamma 2 and platelet integrins. By intravital thrombosis studies we have demonstrated that CAP-PE accelerate thrombosis in TLR2 dependent manner. Furthermore, we demonstrate that TLR2 deficient mice are protected from accelerated thrombosis induced by hyperlipidemia. Taken together, our studies demonstrate a cross-talk between innate immunity and integrin activation signaling pathways in platelets and reveal that TLR2 plays a key role in platelet hyperreactivity and prothrombotic state in hyperlipidemia.


2020 ◽  
Vol 26 (41) ◽  
pp. 7337-7371 ◽  
Author(s):  
Maria A. Chiacchio ◽  
Giuseppe Lanza ◽  
Ugo Chiacchio ◽  
Salvatore V. Giofrè ◽  
Roberto Romeo ◽  
...  

: Heterocyclic compounds represent a significant target for anti-cancer research and drug discovery, due to their structural and chemical diversity. Oxazoles, with oxygen and nitrogen atoms present in the core structure, enable various types of interactions with different enzymes and receptors, favoring the discovery of new drugs. Aim of this review is to describe the most recent reports on the use of oxazole-based compounds in anticancer research, with reference to the newly discovered iso/oxazole-based drugs, to their synthesis and to the evaluation of the most biologically active derivatives. The corresponding dehydrogenated derivatives, i.e. iso/oxazolines and iso/oxazolidines, are also reported.


2020 ◽  
Vol 16 ◽  
Author(s):  
Mayank Chaudhary

Background:: Renin angiotensin system (RAS) is a critical pathway involved in blood pressure regulation. Octapeptide, angiotensin II (Ang aII), is biologically active compound of RAS pathway which mediates its action by binding to either angiotensin II type 1 receptor (AT1R) or angiotensin II type 2 receptor (AT2R). Binding of Ang II to AT1R facilitates blood pressure regulation whereas AT2R is primarily involved in wound healing and tissue remodelling. Objective:: Recent studies have highlighted additional role of AT2R to counter balance detrimental effects of AT1R. Activation of angiotensin II type 2 receptor using AT2R agonist has shown effect on natriuresis and release of nitric oxide. Additionally, AT2R activation has been found to inhibit angiotensin converting enzyme (ACE) and enhance angiotensin receptor blocker (ARB) activity. These findings highlight the potential of AT2R as novel therapeutic target against hypertension. Conclusion:: The potential role of AT2R highlights the importance of exploring additional mechanisms that might be crucial for AT2R expression. Epigenetic mechanisms including DNA methylation and histone modification have been explored vastly with relation to cancer but role of such mechanisms on expression of AT2R has recently gained interest.


2019 ◽  
Vol 20 (18) ◽  
pp. 4416 ◽  
Author(s):  
Lara Console ◽  
Maria Tolomeo ◽  
Matilde Colella ◽  
Maria Barile ◽  
Cesare Indiveri

Background: the SLC52A2 gene encodes for the riboflavin transporter 2 (RFVT2). This transporter is ubiquitously expressed. It mediates the transport of Riboflavin across cell membranes. Riboflavin plays a crucial role in cells since its biologically active forms, FMN and FAD, are essential for the metabolism of carbohydrates, amino acids, and lipids. Mutation of the Riboflavin transporters is a risk factor for anemia, cancer, cardiovascular disease, neurodegeneration. Inborn mutations of SLC52A2 are associated with Brown-Vialetto-van Laere syndrome, a rare neurological disorder characterized by infancy onset. In spite of the important metabolic and physio/pathological role of this transporter few data are available on its function and regulation. Methods: the human recombinant RFVT2 has been overexpressed in E. coli, purified and reconstituted into proteoliposomes in order to characterize its activity following the [3H]Riboflavin transport. Results: the recombinant hRFVT2 showed a Km of 0.26 ± 0.07 µM and was inhibited by lumiflavin, FMN and Mg2+. The Riboflavin uptake was also regulated by Ca2+. The native protein extracted from fibroblast and reconstituted in proteoliposomes also showed inhibition by FMN and lumiflavin. Conclusions: proteoliposomes represent a suitable model to assay the RFVT2 function. It will be useful for screening the mutation of RFVT2.


2021 ◽  
pp. 030098582199932
Author(s):  
Laura Bongiovanni ◽  
Anneloes Andriessen ◽  
Marca H. M. Wauben ◽  
Esther N. M. Nolte-’t Hoen ◽  
Alain de Bruin

With a size range from 30 to 1000 nm, extracellular vesicles (EVs) are one of the smallest cell components able to transport biologically active molecules. They mediate intercellular communications and play a fundamental role in the maintenance of tissue homeostasis and pathogenesis in several types of diseases. In particular, EVs actively contribute to cancer initiation and progression, and there is emerging understanding of their role in creation of the metastatic niche. This fact underlies the recent exponential growth in EV research, which has improved our understanding of their specific roles in disease and their potential applications in diagnosis and therapy. EVs and their biomolecular cargo reflect the state of the diseased donor cells, and can be detected in body fluids and exploited as biomarkers in cancer and other diseases. Relatively few studies have been published on EVs in the veterinary field. This review provides an overview of the features and biology of EVs as well as recent developments in EV research including techniques for isolation and analysis, and will address the way in which the EVs released by diseased tissues can be studied and exploited in the field of veterinary pathology. Uniquely, this review emphasizes the important contribution that pathologists can make to the field of EV research: pathologists can help EV scientists in studying and confirming the role of EVs and their molecular cargo in diseased tissues and as biomarkers in liquid biopsies.


2021 ◽  
pp. 100080
Author(s):  
Martyna Maszota-Zieleniak ◽  
Annemarie Danielsson ◽  
Sergey A. Samsonov

2000 ◽  
Vol 80 (4) ◽  
pp. 1669-1699 ◽  
Author(s):  
Giuseppe Montrucchio ◽  
Giuseppe Alloatti ◽  
Giovanni Camussi

Platelet-activating factor (PAF) is a phospholipid mediator that belongs to a family of biologically active, structurally related alkyl phosphoglycerides. PAF acts via a specific receptor that is coupled with a G protein, which activates a phosphatidylinositol-specific phospholipase C. In this review we focus on the aspects that are more relevant for the cell biology of the cardiovascular system. The in vitro studies provided evidence for a role of PAF both as intercellular and intracellular messenger involved in cell-to-cell communication. In the cardiovascular system, PAF may have a role in embryogenesis because it stimulates endothelial cell migration and angiogenesis and may affect cardiac function because it exhibits mechanical and electrophysiological actions on cardiomyocytes. Moreover, PAF may contribute to modulation of blood pressure mainly by affecting the renal vascular circulation. In pathological conditions, PAF has been involved in the hypotension and cardiac dysfunctions occurring in various cardiovascular stress situations such as cardiac anaphylaxis and hemorrhagic, traumatic, and septic shock syndromes. In addition, experimental studies indicate that PAF has a critical role in the development of myocardial ischemia-reperfusion injury. Indeed, PAF cooperates in the recruitment of leukocytes in inflamed tissue by promoting adhesion to the endothelium and extravascular transmigration of leukocytes. The finding that human heart can produce PAF, expresses PAF receptor, and is sensitive to the negative inotropic action of PAF suggests that this mediator may have a role also in human cardiovascular pathophysiology.


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