Involvement of Metabolic Lipid Mediators in the Regulation of Apoptosis

Apoptosis is the physiological mechanism of cell death and can be modulated by endogenous and exogenous factors, including stress and metabolic alterations. Reactive oxygen species (ROS), as well as ROS-dependent lipid peroxidation products (including isoprostanes and reactive aldehydes including 4-hydroxynonenal) are proapoptotic factors. These mediators can activate apoptosis via mitochondrial-, receptor-, or ER stress-dependent pathways. Phospholipid metabolism is also an essential regulator of apoptosis, producing the proapoptotic prostaglandins of the PGD and PGJ series, as well as the antiapoptotic prostaglandins of the PGE series, but also 12-HETE and 20-HETE. The effect of endocannabinoids and phytocannabinoids on apoptosis depends on cell type-specific differences. Cells where cannabinoid receptor type 1 (CB1) is the dominant cannabinoid receptor, as well as cells with high cyclooxygenase (COX) activity, undergo apoptosis after the administration of cannabinoids. In contrast, in cells where CB2 receptors dominate, and cells with low COX activity, cannabinoids act in a cytoprotective manner. Therefore, cell type-specific differences in the pro- and antiapoptotic effects of lipids and their (oxidative) products might reveal new options for differential bioanalysis between normal, functional, and degenerating or malignant cells, and better integrative biomedical treatments of major stress-associated diseases

Oxidative Stress and Lipid Mediators Modulate Immune Cell Functions in Autoimmune Diseases

Autoimmune diseases, including psoriasis, systemic lupus erythematosus (SLE), and rheumatic arthritis (RA), are caused by a combination of environmental and genetic factors that lead to overactivation of immune cells and chronic inflammation. Since oxidative stress is a common feature of these diseases, which activates leukocytes to intensify inflammation, antioxidants could reduce the severity of these diseases. In addition to activating leukocytes, oxidative stress increases the production of lipid mediators, notably of endocannabinoids and eicosanoids, which are products of enzymatic lipid metabolism that act through specific receptors. Because the anti-inflammatory CB2 receptors are the predominant cannabinoid receptors in leukocytes, endocannabinoids are believed to act as anti-inflammatory factors that regulate compensatory mechanisms in autoimmune diseases. While administration of eicosanoids in vitro leads to the differentiation of lymphocytes into T helper 2 (Th2) cells, eicosanoids are also necessary for the different0iation of Th1 and Th17 cells. Therefore, their antagonists and/or the genetic deletion of their receptors abolish inflammation in animal models of psoriasis—RA and SLE. On the other hand, products of non-enzymatic lipid peroxidation, especially acrolein and 4-hydroxynonenal-protein adducts, mostly generated by an oxidative burst of granulocytes, may enhance inflammation and even acting as autoantigens and extracellular signaling molecules in the vicious circle of autoimmune diseases

Saussureae involucratae Herba (Snow Lotus): Review of chemical compositions and pharmacological properties

Saussureae Involucratae Herba is the dried ground part of Saussurea involucrata (Kar. et Kir.) Sch.-Bip, which is also named as “Snow lotus” and being used in traditional Uyghur and/or Chinese medicine. This rare herb can be found at 4,000 m elevation in western part of Tianshan Mountain, Xinjiang China. According to China Pharmacopoeia (2015), the major pharmaceutical values of “Snow lotus” (Xuě liánhuā in Chinese) are alleviating rheumatoid arthritis, accelerating blood circulation and mitigating other “cold” syndromes. Traditionally, the clinical application of “Snow lotus” includes the treatments in inflammation-associated disorder, blood circulation acceleration and heat and dampness elimination. Recent studies suggested that “Snow lotus” possessed therapeutic effects associating with anti-cancer, anti-oxidation, adipogenesis suppression and neuroprotection activities, which were proposed to be related with its bioactive constitutes, i.e. acacetin, hispidulin, and rutin. In the present review, we aim to summarize pharmacological effects and underlying cell signaling pathways of “Snow lotus” in treating various medical problems. Copyright © 2020 Gong, Huang, Yang, Qi, Han, Zheng, He, Chan, Tsim and Dong. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms

Charles Lyell's Geological Ideas and Their Sources

The aim of the article is presentation of some opinions of historians and philosophers of science about scientific doctrines of Charles Lyell (1797-1875) and the sources of these doctrines. Three main themes are discussed: 1. What was the real meaning of Lyell's uniformitarianism and which doctrine (catastrophism or directionalism) it was opposed to? 2. Which method of geological research was used and recommended by Lyell? 3. What relation connected Lyell's scientific doctrine with his religious and theological views

Between Physics and History. A Place of Geology in the Classification of Sciences

Geology is an example of the "historical-natural" sciences, and it combines methodological elements of typical natural sciences, as physics, and the methodological elements of history. As a result, there are some problems with placing it in the classification of sciences. The article consists of two parts. In the first one there is presented in short form process of developing of modern geology. Using as examples the ideas of James Hutton, Georges Cuvier and Charles Lyell the author shows how the opinion about proper method and aims of geology was changing at the turn of 18th and 19th centuries. The final point of the process was the classification of sciences presented by William Whewell, who classified geology as a palaetiological science. The second part of the article is devoted to the place of geology in the contemporary classifications of sciences presented by main Polish methodologists. There are discussed the classifications of Kazimierz Twardowski, Tadeusz Kotarbiński, Władysław Tatarkiewicz, Kazimierz Ajdukiewicz, Władysław Krajewski and Adam Grobler

Wyjaśnianie w geologii historycznej i paleontologii

Geologia historyczna i paleontologia należą do grupy historycznych nauk przyrodniczych, a więc dyscyplin, których zadaniem jest badanie określonych dziedzin przyrody z uwzględnieniem ich dziejów. Swoistość przedmiotowa tych dziedzin skłania do postawienia pytania o ich odrębność metodologiczną, w tym – o właściwy dla nich sposób wyjaśniania. Celem niniejszego artykułu jest przedstawienie wybranych przykładów stanowisk w kwestii modelu wyjaśniania obowiązującego w wymienionych dyscyplinach. Przegląd ten ma za zadanie, po pierwsze, ukazać rozbieżności w prezentowanych w literaturze filozoficznonaukowej opiniach w tej sprawie, po drugie zaś, wskazać podstawowe trudności związane z poszczególnymi stanowiskami