New Concepts in Coronary Heart Disease (CHD)
Mark C Houston in The Truth About Heart Disease, 2023
All cells are surrounded by a protective layer called a “cell membrane”. This keeps unwanted things outside the cell and allows for all the parts inside the cell to function normally and not become damaged. All cell membranes are composed of “fatty acids”. These include omega-3 fatty acids and monounsaturated fatty acids—good fatty acids that promote a healthy membrane which is elastic, soft, and “fluid like”. However, other fatty acids, such as some long-chain saturated fats (over C12 carbon length) and all trans fats are bad and damage the cell membrane, making it hard, nonelastic, and stiff. When this happens, the cell membrane leaks and the normal receptors of the membrane do not work properly. The cell then becomes damaged inside, dysfunctional, and eventually dies. This is the same process that happens in the coronary arteries leading to CHD.
Role of Tumor Cell Membrane in Hyperthermia
Leopold J. Anghileri, Jacques Robert in Hyperthermia In Cancer Treatment, 2019
From the physiological point of view, cells are units of protoplasma separated from the surrounding medium by a membrane. This membrane must lie outside the cell in order to isolate it from the external medium and for this reason is called cell surface or plasma membrane. Only one out of the four main classes of organic molecules present in the cell, the lipid molecules, shows the physicochemical characteristics of a low dielectric constant and the nonpolar portions required for the formation of extensive membranes. On the other hand, these properties of the lipid molecules imply that the membranes will be low in permeability to solutes and allow the composition of the cytosol to be substantially different from that of the extracellular medium. In addition, from the physical point of view, its electrical resistance permits the cell to develop transmembrane potentials.
Structures and Properties of Self-Assembled Phospholipids in Excess Water
E. Nigel Harris, Thomas Exner, Graham R. V. Hughes, Ronald A. Asherson in Phospholipid-Binding Antibodies, 2020
Since 1935, cell membranes or plasma membranes have been recognized to contain a continuously self-enclosed, two-dimensional structure with a thickness equal to the dimension of two lipid molecules.1 This structure, called the lipid bilayer, has a hydrophobic core which was originally considered to function as a barrier preventing the free flow of ions and polar molecules between the cell interior and its external environment. Over the years, the concept or model about the structure of biological membranes has been evolved and modified considerably.2,3 This can be attributed largely to the fact that the physical and chemical techniques employed to characterize biological membranes are continuously improved and steadily refined. However, the view about the lipid bilayer as a fundamental structural component and permeability barrier for all biological membranes is, nevertheless, maintained, although it is now recognized that such a bilayer structure is highly dynamic in nature at physiological temperature and that it can contain external and internal proteins or glycoproteins with chemical asymmetry.4,5 Moreover, it is generally believed that most cell surface functions are confined to the membrane proteins or glycoproteins.
Ultrastructural analysis of the Krebs-2 ascites cancer cells treated with extracellular double-stranded DNA preparation
Published in Ultrastructural Pathology, 2019
Svetlana S Kirikovich, Oleg S. Taranov, Vladimir V. Omigov, Ekaterina A. Potter, Evgenia V. Dolgova, Anastasia S. Proskurina, Yaroslav R. Efremov, Sergey S. Bogachev
The status of the cell surface is quite important for cellular functions. Intact cancer cells were shown to be of spherical shape; their surface membrane forms multiple, thin, and in most cases regularly located microvilli (Figure 2a,b). This issue is quite poorly attended in the existing literature. There are only a few reports on the topography of the ascitic tumor cells surface, which mediates the cellular interaction with the environment and with each other. In contrast to solid tumors that grow as more or less dense nodes, ascites tumors form a dense suspension of tumor cells proliferating in ascitic fluid and such a suspension is a natural condition for their viability.36,38,39 Ascites tumor cells are known to be of spherical shape, while their surfaces look extremely uneven, with multiple microvilli, protrusions, and folds, which significantly increase absorption surface.
Recent advances in ultrasound-triggered therapy
Published in Journal of Drug Targeting, 2019
Chaopin Yang, Yue Li, Meng Du, Zhiyi Chen
Being a plasma membrane, cell membrane is a barrier to isolate the internal and external environments of cells. However, sonication combined UCAs can cause transient damage to the cell membrane and further results in temporary and reversible holes (Figure 2), which provides a channel for extracellular substances coming into the cell through the cell membrane [28]. Early in 1999, Tachibana et al. observed that the cell membrane underwent porous changes after being treated by ultrasound combing MBs by scanning electron microscope (SEM). It can also boost the absorption of extracellular substances by affecting the endocytosis of cells [29]. A series of following studies have confirmed that ultrasound or ultrasound combined with MBs could improve the permeability of cell membrane through sonoporation to facilitate the entry of extracellular substances into the cell [30,31].
microRNA-130b-3p delivery by mesenchymal stem cells-derived exosomes confers protection on acute lung injury
Published in Autoimmunity, 2022
Xiaoxia Wang, Jifeng Feng, Huijun Dai, Jianlan Mo, Bijun Luo, Cheng Luo, Weikang Zhang, Linghui Pan
CD105, CD29, CD44 and CD34 are commonly used to identify MSCs, among which CD105, CD29 and CD44 is a positive marker, whereas CD34 is a negative marker [36,37]. The specific function of the cells is related to its surface markers, and cell surface markers can reflect some basic characteristics of cells. MSCs are a mixed cell population, and their surface antigens are also non-specific, expressing the surface markers of mesenchymal cells, endothelial cells and epidermal cells [38]. CD29, also known as integrin β1, VLA-β chain or gpIIa, is a receptor for various extracellular matrix proteins, and CD29 acts as a fibronectin receptor involved in various cell–cell and cell–matrix interactions. CD105, also known as endoglin, is a 90-kDa type I transmembrane glycoprotein of the zona pellucida protein (ZP) family. CD44, also known as Hermes, Pgp1, H-CAM or Hutch, is an 80–95 kDa glycoprotein, which is expressed in leukocytes, endothelial cells, hepatocytes and MSCs. CD34 is a transmembrane salivary mucin that may be involved in adhesion and anti-adhesion. Therefore, we chose CD105, CD29, CD44 and CD34 to identify MSCs. Flow cytometry showed that CD105, CD29 and CD44 were positive, and CD34 was negative (Figure 1(A)). Adipogenic and osteogenic differentiation experiments uncovered that after oil red O staining, there were red lipid droplets in the cells; in the osteogenic medium, Alizarin Red stained cubes and formed mineralized nodules, indicating that the cells had multi-directional differentiation abilities (Figure 1(B)).
Related Knowledge Centers
- Cytoplasm
- Extracellular Space
- Integral Membrane Protein
- Lipid Bilayer
- Membrane Fluidity
- Membrane Protein
- Phospholipid
- Biological Membrane
- Cell
- Cholesterol