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Stroke
Published in Henry J. Woodford, Essential Geriatrics, 2022
Mitochondria were originally symbiotic bacteria that migrated into animal cells with the advantage of being able to perform aerobic metabolism. They possess their own DNA and are inherited by the division of the mitochondria contained with the maternal egg cell. Various disorders have been described relating to mutations in mitochondrial DNA.128 One of these is ‘mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes' (MELAS). This disorder is very rare and usually presents in children or young adults with focal neurological deficits, seizures and progressive cognitive impairment. There may be an associated history of exercise intolerance, deafness, diabetes, migraine and/or learning disability. Fasting plasma and CSF lactate levels are elevated. Muscle biopsy may demonstrate ragged red fibres or abnormal mitochondria. There is no treatment for this condition.
Introduction: Background Material
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
All living cells have a surrounding envelope referred to as the cell membrane, or plasma membrane. Animal cells are eukaryotic, that is, they have a well-developed nucleus and other membrane-bounded organelles, which are cell elements that perform some specialized functions. Figure 1.1 illustrates a typical eukaryotic cell and some of its organelles. The part of the cell that is outside the nucleus and bounded by the cell membrane is the cytoplasm. The cytosol, or intracellular fluid, is the liquid part of the cytoplasm, exclusive of organelles. It consists of a complex mixture of substances that are dissolved or suspended in water. The cell membrane is discussed in considerable detail in Sections 2.1 and 2.2. The following cell organelles are particularly relevant for our purposes.
Components of Nutrition
Published in Christopher Cumo, Ancestral Diets and Nutrition, 2020
This caveat aside, fat provides more than energy. All the body’s cells use fatty acids to construct their membranes, without which no cell can function. The membrane separates animal cells (plant cells have a wall) from their surroundings, preserving their integrity. The membrane’s indispensability and the cell’s antiquity as the basic unit in microbes, plants, and animals imply that fatty acids are among the earliest organic molecules as life’s precursors. Fats are important to the central nervous system (CNS), where they form neural membranes and the myelin sheath that surrounds each neuron’s axon. Made of neurons, the brain is roughly 70 percent fat.53 Cognition, a hallmark of humanity, would be impossible without it.
Human ovarian granulosa cells use clathrin-mediated endocytosis for LDL uptake: immunocytochemical and electron microscopic study
Published in Ultrastructural Pathology, 2023
Aynur Abdulova, Merjem Purelku, Hakan Sahin, Gamze Tanrıverdi
Regarding the clathrin-mediated endocytic pathway, an important component is the clathrin protein. Clathrin-coated vesicles have a three-layered structure consisting of an outer region formed by clathrin proteins in the form of a cage, an intermediate region consisting of a lipid membrane, as well as internal adaptor proteins (APs).8 Along with clathrin, more than 60 other cytosolic proteins are involved in the formation of clathrin-coated endocytic vesicles.9 All these proteins assemble from the cytosol to the endocytic region in a highly ordered manner. The collected vesicles are transported to the target site by SNARE (N-ethylmaleimide-sensitive factor binding protein receptor) proteins. SNAREs manage the transfer of material to be transported during vesicular transport. In an animal cell, there are at least 20 different organelle-associated SNARE proteins, each attached to a specific membrane involved in the biosynthetic-secretion or endocytic pathway. These proteins function as transmembrane proteins and are referred to as vesicular SNAREs (v-SNAREs) with characteristic spiral domains.10
Application of plant-derived exosome-like nanoparticles in drug delivery
Published in Pharmaceutical Development and Technology, 2023
Mohadeseh Barzin, Amir Mohammad Bagheri, Mandana Ohadi, Amir Masoud Abhaji, Soodeh Salarpour, Gholamreza Dehghannoudeh
Proteins are macro-biomolecules composed of amino acid residues and perform a wide variety of functions, including DNA replication, stimuli responding, transferring molecules, and catalyzing metabolic reactions (Whitford 2013; Fuxreiter and Vendruscolo 2021). Suharta et al. (2021) revealed that PELNs have a low concentration of protein; Further, most proteins in PELNs are cytosolic proteins, including proteases, actin, and membrane proteins that act as transporters within the membrane. However, determining a complete protein profile inside PELNs is challenging due to various sets of protein databases in different plants (Suharta et al. 2021; Woith et al. 2021). For instance, Ju et al. (2013) identified 580 proteins of lemon-derived exosomes. On the other hand, compared to exosomes extracted from animal cells, PELNs have lower protein content. Somehow, mammalian-derived exosomes contain more than 1000 proteins, whereas plant exosomes derived from ginger have only 28 proteins (Raimondo et al. 2015; Zhang et al. 2016; Salek et al. 2020; Suharta et al. 2021). Moreover, it should be noted that proteins are assumed to play a critical role in interspecies recognition within the plant and mammalian cells (Song et al. 2020; Nemati et al. 2022). For example, lectin proteins, which have a high specific affinity for saccharides and are abundantly found in some plant-derived exosomes such as garlic and mushrooms, are supposed to be the primary interspecies communication mediators between these exosomes and mammalian cells (Song et al. 2020).
Cross talk between exosomes and pancreatic β-cells in diabetes
Published in Archives of Physiology and Biochemistry, 2022
Exosomes are endosomal membrane vesicles released from cells and contain various types of cargo, such as lipids, proteins, and miRNAs, which are involved in intercellular communication (Raposo and Stoorvogel 2013). Exosomes, microvesicles, and apoptotic bodies are collectively called EVs. Exosomes differ from the other two types of EV in that they have different origins. Microvesicles, also called exfoliated vesicles or microparticles, are bilayer lipids derived directly from the plasma membrane and apoptotic bodies. Bilayer lipids are released when apoptotic cells are cleared (Barile and Vassalli 2017). Almost all animal cells can produce and secrete exosomes, including mast cells, lymphocytes, B lymphocytes, platelets, astrocytes, neurons, epithelial cells, dendritic cells, and liver cells (Yao et al.2018). However, in a laboratory pure exosomes cannot be isolated because it is difficult to separate exosomes from other types of EVs. Thus, in the literature exosomes and EVs are both used to describe these mixed vesicle populations (Colombo et al.2014).