China
Africa
Explore chapters and articles related to this topic
Anti-Inflammatory Compounds Derived from Marine Macroalgae
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Snezana Agatonovic-Kustrin, David W. Morton
Galacto-glycerolipids are widely found in plants and photosynthetic bacteria. They are a class of compounds, in which galactose is bound at the glycerol sn-3 position in O-glycosidic linkage to diacylglycerol. While phosphoglycerolipids make the primary building blocks of eukaryotic and prokaryotic cell membranes, non-phosphorous galactoglycerolipids are the main building blocks of plant cells (Benning and Ohta 2005). Galacto-glycerolipids are an important part of plant cell membranes where they constitute the bulk of the polar lipids in photosynthetic membranes. Moreover, galactolipids are the most widespread group of non-phosphorous lipids, being the major constituents of the photosynthetic membranes of higher plants, algae, and bacteria (Dörmann and Benning 2002). They account for 80% of the membrane lipids found in green plant tissues. In contrast, to membranes of animals and yeasts, where phospholipids are the main lipid group, galactolipids are major constituents of the photosynthetic membranes of higher plants, algae and bacteria (Dörmann and Benning 2002). Lipids in plants consists mainly of monogalactosyldiacylglycerols and digalactosyldiacylglycerols (MGDG and DGDG) containing one or two saturated or unsaturated fatty acids linked to the glycerol part of the molecule (Figure 9.2). As in higher plants, the proportions of MGDG are higher in the lipids from marine algae exposed to white light (Radwan et al. 1988).
DTI of Developmental and Pediatric Disorders
Published in Andrei I. Holodny, Functional Neuroimaging, 2019
Michael J. J. Kim, James M. Provenzale
Globoid cell leukodystrophy, also known as Krabbe disease, is an autosomal recessive white matter disorder caused by the deficiency of β-galactocerebrosidase (26). In the normal brain, galactolipids that are toxic to brain tissue are formed during white matter myelination but are quickly hydrolyzed by the enzyme β-galactocerebrosidase. However, in Krabbe disease, diminished levels of this enzyme allow galactolipids to accumulate and myelin-forming oligodendroglia are destroyed. In early-onset Krabbe disease, this leads to the failure of normal myelin production in infants and subsequent development of severe neurological deficits (27). These children typically deteriorate neurologically until they reach a vegetative state and ultimately die within two to four years. Hematopoietic stem cell transplantation has been suggested as a treatment for asymptomatic infantile Krabbe disease (28). There are currently no proven therapeutic options for symptomatic patients with the infantile form of Krabbe disease. Therefore, early diagnosis of the disease is critical for any treatment to be effective.
Carbohydrate and glycosylation disorders
Published in Steve Hannigan, Inherited Metabolic Diseases: A Guide to 100 Conditions, 2018
Treatment of severe GALE deiciency involves management with a low-galactose diet. In contrast to GALT deiciency, a small amount of galactose is usually administered in order to allow production of galactoproteins and galactolipids.
Genetic diseases mimicking multiple sclerosis
Published in Postgraduate Medicine, 2021
Chueh Lin Hsu, Piotr Iwanowski, Chueh Hsuan Hsu, Wojciech Kozubski
Krabbe disease, also known as globoid cell leukodystrophy, is a rare autosomal recessive leukodystrophy caused by deficient galactosylceramidase (GALCase) activity as a result of mutations in the GALC gene. The resulting unmetabolized galactolipids build up and are directly toxic to oligodendrocytes and Schwann cells, which manifests as progressive neurodegenerative symptoms including loss of vision, hearing, seizures, and premature death [73]. The newborn initial screening test of GALC enzyme activity is usually conducted to detect Krabbe disease. However, low levels of GALC enzyme activity cannot indicate the clinical type and the course of the disease. The genetic testing of Krabbe disease should be taken to confirm the diagnosis [73]. The four clinical types are classified by the age of onset [74], of which adult- onset Krabbe disease (AOKD) is of particular interest in this discussion due to its similar clinical pictures to MS [75].
Exome sequencing of a Pakistani family with spastic paraplegia identified an 18 bp deletion in the cytochrome B5 domain of FA2H
Published in Neurological Research, 2021
Safdar Abbas, Beatrice Brugger, Muhammad Zubair, Sana Gul, Jasmin Blatterer, Julian Wenninger, Khurram Rehman, Benjamin Tatrai, Muzammil Ahmad Khan, Christian Windpassinger
Myelination is the process in which myelin proteins and lipids are conjugated by myelinating glial cells. The enzyme that catalyzes 2-hydroxylation of myelin galactolipids, galactosyl-ceramide is encoded by FA2H. Sphingolipids involved in several cellular processes and modification in the hydrophobic ceramide moiety leads to structural diversity. Cellular studies have revealed that mutations in this gene result in defective enzymes that cannot catalyze the synthesis of fatty acids of myelin galactolipids. Myelin is a lipid-enriched component of neuronal cell membranes, which is produced by the oligodendrocytes and Schwann cells. It is predominantly rich in glycosphingolipids, termed as galactocerebrosides. Most of these sphingolipids contain α-hydroxylated fatty acids that may enhance the stability of the myelin sheath [27]. Myelin sheaths provide protection for the axons of nervous system and are responsible for the conduction of proper nerve transmission. Damage to myelin sheaths may lead to defects in the neuronal communication system and several other related disorders like multiple sclerosis and leukodystrophies [25, 28].
A blend containing docosahexaenoic acid, arachidonic acid, vitamin B12, vitamin B9, iron and sphingomyelin promotes myelination in an in vitro model
Published in Nutritional Neuroscience, 2020
Jonas Hauser, Sébastien Sultan, Andreas Rytz, Pascal Steiner, Nora Schneider
Oligodendrocyte precursor cells (OPCs) migrate from within the cortex and will generate the adult population of OLs [8]. Post mitotic OPCs differentiate into myelinating OLs that extend numerous processes to establish contacts with axons from different neurons to initiate myelination. During their maturation, OLs produce the different constituents of myelin sheath such as lipids (cholesterol, galactolipids and phospholipids) and myelin specific proteins [9]. The type of myelin proteins expressed by OLs, such as myelin-associated glycoprotein (MAG) and myelin binding protein (MBP) correlate to their phase of maturation [10]. Myelinating OLs express MAG and its expression increases gradually during OLs maturation. While it represents only a small proportion of the total myelin protein content, MAG, a sialic-acid binding immunoglobulin-like lectins, is expressed mainly in the periaxonal regions of the myelin sheath. It seems to play an important role in oligodendrocyte-axon interaction and mediates bidirectional signalling between axons and OLs to support the formation of the myelin sheath [10,11]. MBP is strongly expressed in mature myelinating OLs and is one of the major components of myelin. MBP seems to have an active role in myelin formation and compaction. Indeed, MBP is polymerizing and forms a cohesive mesh-like protein network essential for saltatory current [10,12,13].