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Diseases of the Nervous System
Published in George Feuer, Felix A. de la Iglesia, Molecular Biochemistry of Human Disease, 2020
George Feuer, Felix A. de la Iglesia
Many biochemical changes are found in children with Down’s disease. These abnormalities are quantitative rather than qualitative. In this disorder, the defective homeostasis is aggravated by the chromosomal anomaly. Serum proteins show some defects, which are age dependent to some extent. Essentially, total serum protein levels are normal, α- and γ- globulins are increased, and albumin is decreased. Abnormalities of protein transport across cell membranes can cause these changes. There are differences in peptide patterns from identical serum-globulin fractions between normal individuals and patients with Down’s disease. Serum calcium is reduced and urinary calcium excretion is low. However, serum phosphate levels are essentially normal, and there is defective transport of fat soluble vitamins. The reduced calcium level is in connection with defects of the skeletal and nervous system found in Down’s disease and may be associated with the deficiency in the absorption, transport, and utilization of vitamin D. Insufficient parathyroid activity may also be related to the altered calcium metabolism.
Macromolecular Absorption From The Digestive Tract In Young Vertebrates
Published in Károly Baintner, Intestinal Absorption of Macromolecules and Immune Transmission from Mother to Young, 2019
Selective protein transport is mediated by specific receptors and coated vesicles in various tissues,454,1191 while other mechanisms are responsible for the nonselective transport of macromolecules (see Chapter 6).
Dynamics of Lymph Formation and its Modification
Published in Waldemar L. Olszewski, Lymph Stasis: Pathophysiology, Diagnosis and Treatment, 2019
Thomas H. Adair, Jean-Pierre Montani
The tissue fluid in most tissues contains protein molecules, and these create an important osmotic force for fluid exchange. Two main modes of transcapillary protein transport are convection and diffusion. Convective transport is induced by a Starling force imbalance which causes protein molecules to be swept along with fluid that flows through pores in the capillary wall. Diffusive transport is driven by protein concentration gradients across the capillary wall, but is influenced by convective flows.
Modifying antibody-FcRn interactions to increase the transport of antibodies through the blood-brain barrier
Published in mAbs, 2023
Jason Tien, Dmitri Leonoudakis, Ralitsa Petrova, Vivian Trinh, Tetsuya Taura, Debapriya Sengupta, Lisa Jo, Angela Sho, Yong Yun, Eric Doan, Anita Jamin, Hussein Hallak, David S. Wilson, Jennifer R. Stratton
Protein transport across the BBB can occur via several different pathways broadly divided into paracellular and transcellular mechanisms.42 Since RMT is a transcellular process, we reasoned that it can only occur if an antibody protein is internalized by brain endothelial cells. We therefore established an antibody internalization assay based on previous work43 to investigate whether O4-YTE hIgG1 transport is accompanied by cellular internalization of the antibody. Since other groups have noted that FcRn-mediated transport is best studied in systems that overexpress both the FcRn heavy chain and β2-microglobulin (β2 M),44–46 we generated a stable HEK293 cell line expressing mouse FcRn and mouse β2 M. In this assay, antibodies were first incubated with cells for up to 4.25 h, after which unbound antibodies were washed off and the cells fixed. Extracellular antibodies were then blocked with unlabeled anti-human Fab, and the cells were washed and fixed again. Finally, cells were permeabilized and stained with anti-human IgG fluorescent conjugates to reveal only intracellularly stained antibodies (see methods for more details).
Effects of 4-phenylbutyric acid on the development of diabetic retinopathy in diabetic rats: regulation of endoplasmic reticulum stress-oxidative activation
Published in Archives of Physiology and Biochemistry, 2023
Amany Abdel-Ghaffar, Ghada G. Elhossary, Atef M. Mahmoud, Amany H. M. Elshazly, Olfat A. Hassanin, Anisa Saleh, Sahar M. Mansour, Fatma G. Metwally, Laila K. Hanafy, Sawsan H. Karam, Neveen Darweesh, Ahmed Mostafa Ata
The main ER stress defence strategy of the cell is up-regulation of the chaperone capacity. In cellular homeostasis, chaperones, as specialised proteins, play a key role. They assist in many cellular processes such as cellular signalling, assembly of the macromolecular complexes, protein folding, and protein transport (Ullman et al.2008). Chaperones’ main function in the ER is to protect against undesirable aggregation of nascent peptide chains while protein synthesis and to direct them towards folding, transport, or degradation pathways. In the unstressed cell, chaperones are expressed and maintained at steady levels but in the condition of stress, they are expressed in a perfectly regulated manner. Upon deregulation of chaperone activity, the misfolded aggregated or unfolded proteins are either targeted to accumulate in cells or to degradation pathways with the result of impairment in function and risk of generation of different pathogenesis (Engin and Hotamisligil 2010). Additionally, chaperones can act as signal transduction molecules by affecting protein-protein interactions, affecting the active and inactive state of signalling molecules in terms of transition, or altering the subcellular localisation. Moreover, they have a prominant role in histone-mediated chromatin remodelling and they are considered important for many cellular homeostasis aspects (Ransom et al.2010).
Recent trends in next generation immunoinformatics harnessed for universal coronavirus vaccine design
Published in Pathogens and Global Health, 2023
Chin Peng Lim, Boon Hui Kok, Hui Ting Lim, Candy Chuah, Badarulhisam Abdul Rahman, Abu Bakar Abdul Majeed, Michelle Wykes, Chiuan Herng Leow, Chiuan Yee Leow
The Allele Frequency Net Database (AFND) is an open resource storing the frequency data on the polymorphisms of immune-related genes such as human leukocyte antigen (HLA) system, killer-cell immunoglobulin-like receptors (KIR), MHC class I chain-related genes (MIC) and cytokine gene polymorphisms. AFND collects information and data from four main sources, which are, (i) peer-reviewed publications, (ii) analysed populations by International HLA and Immunogenetics Workshops (IHWSs), (iii) individual submissions and (iv) short publication reports (SPR) in Human Immunology Journal. The allele, gene, genotype or haplotype frequencies for the abovementioned loci can be searched in this database [92]. AutoPeptiDB is another database, composed of 103 high-resolution peptide-protein complexes. The binding affinity of short peptides and proteins is calculated based on the data arising from these complexes in this database. The peptide–protein interactions being considered, generally take place in cellular activities such as signal transduction, protein transport, antigen binding and enzyme-substrate inhibition. There are no two protein monomers that share more than 70% sequence identity in this dataset [93].