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1.
Breakpoint: Cell Wall and Glycoproteins and their Crucial Role in the Phytopathogenic Fungi Infection.
Plaza, V, Silva-Moreno, E, Castillo, L
Current protein & peptide science. 2020;(3):227-244
Abstract
The cell wall that surrounds fungal cells is essential for their survival, provides protection against physical and chemical stresses, and plays relevant roles during infection. In general, the fungal cell wall is composed of an outer layer of glycoprotein and an inner skeletal layer of β-glucans or α- glucans and chitin. Chitin synthase genes have been shown to be important for septum formation, cell division and virulence. In the same way, chitin can act as a potent elicitor to activate defense response in several plant species; however, the fungi can convert chitin to chitosan during plant infection to evade plant defense mechanisms. Moreover, α-1,3-Glucan, a non-degradable polysaccharide in plants, represents a key feature in fungal cell walls formed in plants and plays a protective role for this fungus against plant lytic enzymes. A similar case is with β-1,3- and β-1,6-glucan which are essential for infection, structure rigidity and pathogenicity during fungal infection. Cell wall glycoproteins are also vital to fungi. They have been associated with conidial separation, the increase of chitin in conidial cell walls, germination, appressorium formation, as well as osmotic and cell wall stress and virulence; however, the specific roles of glycoproteins in filamentous fungi remain unknown. Fungi that can respond to environmental stimuli distinguish these signals and relay them through intracellular signaling pathways to change the cell wall composition. They play a crucial role in appressorium formation and penetration, and release cell wall degrading enzymes, which determine the outcome of the interaction with the host. In this review, we highlight the interaction of phypatophogen cell wall and signaling pathways with its host and their contribution to fungal pathogenesis.
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2.
Digestion of human milk fat in healthy infants.
He, X, McClorry, S, Hernell, O, Lönnerdal, B, Slupsky, CM
Nutrition research (New York, N.Y.). 2020;:15-29
Abstract
Lipid digestion is critical for infant development, and yet, the interconnection between lipid digestion and the microbiota is largely understudied. This review focuses on digestion of the human milk fat globule and summarizes the current understanding of the mechanisms underlying this process in infants. We first discuss the partial hydrolysis of milk fat in the stomach, which leads to rearrangement of lipid droplets, creating a lipid-water interface necessary for duodenal lipolysis. In the first few months of life, secretion of pancreatic triglyceride lipase, phospholipase A2, and bile salts is immature. The dominant lipases aiding fat digestion in the newborn small intestine are therefore pancreatic lipase-related protein 2 and bile salt-stimulated lipase from both the exocrine pancreas and milk. We summarize the interaction between ionic fatty acids and cations to form insoluble fatty acid soaps and how it is influenced by various factors, including cation availability, pH, and bile salt concentration, as well as saturation and chain length of fatty acids. We further argue that the formation of the soap complex does not contribute to lipid bioavailability. Next, the possible roles that the gut microbiota plays in lipid digestion and absorption are discussed. Finally, we provide a perspective on how the manufacturing process of infant formula and dairy products may alter the physical properties and structure of lipid droplets, thereby altering the rate of lipolysis.
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3.
Role of Zinc in Zinc-α2-Glycoprotein Metabolism in Obesity: a Review of Literature.
Severo, JS, Morais, JBS, Beserra, JB, Dos Santos, LR, de Sousa Melo, SR, de Sousa, GS, de Matos Neto, EM, Henriques, GS, do Nascimento Marreiro, D
Biological trace element research. 2020;(1):81-88
Abstract
Excessive adipose tissue promotes the manifestation of endocrine disorders such as reduction of the secretion of zinc-α2-glycoprotein (ZAG), an adipokine with anti-inflammatory and lipid-mobilizing activity. The molecular structure of this adipokine includes binding sites for zinc, a trace element with important antioxidant and immunological proprieties that also participates in energy metabolism and stimulates the function of ZAG. The objective of this review is to highlight current data on the metabolism of ZAG in obesity and the role of zinc in this process. The identified studies show that subjects with obesity have low serum concentrations of zinc and ZAG, as well as low expression of the genes encoding this protein. Thus, zinc appears to be an important regulator of the homeostasis of ZAG in the body; however, alterations in the metabolism of zinc in obesity appear to compromise the functions of ZAG. Therefore, further studies are needed to clarify the relationship between zinc and ZAG metabolism and its repercussions in obesity.
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4.
Pulmonary manifestations in Niemann-Pick type C disease with mutations in NPC2 gene: case report and review of literature.
Sheth, J, Joseph, JJ, Shah, K, Muranjan, M, Mistri, M, Sheth, F
BMC medical genetics. 2017;(1):5
Abstract
BACKGROUND Niemann-Pick disease type C (NPC) is an inherited metabolic disorder; due to defect in cellular cholesterol trafficking. It is clinically a heterogeneous disease with variable age of onset with multiple organ systems being involved. NPC1 gene is involved in 95% cases where as remaining ~5% cases are linked with NPC2 gene. CASE PRESENTATION Case-1, a 14-months-old female presented with recurrent respiratory distress, failure to thrive and hepatosplenomegaly. Lung biopsy was suggestive of alveolar proteinosis and liver biopsy confirmed foamy macrophages. Molecular analysis revealed homozygous mutation c.141C > A in exon 2 of NPC2 gene. Case-2, a 3-year-old male presented with dyspnoea and hepatomegaly noticed at 1 year of age. HRCT-scan of thoracic region showed consolidation with mediastinal lymphadenopathy. Broncho-alveolar lavage revealed moderate amount of foamy macrophages and bone marrow examination detected foam cells. Homozygous T > C transition in intron 1 of the NPC2 gene was identified. CONCLUSION Our study demonstrates that NPC2 can present in early years of life with pulmonary complications like alveolar proteinosis and hepatosplenomegaly or hepatomegaly due to mutation in NPC2 gene. An early suspicion will help clinicians to clinch its diagnosis, management and genetic counselling.
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5.
Protein glycosylation in viral hepatitis-related HCC: Characterization of heterogeneity, biological roles, and clinical implications.
Zhang, S, Cao, X, Gao, Q, Liu, Y
Cancer letters. 2017;:64-70
Abstract
Protein glycosylation is one of the most frequent and well-known posttranslational modifications, playing important roles in physiopathological processes. Glycosylation is catalyzed by enzymatic additions of heterogeneous glycans with specific linkage of monosaccharides and, in a preformed fashion, to specific amino acids within glycoproteins. Altered glycan macroheterogeneity and microheterogeneity have been reported in glycoproteins produced mainly by the liver, facilitating tumorigenesis, progression, and metastasis. Characterizing the heterogeneity and biological functions of glycans in liver diseases would lead to a better understanding of the molecular pathogenesis of liver damage and cancer, providing novel diagnostic, prognostic, and therapeutic clues. Technical advances in glycoproteomics and glycomics have allowed a more comprehensive and deeper understanding of disease-related glycosylation events. Here, we briefly review the structural diversity of glycans in viral hepatitis -related hepatocellular carcinoma, discuss their roles in regulating the initiation and development of liver cancer, and introduce potential clinical applications.
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6.
Diagnostic tests for Niemann-Pick disease type C (NP-C): A critical review.
Vanier, MT, Gissen, P, Bauer, P, Coll, MJ, Burlina, A, Hendriksz, CJ, Latour, P, Goizet, C, Welford, RW, Marquardt, T, et al
Molecular genetics and metabolism. 2016;(4):244-54
Abstract
Niemann-Pick disease type C (NP-C) is a neurovisceral lysosomal cholesterol trafficking and lipid storage disorder caused by mutations in one of the two genes, NPC1 or NPC2. Diagnosis has often been a difficult task, due to the wide range in age of onset of NP-C and clinical presentation of the disease, combined with the complexity of the cell biology (filipin) laboratory testing, even in combination with genetic testing. This has led to substantial delays in diagnosis, largely depending on the access to specialist centres and the level of knowledge about NP-C of the physician in the area. In recent years, advances in mass spectrometry has allowed identification of several sensitive plasma biomarkers elevated in NP-C (e.g. cholestane-3β,5α,6β-triol, lysosphingomyelin isoforms and bile acid metabolites), which, together with the concomitant progress in molecular genetic technology, have greatly impacted the strategy of laboratory testing. Specificity of the biomarkers is currently under investigation and other pathologies are being found to also result in elevations. Molecular genetic testing also has its limitations, notably with unidentified mutations and the classification of new variants. This review is intended to increase awareness on the currently available approaches to laboratory diagnosis of NP-C, to provide an up to date, comprehensive and critical evaluation of the various techniques (cell biology, biochemical biomarkers and molecular genetics), and to briefly discuss ongoing/future developments. The use of current tests in proper combination enables a rapid and correct diagnosis in a large majority of cases. However, even with recent progress, definitive diagnosis remains challenging in some patients, for whom combined genetic/biochemical/cytochemical markers do not provide a clear answer. Expertise and reference laboratories thus remain essential, and further work is still required to fulfill unmet needs.
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7.
The plant secretory pathway for the trafficking of cell wall polysaccharides and glycoproteins.
Kim, SJ, Brandizzi, F
Glycobiology. 2016;(9):940-949
Abstract
Plant endomembranes are required for the biosynthesis and secretion of complex cell wall matrix polysaccharides, glycoproteins and proteoglycans. To define the biochemical roadmap that guides the synthesis and deposition of these cell wall components it is first necessary to outline the localization of the biosynthetic and modifying enzymes involved, as well as the distribution of the intermediate and final constituents of the cell wall. Thus far, a comprehensive understanding of cell wall matrix components has been hampered by the multiplicity of trafficking routes in the secretory pathway, and the diverse biosynthetic roles of the endomembrane organelles, which may exhibit tissue and development specific features. However, the recent identification of protein complexes producing matrix polysaccharides, and those supporting the synthesis and distribution of a grass-specific hemicellulose are advancing our understanding of the functional contribution of the plant secretory pathway in cell wall biosynthesis. In this review, we provide an overview of the plant membrane trafficking routes and report on recent exciting accomplishments in the understanding of the mechanisms underlying secretion with focus on cell wall synthesis in plants.
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8.
An update on cell surface proteins containing extensin-motifs.
Borassi, C, Sede, AR, Mecchia, MA, Salgado Salter, JD, Marzol, E, Muschietti, JP, Estevez, JM
Journal of experimental botany. 2016;(2):477-87
Abstract
In recent years it has become clear that there are several molecular links that interconnect the plant cell surface continuum, which is highly important in many biological processes such as plant growth, development, and interaction with the environment. The plant cell surface continuum can be defined as the space that contains and interlinks the cell wall, plasma membrane and cytoskeleton compartments. In this review, we provide an updated view of cell surface proteins that include modular domains with an extensin (EXT)-motif followed by a cytoplasmic kinase-like domain, known as PERKs (for proline-rich extensin-like receptor kinases); with an EXT-motif and an actin binding domain, known as formins; and with extracellular hybrid-EXTs. We focus our attention on the EXT-motifs with the short sequence Ser-Pro(3-5), which is found in several different protein contexts within the same extracellular space, highlighting a putative conserved structural and functional role. A closer understanding of the dynamic regulation of plant cell surface continuum and its relationship with the downstream signalling cascade is a crucial forthcoming challenge.
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9.
What's new in hepatitis C virus infections in children?
Pawlowska, M, Domagalski, K, Pniewska, A, Smok, B, Halota, W, Tretyn, A
World journal of gastroenterology. 2015;(38):10783-9
Abstract
The number of hepatitis C virus (HCV) infection cases is relatively low in children. This low number may be connected with the lack of screening tests and the asymptomatic course of infection. Currently, mother-to-infant transmission is the most common cause of HCV infection amongst children in developed countries. It is important to introduce routine screening tests for HCV in pregnant women. The risk of vertical transmission of HCV is estimated at approximately 5% (3%-10%). Currently, we do not have HCV transmission prevention methods. Some factors could potentially be eliminated by elective caesarean section. Currently, the method of prevention of perinatal HCV infection is the early identification and effective treatment of infections in young women in the preconception period. We describe genetic tests (IL-28B single nucleotide polymorphisms) to identify children with an increased chance of spontaneous clearance or sustained virologic response achievement and vitamin D level as a potential predictor of treatment response in children. It is also important to develop non-invasive tests that can predict liver fibrosis. The existence of differences in the mechanisms leading to liver injury between children and adults creates new perspectives of action to reduce liver disease progression in children in the early years of life.
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10.
Does intraoperative ulinastatin improve postoperative clinical outcomes in patients undergoing cardiac surgery: a meta-analysis of randomized controlled trials.
He, QL, Zhong, F, Ye, F, Wei, M, Liu, WF, Li, MN, Li, QB, Huang, WQ, Sun, LB, Shu, HH
BioMed research international. 2014;:630835
Abstract
INTRODUCTION The systematic meta-analysis of randomized controlled trials (RCTs) evaluated the effects of intraoperative ulinastatin on early-postoperative recovery in patients undergoing cardiac surgery. METHODS RCTs comparing intraoperative ulinastatin with placebo in cardiac surgery were searched through PubMed, Cochrane databases, Medline, SinoMed, and the China National Knowledge Infrastructure (1966 to May 20th, 2013). The primary endpoints included hospital mortality, postoperative complication rate, length of stay in intensive care unit, and extubation time. The physiological and biochemical parameters illustrating postoperative cardiac and pulmonary function as well as inflammation response were considered as secondary endpoints. RESULTS Fifteen RCTs (509 patients) met the inclusion criteria. Ulinastatin did not affect hospital mortality, postoperative complication rate, or ICU length of stay but reduced extubation time. Ulinastatin also increased the oxygenation index on postoperative day 1 and reduced the plasma level of cardiac troponin-I. Additionally, ulinastatin inhibited the increased level of tumor necrosis factor-alpha, polymorphonuclear neutrophil elastase, interleukin-6, and interleukin-8 associated with cardiac surgery. CONCLUSION Ulinastatin may be of value for the inhibition of postoperative increased inflammatory agents and most likely provided pulmonary protective effects in cardiac surgery. However, larger adequately powered RCTs are required to define the clinical effect of ulinastatin on postoperative outcomes in cardiac surgery.