scholarly journals Evolving immunity: Xenophagy and the removal of intracellular pathogens

2012 ◽  
Vol 34 (2) ◽  
pp. 20-23
Author(s):  
Zhigang Zhou ◽  
Eleanor Cottam ◽  
Matthew Whelband ◽  
Laura Vaux ◽  
Tom Wileman
Keyword(s):  
Amino Acids ◽  
Innate Immunity ◽  
Membrane Trafficking ◽  
Early Stage ◽  
Intracellular Pathogens ◽  
Short Term ◽  
Free Living ◽  
Changing Environments ◽  
Trafficking Pathway ◽  
Powerful Mechanism

Early eukaryotes, such as free-living protozoa and yeasts, had to adapt to rapidly changing environments and an uncertain food supply. Lack of food imposed serious stress on these cells and it is thought that this drove the evolution of a membrane trafficking pathway called autophagy. Autophagy allows cells to deliver cytosolic proteins and organelles to lysosomes for degradation and provides a short-term supply of amino acids. Autophagy allowed early eukaryotes to generate the amino acids they needed to move and search for food and provided an advantage over sedentary cells that generated spores during famine. The capacity to degrade large quantities of cytoplasm also provided these early cells with a powerful mechanism to degrade intracellular pathogens. When autophagy engulfs pathogens the pathway is called ‘xenophagy’ because delivery to lysosomes leads to the removal of foreign organisms1. Xenophagy therefore represents a very early stage in the evolution of innate immunity.

Manipulation of the host by pathogens to survive the lysosome

2010 ◽  
Vol 38 (6) ◽  
pp. 1417-1419 ◽  
Author(s):  
Paul R. Pryor ◽  
Sally A. Raines
Keyword(s):  
Innate Immunity ◽  
Membrane Trafficking ◽  
Molecular Mechanisms ◽  
Regulatory Elements ◽  
Effector Proteins ◽  
Intracellular Pathogens ◽  
Intracellular Environment ◽  
Pathogen Effector ◽  
Form Part ◽  
Survival Mechanisms

Lysosomes form part of our innate immunity and are an important line of defence against microbes, viruses and parasites. Although it is more than 50 years since de Duve discovered lysosomes, it is only in more recent years that we are slowly unravelling the molecular mechanisms involved in the delivery of material to the lysosome. However, successful intracellular pathogens often have a better grip on the mechanisms involved in delivery to the lysosome and can manipulate membrane trafficking pathways to create an intracellular environment that is favourable for replication. By studying pathogen effector proteins that are secreted into the host's cytosol, we can learn about both pathogen-survival mechanisms and further regulatory elements involved in trafficking to the lysosome.

scholarly journals Effect of short-term fasting and glucocorticoids on KLF15 expression and branched-chain amino acids metabolism in Chinese perch

2021 ◽  
Vol 19 ◽  
pp. 100617
Author(s):  
Xin Zhu ◽  
Jiangli Hu ◽  
Jianshe Zhang ◽  
Jingjie Liu ◽  
Lingsheng Bao ◽  
...  
Keyword(s):  
Amino Acids ◽  
Branched Chain Amino Acids ◽  
Short Term ◽  
Chinese Perch ◽  
Branched Chain

scholarly journals Early Confirmation of Mycoplasma pneumoniae Infection by Two Short-Term Serologic IgM Examination

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 353
Author(s):  
Ha Eun Jeon ◽  
Hyun Mi Kang ◽  
Eun Ae Yang ◽  
Hye Young Han ◽  
Seung Beom Han ◽  
...  
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Early Stage ◽  
Immunoglobulin M ◽  
Enzyme Linked Immunosorbent Assay ◽  
Short Term ◽  
Serologic Tests ◽  
Polymerase Chain ◽  
Positive Correlations ◽  
Patient Selection Bias ◽  
Mycoplasma Pneumoniae Infection

The aim of the present study is to re-evaluate the clinical application of two-times serologic immunoglobulin M (IgM) tests using microparticle agglutination assay (MAA), an enzyme-linked immunosorbent assay (ELISA), and polymerase chain reaction (PCR) assay in diagnosing Mycoplasma pneumoniae (MP) infection. A retrospective analysis of 62 children with MP pneumonia during a recent epidemic (2019–2020) was conducted. The MAA and ELISA immunoglobulin M (IgM) and IgG measurements were conducted twice at admission and around discharge, and MP PCR once at presentation. Diagnostic rates in each test were calculated at presentation and at discharge. The seroconverters were 39% (24/62) of patients tested by MAA and 29% (18/62) by ELISA. At presentation, the diagnostic positive rates of MAA, ELISA, and PCR tests were 61%, 71%, and 52%, respectively. After the second examination, the rates were 100% in both serologic tests. There were positive correlations between the titers of MAA and the IgM values of ELISA. The single serologic IgM or PCR tests had limitations to select patients infected with MP in the early stage. The short-term, paired IgM serologic tests during hospitalization can reduce patient-selection bias in MP infection studies.

Effect of Intraduodenal Starch Infusion on Net Portal Absorption of Amino Acids in Growing steers Fed Lucerne

1994 ◽  
Vol 1994 ◽  
pp. 28-28
Author(s):  
C.J. Seal ◽  
D.S. Parker ◽  
J.C. MacRae ◽  
G.E. Lobley
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Gastrointestinal Tract ◽  
Protein Turnover ◽  
Portal Blood ◽  
Intestinal Lumen ◽  
Short Term ◽  
Net Uptake ◽  
Amino Acid Requirements ◽  
Glucose Availability

Amino acid requirements for energy metabolism and protein turnover within the gastrointestinal tract are substantial and may be met from luminal and arterial pools of amino acids. Several studies have demonstrated that the quantity of amino acids appearing in the portal blood does not balance apparent disappearance from the intestinal lumen and that changing diet or the availability of energy-yielding substrates to the gut tissues may influence the uptake of amino acids into the portal blood (Seal & Reynolds, 1993). For example, increased net absorption of amino acids was observed in animals receiving exogenous intraruminal propionate (Seal & Parker, 1991) and this was accompanied by changes in glucose utilisation by the gut tissues. In contrast, there was no apparent change in net uptake of [l-13C]-leucine into the portal vein of sheep receiving short term intraduodenal infusions of glucose (Piccioli Cappelli et al, 1993). This experiment was designed to further investigate the effects on amino acid absorption of changing glucose availability to the gut with short term (seven hours) or prolonged (three days) exposure to starch infused directly into the duodenum.

Influence of short-term atmospheric CO2 enrichment on growth, allocation patterns, and biochemistry of black spruce seedlings at different stages of development

1989 ◽  
Vol 19 (6) ◽  
pp. 773-782 ◽  
Author(s):  
Michel A. Campagna ◽  
Hank A. Margolis
Keyword(s):  
Amino Acids ◽  
Free Amino Acids ◽  
Free Amino ◽  
Black Spruce ◽  
Production Cycle ◽  
Nonstructural Carbohydrates ◽  
Short Term ◽  
Stages Of Development ◽  
Greenhouse Production ◽  
Total Nonstructural Carbohydrates

Black spruce seedlings (Piceamariana Mill.) were exposed to either elevated (1000 ppm) or ambient (340 ppm) atmospheric CO2 levels at different stages of seedling development over a winter greenhouse production cycle. Seedlings germinated in early February and were placed in CO2 chambers for either 3 or 6 weeks during March, April, May, or August. Total seedling biomass increased under high CO2 conditions for the March, April, and May stages of development, but showed no significant response in August. The greater part of the CO2 response occurred during the second 3 weeks of exposure in March and April but during the first 3 weeks of exposure in May. In September, those seedlings exposed to CO2 in April and May had 30 and 14%, respectively, greater biomass than control seedlings, but seedlings from the other stages of development no longer had significant differences remaining from the CO2 treatment. This suggests that it could be very efficient to give a short well-timed CO2 pulse at the beginning of the production cycle in hopes of producing a size difference that is maintained throughout the remainder of the greenhouse production cycle under ambient levels of CO2. Short-term exposure to elevated CO2 also increased the ratio of shoot dry weight to total height for the March, April, and May stages of development. The ratio of total nonstructural carbohydrates to free amino acids was negatively correlated (r2 = 0.98) with the allocation of new growth between shoots and roots as measured by the allocation coefficient, k (milligrams shoot growth per milligrams root growth). As seedlings developed along their seasonal growth cycle, ratios of total nonstructural carbohydrates to free amino acids increased and the values for k decreased. The effect of CO2 enrichment on these two factors is discussed. Monitoring total nonstructural carbohydrate and free amino acid concentrations in foliage could have potential as a method to predict the percentage of carbon allocated to root systems of entire forest stands as well as of individual tree seedlings.

In situ studies on alginic acid synthesis and other aspects of the metabolism of Laminaria digitata

1972 ◽  
Vol 50 (1) ◽  
pp. 177-184 ◽  
Author(s):  
Johan A. Hellebust ◽  
Arne Haug
Keyword(s):  
Amino Acids ◽  
Time Course ◽  
Alginic Acid ◽  
Acid Synthesis ◽  
Short Term ◽  
Fresh Weight Basis ◽  
Mannuronic Acid ◽  
Guluronic Acid ◽  
Rate Of Photosynthesis

Amino acids, particularly alanine and aspartate, become more strongly labeled than mannitol in short-term 14C-photoassimilation experiments. The amino acids are the most likely sources of carbon for alginic acid synthesis and respiration in the dark, in contrast to mannitol, which appears to be relatively unavailable. Temperature is very important in determining the rate of loss of recent photoassimilate in L. digitata. The rate of photosynthesis, on a fresh weight basis, is much higher for blades than for stipes.The time course for incorporation of photoassimilated carbon into alginate differs for the stipe and blade both in light and dark periods. Very little 14C enters alginate in blades in the dark, while alginate in stipes acquires considerable amounts of activity during dark periods. Alginate in both blade and stipe acquires 14C predominantly in mannuronic acid residues of their alginate during short-term photoassimilation periods, while guluronic acid residues become relatively more rapidly labeled during dark periods.

scholarly journals Short-Term High Fat Intake Does Not Significantly Alter Markers of Renal Function or Inflammation in Young Male Sprague-Dawley Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Catherine Crinigan ◽  
Matthew Calhoun ◽  
Karen L. Sweazea
Keyword(s):  
Kidney Disease ◽  
Renal Mass ◽  
Early Stage ◽  
Young Male ◽  
Protective Effects ◽  
Sprague Dawley ◽  
High Fat ◽  
Short Term ◽  
Sprague Dawley Rats ◽  
The Impact

Chronic high fat feeding is correlated with diabetes and kidney disease. However, the impact of short-term high fat diets (HFD) is not well-understood. Six weeks of HFD result in indices of metabolic syndrome (increased adiposity, hyperglycemia, hyperinsulinemia, hyperlipidemia, hyperleptinemia, and impaired endothelium-dependent vasodilation) compared to rats fed on standard chow. The hypothesis was that short-term HFD would induce early signs of renal disease. Young male Sprague-Dawley rats were fed either HFD (60% fat) or standard chow (5% fat) for six weeks. Morphology was determined by measuring changes in renal mass and microstructure. Kidney function was measured by analyzing urinary protein, creatinine, and hydrogen peroxide (H2O2) concentrations, as well as plasma cystatin C concentrations. Renal damage was measured through assessment of urinary oxDNA/RNA concentrations as well as renal lipid peroxidation, tumor necrosis factor alpha (TNFα), and interleukin 6 (IL-6). Despite HFD significantly increasing adiposity and renal mass, there was no evidence of early stage kidney disease as measured by changes in urinary and plasma biomarkers as well as histology. These findings suggest that moderate hyperglycemia and inflammation produced by short-term HFD are not sufficient to damage kidneys or that the ketogenic HFD may have protective effects within the kidneys.

Difficulties in diagnosing atypical variants of Alzheimer’s disease

2021 ◽  
Vol 26 (5) ◽  
pp. 16-23
Author(s):  
A. A. Tappakhov ◽  
T. Ya. Nikolaeva ◽  
T. E. Popova ◽  
N. A. Shnayder
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Clinical Picture ◽  
Short Term Memory ◽  
Late Onset ◽  
Early Stage ◽  
Primary Progressive Aphasia ◽  
Cortical Atrophy ◽  
Posterior Cortical Atrophy ◽  
Short Term

Alzheimer’s disease (AD) is the most common cause of dementia in the population. Late onset AD has a classic clinical picture with short-term memory deficit, apraxia and agnosia. Patients with early-onset AD may have an atypical clinical picture which complicates diagnosis. Atypical AD variants include the logopenic variant of primary progressive aphasia, posterior cortical atrophy, behavioral, biparietal, and cortico-basal variants. These variants have pathomorphological signs similar to classical AD, but at an early stage they are characterized by focal atrophy which explains their clinical polymorphism. This article provides a review of the current literature on atypical types of AD and presents a clinical case of a 62-year-old patient in whom the disease debuted with prosopagnosia due to focal atrophy of the temporo-occipital regions of the non-dominant hemisphere.

Syzygium cumini seed extract ameliorates adenosine deaminase activity and biochemical parameters but does not alter insulin sensitivity and pancreas architecture in a short-term model of diabetes

2015 ◽  
Vol 12 (3) ◽  
Author(s):  
Paula Eliete Rodrigues Bitencourt ◽  
Karine Santos De Bona ◽  
Lariane Oliveira Cargnelutti ◽  
Gabriela Bonfanti ◽  
Aline Pigatto ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Early Stage ◽  
Liver Glycogen ◽  
Protective Role ◽  
Seed Extract ◽  
Diabetic Group ◽  
Short Term ◽  
Short Term Treatment ◽  
Term Model ◽  
Adenosine Deaminase Activity

Abstract: The effects of the aqueous seed extract of: ASc (100 mg/kg) was administered for 21 days in control and streptozotocin (STZ)-induced (60 mg/kg) diabetic rats. ADA activity, lipoperoxidation (cerebral cortex, kidney, liver and pancreas) and biochemical (serum) and histopathological (pancreas) parameters were evaluated.: The main findings in this short-term model of Diabetes mellitus (DM) were that the ASc (i) significantly reverted the increase of ADA activity in serum and kidney; (ii) ameliorated the lipoperoxidation in the cerebral cortex and pancreas of the diabetic group; (iii) demonstrated hypolipidemic and hypoglycemic properties and recovered the liver glycogen; and iv) prevented the HOMA-IR index increase in the diabetic group. Therefore, the ASc can be a positive factor for increasing the availability of substrates with significant protective actions, such as adenosine. Moreover, by maintaining glycogen and HOMA-IR levels, the extract could modulate the hyperglycemic state through the direct peripheral glucose uptake.: Our data revealed that the short-term treatment with ASc has an important protective role under pathophysiological conditions caused by the early stage of DM. These results enhance our understanding of the effect of the ASc on the purinergic system in DM.

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