Complement Activation by Human Lymphocytes from Different Lymphoid Organs: Role of Sialic Acid and Lack of Relationship to Electrical Surface Charge

Complement ◽  
1987 ◽  
Vol 4 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Carmen Gutierrez ◽  
Maria J. Martin ◽  
K.A. Brown
Keyword(s):  
Sialic Acid ◽  
Surface Charge ◽  
Complement Activation ◽  
Human Lymphocytes ◽  
Lymphoid Organs

scholarly journals Role of sialic acid in erythrocyte survival

Blood ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 11-20 ◽  
Author(s):  
JR Durocher ◽  
RC Payne ◽  
ME Conrad
Keyword(s):  
Sialic Acid ◽  
Surface Charge ◽  
Electrophoretic Mobility ◽  
Polyacrylamide Gels ◽  
Membrane Glycoproteins ◽  
Atp Levels ◽  
Erythrocyte Survival ◽  
Pas Staining ◽  
Rapid Clearance

The role of membrane sialic acid in erythrocyte survival is unclear, although there is evidence for a reduction in sialic acid and surface charge in older erythrocytes. We reduced the surface charge of human, rat, and rabbit erythrocytes by removing sialic acid with neuraminidase.Reduction in sialic acid correlated with decreases in electrophoretic mobility and loss of PAS staining of membrane glycoproteins on polyacrylamide gels. No changes in ATP levels or deformability were found. 51Cr erythrocyte survivals in rats and rabbits showed rapid clearance of desialylated erythrocytes with sequestration by the liver.These results suggest that reduction in erythrocyte sialic acid is a mechanism of erythrocyte destruction and may be important in erythrocyte senescence.

scholarly journals Role of sialic acid in erythrocyte survival

Blood ◽  
1975 ◽  
Vol 45 (1) ◽  
pp. 11-20 ◽  
Author(s):  
JR Durocher ◽  
RC Payne ◽  
ME Conrad
Keyword(s):  
Sialic Acid ◽  
Surface Charge ◽  
Electrophoretic Mobility ◽  
Polyacrylamide Gels ◽  
Membrane Glycoproteins ◽  
Atp Levels ◽  
Erythrocyte Survival ◽  
Pas Staining ◽  
Rapid Clearance

Abstract The role of membrane sialic acid in erythrocyte survival is unclear, although there is evidence for a reduction in sialic acid and surface charge in older erythrocytes. We reduced the surface charge of human, rat, and rabbit erythrocytes by removing sialic acid with neuraminidase.Reduction in sialic acid correlated with decreases in electrophoretic mobility and loss of PAS staining of membrane glycoproteins on polyacrylamide gels. No changes in ATP levels or deformability were found. 51Cr erythrocyte survivals in rats and rabbits showed rapid clearance of desialylated erythrocytes with sequestration by the liver.These results suggest that reduction in erythrocyte sialic acid is a mechanism of erythrocyte destruction and may be important in erythrocyte senescence.

scholarly journals Sialic Acid—Modified Nanoparticles—New Approaches in the Glioma Management—Perspective Review

2021 ◽  
Vol 22 (14) ◽  
pp. 7494
Author(s):  
Przemyslaw Wielgat ◽  
Katarzyna Niemirowicz-Laskowska ◽  
Agnieszka Z. Wilczewska ◽  
Halina Car
Keyword(s):  
Sialic Acid ◽  
Clinical Observation ◽  
Malignant Cell ◽  
Cellular Heterogeneity ◽  
Molecular Processes ◽  
Management Perspective ◽  
Therapeutic Tools ◽  
And Function ◽  
Worse Prognosis

The cell surface is covered by a dense and complex network of glycans attached to the membrane proteins and lipids. In gliomas, the aberrant sialylation, as the final stage of glycosylation, is an important regulatory mechanism of malignant cell behavior and correlates with worse prognosis. Better understanding of the role of sialylation in cellular and molecular processes opens a new way in the development of therapeutic tools for human brain tumors. According to the recent clinical observation, the cellular heterogeneity, activity of brain cancer stem cells (BCSCs), immune evasion, and function of the blood–brain barrier (BBB) are attractive targets for new therapeutic strategies. In this review, we summarize the importance of sialic acid-modified nanoparticles in brain tumor progression.

scholarly journals The role of sialic acid in the expression of human MN blood group antigens.

1979 ◽  
Vol 254 (6) ◽  
pp. 2112-2119 ◽  
Author(s):  
J.E. Sadler ◽  
J.C. Paulson ◽  
R.L. Hill
Keyword(s):  
Sialic Acid ◽  
Blood Group ◽  
Blood Group Antigens ◽  
Mn Blood Group

scholarly journals TP53-Induced Glycolysis and Apoptosis Regulator (TIGAR) Is Upregulated in Lymphocytes Stimulated with Concanavalin A

2021 ◽  
Vol 22 (14) ◽  
pp. 7436
Author(s):  
Helga Simon-Molas ◽  
Xavier Vallvé-Martínez ◽  
Irene Caldera-Quevedo ◽  
Pere Fontova ◽  
Claudia Arnedo-Pac ◽  
...  
Keyword(s):  
Concanavalin A ◽  
Carbon Flux ◽  
Human Lymphocytes ◽  
Tumor Development ◽  
Pentose Phosphate ◽  
Akt Signaling Pathway ◽  
G6pdh Activity ◽  
Physiological Conditions ◽  
Glucose 6 Phosphate Dehydrogenase

The glycolytic modulator TP53-Inducible Glycolysis and Apoptosis Regulator (TIGAR) is overexpressed in several types of cancer and has a role in metabolic rewiring during tumor development. However, little is known about the role of this enzyme in proliferative tissues under physiological conditions. In the current work, we analysed the role of TIGAR in primary human lymphocytes stimulated with the mitotic agent Concanavalin A (ConA). We found that TIGAR expression was induced in stimulated lymphocytes through the PI3K/AKT pathway, since Akti-1/2 and LY294002 inhibitors prevented the upregulation of TIGAR in response to ConA. In addition, suppression of TIGAR expression by siRNA decreased the levels of the proliferative marker PCNA and increased cellular ROS levels. In this model, TIGAR was found to support the activity of glucose 6-phosphate dehydrogenase (G6PDH), the first enzyme of the pentose phosphate pathway (PPP), since the inhibition of TIGAR reduced G6PDH activity and increased autophagy. In conclusion, we demonstrate here that TIGAR is upregulated in stimulated human lymphocytes through the PI3K/AKT signaling pathway, which contributes to the redirection of the carbon flux to the PPP.

scholarly journals Protein Synthesis in Human Leukocytes and Lymphocytes: 1. Effect of Steroids and Sterols

Blood ◽  
1969 ◽  
Vol 34 (3) ◽  
pp. 348-356 ◽  
Author(s):  
SEYMOUR WERTHAMER ◽  
CARL HICKS ◽  
LEONARD AMARAL
Keyword(s):  
Protein Synthesis ◽  
Steroid Hormones ◽  
Plasma Protein ◽  
Human Lymphocytes ◽  
Amino Acid Incorporation ◽  
Binding Factor ◽  
In Vitro Effects ◽  
Physiologic Role

Abstract The in vitro effects of sterols, cholesterol and 3-methyl cholanthrene and steroids, cortisol, prednisolone and testosterone on protein synthesis in separate popultions of human lymphocytes and leukocytes has been investigated. It has been shown that all agents used result in the inhibition of protein synthesis under these conditions. It has also been shown that the inhibitory mechanism of the steroid hormones requires the presence of plasma, presumably as a protein binding factor in order to achieve its effect. The sterol, cholesterol and 3-methyl cholanthrene, in the absence of plasma, still inhibit amino acid incorporation. However, in the case of cholesterol, the magnitude of inhibition is lower than that observed in the presence of plasma, perhaps indicating a partial plasma dependence. The results presented therefore support the hypothesis that the inhibition of lymphocyte protein synthesis by steroid hormones occurs only when the steroid is bound to a plasma protein. The physiologic role of the plasma protein-cortisol complex and its relation to the condition of lymphopenia in man is discussed.

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