Opsonic Properties of Human Serum Alpha-2 HS Glycoprotein

Oss, Carel J. van; Gillman, C. F.; Bronson, Paul M.; Border, John R.

doi:10.3109/08820137409061113

Cited by 100 publications

(37 citation statements)

References 4 publications

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“…The opsonizing properties of fetuin-A have been determined several decades ago. [143][144][145] Fetuin-A affects microparticle phagocytosis by dendritic cells, 146 phagocytosis of apoptotic cells by macrophages, 147 and opsonizes phospholipid particles. 148 Fetuin-A is, however, not generally sticky like the "big 12" plasma proteins, which adhere to most materials in blood contact, 149 and fetuin-A was also not listed among specific proteins interacting with Sepharose beads in a study that used quantitative mass spectrometry to determine bead proteomes.…”

Section: Calciprotein Particles Metabolism and Clearingmentioning

confidence: 99%

Fetuin-A Regulation of Calcified Matrix Metabolism

Jahnen-Dechent

Heiss²,

Schäfer³

et al. 2011

Circulation Research

336

271

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The final step of biomineralization is a chemical precipitation reaction that occurs spontaneously in supersaturated or metastable salt solutions. Genetic programs direct precursor cells into a mineralization-competent state in physiological bone formation (osteogenesis) and in pathological mineralization (ectopic mineralization or calcification). Therefore, all tissues not meant to mineralize must be actively protected against chance precipitation of mineral. Fetuin-A is a liver-derived blood protein that acts as a potent inhibitor of ectopic mineralization. Monomeric fetuin-A protein binds small clusters of calcium and phosphate. This interaction results in the formation of prenucleation cluster-laden fetuin-A monomers, calciprotein monomers, and considerably larger aggregates of protein and mineral calciprotein particles. Both monomeric and aggregate forms of fetuin-A mineral accrue acidic plasma protein including albumin, thus stabilizing supersaturated and metastable mineral ion solutions as colloids. Hence, fetuin-A is a mineral carrier protein and a systemic inhibitor of pathological mineralization complementing local inhibitors that act in a cell-restricted or tissue-restricted fashion. Fetuin-A deficiency is associated with soft tissue calcification in mice and humans.

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Section: Calciprotein Particles Metabolism and Clearingmentioning

confidence: 99%

Fetuin-A Regulation of Calcified Matrix Metabolism

Jahnen-Dechent

Heiss²,

Schäfer³

et al. 2011

Circulation Research

336

271

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“…The biological role of fetuin is unknown, although it has been implicated as an immunomodulator that can participate in stimulation of bacterial phagocytosis by neutrophils (21) and promotion of endocytosis by mouse macrophages (22)(23)(24)(25). Hepatocytes are the principal cell source of circulating fetuin, but it also is expressed by monocyte͞macrophages (26).…”

mentioning

confidence: 99%

Fetuin (α₂-HS-glycoprotein) opsonizes cationic macrophagedeactivating molecules

Wang

Zhang

Bianchi

et al. 1998

Proc. Natl. Acad. Sci. U.S.A.

141

107

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Macrophages become activated by bacterial endotoxin (lipopolysaccharide) and other stimuli to release proinflammatory cytokines and NO. To prevent release of toxic or potentially lethal quantities of these factors, the state of macrophage activation is counter-regulated by anti-inflammatory mediators (e.g., glucocorticoid hormones, interleukin 10, and transforming growth factor type ␤). Fetuin, a negative acute-phase protein, recently was implicated as an antiinflammatory mediator, because it is required for macrophage deactivation by spermine. In the present studies, we found that fetuin is necessary for macrophages to respond to CNI-1493, a tetravalent guanylhydrazone inhibitor of p38 mitogen-activated protein kinase phosphorylation. Fetuin dose-dependently increases macrophage uptake of CNI-1493, which can be specifically inhibited by anti-human fetuin antibodies. Anti-human fetuin antibodies render primary human peripheral blood mononuclear cells insensitive to deactivation by CNI-1493. Thus, macrophages use fetuin as an opsonin for cationic-deactivating molecules, both endogenous (e.g., spermine) and pharmacologic (e.g., CNI-1493). This role of fetuin as an opsonic participant in macrophage-deactivating mechanisms has implications for understanding and manipulating the innate immune response.

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“…The protein has been observed to demonstrate opsonic properties (11), to bind DNA and promote endocytosis by macrophages (12), and to participate in chemotaxis leading to the recruitment of peripheral monocytes for osteoclast development (13).…”

mentioning

confidence: 99%

Human alpha 2-HS-glycoprotein: the A and B chains with a connecting sequence are encoded by a single mRNA transcript.

Lee¹,

Bowman²,

Yang³

1987

Proc. Natl. Acad. Sci. U.S.A.

100

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The a2-HS-glycoprotein (AHSG) is a plasma protein reported to play roles in bone mineralization and in the immune response. It is composed of two subunits, the A and B chains. Recombinant plasmids containing human cDNA AHSG have been isolated by screening an adult human liver library with a mixed oligonucleotide probe. The cDNA clones containing AHSG inserts span approximately 1.5 kiobase pairs and include the entire AHSG coding sequence, demonstrating that the A and B chains are encoded by a single mRNA transcript. The cDNA sequence predicts an 18-amino-acid signal peptide, followed by the A-chain sequence of AHSG. A heretofore unseen connecting sequence of 40 amino acids was deduced between the A-and B-chain sequences. The connecting sequence demonstrates the unique amino acid doublets and collagen triplets found in the A and B chains; it is not homologous with other reported amino acid sequences. The connecting sequence may be cleaved in a posttranslational step by limited proteolysis before mature AHSG is released into the circulation or may vary in its presence because of alternative processing. The AHSG cDNA was utilized for mapping the AHSG gene to the 3q21-*qter region of human chromosome 3. The availability of the AHSG cDNA clone will facilitate the analysis of its genetic control and gene expression during development and bone formation.The human a2-HS-glycoprotein (AHSG) is a plasma protein that consists of two subunits, an A chain of 282 amino acids and a B chain of 27 amino acids (1, 2). The A chain and B chain are linked through a disulfide bond. The molecule has interesting and unique features; there are 29 amino acid doublets in circulating AHSG with Ala-Ala or Ala-Ala-Ala

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Opsonic Properties of Human Serum Alpha-2 HS Glycoprotein

Cited by 100 publications

References 4 publications

Fetuin-A Regulation of Calcified Matrix Metabolism

Fetuin-A Regulation of Calcified Matrix Metabolism

Fetuin (α₂-HS-glycoprotein) opsonizes cationic macrophagedeactivating molecules

Human alpha 2-HS-glycoprotein: the A and B chains with a connecting sequence are encoded by a single mRNA transcript.

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Opsonic Properties of Human Serum Alpha-2 HS Glycoprotein

Cited by 100 publications

References 4 publications

Fetuin-A Regulation of Calcified Matrix Metabolism

Fetuin-A Regulation of Calcified Matrix Metabolism

Fetuin (α2-HS-glycoprotein) opsonizes cationic macrophagedeactivating molecules

Human alpha 2-HS-glycoprotein: the A and B chains with a connecting sequence are encoded by a single mRNA transcript.

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Fetuin (α₂-HS-glycoprotein) opsonizes cationic macrophagedeactivating molecules