Serum Amyloid A promotes Acetaminophen-induced liver injury by damaging sinusoidal endothelial cell and exacerbating platelet aggregation in liver

AbstractBackgroundAcetaminophen (APAP) is the most commonly used non-prescription antipyretic and analgesic drugs. Overuse of APAP can cause hepatotoxicity. Liver sinusoidal endothelial cells (LSECs) damage is an important early event in APAP-induced liver injury. Serum amyloid A (SAA) is an acute phase protein that mainly produced by hepatocytes, and promotes endothelial dysfunction via a pro-inflammatory and pro-thrombotic effect in atherosclerosis and renal disease. However, the role of SAA in APAP-induced liver injury remains unclear.MethodsIn this study, we used neutralizing antibody (anti-SAA) or antagonistic small peptide derived from sequence of human SAA1/2 (SAA-pep) to block the functional activity of Saa1/2 in mouse serum. Immunohistochemistry staining, Evans blue and platelet adhesion assays were performed to examine the liver damage, the integrity of sinusoidal endothelium and platelets accumulation in APAP-induce liver injury.ResultsOur study showed that in the early stage of APAP-induced acute liver injury in mice, the intrahepatic and serum Saa1/2 levels were significantly increased within 24 hours, and then gradually reduced to normal level from 3 days. Neutralization of Saa1/2 by antibodies or peptides effectively prevented the destruction of hepatic sinusoids, reduced the intrahepatic hemorrhage and platelet accumulation in liver, as well as increased the survival rate of mice treated with lethal dose of APAP. In vitro experiments showed that Saa1/2 aggravated LSECs death induced by APAP. Moreover, Saa1/2 promoted platelets adhesion on LSECs via Tlr2/Vcam-1 axis.ConclusionOur findings suggest that Saa1/2 promotes APAP-induced liver injury by damaged LSECs and exacerbated platelets aggregation. This study provides a potential target for intervention of acute liver injury/failure caused by hepatotoxic drugs such as APAP.

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Aggregation of Mouse Serum Amyloid A Protein Was Promoted by Amyloid-Enhancing Factors with the More Genetically Homologous Serum Amyloid A

International Journal of Molecular Sciences ◽

10.3390/ijms22031036 ◽

2021 ◽

Vol 22 (3) ◽

pp. 1036

Author(s):

Xuguang Lin ◽

Kenichi Watanabe ◽

Masahiro Kuragano ◽

Kiyotaka Tokuraku

Keyword(s):

Amino Acid ◽

Serum Amyloid A ◽

Animal Species ◽

Amino Acid Sequences ◽

Serum Amyloid ◽

Mouse Serum ◽

Aa Amyloidosis ◽

Basic Residue ◽

Amyloid A ◽

Serum Amyloid A Protein

Amyloid A (AA) amyloidosis is a condition in which amyloid fibrils characterized by a linear morphology and a cross-β structure accumulate and are deposited extracellularly in organs, resulting in chronic inflammatory diseases and infections. The incidence of AA amyloidosis is high in humans and several animal species. Serum amyloid A (SAA) is one of the most important precursor amyloid proteins and plays a vital step in AA amyloidosis. Amyloid enhancing factor (AEF) serves as a seed for fibril formation and shortens the onset of AA amyloidosis sharply. In this study, we examined whether AEFs extracted and purified from five animal species (camel, cat, cattle, goat, and mouse) could promote mouse SAA (mSAA) protein aggregation in vitro using quantum-dot (QD) nanoprobes to visualize the aggregation. The results showed that AEFs shortened and promoted mSAA aggregation. In addition, mouse and cat AEFs showed higher mSAA aggregation-promoting activity than the camel, cattle, and goat AEFs. Interestingly, homology analysis of SAA in these five animal species revealed a more similar amino acid sequence homology between mouse and cat than between other animal species. Furthermore, a detailed comparison of amino acid sequences suggested that it was important to mSAA aggregation-promoting activity that the 48th amino acid was a basic residue (Lys) and the 125th amino acid was an acidic residue (Asp or Glu). These data imply that AA amyloidosis exhibits higher transmission activity among animals carrying genetically homologous SAA gene, and may provide a new understanding of the pathogenesis of amyloidosis.

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NFkB Inhibition Mitigates Serum Amyloid A-Induced Pro-Atherogenic Responses in Endothelial Cells and Leukocyte Adhesion and Adverse Changes to Endothelium Function in Isolated Aorta

10.20944/preprints201810.0766.v1 ◽

2018 ◽

Author(s):

Abigail Vallejo ◽

Belal Chami ◽

Joanne M. Dennis ◽

Martin Simone ◽

Gulfam Ahmad ◽

...

Keyword(s):

Gene Expression ◽

Endothelial Cells ◽

Vascular Function ◽

Serum Amyloid A ◽

Ex Vivo ◽

Early Stage ◽

Leukocyte Adhesion ◽

Serum Amyloid ◽

Amyloid A ◽

Isolated Aorta

The acute phase protein serum amyloid A (SAA) is associated with endothelial dysfunction and early-stage atherogenesis. Stimulation of vascular cells with SAA increases gene expression of pro-inflammation cytokines and tissue factor (TF). Activation of the transcription factor, nuclear factor kappa-B (NFkB), may be central to SAA-mediated endothelial cell inflammation, dysfunction and pro-thrombotic responses, while targeting NFkB with a pharmacologic inhibitor, BAY11-7082, may mitigate SAA activity. Human carotid artery endothelial cells (HCtAEC) were pre-incubated (1.5 h) with 10 µM BAY11-7082 or vehicle (control) followed by SAA (10 μg/mL; 4.5 h). Under these conditions gene expression for TF and TNF increased in SAA-treated HCtAEC and pre-treatment with BAY11-7082 significantly (TNF) and marginally (TF) reduced mRNA expression. Intracellular TNF and IL-6 protein also increased in HCtAEC supplemented with SAA and this expression was inhibited by BAY11-7082. Supplemented BAY11-7082 also significantly decreased SAA-mediated leukocyte adhesion to apolipoprotein E-deficient mouse aorta in ex vivo vascular flow studies. In vascular function studies, isolated aortic rings pre-treated with BAY11-7082 prior to incubation with SAA showed improved endothelium-dependent vasorelaxation and increased vascular cGMP content. Together these data suggest that inhibition of NFkB activation may protect endothelial function by inhibiting the pro-inflammatory and pro-thrombotic activities of SAA.

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Mouse serum amyloid A (SAA) proteins isolated by two-dimensional electrophoresis: characterization of isotypes and the effect of separate and combined administrations of cytokines, dexamethasone and lipopolysaccharide (LPS) on serum levels and isotype dis

Clinical & Experimental Immunology ◽

10.1046/j.1365-2249.1998.00503.x ◽

1998 ◽

Vol 111 (1) ◽

pp. 231-236 ◽

Cited By ~ 12

Author(s):

C. Foyn Bruun ◽

K. Sletten ◽

G. Marhaug

Keyword(s):

Serum Amyloid A ◽

Serum Levels ◽

Serum Amyloid ◽

Mouse Serum ◽

Two Dimensional ◽

Two Dimensional Electrophoresis ◽

Amyloid A ◽

Mouse Serum Amyloid ◽

Dimensional Electrophoresis

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Amyloid-Determining Residues in Mouse Serum Amyloid A

Amyloid and Amyloidosis ◽

10.1201/9781420037494.ch85 ◽

2004 ◽

pp. 253-255

Author(s):

M Benson ◽

J Liepnieks ◽

B Kluve-Beckerman ◽

L Wang ◽

D Marks

Keyword(s):

Serum Amyloid A ◽

Serum Amyloid ◽

Mouse Serum ◽

Amyloid A ◽

Mouse Serum Amyloid

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Serum Amyloid a Levels in Human Renal Allograft Rejection

Clinical Science ◽

10.1042/cs0650547 ◽

1983 ◽

Vol 65 (5) ◽

pp. 547-550 ◽

Cited By ~ 7

Author(s):

C. P. J. Maury ◽

A. M. Teppo ◽

B. Eklund ◽

P. Häyry ◽

J. Ahonen

Keyword(s):

Cyclosporin A ◽

Allograft Rejection ◽

Serum Amyloid A ◽

Renal Allograft ◽

Serum Amyloid ◽

Early Event ◽

Post Transplantation ◽

Renal Allograft Rejection ◽

Amyloid A ◽

Acute Renal Allograft Rejection

1. Serum amyloid A (SAA) levels were studied in 35 recipients of cadaveric renal transplants. Marked SAA elevations were seen during all acute allograft rejection episodes. The mean peak SAA level in well-documented rejections was 446 mg/l (median 415 mg/l, range 132–1040 mg/l; controls < 1 mg/l). 2. Rejections in patients receiving cyclosporin-A alone as post-transplantation immunosuppressive medication were characterized by a significantly higher peak SAA level than rejections in patients receiving cyclosporin-A in combination with methylprednisolone (539 ± 53 mg/l, mean ± sem, vs 226 ± 9 mg/l, P < 0.01). 3. Excluding surgery-induced SAA elevations in the immediate postoperative period, seven significant SAA peaks not related to allograft rejection were observed. These were associated with surgical complications and infections, and in one case probably with the underlying rheumatic disease, which was complicated by amyloidosis. 4. The results show that acute renal allograft rejection induces a dramatic acute phase SAA response. Since SAA is an easily measured serum component and the rejection-induced elevation is an early event, monitoring of SAA in kidney transplant patients-5-have considerable clinical significance.

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Mapping of the mouse serum amyloid A gene cluster by long-range polymerase chain reaction

Immunogenetics ◽

10.1007/s002510050154 ◽

1996 ◽

Vol 44 (6) ◽

pp. 468-474 ◽

Cited By ~ 4

Author(s):

Aileen Butler ◽

Alexander S. Whitehead

Keyword(s):

Polymerase Chain Reaction ◽

Gene Cluster ◽

Long Range ◽

Serum Amyloid A ◽

Serum Amyloid ◽

Mouse Serum ◽

Chain Reaction ◽

Amyloid A ◽

Polymerase Chain ◽

Mouse Serum Amyloid

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Mouse serum amyloid A protein. Complete amino acid sequence and mRNA analysis of a new isoform

Biochemical Journal ◽

10.1042/bj2830673 ◽

1992 ◽

Vol 283 (3) ◽

pp. 673-678 ◽

Cited By ~ 19

Author(s):

M C de Beer ◽

F C de Beer ◽

C M Beach ◽

I Carreras ◽

J D Sipe

Keyword(s):

Amino Acid ◽

Amino Acid Sequence ◽

Serum Amyloid A ◽

Density Lipoprotein ◽

Serum Amyloid ◽

Mouse Serum ◽

F1 Hybrid ◽

Complete Amino Acid Sequence ◽

Amyloid A ◽

Serum Amyloid A Protein

Four serum amyloid A protein (SAA) genes and two gene products, apo-SAA1 and apo-SAA2 were identified in BALB/c mice (type A). SJL/J mice (type B) are thought to be defective in apo-SAA2 expression. A unique variant of mouse apo-SAA was identified in SJL/J mice by isoelectric-focusing analysis of high-density lipoprotein from endotoxin-treated mice. Complete amino-acid-sequence analysis of this quantitatively major form of SJL/J apo-SAA (pI 5.9) showed it to be identical with the apo-SAA2 isoform from BALB/c mice, except for the substitution of aspartic acid for alanine at position 101. Isoform-specific analysis of mRNA from liver of BALB/c and SJL/J mice and their F1 hybrid progeny (CSJLF1/J) mice revealed further differences in the 3′ untranslated regions of the genes, not only encoding apo-SAA2 and apo-SAA pI 5.9, but also apo-SAA1. The SAA genes of SJL/J mice thus differ from BALB/c in exon 4. Additional minor isoforms corresponding to apo-SAA2 (pI 6.3) in SJL/J mice and apo-SAA (pI 5.9) in BALB/c mice were identified. We propose that, when analysing a multigene family such as SAA, thorough analysis at the protein level should complement molecular-biological approaches where the use of a too-limited repertoire of probes can obscure complexities.

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Regulation of mouse serum amyloid A gene expression in transfected hepatoma cells.

Molecular and Cellular Biology ◽

10.1128/mcb.10.7.3619 ◽

1990 ◽

Vol 10 (7) ◽

pp. 3619-3625 ◽

Cited By ~ 29

Author(s):

J H Huang ◽

H Y Rienhoff ◽

W S Liao

Keyword(s):

Serum Amyloid A ◽

Cultured Cells ◽

Regulatory Element ◽

Interleukin 1 ◽

Fold Increase ◽

Conditioned Media ◽

Serum Amyloid ◽

Mouse Serum ◽

Amyloid A ◽

Mouse Serum Amyloid

Expression of mouse serum amyloid A (SAA1, -2, and -3) mRNAs can be induced up to 1,000-fold in the liver in response to acute inflammation. This large increase is primarily the result of a 200-fold increase in the rates of SAA gene transcription. To analyze the cis-acting regulatory element(s) responsible for regulating transcription, we fused 306 base pairs of the mouse SAA3 promoter to a reporter gene, the chloramphenicol acetyltransferase (CAT) gene, and transfected this chimeric DNA into cultured cells. In transient expression assays, this 5' sequence was sufficient to confer cell-specific expression: CAT activity was readily detectable when the construct was transfected into liver-derived cells but was not detectable in nonliver cells. Furthermore, when liver cells transfected with this construct were treated with conditioned media prepared from activated mixed lymphocyte cultures or with recombinant interleukin-1, a 10- to 15-fold increase in CAT activity was detected. Deletion analyses showed two regions of interest: a proximal region that enhanced CAT expression in a cell-specific manner and a distal region that conferred responsiveness to both conditioned media and recombinant interleukin-1. This distal responsive element had properties of an inducible transcriptional enhancer, and deletion of the proximal cell-specific region rendered the distal element responsive to stimulation by conditioned media in nonliver cells.

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