Search results for "alpha-2-HS-Glycoprotein"
showing 10 items of 14 documents
Mammalian plasma fetuin-B is a selective inhibitor of ovastacin and meprin metalloproteinases
2019
AbstractVertebrate fetuins are multi-domain plasma-proteins of the cystatin-superfamily. Human fetuin-A is also known as AHSG, α2-Heremans-Schmid-glycoprotein. Gene-knockout in mice identified fetuin-A as essential for calcified-matrix-metabolism and bone-mineralization. Fetuin-B deficient mice, on the other hand, are female infertile due to zona pellucida ‘hardening’ caused by the metalloproteinase ovastacin in unfertilized oocytes. In wildtype mice fetuin-B inhibits the activity of ovastacin thus maintaining oocytes fertilizable. Here we asked, if fetuins affect further proteases as might be expected from their evolutionary relation to single-domain-cystatins, known as proteinase-inhibito…
The Serum Protein α2-HS Glycoprotein/Fetuin Inhibits Apatite Formation in Vitro and in Mineralizing Calvaria Cells
1996
We present data suggesting a function of alpha2-HS glycoproteins/fetuins in serum and in mineralization, namely interference with calcium salt precipitation. Fetuins occur in high serum concentration during fetal life. They accumulate in bones and teeth as a major fraction of noncollagenous bone proteins. The expression pattern in fetal mice confirms that fetuin is predominantly made in the liver and is accumulated in the mineralized matrix of bones. We arrived at a hypothesis on the molecular basis of fetuin function in bones using primary rat calvaria osteoblast cultures and salt precipitation assays. Our results indicate that fetuins inhibit apatite formation both in cell culture and in …
Fetuin-A and Cystatin C Are Endogenous Inhibitors of Human Meprin Metalloproteases
2010
Meprin α and β, zinc metalloproteinases, play significant roles in inflammation, including inflammatory bowel disease (IBD), possibly by activating cytokines, like interleukin 1β, interleukin 18, or tumor growth factor α. Although a number of potential activators for meprins are known, no endogenous inhibitors have been identified. In this work, we analyzed the inhibitory potential of human plasma and identified bovine fetuin-A as an endogenous meprin inhibitor with a K(i) (inhibition constant) of 4.2 × 10(-5) M for meprin α and a K(i) of 1.1 × 10(-6) M meprin β. This correlated with data obtained for a fetuin-A homologue from carp (nephrosin inhibitor) that revealed a potent meprin α and β…
The Evolving Role of Fetuin-A in Nonalcoholic Fatty Liver Disease: An Overview from Liver to the Heart
2021
Nonalcoholic fatty liver disease (NAFLD) is strongly associated to the features of metabolic syndrome which can progress to cirrhosis, liver failure and hepatocellular carcinoma. However, the most common cause of mortality in people with NAFLD is not liver-related but stems from atherosclerotic cardiovascular disease (CVD). The prevalence of NAFLD is on the rise, mainly as a consequence of its close association with two major worldwide epidemics, obesity and type 2 diabetes (T2D). The exact pathogenesis of NAFLD and especially the mechanisms leading to disease progression and CVD have not been completely elucidated. Human fetuin-A (alpha-2-Heremans Schmid glycoprotein), a glycoprotein produ…
Accelerated Evolution of Fetuin-A (FETUA, also AHSG) is Driven by Positive Darwinian Selection, not GC-Biased Gene Conversion
2009
article i nfo Human Fetuin-A (FETUA, also termed AHSG) is a serum protein composed of two cystatin-like domains D1 and D2 of together 235 amino acids (aa) and an unrelated domain D3 of 114 aa. Though the protein plays a role in diverse physiological and pathological processes, comparably little is known about sequence evolution of FETUA. We therefore analyzed its molecular evolution on the basis of coding sequences of 16 primate species. Ratios of non-synonymous to synonymous substitution rates (dn/ds= ω) suggest that a previously reported acceleration of sequence evolution of exon 7, which encodes domain D3, is driven by positive selection instead of neutral evolution. Irrespective of the …
Human histidine-rich glycoprotein expressed in SF9 insect cells inhibits apatite formation
1997
Histidine-rich glycoprotein (HRG) is structurally related to the alpha2-HS glycoprotein/fetuin family of mammalian plasma proteins; both belong to the cystatin superfamily of proteins. We expressed recombinant human HRG and alpha2-HS in Sf9 insect cells for functional analysis. Recombinant HRG bound heparin and fibrinogen while alpha2-HS did not. Both proteins inhibited the formation of apatite, recombinant HRG (IC50 approximately 1 microM) with 2-fold lower molar activity than alpha2-HS (IC50 approximately 0.5 microM). The inhibition in vitro of apatite formation suggests a new function for plasma HRG protein, inhibition of phase separation in blood vessels.
Fetuin-A serum levels are not correlated to kidney function in long-lived subjects
2012
Objectives: Serum Fetuin A has been identified as an inhibitor of ectopic calcification. It is reduced in subjects with chronic kidney disease (CKD) and it has been proposed as a potential link between CKD and the higher prevalence of arterial calcification observed in these patients. During ageing both the stiffening of arterial wall due to calcification and a decline in kidney function are frequent. The aim of the study is to investigate if Fetuin A serum levels are associated with ageing and with AHSG T256S polymorphism. Moreover, we aim at investigate whether serum Fetuin A is correlated to kidney function in this setting of senescence. Design and Methods: 256 health long-lived subjects…
Subclinical atherosclerosis and fetuin-A plasma levels in essential hypertensive patients
2012
The intima-media thickness (IMT) is considered as a surrogate marker for atherosclerotic disease. The aim of this study was to analyze the relationship of carotid IMT with fetuin-A in patients with essential hypertension (EH) and normal renal function. The plasma levels of fetuin-A, interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α) and the biomarker of oxidative stress 8-iso-PGF2alpha were assayed in samples from 105 untreated EH patients. Carotid IMT measurements were also performed. EH was studied overall and after dividing in EH with IMT ≥ and 0.9 mm (AUC (area under the curve) 0.738, P<0.0001). Our results suggest that in EH, fetuin-A is associated with the IMT independently of oxid…
Fetuin-A is Associated to Serum Calcium and AHSG T256S Genotype but Not to Coronary Artery Calcification
2015
Vascular calcification has been recently associated to an increased cardiovascular risk and mortality. In few studies, Fetuin-A showed an association to coronary artery calcification (CAC), although the physiopathological mechanism underlying this association has not been fully established yet. Seventy-four patients with one or more cardiovascular risk factor and asymptomatic for coronary vasculopathy were included in the study. CAC was evaluated by Agatston score. Serum Fetuin-A levels were determined by ELISA. Molecular analysis of AHSG T256S gene variant (rs4918) was performed by PCR-RFLP. Serum Fetuin-A was correlated to serum calcium (r = 0,321; P = 0,018), but not to serum phosphorous…
Fetuin-A and CD40L plasma levels in acute ischemic stroke: differences in relation to TOAST subtype and correlation with clinical and laboratory vari…
2009
Abstract Introduction Accumulating evidence suggests that inflammation plays an important role in the acute phase of ischemic stroke. CD40 L is a well recognized atherosclerotic inflammatory marker, whereas recent evidence suggests a pro-inflammatory role of Fetuin-A. To analyze the role of an inflammatory marker such as CD40 L and of a candidate pro-inflammatory marker such as Fetuin-A in acute stroke we evaluated their serum levels in subjects with acute ischemic stroke and their possible association with other laboratory and clinical variables. Materials and methods We enrolled 107 consecutive patients with a diagnosis of acute ischemic stroke admitted to the Internal Medicine Department…