Fetuin-A: A Biomarker for Type II Diabetes Mellitus
Chukwunonso Livinus Udeh
International Journal of Biomedical Materials Research
Fetuins are blood glycoproteins manufactured in the liver and secreted into the bloodstream. These glycoproteins make up a large group of binding proteins which mediates the transit and presence of a myriad of substances in the blood stream. Serum albumin, which is the most abundant protein in adult animal plasma is best known as the representative of these carrier proteins. In bone homeostasis, it is the circulating glycoprotein that plays a critical role. It plays major roles also in
... n of vascular calcification, disruption of adipocyte function and impairment of insulin signaling. Even with its major role, it is highly dependable in preventing and/or amplifying of the above disease processes. Certain diseases have been associated with high levels of Fetuin A. Although low levels of it in the plasma assist potentially in the protective effect of artery calcification in non-Chronic Kidney Disease (CKD) patients, high levels of the glycoprotein are the greatest concern in patients at higher risk of cardiovascular disease (CVD) and diabetes. The range of serum fetuin A in healthy adults is between 0.4 and 1mg/ml serum. The most studied function of fetuin A is mediated by the D1 domain. But the domain that binds with insulin receptor is yet to be known. The B chain consists of 27 amino acid residues which are distributed unevenly among the charged and neutral portion. Fetuins are proteins highly expressed in the liver blood plasma. They bear post translational modifications in proteolytic processing, phosphorylation, complex glycosylation and sulfation. The precussors of Fetuin A in humans are single-chained to the mature circulating double-chain form. In septicaemia and bovine, human fetuin A is perceptible to further proteolytic cleavage. Since the discovery of Fetuin A as a glycoprotein that inhibits vascular calcification in early 1990s, the biologic attributed roles has increased and still increasing exponentially. Apart from the roles it plays in type II diabetes mellitus and cardiovascular disease, other roles have been noted. Other effects and roles of Fetuin A are still being researched on.