Determination of biogenic amines by using amperometric biosensors based on grass PEA amine oxidase and OAT polyamine oxidase

Grass pea amine oxidase (GPAO) and oat polyamine oxidase (OPAO) were immobilized along with horseradish peroxidase (HRP) and an Os-redox polymer (Os-RP) onto the surface of a graphite electrode by crosslinking with poly(ethylenglycol) diglycidyl ether. The resulted reagentless amperometric biosensors were inserted in a flow injection setup and used as electrochemical detectors for the biogenic amines (BA) detection. Both biosensors were operated at low applied potential (-50 mV vs. Ag/AgCl, KCl0.1M) where electrochemical interferences are minimal. The quantification of ten BA (tyramine, putrescine, cadaverine, histamine, cystamine, phenylethylamine, agmatine, tryptamine, spermine, and spermidine) either individual or in mixture (after a preliminary separation by using cation exchange chromatography) was reported. G/(Os-RP)-HRP-GPAO biosensor detected all ten BA, while G/(Os-RP)-HRP-OPAO biosensor detected only spermine and spermidine. Finally, a simple and low-cost method for free and acetylated polyamines determination in human urine samples, by using the highly selective G/(Os-RP)-HRP-OPAO biosensor, was proposed

The role of OPG, RANK, RANKL in the bone metabolism, cardiovascular disease and immune system: Clinical and physiopathological implication

The bone remodelling process is characterized by alternate phases of production and resorption of the mineralized matrix, is possible by two types of cells: osteoblasts and osteoclasts. When these ones are subject to hormonal and cytokines stimulus, they express and produce a lot of proteic molecules that play an essential role in regulating the processes of activation and inhibition of osteoclastogenesis. Three molecules have been the subject of intense research in the field of bonebiochemistry: OPG, RANK and RANKL. OPG is a glycoprotein belonging to the TNFR superfamily. The importance of this molecule is confirmed by the presence of specific domains, that are essential for the osteoclastogenesis inhibition. OPG makes it by binding with RANKL. This event prevents the binding of RANKL to RANK, that is expressed in the osteoclasts, and inhibits the differentiation of pre-osteoclasts in mature osteoclast, RANKL is a peptide produced by osteoblasts cells. We review the physiopathologic implications of this molecules, and their implication in the immune and vascular system. Infact in the former it has been observed that RANKL expressed in the activated T cells, binds with RANK determining a inummomodulator final effect; in the latter it has been possible to observe that RANK and RANKL are expressed by endothelial cells, and regulate their survival

Mevolonate Pathway:role of bisphosphonates and statins

Cardiovascular diseases, i.e. high blood pressure, coronary heart disease, and stroke, and osteoporosis are public health problems, with several epidemiological links, and they might be related to each other in terms of pathogenesis and therapeutic agents. Bisphosphonates inhibit bone resorption and are used in the treatment of osteoporosis, whereas statins inhibit cholesterol biosynthesis and are used for the treatment of atherosclerosis and lipid metabolic disorders. Some late clinical studies suggested bisphosphonates may have beneficial effect in vivo on atherosclerotic progression, lipid profiles, and cardiovascular morbidity and mortality, whereas statins might increase bone density, and reduce fracture risk, even if properly designed prospective studies are needed to clearly define clinical effects and potential new roles for these old agents. Moreover mechanism by which these two classes of drugs act, at cellular level, may not be mutually exclusive, and the common target of action might be the mevalonate pathway. In this review, we focused on in vitro and in vivo interactions between mevolanate pathway, bisphosphonates, and statins, examining the possible therapeutic consequences of these link