Using of aptamer as a novel molecular tool for neutralizing endotoxin and its effect on platelet factors in animal model

Background and Aim: Aptamers are high potential molecular tools for diagnostic and therapeutic application. Aptamers are ssDNA or RNA oligonucleotides that could bind to a wide range of biological targets by forming three-dimensional structures. Aptamers are isolate during process called "SELEX". One of the goals of aptamers is detect and neutralize toxins. Endotoxin or Lipopolysaccharide (LPS) is part of outer membrane of Gram-negative bacteria. Endotoxin exposure, even at low concentration, has many detrimental effects on human health such as direct effect on the platelets. Inflammation caused by endotoxemia could lead to change in the number and structure of platelets. It could be considered as a predictive factor in clinical course of treatment and affect patient's mortality. In the present study, the specific aptamers isolated against LPS of E.coli ATCC ۱۰۵۳۶ to observe platelet change.Methods: DNA library is prepare and asymmetric-PCR set up for aptamers. After LPS Purification, DNA library was exposed to LPS and ۱۲ rounds of SELEX were performed by affinity chromatography. The ELISA assay was used to determine the highest affinity of isolated LPS-aptamer. Finally, the effect of aptamers checked in vivo in male adult rats.Results: Platelet analysis of the animal have indicate that purified LPS had deleterious effect on platelet, including a decrease in platelet count (thrombocytopenia), increase in the mean platelet volume (MPV) and platelet distribution width (PDW). In the other hand, in aptamer recipients, platelet factors observe in the normal range.Conclusion: Observation of platelet factors close to the control group in aptamer recipients propose the isolated aptamers are able to bind its target (LPS) optimally and thereby reduce the deleterious effects of LPS on platelets. The results indicate the neutralization potential of isolated aptamers against LPS.

کلیدواژه ها:

Aptamer ، SELEX ، endotoxin ، LPS ، platelet