ABSTRACT
Targeted therapeutics underwent a revolution with the entry of monoclonal antibodies in the medical toolkit. Oligonucleotide aptamers form another family of target agents that have been lagging behind in reaching the clinical arena in spite of their potential clinical translation. Some of the reasons for this might be related to the challenge in identifying aptamers with optimal in vivo specificity, and the nature of their pharmacokinetics. Aptamers usually show exquisite specificity, but they are also molecules that display dynamic structures subject to changing environments. Temperature, ion atmosphere, pH, and other variables are factors that could determine the affinity and specificity of aptamers. Thus, it is important to tune the aptamer selection process to the conditions in which you want your final aptamer to function; ideally, for in vivo applications, aptamers should be selected in an in vivo-like system or, ultimately, in a whole in vivo organism. In this review we recapitulate the implementations in systematic evolution of ligands by exponential enrichment (SELEX) to obtain aptamers with the best in vivo activity.
ABSTRACT
Chronic venous insufficiency (CVI) is a disease that impacts cellular homeostasis. CVI may occur with a valvular destruction process known as venous reflux or valvular incompetence. One of the cellular processes that may be triggered as a consequence of these events is the production of reactive oxygen species (ROS), which may trigger the production of different cellular markers and cell damage processes, such as lipid peroxidation. Therefore, the present study performed an observational, analytical, and prospective cohort study by reviewing 110 patients with CVI, and the activities and plasma levels of iNOS, eNOS, NOX1, and NOX2 were determined using immunohistochemistry and RT-qPCR. Lipid peroxidation (MDA) was also measured. Patients were distributed according to the presence or absence of valvular incompetence-venous reflux, which was diagnosed clinically as the absence of venous reflux (NR = 29) or presence of venous reflux (R = 81). Each group was divided according to age, with a cutoff point of fifty years (NR < 50 = 13, NR ≥ 50 = 16, R < 50 = 32, and R ≥ 50 = 49). The results showed that R patients exhibited significantly increased plasma MDA levels, and R < 50 patients exhibited the highest statistically significant increase. iNOS, NOX1, and NOX2 exhibited the highest gene and protein expression in R patients. The increased expression was maintained in the R < 50 patients. Our data suggest that young patients with valvular incompetence (venous reflux) show higher levels of lipid peroxidation and oxidative stress, which reflects the characteristics of an aged patient.
