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Low circulating high-density lipoproteins (HDL) are not only a defining criteria for metabolic syndrome, but are
more generally associated with atherosclerotic cardiovascular disease (ASCVD) and other chronic diseases. Oxidative
stress, a hallmark of cardio-metabolic disease, further influences HDL activity by suppressing their function. Especially the
leukocyte-derived enzyme myeloperoxidase (MPO) has recently attracted great interest as it catalyzes the formation of oxidizing reactive species that modify the structure and function of HDL, ultimately increasing cardiovascular risk. Contrariwise, paraoxonase-1 (PON1) is an HDL-associated enzyme that protects HDL from lipid oxidation, and then acts as a protective factor against ASCVD. Noteworthy, recent studies have demonstrated how MPO, PON1 and HDL form a functional
complex in which PON1 partially inhibits the MPO activity, while MPO in turn partially inactivates PON1.In line with that,
high MPO/PON1 ratio characterizes patients with ASCVD and metabolic syndrome and has been suggested as a potential
marker of dysfunctional HDL as well as a predictor of ASCVD. In this review, we summarize the evidence on the interactions between MPO and PON1 with regard to their structure, function and interaction with HDL activity. We also provide
an overview on in vitro and experimental animal models, finally focusing on clinical evidence from cohort of patients with
ASCVD and metabolic syndrome.
High-density lipoproteins for therapeutic delivery systems
