Statins are among the most widely used drug classes in the world. Apart from their basic mechanism of action, which is lowering cholesterol levels, many pleiotropic effects have been described so far, such as anti-inflammatory and antiatherosclerotic effects. A growing number of scientific reports have proven that these drugs have a beneficial effect on the functioning of the nervous system. The first reports proving that lipid-lowering therapy can influence the development of neurological and psychiatric diseases appeared in the 1990s. Despite numerous studies about the mechanisms by which statins may affect the functioning of the central nervous system (CNS), there are still no clear data explaining this effect. Most studies have focused on the metabolic effects of this group of drugs, however authors have also described the pleiotropic effects of statins, pointing to their probable impact on the neurotransmitter system and neuroprotective effects. The aim of this paper was to review the literature describing the impacts of statins on dopamine, serotonin, acetylcholine, and glutamate neurotransmission, as well as their neuroprotective role. This paper focuses on the mechanisms by which statins affect neurotransmission, as well as on their impacts on neurological and psychiatric diseases such as Parkinson’s disease (PD), Alzheimer’s disease (AD), vascular dementia (VD), stroke, and depression. The pleiotropic effects of statin usage could potentially open floodgates for research in these treatment domains, catching the attention of researchers and clinicians across the globe.

Proprotein convertase subtilisin/kexin type 9 (PCSK-9) inhibitors are a group of drugs whose main mechanism of action is binding to the PCSK-9 molecule, which reduces the degradation of the low-density lipoprotein receptor (LDL-R) and, hence, increases the uptake of low-density lipoprotein cholesterol (LDLc) from the bloodstream as well as reducing its concentration. The effectiveness of three monoclonal antibodies, namely, alirocumab (human IgG1/κ monoclonal antibody, genetically engineered in Chinese hamster ovary cells), evolocumab (the first fully human monoclonal antibody), and bococizumab (humanized mouse antibody), in inhibiting the action of PCSK-9 and reducing LDLc levels has been confirmed. The first two, after clinical trials, were approved by the Food and Drug Administration (FDA) and are used primarily in the treatment of autosomal familial hypercholesterolemia and in cases of statin intolerance. They are currently used both as monotherapy and in combination with statins and ezetimibe to intensify therapy and achieve therapeutic goals following the American Heart Association (AHA) and European Society of Cardiology (ESC) guidelines. However, the lipid-lowering effect is not the only effect of action described by researchers that PCSK-9 inhibitors have. This paper is a review of the literature describing the pleiotropic effects of PCSK-9 inhibitors, which belong to a group of drugs that are being increasingly used, especially when standard lipid-lowering therapy fails. The article focuses on activities other than lipid-lowering, such as the anti-atherosclerotic effect and stabilization of atherosclerotic plaque, the anti-aggregation effect, the anticoagulant effect, the antineoplastic effect, and the ability to influence the course of bacterial infections. In this publication, we try to systematically review the current scientific data, both from our own scientific work and knowledge from international publications.

Proprotein convertase subtilisin/kexin type 9 (PCSK9) is the last discovered member of the family of proprotein convertases (PCs), mainly synthetized in hepatic cells. This serine protease plays a pivotal role in the reduction of the number of low-density lipoprotein receptors (LDLRs) on the surface of hepatocytes, which leads to an increase in the level of cholesterol in the blood. This mechanism and the fact that gain of function (GOF) mutations in PCSK9 are responsible for causing familial hypercholesterolemia whereas loss-of-function (LOF) mutations are associated with hypocholesterolemia, prompted the invention of drugs that block PCSK9 action. The high efficiency of PCSK9 inhibitors (e.g., alirocumab, evolocumab) in decreasing cardiovascular risk, pleiotropic effects of other lipid-lowering drugs (e.g., statins) and the multifunctional character of other proprotein convertases, were the cause for proceeding studies on functions of PCSK9 beyond cholesterol metabolism. In this article, we summarize the current knowledge on the roles that PCSK9 plays in different tissues and perspectives for its clinical use.

Hypercholesterolemia plays a crucial role in the development of atherosclerosis, but it remains an undertreated and underdiagnosed disease. Taking into consideration the high prevalence of lipid disorders, long duration of the asymptomatic course of the disease, life-threatening complications resulting from inaccurate therapy, and stringent treatment goals concerning LDL cholesterol level in the prevention of cardiovascular events, novel lipid-lowering therapies have been introduced in the last few years. In this article, a drug belonging to the group of small interfering RNA (siRNA) called inclisiran is described. It is a novel molecule that increases the number of LDL receptors (LDLRs) on the surface of hepatic cells by preventing the formation of proprotein convertase subtilisin/kexin type 9 (PCSK9) responsible for the degradation of LDLRs. With great potential for lowering plasma LDL cholesterol level, high liver specificity, comfortable dosing regimen, and good tolerance without significant adverse effects, it could play an important part in future hypolipemic therapies.

Atherosclerosis is a multifactorial, progressive, chronic inflammatory disease. Ultrasound and magnetic resonance imaging are the most accurate predictors of atherosclerotic plaque instability (MRI). Cytokines such as osteopontin, osteoprotegerin, and metalloproteinase 9 could be used as the most recent markers to identify and track the efficacy of anti-atherosclerotic therapy. Patients with USG and MRI-verified unstable atherosclerotic plaque were included in the study. Biomarker concentrations were measured and compared before and after PCSK9 inhibitor therapy. Additionally, concentrations prior to treatment were correlated with MRI images of the carotid artery. After treatment with alirocumab, the concentrations of MMP-9 (p < 0.01) and OPN, OPG (p < 0.05) decreased significantly. Furthermore, the results of OPN, OPG, and MMP 9 varied significantly depending on the type of atherosclerotic plaque in the MRI assay. In stable atherosclerotic plaques, the concentrations of OPN and OPG were greater (p < 0.01), whereas the concentration of MMP9 correlated with the instability of the plaque (p < 0.05). We demonstrated, probably for the first time, that alirocumab therapy significantly decreased the serum concentration of atherosclerotic plaque markers. In addition, we demonstrated the relationship between the type of atherosclerotic plaque as determined by carotid MRI and the concentration of these markers.

Background/Objectives: Hypercholesterolemia, accompanied by vascular inflammation, leads to the premature initiation and progression of atherosclerosis, and both are considered nowadays as well-established cardiovascular (CV) risk factors. For several years, proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9is), drugs that reduce the degradation of the receptors for low-density lipoprotein cholesterol (LDLRs), have appeared to be a very efficient lipid-lowering therapy among patients with complications resulting from atherosclerotic cardiovascular disease (ASCVD). Previous studies showed that drugs used to fight hypercholesterolemia (predominantly statins) have significant pleiotropic effects, including anti-inflammatory effects. To date, data on the potential impact of PCSK9 inhibitors, especially inclisiran, on the course of inflammation is still lacking. Therefore, we conceived a study to evaluate the effects of inclisiran on the markers of subclinical inflammation (e.g., pentraxin 3 (PTX3), interleukin-18 (IL-18), and soluble cluster of differentiation 40 ligand (CD40L)) and compared their magnitude in patients at high CV risk, with and without established heterozygous familial hypercholesterolemia (HeFH). Methods: A total of 24 patients at high cardiovascular risk, according to European Society of Cardiology (ESC) guidelines, with or without concomitant HeFH diagnosed using Dutch Lipid Clinic Network (DLCN) criteria, were enrolled in this study. Lipid concentrations and levels of subclinical inflammatory markers of atherosclerosis were measured at the beginning and after 3 months of therapy. Results: After three months of therapy with inclisiran, a statistically significant reduction included total cholesterol (TC): study group 1: from 287.6 ± 94.15 to 215.2 ± 89.08 [mg/dL], p = 0.022 and study group 2: from 211.71 ± 52.72 to 147.64 ± 55.44 [mg/dL], p < 0.001, and low-density lipoprotein cholesterol (LDL-c): study group 1: from 180.79 ± 73.33 to 114.65 ± 71.54 [mg/dL], p = 0.031 and study group 2: from 129.62 ± 46.75 to 63.39 ± 43.6 [mg/dL], p < 0.001. Moreover significant drops were observed in concentrations of PTX3: study group 1: from 1336.33 ± 395.15 to 1121.75 ± 351.17 [pg/mL], p = 0.013 and study group 2: from 1610.76 ± 537.78 to 1376.92 ± 529.19 [pg/mL], p = 0.017), and IL-18: study group 1: from 11.89 (9.72–13.98) to 9.15 (8.62–10.06) [pg/mL], p = 0.005 and study group 2: from 11.58 (10.87–16.97) to 9.65 (8.43–10.95) [pg/mL], p = 0.003). There were no significant changes in the levels of sCD40L. Conclusions: This study confirmed the ability of inclisiran to reduce LDL-c levels in patients at high cardiovascular risk just after one dose of the drug. Furthermore, it appeared that beyond its lipid-lowering effect, the drug may also affect some inflammatory processes involved in the initiation and progression of atherosclerosis.