# In Vitro Evidence of Stating' Protective Role against COVID-19 Hallmarks _Comptes_ [PERSON]
## 4 Discussion  
Statins are widely prescribed lipid-lowering drugs known for their pleiotropic effects, including anti-inflammatory, immunomodulatory, and anticoagulant properties [37]. As debated during the SARS-CoV-2 pandemic, the use of statins and their role in COVID-19 infection raised controversial opinions mainly sustained by their ability to induce ACE2 receptor expression and their adverse effects in some clinical conditions [16; 17]. An impressive number of clinical studies attempted to clarify the safety, the therapeutic potential, and the impact of statins in clinical outcomes in COVID-19 patients [18; 19; 20; 21; 38]. However, since statins are drugs prescribed for patients with cardiovascular complications that constitute predisposing factors for SARS-CoV-2 infection, the results from these observational studies are often controversial due to multiple confounding factors and clinical bias influencing data interpretation [39]. Despite this, the overall conclusion emerging so far from several meta-analyses is that statins used in COVID-19 patients is associated with improved clinical outcomes and reduced Intensive Care Unit (ICU) admission, mechanical intubation, ARDS, and in-hospital death [20; 40; 41; 42]. The studies included in these meta-analyses and emerging observational studies [43; 44] strongly suggest that statin therapy exerts a protective effect against complications from COVID-19, preventing the worst prognosis. These effects are probably related to the immunomodulatory and anti-inflammatory properties of statins, but it has been also proposed that there is a possible direct inhibitory effect on the key steps of the virus life cycle, including internalization, replication, and virion release [13; 39]. However, to date, few in vitro reports deciphered the exact molecular and cellular events underlying the protective effect of statins against infectious diseases such as COVID-19. In this work we tried to elucidate the effect of statins on specific traits associated with COVID-19 pathogenesis and course. Aiming to understand the host genetic dependence, [PERSON] and colleagues identified the genes required for SARS-CoV-2 infection. Notably, in CaCO2 and A549 ACE2-iperexpressing cells, they identified a group of genes involved in the cholesterol biosynthesis pathway and, intriguingly, strongly involved in SARS-CoV-2 infection. Among others they identified Rab7, a small-GTPase whose activity depends on post-translational prepnylation, highlighting that it is involved in regulation of ACE2 receptor cell surface expression. In particular, loss of Rab7 causes an intracytoplasmic accumulation of ACE2 and, as a consequence, the sequestering of ACE2 receptor inside the cells translates into viral entry reduction [45]. Our results demonstrated that the global increase of ACE2 receptor expression mediated by statins does not necessarily coincide with its functional localization in lipid rafts domains, particularly after treatments with the lipophilic statins ATS. Moreover, in agreement with their role in perturbation of cholesterol contents and membrane fluidity, we demonstrated that ATS efficiently reduces the amount of Flotillin-1 in the lipid rafts fraction, suggesting that the displacement of ACE2 receptor from these domains is probably due to disruption of lipid rafts integrity. These data are coherent with a recent report highlighting that simvastatin, another lipophilic statin, also displaces ACE2 receptor from the cholesterol-enriched domains [24]. As observed, at the doses and times analyzed in our models, the hydrophilic statin PVS failed to interfere with lipid rafts composition and ACE2 receptor displacement. We hypothesize that this difference with ATS could be due to their different lipophilicities. This latter parameter is associated with the ability of statins to diffuse in the cell membranes. Passive diffusion across the plasma membrane is the preferential route used by lipophilic statins.