Hypocholesterolemic potential of Bacillus amyloliquefaciens KAVK1 modulates lipid accumulation on 3T3-L1 adipose cells and high fat diet-induced obese rat model.

The significance of microorganisms occurring in foods is predominantly targeted due to their application for identifying a novel range of the bacterial spectrum. Diverse microbial species are capable of exhibiting potential pharmacological activities like antimicrobial and anticancer. Microbial strains capable of reducing obesity-related syndromes have also been reported. In the present study, the hypocholesterolemic efficacy of Bacillus amyloliquefaciens isolated from dairy products was scrutinised by in vitro (3T3-L1 adipose cells) and in vivo (high-fat diet-induced obese Wistar albino rats) methods. Potential cholesterol-lowering isolates were screened using a plate assay method and optimised by physical parameters. Molecular identification of the topmost five cholesterol-lowering isolates was acquired by amplification of the 16 S rRNA gene region. Bacillus amyloliquefaciens strain KAVK1, followed by strains KAVK2, KAVK3, KAVK4, and KAVK5 were molecularly determined. Further, cholesterol-lowering strains degraded the spectral patterns determined by the side chain of a cholesterol molecule. The anti-lipase activity was demonstrated using the porcine pancreatic lipase inhibitory method and compared with the reference compound Atorvastatin. Lyophilised strain KAVK1 revealed maximum pancreatic lipase inhibition. Strain KAVK1 attenuated lipid accumulation in 3T3-L1 adipose cell line predicted by Oil Red O staining method. Significant reduction of body weight and change in lipid profile was recognised after the supplement of KAVK1 to obese rats. Histopathological changes in organs were predominantly marked. The result of this study implies that the cholesterol-lowering B. amyloliquefaciens KAVK1 strain was used to treat hypercholesterolemia.

Dietary supplements: clinical cholesterol-lowering efficacy and potential mechanisms of action.

This review aims to analyse the efficacy of dietary supplements in reducing plasma cholesterol levels. Focusing on evidence from meta-analyses of randomised controlled clinical trials, with an emphasis on potential mechanisms of action as supported by human, animal, and cell studies. Certain dietary supplements including phytosterols, berberine, viscous soluble dietary fibres, garlic supplements, soy protein, specific probiotic strains, and certain polyphenol extracts could significantly reduce plasma total and low-density lipoprotein (LDL) cholesterol levels by 3-25% in hypercholesterolemic patients depending on the type of supplement. They tended to be more effective in reducing plasma LDL cholesterol level in hypercholesterolemic individuals than in normocholesterolemic individuals. These supplements worked by various mechanisms, such as enhancing the excretion of bile acids, inhibiting the absorption of cholesterol in the intestines, increasing the expression of hepatic LDL receptors, suppressing the activity of enzymes involved in cholesterol synthesis, and activating the adenosine monophosphate-activated protein kinase signalling pathway.

Repositioning of ezetimibe for the treatment of idiopathic pulmonary fibrosis.

BACKGROUND: We previously identified ezetimibe, an inhibitor of Niemann-Pick C1-like intracellular cholesterol transporter 1 and European Medicines Agency-approved lipid-lowering agent, as a potent autophagy activator. However, its efficacy against pulmonary fibrosis has not yet been evaluated. This study aimed to determine whether ezetimibe has therapeutic potential against idiopathic pulmonary fibrosis. METHODS: Primary lung fibroblasts isolated from both humans and mice were employed for mechanistic in vitro experiments. mRNA sequencing of human lung fibroblasts and gene set enrichment analysis were performed to explore the therapeutic mechanism of ezetimibe. A bleomycin-induced pulmonary fibrosis mouse model was used to examine in vivo efficacy of the drug. Tandem fluorescent-tagged microtubule-associated protein 1 light chain 3 transgenic mice were used to measure autophagic flux. Finally, the medical records of patients with idiopathic pulmonary fibrosis from three different hospitals were reviewed retrospectively, and analyses on survival and lung function were conducted to determine the benefits of ezetimibe. RESULTS: Ezetimibe inhibited myofibroblast differentiation by restoring the mechanistic target of rapamycin complex 1-autophagy axis with fine control of intracellular cholesterol distribution. Serum response factor, a potential autophagic substrate, was identified as a primary downstream effector in this process. Similarly, ezetimibe ameliorated bleomycin-induced pulmonary fibrosis in mice by inhibiting mechanistic target of rapamycin complex 1 activity and increasing autophagic flux, as observed in mouse lung samples. Patients with idiopathic pulmonary fibrosis who regularly used ezetimibe showed decreased rates of all-cause mortality and lung function decline. CONCLUSION: Our study presents ezetimibe as a potential novel therapeutic for idiopathic pulmonary fibrosis.

Ezetimibe treatment reduces oxidized low-density lipoprotein in biliary cirrhotic rats.

BACKGROUND: In liver cirrhosis, chronic inflammation is associated with an increase in oxidative stress, and subsequently an increase in the concentration of oxidized low-density lipoprotein (ox-LDL). Ezetimibe is a lipid-lowering agent with anti-inflammation and anti-oxidative stress activities. This study aimed to investigate the effect of ezetimibe treatment on ox-LDL in cirrhotic rats. METHODS: Biliary cirrhosis was induced in Sprague-Dawley rats with common bile duct ligation (BDL). Sham-operated rats served as surgical controls. Ezetimibe (10 mg/kg/d) or vehicle was administered in the sham-operated or BDL rats for 4 weeks, after which hemodynamic parameters, biochemistry data, and oxidative stress were evaluated. Plasma and intrahepatic ox-LDL levels were also examined, and hepatic proteins were analyzed to explore the mechanism of ezetimibe treatment. RESULTS: The BDL rats had typical features of cirrhosis including jaundice, impaired liver function, hyperlipidemia, and elevated ox-LDL levels compared to the sham-operated rats. Ezetimibe treatment did not affect hemodynamics, liver biochemistry, or plasma lipid levels. However, it significantly reduced oxidative stress, plasma levels of ox-LDL, and tumor necrosis factor α. In addition, ezetimibe upregulated the hepatic protein expression of an ox-LDL scavenger (lectin-like ox-LDL rececptor-1), which resulted in reductions in intrahepatic ox-LDL and fat accumulation in the BDL rats. Nevertheless, ezetimibe treatment did not ameliorate hepatic inflammation or liver fibrosis. CONCLUSION: Ezetimibe reduced plasma and intrahepatic ox-LDL levels in the cirrhotic rats. Furthermore, it ameliorated intrahepatic fat accumulation and oxidative stress. However, ezetimibe did not alleviate hepatic fibrosis or inflammation in the biliary cirrhotic rats.

Evinacumab-dgnb (Evkeeza-REGN1500), A Novel Lipid-Lowering Therapy for Homozygous Familial Hypercholesterolemia.

Chronically elevated low-density lipoprotein (LDL) has harmful effects on the vasculature including increased vasoconstriction and the formation of plaques which may rupture, causing coronary heart disease and stroke. In patients with familial hypercholesterolemia, adequate reduction of LDL is especially challenging. Although HMG-CoA reductase inhibitors (statins) are the mainstays for LDL lowering, other treatments such as proprotein convertase subtilisin/kexin type 9 inhibitors, bempedoic acid, incliseran, lomitapide, and apheresis have been employed in an effort to achieve adequate LDL reduction in these patients. Despite these available therapies, many patients with familial hypercholesterolemia do not meet the LDL targets suggested in current guidelines. Evinacumab is a novel lipid-lowering therapy that exerts its LDL-lowering effect through inhibition of angiopoietin-like protein 3 (ANGPTL3). ANGPTL3 inhibits the breakdown of triglyceride-rich lipoproteins, such as very low-density lipoprotein and chylomicrons. By inhibiting ANGPTL3, evinacumab allows these lipoproteins to be degraded, ultimately leading to reductions in LDL, high-density lipoprotein, and triglycerides. Clinical trials have demonstrated evinacumab to be safe and effective in reducing LDL. However, data are lacking regarding its potential to reduce risk of atherosclerotic cardiovascular disease. Evinacumab is generally well tolerated with the primary adverse effects comprising infusion reactions, nasopharyngitis, influenza-like illness, dizziness, rhinorrhea, and nausea. While evinacumab is an interesting therapy, until it is proven to reduce cardiovascular events, its high cost leaves its anticipated role in therapy somewhat ambiguous. In the meantime, it may be a useful therapy for those with homozygous familial hypercholesterolemia.

Widespread xanthomas regression by personalized lipid lowering therapy in heterozygous familial hypercholesterolemia.

"The lower, the better" is the recommended approach in the management of high LDL cholesterol. Unfortunately, this does not always achieve as in the case of a 69-year-old woman referred to our Institute for her lipid profile (LDL cholesterol 412mg/dl), bilateral xanthelasma and cutaneous xanthomas. With a maximized and personalized lipid-lowering therapies (rosuvastatin, ezetimibe, PCSK9i and lipoprotein apheresis), after only six months, the patient showed an impressive regression in her cutaneous xanthomas.

Impact of ezetimibe on markers of inflammation in patients treated with statins: a systematic review.

Statins are the primary pharmacological intervention to reduce LDL cholesterol; they significantly reduce inflammatory markers. Ezetimibe also reduces LDL cholesterol and reduces cardiovascular events when given on top of statin therapy. Whether ezetimibe, like statins, reduces markers of inflammation is less clear. We, therefore, conducted a systematic literature research addressing the impact of ezetimibe on CRP, TNFα and IL-6 when given on top of statin therapy. Our work indicates that overall ezetimibe reduces inflammation on top of statin treatment. However, available data are limited for CRP and even more so for TNFα and IL-6.

Impact of alirocumab/evolocumab on lipoprotein (a) concentrations in patients with familial hypercholesterolaemia: a systematic review and meta-analysis of randomized controlled trials.

INTRODUCTION: Familial hypercholesterolaemia (FH) is a common hereditary genetic disorder, characterized by elevated circulating low-density lipoprotein cholesterol (LDL-C) and lipoprotein (a) [Lp(a)] concentrations, leading to atherosclerotic cardiovascular disease (ASCVD). Two types of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors- alirocumab and evolocumab- are efficient drugs in the treatment of FH, which can effectively reduce Lp(a) levels. MATERIAL AND METHODS: Embase, MEDLINE, and PubMed up to November 2022 were searched for randomized clinical trials (RCTs) evaluating the effect of alirocumab/evolocumab and placebo treatment on plasma Lp(a) levels in FH. Statistics were analysed by Review Manager (RevMan 5.3) and Stata 15.1. RESULTS: Eleven RCTs involved a total of 2408 participants. Alirocumab/evolocumab showed a significant efficacy in reducing Lp(a) [weighted mean difference (WMD): -20.10%, 95% confidence interval (CI): -25.59% to -14.61%] compared with placebo. In the drug type subgroup analyses, although the efficacy of evolocumab was slightly low (WMD: -19.98%, 95% CI: -25.23% to -14.73%), there was no difference with alirocumab (WMD: -20.54%, 95% CI: -30.07% to -11.02%). In the treatment duration subgroup analyses, the efficacy of the 12-week duration group (WMD: -17.61%, 95% CI: -23.84% to -11.38%) was lower than in the group of ≥ 24 weeks' duration (WMD: -22.81%, 95% CI: -31.56% to -14.07%). In the participants' characteristics subgroup analyses, the results showed that no differential effect of alirocumab/evolocumab therapy on plasma Lp(a) concentrations was observed (heterozygous FH [HeFH] WMD: -20.07%, 95% CI: -26.07% to -14.08%; homozygous FH [HoFH] WMD: -20.04%, 95% CI: -36.31% to -3.77%). Evaluation of all-cause adverse events (AEs) between alirocumab/evolocumab groups and placebo groups [relative risk (RR): 1.05, 95% CI: 0.98-1.12] implied no obvious difference between the 2 groups. CONCLUSIONS: Anti-PCSK9 drugs (alirocumab and evolocumab) may be effective as therapy for reducing serum Lp(a) levels in FH, and no differences were observed in treatment durations, participant characteristics, and other aspects of the 2 types of PCSk9 inhibitors. However, further experimental studies and RCTs are warranted to clarify the mechanism of PSCK9 inhibitors to lowering Lp(a) concentrations in FH.

The evolving landscape of PCSK9 inhibition in cancer.

Cancer is a disease with a significant global burden in terms of premature mortality, loss of productivity, healthcare expenditures, and impact on mental health. Recent decades have seen numerous advances in cancer research and treatment options. Recently, a new role of cholesterol-lowering PCSK9 inhibitor therapy has come to light in the context of cancer. PCSK9 is an enzyme that induces the degradation of low-density lipoprotein receptors (LDLRs), which are responsible for clearing cholesterol from the serum. Thus, PCSK9 inhibition is currently used to treat hypercholesterolemia, as it can upregulate LDLRs and enable cholesterol reduction through these receptors. The cholesterol-lowering effects of PCSK9 inhibitors have been suggested as a potential mechanism to combat cancer, as cancer cells have been found to increasingly rely on cholesterol for their growth needs. Additionally, PCSK9 inhibition has demonstrated the potential to induce cancer cell apoptosis through several pathways, increase the efficacy of a class of existing anticancer therapies, and boost the host immune response to cancer. A role in managing cancer- or cancer treatment-related development of dyslipidemia and life-threatening sepsis has also been suggested. This review examines the current evidence regarding the effects of PCSK9 inhibition in the context of different cancers and cancer-associated complications.

A human iPSC-derived hepatocyte screen identifies compounds that inhibit production of Apolipoprotein B.

Familial hypercholesterolemia (FH) patients suffer from excessively high levels of Low Density Lipoprotein Cholesterol (LDL-C), which can cause severe cardiovascular disease. Statins, bile acid sequestrants, PCSK9 inhibitors, and cholesterol absorption inhibitors are all inefficient at treating FH patients with homozygous LDLR gene mutations (hoFH). Drugs approved for hoFH treatment control lipoprotein production by regulating steady-state Apolipoprotein B (apoB) levels. Unfortunately, these drugs have side effects including accumulation of liver triglycerides, hepatic steatosis, and elevated liver enzyme levels. To identify safer compounds, we used an iPSC-derived hepatocyte platform to screen a structurally representative set of 10,000 small molecules from a proprietary library of 130,000 compounds. The screen revealed molecules that could reduce the secretion of apoB from cultured hepatocytes and from humanized livers in mice. These small molecules are highly effective, do not cause abnormal lipid accumulation, and share a chemical structure that is distinct from any known cholesterol lowering drug.

Lipid Lowering in "Very High Risk" Patients Undergoing Coronary Artery Bypass Surgery and Its Projected Reduction in Risk for Recurrent Vascular Events: A Monte Carlo Stepwise Simulation Approach.

ABSTRACT: 2018 AHA guidelines provide criteria to identify patients at very high risk (VHR) for adverse vascular events and recommend an low density lipoprotein-C (LDL-C) level <1.8 mmol/L. Data regarding the 10-year risk for adverse vascular events in coronary artery bypass grafting (CABG) patients at VHR and the need for nonstatin therapies in the VHR cohort are limited. We queried a national cohort of CABG patients to answer these questions. The projected reduction of LDL-C from stepwise escalation of lipid-lowering therapy (LLT) was simulated; Monte Carlo methods were used to account for patient-level heterogeneity in treatment effects. Data on preoperative statin therapy and LDL-C levels were obtained. In the first scenario, all eligible patients not at target LDL-C received high-intensity statins, followed by ezetimibe and then alirocumab; alternatively, bempedoic acid was also used. The 10-year risk for an adverse vascular event was estimated using a validated risk score. Potential risk reduction was estimated after simulating maximal LLT. Before CABG, 8948 of 27,443 patients (median LDL-C 85 mg/dL) were at VHR. In the whole cohort, 31% were receiving high-intensity statins. With stepwise LLT escalation, the proportion of patients at target were 60%, 78%, 86%, and 97% after high-intensity statins, ezetimibe, bempedoic acid, and alirocumab, respectively. The projected 10-year risk to suffer a vascular event reduced by 4.6%. A large proportion of CABG patients who are at VHR for vascular events fail to meet 2018 AHA LDL-C targets. A stepwise approach, particularly with the use of bempedoic acid, can significantly reduce the need for more expensive proprotein convertase subtilisin kexin 9 inhibitors.

Thymus atlanticus polyphenol-rich extract regulates cholesterol metabolism by inhibiting its biosynthesis without affecting its excretion in hamsters fed a high-fat diet.

CONTEXT: Thymus atlanticus has been reported to have significant hypolipidaemic effect in animal models. However, the mechanism of this hypolipidaemic action still unknown. OBJECTIVE: To determinate the possible mechanism(s) of hypolipidaemic action of a Thymus atlanticus polyphenol-rich extract (PRE). MATERIALS AND METHODS: Plasma, faecal, and liver cholesterol, bile acid content in the faeces, and gene expression level of HMG-CoA reductase, CYP7A1, ABCG5 and ABCG8 were analysed after 9 weeks in hamsters feeding normal diet, high-fat diet (HFD) or HFD supplemented with 400 mg/kg body weight/day of PRE. RESULTS: PRE significantly decreased total cholesterol content (p < .05) and HMG-CoA reductase expression (p < .05), but did not affect the faecal cholesterol, bile acid contents and CYP7A1 and ABCG5/G8 expression (p > .05). CONCLUSION: We can conclude that the T. atlanticus extract is efficient in the alleviation of chronic hyperlipidaemia by acting as cholesterol biosynthesis inhibitor.

Barriers to prescribing proprotein convertase subtilisin-kexin type 9 inhibitors after coronary revascularisation.

BACKGROUND: Guidelines advocate for intensive lipid-lowering in patients with atherosclerotic cardiovascular disease (ASCVD). In May 2020, evolocumab, a proprotein convertase subtilisin-kexin type 9 (PCSK9) inhibitor, became government subsidised in Australia for patients with ASCVD requiring further low-density lipoprotein cholesterol (LDL-C) lowering. AIM: To identify barriers to prescribing PCSK9 inhibitors in hospitalised patients with ASCVD. METHODS: A retrospective 3-month, single-site, observational analysis was conducted in consecutive patients undergoing percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery. Lipid-lowering therapy prescriptions, including PSCK9 inhibitors, were assessed using electronic medical records, compared against the Australian Pharmaceutical Benefits eligibility criteria, and barriers to PCSK9 inhibitor use identified. RESULTS: Of 331 patients, 244 (73.7%) underwent PCI and 87 (26.3%) underwent CABG surgery. A lipid profile during or within 8 weeks of admission was measured for 202 (82.8%) patients undergoing PCI and 59 (67.8%) undergoing CABG surgery. In patients taking high-intensity statins on admission (n = 109), LDL-C ≥1.4, ≥1.8 and >2.6mmol/L was seen in 64 (58.7%), 44 (40.4%) and 19 (17.4%) patients respectively. High-intensity statin prescribing at discharge was high (>80%); however, ezetimibe was initiated in zero patients with LDL-C ≥1.4 mmol/L. There was variable advice given by clinicians for LDL-C targets. No patients met the criteria for subsidised PSCK9 inhibitor therapy, largely due to lack of qualifying lipid levels following combined statin and ezetimibe therapy. CONCLUSION: Prescribing of non-statin LDL-C-lowering therapies remains low in patients with ASCVD. Underprescribing of ezetimibe and suboptimal lipid testing rates are barriers to accessing subsidised PCSK9i therapy using current Australian eligibility criteria.

[Inclisiran (Leqvio®), a potent cholesterol-lowering agent by inhibiting PCSK9 using small interfering RNA-based innovative therapy]. / Le médicament du mois. L'inclisiran (Leqvio®), hypocholestérolémiant puissant inhibant la synthèse de PCSK9 par la technique innovante de l'ARN interférent.

PCSK9 (Proprotein Convertase Subtilisin/Kexin type 9) inhibition has proven its interest to potentiate the cholesterol-lowering effects of statins. Indeed, this protein contributes to the intracellular degradation of LDL cholesterol receptors and thereby reduces their recycling and expression at the hepatocyte membrane. PCSK9 inhibition allows a major and sustained reduction of LDL cholesterol (LDL-c) in patients with familial hypercholesterolaemia or with established cardiovascular disease. Two monoclonal antibodies that inhibit the effect of PCSK9 are currently commercialized, alirocumab and evolocumab. Another approach consists in the inhibition of PCSK9 synthesis. Inclisiran is a novel small interfering RNA-based therapy (anti-sense). By binding to the messenger RNA (mRNA) precursor of PCSK9, inclisiran inhibits the PCSK9 gene expression, resulting in increased hepatocyte recycling and membrane expression of LDL receptors and decreased levels of LDL-c. This article summarizes the mode of action, pharmacokinetics, efficacy, safety profile, indications and reimbursement conditions of inclisiran. This novel cholesterol-lowering drug is indicated as add-on therapy in adults with atherosclerotic cardiovascular disease or with heterozygous familial hypercholesterolaemia in whom LDL-c level is ? 100 mg/dl and does not reach target LDL-c levels despite statin and ezetimibe or without statin or ezetimibe in case of intolerance or contra-indication for one of these medications.

L'inhibition de la protéine PCSK9 («Proprotéine Convertase Subtilisine/Kexine type 9¼) a démontré son intérêt hypocholestérolémiant pour potentialiser les effets des statines. En effet, cette protéine dégrade les récepteurs au LDL au niveau intra-cellulaire et empêche leur recyclage et leur expression à la surface membranaire des hépatocytes. L'inhibition de la PCSK9 permet de réduire de façon majeure les concentrations plasmatiques de cholestérol LDL (LDL-c) chez les patients avec hypercholestérolémie familiale ou avec maladie cardiovasculaire avérée. Deux anticorps monoclonaux bloquant l'action de la PCSK9 sont actuellement commercialisés, l'alirocumab et l'évolocumab. Une autre voie d'approche consiste à bloquer la synthèse de PCSK9. L'inclisiran est un petit ARN interférent (anti-sens) qui interfère avec les ARN messagers impliqués dans la synthèse de la PCSK9. Cet article résume le mode d'action, la pharmacocinétique, l'efficacité, le profil de sécurité, les indications et les conditions de remboursement de l'inclisiran. Ce nouvel agent hypocholestérolémiant est indiqué comme traitement d'appoint chez les adultes atteints d'une maladie cardiovasculaire athéroscléreuse documentée ou d'une hypercholestérolémie familiale hétérozygote, dont le taux de LDL-c est égal ou supérieur à 100 mg/dl et qui n'atteignent pas les valeurs cibles de LDL-c malgré la prise d'une statine et d'ézétimibe ou sans ces médicaments en cas d'intolérance ou de contre-indication pour l'un d'entre eux.

Inhibitory Effect of Isoliquiritigenin in Niemann-Pick C1-Like 1-Mediated Cholesterol Uptake.

Isoliquiritigenin (ISL) is a flavonoid with a chalcone structure extracted from the natural herb Glycyrrhiza glabra. Its anti-inflammatory, antibacterial, antioxidant, and anticancer activities have been extensively studied. Moreover, ISL also possess hypolipidemic and atherosclerosis-reducing effects. However, its cholesterol-lowering mechanisms have not been reported yet. Niemann Pick C1 Like 1 (NPC1L1) is a specific transporter of cholesterol uptake. In this study, we found for the first time that ISL downregulates NPC1L1 expression and competitively inhibits cellular cholesterol uptake by binding to NPC1L1 in a concentration-dependent manner in vitro. This study provides a theoretical basis for further investigation of the molecular mechanisms of its cholesterol-lowering effect in vivo and inspired emerging drug research for cholesterol-lowering purposes through NPC1L1 inhibition.

TET2 deficiency sensitizes tumor cells to statins by reducing HMGCS1 expression.

TET2 (ten-eleven-translocation) protein is a Fe(II)- and α-ketoglutarate-dependent dioxygenase that catalyzes DNA demethylation to regulate gene expression. While TET2 gene is frequently mutated in hematological cancer, its enzymatic activity is also compromised in various solid tumors. Whether TET2 deficiency creates vulnerability for cancer cells has not been studied. Here we reported that TET2 deficiency is associated with the change of lipid metabolism processes in acute myeloid leukemia (AML) patient. We demonstrate that statins, the inhibitors of ß-Hydroxy ß-methylglutaryl-CoA (HMG-CoA) reductase and commonly used cholesterol-lowering medicines, significantly sensitize TET2 deficient tumor cells to apoptosis. TET2 directly regulates the expression of HMG-CoA synthase (HMGCS1) by catalyzing demethylation on its promoter region, and conversely TET2 deficiency leads to significant down-regulation of HMGCS1 expression and the mevalonate pathway. Consistently, overexpression of HMGCS1 in TET2-deficient cells rescues statin-induced apoptosis. We further reveal that decrease of geranylgeranyl diphosphate (GGPP), an intermediate metabolite in the mevalonate pathway, is responsible for statin-induced apoptosis. GGPP shortage abolishes normal membrane localization and function of multiple small GTPases, leading to cell dysfunction. Collectively, our study reveals a vulnerability in TET2 deficient tumor and a potential therapeutic strategy using an already approved safe medicine.

New algorithms for treating homozygous familial hypercholesterolemia.

PURPOSE OF REVIEW: We reviewed current and future therapeutic options for patients with homozygous familial hypercholesterolemia (HoFH) and place this evidence in context of an adaptable treatment algorithm. RECENT FINDINGS: Lowering LDL-C levels to normal in patients with HoFH is challenging, but a combination of multiple lipid-lowering therapies (LLT) is key. Patients with (near) absence of LDL receptor expression are most severely affected and frequently require regular lipoprotein apheresis on top of combined pharmacologic LLT. Therapies acting independently of the LDL receptor pathway, such as lomitapide and evinacumab, are considered game changers for many patients with HoFH, and may reduce the need for lipoprotein apheresis in future. Liver transplantation is to be considered a treatment option of last resort. Headway is being made in gene therapy strategies, either aiming to permanently replace or knock out key lipid-related genes, with first translational steps into humans being made. Cardiovascular disease risk management beyond LDL-C, such as residual Lp(a) or inflammatory risk, should be evaluated and addressed accordingly in HoFH. SUMMARY: Hypercholesterolemia is notoriously difficult to control in most patients with HoFH, but multi-LLT, including newer drugs, allows reduction of LDL-C to levels unimaginable until a few years ago. Cost and availability of these new therapies are important future challenges to be addressed.

Activity and Stability of Panx1 Channels in Astrocytes and Neuroblastoma Cells Are Enhanced by Cholesterol Depletion.

Pannexin1 (Panx1) is expressed in both neurons and glia where it forms ATP-permeable channels that are activated under pathological conditions such as epilepsy, migraine, inflammation, and ischemia. Membrane lipid composition affects proper distribution and function of receptors and ion channels, and defects in cholesterol metabolism are associated with neurological diseases. In order to understand the impact of membrane cholesterol on the distribution and function of Panx1 in neural cells, we used fluorescence recovery after photobleaching (FRAP) to evaluate its mobility and electrophysiology and dye uptake to assess channel function. We observed that cholesterol extraction (using methyl-ß-cyclodextrin) and inhibition of its synthesis (lovastatin) decreased the lateral diffusion of Panx1 in the plasma membrane. Panx1 channel activity (dye uptake, ATP release and ionic current) was enhanced in cholesterol-depleted Panx1 transfected cells and in wild-type astrocytes compared to non-depleted or Panx1 null cells. Manipulation of cholesterol levels may, therefore, offer a novel strategy by which Panx1 channel activation might modulate various pathological conditions.

Advancements in the Treatment of Homozygous Familial Hypercholesterolemia.

Homozygous familial hypercholesterolemia (HoFH) is a rare genetic disorder with extreme elevations of low-density lipoprotein cholesterol (LDL-C) leading to premature atherosclerotic cardiovascular disease (ASCVD) as early as in childhood. Management of HoFH centers around aggressive and adequate reduction of LDL-C levels to slow the trajectory of ASCVD development. Historically, lowering LDL-C levels in HoFH has been challenging because of both the markedly elevated LDL-C levels (often ＞400 mg/dL) and reduced response to treatment options, such as statins, for which the mechanism of action requires a functional LDL receptor. However, the treatment landscape for HoFH has rapidly progressed over the last decade. While statins and ezetimibe remain first-line treatment, patients often require addition of multiple therapies to achieve goal LDL-C levels. The PCSK9 inhibitors are an important recent addition to the available treatment options, along with lomitapide, bile acid sequestrants, and, possibly, bempedoic acid. Additionally, ANGPTL3 has emerged as an important therapeutic target, with evinacumab being the first available ANGPTL3 inhibitor on the market for the treatment of patients with HoFH. For patients who cannot achieve adequate LDL-C reduction, lipoprotein apheresis may be necessary, with the added benefit of reducing lipoprotein(a) levels that carries an added risk if also elevated in patients with HoFH. Finally, gene therapy and genome editing using CRISPR/Cas-9 are moving through clinical development and may dramatically alter the future landscape of treatment for HoFH.

The microsomal triglyceride transfer protein inhibitor lomitapide improves vascular function in mice with obesity.

OBJECTIVE: In this study, the effect of lomitapide, a microsomal triglyceride transfer protein inhibitor, on the cardiovascular function in obesity was investigated. METHODS: Eight-week-old C57BL/6 mice were fed with high-fat diet for 12 weeks in the presence and absence of lomitapide. Lomitapide was administered by gavage (1 mg/kg/d) during the last 2 weeks of high-fat feeding. Body weight, blood glucose, body composition, and lipid profile were determined. Vascular function and endothelial function markers were studied in the aorta and mesenteric resistance arteries. RESULTS: Lomitapide treatment reduced body weight in mice with obesity. Blood glucose, percentage of fat mass, total cholesterol, and low-density lipoprotein levels were significantly reduced, and the percentage of lean mass was significantly increased after lomitapide treatment. The vascular response to sodium nitroprusside in the aorta and mesenteric arteries was similar among groups. However, the vascular response to acetylcholine was improved in the treated group. This was associated with decreased levels of vascular endoplasmic reticulum stress, inflammation, and oxidative stress. CONCLUSIONS: Treatment with lomitapide attenuated the increase in body weight in mice with obesity and restored the lipid profile and vascular function. These effects were accompanied by a decrease in inflammation and oxidative stress.