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Phytosterols (PSs) have been proposed as dietary means to lower plasma LDL-C. However, concerns are raised that PSs may exert atherogenic effects, which would offset this benefit. Phytosterolemia was thought to mimic increased plasma PSs observed after the consumption of PS-enriched foods. This expert statement examines the possibility of specific atherogenicity of PSs based on sterol metabolism, experimental, animal, and human data. Observational studies show no evidence that plasma PS concentrations would be associated with an increased risk of atherosclerosis or cardiovascular (CV) events. Since variants of the ABCG5/8 transporter affect the absorption of cholesterol and non-cholesterol sterols, Mendelian randomization studies examining the effects of ABCG5/8 polymorphisms cannot support or refute the potential atherogenic effects of PSs due to pleiotropy. In homozygous patients with phytosterolemia, total PS concentrations are similar to 4000% higher than under physiological conditions. The prevalence of atherosclerosis in these individuals is variable and may mainly relate to concomitant elevated LDL-C. Consuming PS-enriched foods increases PS concentrations by similar to 35%. Hence, PSs, on a molar basis, would need to have 20-40 times higher atherogenicity than cholesterol to offset their cholesterol reduction benefit. Based on their LDL-C lowering and absence of adverse safety signals, PSs offer a dietary approach to cholesterol management. However, their clinical benefits have not been established in long-term CV endpoint studies.

The Niemann-Pick C1-Like 1 protein, a multi-transmembrane domain molecule, is critical for intestinal cholesterol absorption, and is the entry factor for hepatitis C virus (HCV). The Chinese tree shrew (Tupaia belangeri chinensis) is closer to primates in terms of genetic evolution than rodents. Previous studies indicated that the tree shrew was suitable for HCV research; however, little is known about tree shrew NPC1L1. TsNPC1L1 cDNA was amplified by rapid amplification of cDNA ends (RACE) technology. The cDNA sequence, its encoded protein structure, and expression profile were analyzed. Results indicated that the tsNPC1L1 mRNA is 4948 bp in length and encodes a 1326 amino acid protein. TsNPC1L1 possesses 84.97% identity in homology to human NPC1L1 which is higher than both mouse (80.37%) and rat (81.80%). The protein structure was also similar to human with 13 conserved transmembrane helices, and a sterol-sensing domain (SSD). Like human NPC1L1, the tsNPC1L1 mRNA transcript is highly expressed in small intestine, but it was also well-expressed in the lung and pancreas of the tree shrew. The homology of tree shrew NPC1L1 was closer to human than that of rodent NPC1L1. The expression of tsNPC1L1 was the highest in small intestine, and was detectable in lung and pancreas. These results may be useful in the study of tsNPC1L1 function in cholesterol absorption and HCV infection.

Our previous study showed that lycopene reduced the absorption of cholesterol in Caco-2 cells through inhibiting Niemann-Pick C1-Like 1 (NPC1L1) expression. Herein, we aimed to explore whether lycopene supplementation can decrease cholesterol absorption in the intestine and prevent atherosclerosis progression in high-fat diet (HFD)-fed apolipoprotein E knockout (ApoE-/-) mice. Male ApoE-/- mice were fed a high-fat diet with or without lycopene for 19 weeks. Supplementation of lycopene markedly lowered serum total cholesterol and low-density lipoprotein cholesterol (LDL-C) levels. Additionally, serum high-density lipoprotein cholesterol (HDL-C) levels were increased after lycopene administration. Lycopene also downregulated the expression of NPC1L1 and hepatocyte nuclear factor-1α (HNF-1α) in the small intestine. Furthermore, the Oil Red O staining of the aorta and aortic sinus showed that lycopene supplementation remarkably reduced atherosclerotic lesions. These results indicated that lycopene inhibited intestinal cholesterol absorption and protected against HFD-induced atherosclerosis through inhibiting HNF-1α and NPC1L1 expression. Lycopene exhibits a potential antiatherosclerotic effect through suppressing intestinal cholesterol absorption.

Coccidia are obligate apicomplexan parasites that affect humans and animals. In fast replicating species, in vitro merogony takes only 24–48 h. In this context, successful parasite proliferation requires nutrients and other building blocks. Coccidian parasites are auxotrophic for cholesterol, so they need to obtain this molecule from host cells. In humans, ezetimibe has been applied successfully as hypolipidaemic compound, since it reduces intestinal cholesterol absorption via blockage of Niemann−Pick C-1 like-1 protein (NPC1L1), a transmembrane protein expressed in enterocytes. To date, few data are available on its potential anti-parasitic effects in primary host cells infected with apicomplexan parasites of human and veterinary importance, such as Toxoplasma gondii, Neospora caninum and Besnoitia besnoiti. Current inhibition experiments show that ezetimibe effectively blocks T. gondii, B. besnoiti and N. caninum tachyzoite infectivity and replication in primary bovine endothelial host cells. Thus, 20 μm ezetimibe blocked parasite proliferation by 73.1−99.2%, via marked reduction of the number of tachyzoites per meront, confirmed by 3D-holotomographic analyses. The effects were parasitostatic since withdrawal of the compound led to parasite recovery with resumed proliferation. Ezetimibe-glucuronide, the in vivo most effective metabolite, failed to affect parasite proliferation in vitro, thereby suggesting that ezetimibe effects might be NPC1L1-independent.

Background and aims: Extensive research showed a diurnal rhythm of endogenous cholesterol synthesis, whereas recent research reported no diurnal rhythm of intestinal cholesterol absorption in males who consumed low-fat meals. Little is known about the acute effect of macronutrient consumption on cholesterol metabolism, and hence if meal composition may explain this absence of rhythmicity in cholesterol absorption. Therefore, we examined the effect of a high-fat, high-carbohydrate, and high-protein meal on postprandial intestinal cholesterol absorption and endogenous cholesterol synthesis in apparently healthy overweight and slightly obese males.Methods and results: Eighteen males consumed in random order an isoenergetic high-fat, high carbohydrate, and high-protein meal on three occasions. Serum total cholesterol concentrations, cholesterol absorption markers (campesterol, cholestanol, and sitosterol), and cholesterol synthesis intermediates (7-dehydrocholesterol, 7-dehydrodesmosterol, desmosterol, dihydrolanosterol, lanosterol, lathosterol, zymostenol, and zymosterol) were measured at baseline (T0) and 240 min postprandially (T240). Meal consumption did not significantly change total cholesterol concentrations and cholesterol absorption marker levels (all p > 0.05). Serum levels of 7dehydrocholesterol, lanosterol, lathosterol, zymostenol, and zymosterol decreased significantly between T0 and T240 (all p < 0.05). These decreases were not significantly different between the three meals (all p > 0.05), except for a larger decrease in dihydrolanosterol levels after the high-fat versus the high-carbohydrate meal (p Z 0.009).Conclusion: The high-fat, high-carbohydrate, and high-protein meal did not significantly influ-ence postprandial intestinal cholesterol absorption. Several cholesterol synthesis intermediates decreased postprandially, but the individual macronutrients did not differentially affect these intermediates, except for a possible effect on dihydrolanosterol.Trial registration: ClinicalTrials.gov, NCT03139890.(c) 2021 The Italian Diabetes Society, the Italian Society for the Study of Atherosclerosis, the Italian Society of Human Nutrition and the Department of Clinical Medicine and Surgery, Federico II University. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).

Background: Although the food quality of soy protein is known to be as good as that of animal proteins, some soybean proteins are not susceptible to digestion and remain undigested in the intestine. We hypothesized that digestion-resistant soy proteins might interact with the intestinal membrane, microbes, and metabolites, and change the intestinal physiology or the profile of the gut microbiome. Objective: To identify the Protease-Resistant Soy Proteins (PRSPs) and their interaction with intestinal membrane proteins by MS, and to assess the functions of PRSPs in the small intestine. Methods: Soy proteins were sequentially digested with pepsin and pancreatin, and the PRSPs were identified by SDS-PAGE and MS. Intestinal cell membrane proteins interacting with PRSPs were isolated by affinity purification and photo-affinity crosslinking, and identified using MS/MS. Inhibition of cholesterol absorption to lipoprotein-depleted intestinal cells, CaCo-2, and hepatic cells, HepG2, was measured in the presence and absence of PRSPs. FITC-conjugated Gram-positive, Lactobacillus plantarum, and Gram-negative bacteria, Escherichia coli, were incubated with Ca- Co-2 cells in the presence of PRSPs to investigate the regulation of bacterial cell binding to intestinal epithelial cells by PRSPs. Results: MS/MS of PRSPs identified glycinin, β-conglycinin, trypsin inhibitors, lipoxygenase, and sucrose-binding protein. MS analysis also identified the intestinal membrane proteins bound to PRSPs. The functions of the identified interacting proteins included ion transportation, carbohydrate- binding, cytoskeleton formation, hydrolysis, cell-cell junction formation, and cholesterol/steroid- binding. In particular, apolipoprotein E, aminopeptidase N, and Niemann-Pick C1-like protein 1 are known to be involved in cholesterol absorption in the small intestine. The inhibition of cholesterol absorption by CaCo-2 and HepG2 cells by PRSPs confirmed the MS results. Binding of L. plantarum and E. coli to CaCo-2 cells was efficiently inhibited by PRSPs. Conclusion: PRSPs can interact with intestinal membrane proteins, and regulate cholesterol absorption by intestinal epithelial cell and interactions of the gut microbiome. Soy protein in the intestine acts as a nutrient, and triggers changes in intestinal functions by interacting with intestinal cells, microorganisms, and nutrients. These findings will provide valuable new functional information about the effects of soy proteins on human health.

Cholesterol gallstone disease is a common global condition. This study investigated the role of plant sterols (PS) in the prevention of gallstone formation and the underlying mechanisms. Adult male mice were fed a lithogenic diet (LD) alone or supplemented with PS (LD-ps), phospholipids (LD-pl) or both PS and phospholipids (LD-ps/pl) for 8 weeks. Incidences of gallstone formation were compared among the groups. Lipids in the bile, liver and serum were analyzed. The expression of genes involved in cholesterol absorption, transport and metabolism in the liver and small intestine was determined. The incidences of gallstone formation were 100% (10/10), 20% (2/10), 100% (10/10) and 40% (4/10) in the LD, LD-ps, LD-pl and LD-ps/pl groups, respectively. Serum cholesterol and intestinal cholesterol absorption were decreased in PS-supplemented mice. The expression of genes related to cholesterol transport and metabolism in the liver was down-regulated by dietary PS. PS supplementation decreased Niemann-Pick C1-like 1 expression in the small intestine and reduced intestinal cholesterol absorption. Our results demonstrated that PS could inhibit intestinal cholesterol absorption and thus prevent cholesterol gallstone formation.

Plasma concentrations of phytosterols and non-cholesterol sterol precursors of cholesterol synthesis have been used as markers of intestinal cholesterol absorption and synthesis in inherited and secondary dyslipidemias and in population-based investigations to evaluate the risk for cardiovascular disease, respectively. The method aims at replacing initial research procedures such as the use of stable isotopes associated with fecal steroid balance, which are limited by the high cost and tedious procedures. However, we show in this review that numerous results obtained with serum sterol measurements are contradictory. In this regard, the following points are discussed: 1) how phytosterols relate to atherosclerosis considering that defects in biliary output or in the transport of phytosterols from the intestinal mucosa back into the intestinal lumen provide increased content of phytosterols and other sterols in plasma and tissues, thus not allowing to conclude that their presence in arteries and atheromas represents the etiology of atherosclerosis; 2) serum non-cholesterol sterols as markers of cholesterol synthesis and absorption, such as cholestanol, present discrepant results, rendering them often inadequate to identify cases of coronary artery disease as well as alterations in the whole body cholesterol metabolism; 3) such methods of measurement of cholesterol metabolism are confounded by factors like diabetes mellitus, body weight and other pathologies including considerable hereditary hyperlipidemias biological variabilities that influence the efficiency of synthesis and intestinal absorption of cholesterol.

Intestinal cholesterol absorption varies widely between individuals, which may translate into differences in responsiveness to cholesterol-lowering drugs or diets. Therefore, understanding the importance of genetic variation on cholesterol absorption rates and the complex intestinal cholesterol network is important. Based on a systematic review, genetic variants in seven genes (ABCG5, ABCG8, ABO, APOE, MTTP, NPC1L1, and LDLR) were identified that were associated with intestinal cholesterol absorption. No clear associations were found for variants in APOA4, APOB, CETP, CYP7A1, HMGCR, SCARB1, SLCO1B1, and SREBF1. The seven genes were used to construct an intestinal cholesterol absorption network. Finally, a network with fifteen additional genes (APOA1, APOA4, APOB, APOC2, APOC3, CETP, HSPG2, LCAT, LDLRAP1, LIPC, LRP1, OLR1, P4HB, SAR1B, and SDC1) was generated. The constructed network shows that cholesterol absorption is complex. Further studies are needed to validate and improve this network, which may ultimately lead to a better understanding of the wide inter-individual variability in intestinal cholesterol absorption and the development of personalized interventions.

Intestinal cholesterol absorption varies widely between individuals, which may translate into differences in responsiveness to cholesterol-lowering drugs or diets. Therefore, understanding the importance of genetic variation on cholesterol absorption rates and the complex intestinal cholesterol network is important. Based on a systematic review, genetic variants in seven genes (ABCG5, ABCG8, ABO, APOE, MTTP, NPC1L1, and LDLR) were identified that were associated with intestinal cholesterol absorption. No clear associations were found for variants in APOA4, APOB, CETP, CYP7A1, HMGCR, SCARB1, SLCO1B1, and SREBF1. The seven genes were used to construct an intestinal cholesterol absorption network. Finally, a network with fifteen additional genes (APOA1, APOA4, APOB, APOC2, APOC3, CETP, HSPG2, LCAT, LDLRAP1, LIPC, LRP1, OLR1, P4HB, SAR1B, and SDC1) was generated. The constructed network shows that cholesterol absorption is complex. Further studies are needed to validate and improve this network, which may ultimately lead to a better understanding of the wide inter-individual variability in intestinal cholesterol absorption and the development of personalized interventions.

Aims Atherosclerotic cardiovascular disease (ACVD) is a major cause of mortality and morbidity worldwide, and increased low-density lipoproteins (LDLs) play a critical role in development and progression of atherosclerosis. Here, we examined for the first time gut immunomodulatory effects of the microbiota-derived metabolite propionic acid (PA) on intestinal cholesterol metabolism. Methods and results Using both human and animal model studies, we demonstrate that treatment with PA reduces blood total and LDL cholesterol levels. In apolipoprotein E−/− (Apoe −/−) mice fed a high-fat diet (HFD), PA reduced intestinal cholesterol absorption and aortic atherosclerotic lesion area. Further, PA increased regulatory T-cell numbers and interleukin (IL)-10 levels in the intestinal microenvironment, which in turn suppressed the expression of Niemann-Pick C1-like 1 (Npc1l1), a major intestinal cholesterol transporter. Blockade of IL-10 receptor signalling attenuated the PA-related reduction in total and LDL cholesterol and augmented atherosclerotic lesion severity in the HFD-fed Apoe −/− mice. To translate these preclinical findings to humans, we conducted a randomized, double-blinded, placebo-controlled human study (clinical trial no. NCT03590496). Oral supplementation with 500 mg of PA twice daily over the course of 8 weeks significantly reduced LDL [−15.9 mg/dL (−8.1%) vs. −1.6 mg/dL (−0.5%), P = 0.016], total [−19.6 mg/dL (−7.3%) vs. −5.3 mg/dL (−1.7%), P = 0.014] and non-high-density lipoprotein cholesterol levels [PA vs. placebo: −18.9 mg/dL (−9.1%) vs. −0.6 mg/dL (−0.5%), P = 0.002] in subjects with elevated baseline LDL cholesterol levels. Conclusion Our findings reveal a novel immune-mediated pathway linking the gut microbiota-derived metabolite PA with intestinal Npc1l1 expression and cholesterol homeostasis. The results highlight the gut immune system as a potential therapeutic target to control dyslipidaemia that may introduce a new avenue for prevention of ACVDs.

Background and aims Acyl-CoA:diacylglycerol acyltransferase 1 (DGAT1) is the rate-limiting enzyme catalyzing the final step of triglyceride synthesis by esterifying a diglyceride with a fatty acid. We have previously shown that apolipoprotein E-knockout (ApoE−/−) mice lacking Dgat1 have reduced intestinal cholesterol absorption and potentiated macrophage cholesterol efflux, and consequently, exhibit attenuated atherogenesis. However, hematopoietic Dgat1 deficiency lacked beneficial effects on atherosclerosis. Due to our recent results on the critical role of intestinal Dgat1 in murine cholesterol homeostasis, we delineated whether intestinal Dgat1 deficiency regulates atherogenesis in mice. Methods We generated intestine-specific Dgat1−/− mice on the ApoE−/− background (iDgat1−/−ApoE−/−) and determined cholesterol homeostasis and atherosclerosis development. Results When fed a Western-type diet, iDgat1−/−ApoE−/− mice exhibited a substantial decrease in fasting plasma cholesterol content in ApoB-containing lipoproteins. Although lipid absorption was delayed, iDgat1−/−ApoE−/− mice had reduced acute and fractional cholesterol absorption coupled with an elevated fecal caloric loss. In line, increased appearance of i.v. administered [³H]cholesterol in duodena and stool of iDgat1−/−ApoE−/− animals suggested potentiated cholesterol elimination. Atherosclerotic lesions were markedly smaller with beneficial alterations in plaque composition as evidenced by reduced macrophage infiltration and necrotic core size despite unaltered collagen content, indicating improved plaque stability. Conclusions Disruption of Dgat1 activity solely in the small intestine of ApoE−/− mice strongly decreased plasma cholesterol levels by abrogating the assimilation of dietary cholesterol, partly by reduced absorption and increased excretion. Consequently, the reduced cholesterol burden significantly attenuated atherogenesis and improved the lesion phenotype in iDgat1−/−ApoE−/− mice.

Purpose Consumption of the algae spirulina (Arthrospira platensis or maxima) and wakame (Undaria pinnatifida) has been shown to lower LDL cholesterol concentrations in animals and humans, possibly due to the inhibition of intestinal cholesterol absorption. This mechanism, however, has never been investigated in humans. Therefore, we examined in non-hypercholesterolemic men and women the effects of spirulina and wakame consumption on serum markers for intestinal cholesterol absorption. Methods Thirty-five healthy men and women without hypercholesterolemia consumed in a random order daily 4.8 g spirulina, wakame or placebo for 17 days, separated by 14-day washouts. After 17 days, serum cholesterol-standardized campesterol, sitosterol and cholestanol, and lathosterol concentrations were measured as markers for intestinal cholesterol absorption and cholesterol synthesis, respectively. Concentrations of serum total cholesterol, LDL and HDL cholesterol, triacylglycerol, and plasma glucose, and blood pressure were measured as well. Results Compared with placebo, spirulina or wakame did not affect serum cholesterol-standardized campesterol (CI − 0.23 to 0.10 μmol/mmol, P = 0.435 and CI − 0.14 to 0.19 μmol/mmol, P = 0.729, respectively), sitosterol (P = 0.314 and P = 0.112), cholestanol (P = 0.610 and P = 0.809), or lathosterol (P = 0.388 and P = 0.102) concentrations. In addition, serum lipid and plasma glucose concentrations, and blood pressure were not changed. Conclusions Daily consumption of 4.8 g spirulina or wakame for 17 days did not affect plasma markers for intestinal cholesterol absorption or cholesterol synthesis in non-hypercholesterolemic men and women. Serum lipid and glucose concentrations, and blood pressure were also not altered. Electronic supplementary material The online version of this article (10.1007/s00394-019-02073-7) contains supplementary material, which is available to authorized users.

Reverse cholesterol transport (RCT) and transintestinal cholesterol efflux (TICE) are two important pathways for body cholesterol elimination. We studied these pathways in an animal model of diabetes and obesity (ob/ob) where HDL function is compromised as a result of hyperglycemia, low-grade inflammation and oxidative stress. Co-treatment of ob/ob mice with PPAR-α (fenofibrate) and LXR (T0901317) agonists increased fecal cholesterol by 12-fold; PPAR-α and LXR agonists individually showed 2.6- and 4.0-fold fecal cholesterol excretion, respectively. We investigated the mechanism of synergistic efficacy of PPAR-α and LXR agonists in fecal cholesterol excretion. LXR agonist and the combination of PPAR-α and LXR agonists had greater HDL-C elevation. Ex vivo cholesterol efflux showed correlation with the fecal cholesterol excretion but was not sufficient to explain 12-fold increases in the fecal cholesterol in the co-treated mice. Therefore, we examined TICE to explain the 12-fold increases in the fecal cholesterol. A strong positive correlation of fecal cholesterol with ATP binding cassette transporter G5 (ABCG5) and G8 and anegative correlation with NPC1L1 was observed. ABCG5, G8 and NPC1L1 are involved in intestinal cholesterol absorption. The extent of influence of PPAR-α and LXR agonists on RCT and TICE was distinctly different. PPAR-α agonist increased fecal cholesterol primarily by influencing TICE, while LXR agonist influenced fecal cholesterol excretion via both RCT and TICE mechanisms. Synergistic efficacy on fecal cholesterol excretion following co-treatment with PPAR-α and LXR agonists occurred through a combination of RCT, TICE, and the key enzyme in bile synthesis, cholesterol 7-α hydroxylase (cyp7a1). These results suggest that cholesterol efflux, biliary cholesterol excretion, and TICE collectively contributed to the 12-fold increases in the fecal cholesterol excretion in ob/ob mice co-treated with PPAR-α and LXR agonists.

Background: Patients with metabolic syndrome (MetS) have increased endogenous synthesis of cholesterol, together with lower level of intestinal cholesterol absorption. However, less is known about ...

Phytosterol serum concentrations are under tight genetic control. The relationship between phytosterols and coronary artery disease (CAD) is controversially discussed. We perform a genome-wide meta-analysis of 32 phytosterol traits reflecting resorption, cholesterol synthesis and esterification in six studies with up to 9758 subjects and detect ten independent genome-wide significant SNPs at seven genomic loci. We confirm previously established associations at ABCG5/8 and ABO and demonstrate an extended locus heterogeneity at ABCG5/8 with different functional mechanisms. New loci comprise HMGCR, NPC1L1, PNLIPRP2, SCARB1 and APOE. Based on these results, we perform Mendelian Randomization analyses (MR) revealing a risk-increasing causal relationship of sitosterol serum concentrations and CAD, which is partly mediated by cholesterol. Here we report that phytosterols are polygenic traits. MR add evidence of both, direct and indirect causal effects of sitosterol on CAD., Physterols are cholesterol homologs derived from plants, which are found in humans through consumption of plant products. Here the authors have performed a genome-wide meta-analysis of 32 serum phytosterol traits, with evidence suggesting causality between sitosterol and coronary artery disease.

Dietary phytosterols, which comprise plant sterols and stanols, reduce plasma Low-Density Lipoprotein-Cholesterol (LDL-C) levels when given 2 g/day. Since this dose has not been reported to cause health-related side effects in long-term human studies, food products containing these plant compounds are used as potential therapeutic dietary options to reduce LDL-C and cardiovascular disease risk. Several mechanisms have been proposed to explain the cholesterol-lowering action of phytosterols. They may compete with dietary and biliary cholesterol for micellar solubilization in the intestinal lumen, impairing intestinal cholesterol absorption. Recent evidence indicates that phytosterols may also regulate other pathways. Impaired intestinal cholesterol absorption is usually associated with reduced cholesterol transport to the liver, which may reduce the incorporation of cholesterol into Very-Low- Density Lipoprotein (VLDL) particles, thereby lowering the rate of VLDL assembly and secretion. Impaired liver VLDL production may reduce the rate of LDL production. On the other hand, significant evidence supports a role for plant sterols in the Transintestinal Cholesterol Excretion (TICE) pathway, although the exact mechanisms by which they promote the flow of cholesterol from the blood to enterocytes and the intestinal lumen remains unknown. Dietary phytosterols may also alter the conversion of bile acids into secondary bile acids, and may lower the bile acid hydrophobic/hydrophilic ratio, thereby reducing intestinal cholesterol absorption. This article reviews the progress to date in research on the molecular mechanisms underlying the cholesterol-lowering effects of phytosterols.

Sphingomyelin (SM) is a widely occurring sphingolipid that is a major plasma membrane constituent. Milk and dairy products are rich SM sources, and human milk has high SM content. Numerous studies have evaluated the roles of SM in maintaining cell membrane structure and cellular signal transduction. There has been a growing interest in exploring the role of dietary SM, especially from human milk, in imparting health benefits. This review focuses on recent publications regarding SM content in several dietary sources and dietary SM metabolism. SM digestion and absorption are slow and incomplete and mainly occur in the middle sections of the small intestine. This review also evaluates the effect of dietary SM on gut health and cognitive development. Studies indicate that SM may promote gut health by reducing intestinal cholesterol absorption in adults. However, there has been a lack of data supporting clinical trials. An association between milk SM and neural development is evident before childhood. Hence, additional studies and well-designed randomized controlled trials that incorporate dietary SM evaluation, SM metabolism, and its long-term functions on infants and children are required.

Single nucleotide polymorphisms (SNPs) have been associated with cholesterol metabolism and may partly explain large inter-individual variability in intestinal cholesterol absorption and endogenous cholesterol synthesis rates. This cross-sectional study therefore examined whether SNPs in genes encoding for proteins involved in intestinal cholesterol absorption (ABCG5, ABCG8, and NPC1L1) and endogenous cholesterol synthesis (CYP51A1, DHCR7, DHCR24, HMGCR, HSD17B7, LBR, and MSMO1) were associated with intestinal cholesterol absorption markers (total cholesterol (TC) standardized campesterol and sitosterol levels), an endogenous cholesterol synthesis marker (TC-standardized lathosterol levels), and serum low-density lipoprotein cholesterol (LDL-C) concentrations in a European cohort. ABCG5 (rs4245786) and the tag SNP ABCG8 (rs4245791) were significantly associated with serum campesterol and/or sitosterol levels. In contrast, NPC1L1 (rs217429 and rs217416) were significantly associated with serum lathosterol levels. The tag SNP in HMGCR (rs12916) and a SNP in LBR (rs12141732) were significantly associated with serum LDL-C concentrations. SNPs in the cholesterol absorption genes were not associated with serum LDL-C concentrations. SNPs in CYP51A1, DHCR24, HSD17B7, and MSMO1 were not associated with the serum non-cholesterol sterols and LDL-C concentrations. Given the variable efficiency of cholesterol-lowering interventions, the identification of SNPs associated with cholesterol metabolism could be a step forward towards personalized approaches.

Background：Flaxseed peptide (FPs) showed serum cholesterol-lowering activity in SD rats fed a high-cholesterol diet, but the cholesterol-lowering amino acid sequences and mechanism of FPs were still unclear. Methods: FPs were separated via ultrafiltration, and the amino acid sequences of the selected fractions were determined via high-performance liquid chromatography- Electrospray Ionisation - Orbitrap- Mass spectrometry (HPLC-ESI-Orbitrap MS). These peptides then were synthesized by solid-phase synthesis (SPPS). IPPF with the highest CMSR was determined to exist in flaxseed protein by specific antibodies. The effects of IPPF on intestinal cholesterol absorption and hepatic cholesterol metabolism were investigated in Caco-2 cells and HepG2 cells.Results：1 kDa FP5 fraction had the highest cholesterol micelle solubility inhibition rate (CMSR) 72.39% compared with the other ultrafiltration fractions. Then Eleven peptides were identified from FP5. Ile-Pro-Pro-Phe (IPPF), with the highest CMSR 93.47%, was selected to research the cholesterol-lowering mechanism in Caco-2 and HepG2 cells. IPPF significantly reduces the amount of cholesterol transported in Caco2 cells and the amount of total cholesterol in HepG2 cells. IPPF significantly modulated the protein levels of NCP1L1 and ABCG5/8 in Caco2 cells and significantly reduced the mRNA levels of Srebp-2 and Hmgcr in HepG2 cells. Conclusion: IPPF inhibits cholesterol intestinal absorption through modulating the expression of cholesterol transporters in Caco-2 cells and reduces hepatic cholesterol synthesis through inhibiting the SREBP2-regulated mevalonate (HMGCR) pathway in HepG2 cells. IPPF is a new food-derived inhibitor of intestinal cholesterol absorption and hepatic cholesterol synthesis without side effects and provides a nutritional therapy component for hypercholesterolemia.

The prevalence of metabolic disorders characterized by chronic inflammation has been on a sharp rise for decades. As such, tools that address metabolic and inflammatory dysregulation are of great importance. Plant stanols are well-known for reducing intestinal cholesterol absorption and may also have direct anti-inflammatory effects. In this study, our aim was to investigate to what extent the benefits of dietary plant stanol supplementation depend on dietary cholesterol intake in an experimental mouse model for cholesterol-induced metabolic inflammation. Here, we used Ldlr−/− mice transplanted with Npc1nih-derived bone marrow, featuring feature bone marrow-derived immune cells characterized by chronic inflammation induced by lysosomal lipid accumulation. Npc1nih- and Npc1wt-transplanted mice were placed on either a high fat, high cholesterol (HFC) or on a chow diet low in cholesterol, with or without 2% plant stanols supplementation. At the end of the study, the metabolic and inflammatory status of the mice was analyzed. Plant stanol supplementation to the HFC diet reduced liver cholesterol levels and improved lipid metabolism and liver inflammation, particularly in Npc1nih-tp mice. In contrast, plant stanol supplementation to the chow diet did not significantly improve the aforementioned parameters, though similar reductive trends to those in the HFC diet setting were observed regarding liver cholesterol accumulation and liver inflammatory markers. The effects of dietary plant stanol supplementation on dietary cholesterol-induced inflammation are largely dependent on dietary cholesterol intake. Future research should verify whether other models of metabolic inflammation exhibit similar stanol-related effects on inflammation.

Abnormal lipid metabolism leads to the development of hyperlipidemia, a common cause of multiple chronic disorders, including cardiovascular disease (CVD), obesity, diabetes, and cerebrovascular disease. Low-density lipoprotein cholesterol (LDL-C) currently remains the primary target for treatment of hyperlipidemia. Despite the advancement of treatment and prevention of hyperlipidemia, medications used to manage hyperlipidemia are limited to allopathic drugs, which present certain limitations and adverse effects. Increasing evidence indicates that utilization of phytochemicals and plant-based whole foods is an alternative and promising strategy to prevent hyperlipidemia and CVD. The current review focuses on phytochemicals and their pharmacological mode of actions for the regulation of LDL-C and prevention of CVD. The important molecular mechanisms illustrated in detail in this review include elevation of reverse cholesterol transport, inhibition of intestinal cholesterol absorption, acceleration of cholesterol excretion in the liver, and reduction of cholesterol synthesis. Moreover, the beneficial effects of plant-based whole foods, such as fresh fruits, vegetables, dried nuts, flax seeds, whole grains, peas, beans, vegan diets, and dietary fibers in LDL-C reduction and cardiovascular health are summarized. This review concludes that phytochemicals and plant-based whole foods can reduce LDL-C levels and lower the risk for CVD.

Phytosterols reduce intestinal cholesterol absorption and help to lower LDL-cholesterol. Many Chinese adults are lactose-intolerant and cannot tolerate bovine milk enriched with phytosterol. Soya-milk is a common beverage in Asia and it has beneficial effects on general health. We therefore conducted a randomized double-blind controlled trial to assess the effectiveness of a phytosterols-enriched soya drink in lowering serum LDL-cholesterol level (primary outcome) and other cardiovascular parameters (secondary outcomes). One hundred and fifty-nine normocholesterolaemic participants (85 men and 74 women; aged 19–79) were randomized to daily intake of one serving of phytosterols-enriched soya drink (N = 82), equivalent to 2 g of phytosterol per day, or a matched soya drink without phytosterols (N = 77) for 3 weeks. Adverse events, withdrawal and compliance were documented. Among the treatment group (N = 82), phytosterols-enriched soya drink significantly decreased LDL-cholesterol by 5.96% (SE 1.48, 95% CI − 8.91%, − 3.00%) with a median of 6.74% compared with baseline, resulting in a significant reduction of 4.70% (95% CI − 8.89%, − 0.51%; p = 0.028) with a median of 5.20% compared with placebo (N = 77). In contrast, there were no significant changes in other lipid parameters, blood glucose, blood pressure, body weight or waist circumference. Remarkably, 95% of the participants randomized to the fortified drink reported no adverse events at all. Daily consumption of a phytosterols-enriched soya drink may be a simple and cost-neutral means of lowering LDL-cholesterol in individuals in China, with massive population and rising incidence of coronary heart disease (ClinicalTrials.gov identifier: NCT02881658; date of registration: 14 Aug 2016).

Cholecystokinin (CCK) is an important neuro-intestinal peptide hormone produced by the enteroendocrine I-cells in the upper part of small intestine. Protein- and fat-enriched food plays an important role in triggering CCK secretion from the intestine. Carbohydrates stimulate only small amounts of CCK release. The CCK-1 receptor (CCK-1R) is largely localized in the gallbladder, sphincter of Oddi, pancreas, small intestine, gastric mucosa, and pyloric sphincter, where it is responsible for CCK to regulate multiple digestive processes including gallbladder contraction, pancreatic secretion, small intestinal transit, and gastric emptying. Accumulated evidence clearly demonstrates that CCK regulates gallbladder and small intestinal motility through CCK-1R signaling cascade and the effect of CCK-1R on small intestinal transit is a physiological response for regulating intestinal cholesterol absorption. Disruption of the Cck or the Cck-1r gene in mice significantly increases the formation of cholesterol gallstones by disrupting gallbladder emptying and biliary cholesterol metabolism, as well as promoting intestinal absorption of cholesterol. Abnormalities in gallbladder motility function in response to exogenously administered CCK are found primarily in patients with cholesterol gallstones. Patients with pigment gallstones display an intermediate degree of gallbladder motility defect without gallbladder inflammation and enlarged fasting gallbladder. Dysfunctional gallbladder contractility has been found under several conditions such as pregnancy, obesity, diabetes, celiac disease, and total parenteral nutrition although gallstones are not observed. The gallbladder-specific CCK-1R-selective agonist may lead to an efficacious novel way for preventing gallstone formation by promoting gallbladder emptying, particularly for pregnant women and subjects with dysfunctional gallbladder motility function such as celiac patients, as well as patients with total parenteral nutrition.

Transintestinal cholesterol excretion (TICE) is a major route for eliminating cholesterol from the body and a potential therapeutic target for hypercholesterolemia. The underlying mechanism, however, is largely unclear, and its contribution to cholesterol disposal from the body is obscured by the counteracting process of intestinal cholesterol reabsorption. To determine the quantity of TICE independent from its reabsorption, we studied two models of decreased intestinal cholesterol absorption. Cholesterol absorption was inhibited either by ezetimibe or, indirectly, by the genetic inactivation of the intestinal apical sodium-dependent bile acid transporter (ASBT; SLC10A2). Both ezetimibe treatment and Asbt inactivation virtually abrogated fractional cholesterol absorption (from 46% to 4% and 6%, respectively). In both models, fecal neutral sterol excretion and net intestinal cholesterol balance were considerably higher than in control mice (5- and 7-fold, respectively), suggesting that, under physiological conditions, TICE is largely reabsorbed. In addition, the net intestinal cholesterol balance was increased to a similar extent but was not further increased when the models were combined, suggesting that the effect on cholesterol reabsorption was already maximal under either condition alone. On the basis of these findings, we hypothesize that the inhibition of cholesterol (re)absorption combined with stimulating TICE will be most effective in increasing cholesterol disposal.

Hypercholesterolemia is a preventable risk factor for atherosclerosis and cardiovascular disease. However, the mechanisms of diosgenin (DG) that promote cholesterol homeostasis and alleviate hypercholesterolemia remain elusive. To investigate the effects and molecular mechanisms of the promotion of cholesterol metabolism by DG, a rat model of hypercholesterolemia was induced by providing a high-fat diet for 4 weeks. After 4 weeks, the rats were intragastrically administered high-dose DG (0.3 g/kg/d), low-dose DG (0.15 g/kg/d) or simvastatin (4 mg/kg/d) once a day for 8 weeks. The serum and hepatic cholesterol were tested, the mRNA and protein expression levels of Niemann-Pick C1-Like 1 (NPC1L1), liver X receptor-α (LXR-α) and the ATP-binding cassette G5/G8 (ABCG5/G8) transporters were measured. The results indicate that DG could reduce body weight, decrease the serum total cholesterol, triglyceride, low-density lipoprotein cholesterol, liver total cholesterol and free cholesterol levels compared to those in the controls. Simultaneously, liver tissue pathological morphology analyses revealed that DG could attenuate hepatic steatosis compared to that in the high-fat diet group. Further investigation demonstrated that DG significantly decreased the expression of NPC1L1 and LXR-α in the intestine and markedly increased the expression of ABCG5/G8 in the liver and intestine. Compared to the high-fat diet group, the rats in the DG-treated groups ameliorated hypercholesterolemia in a dose- and time-dependent manner. These data suggest that DG may not only inhibit intestinal cholesterol absorption by downregulating NPC1L1 but also enhance cholesterol excretion by increasing the expression of ABCG5/G8. DG could be a new candidate for the prevention of hypercholesterolemia.

Atherosclerosis is the major cause of cardiovascular diseases, which are considered the fatal ailment globally. Hypercholesterolaemia plays a critical role in the development of atherosclerosis and cardiovascular diseases. Many studies have been stated that probiotics could affect hypercholesterolemia via cholesterol metabolism. Probiotics are live bacteria which are good for our health when administered orally in high amounts. Recently, many studies have revealed the beneficial effects of the nutritional ingestion of probiotics which can decrease serum cholesterol levels. The aim of this review is, firstly, to explore the hypercholesterolemia effect of how it progresses into atherosclerosis and, secondly, to summarize the hypocholesterolaemia effect of probiotics on atherosclerosis and the up-to-date information on their basic mechanisms. The most important mechanisms responsible for the hypocholesterolemic effect of probiotics are the suppression of the reabsorption of bile acids and inhibition of the intestinal cholesterol absorption. Current studies indicate that numerous mechanisms within the cholesterol metabolism, e.g., ones involving the Niemann-Pick C1-Like 1 protein, 3-hydroxy-3-methylglutaryl-CoA reductase, and 7α- and 27α-hydroxylases, have been recommended where regulation may take place after oral intake of probiotics. However, these mechanisms are still poorly understood. Thus, further studies are required to examine the possible mechanisms, whereby probiotics can be utilized safely and considered for the treatment of hypercholesterolemia.

BACKGROUND/OBJECTIVES Consumption of cholesterol-rich foods, such as eggs, has a minimal effect on circulating cholesterol levels in healthy humans. To gain insight, we investigated whether phospholipids rich in eggs (EPL) interfere with intestinal cholesterol absorption in vivo. MATERIALS/METHODS To investigate the acute effect of EPL on intestinal cholesterol absorption, male C57BL/6J mice were orally administered with 6, 11, or 19 mg of EPL for three days. We also tested the effect of chronic EPL consumption on cholesterol metabolism in the small intestine and the liver in mice with diet-induced hypercholesterolemia. Male C57BL/6J mice were fed a high fat/high cholesterol (HF/HC; 35% fat, 0.25% cholesterol, w/w) diet for 4 weeks to induce hypercholesterolemia, and subsequently the mice were either fed 0, 0.4 or 0.8% (w/w) of EPL for 6 weeks. RESULTS Intestinal cholesterol absorption was significantly decreased by the highest dose of acute EPL administration compared to control. Chronic EPL supplementation did not significantly alter intestinal cholesterol absorption nor plasma levels of total cholesterol and low-density lipoprotein cholesterol. In the small intestine and the liver, EPL supplementation minimally altered the expression of genes which regulate cellular cholesterol levels. CONCLUSION Although chronic EPL consumption was not able to counteract hypercholesterolemia in HF/HC-fed mice, acute EPL administration decreased intestinal cholesterol absorption. This study provides in vivo evidence that acute administration of PLs in eggs prevent cholesterol absorption in the intestine, suggesting a mechanism for a minimal effect of egg consumption on circulating cholesterol levels.

Cardiovascular diseases caused by atherosclerosis have become one of the leading cause of death. The aim of the present study was to explore how oat fiber regulated lipid metabolism and to elucidate its anti-atherosclerotic potential in ApoE−/− mice. Animals were daily fed a high-fat diet without or with 0.8% oat fiber for 18 weeks. Both serum total cholesterol and low-density cholesterol levels decreased in mice received oat fiber administration than those without Oat fiber inhibited hepatic lipid accumulation by downregulating SREBP-1 expression and accelerated clearance of intestinal cholesterol by upregulating SREBP-2 expression. In addition, oat fiber activated cholesterol sensors LXRα, and then strengthened hepatic and intestinal cholesterol efflux by increasing ATP-binding cassette A1 and G1, and decreased intestinal cholesterol absorption by inhibiting Niemann pick C 1 like 1. The findings implicated that oat fiber had an anti-atherosclerotic potential via mechanisms of activating the SREBPs/LXRα pathway and improving lipid metabolism.

Dietary plant sterols and stanols as present in our diet and in functional foods are well-known for their inhibitory effects on intestinal cholesterol absorption, which translates into lower low-density lipoprotein cholesterol concentrations. However, emerging evidence suggests that plant sterols and stanols have numerous additional health effects, which are largely unnoticed in the current scientific literature. Therefore, in this review we pose the intriguing question "What would have occurred if plant sterols and stanols had been discovered and embraced by disciplines such as immunology, hepatology, pulmonology or gastroenterology before being positioned as cholesterol-lowering molecules?" What would then have been the main benefits and fields of application of plant sterols and stanols today? We here discuss potential effects ranging from its presence and function intrauterine and in breast milk towards a potential role in the development of non-alcoholic steatohepatitis (NASH), cardiovascular disease (CVD), inflammatory bowel diseases (IBD) and allergic asthma. Interestingly, effects clearly depend on the route of entrance as observed in intestinal-failure associated liver disease (IFALD) during parenteral nutrition regimens. It is only until recently that effects beyond lowering of cholesterol concentrations are being explored systematically. Thus, there is a clear need to understand the full health effects of plant sterols and stanols.

[Purpose] / Oxycholesterols (OCs) are produced from cholesterol by oxidation of the steroidal backbone and side-chain. OCs are present in blood and evidence suggests their involvement in disease development and progression. However, limited information is available regarding the absorption mechanisms and relative absorption rates of dietary OCs. Although ezetimibe is known to inhibit intestinal cholesterol absorption via Niemann-Pick C1-Like 1 (NPC1L1), whether it also inhibits dietary OC absorption is unclear. / / [Methods] / We investigated the effects of ezetimibe on OC absorption in rats fed an OC-rich diet containing 10 different OCs. We collected lymphatic fluid using permanent cannulation of the thoracic duct and quantified OC levels. / / [Results] / Ezetimibe treatment significantly reduced the apparent absorption of 5β,6β-epoxycholesterol (5,6β-epoxy) and its levels in the proximal intestinal mucosa in OC-fed rats. Using in silico analyses, the binding energy of NPC1L1 N-terminal domain (NPC1L1-NTD) and 5,6β-epoxy was found to be similar to that of NPC1L1-NTD and cholesterol, suggesting that polar uncharged amino acids located in the steroidal part of 5,6β-epoxy were involved. / / [Conclusion] / Our results indicate that ezetimibe-mediated inhibition of dietary OC absorption varies depending on the specific OC, and only the absorption of 5,6β-epoxy is significantly reduced.

The article discusses the current prevalence of hypercholesterolemia in everyday clinical practice in patients of different risk categories and approaches to its correction in the most frequently used clinical guidelines. High prevalence of hypercholesterolemia in practical health care with little change over time is shown. The existing problems of the practical implementation of the principles of a healthy lifestyle as the basis for reducing cardiovascular risk and possible solutions are described. Attention is focused on a low number of patients taking statins, and even less – reaching recommended target cholesterol levels. It is emphasized the validity of lower, compared to previous, target cholesterol levels in National recommendations on the correction of dyslipidemia in patients with proven atherosclerosis-related cardiovascular diseases as well as the feasibility in some cases of combined lipidlowering therapy (statins in combination with intestinal cholesterol absorption blockers, PCSK9 inhibitors, high doses of ethyl eicosopentaenoic acid). It is commented the need to prescribe statins in persons older than 75 years, but with a careful approach. Particular attention is paid to the use of statins in the primary prevention of cardiovascular complications. The validity of prescribing fixed moderate doses of statins for this purpose is discussed, which is both scientifically based and more realistic in practical terms.

It is well-established that, besides facilitating lipid absorption, bile acids act as signaling molecules that modulate glucose and lipid metabolism. Bile acid metabolism, in turn, is controlled by several nutrient-sensitive transcription factors. Altered intrahepatic glucose signaling in type 2 diabetes associates with perturbed bile acid synthesis. However, an independent role of glucose in regulation of bile acid metabolism has as yet not been established. We aimed to characterize the regulatory role of the primary intracellular metabolite of glucose, glucose-6-phosphate (G6P), on bile acid metabolism. Hepatic gene expression patterns and bile acid composition were analyzed in mice that accumulate G6P in the liver, i.e., liver-specific glucose-6-phosphatase knockout (L-G6pc-/- ) mice, and mice treated with a pharmacological inhibitor of the G6P-transporter. Hepatic G6P accumulation induces Cyp8b1 expression, which is mediated by the major glucose-sensitive transcription factor Carbohydrate Response Element Binding Protein (ChREBP). Activation of the G6P-ChREBP-CYP8B1 axis increases the relative abundance of cholic acid-derived bile acids and induces physiologically relevant shifts in bile composition. The G6P-ChREBP-dependent change in bile acid hydrophobicity associates with elevated plasma campesterol/cholesterol ratio and reduced fecal neutral sterol loss, compatible with enhanced intestinal cholesterol absorption. CONCLUSION: We report that G6P, the primary intracellular metabolite of glucose, controls hepatic bile acid synthesis. Our work identifies hepatic G6P-ChREBP-CYP8B1 signaling as a regulatory axis in control of bile acid and cholesterol metabolism. This article is protected by copyright. All rights reserved.

Contains fulltext : 206793.pdf (Publisher’s version ) (Open Access) Dietary plant sterols and stanols as present in our diet and in functional foods are well-known for their inhibitory effects on intestinal cholesterol absorption, which translates into lower low-density lipoprotein cholesterol concentrations. However, emerging evidence suggests that plant sterols and stanols have numerous additional health effects, which are largely unnoticed in the current scientific literature. Therefore, in this review we pose the intriguing question "What would have occurred if plant sterols and stanols had been discovered and embraced by disciplines such as immunology, hepatology, pulmonology or gastroenterology before being positioned as cholesterol-lowering molecules?" What would then have been the main benefits and fields of application of plant sterols and stanols today? We here discuss potential effects ranging from its presence and function intrauterine and in breast milk towards a potential role in the development of non-alcoholic steatohepatitis (NASH), cardiovascular disease (CVD), inflammatory bowel diseases (IBD) and allergic asthma. Interestingly, effects clearly depend on the route of entrance as observed in intestinal-failure associated liver disease (IFALD) during parenteral nutrition regimens. It is only until recently that effects beyond lowering of cholesterol concentrations are being explored systematically. Thus, there is a clear need to understand the full health effects of plant sterols and stanols.

Intestinal cholesterol absorption is a key regulator of systemic cholesterol homeostasis. Excessive dietary cholesterol and its intestinal uptake lead to hypercholesterolemia, a major risk factor for cardiovascular disease. Intestinal cholesterol uptake is mediated by Niemann-Pick C1-like 1 (NPC1L1), a transmembrane protein localized in membrane microdomains (lipid rafts) enriched in gangliosides and cholesterol. The roles of gangliosides, such as monosialodihexosylganglioside (GM3) and its synthesizing enzyme GM3 synthase (GM3S), in NPC1L1-dependent cholesterol uptake have not been examined previously. Here, we examined NPC1L1-dependent cholesterol uptake in a cell model as well as in wild-type and apoE-deficient mice fed normal or high-cholesterol diets. We showed that NPC1L1-dependent cholesterol uptake was impaired in GM3S-deficient cells and that GM3S deficiency promoted resistance to hypercholesterolemia in both wild-type and apoE-deficient mice fed the high-cholesterol but not the normal diet. Our findings suggest that GM3 and related gangliosides are essential for NPC1L1-mediated intestinal cholesterol absorption and are potential targets for hypercholesterolemia therapy.

Niemann-Pick C1 Like-1 (NPC1L1) mediates the uptake of micellar cholesterol by intestinal epithelial cells and is the molecular target of the cholesterol-lowering drug ezetimibe (EZE). The detailed mechanisms responsible for intracellular shuttling of micellar cholesterol are not fully understood due to the lack of a suitable NPC1L1 substrate that can be traced by fluorescence imaging and biochemical methods. 27-Alkyne cholesterol has been previously shown to serve as a substrate for different cellular processes similar to native cholesterol. However, it is not known whether alkyne cholesterol is absorbed via an NPC1L1-dependent pathway. We aimed to determine whether alkyne cholesterol is a substrate for NPC1L1 in intestinal cells. Human intestinal epithelial Caco2 cells were incubated with micelles containing alkyne cholesterol in the presence or absence of EZE. Small intestinal closed loops in C57BL/6J mice were injected with micelles containing alkyne cholesterol with or without EZE. Alkyne cholesterol esterification in Caco2 cells was significantly inhibited by EZE and by inhibitor of clathrin-mediated endocytosis Pitstop 2. The esterification was similarly reduced by inhibitors of the acyl-CoA cholesterol acyltransferase (ACAT). Alkyne cholesterol efficiently labeled the apical membrane of Caco2 cells and the amount retained on the membrane was significantly increased by EZE as judged by accessibility to exogenous cholesterol oxidase. In mouse small intestine, the presence of EZE reduced total alkyne cholesterol uptake by ∼75%. These data show that alkyne cholesterol acts as a substrate for NPC1L1 and may serve as a nonradioactive tracer to measure cholesterol absorption in both in vitro and in vivo models.

Hypercholesterolemia is a prevalent metabolic disorder that has been implicated in the development of steroid-targeted cancers. However, the link between hypercholesterolemia and urinary bladder cancer (UBC), a non–steroid-targeted cancer, remains unresolved. Here we show that diet-induced and Ldlr deficiency–induced hypercholesterolemia enhances both UBC stemness and progression. Inhibition of intestinal cholesterol absorption by ezetimibe reversed diet-induced hypercholesterolemia and cancer stemness. As a key component in hypercholesterolemic sera, oxidized low-density lipoprotein (ox-LDL), but not native low-density lipoprotein-cholesterol or metabolite 27-hydroxycholesterol, increased cancer stemness through its receptor CD36. Depletion of CD36, ectopic expression of an ox-LDL binding–disabled mutant form of CD36(K164A), and the neutralization of ox-LDL and CD36 via neutralizing antibodies all reversed ox-LDL–induced cancer stemness. Mechanistically, ox-LDL enhanced the interaction of CD36 and JAK2, inducing phosphorylation of JAK2 and subsequently activating STAT3 signaling, which was not mediated by JAK1 or Src in UBC cells. Finally, ox-LDL levels in serum predicted poor prognosis, and the ox-LDLhigh signature predicted worse survival in patients with UBC. These findings indicate that ox-LDL links hypercholesterolemia with UBC progression by enhancing cancer stemness. Lowering serum ox-LDL or targeting the CD36/JAK2/STAT3 axis might serve as a potential therapeutic strategy for UBCs with hypercholesterolemia. Moreover, elevated ox-LDL may serve as a biomarker for UBC. Significance: This study demonstrates how hypercholesterolemia-induced oxidized LDL promotes urinary bladder cancer stemness via a CD36/STAT3 signaling axis, highlighting these factors as biomarkers and potential therapeutic targets of aggressive disease.