Excess Cholesterol Research Articles

Evolution of Cholecystectomy-Gall Bladder must be Removed not because it Contains Stones but Forms them

Normally, human bile contains enough chemicals to dissolve the cholesterol excreted by our liver. But if our liver excretes more cholesterol than the bile can dissolve, the excess cholesterol, too much bilirubin, or not enough bile salts, first form into crystals and eventually turn into stones when stored in the gall bladder. The estimated overall prevalence of cholelithiasis is 10–15% in the general population, with some differences across countries, ethnic and age groups. The good fact is most of the gall stone patients are asymptomatic. The prevalence of gall stones is around 6% of the total population in India, with a clear predominance among females with 10% and 3% in men. In India among 808 million adult population 81 million will suffer Cholelithiasis every year and a conservative 1.6 million (2%) of them would need surgery. Among American adults the prevalence of cholelithiasis is about 10% while in Western Europe the prevalence ranges from 5.9% to 21.9%. More than one million Americans are diagnosed with gallstones every year, joining about 38 million who already have the disorder. Cholecystectomy: the surgical resection and removal was and continues to be the permanent solution and the gold standard for the definitive management of symptomatic cholelithiasis. J. L. W Thudichum proposed a two-stage elective cholecystostomy in 1859, In the first stage, the inflamed gall bladder was sewed to the anterior abdominal wall through a small incision, to serve as a route for the removal of gall stone later in the second stage. Laparoscopic cholecystectomy (LC) since its inception in 1989 has become the gold standard treatment for gall stone disease. The technique of performing LC has undergone many changes and variations. Several surgeons have tried to reduce the size and number of ports to improve cosmetic and postoperative outcomes and developed their own different versions. The most recent development in technique of LC is single incision laparoscopic surgery (SILS) or single site laparoscopic cholecystectomy (SSLC). This review is a consequence of witnessing an elective Cholecystectomy and review of the prevailing cost across the country and health insurance coverage in India. As a public health problem Cholelithiasis can’t be prevented, and Cholecystectomy is needed to 1.6 million Indian adults each year costing a fortune. Currently it cannot be accessed by all, especially the poor and even lower middle socio-economic class. With overall, health insurance coverage of around 30%, that too among urbanites, mainly covered by employers in India is a public health challenge. Ayushman Bharat a national initiative launched on 23rd September 2018, a GOI health assurance initiative adapted by almost all State governments for providing accessible and affordable healthcare to the common man for secondary and tertiary care hospitalization is still in a nascent stage. Methodology: This review is based on an observation of Laparoscopic Cholecystectomy in a 3-star private hospital on a middle socioeconomic woman, followed by literature review and costs across India by the end of 2022.

High-density lipoproteins: from quantitative measures to functional assessment and therapy (review of literature).

The antiatherogenic role of high-density lipoproteins (HDL) is associated primarily with their participation in the reverse transport of excess cholesterol from peripheral tissues to the liver. The efficiency of this mechanism depends on the ability of apolipoprotein A-I (apoA-I), the main protein component of HDL, to capture cholesterol from cells. It is known that the acceptor properties of this protein can change under the influence of various factors. This review discusses modern approaches aimed both at increasing the plasma level of HDL and preserving their native functional properties. As one of the key criteria of HDL functionality it is proposed to determine the ability of HDL to accept labeled cholesterol from macrophages. Studies have shown that injection of recombinant HDL or apoA-I mimetic peptides accelerates cholesterol efflux from peripheral tissues, improves vascular endothelial state, and leads to regression of atherosclerotic plaque. Thus, therapy with recombinant HDL/apoA-I may become an effective way to treat cardiovascular diseases caused by cholesterol accumulation in the vascular wall.

ApoJ/Clusterin concentrations are determinants of cerebrospinal fluid cholesterol efflux capacity and reduced levels are associated with Alzheimer’s disease

BackgroundAlzheimer’s disease (AD) shares risk factors with cardiovascular disease (CVD) and dysregulated cholesterol metabolism is a mechanism common to both diseases. Cholesterol efflux capacity (CEC) is an ex vivo metric of plasma high-density lipoprotein (HDL) function and inversely predicts incident CVD independently of other risk factors. Cholesterol pools in the central nervous system (CNS) are largely separate from those in blood, and CNS cholesterol excess may promote neurodegeneration. CEC of cerebrospinal fluid (CSF) may be a useful measure of CNS cholesterol trafficking. We hypothesized that subjects with AD and mild cognitive impairment (MCI) would have reduced CSF CEC compared with Cognitively Normal (CN) and that CSF apolipoproteins apoA-I, apoJ, and apoE might have associations with CSF CEC.MethodsWe retrieved CSF and same-day ethylenediaminetetraacetic acid (EDTA) plasma from 108 subjects (40 AD; 18 MCI; and 50 CN) from the Center for Neurodegenerative Disease Research biobank at the Perelman School of Medicine, University of Pennsylvania. For CSF CEC assays, we used N9 mouse microglial cells and SH-SY5Y human neuroblastoma cells, and the corresponding plasma assay used J774 cells. Cells were labeled with [3H]-cholesterol for 24 h, had ABCA1 expression upregulated for 6 h, were exposed to 33 μl of CSF, and then were incubated for 2.5 h. CEC was quantified as percent [3H]-cholesterol counts in medium of total counts medium+cells, normalized to a pool sample. ApoA-I, ApoJ, ApoE, and cholesterol were also measured in CSF.ResultsWe found that CSF CEC was significantly lower in MCI compared with controls and was poorly correlated with plasma CEC. CSF levels of ApoJ/Clusterin were also significantly lower in MCI and were significantly associated with CSF CEC. While CSF ApoA-I was also associated with CSF CEC, CSF ApoE had no association with CSF CEC. CSF CEC is significantly and positively associated with CSF Aβ. Taken together, ApoJ/Clusterin may be an important determinant of CSF CEC, which in turn could mitigate risk of MCI and AD risk by promoting cellular efflux of cholesterol or other lipids. In contrast, CSF ApoE does not appear to play a role in determining CSF CEC.

HUBUNGAN KADAR HIGH DENSITY LIPOPROTEIN (HDL) TERHADAP GLUKOSA DARAH SEWAKTU PADA PENDERITA DIABETES MELLITUS DI RS BENYAMIN GULUH KOLAKA

Diabetes Mellitus (DM) is a very common health problem. Diabetes mellitus is a chronic disease that generally affects throughout the life of the patient and requires long-term treatment, in addition to the state of insulin resistance or metabolic syndrome and Diabetes Mellitus (DM) cause’s lipid metabolic abnormalities characterized by an increase or decrease in lipid fraction. Increased cholesterol High Density Lipoprotein (HDL) can reduce the risk of atorosclerosis. Besides that, the HDL function is as the main means of transporting excess cholesterol from extra hepatic tissue and cleaning cells then to be released through the bile. This study aims to determine the relationship between of the High Density Lipoprotein (HDL) levels to blood glucose to the patients' of diabetes mellitus at Benyamin Guluh Hospital in Kolaka. The type of this study is analytic observational with the sampling technique of Accidental Sampling and 30 people of total samples. The results of this study showed that there was no relationship between HDL levels and blood glucose. This could be seen in the p-value of 0.107 and the r value of 0.300. Keywords : High Density Lipoprotein (HDL), Diabetes Mellitus (DM)

Amyloid‐β plus cholesterol treatment impairs the ability of microglia to efflux excess cholesterol

AbstractBackgroundMicroglia, specialized phagocytic cells of the brain, play a critical role in the clearance of amyloid beta (Aβ), which is involved in the pathogenesis of Alzheimer’s disease. The ability of microglia to remove Aβ is influenced by their cellular cholesterol clearance capacity. It is not known to what extent Aβ impairs microglial cholesterol efflux capacity, especially in the context of excess cholesterol.MethodHMC3 microglia were treated with Aβ‐oligomer (AβO, 2µM), cholesterol loading (20µg), or AβO + cholesterol in combination, and with or without cholesterol acceptor, high‐density lipoprotein (HDL), at 0.1 mg/mL. Pooled HDL from 18 individuals in a 2‐hour postprandial state and a 36‐hour fasted state were compared. The cellular content of unesterified and esterified cholesterol was measured.ResultsThe addition of cholesterol, AβO, and cholesterol+AβO increased cellular cholesterol content, which was attenuated by the addition of HDL. Importantly, cells treated with cholesterol plus AβO had the highest overall cholesterol content (27.80+/‐2.85µM), and both fasted (20.67+/‐3.04µM, p≥0.05) and postprandial HDL (21.95+/‐3.84µM, p<0.05) were not able to reduce the cellular cholesterol content as well as in the untreated (fasted: 16.17+/‐2.28µM, p<0.05; postprandial: 18.55+/‐2.01µM, p>0.05), cholesterol only (fasted: 17.72+/‐2.17µM, p<0.05; postprandial: 18.14+/‐3.19µM, p<0.05), or AβO only condition (fasted: 16.80+/‐1.40µM, p<0.05; postprandial: 18.42+/‐2.05µM, p>0.05). Fasted HDL more efficiently removed cellular cholesterol in the untreated and in AβO+cholesterol treated cells. Intriguingly, cellular esterified cholesterol content was significantly lowered with fasted HDL but not postprandial HDL in both AβO alone (fasted: 5.73+/‐2.27 µM, p<0.05; postprandial: 10.32+/‐2.70µM, p>0.05) and AβO + cholesterol (fasted: 2.87+/‐2.13µM, p<0.05; postprandial: 9.03+/‐1.74µM, p>0.05).ConclusionThese findings suggest that microglia exposed to a double‐hit of AβO and excess cholesterol experience an impaired ability to efflux excess cholesterol. Additionally, HDL from fasted individuals displayed an enhanced capacity to efflux cholesterol, especially in microglia dually encumbered by AβO + cholesterol. Further studies are needed to examine the impact of this diminished cholesterol efflux capacity and cholesterol accumulation on the phagocytic capacity of microglia.

A small H2O-soluble ingredient of royal jelly lower cholesterol levels in liver cells by suppressing squalene epoxidase

Excessive cholesterol in the liver is harmful for our health and may cause many diseases, such as fatty liver disease. Many studies in human and animal models have reported that royal jelly (RJ) can be used to treat atherosclerosis. However, the real mechanisms behind this action is unclear. In this study, we investigated the efficacy of RJ on gene expression of squalene epoxidase (SE) a major enzyme involved in cholesterol biosynthesis in HepG2 cells. We found that the expression of SE was decreased in response to RJ treatment. We also found that the origin of the RJ affected its strength. To find out the active fraction of RJ in cholesterol suppression, we separated RJ into two parts based on the molecular weights using ultrafiltration membrane. We found that the fraction <10kDa from RJ had comparable effect on SE expression, especially its water-soluble part. Taken together, we think RJ suppresses cholesterol by decreasing SE gene expression in liver. The active fraction of RJ in this action is <10kDa in water-soluble form.

Effects of Thymoquinone Alone or in Combination with Losartan on the Cardiotoxicity Caused by Oxidative Stress and Inflammation in Hypercholesterolemia.

Dietary cholesterol accelerates oxidative and pro-inflammatory processes, causing hypercholesterolemia and cardiovascular diseases. Thus, the purpose of the current study is to compare the protective effects of thymoquinone (TQ) alone or in combination with losartan (LT) against the heart damage caused by a high-cholesterol diet (HCD). HCD-fed rat groups revealed an elevated activity of indicators of cardiac enzymes in the serum. Serum and cardiac lipids were also found to be significantly higher in HCD-fed rat groups. Cardiac pro-inflammatory and oxidative markers were also increased in HCD-fed rat groups, whereas antioxidant indicators were decreased. However, all of these biochemical, inflammatory, antioxidant, and oxidative change indicators returned to levels similar to those of normal rats after treatment with TQ alone or in combination with LT administered to HCD-fed rat groups. Hypercholesterolemia considerably induced the lipid peroxidation product, thiobarbituric acid reaction substances (TBARs), and oxidative radicals in cardiac cells, which were attenuated by QT and LT treatments, particularly when combined. Finally, QT, LT, and their combination were able to reduce the histological changes changes brought on by cholesterol excess in cardiac tissues. In conclusion, administration of TQ in a combination with LT which has a better protective effect, significantly reduced the hypercholesterolemic-induced oxidative and inflammatory changes that occurred in cardiac tissue.

SOSIALISASI FITOERAPI PENYAKIT KOLESTEROL DI DESA PETUKANGAN KECAMATAN WIRADESA KABUPATEN PEKALONGAN

One of the diseases commonly found in the community, especially those aged &gt; 40 years, is high cholesterol. This type of disease is a chronic disease that is closely related to people's diet and lifestyle. High cholesterol is also commonly found in children and adolescents with excess body weight. Excessive cholesterol levels can cause plaque that clogs arteries and can cause heart attacks or atherosclerosis which will trigger stroke (Abidi et al., 2006). Non-Communicable Diseases (NCD) is currently one of the health problems of national and global concern, the increase in PTM is closely related to the consumption of foods containing high cholesterol. In order to improve the quality of health, we make efforts to prevent cholesterol. This activity was carried out in collaboration with partners in Petukangan Village, Wiradesa District, Pekalongan Regency. The activities carried out are periodic cholesterol checks and deliver material about cholesterol, namely about the causes of cholesterol, prevention, and cholesterol phytotherapy. Before delivering the material, participants were given a pre-test with an average score of 6.4. After delivering the material, the participants did a post-test with an average score of 9.6. The result of this activity is an increase in public knowledge about cholesterol by 33,3 %. Participants understand more about the causes of cholesterol and can use herbal plants to prevent and treat cholesterol.

SOSIALISASI FITOERAPI PENYAKIT KOLESTEROL DI DESA PETUKANGAN KECAMATAN WIRADESA KABUPATEN PEKALONGAN

One of the diseases commonly found in the community, especially those aged &gt; 40 years, is high cholesterol. This type of disease is a chronic disease that is closely related to people's diet and lifestyle. High cholesterol is also commonly found in children and adolescents with excess body weight. Excessive cholesterol levels can cause plaque that clogs arteries and can cause heart attacks or atherosclerosis which will trigger stroke (Abidi et al., 2006). Non- Communicable Diseases (NCD) is currently one of the health problems of national and global concern, the increase in PTM is closely related to the consumption of foods containing high cholesterol. In order to improve the quality of health, we make efforts to prevent cholesterol. This activity was carried out in collaboration with partners in Petukangan Village, Wiradesa District, Pekalongan Regency. The activities carried out are periodic cholesterol checks and deliver material about cholesterol, namely about the causes of cholesterol, prevention, and cholesterol phytotherapy. Before delivering the material, participants were given a pre-test with an average score of 6.4. After delivering the material, the participants did a post-test with an average score of 9.6. The result of this activity is an increase in public knowledge about cholesterol by 33,3 %. Participants understand more about the causes of cholesterol and can use herbal plants to prevent and treat cholesterol.

Epsin Nanotherapy Regulates Cholesterol Transport to Fortify Atheroma Regression.

Excess cholesterol accumulation in lesional macrophages elicits complex responses in atherosclerosis. Epsins, a family of endocytic adaptors, fuel the progression of atherosclerosis; however, the underlying mechanism and therapeutic potential of targeting Epsins remains unknown. In this study, we determined the role of Epsins in macrophage-mediated metabolic regulation. We then developed an innovative method to therapeutically target macrophage Epsins with specially designed S2P-conjugated lipid nanoparticles, which encapsulate small-interfering RNAs to suppress Epsins. We used single-cell RNA sequencing with our newly developed algorithm MEBOCOST (Metabolite-mediated Cell Communication Modeling by Single Cell Transcriptome) to study cell-cell communications mediated by metabolites from sender cells and sensor proteins on receiver cells. Biomedical, cellular, and molecular approaches were utilized to investigate the role of macrophage Epsins in regulating lipid metabolism and transport. We performed this study using myeloid-specific Epsin double knockout (LysM-DKO) mice and mice with a genetic reduction of ABCG1 (ATP-binding cassette subfamily G member 1; LysM-DKO-ABCG1fl/+). The nanoparticles targeting lesional macrophages were developed to encapsulate interfering RNAs to treat atherosclerosis. We revealed that Epsins regulate lipid metabolism and transport in atherosclerotic macrophages. Inhibiting Epsins by nanotherapy halts inflammation and accelerates atheroma resolution. Harnessing lesional macrophage-specific nanoparticle delivery of Epsin small-interfering RNAs, we showed that silencing of macrophage Epsins diminished atherosclerotic plaque size and promoted plaque regression. Mechanistically, we demonstrated that Epsins bound to CD36 to facilitate lipid uptake by enhancing CD36 endocytosis and recycling. Conversely, Epsins promoted ABCG1 degradation via lysosomes and hampered ABCG1-mediated cholesterol efflux and reverse cholesterol transport. In a LysM-DKO-ABCG1fl/+ mouse model, enhanced cholesterol efflux and reverse transport due to Epsin deficiency was suppressed by the reduction of ABCG1. Our findings suggest that targeting Epsins in lesional macrophages may offer therapeutic benefits for advanced atherosclerosis by reducing CD36-mediated lipid uptake and increasing ABCG1-mediated cholesterol efflux.

Recombinant Humanized IgG1 Antibody Promotes Reverse Cholesterol Transport through FcRn-ERK1/2-PPARα Pathway in Hepatocytes

Hyperlipidemia-associated lipid disorders are considered the cause of atherosclerotic cardiovascular disease. Reverse cholesterol transport (RCT) is a mechanism by which excess peripheral cholesterol is transported to the liver and further converted into bile acid for excretion from the body in feces, which contributes to reducing hyperlipidemia as well as cardiovascular disease. We previously found that the recombinant humanized IgG1 antibody promotes macrophages to engulf lipids and increases cholesterol efflux to high-density lipoprotein (HDL) through ATP-binding cassette sub-family A1 (ABCA1), one of the key proteins related to RCT. In the present study, we explored other RCT related proteins expression on hepatocytes, including scavenger receptor class B type I (SR-BI), apolipoprotein A-I (ApoA-I), and apolipoprotein A-II (ApoA-II), and its modulation mechanism involved. We confirmed that the recombinant humanized IgG1 antibody selectively activated ERK1/2 to upregulate SR-BI, ApoA-I, and ApoA-II expression in mice liver and human hepatocellular carcinoma cell lines HepG2 cells. The rate-limiting enzymes of bile acid synthesis, including cholesterol 7α-hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1), exhibited a significant increase when treated with the recombinant humanized IgG1 antibody, as well as increased excretion of bile acids in feces. Besides, abolishment or mutation of peroxisome proliferator-activated receptor α (PPARα)/RXR binding site on SR-BI promoter eliminated SR-BI reporter gene luciferase activity even in the presence of the recombinant humanized IgG1 antibody. Knock down the neonatal Fc receptor (FcRn) on hepatocytes impaired the effect of recombinant humanized IgG1 antibody on activation of ERK1/2, as well as upregulation of SR-BI, ApoA-I, and ApoA-II expression. In conclusion, one of the mechanisms on the recombinant humanized IgG1 antibody attenuates hyperlipidemia in ApoE-/- mice model fed with high-fat-diet might be through reinforcement of liver RCT function in an FcRn-ERK1/2-PPARα dependent manner.

The Association of Dietary Cholesterol from Egg Consumption on Cardiovascular Diseases Risk Varies from Person to Person.

The public and scientists remain skeptical about egg consumption, given that cardiovascular diseases (CVDs) are the leading causes of death in worldwide. This review mainly explained the recurrence of contradictory conclusions about relationships between egg consumption and CVD risk and discussed effects of egg cholesterol intake on cholesterol homeostasis. Factors including individual health status and cholesterol sensitivity, dietary pattern, region, and race should be distinguished when understanding generalized conclusions. Identified compensatory mechanisms in response to dietary cholesterol and the resulting balance in cholesterol biosynthesis, absorption, and efflux supported the view that moderate egg consumption had no substantial overall impacts on cholesterol homeostasis in healthy people. Excessive cholesterol intake is not recommended in individuals with distempered metabolism. More than cholesterol metabolism, impacts of egg consumption as a part of overall diet on CVD risk should be considered from aspects of nutrient intake, lipid metabolism, and energy supply in the future.

Blood vessel segmentation using deep learning architectures for aid diagnosis of diabetic retinopathy

ABSTRACT Diabetes mellitus is a metabolic disorder that causes a variety of vascular issues in the body. When the condition coexists with other general problems (high blood pressure, obesity, excessive cholesterol), the risk of ocular complications increases. Diabetes can damage the small blood vessels in the retina. This is referred to as diabetic retinopathy (DR). Therefore, the segmentation of the vascular network may assist in the automatic and early recognition and screening for DR. Since, manual vessel extraction is time-consuming, automation of this procedure is critical. In this paper, we focus on the implementation of different deep learning networks for accurate retinal vasculature semantic segmentation. We used three distinct models: SegNet, U-Net, and the convolutional neural network (CNN). These approaches were evaluated on three publicly available annotated databases: DRIVE, HRF, and CHASE-DB1. To compare the three proposed models with the previous methodologies, various metrics are calculated. The results produced were good and encouraging in terms of the quality of the visual diagnosis.

Identification of potential inhibitors of brain-specific CYP46A1 from phytoconstituents in Indian traditional medicinal plants.

The online version contains supplementary material available at 10.1007/s42485-022-00098-x.

Red Blood Cell Membrane Cholesterol May Be a Key Regulator of Sickle Cell Disease Microvascular Complications.

Cell membrane lipid composition, especially cholesterol, affects many functions of embedded enzymes, transporters and receptors in red blood cells (RBC). High membrane cholesterol content affects the RBCs' main vital function, O2 and CO2 transport and delivery, with consequences on peripheral tissue physiology and pathology. A high degree of deformability of RBCs is required to accommodate the size of micro-vessels with diameters significantly lower than RBCs. The potential therapeutic role of high-density lipoproteins (HDL) in the removal of cholesterol and its activity regarding maintenance of an optimal concentration of RBC membrane cholesterol have not been well investigated. On the contrary, the focus for HDL research has mainly been on the clearance of cholesterol accumulated in atherosclerotic macrophages and plaques. Since all interventions aiming at decreasing cardiovascular diseases by increasing the plasma level of HDL cholesterol have failed so far in large outcome studies, we reviewed the potential role of HDL to remove excess membrane cholesterol from RBC, especially in sickle cell disease (SCD). Indeed, abundant literature supports a consistent decrease in cholesterol transported by all plasma lipoproteins in SCD, in addition to HDL, low- (LDL) and very low-density lipoproteins (VLDL). Unexpectedly, these decreases in plasma were associated with an increase in RBC membrane cholesterol. The concentration and activity of the main enzyme involved in the removal of cholesterol and generation of large HDL particles-lecithin cholesterol ester transferase (LCAT)-are also significantly decreased in SCD. These observations might partially explain the decrease in RBC deformability, diminished gas exchange and tendency of RBCs to aggregate in SCD. We showed that incubation of RBC from SCD patients with human HDL or the HDL-mimetic peptide Fx5A improves the impaired RBC deformability and decreases intracellular reactive oxygen species levels. We propose that the main physiological role of HDL is to regulate the cholesterol/phospholipid ratio (C/PL), which is fundamental to the transport of oxygen and its delivery to peripheral tissues.

STANDARISASI SIMPLISIA DAUN KELOR (Moringa oleifera L.) DARI DESA LUWUNG SIDOARJO DENGAN MENGGUNAKAN PENGERINGAN FOOD DEHYDRATOR

One of the vegetation that may be used each as meals and medication is the Moringa plant (Moringa oleifera L.). Empirically, Moringa leaves have many advantages and had been proven to be powerful in treating numerous diseases, consisting of diabetes, hepatitis, heart ailment and excessive cholesterol. The chemical parts contained on this plant are terpenoids, tannins, steroids, polyphenols, and alkaloids. This look at aims to pick out medicinal uncooked substances the use of the meals dehydrator drying method whilst on the equal time making sure the drug raw materials, so that the standardization can be accounted for for its quality. Standardization is done by setting specific and non-specific parameters. This study uses descriptive qualitative and quantitative analysis methods. The sample of this research was taken from Luwung village, Sidoarjo regency. The results of standardization for specific parameters showed the determination of the flavonoid content of 16,08±3,62 mgQE/g, the TLC test showed stains in the form of yellow-green fluorescence under UV light at 366 nm, the water-soluble extract test yielded 7.8%, and the water-soluble extract test yielded 7.8%. ethanol yielded 13.58%. The results for non-specific parameters showed that drying shrinkage was 4.2%, water content was 1.80%, and ash content was 1.4%. The results of the microbial contamination test were 3.9x colonies/ml while the total mold/yeast contamination was 3.1x colonies/ml. Based at the results of studies that has been carried out, Moringa leaf simplicia from Luwung village has met the requirements of specific and non-specific parameters, so that the simplicia may be used as raw material for medication.

Identifying the Transcriptional Drivers of Metastasis Embedded within Localized Melanoma.

We analyzed human melanoma transcriptomics data to identify a gene signature predictive of metastasis. To rapidly test clinical signatures, we built a genetic metastasis platform in adult zebrafish and identified GRAMD1B as a suppressor of melanoma metastasis. GRAMD1B-associated cholesterol overload activates an AP-1 program to promote melanoma invasion. This article is highlighted in the In This Issue feature, p. 1.

HDLBP Promotes Hepatocellular Carcinoma Proliferation and Sorafenib Resistance by Suppressing Trim71-dependent RAF1 Degradation

The contribution of abnormal metabolic targets to hepatocellular carcinoma (HCC) progression and the associated regulatory mechanisms are attractive research areas. High-density lipoprotein binding protein (HDLBP) is an important transporter that protects cells from excessive cholesterol accumulation, but few studies have identified a role for HDLBP in HCC progression. HDLBP expression was determined in HCC tissues and published datasets. The biological roles of HDLBP invitro and invivo were examined by performing a series of functional experiments. An integrated analysis confirmed that HDLBP expression was significantly elevated in HCC compared with noncancerous liver tissues. The knockdown or overexpression of HDLBP substantially inhibited or enhanced, respectively, HCC proliferation and sorafenib resistance. Subsequently, a mass spectrometry screen identified RAF1 as a potential downstream target of HDLBP. Mechanistically, when RAF1 was stabilized by HDLBP, MEKK1 continuously induced RAF1Ser259-dependent MAPK signaling. Meanwhile, HDLBP interacted with RAF1 by competing with the TRIM71 E3 ligase and inhibited RAF1 degradation through the ubiquitin-proteasome pathway. Our study reveals that HDLBP is an important mediator that stabilizes the RAF1 protein and maintains its activity, leading to HCC progression and sorafenib resistance. Thus, HDLBP might represent a potential biomarker and future therapeutic target for HCC.

Effects of superoxide anion attack on the lipoprotein HDL

High-density lipoprotein (HDL) is an anti-atherosclerotic lipoprotein. Thanks to the activity of apolipoprotein ApoA1, the principal protein component of HDL, this last is responsible for converting cholesterol into ester form and transporting excessive cholesterol to the liver (“reverse cholesterol transport” RCT). When HDL undergoes oxidation, it becomes dysfunctional and proatherogenic. ApoA1 is a target of oxidation, and its alteration affects RCT and contributes to atherosclerosis development. Until now, the mechanism of HDL oxidation is not fully understood and only hydroxyl radicals seem to induce direct oxidation of protein and lipidic components of lipoproteins. Here we demonstrate that superoxide radical, widely produced in early atherosclerosis, directly oxidizes HDL, and as a consequence, ApoA1 undergoes structural alterations impairing its anti-atherosclerotic functions. Our results highlight in an in vitro system the potential mechanism by which O2·− triggers atherosclerotic pathogenesis in vivo. Our study gets the basis for therapeutic approaches focused on the management of superoxide generation in early atherosclerosis onset.

Assessment of cholesterol homeostasis in the living human brain.

Alterations in brain cholesterol homeostasis have been broadly implicated in neurological disorders. Notwithstanding the complexity by which cholesterol biology is governed in the mammalian brain, excess neuronal cholesterol is primarily eliminated by metabolic clearance via cytochrome P450 46A1 (CYP46A1). No methods are currently available for visualizing cholesterol metabolism in the living human brain; therefore, a noninvasive technology that quantitatively measures the extent of brain cholesterol metabolism via CYP46A1 could broadly affect disease diagnosis and treatment options using targeted therapies. Here, we describe the development and testing of a CYP46A1-targeted positron emission tomography (PET) tracer, 18F-CHL-2205 (18F-Cholestify). Our data show that PET imaging readouts correlate with CYP46A1 protein expression and with the extent to which cholesterol is metabolized in the brain, as assessed by cross-species postmortem analyses of specimens from rodents, nonhuman primates, and humans. Proof of concept of in vivo efficacy is provided in the well-established 3xTg-AD murine model of Alzheimer's disease (AD), where we show that the probe is sensitive to differences in brain cholesterol metabolism between 3xTg-AD mice and control animals. Furthermore, our clinical observations point toward a considerably higher baseline brain cholesterol clearance via CYP46A1 in women, as compared to age-matched men. These findings illustrate the vast potential of assessing brain cholesterol metabolism using PET and establish PET as a sensitive tool for noninvasive assessment of brain cholesterol homeostasis in the clinic.