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Full-Text Articles in Medicine and Health Sciences

Acute Acat1/Soat1 Blockade Increases Mam Cholesterol And Strengthens Er-Mitochondria Connectivity., Taylor C Harned, Radu V Stan, Ze Cao, Rajarshi Chakrabarti, Henry N Higgs, Catherine C Y Chang, Ta Yuan Chang Mar 2023

Acute Acat1/Soat1 Blockade Increases Mam Cholesterol And Strengthens Er-Mitochondria Connectivity., Taylor C Harned, Radu V Stan, Ze Cao, Rajarshi Chakrabarti, Henry N Higgs, Catherine C Y Chang, Ta Yuan Chang

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Cholesterol is a key component of all mammalian cell membranes. Disruptions in cholesterol metabolism have been observed in the context of various diseases, including neurodegenerative disorders such as Alzheimer's disease (AD). The genetic and pharmacological blockade of acyl-CoA:cholesterol acyltransferase 1/sterol O-acyltransferase 1 (ACAT1/SOAT1), a cholesterol storage enzyme found on the endoplasmic reticulum (ER) and enriched at the mitochondria-associated ER membrane (MAM), has been shown to reduce amyloid pathology and rescue cognitive deficits in mouse models of AD. Additionally, blocking ACAT1/SOAT1 activity stimulates autophagy and lysosomal biogenesis; however, the exact molecular connection between the ACAT1/SOAT1 blockade and these observed benefits remain …


Modified Linear Peptides Effectively Silence Stat-3 In Breast Cancer And Ovarian Cancer Cell Lines, Dindyal Mandal, Sandeep Lohan, Muhammad Imran Sajid, Abdulelah Alhazza, Rakesh Kumar Tiwari, Keykavous Parang, Hamidreza Montazeri Aliabadi Feb 2023

Modified Linear Peptides Effectively Silence Stat-3 In Breast Cancer And Ovarian Cancer Cell Lines, Dindyal Mandal, Sandeep Lohan, Muhammad Imran Sajid, Abdulelah Alhazza, Rakesh Kumar Tiwari, Keykavous Parang, Hamidreza Montazeri Aliabadi

Pharmacy Faculty Articles and Research

RNA interference (RNAi) has drawn enormous attention as a powerful tool because of its capability to interfere with mRNA and protein production. However, designing a safe and efficient delivery system in RNAi therapeutics remains challenging. Herein, we have designed and synthesized several linear peptides containing tryptophan (W) and arginine (R) residues separated by the β-alanine (βA) spacer and attached to a lipophilic fatty acyl chain, cholesterol, or PEG. The peptide backbone sequences were: Ac-C-βA-βA-W4-βA-βA-R4-CO-NH2 and Ac-K-βA-βA-W4-βA-βA-R4-CO-NH2, with only a difference in N-terminal amino acid. The cysteine side chain in the first sequence was used for the conjugation with PEG2000 and …


Preventing Cholesterol-Induced Perk (Protein Kinase Rna-Like Endoplasmic Reticulum Kinase) Signaling In Smooth Muscle Cells Blocks Atherosclerotic Plaque Formation, Abhijnan Chattopadhyay, Pujun Guan, Suravi Majumder, Kaveeta Kaw, Zhen Zhou, Chen Zhang, Siddharth K Prakash, Anita Kaw, L Maximillian Buja, Callie S Kwartler, Dianna M Milewicz Aug 2022

Preventing Cholesterol-Induced Perk (Protein Kinase Rna-Like Endoplasmic Reticulum Kinase) Signaling In Smooth Muscle Cells Blocks Atherosclerotic Plaque Formation, Abhijnan Chattopadhyay, Pujun Guan, Suravi Majumder, Kaveeta Kaw, Zhen Zhou, Chen Zhang, Siddharth K Prakash, Anita Kaw, L Maximillian Buja, Callie S Kwartler, Dianna M Milewicz

Journal Articles

BACKGROUND: Vascular smooth muscle cells (SMCs) undergo complex phenotypic modulation with atherosclerotic plaque formation in hyperlipidemic mice, which is characterized by de-differentiation and heterogeneous increases in the expression of macrophage, fibroblast, osteogenic, and stem cell markers. An increase of cellular cholesterol in SMCs triggers similar phenotypic changes in vitro with exposure to free cholesterol due to cholesterol entering the endoplasmic reticulum, triggering endoplasmic reticulum stress and activating Perk (protein kinase RNA-like endoplasmic reticulum kinase) signaling.

METHODS: We generated an SMC-specific

RESULTS: SMC-specific deletion of Perk reduces atherosclerotic plaque formation in male hyperlipidemic mice by 80%. Single-cell transcriptomic data identify 2 …


Dementia Risk Reduction: Why Haven't The Pharmacological Risk Reduction Trials Worked? An In-Depth Exploration Of Seven Established Risk Factors, Ruth Peters, John Breitner, Sarah James, Gregory A. Jicha, Pierre-Francois Meyer, Marcus Richards, A. David Smith, Hussein N. Yassine, Erin L. Abner, Atticus H. Hainsworth, Patrick G. Kehoe, Nigel Beckett, Christopher Weber, Craig Anderson, Kaarin J. Anstey, Hiroko H. Dodge Dec 2021

Dementia Risk Reduction: Why Haven't The Pharmacological Risk Reduction Trials Worked? An In-Depth Exploration Of Seven Established Risk Factors, Ruth Peters, John Breitner, Sarah James, Gregory A. Jicha, Pierre-Francois Meyer, Marcus Richards, A. David Smith, Hussein N. Yassine, Erin L. Abner, Atticus H. Hainsworth, Patrick G. Kehoe, Nigel Beckett, Christopher Weber, Craig Anderson, Kaarin J. Anstey, Hiroko H. Dodge

Neurology Faculty Publications

Identifying the leading health and lifestyle factors for the risk of incident dementia and Alzheimer's disease has yet to translate to risk reduction. To understand why, we examined the discrepancies between observational and clinical trial evidence for seven modifiable risk factors: type 2 diabetes, dyslipidemia, hypertension, estrogens, inflammation, omega-3 fatty acids, and hyperhomocysteinemia. Sample heterogeneity and paucity of intervention details (dose, timing, formulation) were common themes. Epidemiological evidence is more mature for some interventions (eg, non-steroidal anti-inflammatory drugs [NSAIDs]) than others. Trial data are promising for anti-hypertensives and B vitamin supplementation. Taken together, these risk factors highlight a future need …


Sitosterolemia: Twenty Years Of Discovery Of The Function Of Abcg5abcg8, Kori Williams, Allison Segard, Gregory A. Graf Mar 2021

Sitosterolemia: Twenty Years Of Discovery Of The Function Of Abcg5abcg8, Kori Williams, Allison Segard, Gregory A. Graf

Pharmaceutical Sciences Faculty Publications

Sitosterolemia is a lipid disorder characterized by the accumulation of dietary xenosterols in plasma and tissues caused by mutations in either ABCG5 or ABCG8. ABCG5 ABCG8 encodes a pair of ABC half transporters that form a heterodimer (G5G8), which then traffics to the surface of hepatocytes and enterocytes and promotes the secretion of cholesterol and xenosterols into the bile and the intestinal lumen. We review the literature from the initial description of the disease, the discovery of its genetic basis, current therapy, and what has been learned from animal, cellular, and molecular investigations of the transporter in the twenty …


Microrna-148a Regulates Low-Density Lipoprotein Metabolism By Repressing The (Pro)Renin Receptor, Na Wang, Lishu He, Hui Lin, Lunbo Tan, Yuan Sun, Xiaoying Zhang, A. H. Jan Danser, Hong S. Lu, Yongcheng He, Xifeng Lu May 2020

Microrna-148a Regulates Low-Density Lipoprotein Metabolism By Repressing The (Pro)Renin Receptor, Na Wang, Lishu He, Hui Lin, Lunbo Tan, Yuan Sun, Xiaoying Zhang, A. H. Jan Danser, Hong S. Lu, Yongcheng He, Xifeng Lu

Saha Cardiovascular Research Center Faculty Publications

High plasma LDL cholesterol (LDL-c) concentration is a major risk factor for atherosclerosis. Hepatic LDL receptor (LDLR) regulates LDL metabolism, and thereby plasma LDL-c concentration. Recently, we have identified the (pro)renin receptor [(P)RR] as a novel regulator of LDL metabolism, which regulates LDLR degradation and hence its protein abundance and activity. In silico analysis suggests that the (P)RR is a target of miR-148a. In this study we determined whether miR-148a could regulate LDL metabolism by regulating (P)RR expression in HepG2 and Huh7 cells. We found that miR-148a suppressed (P)RR expression by binding to the 3’-untranslated regions (3’-UTR) of the (P)RR …


Activation Of Lxr Receptors And Inhibition Of Trap1 Causes Synthetic Lethality In Solid Tumors, Trang Thi Thu Nguyen, Chiaki Tsuge Ishida, Enyuan Shang, Chang Shu, Elena Bianchetti, Georg Karpel-Massler, Markus D. Siegelin Jun 2019

Activation Of Lxr Receptors And Inhibition Of Trap1 Causes Synthetic Lethality In Solid Tumors, Trang Thi Thu Nguyen, Chiaki Tsuge Ishida, Enyuan Shang, Chang Shu, Elena Bianchetti, Georg Karpel-Massler, Markus D. Siegelin

Publications and Research

Cholesterol is a pivotal factor for cancer cells to entertain their relentless growth. In this case, we provide a novel strategy to inhibit tumor growth by simultaneous activation of liver-X-receptors and interference with Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1). Informed by a transcriptomic and subsequent gene set enrichment analysis, we demonstrate that inhibition of TRAP1 results in suppression of the cholesterol synthesis pathway in stem-like and established glioblastoma (GBM) cells by destabilizing the transcription factor SREBP2. Notably, TRAP1 inhibition induced cell death, which was rescued by cholesterol and mevalonate. Activation of liver X receptor (LXR) by a clinically validated …


Non-Fasting High-Density Lipoprotein Is Associated With White Matter Microstructure In Healthy Older Adults, Nathan F. Johnson, Brian T. Gold, Dorothy Ross, Alison L. Bailey, Jody L. Clasey, Vedant Gupta, Steve W. Leung, David K. Powell May 2019

Non-Fasting High-Density Lipoprotein Is Associated With White Matter Microstructure In Healthy Older Adults, Nathan F. Johnson, Brian T. Gold, Dorothy Ross, Alison L. Bailey, Jody L. Clasey, Vedant Gupta, Steve W. Leung, David K. Powell

Physical Therapy Faculty Publications

A growing body of evidence indicates that biomarkers of cardiovascular risk may be related to cerebral health. However, little is known about the role that non-fasting lipoproteins play in assessing age-related declines in a cerebral biomarker sensitive to vascular compromise, white matter (WM) microstructure. High-density lipoprotein cholesterol (HDL-C) is atheroprotective and low-density lipoprotein cholesterol (LDL-C) is a major atherogenic lipoprotein. This study explored the relationships between non-fasting levels of cholesterol and WM microstructure in healthy older adults. A voxelwise and region of interest approach was used to determine the relationship between cholesterol and fractional anisotropy (FA). Participants included 87 older …


Adropin: An Endocrine Link Between The Biological Clock And Cholesterol Homeostasis, Sarbani Ghoshal, Joseph R. Stevens, Cyrielle Billon, Clemence Girardet, Sadichha Sitaula, Arthur S. Leon, D.C. Rao, James S. Skinner, Tuomo Rankinen, Claude Bouchard, Marinelle V. Nuñez, Kimber L. Stanhope, Deborah A. Howatt, Alan Daugherty, Jinsong Zhang, Matthew Schuelke, Edward P. Weiss, Alisha R. Coffey, Brian J. Bennett, Praveen Sethupathy, Thomas P. Burris, Peter J. Havel, Andrew A. Butler Feb 2018

Adropin: An Endocrine Link Between The Biological Clock And Cholesterol Homeostasis, Sarbani Ghoshal, Joseph R. Stevens, Cyrielle Billon, Clemence Girardet, Sadichha Sitaula, Arthur S. Leon, D.C. Rao, James S. Skinner, Tuomo Rankinen, Claude Bouchard, Marinelle V. Nuñez, Kimber L. Stanhope, Deborah A. Howatt, Alan Daugherty, Jinsong Zhang, Matthew Schuelke, Edward P. Weiss, Alisha R. Coffey, Brian J. Bennett, Praveen Sethupathy, Thomas P. Burris, Peter J. Havel, Andrew A. Butler

Physiology Faculty Publications

Objective

Identify determinants of plasma adropin concentrations, a secreted peptide translated from the Energy Homeostasis Associated (ENHO) gene linked to metabolic control and vascular function.

Methods

Associations between plasma adropin concentrations, demographics (sex, age, BMI) and circulating biomarkers of lipid and glucose metabolism were assessed in plasma obtained after an overnight fast in humans. The regulation of adropin expression was then assessed in silico, in cultured human cells, and in animal models.

Results

In humans, plasma adropin concentrations are inversely related to atherogenic LDL-cholesterol (LDL-C) levels in men (n = 349), but not in women (n = …


The Tmao-Generating Enzyme Flavin Monooxygenase 3 Is A Central Regulator Of Cholesterol Balance, Manya Warrier, Diana M. Shih, Amy C. Burrows, Daniel Ferguson, Anthony D. Gromovsky, Amanda L. Brown, Stephanie Marshall, Allison Mcdaniel, Rebecca C. Schugar, Zeneng Wang, Jessica Sacks, Xin Rong, Thomas De Aguiar Vallim, Jeff Chou, Pavlina T. Ivanova, David S. Myers, H. Alex Brown, Richard G. Lee, Rosanne M. Crooke, Mark J. Graham, Xiuli Liu, Paolo Parini, Peter Tontonoz, Aldon J. Lusis, Stanley L. Hazen, Ryan E. Temel, J. Mark Brown Jan 2015

The Tmao-Generating Enzyme Flavin Monooxygenase 3 Is A Central Regulator Of Cholesterol Balance, Manya Warrier, Diana M. Shih, Amy C. Burrows, Daniel Ferguson, Anthony D. Gromovsky, Amanda L. Brown, Stephanie Marshall, Allison Mcdaniel, Rebecca C. Schugar, Zeneng Wang, Jessica Sacks, Xin Rong, Thomas De Aguiar Vallim, Jeff Chou, Pavlina T. Ivanova, David S. Myers, H. Alex Brown, Richard G. Lee, Rosanne M. Crooke, Mark J. Graham, Xiuli Liu, Paolo Parini, Peter Tontonoz, Aldon J. Lusis, Stanley L. Hazen, Ryan E. Temel, J. Mark Brown

Saha Cardiovascular Research Center Faculty Publications

Circulating levels of the gut microbe-derived metabolite trimethylamine-N-oxide (TMAO) have recently been linked to cardiovascular disease (CVD) risk. Here, we performed transcriptional profiling in mouse models of altered reverse cholesterol transport (RCT) and serendipitously identified the TMAO-generating enzyme flavin monooxygenase 3 (FMO3) as a powerful modifier of cholesterol metabolism and RCT. Knockdown of FMO3 in cholesterol-fed mice alters biliary lipid secretion, blunts intestinal cholesterol absorption, and limits the production of hepatic oxysterols and cholesteryl esters. Furthermore, FMO3 knockdown stimulates basal and liver X receptor (LXR)-stimulated macrophage RCT, thereby improving cholesterol balance. Conversely, FMO3 knockdown exacerbates hepatic endoplasmic reticulum (ER) stress …


Unbiased Analysis Of Pancreatic Cancer Radiation Resistance Reveals Cholesterol Biosynthesis As A Novel Target For Radiosensitisation., Joshua J. Souchek, Michael J. Baine, Chi Lin, Satyanarayana Rachagani, Suprit Gupta, Sukhwinder Kaur, K Lester, D Zheng, S Chen, Lynette Smith, A Lazenby, Sonny L. Johansson, Maneesh Jain, Surinder K. Batra Sep 2014

Unbiased Analysis Of Pancreatic Cancer Radiation Resistance Reveals Cholesterol Biosynthesis As A Novel Target For Radiosensitisation., Joshua J. Souchek, Michael J. Baine, Chi Lin, Satyanarayana Rachagani, Suprit Gupta, Sukhwinder Kaur, K Lester, D Zheng, S Chen, Lynette Smith, A Lazenby, Sonny L. Johansson, Maneesh Jain, Surinder K. Batra

Journal Articles: Biochemistry & Molecular Biology

BACKGROUND: Despite its promise as a highly useful therapy for pancreatic cancer (PC), the addition of external beam radiation therapy to PC treatment has shown varying success in clinical trials. Understanding PC radioresistance and discovery of methods to sensitise PC to radiation will increase patient survival and improve quality of life. In this study, we identified PC radioresistance-associated pathways using global, unbiased techniques.

METHODS: Radioresistant cells were generated by sequential irradiation and recovery, and global genome cDNA microarray analysis was performed to identify differentially expressed genes in radiosensitive and radioresistant cells. Ingenuity pathway analysis was performed to discover cellular pathways …


Childhood Obesity And Familial Hypercholesterolemia: Genetic Diseases That Contribute To Cardiovascular Disease, Alyssa Caudle Apr 2014

Childhood Obesity And Familial Hypercholesterolemia: Genetic Diseases That Contribute To Cardiovascular Disease, Alyssa Caudle

Senior Honors Theses

Childhood obesity occurs as the result of an imbalance between caloric intake and energy expenditure. Genetic risk factors for obesity have become an area of research due to its permanency. Mutated genes such as Fat Mass and Obesity Associated (FTO), Leptin (LEP), Leptin Receptor (LEPR), Melanocortin 4 Receptor (MC4R), Adiponectin C1Q and Collagen Domain Containing (ADIPOQ), Proprotein Convertase Subtilisin/Kexin Type 1 (PCSK1), and Peroxisome Proliferator-Activated Receptor Gamma (PPARG) all contribute to the development of childhood obesity. In the presence of high cholesterol caused by obesity, the genetic condition known as familial hypercholesterolemia is exacerbated. Familial hypercholesterolemia is caused by a …


The Tumor Suppressor Tere1 (Ubiad1) Prenyltransferase Regulates The Elevated Cholesterol Phenotype In Castration Resistant Prostate Cancer By Controlling A Program Of Ligand Dependent Sxr Target Genes., William J. Fredericks, Jorge Sepulveda, Priti Lai, John E. Tomaszewski, Ming-Fong Lin, Terry Mcgarvey, Frank J. Rauscher, S. Bruce Malkowicz Jul 2013

The Tumor Suppressor Tere1 (Ubiad1) Prenyltransferase Regulates The Elevated Cholesterol Phenotype In Castration Resistant Prostate Cancer By Controlling A Program Of Ligand Dependent Sxr Target Genes., William J. Fredericks, Jorge Sepulveda, Priti Lai, John E. Tomaszewski, Ming-Fong Lin, Terry Mcgarvey, Frank J. Rauscher, S. Bruce Malkowicz

Journal Articles: Biochemistry & Molecular Biology

Castrate-Resistant Prostate Cancer (CRPC) is characterized by persistent androgen receptor-driven tumor growth in the apparent absence of systemic androgens. Current evidence suggests that CRPC cells can produce their own androgens from endogenous sterol precursors that act in an intracrine manner to stimulate tumor growth. The mechanisms by which CRPC cells become steroidogenic during tumor progression are not well defined. Herein we describe a novel link between the elevated cholesterol phenotype of CRPC and the TERE1 tumor suppressor protein, a prenyltransferase that synthesizes vitamin K-2, which is a potent endogenous ligand for the SXR nuclear hormone receptor. We show that 50% …


Acat1 Gene Ablation Increases 24(S)-Hydroxycholesterol Content In The Brain And Ameliorates Amyloid Pathology In Mice With Ad, Elena Y. Bryleva, Maximillian A. Rogers, Catherine C. Y. Chang, Floyd Buen Feb 2010

Acat1 Gene Ablation Increases 24(S)-Hydroxycholesterol Content In The Brain And Ameliorates Amyloid Pathology In Mice With Ad, Elena Y. Bryleva, Maximillian A. Rogers, Catherine C. Y. Chang, Floyd Buen

Dartmouth Scholarship

Cholesterol metabolism has been implicated in the pathogenesis of several neurodegenerative diseases, including the abnormal accumulation of amyloid-beta, one of the pathological hallmarks of Alzheimer disease (AD). Acyl-CoA:cholesterol acyltransferases (ACAT1 and ACAT2) are two enzymes that convert free cholesterol to cholesteryl esters. ACAT inhibitors have recently emerged as promising drug candidates for AD therapy. However, how ACAT inhibitors act in the brain has so far remained unclear. Here we show that ACAT1 is the major functional isoenzyme in the mouse brain. ACAT1 gene ablation (A1-) in triple transgenic (i.e., 3XTg-AD) mice leads to more than 60% reduction in full-length human …


Clinical Field-Strength Mri Of Amyloid Plaques Induced By Low-Level Cholesterol Feeding In Rabbits, John A. Ronald, Yuanxin Chen, Lisa Bernas, Hagen H. Kitzler, Kem A. Rogers, Robert A. Hegele, Brian K. Rutt May 2009

Clinical Field-Strength Mri Of Amyloid Plaques Induced By Low-Level Cholesterol Feeding In Rabbits, John A. Ronald, Yuanxin Chen, Lisa Bernas, Hagen H. Kitzler, Kem A. Rogers, Robert A. Hegele, Brian K. Rutt

Robarts Imaging Publications

Two significant barriers have limited the development of effective treatment of Alzheimer’s disease. First, for many cases the aetiology is unknown and likely multi-factorial. Among these factors, hypercholesterolemia is a known risk predictor and has been linked to the formation of b-amyloid plaques, a pathological hallmark this disease. Second, standardized diagnostic tools are unable to definitively diagnose this disease prior to death; hence new diagnostic tools are urgently needed. Magnetic resonance imaging (MRI) using high field-strength scanners has shown promise for direct visualization of b-amyloid plaques, allowing in vivo longitudinal tracking of disease progression in mouse models. Here, we present …


Androgen-Independent Prostate Cancer Cells Acquire The Complete Steroidogenic Potential Of Synthesizing Testosterone From Cholesterol., Paulette R. Dillard, Ming-Fong Lin, Shafiq A. Khan Nov 2008

Androgen-Independent Prostate Cancer Cells Acquire The Complete Steroidogenic Potential Of Synthesizing Testosterone From Cholesterol., Paulette R. Dillard, Ming-Fong Lin, Shafiq A. Khan

Journal Articles: Biochemistry & Molecular Biology

The proliferation and differentiation of normal prostate epithelial cells depends upon the action of androgens produced by the testis. Prostate cancers retain the ability to respond to androgens in the initial stages of cancer development, but progressively become independent of exogenous androgens in advanced stages of the disease while maintaining the expression of functional androgen receptor (AR). In the present study, we have determined the potential of prostate cancer cells to synthesize androgens from cholesterol which may be involved in intracrine regulation of AR in advanced stages of the disease. Established androgen-independent prostate cancer cell lines, PC3 and DU145 cells, …


Transport Of Ldl-Derived Cholesterol From The Npc1 Compartment To The Er Involves The Trans-Golgi Network And The Snare Protein Complex, Yasuomi Urano, Hiroshi Watanabe, Stephanie R. Murphy, Yohei Shibuya, Yong Geng, Andrew Peden, Catherine Chang, Ta Yuan Chang Oct 2008

Transport Of Ldl-Derived Cholesterol From The Npc1 Compartment To The Er Involves The Trans-Golgi Network And The Snare Protein Complex, Yasuomi Urano, Hiroshi Watanabe, Stephanie R. Murphy, Yohei Shibuya, Yong Geng, Andrew Peden, Catherine Chang, Ta Yuan Chang

Dartmouth Scholarship

Mammalian cells acquire cholesterol mainly from LDL. LDL enter the endosomes, allowing cholesteryl esters to be hydrolyzed by acid lipase. The hydrolyzed cholesterol (LDL-CHOL) enters the Niemann-Pick type C1 (NPC1)-containing endosomal compartment en route to various destinations. Whether the Golgi is involved in LDL-CHOL transport downstream of the NPC1 compartment has not been demonstrated. Using subcellular fractionation and immunoadsorption to enrich for specific membrane fractions, here we show that, when parental Chinese hamster ovary (CHO) cells are briefly exposed to (3)H-cholesteryl linoleate (CL) labeled-LDL, newly liberated (3)H-LDL-CHOL appears in membranes rich in trans-Golgi network (TGN) long before it becomes available …


Surface Charge Effects Involved In The Control Of Stability Of Sols Comprising Uniform Cholesterol Particles, Vuk Uskoković Jul 2008

Surface Charge Effects Involved In The Control Of Stability Of Sols Comprising Uniform Cholesterol Particles, Vuk Uskoković

Pharmacy Faculty Articles and Research

The reported is a method for the preparation of stable dispersions of narrowly dispersed cholesterol crystals, which may provide an excellent model for the aggregation studies thereof. The effects of experimental parameters that include concentration, pH, ionic strength, temperature, and aging on the resulting morphologies are acknowledged. Regardless of the cause of destabilization, the multilayered aggregates of cholesterol particles are formed by “face-to-face” stacking of the original platelets, as promoted by higher surface charge density on particle sides comparing to their faces. In accordance with the crucial involvement of surface charge effects in stabilization of cholesterol dispersions produced hereby, aggregation …


Insights Into Morphological Nature Of Precipitation Of Cholesterol, Vuk Uskoković Mar 2008

Insights Into Morphological Nature Of Precipitation Of Cholesterol, Vuk Uskoković

Pharmacy Faculty Articles and Research

Additional effects on the previously reported procedure of precipitation of narrowly dispersed and well-defined, brick-shaped cholesterol particles, including non-solvent addition rate, temperature, solvent purity, aging treatments, ultrasound agitation and fine mechanical effects were investigated. Based on the presented results, significant morphological sensitivity of cholesterol precipitation processes upon variations from the standard established procedure of crystallization is induced. However, the tendency of cholesterol to crystallize in the form of biaxially grown particles was evidenced as dominating the precipitation processes, irrespective of any modifications of experimental parameters involved in the preparation procedure investigated hereby. Prolonged aging time and temperature effects lead to …


Composites Comprising Cholesterol And Carboxymethyl Cellulose, Vuk Uskoković Feb 2008

Composites Comprising Cholesterol And Carboxymethyl Cellulose, Vuk Uskoković

Pharmacy Faculty Articles and Research

Whereby cholesterol presents one of the major fatty substances in human body, carboxymethyl cellulose is a water-soluble derivative of cellulose, the most abundant dietary fiber. Whereas on one hand in vivo precipitation of cholesterol is the major cause of atherosclerosis, dietary fibers are on the other hand known for their ability to clean the fatty plaque deposited on intestinal pathways, and prevent its build-up in other critical areas within the organism. In this work, a method for the preparation of a composite material comprising cholesterol and carboxymethyl cellulose from 1-hexanol/water biphase mixtures is reported. Specificity of the interaction between the …


Alzheimer's Disease: Cholesterol, Membrane Rafts, Isoprenoids And Statins, Patrick C. Reid, Yasuomi Urano, Tatsuhiko Kodama, Takao Hamakubo Apr 2007

Alzheimer's Disease: Cholesterol, Membrane Rafts, Isoprenoids And Statins, Patrick C. Reid, Yasuomi Urano, Tatsuhiko Kodama, Takao Hamakubo

Dartmouth Scholarship

Alzheimer's disease (AD) is a heterogeneous neurodegenerative disorder and the most prevalent form of dementia worldwide. AD is characterized pathologically by amyloid-? plaques, neurofibrillary tangles and neuronal loss, and clinically by a progressive loss of cognitive abilities. At present, the fundamental molecular mechanisms underlying the disease are unclear and no treatment for AD is known. Epidemiological evidence continues to mount linking vascular diseases, such as hypertension and diabetes, and hypercholesterolaemia with an increased risk for developing AD. A growing amount of evidence suggests a mechanistic link between cholesterol metabolism in the brain and the formation of amyloid plaques in AD …


Binding Between The Niemann–Pick C1 Protein And A Photoactivatable Cholesterol Analog Requires A Functional Sterol-Sensing Domain, Nobutaka Ohgami, Dennis C. Ko, Matthew Thomas, Matthew P. Scott, Catherine C. Y. Chang, Ta-Yuan Chang Aug 2004

Binding Between The Niemann–Pick C1 Protein And A Photoactivatable Cholesterol Analog Requires A Functional Sterol-Sensing Domain, Nobutaka Ohgami, Dennis C. Ko, Matthew Thomas, Matthew P. Scott, Catherine C. Y. Chang, Ta-Yuan Chang

Dartmouth Scholarship

Niemann-Pick type C (NPC) 1 protein plays important roles in moving cholesterol and other lipids out of late endosomes by means of vesicular trafficking, but it is not known whether NPC1 directly interacts with cholesterol. We performed photoaffinity labeling of intact cells expressing fluorescent protein (FP)-tagged NPC1 by using [(3)H]7,7-azocholestanol ([(3)H]AC). After immunoprecipitation, (3)H-labeled NPC1-GFP appeared as a single band. Including excess unlabeled sterol to the labeling reaction significantly diminished the labeling. Altering the NPC1 sterol-sensing domain (SSD) with loss-of-function mutations (P692S and Y635C) severely reduced the extent of labeling. To further demonstrate the specificity of labeling, we show that …


Fibroblast Growth Factor 2 Endocytosis In Endothelial Cells Proceed Via Syndecan-4-Dependent Activation Of Rac1 And A Cdc42-Dependent Macropinocytic Pathway, Eugene Tkachenko, Esther Lutgens, Radu-Virgil Stan, Michael Simons Feb 2004

Fibroblast Growth Factor 2 Endocytosis In Endothelial Cells Proceed Via Syndecan-4-Dependent Activation Of Rac1 And A Cdc42-Dependent Macropinocytic Pathway, Eugene Tkachenko, Esther Lutgens, Radu-Virgil Stan, Michael Simons

Dartmouth Scholarship

Full activity of fibroblast growth factors (FGFs) requires their internalization in addition to the interaction with cell surface receptors. Recent studies have suggested that the transmembrane proteoglycan syndecan-4 functions as a FGF2 receptor. In this study we investigated the molecular basis of syndecan endocytosis and its role in FGF2 internalization in endothelial cells. We found that syndecan-4 uptake, induced either by treatment with FGF2 or by antibody clustering, requires the integrity of plasma membrane lipid rafts for its initiation, occurs in a non-clathrin-, non-dynamin-dependent manner and involves Rac1, which is activated by syndecan-4 clustering. FGF2 was internalized in a complex …


Membrane Cholesterol Content Modulates Activation Of Volume-Regulated Anion Current In Bovine Endothelial Cells., I Levitan, A E Christian, T N Tulenko, G H Rothblat Apr 2000

Membrane Cholesterol Content Modulates Activation Of Volume-Regulated Anion Current In Bovine Endothelial Cells., I Levitan, A E Christian, T N Tulenko, G H Rothblat

Department of Biochemistry and Molecular Biology Faculty Papers

Activation of volume-regulated anion current (VRAC) plays a key role in the maintenance of cellular volume homeostasis. The mechanisms, however, that regulate VRAC activity are not fully understood. We have examined whether VRAC activation is modulated by the cholesterol content of the membrane bilayer. The cholesterol content of bovine aortic endothelial cells was increased by two independent methods: (a) exposure to a methyl-beta-cyclodextrin saturated with cholesterol, or (b) exposure to cholesterol-enriched lipid dispersions. Enrichment of bovine aortic endothelial cells with cholesterol resulted in a suppression of VRAC activation in response to a mild osmotic gradient, but not to a strong …


Global Cns Gene Transfer For A Childhood Neurogenetic Enzyme Deficiency: Canavan Disease., Paola Leone, Christopher G Janson, Scott J Mcphee, Matthew J During Aug 1999

Global Cns Gene Transfer For A Childhood Neurogenetic Enzyme Deficiency: Canavan Disease., Paola Leone, Christopher G Janson, Scott J Mcphee, Matthew J During

Department of Neurosurgery Faculty Papers

The neurogenetic prototypic disease on which we chose to test our gene therapy strategy is Canavan disease (CD). CD is an autosomal recessive leukodystrophy associated with spongiform degeneration of the brain. At present the disease is uniformly fatal in affected probands. CD is characterized by mutations in the aspartoacylase (ASPA) gene, resulting in loss of enzyme activity. In this review, recent evidence is summarized on the etiology and possible treatments for CD. In particular, we discuss two gene delivery systems representing recent advances in both viral and liposome technology: a novel cationic liposome-polymer-DNA (LPD) complex, DCChol/DOPE-protamine, as well as recombinant …


Biotransformation Of Bile Acids, Cholesterol And Steroids. Chapter 13 In: The Ecology And Physiology Of Gastrointestinal Microbes. Vol. 1, New York, Chapman And Hall., Stephen Baron, Phillip B. Hylemon Jan 1995

Biotransformation Of Bile Acids, Cholesterol And Steroids. Chapter 13 In: The Ecology And Physiology Of Gastrointestinal Microbes. Vol. 1, New York, Chapman And Hall., Stephen Baron, Phillip B. Hylemon

Biology Faculty Scholarship

No abstract provided.