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Benito-Vicente A, Uribe KB, Jebari S, Galicia-Garcia U, Ostolaza H, Martin C. Familial Hypercholesterolemia: The Most Frequent Cholesterol Metabolism Disorder Caused Disease. Int J Mol Sci 2018; 19:ijms19113426. [PMID: 30388787 PMCID: PMC6275065 DOI: 10.3390/ijms19113426] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/21/2018] [Accepted: 10/29/2018] [Indexed: 12/18/2022] Open
Abstract
Cholesterol is an essential component of cell barrier formation and signaling transduction involved in many essential physiologic processes. For this reason, cholesterol metabolism must be tightly controlled. Cell cholesterol is mainly acquired from two sources: Dietary cholesterol, which is absorbed in the intestine and, intracellularly synthesized cholesterol that is mainly synthesized in the liver. Once acquired, both are delivered to peripheral tissues in a lipoprotein dependent mechanism. Malfunctioning of cholesterol metabolism is caused by multiple hereditary diseases, including Familial Hypercholesterolemia, Sitosterolemia Type C and Niemann-Pick Type C1. Of these, familial hypercholesterolemia (FH) is a common inherited autosomal co-dominant disorder characterized by high plasma cholesterol levels. Its frequency is estimated to be 1:200 and, if untreated, increases the risk of premature cardiovascular disease. This review aims to summarize the current knowledge on cholesterol metabolism and the relation of FH to cholesterol homeostasis with special focus on the genetics, diagnosis and treatment.
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Affiliation(s)
- Asier Benito-Vicente
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Kepa B Uribe
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Shifa Jebari
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Unai Galicia-Garcia
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Helena Ostolaza
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
| | - Cesar Martin
- Departamento de Bioquímica, Instituto Biofisika (UPV/EHU, CSIC), Universidad del País Vasco, Apdo.644, 48080 Bilbao, Spain.
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Zhao L, Chen T, Wang C, Li G, Zhi W, Yin J, Wan Q, Chen L. Atorvastatin in improvement of cognitive impairments caused by amyloid β in mice: involvement of inflammatory reaction. BMC Neurol 2016; 16:18. [PMID: 26846170 PMCID: PMC4743318 DOI: 10.1186/s12883-016-0533-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Accepted: 01/16/2016] [Indexed: 11/23/2022] Open
Abstract
Background The production of inflammatory cytokines resulting from amyloid β (Aβ) is associated with the initiation of Alzheimer’s disease (AD). Atorvastatin (ATV) has been reported to improve AD, however, it is unclear how the anti-inflammatory mechanism is linked with its protection against the impairment of spatial cognitive function in AD. The present study was designed to explore what mechanism was possibly involved in the anti-inflammatory pathway in regard to the ATV treatment of AD. Methods We used an AD model induced by the administration of Aβ25–35 in male C57BL/6 mice and an in vitro culture system to study the protective effects of ATV on the spatial cognitive deficits, hippocampal long-term potentiation (LTP) impairment and inflammatory reaction. Results The intragastric administration of ATV (5 mg/kg) in Aβ25–35-treated mice significantly ameliorated the spatial cognitive deficits and prevented the LTP impairment in hippocampal CA1. The increased Iba-1 positive cells and inflammatory components in the hippocampus were reduced after the ATV treatment. The anti-inflammatory and LTP protection of ATV were abolished using the replenishment of farnesyl pyrophosphate by the administration of farnesol (FOH). The hippocampal slices culture showed Aβ25–35-induced neurotoxicity in the absence of the presence of ATV. Treatment with ATV (0.5, 1, 2.5 μmol/L) dose-dependently prevented the cell damage in hippocampus induced by Aβ25–35. Conclusion The administration of ATV ameliorated the cognitive deficits, depressed the inflammatory responses, improved the LTP impairment, and prevents Aβ25-35-induced neurotoxicity in cultured hippocampal neurons. These protective functions of ATV involved the pathway of reducing farnesyl pyrophosphate (FPP).
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Affiliation(s)
- Liandong Zhao
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, China.,Department of Neurology, The Second Hospital of Huaian, Huaian, Jiangsu, 223002, China
| | - Tingting Chen
- Department of Physiology, Nanjing Medical University, Nanjing, 210029, China
| | - Chonghui Wang
- Department of Physiology, Nanjing Medical University, Nanjing, 210029, China
| | - Guoxi Li
- Department of Physiology, Nanjing Medical University, Nanjing, 210029, China
| | - Wenhui Zhi
- Department of Physiology, Nanjing Medical University, Nanjing, 210029, China
| | - Jun Yin
- Department of Physiology, Nanjing Medical University, Nanjing, 210029, China
| | - Qi Wan
- Department of Neurology, The First Affiliated Hospital of Nanjing Medical University, 300 Guangzhou Road, Nanjing, Jiangsu, 210029, China.
| | - Ling Chen
- Department of Physiology, Nanjing Medical University, Nanjing, 210029, China. .,Laboratory of Reproductive Medicine, Department of Physiology, Nanjing Medical University, 140 Hanzhong Road, Nanjing, China.
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Subramanian T, Ren H, Subramanian KL, Sunkara M, Onono FO, Morris AJ, Spielmann HP. Design and synthesis of non-hydrolyzable homoisoprenoid α-monofluorophosphonate inhibitors of PPAPDC family integral membrane lipid phosphatases. Bioorg Med Chem Lett 2014; 24:4414-4417. [PMID: 25150376 DOI: 10.1016/j.bmcl.2014.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 08/01/2014] [Accepted: 08/05/2014] [Indexed: 12/20/2022]
Abstract
An efficient, diversity oriented synthesis of homoisoprenoid α-monofluorophosphonates utilizing electrophilic fluorination is presented along with their activity as inhibitors of PPAPDC2 family integral membrane lipid phosphatases. These novel phosphatase-resistant analogues of isoprenoid monophosphates are a platform for further structure-activity relationship studies and provide access to other isoprenoid family members where the phosphate ester oxygen is replaced by a α-monofluoromethylene moiety.
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Affiliation(s)
- Thangaiah Subramanian
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Hongmei Ren
- Division of Cardiovascular Medicine UK COM, University of Kentucky, Lexington, KY 40536, USA
| | | | - Manjula Sunkara
- Division of Cardiovascular Medicine UK COM, University of Kentucky, Lexington, KY 40536, USA
| | - Fredrick O Onono
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Andrew J Morris
- Division of Cardiovascular Medicine UK COM, University of Kentucky, Lexington, KY 40536, USA; Lexington Veterans Affairs Medical Center, University of Kentucky, Lexington, KY 40536, USA
| | - H Peter Spielmann
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA; Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA; Kentucky Center for Structural Biology, University of Kentucky, Lexington, KY 40536, USA; Department of Chemistry, University of Kentucky, Lexington, KY 40536, USA.
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Philips KB, Kurtoglu M, Leung HJ, Liu H, Gao N, Lehrman MA, Murray TG, Lampidis TJ. Increased sensitivity to glucose starvation correlates with downregulation of glycogen phosphorylase isoform PYGB in tumor cell lines resistant to 2-deoxy-D-glucose. Cancer Chemother Pharmacol 2014; 73:349-61. [PMID: 24292700 PMCID: PMC4570497 DOI: 10.1007/s00280-013-2358-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 11/11/2013] [Indexed: 12/11/2022]
Abstract
BACKGROUND As tumors evolve, they upregulate glucose metabolism while also encountering intermittent periods of glucose deprivation. Here, we investigate mechanisms by which pancreatic cancer cells respond to therapeutic (2-deoxy-D-glucose, 2-DG) and physiologic (glucose starvation, GS) forms of glucose restriction. METHODS From a tumor cell line (1420) that is unusually sensitive to 2-DG under normoxia, low (14DG2)- and high (14DG5)-dose resistant cell lines were selected and used to probe the metabolic pathways involved with their response to different forms of glucose deprivation. RESULTS Muted induction of the unfolded protein response was found to correlate with resistance to 2-DG. Additionally, 14DG2 displayed reduced 2-DG uptake, while 14DG5 was cross-resistant to tunicamycin, suggesting it has enhanced ability to manage glycosylation defects. Conversely, 2-DG-resistant cell lines were more sensitive than their parental cell line to GS, which coincided with lowered levels of glycogen phosphorylase (PYGB) and reduced breakdown of glycogen to glucose in the 2-DG-resistant cell lines. Moreover, by inhibiting PYGB in the parental cell line, sensitivity to GS was increased. CONCLUSIONS Overall, the data demonstrate that the manner in which glucose is restricted in tumor cells, i.e., therapeutic or physiologic, leads to differential biological responses involving distinct glucose metabolic pathways. Moreover, in evolving tumors where glucose restriction occurs, the identification of PYGB as a metabolic target may have clinical application.
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Affiliation(s)
- Katherine B. Philips
- Sheila and David Fuente Graduate Program in Cancer Biology, University of Miami Miller School of Medicine, 1550 NW 10th Avenue, Fox Building #406, Miami, FL 33136, USA,
| | - Metin Kurtoglu
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, PAP Building, Room 115, 1550 NW 10th Ave, Miami, FL 33136, USA,
| | - Howard J. Leung
- Sheila and David Fuente Graduate Program in Cancer Biology, University of Miami Miller School of Medicine, 1550 NW 10th Avenue, Fox Building #406, Miami, FL 33136, USA,
| | - Huaping Liu
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, PAP Building, Room 115, 1550 NW 10th Ave, Miami, FL 33136, USA,
| | - Ningguo Gao
- Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA,
| | - Mark A. Lehrman
- Department of Pharmacology, University of Texas Southwestern Medical Center, 6001 Forest Park Rd., Dallas, TX 75390-9041, USA,
| | - Timothy G. Murray
- Department of Ophthalmology, Bascom Palmer Eye Institute, University of Miami, 900 NW 17th St., Miami, FL 33136, USA,
| | - Theodore J. Lampidis
- Department of Cell Biology (R-124), University of Miami Miller School of Medicine, 1600 NW 10th Avenue, Rosenstiel Medical Sciences Building #4026/4027, P.O. Box 016960, Miami, FL 33101, USA,
- Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, 1475 NW 12th Avenue, P.O. Box 016960, Miami, FL 33101, USA
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Simvastatin promotes adult hippocampal neurogenesis by enhancing Wnt/β-catenin signaling. Stem Cell Reports 2013; 2:9-17. [PMID: 24511465 PMCID: PMC3916759 DOI: 10.1016/j.stemcr.2013.11.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 11/05/2013] [Accepted: 11/06/2013] [Indexed: 02/01/2023] Open
Abstract
Statins improve recovery from traumatic brain injury and show promise in preventing Alzheimer disease. However, the mechanisms by which statins may be therapeutic for neurological conditions are not fully understood. In this study, we present the initial evidence that oral administration of simvastatin in mice enhances Wnt signaling in vivo. Concomitantly, simvastatin enhances neurogenesis in cultured adult neural progenitor cells as well as in the dentate gyrus of adult mice. Finally, we find that statins enhance Wnt signaling through regulation of isoprenoid synthesis and not through cholesterol. These findings provide direct evidence that Wnt signaling is enhanced in vivo by simvastatin and that this elevation of Wnt signaling is required for the neurogenic effects of simvastatin. Collectively, these data add to the growing body of evidence that statins may have therapeutic value for treating certain neurological disorders.
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Marcuzzi A, Zanin V, Kleiner G, Monasta L, Crovella S. Mouse model of mevalonate kinase deficiency: comparison of cytokine and chemokine profile with that of human patients. Pediatr Res 2013; 74:266-71. [PMID: 23760140 DOI: 10.1038/pr.2013.96] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 01/18/2013] [Indexed: 01/22/2023]
Abstract
BACKGROUND Mevalonate kinase deficiency (MKD) is a rare genetic autoinflammatory disease caused by blocking of the enzyme mevalonate kinase in the pathway of cholesterol and isoprenoids. The pathogenic mechanism originating an immune response in MKD patients has not been clearly understood. METHODS We investigated the dysregulation of expression of selected cytokines and chemokines in the serum of MKD patients. The results have been compared with those observed in an MKD mouse model obtained by treating the mice with aminobisphosphonate, a molecule that is able to inhibit the cholesterol pathway, mimicking the genetic block characteristic of the disease. RESULTS Interleukin (IL)-1β, IL-5, IL-6, IL-9, IL-17, granulocyte colony-stimulating factor, monocyte chemotactic protein-1, tumor necrosis factor-α, and IL-4 expression were dysregulated in sera from MKD patients and mice. Moreover, geraniol, an exogenous isoprenoid, when administered to MKD mice, restored cytokines and chemokines levels with values similar to those of untreated mice. CONCLUSION Our findings, which were obtained in patients and a mouse model mimicking the human disease, suggest that these cytokines and chemokines could be MKD specific and that isoprenoids could be considered as potential therapeutic molecules. The mouse model, even if with some limitations, was robust and suitable for routine testing of potential MKD drugs.
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Affiliation(s)
- Annalisa Marcuzzi
- Health Genetics Unit, Institute for Maternal and Child Health-IRCCS Burlo Garofolo, Trieste, Italy.
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De Leo L, Marcuzzi A, Decorti G, Tommasini A, Crovella S, Pontillo A. Targeting farnesyl-transferase as a novel therapeutic strategy for mevalonate kinase deficiency: In vitro and in vivo approaches. Pharmacol Res 2010; 61:506-10. [DOI: 10.1016/j.phrs.2010.02.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 02/23/2010] [Accepted: 02/24/2010] [Indexed: 11/29/2022]
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Decreased cholesterol levels reflect a consumption of anti-inflammatory isoprenoids associated with an impaired control of inflammation in a mouse model of mevalonate kinase deficiency. Inflamm Res 2010; 59:335-8. [PMID: 20174853 DOI: 10.1007/s00011-010-0168-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 01/22/2010] [Indexed: 10/19/2022] Open
Abstract
OBJECTIVE The aim of this study was to evaluate, in a mouse model of mevalonate kinase deficiency (MKD), the possible link between inflammatory symptoms and serum cholesterol levels. MATERIALS AND METHODS Balb/c mice were treated with alendronate and bacterial muramyl dipeptide. Body temperature, interleukin-1 beta (IL-1 beta) secretion and serum cholesterol levels were measured. RESULTS An increased production of the pro-inflammatory cytokine IL-1 beta (p < 0.05) and a rise in body temperature (p < 0.05) was observed, while, in parallel, serum cholesterol concentration significantly decreased (p < 0.05). These effects were completely reversed when animals were treated with exogenous isoprenoids. CONCLUSIONS In the mouse model of MKD, the inflammatory response is associated with a reduction in cholesterol levels, and hence this parameter could be used as an indicator of isoprenoid consumption. In addition, plant derived isoprenoids could represent candidate treatments for this disease.
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9
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von Gunten CF, Sinensky M. Treatment of CHO-K1 cells with 25-hydroxycholesterol produces a more rapid loss of 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity than can be accounted for by enzyme turnover. BIOCHIMICA ET BIOPHYSICA ACTA 1989; 1001:218-24. [PMID: 2917146 DOI: 10.1016/0005-2760(89)90151-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A key enzyme in the regulation of mammalian cellular cholesterol biosynthesis is 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoA reductase). It is well established that treatment with the compound 25-hydroxycholesterol lowers HMG-CoA reductase activity in cultured Chinese hamster ovary (CHO-K1) cells. After brief incubation (0-4 h) with 25-hydroxycholesterol (0.5 microgram/ml), cellular HMG-CoA reductase activity is decreased to 40% of its original level. This also occurs in the presence of exogenous mevinolin, a competitive inhibitor of HMG-CoA reductase which has previously been shown to inhibit its degradation. The inhibition of HMG-CoA reductase activity by 25-hydroxycholesterol is complete after 2 h. Radio-immune precipitation analysis of the native enzyme under these conditions shows a degradation half-life which is considerably longer than that of the observed inhibition. Studies with sodium fluoride, phosphatase 2A, bacterial alkaline phosphatase and calf alkaline phosphatase indicate that the observed loss of activity is not due to phosphorylation. These data are not consistent with described mechanisms of HMG-CoA reductase activity regulation by phosphorylation or degradation but are consistent with a novel mechanism that regulates the catalytic efficiency of this enzyme.
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Affiliation(s)
- C F von Gunten
- Eleanor Roosevelt Institute for Cancer Research, Denver, CO 80206
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Strandberg TE, Tilvis RS. Physiological and pharmacological regulation of small intestinal cholesterol synthesis. GENERAL PHARMACOLOGY 1988; 19:321-9. [PMID: 3046994 DOI: 10.1016/0306-3623(88)90024-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
1. The small intestine is an important site of cholesterol synthesis in the body and at least in experimental animals, it also contributes to the circulating plasma pool of cholesterol. 2. Studies on synthesis regulation have been partly contradictory but it is now concluded that the cellular cholesterol balance is the basic regulatory factor of intestinal cholesterol synthesis. However, the balance is affected differently in various specialized cells and parts of the small intestine. 3. Most data on synthesis regulation are derived from experimental animals but the few human studies suggest that similar regulatory factors function in man, too.
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Affiliation(s)
- T E Strandberg
- Second Department of Medicine, University of Helsinki, Finland
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11
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Kuhn DE, Logan DM. Fiber-specific cholesterol changes in murine dystrophy. BIOCHIMICA ET BIOPHYSICA ACTA 1987; 921:13-24. [PMID: 3620485 DOI: 10.1016/0005-2760(87)90165-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The cholesterol concentration in dystrophic mouse muscle is reported to be increased compared to normal. The muscles studied are, however, composed in most cases of more than one fiber type. As a result, the observed concentration increase may be due to a general increase or may be due to changes in the proportion of individual fiber types which themselves differ in cholesterol concentration. To decide between these possibilities we have measured the cholesterol concentrations (both free cholesterol and cholesterol esters) in normal and dystrophic whole gastrocnemius muscles and compared the values with the concentrations in fast-glycolytic muscle tissue alone. The cholesterol concentrations in both whole and fast-glycolytic sections of dystrophic muscle are increased compared to normal, with the largest increase in the cholesterol ester fraction. Furthermore, the concentration changes in fast-glycolytic fibers are due mainly to cholesterol ester differences in both membrane and sarcoplasm fractions, with differences in the latter being larger. The data show that changes in whole muscle concentrations cannot be ascribed solely to altered fiber type proportions.
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Renaud JF, Schmid A, Romey G, Nano JL, Lazdunski M. Mevinolin, an inhibitor of cholesterol biosynthesis, drastically depresses Ca2+ channel activity and uncouples excitation from contraction in cardiac cells in culture. Proc Natl Acad Sci U S A 1986; 83:8007-11. [PMID: 2429325 PMCID: PMC386854 DOI: 10.1073/pnas.83.20.8007] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Mevinolin (MK803), a potent inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase) (Ki, 30 X 10(-9) M), depressed de novo synthesis of cholesterol in 11-day chicken embryonic cardiac cells cultured in lipoprotein-deficient serum (LPDS). Cardiac cells exposed to different concentrations of mevinolin for 1-3 days presented different electrophysiological and mechanical properties: The resting membrane potential, the rate of increase, and the shape of the action potential and contractile properties were changed at concentrations as low as 0.1 microM mevinolin. At a concentration of 1 microM mevinolin, the cardiac cells became quiescent and electrical stimulation induced action potentials of short duration without contraction. Isoproterenol and Bay K8644 were unable to restore excitability and contraction. Although the number of receptors for the tritiated Ca2+ channel blocker nitrendipine was the same in control and in mevinolin-treated cells, voltage-clamp data on isolated cardiac cells and 45Ca2+ flux experiments on monolayers showed that most of the slow Ca2+ channel activity was lost in mevinolin-treated cells. These results suggest that the disappearance of Ca2+ channel activity is most probably at the origin of the loss of cardiac contractility.
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Maurey K, Wolf F, Golbeck J. 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase Activity in Ochromonas malhamensis: A System to Study the Relationship between Enzyme Activity and Rate of Steroid Biosynthesis. PLANT PHYSIOLOGY 1986; 82:523-7. [PMID: 16665062 PMCID: PMC1056152 DOI: 10.1104/pp.82.2.523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, the key regulatory enzyme of the isoprenoid pathway, was found to be predominantly microsomal in Ochromonas malhamensis, a chrysophytic alga. Detection of HMG-CoA reductase requires the presence of 1% bovine serum albumin during cell homogenization, and the activity is stimulated by the presence of Triton X-100. The enzyme has a pH optimum of 8.0 and an absolute requirement for NADPH. When grown in 10 micromolar mevinolin, a competitive inhibitor of HMG-CoA reductase, O. malhamensis shows a 10- to 15-fold increase in HMG-CoA reductase activity (after washing) with little or no effect on cell growth rate. Cultures can be maintained in 10 micromolar mevinolin for months. O. malhamensis produces a large amount (1% dry weight) of poriferasterol, a product of the isoprenoid pathway. The addition of 10 micromolar mevinolin initially blocked poriferasterol biosynthesis by >90%; within 2 days the rate of synthesis returned to normal levels. Immediately after mevinolin was washed from the 2-day culture, there was a transient 2.5-fold increase in the rate of poriferasterol biosynthesis. The rate of poriferasterol biosynthesis and the level of HMG-CoA reductase activity both fell to control levels within hours.
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Affiliation(s)
- K Maurey
- Department of Chemistry, Portland State University, Portland, Oregon 97207
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Patel DD, Knight BL. The effect of mevalonate on 3-hydroxy-3-methylglutaryl-CoA reductase activity and the absolute rate of cholesterol biosynthesis in human monocyte-derived macrophages. EUROPEAN JOURNAL OF BIOCHEMISTRY 1985; 153:117-23. [PMID: 4065145 DOI: 10.1111/j.1432-1033.1985.tb09276.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Normal monocyte-derived macrophages maintained in medium containing 20% whole serum exhibited a high activity of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase while expressing appreciable, but not maximal receptor-mediated uptake and degradation of low-density lipoprotein (LDL). Addition of extracellular mevalonate led to a concentration-dependent fall in both processes, although a higher concentration was required to produce the same effect on LDL degradation as on HMG-CoA reductase activity. The true rate of cholesterol synthesis by the cells was already high without mevalonate and was not further increased when the intracellular pool of mevalonate was expanded. After preincubation with lipoprotein-deficient serum receptor-mediated degradation of LDL was increased but HMG-CoA reductase activity was decreased. Both were more sensitive to extracellular mevalonate and a given concentration of mevalonate now produced the same percentage fall in LDL degradation and reductase activity. The amount of cholesterol synthesized by the cells was markedly reduced during incubation with lipoprotein-deficient serum, probably as a result of the decreased reductase activity compounded by a lack of endogenous substrate. If these were circumvented by adding mevalonate, cholesterol synthesis was restored to normal. These results suggest that the fall in HMG-CoA reductase activity during incubation with lipoprotein-deficient serum resulted from repression by some non-sterol product of mevalonate metabolism. They imply that the need for this product by cells growing in whole serum leads to a particularly high HMG-CoA reductase activity and could account for their apparent preference for endogenous synthesis of cholesterol rather than for receptor-mediated uptake of LDL.
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Abstract
A polar photoproduct of cholesterol oxidation, 7-ketocholesterol, was able to inhibit in a dose-dependent manner the mouse ear-swelling response to irritants such as croton oil or cantharidin. Its anti-inflammatory properties were much less than equivalent concentrations of hydrocortisone, but the oxidized sterol did not induce any systemic effects (as measured by thymolytic activity), as did topical hydrocortisone. It is concluded that 7-ketocholesterol has weak anti-inflammatory activity, and its mode of action may be different from that of glucocorticoids.
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Madden EA, Melnykovych G, Fiskin AM. Compactin (ML-236B) reduces the content of filipin-cholesterol complexes in the plasma membrane of chronic lymphocytic leukemia cells. Exp Cell Res 1984; 153:91-8. [PMID: 6610562 DOI: 10.1016/0014-4827(84)90451-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The polyene antibiotic filipin was used to visualize the presence and distribution of cholesterol in the plasma membrane of glutaraldehyde-fixed human chronic lymphocytic leukemia (CLL) cells. Both compactin (ML-236B), a competitive inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, and 25-hydroxycholesterol reduced the content of filipin-cholesterol complexes in the plasma membrane of CLL cells grown in media supplemented with either 15% delipidized horse serum or 15% normal (whole) horse serum. The reduction due to compactin was reversed by the concomitant addition of mevalonolactone. The ability of compactin to reduce the relative cholesterol content (as judged by filipin labeling) in CLL cells grown in lipoprotein-containing (normal) serum suggest that either CLL cells are different from other cells in that they predominantly utilize endogenously synthesized cholesterol for incorporation into the plasma membrane, or that a separate pool of endogenously synthesized cholesterol provides cholesterol for the plasma membrane.
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Gospodarowicz D, Cohen DC, Massoglia SL. Stimulation of the proliferation of the Madin-Darby canine kidney (MDCK) epithelial cell line by high-density lipoproteins and their induction of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity. J Cell Physiol 1983; 117:76-90. [PMID: 6352714 DOI: 10.1002/jcp.1041170112] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
MDCK Cells seeded on extracellular matrix- (ECM) coated dishes and exposed to medium supplemented with high-density lipoproteins (HDLs, 750 micrograms protein/ml) and transferrin (10 micrograms/ml) have a proliferative rate, final cell density, and morphological appearance similar to those of cells grown in serum-supplemented medium. The mitogenic stimulus provided by HDLs is not limited by the initial cell density at which cultures are seeded, nor is it limited in time, since cells grown in medium supplemented with transferrin and HDLs grew to at least 50 generations. The presence of HDLs in the medium is required in order for cells to survive, since cells actively proliferating in the presence of medium supplemented with HDLs and transferrin begin to die within 2 days after being transferred to medium supplemented only with transferrin. Low-density lipoprotein (LDL) is mitogenic for MDCK cells when present at low concentrations (from 2.5 to 100 micrograms protein/ml). Above 100 micrograms protein/ml, LDL is cytotoxic and therefore cannot support cell proliferation at an optimal rate. The mitogenic effect of HDLs is also observed when cells are maintained on fibronectin-coated dishes. However, the proliferative rate of the cells is suboptimal and cultures cannot be passaged on this substrate indefinitely, as they can be on ECM-coated dishes. A close association between the ability of HDLs to support cell proliferation and their ability to induce the activity of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase is observed. HMG CoA reductase activity is 18 times higher (70 pmoles/min/10(6) cells) in proliferating cells than in confluent, nondividing cells (4 pmoles/min/10(6) cells). The HMG Coa reductase activity of sparse cells is more sensitive to induction by HDLs (eight-fold higher than control cells) than is the enzyme activity of confluent cells (two-fold higher than control levels). The dose-response relationship between the abilities of HDLs to support proliferation and to induce HMG CoA reductase activity are similar. The time course of the stimulation of proliferation and the increase in enzyme activity of sparse, quiescent cells after exposure to HDLs are parallel. The HMG CoA reductase activity of sparse MDCK cells is induced six-fold by exposure to compactin, a competitive inhibitor of HMG CoA reductase. This induction of HMG CoA reductase is prevented by mevalonic acid, not affected by LDL, and synergistically enhanced by simultaneous exposure to HDLs. HDLs effect a rescue from the cytotoxic effect of compactin, whereas LDL does not.(ABSTRACT TRUNCATED AT 400 WORDS)
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Ferres H, Hatton I, Jennings L, Tyrrell A, Williams D. A diastereoselective synthesis of 4(RS), 6(SR)-mercaptomethylmevalonolactone, a key intermediate in the preparation of a new class of inhibitors of HMG-CoA reductase. Tetrahedron Lett 1983. [DOI: 10.1016/s0040-4039(00)94530-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Cohen DC, Massoglia SL, Gospodarowicz D. Feedback regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase in vascular endothelial cells. Separate sterol and non-sterol components. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)33939-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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Cohen DC, Massoglia SL, Gospodarowicz D. Correlation between two effects of high density lipoproteins on vascular endothelial cells. The induction of 3-hydroxy-3-methylglutaryl coenzyme A reductase activity and the support of cellular proliferation. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34088-2] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Jabalquinto AM, Cardemil E. Comparative aspects of mevalonate metabolism in rat liver and kidney. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY. B, COMPARATIVE BIOCHEMISTRY 1982; 73:181-7. [PMID: 6756767 DOI: 10.1016/0305-0491(82)90269-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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