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Küry S, Stanton JE, van Woerden G, Hsieh TC, Rosenfelt C, Scott-Boyer MP, Most V, Wang T, Papendorf JJ, de Konink C, Deb W, Vignard V, Studencka-Turski M, Besnard T, Hajdukowicz AM, Thiel F, Möller S, Florenceau L, Cuinat S, Marsac S, Wentzensen I, Tuttle A, Forster C, Striesow J, Golnik R, Ortiz D, Jenkins L, Rosenfeld JA, Ziegler A, Houdayer C, Bonneau D, Torti E, Begtrup A, Monaghan KG, Mullegama SV, Volker-Touw CMLN, van Gassen KLI, Oegema R, de Pagter M, Steindl K, Rauch A, Ivanovski I, McDonald K, Boothe E, Dauber A, Baker J, Fabie NAV, Bernier RA, Turner TN, Srivastava S, Dies KA, Swanson L, Costin C, Jobling RK, Pappas J, Rabin R, Niyazov D, Tsai ACH, Kovak K, Beck DB, Malicdan M, Adams DR, Wolfe L, Ganetzky RD, Muraresku C, Babikyan D, Sedláček Z, Hančárová M, Timberlake AT, Al Saif H, Nestler B, King K, Hajianpour MJ, Costain G, Prendergast D, Li C, Geneviève D, Vitobello A, Sorlin A, Philippe C, Harel T, Toker O, Sabir A, Lim D, Hamilton M, Bryson L, Cleary E, Weber S, Hoffman TL, Cueto-González AM, Tizzano EF, Gómez-Andrés D, Codina-Solà M, Ververi A, Pavlidou E, Lambropoulos A, Garganis K, Rio M, Levy J, Jurgensmeyer S, McRae AM, Lessard MK, D'Agostino MD, De Bie I, Wegler M, Jamra RA, Kamphausen SB, Bothe V, Busch LM, Völker U, Hammer E, Wende K, Cogné B, Isidor B, Meiler J, Bosc-Rosati A, Marcoux J, Bousquet MP, Poschmann J, Laumonnier F, Hildebrand PW, Eichler EE, McWalter K, Krawitz PM, Droit A, Elgersma Y, Grabrucker AM, Bolduc FV, Bézieau S, Ebstein F, Krüger E. Unveiling the crucial neuronal role of the proteasomal ATPase subunit gene PSMC5 in neurodevelopmental proteasomopathies. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.01.13.24301174. [PMID: 38293138 PMCID: PMC10827246 DOI: 10.1101/2024.01.13.24301174] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Neurodevelopmental proteasomopathies represent a distinctive category of neurodevelopmental disorders (NDD) characterized by genetic variations within the 26S proteasome, a protein complex governing eukaryotic cellular protein homeostasis. In our comprehensive study, we identified 23 unique variants in PSMC5 , which encodes the AAA-ATPase proteasome subunit PSMC5/Rpt6, causing syndromic NDD in 38 unrelated individuals. Overexpression of PSMC5 variants altered human hippocampal neuron morphology, while PSMC5 knockdown led to impaired reversal learning in flies and loss of excitatory synapses in rat hippocampal neurons. PSMC5 loss-of-function resulted in abnormal protein aggregation, profoundly impacting innate immune signaling, mitophagy rates, and lipid metabolism in affected individuals. Importantly, targeting key components of the integrated stress response, such as PKR and GCN2 kinases, ameliorated immune dysregulations in cells from affected individuals. These findings significantly advance our understanding of the molecular mechanisms underlying neurodevelopmental proteasomopathies, provide links to research in neurodegenerative diseases, and open up potential therapeutic avenues.
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Idris IM, Botchwey EA, Hyacinth HI. Sickle cell disease as an accelerated aging syndrome. Exp Biol Med (Maywood) 2022; 247:368-374. [PMID: 35172625 DOI: 10.1177/15353702211068522] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Sickle cell disease (SCD) is characterized by vaso-occlusion, hemolysis, and systemic manifestations that form the hallmark of the disease. Apart from morbidity, SCD is also associated with increased mortality and decreased quality of life. Aging is a natural phenomenon that is associated with changes at cellular, tissue, and organ levels, in addition to the loss of physical fitness, increased susceptibility to diseases, and a higher likelihood of mortality. Some of the cellular mechanisms involved in normal (or physiological) aging include abnormalities of sphingolipids (ceramides) and reduced length of the telomere. These changes have also been documented in SCD. Cellular, organs, and physical manifestations of SCD resemble an accelerated aging syndrome. Sickle erythrocytes also acquire morphological features similar to that of aged normal erythrocytes and are thus picked up early by the macrophages for destruction. Brain, kidney, heart, innate and adaptive immune system, and musculoskeletal system of patients with SCD exhibit morphological and functional changes that are ordinarily seen in the elderly in the general population. Stroke, silent cerebral infarcts, cardiomegaly, heart failure, pulmonary hypertension, nephropathy with proteinuria, osteopenia, osteoporosis, osteonecrosis, gout, and infections are exceedingly common in SCD. In this review, we have attempted to draw parallels between SCD and accelerated aging syndromes.
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Affiliation(s)
- Ibrahim M Idris
- Department of Hematology Aminu Kano Teaching Hospital and Bayero University, Kano 11399, Nigeria
| | - Edward A Botchwey
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
| | - Hyacinth I Hyacinth
- Department of Neurology and Rehabilitation Medicine, University of Cincinnati, Cincinnati, OH 45267, USA
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Gee BE, Pearson A, Buchanan-Perry I, Simon RP, Archer DR, Meller R. Whole Blood Transcriptome Analysis in Children with Sickle Cell Anemia. Front Genet 2022; 12:737741. [PMID: 35095995 PMCID: PMC8793691 DOI: 10.3389/fgene.2021.737741] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 10/20/2021] [Indexed: 12/27/2022] Open
Abstract
Whole transcriptome RNA-sequencing was performed to quantify RNA expression changes in whole blood samples collected from steady state sickle cell anemia (SCA) and control subjects. Pediatric SCA and control subjects were recruited from Atlanta (GA)—based hospital(s) systems and consented for RNA sequencing. RNA sequencing was performed on an Ion Torrent S5 sequencer, using the Ion Total RNA-seq v2 protocol. Data were aligned to the hg19 reference genome and analyzed in the Partek Genomics studio package (v7.0). 223 genes were differentially expressed between SCA and controls (± 1.5 fold change FDR p < 0.001) and 441 genes show differential transcript expression (± 1.5 fold FDR p < 0.001). Differentially expressed RNA are enriched for hemoglobin associated genes and ubiquitin-proteasome pathway genes. Further analysis shows higher gamma globin gene expression in SCA (33-fold HBG1 and 49-fold HBG2, both FDR p < 0.05), which did not correlate with hemoglobin F protein levels. eQTL analysis identified SNPs in novel non-coding RNA RYR2 gene as having a potential regulatory role in HBG1 and HBG2 expression levels. Gene expression correlation identified JHDM1D-AS1(KDM7A-DT), a non-coding RNA associated with angiogenesis, enhanced GATA1 and decreased JAK-STAT signaling to correlate with HBG1 and HBG2 mRNA levels. These data suggest novel regulatory mechanisms for fetal hemoglobin regulation, which may offer innovative therapeutic approaches for SCA.
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Affiliation(s)
- Beatrice E. Gee
- Department of Pediatrics, Morehouse School of Medicine, Atlanta, GA, United States
- Morehouse School of Medicine, Cardiovascular Research Institute, Atlanta, GA, United States
- Children’s Healthcare of Atlanta, Atlanta, GA, United States
| | - Andrea Pearson
- Translational Stroke Program, Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States
| | - Iris Buchanan-Perry
- Department of Pediatrics, Morehouse School of Medicine, Atlanta, GA, United States
- Children’s Healthcare of Atlanta, Atlanta, GA, United States
| | - Roger P. Simon
- Translational Stroke Program, Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States
- Grady Memorial Hospital, Atlanta, GA, United States
- Department of Neurology, Morehouse School of Medicine, Atlanta, GA, United States
| | - David R. Archer
- Aflac Cancer and Blood Disorders Center of Emory University and Children’s Healthcare of Atlanta, Atlanta, GA, United States
| | - Robert Meller
- Translational Stroke Program, Neuroscience Institute, Morehouse School of Medicine, Atlanta, GA, United States
- *Correspondence: Robert Meller,
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Paul S, Gangwar A, Bhargava K, Ahmad Y. D4F prophylaxis enables redox and energy homeostasis while preventing inflammation during hypoxia exposure. Biomed Pharmacother 2021; 133:111083. [PMID: 33378979 DOI: 10.1016/j.biopha.2020.111083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 11/18/2020] [Accepted: 11/28/2020] [Indexed: 02/02/2023] Open
Abstract
Apo-A1 is correlated with conditions like hyperlipidemia, cardiovascular diseases, high altitude pulmonary edema and etc. where hypoxia constitutes an important facet.Hypoxia causes oxidative stress, vaso-destructive and inflammatory outcomes.Apo-A1 is reported to have vasoprotective, anti-oxidative, anti-apoptotic, and anti-inflammatory effects. However, effects of Apo-A1 augmentation during hypoxia exposure are unknown.In this study, we investigated the effects of exogenously supplementing Apo-A1-mimetic peptide on SD rats during hypoxia exposure. For easing the processes of delivery, absorption and bio-availability, Apo-A1 mimetic peptide D4F was used. The rats were given 10 mg/kg BW dose (i.p.) of D4F for 7 days and then exposed to hypoxia. D4F was observed to attenuate both oxidative stress and inflammation during hypoxic exposure. D4F improved energy homeostasis during hypoxic exposure. D4F did not affect HIF-1a levels during hypoxia but increased MnSOD levels while decreasing CRP and Apo-B levels. D4F showed promise as a prophylactic against hypoxia exposure.
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Affiliation(s)
- Subhojit Paul
- Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi, 110054, India
| | - Anamika Gangwar
- Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi, 110054, India
| | - Kalpana Bhargava
- Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi, 110054, India
| | - Yasmin Ahmad
- Defence Institute of Physiology & Allied Sciences (DIPAS), Defence R&D Organization (DRDO), Timarpur, New Delhi, 110054, India.
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Saraf SL, Zhang X, Shah BN, Raslan R, Tayo BO, Lash JP, Franceschini N, Gordeuk VR. Engulfment and cell motility 1 (ELMO1) and apolipoprotein A1 (APOA1) as candidate genes for sickle cell nephropathy. Br J Haematol 2020; 193:628-632. [PMID: 33216373 DOI: 10.1111/bjh.17224] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/16/2020] [Indexed: 01/08/2023]
Abstract
Sickle cell disease (SCD) and apolipoprotein L1 (APOL1) G1/G2 variants increase chronic kidney disease (CKD) risk in African Americans by poorly understood mechanisms. We applied bioinformatics to identify new candidate genes associated with SCD-related CKD. An interaction network demonstrated APOA1 connecting haemoglobin subunit β (HBB) and APOL1 with 36 other candidate genes. Gene expression revealed upregulation of engulfment and cell motility 1 (ELMO1) and downregulation of APOA1 in the kidney cortex of SCD versus non-SCD mice. Analysis of candidate genes identified ELMO1 rs10951509 to be associated with albuminuria and APOA1 rs11216132 with haemoglobinuria in patients with SCD. A bioinformatic approach highlights ELMO1 and APOA1 as potentially associated with SCD nephropathy.
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Affiliation(s)
- Santosh L Saraf
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Xu Zhang
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Binal N Shah
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Rasha Raslan
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Bamidele O Tayo
- Department of Public Health Sciences, Loyola University Chicago Stritch School of Medicine, Maywood, IL, USA
| | - James P Lash
- Division of Nephrology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
| | - Nora Franceschini
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC, USA
| | - Victor R Gordeuk
- Division of Hematology and Oncology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
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Lenahan C, Huang L, Travis ZD, Zhang JH. Scavenger Receptor Class B type 1 (SR-B1) and the modifiable risk factors of stroke. Chin Neurosurg J 2019; 5:30. [PMID: 32922929 PMCID: PMC7398188 DOI: 10.1186/s41016-019-0178-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 10/30/2019] [Indexed: 01/11/2023] Open
Abstract
Stroke is a devastating disease that occurs when a blood vessel in the brain is either blocked or ruptured, consequently leading to deficits in neurological function. Stroke consistently ranked as one of the top causes of mortality, and with the mean age of incidence decreasing, there is renewed interest to seek novel therapeutic treatments. The Scavenger Receptor Class B type 1 (SR-B1) is a multifunctional protein found on the surface of a variety of cells. Research has found that that SR-B1 primarily functions in an anti-inflammatory and anti-atherosclerotic capacity. In this review, we discuss the characteristics of SR-B1 and focus on its potential correlation with the modifiable risk factors of stroke. SR-B1 likely has an impact on stroke through its interaction with smoking, diabetes mellitus, diet, physical inactivity, obesity, hypercholesterolemia, atherosclerosis, coronary heart disease, hypertension, and sickle cell disease, all of which are critical risk factors in the pathogenesis of stroke.
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Affiliation(s)
- Cameron Lenahan
- Burrell College of Osteopathic Medicine, Las Cruces, NM 88003 USA
- Center for Neuroscience Research, School of Medicine, Loma Linda University, Loma Linda, CA 92324 USA
| | - Lei Huang
- Center for Neuroscience Research, School of Medicine, Loma Linda University, Loma Linda, CA 92324 USA
- Department of Neurosurgery, School of Medicine, Loma Linda University, Loma Linda, CA 92350 USA
- Department of Physiology & Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92350 USA
| | - Zachary D. Travis
- Center for Neuroscience Research, School of Medicine, Loma Linda University, Loma Linda, CA 92324 USA
- Department of Earth and Biological Sciences, School of Medicine, Loma Linda University, Loma Linda, CA 92350 USA
| | - John H. Zhang
- Center for Neuroscience Research, School of Medicine, Loma Linda University, Loma Linda, CA 92324 USA
- Department of Neurosurgery, School of Medicine, Loma Linda University, Loma Linda, CA 92350 USA
- Department of Physiology & Pharmacology, School of Medicine, Loma Linda University, Loma Linda, CA 92350 USA
- Department of Anesthesiology, School of Medicine, Loma Linda University, Loma Linda, CA 92324 USA
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7
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Warang P, Homma T, Pandya R, Sawant A, Shinde N, Pandey D, Fujii J, Madkaikar M, Mukherjee MB. Potential involvement of ubiquitin-proteasome system dysfunction associated with oxidative stress in the pathogenesis of sickle cell disease. Br J Haematol 2018; 182:559-566. [PMID: 29974957 DOI: 10.1111/bjh.15437] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/04/2018] [Indexed: 12/19/2022]
Abstract
The ubiquitin-proteasome system (UPS) is an important intracellular proteolytic pathway responsible for the degradation of proteins and oxidative damage; hence it plays a central role in maintaining homeostasis of red blood cells (RBCs). The present study investigated the levels of polyubiquitination, the function of proteasomes and effect of hydroxycarbamide (HC) therapy in RBCs from sickle cell disease (SCD) patients. Polyubiquitinated proteins were found to be elevated in untreated SCD (UT-SCD) patients compared to those in HC-treated SCD patients (HC-SCD) and controls. Activities of β1 and β2 subunits were a little higher in UT-SCD patients, and much higher proteolytic activities were observed in all three subunits (β1, β2 and β5) of RBCs in HC-SCD patients compared to those of UT-SCD patients and controls, although the protein levels of these subunits remained approximately the same. It is notable that, despite HC therapy, some patients showed persistent complications and accumulation of polyubiquitinated proteins. The enhanced proteasomal activity among HC-treated patients might remove the polyubiquitinated protein and could be one of the important mechanisms of therapeutic action. These findings could be useful to understand the pathophysiology of SCD and its clinical heterogeneity and identify a suitable therapeutic target for the better management of these patients.
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Affiliation(s)
- Prashant Warang
- Department of Haematogenetics, National Institute of Immunohaematology, ICMR, Mumbai, India
| | - Takujiro Homma
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
| | - Riddhi Pandya
- Department of Haematogenetics, National Institute of Immunohaematology, ICMR, Mumbai, India
| | - Anuja Sawant
- Department of Haematogenetics, National Institute of Immunohaematology, ICMR, Mumbai, India
| | - Nikhil Shinde
- Department of Haematogenetics, National Institute of Immunohaematology, ICMR, Mumbai, India
| | - Debjeet Pandey
- Department of Haematogenetics, National Institute of Immunohaematology, ICMR, Mumbai, India
| | - Junichi Fujii
- Department of Biochemistry and Molecular Biology, Graduate School of Medical Science, Yamagata University, Yamagata, Japan
| | - Manisha Madkaikar
- Department of Haematogenetics, National Institute of Immunohaematology, ICMR, Mumbai, India
| | - Malay B Mukherjee
- Department of Haematogenetics, National Institute of Immunohaematology, ICMR, Mumbai, India
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Soupene E, Larkin SK, Kuypers FA. Featured Article: Depletion of HDL 3 high density lipoprotein and altered functionality of HDL 2 in blood from sickle cell patients. Exp Biol Med (Maywood) 2017; 242:1244-1253. [PMID: 28436274 DOI: 10.1177/1535370217706966] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
In sickle cell disease (SCD), alterations of cholesterol metabolism is in part related to abnormal levels and activity of plasma proteins such as lecithin cholesterol acyltransferase (LCAT), and apolipoprotein A-I (ApoA-I). In addition, the size distribution of ApoA-I high density lipoproteins (HDL) differs from normal blood. The ratio of the amount of HDL2 particle relative to the smaller higher density pre-β HDL (HDL3) particle was shifted toward HDL2. This lipoprotein imbalance is exacerbated during acute vaso-occlusive episodes (VOE) as the relative levels of HDL3 decrease. HDL3 deficiency in SCD plasma was found to relate to a slower ApoA-I exchange rate, which suggests an impaired ABCA1-mediated cholesterol efflux in SCD. HDL2 isolated from SCD plasma displayed an antioxidant capacity normally associated with HDL3, providing evidence for a change in function of HDL2 in SCD as compared to HDL2 in normal plasma. Although SCD plasma is depleted in HDL3, this altered capacity of HDL2 could account for the lack of difference in pro-inflammatory HDL levels in SCD as compared to normal. Exposure of human umbilical vein endothelial cells to HDL2 isolated from SCD plasma resulted in higher mRNA levels of the acute phase protein long pentraxin 3 (PTX3) as compared to incubation with HDL2 from control plasma. Addition of the heme-scavenger hemopexin protein prevented increased expression of PTX3 in sickle HDL2-treated cells. These findings suggest that ApoA-I lipoprotein composition and functions are altered in SCD plasma, and that whole blood transfusion may be considered as a blood replacement therapy in SCD. Impact statement Our study adds to the growing evidence that the dysfunctional red blood cell (RBC) in sickle cell disease (SCD) affects the plasma environment, which contributes significantly in the vasculopathy that defines the disease. Remodeling of anti-inflammatory high density lipoprotein (HDL) to pro-inflammatory entities can occur during the acute phase response. SCD plasma is depleted of the pre-β particle (HDL3), which is essential for stimulation of reverse cholesterol from macrophages, and the function of the larger HDL2 particle is altered. These dysfunctions are exacerbated during vaso-occlusive episodes. Interaction of lipoproteins with endothelium increases formation of inflammatory mediators, a process counteracted by the heme-scavenger hemopexin. This links hemolysis to lipoprotein-mediated inflammation in SCD, and hemopexin treatment could be considered. The use of RBC concentrates in transfusion therapy of SCD patients underestimates the importance of the dysfunctional plasma compartment, and transfusion of whole blood or plasma may be warranted.
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Affiliation(s)
- Eric Soupene
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
| | - Sandra K Larkin
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
| | - Frans A Kuypers
- Children's Hospital Oakland Research Institute, Oakland, CA 94609, USA
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Soupene E, Borja MS, Borda M, Larkin SK, Kuypers FA. Featured Article: Alterations of lecithin cholesterol acyltransferase activity and apolipoprotein A-I functionality in human sickle blood. Exp Biol Med (Maywood) 2016; 241:1933-1942. [PMID: 27354333 DOI: 10.1177/1535370216657447] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2016] [Accepted: 06/04/2016] [Indexed: 01/25/2023] Open
Abstract
In sickle cell disease (SCD) cholesterol metabolism appears dysfunctional as evidenced by abnormal plasma cholesterol content in a subpopulation of SCD patients. Specific activity of the high density lipoprotein (HDL)-bound lecithin cholesterol acyltransferase (LCAT) enzyme, which catalyzes esterification of cholesterol, and generates lysoPC (LPC) was significantly lower in sickle plasma compared to normal. Inhibitory amounts of LPC were present in sickle plasma, and the red blood cell (RBC) lysophosphatidylcholine acyltransferase (LPCAT), essential for the removal of LPC, displayed a broad range of activity. The functionality of sickle HDL appeared to be altered as evidenced by a decreased HDL-Apolipoprotein A-I exchange in sickle plasma as compared to control. Increased levels of oxidized proteins including ApoA-I were detected in sickle plasma. In vitro incubation of sickle plasma with washed erythrocytes affected the ApoA-I-exchange supporting the view that the RBC blood compartment can affect cholesterol metabolism in plasma. HDL functionality appeared to decrease during acute vaso-occlusive episodes in sickle patients and was associated with an increase of secretory PLA2, a marker for increased inflammation. Simvastatin treatment to improve the anti-inflammatory function of HDL did not ameliorate HDL-ApoA-I exchange in sickle patients. Thus, the cumulative effect of an inflammatory and highly oxidative environment in sickle blood contributes to a decrease in cholesterol esterification and HDL function, related to hypocholesterolemia in SCD.
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Affiliation(s)
- Eric Soupene
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA
| | - Mark S Borja
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA
| | - Mauricio Borda
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA
| | - Sandra K Larkin
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA
| | - Frans A Kuypers
- Children's Hospital Oakland Research Institute, Oakland, California 94609, USA
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