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Hao D, Guo L, Wang Q, Ito M, Huang B, Mineo C, Shaul PW, Li XA. Relative Adrenal Insufficiency Is a Risk Factor for Pediatric Sepsis: A Proof-of-Concept Study. J Infect Dis 2024; 229:1166-1177. [PMID: 37633660 PMCID: PMC11011189 DOI: 10.1093/infdis/jiad369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 08/16/2023] [Accepted: 08/24/2023] [Indexed: 08/28/2023] Open
Abstract
Glucocorticoid (GC) therapy had been strongly recommended for pediatric sepsis (grade 1A). However, the recommendation was changed to grade 2C in 2020 due to weak evidence. About 32.8% of patients with pediatric septic develop relative adrenal insufficiency (RAI). But whether GC therapy should be determined by RAI status is controversial. This study utilized 21-day-old SF1CreSRBIfl/fl mice as the first pediatric RAI mouse model to assess the pathogenesis of RAI and evaluate GC therapy. RAI mice exhibited a substantially higher mortality rate in cecal ligation and puncture and cecal slurry-induced sepsis. These mice featured persistent inflammatory responses and were effectively rescued by GC therapy. RNA sequencing analysis revealed persistent inflammatory responses in RAI mice, caused by transcriptional dysregulation of AP-1 and NF-κB, and cytokine-induced secondary inflammatory response. Our findings support a precision medicine approach to guide GC therapy for pediatric patients based on the status of RAI.
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Affiliation(s)
- Dan Hao
- Department of Pharmacology and Nutritional Sciences
| | - Ling Guo
- Saha Cardiovascular Research Center
| | | | - Misa Ito
- Department of Pharmacology and Nutritional Sciences
| | - Bin Huang
- Division of Cancer Biostatistics, College of Medicine, University of Kentucky, Lexington
| | - Chieko Mineo
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas
| | - Philip W Shaul
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas
| | - Xiang-An Li
- Department of Pharmacology and Nutritional Sciences
- Saha Cardiovascular Research Center
- Lexington VA Healthcare System
- Department of Physiology, College of Medicine, University of Kentucky, Lexington
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2
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Guo L, Wang W, Wang Q, Hao D, Ito M, Huang B, Mineo C, Shaul PW, Choi J, Huang LF, Li XA. The adrenal stress response is an essential host response against therapy-induced lethal immune activation. Sci Signal 2023; 16:eadd4900. [PMID: 36943922 PMCID: PMC10091512 DOI: 10.1126/scisignal.add4900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Cytokine release syndrome (CRS) is a systemic inflammatory syndrome associated with infection- or drug-induced T cell activation and can cause multiple organ failure and even death. Because current treatments are ineffective in some patients with severe CRS, we set out to identify risk factors and mechanisms behind severe CRS that might lead to preventive therapies and better clinical outcomes in patients. In mice, we found that deficiency in the adrenal stress response-with similarities to such in patients called relative adrenal insufficiency (RAI)-conferred a high risk for lethal CRS. Mice treated with CD3 antibodies were protected against lethal CRS by the production of glucocorticoids (GC) induced by the adrenal stress response in a manner dependent on the scavenger receptor B1 (SR-BI), a receptor for high-density lipoprotein (HDL). Mice with whole-body or adrenal gland-specific SR-BI deficiency exhibited impaired GC production, more severe CRS, and increased mortality in response to CD3 antibodies. Pretreatment with a low dose of GC effectively suppressed the development of CRS and rescued survival in SR-BI-deficient mice without compromising T cell function through apoptosis. Our findings suggest that RAI may be a risk factor for therapy-induced CRS and that pretreating RAI patients with GC may prevent lethal CRS.
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Affiliation(s)
- Ling Guo
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Weinan Wang
- Division of Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
| | - Qian Wang
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Dan Hao
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Misa Ito
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Bin Huang
- Division of Cancer Biostatistics, University of Kentucky College of Medicine, Lexington, KY 40536, USA
| | - Chieko Mineo
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Philip W Shaul
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jaebok Choi
- Department of Medicine, Washington University School of Medicine at St. Louis, St. Louis, MO 63110, USA
| | - L Frank Huang
- Division of Experimental Hematology and Cancer Biology, Brain Tumor Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, 45229, USA
| | - Xiang-An Li
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY 40536, USA
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY 40536, USA
- Lexington VA Healthcare System, 1101 Veterans Drive, Lexington, KY 40502, USA
- Department of Physiology, University of Kentucky College of Medicine, Lexington, KY 40536, USA
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3
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Zhang J, Ding W, Liu J, Wan J, Wang M. Scavenger Receptors in Myocardial Infarction and Ischemia/Reperfusion Injury: The Potential for Disease Evaluation and Therapy. J Am Heart Assoc 2023; 12:e027862. [PMID: 36645089 PMCID: PMC9939064 DOI: 10.1161/jaha.122.027862] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Scavenger receptors (SRs) are a structurally heterogeneous superfamily of evolutionarily conserved receptors that are divided into classes A to J. SRs can recognize multiple ligands, such as modified lipoproteins, damage-associated molecular patterns, and pathogen-associated molecular patterns, and regulate lipid metabolism, immunity, and homeostasis. According to the literature, SRs may play a critical role in myocardial infarction and ischemia/reperfusion injury, and the soluble types of SRs may be a series of promising biomarkers for the diagnosis and prognosis of patients with acute coronary syndrome or acute myocardial infarction. In this review, we briefly summarize the structure and function of SRs and discuss the association between each SR and ischemic cardiac injury in patients and animal models in detail. A better understanding of the effect of SRs on ischemic cardiac injury will inspire novel ideas for therapeutic drug discovery and disease evaluation in patients with myocardial infarction.
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Affiliation(s)
- Jishou Zhang
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina,Cardiovascular Research InstituteWuhan UniversityWuhanChina,Hubei Key Laboratory of CardiologyWuhanChina
| | - Wen Ding
- Department of RadiologyThe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Jianfang Liu
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina,Cardiovascular Research InstituteWuhan UniversityWuhanChina,Hubei Key Laboratory of CardiologyWuhanChina
| | - Jun Wan
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina,Cardiovascular Research InstituteWuhan UniversityWuhanChina,Hubei Key Laboratory of CardiologyWuhanChina
| | - Menglong Wang
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina,Cardiovascular Research InstituteWuhan UniversityWuhanChina,Hubei Key Laboratory of CardiologyWuhanChina
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4
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Wu CH, Guo L, Hao D, Wang Q, Ye X, Ito M, Huang B, Mineo C, Shaul PW, Li XA. Relative adrenal insufficiency is a risk factor and endotype of sepsis - A proof-of-concept study to support a precision medicine approach to guide glucocorticoid therapy for sepsis. Front Immunol 2023; 13:1110516. [PMID: 36713379 PMCID: PMC9878847 DOI: 10.3389/fimmu.2022.1110516] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 12/28/2022] [Indexed: 01/13/2023] Open
Abstract
Introduction 25-60% of septic patients experience relative adrenal insufficiency (RAI) and glucocorticoid (GC) is frequently used in septic patients. However, the efficacy of GC therapy and whether GC therapy should be based on the status of RAI are highly controversial. Our poor understanding about the pathogenesis of RAI and a lack of RAI animal model present significant barriers to address these critical issues. Methods Scavenger receptor BI (SR-BI) regulates stress-induced GC (iGC) production in response to stress. We generated SF1CreSR-BIfl/fl mice and utilized the mice as a RAI model to elucidate the pathogenesis of RAI and GC therapy in sepsis. SF1CreSR-BIfl/fl mice did not express SR-BI in adrenal gland and lacked iGC production upon ACTH stimulation, thus, they are RAI. Results and Discussion RAI mice were susceptible to cecal ligation and puncture (CLP)-induced sepsis (6.7% survival in SF1CreSR-BIfl/fl mice versus 86.4% in SR-BIfl/fl mice; p = 0.0001). Compared to a well-controlled systemic inflammatory response in SR-BIfl/fl mice, SF1CreSR-BIfl/fl mice featured a persistent hyperinflammatory response. Supplementation of a low stress dose of GC to SF1CreSR-BIfl/fl mice kept the inflammatory response under control and rescued the mice. However, SR-BIfl/fl mice receiving GC treatment exhibited significantly less survival compared to SR-BIfl/fl mice without GC treatment. In conclusions, we demonstrated that RAI is a risk factor for death in this mouse model of sepsis. We further demonstrated that RAI is an endotype of sepsis, which features persistent hyperinflammatory response. We found that GC treatment benefits mice with RAI but harms mice without RAI. Our study provides a proof of concept to support a precision medicine approach for sepsis therapy - selectively applying GC therapy for a subgroup of patients with RAI.
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Affiliation(s)
- Chia-Hua Wu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Ling Guo
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Dan Hao
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Qian Wang
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Xiang Ye
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Misa Ito
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Bin Huang
- Division of Cancer Biostatistics, Department of Internal Medicine, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Chieko Mineo
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Philip W. Shaul
- Department of Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Xiang-An Li
- Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
- Saha Cardiovascular Research Center, University of Kentucky College of Medicine, Lexington, KY, United States
- Lexington Veterans Affairs (VA), Healthcare System, Lexington, KY, United States
- Department of Physiology, University of Kentucky College of Medicine, Lexington, KY, United States
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5
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Taban Q, Ahmad SM, Mumtaz PT, Bhat B, Haq E, Magray S, Saleem S, Shabir N, Muhee A, Kashoo ZA, Zargar MH, Malik AA, Ganai NA, Shah RA. Scavenger receptor B1 facilitates the endocytosis of Escherichia coli via TLR4 signaling in mammary gland infection. Cell Commun Signal 2023; 21:3. [PMID: 36604713 PMCID: PMC9813905 DOI: 10.1186/s12964-022-01014-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/11/2022] [Indexed: 01/06/2023] Open
Abstract
SCARB1 belongs to class B of Scavenger receptors (SRs) that are known to be involved in binding and endocytosis of various pathogens. SRs have emerging role in regulating innate immunity and host-pathogen interactions by acting in co-ordination with Toll-like receptors.Query Little is known about the function of SCARB1 in milk-derived mammary epithelial cells (MECs). This study reports the role of SCARB1 in infection and its potential association in TLR4 signaling on bacterial challenge in Goat mammary epithelial cells (GMECs). The novelty in the establishment of MEC culture lies in the method that aims to enhance the viability of the cells with intact characteristics upto a higher passage number. We represent MEC culture to be used as a potential infection model for deeper understanding of animal physiology especially around the mammary gland. On E.coli challenge the expression of SCARB1 was significant in induced GMECs at 6 h. Endoribonuclease-esiRNA based silencing of SCARB1 affects the expression of TLR4 and its pathways i.e. MyD88 and TRIF pathways on infection. Knockdown also affected the endocytosis of E.coli in GMECs demonstrating that E.coli uses SCARB1 function to gain entry in cells. Furthermore, we predict 3 unique protein structures of uncharacterized SCARB1 (Capra hircus) protein. Overall, we highlight SCARB1 as a main participant in host defence and its function in antibacterial advances to check mammary gland infections. Video Abstract.
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Affiliation(s)
- Qamar Taban
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India ,grid.412997.00000 0001 2294 5433Department of Biotechnology, University of Kashmir, Hazratbal Srinagar, Jammu and Kashmir India
| | - Syed Mudasir Ahmad
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Peerzada Tajamul Mumtaz
- grid.24434.350000 0004 1937 0060Department of Nutrition and Health Sciences, University of Nebraska-Lincoln, Lincoln, USA
| | - Basharat Bhat
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Ehtishamul Haq
- grid.412997.00000 0001 2294 5433Department of Biotechnology, University of Kashmir, Hazratbal Srinagar, Jammu and Kashmir India
| | - Suhail Magray
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Sahar Saleem
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Nadeem Shabir
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Amatul Muhee
- grid.444725.40000 0004 0500 6225Department of Clinical Veterinary Medicine, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Zahid Amin Kashoo
- grid.444725.40000 0004 0500 6225Department of Veterinary Microbiology & Immunology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Mahrukh Hameed Zargar
- grid.414739.c0000 0001 0174 2901Department of Advanced Centre for Human Genetics, Sher-I-Kashmir Institute of Medical Sciences, Srinagar, Jammu and Kashmir India
| | - Abrar A. Malik
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Nazir A. Ganai
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
| | - Riaz A. Shah
- grid.444725.40000 0004 0500 6225Division of Animal Biotechnology, Sher-E-Kashmir University of Agricultural Sciences and Technology of Kashmir, FV.Sc and A.H, Shuhama, Jammu and Kashmir India
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6
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Abe RJ, Abe JI, Nguyen MTH, Olmsted-Davis EA, Mamun A, Banerjee P, Cooke JP, Fang L, Pownall H, Le NT. Free Cholesterol Bioavailability and Atherosclerosis. Curr Atheroscler Rep 2022; 24:323-336. [PMID: 35332444 PMCID: PMC9050774 DOI: 10.1007/s11883-022-01011-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/02/2022] [Indexed: 11/30/2022]
Abstract
PURPOSE OF REVIEW As both a cholesterol acceptor and carrier in the reverse cholesterol transport (RCT) pathway, high-density lipoprotein (HDL) is putatively atheroprotective. However, current pharmacological therapies to increase plasma HDL cholesterol (HDL-c) concentration have paradoxically failed to prevent or reduce atherosclerosis and cardiovascular disease (CVD). Given that free cholesterol (FC) transfer between surfaces of lipoproteins and cells is reversible, excess plasma FC can be transferred to the cells of peripheral tissue sites resulting in atherosclerosis. Here, we summarize potential mechanisms contributing to this paradox and highlight the role of excess free cholesterol (FC) bioavailability in atherosclerosis vs. atheroprotection. RECENT FINDINGS Recent findings have established a complex relationship between HDL-c concentration and atherosclerosis. Systemic scavenger receptor class B type 1 (SR-B1) knock out (KO) mice exhibit with increased diet-induced atherosclerosis despite having an elevated plasma HDL-c concentration compared to wild type (WT) mice. The greater bioavailability of HDL-FC in SR-B1 vs. WT mice is associated with a higher FC content in multiple cell types and tissue sites. These results suggest that dysfunctional HDL with high FC bioavailability is atheroprone despite high HDL-c concentration. Past oversimplification of HDL-c involvement in cholesterol transport has led to the failures in HDL targeted therapy. Evidence suggests that FC-mediated functionality of HDL is of higher importance than its quantity; as a result, deciphering the regulatory mechanisms by which HDL-FC bioavailability can induce atherosclerosis can have far-reaching clinical implications.
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Affiliation(s)
- Rei J Abe
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- Department of Physiology and Biophysics, Weill Cornell Medicine, New York, NY, USA
| | - Jun-Ichi Abe
- Department of Cardiology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Minh T H Nguyen
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- University of Science and Technology of Hanoi, Vietnam Academy of Science and Technology, Hanoi, Vietnam
| | | | - Abrar Mamun
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
| | - Priyanka Banerjee
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
| | - John P Cooke
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- Weill Cornell Medicine, New York, NY, USA
| | - Longhou Fang
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA
- Weill Cornell Medicine, New York, NY, USA
| | - Henry Pownall
- Weill Cornell Medicine, New York, NY, USA
- Center for Bioenergetics, Department of Medicine, Houston Methodist Research Institute, Houston, TX, USA
| | - Nhat-Tu Le
- Center for Cardiovascular Sciences, Houston Methodist Research Institute, Houston, TX, USA.
- Weill Cornell Medicine, New York, NY, USA.
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7
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Chen C, Chang X, Zhang S, Zhao Q, Lei C. CircRNA CTNNB1 (circCTNNB1) ameliorates cerebral ischemia/reperfusion injury by sponging miR-96-5p to up-regulate scavenger receptor class B type 1 (SRB1) expression. Bioengineered 2022; 13:10258-10273. [PMID: 35435123 PMCID: PMC9162012 DOI: 10.1080/21655979.2022.2061304] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Emerging studies show that circRNA catenin beta 1 (circCTNNB1) plays a critical role in cancer. However, the expression and function of circCTNNB1 in cerebral ischemia/reperfusion injury (IRI) have not been reported. The present study discovered that circCTNNB1 and scavenger receptor class B type 1 (SRB1) expression levels were significantly down-regulated in mouse astrocytes (mAS) treated with oxygen glucose deprivation and reperfusion (OGD/R), and similar results were observed in a mouse middle cerebral artery occlusion model. Overexpression of circCTNNB1 alleviated cell apoptosis, oxidative stress and the inflammatory response induced by OGD/R in vitro. Up-regulation of circCTNNB1 increased SRB1 expression levels to protect mAS cells from OGD/R-induced damage. CircCTNNB1 and SRB1 interacted with miR-96-5p, and the overexpression of miR-96-5p efficiently reversed the function of circCTNNB1 in OGD/R-treated mAS cells. CircCTNNB1 protected against cerebral ischemia-reperfusion injury by up-regulating SRB1 in vivo. In conclusion, our findings suggest that circCTNNB1 acts as a competitive endogenous RNA for miR-96-5p to alleviate cerebral IRI, which provides novel evidence that circCTNNB1 and SRB1 may be biomarkers and therapeutic targets for cerebral IRI.
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Affiliation(s)
- Chun Chen
- Department of Neurology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Xiaolong Chang
- Department of Neurology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Shifei Zhang
- Department of Neurology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Qi Zhao
- Department of Neurology, First Affiliated Hospital of Kunming Medical University, Kunming, China
| | - Chunyan Lei
- Department of Neurology, First Affiliated Hospital of Kunming Medical University, Kunming, China
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8
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Inhibition of Scavenger Receptor Class B Type 1 (SR-B1) Expression and Activity as a Potential Novel Target to Disrupt Cholesterol Availability in Castration-Resistant Prostate Cancer. Pharmaceutics 2021; 13:pharmaceutics13091509. [PMID: 34575583 PMCID: PMC8467449 DOI: 10.3390/pharmaceutics13091509] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/04/2021] [Accepted: 09/08/2021] [Indexed: 02/07/2023] Open
Abstract
There have been several studies that have linked elevated scavenger receptor class b type 1 (SR-B1) expression and activity to the development and progression of castration-resistant prostate cancer (CRPC). SR-B1 facilitates the influx of cholesterol to the cell from lipoproteins in systemic circulation. This influx of cholesterol may be important for many cellular functions, including the synthesis of androgens. Castration-resistant prostate cancer tumors can synthesize androgens de novo to supplement the loss of exogenous sources often induced by androgen deprivation therapy. Silencing of SR-B1 may impact the ability of prostate cancer cells, particularly those of the castration-resistant state, to maintain the intracellular supply of androgens by removing a supply of cholesterol. SR-B1 expression is elevated in CRPC models and has been linked to poor survival of patients. The overarching belief has been that cholesterol modulation, through either synthesis or uptake inhibition, will impact essential signaling processes, impeding the proliferation of prostate cancer. The reduction in cellular cholesterol availability can impede prostate cancer proliferation through both decreased steroid synthesis and steroid-independent mechanisms, providing a potential therapeutic target for the treatment of prostate cancer. In this article, we discuss and highlight the work on SR-B1 as a potential novel drug target for CRPC management.
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9
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Zhou LZ, Wang RJ, Yan YY, Zeng S, Zou Z, Lu Z. Scavenger receptor B1 mediates phagocytosis and the antimicrobial peptide pathway in the endoparasitic wasp Micropilits mediator. DEVELOPMENTAL AND COMPARATIVE IMMUNOLOGY 2021; 119:104039. [PMID: 33549640 DOI: 10.1016/j.dci.2021.104039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 01/29/2021] [Accepted: 01/31/2021] [Indexed: 06/12/2023]
Abstract
Scavenger receptors (SRs) are a family of pattern recognition receptors (PRRs) in the immune system. They are required for phagocytosis and act as co-receptors of Toll-like receptors to regulate immune signaling pathways in the fight against pathogens. Little is known about the function of SRs in insects. Here, we reported on a member of the SR family from the parasitic wasp Micropilits mediator (designated MmSR-B1) that is responsive to bacterial infection. The recombinant extracellular CD36 domain of MmSR-B1 produced in Escherichia coli cells is capable of binding to peptidoglycans and bacterial cells, causing agglutination of bacteria. Furthermore, we demonstrated that double-stranded RNA-mediated knockdown of MmSR-B1 impedes hemocyte phagocytosis and downregulates the expression of antimicrobial peptide (AMP) genes defensins and hymenoptaecins. Knockdown of MmSR-B1 led to increased death of the wasps when challenged by bacteria. Our study suggests that MmSR-B1 mediates phagocytosis and the production of AMPs in M. mediator wasps.
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Affiliation(s)
- Li-Zhen Zhou
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
| | - Rui-Juan Wang
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
| | - You-Ying Yan
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China.
| | - Shuocheng Zeng
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Zhen Zou
- State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
| | - Zhiqiang Lu
- Department of Entomology, College of Plant Protection, Northwest A&F University, Yangling, Shaanxi, China; State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling, Shaanxi, China.
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10
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Tao H, Yancey PG, Blakemore JL, Zhang Y, Ding L, Jerome WG, Brown JD, Vickers KC, Linton MF. Macrophage SR-BI modulates autophagy via VPS34 complex and PPARα transcription of Tfeb in atherosclerosis. J Clin Invest 2021; 131:94229. [PMID: 33661763 PMCID: PMC8011903 DOI: 10.1172/jci94229] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 02/17/2021] [Indexed: 12/11/2022] Open
Abstract
Autophagy modulates lipid turnover, cell survival, inflammation, and atherogenesis. Scavenger receptor class B type I (SR-BI) plays a crucial role in lysosome function. Here, we demonstrate that SR-BI regulates autophagy in atherosclerosis. SR-BI deletion attenuated lipid-induced expression of autophagy mediators in macrophages and atherosclerotic aortas. Consequently, SR-BI deletion resulted in 1.8- and 2.5-fold increases in foam cell formation and apoptosis, respectively, and increased oxidized LDL-induced inflammatory cytokine expression. Pharmacological activation of autophagy failed to reduce lipid content or apoptosis in Sr-b1-/- macrophages. SR-BI deletion reduced both basal and inducible levels of transcription factor EB (TFEB), a master regulator of autophagy, causing decreased expression of autophagy genes encoding VPS34 and Beclin-1. Notably, SR-BI regulated Tfeb expression by enhancing PPARα activation. Moreover, intracellular macrophage SR-BI localized to autophagosomes, where it formed cholesterol domains resulting in enhanced association of Barkor and recruitment of the VPS34-Beclin-1 complex. Thus, SR-BI deficiency led to lower VPS34 activity in macrophages and in atherosclerotic aortic tissues. Overexpression of Tfeb or Vps34 rescued the defective autophagy in Sr-b1-/- macrophages. Taken together, our results show that macrophage SR-BI regulates autophagy via Tfeb expression and recruitment of the VPS34-Beclin-1 complex, thus identifying previously unrecognized roles for SR-BI and potentially novel targets for the treatment of atherosclerosis.
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Affiliation(s)
- Huan Tao
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - Patricia G. Yancey
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - John L. Blakemore
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - Youmin Zhang
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - Lei Ding
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - W. Gray Jerome
- Department of Pathology, Microbiology and Immunology, and
| | - Jonathan D. Brown
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - Kasey C. Vickers
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
| | - MacRae F. Linton
- Department of Medicine, Atherosclerosis Research Unit, Division of Cardiovascular Medicine
- Department of Pharmacology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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11
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Ito M, Ye X, Wang Q, Guo L, Hao D, Howatt D, Daugherty A, Cai L, Temel R, Li XA. SR-BI (Scavenger Receptor BI), Not LDL (Low-Density Lipoprotein) Receptor, Mediates Adrenal Stress Response-Brief Report. Arterioscler Thromb Vasc Biol 2020; 40:1830-1837. [PMID: 32522007 DOI: 10.1161/atvbaha.120.314506] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE Adrenal gland secretes stress-induced glucocorticoids (iGCs) to coping with stress. Previous study showed that SR-BI (scavenger receptor BI) null (SR-BI-/-) mice failed to generate iGC in stress conditions, suggesting that SR-BI-mediated cholesterol uptake from HDL (high-density lipoprotein) is a key regulator for iGC production. However, the LDL (low-density lipoprotein)/LDLr (LDL receptor) pathway can also provide cholesterol for iGC synthesis, but rodents have limited LDL levels in circulation. Here, we generated SR-BI-/-ApoBtg (apolipoprotein B transgenic) mice with normal LDL levels in circulation to determine the relative contribution of the HDL/SR-BI and LDL/LDLr pathways to iGC production in stress conditions. Approach and Results: To obtain mouse models with normal LDL levels, SR-BI-/- mice were bred to ApoBtg mice. Then, the F1 SR-BI±ApoBtg mice were backcrossed to SR-BI-/- to obtain SR-BI-/-ApoBtg, SR-BI-/-ApoBwt (apolipoprotein B wild type), and SR-BI+/+ApoBtg mice. We first examined the lipoprotein profile, which shows a 6.5-fold increase in LDL levels in SR-BI-/-ApoBtg mice compared with SR-BI-/-ApoBwt mice. Then, we induced stress with adrenocorticotropic hormone and cecal ligation and puncture. One hour after adrenocorticotropic hormone stimulation, SR-BI+/+ApoBtg control mice produced iGC (14.9-fold), but both SR-BI-/-ApoBwt and SR-BI-/-ApoBtg showed no iGC production (P<0.001). Three hours after cecal ligation and puncture treatment, SR-BI+/+ApoBtg control mice showed iGC production (6.4-fold), but both SR-BI-/-ApoBwt and SR-BI-/-ApoBtg mice showed no iGC production (P<0.001). CONCLUSIONS SR-BI-/-ApoBtg mice fail to produce iGC in stress conditions even though with restored LDL levels in circulation. These findings clarify that the HDL/SR-BI, not LDL/LDLr, pathway is responsible for iGC production in stress conditions.
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Affiliation(s)
- Misa Ito
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Pharmacology and Nutritional Sciences (M.I., D. Hao, A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Xiang Ye
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Qian Wang
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Ling Guo
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Dan Hao
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Pharmacology and Nutritional Sciences (M.I., D. Hao, A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Deborah Howatt
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Alan Daugherty
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Pharmacology and Nutritional Sciences (M.I., D. Hao, A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Physiology (A.D., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Lei Cai
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Ryan Temel
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Physiology (A.D., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Xiang-An Li
- From the Saha Cardiovascular Research Center (M.I., X.Y., Q.W., L.G., D. Hao, D. Howatt, A.D., L.C., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Pharmacology and Nutritional Sciences (M.I., D. Hao, A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Physiology (A.D., R.T., X.-A.L.), University of Kentucky College of Medicine, Lexington
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12
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Li C, Ge X, Su B, Fu Q, Wang B, Liu X, Ren Y, Song L, Yang N. Characterization of class B scavenger receptor type 1 (SRB1) in turbot (Scophthalmus maximus L.). FISH & SHELLFISH IMMUNOLOGY 2020; 100:358-367. [PMID: 32169665 DOI: 10.1016/j.fsi.2020.03.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 03/05/2020] [Accepted: 03/06/2020] [Indexed: 06/10/2023]
Abstract
Class B scavenger receptor type 1 (SRB1) serves as a high-density lipoprotein (HDL) receptor essential for HDL metabolism, and plays vital roles in innate immunity. In this study, the turbot (Scophthalmus maximus) SRB1 was cloned and characterized. The gene structure consists of a coding region of 1,527 bp nucleotides dividing into 13 exons and 12 introns. Such genome structure is highly conserved among teleost fishes. The deduced SRB1 encodes 508 amino acids that mainly has a CD36 transmembrane domain. Tissue distribution of SRB1 showed the lowest expression in liver, while the highest expression was found in intestine. Significantly down-regulation pattern of SmSRB1 expression in intestine was shared after infection with Vibrio anguillarum and Streptococcus iniae. Brach and site models in CODEML program showed that SmSRB1 underwent a conservative evolutionary and three potential positive selected sites 470K, 496E, and 501Y were detected, which requires further investigation and confirmation using base-editing technologies. Subcellular localization demonstrated that turbot SRB1 was distributed in the membrane and cytoplasm. rSmSRB1 showed binding ability in vitro to bacteria, LPS, PGN, LTA and virus. Protein-protein interaction network agrees the function of SRB1 as lipoprotein receptor. Our results indicated SmSRB1 might act as co-receptors to TLRs and NLRs to modulate the immune response to pathogens. Further studies should pay attention to evaluate the specific co-receptor for SRB1 in recognition of different pathogens and selective mechanisms involved.
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Affiliation(s)
- Chao Li
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xuefeng Ge
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Baofeng Su
- School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL, 36849, USA
| | - Qiang Fu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Beibei Wang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Xiaoli Liu
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Yichao Ren
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China
| | - Lin Song
- College of Marine Science and Biological Engineering, Qingdao University of Science & Technology, Qingdao, 266011, China
| | - Ning Yang
- School of Marine Science and Engineering, Qingdao Agricultural University, Qingdao, 266109, China.
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13
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Zheng Z, Ai J, Guo L, Ye X, Bondada S, Howatt D, Daugherty A, Li XA. SR-BI (Scavenger Receptor Class B Type 1) Is Critical in Maintaining Normal T-Cell Development and Enhancing Thymic Regeneration. Arterioscler Thromb Vasc Biol 2019; 38:2706-2717. [PMID: 30354229 DOI: 10.1161/atvbaha.118.311728] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Objective- Continuous T-cell production from thymus is essential in replenishing naïve T-cell pool and maintaining optimal T-cell functions. However, the underlying mechanisms regulating the T-cell development in thymus remains largely unknown. Approach and Results- We identified SR-BI (scavenger receptor class B type 1), an HDL (high-density lipoprotein) receptor, as a novel modulator in T-cell development. We found that SR-BI deficiency in mice led to reduced thymus size and decreased T-cell production, which was accompanied by narrowed peripheral naïve T-cell pool. Further investigation revealed that SR-BI deficiency impaired progenitor thymic homing, causing a dramatic reduction in the percentage of earliest thymic progenitors, but did not affect other downstream T-cell developmental steps inside the thymus. As a result of the impaired progenitor thymic homing, SR-BI-deficient mice displayed delayed thymic regeneration postirradiation. Using a variety of experimental approaches, we revealed that the impaired T-cell development in SR-BI-deficient mice was not caused by hematopoietic SR-BI deficiency or SR-BI deficiency-induced hypercholesterolemia, but mainly attributed to the SR-BI deficiency in adrenal glands, as adrenal-specific SR-BI-deficient mice exhibited similar defects in T-cell development and thymic regeneration with SR-BI-deficient mice. Conclusions- This study demonstrates that SR-BI deficiency impaired T-cell development and delayed thymic regeneration by affecting progenitor thymic homing in mice, elucidating a previously unrecognized link between SR-BI and adaptive immunity.
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Affiliation(s)
- Zhong Zheng
- From the Department of Pharmacology and Nutritional Sciences (Z.Z., J.A., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Saha Cardiovascular Research Center (Z.Z., J.A., L.G., X.Y., D.H., A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Junting Ai
- From the Department of Pharmacology and Nutritional Sciences (Z.Z., J.A., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Saha Cardiovascular Research Center (Z.Z., J.A., L.G., X.Y., D.H., A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Ling Guo
- Saha Cardiovascular Research Center (Z.Z., J.A., L.G., X.Y., D.H., A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Xiang Ye
- Saha Cardiovascular Research Center (Z.Z., J.A., L.G., X.Y., D.H., A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Subbarao Bondada
- Department of Microbiology (S.B.), University of Kentucky College of Medicine, Lexington
| | - Deborah Howatt
- Saha Cardiovascular Research Center (Z.Z., J.A., L.G., X.Y., D.H., A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Alan Daugherty
- Saha Cardiovascular Research Center (Z.Z., J.A., L.G., X.Y., D.H., A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Physiology (A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
| | - Xiang-An Li
- From the Department of Pharmacology and Nutritional Sciences (Z.Z., J.A., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Saha Cardiovascular Research Center (Z.Z., J.A., L.G., X.Y., D.H., A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington.,Department of Physiology (A.D., X.-A.L.), University of Kentucky College of Medicine, Lexington
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14
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Resistin-Inhibited Neural Stem Cell-Derived Astrocyte Differentiation Contributes to Permeability Destruction of the Blood-Brain Barrier. Neurochem Res 2019; 44:905-916. [PMID: 30690681 DOI: 10.1007/s11064-019-02726-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Accepted: 01/09/2019] [Indexed: 12/12/2022]
Abstract
Neuroinflammation is an important part of the development of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's and amyotrophic lateral sclerosis. Inflammatory factors destroy the balance of the microenvironment, which results in changes in neural stem cell differentiation and proliferation behaviour. However, the mechanism underlying inflammatory factor-induced NSC behavioural changes is not clear. Resistin is a proinflammatory and adipogenic factor and is involved in several human pathology processes. The neural stem cell microenvironment changes when the concentration of resistin in the brain during an inflammatory response disease increases. In the present study, we explored the effect and mechanism of resistin on the proliferation and differentiation of neural stem cells. We found that intracerebroventricular injection of resistin induced a decrease in GFAP-positive cells in mice by influencing NSC differentiation. Resistin significantly decreased TEER and increased permeability in an in vitro blood-brain barrier model, which is consistent with the results of an HBMEC-astrocyte coculture system. Resistin-inhibited astrocyte differentiation is mediated through TLR4 on neural stem cells. To our knowledge, this is the first study reporting the effect of resistin on neural stem cells. Our findings shed light on resistin-involved neural stem cell degeneration mechanisms.
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15
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Shen WJ, Asthana S, Kraemer FB, Azhar S. Scavenger receptor B type 1: expression, molecular regulation, and cholesterol transport function. J Lipid Res 2018; 59:1114-1131. [PMID: 29720388 DOI: 10.1194/jlr.r083121] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 04/26/2018] [Indexed: 12/16/2022] Open
Abstract
Cholesterol is required for maintenance of plasma membrane fluidity and integrity and for many cellular functions. Cellular cholesterol can be obtained from lipoproteins in a selective pathway of HDL-cholesteryl ester (CE) uptake without parallel apolipoprotein uptake. Scavenger receptor B type 1 (SR-B1) is a cell surface HDL receptor that mediates HDL-CE uptake. It is most abundantly expressed in liver, where it provides cholesterol for bile acid synthesis, and in steroidogenic tissues, where it delivers cholesterol needed for storage or steroidogenesis in rodents. SR-B1 transcription is regulated by trophic hormones in the adrenal gland, ovary, and testis; in the liver and elsewhere, SR-B1 is subject to posttranscriptional and posttranslational regulation. SR-B1 operates in several metabolic processes and contributes to pathogenesis of atherosclerosis, inflammation, hepatitis C virus infection, and other conditions. Here, we summarize characteristics of the selective uptake pathway and involvement of microvillar channels as facilitators of selective HDL-CE uptake. We also present the potential mechanisms of SR-B1-mediated selective cholesterol transport; the transcriptional, posttranscriptional, and posttranslational regulation of SR-B1; and the impact of gene variants on expression and function of human SR-B1. A better understanding of this unique pathway and SR-B1's role may yield improved therapies for a wide variety of conditions.
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Affiliation(s)
- Wen-Jun Shen
- Geriatric Research, Education, and Clinical Research Center (GRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304 and Division of Endocrinology, Gerontology, and Metabolism, Stanford University School of Medicine, Stanford, CA 94305
| | - Shailendra Asthana
- Drug Discovery Research Center (DDRC), Translational Health Science and Technology Institute (THSTI), NCR Biotech Science Cluster, Faridabad 121001, Haryana, India
| | - Fredric B Kraemer
- Geriatric Research, Education, and Clinical Research Center (GRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304 and Division of Endocrinology, Gerontology, and Metabolism, Stanford University School of Medicine, Stanford, CA 94305
| | - Salman Azhar
- Geriatric Research, Education, and Clinical Research Center (GRECC), Veterans Affairs Palo Alto Health Care System, Palo Alto, CA 94304 and Division of Endocrinology, Gerontology, and Metabolism, Stanford University School of Medicine, Stanford, CA 94305
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16
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Corticosteroid Therapy Benefits Septic Mice With Adrenal Insufficiency But Harms Septic Mice Without Adrenal Insufficiency. Crit Care Med 2015; 43:e490-8. [PMID: 26308430 PMCID: PMC9798902 DOI: 10.1097/ccm.0000000000001264] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Corticosteroid therapy is frequently used in septic patients given the rationale that there is an increased demand for corticosteroid in sepsis, and up to 60% of severe septic patients experience adrenal insufficiency. However, the efficacy of corticosteroid therapy and whether the therapy should be based on the results of adrenal function testing are highly controversial. The lack of an adrenal insufficiency animal model and our poor understanding of the pathogenesis caused by adrenal insufficiency present significant barriers to address this long-standing clinical issue. DESIGN Prospective experimental study. SETTING University laboratory. SUBJECTS Scavenger receptor BI null and adrenal-specific scavenger receptor BI null mice. INTERVENTIONS Sepsis was induced by cecal ligation and puncture. MEASUREMENTS AND MAIN RESULTS Using scavenger receptor BI mice as the first relative adrenal insufficiency animal model, we found that corticosteroid therapy significantly improved the survival in cecal ligation and puncture-treated scavenger receptor BI mice but causes more septic death in wild-type mice. We identified a corticosteroid cocktail that provides effective protection 18 hours post cecal ligation and puncture; using adrenal-specific scavenger receptor BI mice as an inducible corticosteroid-deficient animal model, we found that inducible corticosteroid specifically suppresses interleukin-6 production without affecting tumor necrosis factor-α, nitric oxide, and interleukin-10 production. We further found that inducible corticosteroid does not induce peripheral lymphocyte apoptosis but promotes phagocytic activity of macrophages and neutrophils. CONCLUSIONS This study demonstrates that corticosteroid treatment benefits mice with adrenal insufficiency but harms mice without adrenal insufficiency. This study also reveals that inducible corticosteroid has both immunosuppressive and immunopermissive properties, suppressing interleukin-6 production, promoting phagocytosis of immune effector cells, but not inducing peripheral lymphocyte apoptosis. These findings support our hypothesis that corticosteroid is an effective therapy for a subgroup of septic patients with adrenal insufficiency but harms septic patients without adrenal insufficiency and encourage further efforts to test this hypothesis in clinic.
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17
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Shen WJ, Hu J, Hu Z, Kraemer FB, Azhar S. Scavenger receptor class B type I (SR-BI): a versatile receptor with multiple functions and actions. Metabolism 2014; 63:875-86. [PMID: 24854385 PMCID: PMC8078058 DOI: 10.1016/j.metabol.2014.03.011] [Citation(s) in RCA: 101] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 03/12/2014] [Accepted: 03/18/2014] [Indexed: 11/16/2022]
Abstract
Scavenger receptor class B type I (SR-BI), is a physiologically relevant HDL receptor that mediates selective uptake of lipoprotein (HDL)-derived cholesteryl ester (CE) in vitro and in vivo. Mammalian SR-BI is a 509-amino acid, ~82 kDa glycoprotein that contains N- and C-terminal cytoplasmic domains, two-transmembrane domains, as well as a large extracellular domain containing 5-6 cysteine residues and multiple sites for N-linked glycosylation. The size and structural characteristics of SR-BI, however, vary considerably among lower vertebrates and insects. Recently, significant progress has been made in understanding the molecular mechanisms involved in the posttranscriptional/posttranslational regulation of SR-BI in a tissue specific manner. The purpose of this review is to summarize the current body of knowledge about the events and molecules connected with the posttranscriptional/posttranslational regulation of SR-BI and to update the molecular and functional characteristics of the insect SR-BI orthologs.
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MESH Headings
- Animals
- Biological Transport
- Gene Expression Regulation
- Glycosylation
- Humans
- Insect Proteins/chemistry
- Insect Proteins/genetics
- Insect Proteins/metabolism
- Lipoproteins, HDL/chemistry
- Lipoproteins, HDL/genetics
- Lipoproteins, HDL/metabolism
- Liver/metabolism
- Organ Specificity
- Protein Conformation
- Protein Processing, Post-Translational
- Receptors, Lipoprotein/chemistry
- Receptors, Lipoprotein/genetics
- Receptors, Lipoprotein/metabolism
- Scavenger Receptors, Class B/chemistry
- Scavenger Receptors, Class B/genetics
- Scavenger Receptors, Class B/metabolism
- Species Specificity
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Affiliation(s)
- Wen-Jun Shen
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Endocrinology, Stanford University, Stanford, California 94305
| | - Jie Hu
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304
| | - Zhigang Hu
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Endocrinology, Stanford University, Stanford, California 94305
| | - Fredric B Kraemer
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Endocrinology, Stanford University, Stanford, California 94305
| | - Salman Azhar
- Geriatric Research, Education and Clinical Center, VA Palo Alto Health Care System, Palo Alto, California 94304; Division of Gastroenterology and Hepatology, Stanford University, Stanford, California 94305.
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