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Han L, Hao P, Wang W, Wu Y, Ruan S, Gao C, Tian W, Tian Y, Li X, Wang L, Zhang W, Wang H, Chang Y, Ding J. Molecular mechanisms that regulate the heat stress response in sea urchins (Strongylocentrotus intermedius) by comparative heat tolerance performance and whole-transcriptome RNA sequencing. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 901:165846. [PMID: 37541492 DOI: 10.1016/j.scitotenv.2023.165846] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/07/2023] [Accepted: 07/26/2023] [Indexed: 08/06/2023]
Abstract
In the context of climate change and extreme high temperature, the commercially important sea urchin Strongylocentrotus intermedius suffers high mortality during summer in Northern China. How sea urchins respond to high temperatures is of great concern to academia and industry. How to understand the heat tolerance of sea urchin from the whole transcriptome level. In this study, the heat-resistant S. intermedius bred by our team and its control group were used as the research objects, then we applied whole-transcriptome RNA sequencing to detect differentially expressed mRNAs, microRNAs, long noncoding RNAs that respond to heat stress in the heat-resistant and control S. intermedius. A competitive endogenous RNA (ceRNA) regulatory network was constructed with predicted pairs of differentially expressed mRNAs and noncoding RNAs and revealed the molecular regulatory mechanisms in S. intermedius responding to heat stress. A functional analysis suggested that the ceRNAs were involved in basal metabolism, calcium ion transport, endoplasmic reticulum stress, and apoptosis. This is the whole-transcriptomic analysis of S. intermedius under heat stress to propose ceRNA networks that will provide a basis for studying the potential functions of long noncoding RNAs and miRNAs in the heat stress response in S. intermedius and provide a theoretical basis for the study of the molecular mechanism of sea urchins in response to environmental changes.
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Affiliation(s)
- Lingshu Han
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China; School of Marine Sciences, Ningbo University, Ningbo 315211, China
| | - Pengfei Hao
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Wenpei Wang
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Yanglei Wu
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Shuchao Ruan
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Chuang Gao
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Wanrong Tian
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Ye Tian
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Xiaonan Li
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Luo Wang
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Weijie Zhang
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Heng Wang
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Yaqing Chang
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China
| | - Jun Ding
- Key Laboratory of Northern Aquatic Germplasm Resources and Genetic Breeding in Liaoning Province, Dalian 116023, China; Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, China.
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Hao P, Han L, Quan Z, Jin X, Li Y, Wu Y, Zhang X, Wang W, Gao C, Wang L, Wang H, Zhang W, Chang Y, Ding J. Integrative mRNA-miRNA interaction analysis associated with the immune response of Strongylocentrotus intermedius to Vibrio harveyi infection. FISH & SHELLFISH IMMUNOLOGY 2023; 134:108577. [PMID: 36773712 DOI: 10.1016/j.fsi.2023.108577] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 11/08/2022] [Accepted: 01/31/2023] [Indexed: 06/18/2023]
Abstract
Strongylocentrotus intermedius is one of the most economically valuable sea urchin species in China and has experienced mass mortality owing to outbreaks of bacterial diseases such as black mouth disease. This has caused serious economic losses to the sea urchin farming industry. To investigate the immune response mechanism of S. intermedius with different tube feet colors in response to Vibrio harveyi infection, we examined the different tube feet-colored S. intermedius under V. harveyi challenge and compared their transcriptome and microRNA (miRNA) profiles using RNA-Seq. We obtained 1813 differentially expressed genes (DEGs), 28 DE miRNAs, and 303 DE miRNA-DEG pairs in different tube feet-colored S. intermedius under V. harveyi challenge. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis showed that the most significant DEGs were associated with the Notch signaling and phagosome pathways. The target genes of immune-related miRNAs (miR-71, miR-184, miR-193) and genes (CALM1, SPSB4, DMBT, CSRP1) in S. intermedius were predicted and validated. This study provides insight into the molecular mechanisms that regulate genes involved in the immune response of S. intermedius infected with V. harveyi.
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Affiliation(s)
- Pengfei Hao
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Lingshu Han
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China; Ningbo University, Ningbo, Zhejiang, 315832, PR China
| | - Zijiao Quan
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Xin Jin
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Yuanxin Li
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Yanglei Wu
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Xianglei Zhang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Wenpei Wang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Chuang Gao
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Luo Wang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Heng Wang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Weijie Zhang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Yaqing Chang
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China
| | - Jun Ding
- Key Laboratory of Mariculture & Stock Enhancement in North China's Sea, Ministry of Agriculture and Rural Affairs, Dalian Ocean University, Dalian, Liaoning, 116023, PR China.
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Liu J, Li T, Pei W, Zhao Y, Zhang X, Shi X, Li Y, Xu W. Lipidomics reveals the dysregulated ceramide metabolism in oxidized low-density lipoprotein-induced macrophage-derived foam cell. Biomed Chromatogr 2021; 36:e5297. [PMID: 34893994 DOI: 10.1002/bmc.5297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 10/01/2021] [Accepted: 11/23/2021] [Indexed: 12/12/2022]
Abstract
Atherosclerosis (AS) is associated with increasing lipid peroxidation. Oxidative modification of low-density lipoproteins (ox-LDL) is one most important factors contributing to the pathogenesis and clinical features of AS. The lipid composition influenced by ox-LDL is not known clearly. In this work, a UHPLC/Orbitrap MS-based lipidomics approach integrated pathway analysis was performed to advance understanding of the lipid composition and feature pathway in an ox-LDL-induced foamy macrophage cell. In the lipid metabolic profiling, 196 lipid species from 15 (sub)classes were identified. Lipid profiling indicated that increasing ox-LDL caused lipid metabolic alternations, manifesting as phospholipids being down-regulated and sphingolipids being up-regulated. Pathway analysis explored glycerophospholipid and sphingolipid metabolism, which was involved in atherogenic changes. Notably, dysregulated ceramide metabolism was a typical feature of foamy cell formation. qRT-PCR analysis was conducted to explore the differentially expressed genes. It indicated that ceramide metabolic balance might be disordered, performing higher synthesis and lower hydrolysis, with the ratio of SMPD1/SGMS2 being significantly up-regulated (p < 0.05) in the ox-LDL induced group. Our work offers a comprehensive understanding of macrophage-derived foam cells and screen feature pathways associated with foamy cell formation, which provides a reference for the clinic diagnosis of AS and drug interventions.
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Affiliation(s)
- Jie Liu
- Beijing Research Institute of Chinese Medicine, Beijing University of Chinese Medicine, Beijing, China
| | - Tong Li
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Wenxuan Pei
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Ye Zhao
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
| | - Xin Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Xiujia Shi
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Yanping Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing, China
| | - Wenjuan Xu
- School of Life Sciences, Beijing University of Chinese Medicine, Beijing, China
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Ursolic Acid and Related Analogues: Triterpenoids with Broad Health Benefits. Antioxidants (Basel) 2021; 10:antiox10081161. [PMID: 34439409 PMCID: PMC8388988 DOI: 10.3390/antiox10081161] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 06/04/2021] [Accepted: 06/22/2021] [Indexed: 12/14/2022] Open
Abstract
Ursolic acid (UA) is a well-studied natural pentacyclic triterpenoid found in herbs, fruit and a number of traditional Chinese medicinal plants. UA has a broad range of biological activities and numerous potential health benefits. In this review, we summarize the current data on the bioavailability and pharmacokinetics of UA and review the literature on the biological activities of UA and its closest analogues in the context of inflammation, metabolic diseases, including liver and kidney diseases, obesity and diabetes, cardiovascular diseases, cancer, and neurological disorders. We end with a brief overview of UA’s main analogues with a special focus on a newly discovered naturally occurring analogue with intriguing biological properties and potential health benefits, 23-hydroxy ursolic acid.
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Ma Z, Ketelhuth DFJ, Wirström T, Ohki T, Forteza MJ, Wang H, Grill V, Wollheim CB, Björklund A. Increased uptake of oxLDL does not exert lipotoxic effects in insulin-secreting cells. J Mol Endocrinol 2019; 62:159-168. [PMID: 30917339 DOI: 10.1530/jme-18-0146] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Accepted: 02/27/2019] [Indexed: 01/13/2023]
Abstract
Modified lipoproteins can negatively affect beta cell function and survival. However, the mechanisms behind interactions of modified lipoproteins with beta cells - and in particular, relationships to increased uptake - are only partly clarified. By over-expressing the scavenger receptor CD36 (Tet-on), we increased the uptake of fluorescent low-density modified lipoprotein (oxLDL) into insulin-secreting INS-1 cells. The magnitude of uptake followed the degree of CD36 over-expression. CD36 over-expression increased concomitant efflux of 3H-cholesterol in proportion to the cellular contents of 3H-cholesterol. Exposure to concentrations of oxLDL from 20 to 100 µg/mL dose-dependently increased toxicity (evaluated by MTT) as well as apoptosis. However, the increased uptake of oxLDL due to CD36 over-expression did not exert additive effects on oxLDL toxicity - neither on viability, nor on glucose-induced insulin release and cellular content. Reciprocally, blocking CD36 receptors by Sulfo-N-Succinimidyl Oleate decreased the uptake of oxLDL but did not diminish the toxicity. Pancreatic islets of CD36-/- mice displayed reduced uptake of 3H-cholesterol-labeled oxLDL vs wild type but similar toxicity to oxLDL. OxLDL was found to increase the expression of CD36 in islets and INS-1 cells. In summary, given the experimental conditions, our results indicate that (1) increased uptake of oxLDL is not responsible for toxicity of oxLDL, (2) increased efflux of the cholesterol moiety of oxLDL counterbalances, at least in part, increased uptake and (3) oxLDL participates in the regulation of CD36 in pancreatic islets and in INS-1 cells.
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Affiliation(s)
- Z Ma
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - D F J Ketelhuth
- Department of Medicine, Centre for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - T Wirström
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - T Ohki
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - M J Forteza
- Department of Medicine, Centre for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden
| | - H Wang
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - V Grill
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Institute of Clinical and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - C B Wollheim
- Department of Cell Physiology and Metabolism, University of Geneva, Geneva, Switzerland
| | - A Björklund
- Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
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Arjuman A, Chandra NC. LOX-1: A potential target for therapy in atherosclerosis; an in vitro study. Int J Biochem Cell Biol 2017; 91:65-80. [DOI: 10.1016/j.biocel.2017.08.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 08/21/2017] [Accepted: 08/23/2017] [Indexed: 01/16/2023]
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Antunes BMM, Cayres SU, Lira FS, Fernandes RA. Arterial Thickness and Immunometabolism: The Mediating role of Chronic Exercise. Curr Cardiol Rev 2016; 12:47-51. [PMID: 26818486 PMCID: PMC4807718 DOI: 10.2174/1573403x12666160126115317] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 11/28/2015] [Indexed: 01/09/2023] Open
Abstract
Metabolic alterations and cardiovascular diseases, such as atherosclerosis, are associated
with lifestyle modifications, particularly the increase of physical inactivity and poor eating habits,
which contribute to one of the main causes of death in modern times. Cardiovascular diseases are
positively correlated with several illnesses, such as obesity, hypertension and dyslipidemia, and these
disorders are known to contribute to changes in immune cells, cytokines and metabolism. Atherosclerosis
is a chronic inflammatory disease characterized by the formation of lipid plaques and fibrous
tissue (atheroma) in the artery walls and this process is related to the oxidation of LDL-c (low density lipoprotein) and the
formation of a particle, termed LDLox, which can generate toxic injury to the vessel wall. In this atherogenic process there
is an inflammatory response generated by the injury in the vascular endothelium, which in itself is able to express and
secrete a variety of molecules, such as myeloid colony-stimulating factors (M-CSF), monocyte chemotactic protein-1
(MCP-1) and tumor necrosis factor alpha (TNF-α), that act as activators of the immune system. Therefore, the main
purpose of this review is to highlight the immuno-metabolic alterations involving the thickening and stiffness of arteries
observed in atherosclerosis, and how chronic exercise can act as an anti-inflammatory and anti-atherogenic approach.
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Affiliation(s)
- B M M Antunes
- Exercise and Immunometabolism Research Group, Department of Physical Education, Universidade Estadual Paulista, UNESP, Rua Roberto Simonsen, 305, 19060-900, Presidente Prudente, São Paulo, Brazil.
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Tavakoli S, Asmis R. Reactive oxygen species and thiol redox signaling in the macrophage biology of atherosclerosis. Antioxid Redox Signal 2012; 17:1785-95. [PMID: 22540532 PMCID: PMC3474194 DOI: 10.1089/ars.2012.4638] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SIGNIFICANCE Despite the recent decline in the prevalence of cardiovascular diseases, atherosclerosis remains the leading cause of death in industrialized countries. Monocyte recruitment into the vessel wall is a rate-limiting step in atherogenesis. Death of macrophage-derived foam cells promotes lesion progression and the majority of acute complications of atherosclerotic disease (e.g., myocardial infarction) occur in lesions that are intensely infiltrated with monocyte-derived macrophages, underlining the critical roles monocytes and macrophages play in this complex chronic inflammatory disease. RECENT ADVANCES A rapidly growing body of literature supports a critical role for reactive oxygen species (ROS) in the regulation of monocyte and macrophage (dys)function associated with atherogenesis and macrophage death in atherosclerotic plaque. CRITICAL ISSUES In this review we highlight the important roles of NADHP oxidase 4 recently identified in monocytes and macrophages and the role of ROS and (thiol) redox signaling in different aspects of monocytes and macrophage biology associated with atherosclerosis. FUTURE DIRECTIONS Studies aimed at identifying the intracellular targets of ROS involved in redox signaling in macrophages and at elucidating the redox signaling mechanisms that control differentiation, activation, polarization, and death of monocytes and macrophages may ultimately lead to the development of novel preventive and therapeutic strategies for atherosclerosis.
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Affiliation(s)
- Sina Tavakoli
- Department of Radiology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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Yimin, Furumaki H, Matsuoka S, Sakurai T, Kohanawa M, Zhao S, Kuge Y, Tamaki N, Chiba H. A novel murine model for non-alcoholic steatohepatitis developed by combination of a high-fat diet and oxidized low-density lipoprotein. J Transl Med 2012; 92:265-81. [PMID: 22064320 DOI: 10.1038/labinvest.2011.159] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Non-alcoholic steatohepatitis (NASH) is the hepatic manifestation of metabolic syndrome that is characterized by steatosis, inflammation, and fibrosis, and may progress to cirrhosis and carcinoma. To investigate its pathogenic processes, we established a novel murine model for NASH by combination of a high-fat diet (HFD) and oxidized low-density lipoprotein (oxLDL). Mice that received HFD for 23 weeks showed hepatic steatosis, slight fibrosis, and a high level of lipid peroxidation compared with a regular diet (RD)-fed mice. Hepatic injury and elevated tumor necrosis factor (TNF)-α mRNA expression were also detected in these mice. Moreover, oxLDL administration to HFD-fed mice during weeks 21-23 not only aggravated hepatic steatosis, fibrosis, and lipid metabolism, but also resulted in intense inflammation, including severe hepatic injury and inflammatory cell infiltration, which are the typical histological features of NASH. Inflammation was accompanied by increased gene expression of TNF-α and interleukin (IL)-6. Additionally, the livers of RD-fed animals treated with oxLDL during weeks 21-23 were characterized by foamy macrophages and inflammatory cell infiltration along with an elevated IL-6 mRNA level. These results suggest that an increased oxidative state, including HFD-induced intracellular lipid peroxidation and its extracellular source from oxLDL, is the actual trigger for hepatic inflammation in which liver injury is mediated by TNF-α and inflammatory cell accumulation is dependent on IL-6. HFD and oxLDL also induced insulin resistance in mice; additionally, oxLDL downregulated insulin secretion. In this model, CD36 overexpression was observed in the hepatocytes of HFD-fed mice and those treated with HFD and oxLDL, and in the hepatic macrophages of RD-fed mice immediately after oxLDL treatment. In vitro experiments indicated a rapid and transient elevation of CD36 on macrophage plasma membrane in response to oxLDL. Our findings demonstrate that CD36 expressed on hepatocytes and hepatic macrophages mediates the pathophysiology of NASH.
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Affiliation(s)
- Yimin
- Department of Advanced Medicine, Graduate School of Medicine, Hokkaido University, Sapporo, Japan
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Wang Y, Qiao M, Mieyal JJ, Asmis LM, Asmis R. Molecular mechanism of glutathione-mediated protection from oxidized low-density lipoprotein-induced cell injury in human macrophages: role of glutathione reductase and glutaredoxin. Free Radic Biol Med 2006; 41:775-85. [PMID: 16895798 DOI: 10.1016/j.freeradbiomed.2006.05.029] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Revised: 04/25/2006] [Accepted: 05/23/2006] [Indexed: 12/29/2022]
Abstract
Macrophage death is a hallmark of advanced atherosclerotic plaque, and oxidized low-density lipoprotein (OxLDL) found in these lesions is believed to contribute to macrophage injury. However, the underlying mechanisms of this phenomenon are only poorly understood. Here we show that in human monocyte-derived macrophages, OxLDL depleted intracellular glutathione (GSH) and inhibited glutathione reductase, resulting in a marked diminution of the glutathione/glutathione disulfide ratio. In the absence of OxLDL, an 80% depletion of intracellular GSH levels did not affect cell viability, but glutathione depletion dramatically increased OxLDL-induced cell death. Conversely, supplementation of intracellular GSH stores with glutathione diethyl ester substantially diminished OxLDL toxicity. OxLDL also promoted protein-S-glutathionylation, which was increased in macrophages pretreated with the glutathione reductase inhibitor BCNU. Knockdown experiments with siRNA directed against glutathione reductase and glutaredoxin showed that both enzymes are essential for the protection of macrophages against OxLDL. Finally, the peroxyl-radical scavenger Trolox did not prevent GSH depletion but completely blocked OxLDL-induced protein-S-glutathionylation and cell death. These data suggest that OxLDL promotes ROS formation and protein-S-glutathionylation by a mechanism independent from its effect on GSH depletion. Neither mechanism was sufficient to induce macrophage injury, but when stimulated concurrently, these pathways promoted the accumulation of protein-glutathione mixed disulfides and cell death.
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Affiliation(s)
- Yanmei Wang
- Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40506, USA
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