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Xu G, Peng H, Yao R, Yang Y, Li B. TFEB and TFE3 cooperate in regulating inorganic arsenic-induced autophagy-lysosome impairment and immuno-dysfunction in primary dendritic cells. Cell Biol Toxicol 2024; 40:4. [PMID: 38267572 PMCID: PMC10808261 DOI: 10.1007/s10565-024-09841-0] [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: 09/22/2023] [Accepted: 12/04/2023] [Indexed: 01/26/2024]
Abstract
Arsenic (As) is a prevalent and hazardous environmental toxicant associated with cancer and various health problems, which has been shown suppressive effects on dendritic cells (DCs). Autophagy is essential for the innate and adaptive immune responses of DCs, and the transcription factors TFEB and TFE3 are key regulators of autophagic and lysosomal target genes. However, the detrimental alterations of the autophagy-lysosome pathway in As-exposed DCs and the possible coordinating roles of TFEB and TFE3 in the immune dysfunction of this cell are less understood. In this paper, we found that As exposure significantly impaired lysosomal number, lysosomal acidic environment, and lysosomal membrane permeabilization, which might lead to blocked autophagic flux in cultured DCs. Furthermore, our results confirmed that TFEB or TFE3 knockdown exacerbated the disorders of lysosome and the blockade of autophagic flux in As-exposed DCs, and also enhanced the inhibitory expression of co-stimulatory molecules Cd80 and Cd83; adhesion molecule Icam1; cytokines TNF-α, IL-1β, and IL-6; chemokine receptor Ccr7; and antigen-presenting molecules MHC II and MHC I. By contrast, overexpression of TFEB or TFE3 partially alleviated the above-mentioned impairment of DCs by inorganic As exposure. In conclusion, these findings reveal a previously unappreciated inhibition of lysosome-mediated degradation and damage of lysosomal membrane integrity leading to dysregulated autophagy and impaired immune functions of DCs by arsenicals, and also suggest TFEB and TFE3 as potential therapeutic targets for ameliorating As toxicity.
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Affiliation(s)
- Guowei Xu
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Huaguang Peng
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Ran Yao
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Yuqing Yang
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China
| | - Bing Li
- Key Laboratory of Environmental Stress and Chronic Disease Control and Prevention, Ministry of Education (China Medical University), Shenyang, Liaoning, People's Republic of China.
- Environment and Non-Communicable Disease Research Center, Key Laboratory of Arsenic-Related Biological Effects and Prevention and Treatment in Liaoning Province, School of Public Health, China Medical University, No.77 Puhe Road, Shenyang North New Area Liaoning Province, Shenyang, 110122, People's Republic of China.
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Takla M, Keshri S, Rubinsztein DC. The post-translational regulation of transcription factor EB (TFEB) in health and disease. EMBO Rep 2023; 24:e57574. [PMID: 37728021 PMCID: PMC10626434 DOI: 10.15252/embr.202357574] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 08/10/2023] [Accepted: 08/25/2023] [Indexed: 09/21/2023] Open
Abstract
Transcription factor EB (TFEB) is a basic helix-loop-helix leucine zipper transcription factor that acts as a master regulator of lysosomal biogenesis, lysosomal exocytosis, and macro-autophagy. TFEB contributes to a wide range of physiological functions, including mitochondrial biogenesis and innate and adaptive immunity. As such, TFEB is an essential component of cellular adaptation to stressors, ranging from nutrient deprivation to pathogenic invasion. The activity of TFEB depends on its subcellular localisation, turnover, and DNA-binding capacity, all of which are regulated at the post-translational level. Pathological states are characterised by a specific set of stressors, which elicit post-translational modifications that promote gain or loss of TFEB function in the affected tissue. In turn, the resulting increase or decrease in survival of the tissue in which TFEB is more or less active, respectively, may either benefit or harm the organism as a whole. In this way, the post-translational modifications of TFEB account for its otherwise paradoxical protective and deleterious effects on organismal fitness in diseases ranging from neurodegeneration to cancer. In this review, we describe how the intracellular environment characteristic of different diseases alters the post-translational modification profile of TFEB, enabling cellular adaptation to a particular pathological state.
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Affiliation(s)
- Michael Takla
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
- UK Dementia Research Institute, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
| | - Swati Keshri
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
- UK Dementia Research Institute, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
| | - David C Rubinsztein
- Department of Medical Genetics, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
- UK Dementia Research Institute, Cambridge Institute for Medical Research (CIMR)University of CambridgeCambridgeUK
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3
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Palmitate Inhibits Mouse Macrophage Efferocytosis by Activating an mTORC1-Regulated Rho Kinase 1 Pathway: Therapeutic Implications for the Treatment of Obesity. Cells 2022; 11:cells11213502. [PMID: 36359898 PMCID: PMC9657837 DOI: 10.3390/cells11213502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 10/24/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Every day, billions of our cells die and get cleared without inducing inflammation. When, clearance is improper, uncleared cells undergo secondary necrosis and trigger inflammation. In addition, proper efferocytosis would be required for inducing resolution of inflammation, thus clearance deficiencies in the long term lead to development of various chronic inflammatory diseases. Increasing evidence indicates that obesity, itself being a low-grade inflammatory disease, predisposes to a variety of other chronic inflammatory diseases. Previous studies indicated that this later might be partially related to an impaired efferocytosis induced by increased uptake of circulating saturated fatty acids by macrophages in obese people. Here, we show that palmitate inhibits efferocytosis by bone marrow-derived macrophages in a dose-dependent manner. Palmitate triggers autophagy but also activates an energy-sensing mTORC1/ROCK1 signaling pathway, which interferes with the autophagosome–lysosome fusion, resulting in accumulation of the cellular membranes in autophagosomes. We propose that lack of sufficient plasma membrane supply attenuates efferocytosis of palmitate-exposed macrophages. AMP-activated protein kinase activators lead to mTORC1 inhibition and, consequently, released the palmitate-induced efferocytosis block in macrophages. Thus, they might be useful in the treatment of obesity not only by affecting metabolism thought so far. ROCK1 inhibitors could also be considered.
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Satoh-Asahara N, Yamakage H, Tanaka M, Kawasaki T, Matsuura S, Tatebe H, Akiguchi I, Tokuda T. Soluble TREM2 and Alzheimer-related biomarker trajectories in the blood of patients with diabetes based on their cognitive status. Diabetes Res Clin Pract 2022; 193:110121. [PMID: 36272585 DOI: 10.1016/j.diabres.2022.110121] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 10/11/2022] [Accepted: 10/13/2022] [Indexed: 12/01/2022]
Abstract
AIM We aimed to elucidate the dynamics of blood biomarkers according to the severity of cognitive impairment in patients with type 2 diabetes mellitus (DM) and to identify useful biomarkers for diabetes-related dementia. METHODS This was a cross-sectional, nested case-control study of 121 Japanese DM and non-DM patients with different levels of cognitive functioning. We evaluated participants' cognitive functions, blood biomarkers related to Alzheimer's disease, and soluble triggering receptors expressed on myeloid cells 2 (sTREM2). We then compared these biomarkers between the DM and non-DM and across the different cognitive strata. RESULTS In all cognitive strata, significantly lower levels of serum sTREM2 were observed in the DM than in the non-DM. We also found that plasma levels of phosphorylated tau (p-tau) increased with increasing levels of cognitive decline in both the DM and non-DM. However, this was accompanied by a decrease in plasma amyloid-β(Aβ42/Aβ40 ratios in non-DM only. CONCLUSION This study revealed novel characteristic trajectories of dementia-related blood biomarkers in diabetes-related dementia, suggesting the pathological involvement of molecular cascades initiated by impaired microglial activation. This results in decreased serum sTREM2, followed by tauopathy without substantial amyloid plaques, reflected by plasma p-tau elevation with no decrease in the Aβ42/Aβ40 ratio. Clinical trials (the unique trial number and the name of the registry): UMIN000048032, https://www.umin.ac.jp.
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Affiliation(s)
- Noriko Satoh-Asahara
- Clinical Research Institute for Endocrine & Metabolic Disease, National Hospital Organization, Kyoto Medical Center, 1-1 Fukakusa Mukaihata-cho, Fushimi-ku, Kyoto 612-8555, Japan; Department of Metabolic Syndrome and Nutritional Science, Research Institute of Environmental Medicine, Nagoya University, Aichi 464-8601, Japan.
| | - Hajime Yamakage
- Clinical Research Institute for Endocrine & Metabolic Disease, National Hospital Organization, Kyoto Medical Center, 1-1 Fukakusa Mukaihata-cho, Fushimi-ku, Kyoto 612-8555, Japan
| | - Masashi Tanaka
- Clinical Research Institute for Endocrine & Metabolic Disease, National Hospital Organization, Kyoto Medical Center, 1-1 Fukakusa Mukaihata-cho, Fushimi-ku, Kyoto 612-8555, Japan; Department of Physical Therapy, Health Science University, Yamanashi 401-0380, Japan
| | - Teruaki Kawasaki
- Center of Neurological and Cerebrovascular Diseases, Koseikai Takeda Hospital, Kyoto, Japan
| | - Sayo Matsuura
- Department of Functional Brain Imaging, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-0024, Japan
| | - Harutsugu Tatebe
- Department of Functional Brain Imaging, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-0024, Japan
| | - Ichiro Akiguchi
- Center of Neurological and Cerebrovascular Diseases, Koseikai Takeda Hospital, Kyoto, Japan
| | - Takahiko Tokuda
- Department of Functional Brain Imaging, Institute for Quantum Medical Science, Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology (QST), 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-0024, Japan
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5
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Yang DJ, Wang XD, Fu XY, Lu HM, Zhou ZG, Liu Y. MyD88 deficiency aggravates the severity of acute pancreatitis by promoting MyD88-independent TRIF pathway-mediated necrosis. ANNALS OF TRANSLATIONAL MEDICINE 2022; 10:1214. [PMID: 36544673 PMCID: PMC9761135 DOI: 10.21037/atm-22-5134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 11/07/2022] [Indexed: 11/23/2022]
Abstract
Background With uncontrolled inflammatory progression, acute pancreatitis (AP) can progress to severe acute pancreatitis (SAP). Inflammation and parenchymal cell death are key pathologic responses of AP. Toll-like receptor 4 (TLR4) plays a pro-inflammatory role in AP. Myeloid differentiation primary response protein 88 (MyD88) is the most essential utilized adaptor of TLR4, but its role in AP remains unclear. We investigated the potential role of MyD88 in the pathogenesis of AP. Methods An AP model was induced by administering either cerulein or L-arginine to wild-type or MyD88-deficient mice. Additionally, receptor-interacting protein kinase 1 (RIP1) inhibitor necrostatin-1 (Nec-1) was administered to the MyD88-/- mice. The severity of AP was determined by measuring serum amylase and lipase activities, quantifying pancreatic myeloperoxidase (MPO) activity, and histological examination. The effects of MyD88 deletion on cell death and the inflammatory response were determined by measuring apoptosis, necrosis, and inflammatory cytokines. Western blot was used to assess the necrotic mediators, RIP1 and RIP3. Results The deletion of MyD88 resulted in more severe acute experimental pancreatitis as assessed by increased amylase and lipase activities, increased pancreatic MPO activity, a reduced anti-inflammatory response, reduced apoptosis, and increased necrosis. Additionally, Nec-1 treatment significantly reduced necrosis in the MyD88-/- mice. Conclusions The deletion of MyD88 inhibited the TLR4/MyD88-dependent pathway mediated protective immune defense response and enhanced TLR4/MyD88-independent TRIF pathway-mediated pancreatic necrosis, which in turn aggravated the severity of AP. The critical role of MyD88 in immune defense response and cell death indicates that MyD88 represents a potential therapeutic target in the management of AP.
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Affiliation(s)
- Du-Jiang Yang
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Xiao-Dong Wang
- Department of Gastroenterological Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Xiao-Ying Fu
- Colorectal Cancer Center, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Hui-Min Lu
- Department of Pancreatic Surgery, West China Hospital, Sichuan University, Chengdu, China
| | - Zong-Guang Zhou
- Colorectal Cancer Center, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, China;,Institute of Digestive Surgery and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yong Liu
- Colorectal Cancer Center, Department of General Surgery, West China Hospital, Sichuan University, Chengdu, China;,Institute of Digestive Surgery and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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6
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Ding J, Xie Y, Sun X, Shao F, Pan J, Chen J, Zhu Z, Qi C. Inhibition of TFEB promotes tumor-educated dendritic cells activation to enhance antitumor immune responses. Mol Immunol 2022; 147:30-39. [DOI: 10.1016/j.molimm.2022.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 03/01/2022] [Accepted: 04/21/2022] [Indexed: 10/18/2022]
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7
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Lipke K, Kubis-Kubiak A, Piwowar A. Molecular Mechanism of Lipotoxicity as an Interesting Aspect in the Development of Pathological States-Current View of Knowledge. Cells 2022; 11:cells11050844. [PMID: 35269467 PMCID: PMC8909283 DOI: 10.3390/cells11050844] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/22/2022] [Accepted: 02/25/2022] [Indexed: 02/06/2023] Open
Abstract
Free fatty acids (FFAs) play numerous vital roles in the organism, such as contribution to energy generation and reserve, serving as an essential component of the cell membrane, or as ligands for nuclear receptors. However, the disturbance in fatty acid homeostasis, such as inefficient metabolism or intensified release from the site of storage, may result in increased serum FFA levels and eventually result in ectopic fat deposition, which is unfavorable for the organism. The cells are adjusted for the accumulation of FFA to a limited extent and so prolonged exposure to elevated FFA levels results in deleterious effects referred to as lipotoxicity. Lipotoxicity contributes to the development of diseases such as insulin resistance, diabetes, cardiovascular diseases, metabolic syndrome, and inflammation. The nonobvious organs recognized as the main lipotoxic goal of action are the pancreas, liver, skeletal muscles, cardiac muscle, and kidneys. However, lipotoxic effects to a significant extent are not organ-specific but affect fundamental cellular processes occurring in most cells. Therefore, the wider perception of cellular lipotoxic mechanisms and their interrelation may be beneficial for a better understanding of various diseases’ pathogenesis and seeking new pharmacological treatment approaches.
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8
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Liu X, Zheng X, Lu Y, Chen Q, Zheng J, Zhou H. TFEB Dependent Autophagy-Lysosomal Pathway: An Emerging Pharmacological Target in Sepsis. Front Pharmacol 2021; 12:794298. [PMID: 34899355 PMCID: PMC8664376 DOI: 10.3389/fphar.2021.794298] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/05/2021] [Indexed: 12/29/2022] Open
Abstract
Sepsis is a life-threatening syndrome induced by aberrant host response towards infection. The autophagy-lysosomal pathway (ALP) plays a fundamental role in maintaining cellular homeostasis and conferring organ protection. However, this pathway is often impaired in sepsis, resulting in dysregulated host response and organ dysfunction. Transcription factor EB (TFEB) is a master modulator of the ALP. TFEB promotes both autophagy and lysosomal biogenesis via transcriptional regulation of target genes bearing the coordinated lysosomal expression and regulation (CLEAR) motif. Recently, increasing evidences have linked TFEB and the TFEB dependent ALP with pathogenetic mechanisms and therapeutic implications in sepsis. Therefore, this review describes the existed knowledge about the mechanisms of TFEB activation in regulating the ALP and the evidences of their protection against sepsis, such as immune modulation and organ protection. In addition, TFEB activators with diversified pharmacological targets are summarized, along with recent advances of their potential therapeutic applications in treating sepsis.
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Affiliation(s)
- Xin Liu
- Medical Research Center, Southwest Hospital, Army Military Medical University, Chongqing, China
| | - Xinchuan Zheng
- Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing, China
| | - Yongling Lu
- Medical Research Center, Southwest Hospital, Army Military Medical University, Chongqing, China
| | - Qian Chen
- Medical Research Center, Southwest Hospital, Army Military Medical University, Chongqing, China
| | - Jiang Zheng
- Medical Research Center, Southwest Hospital, Army Military Medical University, Chongqing, China
| | - Hong Zhou
- Key Laboratory of Basic Pharmacology of Ministry of Education and Joint International Research Laboratory of Ethnomedicine of Ministry of Education, Zunyi Medical University, Zunyi, China
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Loss of SNORA73 reprograms cellular metabolism and protects against steatohepatitis. Nat Commun 2021; 12:5214. [PMID: 34471131 PMCID: PMC8410784 DOI: 10.1038/s41467-021-25457-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 08/06/2021] [Indexed: 02/07/2023] Open
Abstract
Dyslipidemia and resulting lipotoxicity are pathologic signatures of metabolic syndrome and type 2 diabetes. Excess lipid causes cell dysfunction and induces cell death through pleiotropic mechanisms that link to oxidative stress. However, pathways that regulate the response to metabolic stress are not well understood. Herein, we show that disruption of the box H/ACA SNORA73 small nucleolar RNAs encoded within the small nucleolar RNA hosting gene 3 (Snhg3) causes resistance to lipid-induced cell death and general oxidative stress in cultured cells. This protection from metabolic stress is associated with broad reprogramming of oxidative metabolism that is dependent on the mammalian target of rapamycin signaling axis. Furthermore, we show that knockdown of SNORA73 in vivo protects against hepatic steatosis and lipid-induced oxidative stress and inflammation. Our findings demonstrate a role for SNORA73 in the regulation of metabolism and lipotoxicity.
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10
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Gautier EL, Askia H, Murcy F, Yvan-Charvet L. Macrophage ontogeny and functional diversity in cardiometabolic diseases. Semin Cell Dev Biol 2021; 119:119-129. [PMID: 34229949 DOI: 10.1016/j.semcdb.2021.06.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 06/01/2021] [Accepted: 06/28/2021] [Indexed: 12/24/2022]
Abstract
Macrophages are the dominant immune cell types in the adipose tissue, the liver or the aortic wall and they were originally believed to mainly derived from monocytes to fuel tissue inflammation in cardiometabolic diseases. However, over the last decade the identification of tissue resident macrophages (trMacs) from embryonic origin in these metabolic tissues has provided a breakthrough in the field forcing to better comprehend macrophage diversity during pathological states. Infiltrated monocyte-derived macrophages (moMacs), similar to trMacs, adapt to the local metabolic environment that eventually shapes their functions. In this review, we will summarize the emerging versatility of macrophages in cardiometabolic diseases with a focus in the control of adipose tissue, liver and large vessels homeostasis.
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Affiliation(s)
- Emmanuel L Gautier
- Institut National de la Santé et de la Recherche Médicale (Inserm) UMR-S 1166, Sorbonne Université, 75013 Paris, France.
| | - Haoussa Askia
- Institut National de la Santé et de la Recherche Médicale (Inserm) UMR-S 1166, Sorbonne Université, 75013 Paris, France
| | - Florent Murcy
- Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, 06204 Nice, France
| | - Laurent Yvan-Charvet
- Institut National de la Santé et de la Recherche Médicale (Inserm) U1065, Université Côte d'Azur, Centre Méditerranéen de Médecine Moléculaire (C3M), Atip-Avenir, Fédération Hospitalo-Universitaire (FHU) Oncoage, 06204 Nice, France.
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11
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Kim S, Song HS, Yu J, Kim YM. MiT Family Transcriptional Factors in Immune Cell Functions. Mol Cells 2021; 44:342-355. [PMID: 33972476 PMCID: PMC8175148 DOI: 10.14348/molcells.2021.0067] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 04/01/2021] [Accepted: 04/01/2021] [Indexed: 11/27/2022] Open
Abstract
The microphthalmia-associated transcription factor family (MiT family) proteins are evolutionarily conserved transcription factors that perform many essential biological functions. In mammals, the MiT family consists of MITF (microphthalmia-associated transcription factor or melanocyte-inducing transcription factor), TFEB (transcription factor EB), TFE3 (transcription factor E3), and TFEC (transcription factor EC). These transcriptional factors belong to the basic helix-loop-helix-leucine zipper (bHLH-LZ) transcription factor family and bind the E-box DNA motifs in the promoter regions of target genes to enhance transcription. The best studied functions of MiT proteins include lysosome biogenesis and autophagy induction. In addition, they modulate cellular metabolism, mitochondria dynamics, and various stress responses. The control of nuclear localization via phosphorylation and dephosphorylation serves as the primary regulatory mechanism for MiT family proteins, and several kinases and phosphatases have been identified to directly determine the transcriptional activities of MiT proteins. In different immune cell types, each MiT family member is shown to play distinct or redundant roles and we expect that there is far more to learn about their functions and regulatory mechanisms in host defense and inflammatory responses.
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Affiliation(s)
- Seongryong Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hyun-Sup Song
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jihyun Yu
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
| | - You-Me Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, Korea
- The Center for Epidemic Preparedness, KAIST, Daejeon 34141, Korea
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12
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Sommer F, Torraca V, Xie Y, In 't Veld AE, Willemse J, Meijer AH. Disruption of Cxcr3 chemotactic signaling alters lysosomal function and renders macrophages more microbicidal. Cell Rep 2021; 35:109000. [PMID: 33852860 DOI: 10.1016/j.celrep.2021.109000] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 01/11/2021] [Accepted: 03/23/2021] [Indexed: 12/12/2022] Open
Abstract
Chemotaxis and lysosomal function are closely intertwined processes essential for the inflammatory response and clearance of intracellular bacteria. We used the zebrafish model to examine the link between chemotactic signaling and lysosome physiology in macrophages during mycobacterial infection and wound-induced inflammation in vivo. Macrophages from zebrafish larvae carrying a mutation in a chemokine receptor of the Cxcr3 family display upregulated expression of vesicle trafficking and lysosomal genes and possess enlarged lysosomes that enhance intracellular bacterial clearance. This increased microbicidal capacity is phenocopied by inhibiting the lysosomal transcription factor EC, while its overexpression counteracts the protective effect of chemokine receptor mutation. Tracking macrophage migration in zebrafish revealed that lysosomes of chemokine receptor mutants accumulate in the front half of cells, preventing macrophage polarization during chemotaxis and reaching sites of inflammation. Our work shows that chemotactic signaling affects the bactericidal properties and localization during chemotaxis, key aspects of the inflammatory response.
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Affiliation(s)
- Frida Sommer
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
| | - Vincenzo Torraca
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands; Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Yufei Xie
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
| | | | - Joost Willemse
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands
| | - Annemarie H Meijer
- Institute of Biology Leiden, Leiden University, Leiden, the Netherlands.
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13
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Ye L, Li G, Goebel A, Raju AV, Kong F, Lv Y, Li K, Zhu Y, Raja S, He P, Li F, Mwangi SM, Hu W, Srinivasan S. Caspase-11-mediated enteric neuronal pyroptosis underlies Western diet-induced colonic dysmotility. J Clin Invest 2020; 130:3621-3636. [PMID: 32484462 PMCID: PMC7324173 DOI: 10.1172/jci130176] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 03/24/2020] [Indexed: 02/06/2023] Open
Abstract
Enteric neuronal degeneration, as seen in inflammatory bowel disease, obesity, and diabetes, can lead to gastrointestinal dysmotility. Pyroptosis is a novel form of programmed cell death but little is known about its role in enteric neuronal degeneration. We observed higher levels of cleaved caspase-1, a marker of pyroptosis, in myenteric ganglia of overweight and obese human subjects compared with normal-weight subjects. Western diet-fed (WD-fed) mice exhibited increased myenteric neuronal pyroptosis, delayed colonic transit, and impaired electric field stimulation-induced colonic relaxation responses. WD increased TLR4 expression and cleaved caspase-1 in myenteric nitrergic neurons. Overactivation of nitrergic neuronal NF-κB signaling resulted in increased pyroptosis and delayed colonic motility. In caspase-11-deficient mice, WD did not induce nitrergic myenteric neuronal pyroptosis and colonic dysmotility. To understand the contributions of saturated fatty acids and bacterial products to the steps leading to enteric neurodegeneration, we performed in vitro experiments using mouse enteric neurons. Palmitate and lipopolysaccharide (LPS) increased nitrergic, but not cholinergic, enteric neuronal pyroptosis. LPS gained entry to the cytosol in the presence of palmitate, activating caspase-11 and gasdermin D, leading to pyroptosis. These results support a role of the caspase-11-mediated pyroptotic pathway in WD-induced myenteric nitrergic neuronal degeneration and colonic dysmotility, providing important therapeutic targets for enteric neuropathy.
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Affiliation(s)
- Lan Ye
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Gastroenterology Research, Atlanta VA Health Care System, Decatur, Georgia, USA
| | - Ge Li
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Gastroenterology Research, Atlanta VA Health Care System, Decatur, Georgia, USA
| | - Anna Goebel
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Gastroenterology Research, Atlanta VA Health Care System, Decatur, Georgia, USA
| | - Abhinav V. Raju
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Gastroenterology Research, Atlanta VA Health Care System, Decatur, Georgia, USA
| | - Feng Kong
- Second Hospital of Shandong University, Jinan, China
| | - Yanfei Lv
- Second Hospital of Shandong University, Jinan, China
| | - Kailin Li
- Second Hospital of Shandong University, Jinan, China
| | - Yuanjun Zhu
- Center for Metabolic Disease Research, Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
| | - Shreya Raja
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Gastroenterology Research, Atlanta VA Health Care System, Decatur, Georgia, USA
| | - Peijian He
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Fang Li
- Center for Metabolic Disease Research, Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
| | - Simon Musyoka Mwangi
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Gastroenterology Research, Atlanta VA Health Care System, Decatur, Georgia, USA
| | - Wenhui Hu
- Center for Metabolic Disease Research, Department of Pathology and Laboratory Medicine, Temple University Lewis Katz School of Medicine, Philadelphia, Pennsylvania, USA
| | - Shanthi Srinivasan
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia, USA
- Gastroenterology Research, Atlanta VA Health Care System, Decatur, Georgia, USA
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14
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Javaheri A, Bajpai G, Picataggi A, Mani S, Foroughi L, Evie H, Kovacs A, Weinheimer CJ, Hyrc K, Xiao Q, Ballabio A, Lee JM, Matkovich SJ, Razani B, Schilling JD, Lavine KJ, Diwan A. TFEB activation in macrophages attenuates postmyocardial infarction ventricular dysfunction independently of ATG5-mediated autophagy. JCI Insight 2019; 4:127312. [PMID: 31672943 DOI: 10.1172/jci.insight.127312] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 09/25/2019] [Indexed: 12/13/2022] Open
Abstract
Lysosomes are at the epicenter of cellular processes critical for inflammasome activation in macrophages. Inflammasome activation and IL-1β secretion are implicated in myocardial infarction (MI) and resultant heart failure; however, little is known about how macrophage lysosomes regulate these processes. In mice subjected to cardiac ischemia/reperfusion (IR) injury and humans with ischemic cardiomyopathy, we observed evidence of lysosomal impairment in macrophages. Inducible macrophage-specific overexpression of transcription factor EB (TFEB), a master regulator of lysosome biogenesis (Mϕ-TFEB), attenuated postinfarction remodeling, decreased abundance of proinflammatory macrophages, and reduced levels of myocardial IL-1β compared with controls. Surprisingly, neither inflammasome suppression nor Mϕ-TFEB-mediated attenuation of postinfarction myocardial dysfunction required intact ATG5-dependent macroautophagy (hereafter termed "autophagy"). RNA-seq of flow-sorted macrophages postinfarction revealed that Mϕ-TFEB upregulated key targets involved in lysosomal lipid metabolism. Specifically, inhibition of the TFEB target, lysosomal acid lipase, in vivo abrogated the beneficial effect of Mϕ-TFEB on postinfarction ventricular function. Thus, TFEB reprograms macrophage lysosomal lipid metabolism to attenuate remodeling after IR, suggesting an alternative paradigm whereby lysosome function affects inflammation.
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Affiliation(s)
- Ali Javaheri
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Geetika Bajpai
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Antonino Picataggi
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Smrithi Mani
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Layla Foroughi
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Hosannah Evie
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Attila Kovacs
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Carla J Weinheimer
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | | | - Qingli Xiao
- Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Medical Genetics, Department of Medical and Translational Sciences, Federico II University, Naples, Italy.,Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, Texas, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas, USA
| | - Jin-Moo Lee
- Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Scot J Matkovich
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Babak Razani
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine.,John Cochran Veterans Affairs Medical Center, Saint Louis, Missouri, USA
| | - Joel D Schilling
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Kory J Lavine
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine
| | - Abhinav Diwan
- Cardiovascular Division and Center for Cardiovascular Research, Department of Medicine.,John Cochran Veterans Affairs Medical Center, Saint Louis, Missouri, USA
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15
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Kalugotla G, He L, Weber KJ, Daemen S, Reller A, Razani B, Schilling JD. Frontline Science: Acyl-CoA synthetase 1 exacerbates lipotoxic inflammasome activation in primary macrophages. J Leukoc Biol 2019; 106:803-814. [PMID: 31166619 DOI: 10.1002/jlb.3hi0219-045rr] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/19/2022] Open
Abstract
Obesity and diabetes are associated with macrophage dysfunction and increased NLRP3 inflammasome activation. Saturated fatty acids (FAs) are abundant in these metabolic disorders and have been associated with lysosome dysfunction and inflammasome activation in macrophages. However, the interplay between cellular metabolic pathways and lipid-induced toxicity in macrophages remains poorly understood. In this study, we investigated the role of the lipid metabolic enzyme long chain acyl-CoA synthetase (ACSL1) in primary macrophages. ACSL1 is upregulated in TLR4-activated macrophages via a TIR (toll/IL-1R) domain-containing adapter inducing IFN-β (TRIF)-dependent pathway, and knockout of this enzyme decreased NLRP3 inflammasome activation. The mechanism of this response was not related to inflammasome priming, lipid uptake, or endoplasmic reticulum (ER) stress generation. Rather, ACSL1 was associated with mitochondria where it modulated fatty acid metabolism. The development of lysosome damage with palmitate exposure likely occurs via the formation of intracellular crystals. Herein, we provide evidence that loss of ACSL1 in macrophages decreases FA crystal formation thereby reducing lysosome damage and IL-1β release. These findings suggest that targeting lipid metabolic pathways in macrophages may be a strategy to reduce lipotoxity and to decrease pathologic inflammation in metabolic disease.
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Affiliation(s)
- Gowri Kalugotla
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Li He
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Kassandra J Weber
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Sabine Daemen
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Abigail Reller
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Babak Razani
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Joel D Schilling
- Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
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16
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Sletten AC, Peterson LR, Schaffer JE. Manifestations and mechanisms of myocardial lipotoxicity in obesity. J Intern Med 2018; 284:478-491. [PMID: 29331057 PMCID: PMC6045461 DOI: 10.1111/joim.12728] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Environmental and socioeconomic changes over the past thirty years have contributed to a dramatic rise in the worldwide prevalence of obesity. Heart disease is amongst the most serious health risks of obesity, with increases in both atherosclerotic coronary heart disease and heart failure among obese individuals. In this review, we focus on primary myocardial alterations in obesity that include hypertrophic remodelling and diastolic dysfunction. Obesity-associated perturbations in myocardial and systemic lipid metabolism are important contributors to cardiovascular complications of obesity. Accumulation of excess lipid in nonadipose cells of the cardiovascular system can cause cell dysfunction and cell death, a process known as lipotoxicity. Lipotoxicity has been modelled in mice using high-fat diet feeding, inbred lines with mutations in leptin receptor signalling, and in genetically engineered mice with enhanced myocardial fatty acid uptake, altered lipid droplet homoeostasis or decreased cardiac fatty acid oxidation. These studies, along with findings in cell culture model systems, indicate that the molecular pathophysiology of lipid overload involves endoplasmic reticulum stress, alterations in autophagy, de novo ceramide synthesis, oxidative stress, inflammation and changes in gene expression. We highlight recent advances that extend our understanding of the impact of obesity and altered lipid metabolism on cardiac function.
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Affiliation(s)
- A C Sletten
- Department of Medicine, Washington University, St Louis, MO, USA
| | - L R Peterson
- Department of Medicine, Washington University, St Louis, MO, USA
| | - J E Schaffer
- Department of Medicine, Washington University, St Louis, MO, USA
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17
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Weber KJ, Sauer M, He L, Tycksen E, Kalugotla G, Razani B, Schilling JD. PPARγ Deficiency Suppresses the Release of IL-1β and IL-1α in Macrophages via a Type 1 IFN-Dependent Mechanism. THE JOURNAL OF IMMUNOLOGY 2018; 201:2054-2069. [PMID: 30143592 DOI: 10.4049/jimmunol.1800224] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/30/2018] [Indexed: 12/21/2022]
Abstract
Obesity and diabetes modulate macrophage activation, often leading to prolonged inflammation and dysfunctional tissue repair. Increasing evidence suggests that the NLRP3 inflammasome plays an important role in obesity-associated inflammation. We have previously shown that activation of the lipotoxic inflammasome by excess fatty acids in macrophages occurs via a lysosome-dependent pathway. However, the mechanisms that link cellular lipid metabolism to altered inflammation remain poorly understood. PPARγ is a nuclear receptor transcription factor expressed by macrophages that is known to alter lipid handling, mitochondrial function, and inflammatory cytokine expression. To undercover novel links between metabolic signaling and lipotoxic inflammasome activation, we investigated mouse primary macrophages deficient in PPARγ. Contrary to our expectation, PPARγ knockout (KO) macrophages released significantly less IL-1β and IL-1α in response to lipotoxic stimulation. The suppression occurred at the transcriptional level and was apparent for multiple activators of the NLRP3 inflammasome. RNA sequencing revealed upregulation of IFN-β in activated PPARγKO macrophages, and this was confirmed at the protein level. A blocking Ab against the type 1 IFNR restored the release of IL-1β to wild type levels in PPARγKO cells, confirming the mechanistic link between these events. Conversely, PPARγ activation with rosiglitazone selectively suppressed IFN-β expression in activated macrophages. Loss of PPARγ also resulted in diminished expression of genes involved in sterol biosynthesis, a pathway known to influence IFN production. Together, these findings demonstrate a cross-talk pathway that influences the interplay between metabolism and inflammation in macrophages.
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Affiliation(s)
- Kassandra J Weber
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, MO 63110.,Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Madeline Sauer
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, MO 63110.,Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Li He
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, MO 63110.,Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Eric Tycksen
- Genome Technology Access Center, Washington University School of Medicine, St. Louis, MO 63110; and
| | - Gowri Kalugotla
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, MO 63110.,Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110
| | - Babak Razani
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, MO 63110.,Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
| | - Joel D Schilling
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, MO 63110; .,Department of Medicine, Washington University School of Medicine, St. Louis, MO 63110.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110
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18
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Shi H, Hua X, Kong D, Stein D, Hua F. Role of Toll-like receptor mediated signaling in traumatic brain injury. Neuropharmacology 2018; 145:259-267. [PMID: 30075158 DOI: 10.1016/j.neuropharm.2018.07.022] [Citation(s) in RCA: 46] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2018] [Revised: 07/04/2018] [Accepted: 07/18/2018] [Indexed: 12/13/2022]
Abstract
The mechanisms underlying secondary brain damage following traumatic brain injury (TBI) remain unclear. A great many studies have demonstrated that inflammatory cascades contribute to brain damage through the activation of immune/inflammatory responses, including the increased release of cytokines and chemokines, and the recruitment of leukocytes. The cells and tissues damaged by primary mechanical injury release a number of endogenous factors acting as damage-associated molecular patterns (DAMPs), which initiate and perpetuate noninfectious inflammatory responses through transduction signaling pathways. Toll-like receptors (TLRs) are a transmembrane receptor family that can recognize the specific DAMPs released from damaged cells and recruit a set of adaptors leading to the activation of downstream kinases and nuclear factors which regulate the expression of inflammatory genes. The activation of inflammatory responses mediated by TLR signaling is closely associated with brain tissue damage and neurological dysfunction following TBI. TLRs and their downstream protein kinases may be potential targets for the treatment of TBI. Modulation of TLR-mediated signaling may attenuate brain damage and improve TBI outcome. In this review, we briefly discuss the role of TLR-mediated signaling in TBI and the new treatments targeting TLR signaling. This article is part of the Special Issue entitled "Novel Treatments for Traumatic Brain Injury".
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Affiliation(s)
- Hongjuan Shi
- Department of Neurology, The Affiliated Hospital, Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China
| | - Xiaodong Hua
- Augusta University/University of Georgia Medical Partnership, Athens, GA, 30606, USA; Medical College of Georgia, Augusta University, Augusta, GA, 30912, USA
| | - Delian Kong
- Department of Neurology, The Affiliated Hospital, Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China
| | - Donald Stein
- Brain Research Laboratory, Department of Emergency Medicine, Emory University School of Medicine, Atlanta, GA, 30032, USA
| | - Fang Hua
- Department of Neurology, The Affiliated Hospital, Xuzhou Medical University, Xuzhou, Jiangsu, 221002, China; Key Laboratory of Anesthesiology of Jiangsu Province, Xuzhou, 221002, China.
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19
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Shen C, Ma W, Ding L, Li S, Dou X, Song Z. The TLR4-IRE1α pathway activation contributes to palmitate-elicited lipotoxicity in hepatocytes. J Cell Mol Med 2018; 22:3572-3581. [PMID: 29673059 PMCID: PMC6010797 DOI: 10.1111/jcmm.13636] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 03/10/2018] [Indexed: 02/06/2023] Open
Abstract
Lipotoxicity induced by saturated fatty acids (SFAs) plays a pathological role in the development of non‐alcoholic fatty liver disease (NAFLD); however, the exact mechanism(s) remain to be clearly elucidated. Toll‐like receptor (TLR) 4 plays a fundamental role in activating the innate immune system. Intriguingly, hepatocytes express TLR4 and machinery for TLR4 signalling pathway. That liver‐specific TLR4 knockout mice are protective against diet‐induced NAFLD suggests that hepatocyte TLR4 signalling pathway plays an important role in NAFLD pathogenesis. Herein, using cultured hepatocytes, we sought to directly examine the role of TLR4 signalling pathway in palmitate‐elicited hepatotoxicity and to elucidate underlying mechanism(s). Our data reveal that palmitate exposure up‐regulates TLR4 expression at both mRNA and protein levels in hepatocytes, which are associated with NF‐κB activation. The inhibition of TLR4 signalling pathway through both pharmacological and genetic approaches abolished palmitate‐induced cell death, suggesting that TLR4 signalling pathway activation contributes to palmitate‐induced hepatotoxicity. Mechanistic investigations demonstrate that inositol‐requiring enzyme 1α (IRE1α), one of three major signal transduction pathways activated during endoplasmic reticulum (ER) stress, is the downstream target of palmitate‐elicited TLR4 activation and mechanistically implicated in TLR4 activation‐triggered cell death in response to palmitate exposure. Collectively, our data identify that the TLR4‐IRE1α pathway activation contributes to palmitate‐elicited lipotoxicity in hepatocytes. Our findings suggest that targeting TLR4‐IRE1α pathway can be a potential therapeutic choice for the treatment of NAFLD as well as other metabolic disorders, with lipotoxicity being the principal pathomechanism.
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Affiliation(s)
- Chen Shen
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA
| | - Wang Ma
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Lei Ding
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Songtao Li
- Department of Nutrition and Food Hygiene, Public Health College, Harbin Medical University, Harbin, China
| | - Xiaobing Dou
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhenyuan Song
- Department of Kinesiology and Nutrition, University of Illinois at Chicago, Chicago, IL, USA.,College of Life Science, Zhejiang Chinese Medical University, Hangzhou, China.,Department of Pathology, University of Illinois, Medical Center, Chicago, IL, USA
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20
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Pinheiro CR, Coelho AL, de Oliveira CE, Gasparoto TH, Garlet GP, Silva JS, Santos CF, Cavassani KA, Hogaboam CM, Campanelli AP. Recognition of Candida albicans by gingival fibroblasts: The role of TLR2, TLR4/CD14, and MyD88. Cytokine 2017; 106:67-75. [PMID: 29128406 DOI: 10.1016/j.cyto.2017.10.013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 12/12/2022]
Abstract
Recent evidence indicates that nonprofessional immune cells such as epithelial cells, endothelial cells, and fibroblasts also contribute to innate immunity via secretion of cytokines. Fibroblasts are the principal type of cell found in the periodontal connective tissues and they are involved in the immune response during periodontal disease. The role of fibroblasts in the recognition of pathogens via Toll-like receptors (TLRs) has been established; however, few studies have been conducted concerning the involvement of innate immune receptors in the recognition of Candida albicans by gingival fibroblast. In the current study, we investigate the functional activity of TLR2, cluster of differentiation 14 (CD14), and myeloid differentiation primary response gene 88 (MyD88) molecules in the recognition of C. albicans by gingival fibroblast. First, we identified that gingival fibroblasts expressed TLR2, TLR3, and TLR4. Our results showed that TLR agonists had no effect on these receptors' expression by TLR2, MyD88, and CD14-deficient cells. Notably, C. albicans and a synthetic triacylated lipoprotein (Pam3CSK4) induced a remarkable increase of TLR3 expression on MyD88-deficient gingival fibroblasts. TLR4 expression levels were lower than TLR2 and TLR3 levels and remained unchanged after TLR agonist stimulation. Gingival fibroblasts presented morphological similarities; however, TLR2 deficiency on these cells leads to a lower proliferative response, whereas the deficiency on CD14 expression resulted in lower levels of type I collagen by these cells. In addition, the recognition of C. albicans by gingival fibroblasts had an effect on the secretion of cytokines and it was dependent on a specific recognition molecule. Specifically, tumor necrosis factor-α (TNF-α) production after the recognition of C. albicans was dependent on MyD88, CD14, and TLR2 molecules, whereas the production of interleukin-1β (IL-1β) and IL-13 was dependent on TLR2. These findings are the first to describe a role of gingival fibroblast in the recognition of C. albicans and the pathways involved in this process. An understanding of these pathways may lead to alternative treatments for patients with periodontal disease.
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Affiliation(s)
- Claudia Ramos Pinheiro
- Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - Ana Lúcia Coelho
- Department of Medicine, Advanced Health Sciences Pavilion, Cedars Sinai Medical Center, Los Angeles, CA, USA
| | | | - Thaís Helena Gasparoto
- Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - Gustavo Pompermaier Garlet
- Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - João Santana Silva
- Department of Biochemistry and Immunology, School of Medicine of Ribeirão Preto - University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Carlos Ferreira Santos
- Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil
| | - Karen Angélica Cavassani
- Department of Medicine, Advanced Health Sciences Pavilion, Cedars Sinai Medical Center, Los Angeles, CA, USA
| | - Cory M Hogaboam
- Department of Medicine, Advanced Health Sciences Pavilion, Cedars Sinai Medical Center, Los Angeles, CA, USA
| | - Ana Paula Campanelli
- Department of Biological Sciences, Bauru School of Dentistry - University of São Paulo, Bauru, SP, Brazil.
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21
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Colvin BN, Longtine MS, Chen B, Costa ML, Nelson DM. Oleate attenuates palmitate-induced endoplasmic reticulum stress and apoptosis in placental trophoblasts. Reproduction 2017; 153:369-380. [PMID: 28159805 DOI: 10.1530/rep-16-0576] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/02/2016] [Accepted: 01/03/2017] [Indexed: 12/24/2022]
Abstract
Pre-pregnancy obesity is increasingly common and predisposes pregnant women and offspring to gestational diabetes, pre-eclampsia, fetal growth abnormalities and stillbirth. Obese women exhibit elevated levels of the two most common dietary fatty acids, palmitate and oleate, and the maternal blood containing these nutrients bathes the surface of trophoblasts of placental villi in vivo We test the hypothesis that the composition and concentration of free fatty acids modulate viability and function of primary human villous trophoblasts in culture. We found that palmitate increases syncytiotrophoblast death, specifically by caspase-mediated apoptosis, whereas oleate does not cause enhanced cell death. Importantly, exposure to both fatty acids in equimolar amounts yielded no increase in death or apoptosis, suggesting that oleate can protect syncytiotrophoblasts from palmitate-induced death. We further found that palmitate, but not oleate or oleate with palmitate, increases endoplasmic reticulum (ER) stress, signaling through the unfolded protein response, and yielding CHOP-mediated induction of apoptosis. Finally, we show that oleate or oleate plus palmitate both lead to increased lipid droplets in syncytiotrophoblasts, whereas palmitate does not. The data show palmitate is toxic to human syncytiotrophoblasts, through the induction of ER stress and apoptosis mediated by CHOP, whereas oleate is not toxic, abrogates palmitate toxicity and induces fat accumulation. We speculate that our in vitro results offer pathways by which the metabolic milieu of the obese pregnant woman can yield villous trophoblast dysfunction and sub-optimal placental function.
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Affiliation(s)
| | - Mark S Longtine
- Department of Obstetrics and GynecologyWashington University School of Medicine, St Louis, Missouri, USA
| | - Baosheng Chen
- Department of Obstetrics and GynecologyWashington University School of Medicine, St Louis, Missouri, USA
| | - Maria Laura Costa
- Department of Obstetrics and GynecologyWashington University School of Medicine, St Louis, Missouri, USA.,Department of Obstetrics and GynecologyUniversidade Estadual de Campinas, Cidade Universitaria Zeferino Vaz, Campinas, Brazil
| | - D Michael Nelson
- Department of Obstetrics and GynecologyWashington University School of Medicine, St Louis, Missouri, USA
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22
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Macrophage-like nanoparticles concurrently absorbing endotoxins and proinflammatory cytokines for sepsis management. Proc Natl Acad Sci U S A 2017; 114:11488-11493. [PMID: 29073076 DOI: 10.1073/pnas.1714267114] [Citation(s) in RCA: 335] [Impact Index Per Article: 47.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Sepsis, resulting from uncontrolled inflammatory responses to bacterial infections, continues to cause high morbidity and mortality worldwide. Currently, effective sepsis treatments are lacking in the clinic, and care remains primarily supportive. Here we report the development of macrophage biomimetic nanoparticles for the management of sepsis. The nanoparticles, made by wrapping polymeric cores with cell membrane derived from macrophages, possess an antigenic exterior the same as the source cells. By acting as macrophage decoys, these nanoparticles bind and neutralize endotoxins that would otherwise trigger immune activation. In addition, these macrophage-like nanoparticles sequester proinflammatory cytokines and inhibit their ability to potentiate the sepsis cascade. In a mouse Escherichia coli bacteremia model, treatment with macrophage mimicking nanoparticles, termed MΦ-NPs, reduced proinflammatory cytokine levels, inhibited bacterial dissemination, and ultimately conferred a significant survival advantage to infected mice. Employing MΦ-NPs as a biomimetic detoxification strategy shows promise for improving patient outcomes, potentially shifting the current paradigm of sepsis management.
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23
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Fang L, Hodge J, Saaoud F, Wang J, Iwanowycz S, Wang Y, Hui Y, Evans TD, Razani B, Fan D. Transcriptional factor EB regulates macrophage polarization in the tumor microenvironment. Oncoimmunology 2017. [PMID: 28638736 DOI: 10.1080/2162402x.2017.1312042] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Tumor microenvironment (TME) contains a variety of infiltrating immune cells. Among them, tumor-associated macrophages (TAMs) and their alternative activation contribute greatly to the progression of tumors. The mechanisms governing macrophage polarization in the TME are unclear. Here, we show that in TAMs or macrophages under tumor-conditioned medium treatment, the expression of transcription factor EB (TFEB) is reduced and more of the TFEB protein is in an inactive cytosolic form. Transforming growth factor (TGF)-β is identified as a main driving force for the reduced TFEB expression and activity in TAMs via activating ERK signaling. TFEB interference in macrophages significantly enhanced their alternative activation, with reduced expression of MHC-II and co-stimulatory molecule CD80, decreased ability to activate T cells, and increased ability to attract tumor cells. When co-inoculated with tumor cells, macrophages with TFEB knockdown significantly enhanced tumor growth with increased infiltration of M2-like macrophages, reduced infiltration of CD8+ T cells, and enhanced angiogenesis in the tumors. Mechanistic studies revealed that TFEB downregulation resulted in macrophage M2 polarization through reducing SOCS3 production and enhancing STAT3 activation. We further demonstrate that the activation of TFEB by hydroxypropyl-β-cyclodextrin in macrophages suppressed their M2 polarization and tumor-promoting capacity, and that macrophage-specific TFEB overexpression inhibited breast tumor growth in mice. Therefore, our data suggest that TFEB plays critical roles in macrophage polarization, and the downregulation of TFEB expression and activation is an integral part of tumor-induced immune editing in the TME. This study provides a rationale for a new cancer treatment strategy by modulating macrophage polarization through activating TFEB.
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Affiliation(s)
- Liang Fang
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA.,Department of Immunology, Fourth Military Medical University, Xi'an, China
| | - Johnie Hodge
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Fatma Saaoud
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Junfeng Wang
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Stephen Iwanowycz
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Yuzhen Wang
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Yvonne Hui
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
| | - Trent D Evans
- Cardiovascular Division, Department of Medicine and Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Babak Razani
- Cardiovascular Division, Department of Medicine and Department of Pathology & Immunology, Washington University School of Medicine, St. Louis, MO, USA
| | - Daping Fan
- Department of Cell Biology and Anatomy, University of South Carolina School of Medicine, Columbia, SC, USA
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24
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Bartlett JJ, Trivedi PC, Pulinilkunnil T. Autophagic dysregulation in doxorubicin cardiomyopathy. J Mol Cell Cardiol 2017; 104:1-8. [DOI: 10.1016/j.yjmcc.2017.01.007] [Citation(s) in RCA: 112] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 01/12/2017] [Accepted: 01/16/2017] [Indexed: 12/22/2022]
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25
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Zhang Y, Rao E, Zeng J, Hao J, Sun Y, Liu S, Sauter ER, Bernlohr DA, Cleary MP, Suttles J, Li B. Adipose Fatty Acid Binding Protein Promotes Saturated Fatty Acid-Induced Macrophage Cell Death through Enhancing Ceramide Production. THE JOURNAL OF IMMUNOLOGY 2016; 198:798-807. [PMID: 27920274 DOI: 10.4049/jimmunol.1601403] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 11/09/2016] [Indexed: 01/12/2023]
Abstract
Macrophages play a critical role in obesity-associated chronic inflammation and disorders. However, the molecular mechanisms underlying the response of macrophages to elevated fatty acids (FAs) and their contribution to metabolic inflammation in obesity remain to be fully elucidated. In this article, we report a new mechanism by which dietary FAs, in particular, saturated FAs (sFAs), are able to directly trigger macrophage cell death. We demonstrated that excess sFAs, but not unsaturated FAs, induced the production of cytotoxic ceramides (Cers) in macrophage cell lines. Most importantly, expression of adipose FA binding protein (A-FABP) in macrophages facilitated metabolism of excess sFAs for Cer synthesis. Inhibition or deficiency of A-FABP in macrophage cell lines decreased sFA-induced Cer production, thereby resulting in reduced cell death. Furthermore, we validated the role of A-FABP in promoting sFA-induced macrophage cell death with primary bone marrow-derived macrophages and high-fat diet-induced obese mice. Altogether, our data reveal that excess dietary sFAs may serve as direct triggers in induction of Cer production and macrophage cell death through elevated expression of A-FABP, thus establishing A-FABP as a new molecular sensor in triggering macrophage-associated sterile inflammation in obesity.
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Affiliation(s)
- Yuwen Zhang
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202
| | - Enyu Rao
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202
| | - Jun Zeng
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202
| | - Jiaqing Hao
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202
| | - Yanwen Sun
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202
| | - Shujun Liu
- The Hormel Institute, University of Minnesota, Austin, MN 55912
| | - Edward R Sauter
- Hartford Healthcare Cancer Institute, Hartford, CT 06103; and
| | - David A Bernlohr
- College of Biological Sciences, University of Minnesota, Minneapolis, MN 55455
| | - Margot P Cleary
- The Hormel Institute, University of Minnesota, Austin, MN 55912
| | - Jill Suttles
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202
| | - Bing Li
- Department of Microbiology and Immunology, University of Louisville, Louisville, KY 40202;
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Abstract
PURPOSE OF REVIEW Acute pancreatitis is a major cause of gastrointestinal morbidity for which specific therapy is greatly needed to prevent progression to and induce resolution of severe disease. RECENT FINDINGS Innate immune components and metabolite signaling are recently identified as strong determinants of disease severity and resolution in acute pancreatitis and this work will be discussed herein. SUMMARY Targeting innate immune cell populations and metabolite signaling pathways in acute pancreatitis may result in broader and ultimately more efficacious re-direction of the inflammatory programme toward disease resolution and improved clinical outcomes.
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27
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Pillon NJ, Chan KL, Zhang S, Mejdani M, Jacobson MR, Ducos A, Bilan PJ, Niu W, Klip A. Saturated fatty acids activate caspase-4/5 in human monocytes, triggering IL-1β and IL-18 release. Am J Physiol Endocrinol Metab 2016; 311:E825-E835. [PMID: 27624102 DOI: 10.1152/ajpendo.00296.2016] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Accepted: 09/11/2016] [Indexed: 12/14/2022]
Abstract
Obesity is associated with metabolic tissue infiltration by monocyte-derived macrophages. Saturated fatty acids contribute to proinflammatory gene induction in tissue-embedded immune cells. However, it is unknown how circulating monocytes, the macrophage precursors, react to high-fat environments. In macrophages, saturated fatty acids activate inflammatory pathways and, notably, prime caspase-associated inflammasomes. Inflammasome-activated IL-1β contributes to type 2 diabetes. We hypothesized that 1) human monocytes from obese patients show caspase activation, and 2) fatty acids trigger this response and consequent release of IL-1β/IL-18. Human peripheral blood monocytes were sorted by flow cytometry, and caspase activity was measured with a FLICA dye-based assay. Blood monocytes from obese individuals exhibited elevated caspase activity. To explore the nature and consequence of this activity, human THP1 monocytes were exposed to saturated or unsaturated fatty acids. Caspase activity was revealed by isoform-specific cleavage and enzymatic activity; cytokine expression/release was measured by qPCR and ELISA. Palmitate, but not palmitoleate, increased caspase activity in parallel to the release of IL-1β and IL-18. Palmitate induced eventual monocyte cell death with features of pyroptosis (an inflammation-linked cell death program involving caspase-4/5), scored through LDH release, vital dye influx, cell volume changes, and nuclear morphology. Notably, selective gene silencing or inhibition of caspase-4/5 reduced palmitate-induced release of IL-1β and IL-18. In summary, monocytes from obese individuals present elevated caspase activity. Mechanistically, palmitate activates a pyroptotic program in monocytes through caspase-4/5, causing inflammatory cytokine release, additional to inflammasomes. These caspases represent potential, novel, therapeutic targets to taper obesity-associated inflammation.
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Affiliation(s)
- Nicolas J Pillon
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Kenny L Chan
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Shitian Zhang
- Department of Immunology, Key Laboratory of Immuno Microenvironment and Disease of the Educational Ministry of China, Tianjin Medical University, Tianjin, China; and
| | - Marios Mejdani
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Maya R Jacobson
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Alexandre Ducos
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Philip J Bilan
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Wenyan Niu
- Department of Immunology, Key Laboratory of Immuno Microenvironment and Disease of the Educational Ministry of China, Tianjin Medical University, Tianjin, China; and
- Key Laboratory of Hormones and Development (Ministry of Health), Metabolic Diseases Hospital and Tianjin Institute of Endocrinology, Tianjin Medical University, Tianjin, China
| | - Amira Klip
- Program in Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada;
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28
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Trivedi PC, Bartlett JJ, Perez LJ, Brunt KR, Legare JF, Hassan A, Kienesberger PC, Pulinilkunnil T. Glucolipotoxicity diminishes cardiomyocyte TFEB and inhibits lysosomal autophagy during obesity and diabetes. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1893-1910. [PMID: 27620487 DOI: 10.1016/j.bbalip.2016.09.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/05/2016] [Accepted: 09/07/2016] [Indexed: 01/07/2023]
Abstract
Impaired cardiac metabolism in the obese and diabetic heart leads to glucolipotoxicity and ensuing cardiomyopathy. Glucolipotoxicity causes cardiomyocyte injury by increasing energy insufficiency, impairing proteasomal-mediated protein degradation and inducing apoptosis. Proteasome-evading proteins are degraded by autophagy in the lysosome, whose metabolism and function are regulated by master regulator transcription factor EB (TFEB). Limited studies have examined the impact of glucolipotoxicity on intra-lysosomal signaling proteins and their regulators. By utilizing a mouse model of diet-induced obesity, type-1 diabetes (Akita) and ex-vivo model of glucolipotoxicity (H9C2 cells and NRCM, neonatal rat cardiomyocyte), we examined whether glucolipotoxicity negatively targets TFEB and lysosomal proteins to dysregulate autophagy and cause cardiac injury. Despite differential effects of obesity and diabetes on LC3B-II, expression of proteins facilitating autophagosomal clearance such as TFEB, LAMP-2A, Hsc70 and Hsp90 were decreased in the obese and diabetic heart. In-vivo data was recapitulated in H9C2 and NRCM cells, which exhibited impaired autophagic flux and reduced TFEB content when exposed to a glucolipotoxic milieu. Notably, overloading myocytes with a saturated fatty acid (palmitate) but not an unsaturated fatty acid (oleate) depleted cellular TFEB and suppressed autophagy, suggesting a fatty acid specific regulation of TFEB and autophagy in the cardiomyocyte. The effect of glucolipotoxicity to reduce TFEB content was also confirmed in heart tissue from patients with Class-I obesity. Therefore, during glucolipotoxicity, suppression of lysosomal autophagy was associated with reduced lysosomal content, decreased cathepsin-B activity and diminished cellular TFEB content likely rendering myocytes susceptible to cardiac injury.
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Affiliation(s)
- Purvi C Trivedi
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada
| | - Jordan J Bartlett
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada
| | - Lester J Perez
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada
| | - Keith R Brunt
- Deparment of Pharmacology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada
| | - Jean Francois Legare
- Department of Surgery, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada
| | - Ansar Hassan
- Department of Surgery, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada
| | - Petra C Kienesberger
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada
| | - Thomas Pulinilkunnil
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, Dalhousie University, Dalhousie Medicine New Brunswick, 100 Tucker Park Road, Saint John E2L4L5, New Brunswick, Canada.
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29
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Namgaladze D, Brüne B. Macrophage fatty acid oxidation and its roles in macrophage polarization and fatty acid-induced inflammation. Biochim Biophys Acta Mol Cell Biol Lipids 2016; 1861:1796-1807. [PMID: 27614008 DOI: 10.1016/j.bbalip.2016.09.002] [Citation(s) in RCA: 92] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 08/26/2016] [Accepted: 09/02/2016] [Indexed: 12/14/2022]
Abstract
Recent research considerably changed our knowledge how cellular metabolism affects the immune system. We appreciate that metabolism not only provides energy to immune cells, but also actively influences diverse immune cell phenotypes. Fatty acid metabolism, particularly mitochondrial fatty acid oxidation (FAO) emerges as an important regulator of innate and adaptive immunity. Catabolism of fatty acids also modulates the progression of disease, such as the development of obesity-driven insulin resistance and type II diabetes. Here, we summarize (i) recent developments in research how FAO modulates inflammatory signatures in macrophages in response to saturated fatty acids, and (ii) the role of FAO in regulating anti-inflammatory macrophage polarization. In addition, we define the contribution of AMP-activated protein kinase (AMPK) and peroxisome proliferator-activated receptors (PPARs), in controlling macrophage biology towards fatty acid metabolism and inflammation.
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Affiliation(s)
- Dmitry Namgaladze
- Goethe-University Frankfurt, Faculty of Medicine, Institute of Biochemistry I, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany.
| | - Bernhard Brüne
- Goethe-University Frankfurt, Faculty of Medicine, Institute of Biochemistry I, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
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30
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He L, Weber KJ, Diwan A, Schilling JD. Inhibition of mTOR reduces lipotoxic cell death in primary macrophages through an autophagy-independent mechanism. J Leukoc Biol 2016; 100:1113-1124. [PMID: 27312848 DOI: 10.1189/jlb.3a1015-463r] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 06/01/2016] [Indexed: 12/14/2022] Open
Abstract
Macrophage dysfunction in obesity and diabetes is associated with persistent inflammation and poor wound healing responses. Relevant to these phenotypes, we have previously shown that macrophage activation in a high-fat environment results in cell death via a mechanism that involves lysosome damage. While searching for signaling pathways that were required for this response, we discovered that mTOR inhibitors, torin and rapamycin, were protective against lipotoxic cell death in primary peritoneal macrophages. The protective effect of mTOR inhibition was also confirmed by using genetic loss-of-function approaches. Given the importance of mTOR in regulation of autophagy we hypothesized that this pathway would be important in protection from cell death. We first demonstrated that autophagy was disrupted in response to palmitate and LPS as a consequence of impaired lysosome function. Conversely, the mTOR inhibitor, torin, increased macrophage autophagy and protected against lysosome damage; however, the beneficial effects of torin persisted in autophagy-deficient cells. Inhibition of mTOR also triggered nuclear localization of TFEB, a transcription factor that regulates lysosome biogenesis and function, but the rescue phenotype did not require the presence of TFEB. Instead, we demonstrated that mTOR inhibition reduces mitochondrial oxidative metabolism and attenuates the negative effects of palmitate on LPS-induced mitochondrial respiration. These results suggest that inhibition of mTOR is protective against lipotoxicity via an autophagy-independent mechanism that involves relieving mitochondrial substrate overload. On the basis of these findings, we suggest that therapies to reduce macrophage mTOR activation may protect against dysfunctional inflammation in states of overnutrition, such as diabetes.
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Affiliation(s)
- Li He
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA; and
| | - Kassandra J Weber
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA; and
| | - Abhinav Diwan
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, Missouri, USA.,Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA; and
| | - Joel D Schilling
- Diabetic Cardiovascular Disease Center, Washington University School of Medicine, St. Louis, Missouri, USA; .,Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA; and.,Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
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31
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Abstract
In recent years, our vision of lysosomes has drastically changed. Formerly considered to be mere degradative compartments, they are now recognized as key players in many cellular processes. The ability of lysosomes to respond to different stimuli revealed a complex and coordinated regulation of lysosomal gene expression. This review discusses the participation of the transcription factors TFEB and TFE3 in the regulation of lysosomal function and biogenesis, as well as the role of the lysosomal pathway in cellular adaptation to a variety of stress conditions, including nutrient deprivation, mitochondrial dysfunction, protein misfolding, and pathogen infection. We also describe how cancer cells make use of TFEB and TFE3 to promote their own survival and highlight the potential of these transcription factors as therapeutic targets for the treatment of neurological and lysosomal diseases.
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Affiliation(s)
- Nina Raben
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, Maryland 20892;
| | - Rosa Puertollano
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892;
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32
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Glutamine Modulates Macrophage Lipotoxicity. Nutrients 2016; 8:215. [PMID: 27077881 PMCID: PMC4848684 DOI: 10.3390/nu8040215] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Revised: 03/24/2016] [Accepted: 04/06/2016] [Indexed: 12/01/2022] Open
Abstract
Obesity and diabetes are associated with excessive inflammation and impaired wound healing. Increasing evidence suggests that macrophage dysfunction is responsible for these inflammatory defects. In the setting of excess nutrients, particularly dietary saturated fatty acids (SFAs), activated macrophages develop lysosome dysfunction, which triggers activation of the NLRP3 inflammasome and cell death. The molecular pathways that connect lipid stress to lysosome pathology are not well understood, but may represent a viable target for therapy. Glutamine uptake is increased in activated macrophages leading us to hypothesize that in the context of excess lipids glutamine metabolism could overwhelm the mitochondria and promote the accumulation of toxic metabolites. To investigate this question we assessed macrophage lipotoxicity in the absence of glutamine using LPS-activated peritoneal macrophages exposed to the SFA palmitate. We found that glutamine deficiency reduced lipid induced lysosome dysfunction, inflammasome activation, and cell death. Under glutamine deficient conditions mTOR activation was decreased and autophagy was enhanced; however, autophagy was dispensable for the rescue phenotype. Rather, glutamine deficiency prevented the suppressive effect of the SFA palmitate on mitochondrial respiration and this phenotype was associated with protection from macrophage cell death. Together, these findings reveal that crosstalk between activation-induced metabolic reprogramming and the nutrient microenvironment can dramatically alter macrophage responses to inflammatory stimuli.
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33
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Demir S, Özer S, Alim S, Güneş A, Ortak H, Yılmaz R. Retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness in children with obesity. Int J Ophthalmol 2016; 9:434-8. [PMID: 27158616 DOI: 10.18240/ijo.2016.03.19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/07/2016] [Indexed: 12/27/2022] Open
Abstract
AIM To evaluate retinal nerve fiber layer (RNFL) thickness analysis of peripapillary optic nerve head (PONH) and macula as well as ganglion cell-inner plexiform layer (GCIPL) thickness in obese children. METHODS Eighty-five children with obesity and 30 controls were included in the study. The thicknesses of the PONH and macula of each subject's right eye were measured by high-resolution spectral-domain optic coherence tomography (OCT). RESULTS The RNFL thicknesses of central macular and PONH were similar between the groups (all P>0.05). The GCIPL thickness was also similar between the groups. However, the RNFL thickness of temporal outer macula were 261.7±13.7 and 268.9±14.3 µm for the obesity and the control group, respectively (P=0.034). CONCLUSION Obesity may cause a reduction in temporal outer macular RNFL thickness.
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Affiliation(s)
- Selim Demir
- Department of Ophthalmology, Faculty of Medicine, Gaziosmanpasa University, Tokat 60030, Turkey
| | - Samet Özer
- Department of Pediatrics, Faculty of Medicine, Gaziosmanpasa University, Tokat 60030, Turkey
| | - Sait Alim
- Department of Ophthalmology, Faculty of Medicine, Gaziosmanpasa University, Tokat 60030, Turkey
| | - Alper Güneş
- Department of Ophthalmology, Faculty of Medicine, Gaziosmanpasa University, Tokat 60030, Turkey
| | - Hüseyin Ortak
- Department of Ophthalmology, Faculty of Medicine, Gaziosmanpasa University, Tokat 60030, Turkey
| | - Resul Yılmaz
- Department of Pediatrics, Faculty of Medicine, Gaziosmanpasa University, Tokat 60030, Turkey
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34
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Magtanong L, Ko PJ, Dixon SJ. Emerging roles for lipids in non-apoptotic cell death. Cell Death Differ 2016; 23:1099-109. [PMID: 26967968 PMCID: PMC5399169 DOI: 10.1038/cdd.2016.25] [Citation(s) in RCA: 173] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/08/2016] [Accepted: 02/10/2016] [Indexed: 12/12/2022] Open
Abstract
Non-apoptotic regulated cell death (RCD) is essential to maintain organismal homeostasis and may be aberrantly activated during certain pathological states. Lipids are emerging as key components of several non-apoptotic RCD pathways. For example, a direct interaction between membrane phospholipids and the pore-forming protein mixed lineage kinase domain-like (MLKL) is needed for the execution of necroptosis, while the oxidative destruction of membrane polyunsaturated fatty acids (PUFAs), following the inactivation of glutathione peroxidase 4 (GPX4), is a requisite gateway to ferroptosis. Here, we review the roles of lipids in the initiation and execution of these and other forms of non-apoptotic cell death. We also consider new technologies that are allowing for the roles of lipids and lipid metabolism in RCD to be probed in increasingly sophisticated ways. In certain cases, this new knowledge may enable the development of therapies that target lipids and lipid metabolic processes to enhance or suppress specific non-apoptotic RCD pathways.
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Affiliation(s)
- L Magtanong
- Department of Biology, Stanford University, 337 Campus Drive, Stanford, CA, USA
| | - P J Ko
- Department of Biology, Stanford University, 337 Campus Drive, Stanford, CA, USA
| | - S J Dixon
- Department of Biology, Stanford University, 337 Campus Drive, Stanford, CA, USA
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35
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Jo EK, Kim JK, Shin DM, Sasakawa C. Molecular mechanisms regulating NLRP3 inflammasome activation. Cell Mol Immunol 2015; 13:148-59. [PMID: 26549800 DOI: 10.1038/cmi.2015.95] [Citation(s) in RCA: 929] [Impact Index Per Article: 103.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 10/14/2015] [Accepted: 10/14/2015] [Indexed: 02/06/2023] Open
Abstract
Inflammasomes are multi-protein signaling complexes that trigger the activation of inflammatory caspases and the maturation of interleukin-1β. Among various inflammasome complexes, the NLRP3 inflammasome is best characterized and has been linked with various human autoinflammatory and autoimmune diseases. Thus, the NLRP3 inflammasome may be a promising target for anti-inflammatory therapies. In this review, we summarize the current understanding of the mechanisms by which the NLRP3 inflammasome is activated in the cytosol. We also describe the binding partners of NLRP3 inflammasome complexes activating or inhibiting the inflammasome assembly. Our knowledge of the mechanisms regulating NLRP3 inflammasome signaling and how these influence inflammatory responses offers further insight into potential therapeutic strategies to treat inflammatory diseases associated with dysregulation of the NLRP3 inflammasome.
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Affiliation(s)
- Eun-Kyeong Jo
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 301-747, South Korea.,Infection Signaling Network Research Center, Chungnam National University School of Medicine, Daejeon 301-747, South Korea
| | - Jin Kyung Kim
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 301-747, South Korea.,Infection Signaling Network Research Center, Chungnam National University School of Medicine, Daejeon 301-747, South Korea
| | - Dong-Min Shin
- Department of Microbiology, Chungnam National University School of Medicine, Daejeon 301-747, South Korea.,Infection Signaling Network Research Center, Chungnam National University School of Medicine, Daejeon 301-747, South Korea
| | - Chihiro Sasakawa
- Medical Mycology Research Center, Chiba University, Chiba 260-8673, Japan.,Nippon Institute for Biological Science, Tokyo 198-0024, Japan
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36
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The C-terminal Domain Supports a Novel Function for CETPI as a New Plasma Lipopolysaccharide-Binding Protein. Sci Rep 2015; 5:16091. [PMID: 26537318 PMCID: PMC4633601 DOI: 10.1038/srep16091] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Accepted: 10/08/2015] [Indexed: 12/22/2022] Open
Abstract
Described by our group a few years ago, the cholesteryl-ester transfer protein isoform (CETPI), exclusively expressed in the small intestine and present in human plasma, lacked a functional identification for a role of physiological relevance. Now, this study introduces CETPI as a new protein with the potential capability to recognise, bind and neutralise lipopolysaccharides (LPS). Peptides derived from the C-terminal domain of CETPI showed that CETPI not only might interact with several LPS serotypes but also might displace LPS bound to the surface of cells. Peptide VSAK, derived from the last 18 residues of CETPI, protected against the cytotoxic effect of LPS on macrophages. At high concentrations, when different cell types were tested in culture, it did not exhibit cytotoxicity by itself and it did prevent the expression of pro-inflammatory cytokines as well as the generation of oxidative stress conditions. In a rabbit model of septic shock, the infusion of peptide VSAK exerted a protective effect against the effects of LPS and reduced the presence of tumor necrosis factor-alpha (TNFα) in plasma. Therefore, CETPI is proposed as a new protein with the capability to advance the possibilities for better understanding and treatment of the dangerous effects of LPS in vivo.
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37
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Abstract
Peripheral and CNS inflammation leads to aberrations in developmental and postnatal neurogenesis, yet little is known about the mechanism linking inflammation to neurogenic abnormalities. Specific miRs regulate peripheral and CNS inflammatory responses. miR-155 is the most significantly upregulated miR in primary murine microglia stimulated with lipopolysaccharide (LPS), a proinflammatory Toll-Like Receptor 4 ligand. Here, we demonstrate that miR-155 is essential for robust IL6 gene induction in microglia under LPS stimulation in vitro. LPS-stimulated microglia enhance astrogliogenesis of cocultured neural stem cells (NSCs), whereas blockade of IL6 or genetic ablation of microglial miR-155 restores neural differentiation. miR-155 knock-out mice show reversal of LPS-induced neurogenic deficits and microglial activation in vivo. Moreover, mice with transgenic elevated expression of miR-155 in nestin-positive neural and hematopoietic stem cells, including microglia, show increased cell proliferation and ectopically localized doublecortin-positive immature neurons and radial glia-like cells in the hippocampal dentate gyrus (DG) granular cell layer. Microglia have proliferative and neurogenic effects on NSCs, which are significantly altered by microglial miR-155 overexpression. In addition, miR-155 elevation leads to increased microglial numbers and amoeboid morphology in the DG. Our study demonstrates that miR-155 is essential for inflammation-induced neurogenic deficits via microglial activation and induction of IL6 and is sufficient for disrupting normal hippocampal development.
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Nature and nurture in atherosclerosis: The roles of acylcarnitine and cell membrane-fatty acid intermediates. Vascul Pharmacol 2015; 78:17-23. [PMID: 26133667 DOI: 10.1016/j.vph.2015.06.012] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 06/26/2015] [Accepted: 06/27/2015] [Indexed: 12/22/2022]
Abstract
Macrophages recycle components of dead cells, including cell membranes. When quantities of lipids from cell membranes of dead cells exceed processing capacity, phospholipid and cholesterol debris accumulate as atheromas. Plasma lipid profiles, particularly HDL and LDL cholesterol, are important tools to monitor atherosclerosis risk. Membrane lipids are exported, as triglycerides or phospholipids, or as cholesterol or cholesterol esters, via lipoproteins for disposal, for re-use in cell membranes, or for fat storage. Alternative assays evaluate other aspects of lipid pathology. A key process underlying atherosclerosis is backup of macrophage fatty acid catabolism. This can be quantified by accumulation of acylcarnitine intermediates in extracellular fluid, a direct assay of adequacy of β-oxidation to deal with membrane fatty acid recycling. Further, membranes of somatic cells, such as red blood cells (RBC), incorporate fatty acids that reflect dietary intake. Changes in RBC lipid composition occur within days of ingesting modified fats. Since diets with high saturated fat content or artificial trans-fatty acids promote atherosclerosis, RBC lipid content shifts occur with atherosclerosis, and can show cellular adaptation to pathologically stiff membranes by increased long-chain doubly unsaturated fatty acid production. Additional metabolic changes with atherosclerosis of potential utility include inflammatory cytokine production, modified macrophage signaling pathways, and altered lipid-handling enzymes. Even after atherosclerotic lesions appear, approaches to minimize macrophage overload by reducing rate of fat metabolism are promising. These include preventive measures, and drugs including statins and the newer PCSK9 inhibitors. New cell-based biochemical and cytokine assays provide data to prevent or monitor atherosclerosis progression.
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Shaikh SR, Haas KM, Beck MA, Teague H. The effects of diet-induced obesity on B cell function. Clin Exp Immunol 2015; 179:90-9. [PMID: 25169121 DOI: 10.1111/cei.12444] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/20/2014] [Indexed: 12/12/2022] Open
Abstract
B-1 and B-2 B cell subsets carry out a diverse array of functions that range broadly from responding to innate stimuli, antigen presentation, cytokine secretion and antibody production. In this review, we first cover the functional roles of the major murine B cell subsets. We then highlight emerging evidence, primarily in preclinical rodent studies, to show that select B cell subsets are a therapeutic target in obesity and its associated co-morbidities. High fat diets promote accumulation of select murine B cell phenotypes in visceral adipose tissue. As a consequence, B cells exacerbate inflammation and thereby insulin sensitivity through the production of autoantibodies and via cross-talk with select adipose resident macrophages, CD4(+) and CD8(+) T cells. In contrast, interleukin (IL)-10-secreting regulatory B cells counteract the proinflammatory profile and improve glucose sensitivity. We subsequently review data from rodent studies that show pharmacological supplementation of obesogenic diets with long chain n-3 polyunsaturated fatty acids or specialized pro-resolving lipid mediators synthesized from endogenous n-3 polyunsaturated fatty acids boost B cell activation and antibody production. This may have potential benefits for improving inflammation in addition to combating the increased risk of viral infection that is an associated complication of obesity and type II diabetes. Finally, we propose potential underlying mechanisms throughout the review by which B cell activity could be differentially regulated in response to high fat diets.
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Affiliation(s)
- S R Shaikh
- Department of Biochemistry and Molecular Biology, East Carolina Diabetes and Obesity Institute, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC, USA; Department of Microbiology and Immunology, East Carolina Diabetes and Obesity Institute, East Carolina Heart Institute, Brody School of Medicine, East Carolina University, Greenville, NC, USA
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40
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Cheng X, Gao DX, Song JJ, Ren FZ, Mao XY. Casein glycomacropeptide hydrolysate exerts cytoprotection against H2O2-induced oxidative stress in RAW 264.7 macrophages via ROS-dependent heme oxygenase-1 expression. RSC Adv 2015. [DOI: 10.1039/c4ra10034d] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Casein glycomacropeptide hydrolysate had antioxidant activity and exerted protective actions against H2O2-induced oxidative stress via induction of Nrf2-mediated HO-1 expression in RAW 264.7 macrophages.
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Affiliation(s)
- Xue Cheng
- Key Laboratory of Functional Dairy
- College of Food Science and Nutritional Engineering
- China Agricultural University
- Beijing
- P. R. China
| | - Dong-Xiao Gao
- Key Laboratory of Functional Dairy
- College of Food Science and Nutritional Engineering
- China Agricultural University
- Beijing
- P. R. China
| | - Jia-Jia Song
- Key Laboratory of Functional Dairy
- College of Food Science and Nutritional Engineering
- China Agricultural University
- Beijing
- P. R. China
| | - Fa-Zheng Ren
- Key Laboratory of Functional Dairy
- College of Food Science and Nutritional Engineering
- China Agricultural University
- Beijing
- P. R. China
| | - Xue-Ying Mao
- Key Laboratory of Functional Dairy
- College of Food Science and Nutritional Engineering
- China Agricultural University
- Beijing
- P. R. China
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41
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Distinct lysosome phenotypes influence inflammatory function in peritoneal and bone marrow-derived macrophages. Int J Inflam 2014; 2014:154936. [PMID: 25587484 PMCID: PMC4284938 DOI: 10.1155/2014/154936] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 12/09/2014] [Indexed: 01/30/2023] Open
Abstract
Lysosomes play a critical role in the degradation of both extracellular and intracellular material. These dynamic organelles also contribute to nutrient sensing and cell signaling pathways. Macrophages represent a heterogeneous group of phagocytic cells that contribute to tissue homeostasis and inflammation. Recently, there has been a renewed interest in understanding the role of macrophage autophagy and lysosome function in health and disease. Thioglycollate-elicited peritoneal and bone marrow-derived macrophages are commonly used ex vivo systems to study primary macrophage function. In this study, we reveal dramatic baseline differences in the lysosome morphology and function between these macrophage populations and provide evidence that these differences can be functionally relevant. Our results provide important insights into the diversity of lysosomes in primary macrophages and illustrate the importance of accounting for this in data interpretation.
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Schilling JD, Mann DL. Diabetic Cardiomyopathy: Distinct and Preventable Entity or Inevitable Consequence? CURRENT CARDIOVASCULAR RISK REPORTS 2014. [DOI: 10.1007/s12170-014-0417-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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43
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Guo H, Jin D, Chen X. Lipocalin 2 is a regulator of macrophage polarization and NF-κB/STAT3 pathway activation. Mol Endocrinol 2014; 28:1616-28. [PMID: 25127375 DOI: 10.1210/me.2014-1092] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Lipocalin 2 (Lcn2) has been previously characterized as an adipokine/cytokine and implicated in obesity and inflammation. Herein, we investigated the role and potential mechanism of Lcn2 in the regulation of macrophage polarization in obesity-associated inflammation. We observed that Lcn2-/- mice displayed an up-regulation of expression of M1 macrophage marker Cd11c but a down-regulation of M2 marker arginase 1 in adipose tissue and liver of mice upon a high-fat diet feeding. Lcn2-deficient bone marrow-derived macrophages (BMDMs) were more sensitive to lipopolysaccharide (LPS) stimulation, leading to a more profound up-regulation of expression of pro-inflammatory markers than wild-type (WT) BMDMs. Accordingly, LPS stimulation elicited an increase in the activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), c-Jun, and STAT3 signaling pathways as well as an up-regualtion of expression of NF-κB and STAT3 target genes such as IL-1β, IL-6, iNOS, and MCP-1 in Lcn2-/- BMDMs compared with WT controls. Pre-treatment of recombinant Lcn2 attenuated LPS-stimulated degradation of IκBα and STAT3 phosphorylation as well as LPS-induced gene expression of IL-6 and iNOS in Lcn2-/- BMDMs. Moreover, the NFκB inhibitor markedly blocked LPS-stimulated STAT3 phosphorylation in Lcn2-/- BMDMs. These results together with the time course of Lcn2 secretion, NFκB and STAT3 phosphorylation in response to LPS stimulation, suggest that Lcn2 plays a role as an anti-inflammatory regulator in macrophage activation via modulating a feed-forward activation of NFκB-STAT3 loop.
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Affiliation(s)
- Hong Guo
- Department of Food Science and Nutrition, University of Minnesota-Twin Cities, Saint Paul, Minnesota 55108
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44
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Jung ID, Shin SJ, Lee MG, Kang TH, Han HD, Lee SJ, Kim WS, Kim HM, Park WS, Kim HW, Yun CH, Lee EK, Wu TC, Park YM. Enhancement of tumor-specific T cell-mediated immunity in dendritic cell-based vaccines by Mycobacterium tuberculosis heat shock protein X. THE JOURNAL OF IMMUNOLOGY 2014; 193:1233-45. [PMID: 24990079 DOI: 10.4049/jimmunol.1400656] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Despite the potential for stimulation of robust antitumor immunity by dendritic cells (DCs), clinical applications of DC-based immunotherapy are limited by the low potency in generating tumor Ag-specific T cell responses. Therefore, optimal conditions for generating potent immunostimulatory DCs that overcome tolerance and suppression are key factors in DC-based tumor immunotherapy. In this study, we demonstrate that use of the Mycobacterium tuberculosis heat shock protein X (HspX) as an immunoadjuvant in DC-based tumor immunotherapy has significant potential in therapeutics. In particular, the treatment aids the induction of tumor-reactive T cell responses, especially tumor-specific CTLs. The HspX protein induces DC maturation and proinflammatory cytokine production (TNF-α, IL-1β, IL-6, and IFN-β) through TLR4 binding partially mediated by both the MyD88 and the TRIF signaling pathways. We employed two models of tumor progression and metastasis to evaluate HspX-stimulated DCs in vivo. The administration of HspX-stimulated DCs increased the activation of naive T cells, effectively polarizing the CD4(+) and CD8(+) T cells to secrete IFN-γ, as well as enhanced the cytotoxicity of splenocytes against HPV-16 E7 (E7)-expressing TC-1 murine tumor cells in therapeutic experimental animals. Moreover, the metastatic capacity of B16-BL6 melanoma cancer cells toward the lungs was remarkably attenuated in mice that received HspX-stimulated DCs. In conclusion, the high therapeutic response rates with tumor-targeted Th1-type T cell immunity as a result of HspX-stimulated DCs in two models suggest that HspX harnesses the exquisite immunological power and specificity of DCs for the treatment of tumors.
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Affiliation(s)
- In Duk Jung
- Department of Immunology, Laboratory of Dendritic Cell Differentiation and Regulation, School of Medicine, Konkuk University, Chungju 380-701, South Korea
| | - Sung Jae Shin
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Min-Goo Lee
- Department of Physiology, College of Medicine, Korea University, Seoul 136-705, South Korea
| | - Tae Heung Kang
- Department of Immunology, Laboratory of Dendritic Cell Differentiation and Regulation, School of Medicine, Konkuk University, Chungju 380-701, South Korea
| | - Hee Dong Han
- Department of Immunology, Laboratory of Dendritic Cell Differentiation and Regulation, School of Medicine, Konkuk University, Chungju 380-701, South Korea
| | - Seung Jun Lee
- Department of Immunology, Laboratory of Dendritic Cell Differentiation and Regulation, School of Medicine, Konkuk University, Chungju 380-701, South Korea
| | - Woo Sik Kim
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Hong Min Kim
- Department of Microbiology, Institute for Immunology and Immunological Diseases, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, South Korea
| | - Won Sun Park
- Department of Physiology, School of Medicine, Kangwon National University, Chuncheon 200-701, South Korea
| | - Han Wool Kim
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, South Korea; Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, South Korea
| | - Cheol-Heui Yun
- Department of Agricultural Biotechnology, Seoul National University, Seoul 151-921, South Korea; Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, South Korea
| | - Eun Kyung Lee
- Yongsan Hospital College of Medicine, Chung-Ang University, Seoul 156-756, South Korea
| | - T-C Wu
- Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, MD 21205; Department of Obstetrics and Gynecology, Johns Hopkins Medical Institutions, Baltimore, MD 21205; Department of Molecular Microbiology and Immunology, Johns Hopkins Medical Institutions, Baltimore, MD 21205; and Department of Oncology, Johns Hopkins Medical Institutions, Baltimore, MD 21205
| | - Yeong-Min Park
- Department of Immunology, Laboratory of Dendritic Cell Differentiation and Regulation, School of Medicine, Konkuk University, Chungju 380-701, South Korea;
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Beneficial Effects of Fractions of Nardostachys jatamansi on Lipopolysaccharide-Induced Inflammatory Response. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2014; 2014:837835. [PMID: 24795771 PMCID: PMC3985203 DOI: 10.1155/2014/837835] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 02/28/2014] [Accepted: 03/03/2014] [Indexed: 12/02/2022]
Abstract
It has been previously shown that Nardostachys jatamansi (NJ) exhibits anti-inflammatory properties against lipopolysaccharide (LPS) challenges. However, the potency of NJ constituents against LPS-induced inflammatory responses has not been examined. In this present study, we determined which NJ extract fractions exhibit inhibitory effects against LPS-induced inflammatory responses. Among the NJ fractions, NJ-1, NJ-3, NJ-4, and NJ-6 inhibited LPS-induced production of NO. The NJ-3, NJ-4, and NJ-6 fractions also inhibited the production of cytokines, such as IL-1β, IL-6, and TNF-α. However, NJ-1, NJ-3, NJ-4, and NJ-6 showed differential inhibitory mechanisms against LPS-induced inflammatory responses. NJ-1, NJ-3, and NJ-4 inhibited LPS-induced activation of c-jun NH2-terminal kinase (JNK) and p38 but did not affect activation of extracellular signal-regulated kinase (ERK) or NF-κB. On the other hand, NJ-6 inhibited activation of MAPKs and NF-κB. In addition, in vivo experiments revealed that administration of NJ-1, NJ-3, NJ-4, and NJ-6 reduced LPS-induced endotoxin shock, with NJ-6 especially showing a marked protective effect. Taken together, these results provide the evidence for the potential of selective NJ fractions against LPS-induced inflammation. Thus, it will be advantageous to further isolate and determine single effective compounds from these potent fractions.
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Weber K, Schilling JD. Lysosomes integrate metabolic-inflammatory cross-talk in primary macrophage inflammasome activation. J Biol Chem 2014; 289:9158-71. [PMID: 24532802 DOI: 10.1074/jbc.m113.531202] [Citation(s) in RCA: 97] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Macrophage dysfunction and inflammasome activation have been implicated in the pathogenesis of diabetes and its complications. Prolonged inflammation and impaired healing are hallmarks of the diabetic response to tissue injury, and excessive inflammasome activation has been associated in these phenotypes. However, the mechanisms that regulate the inflammasome in response to lipid metabolic and inflammatory stress are incompletely understood. We have shown previously that IL-1β secretion is induced in primary macrophages exposed to the dietary saturated fatty acid palmitate in combination with LPS. In this study, we sought to unravel the mechanisms underlying the activation of this lipotoxic inflammasome. We demonstrate that palmitate-loaded primary macrophages challenged with LPS activate the NLRP3 inflammasome through a mechanism that involves the lysosome. Interestingly, the lysosome was involved in both the regulation of pro-IL-1β levels and its subsequent cleavage/release. The lysosomal protease cathepsin B was required for IL-1β release but not pro-IL-1β production. In contrast, disrupting lysosomal calcium regulation decreased IL-1β release by reducing pro-IL-1β levels. The calcium pathway involved the calcium-activated phosphatase calcineurin, which stabilized IL-1β mRNA. Our findings provide evidence that the lysosome plays a key role in both the priming and assembly phases of the lipostoxic inflammasome. These findings have potential relevance to the hyperinflammatory phenotypes observed in diabetics during tissue damage or infection and identify lysosomes and calcineurin as potential therapeutic targets.
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