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Tu Y, Yang Q, Tang M, Gao L, Wang Y, Wang J, Liu Z, Li X, Mao L, Jia RZ, Wang Y, Tang TS, Xu P, Liu Y, Dai L, Jia D. TBC1D23 mediates Golgi-specific LKB1 signaling. Nat Commun 2024; 15:1785. [PMID: 38413626 PMCID: PMC10899256 DOI: 10.1038/s41467-024-46166-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 02/13/2024] [Indexed: 02/29/2024] Open
Abstract
Liver kinase B1 (LKB1), an evolutionarily conserved serine/threonine kinase, is a master regulator of the AMPK subfamily and controls cellular events such as polarity, proliferation, and energy homeostasis. Functions and mechanisms of the LKB1-AMPK axis at specific subcellular compartments, such as lysosome and mitochondria, have been established. AMPK is known to be activated at the Golgi; however, functions and regulatory mechanisms of the LKB1-AMPK axis at the Golgi apparatus remain elusive. Here, we show that TBC1D23, a Golgi-localized protein that is frequently mutated in the neurodevelopment disorder pontocerebellar hypoplasia (PCH), is specifically required for the LKB1 signaling at the Golgi. TBC1D23 directly interacts with LKB1 and recruits LKB1 to Golgi, promoting Golgi-specific activation of AMPK upon energy stress. Notably, Golgi-targeted expression of LKB1 rescues TBC1D23 deficiency in zebrafish models. Furthermore, the loss of LKB1 causes neurodevelopmental abnormalities in zebrafish, which partially recapitulates defects in TBC1D23-deficient zebrafish, and LKB1 sustains normal neuronal development via TBC1D23 interaction. Our study uncovers a regulatory mechanism of the LKB1 signaling, and reveals that a disrupted Golgi-LKB1 signaling underlies the pathogenesis of PCH.
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Affiliation(s)
- Yingfeng Tu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Qin Yang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Min Tang
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Li Gao
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Yuanhao Wang
- State Key Laboratory of Reproductive Medicine, Interdisciplinary InnoCenter for Organoids, Institute for Stem Cell and Neural Regeneration, School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Jiuqiang Wang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
- Binzhou Medical University, Yantai, 264003, China
| | - Zhe Liu
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Xiaoyu Li
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Lejiao Mao
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Rui Zhen Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China
| | - Yuan Wang
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Tie-Shan Tang
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- Beijing Institute for Stem Cell and Regenerative Medicine, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Pinglong Xu
- The MOE Key Laboratory of Biosystems Homeostasis & Protection and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, 310058, China
| | - Yan Liu
- State Key Laboratory of Reproductive Medicine, Interdisciplinary InnoCenter for Organoids, Institute for Stem Cell and Neural Regeneration, School of Pharmacy, Nanjing Medical University, Nanjing, China
| | - Lunzhi Dai
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Da Jia
- Key Laboratory of Birth Defects and Related Diseases of Women and Children, Department of Paediatrics, West China Second University Hospital, State Key Laboratory of Biotherapy, Sichuan University, Chengdu, 610041, China.
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Cantacorps L, Zhu J, Yagoub S, Coull BM, Falck J, Chesters RA, Ritter K, Serrano-Lope M, Tscherepentschuk K, Kasch LS, Paterson M, Täger P, Baidoe-Ansah D, Pandey S, Igual-Gil C, Braune A, Lippert RN. Developmental metformin exposure does not rescue physiological impairments derived from early exposure to altered maternal metabolic state in offspring mice. Mol Metab 2024; 79:101860. [PMID: 38142972 PMCID: PMC10792763 DOI: 10.1016/j.molmet.2023.101860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Revised: 12/18/2023] [Accepted: 12/20/2023] [Indexed: 12/26/2023] Open
Abstract
OBJECTIVE The incidence of gestational diabetes mellitus (GDM) and metabolic disorders during pregnancy are increasing globally. This has resulted in increased use of therapeutic interventions such as metformin to aid in glycemic control during pregnancy. Even though metformin can cross the placental barrier, its impact on offspring brain development remains poorly understood. As metformin promotes AMPK signaling, which plays a key role in axonal growth during development, we hypothesized that it may have an impact on hypothalamic signaling and the formation of neuronal projections in the hypothalamus, the key regulator of energy homeostasis. We further hypothesized that this is dependent on the metabolic and nutritional status of the mother at the time of metformin intervention. Using mouse models of maternal overnutrition, we aimed to assess the effects of metformin exposure on offspring physiology and hypothalamic neuronal circuits during key periods of development. METHODS Female C57BL/6N mice received either a control diet or a high-fat diet (HFD) during pregnancy and lactation periods. A subset of dams was fed a HFD exclusively during the lactation. Anti-diabetic treatments were given during the first postnatal weeks. Body weights of male and female offspring were monitored daily until weaning. Circulating metabolic factors and molecular changes in the hypothalamus were assessed at postnatal day 16 using ELISA and Western Blot, respectively. Hypothalamic innervation was assessed by immunostaining at postnatal days 16 and 21. RESULTS We identified alterations in weight gain and circulating hormones in male and female offspring induced by anti-diabetic treatment during the early postnatal period, which were critically dependent on the maternal metabolic state. Furthermore, hypothalamic agouti-related peptide (AgRP) and proopiomelanocortin (POMC) neuronal innervation outcomes in response to anti-diabetic treatment were also modulated by maternal metabolic state. We also identified sex-specific changes in hypothalamic AMPK signaling in response to metformin exposure. CONCLUSION We demonstrate a unique interaction between anti-diabetic treatment and maternal metabolic state, resulting in sex-specific effects on offspring brain development and physiological outcomes. Overall, based on our findings, no positive effect of metformin intervention was observed in the offspring, despite ameliorating effects on maternal metabolic outcomes. In fact, the metabolic state of the mother drives the most dramatic differences in offspring physiology and metformin had no rescuing effect. Our results therefore highlight the need for a deeper understanding of how maternal metabolic state (excessive weight gain versus stable weight during GDM treatment) affects the developing offspring. Further, these results emphasize that the interventions to treat alterations in maternal metabolism during pregnancy need to be reassessed from the perspective of the offspring physiology.
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Affiliation(s)
- Lídia Cantacorps
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany; German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Jiajie Zhu
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Selma Yagoub
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Bethany M Coull
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Joanne Falck
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Robert A Chesters
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Katrin Ritter
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Miguel Serrano-Lope
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Katharina Tscherepentschuk
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Lea-Sophie Kasch
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Maya Paterson
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Paula Täger
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - David Baidoe-Ansah
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Shuchita Pandey
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Carla Igual-Gil
- Department of Physiology of Energy Metabolism, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal, Germany
| | - Annett Braune
- Research Group Intestinal Microbiology, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany
| | - Rachel N Lippert
- Department of Neurocircuit Development and Function, German Institute of Human Nutrition Potsdam-Rehbruecke, Nuthetal, Germany; German Center for Diabetes Research (DZD), München-Neuherberg, Germany; NeuroCure Cluster of Excellence, Charité-Universitätsmedizin, Berlin, Germany.
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Heitmann T, Barrow JC. The Role of Inositol Hexakisphosphate Kinase in the Central Nervous System. Biomolecules 2023; 13:1317. [PMID: 37759717 PMCID: PMC10526494 DOI: 10.3390/biom13091317] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 08/23/2023] [Accepted: 08/26/2023] [Indexed: 09/29/2023] Open
Abstract
Inositol is a unique biological small molecule that can be phosphorylated or even further pyrophosphorylated on each of its six hydroxyl groups. These numerous phosphorylation states of inositol along with the kinases and phosphatases that interconvert them comprise the inositol phosphate signaling pathway. Inositol hexakisphosphate kinases, or IP6Ks, convert the fully mono-phosphorylated inositol to the pyrophosphate 5-IP7 (also denoted IP7). There are three isoforms of IP6K: IP6K1, 2, and 3. Decades of work have established a central role for IP6Ks in cell signaling. Genetic and pharmacologic manipulation of IP6Ks in vivo and in vitro has shown their importance in metabolic disease, chronic kidney disease, insulin signaling, phosphate homeostasis, and numerous other cellular and physiologic processes. In addition to these peripheral processes, a growing body of literature has shown the role of IP6Ks in the central nervous system (CNS). IP6Ks have a key role in synaptic vesicle regulation, Akt/GSK3 signaling, neuronal migration, cell death, autophagy, nuclear translocation, and phosphate homeostasis. IP6Ks' regulation of these cellular processes has functional implications in vivo in behavior and CNS anatomy.
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Affiliation(s)
- Tyler Heitmann
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, 725 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
- The Lieber Institute for Brain Development, 855 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
| | - James C. Barrow
- Department of Pharmacology and Molecular Sciences, School of Medicine, Johns Hopkins University, 725 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
- The Lieber Institute for Brain Development, 855 North Wolfe Street Suite 300, Baltimore, MD 21205, USA
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Leung A, Rangamani P. Computational modeling of AMPK and mTOR crosstalk in glutamatergic synapse calcium signaling. NPJ Syst Biol Appl 2023; 9:34. [PMID: 37460570 DOI: 10.1038/s41540-023-00295-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 06/29/2023] [Indexed: 07/20/2023] Open
Abstract
Neuronal energy consumption is vital for information processing and memory formation in synapses. The brain consists of just 2% of the human body's mass, but consumes almost 20% of the body's energy budget. Most of this energy is attributed to active transport in ion signaling, with calcium being the canonical second messenger of synaptic transmission. Here, we develop a computational model of synaptic signaling resulting in the activation of two protein kinases critical in metabolic regulation and cell fate, AMP-Activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) and investigate the effect of glutamate stimulus frequency on their dynamics. Our model predicts that frequencies of glutamate stimulus over 10 Hz perturb AMPK and mTOR oscillations at higher magnitudes by up to 36% and change the area under curve (AUC) by 5%. This dynamic difference in AMPK and mTOR activation trajectories potentially differentiates high frequency stimulus bursts from basal neuronal signaling leading to a downstream change in synaptic plasticity. Further, we also investigate the crosstalk between insulin receptor and calcium signaling on AMPK and mTOR activation and predict that the pathways demonstrate multistability dependent on strength of insulin signaling and metabolic consumption rate. Our predictions have implications for improving our understanding of neuronal metabolism, synaptic pruning, and synaptic plasticity.
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Affiliation(s)
- A Leung
- Chemical Engineering Graduate Program, University of California San Diego, La Jolla, CA, USA
| | - P Rangamani
- Department of Mechanical and Aerospace Engineering, University of California San Diego, La Jolla, CA, USA.
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5
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Song Z, Mao H, Liu J, Sun W, Wu S, Lu X, Jin C, Yang J. Lanthanum Chloride Induces Axon Abnormality Through LKB1-MARK2 and LKB1-STK25-GM130 Signaling Pathways. Cell Mol Neurobiol 2023; 43:1181-1196. [PMID: 35661286 DOI: 10.1007/s10571-022-01237-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/23/2022] [Indexed: 11/24/2022]
Abstract
Lanthanum (La) is a natural rare-earth element that can damage the central nervous system and impair learning and memory. However, its neurotoxic mechanism remains unclear. In this study, adult female rats were divided into 4 groups and given distilled water solution containing 0%, 0.125%, 0.25%, and 0.5% LaCl3, respectively, and this was done from conception to the end of the location. Their offspring rats were used to establish animal models to investigate LaCl3 neurotoxicity. Primary neurons cultured in vitro were treated with LaCl3 and infected with LKB1 overexpression lentivirus. The results showed that LaCl3 exposure resulted in abnormal axons in the hippocampus and primary cultured neurons. LaCl3 reduced the expression of LKB1, p-LKB1, STRAD and MO25 proteins, and directly or indirectly affected the expression of LKB1, leading to decreased activity of LKB1-MARK2 and LKB1-STK25-GM130 pathways. This study indicated that LaCl3 exposure could interfere with the normal effects of LKB1 in the brain and downregulate LKB1-MARK2 and LKB1-STK25-GM130 signaling pathways, resulting in abnormal axon in offspring rats.
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Affiliation(s)
- Zeli Song
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China
| | - Haoyue Mao
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China
| | - Jinxuan Liu
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China
| | - Wenchang Sun
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China
| | - Shengwen Wu
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China
| | - Xiaobo Lu
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China
| | - Cuihong Jin
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China
| | - Jinghua Yang
- Department of Toxicology, School of Public Health, China Medical University, No. 77 Puhe Road, Shenyang, 110122, People's Republic of China.
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SGLT-2 Inhibitors in NAFLD: Expanding Their Role beyond Diabetes and Cardioprotection. Int J Mol Sci 2022; 23:ijms23063107. [PMID: 35328527 PMCID: PMC8953901 DOI: 10.3390/ijms23063107] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/03/2022] [Accepted: 03/09/2022] [Indexed: 12/16/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is an ‘umbrella’ term, comprising a spectrum ranging from benign, liver steatosis to non-alcoholic steatohepatitis, liver fibrosis and eventually cirrhosis and hepatocellular carcinoma. NAFLD has evolved as a major health problem in recent years. Discovering ways to prevent or delay the progression of NAFLD has become a global focus. Lifestyle modifications remain the cornerstone of NAFLD treatment, even though various pharmaceutical interventions are currently under clinical trial. Among them, sodium-glucose co-transporter type-2 inhibitors (SGLT-2i) are emerging as promising agents. Processes regulated by SGLT-2i, such as endoplasmic reticulum (ER) and oxidative stress, low-grade inflammation, autophagy and apoptosis are all implicated in NAFLD pathogenesis. In this review, we summarize the current understanding of the NAFLD pathophysiology, and specifically focus on the potential impact of SGLT-2i in NAFLD development and progression, providing current evidence from in vitro, animal and human studies. Given this evidence, further mechanistic studies would advance our understanding of the exact mechanisms underlying the pathogenesis of NAFLD and the potential beneficial actions of SGLT-2i in the context of NAFLD treatment.
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Burger CA, Albrecht NE, Jiang D, Liang JH, Poché RA, Samuel MA. LKB1 and AMPK instruct cone nuclear position to modify visual function. Cell Rep 2021; 34:108698. [PMID: 33535040 PMCID: PMC7906279 DOI: 10.1016/j.celrep.2021.108698] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 11/06/2020] [Accepted: 01/06/2021] [Indexed: 12/17/2022] Open
Abstract
Cone photoreceptors detect light and are responsible for color vision. These cells display a distinct polarized morphology where nuclei are precisely aligned in the apical retina. However, little is known about the mechanisms involved in cone nuclear positioning or the impact of this organization on retina function. We show that the serine/threonine kinase LKB1 and one of its substrates, AMPK, regulate cone nuclear positioning. In the absence of either molecule, cone nuclei are misplaced along the axon, resulting in altered nuclear lamination. LKB1 is required specifically in cones to mediate this process, and disruptions in nuclear alignment result in reduced cone function. Together, these results identify molecular determinants of cone nuclear position and indicate that cone nuclear position alignment enables proper visual function.
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Affiliation(s)
- Courtney A Burger
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Nicholas E Albrecht
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Danye Jiang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Justine H Liang
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA
| | - Ross A Poché
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Melanie A Samuel
- Department of Neuroscience, Baylor College of Medicine, Houston, TX 77030, USA; Huffington Center on Aging, Baylor College of Medicine, Houston, TX 77030, USA.
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Retinoid X receptor agonists attenuates cardiomyopathy in streptozotocin-induced type 1 diabetes through LKB1-dependent anti-fibrosis effects. Clin Sci (Lond) 2020; 134:609-628. [PMID: 32175563 DOI: 10.1042/cs20190985] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 02/27/2020] [Accepted: 03/16/2020] [Indexed: 12/15/2022]
Abstract
Diabetic cardiac fibrosis increases ventricular stiffness and facilitates the occurrence of diastolic dysfunction. Retinoid X receptor (RXR) plays an important role in cardiac development and has been implicated in cardiovascular diseases. In the present study, we investigated the effects of RXR agonist treatment on streptozotocin (STZ)-induced diabetic cardiomyopathy (DCM) and the underlying mechanism. Sprague-Dawley (SD) rats induced by STZ injection were treated with either RXR agonist bexarotene (Bex) or vehicle alone. Echocardiography was performed to determine cardiac structure and function. Cardiac fibroblasts (CFs) were treated with high glucose (HG) with or without the indicated concentration of Bex or the RXR ligand 9-cis-retinoic acid (9-cis-RA). The protein abundance levels were measured along with collagen, body weight (BW), blood biochemical indexes and transforming growth factor-β (TGF-β) levels. The effects of RXRα down-regulation by RXRα small interfering RNA (siRNA) were examined. The results showed that bexarotene treatment resulted in amelioration of left ventricular dysfunction by inhibiting cardiomyocyte apoptosis and myocardial fibrosis. Immunoblot with heart tissue homogenates from diabetic rats revealed that bexarotene activated liver kinase B1 (LKB1) signaling and inhibited p70 ribosomal protein S6 kinase (p70S6K). The increased collagen levels in the heart tissues of DCM rats were reduced by bexarotene treatment. Treatment of CFs with HG resulted in significantly reduced LKB1 activity and increased p70S6K activity. RXRα mediated the antagonism of 9-cis-RA on HG-induced LKB1/p70S6K activation changes in vitro. Our findings suggest that RXR agonist ameliorates STZ-induced DCM by inhibiting myocardial fibrosis via modulation of the LKB1/p70S6K signaling pathway. RXR agonists may serve as novel therapeutic agents for the treatment of DCM.
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9
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Mechanisms of axon polarization in pyramidal neurons. Mol Cell Neurosci 2020; 107:103522. [PMID: 32653476 DOI: 10.1016/j.mcn.2020.103522] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 06/19/2020] [Accepted: 06/29/2020] [Indexed: 01/19/2023] Open
Abstract
Neurons are highly polarized cells that have specialized regions for synaptic input, the dendrites, and synaptic output, the axons. This polarity is critical for appropriate neural circuit formation and function. One of the central gaps in our knowledge is understanding how developing neurons initiate axon polarity. Given the critical nature of this polarity on neural circuit formation and function, neurons have evolved multiple mechanisms comprised of extracellular and intracellular cues that allow them to initiate and form axons. These mechanisms engage a variety of signaling cascades that provide positive and negative cues to ensure axon polarization. This review highlights our current knowledge of the molecular underpinnings of axon polarization in pyramidal neurons and their relevance to the development of the brain.
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Han W, Li Y, Cheng J, Zhang J, Chen D, Fang M, Xiang G, Wu Y, Zhang H, Xu K, Wang H, Xie L, Xiao J. Sitagliptin improves functional recovery via GLP-1R-induced anti-apoptosis and facilitation of axonal regeneration after spinal cord injury. J Cell Mol Med 2020; 24:8687-8702. [PMID: 32573108 PMCID: PMC7412681 DOI: 10.1111/jcmm.15501] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2019] [Revised: 05/18/2020] [Accepted: 05/28/2020] [Indexed: 12/18/2022] Open
Abstract
Axon growth and neuronal apoptosis are considered to be crucial therapeutic targets against spinal cord injury (SCI). Growing evidences have reported stimulation of glucagon‐like peptide‐1 (GLP‐1)/GLP‐1 receptor (GLP‐1R) signalling axis provides neuroprotection in experimental models of neurodegeneration disease. Endogenous GLP‐1 is rapidly degraded by dipeptidyl peptidase‐IV (DPP4), resulting in blocking of GLP‐1/GLP1R signalling process. Sitagliptin, a highly selective inhibitor of DPP4, has approved to have beneficial effects on diseases in which neurons damaged. However, the roles and the underlying mechanisms of sitagliptin in SCI repairing remain unclear. In this study, we used a rat model of SCI and PC12 cells/primary cortical neurons to explore the mechanism of sitagliptin underlying SCI recovery. We discovered the expression of GLP‐1R decreased in the SCI model. Administration of sitagliptin significantly increased GLP‐1R protein level, alleviated neuronal apoptosis, enhanced axon regeneration and improved functional recovery following SCI. Nevertheless, treatment with exendin9‐39, a GLP‐1R inhibitor, remarkably reversed the protective effect of sitagliptin. Additionally, we detected the AMPK/PGC‐1α signalling pathway was activated by sitagliptin stimulating GLP‐1R. Taken together, sitagliptin may be a potential agent for axon regrowth and locomotor functional repair via GLP‐1R‐induced AMPK/ PGC‐1α signalling pathway after SCI.
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Affiliation(s)
- Wen Han
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Yao Li
- Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Jiangting Cheng
- Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, School of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Jing Zhang
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Dingwen Chen
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Mingqiao Fang
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China.,Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Guangheng Xiang
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China.,Department of Orthopaedics, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yanqing Wu
- Engineering Laboratory of Zhejiang Province for Pharmaceutical Development of Growth Factors, Biomedical Collaborative Innovation Center of Wenzhou, The Institute of Life Sciences, Wenzhou University, Wenzhou, China
| | - Hongyu Zhang
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Ke Xu
- Engineering Laboratory of Zhejiang Province for Pharmaceutical Development of Growth Factors, Biomedical Collaborative Innovation Center of Wenzhou, The Institute of Life Sciences, Wenzhou University, Wenzhou, China
| | - Hangxiang Wang
- Key Laboratory of Combined Multi-Organ Transplantation, Ministry of Public Health, School of Medicine, The First Affiliated Hospital, Zhejiang University, Hangzhou, China
| | - Ling Xie
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
| | - Jian Xiao
- Molecular Pharmacology Research Center, School of Pharmaceutical Science, Wenzhou Medical University, Wenzhou, China
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Cespedes A, Villa M, Benito-Cuesta I, Perez-Alvarez MJ, Ordoñez L, Wandosell F. Energy-Sensing Pathways in Ischemia: The Counterbalance Between AMPK and mTORC. Curr Pharm Des 2020; 25:4763-4770. [PMID: 31820693 DOI: 10.2174/1381612825666191210152156] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Accepted: 12/06/2019] [Indexed: 01/02/2023]
Abstract
Stroke is an important cause of death and disability, and it is the second leading cause of death worldwide. In humans, middle cerebral artery occlusion (MCAO) is the most common cause of ischemic stroke. The damage occurs due to the lack of nutrients and oxygen contributed by the blood flow. The present review aims to analyze to what extent the lack of each of the elements of the system leads to damage and which mechanisms are unaffected by this deficiency. We believe that the specific analysis of the effect of lack of each component could lead to the emergence of new therapeutic targets for this important brain pathology.
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Affiliation(s)
- Angel Cespedes
- Centro de Biología Molecular "Severo Ochoa". CSIC-UAM. Nicolás Cabrera 1, 28049 Madrid, Spain.,Research Group of Neurodegenerative Diseases, Department of Animal Health, Faculty of Veterinary Medicine and Zootechnics - Tolima University, Santa Helena - 730006299, Ibagué, Colombia
| | - Mario Villa
- Centro de Biología Molecular "Severo Ochoa". CSIC-UAM. Nicolás Cabrera 1, 28049 Madrid, Spain.,Departamento de Biología (Fisiología Animal). Facultad de Ciencias. Universidad Autónoma de Madrid. C/Darwin 2. 28049 Madrid, Spain
| | - Irene Benito-Cuesta
- Centro de Biología Molecular "Severo Ochoa". CSIC-UAM. Nicolás Cabrera 1, 28049 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Maria J Perez-Alvarez
- Centro de Biología Molecular "Severo Ochoa". CSIC-UAM. Nicolás Cabrera 1, 28049 Madrid, Spain.,Departamento de Biología (Fisiología Animal). Facultad de Ciencias. Universidad Autónoma de Madrid. C/Darwin 2. 28049 Madrid, Spain
| | - Lara Ordoñez
- Centro de Biología Molecular "Severo Ochoa". CSIC-UAM. Nicolás Cabrera 1, 28049 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
| | - Francisco Wandosell
- Centro de Biología Molecular "Severo Ochoa". CSIC-UAM. Nicolás Cabrera 1, 28049 Madrid, Spain.,Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED), Madrid, Spain
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12
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Pedrero-Prieto CM, García-Carpintero S, Frontiñán-Rubio J, Llanos-González E, Aguilera García C, Alcaín FJ, Lindberg I, Durán-Prado M, Peinado JR, Rabanal-Ruiz Y. A comprehensive systematic review of CSF proteins and peptides that define Alzheimer's disease. Clin Proteomics 2020; 17:21. [PMID: 32518535 PMCID: PMC7273668 DOI: 10.1186/s12014-020-09276-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 04/09/2020] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND During the last two decades, over 100 proteomics studies have identified a variety of potential biomarkers in CSF of Alzheimer's (AD) patients. Although several reviews have proposed specific biomarkers, to date, the statistical relevance of these proteins has not been investigated and no peptidomic analyses have been generated on the basis of specific up- or down- regulation. Herein, we perform an analysis of all unbiased explorative proteomics studies of CSF biomarkers in AD to critically evaluate whether proteins and peptides identified in each study are consistent in distribution; direction change; and significance, which would strengthen their potential use in studies of AD pathology and progression. METHODS We generated a database containing all CSF proteins whose levels are known to be significantly altered in human AD from 47 independent, validated, proteomics studies. Using this database, which contains 2022 AD and 2562 control human samples, we examined whether each protein is consistently present on the basis of reliable statistical studies; and if so, whether it is over- or under-represented in AD. Additionally, we performed a direct analysis of available mass spectrometric data of these proteins to generate an AD CSF peptide database with 3221 peptides for further analysis. RESULTS Of the 162 proteins that were identified in 2 or more studies, we investigated their enrichment or depletion in AD CSF. This allowed us to identify 23 proteins which were increased and 50 proteins which were decreased in AD, some of which have never been revealed as consistent AD biomarkers (i.e. SPRC or MUC18). Regarding the analysis of the tryptic peptide database, we identified 87 peptides corresponding to 13 proteins as the most highly consistently altered peptides in AD. Analysis of tryptic peptide fingerprinting revealed specific peptides encoded by CH3L1, VGF, SCG2, PCSK1N, FBLN3 and APOC2 with the highest probability of detection in AD. CONCLUSIONS Our study reveals a panel of 27 proteins and 21 peptides highly altered in AD with consistent statistical significance; this panel constitutes a potent tool for the classification and diagnosis of AD.
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Affiliation(s)
- Cristina M. Pedrero-Prieto
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Sonia García-Carpintero
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Javier Frontiñán-Rubio
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Emilio Llanos-González
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Cristina Aguilera García
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Francisco J. Alcaín
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Iris Lindberg
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, University of Maryland, Baltimore, MD 21201 USA
| | - Mario Durán-Prado
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Juan R. Peinado
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
| | - Yoana Rabanal-Ruiz
- Department of Medical Sciences, Ciudad Real Medical School, Oxidative Stress and Neurodegeneration Group, Regional Center for Biomedical Research, University of Castilla-La Mancha, Ciudad Real, Spain
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13
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Jossin Y. Molecular mechanisms of cell polarity in a range of model systems and in migrating neurons. Mol Cell Neurosci 2020; 106:103503. [PMID: 32485296 DOI: 10.1016/j.mcn.2020.103503] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/20/2020] [Accepted: 05/23/2020] [Indexed: 01/09/2023] Open
Abstract
Cell polarity is defined as the asymmetric distribution of cellular components along an axis. Most cells, from the simplest single-cell organisms to highly specialized mammalian cells, are polarized and use similar mechanisms to generate and maintain polarity. Cell polarity is important for cells to migrate, form tissues, and coordinate activities. During development of the mammalian cerebral cortex, cell polarity is essential for neurogenesis and for the migration of newborn but as-yet undifferentiated neurons. These oriented migrations include both the radial migration of excitatory projection neurons and the tangential migration of inhibitory interneurons. In this review, I will first describe the development of the cerebral cortex, as revealed at the cellular level. I will then define the core molecular mechanisms - the Par/Crb/Scrib polarity complexes, small GTPases, the actin and microtubule cytoskeletons, and phosphoinositides/PI3K signaling - that are required for asymmetric cell division, apico-basal and front-rear polarity in model systems, including C elegans zygote, Drosophila embryos and cultured mammalian cells. As I go through each core mechanism I will explain what is known about its importance in radial and tangential migration in the developing mammalian cerebral cortex.
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Affiliation(s)
- Yves Jossin
- Laboratory of Mammalian Development & Cell Biology, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
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14
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Burger CA, Alevy J, Casasent AK, Jiang D, Albrecht NE, Liang JH, Hirano AA, Brecha NC, Samuel MA. LKB1 coordinates neurite remodeling to drive synapse layer emergence in the outer retina. eLife 2020; 9:e56931. [PMID: 32378514 PMCID: PMC7237215 DOI: 10.7554/elife.56931] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 04/11/2020] [Indexed: 12/04/2022] Open
Abstract
Structural changes in pre and postsynaptic neurons that accompany synapse formation often temporally and spatially overlap. Thus, it has been difficult to resolve which processes drive patterned connectivity. To overcome this, we use the laminated outer murine retina. We identify the serine/threonine kinase LKB1 as a key driver of synapse layer emergence. The absence of LKB1 in the retina caused a marked mislocalization and delay in synapse layer formation. In parallel, LKB1 modulated postsynaptic horizontal cell refinement and presynaptic photoreceptor axon growth. Mislocalized horizontal cell processes contacted aberrant cone axons in LKB1 mutants. These defects coincided with altered synapse protein organization, and horizontal cell neurites were misdirected to ectopic synapse protein regions. Together, these data suggest that LKB1 instructs the timing and location of connectivity in the outer retina via coordinate regulation of pre and postsynaptic neuron structure and the localization of synapse-associated proteins.
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Affiliation(s)
- Courtney A Burger
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Jonathan Alevy
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Anna K Casasent
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Danye Jiang
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Nicholas E Albrecht
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Justine H Liang
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
| | - Arlene A Hirano
- Department of Neurobiology, David Geffen School of Medicine at UCLALos AngelesUnited States
- United States Veterans Administration Greater Los Angeles Healthcare SystemLos AngelesUnited States
| | - Nicholas C Brecha
- Department of Neurobiology, David Geffen School of Medicine at UCLALos AngelesUnited States
- United States Veterans Administration Greater Los Angeles Healthcare SystemLos AngelesUnited States
| | - Melanie A Samuel
- Department of Neuroscience, Baylor College of MedicineHoustonUnited States
- Huffington Center on Aging, Baylor College of MedicineHoustonUnited States
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15
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Murray CW, Brady JJ, Tsai MK, Li C, Winters IP, Tang R, Andrejka L, Ma RK, Kunder CA, Chu P, Winslow MM. An LKB1-SIK Axis Suppresses Lung Tumor Growth and Controls Differentiation. Cancer Discov 2019; 9:1590-1605. [PMID: 31350327 PMCID: PMC6825558 DOI: 10.1158/2159-8290.cd-18-1237] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 05/09/2019] [Accepted: 07/22/2019] [Indexed: 12/29/2022]
Abstract
The kinase LKB1 is a critical tumor suppressor in sporadic and familial human cancers, yet the mechanisms by which it suppresses tumor growth remain poorly understood. To investigate the tumor-suppressive capacity of four canonical families of LKB1 substrates in vivo, we used CRISPR/Cas9-mediated combinatorial genome editing in a mouse model of oncogenic KRAS-driven lung adenocarcinoma. We demonstrate that members of the SIK family are critical for constraining tumor development. Histologic and gene-expression similarities between LKB1- and SIK-deficient tumors suggest that SIKs and LKB1 operate within the same axis. Furthermore, a gene-expression signature reflecting SIK deficiency is enriched in LKB1-mutant human lung adenocarcinomas and is regulated by LKB1 in human cancer cell lines. Together, these findings reveal a key LKB1-SIK tumor-suppressive axis and underscore the need to redirect efforts to elucidate the mechanisms through which LKB1 mediates tumor suppression. SIGNIFICANCE: Uncovering the effectors of frequently altered tumor suppressor genes is critical for understanding the fundamental driving forces of cancer growth. Our identification of the SIK family of kinases as effectors of LKB1-mediated tumor suppression will refocus future mechanistic studies and may lead to new avenues for genotype-specific therapeutic interventions.This article is highlighted in the In This Issue feature, p. 1469.
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Affiliation(s)
- Christopher W Murray
- Cancer Biology Program, Stanford University School of Medicine, Stanford, California
| | - Jennifer J Brady
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Min K Tsai
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Chuan Li
- Department of Biology, Stanford University, Stanford, California
| | - Ian P Winters
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Rui Tang
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Laura Andrejka
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Rosanna K Ma
- Department of Genetics, Stanford University School of Medicine, Stanford, California
| | - Christian A Kunder
- Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Pauline Chu
- Department of Pathology, Stanford University School of Medicine, Stanford, California
| | - Monte M Winslow
- Cancer Biology Program, Stanford University School of Medicine, Stanford, California.
- Department of Genetics, Stanford University School of Medicine, Stanford, California
- Department of Pathology, Stanford University School of Medicine, Stanford, California
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
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16
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Kalinin S, Meares GP, Lin SX, Pietruczyk EA, Saher G, Spieth L, Nave KA, Boullerne AI, Lutz SE, Benveniste EN, Feinstein DL. Liver kinase B1 depletion from astrocytes worsens disease in a mouse model of multiple sclerosis. Glia 2019; 68:600-616. [PMID: 31664743 PMCID: PMC7337013 DOI: 10.1002/glia.23742] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 09/19/2019] [Accepted: 10/05/2019] [Indexed: 12/15/2022]
Abstract
Liver kinase B1 (LKB1) is a ubiquitously expressed kinase involved in the regulation of cell metabolism, growth, and inflammatory activation. We previously reported that a single nucleotide polymorphism in the gene encoding LKB1 is a risk factor for multiple sclerosis (MS). Since astrocyte activation and metabolic function have important roles in regulating neuroinflammation and neuropathology, we examined the serine/threonine kinase LKB1 in astrocytes in a chronic experimental autoimmune encephalomyelitis mouse model of MS. To reduce LKB1, a heterozygous astrocyte-selective conditional knockout (het-cKO) model was used. While disease incidence was similar, disease severity was worsened in het-cKO mice. RNAseq analysis identified Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways enriched in het-cKO mice relating to mitochondrial function, confirmed by alterations in mitochondrial complex proteins and reductions in mRNAs related to astrocyte metabolism. Enriched pathways included major histocompatibility class II genes, confirmed by increases in MHCII protein in spinal cord and cerebellum of het-cKO mice. We observed increased numbers of CD4+ Th17 cells and increased neuronal damage in spinal cords of het-cKO mice, associated with reduced expression of choline acetyltransferase, accumulation of immunoglobulin-γ, and reduced expression of factors involved in motor neuron survival. In vitro, LKB1-deficient astrocytes showed reduced metabolic function and increased inflammatory activation. These data suggest that metabolic dysfunction in astrocytes, in this case due to LKB1 deficiency, can exacerbate demyelinating disease by loss of metabolic support and increase in the inflammatory environment.
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Affiliation(s)
- Sergey Kalinin
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | - Gordon P Meares
- Department of Microbiology, Immunology and Cell Biology, West Virginia University, Morgantown, West Virginia
| | - Shao Xia Lin
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | | | - Gesine Saher
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Lena Spieth
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Gottingen, Germany
| | - Anne I Boullerne
- Department of Anesthesiology, University of Illinois, Chicago, Illinois
| | - Sarah E Lutz
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, Illinois
| | - Etty N Benveniste
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Douglas L Feinstein
- Department of Anesthesiology, University of Illinois, Chicago, Illinois.,Department of Veterans Affairs, Jesse Brown VA Medical Center, Chicago, Illinois
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