1
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Lei Z, Pan C, Li F, Wei D, Ma Y. SGK1 promotes the lipid accumulation via regulating the transcriptional activity of FOXO1 in bovine. BMC Genomics 2024; 25:737. [PMID: 39080526 PMCID: PMC11290151 DOI: 10.1186/s12864-024-10644-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 07/22/2024] [Indexed: 08/02/2024] Open
Abstract
OBJECTIVES Serum/glucocorticoid-inducible kinase 1 (SGK1) gene encodes a serine/threonine protein kinase that plays an essential role in cellular stress response and regulation of multiple metabolic processes. However, its role in bovine adipogenesis remains unknown. In this study, we aimed to clarify the role of SGK1 in bovine lipid accumulation and improvement of meat quality. METHODS Preadipocytes were induced to differentiation to detect the temporal expression pattern of SGK1. Heart, liver, lung, spleen, kidney, muscle and fat tissues were collected to detect its tissue expression profile. Recombinant adenovirus and the lentivirus were packaged for overexpression and knockdown. Oil Red O staining, quantitative real-time PCR, Western blot analysis, Yeast two-hybrid assay, luciferase assay and RNA-seq were performed to study the regulatory mechanism of SGK1. RESULTS SGK1 showed significantly higher expression in adipose and significantly induced expression in differentiated adipocytes. Furthermore, overexpression of SGK1 greatly promoted adipogenesis and inhibited proliferation, which could be shown by the remarkable increasement of lipid droplet, and the expression levels of adipogenic marker genes and cell cycle-related genes. Inversely, its knockdown inhibited adipogenesis and facilitated proliferation. Mechanistically, SGK1 regulates the phosphorylation and expression of two critical proteins of FoxO family, FOXO1/FOXO3. Importantly, SGK1 attenuates the transcriptional repression role of FOXO1 for PPARγ via phosphorylating the site S256, then promoting the bovine fat deposition. CONCLUSIONS SGK1 is a required epigenetic regulatory factor for bovine preadipocyte proliferation and differentiation, which contributes to a better understanding of fat deposition and meat quality improvement in cattle.
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Affiliation(s)
- Zhaoxiong Lei
- College of Animal Science and Technology, Ningxia University, Yinchuan, 750021, China
| | - Cuili Pan
- College of Animal Science and Technology, Ningxia University, Yinchuan, 750021, China
| | - Fen Li
- College of Animal Science and Technology, Ningxia University, Yinchuan, 750021, China
| | - Dawei Wei
- College of Animal Science and Technology, Ningxia University, Yinchuan, 750021, China.
| | - Yun Ma
- College of Animal Science and Technology, Ningxia University, Yinchuan, 750021, China.
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2
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Xu W, Chen H, Xiao H. mTORC2: A neglected player in aging regulation. J Cell Physiol 2024:e31363. [PMID: 38982866 DOI: 10.1002/jcp.31363] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 05/21/2024] [Accepted: 06/19/2024] [Indexed: 07/11/2024]
Abstract
Mammalian target of rapamycin (mTOR) is a serine/threonine kinase that plays a pivotal role in various biological processes, through integrating external and internal signals, facilitating gene transcription and protein translation, as well as by regulating mitochondria and autophagy functions. mTOR kinase operates within two distinct protein complexes known as mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2), which engage separate downstream signaling pathways impacting diverse cellular processes. Although mTORC1 has been extensively studied as a pro-proliferative factor and a pro-aging hub if activated aberrantly, mTORC2 received less attention, particularly regarding its implication in aging regulation. However, recent studies brought increasing evidence or clues for us, which implies the associations of mTORC2 with aging, as the genetic elimination of unique subunits of mTORC2, such as RICTOR, has been shown to alleviate aging progression in comparison to mTORC1 inhibition. In this review, we first summarized the basic characteristics of mTORC2, including its protein architecture and signaling network. We then focused on reviewing the molecular signaling regulation of mTORC2 in cellular senescence and organismal aging, and proposed the multifaceted regulatory characteristics under senescent and nonsenescent contexts. Next, we outlined the research progress of mTOR inhibitors in the field of antiaging and discussed future prospects and challenges. It is our pleasure if this review article could provide meaningful information for our readers and call forth more investigations working on this topic.
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Affiliation(s)
- Weitong Xu
- The Lab of Aging Research, National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Honghan Chen
- The Lab of Aging Research, National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
| | - Hengyi Xiao
- The Lab of Aging Research, National Clinical Research Center for Geriatrics, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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3
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Gulzar M, Noor S, Hasan GM, Hassan MI. The role of serum and glucocorticoid-regulated kinase 1 in cellular signaling: Implications for drug development. Int J Biol Macromol 2024; 258:128725. [PMID: 38092114 DOI: 10.1016/j.ijbiomac.2023.128725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 11/23/2023] [Accepted: 12/08/2023] [Indexed: 12/24/2023]
Abstract
Serum and glucocorticoid-regulated kinase 1 (SGK1) is a ubiquitously expressed protein belonging to the Ser/Thr kinase family. It regulates diverse physiological processes, including epithelial sodium channel activity, hypertension, cell proliferation, and insulin sensitivity. Due to its significant role in the pathogenesis of numerous diseases, SGK1 can be exploited as a potential therapeutic target to address challenging health problems. SGK1 is associated with the development of obesity, and its overexpression enhances the sodium-glucose co-transporter 1 activity, which absorbs intestinal glucose. This review highlighted the detailed functional significance of SGK1 signaling and role in different diseases and subsequent therapeutic targeting. We aim to provide deeper mechanistic insights into understanding the pathogenesis and recent advancements in the SGK1 targeted drug development process. Small-molecule inhibitors are being developed with excellent binding affinity and improved SGK1 inhibition with desired selectivity. We have discussed small molecule inhibitors designed explicitly as potent SGK1 inhibitors and their therapeutic implications in various diseases. We further addressed the therapeutic potential and mechanism of action of these SGK1 inhibitors and provided a strong scientific foundation for developing effective therapeutics.
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Affiliation(s)
- Mehak Gulzar
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Saba Noor
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India
| | - Gulam Mustafa Hasan
- Department of Basic Medical Science, College of Medicine, Prince Sattam Bin Abdulaziz University, P.O. Box 173, Al-Kharj 11942, Saudi Arabia
| | - Md Imtaiyaz Hassan
- Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India.
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4
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Ragupathi A, Kim C, Jacinto E. The mTORC2 signaling network: targets and cross-talks. Biochem J 2024; 481:45-91. [PMID: 38270460 PMCID: PMC10903481 DOI: 10.1042/bcj20220325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.
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Affiliation(s)
- Aparna Ragupathi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Christian Kim
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
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5
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Maestro I, Madruga E, Boya P, Martínez A. Identification of a new structural family of SGK1 inhibitors as potential neuroprotective agents. J Enzyme Inhib Med Chem 2023; 38:2153841. [PMID: 36637025 PMCID: PMC9848319 DOI: 10.1080/14756366.2022.2153841] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
SGK1 is a serine/threonine kinase involved in several neurodegenerative-related pathways such as apoptosis, neuroinflammation, ionic channel regulation, and autophagy, among others. Despite its potential role as a pharmacological target against this kind of diseases, there are no reported inhibitors able to cross the BBB so far, being a field yet to be explored. In this context, a structure-based virtual screening against this kinase was performed, pointing out the deazapurine moiety as an interesting and easy-to-derivatize scaffold. Moreover, these inhibitors are able to i) exert neuroprotection in an in vitro model of AD and ii) block mitophagy in a PRKN-independent manner, reinforcing the hypothesis of SGK1 inhibitors as neuroprotective chemical tools.
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Affiliation(s)
- Ines Maestro
- Centro de Investigaciones, Biológicas Margarita Salas-CSIC, Madrid, Spain,Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
| | - Enrique Madruga
- Centro de Investigaciones, Biológicas Margarita Salas-CSIC, Madrid, Spain
| | - Patricia Boya
- Centro de Investigaciones, Biológicas Margarita Salas-CSIC, Madrid, Spain
| | - Ana Martínez
- Centro de Investigaciones, Biológicas Margarita Salas-CSIC, Madrid, Spain,Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain,CONTACT Ana Martínez CIB-CSIC, Ramiro Maeztu 9, Madrid, 28040, Spain
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6
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Sun Y, Wang H, Qu T, Luo J, An P, Ren F, Luo Y, Li Y. mTORC2: a multifaceted regulator of autophagy. Cell Commun Signal 2023; 21:4. [PMID: 36604720 PMCID: PMC9814435 DOI: 10.1186/s12964-022-00859-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 03/06/2022] [Indexed: 01/06/2023] Open
Abstract
Autophagy is a multi-step catabolic process that delivers cellular components to lysosomes for degradation and recycling. The dysregulation of this precisely controlled process disrupts cellular homeostasis and leads to many pathophysiological conditions. The mechanistic target of rapamycin (mTOR) is a central nutrient sensor that integrates growth signals with anabolism to fulfil biosynthetic and bioenergetic requirements. mTOR nucleates two distinct evolutionarily conserved complexes (mTORC1 and mTORC2). However, only mTORC1 is acutely inhibited by rapamycin. Consequently, mTORC1 is a well characterized regulator of autophagy. While less is known about mTORC2, the availability of acute small molecule inhibitors and multiple genetic models has led to increased understanding about the role of mTORC2 in autophagy. Emerging evidence suggests that the regulation of mTORC2 in autophagy is mainly through its downstream effector proteins, and is variable under different conditions and cellular contexts. Here, we review recent advances that describe a role for mTORC2 in this catabolic process, and propose that mTORC2 could be a potential clinical target for the treatment of autophagy-related diseases. Video abstract.
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Affiliation(s)
- Yanan Sun
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Huihui Wang
- grid.411734.40000 0004 1798 5176College of Food Science and Engineering, Gansu Agricultural University, Lanzhou, 730070 China
| | - Taiqi Qu
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Junjie Luo
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Peng An
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Fazheng Ren
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Yongting Luo
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
| | - Yixuan Li
- grid.22935.3f0000 0004 0530 8290Key Laboratory of Precision Nutrition and Food Quality, Department of Nutrition and Health, China Agricultural University, Beijing, 100083 China
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7
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Shu H, Huang Y, Zhang W, Ling L, Hua Y, Xiong Z. An integrated study of hormone-related sarcopenia for modeling and comparative transcriptome in rats. Front Endocrinol (Lausanne) 2023; 14:1073587. [PMID: 36817606 PMCID: PMC9929355 DOI: 10.3389/fendo.2023.1073587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 01/19/2023] [Indexed: 02/04/2023] Open
Abstract
Sarcopenia is a senile disease with high morbidity, serious complications and limited clinical treatments. Menopause increases the risk of sarcopenia in females, while the exact pathogenesis remains unclear. To systematically investigate the development of hormone-related sarcopenia, we established a model of sarcopenia by ovariectomy and recorded successive characteristic changes. Furthermore, we performed the transcriptome RNA sequencing and bioinformatics analysis on this model to explore the underlying mechanism. In our study, we identified an integrated model combining obesity, osteoporosis and sarcopenia. Functional enrichment analyses showed that most of the significantly enriched pathways were down-regulated and closely correlated with endocrine and metabolism, muscle dysfunction, cognitive impairment and multiple important signaling pathways. We finally selected eight candidate genes to verify their expression levels. These findings confirmed the importance of estrogen in the maintenance of skeletal muscle function and homeostasis, and provided potential targets for further study on hormone-related sarcopenia.
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Affiliation(s)
- Han Shu
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yubing Huang
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Wenqian Zhang
- Department of Nuclear Medicine, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Li Ling
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuanyuan Hua
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Zhengai Xiong
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- *Correspondence: Zhengai Xiong,
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8
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Wu ZW, Gao ZR, Liang H, Fang T, Wang Y, Du ZQ, Yang CX. Network analysis reveals different hub genes and molecular pathways for pig in vitro fertilized early embryos and parthenogenotes. Reprod Domest Anim 2022; 57:1544-1553. [PMID: 35997106 DOI: 10.1111/rda.14231] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/21/2022] [Indexed: 12/01/2022]
Abstract
Maternal-to-zygotic transition (MZT) occurs when maternal transcripts decay and zygotic genome is activated gradually at early stage of embryo development. Previously, single cell RNA-seq (scRNA-seq) has helped us to uncover the MZT-associated mRNA dynamics of in vitro produced pig early embryos. Here, to further investigate functional modules and hub genes associated with MZT process, the weighted gene-coexpression network analysis (WGCNA) was performed on our previously generated 45 scRNA-seq datasets. For the in vitro fertilized embryo (IVF) group, 5 significant modules were identified (midnightblue/black/red and blue/brown modules, positively correlated with 1-cell (IVF1) and 8-cell (IVF8), respectively), containing genes mainly enriched in signaling pathways such as Wnt, regulation of RNA transcription, fatty acid metabolic process, poly(A) RNA binding and lysosome. For the parthenogenetically activated embryo (PA) group, 9 significant modules were identified (black/purple/red, brown/turquoise/yellow, and magenta/blue/green modules, positively correlated with MII oocytes, 1-cell (PA1), and 8-cell (PA8), respectively), mainly enriched in extracellular exosome, poly(A) RNA binding, mitochondrion, transcription factor activity. Moreover, some of identified hub genes within 3 IVF and 9 PA significant modules, including ADCY2, DHX34, KDM4A, GDF10, ABCC10, PAFAH2, HEXIM2, COQ9, DCAF11, SGK1, ESRRB etc., have been reported to play vital roles in different biological processes. Our findings provide information and resources for subsequent in-depth study on the regulation and function of MZT in pig embryos.
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Affiliation(s)
- Zi-Wei Wu
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Zhuo-Ran Gao
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Hao Liang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Ting Fang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Yi Wang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Zhi-Qiang Du
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
| | - Cai-Xia Yang
- College of Animal Science, Yangtze University, 434025, Jingzhou, Hubei, China
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9
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Abstract
BACKGROUND The serum and glucocorticoid-induced kinase-1 (SGK1) belonging to the AGC protein kinase family phosphorylates serine and threonine residues of target proteins. It regulates numerous ion channels and transporters and promotes survival under cellular stress. Unique to SGK1 is a tight control at transcriptional and post-transcriptional levels. SGK1 regulates multiple signal transduction pathways related to tumor development. Several studies have reported that SGK1 is upregulated in different types of human malignancies and induces resistance against inhibitors, drugs, and targeted therapies. RESULTS AND CONCLUSION This review highlights the cellular functions of SGK1, its crucial role in cancer development, and clinical insights for SGK1 targeted therapies. Furthermore, the role of SGK1-mediated autophagy as a potential therapeutic target for cancer has been discussed.
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10
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Ballesteros‐Álvarez J, Andersen JK. mTORC2: The other mTOR in autophagy regulation. Aging Cell 2021; 20:e13431. [PMID: 34250734 PMCID: PMC8373318 DOI: 10.1111/acel.13431] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/15/2021] [Accepted: 06/24/2021] [Indexed: 12/13/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR) has gathered significant attention as a ubiquitously expressed multimeric kinase with key implications for cell growth, proliferation, and survival. This kinase forms the central core of two distinct complexes, mTORC1 and mTORC2, which share the ability of integrating environmental, nutritional, and hormonal cues but which regulate separate molecular pathways that result in different cellular responses. Particularly, mTORC1 has been described as a major negative regulator of endosomal biogenesis and autophagy, a catabolic process that degrades intracellular components and organelles within the lysosomes and is thought to play a key role in human health and disease. In contrast, the role of mTORC2 in the regulation of autophagy has been considerably less studied despite mounting evidence this complex may regulate autophagy in a different and perhaps complementary manner to that of mTORC1. Genetic ablation of unique subunits is currently being utilized to study the differential effects of the two mTOR complexes. RICTOR is the best‐described subunit specific to mTORC2 and as such has become a useful tool for investigating the specific actions of this complex. The development of complex‐specific inhibitors for mTORC2 is also an area of intense interest. Studies to date have demonstrated that mTORC1/2 complexes each signal to a variety of exclusive downstream molecules with distinct biological roles. Pinpointing the particular effects of these downstream effectors is crucial toward the development of novel therapies aimed at accurately modulating autophagy in the context of human aging and disease.
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11
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Deleyto-Seldas N, Efeyan A. The mTOR-Autophagy Axis and the Control of Metabolism. Front Cell Dev Biol 2021; 9:655731. [PMID: 34277603 PMCID: PMC8281972 DOI: 10.3389/fcell.2021.655731] [Citation(s) in RCA: 136] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 05/19/2021] [Indexed: 12/12/2022] Open
Abstract
The mechanistic target of rapamycin (mTOR), master regulator of cellular metabolism, exists in two distinct complexes: mTOR complex 1 and mTOR complex 2 (mTORC1 and 2). MTORC1 is a master switch for most energetically onerous processes in the cell, driving cell growth and building cellular biomass in instances of nutrient sufficiency, and conversely, allowing autophagic recycling of cellular components upon nutrient limitation. The means by which the mTOR kinase blocks autophagy include direct inhibition of the early steps of the process, and the control of the lysosomal degradative capacity of the cell by inhibiting the transactivation of genes encoding structural, regulatory, and catalytic factors. Upon inhibition of mTOR, autophagic recycling of cellular components results in the reactivation of mTORC1; thus, autophagy lies both downstream and upstream of mTOR. The functional relationship between the mTOR pathway and autophagy involves complex regulatory loops that are significantly deciphered at the cellular level, but incompletely understood at the physiological level. Nevertheless, genetic evidence stemming from the use of engineered strains of mice has provided significant insight into the overlapping and complementary metabolic effects that physiological autophagy and the control of mTOR activity exert during fasting and nutrient overload.
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Affiliation(s)
- Nerea Deleyto-Seldas
- Metabolism and Cell Signaling Laboratory, Spanish National Cancer Research Center (CNIO), Madrid, Spain
| | - Alejo Efeyan
- Metabolism and Cell Signaling Laboratory, Spanish National Cancer Research Center (CNIO), Madrid, Spain
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12
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Ugwu N, Atzmony L, Ellis KT, Panse G, Jain D, Ko CJ, Nassiri N, Choate KA. Cutaneous and hepatic vascular lesions due to a recurrent somatic GJA4 mutation reveal a pathway for vascular malformation. HGG ADVANCES 2021; 2. [PMID: 33912852 PMCID: PMC8078848 DOI: 10.1016/j.xhgg.2021.100028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The term “cavernous hemangioma” has been used to describe vascular anomalies with histology featuring dilated vascular spaces, vessel walls consisting mainly of fibrous stromal bands lined by a layer of flattened endothelial cells, and an irregular outer rim of interrupted smooth muscle cells. Hepatic hemangiomas (HHs) and cutaneous venous malformations (VMs) share this histologic pattern, and we examined lesions in both tissues to identify genetic drivers. Paired whole-exome sequencing (WES) of lesional tissue and normal liver in HH subjects revealed a recurrent GJA4 c.121G>T (p.Gly41Cys) somatic mutation in four of five unrelated individuals, and targeted sequencing in paired tissue from 9 additional HH individuals identified the same mutation in 8. In cutaneous lesions, paired targeted sequencing in 5 VMs and normal epidermis found the same GJA4 c.121G>T (p.Gly41Cys) somatic mutation in three. GJA4 encodes gap junction protein alpha 4, also called connexin 37 (Cx37), and the p.Gly41Cys mutation falls within the first transmembrane domain at a residue highly conserved among vertebrates. We interrogated the impact of the Cx37 mutant via lentiviral transduction of primary human endothelial cells. We found that the mutant induced changes in cell morphology and activated serum/glucocorticoid-regulated kinase 1 (SGK1), a serine/threonine kinase known to regulate cell proliferation and apoptosis, via non-canonical activation. Treatment with spironolactone, an inhibitor of angiogenesis, suppressed mutant SGK1 activation and reversed changes in cell morphology. These findings identify a recurrent somatic GJA4 c.121G>T mutation as a driver of hepatic and cutaneous VMs, revealing a new pathway for vascular anomalies, with spironolactone a potential pathogenesis-based therapy.
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Affiliation(s)
- Nelson Ugwu
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA.,Vascular Malformations Program (VaMP), Yale New Haven Hospital, New Haven, CT, USA
| | - Lihi Atzmony
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA.,Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.,Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.,Vascular Malformations Program (VaMP), Yale New Haven Hospital, New Haven, CT, USA
| | - Katharine T Ellis
- Department of Genetics, Yale University School of Medicine, New Haven, CT, USA
| | - Gauri Panse
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA.,Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.,Vascular Malformations Program (VaMP), Yale New Haven Hospital, New Haven, CT, USA
| | - Dhanpat Jain
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.,Department of Internal Medicine, Yale University School of Medicine, New Haven, CT, USA
| | - Christine J Ko
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA.,Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.,Vascular Malformations Program (VaMP), Yale New Haven Hospital, New Haven, CT, USA
| | - Naiem Nassiri
- Division of Vascular and Endovascular Surgery, Department of Surgery, Yale University School of Medicine, New Haven, CT 06510, USA.,Vascular Malformations Program (VaMP), Yale New Haven Hospital, New Haven, CT, USA.,Senior author
| | - Keith A Choate
- Department of Dermatology, School of Medicine, Yale University, New Haven, CT 06510, USA.,Department of Genetics, Yale University School of Medicine, New Haven, CT, USA.,Department of Pathology, Yale University School of Medicine, New Haven, CT, USA.,Vascular Malformations Program (VaMP), Yale New Haven Hospital, New Haven, CT, USA.,Senior author
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13
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Yang C, Li J, Sun F, Zhou H, Yang J, Yang C. The functional duality of SGK1 in the regulation of hyperglycemia. Endocr Connect 2020; 9:R187-R194. [PMID: 32621586 PMCID: PMC7424354 DOI: 10.1530/ec-20-0225] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 07/02/2020] [Indexed: 12/11/2022]
Abstract
Hyperglycemia is the consequence of blood glucose dysregulation and a driving force of diabetic complications including retinopathy, nephropathy and cardiovascular diseases. The serum and glucocorticoid inducible kinase-1 (SGK1) has been suggested in the modulation of various pathophysiological activities. However, the role of SGK1 in blood glucose homeostasis remains less appreciated. In this review, we intend to summarize the function of SGK1 in glucose level regulation and to examine the evidence supporting the therapeutic potential of SGK1 inhibitors in hyperglycemia. Ample evidence points to the controversial roles of SGK1 in pancreatic insulin secretion and peripheral insulin sensitivity, which reflects the complex interplay between SGK1 activation and blood glucose fluctuation. Furthermore, SGK1 is engaged in glucose absorption and excretion in intestine and kidney and participates in the progression of hyperglycemia-induced secondary organ damage. As a net effect, blockage of SGK1 activation via either pharmacological inhibition or genetic manipulation seems to be helpful in glucose control at varying diabetic stages.
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Affiliation(s)
- Chunliang Yang
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- The Center for Biomedical Research, Tongji Hospital Research Building, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Junyi Li
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Fei Sun
- The Center for Biomedical Research, Tongji Hospital Research Building, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Haifeng Zhou
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jia Yang
- Department of Integrated Traditional Chinese and Western Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Correspondence should be addressed to C Yang or J Yang: or
| | - Chao Yang
- Department of Gerontology, Hubei Provincial Hospital of Integrated Chinese and Western Medicine, Wuhan, China
- Correspondence should be addressed to C Yang or J Yang: or
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14
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Maestro I, Boya P, Martinez A. Serum- and glucocorticoid-induced kinase 1, a new therapeutic target for autophagy modulation in chronic diseases. Expert Opin Ther Targets 2020; 24:231-243. [PMID: 32067528 DOI: 10.1080/14728222.2020.1730328] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Introduction: Autophagy, a basic cellular degradation pathway essential for survival, is altered both in aging and in many chronic human diseases, including infections, cancer, heart disease, and neurodegeneration. Identifying new therapeutic targets for the control and modulation of autophagy events is therefore of utmost importance in drug discovery. Serum and glucocorticoid activated kinase 1 (SGK1), known for decades for its role in ion channel modulation, is now known to act as a switch for autophagy homeostasis, and has emerged as a novel and important therapeutic target likely to attract considerable research attention in the coming years.Areas covered: In this general review of SGK1 we describe the kinase's structure and its roles in physiological and pathological contexts. We also discuss small-molecule modulators of SGK1 activity. These modulators are of particular interest to medicinal chemists and pharmacists seeking to develop more potent and selective drug candidates for SGK1, which, despite its key role in autophagy, remains relatively understudied.Expert opinion: The main future challenges in this area are (i) deciphering the role of SGK1 in selective autophagy processes (e.g. mitophagy, lipophagy, and aggrephagy); (ii) identifying selective allosteric modulators of SGK1 with specific biological functions; and (iii) conducting first-in-man clinical studies.
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Affiliation(s)
- Inés Maestro
- Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain
| | - Patricia Boya
- Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain
| | - Ana Martinez
- Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain.,Centro de Investigación Biomédica en Red en Enfermedades Neurodegenerativas (CIBERNED), Instituto de Salud Carlos III, Madrid, Spain
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15
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Mitochondrial Perturbations Couple mTORC2 to Autophagy in C. elegans. Cell Rep 2019; 29:1399-1409.e5. [DOI: 10.1016/j.celrep.2019.09.072] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 07/05/2019] [Accepted: 09/25/2019] [Indexed: 12/14/2022] Open
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16
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König J, Grune T, Ott C. Assessing autophagy in murine skeletal muscle: current findings to modulate and quantify the autophagic flux. Curr Opin Clin Nutr Metab Care 2019; 22:355-362. [PMID: 31145123 DOI: 10.1097/mco.0000000000000579] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
PURPOSE OF REVIEW In addition to the currently available lysosomotropic drugs and autophagy whole-body knockout mouse models, we provide alternative methods that enable the modulation and detection of autophagic flux in vivo, discussing advantages and disadvantages of each method. RECENT FINDINGS With the autophagosome-lysosome fusion inhibitor colchicine in skeletal muscle and temporal downregulation of autophagy using a novel Autophagy related 5-short hairpin RNA (Atg5-shRNA) mouse model we mention two models that directly modulate autophagy flux in vivo. Furthermore, methods to quantify autophagy flux, such as mitophagy transgenic reporters, in situ immunofluorescent staining and multispectral imaging flow cytometry, in mature skeletal muscle and cells are addressed. SUMMARY To achieve clinical benefit, less toxic, temporary and cell-type-specific modulation of autophagy should be pursued further. A temporary knockdown as described for the Atg5-shRNA mice could provide a first insight into possible implications of autophagy inhibition. However, it is also important to take a closer look into the methods to evaluate autophagy after harvesting the tissue. In particular caution is required when experimental conditions can influence the final measurement and this should be pretested carefully.
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Affiliation(s)
- Jeannette König
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal
- German Center for Diabetes Research (DZD), Munich
| | - Tilman Grune
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal
- German Center for Diabetes Research (DZD), Munich
- Institute of Nutrition, University of Potsdam, Nuthetal
| | - Christiane Ott
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), Nuthetal
- DZHK (German Centre of Cardiovascular Research), partner site Berlin, Germany
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Wang D, Huang Z, Li L, Yuan Y, Xiang L, Wu X, Ni C, Yu W. Intracarotid cold saline infusion contributes to neuroprotection in MCAO‑induced ischemic stroke in rats via serum and glucocorticoid‑regulated kinase 1. Mol Med Rep 2019; 20:3942-3950. [PMID: 31485662 DOI: 10.3892/mmr.2019.10599] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Accepted: 07/16/2019] [Indexed: 11/05/2022] Open
Abstract
Intracarotid cold saline infusion (ICSI) brings about neuroprotective effects in ischemic stroke. However, the involvement of serum and glucocorticoid‑regulated kinase 1 (SGK1) in the underlying mechanism of ICSI is not fully understood; therefore, we used the rat middle cerebral artery occlusion (MCAO) model to investigate the neuroprotective effects of ICSI on ischemic stroke in rats, as well as the involvement of SGK1 in these effects. ICSI decreased infarct size and brain swelling, as determined by 2,3,5‑triphenyltetrazolium chloride staining and the dry‑wet weight method, respectively. The results of terminal deoxynucleotidyl transferase mediated nick end labeling (TUNEL) and Nissl staining showed that ICSI also suppressed apoptosis and increased the relative integral optical density (IOD) values of Nissl bodies in the rat MCAO model. Regarding the mechanism, the results of immunohistochemistry and western blotting revealed that ICSI upregulated SGK1 expression and downregulated beclin‑1 and LC‑3 expression in the rat MCAO model. In addition, SGK1 knockdown increased ICSI‑mediated infarct size and brain swelling, promoted apoptosis, and reduced the IOD values of Nissl bodies in the rat MCAO model. In addition, we found that SGK1 knockdown upregulated beclin‑1 and LC‑3 expression mediated by ICSI. Overall, ICSI had a neuroprotective effect on ischemic stroke after reperfusion by upregulating SGK1 and inhibiting autophagy.
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Affiliation(s)
- Dazhi Wang
- Department of Interventional Radiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Zhi Huang
- Department of Interventional Radiology, The Second Affiliated Hospital of Guizhou Medical University, Kaili, Guizhou 556000, P.R. China
| | - Lei Li
- Department of General Courses, People's Armed College of Guizhou University, Guiyang, Guizhou 550025, P.R. China
| | - Yingnan Yuan
- School of Medical Imaging, Guizhou Medical University, Guiyang, Guizhou 550002, P.R. China
| | - Lei Xiang
- School of Medical Imaging, Guizhou Medical University, Guiyang, Guizhou 550002, P.R. China
| | - Xiaowen Wu
- School of Medical Imaging, Guizhou Medical University, Guiyang, Guizhou 550002, P.R. China
| | - Caifang Ni
- Department of Interventional Radiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215006, P.R. China
| | - Wenfeng Yu
- Key Laboratory of Molecular Biology, Guizhou Medical University, Guiyang, Guizhou 550002, P.R. China
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Huang W, Cheng C, Shan W, Ding Z, Liu F, Lu W, He W, Xu J, Yin Z. Knockdown of SGK1 alleviates the IL‐1β‐induced chondrocyte anabolic and catabolic imbalance by activating FoxO1‐mediated autophagy in human chondrocytes. FEBS J 2019; 287:94-107. [PMID: 31330080 DOI: 10.1111/febs.15009] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 05/11/2019] [Accepted: 07/19/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Wei Huang
- Department of Orthopaedics The First Affiliated Hospital of Anhui Medical University Hefei China
- Department of Orthopaedics, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine University of Science and Technology of China Hefei China
| | - Chao Cheng
- Department of Orthopaedics The First Affiliated Hospital of Anhui Medical University Hefei China
| | - Wen‐Shan Shan
- Department of Orthopaedics The First Affiliated Hospital of Anhui Medical University Hefei China
| | - Zhen‐Fei Ding
- Department of Orthopaedics The First Affiliated Hospital of Anhui Medical University Hefei China
| | - Fu‐En Liu
- Department of Orthopaedics The First Affiliated Hospital of Anhui Medical University Hefei China
| | - Wei Lu
- Department of Orthopaedics The First Affiliated Hospital of Anhui Medical University Hefei China
| | - Wei He
- School of Basic Medical Sciences Anhui Medical University Hefei China
| | - Jie‐Gou Xu
- School of Basic Medical Sciences Anhui Medical University Hefei China
| | - Zong‐Sheng Yin
- Department of Orthopaedics The First Affiliated Hospital of Anhui Medical University Hefei China
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