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Dubey G, Singh M, Singh H, Agarwal M, Chandel SS, Mishra A, Singh RP, Kukreti N. Emerging roles of SnoRNAs in the pathogenesis and treatment of autoimmune disorders. Pathol Res Pract 2024; 253:154952. [PMID: 38000202 DOI: 10.1016/j.prp.2023.154952] [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: 10/23/2023] [Revised: 11/13/2023] [Accepted: 11/15/2023] [Indexed: 11/26/2023]
Abstract
SnoRNAs (small non-coding RNAs) have recently gained prominence in autoimmune diseases, revealing their crucial role in modulating the immune response and contributing to disease pathogenesis. Initially known for their involvement in ribosomal RNA processing and modification, molecular biology and genomics advancements have uncovered their broader impact on cellular function, especially in autoimmune disorders. Autoimmune diseases represent conditions characterized by the immune system's erroneous attacks on self-tissues, encompassing disorders like systemic lupus erythematosus, rheumatoid arthritis, and multiple sclerosis. The complex etiology of these conditions involves a delicate interplay of genetic and environmental factors. Emerging evidence suggests that snoRNAs initially recognized for their housekeeping roles, extend their influence on immune regulation through diverse mechanisms. SnoRNAs have been implicated in epigenetic modification, directly affecting the gene expression profiles of immune cells. Their ability to guide site-specific changes on ribosomal RNAs and other non-coding RNAs can significantly influence the translation of proteins involved in immune response pathways. Moreover, snoRNAs interact with key immune-related proteins, modulating their functions and subsequently impacting immune cell development, activation, and tolerance. Dysregulation of snoRNA expression has been observed in various autoimmune diseases, underscoring their potential as biomarkers for disease diagnosis, prognosis, and therapeutic targets. Manipulating snoRNA expression or activity is a promising therapeutic intervention avenue, offering the potential for personalized treatment strategies in autoimmune diseases. However, there remains a need for comprehensive research efforts to elucidate the precise molecular mechanisms underlying snoRNA-mediated immune modulation. Further investigations in this domain are essential to unravel the potential of snoRNAs in autoimmune disorders.
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Affiliation(s)
- Gaurav Dubey
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, India
| | - Mithilesh Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, India.
| | - Himmat Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, India
| | - Mohit Agarwal
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, India
| | | | - Anurag Mishra
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, India
| | - Ravindra Pal Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, India
| | - Neelima Kukreti
- School of Pharmacy, Graphic Era Hill University, Dehradun 248007, India
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2
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Sun X, Wang G, Luo W, Gu H, Ma W, Wei X, Liu D, Jia S, Cao S, Wang Y, Yuan Z. Small but strong: the emerging role of small nucleolar RNA in cardiovascular diseases. Front Cell Dev Biol 2023; 11:1292925. [PMID: 38033868 PMCID: PMC10682241 DOI: 10.3389/fcell.2023.1292925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 10/30/2023] [Indexed: 12/02/2023] Open
Abstract
Cardiovascular diseases (CVDs) are the leading cause of mortality and disability worldwide. Numerous studies have demonstrated that non-coding RNAs (ncRNAs) play a primary role in CVD development. Therefore, studies on the mechanisms of ncRNAs are essential for further efforts to prevent and treat CVDs. Small nucleolar RNAs (snoRNAs) are a novel species of non-conventional ncRNAs that guide post-transcriptional modifications and the subsequent maturation of small nuclear RNA and ribosomal RNA. Evidently, snoRNAs are extensively expressed in human tissues and may regulate different illnesses. Particularly, as the next-generation sequencing techniques have progressed, snoRNAs have been shown to be differentially expressed in CVDs, suggesting that they may play a role in the occurrence and progression of cardiac illnesses. However, the molecular processes and signaling pathways underlying the function of snoRNAs remain unidentified. Therefore, it is of great value to comprehensively investigate the association between snoRNAs and CVDs. The aim of this review was to collate existing literature on the biogenesis, characteristics, and potential regulatory mechanisms of snoRNAs. In particular, we present a scientific update on these snoRNAs and their relevance to CVDs in an effort to cast new light on the functions of snoRNAs in the clinical diagnosis of CVDs.
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Affiliation(s)
- Xue Sun
- Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Gebang Wang
- Department of Thoracic Surgery, Liaoning Cancer Hospital and Institute, Cancer Hospital of Dalian University of Technology, Shenyang, Liaoning, China
| | - Wenting Luo
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Hui Gu
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Wei Ma
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Xiaowei Wei
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Dan Liu
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Shanshan Jia
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Songying Cao
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Yu Wang
- Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
| | - Zhengwei Yuan
- Key Laboratory of Health Ministry for Congenital Malformation, Shengjing Hospital of China Medical University, Shenyang, Liaoning, China
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Hammoudeh N, Soukkarieh C, Murphy DJ, Hanano A. Mammalian lipid droplets: structural, pathological, immunological and anti-toxicological roles. Prog Lipid Res 2023; 91:101233. [PMID: 37156444 DOI: 10.1016/j.plipres.2023.101233] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 04/30/2023] [Accepted: 05/05/2023] [Indexed: 05/10/2023]
Abstract
Mammalian lipid droplets (LDs) are specialized cytosolic organelles consisting of a neutral lipid core surrounded by a membrane made up of a phospholipid monolayer and a specific population of proteins that varies according to the location and function of each LD. Over the past decade, there have been significant advances in the understanding of LD biogenesis and functions. LDs are now recognized as dynamic organelles that participate in many aspects of cellular homeostasis plus other vital functions. LD biogenesis is a complex, highly-regulated process with assembly occurring on the endoplasmic reticulum although aspects of the underpinning molecular mechanisms remain elusive. For example, it is unclear how many enzymes participate in the biosynthesis of the neutral lipid components of LDs and how this process is coordinated in response to different metabolic cues to promote or suppress LD formation and turnover. In addition to enzymes involved in the biosynthesis of neutral lipids, various scaffolding proteins play roles in coordinating LD formation. Despite their lack of ultrastructural diversity, LDs in different mammalian cell types are involved in a wide range of biological functions. These include roles in membrane homeostasis, regulation of hypoxia, neoplastic inflammatory responses, cellular oxidative status, lipid peroxidation, and protection against potentially toxic intracellular fatty acids and lipophilic xenobiotics. Herein, the roles of mammalian LDs and their associated proteins are reviewed with a particular focus on their roles in pathological, immunological and anti-toxicological processes.
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Affiliation(s)
- Nour Hammoudeh
- Department of Animal Biology, Faculty of Sciences, University of Damascus, Damascus, Syria
| | - Chadi Soukkarieh
- Department of Animal Biology, Faculty of Sciences, University of Damascus, Damascus, Syria
| | - Denis J Murphy
- School of Applied Sciences, University of South Wales, Pontypridd, CF37 1DL, Wales, United Kingdom..
| | - Abdulsamie Hanano
- Department of Molecular Biology and Biotechnology, Atomic Energy Commission of Syria (AECS), P.O. Box 6091, Damascus, Syria..
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4
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Nossent AY, Binder CJ. Noncoding RNAs in atherosclerosis. Atherosclerosis 2023; 374:21-23. [PMID: 37169701 DOI: 10.1016/j.atherosclerosis.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Affiliation(s)
- Anne Yaël Nossent
- Department of Surgery and Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands.
| | - Christoph J Binder
- Department for Laboratory Medicine, Medical University of Vienna, Vienna, Austria.
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Dou J, Thangaraj SV, Puttabyatappa M, Elangovan VR, Bakulski K, Padmanabhan V. Developmental programming: Adipose depot-specific regulation of non-coding RNAs and their relation to coding RNA expression in prenatal testosterone and prenatal bisphenol-A -treated female sheep. Mol Cell Endocrinol 2023; 564:111868. [PMID: 36708980 PMCID: PMC10069610 DOI: 10.1016/j.mce.2023.111868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/19/2023] [Accepted: 01/22/2023] [Indexed: 01/27/2023]
Abstract
Inappropriate developmental exposure to steroids is linked to metabolic disorders. Prenatal testosterone excess or bisphenol A (BPA, an environmental estrogen mimic) leads to insulin resistance and adipocyte disruptions in female lambs. Adipocytes are key regulators of insulin sensitivity. Metabolic tissue-specific differences in insulin sensitivity coupled with adipose depot-specific changes in key mRNAs, were previously observed with prenatal steroid exposure. We hypothesized that depot-specific changes in the non-coding RNA (ncRNA) - regulators of gene expression would account for the direction of changes seen in mRNAs. Non-coding RNA (lncRNA, miRNA, snoRNA, snRNA) from various adipose depots of prenatal testosterone and BPA-treated animals were sequenced. Adipose depot-specific changes in the ncRNA that are consistent with the depot-specific mRNA expression in terms of directionality of changes and functional implications in insulin resistance, adipocyte differentiation and cardiac hypertrophy were found. Importantly, the adipose depot-specific ncRNA changes were model-specific and mutually exclusive, suggestive of different regulatory entry points in this regulation.
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Affiliation(s)
- John Dou
- Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA
| | | | | | | | - Kelly Bakulski
- Department of Epidemiology, University of Michigan, Ann Arbor, MI, USA.
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Webster SF, Ghalei H. Maturation of small nucleolar RNAs: from production to function. RNA Biol 2023; 20:715-736. [PMID: 37796118 PMCID: PMC10557570 DOI: 10.1080/15476286.2023.2254540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2023] [Indexed: 10/06/2023] Open
Abstract
Small Nucleolar RNAs (snoRNAs) are an abundant group of non-coding RNAs with well-defined roles in ribosomal RNA processing, folding and chemical modification. Besides their classic roles in ribosome biogenesis, snoRNAs are also implicated in several other cellular activities including regulation of splicing, transcription, RNA editing, cellular trafficking, and miRNA-like functions. Mature snoRNAs must undergo a series of processing steps tightly regulated by transiently associating factors and coordinated with other cellular processes including transcription and splicing. In addition to their mature forms, snoRNAs can contribute to gene expression regulation through their derivatives and degradation products. Here, we review the current knowledge on mechanisms of snoRNA maturation, including the different pathways of processing, and the regulatory mechanisms that control snoRNA levels and complex assembly. We also discuss the significance of studying snoRNA maturation, highlight the gaps in the current knowledge and suggest directions for future research in this area.
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Affiliation(s)
- Sarah F. Webster
- Biochemistry, Cell, and Developmental Biology Graduate Program, Emory University, Atlanta, Georgia, USA
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
| | - Homa Ghalei
- Department of Biochemistry, Emory University, Atlanta, Georgia, USA
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Nucleolus and Nucleolar Stress: From Cell Fate Decision to Disease Development. Cells 2022; 11:cells11193017. [PMID: 36230979 PMCID: PMC9563748 DOI: 10.3390/cells11193017] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 09/19/2022] [Accepted: 09/22/2022] [Indexed: 11/30/2022] Open
Abstract
Besides the canonical function in ribosome biogenesis, there have been significant recent advances towards the fascinating roles of the nucleolus in stress response, cell destiny decision and disease progression. Nucleolar stress, an emerging concept describing aberrant nucleolar structure and function as a result of impaired rRNA synthesis and ribosome biogenesis under stress conditions, has been linked to a variety of signaling transductions, including but not limited to Mdm2-p53, NF-κB and HIF-1α pathways. Studies have uncovered that nucleolus is a stress sensor and signaling hub when cells encounter various stress conditions, such as nutrient deprivation, DNA damage and oxidative and thermal stress. Consequently, nucleolar stress plays a pivotal role in the determination of cell fate, such as apoptosis, senescence, autophagy and differentiation, in response to stress-induced damage. Nucleolar homeostasis has been involved in the pathogenesis of various chronic diseases, particularly tumorigenesis, neurodegenerative diseases and metabolic disorders. Mechanistic insights have revealed the indispensable role of nucleolus-initiated signaling in the progression of these diseases. Accordingly, the intervention of nucleolar stress may pave the path for developing novel therapies against these diseases. In this review, we systemically summarize recent findings linking the nucleolus to stress responses, signaling transduction and cell-fate decision, set the spotlight on the mechanisms by which nucleolar stress drives disease progression, and highlight the merit of the intervening nucleolus in disease treatment.
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Sommerauer C, Kutter C. Noncoding RNAs in liver physiology and metabolic diseases. Am J Physiol Cell Physiol 2022; 323:C1003-C1017. [PMID: 35968891 DOI: 10.1152/ajpcell.00232.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The liver holds central roles in detoxification, energy metabolism and whole-body homeostasis but can develop malignant phenotypes when being chronically overwhelmed with fatty acids and glucose. The global rise of metabolic-associated fatty liver disease (MAFLD) is already affecting a quarter of the global population. Pharmaceutical treatment options against different stages of MAFLD do not yet exist and several clinical trials against hepatic transcription factors and other proteins have failed. However, emerging roles of noncoding RNAs, including long (lncRNA) and short noncoding RNAs (sRNA), in various cellular processes pose exciting new avenues for treatment interventions. Actions of noncoding RNAs mostly rely on interactions with proteins, whereby the noncoding RNA fine-tunes protein function in a process termed riboregulation. The developmental stage-, disease stage- and cell type-specific nature of noncoding RNAs harbors enormous potential to precisely target certain cellular pathways in a spatio-temporally defined manner. Proteins interacting with RNAs can be categorized into canonical or non-canonical RNA binding proteins (RBPs) depending on the existence of classical RNA binding domains. Both, RNA- and RBP-centric methods have generated new knowledge of the RNA-RBP interface and added an additional regulatory layer. In this review, we summarize recent advances of how of RBP-lncRNA interactions and various sRNAs shape cellular physiology and the development of liver diseases such as MAFLD and hepatocellular carcinoma.
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Affiliation(s)
- Christian Sommerauer
- Science for Life Laboratory, Department of Microbiology, Tumor and Cell Biology, grid.4714.6Karolinska Institute, Stockholm, Sweden
| | - Claudia Kutter
- Science for Life Laboratory, Department of Microbiology, Tumor and Cell Biology, grid.4714.6Karolinska Institute, Stockholm, Sweden
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Splicing inactivation generates hybrid mRNA-snoRNA transcripts targeted by cytoplasmic RNA decay. Proc Natl Acad Sci U S A 2022; 119:e2202473119. [PMID: 35878033 PMCID: PMC9351541 DOI: 10.1073/pnas.2202473119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Many small nucleolar RNAs (snoRNA)s are processed from introns of host genes, but the importance of splicing for proper biogenesis and the fate of the snoRNAs is not well understood. Here, we show that inactivation of splicing factors or mutation of splicing signals leads to the accumulation of partially processed hybrid messenger RNA-snoRNA (hmsnoRNA) transcripts. hmsnoRNAs are processed to the mature 3' ends of the snoRNAs by the nuclear exosome and bound by small nucleolar ribonucleoproteins. hmsnoRNAs are unaffected by translation-coupled RNA quality-control pathways, but they are degraded by the major cytoplasmic exonuclease Xrn1p, due to their messenger RNA (mRNA)-like 5' extensions. These results show that completion of splicing is required to promote complete and accurate processing of intron-encoded snoRNAs and that splicing defects lead to degradation of hybrid mRNA-snoRNA species by cytoplasmic decay, underscoring the importance of splicing for the biogenesis of intron-encoded snoRNAs.
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10
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Bathish B, Robertson H, Dillon JF, Dinkova-Kostova AT, Hayes JD. Nonalcoholic steatohepatitis and mechanisms by which it is ameliorated by activation of the CNC-bZIP transcription factor Nrf2. Free Radic Biol Med 2022; 188:221-261. [PMID: 35728768 DOI: 10.1016/j.freeradbiomed.2022.06.226] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 06/13/2022] [Indexed: 12/11/2022]
Abstract
Non-alcoholic steatohepatitis (NASH) represents a global health concern. It is characterised by fatty liver, hepatocyte cell death and inflammation, which are associated with lipotoxicity, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, iron overload and oxidative stress. NF-E2 p45-related factor 2 (Nrf2) is a transcription factor that combats oxidative stress. Remarkably, Nrf2 is downregulated during the development of NASH, which probably accelerates disease, whereas in pre-clinical studies the upregulation of Nrf2 inhibits NASH. We now review the scientific literature that proposes Nrf2 downregulation during NASH involves its increased ubiquitylation and proteasomal degradation, mediated by Kelch-like ECH-associated protein 1 (Keap1) and/or β-transducin repeat-containing protein (β-TrCP) and/or HMG-CoA reductase degradation protein 1 (Hrd1, also called synoviolin (SYVN1)). Additionally, downregulation of Nrf2-mediated transcription during NASH may involve diminished recruitment of coactivators by Nrf2, due to increased levels of activating transcription factor 3 (ATF3) and nuclear factor-kappaB (NF-κB) p65, or competition for promoter binding due to upregulation of BTB and CNC homology 1 (Bach1). Many processes that downregulate Nrf2 are triggered by transforming growth factor-beta (TGF-β), with oxidative stress amplifying its signalling. Oxidative stress may also increase suppression of Nrf2 by β-TrCP through facilitating formation of the DSGIS-containing phosphodegron in Nrf2 by glycogen synthase kinase-3. In animal models, knockout of Nrf2 increases susceptibility to NASH, while pharmacological activation of Nrf2 by inducing agents that target Keap1 inhibits development of NASH. These inducing agents probably counter Nrf2 downregulation affected by β-TrCP, Hrd1/SYVN1, ATF3, NF-κB p65 and Bach1, by suppressing oxidative stress. Activation of Nrf2 is also likely to inhibit NASH by ameliorating lipotoxicity, inflammation, ER stress and iron overload. Crucially, pharmacological activation of Nrf2 in mice in which NASH has already been established supresses liver steatosis and inflammation. There is therefore compelling evidence that pharmacological activation of Nrf2 provides a comprehensive multipronged strategy to treat NASH.
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Affiliation(s)
- Boushra Bathish
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, Scotland, UK
| | - Holly Robertson
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, Scotland, UK; Wellcome Trust Sanger Institute, Wellcome Genome Campus, Cambridge, CB10 1SA, UK
| | - John F Dillon
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK
| | - Albena T Dinkova-Kostova
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, Scotland, UK
| | - John D Hayes
- Jacqui Wood Cancer Centre, Division of Cellular Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, Scotland, UK.
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11
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The Importance of Lipoprotein Lipase Regulation in Atherosclerosis. Biomedicines 2021; 9:biomedicines9070782. [PMID: 34356847 PMCID: PMC8301479 DOI: 10.3390/biomedicines9070782] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/02/2021] [Accepted: 07/04/2021] [Indexed: 02/07/2023] Open
Abstract
Lipoprotein lipase (LPL) plays a major role in the lipid homeostasis mainly by mediating the intravascular lipolysis of triglyceride rich lipoproteins. Impaired LPL activity leads to the accumulation of chylomicrons and very low-density lipoproteins (VLDL) in plasma, resulting in hypertriglyceridemia. While low-density lipoprotein cholesterol (LDL-C) is recognized as a primary risk factor for atherosclerosis, hypertriglyceridemia has been shown to be an independent risk factor for cardiovascular disease (CVD) and a residual risk factor in atherosclerosis development. In this review, we focus on the lipolysis machinery and discuss the potential role of triglycerides, remnant particles, and lipolysis mediators in the onset and progression of atherosclerotic cardiovascular disease (ASCVD). This review details a number of important factors involved in the maturation and transportation of LPL to the capillaries, where the triglycerides are hydrolyzed, generating remnant lipoproteins. Moreover, LPL and other factors involved in intravascular lipolysis are also reported to impact the clearance of remnant lipoproteins from plasma and promote lipoprotein retention in capillaries. Apolipoproteins (Apo) and angiopoietin-like proteins (ANGPTLs) play a crucial role in regulating LPL activity and recent insights into LPL regulation may elucidate new pharmacological means to address the challenge of hypertriglyceridemia in atherosclerosis development.
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Fafard-Couture É, Bergeron D, Couture S, Abou-Elela S, Scott MS. Annotation of snoRNA abundance across human tissues reveals complex snoRNA-host gene relationships. Genome Biol 2021; 22:172. [PMID: 34088344 PMCID: PMC8176728 DOI: 10.1186/s13059-021-02391-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Accepted: 05/26/2021] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Small nucleolar RNAs (snoRNAs) are mid-size non-coding RNAs required for ribosomal RNA modification, implying a ubiquitous tissue distribution linked to ribosome synthesis. However, increasing numbers of studies identify extra-ribosomal roles of snoRNAs in modulating gene expression, suggesting more complex snoRNA abundance patterns. Therefore, there is a great need for mapping the snoRNome in different human tissues as the blueprint for snoRNA functions. RESULTS We used a low structure bias RNA-Seq approach to accurately quantify snoRNAs and compare them to the entire transcriptome in seven healthy human tissues (breast, ovary, prostate, testis, skeletal muscle, liver, and brain). We identify 475 expressed snoRNAs categorized in two abundance classes that differ significantly in their function, conservation level, and correlation with their host gene: 390 snoRNAs are uniformly expressed and 85 are enriched in the brain or reproductive tissues. Most tissue-enriched snoRNAs are embedded in lncRNAs and display strong correlation of abundance with them, whereas uniformly expressed snoRNAs are mostly embedded in protein-coding host genes and are mainly non- or anticorrelated with them. Fifty-nine percent of the non-correlated or anticorrelated protein-coding host gene/snoRNA pairs feature dual-initiation promoters, compared to only 16% of the correlated non-coding host gene/snoRNA pairs. CONCLUSIONS Our results demonstrate that snoRNAs are not a single homogeneous group of housekeeping genes but include highly regulated tissue-enriched RNAs. Indeed, our work indicates that the architecture of snoRNA host genes varies to uncouple the host and snoRNA expressions in order to meet the different snoRNA abundance levels and functional needs of human tissues.
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Affiliation(s)
- Étienne Fafard-Couture
- Département de biochimie et de génomique fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, J1E 4 K8, Canada
| | - Danny Bergeron
- Département de biochimie et de génomique fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, J1E 4 K8, Canada
| | - Sonia Couture
- Département de microbiologie et d'infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, J1E 4 K8, Canada
| | - Sherif Abou-Elela
- Département de microbiologie et d'infectiologie, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, J1E 4 K8, Canada.
| | - Michelle S Scott
- Département de biochimie et de génomique fonctionnelle, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, J1E 4 K8, Canada.
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13
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Kakiyama G, Marques D, Martin R, Takei H, Rodriguez-Agudo D, LaSalle SA, Hashiguchi T, Liu X, Green R, Erickson S, Gil G, Fuchs M, Suzuki M, Murai T, Nittono H, Hylemon PB, Zhou H, Pandak WM. Insulin resistance dysregulates CYP7B1 leading to oxysterol accumulation: a pathway for NAFL to NASH transition. J Lipid Res 2020; 61:1629-1644. [PMID: 33008924 DOI: 10.1194/jlr.ra120000924] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
NAFLD is an important public health issue closely associated with the pervasive epidemics of diabetes and obesity. Yet, despite NAFLD being among the most common of chronic liver diseases, the biological factors responsible for its transition from benign nonalcoholic fatty liver (NAFL) to NASH remain unclear. This lack of knowledge leads to a decreased ability to find relevant animal models, predict disease progression, or develop clinical treatments. In the current study, we used multiple mouse models of NAFLD, human correlation data, and selective gene overexpression of steroidogenic acute regulatory protein (StarD1) in mice to elucidate a plausible mechanistic pathway for promoting the transition from NAFL to NASH. We show that oxysterol 7α-hydroxylase (CYP7B1) controls the levels of intracellular regulatory oxysterols generated by the "acidic/alternative" pathway of cholesterol metabolism. Specifically, we report data showing that an inability to upregulate CYP7B1, in the setting of insulin resistance, results in the accumulation of toxic intracellular cholesterol metabolites that promote inflammation and hepatocyte injury. This metabolic pathway, initiated and exacerbated by insulin resistance, offers insight into approaches for the treatment of NAFLD.
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Affiliation(s)
- Genta Kakiyama
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA; Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA.
| | - Dalila Marques
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA; Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | - Rebecca Martin
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Hajime Takei
- Junshin Clinic Bile Acid Institute, Tokyo, Japan
| | - Daniel Rodriguez-Agudo
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA; Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | - Sandra A LaSalle
- Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | | | - Xiaoying Liu
- Department of Medicine, Northwestern University, Chicago, IL, USA
| | - Richard Green
- Department of Medicine, Northwestern University, Chicago, IL, USA
| | - Sandra Erickson
- School of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Gregorio Gil
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, VA, USA; Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Michael Fuchs
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA; Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA
| | - Mitsuyoshi Suzuki
- Department of Pediatrics, Juntendo University Faculty of Medicine, Tokyo, Japan
| | - Tsuyoshi Murai
- School of Pharmaceutical Sciences, Health Sciences University of Hokkaido, Hokkaido, Japan
| | | | - Phillip B Hylemon
- Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA; Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA; Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - Huiping Zhou
- Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA; Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA; Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
| | - William M Pandak
- Department of Internal Medicine, Virginia Commonwealth University, Richmond, VA, USA; Department of Veterans Affairs, McGuire Veterans Administration Medical Center, Richmond, VA, USA; Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, USA
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