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Feng R, Patil S, Zhao X, Miao Z, Qian A. RNA Therapeutics - Research and Clinical Advancements. Front Mol Biosci 2021; 8:710738. [PMID: 34631795 PMCID: PMC8492966 DOI: 10.3389/fmolb.2021.710738] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 09/07/2021] [Indexed: 12/16/2022] Open
Abstract
RNA therapeutics involve the use of coding RNA such as mRNA as well as non-coding RNAs such as small interfering RNAs (siRNA), antisense oligonucleotides (ASO) to target mRNA, aptamers, ribozymes, and clustered regularly interspaced short palindromic repeats-CRISPR-associated (CRISPR/Cas) endonuclease to target proteins and DNA. Due to their diverse targeting ability and research in RNA modification and delivery systems, RNA-based formulations have emerged as suitable treatment options for many diseases. Therefore, in this article, we have summarized different RNA therapeutics, their targeting strategies, and clinical progress for various diseases as well as limitations; so that it might help researchers formulate new and advanced RNA therapeutics for various diseases. Additionally, U.S. Food and Drug Administration (USFDA)-approved RNA-based therapeutics have also been discussed.
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Affiliation(s)
- Rundong Feng
- Shaanxi Institute for Food and Drug Control, Xi'an, China
| | - Suryaji Patil
- Lab for Bone Metabolism, Xi'an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Xin Zhao
- School of Pharmacy, Shaanxi Institute of International Trade & Commerce, Xi'an, China
| | - Zhiping Miao
- Lab for Bone Metabolism, Xi'an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
| | - Airong Qian
- Lab for Bone Metabolism, Xi'an Key Laboratory of Special Medicine and Health Engineering, Key Lab for Space Biosciences and Biotechnology, Research Center for Special Medicine and Health Systems Engineering, NPU-UAB Joint Laboratory for Bone Metabolism, School of Life Sciences, Northwestern Polytechnical University, Xi'an, China
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Churm R, Davies JS, Stephens JW, Prior SL. Ghrelin function in human obesity and type 2 diabetes: a concise review. Obes Rev 2017; 18:140-148. [PMID: 27899023 DOI: 10.1111/obr.12474] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/06/2016] [Accepted: 09/06/2016] [Indexed: 12/12/2022]
Abstract
The 28 amino acid hormone, ghrelin, has been found to have various effects on metabolism. This review will focus on the pathways integrated into ghrelin's effect within the hypothalamus, pancreas and adipocytes. The identification of molecules and pathways that regulate ghrelin-mediated lipid retention could establish new mechanisms underlying cellular energy homeostasis. The impact of acyl-ghrelin on glucose metabolism and lipid homeostasis may allow for novel preventative or early intervention therapeutic strategies to treat obesity related type 2 diabetes and associated metabolic dysfunction.
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Affiliation(s)
- R Churm
- Diabetes Research Group, Institute of Life Science 1, Swansea University, Swansea, UK
| | - J S Davies
- Molecular Neurobiology Research Group, Institute of Life Science 1, Swansea University, Swansea, UK
| | - J W Stephens
- Diabetes Research Group, Institute of Life Science 1, Swansea University, Swansea, UK
| | - S L Prior
- Diabetes Research Group, Institute of Life Science 1, Swansea University, Swansea, UK
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Merlino DJ, Blomain ES, Aing AS, Waldman SA. Gut-Brain Endocrine Axes in Weight Regulation and Obesity Pharmacotherapy. J Clin Med 2014; 3:763-94. [PMID: 26237477 PMCID: PMC4449653 DOI: 10.3390/jcm3030763] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 05/29/2014] [Accepted: 06/16/2014] [Indexed: 12/21/2022] Open
Abstract
In recent years, the obesity epidemic has developed into a major health crisis both in the United States as well as throughout the developed world. With current treatments limited to expensive, high-risk surgery and minimally efficacious pharmacotherapy, new therapeutic options are urgently needed to combat this alarming trend. This review focuses on the endogenous gut-brain signaling axes that regulate appetite under physiological conditions, and discusses their clinical relevance by summarizing the clinical and preclinical studies that have investigated manipulation of these pathways to treat obesity.
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Affiliation(s)
- Dante J Merlino
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, JAH 368, Philadelphia, PA 19107, USA.
| | - Erik S Blomain
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, JAH 368, Philadelphia, PA 19107, USA.
| | - Amanda S Aing
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, JAH 368, Philadelphia, PA 19107, USA.
| | - Scott A Waldman
- Department of Pharmacology and Experimental Therapeutics, Thomas Jefferson University, 1020 Locust Street, JAH 368, Philadelphia, PA 19107, USA.
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Fung JNT, Jeffery PL, Lee JD, Seim I, Roche D, Obermair A, Chopin LK, Chen C. Silencing of ghrelin receptor expression inhibits endometrial cancer cell growth in vitro and in vivo. Am J Physiol Endocrinol Metab 2013; 305:E305-13. [PMID: 23736537 DOI: 10.1152/ajpendo.00156.2013] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ghrelin is a 28-amino acid peptide hormone produced predominantly in the stomach but also in a range of normal cell types and tumors, where it has endocrine, paracrine, and autocrine roles. Previously, we have demonstrated that ghrelin has proliferative and antiapoptotic effects in endometrial cancer cell lines, suggesting a potential role in promoting tumor growth. In the present study, we investigated the effect of ghrelin receptor, GHSR, and gene silencing in vitro and in vivo and characterized ghrelin and GHSR1a protein expression in human endometrial tumors. GHSR gene silencing was achieved in the Ishikawa and KLE endometrial cancer cell lines, using a lentiviral short-hairpin RNA targeting GHSR. The effects of GHSR1a knockdown were further analyzed in vivo using the Ishikawa cell line in a NOD/SCID xenograft model. Cell proliferation was reduced in cultured GHSR1a knockdown Ishikawa and KLE cells compared with scrambled controls in the absence of exogenously applied ghrelin and in response to exogenous ghrelin (1,000 nM). The tumor volumes were reduced significantly in GHSR1a knockdown Ishikawa mouse xenograft tumors compared with scrambled control tumours. Using immunohistochemistry, we demonstrated that ghrelin and GHSR1a are expressed in benign and cancerous glands in human endometrial tissue specimens, although there was no correlation between the intensity of staining and cancer grade. These data indicate that downregulation of GHSR expression significantly inhibits endometrial cancer cell line and mouse xenograft tumour growth. This is the first preclinical evidence that downregulation of GHSR may be therapeutic in endometrial cancer.
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Affiliation(s)
- Jenny N T Fung
- School of Biomedical Sciences, University of Queensland, St. Lucia, Queensland, Australia
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Kim GW, Lin JE, Blomain ES, Waldman SA. New advances in models and strategies for developing anti-obesity drugs. Expert Opin Drug Discov 2013; 8:655-71. [PMID: 23621300 DOI: 10.1517/17460441.2013.792804] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
INTRODUCTION Obesity is a worldwide pandemic. Obesity-related health and economic costs are staggering. Existing strategies to combat obesity through lifestyle improvements and medical intervention have had limited success. Pharmacotherapy, in combination with lifestyle modification, may play a vital role in reversing the disease burden. However, past and current weight-loss medications have had serious safety risks, notably cardiovascular and psychiatric events. AREAS COVERED The authors review the strategies for designing new anti-obesity drugs by describing those currently in development. They describe their target, mechanism of action and developmental or regulatory status. Furthermore, they discuss the problem of weight regain following weight loss, and its relevance to the long-term success of anti-obesity pharmacotherapy. EXPERT OPINION For weight management drugs to achieve the safety and efficacy required to be impactful, current studies are uncovering and characterizing new targets, including new signaling circuits and hormones regulating appetite and metabolism, and re-evaluating the role of pharmacotherapy in weight management. To avoid the safety failures of many past weight-loss drugs, the models and strategies covered in this article incorporate recent advances in knowledge and technology. We discuss the emergence of cGMP signaling as a potentially transformative target in weight management. Modulating cGMP signaling may represent an ideal goal for an anti-obesity pharmacotherapy, reflecting some of the major themes described in the present review: targeting pathways that are newly realized as relevant for weight management; promoting safety by re-purposing drugs that are safe, proven, and approved for clinical use; and having a synergistic effect on multiple, reinforcing pathways.
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Affiliation(s)
- Gilbert W Kim
- Thomas Jefferson University, Department of Pharmacology and Experimental Therapeutics, Philadelphia, PA 19107, USA
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Patterson M, Bloom SR, Gardiner JV. Ghrelin and appetite control in humans--potential application in the treatment of obesity. Peptides 2011; 32:2290-4. [PMID: 21835215 DOI: 10.1016/j.peptides.2011.07.021] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Revised: 06/13/2011] [Accepted: 07/22/2011] [Indexed: 12/15/2022]
Abstract
Ghrelin is a peptide hormone secreted into circulation from the stomach. It has been postulated to act as a signal of hunger. Ghrelin administration acutely increases energy intake in lean and obese humans and chronically induces weight gain and adiposity in rodents. Circulating ghrelin levels are elevated by fasting and suppressed following a meal. Inhibiting ghrelin signaling therefore appears an attractive target for anti-obesity therapies. A number of different approaches to inhibiting the ghrelin system to treat obesity have been explored. Despite this, over a decade after its discovery, no ghrelin based anti-obesity therapies are close to reaching the market. This article discusses the role of ghrelin in appetite control in humans, examines different approaches to inhibiting the ghrelin system and assesses their potential as anti-obesity therapies.
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Affiliation(s)
- Michael Patterson
- Department of Investigative Medicine, Hammersmith Hospital, Imperial College London, 6th Floor Commonwealth Building, Du Cane Road, London W12 0NN, UK
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Smit MJ, Vischer HF, Bakker RA, Jongejan A, Timmerman H, Pardo L, Leurs R. Pharmacogenomic and Structural Analysis of Constitutive G Protein–Coupled Receptor Activity. Annu Rev Pharmacol Toxicol 2007; 47:53-87. [PMID: 17029567 DOI: 10.1146/annurev.pharmtox.47.120505.105126] [Citation(s) in RCA: 145] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
G protein-coupled receptors (GPCRs) respond to a chemically diverse plethora of signal transduction molecules. The notion that GPCRs also signal without an external chemical trigger, i.e., in a constitutive or spontaneous manner, resulted in a paradigm shift in the field of GPCR pharmacology. The discovery of constitutive GPCR activity and the fact that GPCR binding and signaling can be strongly affected by a single point mutation drew attention to the evolving area of GPCR pharmacogenomics. For a variety of GPCRs, point mutations have been convincingly linked to human disease. Mutations within conserved motifs, known to be involved in GPCR activation, might explain the properties of some naturally occurring, constitutively active GPCR variants linked to disease. In this review, we provide a brief historical introduction to the concept of constitutive receptor activity and the pharmacogenomic and structural aspects of constitutive receptor activity.
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Affiliation(s)
- Martine J Smit
- Leiden/Amsterdam Center for Drug Research, Division of Medicinal Chemistry, Vrije Universiteit, Faculty of Sciences, Department of Chemistry, 1081 HV Amsterdam, The Netherlands.
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Muccioli G, Baragli A, Granata R, Papotti M, Ghigo E. Heterogeneity of ghrelin/growth hormone secretagogue receptors. Toward the understanding of the molecular identity of novel ghrelin/GHS receptors. Neuroendocrinology 2007; 86:147-64. [PMID: 17622734 DOI: 10.1159/000105141] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Accepted: 05/21/2007] [Indexed: 12/23/2022]
Abstract
Ghrelin is a gastric polypeptide displaying strong GH-releasing activity by activation of the type 1a GH secretagogue receptor (GHS-R1a) located in the hypothalamus-pituitary axis. GHS-R1a is a G-protein-coupled receptor that, upon the binding of ghrelin or synthetic peptidyl and non-peptidyl ghrelin-mimetic agents known as GHS, preferentially couples to G(q), ultimately leading to increased intracellular calcium content. Beside the potent GH-releasing action, ghrelin and GHS influence food intake, gut motility, sleep, memory and behavior, glucose and lipid metabolism, cardiovascular performances, cell proliferation, immunological responses and reproduction. A growing body of evidence suggests that the cloned GHS-R1a alone cannot be the responsible for all these effects. The cloned GHS-R1b splice variant is apparently non-ghrelin/GHS-responsive, despite demonstration of expression in neoplastic tissues responsive to ghrelin not expressing GHS-R1a; GHS-R1a homologues sensitive to ghrelin are capable of interaction with GHS-R1b, forming heterodimeric species. Furthermore, GHS-R1a-deficient mice do not show evident abnormalities in growth and diet-induced obesity, suggesting the involvement of another receptor. Additional evidence of the existence of another receptor is that ghrelin and GHS do not always share the same biological activities and activate a variety of intracellular signalling systems besides G(q). The biological actions on the heart, adipose tissue, pancreas, cancer cells and brain shared by ghrelin and the non-acylated form of ghrelin (des-octanoyl ghrelin), which does not bind GHS-R1a, represent the best evidence for the existence of a still unknown, functionally active binding site for this family of molecules. Finally, located in the heart and blood vessels is the scavenger receptor CD36, involved in the endocytosis of the pro-atherogenic oxidized low-density lipoproteins, which is a pharmacologically and structurally distinct receptor for peptidyl GHS and not for ghrelin. This review highlights the most recently discovered features of GHS-R1a and the emerging evidence for a novel group of receptors that are not of the GHS1a type; these appear involved in the transduction of the multiple levels of information provided by GHS and ghrelin.
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Affiliation(s)
- Giampiero Muccioli
- Division of Pharmacology, Department of Anatomy, Pharmacology and Forensic Medicine, University of Turin, Turin, Italy
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