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Khant Aung Z, Ladyman SR, Brown RSE. Transient loss of satiety effects of leptin in middle-aged male mice. J Neuroendocrinol 2024; 36:e13386. [PMID: 38549242 DOI: 10.1111/jne.13386] [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: 09/19/2023] [Revised: 02/08/2024] [Accepted: 03/18/2024] [Indexed: 05/03/2024]
Abstract
Extensive research is undertaken in rodents to determine the mechanism underlying obesity-induced leptin resistance. While body weight is generally tightly controlled in these studies, the effect of age of experimental animals has received less attention. Specifically, there has been little investigation into leptin regulation of food intake in middle-aged animals, which is a period of particular relevance for weight gain in humans. We investigated whether the satiety effects of leptin remained constant in young (3 months), middle-aged (12 months) or aged (18-22 months) male mice. Although mean body weight increased with age, leptin concentrations did not significantly increase in male mice beyond 12 months of age. Exogenous leptin administration led to a significant reduction in food intake in young mice but had no effect on food intake in middle-aged male mice. This loss of the satiety effect of leptin appeared to be transient, with leptin administration leading to the greatest inhibition of food intake in the aged male mice. Subsequently, we investigated whether these differences were due to changes in leptin transport into the brain with ageing. No change in leptin clearance from the blood or transport into the brain was observed, suggesting the emergence of central resistance to leptin in middle age. These studies demonstrate the presence of dynamic and age-specific changes in the satiety effects of leptin in male mice and highlight the requirement for age to be carefully considered when undertaking metabolic studies in rodents.
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Affiliation(s)
- Zin Khant Aung
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Sharon R Ladyman
- Centre for Neuroendocrinology and Department of Anatomy, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
| | - Rosemary S E Brown
- Centre for Neuroendocrinology and Department of Physiology, School of Biomedical Sciences, University of Otago, Dunedin, New Zealand
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2
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Kaur J, Gulati M, Kapoor B, Jha NK, Gupta PK, Gupta G, Chellappan DK, Devkota HP, Prasher P, Ansari MS, Aba Alkhayl FF, Arshad MF, Morris A, Choonara YE, Adams J, Dua K, Singh SK. Advances in designing of polymeric micelles for biomedical application in brain related diseases. Chem Biol Interact 2022; 361:109960. [DOI: 10.1016/j.cbi.2022.109960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 04/11/2022] [Accepted: 04/22/2022] [Indexed: 12/12/2022]
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3
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Zaghmi A, Pérez-Mato M, Dopico-López A, Candamo-Lourido M, Campos F, Gauthier MA. New Perspectives for Developing Therapeutic Bioconjugates of Metabolite-Depleting Enzymes: Lessons Learned Combating Glutamate Excitotoxicity. Biomacromolecules 2022; 23:1864-1872. [PMID: 35394759 DOI: 10.1021/acs.biomac.2c00117] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Glutamate, the main excitatory neurotransmitter in the central nervous system, plays an essential role in several cognitive activities such as memorizing and learning. Excessive glutamate release and disturbance of glutamate homeostasis participates in multiple neuronal pathologies including cerebral ischemia (inadequate blood supply), traumatic brain injury (e.g., from a fall or an accident), multiple sclerosis, epilepsy, migraine, fetal hypoxia, or Alzheimer's disease. Attenuating excitotoxicity by, for example, targeting glutamate receptors has proved to be beneficial in animal models but has largely failed in clinical trials because of toxic side effects. New therapeutic concepts have been explored to reduce the excitotoxic effect caused by the excessive glutamate release by using or stimulating glutamate-depleting enzymes in the bloodstream. These enzymes indirectly act upon the brain by depleting glutamate in the bloodstream, which is believed to siphon it out of the brain. Recent studies have shown that bioconjugate approaches applied to such enzymes exacerbate this therapeutic effect but raise additional questions for future research. This Perspective provides an overview of lessons learned by our group when exploring bioconjugate approaches for combatting glutamate excitotoxicity as an illustration of how research on therapeutic bioconjugates is evolving.
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Affiliation(s)
- Ahlem Zaghmi
- Institut National de la Recherche Scientifique, EMT Research Center, Varennes J3X 1S2, Canada
| | - María Pérez-Mato
- Neuroscience and Cerebrovascular Research Laboratory, Department of Neurology and Stroke Center, La Paz University Hospital, Neuroscience Area of IdiPAZ Health Research Institute, Universidad Autónoma de Madrid, Madrid 28049, Spain
| | - Antonio Dopico-López
- Clinical Neuroscience Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15782, Spain
| | - María Candamo-Lourido
- Clinical Neuroscience Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15782, Spain
| | - Francisco Campos
- Clinical Neuroscience Research Laboratory, Health Research Institute of Santiago de Compostela (IDIS), Santiago de Compostela 15782, Spain
| | - Marc A Gauthier
- Institut National de la Recherche Scientifique, EMT Research Center, Varennes J3X 1S2, Canada
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4
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Cheang I, Zhu X, Zhu Q, Li M, Liao S, Zuo Z, Yao W, Zhou Y, Zhang H, Li X. Inverse association between blood ethylene oxide levels and obesity in the general population: NHANES 2013-2016. Front Endocrinol (Lausanne) 2022; 13:926971. [PMID: 36171904 PMCID: PMC9510609 DOI: 10.3389/fendo.2022.926971] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2022] [Accepted: 08/18/2022] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Ethylene oxide (EO) has been shown to associate with increased cardiovascular risk. This study aimed to explore the relationship and its meditating factors between EO exposure and the major cardiovascular risk factor of obesity among the general adult population. METHODS Cross-sectional data of 3,220 participants from National Health and Nutritional Examination Survey (NHANES) 2013-2016 were enrolled. Obesity was defined as body mass index (BMI) ≥30 kg/m2, and abdominal obesity was defined as waist circumference (WC) ≥102 cm in men and ≥88 cm in women. The association among hemoglobin adduct of EO (HbEO), inflammatory biomarkers, and obesity was evaluated using restricted cubic splines and the multivariable linear regression model. Mediation analysis was used to further assess their association. RESULTS The increased quartiles of HbEO were inversely associated with BMI and WC [Q1 vs. Q4, BMI: β = -2.98 (-3.74, -2.22), WC: β = -6.50 (-8.60, -4.39); all p for trend < 0.05], and were inversely associated with obesity after full adjustment [obesity: OR = 0.43 (0.31, 0.58), abdominal obesity: OR = 0.42 (0.27, 0.65); all p for trend < 0.05]. The levels of alkaline phosphatase, white blood cells, lymphocytes, and neutrophils were also positively associated with BMI and WC (all p < 0.05). Mediation analysis showed that exposure of EO not only had a negative direct effect on BMI and WC, but also generated an inverse indirect effect. CONCLUSIONS Current findings showed an inverse association between HbEO and obesity, and suggested that systemic inflammation may not be their only mediator. Additional research is required to explore the underlying link of EO and system metabolism.
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Affiliation(s)
- Iokfai Cheang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Xu Zhu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Qingqing Zhu
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Menghuan Li
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Shengen Liao
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Zhi Zuo
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Wenming Yao
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Yanli Zhou
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
| | - Haifeng Zhang
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
- Department of Cardiology, Affiliated Suzhou Hospital of Nanjing Medical University, Suzhou Municipal Hospital, Suzhou, China
| | - Xinli Li
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Jiangsu Province Hospital, Nanjing, China
- *Correspondence: Xinli Li,
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5
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Abstract
Leptin for over 25 years has been a central theme in the study of appetite, obesity, and starvation. As the major site of leptin production is peripheral, and the site of action of greatest interest is the hypothalamus, how leptin accesses the central nervous system (CNS) and crosses the blood-brain barrier (BBB) has been of great interest. We review here the ongoing research that addresses fundamental questions such as the sites of leptin resistances in obesity and other conditions, the causes of resistances and their relations to one another, the three barrier sites of entry into the CNS, why recent studies using suprapharmacological doses cannot address these questions but give insight into nonsaturable entry of leptin into the CNS, and how that might be useful in using leptin therapeutically. The current status of the controversy of whether the short form of the leptin receptor acts as the BBB leptin transporter and how obesity may transform leptin transport is reviewed. Review of these and other topics summarizes in a new appreciation of what leptin may have actually evolved to do and what physiological role leptin resistance may play. © 2021 American Physiological Society. Compr Physiol 11:1-19, 2021.
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Affiliation(s)
- William A Banks
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, USA.,Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, Washington, USA
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6
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Raval J, Trivedi R, Suman S, Kukrety A, Prajapati P. NANO-BIOTECHNOLOGY AND ITS INNOVATIVE PERSPECTIVE IN DIABETES MANAGEMENT. Mini Rev Med Chem 2021; 22:89-114. [PMID: 34165408 DOI: 10.2174/1389557521666210623164052] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 01/11/2021] [Accepted: 01/18/2021] [Indexed: 11/22/2022]
Abstract
Diabetes occurs due to the imbalance of glucose in the body known as glucose homeostasis, thus leading to metabolic changes in the body. The two stages hypoglycemia or hyperglycemia classify diabetes into various categories. Various bio-nanotechnological approaches are coupled up with nano particulates, polymers, liposome, various gold plated and solid lipid particulates, regulating transcellular transport, non specific cellular uptake, and paracellular transport, leading to oral, trans-dermal , pulmonary, buccal , nasal , specific gene oriented administration to avoid the patient's non compliance with the parental routes of administration. Phytochemicals are emerging strategies for the future prospects of diabetes management.
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Affiliation(s)
- Jigar Raval
- Institute of Research and Development, Gujarat Forensic Sciences University, Gandhinagar-382007, Gujarat, India
| | - Riddhi Trivedi
- Institute of Research and Development, Gujarat Forensic Sciences University, Gandhinagar-382007, Gujarat, India
| | - Sonali Suman
- CDSCO, Meghaninagar, Ahmedabad, Gujarat 380003, India
| | | | - Prajesh Prajapati
- Institute of Research and Development, Gujarat Forensic Sciences University, Gandhinagar-382007, Gujarat, India
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7
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Zaghmi A, Drouin-Ouellet J, Brambilla D, Gauthier MA. Treating brain diseases using systemic parenterally-administered protein therapeutics: Dysfunction of the brain barriers and potential strategies. Biomaterials 2020; 269:120461. [PMID: 33218788 DOI: 10.1016/j.biomaterials.2020.120461] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/23/2020] [Accepted: 10/18/2020] [Indexed: 12/12/2022]
Abstract
The parenteral administration of protein therapeutics is increasingly gaining importance for the treatment of human diseases. However, the presence of practically impermeable blood-brain barriers greatly restricts access of such pharmaceutics to the brain. Treating brain disorders with proteins thus remains a great challenge, and the slow clinical translation of these therapeutics may be largely ascribed to the lack of appropriate brain delivery system. Exploring new approaches to deliver proteins to the brain by circumventing physiological barriers is thus of great interest. Moreover, parallel advances in the molecular neurosciences are important for better characterizing blood-brain interfaces, particularly under different pathological conditions (e.g., stroke, multiple sclerosis, Parkinson's disease, and Alzheimer's disease). This review presents the current state of knowledge of the structure and the function of the main physiological barriers of the brain, the mechanisms of transport across these interfaces, as well as alterations to these concomitant with brain disorders. Further, the different strategies to promote protein delivery into the brain are presented, including the use of molecular Trojan horses, the formulation of nanosystems conjugated/loaded with proteins, protein-engineering technologies, the conjugation of proteins to polymers, and the modulation of intercellular junctions. Additionally, therapeutic approaches for brain diseases that do not involve targeting to the brain are presented (i.e., sink and scavenging mechanisms).
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Affiliation(s)
- A Zaghmi
- Institut National de la Recherche Scientifique (INRS), EMT Research Center, Varennes, QC, J3X 1S2, Canada
| | - J Drouin-Ouellet
- Faculty of Pharmacy, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
| | - D Brambilla
- Faculty of Pharmacy, Université de Montréal, CP 6128, succ. Centre-ville, Montréal, QC, H3C 3J7, Canada
| | - M A Gauthier
- Institut National de la Recherche Scientifique (INRS), EMT Research Center, Varennes, QC, J3X 1S2, Canada.
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8
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Lübtow MM, Oerter S, Quader S, Jeanclos E, Cubukova A, Krafft M, Haider MS, Schulte C, Meier L, Rist M, Sampetrean O, Kinoh H, Gohla A, Kataoka K, Appelt-Menzel A, Luxenhofer R. In Vitro Blood–Brain Barrier Permeability and Cytotoxicity of an Atorvastatin-Loaded Nanoformulation Against Glioblastoma in 2D and 3D Models. Mol Pharm 2020; 17:1835-1847. [DOI: 10.1021/acs.molpharmaceut.9b01117] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Michael M. Lübtow
- Functional Polymer Materials, Chair for Advanced Materials Synthesis, Department of Chemistry and Pharmacy and Bavarian Polymer Institute, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Sabrina Oerter
- Chair Tissue Engineering and Regenerative Medicine (TERM), University Hospital Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Sabina Quader
- Innovation Center of Nanomedicine (iCONM), Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-Ku, Kawasaki-Shi 210-0821, Japan
| | - Elisabeth Jeanclos
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078 Würzburg, Germany
- Rudolf Virchow Center for Experimental Biomedicine, University of Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany
| | - Alevtina Cubukova
- Fraunhofer Institute for Silicate Research ISC, Translational Center Regenerative Therapies TLC-RT, Röntgenring 11, 97070 Würzburg, Germany
| | - Marion Krafft
- Chair Tissue Engineering and Regenerative Medicine (TERM), University Hospital Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Malik Salman Haider
- Functional Polymer Materials, Chair for Advanced Materials Synthesis, Department of Chemistry and Pharmacy and Bavarian Polymer Institute, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Clemens Schulte
- Functional Polymer Materials, Chair for Advanced Materials Synthesis, Department of Chemistry and Pharmacy and Bavarian Polymer Institute, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Laura Meier
- Functional Polymer Materials, Chair for Advanced Materials Synthesis, Department of Chemistry and Pharmacy and Bavarian Polymer Institute, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Maximilian Rist
- Functional Polymer Materials, Chair for Advanced Materials Synthesis, Department of Chemistry and Pharmacy and Bavarian Polymer Institute, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
| | - Oltea Sampetrean
- Institute for Advanced Medical Research (IAMR), Division of Gene Regulation, Keio University School of Medicine, 35 Shinanomachi, Shinjuku-ku, Tokyo 160-8582, Japan
| | - Hiroaki Kinoh
- Innovation Center of Nanomedicine (iCONM), Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-Ku, Kawasaki-Shi 210-0821, Japan
| | - Antje Gohla
- Institute of Pharmacology and Toxicology, University of Würzburg, Versbacher Straße 9, 97078 Würzburg, Germany
| | - Kazunori Kataoka
- Innovation Center of Nanomedicine (iCONM), Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-Ku, Kawasaki-Shi 210-0821, Japan
- Policy Alternatives Research Institute, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Antje Appelt-Menzel
- Chair Tissue Engineering and Regenerative Medicine (TERM), University Hospital Würzburg, Röntgenring 11, 97070 Würzburg, Germany
- Fraunhofer Institute for Silicate Research ISC, Translational Center Regenerative Therapies TLC-RT, Röntgenring 11, 97070 Würzburg, Germany
| | - Robert Luxenhofer
- Functional Polymer Materials, Chair for Advanced Materials Synthesis, Department of Chemistry and Pharmacy and Bavarian Polymer Institute, University of Würzburg, Röntgenring 11, 97070 Würzburg, Germany
- Soft Matter Chemistry, Department of Chemistry, University of Helsinki, 00014 Helsinki, Finland
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9
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Abstract
Drug targets for the treatment of obesity and comorbidities represent an ever-renewable source of research opportunities worldwide. One of the earliest is the leptin–leptin receptor system that was discovered in the mid-1990s. Leptin, a satiety hormone, is overproduced in overweight patients but the protein is unable to cross the blood–brain barrier and remains inactive. Circulating high levels of leptin induces a series of conditions that would not be manifested without leptin overproduction, including various forms of cancer and inflammatory and cardiovascular diseases. Current pharmaceutical research focuses on improving the blood–brain barrier penetration of leptin receptor agonists and the development of monofunctional antagonists with broad spectrum therapeutic efficacies but without unwanted side effects. Designer peptides with their expanded chemical space as well as well controllable receptor binding and elimination properties slowly replace full-sized leptin products in the drug development pipeline.
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10
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Izquierdo AG, Crujeiras AB, Casanueva FF, Carreira MC. Leptin, Obesity, and Leptin Resistance: Where Are We 25 Years Later? Nutrients 2019; 11:nu11112704. [PMID: 31717265 PMCID: PMC6893721 DOI: 10.3390/nu11112704] [Citation(s) in RCA: 243] [Impact Index Per Article: 48.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Revised: 09/27/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Leptin, a hormone that is capable of effectively reducing food intake and body weight, was initially considered for use in the treatment of obesity. However, obese subjects have since been found to have high levels of circulating leptin and to be insensitive to the exogenous administration of leptin. The inability of leptin to exert its anorexigenic effects in obese individuals, and therefore, the lack of clinical utility of leptin in obesity, is defined as leptin resistance. This phenomenon has not yet been adequately characterized. Elucidation of the molecular mechanisms underlying leptin resistance is of vital importance for the application of leptin as an effective treatment for obesity. Leptin must cross the blood–brain barrier (BBB) to reach the hypothalamus and exert its anorexigenic functions. The mechanisms involved in leptin transportation across the blood–brain barrier continue to be unclear, thereby preventing the clinical application of leptin in the treatment of obesity. In recent years, new strategies have been developed to recover the response to leptin in obesity. We have summarized these strategies in this review.
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Affiliation(s)
- Andrea G. Izquierdo
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Ana B. Crujeiras
- Laboratory of Epigenomics in Endocrinology and Nutrition, Epigenomics Unit, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS/SERGAS), 15706 Santiago de Compostela, Spain; (A.G.I.); (A.B.C.)
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
| | - Felipe F. Casanueva
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Molecular Endocrinolgy, Universidad de Santiago de Compostela (USC), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
| | - Marcos C. Carreira
- CIBER de Fisiopatologia de la Obesidad y Nutricion (CIBERobn), Instituto Salud Carlos III, 28029 Madrid, Spain
- Laboratory of Molecular Endocrinology, Instituto de Investigacion Sanitaria de Santiago (IDIS), Complejo Hospitalario Universitario de Santiago (CHUS), 15706 Santiago de Compostela, Spain
- Correspondence: (F.F.C.); (M.C.C.); Tel.: +34-9-8195-6189 (F.F.C.); +34-9-8195-6189 (M.C.C.)
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11
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Hackl MT, Fürnsinn C, Schuh CM, Krssak M, Carli F, Guerra S, Freudenthaler A, Baumgartner-Parzer S, Helbich TH, Luger A, Zeyda M, Gastaldelli A, Buettner C, Scherer T. Brain leptin reduces liver lipids by increasing hepatic triglyceride secretion and lowering lipogenesis. Nat Commun 2019; 10:2717. [PMID: 31222048 PMCID: PMC6586634 DOI: 10.1038/s41467-019-10684-1] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 05/24/2019] [Indexed: 12/31/2022] Open
Abstract
Hepatic steatosis develops when lipid influx and production exceed the liver’s ability to utilize/export triglycerides. Obesity promotes steatosis and is characterized by leptin resistance. A role of leptin in hepatic lipid handling is highlighted by the observation that recombinant leptin reverses steatosis of hypoleptinemic patients with lipodystrophy by an unknown mechanism. Since leptin mainly functions via CNS signaling, we here examine in rats whether leptin regulates hepatic lipid flux via the brain in a series of stereotaxic infusion experiments. We demonstrate that brain leptin protects from steatosis by promoting hepatic triglyceride export and decreasing de novo lipogenesis independently of caloric intake. Leptin’s anti-steatotic effects are generated in the dorsal vagal complex, require hepatic vagal innervation, and are preserved in high-fat-diet-fed rats when the blood brain barrier is bypassed. Thus, CNS leptin protects from ectopic lipid accumulation via a brain-vagus-liver axis and may be a therapeutic strategy to ameliorate obesity-related steatosis. Obesity is associated with leptin resistance and rising blood leptin levels while central leptin exposure may be limited. Here, the authors show that brain leptin infusion reduces hepatic lipid content in rats by increasing hepatic VLDL secretion and lowering liver de novo lipogenesis via a vagal mechanism.
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Affiliation(s)
- Martina Theresa Hackl
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Clemens Fürnsinn
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Christina Maria Schuh
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Martin Krssak
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.,Department of Biomedical Imaging and Image-Guided Therapy, High-Field MR Center, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.,Christian Doppler Laboratory for Clinical Molecular MR Imaging, MOLIMA, Waehringer Guertel 18-20, 1090, Vienna, Austria
| | - Fabrizia Carli
- Institute of Clinical Physiology, National Research Council, Via G. Moruzzi 1, 56124, Pisa, Italy
| | - Sara Guerra
- Institute of Clinical Physiology, National Research Council, Via G. Moruzzi 1, 56124, Pisa, Italy.,Institute of Life Sciences, Sant'Anna School of Advanced Studies, Via Santa Cecilia 3, 56127, Pisa, Italy
| | - Angelika Freudenthaler
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Sabina Baumgartner-Parzer
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Thomas H Helbich
- Department of Biomedical Imaging and Image-Guided Therapy, Division of Molecular and Gender Imaging, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Anton Luger
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Maximilian Zeyda
- Department of Pediatrics and Adolescent Medicine, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria
| | - Amalia Gastaldelli
- Institute of Clinical Physiology, National Research Council, Via G. Moruzzi 1, 56124, Pisa, Italy.,Institute of Life Sciences, Sant'Anna School of Advanced Studies, Via Santa Cecilia 3, 56127, Pisa, Italy
| | - Christoph Buettner
- Departments of Medicine and Neuroscience, and Diabetes, Obesity and Metabolism Institute (DOMI), Icahn School of Medicine at Mt Sinai, One Gustave L. Levy Pl, New York, NY, 10029, USA
| | - Thomas Scherer
- Department of Endocrinology and Metabolism, Department of Medicine III, Medical University of Vienna, Spitalgasse 23, 1090, Vienna, Austria.
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12
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Shi S, Kong N, Feng C, Shajii A, Bejgrowicz C, Tao W, Farokhzad OC. Drug Delivery Strategies for the Treatment of Metabolic Diseases. Adv Healthc Mater 2019; 8:e1801655. [PMID: 30957991 PMCID: PMC6663576 DOI: 10.1002/adhm.201801655] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 02/11/2019] [Indexed: 12/24/2022]
Abstract
Metabolic diseases occur when normal metabolic processes are disrupted in the human body, which can be congenital or acquired. The incidence of metabolic diseases worldwide has reached epidemic proportions. So far, various methods including systemic drug therapy and surgery are exploited to prevent and treat metabolic diseases. However, current pharmacotherapeutic options for treatment of these metabolic disorders remain limited and ineffective, especially reducing patient compliance to treatment. Therefore, it is desirable to exploit effective drug delivery approaches to effectively treat metabolic diseases and reduce side effects. This brief review summarizes novel delivery strategies including local, targeted, and oral drug delivery strategies, as well as intelligent stimulus-responsive drug delivery strategy, for the treatment of metabolic disorders including diabetes, obesity, and atherosclerosis.
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Affiliation(s)
- Sanjun Shi
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Na Kong
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Chan Feng
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Aram Shajii
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Claire Bejgrowicz
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Wei Tao
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
| | - Omid C Farokhzad
- Center for Nanomedicine and Department of Anesthesiology, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, 02115, USA
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Ashizawa AT, Holt J, Faust K, Liu W, Tiwari A, Zhang N, Ashizawa T. Intravenously Administered Novel Liposomes, DCL64, Deliver Oligonucleotides to Cerebellar Purkinje Cells. THE CEREBELLUM 2019; 18:99-108. [PMID: 29987489 DOI: 10.1007/s12311-018-0961-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cerebellar Purkinje cells (PCs) show conspicuous damages in many ataxic disorders. Targeted delivery of short nucleic acids, such as antisense oligonucleotides, to PCs may be a potential treatment for ataxic disorders, especially spinocerebellar ataxias (SCAs), which are mostly caused by a gain of toxic function of the mutant RNA or protein. However, oligonucleotides do not cross the blood-brain barrier (BBB), necessitating direct delivery into the central nervous system (CNS) through intra-thecal, intra-cisternal, intra-cerebral ventricular, or stereotactic parenchymal administration. We have developed a novel liposome (100 to 200 nm in diameter) formulation, DCL64, composed of dipalmitoyl-phosphatidylcholine, cholesterol, and poloxamer L64, which incorporates oligonucleotides efficiently (≥ 70%). Confocal microscopy showed that DCL64 was selectively taken up by brain microvascular endothelial cells by interacting with low-density lipoprotein receptor (LDLr) family members on cell surface, but not with other types of lipid receptors such as caveolin or scavenger receptor class B type 1. LDLr family members are implicated in brain microvascular endothelial cell endocytosis/transcytosis, and are abundantly localized on cerebellar PCs. Intravenous administration of DCL64 in normal mice showed distribution of oligonucleotides to the brain, preferentially in PCs. Mice that received DCL64 showed no adverse effect on hematological, hepatic, and renal functions in blood tests, and no histopathological abnormalities in major organs. These studies suggest that DCL64 delivers oligonucleotides to PCs across the BBB via intravenous injection with no detectable adverse effects. This property potentially makes DCL64 particularly attractive as a delivery vehicle in treatments of SCAs.
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Affiliation(s)
- Ana Tari Ashizawa
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, USA.,Bio-Path Holdings, Inc., Bellaire, TX, USA
| | - Jenny Holt
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neurology, University of Florida, Gainesville, FL, USA
| | - Kelsey Faust
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Weier Liu
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA.,Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Anjana Tiwari
- Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, 6670 Bertner Avenue, R11-117, Houston, TX, 77030, USA
| | - Nan Zhang
- Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, 6670 Bertner Avenue, R11-117, Houston, TX, 77030, USA
| | - Tetsuo Ashizawa
- McKnight Brain Institute, University of Florida, Gainesville, FL, USA. .,Department of Neurology, University of Florida, Gainesville, FL, USA. .,Stanley H. Appel Department of Neurology, Houston Methodist Research Institute, 6670 Bertner Avenue, R11-117, Houston, TX, 77030, USA.
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Leptin regulates neuropeptides associated with food intake and GnRH secretion. ANNALES D'ENDOCRINOLOGIE 2019; 80:38-46. [DOI: 10.1016/j.ando.2018.07.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 05/31/2018] [Accepted: 07/26/2018] [Indexed: 12/18/2022]
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15
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Frase L, Doerr JP, Feige B, Rechenbach M, Fiebich BL, Riemann D, Nissen C, Voderholzer U. Different Endocrine Effects of an Evening Dose of Amitriptyline, Escitalopram, and Placebo in Healthy Participants. CLINICAL PSYCHOPHARMACOLOGY AND NEUROSCIENCE 2018; 16:253-261. [PMID: 30121974 PMCID: PMC6124878 DOI: 10.9758/cpn.2018.16.3.253] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Revised: 07/07/2017] [Accepted: 07/10/2017] [Indexed: 11/18/2022]
Abstract
Objective The primary aim of this study was to further characterize the acute effects of amitriptyline (AMI) and escitalopram (ESC) on serum levels of ghrelin, leptin, cortisol and prolactin in healthy humans. Methods Eleven healthy male participants received a single dose of AMI 75 mg, ESC 10 mg, or placebo (PLA) at 9:00 PM in a double blind, randomized, controlled, repeated measures study separated by one week. Fasting morning serum levels (7:00 AM) of ghrelin, leptin, cortisol and prolactin were assessed. Results A repeated measures multivariate analysis of variance revealed a significant main effect for the factor condition (AMI, ESC, PLA). Subsequent univariate analyses demonstrated significant condition effects for ghrelin and cortisol. Post-hoc analyses demonstrated a significant reduction of ghrelin levels after AMI in comparison to PLA, and a significant reduction of cortisol levels after AMI in comparison to both ESC and PLA. Other contrasts did not reach statistical significance. Conclusion Administration of a single dose of AMI, but not of ESC, leads to a significant reduction in morning serum ghrelin and cortisol levels. No effects on leptin and prolactin levels were observed. The differential impact of AMI and ESC on hormones might contribute to different adverse effect profiles of both substances.
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Affiliation(s)
- Lukas Frase
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine-University of Freiburg, Freiburg, Germany
| | - John Peter Doerr
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine-University of Freiburg, Freiburg, Germany
| | - Bernd Feige
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine-University of Freiburg, Freiburg, Germany
| | - Maria Rechenbach
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine-University of Freiburg, Freiburg, Germany
| | - Bernd L Fiebich
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine-University of Freiburg, Freiburg, Germany
| | - Dieter Riemann
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine-University of Freiburg, Freiburg, Germany
| | - Christoph Nissen
- Department of Psychiatry and Psychotherapy, Medical Center-University of Freiburg, Faculty of Medicine-University of Freiburg, Freiburg, Germany.,University Hospital of Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland.,Neuroscience Center, University of Bern, Bern, Switzerland
| | - Ulrich Voderholzer
- Department of Psychiatry and Psychotherapy, Medical Center - University of Freiburg, Faculty of Medicine - University of Freiburg, Freiburg, Germany.,Schön Klinik Roseneck, Prien, Germany
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Wu A, Wang Y, Min S, Liu H, Xie F. Etomidate-loaded micelles for short-acting general anesthesia: Preparation, characterizations, and in vivo studies. J Drug Deliv Sci Technol 2018. [DOI: 10.1016/j.jddst.2018.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
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Rodriguez‐Otormin F, Duro‐Castano A, Conejos‐Sánchez I, Vicent MJ. Envisioning the future of polymer therapeutics for brain disorders. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2018; 11:e1532. [DOI: 10.1002/wnan.1532] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 04/24/2018] [Accepted: 05/09/2018] [Indexed: 01/09/2023]
Affiliation(s)
| | - Aroa Duro‐Castano
- Polymer Therapeutics Laboratory Centro de Investigación Príncipe Felipe Valencia Spain
| | | | - María J. Vicent
- Polymer Therapeutics Laboratory Centro de Investigación Príncipe Felipe Valencia Spain
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Yuan D, Yi X, Zhao Y, Poon CD, Bullock KM, Hansen KM, Salameh TS, Farr SA, Banks WA, Kabanov AV. Intranasal delivery of N-terminal modified leptin-pluronic conjugate for treatment of obesity. J Control Release 2017; 263:172-184. [PMID: 28344017 DOI: 10.1016/j.jconrel.2017.03.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 03/07/2017] [Accepted: 03/17/2017] [Indexed: 10/19/2022]
Abstract
Leptin is an adipocyte-secreted hormone that is delivered via a specific transport system across the blood-brain barrier (BBB) to the brain where it acts on the hypothalamus receptors to control appetite and thermogenesis. Peripheral resistance to leptin due to its impaired brain delivery prevents therapeutic use of leptin in overweight and moderately obese patients. To address this problem, we modified the N-terminal amine of leptin with Pluronic P85 (LepNP85) and administered this conjugate intranasally using the nose-to-brain (INB) route to bypass the BBB. We compared this conjugate with the native leptin, the N-terminal leptin conjugate with poly(ethylene glycol) (LepNPEG5K), and two conjugates of leptin with Pluronic P85 attached randomly to the lysine amino groups of the hormone. Compared to the random conjugates of leptin with P85, LepNP85 has shown higher affinity upon binding with the leptin receptor, and similarly to native hormone activated hypothalamus receptors after direct injection into brain. After INB delivery, LepNP85 conjugate was transported to the brain and accumulated in the hypothalamus and hippocampus to a greater extent than the native leptin and LepNPEG5K and activated leptin receptors in hypothalamus at lower dose than native leptin. Our work suggests that LepNP85 can access the brain directly after INB delivery and confirms our hypothesis that the improvement in brain accumulation of this conjugate is due to its enhanced brain absorption. In conclusion, the LepNP85 with optimized conjugation chemistry is a promising candidate for treatment of obesity.
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Affiliation(s)
- Dongfen Yuan
- Center for Nanotechnology in Drug Delivery, Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Xiang Yi
- Center for Nanotechnology in Drug Delivery, Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Yuling Zhao
- Center for Nanotechnology in Drug Delivery, Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Chi-Duen Poon
- Research Computer Center, University of North Carolina at Chapel Hill, NC 27599, USA
| | - Kristin M Bullock
- Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
| | - Kim M Hansen
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA
| | - Therese S Salameh
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA
| | - Susan A Farr
- Research and Development, VA Medical Center and Division of Geriatrics, School of Medicine, St. Louis University, St. Louis, MO 63110, USA
| | - William A Banks
- Geriatric Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98104, USA
| | - Alexander V Kabanov
- Center for Nanotechnology in Drug Delivery, Division of Pharmacoengineering and Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC 27599, USA; Laboratory of Chemical Design of Bionanomaterials, Faculty of Chemistry, M.V. Lomonosov Moscow State University, Moscow 119992, Russia.
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Shabanpoor F, Hammond SM, Abendroth F, Hazell G, Wood MJA, Gait MJ. Identification of a Peptide for Systemic Brain Delivery of a Morpholino Oligonucleotide in Mouse Models of Spinal Muscular Atrophy. Nucleic Acid Ther 2017; 27:130-143. [PMID: 28118087 PMCID: PMC5467147 DOI: 10.1089/nat.2016.0652] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Splice-switching antisense oligonucleotides are emerging treatments for neuromuscular diseases, with several splice-switching oligonucleotides (SSOs) currently undergoing clinical trials such as for Duchenne muscular dystrophy (DMD) and spinal muscular atrophy (SMA). However, the development of systemically delivered antisense therapeutics has been hampered by poor tissue penetration and cellular uptake, including crossing of the blood–brain barrier (BBB) to reach targets in the central nervous system (CNS). For SMA application, we have investigated the ability of various BBB-crossing peptides for CNS delivery of a splice-switching phosphorodiamidate morpholino oligonucleotide (PMO) targeting survival motor neuron 2 (SMN2) exon 7 inclusion. We identified a branched derivative of the well-known ApoE (141–150) peptide, which as a PMO conjugate was capable of exon inclusion in the CNS following systemic administration, leading to an increase in the level of full-length SMN2 transcript. Treatment of newborn SMA mice with this peptide-PMO (P-PMO) conjugate resulted in a significant increase in the average lifespan and gains in weight, muscle strength, and righting reflexes. Systemic treatment of adult SMA mice with this newly identified P-PMO also resulted in small but significant increases in the levels of SMN2 pre-messenger RNA (mRNA) exon inclusion in the CNS and peripheral tissues. This work provides proof of principle for the ability to select new peptide paradigms to enhance CNS delivery and activity of a PMO SSO through use of a peptide-based delivery platform for the treatment of SMA potentially extending to other neuromuscular and neurodegenerative diseases.
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Affiliation(s)
- Fazel Shabanpoor
- 1 Medical Research Council, Laboratory of Molecular Biology , Cambridge, United Kingdom
| | - Suzan M Hammond
- 2 Department of Physiology, Anatomy, and Genetics, University of Oxford , Oxford, United Kingdom
| | - Frank Abendroth
- 1 Medical Research Council, Laboratory of Molecular Biology , Cambridge, United Kingdom
| | - Gareth Hazell
- 2 Department of Physiology, Anatomy, and Genetics, University of Oxford , Oxford, United Kingdom
| | - Matthew J A Wood
- 2 Department of Physiology, Anatomy, and Genetics, University of Oxford , Oxford, United Kingdom
| | - Michael J Gait
- 1 Medical Research Council, Laboratory of Molecular Biology , Cambridge, United Kingdom
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Short peptides interfering with signaling pathways as new therapeutic tools for cancer treatment. Future Med Chem 2017; 9:199-221. [PMID: 28111982 DOI: 10.4155/fmc-2016-0189] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Short peptides have many advantages, such as low molecular weight, selectivity for a specific target, organelles or cells with minimal toxicity. We describe properties of short peptides, which interfere with communication networks in tumor cells and within microenvironment of malignant gliomas, the most common brain tumors. We focus on ligand/receptor axes and intracellular signaling pathways critical for gliomagenesis that could be targeted with interfering peptides. We review structures and efficacy of organelle-specific and cell-penetrating peptides and describe diverse chemical modifications increasing proteolytic stability and protecting synthetic peptides against degradation. We report results of application of short peptides in glioma therapy clinical trials, their rises and falls. The most advanced examples of therapeutics such as short interfering peptides combined with cell-penetrating peptides that show good effectiveness in disease models are presented. It is foreseen that identification of peptides with better clinical properties may improve their success rates in clinical trials.
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Immunohistochemical Evaluation of Leptin Expression in Wound Healing: A Clue to Exuberant Scar Formation. Appl Immunohistochem Mol Morphol 2016; 24:296-306. [PMID: 26258753 DOI: 10.1097/pai.0000000000000187] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Leptin has been recognized as an important factor for promoting normal cutaneous wound healing. The aim of this work was to explore leptin expression in keloid and hypertrophic scars (HS) compared with surgical scars and normal skin. The relationship of this expression with clinicopathologic parameters of studied cases was also evaluated. Using immunohistochemical techniques, leptin was analyzed in skin biopsies of 60 nonobese subjects without metabolic syndrome who presented with keloids (20), HS (20), and surgical scars (20). Twenty normal skin samples, from age-matched, sex-matched, and body mass index-matched subjects, were enrolled as a control group. Leptin showed positive immunoreactivity in epidermis in all cases of surgical scars and keloids and in 75% of HS cases. Dermal expression in fibroblasts, inflammatory cells, and endothelial cells was positive in all cases of surgical scars and keloids and in 70% of HS cases. Leptin was overexpressed in keloids and HS compared with normal skin in epidermis (P<0.001 for both) and dermis (P<0.001 for both) and to surgical scars both in epidermis (P=0.0006, P=0.01, respectively) and dermis (P=0.0001, P=0.001, respectively). Higher leptin H score was significantly associated with older age (P=0.02) and positive family history (P=0.002) in keloid cases and with axial site in keloid and HS cases (P=0.001, P=0.02, respectively). Significant positive correlation was noted between epidermal and dermal leptin H scores in keloids (r=+0.37, P=0.04) and HS (r=+0.39, P=0.02). This may be due to epithelial-mesenchymal interactions in scar pathogenesis. In conclusion, in situ leptin overexpression may increase the possibility of keloid and HS occurrence through altered cytokine production and prolonged healing phases with excessive deposition and delayed collagen degradation. This may open an avenue for research for new therapeutic modalities based on its inhibition.
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Figueroa-Ochoa EB, Villar-Alvarez EM, Cambón A, Mistry D, Llovo J, Attwood D, Barbosa S, Soltero J, Taboada P. Lenghty reverse poly(butylene oxide)-poly(ethylene oxide)-poly(butylene oxide) polymeric micelles and gels for sustained release of antifungal drugs. Int J Pharm 2016; 510:17-29. [DOI: 10.1016/j.ijpharm.2016.06.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Revised: 05/31/2016] [Accepted: 06/06/2016] [Indexed: 12/21/2022]
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Santoro A, Mattace Raso G, Meli R. Drug targeting of leptin resistance. Life Sci 2015; 140:64-74. [DOI: 10.1016/j.lfs.2015.05.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Revised: 05/06/2015] [Accepted: 05/13/2015] [Indexed: 12/21/2022]
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Jiang Y, Brynskikh AM, S-Manickam D, Kabanov AV. SOD1 nanozyme salvages ischemic brain by locally protecting cerebral vasculature. J Control Release 2015; 213:36-44. [PMID: 26093094 PMCID: PMC4684498 DOI: 10.1016/j.jconrel.2015.06.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 06/15/2015] [Indexed: 11/30/2022]
Abstract
Copper/zinc superoxide dismutase (CuZnSOD; SOD1) is widely considered as a potential therapeutic candidate for pathologies involving oxidative stress, but its application has been greatly hindered by delivery issues. In our previous study, nanoformulated SOD1 (cl-nanozyme) was shown to decrease infarct volume and improve sensorimotor functions after a single intravenous (IV) injection in a rat middle cerebral artery occlusion (MCAO) model of ischemia/reperfusion (I/R) injury (stroke). However, it remained unclear how cl-nanozyme was able to deliver SOD1 to the brain and exert therapeutic efficacy. The present study aims to answer this question by exploring micro-distribution pattern of cl-nanozyme in the rat brain after stroke. Immunohistochemistry studies demonstrated cl-nanozyme co-localization with fibrin along damaged arteries and capillaries in the ischemic hemisphere. We further found that cl-nanozyme can be cross-linked into thrombi formed after I/R injury in the brain, and this effect is independent of animal species (rat/mouse) used for modeling I/R injury. This work is also the first report reinforcing therapeutic potential of cl-nanozyme in a well-characterized mouse MCAO model of I/R injury.
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Affiliation(s)
- Yuhang Jiang
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Anna M Brynskikh
- Department of Pharmaceutical Sciences and Center for Drug Delivery and Nanomedicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Devika S-Manickam
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Alexander V Kabanov
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Laboratory for Chemical Design of Bionanomaterials, Faculty of Chemistry, M.V. Lomonosov Moscow State University, Moscow 117234, Russia.
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Zarouna S, Wozniak G, Papachristou AI. Mood disorders: A potential link between ghrelin and leptin on human body? World J Exp Med 2015; 5:103-109. [PMID: 25992324 PMCID: PMC4436933 DOI: 10.5493/wjem.v5.i2.103] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/28/2014] [Accepted: 02/02/2015] [Indexed: 02/06/2023] Open
Abstract
Leptin and ghrelin are two hormones associated with multiple physiological functions, especially energy balance. Leptin is an adipocyte-secreted hormone discovered in 1950 and ghrelin which was found in 1999, is a peptide hormone produced and secreted in the stomach. A number of previous studies showed that these hormones could be associated with different types of mood disorders. The results of previous studies, nevertheless, are confounded by diverse sample selection and different methodologies. A search for related articles in the PubMed database was attempted. The search covered studies, reports, reviews and editorials published in the last ten years. Older references served as auxiliary sources for comparison purposes. However, due to the different results of the studies, there is a need for more investigation in order to establish the exact biochemical mechanisms that are responsible for these diseases and ghrelin’s and leptin’s effects on mood.
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Olberg DE, Hausner SH, Bauer N, Klaveness J, Indrevoll B, Andressen KW, Dahl M, Levy FO, Sutcliffe JL, Haraldsen I. Radiosynthesis of high affinity fluorine-18 labeled GnRH peptide analogues: in vitro studies and in vivo assessment of brain uptake in rats. MEDCHEMCOMM 2015. [DOI: 10.1039/c4md00486h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of high affinity 18F-GnRH peptides have been synthesized and show utility as imaging agents for GnRH receptor expression in vivo.
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Affiliation(s)
| | - Sven H. Hausner
- Department of Biomedical Engineering
- University of California Davis
- Davis
- USA
- Department of Internal Medicine
| | - Nadine Bauer
- Department of Biomedical Engineering
- University of California Davis
- Davis
- USA
| | | | | | - Kjetil Wessel Andressen
- Department of Pharmacology
- Faculty of Medicine
- University of Oslo and Oslo University Hospital
- Oslo
- Norway
| | - Marie Dahl
- Department of Pharmacology
- Faculty of Medicine
- University of Oslo and Oslo University Hospital
- Oslo
- Norway
| | - Finn Olav Levy
- Department of Pharmacology
- Faculty of Medicine
- University of Oslo and Oslo University Hospital
- Oslo
- Norway
| | - Julie L. Sutcliffe
- Department of Biomedical Engineering
- University of California Davis
- Davis
- USA
- Department of Internal Medicine
| | - Ira Haraldsen
- Department of Neuropsychiatry and Psychosomatic Medicine
- Oslo University Hospital
- Oslo
- Norway
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Wang H, Jiang Y, Peng H, Chen Y, Zhu P, Huang Y. Recent progress in microRNA delivery for cancer therapy by non-viral synthetic vectors. Adv Drug Deliv Rev 2015; 81:142-60. [PMID: 25450259 DOI: 10.1016/j.addr.2014.10.031] [Citation(s) in RCA: 167] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2014] [Revised: 10/26/2014] [Accepted: 10/30/2014] [Indexed: 12/22/2022]
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression. Because of significant changes in their expression in cancer, miRNAs are believed to be key factors in cancer genetics and to have potential as anticancer drugs. However, the delivery of miRNAs is limited by many barriers, such as low cellular uptake, immunogenicity, renal clearance, degradation by nucleases, elimination by phagocytic immune cells, poor endosomal release, and untoward side effects. Nonviral delivery systems have been developed to overcome these obstacles. In this review, we provide insights into the development of non-viral synthetic miRNA vectors and the promise of miRNA-based anticancer therapies, including therapeutic applications of miRNAs, challenges of vector design to overcome the delivery obstacles, and the development of miRNA delivery systems for cancer therapy. Additionally, we highlight some representative examples that give a glimpse into the current trends into the design and application of efficient synthetic systems for miRNA delivery. Overall, a better understanding of the rational design of miRNA delivery systems will promote their translation into effective clinical treatments.
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Yi X, Yuan D, Farr SA, Banks WA, Poon CD, Kabanov AV. Pluronic modified leptin with increased systemic circulation, brain uptake and efficacy for treatment of obesity. J Control Release 2014; 191:34-46. [PMID: 24881856 PMCID: PMC4197010 DOI: 10.1016/j.jconrel.2014.05.044] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/12/2014] [Accepted: 05/21/2014] [Indexed: 11/30/2022]
Abstract
Modification of hydrophilic proteins with amphiphilic block copolymers capable of crossing cell membranes is a new strategy to improve protein delivery to the brain. Leptin, a candidate for the treatment of epidemic obesity, has failed in part because of impairment in its transport across the blood-brain barrier (BBB) that develops with obesity. We posit that modification of leptin with poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide), Pluronic P85 (P85) might permit this protein to penetrate the BBB independently of its transporter, thereby overcoming peripheral leptin resistance. Here we report that peripherally administered leptin-P85 conjugates exhibit biological activity by reducing food intake in mouse models of obesity (ob/ob, and diet-induced obese mouse). We further generated two new leptin-P85 conjugates: one, Lep(ss)-P85(L), containing one P85 chain and another, Lep(ss)-P85(H), containing multiple P85 chains. We report data on their purification, analytical characterization, peripheral and brain pharmacokinetics (PK). Lep(ss)-P85(L) crosses the BBB using the leptin transporter, and exhibits improved peripheral PK along with increased accumulation in the brain compared to unmodified leptin. Lep(ss)-P85(H) also has improved peripheral PK but in a striking difference to the first conjugate penetrates the BBB independently of the leptin transporter via a non-saturable mechanism. The results demonstrate that leptin analogs can be developed through chemical modification of the native leptin with P85 to overcome leptin resistance at the level of the BBB, thus improving the potential for the treatment of obesity.
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Affiliation(s)
- Xiang Yi
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.
| | - Dongfen Yuan
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Susan A Farr
- Research and Development, VA Medical Center and Division of Geriatrics, St. Louis University School of Medicine, St. Louis, MI, USA
| | - William A Banks
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA; Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98108, USA
| | - Chi-Duen Poon
- Research Computer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Alexander V Kabanov
- Center for Nanotechnology in Drug Delivery and Division of Molecular Pharmaceutics, Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; Faculty of Chemistry, M.V. Lomonosov Moscow State University, 119899 Moscow, Russia.
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Mitragotri S, Burke PA, Langer R. Overcoming the challenges in administering biopharmaceuticals: formulation and delivery strategies. Nat Rev Drug Discov 2014; 13:655-72. [PMID: 25103255 PMCID: PMC4455970 DOI: 10.1038/nrd4363] [Citation(s) in RCA: 1069] [Impact Index Per Article: 106.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
The formulation and delivery of biopharmaceutical drugs, such as monoclonal antibodies and recombinant proteins, poses substantial challenges owing to their large size and susceptibility to degradation. In this Review we highlight recent advances in formulation and delivery strategies--such as the use of microsphere-based controlled-release technologies, protein modification methods that make use of polyethylene glycol and other polymers, and genetic manipulation of biopharmaceutical drugs--and discuss their advantages and limitations. We also highlight current and emerging delivery routes that provide an alternative to injection, including transdermal, oral and pulmonary delivery routes. In addition, the potential of targeted and intracellular protein delivery is discussed.
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Affiliation(s)
- Samir Mitragotri
- Department of Chemical Engineering, Center for Bioengineering, University of California, Santa Barbara, California 92106, USA
| | - Paul A Burke
- Burke Bioventures LLC, 277 Broadway, Cambridge, Massachusetts 02139, USA
| | - Robert Langer
- Department of Chemical Engineering, Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA
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Kiss É, Gyulai G, Pénzes CB, Idei M, Horváti K, Bacsa B, Bősze S. Tuneable surface modification of PLGA nanoparticles carrying new antitubercular drug candidate. Colloids Surf A Physicochem Eng Asp 2014. [DOI: 10.1016/j.colsurfa.2014.05.048] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Peddada LY, Garbuzenko OB, Devore DI, Minko T, Roth CM. Delivery of antisense oligonucleotides using poly(alkylene oxide)-poly(propylacrylic acid) graft copolymers in conjunction with cationic liposomes. J Control Release 2014; 194:103-12. [PMID: 25192941 DOI: 10.1016/j.jconrel.2014.08.023] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 06/02/2014] [Accepted: 08/23/2014] [Indexed: 12/18/2022]
Abstract
The clinical application of gene silencing is hindered by poor stability and low delivery efficiency of naked oligonucleotides. Here, we present the in vitro and in vivo behaviors of a rationally designed, ternary, self-assembled nanoparticle complex, consisting of an anionic copolymer, cationic DOTAP liposome, and antisense oligonucleotide (AON). The multifunctional copolymers are based on backbone poly(propylacrylic acid) (PPAA), a pH-sensitive hydrophobic polymer, with grafted poly(alkylene oxides) (PAOs) varying in extent of grafting and PAO chemistry. The nanoparticle complexes with PPAA-g-PAO copolymers enhance antisense gene silencing effects in A2780 human ovarian cancer cells. A greater amount of AON is delivered to ovarian tumor xenografts using the ternary copolymer-stabilized delivery system, compared to a binary DOTAP/AON complex, following intraperitoneal injection in mice. Further, intratumoral injection of the nanoparticle complexes containing 1 mol% grafted PAO reduced tumoral bcl-2 expression by up to 60%. The data for complexes across the set of PAO polymers support a strong role for the hydrophilic-lipophilic balance of the graft copolymer in achieving serum stability and cellular uptake. Based upon these results, we anticipate that this novel nanoparticle delivery system can be extended to the delivery of plasmid DNA, siRNA, or aptamers for preclinical and clinical development.
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Affiliation(s)
- Lavanya Y Peddada
- Department of Biomedical Engineering, Rutgers University, Piscataway, USA
| | | | - David I Devore
- U.S. Army Institute of Surgical Research, Fort Sam Houston, 78234, USA
| | - Tamara Minko
- Department of Pharmaceutics, Rutgers University, Piscataway, USA
| | - Charles M Roth
- Department of Biomedical Engineering, Rutgers University, Piscataway, USA; Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, USA.
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Farkhani SM, Valizadeh A, Karami H, Mohammadi S, Sohrabi N, Badrzadeh F. Cell penetrating peptides: efficient vectors for delivery of nanoparticles, nanocarriers, therapeutic and diagnostic molecules. Peptides 2014; 57:78-94. [PMID: 24795041 DOI: 10.1016/j.peptides.2014.04.015] [Citation(s) in RCA: 200] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/19/2014] [Accepted: 04/19/2014] [Indexed: 01/24/2023]
Abstract
Efficient delivery of therapeutic and diagnostic molecules to the cells and tissues is a difficult challenge. The cellular membrane is very effective in its role as a selectively permeable barrier. While it is essential for cell survival and function, also presents a major barrier for intracellular delivery of cargo such as therapeutic and diagnostic agents. In recent years, cell-penetrating peptides (CPPs), that are relatively short cationic and/or amphipathic peptides, received great attention as efficient cellular delivery vectors due to their intrinsic ability to enter cells and mediate uptake of a wide range of macromolecular cargo such as plasmid DNA (pDNA), small interfering RNA (siRNAs), drugs, and nanoparticulate pharmaceutical carriers. This review discusses the various uptake mechanisms of these peptides. Furthermore, we discuss recent advances in the use of CPP for the efficient delivery of nanoparticles, nanocarriers, DNA, siRNA, and anticancer drugs to the cells. In addition, we have been highlighting new results for improving endosomal escape of CPP-cargo molecules. Finally, pH-responsive and activable CPPs for tumor-targeting therapy have been described.
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Affiliation(s)
- Samad Mussa Farkhani
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Golgasht Street, 51664 Tabriz, Iran; Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, Iran.
| | - Alireza Valizadeh
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Golgasht Street, 51664 Tabriz, Iran.
| | - Hadi Karami
- Department of Medical Biotechnology, Faculty of Medicine, Arak University of Medical Sciences, Sardasht, 38481 Arak, Iran.
| | - Samane Mohammadi
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Golgasht Street, 51664 Tabriz, Iran.
| | - Nasrin Sohrabi
- Department of Medical Genetics, Faculty of Medicine, Tabriz University of Medical Sciences, Golgasht Street, 51664 Tabriz, Iran.
| | - Fariba Badrzadeh
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Golgasht Street, 51664 Tabriz, Iran.
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Yi X, Kabanov AV. Brain delivery of proteins via their fatty acid and block copolymer modifications. J Drug Target 2014; 21:940-55. [PMID: 24160902 DOI: 10.3109/1061186x.2013.847098] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
It is well known that hydrophobic small molecules penetrate cell membranes better than hydrophilic molecules. Amphiphilic molecules that dissolve both in lipid and aqueous phases are best suited for membrane transport. Transport of biomacromolecules across physiological barriers, e.g. the blood-brain barrier, is greatly complicated by the unique structure and function of such barriers. Two decades ago we adopted a simple philosophy that to increase protein delivery to the brain one needs to modify this protein with hydrophobic moieties. With this general idea we began modifying proteins (antibodies, enzymes, hormones, etc.) with either hydrophobic fatty acid residues or amphiphilic block copolymer moieties, such as poy(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (pluronics or poloxamers) and more recently, poly(2-oxasolines). This simple approach has resulted in impressive successes in CNS drug delivery. We present a retrospective overview of these works initiated in the Soviet Union in 1980s, and then continued in the United States and other countries. Notably some of the early findings were later corroborated by brain pharmacokinetic data. Industrial development of several drug candidates employing these strategies has followed. Overall modification by hydrophobic fatty acids residues or amphiphilic block copolymers represents a promising and relatively safe strategy to deliver proteins to the brain.
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Affiliation(s)
- Xiang Yi
- Division of Molecular Pharmaceutics and Center for Nanotechnology in Drug Delivery, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill , Chapel Hill, NC , USA and
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Agile delivery of protein therapeutics to CNS. J Control Release 2014; 190:637-63. [PMID: 24956489 DOI: 10.1016/j.jconrel.2014.06.017] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2014] [Revised: 06/10/2014] [Accepted: 06/13/2014] [Indexed: 12/11/2022]
Abstract
A variety of therapeutic proteins have shown potential to treat central nervous system (CNS) disorders. Challenge to deliver these protein molecules to the brain is well known. Proteins administered through parenteral routes are often excluded from the brain because of their poor bioavailability and the existence of the blood-brain barrier (BBB). Barriers also exist to proteins administered through non-parenteral routes that bypass the BBB. Several strategies have shown promise in delivering proteins to the brain. This review, first, describes the physiology and pathology of the BBB that underscore the rationale and needs of each strategy to be applied. Second, major classes of protein therapeutics along with some key factors that affect their delivery outcomes are presented. Third, different routes of protein administration (parenteral, central intracerebroventricular and intraparenchymal, intranasal and intrathecal) are discussed along with key barriers to CNS delivery associated with each route. Finally, current delivery strategies involving chemical modification of proteins and use of particle-based carriers are overviewed using examples from literature and our own work. Whereas most of these studies are in the early stage, some provide proof of mechanism of increased protein delivery to the brain in relevant models of CNS diseases, while in few cases proof of concept had been attained in clinical studies. This review will be useful to broad audience of students, academicians and industry professionals who consider critical issues of protein delivery to the brain and aim developing and studying effective brain delivery systems for protein therapeutics.
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Pan H, Guo J, Su Z. Advances in understanding the interrelations between leptin resistance and obesity. Physiol Behav 2014; 130:157-69. [PMID: 24726399 DOI: 10.1016/j.physbeh.2014.04.003] [Citation(s) in RCA: 122] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Revised: 03/07/2014] [Accepted: 04/02/2014] [Indexed: 02/09/2023]
Abstract
Obesity, which has developed into a global epidemic, is a risk factor in most chronic diseases and some forms of malignancy. The discovery of leptin in 1994 has opened a new field in obesity research. Currently, we know that leptin is the primary signal from energy stores and exerts negative feedback effects on energy intake. However, most individuals with diet-induced obesity (DIO) develop leptin resistance, which is characterized by elevated circulating leptin levels and decreased leptin sensitivity. To date, though various mechanisms have been proposed to explain leptin resistance, the exact mechanisms of leptin resistance in obesity are poorly understood. Consequently, it's an important issue worth discussing regarding what the exact interrelations between leptin resistance and obesity are. Here, we review the latest advancements in the molecular mechanisms of leptin resistance and the exact interrelations between leptin resistance, obesity, and obesity-related diseases, in order to supply new ideas for the study of obesity.
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Affiliation(s)
- Haitao Pan
- Key Research Center of Liver Regulation for Hyperlipidemia SATCM/Class III Laboratory of Metabolism SATCM, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China
| | - Jiao Guo
- Key Research Center of Liver Regulation for Hyperlipidemia SATCM/Class III Laboratory of Metabolism SATCM, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China.
| | - Zhengquan Su
- Key Research Center of Liver Regulation for Hyperlipidemia SATCM/Class III Laboratory of Metabolism SATCM, Guangdong TCM Key Laboratory for Metabolic Diseases, Guangdong Pharmaceutical University, Guangzhou, Guangdong, China.
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Roujeau C, Jockers R, Dam J. New pharmacological perspectives for the leptin receptor in the treatment of obesity. Front Endocrinol (Lausanne) 2014; 5:167. [PMID: 25352831 PMCID: PMC4195360 DOI: 10.3389/fendo.2014.00167] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Accepted: 09/26/2014] [Indexed: 12/24/2022] Open
Abstract
After its discovery in 1994, leptin became the great hope as an anti-obesity treatment based on its ability to reduce food intake and increase energy expenditure. However, treating obese people with exogenous leptin was unsuccessful in most cases since most of them present already high circulating leptin levels to which they do not respond anymore defining the so-called state of "leptin resistance." Indeed, leptin therapy is unsuccessful to lower body weight in commonly obese people but effective in people with rare single gene mutations of the leptin gene. Consequently, treatment of obese people with leptin was given less attention and the focus of obesity research shifted toward the prevention and reversal of the state of leptin resistance. Many of these new promising approaches aim to restore or sensitize the impaired function of the leptin receptor by pharmacological means. The current review will focus on the different emerging therapeutic strategies in obesity research that are related to leptin and its receptor.
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Affiliation(s)
- Clara Roujeau
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Ralf Jockers
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
| | - Julie Dam
- INSERM, U1016, Institut Cochin, Paris, France
- CNRS UMR 8104, Paris, France
- University of Paris Descartes, Sorbonne Paris Cité, Paris, France
- *Correspondence: Julie Dam, Institut Cochin, 22 rue Méchain, 75014, Paris, France e-mail:
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Simerska P, Christie MP, Goodwin D, Jen FEC, Jennings MP, Toth I. α-1,4-Galactosyltransferase-catalyzed glycosylation of sugar and lipid modified Leu-enkephalins. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2013.08.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Zhou X, Chai Y, Chen K, Yang Y, Liu Z. A meta-analysis of reference values of leptin concentration in healthy postmenopausal women. PLoS One 2013; 8:e72734. [PMID: 24023638 PMCID: PMC3758328 DOI: 10.1371/journal.pone.0072734] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 07/12/2013] [Indexed: 02/07/2023] Open
Abstract
Objective There are numerous reports about the leptin concentration (LC) in postmenopausal women (PW). Changes in LC can elicit different clinical outcomes. We systematically analyzed the LC in PW. Methods A search was conducted in original English-language studies published from 1994 to October 2012 in the following databases: Medline (78), Cochrane Center (123) Embase (505), Biological abstracts (108), Cochrane (53) and Science Finder Scholar (0). A meta-analysis was undertaken on the correction coefficient (r) between the serum LC and body mass index (BMI) for healthy PW across studies containing a dataset and sample size. Pre-analytical and analytical variations were examined. Pre-analytical variables included fasting status (FS) and sampling timing. Analytical variation comprised assay methodology, LC in those undertaking hormone replacement therapy (HRT) and those not having HRT as well as LC change according to age. Results Twenty-seven studies met the inclusion criteria. Eighteen studies detected LC in the morning in a FS, 15 studies denoted the r between leptin and the BMI. A combined r was counted for the 15 studies (r = 0.51 [95% confidence interval (CI), 0.46–0.54], P = 0.025), and if sampling collection was in the FSat morning, a combined r was form 10 studies (r = 0.54 [95% CI, 0.45–0.54], P = 0.299) and heterogeneity was diminished. LC did not change between HRT users and non-users in 7 studies. Five studies analyzed changes in LC according to age. Conclusion Based on all studies that investigated both LC and BMI, LC was positively correlated with the BMI. No studies established reference ranges according to the Clinical and Laboratory Standards Institute (CLSI) in healthy PW, and there was a wide variation in LC values. These differences suggest that caution should be used in the interpretation and comparison between studies.
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Affiliation(s)
- Xi Zhou
- Department of Radiation Oncology, The First Affiliated Hospital of the Medical College, Xi'an Jiaotong University, China
- Renmin Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - YanLan Chai
- Department of Radiation Oncology, The First Affiliated Hospital of the Medical College, Xi'an Jiaotong University, China
| | - Ke Chen
- Department of Physiology and Pathophysiology, Health Science Center, Xi'an Jiaotong University, China
| | - YunYi Yang
- Department of Radiation Oncology, The First Affiliated Hospital of the Medical College, Xi'an Jiaotong University, China
| | - Zi Liu
- Department of Radiation Oncology, The First Affiliated Hospital of the Medical College, Xi'an Jiaotong University, China
- * E-mail:
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Perera RH, Patel R, Wu H, Gangolli M, Traughber B, Oleinick N, Exner AA. Preclinical evaluation of radiosensitizing activity of Pluronic block copolymers. Int J Radiat Biol 2013; 89:801-12. [PMID: 23631609 DOI: 10.3109/09553002.2013.800246] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE Pluronic block copolymers are non-ionic surfactants with demonstrated sensitizing activity in chemotherapy and hyperthermia in various tumor cell lines. In the current study we investigated the potential activity of Pluronic as a radiosensitizing agent. MATERIALS AND METHODS As a possible mechanism, the effect of Pluronic on Hsp70 and Hsp90 was examined. Gli36 human glioma cells were treated with radiation alone as well as with a combination treatment of Pluronic and radiation. RESULTS Clonogenic cell survival assays show that Pluronic has an elevated effect on radiosensitization (50% high, p < 0.01), even with radiation doses as low as 2 Gy. The Hsp90 level was reduced 24 h after the combined treatment in both in vitro and in vivo. Similarly, Hsp70 levels were also decreased 24 h post treatment. When Gli36 cells were exposed to Pluronic before and during irradiation, DNA DSB: double-strand breaks repair was reduced, and elevated apoptosis was also seen in tumor xenografts. CONCLUSION Data suggest the potential use of L10 as a radiosensitizer. While the mechanism of sensitization requires additional investigation, the presented results indicate that the effect may be due, in part, to a decrease in Hsp90 and 70 levels and increased DNA damage.
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Affiliation(s)
- Reshani H Perera
- Department of Radiology, Case Western Reserve University , Cleveland, Ohio , USA
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Rosenbaugh EG, Savalia KK, Manickam DS, Zimmerman MC. Antioxidant-based therapies for angiotensin II-associated cardiovascular diseases. Am J Physiol Regul Integr Comp Physiol 2013; 304:R917-28. [PMID: 23552499 DOI: 10.1152/ajpregu.00395.2012] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Cardiovascular diseases, including hypertension and heart failure, are associated with activation of the renin-angiotensin system (RAS) and increased circulating and tissue levels of ANG II, a primary effector peptide of the RAS. Through its actions on various cell types and organ systems, ANG II contributes to the pathogenesis of cardiovascular diseases by inducing cardiac and vascular hypertrophy, vasoconstriction, sodium and water reabsorption in kidneys, sympathoexcitation, and activation of the immune system. Cardiovascular research over the past 15-20 years has clearly implicated an important role for elevated levels of reactive oxygen species (ROS) in mediating these pathophysiological actions of ANG II. As such, the use of antioxidants, to reduce the elevated levels of ROS, as potential therapies for various ANG II-associated cardiovascular diseases has been intensely investigated. Although some antioxidant-based therapies have shown therapeutic impact in animal models of cardiovascular disease and in human patients, others have failed. In this review, we discuss the benefits and limitations of recent strategies, including gene therapy, dietary sources, low-molecular-weight free radical scavengers, polyethylene glycol conjugation, and nanomedicine-based technologies, which are designed to deliver antioxidants for the improved treatment of cardiovascular diseases. Although much work has been completed, additional research focusing on developing specific antioxidant molecules or proteins and identifying the ideal in vivo delivery system for such antioxidants is necessary before the use of antioxidant-based therapies for cardiovascular diseases become a clinical reality.
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Affiliation(s)
- Erin G Rosenbaugh
- Department of Cellular and Integrative Physiology, Nebraska Center for Nanomedicine, University of Nebraska Medical Center, Omaha, NE 68198, USA
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A simple way to enhance Doxil® therapy: drug release from liposomes at the tumor site by amphiphilic block copolymer. J Control Release 2013; 168:61-9. [PMID: 23474033 DOI: 10.1016/j.jconrel.2013.02.026] [Citation(s) in RCA: 90] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 02/28/2013] [Indexed: 11/20/2022]
Abstract
The antitumor efficacy of Doxil® is hindered by the poor release of the active drug from the liposome at the tumor sites. This study investigates a possibility to enhance drug release from the liposomes and increase therapeutic efficacy of Doxil® by administering Pluronic block copolymers once the liposomal drug accumulates in the tumor sites. In our study, the fluorescence de-quenching experiments were designed to investigate the drug release from liposome by Pluronic P85. MTT cytotoxicity assay and confocal microscopy images were carried out to determine whether Pluronic P85 could facilitate release of Dox from Doxil®. Anti-tumor growth and distribution of drug were evaluated when Pluronic P85 was injected 1h, 48h, or 96h after the Doxil® administration in A2780 human ovarian cancer xenografts. Addition of Pluronic P85 resulted in release of Dox from the liposomes accompanied with significant increases of Dox delivery and cytotoxic effect in cancer cells. The greatest anti-tumor effect of single injection of Doxil® was achieved when Pluronic P85 was administered 48h after Doxil®. The confocal tile scanning images of tumor section showed that copolymer treatment induced the release of the drug in the tumors from the vessels regions to the bulk of the tumor. No release of the drug remaining in circulation was observed. Our study has demonstrated a simple approach for localized release of Dox from liposome by Pluronic P85 at the tumor site, which was therapeutically beneficial.
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White SJ, Taylor MJ, Hurt RT, Jensen MD, Poland GA. Leptin-based adjuvants: an innovative approach to improve vaccine response. Vaccine 2013; 31:1666-72. [PMID: 23370154 DOI: 10.1016/j.vaccine.2013.01.032] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 01/04/2013] [Accepted: 01/15/2013] [Indexed: 12/22/2022]
Abstract
Leptin is a pleiotropic hormone with multiple direct and regulatory immune functions. Leptin deficiency or resistance hinders the immunologic, metabolic, and neuroendocrinologic processes necessary to thwart infections and their associated complications, and to possibly protect against infectious diseases following vaccination. Circulating leptin levels are proportional to body fat mass. High circulating leptin concentrations, as observed in obesity, are indicative of the development of leptin transport saturation/signaling desensitization. Leptin bridges nutritional status and immunity. Although its role in vaccine response is currently unknown, over-nutrition has been shown to suppress vaccine-induced immune responses. For instance, obesity (BMI ≥30 kg/m(2)) is associated with lower antigen-specific antibody titers following influenza, hepatitis B, and tetanus vaccinations. This suggests that obesity, and possibly saturable leptin levels, are contributing factors to poor vaccine immunogenicity. While leptin-based therapies have not been investigated as vaccine adjuvants thus far, leptin's role in immunity suggests that application of these therapies is promising and worth investigation to enhance vaccine response in people with leptin signaling impairments. This review will examine the possibility of using leptin as a vaccine adjuvant by: briefly reviewing the distribution and signal transduction of leptin and its receptors; discussing the physiology of leptin with emphasis on its immune functions; reviewing the causes of attenuation of leptin signaling; and finally, providing plausible inferences for the innovative use of leptin-based pharmacotherapies as vaccine adjuvants.
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Affiliation(s)
- Sarah J White
- Mayo Clinic Vaccine Research Group, Mayo Clinic, 200 First Street SW, Rochester, MN 55905, United States
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Tong J, Yi X, Luxenhofer R, Banks WA, Jordan R, Zimmerman MC, Kabanov AV. Conjugates of superoxide dismutase 1 with amphiphilic poly(2-oxazoline) block copolymers for enhanced brain delivery: synthesis, characterization and evaluation in vitro and in vivo. Mol Pharm 2012; 10:360-77. [PMID: 23163230 DOI: 10.1021/mp300496x] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Superoxide dismutase 1 (SOD1) efficiently catalyzes dismutation of superoxide, but its poor delivery to the target sites in the body, such as brain, hinders its use as a therapeutic agent for superoxide-associated disorders. Here to enhance the delivery of SOD1 across the blood-brain barrier (BBB) and in neurons the enzyme was conjugated with poly(2-oxazoline) (POx) block copolymers, P(MeOx-b-BuOx) or P(EtOx-b-BuOx), composed of (1) hydrophilic 2-methyl-2-oxazoline (MeOx) or 2-ethyl-2-oxazoline (EtOx) and (2) hydrophobic 2-butyl-2-oxazoline (BuOx) repeating units. The conjugates contained from 2 to 3 POx chains joining the protein amino groups via cleavable -(ss)- or noncleavable -(cc)- linkers at the BuOx block terminus. They retained 30% to 50% of initial SOD1 activity, were conformationally and thermally stable, and assembled in 8 or 20 nm aggregates in aqueous solution. They had little if any toxicity to CATH.a neurons and displayed enhanced uptake in these neurons as compared to native or PEGylated SOD1. Of the two conjugates, SOD1-(cc)-P(MeOx-b-BuOx) and SOD1-(cc)-P(EtOx-b-BuOx), compared, the latter was entering cells 4 to 7 times faster and at 6 h colocalized predominantly with endoplasmic reticulum (41 ± 3%) and mitochondria (21 ± 2%). Colocalization with endocytosis markers and pathway inhibition assays suggested that it was internalized through lipid raft/caveolae, also employed by the P(EtOx-b-BuOx) copolymer. The SOD activity in cell lysates and ability to attenuate angiotensin II (Ang II)-induced superoxide in live cells were increased for this conjugate compared to SOD1 and PEG-SOD1. Studies in mice showed that SOD1-POx had ca. 1.75 times longer half-life in blood than native SOD1 (28.4 vs 15.9 min) and after iv administration penetrated the BBB significantly faster than albumin to accumulate in brain parenchyma. The conjugate maintained high stability both in serum and in brain (77% vs 84% at 1 h postinjection). Its amount taken up by the brain reached a maximum value of 0.08% ID/g (percent of the injected dose taken up per gram of brain) 4 h postinjection. The entry of SOD1-(cc)-P(EtOx-b-BuOx) to the brain was mediated by a nonsaturable mechanism. Altogether, SOD1-POx conjugates are promising candidates as macromolecular antioxidant therapies for superoxide-associated diseases such as Ang II-induced neurocardiovascular diseases.
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Affiliation(s)
- Jing Tong
- Center for Drug Delivery and Nanomedicine, Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, Nebraska 68198, United States
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Luxenhofer R, Han Y, Schulz A, Tong J, He Z, Kabanov AV, Jordan R. Poly(2-oxazoline)s as polymer therapeutics. Macromol Rapid Commun 2012; 33:1613-31. [PMID: 22865555 PMCID: PMC3608391 DOI: 10.1002/marc.201200354] [Citation(s) in RCA: 326] [Impact Index Per Article: 27.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 06/12/2012] [Indexed: 01/21/2023]
Abstract
Poly(2-oxazoline)s (POx) are currently discussed as an upcoming polymer platform for biomaterials design and especially for polymer therapeutics. POx meet specific requirements needed for the development of next-generation polymer therapeutics such as biocompatibility, high modulation of solubility, variation of size, architecture as well as chemical functionality. Although in the early 1990s first and promising POx-based systems were presented, the field lay dormant for almost two decades. Only very recently, POx-based polymer therapeutics came back into the focus of very intensive research. In this review, we give an overview on the chemistry and physicochemical properties of POx and summarize the research of POx-protein conjugates, POx-drug conjugates, POx-based polyplexes and POx micelles for drug delivery.
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Affiliation(s)
- Robert Luxenhofer
- Professur für Makromolekulare Chemie, Department Chemie, Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden, Germany
| | - Yingchao Han
- Center for Drug Delivery and Nanomedicine and Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-5830, U.S.A
| | - Anita Schulz
- Professur für Makromolekulare Chemie, Department Chemie, Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden, Germany
| | - Jing Tong
- Center for Drug Delivery and Nanomedicine and Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-5830, U.S.A
| | - Zhijian He
- Center for Drug Delivery and Nanomedicine and Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-5830, U.S.A
| | - Alexander V. Kabanov
- Center for Drug Delivery and Nanomedicine and Department of Pharmaceutical Sciences, College of Pharmacy, University of Nebraska Medical Center, Omaha, NE 68198-5830, U.S.A
| | - Rainer Jordan
- Professur für Makromolekulare Chemie, Department Chemie, Technische Universität Dresden, Zellescher Weg 19, 01069 Dresden, Germany
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Orthmann A, Fichtner I, Zeisig R. Improving the transport of chemotherapeutic drugs across the blood-brain barrier. Expert Rev Clin Pharmacol 2012; 4:477-90. [PMID: 22114857 DOI: 10.1586/ecp.11.26] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The successful treatment of brain tumors or metastases in the brain is still hampered by the very efficient blood-brain barrier, which prevents the cerebral accumulation of a pharmacologically sufficient amount of a drug. Beside the possibility of disintegrating the functionality of this effective working barrier, a nanocarrier-mediated transport is presently an interesting and promising method to increase the drug concentration in the brain. Nanocarriers are small vesicles (<200 nm) and can be prepared by polymerization, resulting in nanoparticles, or by producing superficial lipid structures to incorporate the drug. In this context, liposomes are of importance owing to their ability to adapt their properties to the pharmacological requirements. In this article, we will give an overview of current possibilities of enhancing anticancer drug transport across the blood-brain barrier, based on its structure and functionality. Special consideration will be given to recent liposomal approaches that use active targeting for receptor-mediated transport across this physiological barrier.
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Affiliation(s)
- Andrea Orthmann
- Max Delbrück Center for Molecular Medicine, Experimental Pharmacology, Robert-Rössle-Str. 10, 13122 Berlin, German
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Davidson TL, Monnot A, Neal AU, Martin AA, Horton JJ, Zheng W. The effects of a high-energy diet on hippocampal-dependent discrimination performance and blood-brain barrier integrity differ for diet-induced obese and diet-resistant rats. Physiol Behav 2012; 107:26-33. [PMID: 22634281 PMCID: PMC3409296 DOI: 10.1016/j.physbeh.2012.05.015] [Citation(s) in RCA: 143] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 03/13/2012] [Accepted: 05/14/2012] [Indexed: 02/01/2023]
Abstract
Rats that consume high-energy (HE) diets (i.e., diets high in saturated fats and sugar) show impaired hippocampal-dependent learning and memory (e.g., Kanoski and Davidson (2011) [1]). To further investigate this effect, we trained rats given restricted access to low-fat lab chow on hippocampal-dependent serial feature-negative (FN) and hippocampal-independent simple discrimination problems. When training was completed, Group Chow received ad libitum lab chow. The remaining rats received ad libitum HE diet. Performance on both discrimination problems was tested following 7, 14, 21 and 28 days of HE diet exposure. FN, but not simple discrimination, was abolished initially for all rats, and then re-emerged for Group Chow. For rats fed HE diet, those that weighed the least and had the lowest amount of body fat (HE-diet resistant (HE-DR) rats), performed like Group Chow on both discrimination problems. However, HE diet-induced obese (HE-DIO) rats (i.e., rats that weighed the most weight and had the most body fat) performed like Group Chow on the simple discrimination problem, but were impaired throughout testing on the FN problem. Subsequent assessment of blood-brain barrier (BBB) permeability revealed that concentrations of an exogenously administered dye were elevated in the hippocampus, but not in the striatum or prefrontal cortex for HE-DIO rats relative to the HE-DR and Chow groups. The results indicate that the adverse consequences of HE diet on hippocampal-dependent cognitive functioning are associated with detrimental effects on the BBB and that both of these outcomes vary with sensitivity to HE diet-induced increases in weight and adiposity.
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Affiliation(s)
- Terry L Davidson
- Department of Psychological Sciences, Purdue University, 703 Third Street, West Lafayette, IN 47907, USA.
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Roubos EW, Dahmen M, Kozicz T, Xu L. Leptin and the hypothalamo-pituitary-adrenal stress axis. Gen Comp Endocrinol 2012; 177:28-36. [PMID: 22293575 DOI: 10.1016/j.ygcen.2012.01.009] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2011] [Revised: 01/10/2012] [Accepted: 01/12/2012] [Indexed: 12/20/2022]
Abstract
Leptin is a 16-kDa protein mainly produced and secreted by white adipose tissue and informing various brain centers via leptin receptor long and short forms about the amount of fat stored in the body. In this way leptin exerts a plethora of regulatory functions especially related to energy intake and metabolism, one of which is controlling the activity of the hypothalamo-pituitary-adrenal (HPA) stress axis. First, this review deals with the basic properties of leptin's structure and signaling at the organ, cell and molecule level, from lower vertebrates to humans but with emphasis on rodents because these have been investigated in most detail. Then, attention is given to the various interactions of adipose leptin with the HPA-axis, at the levels of the hypothalamus (especially the paraventricular nucleus), the anterior lobe of the pituitary gland (action on corticotropes) and the adrenal gland, where it releases corticosteroids needed for adequate stress adaptation. Also, possible local production and autocrine and paracrine actions of leptin at the hypothalamic and pituitary levels of the HPA-axis are being considered. Finally, a schematic model is presented showing the ways peripherally and centrally produced leptin may modulate, via the HPA-axis, stress adaptation in conjunction with the control of energy homeostasis.
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Affiliation(s)
- Eric W Roubos
- Department of Cellular Animal Physiology, Faculty of Science, Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen, The Netherlands.
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Uner AG, Sulu N. In vivo effects of leptin on lymphocyte subpopulations in mice. Immunobiology 2012; 217:882-8. [PMID: 22317748 DOI: 10.1016/j.imbio.2011.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Revised: 12/22/2011] [Accepted: 12/29/2011] [Indexed: 11/18/2022]
Abstract
Leptin, a hormone-cytokine mainly produced by the adipose tissue, has pleitropic effects on many biological system including metabolic, endocrine, and immune system. Although it is well known that leptin controls food intake on hypothalamic regions of brain, the role of leptin in hematopoietic and immune processes has been mainly investigated with in vitro and transgenic mouse studies. The aim of this study was to investigate the effects of peripheral leptin on lymphocyte subpopulation. Initially forty male Swiss albino mice were divided into five groups. Mice in group I (Control) were given serum physiologic (SP) and group L100, group L250, group L500, and group L1000 were given 100, 250, 500 and 1000 μg/kg/day recombinant mouse leptin, respectively. Leptin or SP was injected subcutaneously for the next 6 days. Daily food/water intake was recorded for each group. At the end of the study, whole blood samples (500 μl) were obtained via intracardiac punction in anesthetized mice. Leptin levels and lymphocyte subpopulations in blood samples were analyzed. We show that no in vivo dose-dependent effect of leptin is existed on lymphocyte subpopulations count in mice. Treatment of mice with high-dose leptin led to increase only CD4+ cells (P<0.05). In addition, high-dose leptin slightly increased CD3+ cells but this was not statistically confirmed (P=0.08). Notably, it was found that leptin caused insignificant changes on body weight and food intake in normal body weight mice. The data support that high-dose leptin has proliferative effect on CD4+ cells in vivo. However, more in vivo study needs to be examined to clarify how leptin affect lymphocyte subpopulations.
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Affiliation(s)
- Aykut G Uner
- Department of Physiology, Adnan Menderes University, Aydin, Turkey.
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Drug transport into the central nervous system: using newer findings about the blood–brain barriers. Drug Deliv Transl Res 2012; 2:152-9. [DOI: 10.1007/s13346-012-0058-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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