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Zhan C, Huang M, Yang X, Hou J. Dental nerves: a neglected mediator of pulpitis. Int Endod J 2020; 54:85-99. [PMID: 32880979 DOI: 10.1111/iej.13400] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 08/26/2020] [Indexed: 12/18/2022]
Abstract
As one of the most densely innervated tissues, the dental pulp contains abundant nerve fibres, including sensory, sympathetic and parasympathetic nerve fibres. Studies in animal models and human patients with pulpitis have revealed distinct alterations in protein expression and histological appearance in all types of dental nerve fibres. Various molecules secreted by neurons, such as classical neurotransmitters, neuropeptides and amino acids, not only contribute to the induction, sensitization and maintenance of tooth pain, but also regulate non-neuronal cells, including fibroblasts, odontoblasts, immune cells and vascular endothelial cells. Dental nerves are particularly important for the microcirculatory and immune responses in pulpitis via their release of a variety of functional substances. Further, nerve fibres are found to be involved in dental soft and hard tissue repair. Thus, understanding how dental nerves participate in pulpitis could have important clinical ramifications for endodontic treatment. In this review, the roles of dental nerves in regulating pulpal inflammatory processes are highlighted and their implications for future research on this topic are discussed.
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Affiliation(s)
- C Zhan
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - M Huang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - X Yang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - J Hou
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
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Uhrich E, Gautam M, Hatton J, Rowland K. Corticotropin releasing factor receptor expression in painful human dental pulp. Arch Oral Biol 2015; 60:1048-53. [PMID: 25924915 DOI: 10.1016/j.archoralbio.2015.03.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 02/03/2015] [Accepted: 03/18/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Our objective was to correlate the presence of symptoms and dental pulp injury with the amount of a subtype of corticotropin releasing factor receptor (CRF-R) in symptomatic and asymptomatic human teeth. We hypothesized that patients diagnosed with irreversible pulpitis have increased levels of CRF-R. MATERIALS AND METHODS Dental history, diagnosis and radiographs were obtained from treatment records following extractions. Teeth were diagnosed as asymptomatic or symptomatic demonstrated by clinical and radiographic evaluation. Tissue sections from tooth pulp were immunoreacted with antibodies directed against CRF receptor 2 (CRF-R2) and neurofilament protein and examined to correlate CRF-R expression with pulpal diagnosis. RESULTS Our results indicated that symptomatic pulps demonstrated significantly greater expression of CRF-R2. The increased expression was localized on distinct cellular profiles throughout the pulp and was not directly correlated with neurofilament expression. CONCLUSIONS Our findings suggest that the analgesic effects of endogenously produced CRF may be enhanced via upregulation of CRF-R2 expression, and may explain the occurrence of reduced pain symptoms in some patients with irreversible pulpitis. The application of CRF-R agonists may be a feasible strategy in reducing pain associated with irreversible pulpitis.
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Affiliation(s)
- Elizabeth Uhrich
- Southern Illinois University, School of Dental Medicine, 2800 College Avenue, Alton, IL 62002, United States
| | - Medha Gautam
- Southern Illinois University, School of Dental Medicine, 2800 College Avenue, Alton, IL 62002, United States
| | - John Hatton
- Center for Advanced Dental Education, Saint Louis University, St. Louis, MO 63103, United States
| | - Kevin Rowland
- Southern Illinois University, School of Dental Medicine, 2800 College Avenue, Alton, IL 62002, United States.
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Moncayo R. Reflections on the theory of "silver bullet" octreotide tracers: implications for ligand-receptor interactions in the age of peptides, heterodimers, receptor mosaics, truncated receptors, and multifractal analysis. EJNMMI Res 2011; 1:9. [PMID: 22214590 PMCID: PMC3251005 DOI: 10.1186/2191-219x-1-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 07/26/2011] [Indexed: 12/25/2022] Open
Abstract
The classical attitude of Nuclear Medicine practitioners on matters of peptide-receptor interactions has maintained an intrinsic monogamic character since many years. New advances in the field of biochemistry and even in clinical Nuclear Medicine have challenged this type of thinking, which prompted me to work on this review. The central issue of this paper will be the use of somatostatin analogs, i.e., octreotide, in clinical imaging procedures as well as in relation to neuroendocirne tumors. Newly described characteristics of G-protein coupled receptors such as the formation of receptor mosaics will be discussed. A small section will enumerate the regulatory processes found in the cell membrane. Possible new interpretations, other than tumor detection, based on imaging procedures with somatostatin analogs will be presented. The readers will be taken to situations such as inflammation, nociception, mechanosensing, chemosensing, fibrosis, taste, and vascularity where somatostatin is involved. Thyroid-associated orbitopathy will be used as a model for the development of multi-agent therapeutics. The final graphical summary depicts the multifactorial properties of ligand binding.
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Affiliation(s)
- Roy Moncayo
- Department of Nuclear Medicine, Medical University of Innsbruck, Innsbruck, Austria.
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Csaba G. [The immuno-endocrine system. A new endocrine theory: the problem of the packed transport]. Orv Hetil 2011; 152:777-84. [PMID: 21540150 DOI: 10.1556/oh.2011.29122] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Since the eighties of the last century hormone content was justified in immune cells (lymphocytes, granulocytes, monocytes, macrophages and mast cells), which produce, store and secrete these hormones. Although the amount of these materials in immune cells is relatively small, the mass of the producers (immune cells) is so large, that the phenomenon must be considered from endocrinological point of view, underlying the important differences between the "classical" and immuno-endocrine systems. Cells of the classic (built-in) endocrine system are mono-producers, while immune cells can synthesize many types of hormones (polyproducers). In addition, these cells can transport the whole hormone-producing machinery to the site of need, producing a local effect. This can be observed, for example, in the case of endorphin producing immune cells during inflammation and during early pregnancy around the chorionic villi. Hormone producing immune cells also have receptors for many hormones, so that they are poly-receivers. Via hormone producing and receiving capacity there is a bidirectional connection between the neuro-endocrine and immuno-endocrine systems. In addition, there is a network inside the immuno-endocrine system. The packed transport theory attempts to explain the mechanism and importance of the immuno-endocrine system.
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Affiliation(s)
- György Csaba
- Semmelweis Egyetem, Általános Orvostudományi Kar, Genetikai, Sejt- és Immunbiológiai Intézet Budapest.
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Pacheco CMF, Queiroz-Junior CM, Maltos KLM, Caliari MV, Pacheco DF, Duarte IDG, Francischi JN. Crucial role of peripheral kappa-opioid receptors in a model of periodontal disease in rats. J Periodontal Res 2008; 43:730-6. [PMID: 18705652 DOI: 10.1111/j.1600-0765.2008.01102.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND AND OBJECTIVE Periodontal disease is a chronic inflammatory condition of the tooth supporting tissues, the periodontium. Opioids have been shown to account for the relief of various chronic and acute inflammatory conditions. The aim of the present study was to investigate the participation of peripheral opioid receptors in development of periodontal disease. MATERIAL AND METHODS Morphine and selective agonists and antagonists of opioid receptors were used in an experimental model of ligature-induced periodontal disease in rats. To evaluate the development of disease, the loss of fiber attachment, alveolar bone and number of cells in periodontal tissues were assessed. Measurements of these indicators were obtained by morphometric analysis of histological sections of periodontal-diseased tissues stained with hematoxylin and eosin. RESULTS Local administration of either morphine or a selective kappa-opioid agonist for three consecutive days from the onset of periodontal disease reduced the loss of periodontal tissues, without changing the number of leukocytes in inflamed periodontium. Nor-binaltorphimine, a selective kappa-antagonist, reversed the beneficial effects of both morphine and the compound U-50,488 in this model. The use of either an agonist or an antagonist of delta-opioid receptors, however, did not affect disease progression. CONCLUSION Our results showed that the beneficial effect of opioids in periodontal disease depended mainly on the activation of specific kappa-opioid receptors located in the periphery. Activation of such receptors could be considered in the management of periodontal disease, since it would not present the classical central side-effects associated with opioid use.
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Affiliation(s)
- C M F Pacheco
- Department of Pharmacology, Institute of Biological Sciences, Federal University of Minas Gerais (UFMG), Belo Horizonte, Minas Gerais, Brazil
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Abstract
This paper is the 29th consecutive installment of the annual review of research concerning the endogenous opioid system, now spanning 30 years of research. It summarizes papers published during 2006 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides, opioid receptors, opioid agonists and opioid antagonists. The particular topics that continue to be covered include the molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors related to behavior (Section 2), and the roles of these opioid peptides and receptors in pain and analgesia (Section 3); stress and social status (Section 4); tolerance and dependence (Section 5); learning and memory (Section 6); eating and drinking (Section 7); alcohol and drugs of abuse (Section 8); sexual activity and hormones, pregnancy, development and endocrinology (Section 9); mental illness and mood (Section 10); seizures and neurological disorders (Section 11); electrical-related activity and neurophysiology (Section 12); general activity and locomotion (Section 13); gastrointestinal, renal and hepatic functions (Section 14); cardiovascular responses (Section 15); respiration and thermoregulation (Section 16); and immunological responses (Section 17).
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Affiliation(s)
- Richard J Bodnar
- Department of Psychology and Neuropsychology Doctoral Sub-Program, Queens College, City University of New York, CUNY, 65-30 Kissena Blvd., Flushing, NY 11367, United States.
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Localized increases in corticotropin-releasing factor receptors in pulp after dental injury. J Endod 2007; 33:1319-24. [PMID: 17963955 DOI: 10.1016/j.joen.2007.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2007] [Revised: 08/03/2007] [Accepted: 08/04/2007] [Indexed: 11/22/2022]
Abstract
Corticotropin-releasing factor (CRF) binds to membrane-bound CRF receptors (CRF-Rs). Among the actions mediated by activated CRF-Rs is beta-endorphin (END) release from immune cells, increasing peripheral antinociception. For assessment of inflammatory regulation of CRF-R expression, rats underwent pulp exposure of left, first mandibular molars and recovered for 6 days. Control pulpal tissue consisted of contralateral, uninjured molars and left, first mandibular molars of uninjured animals. Pulp tissue specimens were incubated with antibodies directed against CRF-R (both isoforms), neurofilament, CD45, and END. We observed (1) increases in pulp CRF-R immunoreactivity after injury, (2) increased CRF-R immunoreactivity expressed in 3 distinct zones in relation to the injury, and (3) increased CD45 and END immunoreactivity in regions surrounding the pulpal abscess. CRF-Rs might provide an additional target for novel analgesics to treat pulpal pain.
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Hahn CL, Liewehr FR. Innate Immune Responses of the Dental Pulp to Caries. J Endod 2007; 33:643-51. [PMID: 17509400 DOI: 10.1016/j.joen.2007.01.001] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2006] [Revised: 12/19/2006] [Accepted: 01/01/2007] [Indexed: 11/29/2022]
Abstract
Various cells and inflammatory mediators are involved in the initial pulpal responses to caries. This review focuses on the cellular, neuronal, and vascular components of pulpal innate responses to caries. Discussion will include dentinal fluid, odontoblasts, neuropeptides, and neurogenic inflammation, which are not classic immune components but actively participate in the inflammatory response as the caries progress pulpally. Summaries of innate immune cells as well as their cytokines and chemokines in healthy and reversible pulpitis tissues are presented.
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Affiliation(s)
- Chin-Lo Hahn
- Department of Endodontics, School of Dentistry, Virginia Commonwealth University, 520 North 12th Street, Richmond, Virginia 3298-0566, USA
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Abstract
In this article, we review the key basic mechanisms associated with this phenomena and more recently identified mechanisms that are current areas of interest. Although many of these pain mechanisms apply throughout the body, we attempt to describe these mechanisms in the context of trigeminal pain.
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Affiliation(s)
- Michael A Henry
- Department of Endodontics, University of Texas Health Science Center at San Antonio School of Dentistry, Mail Code 7892, 7703 Floyd Curl Drive, San Antonio, TX 78229, USA.
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