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Zhan C, Huang M, Zeng J, Chen T, Lu Y, Chen J, Li X, Yin L, Yang X, Hou J. Irritation of Dental Sensory Nerves Promotes the Occurrence of Pulp Calcification. J Endod 2023; 49:402-409. [PMID: 36758674 DOI: 10.1016/j.joen.2023.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 12/27/2022] [Accepted: 01/05/2023] [Indexed: 02/10/2023]
Abstract
INTRODUCTION Pulp calcification (PC) often appears in strong association with nerve fiber bundles, which indicates the important role of dental nerves in the formation of PC. Additionally, given that sensory nerves and calcitonin gene-related peptide (CGRP) secreted from sensory nerve fibers are involved in physiological and pathological bone formation, we aimed to determine whether chronic irritation of sensory nerves can promote the occurrence of PC. METHODS A sensory nerve irritation rat model was established via ligation of the inferior alveolar nerve (IAN), and face grooming behavior was analyzed as a measure of pain sensation. Two months post-surgery, PC was determined by imaging and histologic analyses. RESULTS Rats in the IAN-chronic constriction injury (IAN-CCI) group showed spontaneous pain-associated behavior after the operations and pain tolerance on the 60th postoperative day. The imaging and histological analysis showed more calcified particles in the IAN-innervated first and second molars after day 60 of the dental sensory nerve irritation. These calcified masses had a dentin-like structure that contained sparse, irregularly oriented tubules. Compared to the control and sham groups, the odontoblasts located in the periphery of radicular pulp aligned along a thicker layer of predentin; which expressed more nestin with longer and stouter processes in the IAN-CCI group. Additionally, more CGRP-positive nerves were observed in the IAN-CCI group. CONCLUSIONS Irritation of sensory nerves promotes PC formation, and the increased density of CGRP-immunolabeled fibers probably contributes to this process. This highlights the significance of dental sensory nerves in the formation of PC.
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Affiliation(s)
- Chaoning Zhan
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Minchun Huang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Jiao Zeng
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Ting Chen
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Yanli Lu
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Junyang Chen
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xinzhu Li
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Linying Yin
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xiaojun Yang
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
| | - Jin Hou
- Department of Stomatology, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Han HM, Jeong SY, Cho YS, Choi SY, Bae YC. Expression of Piezo2 in the dental pulp, sensory root and trigeminal ganglion and it's coexpression with vesicular glutamate transporters. J Endod 2022; 48:1407-1413. [PMID: 35952898 DOI: 10.1016/j.joen.2022.07.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 07/14/2022] [Accepted: 07/21/2022] [Indexed: 01/10/2023]
Abstract
INTRODUCTION Information on the type of vesicular glutamate transporter (VGLUT) that is expressed in the Piezo2-positive (+) neurons in the trigeminal ganglion (TG), and on the type of Piezo2+ axons and their distribution in the dental pulp is important for understanding dental pain elicited by mechanical stimuli and developing new therapeutic strategies. METHODS We examined expression of Piezo2 and its coexpression with VGLUT1 and VGLUT2 in rat TG, sensory root and in human dental pulp by light and electron microscopic immunohistochemistry and quantitative analysis. RESULTS VGLUT1 and VGLUT2 were expressed in the TG neurons. Piezo2 was expressed in axons of all types but primarily in small myelinated (Aδ) axons in the sensory root. In the dental pulp, Piezo2 was expressed densely in the numerous axons that form plexus in the peripheral pulp. Piezo2+ axons in the peripheral pulp were mostly unmyelinated and the Piezo2-immunoreactivity was often concentrated near the axolemma, suggesting that it may represent functional receptors. CONCLUSIONS These findings suggest that 1) VGLUT1 and VGLUT2 are involved in the glutamate signaling in Piezo2+ neurons, 2) Piezo2 may be primarily activated by noxious mechanical stimuli and 3) Piezo2-mediated dental mechanotransduction may be primarily elicited in the peripheral pulp.
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Affiliation(s)
- Hye Min Han
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Soon Youn Jeong
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Yi Sul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - So Young Choi
- Department of Oral & Maxillofacial Surgery, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
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Cho YS, Han HM, Jeong SY, Kim TH, Choi SY, Kim YS, Bae YC. Expression of Piezo1 in the Trigeminal Neurons and in the Axons That Innervate the Dental Pulp. Front Cell Neurosci 2022; 16:945948. [PMID: 35846568 PMCID: PMC9276962 DOI: 10.3389/fncel.2022.945948] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 06/03/2022] [Indexed: 12/02/2022] Open
Abstract
Information on the neurons and axons that express the mechanosensitive channel Piezo1 and its expression in axons innervating the dental pulp may help understand the nature of the Piezo1-mediated mechanosensation and the underlying mechanism of dentin sensitivity elicited by mechanical stimuli. For this, we here investigated the neurochemical properties of the neurons in the rat trigeminal ganglion (TG) and their axons in its sensory root that express Piezo1 and the expression of Piezo1 in the rat and human dental pulp by light and electron microscopic immunohistochemistry and quantitative analysis. Piezo1 was expressed mainly in medium-sized and large TG neurons. Piezo1-immunopositive (+) neurons frequently coexpressed the marker for neurons with myelinated axons, NF200, but rarely the markers for neurons with unmyelinated axons, CGRP or IB4. In the sensory root of TG, Piezo1 was expressed primarily in small myelinated axons (Aδ, 60.2%) but also in large myelinated (Aβ, 24.3%) and unmyelinated (C, 15.5%) axons. In the human dental pulp, Piezo1 was expressed in numerous NF200+ axons, which formed a network in the peripheral pulp and often “ascended” toward the dentin. Most Piezo1+ myelinated axons in the radicular pulp became unmyelinated in the peripheral pulp, where Piezo1 immunoreaction product was associated with the axonal plasma membrane, suggesting a functional role of Piezo1 in the peripheral pulp. These findings suggest that Piezo1 is involved primarily in mediating the acute pain elicited by high-threshold mechanical stimuli, and that the Piezo1-mediated dental mechanotransduction occurs primarily in the axons in the peripheral pulp.
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Affiliation(s)
- Yi Sul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Hye Min Han
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Soon Youn Jeong
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Tae Heon Kim
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - So Young Choi
- Department of Oral & Maxillofacial Surgery, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Yun Sook Kim
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
- *Correspondence: Yong Chul Bae
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Glia and Orofacial Pain: Progress and Future Directions. Int J Mol Sci 2021; 22:ijms22105345. [PMID: 34069553 PMCID: PMC8160907 DOI: 10.3390/ijms22105345] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Revised: 05/12/2021] [Accepted: 05/14/2021] [Indexed: 12/14/2022] Open
Abstract
Orofacial pain is a universal predicament, afflicting millions of individuals worldwide. Research on the molecular mechanisms of orofacial pain has predominately focused on the role of neurons underlying nociception. However, aside from neural mechanisms, non-neuronal cells, such as Schwann cells and satellite ganglion cells in the peripheral nervous system, and microglia and astrocytes in the central nervous system, are important players in both peripheral and central processing of pain in the orofacial region. This review highlights recent molecular and cellular findings of the glia involvement and glia–neuron interactions in four common orofacial pain conditions such as headache, dental pulp injury, temporomandibular joint dysfunction/inflammation, and head and neck cancer. We will discuss the remaining questions and future directions on glial involvement in these four orofacial pain conditions.
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Yoshimatsu M, Nakamura R, Kishimoto Y, Yurie H, Hayashi Y, Kaba S, Ohnishi H, Yamashita M, Tateya I, Omori K. Recurrent laryngeal nerve regeneration using a self‐assembling peptide hydrogel. Laryngoscope 2019; 130:2420-2427. [DOI: 10.1002/lary.28434] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 10/28/2019] [Accepted: 11/04/2019] [Indexed: 12/11/2022]
Affiliation(s)
- Masayoshi Yoshimatsu
- Department of Otolaryngology–Head and Neck Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
| | - Ryosuke Nakamura
- Department of Otolaryngology–Head and Neck Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
| | - Yo Kishimoto
- Department of Otolaryngology–Head and Neck Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
| | - Hirofumi Yurie
- Department of Orthopaedic Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
| | - Yasuyuki Hayashi
- Department of Otolaryngology–Head and Neck Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
| | - Shinji Kaba
- Department of Otolaryngology–Head and Neck Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
| | - Hiroe Ohnishi
- Department of Otolaryngology–Head and Neck Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
| | - Masaru Yamashita
- Department of Otorhinolaryngology–Head and Neck Surgery Shizuoka General Hospital Shizuoka Japan
| | - Ichiro Tateya
- Department of Otolaryngology School of Medicine, Fujita Health University Toyoake Japan
| | - Koichi Omori
- Department of Otolaryngology–Head and Neck Surgery Graduate School of Medicine, Kyoto University Kyoto Japan
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Hossain MZ, Bakri MM, Yahya F, Ando H, Unno S, Kitagawa J. The Role of Transient Receptor Potential (TRP) Channels in the Transduction of Dental Pain. Int J Mol Sci 2019; 20:ijms20030526. [PMID: 30691193 PMCID: PMC6387147 DOI: 10.3390/ijms20030526] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 01/18/2019] [Accepted: 01/24/2019] [Indexed: 12/18/2022] Open
Abstract
Dental pain is a common health problem that negatively impacts the activities of daily living. Dentine hypersensitivity and pulpitis-associated pain are among the most common types of dental pain. Patients with these conditions feel pain upon exposure of the affected tooth to various external stimuli. However, the molecular mechanisms underlying dental pain, especially the transduction of external stimuli to electrical signals in the nerve, remain unclear. Numerous ion channels and receptors localized in the dental primary afferent neurons (DPAs) and odontoblasts have been implicated in the transduction of dental pain, and functional expression of various polymodal transient receptor potential (TRP) channels has been detected in DPAs and odontoblasts. External stimuli-induced dentinal tubular fluid movement can activate TRP channels on DPAs and odontoblasts. The odontoblasts can in turn activate the DPAs by paracrine signaling through ATP and glutamate release. In pulpitis, inflammatory mediators may sensitize the DPAs. They could also induce post-translational modifications of TRP channels, increase trafficking of these channels to nerve terminals, and increase the sensitivity of these channels to stimuli. Additionally, in caries-induced pulpitis, bacterial products can directly activate TRP channels on DPAs. In this review, we provide an overview of the TRP channels expressed in the various tooth structures, and we discuss their involvement in the development of dental pain.
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Affiliation(s)
- Mohammad Zakir Hossain
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Marina Mohd Bakri
- Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Farhana Yahya
- Department of Oral and Craniofacial Sciences, Faculty of Dentistry, University of Malaya, Kuala Lumpur 50603, Malaysia.
| | - Hiroshi Ando
- Department of Biology, School of Dentistry, Matsumoto Dental University, 1780 Gobara, Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Shumpei Unno
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
| | - Junichi Kitagawa
- Department of Oral Physiology, School of Dentistry, Matsumoto Dental University, 1780 Gobara Hirooka, Shiojiri, Nagano 399-0781, Japan.
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Won J, Vang H, Lee P, Kim Y, Kim H, Kang Y, Oh S. Piezo2 Expression in Mechanosensitive Dental Primary Afferent Neurons. J Dent Res 2017; 96:931-937. [DOI: 10.1177/0022034517702342] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Mechanosensitive ion channels have been suggested to be expressed in dental primary afferent (DPA) neurons to transduce the movement of dentinal fluid since the proposal of hydrodynamic theory. Piezo2, a mechanosensitive, rapidly inactivating (RI) ion channel, has been recently identified in dorsal root ganglion (DRG) neurons to mediate tactile transduction. Here, we examined the expression of Piezo2 in DPA neurons by in situ hybridization, single-cell reverse transcriptase polymerase chain reaction, and whole-cell patch-clamp recordings. DPA neurons with Piezo2 messenger RNA (mRNA) or Piezo2-like currents were further characterized based on their neurochemical and electrophysiological properties. Piezo2 mRNA was found mostly in medium- to large-sized DPA neurons, with the majority of these neurons also positive for Nav1.8, CGRP, and NF200, whereas only a minor population was positive for IB4 and peripherin. Whole-cell patch-clamp recordings revealed Piezo2-like, RI currents evoked by mechanical stimulation in a subpopulation of DPA neurons. RI currents were pharmacologically blocked by ruthenium red, a compound known to block Piezo2, and were also reduced by small interfering RNA-mediated Piezo2 knockdown. Piezo2-like currents were observed almost exclusively in IB4-negative DPA neurons, with the current amplitude larger in capsaicin-insensitive DPA neurons than the capsaicin-sensitive population. Our findings show that subpopulation of DPA neurons is indeed mechanically sensitive. Within this subpopulation of mechanosensitive DPA neurons, we have identified the Piezo2 ion channel as a potential transducer for mechanical stimuli, contributing to RI inward currents. Piezo2-positive DPA neurons were characterized as medium- to large-sized neurons with myelinated A-fibers, containing nociceptive peptidergic neurotransmitters.
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Affiliation(s)
- J. Won
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - H. Vang
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - P.R. Lee
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Y.H. Kim
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
- Department of Physiology, College of Medicine, Gachon University, Incheon, Republic of Korea (present address)
| | - H.W. Kim
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
| | - Y. Kang
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
- Department of Neuroscience and Oral Physiology, Osaka University Graduate School of Dentistry, Osaka, Japan
| | - S.B. Oh
- Department of Brain and Cognitive Sciences, College of Natural Sciences, Seoul National University, Seoul, Republic of Korea
- Dental Research Institute and Department of Neurobiology & Physiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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Kim TH, Park SK, Choi SY, Lee JS, Bae YC. Morphologic Change of Parvalbumin-positive Myelinated Axons in the Human Dental Pulp. J Endod 2017; 43:977-981. [PMID: 28389070 DOI: 10.1016/j.joen.2017.01.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Revised: 12/22/2016] [Accepted: 01/09/2017] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Information on the nerve fibers innervating the dental pulp is crucial for understanding dental pain and hypersensitivity. This study investigated the morphologic differences of parvalbumin (PV)-positive (+) myelinated fibers in 3 different regions of the human dental pulp. METHODS Light and electron microscopic immunohistochemistry for parvalbumin, a marker for myelinated fibers, and quantitative analysis were performed in the apical root, core of coronal pulp, and peripheral pulp of human premolar teeth. RESULTS About 40% of the myelinated fibers in the apical root pulp became unmyelinated in the core of the coronal pulp, and virtually all the remaining fibers became unmyelinated at the peripheral pulp. The size of myelinated axons decreased from root to peripheral pulp. PV+ axons showed extensive axonal varicosities in the peripheral pulp. CONCLUSIONS These findings suggest that the myelinated fibers innervating the human dental pulp undergo extensive morphologic change in the extrapulpal region and in the coronal and peripheral pulp, and that PV-mediated regulation of calcium concentration and its downstream events may occur primarily in axonal varicosities in the peripheral pulp.
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Affiliation(s)
- Tae Heon Kim
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Sook Kyung Park
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - So Young Choi
- Department of Oral & Maxillofacial Surgery, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Jae Sik Lee
- Department of Pediatric Dentistry, School of Dentistry, Kyungpook National University, Daegu, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, South Korea.
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Liang W, Zhang W, Zhao S, Li Q, Liang H, Ceng R. Altered expression of neurofilament 200 and amyloid-β peptide (1-40) in a rat model of chronic cerebral hypoperfusion. Neurol Sci 2014; 36:707-12. [PMID: 25452168 DOI: 10.1007/s10072-014-2014-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 11/19/2014] [Indexed: 12/21/2022]
Abstract
Chronic cerebral hypoperfusion (CCH) is damaging to white matter in the brain. So far few studies have investigated long-term axonal damage following CCH. The aim of this study was to investigate the involvement of neurofilament 200 (NF200) and amyloid-β (1-40) [Aβ (1-40)] in the pathological mechanism for neuronal damage, and to quantify changes in their expression over time in a rat model of CCH. A rat model of CCH was established using partial bilateral ligation of the common carotid arteries. The extent of stenosis was verified by measuring the changes in cerebral blood flow after surgery. Histology was used to assess hippocampal neuronal pathology, and immunohistochemistry was used to quantify the expression of NF200 and Aβ (1-40) at 2, 4, and 12 weeks after surgery. The cerebral blood flow reduced to 33.89 ± 5.48 % at 2 weeks, 36.83 ± 4.63 % at 4 weeks and 51.44 ± 4.90 % at 12 weeks. Immunofluorescence staining of neuronal perikarya sections revealed a marked decrease in the population of surviving pyramidal cells in the hippocampal CA1 region, a significant up-regulation in the expression of Aβ (1-40), and a significant reduction in the expression of NF200 following CCH surgery. Moreover, this trend was increasingly obvious over time. Our data demonstrate that CCH leads to axonal damage over time. We also confirmed that the expression of Aβ (1-40) and NF200 may be useful biomarkers of axonal damage following CCH.
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Affiliation(s)
- Weihua Liang
- Department of Neurology, Xinqiao Hospital, The Third Military Medical University, No. 183 Xinqiao Street, Shapingba District, Chongqing, 400038, China,
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Bae JY, Kim JH, Cho YS, Mah W, Bae YC. Quantitative analysis of afferents expressing substance P, calcitonin gene-related peptide, isolectin B4, neurofilament 200, and Peripherin in the sensory root of the rat trigeminal ganglion. J Comp Neurol 2014; 523:126-38. [DOI: 10.1002/cne.23672] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Revised: 08/21/2014] [Accepted: 08/25/2014] [Indexed: 12/19/2022]
Affiliation(s)
- Jin Young Bae
- Department of Anatomy and Neurobiology; School of Dentistry, Kyungpook National University; Daegu 700-412 South Korea
| | - Jae Hyun Kim
- Department of Anatomy and Neurobiology; School of Dentistry, Kyungpook National University; Daegu 700-412 South Korea
| | - Yi Sul Cho
- Department of Anatomy and Neurobiology; School of Dentistry, Kyungpook National University; Daegu 700-412 South Korea
| | - Won Mah
- Department of Anatomy and Neurobiology; School of Dentistry, Kyungpook National University; Daegu 700-412 South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology; School of Dentistry, Kyungpook National University; Daegu 700-412 South Korea
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Song Y, Wang Z, Wang Z, Zhang H, Li X, Chen B. Use of FK506 and bone marrow mesenchymal stem cells for rat hind limb allografts. Neural Regen Res 2014; 7:2681-8. [PMID: 25337114 PMCID: PMC4200736 DOI: 10.3969/j.issn.1673-5374.2012.34.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2012] [Accepted: 11/29/2012] [Indexed: 01/08/2023] Open
Abstract
Dark Agouti rat donor hind limbs were orthotopically transplanted into Lewis rat recipients to verify the effects of bone marrow mesenchymal stem cells on neural regeneration and functional recovery of allotransplanted limbs in the microenvironment of immunotolerance. bone marrow mesenchymal stem cells were intramuscularly (gluteus maximus) injected with FK506 (tacrolimus) daily, and were transplanted to the injured nerves. Results indicated that the allograft group not receiving therapy showed severe rejection, with transplanted limbs detaching at 10 days after transplantation with complete necrosis. The number of myelinated axons and Schwann cells in the FK506 and FK506 + bone marrow mesenchymal stem cells groups were significantly increased. We observed a lesser degree of gastrocnemius muscle degeneration, and increased polymorphic fibers along with other pathological changes in the FK506 + bone marrow mesenchymal stem cells group. The FK506 + bone marrow mesenchymal stem cells group showed significantly better recovery than the autograft and FK506 groups. The results demonstrated that FK506 improved the immune microenvironment. FK506 combined with bone marrow mesenchymal stem cells significantly promoted sciatic nerve regeneration, and improved sensory recovery and motor function in hind limb allotransplant.
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Affiliation(s)
- Youxin Song
- Department of Orthopedics, Affiliated Hospital of Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Zhujun Wang
- Department of Research, Affiliated Hospital of Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Zhixue Wang
- Department of Anesthesia, Affiliated Hospital of Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Hong Zhang
- Department of Surgery, Affiliated Hospital of Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Xiaohui Li
- Department of Research, Affiliated Hospital of Chengde Medical College, Chengde 067000, Hebei Province, China
| | - Bin Chen
- Department of Orthopedics, Affiliated Hospital of Chengde Medical College, Chengde 067000, Hebei Province, China
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Wang Y, Zhai S, Wang H, Jia Q, Jiang W, Zhang X, Zhang A, Liu J, Ni L. Absent in melanoma 2 (AIM2) in rat dental pulp mediates the inflammatory response during pulpitis. J Endod 2013; 39:1390-4. [PMID: 24139260 DOI: 10.1016/j.joen.2013.07.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2012] [Revised: 07/05/2013] [Accepted: 07/21/2013] [Indexed: 10/26/2022]
Abstract
INTRODUCTION In recent years, the inflammasome has been determined to play an important role in inflammatory diseases. However, the role of the inflammasome in pulpitis remains unclear. Absent in melanoma 2 (AIM2) is a type of inflammasome that recognizes cytosolic double stranded DNA and forms a caspase-1-activating inflammasome with apoptosis-associated speck-like protein containing a caspase activating recruiting domain. In this study, we determined whether AIM2 was expressed in pulp cells and defined the role of AIM2 in the initiation of inflammation within the dental pulp. METHODS In the in vivo study, the right maxillary molars from male adult Sprague-Dawley rats (250-350 g) were exposed to the pulp. In the in vitro study, the pulp cells isolated from the mandibular incisors of the Sprague-Dawley rats (2 weeks) were conventionally cultured. Immunofluorescence staining was used to determine the expression and distribution of AIM2 in the rat dental pulp tissues and cells in the presence or absence of inflammatory stimulation. Western blotting and real-time polymerase chain reaction were performed to determine whether there was a correlation between AIM2 expression levels and inflammation both in vivo and in vitro. RESULTS In healthy dental pulp tissues and cells, AIM2 was only detected in the odontoblast layer. Stimulation significantly increased AIM2 expression in both the dental pulp tissues and cultured cells. The mRNA and protein levels of AIM2 were significantly up-regulated in response to inflammatory stimulation in a dose-dependent manner. Moreover, we also found that AIM2 expression correlated with interleukin-1 levels. These results reveal a direct relationship between the AIM2 inflammasome and pulpitis. CONCLUSIONS Our study demonstrates that AIM2 is expressed in dental pulp tissues and mediates the inflammatory response during pulpitis. Therapeutic interventions aimed at reducing AIM2 expression may be beneficial in the treatment of pulpitis.
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Affiliation(s)
- Yafei Wang
- Department of Operative Dentistry and Endodontics, School of Stomatology, Fourth Military Medical University, Shaanxi, China
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Tsunozaki M, Lennertz RC, Vilceanu D, Katta S, Stucky CL, Bautista DM. A 'toothache tree' alkylamide inhibits Aδ mechanonociceptors to alleviate mechanical pain. J Physiol 2013; 591:3325-40. [PMID: 23652591 DOI: 10.1113/jphysiol.2013.252106] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In traditional medicine, the 'toothache tree' and other plants of the Zanthoxylum genus have been used to treat inflammatory pain conditions, such as toothache and rheumatoid arthritis. Here we examined the cellular and molecular mechanisms underlying the analgesic properties of hydroxy-α-sanshool, the active alkylamide produced by Zanthoxylum plants. Consistent with its analgesic effects in humans, sanshool treatment in mice caused a selective attenuation of mechanical sensitivity under naïve and inflammatory conditions, with no effect on thermal sensitivity. To elucidate the molecular mechanisms by which sanshool attenuates mechanical pain, we performed single fibre recordings, calcium imaging and whole-cell electrophysiology of cultured sensory neurons. We found that: (1) sanshool potently inhibits Aδ mechanonociceptors that mediate both sharp acute pain and inflammatory pain; (2) sanshool inhibits action potential firing by blocking voltage-gated sodium currents in a subset of somatosensory neurons, which express a unique combination of voltage-gated sodium channels; and (3) heterologously expressed Nav1.7 is most strongly inhibited by sanshool as compared to other sodium channels expressed in sensory neurons. These results suggest that sanshool targets voltage-gated sodium channels on Aδ mechanosensory nociceptors to dampen excitability and thus induce 'fast pain' analgesia.
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Affiliation(s)
- Makoto Tsunozaki
- Department of Molecular and Cell Biology, UC Berkeley, Berkeley, CA 94720, USA
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Vesicular Glutamate Transporters in Axons That Innervate the Human Dental Pulp. J Endod 2012; 38:470-4. [DOI: 10.1016/j.joen.2011.12.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2011] [Revised: 12/07/2011] [Accepted: 12/08/2011] [Indexed: 11/15/2022]
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Unmyelinated nerve fibers in the human dental pulp express markers for myelinated fibers and show sodium channel accumulations. BMC Neurosci 2012; 13:29. [PMID: 22429267 PMCID: PMC3323891 DOI: 10.1186/1471-2202-13-29] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 03/19/2012] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND The dental pulp is a common source of pain and is used to study peripheral inflammatory pain mechanisms. Results show most fibers are unmyelinated, yet recent findings in experimental animals suggest many pulpal afferents originate from fibers that are myelinated at more proximal locations. Here we use the human dental pulp and confocal microscopy to examine the staining relationships of neurofilament heavy (NFH), a protein commonly expressed in myelinated afferents, with other markers to test the possibility that unmyelinated pulpal afferents originate from myelinated axons. Other staining relationships studied included myelin basic protein (MBP), protein gene product (PGP) 9.5 to identify all nerve fibers, tyrosine hydroxylase (TH) to identify sympathetic fibers, contactin-associated protein (caspr) to identify nodal sites, S-100 to identify Schwann cells and sodium channels (NaChs). RESULTS Results show NFH expression in most PGP9.5 fibers except those with TH and include the broad expression of NFH in axons lacking MBP. Fibers with NFH and MBP show NaCh clusters at nodal sites as expected, but surprisingly, NaCh accumulations are also seen in unmyelinated fibers with NFH, and in fibers with NFH that lack Schwann cell associations. CONCLUSIONS The expression of NFH in most axons suggests a myelinated origin for many pulpal afferents, while the presence of NaCh clusters in unmyelinated fibers suggests an inherent capacity for the unmyelinated segments of myelinated fibers to form NaCh accumulations. These findings have broad implications on the use of dental pulp to study pain mechanisms and suggest possible novel mechanisms responsible for NaCh cluster formation and neuronal excitability.
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Namavari A, Chaudhary S, Sarkar J, Yco L, Patel K, Han KY, Yue BY, Chang JH, Jain S. In vivo serial imaging of regenerating corneal nerves after surgical transection in transgenic thy1-YFP mice. Invest Ophthalmol Vis Sci 2011; 52:8025-32. [PMID: 21896845 DOI: 10.1167/iovs.11-8332] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To determine the effect of lamellar transection surgery on the nerve fiber density (NFD) and pattern of nerve regeneration in the cornea of thy1-YFP transgenic mice. METHODS Wide-field stereo fluorescence microscopy was used to obtain serial images of nerves in live thy1-YFP mice, which express a fluorescent protein in their axons. NFD (mm/mm(2)) was calculated from maximum intensity projection images as the total length of fibers within the area of the contour in which nerves were traced. Whole-mount confocal microscopy was performed to analyze the arrangement of nerves and the types of regenerating fibers. RESULTS NFD in normal corneas was 35.3 ± 1.8 mm/mm(2). Stereo fluorescence microscopy revealed the presence of a subbasal hairpin nerve layer and an intrastromal nerve trunk layer. After surgery, regenerative sprouting was observed from transected distal ends of intrastromal nerve trunks. NFD also increased, with this increase being maximal between 4 and 6 weeks after surgery. NFD approximated baseline values at 6 weeks and did not change any further at 8 weeks. Regenerated nerves did not readopt the normal corneal nerve arrangement. A dense interlacing network of regenerated nerves was present in the corneal bed. Branches from this network traversed the flap to innervate the epithelium. Immunofluorescence staining revealed that regenerating fronds contained peptidergic nociceptive fibers (positive for calcitonin gene-related peptide and substance P) and myelinated non-nociceptive fibers (positive for neurofilament 200). CONCLUSIONS Although corneal NFD recovers to normal levels by 8 weeks after nerve transection, the arrangement of regenerated nerves is abnormal.
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Affiliation(s)
- Abed Namavari
- Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine, Chicago, Illinois 60612, USA
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Ultrastructural Basis for Craniofacial Sensory Processing in The Brainstem. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2011. [DOI: 10.1016/b978-0-12-385198-7.00005-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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