Organ culture of the trigeminal ganglion induces enhanced expression of calcitonin gene-related peptide via activation of extracellular signal-regulated protein kinase 1/2

Background and objective: Clinical and experimental studies have revealed a central role of calcitonin gene-related peptide (CGRP) in primary headaches. The role of extracellular signal-regulated kinase 1 and 2 (ERK1/2) in neuronal and glial cell expression of CGRP- immunoreactivity (-ir) in rat trigeminal ganglia was studied with an organ culture method. Experimental procedures: Sections of adult rat trigeminal ganglia were cultured for up to 48 hours, examined with immunohistochemistry and quantitative real-time polymerase chain reaction (PCR) assay. Specific antibodies against CGRP, phosphorylated ERK1/2 (pERK1/2), total ERK1/2 (tERK1/2), phosphorylated p38 (pp38), phosphorylated C-Jun-N-terminal protein kinase (pJNK), pro-calcitonin (pro-CT), CGRP receptor activity modifying protein 1 (RAMP1), glutamine synthetase (GS) and pro-CT were used. To explore molecular mechanisms involved in the organ culture–induced CGRP-ir in neurons and glial cells, the effects of the MEK/ERK1/2 inhibitor U0126, its inactive analogue U0124, the p38 inhibitor SB203580 and the JNK inhibitor SP600125 were studied. Results: In fresh ganglia, small- and medium-sized neurons were CGRP-ir while some larger neurons displayed RAMP1-ir. Glial cells were negative to both. After organ culture, neurons showed enhanced CGRP- and RAMP1-ir. In addition, some glial cells were RAMP1- and CGRP-ir. Isolated glial cells and neurons were found to contain CGRP mRNA, and showed pro-CT-ir, suggestive of local formation of CGRP. Neurons and glial cells showed enhanced pERK1/2-ir already after two hours of organ culture and this remained elevated for 48 hours. There was transient pJNK-ir in neurons at two hours, while pp38-ir was not altered. U0126 reduced the enhanced pERK1/2-ir, while U0124 had no such effect; the CGRP-ir in neurons and glial cells was reduced at 48 hours and in parallel the CGRP mRNA expression was lower at 24 hours. Conclusion: We suggest that in conditions of elevated CGRP expression, inhibition of ERK1/2 might be an option for novel treatment.

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Current understanding of trigeminal ganglion structure and function in headache

Cephalalgia ◽

10.1177/0333102418786261 ◽

2018 ◽

Vol 39 (13) ◽

pp. 1661-1674 ◽

Cited By ~ 17

Author(s):

Karl Messlinger ◽

Andrew F Russo

Keyword(s):

Glial Cells ◽

Trigeminal Ganglion ◽

Ganglion Cells ◽

Sensory Information ◽

Calcitonin Gene Related Peptide ◽

Primary Headaches ◽

Satellite Glial Cells ◽

Related Peptide ◽

Signaling Mechanisms ◽

Calcitonin Gene

Introduction The trigeminal ganglion is unique among the somatosensory ganglia regarding its topography, structure, composition and possibly some functional properties of its cellular components. Being mainly responsible for the sensory innervation of the anterior regions of the head, it is a major target for headache research. One intriguing question is if the trigeminal ganglion is merely a transition site for sensory information from the periphery to the central nervous system, or if intracellular modulatory mechanisms and intercellular signaling are capable of controlling sensory information relevant for the pathophysiology of headaches. Methods An online search based on PubMed was made using the keyword “trigeminal ganglion” in combination with “anatomy”, “headache”, “migraine”, “neuropeptides”, “receptors” and “signaling”. From the relevant literature, further references were selected in view of their relevance for headache mechanisms. The essential information was organized based on location and cell types of the trigeminal ganglion, neuropeptides, receptors for signaling molecules, signaling mechanisms, and their possible relevance for headache generation. Results The trigeminal ganglion consists of clusters of sensory neurons and their peripheral and central axon processes, which are arranged according to the three trigeminal partitions V1–V3. The neurons are surrounded by satellite glial cells, the axons by Schwann cells. In addition, macrophage-like cells can be found in the trigeminal ganglion. Neurons express various neuropeptides, among which calcitonin gene-related peptide is the most prominent in terms of its prevalence and its role in primary headaches. The classical calcitonin gene-related peptide receptors are expressed in non-calcitonin gene-related peptide neurons and satellite glial cells, although the possibility of a second calcitonin gene-related peptide receptor in calcitonin gene-related peptide neurons remains to be investigated. A variety of other signal molecules like adenosine triphosphate, nitric oxide, cytokines, and neurotrophic factors are released from trigeminal ganglion cells and may act at receptors on adjacent neurons or satellite glial cells. Conclusions The trigeminal ganglion may act as an integrative organ. The morphological and functional arrangement of trigeminal ganglion cells suggests that intercellular and possibly also autocrine signaling mechanisms interact with intracellular mechanisms, including gene expression, to modulate sensory information. Receptors and neurotrophic factors delivered to the periphery or the trigeminal brainstem can contribute to peripheral and central sensitization, as in the case of primary headaches. The trigeminal ganglion as a target of drug action outside the blood-brain barrier should therefore be taken into account.

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Mitogen-Activated Protein Kinase Pathways are Involved in the Upregulation of Calcitonin Gene-Related Peptide of Rat Trigeminal Ganglion After Organ Culture

Journal of Molecular Neuroscience ◽

10.1007/s12031-012-9772-y ◽

2012 ◽

Vol 48 (1) ◽

pp. 53-65 ◽

Cited By ~ 15

Author(s):

Li Lei ◽

Xingyun Yuan ◽

Shaolan Wang ◽

Fujun Zhang ◽

Yan Han ◽

...

Keyword(s):

Protein Kinase ◽

Organ Culture ◽

Trigeminal Ganglion ◽

Calcitonin Gene Related Peptide ◽

Mitogen Activated Protein Kinase ◽

Related Peptide ◽

Calcitonin Gene ◽

Mitogen Activated Protein

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PD-L1 and PD-1 expressed in trigeminal ganglia may inhibit pain in an acute migraine model

Cephalalgia ◽

10.1177/0333102419883374 ◽

2019 ◽

Vol 40 (3) ◽

pp. 288-298

Author(s):

Suming Shi ◽

Yuhang Han ◽

Dan Wang ◽

Ping Guo ◽

Jiali Wang ◽

...

Keyword(s):

Cell Death ◽

Programmed Cell Death ◽

Calcitonin Gene Related Peptide ◽

Trigeminal Ganglia ◽

Acute Migraine ◽

Related Peptide ◽

Calcitonin Gene ◽

Tnf Α ◽

Immunofluorescence Labeling

Background Neurogenic inflammation, mediated by the activation of primary neurons, is thought to be an important factor in migraine pathophysiology. Programmed cell death ligand-1 (PD-L1) can suppress the immune response through the Programmed cell death-1 receptor. However, the role of PD-L1/PD-1 in migraine remains unclear. In this study we evaluated the expression and role of PD-L1/PD-1 in the trigeminal ganglia in an animal model of acute migraine. Methods Acute nitroglycerin induces acute mechanical hyperalgesia that can be used as a readout of migraine-like pain. We investigated the expression of PD-L1 and PD-1 in the trigeminal ganglia in a mouse model by means of immunofluorescence labeling, quantitative reverse transcription-polymerase chain reaction and western blotting. We explored the effects of PD-1 in a migraine model by the von Frey test and by analyzing the expression of calcitonin gene-related peptide, interleukin-1β (IL-1β), interleukin-18 (IL-18), Tumor Necrosis Factor-α (TNF-α), interleukin-6 (IL-6) and transient receptor potential vanilloid (TRPV4) after the intravenous injection of a PD-1 inhibitor. Results PD-L1 and PD-1 immunoreactivity were present in healthy trigeminal ganglia neurons. The mRNA levels of PD-L1 and PD-1 were significantly elevated 2 h, 4 h and 6 h after acute nitroglycerin treatment ( p < 0.05). The protein levels of PD-L1 were significantly increased 2 h, 4 h and 6 h after treatment, and PD-1 was significantly increased at 2 h and 6 h. The blockade of PD-1 increased acute nitroglycerin-induced hyperalgesia, and this effect was accompanied by a more significant increase in calcitonin gene-related peptide, IL-1β, TNF-α, IL-6 and IL-18 in the trigeminal ganglia. Conclusion These findings suggest that PD-L1 and PD-1 might inhibit migraine-like pain by downregulating CGRP and inflammatory factors in the trigeminal ganglia. The use of PD-L1 and PD-1 as analgesics should be further studied.

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Activation of Extracellular Signal-Regulated Protein Kinase 5 is Essential for Cystitis- and Nerve Growth Factor-Induced Calcitonin Gene-Related Peptide Expression in Sensory Neurons

Molecular Pain ◽

10.1186/1744-8069-8-48 ◽

2012 ◽

Vol 8 ◽

pp. 1744-8069-8-48 ◽

Cited By ~ 15

Author(s):

Sharon J Yu ◽

Chun-Mei Xia ◽

Jarren C Kay ◽

Li-Ya Qiao

Keyword(s):

Nerve Growth Factor ◽

Growth Factor ◽

Protein Kinase ◽

Sensory Neurons ◽

Calcitonin Gene Related Peptide ◽

Nerve Growth ◽

Related Peptide ◽

Extracellular Signal ◽

Calcitonin Gene ◽

Peptide Expression

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Role of phosphorylated extracellular signal-regulated kinase, calcitonin gene-related peptide and cyclooxygenase-2 in experimental rat models of migraine

Molecular Medicine Reports ◽

10.3892/mmr.2015.3616 ◽

2015 ◽

Vol 12 (2) ◽

pp. 1803-1809 ◽

Cited By ~ 9

Author(s):

XIAOMENG DONG ◽

YAOZHI HU ◽

LONG JING ◽

JINBO CHEN

Keyword(s):

Calcitonin Gene Related Peptide ◽

Cyclooxygenase 2 ◽

Rat Models ◽

Extracellular Signal Regulated Kinase ◽

Related Peptide ◽

Extracellular Signal ◽

Calcitonin Gene

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Calcitonin Gene-Related Peptide in Tension-Type Headache

The Scientific World JOURNAL ◽

10.1100/tsw.2002.808 ◽

2002 ◽

Vol 2 ◽

pp. 1527-1531 ◽

Cited By ~ 3

Author(s):

M. Ashina

Keyword(s):

Plasma Levels ◽

Calcitonin Gene Related Peptide ◽

Tension Type Headache ◽

Nerve Fibers ◽

Primary Headaches ◽

Chronic Tension Type Headache ◽

Related Peptide ◽

Calcitonin Gene ◽

Type Headache

In the last 10 years there has been increasing interest in the role of calcitonin gene-related peptide (CGRP) in primary headaches. Tension-type headache is one of the most common and important types of primary headaches, and ongoing nociception from myofascial tissues may play an important role in the pathophysiology of this disorder. CGRP sensory fibers are preferentially located in the walls of arteries, and nerve fibers containing CGRP accompany small blood vessels in human cranial muscles. It is well established that nociception may lead to release of CGRP from sensory nerve endings and from central terminals of sensory afferents into the spinal cord. It has also been shown that density of CGRP fibers around arteries is increased in persistently inflamed muscle. These findings indicate that ongoing activity in sensory neurons in the cranial muscles may be reflected in changes of plasma levels of neuropeptides in patients with chronic tension-type headache. To explore the possible role of CGRP in tension-type headache, plasma levels of CGRP were measured in patients with chronic tension-type headache. This study showed that plasma levels of CGRP are normal in patients and unrelated to headache state. However, the findings of normal plasma levels of CGRP do not exclude the possibility that abnormalities of this neuropeptide at the neuronal or peripheral (pericranial muscles) levels play a role in the pathophysiology of tension-type headache. Investigation of CGRP in other compartments with new sensitive methods of analysis is necessary to clarify its role in tension-type headache.

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