At high concentrations, free radicals and radical-derived, nonradical reactive species are hazardous for living organisms and damage all major cellular constituents. At moderate concentrations, how...

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Free Radicals in the Physiological Control of Cell Function

In recent years, members of the protein kinase family have been discovered at an accelerated pace. Most were first described, not through the traditional biochemical approach of protein purification and enzyme assay, but as putative protein kinase amino acid sequences deduced from the nucleotide sequences of molecularly cloned genes or complementary DNAs. Phylogenetic mapping of the conserved protein kinase catalytic domains can serve as a useful first step in the functional characterization of these newly identified family members.

http://science.sciencemag.org/content/sci/241/4861/42.full.pdf

The protein kinase family: conserved features and deduced phylogeny of the catalytic domains.

Imaging neuronal subsets in transgenic mice expressing multiple spectral variants of GFP.

http://www.back-in-business-physiotherapy.com/images/files/DescendingControl.pdf

Descending control of pain.

Neurotechnique Imaging Neuronal Subsets in Transgenic Mice Expressing Multiple Spectral Variants of GFP

Migraine is a neurological disorder that manifests as a debilitating headache associated with altered sensory perception. The neuropeptide calcitonin gene-related peptide (CGRP) is now firmly established as a key player in migraine. Clinical trials carried out during the past decade have proved that CGRP receptor antagonists are effective for treating migraine, and antibodies to the receptor and CGRP are currently under investigation. Despite this progress in the clinical arena, the mechanisms by which CGRP triggers migraine remain uncertain. This review discusses mechanisms whereby CGRP enhances sensitivity to sensory input at multiple levels in both the periphery and central nervous system. Future studies on epistatic and epigenetic regulators of CGRP actions are expected to shed further light on CGRP actions in migraine. In conclusion, targeting CGRP represents an approachable therapeutic strategy for migraine.

Calcitonin gene-related peptide (CGRP): a new target for migraine.

A calcium/calmodulin-dependent protein kinase type II (CaM-K) alpha-subunit cDNA has been cloned from rat brain. This enzyme is encoded by a 5.1-kilobase mRNA expressed exclusively in the brain. Hybridization histochemistry reveals that the CaM-K mRNA expression corresponds to the distribution of the immunoreactive alpha-subunit protein, suggesting that the high enzyme levels in specific brain areas reflect regional differences in gene expression. The sequence of CaM-K alpha-subunit cDNA indicates a 478-amino acid (54-kDa) protein with three functional domains. The domain organization suggests a structural model for calcium/calmodulin-dependent and independent states that might subserve short- and long-term responses to transient stimuli.

https://www.pnas.org/content/pnas/84/16/5962.full.pdf

Molecular cloning of a brain-specific calcium/calmodulin-dependent protein kinase.

The neuropeptide calcitonin gene-related peptide (CGRP) from the trigeminal ganglion has been established as a key player in the pathogenesis of migraine In this study, we provide evidence that the responsiveness of neuronal CGRP receptors is strongly enhanced in vitro and in vivo by expression of human receptor activity-modifying protein-1 (hRAMP1), an obligatory subunit of the CGRP receptor We first demonstrated that activation of CGRP receptors on cultured trigeminal ganglion neurons increased endogenous CGRP mRNA levels and promoter activity The promoter activation was cAMP dependent and blocked by the antagonist BIBN4096BS [1-piperidinecarboxamide, N-[2-[[5-amino-l-[[4-(4-pyridinyl)-l-piperazinyl]carbonyl]pentyl]amino]-1-[(3,5-dibromo-4-hydroxyphenyl)methyl]-2-oxoethyl]-4-(1,4-dihydro-2-oxo-3(2H)-quinazolinyl)], a new antimigraine drug Gene transfer using an adenoviral hRAMP1 expression vector increased the maximal production of cAMP by 18 +/- 02-fold and decreased the EC50 to 23 +/- 08 nM from 90 +/- 59 nM and 156 +/- 52 nM in uninfected and control-infected cultures, respectively To establish whether RAMP1 is limiting in vivo as indicated from the culture studies, a transgenic mouse expressing hRAMP1 in the nervous system was generated After CGRP injection into the whiskerpad, the hRAMP1 transgenic mice displayed 22 +/- 02-fold greater plasma extravasation, which is a measure of neurogenic inflammation These results demonstrate that RAMP1 is functionally rate limiting for CGRP receptor activity in the trigeminal ganglion, which raises the possibility that elevated RAMP1 might sensitize some individuals to CGRP actions in migraine

https://www.jneurosci.org/content/jneuro/27/10/2693.full.pdf

Sensitization of Calcitonin Gene-Related Peptide Receptors by Receptor Activity-Modifying Protein-1 in the Trigeminal Ganglion

We have investigated the regulation of calcitonin gene-related peptide (CGRP) release from trigeminal neurons by the serotonergic antimigraine drug sumatriptan. Serum levels of the neuropeptide CGRP are elevated during migraine. Treatment with the drug sumatriptan returns CGRP levels to normal coincident with the alleviation of headache. However, despite this clinical efficacy, the cellular target and mechanism of sumatriptan action are not well understood beyond the pharmacology of its recognition of the 5-HT1 class of serotonin receptors. We have used cultured trigeminal neurons to demonstrate that sumatriptan can directly repress CGRP secretion from sensory neurons. The stimulated secretion in response to depolarization or inflammatory agents was inhibited, but not the basal secretion rate. Unexpectedly, sumatriptan did not lower cAMP levels, in contrast to the classical role ascribed to the 5-HT1 receptors. Instead, activation of 5-HT1 receptors caused a slow and remarkably prolonged increase in intracellular calcium. The inhibition of CGRP secretion is attenuated by the phosphatase inhibitor okadaic acid, suggesting that sumatriptan action is mediated by calcium-recruited phosphatases. These results suggest that 5-HT1 agonists may block a deleterious feedback loop in migraine at the trigeminal neurons and provide a general mechanism by which this class of drugs can attenuate stimulated neuropeptide release.

https://www.jneurosci.org/content/jneuro/19/9/3423.full.pdf

Regulation of Calcitonin Gene-Related Peptide Secretion by a Serotonergic Antimigraine Drug

Migraine is a chronic neurological disorder characterized by recurrent episodes of severe unilateral throbbing head pain and associated symptoms, such as photophobia. Our current understanding of the mechanisms underlying migraine has been hampered by limitations in ascertaining migraine symptoms in animal models. Clinical studies have established the neuropeptide calcitonin gene-related peptide (CGRP) as a key player in migraine. Here, we establish a genetic model of photophobia by engineering increased sensitivity to CGRP in mice. These transgenic mice (nestin/hRAMP1) display light-aversive behavior that is greatly enhanced by intracerebroventricular injection of CGRP and blocked by coadministration of the CGRP receptor antagonist olcegepant. This behavior appears to be an indicator of photophobia and cannot be fully explained by gross abnormality of ocular anatomy or differences in general anxiety or motor activity. Our findings demonstrate that a single gene, receptor activity-modifying protein 1 (RAMP1), can be a modifier of photophobia and, by extension, suggest that genetic or epigenetic modulation of RAMP1 levels may contribute to migraine susceptibility. Moreover, they validate CGRP hypersensitive mice as a tool for exploring the neurobiology and novel therapies for migraine and other disorders involving photophobia.

https://www.jneurosci.org/content/jneuro/29/27/8798.full.pdf

Andrew F. Russo

Papers

Calcitonin gene-related peptide (CGRP): a new target for migraine.

Molecular cloning of a brain-specific calcium/calmodulin-dependent protein kinase.

Sensitization of Calcitonin Gene-Related Peptide Receptors by Receptor Activity-Modifying Protein-1 in the Trigeminal Ganglion

Regulation of Calcitonin Gene-Related Peptide Secretion by a Serotonergic Antimigraine Drug

Role of calcitonin gene-related peptide in light-aversive behavior: implications for migraine.