cyclic-gmp and Amyotrophic-Lateral-Sclerosis

The cGMP-AMP Synthase (cGAS)-Stimulator of Interferon Genes (STING) pathway plays a critical role in sensing dsDNA localized to the cytosol, resulting in the activation of a robust inflammatory response. While cGAS-STING signaling is essential for antiviral immunity, aberrant STING activation is observed in amyotrophic lateral sclerosis (ALS), lupus, and autoinflammatory diseases such as Aicardi-Goutières syndrome (AGS) and STING associated vasculopathy with onset in infancy (SAVI). Significant efforts have therefore focused on the development of STING inhibitors. In a concurrent submission, we reported that

Topics: Amyotrophic Lateral Sclerosis; Antiviral Agents; Autoimmune Diseases of the Nervous System; Cyclic GMP; Humans; Nucleotidyltransferases; Proteome

The cyclic nucleotides cyclic adenosine-3',5'-monophosphate (cAMP) and cyclic guanosine-3',5'-monophosphate (cGMP) are important second messengers and are potential biomarkers for Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and Creutzfeldt-Jakob disease (CJD).. Here, we investigated by liquid chromatography/tandem mass spectrometry (LC-MS/MS) the cerebrospinal fluid (CSF) concentrations of cAMP and cGMP of 82 patients and evaluated their diagnostic potency as biomarkers. For comparison with a well-accepted biomarker, we measured tau concentrations in CSF of CJD and control patients. CJD patients (n = 15) had lower cAMP (-70%) and cGMP (-55%) concentrations in CSF compared with controls (n = 11). There was no difference in PD, PD dementia (PDD) and ALS cases. Receiver operating characteristic (ROC) curve analyses confirmed cAMP and cGMP as valuable diagnostic markers for CJD indicated by the area under the curve (AUC) of 0.86 (cAMP) and 0.85 (cGMP). We calculated a sensitivity of 100% and specificity of 64% for cAMP and a sensitivity of 67% and specificity of 100% for cGMP. The combination of both nucleotides increased the sensitivity to 80% and specificity to 91% for the term cAMPxcGMP (AUC 0.92) and to 93% and 100% for the ratio tau/cAMP (AUC 0.99).. We conclude that the CSF determination of cAMP and cGMP may easily be included in the diagnosis of CJD and could be helpful in monitoring disease progression as well as in therapy control.

Topics: Adult; Aged; Amyotrophic Lateral Sclerosis; Area Under Curve; Biomarkers; Brain; Creutzfeldt-Jakob Syndrome; Cyclic AMP; Cyclic GMP; Female; Humans; Male; Middle Aged; Parkinson Disease; Predictive Value of Tests; Sensitivity and Specificity; Spectrometry, Mass, Electrospray Ionization; tau Proteins

The role of cyclic guanosine 5' monophosphate (cGMP) in neurodegeneration of motor neurons in amyotrophic lateral sclerosis (ALS) is still controversial. The aim of this study was to measure levels of cGMP in cerebrospinal fluid (CSF) of patients with ALS, and to investigate whether there is a relationship between CSF cGMP levels and clinical parameters of the disease. The study involved 30 ALS and 20 control group patients. The CSF cGMP was measured by the enzyme-linked immunosorbent assay. The results showed that levels of CSF cGMP were significantly decreased in the group of ALS patients compared to controls and did not depend on clinical state of ALS patients, type of ALS onset, or the duration of the disease. Decreased levels of CSF cGMP observed in this study may suggest the role of cGMP in neurodegeneration in ALS. The CSF cGMP cannot be a marker of the disease activity.

Topics: Adult; Aged; Amyotrophic Lateral Sclerosis; Cyclic GMP; Female; Humans; Male; Middle Aged; Statistics, Nonparametric

Missense mutations in the human Cu/Zn superoxide dismutase gene (SOD-1) cause many cases of autosomal dominant familial amyotrophic lateral sclerosis (FALS). The accumulation of intracellular calcium is one of the primary mechanisms of motor neuronal degeneration associated with mutations in SOD-1. In order to investigate the effect of various calcium modulators and the SOD-1 mutation on neuronal death, we tested motoneuron-neuroblastoma hybrid (VSC 4.1) cells constitutively expressing human SOD-1 gene with mutations (A4V, G93A) or wild-type. These cells were treated with endogenous calcium releaser (ryanodine, thapsigargin, cyclic ADP-ribose) or calcium mobilizer through cell membrane (4-bromo-calcium ionophore A23187). In particular, calcium ionophore reduced survival in the cells expressing mutant SOD-1. Cell death was associated with increased nitric oxide (NO) generation. This toxicity was attenuated when a nitric oxide synthase (NOS) inhibitor was added. Exogenous NOadministration (S-nitrosoglutathione) also induced cell death. The NO-dependent guanylyl cyclase-cGMP cascade inhibitor protected the mutant cells from the toxic effects of calcium ionophore. Our data suggests that motoneuron degeneration with the SOD-1 mutation may be mediated by calcium dysregulation, particularly by the exogenous calcium influx. This process induces oxidative stress generation that results in motor neuronal death through the guanylyl cyclase-cGMP dependent cascade.

Topics: Amyotrophic Lateral Sclerosis; Animals; Calcium Signaling; Cell Survival; Cyclic GMP; Dose-Response Relationship, Drug; Enzyme Inhibitors; Homeostasis; Humans; Intracellular Fluid; Ionophores; Motor Neurons; Mutation; Nitric Oxide; Nitric Oxide Donors; Nitric Oxide Synthase; Ryanodine; S-Nitrosoglutathione; Spinal Cord; Superoxide Dismutase; Tumor Cells, Cultured; Up-Regulation

In this study, we examined the effects of oxidative stress on a nitric oxide (NO)-regulated neuroendocrine function, the release of arginine vasopressin (AVP) by the hypothalamo-neurohypophyseal axis. Treatment of mouse-isolated hypothalami and neurointermediate lobes (NIL) with H2O2 increased AVP release. This effect was inhibited by copper-zinc superoxide dismutase-1 (SOD1) analogs. By measuring cGMP accumulation as an indicator of biologically active NO, we found that H2O2 treatment decreased cGMP formation in both hypothalami and NIL. We have previously shown that NO inhibits AVP release by a cGMP-independent mechanism. Given that H2O2 stimulated AVP release, while it reduced cGMP production, our findings strongly suggest that oxidative damage affects neurosecretion by reducing NO availability. To test whether such a mechanism may operate under pathological conditions with pronounced oxidative stress, we compared neurosecretion in wild-type and transgenic mice carrying a mutated form of SOD1 associated with human familial amyotrophic lateral sclerosis. Reminiscent of the data obtained from H2O2-treated tissues, hypothalami and NIL from SOD1 mutants displayed decreased cGMP accumulation and increased AVP release, compared with tissues from wild-type littermates. Since neuronal NO synthase expression was not modified, we conclude that the perturbed free radical metabolism associated with the SOD1 mutation is likely to trap NO, and thereby alter neurosecretion, a mechanism that can be exacerbated in specific physiopathological conditions.

Topics: Amyotrophic Lateral Sclerosis; Animals; Blotting, Western; Cyclic AMP; Cyclic GMP; Female; Hydrogen Peroxide; Hypothalamo-Hypophyseal System; Hypothalamus; Lipid Peroxidation; Mice; Mice, Transgenic; Mutation; Neuropeptides; Neurosecretory Systems; Nitric Oxide Synthase; Nitric Oxide Synthase Type I; Oxidants; Oxidative Stress; Pituitary Adenylate Cyclase-Activating Polypeptide; Pituitary Gland; Superoxide Dismutase

In this study, we analyzed the mechanism of selective motor neuronal death, a characteristic of amyotrophic lateral sclerosis, using embryonic rat spinal cord culture. When dissociated cultures were exposed to low-level glutamate (Glu) coadministered with the Glu transporter inhibitor L-trans-pyrrolidine-2,4-decarboxylate (PDC) for 24 hours, motor neurons were selectively injured through N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate receptors. Nitric oxide synthase (NOS) inhibitors attenuated this toxicity, and long-acting nitric oxide (NO) donors damaged motor neurons selectively. Nonmotor neurons survived after exposure to low-dose Glu/PDC, but Glu-induced toxicity was potentiated by coadministration of an NO-dependent guanylyl cyclase inhibitor. In addition, 8-bromo-cyclic GMP, a soluble cyclic GMP analogue, rescued nonmotor neurons, but not motor neurons, exposed to high-dose Glu/PDC. Twenty-four hours' incubation with PDC elevated the number of neuronal NOS-immunoreactive neurons by about twofold compared with controls, and a double-staining study, using the motor neuron marker SMI32, revealed that most of them were nonmotor neurons. These findings suggest that selective motor neuronal death caused by chronic low-level exposure to Glu is mediated by the formation of NO in nonmotor neurons, which inversely protects nonmotor neurons through the guanylyl cyclase-cyclic GMP cascade. Induction of neuronal NOS in nonmotor neurons might enhance both the toxicity of motor neurons and the protection of nonmotor neurons, which could explain the pathology of amyotrophic lateral sclerosis.

Topics: Amyotrophic Lateral Sclerosis; Animals; Cell Death; Cell Survival; Cells, Cultured; Cyclic GMP; Dicarboxylic Acids; Embryo, Mammalian; Glutamic Acid; Models, Neurological; Motor Neurons; N-Methylaspartate; Neurons; Neurotransmitter Uptake Inhibitors; Nitric Oxide; Nitric Oxide Donors; Pyrrolidines; Rats; Rats, Wistar; Spinal Cord

Peroxynitrite, formed from nitric oxide and superoxide, may affect neurofilament assembly and cause neurofilament accumulation in motoneurons. This hypothesis may reconcile the mutations of two genes: superoxide dismutase-1 in some patients with familial amyotrophic lateral sclerosis, and the gene for the heavy neurofilament in some patients with sporadic amyotrophic lateral sclerosis previously reported. We found colocalization of superoxide dismutase-1 and nitric oxide synthase in the foci of neurofilament accumulation as 'conglomerates' in upper motor neurons and 'axonal spheroids' in lower motor neurons. In addition, all the specific molecules related to the reactions, including calmodulin, 3', 5'-cyclic guanosine-monophosphate, citrulline, and nitrotyrosine were found strongly immunopositive in the site of neurofilament accumulation. Our data support the view that the neurofilament aggregates are tightly linked with superoxide dismutase-1 and nitric oxide synthase activities. Both enzymes may focally contribute to peroxynitrite formation at light neurofilament, which is rich in both tyrosine and arginine residues and hence considered as the vulnerable site for nitrotyrosine formation. Nitrotyrosine is known to inhibit phosphorylation and if it impairs phosphorylation of neurofilament subunits, either light or heavy, may alter the slow axonal transport culminating in proximo-distal accumulation of NF and slowly progressive motoneuron death.

Topics: Amyotrophic Lateral Sclerosis; Citrulline; Cyclic GMP; Cytoplasm; Humans; Immunohistochemistry; Motor Neurons; Neurofilament Proteins; Nitrates; Nitric Oxide; Nitrogen; Oxidation-Reduction; Superoxide Dismutase; Tyrosine

A number of free radicals such as superoxide and nitric oxide may cause damage to motor neurons but the exact mechanism remains to be elucidated. A potent free radical, peroxynitrite, is readily formed from superoxide and nitric oxide, which captures superoxide three times faster than SOD-1. Peroxynitrite may nitrate tyrosine residues of light neurofilaments (NF-I), thereby altering NF assembly and causing NF accumulation in motor neurons. To test this hypothesis we have probed the massive NF aggregates which are histopathological hallmarks of ALS/MND with immunohistochemistry. We investigated localization of reaction products related to SOD-1, nitric oxide synthase (NOS) and cyclic GMP activities. Our studies show colocalization of NF aggregates with SOD-1/b-NOS/calmodulin /citrulline/cGMP and nitrotyrosine in upper motor neuron conglomerates (Cgl) and lower motor neutron axonal spheroids (Axs). This strongly supports the notion that peroxynitrite deranges NF phosphorylation and assembly, by nitrating tyrosine residues in NF-L. Impaired phosphorylation of NF subunits, either at NF-I or at NF-H, may affect the slow axonal transport culminating in proximo-distal accumulation of NF and slowly progressive motoneuron death.

Topics: Aged; Amyotrophic Lateral Sclerosis; Axons; Calmodulin; Citrulline; Cyclic GMP; Female; Humans; Inclusion Bodies; Male; Microscopy, Electron; Middle Aged; Motor Neurons; Neurofilament Proteins; Nitric Oxide; Nitric Oxide Synthase; Nitrogen Compounds; Superoxide Dismutase; Tyrosine; Ubiquitins

To investigate whether nitric oxide (NO) plays a role in degenerative neurologic disease (DND), we measured nitrite, nitrate and cyclic GMP in cerebrospinal fluid (CSF) samples from patients with Parkinson's disease (PD), spinocerebellar ataxia (SCA) and amyotrophic lateral sclerosis (ALS). We found no significant change in CSF nitrite, nitrate or cyclic GMP in patients with any DND compared with control values. These results suggest that NO production is preserved in PD, SCA and ALS.

Topics: Aged; Amyotrophic Lateral Sclerosis; Biomarkers; Cyclic GMP; Female; Humans; Male; Middle Aged; Nerve Degeneration; Nervous System Diseases; Nitrates; Nitric Oxide; Nitrites; Parkinson Disease; Spinocerebellar Degenerations

Topics: Adolescent; Adult; Age Factors; Aged; Amyotrophic Lateral Sclerosis; Bulbar Palsy, Progressive; Cyclic AMP; Cyclic GMP; Female; Glucagon; Humans; Male; Middle Aged; Muscular Atrophy; Muscular Dystrophies; Myositis; Neuromuscular Diseases; Nucleotides, Cyclic; Radioimmunoassay