The presence of the Hfe mutation disrupted expression of tubulin and actin at the protein levels potentially consistent with the disruption of axonal transport seen in ALS and was also associated with a decrease in CuZnSOD1 expression.
The identification of familial ALS mutations in the actin-binding protein profilin 1 directly implicates actin dynamics and regulation in the pathogenesis of ALS.
Optineurin, a cytosolic protein associated with the actin cytoskeleton, microtubules, and the Golgi complex, appears to have an important function in neurons, as mutations in its gene are causative for neurodegenerative diseases such as primary open-angle glaucoma and amyotrophic lateral sclerosis.
Mutations in the profilin 1 (PFN1) gene, encoding a protein regulating filamentous actin growth through its binding to monomeric G-actin, have been recently identified in familial amyotrophic lateral sclerosis (ALS).
We propose that MyBP-H expression level serves, as a putative biomarker in the skeletal muscle, to discriminate ALS from motor neuropathies, and that it signals the onset of dysregulation in actin-myosin interaction; this in turn might contribute to the pathogenesis of ALS.
Impaired actin binding is a common denominator of several PFN1 mutations associated with amyotrophic lateral sclerosis, although further mechanisms may also contribute to the death of motor neurons.
We have examined the steady-state levels of intermediate filament mRNA in amyotrophic lateral sclerosis using the RNAse protection assay (NFL, NFM, NFH; corrected against GAPDH) or by PCR (peripherin, alpha-internexin, nestin, and vimentin; corrected against beta-actin).
However, the observation that some ALS-linked PFN1 mutants fail to alter cellular actin organization or dynamics [5-8] or in vitro actin-monomer affinity [9] has been perplexing, given that profilin is best understood as an actin regulator.
Collectively, our data link NCT defects to ALS-associated cellular pathology and propose the regulation of actin homeostasis as a novel therapeutic strategy for ALS and other neurodegenerative diseases.
Thus, in this review, we focus on the interaction of TDP-43 with the different cytoskeleton components such as actin filaments, neurofilaments, and microtubules as well as their associated proteins as one aspect in the complex pathogenesis of ALS.
Plasma measures of OMD, ACY1, and GHR differed in PD versus NC but did not differ between individuals with amyotrophic lateral sclerosis (ALS, n = 59) versus NC.
Here, we provide evidence that the RNA editing enzyme adenosine deaminase acting on RNA 2 (ADAR2) is mislocalized in C9orf72 repeat expansion mediated ALS/FTD.
TAR DNA-binding protein (TDP-43) pathology in the motor neurons is the most reliable pathological hallmark of amyotrophic lateral sclerosis (ALS), and motor neurons bearing TDP-43 pathology invariably exhibit failure in RNA editing at the GluA2 glutamine/arginine (Q/R) site due to down-regulation of adenosine deaminase acting on RNA 2 (ADAR2).
TAR DNA-binding protein (TDP-43) pathology and reduced expression of adenosine deaminase acting on RNA 2 (ADAR2), which is the RNA editing enzyme responsible for adenosine-to-inosine conversion at the GluA2 glutamine/arginine (Q/R) site, concomitantly occur in the same motor neurons of amyotrophic lateral sclerosis (ALS) patients; this finding suggests a link between these two ALS-specific molecular abnormalities.
Inosine supplementation, in combination with modulation of the level of adenosine deaminase may represent a beneficial therapeutic approach to evaluate in patients with amyotrophic lateral sclerosis.
Because adenosine deaminase acting on RNA type 2 (ADAR2) specifically catalyzes GluR2 Q/R site-editing, it is likely that ADAR2 activity is not sufficient to edit this site completely in motor neurons of patients with sporadic ALS.
Failure of GluA2 RNA editing resulting from downregulation of the RNA-editing enzyme adenosine deaminase acting on RNA 2 (ADAR2) occurs in the majority of ALS cases and causes the death of motor neurons via a Ca(2+) -permeable AMPA receptor-mediated mechanism.
Adenosine deaminase acting on RNA type 2 (ADAR2) specifically mediates GluR2 Q/R site-editing, hence, it is likely a molecule relevant to the pathogenesis of sporadic ALS.
We immunohistochemically examined the expression of adenosine deaminase acting on RNA 2 (ADAR2), the enzyme that specifically catalyzes GluR2 Q/R site-editing, and the expression of phosphorylated and non-phosphorylated TDP-43 in the spinal motor neurons of patients with sporadic ALS.
Here, we investigated the mechanism by which the nuclear pore complex (NPC) is disrupted in dying motor neurons in a mechanistic ALS mouse model (adenosine deaminase acting on RNA 2 (ADAR2) conditional knockout (AR2) mice) and in ALS patients.
Then, we discuss the contributions of ADAMTS-4 to mechanisms mediating neuroplasticity, neuroinflammation and neurodegeneration during spinal cord injury, ischemic stroke, amyotrophic lateral sclerosis and Alzheimer's disease.