Article

Another angiogenic gene linked to amyotrophic lateral sclerosis.

The Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology (VIB), KU Leuven, B-3000 Leuven, Belgium.
Trends in Molecular Medicine (Impact Factor: 9.57). 09/2006; 12(8):345-7. DOI: 10.1016/j.molmed.2006.06.008
Source: PubMed

ABSTRACT A new study by Greenway and colleagues links mutations in the angiogenin gene to patients with amyotrophic lateral sclerosis (ALS)--a progressive and fatal motoneuron disease. This is an unexpected finding because angiogenin was originally identified as a molecule involved in the formation of blood vessels (angiogenesis). Angiogenin bears striking similarity to vascular endothelial growth factor (VEGF), which is the prototypic angiogenic factor that has recently emerged as a molecule with important neuroprotective activities. Besides VEGF, angiogenin is the second so-called angiogenic factor implicated in ALS, raising the question of whether additional angiogenic factors might have a role in ALS. Overall, these findings identify angiogenin as a novel candidate gene in the pathogenesis of ALS--a discovery that ultimately might lead to the development of new therapeutic strategies.

0 Bookmarks
 · 
131 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The angiogenic factor, angiogenin, has been recently linked to both Amyotrophic Lateral Sclerosis (ALS) and Parkinson Disease (PD). We have recently shown that endogenous angiogenin levels are dramatically reduced in an alpha-synuclein mouse model of PD and that exogenous angiogenin protects against cell loss in neurotoxin-based cellular models of PD. Here, we extend our studies to examine whether activation of the prosurvival Akt pathway is required for angiogenin's neuroprotective effects against 1-methyl-4-phenylpyridinium (MPP+), as observed in ALS models, and to test the effect of virally-mediated overexpression of angiogenin in an in vivo PD model. Using a dominant negative Akt construct, we demonstrate that inhibition of the Akt pathway does not reduce the protective effect of angiogenin against MPP+ toxicity in the dopaminergic SH-SY5Y cell line. Furthermore, an ALS-associated mutant of angiogenin, K40I, which fails to induce Akt phosphorylation, was similar to wildtype angiogenin in protection against MPP+. These results confirm previous work showing neuroprotective effects of angiogenin against MPP+, and indicate that Akt is not required for this protective effect. We also investigated whether adeno-associated viral serotype 2 (AAV2)-mediated overexpression of angiogenin protects against dopaminergic neuron loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model. We found that angiogenin overexpression using this approach does not reduce the MPTP-induced degeneration of dopaminergic cells in the substantia nigra, nor limit the depletion of dopamine and its metabolites in the striatum. Together, these findings extend the evidence for protective effects of angiogenin in vitro, but also suggest that further study of in vivo models is required to translate these effects into meaningful therapies.
    PLoS ONE 01/2013; 8(2):e56092. · 3.53 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Altered RNA processing is an underlying mechanism of amyotrophic lateral sclerosis (ALS). Missense mutations in a number of genes involved in RNA function and metabolisms are associated with ALS. Among these genes is angiogenin (ANG), the fifth member of the vertebrate-specific, secreted ribonuclease superfamily. ANG is an angiogenic ribonuclease, and both its angiogenic and ribonucleolytic activities are important for motor neuron health. Ribonuclease 4 (RNASE4), the fourth member of this superfamily, shares the same promoters with ANG and is co-expressed with ANG. However, the biological role of RNASE4 is unknown. To determine whether RNASE4 is involved in ALS pathogenesis, we sequenced the coding region of RNASE4 in ALS and control subjects and characterized the angiogenic, neurogenic, and neuroprotective activities of RNASE4 protein. We identified an allelic association of SNP rs3748338 with ALS and demonstrated that RNASE4 protein is able to induce angiogenesis in in vitro, ex vivo, and in vivo assays. RNASE4 also induces neural differentiation of P19 mouse embryonal carcinoma cells and mouse embryonic stem cells. Moreover, RNASE4 not only stimulates the formation of neurofilaments from mouse embryonic cortical neurons, but also protects hypothermia-induced degeneration. Importantly, systemic treatment with RNASE4 protein slowed weight loss and enhanced neuromuscular function of SOD1 ( G93A ) mice.
    Angiogenesis 11/2012; · 4.41 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Oxidative stress and angiogenic factors have been placed as the prime focus of scientific investigations after an establishment of link between vascular endothelial growth factor promoter (VEGF), hypoxia, and amyotrophic lateral sclerosis (ALS) pathogenesis. Deletion of the hypoxia-response element in the vascular endothelial growth factor promoter and mutant superoxide dismutase 1 (SOD1) which are characterised by atrophy and muscle weakness resulted in phenotype resembling human ALS in mice. This results in lower motor neurodegeneration thus establishing an important link between motor neuron degeneration, vasculature, and angiogenic molecules. In this review, we have presented human, animal, and in vitro studies which suggest that molecules like VEGF have a therapeutic, diagnostic, and prognostic potential in ALS. Involvement of vascular growth factors and hypoxia response elements also highlights the converging role of oxidative stress and neurovascular network for understanding and treatment of various neurodegenerative disorders like ALS.
    Oxidative Medicine and Cellular Longevity 01/2013; 2013:635831.

Full-text

View
72 Downloads
Available from
Jun 5, 2014