Life or death by NFκB, Losartan promotes survival in dy2J/dy2J mouse of MDC1A

Cell Death Dis. 2015 Mar 12;6(3):e1690. doi: 10.1038/cddis.2015.60.

Abstract

Inflammation and fibrosis are well-defined mechanisms involved in the pathogenesis of the incurable Laminin α2-deficient congenital muscular dystrophy (MDC1A), while apoptosis mechanism is barely discussed. Our previous study showed treatment with Losartan, an angiotensin II type I receptor antagonist, improved muscle strength and reduced fibrosis through transforming growth factor beta (TGF-β) and mitogen-activated protein kinases (MAPK) signaling inhibition in the dy(2J)/dy(2J) mouse model of MDC1A. Here we show for the first time that Losartan treatment up-regulates and shifts the nuclear factor kappa B (NFκB) signaling pathway to favor survival versus apoptosis/damage in this animal model. Losartan treatment was associated with significantly increased serum tumor necrosis factor alpha (TNF-α) level, p65 nuclei accumulation, and decreased muscle IκB-β protein level, indicating NFκB activation. Moreover, NFκB anti-apoptotic target genes TNF receptor-associated factor 1 (TRAF1), TNF receptor-associated factor 2 (TRAF2), cellular inhibitor of apoptosis (cIAP2), and Ferritin heavy chain (FTH1) were increased following Losartan treatment. Losartan induced protein expression toward a pro-survival profile as BCL-2 expression levels were increased and Caspase-3 expression levels were decreased. Muscle apoptosis reduction was further confirmed using terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling (TUNEL) assay. Thus, along with TGF-β and MAPK signaling, NFκB serves as an important regulatory pathway which following Losartan treatment promotes survival in the dy(2J)/dy(2J) mouse model of MDC1A.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Caspase 3 / metabolism
  • Disease Models, Animal
  • Ferritins / biosynthesis
  • Humans
  • Inhibitor of Apoptosis Proteins / biosynthesis
  • Losartan / administration & dosage
  • Mice
  • Muscle Strength / drug effects
  • Muscle, Skeletal / drug effects
  • Muscle, Skeletal / metabolism
  • Muscle, Skeletal / pathology
  • Muscular Dystrophies / drug therapy
  • Muscular Dystrophies / genetics*
  • Muscular Dystrophies / pathology
  • NF-kappa B / genetics*
  • Signal Transduction
  • TNF Receptor-Associated Factor 1 / biosynthesis*
  • TNF Receptor-Associated Factor 1 / genetics
  • TNF Receptor-Associated Factor 2 / biosynthesis*
  • TNF Receptor-Associated Factor 2 / genetics
  • Transcription Factor RelA / metabolism

Substances

  • Inhibitor of Apoptosis Proteins
  • NF-kappa B
  • Rela protein, mouse
  • TNF Receptor-Associated Factor 1
  • TNF Receptor-Associated Factor 2
  • Transcription Factor RelA
  • Ferritins
  • Caspase 3
  • Losartan

Supplementary concepts

  • Muscular dystrophy congenital, merosin negative