ADAR1 Inhibits ZBP1-Driven Neuronal Necroptosis After Intracerebral Hemorrhage.

ADAR1p150 expression is reduced after intracerebral hemorrhage in both human patients and mice.

• Reduction was observed in ICH patients and in collagenase VII-induced ICH mice.
• Expression was assessed using qPCR, western blot, immunofluorescence, and ELISA.
• The abstract does not give sample sizes or effect sizes for this finding.

ZBP1 and ADAR1 both bind to dsRNA in the context of ICH.

• Protein–RNA and protein–protein interactions were examined, including co-immunoprecipitation.
• ZBP1 binds dsRNA and promotes RIPK3 activation, the pathway implicated in necroptosis.

ADAR1p150 suppresses ZBP1 activation, potentially through functional antagonism and dsRNA editing, but causality has not been established.

• The authors explicitly state that causality remains to be established.
• Proposed mechanisms are functional antagonism with ZBP1 and dsRNA editing.

Knockout of ZBP1 increased ADAR1p150 expression and reduced brain edema after ICH.

• Experiments used ZBP1flox/flox/Thy1-Cre+/- mice (neuron-specific ZBP1 deletion) subjected to collagenase VII-induced ICH.
• Brain edema and neurobehavioral deficits were assessed.

Etanercept and shRNA-mediated ADAR1 knockdown promoted ZBP1 expression.

• ADAR1-knockdown mice were used.
• The abstract does not report quantitative effect sizes.

Complementing ADAR1-knockdown cells with a Zα-truncated ADAR1 did not reduce ZBP1 expression.

• This indicates the Zα domain is needed for ADAR1 to lower ZBP1.
• Full-length complementation was the implied comparison.

The inhibitory effect of ADAR1 on ZBP1 was attenuated in ADAR1 Zα-/- cells.

• This supports a requirement for the Zα domain in ADAR1-mediated ZBP1 suppression.
• The authors state the data do not establish whether suppression depends on RNA editing or on dsRNA binding alone.