Biventricular differences in β-adrenergic receptor signaling following burn injury

Model System:

Burn

Reference Type:

Journal article

Accession No.:

J81098

Journal:

PLoS One

Year, Volume, Issue, Page(s):

2017 , 12, 12, e0189527

Publication Website:

Abstract:

Burn injury detrimentally affects the myocardium, primarily due to over-activation of β-adrenergic receptors (β-AR). Autopsy reports reveal that patients often suffer from right ventricle (RV) failure. Since burn injury affects β-AR signaling in the left ventricle (LV), the authors proposed that β-AR signaling may also be altered in the RV. A rodent model with a scald burn of 60 percent of the total body surface area was used to test this hypothesis. Ventricles were isolated 7 days post-burn. The expression of β-ARs was examined via Western blotting and the mRNA expression of downstream signaling proteins via qRT-PCR. Cyclic adenosine monophosphate (cAMP) production and protein kinase A (PKA) activity were measured in membrane and cytosolic fractions, respectively, using enzyme immunoassay kits. β1-AR protein expression was significantly increased in the RV following burn injury compared to non-burned RV but not in the LV. In contrast, β2-AR expression was unaltered among the groups while Gαi expression was significantly higher in the LV post-burn. B-arrestin-1 and G-protein coupled receptor kinase-2 mRNA expression were significantly increased in the left ventricle post-burn. cAMP production and PKA activity were significantly lower in the LV post-burn. These data indicate that burn injury affects the β-AR signaling pathway in the RV independently of the LV. Additionally, non-canonical β-AR signaling may be activated in the RV as cAMP production and PKA activity were unchanged despite changes in β1-AR protein expression.

Author(s):