Targeting neurohormonal signaling cascades in cardiac hypertrophy: Multi-layered anti-hypertrophic paradigm of pyrogallol.

Pathological cardiac hypertrophy represents a maladaptive response to chronic neurohumoral stimuli mediated by the overlapping renin-angiotensin system (RAS) and sympathetic nervous system (SNS). Continuous stimulation by Angiotensin II (Ang II) and norepinephrine (NE) drives adverse cardiac remodeling, subcellular microdomain remodeling, and embryonic fetal gene re-expression, accelerating progression to heart failure. Recent paradigms highlight the critical role of compartmentalized receptors situated in Golgi membranes in sustaining pro-hypertrophic signaling. Here, we examine the integrated signaling networks activated by Ang II and NE and delineate the multi-layered mechanisms by which the lipophilic polyphenol pyrogallol interrupts these cascades. Lipophilic properties may allow pyrogallol to act across compartments: (1) attenuating plasma membrane GPCR-G protein coupling (AT1R, α1-AR, β1-AR) and second messenger production (IP3, DAG, cAMP); (2) mitigating cytosolic Ca2+ overload and suppressing downstream MAPK signaling (ERK1/2, p38, JNK); (3) disrupting Golgi-localized Epac/PLCε complexes to prevent Protein Kinase D (PKD) phosphorylation; and (4) limiting nuclear translocation of transcription factors associated with embryonic fetal genes (ANP, BNP,β-MHC). Based on these preliminary mechanistic frameworks, pyrogallol represents a candidate molecule warranting further empirical validation as a potential neurohormonal stress brake.