Decoding intracellular signaling in atrial fibrillation — From the magic lens of Western blot to clinical practice

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and is associated with significant morbidity and mortality. The occurrence of AF is based on complex processes of atrial electrical and structural remodeling, which are governed by interconnected intracellular signaling pathways.

Among the most relevant pathways involved are Ca²⁺/CaMKII, MAPK (ERK, JNK and p38), NF-κB, TGF-β/Smad, and PI3K/AKT/mTOR. All these pathways contribute through distinct but convergent mechanisms to the dysregulation of calcium handling, atrial fibrosis, cell proliferation and survival, and metabolic support. Previous studies have demonstrated the essential role of the Western blot technique in elucidating these mechanisms, allowing the identification of changes in expression and phosphorylation of key proteins in atrial tissue. Moreover, using this approach, both clinical and experimental studies have revealed the simultaneous activation of multiple signaling pathways in AF.

The development of AF is driven by a series of integrated intracellular signaling pathways. Western blot remains an essential technique for characterizing the molecular mechanisms involved in AF and providing a solid basis for the substrate-targeted therapeutic strategies.