atriallike

Atriallike is an adjective used in physiology and biomedical research to describe cells, tissues, or models that resemble atrial cardiomyocytes of the heart, particularly in terms of gene expression, morphology, and electrophysiology. It is commonly used in stem cell differentiation to categorize derived cardiomyocytes into atrial-like, ventricular-like, or nodal-like subtypes, as part of efforts to create chamber-specific models for research and therapy.

In practice, atrial-like cardiomyocytes can be identified by the expression of atrial-associated markers such as atrial natriuretic peptide (NPPA), connexin 40 (GJA5), and tandem markers like MYL7 (MLC-2a), as well as by electrophysiological features that resemble atrial tissue. These features typically include a shorter action potential duration and a more triangular action potential morphology compared with ventricular-like cells, alongside the presence of atrial-specific ion channels such as Kv1.5 (KCNA5) contributing to the ultrarapid rectifier current IKur. Atrial-like cells often exhibit a distinct calcium handling profile that aligns with atrial physiology.

Applications of atrial-like models include studying atrial function and atrial fibrillation mechanisms, screening atrial-selective drugs, and exploring atrial development. They are also used in tissue engineering to create atrial-like patches or organoids. Limitations include that in vitro atrial-like models may not fully recapitulate adult atrial physiology, and challenges remain in achieving consistent maturation and cellular heterogeneity. Validation typically requires multiple molecular markers and functional assays.