atrioventricular node cell differentiation

Definition

Target type: biologicalprocess

The process in which a relatively unspecialized cell acquires specialized features of an atrioventricular (AV) node cell. AV node cells are pacemaker cells that are found in the atrioventricular node. [GOC:mtg_heart]

Atrioventricular (AV) node cell differentiation is a complex and intricate process that involves a series of precisely orchestrated molecular events, ultimately leading to the formation of specialized cardiac cells responsible for regulating heart rhythm. The AV node, located at the junction between the atria and ventricles, plays a crucial role in this process, acting as a gatekeeper that delays the electrical signal from the atria to the ventricles, allowing for proper ventricular filling before contraction.

The differentiation of AV node cells begins with the commitment of multipotent progenitor cells to a cardiac fate. These progenitor cells express a specific set of transcription factors and signaling molecules that drive their differentiation into cardiomyocytes. The process of AV node cell specification is influenced by a complex interplay of intrinsic genetic factors and extrinsic signaling cues from the surrounding environment.

Several key transcription factors, such as Tbx2, Nkx2.5, and Shox2, play critical roles in the development of the AV node. These factors regulate the expression of downstream genes involved in the development of the conductive system, including genes encoding ion channels and gap junction proteins.

Importantly, the differentiation of AV node cells is characterized by the acquisition of unique electrophysiological properties that distinguish them from other cardiomyocytes. AV node cells exhibit slow conduction velocity and exhibit a unique pacemaker activity, spontaneously generating electrical impulses that drive the rhythmic contractions of the heart.

During differentiation, AV node cells undergo changes in their expression of ion channels, such as the hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, which contribute to the characteristic slow depolarization phase of the pacemaker potential. The expression of connexin 45 gap junction proteins also plays a crucial role in allowing for the efficient spread of electrical signals between AV node cells.

The process of AV node cell differentiation is tightly regulated by a variety of signaling pathways, including Wnt, Hedgehog, and Notch signaling. These pathways interact with transcription factors and other signaling molecules to fine-tune the expression of genes involved in AV node development.

In summary, the differentiation of AV node cells is a complex and highly regulated process involving a series of molecular events that ultimately lead to the formation of specialized cardiac cells responsible for regulating heart rhythm. This process is influenced by a complex interplay of genetic factors and signaling cues from the surrounding environment, and it is essential for maintaining proper cardiac function.'
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Proteins (1)

Compounds (6)