*Review* **p38 MAPK Pathway in the Heart: New Insights in Health and Disease**

#### **Rafael Romero-Becerra, Ayelén M. Santamans, Cintia Folgueira and Guadalupe Sabio \***

Centro Nacional de Investigaciones Cardiovasculares (CNIC), 28029 Madrid, Spain;

rafael.romero@cnic.es (R.R.-B.); ayelenmelina.santamans@cnic.es (A.M.S.); cintia.folgueira@cnic.es (C.F.)

**\*** Correspondence: guadalupe.sabio@cnic.es; Tel.: +34-91453-12-00 (ext. 2004)

Received: 3 August 2020; Accepted: 5 October 2020; Published: 8 October 2020

**Abstract:** The p38 mitogen-activated kinase (MAPK) family controls cell adaptation to stress stimuli. p38 function has been studied in depth in relation to cardiac development and function. The first isoform demonstrated to play an important role in cardiac development was p38α; however, all p38 family members are now known to collaborate in different aspects of cardiomyocyte differentiation and growth. p38 family members have been proposed to have protective and deleterious actions in the stressed myocardium, with the outcome of their action in part dependent on the model system under study and the identity of the activated p38 family member. Most studies to date have been performed with inhibitors that are not isoform-specific, and, consequently, knowledge remains very limited about how the different p38s control cardiac physiology and respond to cardiac stress. In this review, we summarize the current understanding of the role of the p38 pathway in cardiac physiology and discuss recent advances in the field.

**Keywords:** MAPK; p38; physiology; metabolism; signaling; hypoxia; arrhythmia
