This Month in AJP

Promoting Heart ProtectionThe anti-inflammatory cytokine transforming growth factor b1 (TGF-b1) is released endogenously upon infection or tissue injury; however, the underlying pathogenesis of ischemia reperfusion injury is unclear.Using a mouse model of myocardial ischemia (MI) and reperfusion, Redgrave et al (Am J Pathol 2024, 562e574) studied the protective effects of TGF-b1 when administered exogenously following MI.Administration of TGF-b1 as well as its mimic, Heligmosomoides polygyrus TGM (HpTGM), resulted in a reduction in infarct size and inflammatory cytokines.HpTGM may offer protection to the heart following cardiac infarction. Preventing Proinflammatory MediatoreInduced Capillary RegressionThe mechanisms underlying capillary assembly processes are unclear.Using human umbilical vein endothelial cell (EC) cultures, Lin et al (Am J Pathol 2024, 575e599) studied some of the key molecules and signals implicated in vascular morphogenesis to understand the underlying mechanisms.The effects of overexpression of active kRas, Mek1, PIK3CA, Akt1, Rheb, Jak2, and Stat3 on EC lumen creation, EC tip cell sprouting, pericyte recruitment, and pericyte-induced capillary basement membrane deposition were studied.EC-expressed oncogenic activating mutations may predispose stimuli for the development of vascular malformations.