DIAPH1, also known as Diaphanous-1, is a formin that regulates actin dynamics, signal transduction, and metabolic functions. It is involved in multiple pathways such as the RAGE-DIAPH1 signaling pathway, which is associated with atherosclerosis [2,3,4,5]. It also plays a role in maintaining cellular homeostasis through regulating inter-organelle contact between mitochondria and sarco/endoplasmic reticulum (SR/ER) [1]. Genetic models, like KO mouse models, are valuable for studying its functions.

In KO mouse models, global deletion of Diaph1 in Ldlr-/-mice significantly attenuates atherosclerosis, with lower plasma and liver concentrations of cholesterol and triglyceride, suggesting its role in regulating hepatic lipid metabolism and the progression of atherosclerosis [2,3,5]. In addition, DIAPH1-MFN2 interaction in male rodent and human cardiomyocytes regulates mitochondrial turnover, mitophagy, and oxidative stress, and shortening the mitochondria-SR/ER distance can mitigate the effects of DIAPH1 silencing in ischemia [1]. Homozygous loss of DIAPH1 in humans causes seizures, cortical blindness, and microcephaly syndrome (SCBMS), combined immunodeficiency, and mitochondrial dysfunction, as seen in studies on patients with loss-of-function mutations [6,7].

In conclusion, DIAPH1 is crucial for various biological processes. Model-based research, especially KO mouse models, has revealed its significance in diseases like atherosclerosis, ischemia-related conditions, and SCBMS. Understanding DIAPH1's functions provides insights into the underlying mechanisms of these diseases and potential therapeutic targets.