Diaph1, also known as mammalian diaphanous-1, is a formin that regulates actin dynamics, signal transduction, and metabolic functions. It is involved in pathways such as the RAGE signaling pathway and plays a role in maintaining cellular homeostasis. Genetic models, like gene knockout mice, have been valuable for studying its functions [1-3, 5-10].

In gene knockout studies, deletion of Diaph1 in atherosclerosis-prone Ldlr-/-mice led to significantly less atherosclerosis, along with lower plasma cholesterol and triglyceride levels, suggesting its role in the progression of atherosclerosis and hepatic lipid metabolism [2]. In male rodent and human cardiomyocytes, the interaction between DIAPH1 and MFN2 regulates mitochondrial turnover, mitophagy, and oxidative stress, and shortening the mitochondria-SR/ER distance mitigated the effects of DIAPH1 silencing in ischemia [1]. In non-East Asian patients with sporadic Moyamoya disease, variants in DIAPH1 were identified, suggesting it as a novel risk gene in this vasculopathy [3]. Loss of DIAPH1 in humans is associated with major T, NK, and ILC defects, and in mice, Diaph1 knockout inhibits primordial germ cell proliferation and affects gonadal development [4,5].

In conclusion, Diaph1 is crucial for multiple biological processes, including lipid metabolism, mitochondrial regulation, and cell proliferation in various tissues. Studies using Diaph1 knockout mouse models have provided insights into its role in diseases such as atherosclerosis, Moyamoya disease, and immunodeficiency-related conditions, contributing to a better understanding of disease mechanisms and potential therapeutic targets.