Molecular characteristics of apolipoprotein M and its biological functions in kidney diseases.

Apolipoprotein M (apoM) is a subclass of apolipoproteins primarily found in high-density lipoprotein (HDL), it was mainly expressed and secreted in the liver and kidneys. ApoM functions as the carrier of sphingosine-1-phosphate (S1P) to form apoM-S1P complex, further mediating various physiological and pathological processes in the body. Most research has focused on cardiovascular diseases, such as anti-atherosclerosis, with very few studies in the field of nephrology. In recent years, scholars have found that it plays a crucial role in kidney disease. Thereby, this review would summarize the potential roles of apoM and the apoM-S1P axis in various kidney diseases, including chronic kidney disease, diabetic nephropathy, acute kidney injury, glomerular diseases, and renal clear cell carcinoma, providing new insights for the diagnosis and treatment of kidney diseases.