RN-0001

RN-0001 is a cyclophilin (Cyp) inhibitor with a Ki of 4.1 nM for CypA and 12.0 nM for CypD, and an EC50 of 916 nM for CypD. It binds directly to CypD, inhibiting the peptidyl-prolyl cis-trans isomerase activity of both CypD and CypA, and prevents CypD-dependent mitochondrial permeability transition pore opening. RN-0001 enhances mitochondrial function, reduces ROS production and apoptosis, prevents NF-κBp65 nuclear translocation, and decreases the release of activated caspase-3 and cytochrome c. This compound is applicable in the study of alcohol-related liver diseases.

RN-0001 exhibits weak direct inhibition of calcineurin phosphatase activity in cell-free assays, with an IC 50 of 2276 nM, and shows moderately enhanced inhibition when bound to cyclophilin A (IC 50 = 1551 nM). In cell-free isolated mitochondria assays, RN-0001 maintains mitochondrial calcium retention capacity at an EC 50 of 916 nM. This compound demonstrates reduced immunosuppressive activity by inhibiting IL-2 release in cell-based immune assays, with an EC 50 of 347.90 nM. Treatment with RN-0001 (0.01-10 μM; 24 h) increases the survival rate of ethanol-injured AML12 hepatocytes (IC 50 = 102.7 μM) and RAW264.7 macrophages (IC 50 = 60.73 μM) in a concentration-dependent manner. Additionally, RN-0001 (0.01-10 μM; 24 h) reduces the release of LDH, apoptosis, lipogenesis, and abnormal expression of inflammation, oxidative stress, and apoptosis-related proteins in ethanol-injured AML12 hepatocytes in a concentration-dependent manner.

RN-0001 (10 mg/kg; intraperitoneal injection; administered daily; for 11 days) effectively alleviates ethanol-induced liver injury, mitochondrial dysfunction, steatosis, and inflammatory responses in a mouse model of ALD. Additionally, when RN-0001 is administered (10 mg/kg; intraperitoneal injection; once every 2 days; for 90 days), it is well-tolerated and does not cause adverse effects in healthy mice.