TRAP1 Knockout HK-2 Cell Line

The TRAP1 Knockout HK-2 Cell Line is a CRISPR/Cas9-edited knockout cell line featuring targeted disruption of the TRAP1 gene in the HK-2 human proximal tubule epithelial background. This loss-of-function model enables dissection of TRAP1-mediated mitochondrial chaperone functions and cytoprotective mechanisms.

HK-2 is an immortalized cell line originating from normal adult human kidney proximal tubule epithelium. It retains characteristic features including polarized architecture, transporter expression, and metabolic activities, making it a standard in vitro system for renal drug disposition, toxicity screening, and mechanistic studies of proximal tubule function.

TRAP1, a mitochondrial HSP90 paralog, operates centrally in mitochondrial stress responses. It is phosphorylated and stabilized by PINK1, activated downstream of the PI3K/Akt pathway, and transcriptionally induced by HSF1 under oxidative conditions. TRAP1 directly binds Cyclophilin D (CypD), preventing mPTP opening and thereby preserving membrane potential, blocking cytochrome c release, and inhibiting caspase-3 activation. TRAP1 also restrains succinate dehydrogenase complex II activity to reduce ROS generation. It associates with cochaperones p23 and Aha1, and is cleaved by HTRA2/Omi protease, illustrating dynamic regulatory inputs.

In renal proximal tubule cells, high mitochondrial activity exposes them to constant oxidative risk. TRAP1 knockout disrupts this protective chaperone network, lifting inhibition on CypD-mediated mPTP opening and increasing vulnerability to ROS-triggered apoptosis. This mimics the mitochondrial failure seen in acute kidney injury, cisplatin nephrotoxicity, and renal carcinoma, positioning the model as a valuable tool to study redox balance and mitochondrial quality control in kidney epithelia.

Applications range from investigating mitochondrial dysfunction in ischemia?Creperfusion and nephrotoxic injury to screening nephroprotective agents that target the PINK1-TRAP1-CypD axis. The knockout line also facilitates cancer research, where TRAP1??s pro-survival role may be explored in renal cell carcinoma. Compatible assays include JC-1 membrane potential measurements, H2DCFDA ROS detection, caspase-3 and PARP immunoblotting, cytochrome c release immunofluorescence, and ATP bioluminescence to assess metabolic health. Co-immunoprecipitation and RT-qPCR for BAX, BCL2, and SOD2 further validate pathway engagement. For further information, contact Ascent Research.