Podocyte endoplasmic reticulum stress pathway (Podocyte ER stress pathway)

The podocyte endoplasmic reticulum (ER) stress pathway is a critical cellular signaling network activated when the protein-folding capacity of the ER is overwhelmed, leading to the accumulation of misfolded proteins [1, 2]. This response, known as the Unfolded Protein Response (UPR), is mediated by three primary sensors: protein kinase RNA-like ER kinase (PERK), inositol-requiring enzyme 1α (IRE1α), and activating transcription factor 6 (ATF6) [2, 13]. In podocytes—highly specialized kidney cells that maintain the glomerular filtration barrier—chronic ER stress is a major driver of injury in diseases such as diabetic nephropathy, focal segmental glomerulosclerosis (FSGS), and membranous nephropathy [1, 15]. Prolonged activation of the pathway shifts the cellular response from an adaptive state to a pro-apoptotic one, primarily through the induction of CHOP and caspase-12, resulting in podocyte loss and proteinuria [13, 15]. Therapeutic interventions include chemical chaperones like 4-phenylbutyric acid (4-PBA) and TUDCA to enhance folding, as well as novel agents like K201 and MANF that stabilize ER calcium and proteostasis [3, 5, 14]. Monitoring urinary levels of ER-associated proteins such as MANF and ERdj3 serves as a promising non-invasive biomarker strategy for early disease detection and treatment monitoring [12].

Other names

Unfolded protein response in podocytesPodocyte ERS pathwayPodocyte UPR pathwayEndoplasmic reticulum stress-mediated podocyte injury pathway

Therapeutic intervention involves the use of chemical chaperones to enhance protein folding capacity, inhibitors of the PERK-eIF2α-ATF4-CHOP axis to prevent apoptosis, and stabilizers of ER calcium channels to maintain homeostasis.