Transient response of serpinA3 during cellular stress

• Published in: The FASEB journal Vol. 36; no. 3; p. e22190
• Main Authors: Sánchez-Navarro, Andrea, Murillo-de-Ozores, Adrián Rafael, Pérez-Villalva, Rosalba, Linares, Nadyeli, Carbajal-Contreras, Héctor, Flores, María Elena, Gamba, Gerardo, Castañeda-Bueno, María, Bobadilla, Norma A
• Format: Journal Article
• Language: English
• Published: United States 01.03.2022
• Subjects: Acute Kidney Injury - metabolism; Acute Kidney Injury - urine; alpha 1-Antichymotrypsin - genetics; alpha 1-Antichymotrypsin - metabolism; alpha 1-Antichymotrypsin - urine; Animals; Glycosylation; HEK293 Cells; Humans; Male; Mutation; Rats; Stress, Physiological; starvation; acute kidney injury; oxidative stress; cellular stress
• ISSN: 1530-6860
• DOI: 10.1096/fj.202101912R

We demonstrated that serpinA3c/k relocates from the cytoplasm to the apical tubular membrane (ATM) in chronic kidney disease (CKD), suggesting its secretion in luminal space in pathophysiological contexts. Here, we studied serpinA3c/k expression and secretion under different stressful conditions in vitro and in vivo. HEK-293 cells were transfected with a FLAG-tagged serpinA3c/k clone and exposed to H O or starvation. Both stressors induced serpinA3c/k secretion but with a higher molecular weight. Glycanase treatment established that serpinA3c/k is glycosylated. Site-directed mutagenesis for each of the four glycosylation sites was performed. During cellular stress, serpinA3c/k secretion increased with each mutant except in the quadruple mutant. In rats and patients suffering acute kidney injury (AKI), an atypical urinary serpinA3c/k excretion (uSerpinA3c/k) was observed. In rats with AKI, the greater the induced kidney damage, the greater the uSerpinA3 c/k, together with relocation toward ATM. Our findings show that: (1) serpinA3c/k is glycosylated and secreted, (2) serpinA3c/k secretion increases during cellular stress, (3) its appearance in urine reveals a pathophysiological state, and (4) urinary serpinA3 excretion could become a potential biomarker for AKI.