SO026HUMAN KIDNEY PROXIMAL TUBULAR 3D SPHEROIDS TO STUDY THE ROLE OF ADAM17 IN DIABETIC NEPHROPATHY

Abstract

Abstract Background and Aims ADAM17 is a disintegrin and metalloproteinase initially described to cleave the tumor necrosis factor α (TNFα). Currently, it is known that it can also release ectodomains of a diverse variety of molecules such as, transforming growth factor α (TGFα), L-selectin, and angiotensin-converting enzyme 2 (ACE2). It has been shown that ADAM17 protein expression increases in kidney mesangial cells after incubation with high glucose media mimicking what has been observed in diabetic patients and experimental models of diabetic nephropathy. We now studied the effect ADAM17 deletion on human kidney cells (HKC-8) in a 3D spheroids in vitro cell culture incubated with high glucose, low glucose and mannitol medium resembling the in vivo human kidney diabetic environment. Method ADAM17 deletion was performed using the CRISPR/Cas9 technology. HKC8 cells grew inside a RGD-functionalized dextran hydrogel to obtain 3D spheroids. 13 days post-seeding, the spheroids were incubated with 35mM of D-glucose (HG), 5mM of D-glucose (LG) or 35mM of mannitol as osmotic control for 6h, 24h or 72h. The quality of the established 3D cell culture of mature HKC-8 spheroids was assessed by Aquoporin-1 and Glut-1 staining. After incubations quantitative-PCR analyses were performed for fibrotic and inflammatory markers. Immunofluorescence for fibrotic markers was performed on HKC-8 spheroids incubated for 72h. Results High glucose (HG) medium induced CCL5 gene expression on wild-type HKC-8 spheroids after 6h and 24h of incubation in comparison with the control group. Interestingly, in the ADAM17-deleted spheroids, CCL5 gene expression maintained similar to control after 6h of incubation with HG medium and tended to decrease after 24h of incubation in comparison with the wild-type. Collagen IV gene expression was increased in the wild-type spheroids incubated with HG in comparison with the control group. In ADAM17-deleted spheroids, Collagen IV gene expression was significantly decreased in the cells incubated with HG in comparison with the wild-type cells incubated with HG. HG increased the expression of α-SMA, fibronectin and Collagen IV in wild-type spheroids. Adam17 deletion blocked the increase of α-SMA, fibronectin and Collagen IV expression compared with wild-type cells after 72h of incubation. Conclusion ADAM17 blockade protects against fibrosis and inflammation in human kidney tubular spheroids under high glucose.