Background: LncRNA AK044604(regulator of insulin sensitivity and autophagy, Risa) and autophagy-related factors Sirt1 and GSK3β play important roles in diabetic nephropathy(DN). In this study, we sought to explore th...Background: LncRNA AK044604(regulator of insulin sensitivity and autophagy, Risa) and autophagy-related factors Sirt1 and GSK3β play important roles in diabetic nephropathy(DN). In this study, we sought to explore the effect of Risa on Sirt1/GSK3β-induced podocyte injury.Methods: Diabetic db/db mice received Risa-inhibition adeno-associated virus(AAV) via tail vein injection, and intraperitoneal injection of lithium chloride(LiCl). Blood, urine, and kidney tissue samples were collected and analyzed at different time points. Immortalized mouse podocyte cells(MPCs) were cultured and treated with Risa-inhibition lentivirus(LV), EX-527, and LiCl. MPCs were collected under different stimulations as noted. The effects of Risa on podocyte autophagy were examined by qRT-PCR, Western blotting analysis, transmission electron microscopy,Periodic Acid-Schiff staining, and immunofluorescence staining.Results: Risa and activated GSK3β were overexpressed, but Sirt1 was downregulated in DN mice and high glucosetreated MPCs(P<0.001, db/m vs. db/db, NG or HM vs. HG), which was correlated with poor prognosis. Risa overexpression attenuated Sirt1-mediated downstream autophagy levels and aggravated podocyte injury by inhibiting the expression of Sirt1(P<0.001, db/m vs. db/db, NG or HM vs. HG). In contrast, Risa suppression enhanced Sirt1-induced autophagy and attenuated podocyte injury, which could be abrogated by EX-527(P<0.001, db/db+Risa-AAV vs. db/db, HG+Risa-LV vs. HG). Furthermore, LiCl treatment could restore GSK3β-mediated autophagy of podocytes(P<0.001, db/db+LiCl vs. db/db, HG+LiCl vs. HG), suggesting that Risa overexpression aggravated podocyte injury by decreasing autophagy.Conclusions: Risa could inhibit autophagy by regulating the Sirt1/GSK3β axis, thereby aggravating podocyte injury in DN. Risa may serve as a therapeutic target for the treatment of DN.展开更多
基金supported by grants from the Joint construction project of Henan Province(SB201901015)the General Program of the National Natural Science Foundation of China General Project(81970633)+2 种基金the Major public welfare special projects in Henan Province(201300310600)the National Natural Science Young Scientists Foundation of China(81800648)the Excellent Young Scientists Fund Program of the Natural Science Foundation of Henan Province(202300410363)。
文摘Background: LncRNA AK044604(regulator of insulin sensitivity and autophagy, Risa) and autophagy-related factors Sirt1 and GSK3β play important roles in diabetic nephropathy(DN). In this study, we sought to explore the effect of Risa on Sirt1/GSK3β-induced podocyte injury.Methods: Diabetic db/db mice received Risa-inhibition adeno-associated virus(AAV) via tail vein injection, and intraperitoneal injection of lithium chloride(LiCl). Blood, urine, and kidney tissue samples were collected and analyzed at different time points. Immortalized mouse podocyte cells(MPCs) were cultured and treated with Risa-inhibition lentivirus(LV), EX-527, and LiCl. MPCs were collected under different stimulations as noted. The effects of Risa on podocyte autophagy were examined by qRT-PCR, Western blotting analysis, transmission electron microscopy,Periodic Acid-Schiff staining, and immunofluorescence staining.Results: Risa and activated GSK3β were overexpressed, but Sirt1 was downregulated in DN mice and high glucosetreated MPCs(P<0.001, db/m vs. db/db, NG or HM vs. HG), which was correlated with poor prognosis. Risa overexpression attenuated Sirt1-mediated downstream autophagy levels and aggravated podocyte injury by inhibiting the expression of Sirt1(P<0.001, db/m vs. db/db, NG or HM vs. HG). In contrast, Risa suppression enhanced Sirt1-induced autophagy and attenuated podocyte injury, which could be abrogated by EX-527(P<0.001, db/db+Risa-AAV vs. db/db, HG+Risa-LV vs. HG). Furthermore, LiCl treatment could restore GSK3β-mediated autophagy of podocytes(P<0.001, db/db+LiCl vs. db/db, HG+LiCl vs. HG), suggesting that Risa overexpression aggravated podocyte injury by decreasing autophagy.Conclusions: Risa could inhibit autophagy by regulating the Sirt1/GSK3β axis, thereby aggravating podocyte injury in DN. Risa may serve as a therapeutic target for the treatment of DN.
