RESUMO
Objectives To evaluate the role of PCSK9 (proprotein convertase subtilisin kexin type 9) on the lipid accumulation and kidney injury of C57BL/6 mice. Methods The 24 h urine of 12 weeks old wide type C57BL/6 mice and PCSK9 knockout (KO) mice were collected through a metabolic cage, followed by perfusion and sacrifice. Urinary microalbumin?to?creatinine ratio (UACr), total cholesterol and triglyceride in kidney tissues were measured by ELISA. BODIPY 493/503 staining and standard transmission electron microscopy (TEM) of kidney tissues was performed for evaluating lipid accumulation and podocyte foot effacement in the kidney. Kidney tissues were also evaluated by PAS stain and TUNNEL stain. PCSK9, podocin and nephrin were quantified through real?time PCR, and the Bcl?2, Bax and cleaved caspase 3 were evaluated by Western blotting. Results Total cholesterol and triglyceride contents were higher in the kidneys of PCSK9 KO mice than controls (P<0.05). The level of lipid accumulation in glomeruli and tubules through BODIPY 493/503 stain, and the amount of lipid drop in TEM were more serious in PCSK9 KO mice. UACr and podocyte foot process effacement were increased, and the transcription of podocin and nephrin were decreased in the kidneys of PCSK9 KO mice (all P<0.05). The expression of Bcl?2 was decreased, and Bax and cleavedcaspase 3 were increased in the kidney samples of PCSK9 KO mice. Conclusion PCSK9 might be reversely involved in lipid homeostasis and accumulation, resulting in injury and apoptosis in the kidneys of C57BL/6 mice.
RESUMO
Objective Previous studies have shown that vitamin D deficiency is closely related to cardiac remodeling. How?ever, the underlying mechanisms have not been fully elucidated. Moreover, oxidative stress plays an important role on the pathologies of cardiac remodeling. The aim of this study was to explore the influence of VD deficiency on cardiac oxidative stress and the potential sig?nal pathway. Methods The male C57 mice ( 3 weeks old) were randomly divided into three groups: vitamin D deficiency ( VDD ) group ( vitamin D deficiency feed for 10 weeks) , vitamin D deficiency ( VDA) group ( vitamin D sufficiency feed for 10 weeks) and VDD+calcitriol ( CAL) group ( vitamin D deficiency feed for 10 weeks and then vitamin D sufficiency feed and calcitriol treatment for 10 weeks) . Results There were significant differences between the VDD group and the VDA group in the left ventricular end?diastolic diameter and left ventricular mass index (3.82±0.125 mm vs 3.748±0.092 mm, P<0.05) (119.30±8.54 vs 97.60±3.65, P<0.05). The number of myocardial cells stained with 8?OHDG was higher in the VDD group compared with the VDA group ( 65. 4 ± 2. 3 vs 21. 8 ± 1. 6, P<0.05) whereas was lower after calcitriol supplement. Furthermore, the expression of thioredoxin interacting protein (TXNIP) was sig?nificantly up?regulated and the ratio of p?ASK?1/ASK?1, cytochrome C release, and caspase3 activation were increased in the VDD group . Conclusion VDD can lead to cardiac oxidative injury and the up?regulation of TXNIP and the activation of ASK?1 related apoptotic signal cascade may be involved in this procedure.