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Objective To evaluate the effect of over-expression of phosphatase and tensin homolog does on chromosome ten (PTEN) in podocytes on kidney under high fat diet (HFD) in vivo and clarify the mechanism how PTEN regulates scavenger receptor A (SR-A) expression exposed to oxidized low density lipoprotein (ox-LDL) in podocytes in vitro.Methods The podocyte-specific PTEN knockin (PPKI) mice were fed with HFD to establish mouse model of lipid-induced renal injury.Mice were divided into four groups:ND+Ctrl group,ND+PPKI group,HFD+Ctrl group and HFD+PPKI group.After 24 weeks of dietary intervention,all mice were tested for clinical and biochemical parameters,including serum creatinine (Scr) as well as urine albumin excretion rate (UAER);renal lipid content was measured by oil red O staining and cholesterol quantitative analysis;the pathological changes of glomeruli were observed by PAS staining and electron microscope.Podocyte injury was induced by ox-LDL in vitro.Western blotting was used to detect the changes of SR-A expression induced by ox-LDL after YAP-siRNA interfering (si-YAP),as well as YAP phosphorylation induced by ox-LDL after interfering by PTEN-siRNA (si-PTEN) and PTEN phosphatase inhibitor (Bpv-PTEN),and overexpressing by recombinant adenovirus (ad-PTEN).Results Compared with ND+Ctrl group,HFD+ Ctrl group significantly aggravated the levels of Scr and UAER,the expression of SR-A in podocytes,renal lipid content,mesangial matrix expansion,effacement of podocyte foot processes,and incrassation of glomerular basement membrane (all P ＜ 0.05).Conversely,compared with HFD+Ctrl group,HFD+ PPKI group obviously alleviated the above lipid-induced renal damage (all P ＜ 0.05).In vitro,the expression of SR-A in podocytes was up-regulated when stimulated with ox-LDL (P ＜ 0.05),and the knockout of YAP significantly down-regulated the expression of SR-A induced by ox-LDL (P ＜ 0.05).Exposed to ox-LDL,the expression of p-YAP increased in podocytes (P ＜ 0.05);over-expression of PTEN inhibited p-YAP up-regulation induced by ox-LDL (P ＜ 0.05),while either knockdown of PTEN or inhibition of PTEN phosphatase activity displayed opposite effect (all P ＜ 0.05).Conclusions Over-expression of PTEN in podocytes protected the kidney against damage from HFD in vivo and PTEN might suppress SR-A mediated lipid uptake via dephosphorylating p-YAP to prevent podocyte injury from ox-LDL.
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Objective To explore the effect of ACE-inhibitor perindopril on the expression of scavenger receptor A (SR-A) gene in the kidney of diabetic rats.Methods Diabetes were induced in male Sprague-Dawley rats by peritoneal injection with streptozotocin (60mg/kg).The rats were then random di vided into normal control group, diabetes group and ACEI treatment group [4mg/(kg·d) for 24 weeks].Blood glucose concentration and 24h urinary albumin excretion were determined.The renal morphological change was observed.Immunohistochemistry was used to analyze CD68 positive macrophages,and the Mrna of SR-A in renal tissue was detected by quantitative real-time PCR.Results Compared with normal control group,blood glucose concentration,24h urinary albumin excretion and the number of CD68 positive macrophages were significantly increased [(5.3 ± 0.6) mmol/L vs (26.7 ± 3.3) mmol/L;(2.7 ± 1.3) mg/24h vs (26.7 ± 1.8)mg/24h;(0.77 ±0.24)/gcs vs (2.55 ±0.46)/gcs;(6.13 ±0.50)/HPF vs (11.9 ±2.12)/HPF;P ＜0.05],and the expression of SR-A Mrna were significantly up-regulated in diabetes group [ (5.6 ± 1.2 vs 1.5 ±0.2),P ＜0.05].After intervention with ACE-inhibitor,the up-regulations of the above mentioned parameters,except blood glucose concentration,were all significantly inhibited [ (3.6 ±1.4)mg/24h;(1.03±0.37)/gcs;(8.28±1.19)/HPF;3.4±0.7;P ＜0.05].Conclusion ACE-inhibitor might have renoprotective effects of diabetic nephropathy,it probably was associated with inhibiting the expression of SR-A gene.
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Objective To investigate the influence of transforming growth factor-?1(TGF-?1) on macrophage scavenger receptor (ScR) class A and B(ScR-B,CD36) in order to provide theoretical foundation for expounding the formation and therapy of atherosclerosis(AS).Methods THP-1 derived macrophages were divided into control group and experimental group,the cells in experimental group were treated with 3.0 mg?L-1Anti TGF-?1 Ab,the cells in control group were treated with 3.0 mg?L-1 IgG. The 125I-acetylated low density lipoprotein (125I-Ac-LDL for ScR-A) and 125I-oxidized low density lipoprotein (125I-Ox-LDL for CD36) uptaking (including 4℃ binding,37℃ association and degradation) were measured respectively.Influence of anti TGF-?1 antibody (Anti TGF-?1 Ab) on the ScR-A and CD36 mRNA expressions in THP-1 derived macrophages was measured meanwhile,respectively.Results Compared with control group ( binding: 8.23 ?g?g-1 ?1.24 ?g?g-1 protein,association:45.69 ?g?g-1 ?6.92 ?g?g-1 protein,and degradation: 112.18 ?g?g-1 ?20.15 ?g?g-1 protein),Anti TGF-?1 Ab increased 125I-Ac-LDL binding(48.67 ?g?g-1 ?6.52 ?g?g-1 protein),association (412.30 ?g?g-1?12.21 ?g?g-1 protein),and degradation (896.48 ?g?g-1 ?32.74 ?g?g-1 protein) significantly (P
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Objective To investigated the expression of scavenger receptor A(SR-A) and lipopolysaccharide(LPS) receptor CD14 in endotoxin-induced acute liver injury.Methods Ninety Wistar rats were randomly divided into endotoxaemia group(LPS group) and normal saline group(NS group).The model of endotoxaemia and acute endotoxin-induced liver injury was established by injection of endotoxin(5mg/kg) via tail veins in LPS group,while the rats in NS group received injection of 0.2ml normal saline as control.At 0,1.5,3,6,12h after injection,the levels of endotoxin,TNF-?,IL-1,alanine transaminase(ALT) and total bilirubin(TB) in plasma,SR-A and CD14 expressions in liver tissues were determined,pathological changes of liver tissues and ultrastructural changes of Kupffer cells(KCs) were observed by light and electron microscopy respectively,while the phagocytosis of KCs was determined too.Results Compared with NS group,KCs were activated on morphology and functions(proliferated diffusely,enlarged in size and increased in phagocytosis function),levels of TNF-? and IL-1 increased markedly,the pathological changes of cell degeneration and necrosis and the liver function were gradually aggravated,while SR-A expression decreased and CD14 expression increased obviously(P