Liuwei Dihuang Pills-elicited inhibition of MMP-2/MMP-9 via RAGE on tight junction protein of Aβ1-40-injured bEnd.3 cells / 中成药

AIM To investigate the protective effects and the mechanism of the Liuwei Dihuang Pills on mouse brain microvascular endothelial(bEnd.3)cells damaged by β-Amyloid protein1-40(Aβ1-40).METHODS CCK8 method was used to detect the effects of Aβ1-40 and medicated serum of Liuwei Dihuang Pills(MSLDP)on cell activity,and to screen the appropriate concentration.bEnd.3 cells of the control group,the Aβ1-40 group,the MSLDP+Aβ1-40 group and the MSLDP group had their low density lipoprotein-associated protein 1(LRP1),receptor for advanced glycation end products(RAGE),matrix metalloproteinase-2(MMP-2),MMP-9,scaffold protein zonule protein-1(ZO-1)detected by Western blot.bEnd.3 cells assigned into the control group,the Aβ1-40 group,the FPS-ZM1(RAGE inhibitor)+Aβ1-40 group and the FPS-ZM1+Aβ1-40+MSLDP group had their expressions of RAGE,MMP-9,MMP-2 and ZO-1 detected by Western blot as well.RESULTS The cell activity of bEnd.3,was dose-dependently decreased by Aβ1-40(P<0.01),but was protected by MSLDP(P<0.05,P<0.01).And 10 μmol/L Aβ1-40 and 10%MSLDP were selected for subsequent experiments.Compared with the control group,the Aβ1-40 group displayed increased protein expressions of RAGE,MMP-2 and MMP-9(P<0.01),decreased protein expressions of LRP1,ZO-1 and BDNF(P<0.05,P<0.01),and decreased fluorescence intensities of LRP1 and ZO-1(P<0.01).Compared with the Aβ1-40 group,the MSLDP group shared decreased expressions of RAGE,MMP-2,MMP-9 proteins and RAGE fluorescence intensity(P<0.05,P<0.01),and increased expressions of LRP1,ZO-1 and BDNF proteins,and the fluorescence intensity of LRP1 and ZO-1(P<0.05,P<0.01);the Aβ1-40+FPS-ZM1 group displayed decreased protein expressions of MMP-2,MMP9 and RAGE(P<0.05,P<0.01),and increased ZO-1 protein expression(P<0.05);and the Aβ1-40+FPS-ZM1+ MSLDP group displayed an even more decreased protein expressions of MMP-2,MMP9 and RAGE(P<0.01),increased ZO-1 protein expression(P<0.01)due to the the combination use of FPS-ZM1 and MSLDP.CONCLUSION Liuwei Dihuang Pills can protect the tight junction of bEnd.3 injured by Aβ1-40 and neurovascular units from Alzheimer's disease by alleviating the dysfunction of the blood-brain barrier via RAGE-mediated MMP-2/MMP-9 pathway inhibition.

Mechanism of Yitangkang Granule in Promoting Podocyte Autophagy Through Regulation of PI3K/Akt/FoxO1 Signaling Pathway Mediated by SIRT1 via AGE-RAGE Axis / 中国实验方剂学杂志

ObjectiveTo explore the underlying mechanism by which the Chinese medicine compound Yitangkang granule（YTK） treats diabetic kidney disease （DKD） by observing its effects on podocyte autophagy through the regulation of phosphatidylinositol 3-kinase （PI3K）/protein kinase B （Akt）/forkhead transcription factor O1 （FoxO1） signaling pathway mediated by silent information regulator 1 （SIRT1） via advanced glycation end products （AGE）/receptor for AGE （RAGE） axis. MethodNinety-six 8-week-old healthy male SPF-grade Wistar rats were selected and randomly divided into blank control group （B）， model control group， high-dose YTK （40 g·kg-1）， medium-dose YTK （20 g·kg-1）， low-dose YTK （10 g·kg-1）， and Western medicine control （20 mg·kg-1 losartan） groups. The DKD rat model was established by high-fat diet feeding combined with intraperitoneal injection of streptozotocin. After successful modeling， the rats in each group received the corresponding treatments for eight weeks. The levels of superoxide dismutase （SOD）， malondialdehyde （MDA）， glutathione peroxidase （GSH-Px）， and catalase （CAT） were measured according to the instructions of the respective assay kits. Hematoxylin and eosin （HE） staining was used to observe pathological changes in kidney tissues. Immunohistochemistry was employed to detect the average optical density values of α-smooth muscle actin （α-SMA）， fibronectin （FN）， desmin， and nephrin. Western blot analysis was used to measure the expression levels of PI3K， phosphorylated PI3K （p-PI3K）， Akt， phosphorylated Akt （p-Akt）， RAGE， SIRT1， Caspase-3， and FoxO1 proteins in kidney tissues of DKD rats. ResultCompared with the blank control group， the model group showed significantly lower levels of SOD， GSH-Px， and CAT， and significantly higher levels of MDA （P<0.01）. The rats exhibited severe kidney damage. The positive expression of podocyte marker proteins α-SMA， FN， and desmin increased significantly， while nephrin and podocin significantly decreased （P<0.01）. The expression levels of PI3K， p-PI3K， Akt， p-Akt， RAGE， and Caspase-3 proteins were significantly elevated， while SIRT1 and FoxO1 protein levels were significantly reduced （P<0.01）. Compared with the model control group， rats in the YTK treatment groups showed significantly higher levels of SOD， GSH-Px， and CAT， and significantly lower levels of MDA in serum （P<0.01）. The degree of kidney damage was reduced to varying extents. The average optical density values of podocyte marker proteins α-SMA， FN， and desmin were significantly decreased， while nephrin and podocin significantly increased （P<0.01）. The expression levels of PI3K， p-PI3K， Akt， p-Akt， RAGE， and Caspase-3 in kidney tissues were significantly reduced， while SIRT1 and FoxO1 expression levels significantly increased （P<0.01）. The Chinese medicine groups demonstrated a clear dose-response trend. ConclusionYTK may alleviate kidney pathological damage， reduce proteinuria， and protect kidney function in DKD rats， thereby delaying the progression of DKD by improving podocyte autophagy through the AGE-RAGE axis-mediated SIRT1 regulation of the PI3K/Akt/FoxO1 signaling pathway. Additionally， a dose-response relationship was observed in the Chinese medicine groups.

Effect of Betulic Acid on RAGE/NF-κB/iNOS Signaling Pathway Expression in Steatosis Cell / 中国实验方剂学杂志

Objective::To investigate the effect of betulic acid(BA) on steatosis LO2 cells. Method::LO2 cells were intervened with BA at different gradient concentrations (0, 10, 20, 40, 80, 160, 250 μmol·L-1) for 24 hours. methyl thiazolyl tetrazolium(MTT) staining was used to observed cell viability to determine the final concentration of BA. The cells were divided into control, model, dimethylsulfoxide (DMSO) and BA groups, as well as BA groups intervened with low, middle and high concentrations. First, model, DMSO and BA group's cells were cultured in 10% Lipid Mix 1 medium for 24 hours to establish a nonalcoholic fatty liver model. Then, DMSO group and low, medium and high-concentration groups were separately cultured with 0.1%DMSO medium and 20, 40, 80 μmol·L-1 BA medium for 24 hours. And control and model groups were cultured in drug-free medium for 24 hours. Oil red O staining and Nile red staining were used to observe the intracellular lipid droplets. Immunofluorescence was used to detect the protein expression of inducible nitric oxide synthase (iNOS). Western blot was used to detect the protein expression levels of receptor for advanced glycation end-products (RAGE), nuclear factor κB p65 (NF-κB p55) and iNOS. Result::BA within the concentration of 80 μmol·L-1 had no significant toxicity on LO2 cells. Compared with control group, the intracellular lipid droplets were significantly increased in the model group, and the expressions of oxidative stress-related proteins RAGE, NF-κB p65 and iNOS also increased significantly(P<0.05). Compared with model group, the intracellular lipid droplets in DMSO group were similar to those in model group, with no significant difference in the three protein expressions between the two groups. However, the intracellular lipid droplets deposition in the BA group was significantly decreased. And the expressions of RAGE, NF-κB p65 and iNOS proteins in high-concentration BA group were significantly decreased(P<0.05, P<0.01). Conclusion::BA can significantly improve the intracellular fat deposition in LO2 cells, which was probably related to the inhibition of the expressions of oxidative stress-related proteins RAGE, NF-κB p65 and iNOS.

High-mobility group box protein1 increases tumor necrosis factorαexpression in human bronchial epithelial cells / 实用医学杂志

Objective To investigate the effect of high-mobility group box protein1 (HMGB1) on the expression of TNF-αand its mechanism in 16HBE in vitro. Methods groups with different HMGB1 (0, 100, 500, 2 000 ng/mL) concentration was set; RAGE antagonizing groups were as control, HMGB1-2000ng, anti-RAGE and anti-RAGE+HMGB1. The changes of TNF-αmRNA and secretion were determined by quantitative PCR and ELISA. RAGE protein level was measured by western blotting. Results HMGB1 intervention and TNF-α expression of 16HBE presented a positive dose-dependent relationship. Thechanges of RAGE was HMGB1positively concentration dependent. In comparison with HMGB1 2 000 ng/mL group, anti-RAGE+HMGB1showed a remarkable reduction of TNF-α secretion. Conclusion In vitro, HMGB1 increases TNF-α expression in 16HBE with a dose-dependent manner through RAGE.

Increased expression of the receptor for advanced glycation end products in neurons and astrocytes in a triple transgenic mouse model of Alzheimer's disease

The receptor for advanced glycation end products (RAGE) has been reported to have a pivotal role in the pathogenesis of Alzheimer's disease (AD). This study investigated RAGE levels in the hippocampus and cortex of a triple transgenic mouse model of AD (3xTg-AD) using western blotting and immunohistochemical double-labeling to assess cellular localization. Analysis of western blots showed that there were no differences in the hippocampal and cortical RAGE levels in 10-month-old adult 3xTg-AD mice, but significant increases in RAGE expression were found in the 22- to 24-month-old aged 3xTg-AD mice compared with those of age-matched controls. RAGE-positive immunoreactivity was observed primarily in neurons of aged 3xTg-AD mice with very little labeling in non-neuronal cells, with the notable exception of RAGE presence in astrocytes in the hippocampal area CA1. In addition, RAGE signals were co-localized with the intracellular amyloid precursor protein (APP)/amyloid beta (Abeta) but not with the extracellular APP/Abeta. In aged 3xTg-AD mice, expression of human tau was observed in the hippocampal area CA1 and co-localized with RAGE signals. The increased presence of RAGE in the 3xTg-AD animal model showing critical aspects of AD neuropathology indicates that RAGE may contribute to cellular dysfunction in the AD brain.

Insulinorresistencia y generación de productos finales de la glucosilación avanzada / Insulin resistance and generation of advanced glycation end products

La diabetes mellitus tipo 2 constituye una de las enfermedades más comúnmente diagnosticadas y a largo plazo lleva a diferentes complicaciones. Uno de los mecanismos por el cual se desarrollan estas alteraciones es la insulinorresistencia que impide que la glucosa sea utilizada por los diferentes órganos y tejidos, determinando alteraciones estructurales y funcionales a nivel celular. Dentro de este espectro la formación de los productos finales de la glucosilación avanzada ha alcanzado singular importancia, ya que han sido implicados en varios procesos degenerativos. Ello vuelve imperativa la necesidad de investigar potenciales blancos terapéuticos que permitan mejorar el pronóstico y la calidad de vida de los pacientes afectados por estas enfermedades.

Diabetes mellitus type 2 is one of the most frequently diagnosed diseases and in the long-term leads to a variety of complications. One of the mechanisms involved in these effects is insulin resistance which prevents glucose from being used by the different target organs and tissues, which in turn leads to structural and functional changes at the cellular level. In this context, the formation of advanced glycation end products has attained special importance as they have been implicated in several degenerative processes. It thus becomes necessary to look into potential therapeutic targets with the purpose of improving prognosis and quality of life of patients suffering from these diseases.

Effect of Vitamin E on advanced glycosylation end-products and their receptors in renal tissue of diabetic rats / 西安交通大学学报(医学版)

Objective To observe the effect of Vitamin E on advanced glycosylation end-products(AGEs) and their receptors in renal tissue of diabetic rats.Methods Rat diabetic nephropathy was induced by intraperitoneal injection of STZ.Rats were allocated to normal control group(NC group),diabetes mellitus group(DM group),and Vitamin E group(VE group).All rats were treated with corresponding drugs for 8 weeks.During and after the treatment,the general state,blood glucose level(BGL),blood urea nitrogen(BUN),serum creatinine(Scr),urinary albumin excretion rate(UAER),glycosylated hemoglobin(HbA1C),clearance rate of creatinine(Ccr) and kidney weight/body weight ratio were determined in different groups.The fluorescence microscope was used to observe advanced glycosylation end-products fluorescence intensity in iced slices.The expression of RAGE in rats' renal tissue slices was measured by immunohistochemistry.Results ① Compared with those in NC group,GLU,HbA1C,BUN,UAER,kidney weight/body weight ratio,contents of AGEs,and RAGE increased significantly(P